uca substation cost

February 5, 2003

The Cost of a UCA® Substation

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Craig PreussElectrical EngineerSubstation Integration and AutomationBlack & Veatch Corporation4004 Kruse Way PlaceSuite 200Lake Oswego, OR 97035Telephone: (503)-699-2339Fax: (503)-697-3699


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1 Abstract UCA® provides an open architecture for bringing vast amounts of substation data to the utility enterprise. While a simple statement, many have argued that UCA is “not here yet” and that other architectures may be better suited in certain situations. Justifying substation integration and automation projects can be a daunting and difficult equation to calculate. Not only does the previously mentioned factor impact the justification, but also impacting the equation is the breadth of the utility enterprise that now needs to work together, the number of utility standards that will require review, and the actual cost of an installed substation integration and automation system. Where there are a few UCA demonstration substations and a growing list of utilities using UCA, there are not many existing UCA substations. There is also very little cost information available on how much is it going to cost to do “just this much” versus “doing that much” and where is the “bang for my buck”.

This manuscript will examine what UCA components exist today on the market from relays, to meters, to networking components. This manuscript will also examine the total cost of substation integration and automation projects from the panel shop, to the factory test, to the site acceptance test. This manuscript will also examine the impact of different types of substations will have on total system cost. Also included will be an analysis of the different types of substation integration and automation system components and architectures. The analysis will also point out significant issues that can cause significant increases or decreases in the estimated costs of a commissioned substation automation system. Gaps in system functions will also be identified where additional product functionality is required and not available on the market.

2 Basis for AnalysisThe UCA Users Group provides a list of UCA 2.0 compliant substation products that is available for download from its website. This paper uses the December 20, 2002 version of the list. Only a few inaccuracies were found in the listed information. As this list is the only known clearinghouse of devices that support UCA, vendors who are developing UCA devices are highly encouraged to provide product information to the UCA Users Group.

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UCA: Utility Communications

Architecture A registered trademark of

the Electric Power Research Institute

For more information see www.ucainternational.or g

UCA Products Include: Relays Meters Equipment monitors Communication

processors Data Concentrators Operator Interfaces RTU’s Networking

http://www.ucainternational.org/


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3 Cost AnalysisA life cycle costing approach is a means to determine the total cost of ownership for substation integration and automation systems. It is important to calculate the right cost, as only including material costs does not include such items such as training, support, and testing. Life cycle cost analysis needs to include the following cost categories1:

General Management and Administrative Support Design and Engineering Purchased Components Testing Construction Maintenance, Support and Recurring Costs Phase Out

These categories represent the total cost of ownership, from the formation of requirements through equipment replacement or upgrade. Note that purchased components represent the only known cost for a UCA system. This is true if custom features or enhancements to standard products are not required, because this typically results in additional costs that can not be accurately estimated until a vendor provides a quote. The remainder of the costs, including customization costs, can be estimated through several different methods:

Empirical – getting bids for everything Statistical – figuring out a cost model Comparative – knowing how much a similar system costs and

applying those costs to a different system Expert opinion – finding someone who has an opinion on how

much everything costs

Each one of these methods presents advantages and disadvantages, which can be further defined when using a well-used or well-known technology. So which estimation method should be used? Any one of the above estimation methods can be used. The following sections will use all of the methods to provide estimated cost differentials between available protocol choices in order to provide a roadmap in estimating

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Life Cycle Cost Analysis: The National Institute of

Standards and Technology Handbook 135, 1995 edition, defines Life Cycle Cost as “the total discounted dollar cost of owning, operating, maintaining, and disposing of a building or a building system” over a period of time. Life Cycle Cost Analysis is an economic evaluation technique that determines the total cost of owning and operating a system over a period of time.

Total Cost of Ownership: The Gartner Group

developed this model to analyze the direct and indirect costs of owning and using hardware and software.

Cost Estimating:Substation integration and automation system costs include hidden and hard to define costs. Making a decision solely based on hard costs, without including any soft costs, runs the risk of losing the opportunities to create competitive advantage through substation integration and automation technologies.


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the total lifecycle costs of a UCA-based system.

3.1. General Management and Support

This work is that done by project management and administrative personnel, which can be estimated based upon any of the methods previously discussed.

3.2. Design & Engineering

The design and engineering tasks are shown in Table 2 on page 5. The conceptual design process represents the formation of the automation system. In this stage, it is critical to separate products from services in order to get the right information from the right industry segment. There are two ways to conceptually design a system: around specific products and make the communications work or around a desired architecture and make the products work. This analysis starts during the conceptual design after Ethernet and TCP/IP is chosen as the desired architecture. This choice represents the emerging trend in both industry2,3,4,5,6 and utility domains7. Prior to this choice, significant work must be completed to analyze design issues related to system architecture, as shown in references [8], [9], [10], [11] and [12].

Description Modbus13 UCA14 DNP15

Registered User Group Members 2280 206 250

Products >200 52 >48

Ethernet-based Conformace tested products

15 0 33

Free User Community Yes Yes No

Fee-based User Group UD Yes Yes

Technical Committee UD Yes Yes

Document control Yes Some Yes

Test documentation Yes UD Yes

Independent testing Yes UD Yes

Inherent time-stamped events No Yes Yes

Master/slave communications Yes No Yes

Client/server communications No Yes No

Unsolicited reporting AD Yes Yes

Peer-to-peer communication AD Yes AD

Broadcast messages Yes Yes Yes

Custom data objects Yes Yes Yes

Self-description No Yes No

Select-before-operate No Yes Yes

Table 1: Comparison of Protocols Using Ethernet

Once Ethernet and TCP/IP are chosen, a specific protocol must be selected. While the industrial world has different protocol choices, the utility world has three: UCA, DNP, and Modbus. Table 1 on page 4 provides a comparison between these three protocols that is based upon an integrator’s experience and available information.

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Ethernet:The most popular physical and lower data link OSI layers in use today.

TCP/IP:The Transmission Control Protocol/Internet Protocol is the protocol suite that drives the Internet. TCP/IP handles the network communications between devices.

TABLE DEFINITIONS

UD:Under development – the User Group is presently developing the item.

AD:Application dependent – protocol can support item but must also be supported by the devices.


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Once UCA is chosen (probably no small task), additional design work still needs to be completed:

Establishing specific system requirements Defining the risk management plan

The costs associated with these tasks can be minimized by:

Adopting requirements that are not more stringent than the emerging standards or the de facto standards used by vendors

Adopting an architecture and technology that is supported by international standards and vendors

Selecting hardened equipment to minimize the probability of equipment failure

Working with stakeholders to identify acceptable changes to existing corporate standards

Table 2 on page 5 shows that when UCA is chosen instead of the other Ethernet protocols, most design tasks will require more effort, which will be reflected in higher design costs. System drawing development and system procurement tasks will remain consistent regardless of the selected protocol. Even if software control logic is required, this will require the same drawing documentation.

Tasks UCA DNP Modbus

Conceptual design Large Medium Small

System requirements Large Medium Large

Integration of legacy and serial devices

Large Medium Medium

Creation of test plan & procedures Large Medium Small

System validation Large Medium Large

Protection settings/additional relay settings

Large Medium Small

Additional control logic and drawings

Large Large Large

HMI programming Large Medium Large

Programming and configuration management

Large Medium Small

System point list Large Medium Small

Report management Large Medium Small

Drawing development Yes Yes Yes

Procurement Yes Yes Yes

System documentation Large Medium Small

Table 2: Engineering Costs Associated with Ethernet-based Protocols

The direct costs will vary proportionally with the type of substation, which is related to the number of distribution/transmission lines, circuit breakers, power transformers, capacitors, and other substation equipment. Ultimately, these criteria present the total number of devices to be integrated and the total number of independent vendors. The more devices and vendors, the more complex the project will be and the higher

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UCA: Utility Communications

Architecture For more information see

www.ucainternational.org

DNP: Distributed Network

Protocol For more information see

www.dnp.org

Modbus: Modbus was created by

Modicon in 1979 and is now an open standard.

For more information see www.modbus.org

Integration of legacy devices and/or serial devices will increase system costs and risks for the first of kind implementations. As vendors, integrators, and utilities gain more experience with a specific implementation, the impact on project costs and risks will reduce.

http://www.modbus.org/

http://www.dnp.org/



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the design and engineering costs.

When legacy devices or serial devices are included in the system architecture, the project costs will most likely increase due to a steep learning curve for the UCA object model, which also increases project risk. Until configuration databases become more flexible, the substation configuration language is implemented, and automated configuration tools are developed, integrating legacy and serial devices will represent a significant challenge for automation projects.16 As vendors, integrators, and utilities gain more experience with a specific implementation, the impact on project costs and risks will reduce.

3.3. Purchased components

This paper focuses on those components that exist in the market today and support UCA. These devices have been divided into categories for relays, meters, substation host, networking, operator interfaces, and equipment monitors. Note that there are many vendors of equipment that are not included in the following sections because their products do not directly support UCA. This does not mean that these devices can not be used on a UCA network, only that the costs of adding these devices to the network will generally be more because of the requirements for protocol conversion and object modeling. Devices that do not support UCA directly can many times be connected to a data concentrator/communication processor or other device that can poll the device in a native protocol and provide an interface to a UCA network. The devices that can perform this type of conversion are discussed in section 3.3.5.

The pricing included in the following sections is not listed on device basis, but only on a minimum, average, and maximum price due to the sensitivity of pricing information from vendors. While products are listed, the vendors are not, and no bias is given towards the products offered by any vendor in order to maintain the non-commercial nature of this manuscript. The price shown is the list price of adding UCA capability to the base device. These prices were obtained from any one of the following resources: vendor web sites, vendor-authorized dealers, or vendor sales representatives. Many vendors are also willing to put UCA in a device when UCA becomes “stable” or when a viable market for UCA develops. Note that the categories are not broken down to specific type of device, for example high impedance bus differential relays and line relays.

3.3.1. Relays

Relays come in a variety of classifications (transmission, distribution, line, bay, transformer, capacitor, motor, generator, etc) and vendors, but only a few vendors directly support UCA in a relay as one of the multitude of option items. Table 3 on page 7 shows that many of the relays that support UCA also support other Ethernet-based protocols

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The table of relay listings demonstrates that one product line from one vendor dominates the relays available that directly support Ethernet protocols. Additional UCA-enabled relays are scheduled for release in 2003.


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such as DNP over Ethernet and/or Modbus TCP. Subsequently, for some of these devices, the cost of adding UCA to a relay is the same for all of the supported protocols since the same Ethernet port supports multiple protocols. Note that some vendors are releasing UCA-based relays in 2003.

While the hardware cost in these relays is the same for the supported protocols, the other costs associated with testing and commissioning are different because the protocols are different (see Table 2 on page 5).

Description Modbus DNP UCA

DPU2000R Yes No Yes

F60 Yes Yes Yes

C60 Yes Yes Yes

D60 Yes Yes Yes

L90 Yes Yes Yes

L60 Yes Yes Yes

T60 Yes Yes Yes

T35 Yes Yes Yes

F35 Yes Yes Yes

B30 Yes Yes Yes

G60 Yes Yes Yes

9745 Yes

9300 Yes

421 No No Yes

BCD-G Yes

Minimum Cost $ 744.72 $ 744.72 $ 744.72

Average Cost $ 744.72 $ 744.72 $ 848.52

Maximum Cost $ 744.72 $ 744.72 $1,840.00

Table 3: Relays Supporting Ethernet Protocols

3.3.2. Meters

Table 4 on page 8 shows that only two meters that support UCA. While the number of available meters is a concern, many relays now provide non-revenue accuracy metering values and that the requirement for better accuracy, power quality, or other features can obtained by adding meters that can provide this data. In addition, one available product could also be used to migrate to a UCA system architecture by using it as an intermediate platform to add control, status, and analogs without requiring the replacement of relays that do not support UCA.

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The table of meter listings demonstrates that there are few meters available that support UCA. Since non-revenue metering quantities are available in relays, the use of metering IEDs will be limited to revenue, migration, or mixed-use applications.


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Description UCA DNP Modbus

Signature System 5530 DataNode Yes No No

PowerServe Yes Yes Yes

Minimum Cost

Average Cost $ 265

Maximum Cost

Table 4: Meters Supporting UCA

3.3.3. Networking Components

Networking components is the only category to list more equipment than available on the UCA product listing because these devices are specific to Ethernet and not UCA. With UCA, the detailed design required to evaluate system architectures and design is reduced because using UCA means using only Ethernet-based devices. While it is possible to have a device support UCA over a serial connection, only one vendor is known to presently and actively support this, while all other vendors support an Ethernet connection. Therefore, this paper only addresses the Ethernet products and design requirements, which reduces the design evaluation requirements.

The cost of networking components can vary with the type of equipment used – from hubs, switches, managed switches, and routers – to the number of ports required and the type of connections required (copper, multi-mode fiber, and single-mode fiber). Additional variation is also introduced with the connection required to the “network cloud” via SONNET, frame-relay, VPN, ATM, FDDI, fractional T1, xDSL, ISDN, etc. In order to keep the analysis simpler, this paper includes the substation LAN “cloud”, that is the network architecture up to and including hubs and switches. This removes additional costs that can be associated with connecting a substation to the corporate “network cloud”, which can be minimal costs if that network is already present to substantial costs if that network must be established.

Additional variation in networking components results from the standards applied to the networking components, otherwise known as the “substation hardened” versus “commercial grade” argument. This is not a trivial argument, as the substation environment presents realistic environmental challenges to commercial grade networking components that are required by many corporate IT departments. A few excellent discussions on this debate are available in [17], [18], and [19]. This manuscript has separated switches/hubs into fiber hardened, fiber commercial, and copper commercial groups.

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VPN:Virtual Private Network

SONET:Synchronous Optical Network

ATM:Asynchronous Transfer Mode

FDDI:Fiber Distributed Data Interface

xDSLAll types of digital subscriber lines

ISDNIntegrated services digital network

Substation Hardened: Fiber ports, not copper

ports Expanded temperature

ranges somewhere between -40 to 80ºC, beyond the typical commercial range of 0 to 45ºC.

Ability to withstand a variety of electromagnetic interference phenomena: electrostatic discharge, radiated radio frequency interference, fast transients, surge, induced radio frequency interference, magnetic field, voltage dips in AC and DC power, damped oscillatory, mains frequency, and AC ripple.


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Description Multi Mode Single Mode Copper Ports

4900 Yes Yes No

RS500 Yes Available No

FSU100 Yes Yes Yes

FSU200 Yes Yes Yes

QS5116 Yes Yes Yes

Minimum Cost $ 268.75 $ 568.75 $ 99.00

Average Cost $ 340.18 $ 846.00 $ 129.44

Maximum Cost $ 435.00 $ 1,137.50 $ 150.00

Table 5: Fiber Hardened Unmanaged Ethernet Switches/Hubs


RS8000 Yes Available No

RS8000T Yes Available Yes

RS1600 Yes Available Yes

RS1600T Yes Available Yes

FSR200 Yes Yes Yes

FST200 Yes Yes Yes

6K25 Yes Yes Yes

Minimum Cost $ 212.00 $ 416.00 $ 104.00

Average Cost $ 392.43 $ 992.83 $ 194.42

Maximum Cost $ 650.00 $ 1,375.00 $ 425.00

Table 6: Fiber Hardened Managed Ethernet Switches

Note that the application of single-mode fiber optic cables in a substation should not be required unless the substation network is to be expanded to another location at a significant distance away. Also note that a hardened, managed multi-mode switch costs approximately 3 to 33 times more than a managed commercial copper switch and 5 to 72 times more than a commercial copper unmanaged switch/hub. A $100 commercial hub can be replaced with a $4300 hardened, multi-mode fiber, and managed switch. It is clear from these price differences that networking equipment can represent a minimal to significant impact on material cost, so cost should not be considered alone.

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What is OPC?OLE for Process Control

OLE:Object Linking and Embedding – Now ActiveX. The predecessor to OLE was Dynamic Data Exchange (DDE).

ActiveX:An umbrella term of a broad range of technologies that used to be known as OLE, it is object-based rather than object-oriented.

For more information on OPC, see www.opcfoundation.org.

http://www.opcfoundation.org/


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4000-ST Yes No No

4000-SC Yes No No

4000-MT Yes No No

CFX-1432 Yes No Yes

SF-16ST Yes No No

Minimum Cost $ 61.04

Average Cost $ 95.19

Maximum Cost $ 108.06

Table 7: Fiber Commercial Unmanaged Ethernet Switches/Hubs

Description Unmanaged12 products

Managed14 products

Minimum Cost $3.75 $7.96

Average Cost $17.79 $64.84

Maximum Cost $81.04 $137.50

Table 8: Commercial Copper Switches/Hubs

3.3.4. Operator Interfaces

UCA compliance of operator interfaces is more difficult to assess because any operator interface that is OPC compliant can have an OPC client/server for UCA installed on the computer with only having the base product offering OPC connectivity. In critical applications, such as device control, use of an OPC client/server can result in timing issues that may not be adequately addressed by the capabilities of a particular OPC clients/servers on a particular operating system or computer configuration.

Description UCA Client UCA Server

AXS-4MMS Yes Yes

BASE Yes Yes

Minimum Cost

Average Cost $ 2,748.33

Maximum Cost

Table 9: OPC Servers Supporting UCA

There are presently two OPC servers available at this time that support UCA, so only an average cost is presented in Table 9 on page 10. The capabilities of both products are similar in some areas and the pricing structure is different. When considering software costs for both an OPC server and operator interfaces, the annual support fees and what they contain needs to be included in the cost analysis because these “maintenance” costs are usually the first costs to be cut by an organization when budgets are cut.

One cost that should also be included here is the monitoring of the

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What is a UCA Client?A UCA client is capable of reading data from UCA servers.

What is a UCA Server?A UCA server is capable of providing data to UCA clients.

What is SNMP?Simple network management protocol.

Multi-mode fiber:This fiber cable has a large-diameter core that allows multiple pathways of light generated from LEDs. Core diameters are 50, 62.5, or 100 microns.

Single-mode fiber:This fiber cable has a small core and only one pathway of light generated from a laser. Core diameter is around 8.5 microns. Distance can be up to 50 times greater than multi-mode fiber. This fiber is typically used for long-haul network connections spread out over a large area.


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substation Ethernet network. These costs are presented in Table 10 because monitoring the Ethernet network can be easily overlooked. There is Ethernet test equipment available to monitor a local area network and sophisticated software packages that can monitor a corporate WAN. However, operators need to obtain a real-time view of the health of the substation LAN devices (switches, routers, or any other manageable device), the overall substation LAN network traffic volume, and the overall substation LAN network status from within their substation integration and automation system. Bringing this data back to the system will allow quicker diagnostics so that if trouble occurs the correct substation technicians and/or corporate IT specialists can be sent to the substation site.

Description

iSNMP

SNMP-OPC Gateway

Minimum Cost

Average Cost $ 1,456

Maximum Cost

Table 10: SNMP OPC Servers

3.3.5. Substation Host

A substation host includes devices such as data concentrators, PLCs, communication processors, and RTUs. While some of these devices support the same functionality of the other devices, not all devices support all functionality. This is an interesting category, as it serves as a catchall for everything else not otherwise categorized so far. These devices may provide complex programming capabilities, analog inputs/outputs, digital inputs/outputs, protocol conversion for SCADA master protocols and/or serial device protocols, database connectivity, web servers, internal security implementations, routing, communication monitoring, UCA client, UCA server, and multiple communication ports. While some of these products provide different levels of capabilities in these categories, they have all been grouped together because of their functional similarities. Because of the range of capabilities, however, the choice of equipment must be made based upon more than cost as the choice will impact all aspects of the

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Software CostsComparing software products is not just comparing product features, but also the total cost of the product. This includes: Software license on a per

point, per connection, or other basis.

Software support: 24x7, normal business hours, on-line knowledge base, toll-free support line, per incident costs, etc.

Software upgrades: sometimes this is bundled with product support.


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substation integration system design.

Note that out of all of the products in this category, only the PLC does not presently have a vendor that supports UCA. This is possibly because PLCs are more heavily used in industry, where there are other protocols that exist or are developing that are based upon Ethernet. At one time, it was possible to place a PLC directly on a UCA network, but that product has been removed from the market. While there is no UCA product available for PLCs, several PLC vendors may provide UCA products when UCA becomes “stable” and a “market develops”. Until that time, PLC functionality on a UCA network can only be obtained through protocol conversion or by adding PLC functionality to a substation computer or other devices in this category.

Description UCA Client UCA Server

StationMANAGER/Substation Host Yes Yes

C30 Yes Yes

D25 UD Yes

D20 UD Yes

2030 Yes Yes

RT Integration Server Yes Yes

e-terracomm control 3.0 Yes Yes

ePAQ-9100 Yes Yes

RTU-9100 Yes Yes

SOS Supervisor No Yes

Minimum Cost $ 0

Average Cost $ 2,204

Maximum Cost $10,000

Table 11: Controllers, PLCs, RTUs, and Communication Processors Supporting UCA

3.3.6. Equipment Monitors

Equipment monitors include circuit breaker monitors, transformer monitors, LTC monitors/controllers, CT/PT monitors, and bushing monitors. Only one LTC monitor/controller supports serial UCA, while one CT/PT/bushing monitor supports UCA. From this, it is obvious that there are very limited choices in equipment monitors and that getting data from network monitors onto a UCA network will involve protocol conversion from a native protocol to UCA. Note that the DNP User Group and Modbus User Group web sites do not list any conformance-tested products in this category.

It is clear that integrating equipment monitors will most likely require protocol conversion to convert a native protocol into UCA. This adds significant requirements and costs to a project, as the UCA object model must be fundamentally understood as well as the native protocol and how

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Equipment Monitors: Circuit breakers Transformers LTCs Gas CTs/PTs Bushings

Presently very few equipment monitors support UCA.

What is a PLC?A PLC is a programmable logic controller that has a central processing unit, inputs, and outputs. PLCs were originally developed for process control in the industrial world, but have also been applied in substations. No PLC vendor presently supports UCA directly, although future products may be supported.


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the two map onto each other.

3.4. Testing

Ultimately the testing required for UCA is a function of the specifications to which hardware and software must meet. Testing should be separated into four stages: conformance testing, conceptual testing, factory acceptance testing, and site acceptance testing. The testing that a system ultimately goes through is dependent upon the criteria established in the initial project design. In addition to these test stages, adequate test documentation needs to be developed so that system performance is understood and documented.

Conformance testing can be broken down further into environmental conformance and process performance, both of which can be specified using international standards and/or utility standards. Typical environmental requirements are surge withstand capability and temperature range. Environmental testing can be problematic, as the IEEE has only a draft standard for communications equipment in substations (P1613 Standard Environmental Requirements for Communications Networking Devices Installed in Electric Power Substations) and finding equipment that meets this standard as well as existing corporate IT standards can be difficult. In addition, many utilities do not have the required laboratory equipment or knowledge base to perform the environmental testing while manufacturers regularly test equipment to the standards to which the equipment was designed and to obtain certificates of conformance.


Protocol Conformance Testing UD $ 5,000 $ 1,500

Table 12: Protocol Conformance Testing Costs

Process requirements could be items such as the number of simultaneous socket connections allowed, GOOSE message processing time, performance under denial of service attacks, performance under multiple connections, and protocol conformance testing. Communications testing can be problematic, as the IEEE has discovered that there is no coherent communication modeling, terminology, and communication test scenarios for the evaluation of communication networks involving substations20. To help solve this problem, the IEEE has balloted C37.115 “Test Method for Use in the Evaluation of Message Communications Between Intelligent Electronic Devices in an Integrated Substation Protection, Control and Data Acquisition System”.

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Testing the System: Conformance – testing

whether the devices meet the environmental and process performance standards. Testing is usually performed by an independent testing company.

Conceptual – testing in a laboratory setting to determine whether the system design meets the defined system requirements. Testing is performed by integrator and/or utility to work out the bugs before they make it to the field.

Factory Acceptance – testing all defined system points at the factory.

Site Acceptance – testing all defined system points at the substation site.


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Installing Ethernet-enabled devices in a substation adds a significant level of complexity to communications testing. The only test to perform is no longer SCADA configuration and communications with an RTU, but depending upon the complexity of the system, the following may also need to be tested:

Device Ethernet configuration and communications Peer-to-peer communications and related configuration Local substation host configuration and communications Remote host configuration and communications Remote database configuration and communications

Ultimately the amount of testing required depends upon the requirements specified by the utility. If there are no conformance testing requirements specified by the utility, then there are no conformance testing costs but the project risks increase as the project moves forward to detailed design. If a vendor provides independent third party testing or certified testing to the required specifications, then testing costs could be minimized to no costs without introducing additional project risks.

After conformance testing is addressed and before the system design is completed, the overall system needs to be tested for interoperability and performance in a laboratory setting. These types of tests would include some of the same tests performed on device conformance but performed on the connected system, including GOOSE transmission time under various network loads, status point update times, momentary change detection, operate times, fail safe tests, and analog update times. Some of these tests may also have to be performed with remote databases and SCADA masters as well. If these tests are delayed until the factory acceptance test, then product defects, network architecture problems, and other problems will be discovered after the design is completed, increasing the costs as the system implementation is delayed due to a redesign. When this testing is successfully completed, it is known that the system design meets the desired requirements, shortening the factory acceptance test and site acceptance test by limiting the tests to point tests: control points operate properly, analog values are reported properly, accumulator points accumulate properly, analog outputs function properly, status points function properly, etc.

Once the first system is assembled at the factory, the factory acceptance test (FAT) should occur. If the previous tests have been completed already, the FAT becomes a relatively simple test that confirms the system points. If the previous tests have not been completed, the FAT will become a risky endeavor whose outcome may require substantial re-design of the automation system. Once the automation system is delivered on site and completely installed, the site acceptance test (SAT) should be completed. The SAT should be based upon the FAT. The SAT ensures that the system has been connected and installed properly and all points are functioning as required.

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3.5. Construction

Construction of the substation integration and automation system panel(s) depends more on extent of integration than the choice of protocol. For new substations, the substation automation system can be fabricated off or on site. Off-site fabrication will generally present the lower costs. If an automation system is to be installed on site, additional costs will be incurred due to the systematic replacement of existing equipment in existing panels or to the switchover from the old control house to a new control house.

Panel fabrication costs typically include construction of the panels, mounting of equipment, inter-panel wiring, intra-panel wiring, creation of wiring diagrams from schematics (optional), and panel testing. As shown in Table 13 on page 15, most of these costs will not vary on the choice of protocol, but on the amount of integration chosen.


Remove control switches$2500 installed savings

Yes Yes Yes

Remove test switches No No No

Remove selector switches$1500 installed savings per switch

Yes Yes Yes

Remove local non-revenue meter Yes Yes Yes

Remove hard-wired contacts Yes AD AD

Use high-speed “soft contacts” Yes No AD

Local operator interface for local control/indication

Yes Yes Yes

Table 13: Panel Fabrication Costs with Ethernet-based Protocols

The difference in panel fabrication costs will result mainly from the use of “soft contacts” in implementing GOOSE to substitute all or a majority of hard-wired contacts. Depending upon the protection and control schemes implemented, the panel fabrication costs could be reduced minimally or significantly. However, any of these cost reductions will be offset by the required programming in the devices for GOOSE messaging and software testing. It can be expected that these programming and testing costs will be more than the cost reduction obtained from panel fabrication cost reductions. Over time, with an active and aggressive substation automation deployment, the cost savings

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Construction: Panel fabrication is

simplified depending upon the extent of UCA integration. This is true whether the panels are constructed off-site or on-site

Fabrication offsite requires transportation to site, whose costs will not be reduced given that the number of panels is not reduced.

Panel cabling to external sensors could be reduced if a process bus is implemented. This consideration is not included since a majority of relays does not support a process bus.


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from panel fabrication may be more than implementing GOOSE.

3.6. Maintenance, Support, and Recurring Costs

Cyclical maintenance costs include equipment maintenance as required and equipment replacement costs, as well as those costs associated with hardware and software upgrades to newer versions or new technologies. For example, moving to Windows XP when Microsoft support for Windows NT effectively ends, upgrading relay firmware to the latest release and other associated programming changes, or annual renewal of software support services from a software provider.

Some substation integration equipment includes self-diagnostics that can provide an alarm when maintenance needs to be performed. This can change maintenance of hardware from a cyclical procedure to only when it is required. This capability can also impact substation communication network topologies.

Recurring costs should include all training and facility/component maintenance as well as all software licensing costs. Note that for software the licensing cost may or may not include support costs as well. Recurring costs tend to ramp-up sharply during the first few substations; but after a few substations are commissioned for operation, the sustaining cost for operation should become stable.

Support costs for integrated systems can be approached from two different perspectives – the systems integrator supplies the support for the individual components of the integrated systems or the utility maintains support contracts with the vendors of the individual components. While obtaining support from a systems integrator provides one point of contact, the systems integrator may have to rely on vendor support anyway to maintain technical competence. Support directly from the vendors may provide better technical competency for each individual component, but this does not provide support for the overall integrated system. Neither of these options may be entirely satisfactory, so a blend of both is another possible solution. An example of this would be that calling a vendor regarding why a device is not communicating with another vendor’s device may result in blank stares from both vendors but a system integrator will be knowledgeable about both devices and can work with both vendors to reach the solution.

3.7. Phase Out

Phase out costs are incurred via several different avenues: software tools are only supported on operating systems for as long as the operating systems are supported; firmware must be upgraded to enhance product functionality; subsystem components become obsolescent due to rapidly changing technology. However these changes occur, great support contracts can include free upgrades while good support contracts have reduced upgrade costs. Another key in the support contracts is who is providing the support: a system integrator or vendor.

Lifecycle lengths can dramatically change the analysis results, so it is important to consider typical life-cycle periods:

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Recurring costs: Software licenses may or

may not include support, or free upgrades. These recurring costs need to be included in the analysis.

Maintenance costs may be reduced depending upon the maintenance practices of the utility and the self-diagnostics of the installed intelligent electronic devices. This may provide additional cost justification for the system installation.

Training costs should be included in the analysis not on a substation basis, but on a cyclical basis so that personnel remain competent with the installed systems.

Support costs will depend upon who is providing the support and the scope of those services.


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Software 1-5 years Computer hardware 1-5 years Network hardware 5-15 years Physical plant 30 years

The overall lifecycle of each component needs to be considered separately and depends upon the technology used in the device. For example, software and hardware based upon Microsoft products should be considered to have a five-year life-cycle period. This choice is mainly driven by Microsoft recently announcing operating system support times of four years and software support times of up to 10 years21. For other hardware and software, using the product warranty period can be indicative of an appropriate period length from five to ten years.

4 Costs for Mythical SubstationsAs a simple example of cost analysis, look at Mythical Small Substation, Mythical Medium Substation, and Mythical Large Substation. These three mythical substations have similar configurations as shown in Table14.

The analysis presented in Table 15 on page 18 is simplified to a one-time cost at one substation because the areas of maintenance, support, recurring costs, and phase out rely on critical information that presents too wide of variability: maintenance and support contracts, system life-cycle period, as well as replacement and upgrade costs.

The cost analysis is based upon the following:

Minimum 16-port switch configuration Operator interface costs include only the costs to add an OPC

server for UCA and SNMP data. Substation host cost is average cost. Relay cost is average cost. No revenue meters are at the mythical substations. All metering

data is brought back from relays. Design and Engineering costs based upon 14 tasks taking X

amount of time for each Ethernet device. X is reduced across the size of the substation: 8 hours, 6 hours, and 1.75 hours for each substation.

Testing costs assume $5,000 of conformance testing costs for each of the primary relay, backup relay, substation host, and switch. Testing costs include an additional amount Y of testing task time for each serial and Ethernet device. Y is reduced across the size of the substation: 8 hours, 6 hours, and 4 hours.

Construction costs include the savings in panel fabrication. Each line and transformer is considered to take one full rack with cost savings of Z per rack using a full implementation of UCA. Z is reduced across the size of the substation: $1,000, $900, and $800.

General management and support is taken as 15% of the

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previous costs. Average hourly labor rate taken as $80 for all personnel involved

in the project.

Description Small Medium Large

Number of Lines 4 8 16

Number of Transformers 1 2 2

Serial Legacy SCADA Connection 1 1 1

Serial transformer monitors 1 2 2

Serial breaker monitors 4 8 16

Ethernet 16-port managed switches 1 1 2

Operator Interface 1 1 1

Substation Host 1 1 1

Ethernet Primary Relays 4 8 16

Serial Backup Relays 0 8 16

Revenue Meters 0 0 0

Total Number of Ethernet devices 6 9 18

Total Number of serial devices 6 19 35

Table 14: Mythical Substation Configurations

Description Small Medium Large

Switch (Table 6) 6278.88 6278.88 12557.76

Operator Interface (Table 9 and Table 10)

2206 2206 2206

Substation Host (Table 11) $2,204 $2,204 $2,204

Relays (Table 3) 3394.08 6788.16 13576.32

Revenue Metering (Table 4) $0 $0 $0

Design & Engineering 53760 60480 68600

Testing (Table 12) 45720 73760 87840

Construction (Table 13) 27500 49500 93500

Maintenance, Support, andRecurring Costs

$0 $0 $0

Phase Out $0 $0 $0

General Management andSupport

$17,334 $23,057 $28,347

Additional Cost to add UCA $105,395 $127,272 $123,829

Table 15: Cost to add UCA to Mythical Substations

The analysis shows some important results:

The cost increase to add UCA devices to a substation is not driven by equipment costs as they account for only an average of 13% of the total increase. This compares with the Gartner Group

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analysis of total cost of ownership where capital expenses are 14% of the total cost of ownership22.

The testing cost on average represents 39% of the total increase in costs. This represents a significant cost that could be reduced if different aspects of testing could be eliminated, thus increasing the risk to the project. Fine-tuning the estimates for this work may reveal different results.

The design and engineering costs on average account for 35% of the total increase in cost. Fine-tuning the estimates for this work may reveal significantly different results.

General management and support averages as 13% of the total increase in costs. Fine-tuning the estimates for this work may reveal different results.

Constructions savings are based upon each panel losing one control switch and two selector switches. Removal of a panel meter is not included as this cost depends upon the type of meter removed. Construction savings average 31% of the total increase in costs and are substantially more than the material cost of adding UCA to the devices. This comparison, however, may appear as comparing apples to oranges: comparing the installed cost of the removed switches (material, wires, and labor) to material cost of adding UCA devices. However, the installation cost of adding UCA to devices is negligible, which leaves only the installed cost of the networking equipment that can be assumed to be similar to the installation cost of the wiring and equipment for another communication architecture. Note that fine-tuning the estimates for this work may reveal significantly different results.

5 ConclusionThere are many factors impacting the cost of a UCA substation and making that cost a huge question mark. Costs depend upon the type of substation, utility experience with integration and automation technologies, development or revising of substation standards, substation retrofit or greenfield, training requirements, integration of legacy devices, communications with the SCADA master, the extent of integration and automation required, testing, and many others. Unfortunately, the known costs are few: substation equipment hardware and software. This manuscript has not compared the capabilities of each device in each category, rather the additional cost of adding UCA to each device. This issue alone does not address the substantial costs involved with changing to a new device standard that supports UCA and the host of other associated issues and costs.

Ultimately the cost is dependent upon the number of devices to be integrated and the number of substations where the design will be applied. As the number of devices increases, the amount of construction, testing, and other work also increases. The number of devices is an independent variable of substation type: some transmission substations will have fewer devices than some distribution substations. As the

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number of substations increases some costs will lower on a device level: quantity discounts can be obtained; design, testing, and training costs will decrease on a per device level because the costs can be spread out over more devices. Ultimately, it is the number of devices that drives the cost model.

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References

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1 “The automation of new and existing substations: why and how”, a draft final report sponsored by the CIGRE Study Committee B5

2 Sheble, Nicholas, “Ethernet Usage Up, Linux on Radar Screen”, InTech Magazine, December 2002.

3 Brenes, Enrique, “Industrial Ethernet gaining factory floor strength”, InTech Magazine, September 2002.

4 Marshall, Perry, “English, TCP/IP, and language translation”, Industrial Computing, May 2002.

5 Marshall, Perry “Deja Vu All Over Again”, InTech Magazine, September 2002.

6 Montague, Jim, “Trends in Industrial Networking”, Control Engineering, January 2002.

7 Newton, Charles, “Market and Technology Trends in Substation Integration and Automation”, Presented at the 2002 Western Power Delivery Automation Conference.

8 Woodward, Darold and Tao, David, “Comparing Throughput Of Substation Networks”. Proceedings of the Second Annual Western Power Delivery and Automation Conference, Spokane, WA, April 3-6, 2000.

9 Dolezilek, David, “Choosing Between Communications Processors, RTUs, And PLCs As Substation Automation Controllers”. SEL White Paper available from www.selinc.com.

10 Woodward, Darold, “Protocols and Architectures for Power Delivery Automation”. Proceedings of the Western Power Delivery and Automation 1999 Conference.

11 Scheer, Gary and Woodward, Darold, “Speed and Reliability of Ethernet Networks for Teleprotection and Control”. Proceedings of the Western Power Delivery and Automation 2001 Conference.

12 Woodward, Darold, “Ethernet in the Substation: Just the Facts”. Utility Automation, September/October 2002.

13 Data available from www.modbus.org during January 2003.14 Data available from www.ucainternati o nal.org during December 2002.15 DNP Users Group e-mail, dated 1/02/02.16 Gilchrist, Grant, “Lessons Learned Making UCA Configurable”.

Proceedings of the DistribuTech 2002 Conference.17 Pozzuoli, Marzio, “The Need for “Substation Hardened” Ethernet

Switches”. RuggedCom White Paper available from www.ruggedcom.com.

18 Pozzuoli, Marzio, “Ethernet in Substation Automation Applications”. Proceedings of the Western Power Delivery and Automation 2003 Conference.

19 Tengdin, John, “A New IEEE Standard – P1613 – Environmental Requirements for Communication Networking Devices in Electrical Power Substations”. Proceedings of the 2003 DistribuTech Conference.

20 IEEE PC37.115 Draft 8r1 “Draft Standard Test Method for Use in the Evaluation of Message Communications between Intelligent Electronic Devices in an Integrated Substation Protection, Control, and Data Acquisition System”. Institute of Electrical and Electronics Engineers, Inc. 2002.

21 See http://www.win2000mag.net/Articles/Index.cfm?ArticleID=2706622 “Total Cost of Ownership”, available from

http://www.acs.unimelb.edu. a u/tco/

http://www.acs.unimelb.edu.au/tco/

http://www.win2000mag.net/Articles/Index.cfm?ArticleID=27066


http://www.modbus.org/

uca substation cost

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