Installation of a Static Var Compensator on to an 11kV network Substation Technology 2011 Jonathan Berry 26.10.2011

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

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

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

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

Understanding of the problem

Understanding of the problem

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

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

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

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

STATCOM Project

STATCOM Project Strand 2

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

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