1. Installation of a Static Var Compensator on to an 11kV network
Substation Technology 2011
Jonathan Berry

2. Content Introduction WPD Overview Understanding of the problem
STATCOM Project
Future learning and developments

3. Introduction
Jonathan Berry – Innovation and Low Carbon Networks Engineer
Background in primary network and substation design
Focussed on generation inclusion
Currently working on IFI and LCNF projects
Working on DG inclusion and network optimisation to support the low carbon transition

4. Western Power Distribution
7.6 Million customers over a 55,300 sq kms service area
Our network consists of 216,000 kms of overhead lines and underground cables, and 184,000 substations
LV to 132kV Network ownership

5. Understanding of the problem
As the level of embedded renewable generation and low carbon loads on the DNO’s network increases a core problem is created; maintaining statutory voltage levels.
Example:
An overhead network with a high level of wind generation connected:
At times of low load and high generation, network voltages move towards higher statutory limits, similarly at times of high load and low generation, voltages move towards lower statutory limits

6. Understanding of the problem

7. Understanding of the problem

8. STATCOM Project Challenge Technology
Distribution Voltage Control to mitigate the voltage fluctuation caused by variations in Load and Generation
Technology
D-STATCOM
(Distribution STATic synchronous COMpensator) X
△V≒Q・X
Distribution network Q
(reactive power)
Trans.
Controller
Inverter
D-STATCOM
DC Capacitor

9. STATCOM Project Goals Scope Benefits 4 Project locations: Agreed
Tentative
Trial D-STATCOM in rural 11kV networks to address voltage fluctuations
Identify optimum settings to achieve optimum voltage regulation
Development of D-VQC to optimise multiple networked D-STATCOMs
Goals
Strand 1 – a single D-STATCOM as a stand-alone voltage control system
Strand 2 – Three additional D-STATCOM units with a D-VQC (Voltage and Reactive Power (Q) Control System) to network devices and optimise across two primary substations
Scope
Improvement of power quality, mitigation of voltage spikes issues
Increase of network stability, efficiency and load capacity
Learning process will have a direct impact on the operation of a
DNO’s distribution system
Inform DNO’s business case for alternative responses to network rebuild
Benefits

10. STATCOM Project Strand 1 Wind Farm Substation Network open point
11kv over-head line
D-STATCOM

11. STATCOM Project SVR operation D-STATCOM operation
7000
600
Line Voltage with D-STATCOM
6800
Line Voltage without D-STATCOM (estimation)
450
SVR operation
6600
300
6515
SVR2 tap V
tap 4
6400
150
tap 2
Distribution Line Voltage (V)
tap 3
Q (kvar)
6250V
6200
60 sec
-100kVar
6000
D-STATCOM Q
-150
-195kVar
D-STATCOM operation
5800
-300
5600
-450 60
120
180
240
300
Time (sec)
DG sudden power change

12. STATCOM Project

13. STATCOM Project
Strand 2

14. Line impedance, configuration
STATCOM Project
A supervisory and control system for distribution system considering distributed generators to maintain power quality
Voltage dip
Voltage
violation
Line voltage
Line voltage
Flicker
S/S
Feeder length
End
DG stop
Time
Concept of supervisory and control system
State estimation
Load current
System voltage
Optimal control
parameter decision
Q(var), Tr.tap, …
Voltage
controller
D-STATCOM
SVR
LBC
Monitoring
P, Q, V, I
System DB
Line impedance, configuration
Load, DG, …
System modeling
Network
Load profiling
Simulation/Analysis
Power quality
Power flow

15. Future learning and developments
Conclusion and next steps
Voltage control is key to ensuring system stability in networks where there is embedded renewable energy generation and varying power demand
Further development and product optimisation
Policy discussions around network inclusion, ownership and operation