3.problems svc-- static var or solved

8/9/2019 3.Problems SVC-- Static Var or Solved

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Problems SVC-- Static Var Compensator solved:

1. For electric arc furnace

Electric Arc Furnace as a nonlinear and erratic load in the power grid will bring a

series of adverse effects to the power grid, such as:

1. Lead serious three-phase unbalance of the power grid, create negative

sequence current.

2. Produce high order harmonics, such as coexist of 2ed, 4th even harmonics

and 3rd, 5th, 7th odd harmonic, then make severe voltage distortion become

more complicated.

3. Serious voltage flicker.

4. Low power factor.

The beat method to completely resolve the problems mentioned above is to install

fast-acting reactive power compensation device (SVC). The response time of SVC

system of RXPE is less than l0ms, which met the strict technical requirements. The

SVC can supply reactive current to electric arc furnace and stabilizes the voltage level

in the power grid. Then the output of the metallurgical active power can be increased,

and the impact of flicker can be minimized. The separated phase compensation

function of SVC can eliminate the three-phase unbalance caused by electric arc

furnace. The filtering devices of the SVC, can remove the harmful high order

harmonics so as to improve power quality, then the power factor can be increased

through providing capacitive reactive power to the system.

2. Forrolling mill

During working, the reactive power impulsion caused by rolling mill and other

industrial symmetry loads will lead to the following problems to the power grid:

1. Degrade the voltage level and create voltage fluctuation, even make the electrical

equipment inoperative, and reduce the production efficiency.

2. Lessen the power factor

3. Harmful high order harmonics in transmission device of load, mainly including

odd harmonics, such as 5th, 7th, 11th, 13th and side frequency, which will create

serious distortion of voltage level.

RXPEs SVC can remove the above problems to maintain a stable bus voltage, avoid

the harmonic , and make the power factor close to 1.

3. For Power supply of electric locomotive

Electric locomotive transportation also generates the averse effect to the power

grid. Because the electric locomotive is single phase power supplied, such

single-phase load causes a serious three-phase unbalance in the power grid and a

low power factor, then negative sequence current is formed.
http://en.wikipedia.org/wiki/Reactive_powerhttp://en.wikipedia.org/wiki/Reactive_power


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Presently, the only method to resolve this problem is to install SVC at appropriate

locations along the railway. The three-phase balance of the power grid is got

through the quick isolated phase compensation function of SVC, and the improved

power factor is achieved through filters. RXPE can supply the SVC to solve the

problems perfectly.

4. Forhoist

Hoist and other heavy loads will have the following effects on power grids when they

are at the working state:

1. Reduce the voltage level and generate voltage fluctuation in the power grid.

2. Low power factor

3. Harmful high order harmonics in transmission device

All of these problems can be removed by use of RXPEs SVC.5. ForLong-distance power transmission

In the global electric power industry, we are trending to conduct long-distance

electricity transmission. The high energy consumption requires the transmission and

more effective distribution system. SVC can significantly improve the transmission

and distribution performance of power system, which has been widely proved in the

world. In order to maintain a balanced voltage as the power system in different

conditions, the installation of SVC at one or more suitable locations of the power grid

is necessary. The following purposes are achieved:1. Stabilization of the voltage of weak system

2. Reduction of the transmission losses

3. Increment of transmission capacity makes the existing power grid play its

maximum efficiency

4. Increment of transient stability limit

5. Increment of damping under small interference

6.Enhancement of voltage control and stability

7. Elimination of power fluctuation

6. ForSecondary substation in city (66/110 kV)

In regional power grid, we generally use the TSC to compensate the reactive power

and improve power factor. However, this method can only provide capacitive reactive

power to the system, but not achieve rapidly and precisely regulation with the changes

of load which is easy to cause inverted injection of reactive power to the system, the

fluctuation of the bus voltage, the damage of the electrical equipment and instability

of the system.

RXPEs SVC system can quickly and accurately make capacitive and inductivereactive power compensation. When SVC stabilizes the bus voltage and improves


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the power factor, the inverted injection of reactive power is solved thoroughly. In

addition, the SVC may take full advantage of original existing fixed capacitors

bank, achieving the best efficiency with the least investment. It becomes the most

effective way to improve the quality of power supply of regional power grid.

Working principles of SVC-- Static Var Compensator:

Principle of TCR Type SVC

While the SVC is installed into the system, the capacitor provides fixed capacitive

reactive power Qc, the current passing through the compensation reactor determines

the amount of the inductive reactive power QTCR outputted by the compensation

reactor. The inductive reactive power offset the capacitive reactive power. As long as

the reactive power of the system Qn=Qv (required by the system)-Qc+

QTCR=constant (or 0), it can be realized that power factor of electrical network is a

constant. The voltage will not change, what is of importance is the required current

passing through the compensation reactor on the triggering angle which is used to

control the thyristor. The converter and control system of the thyristor can achieve

this function, collecting current value and voltage value of reactive power of the bus

to compose the value of reactive power. Compared with the set constant value of

reactive power (may be 0), the magnitude of triggering angle is calculated, and the

required current pass through the thyristor is got.

As for asymmetric loads, by the theory of Steinmets, the system achieves separated

phase regulation, which can eliminate negative sequence current, and balance

three-phase of the power grid.

Configuration of SVC-- Static Var Compensator:

1. Full digital control system:

Cabinet structure; used to calculate reactive power of the electrical network at

real-time, control magnitude of triggering angle of thyristor so as to control the

amount of compensation of reactive power.

2. Thyristor converter:

1.Frame structure.

2. Receive signal from the control system, change size of the triggering angle of

thyristor, generate corresponding reactive power compensation current.

3. Compensation reactor:

1.Tubular dry type, double coils at top and bottom, natural cooling.

2. When the current passing through the thyristor flows through the compensationreactor, it generates the inductive reactive power required by the system, which is


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used to balance the reactive power of the system and maintain stability of bus voltage

and power factor.

4. High order harmonics filtering device:

1. Components: reactor, power capacitor, resistor (used when there is a high-passchannel), these three components shape a filtering channel. Multiple filtering

channels can be formed according to system requirements, which are used to filter

out corresponding high order harmonics, respectively.

2. Structure: The reactor is tubular dry type, with double coils at top and bottom,

natural cooling, the power capacitor is installed in a frame structure, with natural

cooling property.

3. Purpose: Remove the high order harmonics running through the system; supply capacitive

reactive power to the system and increase the power factor.4. Connection: Each filtering channel is connected to the bus of the system through switch

abinet (can also be connected directly).c

Technical parameters of SVC-- Static Var Compensator:

Item Specification

Voltage Level (kV) 6 10 27.5 35 66

TCR rated capacity (Mvar) 6-300

Structure of thyristor valve Standard frame structureCooling method of thyristor Heat pipe natural cooling or water cooling

Model of thyristor Electricity triggered thyristor (ETT) or

light

triggered thyristor (LTT )

Triggering method Photoelectricity triggered or light triggered

Control system DSP full digital control system

Control method Reactive power

Regulation scope of reactive power -100% - +100%

Regulation method Phase-splitting regulation

Response time of regulation system 20 years

Applications of SVC-- Static Var Compensator:


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RXPE SVC--Static VAR Compensator, regarded as the power quality solutions have

exceeded 600 sets, which are widely used in metallurgy, electric railway, electricity,

coal, nonferrous metals, and other industries.

RXPEs SVC/ Static VAR Compensator has been exported to Germany, Italy, India,

Turkey, Vietnam, Thailand, Myanmar, Nigeria, Sudan and other African countries, as

well as Brazil and other South American countries, just to name a few. And we have

provided SVC subcontract services to Italian Danieli and other international

engineering contractors.

I. Power Quality Solutions SVC Applications Metallurgy

1250 tons Hot rolling 10 kV SVC project of Qianan Steel in Tangshan China

The first LTT water cooling SVC in China

1. Project conditions: 1250 mm Hot rolling production line, the main motors are DC

motor

2.Time SVC takes effect: January, 2007

3. Operation results:

--The distortion of harmonic current and harmonic voltage is superior to national

standards;

--Voltage fluctuation is less than 1.0%;

--The unbalance of three-phase of voltage level is less than 0.5%;--Power factor is stabilized around 0.98.

4. Technical Specification

Technical data

Application 1250mm hot-rolling

voltage level 10KV

Model TCR+FC

TCR capacity 33 Mvar

Triggering method LTTStructure of valves framework structure

Cooling method water cooling

Control System Full digital control system

Response time of control system


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Baosteel 2050 Hot rolling 35 kV right bus bar SVC Reconstruction ProjectThe first LTT

SVC with large capacity in China

1. Reconstruction reasons: In Baosteel, the original SVC equipment of 2050 Hot rolling 35 kV

right bus bar is the whole set products of German Siemens in the 1980s, after operation over 20

years, the level of the equipment, technology, controlling precision and other aspects has behind

the times, and the components are aging increasingly, can not meet the needs of production of

Baosteel.

2. The transformation project: in this transformation, the photoelectric triggered valve was

replaced by the most advanced LTT silicon valve in the world, and substitute DSP full digital

control system for the original control system, the human-computer interface was much friendly,

and the monitoring system could supply more information to ensure the safety and stable

operation of SVC equipment.

3. Time RXPEs SVC takes effect: March 2007

4. Operation results: the power quality indicators were better than that of original SVC devices,

effectively balanced the reactive power, stabilized voltage and improved power quality.

5. Technical Data:

Technical Data

Applications 2050 Hot rolling

Voltage level 35kV

Model TCR+FC

TCR capacity 60 MvarTriggering method LTT

Valve structure framework structure

Cooling method Fully closed pure water cooling

Control system Full digital control system

Response time of the control system


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electrical network, limited voltage fluctuation of public connection points of power

grid, voltage flicker, voltage waveform distortion rate and value of harmonic current,

decreased the power consumption per ton and improved power factor.

4. Technical Data

Technical Data

Applications 1780mm hot strip mill

Voltage level 35kV

Model TCR+FC

TCR capacity 120Mvar

Triggering method photoelectric triggered

Valve structure framework structure

Cooling method High efficiency heat pipe cooling




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Degree of asymmetry of (negative

sequence) voltage

Seriously exceed

standard


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FC capacity 40Mvar

Filtering channel H3H5

Triggering method photoelectric trigger

Valve structure Open type, heat pipe natural cooling


Response time


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1. Project introduction: A 138/34.5 kV transformer and a set of 34.5 kV distribution

equipment supply power for a electric furnace, a LF furnace, in addition, another two

138/13.8 kV 37.5MVA transformer and a set of 13.8 kV distribution equipment

supply power for steelmaking, continuous casting, high-speed wire rod rolling mills.

2. Requirements of the client: Remove pollution to the power grid caused by

harmonic, reduce voltage distortion rate, improve the load bearing ability of power

system, purify and improve the power quality of the power grid.

3.Operation results: Improved the power quality of the power grid, eliminated

harmonics, reduced voltage distortion rate, and fully met requirements of the client.

Wide and thick plate project, 35 KV dynamic reactive power compensation

device SVC project of Wuyang Steel Company

1. Working conditions before RXPEs SVC takes effect: A 220 KV substations

mainly supply power for smelting loads, the smelting loads include a 100t

super-power electric arc furnace and two refining furnace. As large-capacity electric

furnace has features of short-circuit overload impulse, unbalance of three-phase,

harmonic, negative sequence and low power factor, etc., may cause serious impact on

power quality of the power grid, if do not administrate it, it would harm normal use of

other electrical loads in the power supply system.

2. Time RXPEs SVC takes effect: January 2008

3. Operation results of SVC: Effectively reduced the harmonic and negative sequence,restricted voltage fluctuation and voltage flicker, increased power factor and

improved power quality of the power grid.

4. Technical data:

Technical data

Applications 220kV Substation 100t EAF 120t LF

Voltage level 35kV

Model TCR+FC

TCR capacity 120 MvarTriggering method photoelectric trigger

Valves Structure framework structure

Cooling method high efficiency heat pipe cooling system




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conducting steel business over 50 years. On December 2007, the annual output of

downstream products of 14 associated steel enterprises in Thailand involved with it

has reached 14 million tons, and the market share of its products in Thailand has

exceeded 60%. As the percentage of non-linear loads in the system was large, the

quality of power supply was reduced. In order to improve the power factor, Thailand

Weichengfa inhibited the distortion of high order harmonic to the power grid, made

comprehensive administration in accordance with provisions of relevant standards of

power quality.

In March 2006, Thailand Weichengfa Wire Rod Factory came to visit our company,

made a full recognition to hardware facilities and software technology of our

company, and decided to use the FC device produced by RXPE to improve

performance, productivity of equipment .

The rated voltage of the project is 22 KV, filtering capacity is 9.35 Mvar.

2. Operation results: Since FC of RXPE has been put into operation in Thailand

Weichengfa, the equipment has been operated stably and in good conditions, the

power factor was improved, and the unbalance degree of voltage was also better than

national standard, reached the expected purpose, met the requirements of assessment

of the user and reduced operating costs of the enterprise.

II Power Quality Solutions - SVC - Application- Electric railway

Baotou-Lanzhou line substation SVC project

1. Project Overview: The main loads of Lanzhou Railway Bureau Baotou-Lanzhou

line traction substation are electric railway locomotives, the main transformer bus are

divided into two sections, an AFF33-2240-1W close type power capacitor is hung on

each section of bus, used to compensate reactive power of the locomotive, and

improve the power factor of the traction substation.

2. Time RXPEs SVC takes effect: May 2002

3. Functions of SVC

Functions of SVC

Eliminate inverted sent reactive power, and increase power factor

Before the SVC was put into operation, the original capacitor injected a large number

of reactive power to the system at the section under the condition that no locomotive

was running, the average power factor of the substation was 0.88; after the SVC was

put into operation, the problem of inverted sent reactive power was effectively solved,

the average power factor of the substation was increased above 0.92.

Restrict high order harmonic

The high order harmonic generated by the filtering device of SVC on the electric
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railway has good regulation function, particularly on the 3rd, 5th, 7th harmonic, the

administration effect is particularly evident. After SVC was put into operation, the

distortion rate of voltage of various order harmonics has not exceeded standards,

which meet operational requirements of the user.

Reduce the unbalance of voltage, decrease the negative sequence interference

After SVC was put into operation, it effectively improve voltage unbalance state, the

unbalance degree of voltage was reduced significantly, which was fully comply with

requirements of various standards.

Reduce the current impulse and voltage fluctuation caused by the locomotive, and

optimize power quality and enhance transport capacity

The real-time dynamic reactive power compensation performance of SVC, effectively

reduced the current impulse and voltage fluctuation caused by the locomotive, and

optimized the power quality, enhanced the transport capacity of electric railway.

4. Technical Data

Technical Data

Applications Traction substation of electric railway

Voltage level 27.5KV

Model TCR+FC

TCR capacity 3.6Mvar

FC capacity 4.8MvarFiltering channel H3

Triggering method Photoelectric trigger

Valve structure Open type, heat pipe natural cooling

Control system Double CPU full digital control system

Response time


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administration for compensation between electric railway and power grid in China.

2. Time RXPEs SVC takes effect: May 2002

3. Operation results:

Before SVC device was put into operation, because of the impact of negative

sequence current, the loads of two generators were restricted, the daily average output

per unit was down to 20,000 kilowatts per three hours. After SVC was installed and

put into operation, administration of units was no longer be restricted, could operate

with full load at any time according to scheduling requirements.

Name of

technical

specification SVC

Before SVC

put into

operation

Expected value of

feasible scheme

After SVC

put into

operation

Reduction

Voltage

fluctuation

4.7% 2.0% 1.5% 68.1%

Average power

factor

0.8-0.85 0.9 Over 0.97

4. Technical Data

Technical Data

Applications: 110kV regional power grid Triggering method: Photoelectric triggered

Voltage level: 35KV vertical Valve structure: heat pipe natural cooling

Model: TCR+FCControl system: Double CPU Full digital

control system

TCR capacity: 100Mvar Response time:


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Applications 220kV substation

Voltage level 35KV

Model TCR+FC

TCR capacity 120

Triggering method Photoelectric trigger

Valve structure Open type structure





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accounting for 50% of coal reserves in East China, 74% of coal reserves of Anhui

Province, which is the sum of reserves of Shandong and Henan provinces, and

equivalent to 11 times of the reserves in Jiangxi Province. With 20 million tons/year

of coal production, it is a new enterprise taking the coal mining as its leading industry,

and integrating with coal, electricity and chemical.

2. Problems of the client: The winch in main well of the AC/AC frequency conversion

power supply, and the winch in vice well of thyristor converter DC power supply of

110 KV substation of Huainan Mining, is the main impulsive loads on section I, II of

the 10KV bus. The reactive impulse of the system is large, which causes a lot of

fluctuation to the power grid, resulting in extremely low power factor, the harmonic

current injected is also large, especially 5th, 7th, 11th is the most significant.

3. Time RXPEs SVC takes effect: September 2005

4. Operation results: Through tracking and measurement, performance of the

equipment is stable, with safe and reliable operation, good indicators, it effectively

solved above problems to loads of the user, achieved the expected results.

Typical project in coal mine industry

Huainan Mine Industry 110kV substation

1.Background: Huainan is located in Anhui province, total gross value over 10 billion

Yuan. Annual production is 20 million tons. Coal mine is the leading industry of

Huainan, and Coal electricity is auxiliary industry.

2. Customer problems: Main hoist and auxiliary hoist are main impact loads of 10kVbusbar and . The reactive power rush causes obvious voltage vibration and low

power factor to the grid, furthermore, the load brings abundant harmonic current to

the system, especially 5th, 7th, and 11th harmonics.

3. Operation date Sep. 2005

4. Operation benefitsAfter actual tests, the equipment operates safely and stably,

customs problems are solved completely.

Typical project in nonferrous metal industry

Yunnan Xinli Nonferrous Metal Company, 80000t/year high titanium slag project

1. Background: 80000t/year high titanium slag project is a key project of Yunnan

Metallurgy Group during 11th five-year period. The project adopts international

advanced technology, which play a active role in energy saving and environment

protection.

2. Customer problems: Harmonics and reactive power rush during DC EAF operation

will cause voltage vibration and flicker, which will influence safe operation of

electrical equipments in grid, and worsen the power quality.

3. Time RXPEs SVC takes effectDec. 2007

4. Operation benefits: Effectively eliminate harmonic current in grid, smooth voltage


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vibration, suppress voltage flicker, reduce production cost, and improve power factor.

V.Power Quality SeriesSVCApplication-Non-ferrous Metal

Industry

The 80,000 tons/year High Titanium Slag Project of Yunnan Xinli Non-ferrous Metal

Company

1. Project description: The 80,000 tons/year High Titanium Slag Project of Yunnan

Xinli Non-ferrous Metal Company, is the key project during the 11th Five-Year

Plan of China Yunnan Metallurgical Group, it firstly introduced high-power direct

current closed electrical furnace smelting high titanium slag technology in China,

which is at advanced level in the world, at the same time, it adopted the international

advanced raw materials preheating and exhaust new comprehensive recovery

technology, which has played a positive role for energy conservation and protection

of environment. The project is expected to invest 600 million, after it is put into

production and achieves standard, the capacity of output will be 80,000 tons of

chloride slag, 20,000 tons of acid slag and nearly 70,000 tons of pig iron, the annual

sales income will reach 470 million yuan, profit tax will reach 120 million yuan, it

will play a positive role to promote the resource advantages of Yunnan Province to

transfer into economic advantages, and drive development of local economy, enhance

the competitiveness of the metallurgical group.

2. Problems of the client: DC electric furnace generated a large number of harmoniccurrent, voltage fluctuation and flicker caused by reactive impulse in the process of

running, which seriously impacted on the safe operation of electrical equipment of the

power grid and the client itself, reduced power quality of the power supply grid.

3. Time to put into operation: December 2007

4. Operation results: Effectively restricted the harmonic current injected into the

power grid, restrained the voltage fluctuation, voltage flicker, reduced the power

consumption per ton, increased power factor, greatly improved efficiency of

steel-making of the electric furnace, shortened the steel-making time, at the same time

reduced the cost of steel making, which has played a positive role for energy

conservation and protection of environment.

SVC-Service Guide

Complete service

System Design

SVC Manufacture

Equipment Design and Civil Design

Mounting supervision
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Commissioning

Training

Spare Parts Supply

Maintenance

Remote Monitoring

3.problems svc-- static var or solved

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