electra irp use cases simulations - erigrid.eu · designing and validating the future, intelligent,...

Designing and validating the future, intelligent, electric power systems

Kassel, Sept. 6th 2017

Julia Merino Fernández

ELECTRA IRP Use Cases

Simulations

www.ElectraIRP.eu

The research leading to these results has

received funding from the European Union

Seventh Framework Programme (FP7/2007-

2013) under grant agreement n° 609687

2 ELECTRA IRP on Smart Grids

Designing and validating the future, intelligent, electric power systems– Sept 6th 2017, Kassel

Overview

• PPVC

• Adaptive FCC

• BRC+FCC = DLFC

• IRPC vs. Fast FCC

Fundamentals Setup Simulation

results



PPVC



PPVC Fundamentals

Two operation modes Planning phase: Proactive

Real-time operation: Corrective

Proactive Proactive Corrective



A PPVC single-cell test setup

European CIGRÉ MV grid benchmark (modified with DERs)

• Two feeders

• DERs

• 8 PV plants

• 2 batteries

• 2 fuel cells

• 2 CHPs

• 1 Wind Turbine

Load, PV pannels DERs patterns adjusted to match the grid requirements and

dynamic controls have been modeled

Note: Implementation in PowerFactory software

PV panels generation forecast

PQ load forecast



PPVC Results (I)

A) Planning phase (‘Proactive’ mode)

Optimal voltage set-point are calculated for the next 15-min windows in 1-min intervals

Why optimal power flows in a “Planning phase”?

The advantages of the WoC…

• Full observability

• Advanced communication technologies (less communication efforts)

• Increase in the calculation speed and data storage managment capabilities

Non-optimized planned voltage in t є (t’A+1 – t’A+2)

(current practice)

Optimized planned voltage in t є (t’A+1 – t’A+2)

(WoC proposed practice)

Total P losses = 0.0483 MW

Total Q losses = 0.4778 MVAr

Total P losses = 0.0462 MW (-4,3574%)

Total Q losses = 0.4645 MVAr (-2.7914%)

Voltage control optimization

in a single step



PPVC results (II)

B) Real-time operation (‘Corrective’ mode)

An unexpected event occurs during the

real-time cell operation (tA’) and the

previous calculated pattern (in the

proactive mode) needs to be recalculated

En t=tA’, U_NODE12<lower

limit_safe band

Real node voltages

Optimal set-points before/after the event



PPVC results (III)

B) Proactive vs. Corrective’mode



PV GS

The WoC

WP



Adaptative FCC



Adaptive FCC fundamentals

• Frequency Droop responsibility explicitly delegated to

cells

• Optimal decomposition of the cell’s CPFC (contribution

to NPFC) over the available resources adding a droop

scaling factor that depends on the state of the cells

− Avoid that FCC activations cause imbalances

− Responsibilization



Test assumptions

• CIGRE MV reference grid

• 1HV and 3MV cells

• Two adaptive controllers in cells 1

and 2

• Only the HV cell was equipped

with frequency restoration

process

Δfi

ΔPtie,i NH NL ZE PL PH

NH 0% 33% 100% 100% 100%

NL 33% 66% 100% 100% 100%

ZE 66% 100% 100% 100% 66%

PL 100% 100% 100% 66% 33%

PH 100% 100% 100% 33% 0%

Test Grid setup

Rule table

A-FCC test setup



Short-term performance (200s) 3MW increase in Node 02

Long-term performance (24-hour tests) Small droop of 1MW/Hz in the HV cell / Load step reductions every 15 min

Overall use of reserves

Reduction is use of renewables

𝐴𝐵𝑆 = ∆𝑃𝑑𝑟𝑜𝑜𝑝,1 +⋯+ ∆𝑃𝑑𝑟𝑜𝑜𝑝,𝑛 𝑑𝑡∞

0

𝐶𝑜𝑠𝑡 = ∆𝑃𝑑𝑟𝑜𝑜𝑝,12+⋯+ ∆𝑃𝑑𝑟𝑜𝑜𝑝,𝑛

2𝑑𝑡

∞

0

Function With Adaptive FCC With Fixed Droop ABS

(Reduction) 8.59e+7(Ws)

-19.7% 1.07e+8(Ws)

Cost 6.94e+12(W2s) 9.46e+12(W2s) (Reduction) -26.7%

RES With Adaptive FCC With Fixed Droop WG

(Reduction) 1.24e+7(Ws)

-18.0% 1.51e+7(Ws)

PVs 8.97e+6(Ws) 9.56e+6(Ws) (Reduction) -6.2%

A-FCC test results

Max. Freq F-FCC = 52.54 Hz

M. Freq. A-FCC = 52.50 Hz

Min. Freq F-FCC = 49.51 Hz

M. Freq. A-FCC = 49.42 Hz



FCC+BRC = DLFC



DTLC Fundamentals

Currently employed AGCs use PI controllers

• Rigid tuning, susceptible to parameter variations

• Non-linearities (ramp rates, delays) problematic, only working points can be optimally tuned

Proposed LFC

• Supported by the Web-of-Cells (WoC) capabilities: high degree of observability and comm.

• Two-staged control

Power matching through direct observations

Primary reference frequency control to balance unobserved powers and inaccurate measurements

• Tuning-free, adaptive, handles variable droops

• Stable over a wide range of parameters, agnostic to actuator non-linearities

WoC’s “keep local problems local”

• Secondary response decoupled from the system response

• Primary resources actively involved in frequency control

• Frequency is treated as a local quantity ← Inferred over primary resources’ states

16

AGC vs. DLFC

17

Scenario Parameter Cell 1 Cell 2 Cell 3

High J J [kg·m²] 20 20 0.2

H [s] 4.1 10.25 0.24

P_pri_ramp [kW/s] 2 5 0

T_sec_delay [s] 5 2.5 1

Low J J[kg·m²] 2 0.2 0.2

2 H [s] 0.41 0.1 0.16

P_pri_ramp[kW/s] 25 15 0

T_sec_delay [s] 0.1 0.1 0.1

Controller Parameter Cell 1 Cell 2 Cell 3

AGC T_ctrl [s] 1 1 1

KP [1] 0.065 0.09 0.1

KI [1/s] 0.08 0.11 0.13

BRC T_ctrl [s] 1 1 1

omega_f 1/3 1/3 1/3

omega_P 1/3 1/3 1/3

All load events (observed and

unobserved) are 5 kW

DTLC simulation results



DTLC conclusions

The DLFC shows satisfying performance

• AGC only performing better in working points it was tuned against

• Non-linearities are handled very well, stability was proven on paper and in real

experiments

• Frequency control works also under partial observability

DLFC fits well into the BRC/WoC context

• Supports adaptive droop (FCC)

• Benefits from fast secondary response (BRC variant)

Known shortcomings

• Good knowledge of controlled devices’ droop capability

needed (but AGC needs it for the whole area)

• Can only balance tielines in case of total observability

• → Tieline imbalance observer needed



IRPC vs. Fast FCC

IRPC+FCC Overview



IRPC vs. FCC Overview

This study aims at evaluating the capability of frequency

containment control (FCC) and Inertia response control

(IRPC) in mitigating the RoCoF as well as the two controllers

effects on the frequency performance.

The study is divided into two parts:

• Simulations study in DIgSILENT PowerFactory

• Experimental validation in SYSLAB (PowerLab DK)



IRPC vs. FCC setup

22

Measurement delay

(100ms)

Device delay

(10ms, 50ms, 100ms, 250ms)

RoCoF calculation and

Measurement delay (100ms)

Device delay

(10ms, 50ms, 100ms, 250ms)

2% droop

IRPC vs. FCC Controllers



IRPC vs. FCC results

EVs are used as flexibility

resources

Applied droops

Frequency standard deviation

for the two controllers

Different granularity from EVs

(i.e. EVs’ charging current are

modulated with 1A granularity)

Variation of Load steps

IRPC 2 kW load event

24

Can Fast frequency containment control compensate or replace the

need for Inertia response control?

• This work analytically showed the interdependence between frequency

containment and synthetic inertia control on the transient frequency

variation and the RoCoF

• On the simulation level, it presented the ability of fast frequency control in

improving the frequency in terms of nadir, steady state value and RoCoF. It

also presented the ability of synthetic inertia control (IRPC) to improve the

frequency nadir and slope following an event.

• Finally, an experimental validation was conducted, presenting the

capabilities and limitations of the two controllers under two different

circumstances: following load events in both directions and exogenous

wind generation profiles

25

CONTACT

INFORMATION

ELECTRA IRP on Smart Grids Event details – date and Place

Julia Merino Fernández, Ph.D.

[email protected]

ELECTRA IRP website Link: www.ElectraIRP.eu

mailto:[email protected]

electra irp use cases simulations - erigrid.eu · designing and validating the future, intelligent,...

Documents