REAL TIME IMPLEMENTATION OF OPF BASED VOLTAGE...

1

REAL TIME IMPLEMENTATION OF OPF BASED VOLTAGE CONTROL TOOL IN BCHydro Advanced Voltage Control Workshop, EPRI, May 19-20, 2011, Pennsylvania,U.S.A. Veera Raju VINNAKOTA (veera.raju.vinnakota@bchydro.com), Djordje ATANACKOVIC

- PRESENTATION OVERVIEW• Implementation of OPF

for Voltage control recommendations in real time

• Refinements to Loss minimization (Ongoing)

• Conclusions

2

- BC ELECTRIC SYSTEM– 18,000 circuit km of

transmission lines ( 60 kv – 500 kv)

– 20 Major Generating plants ( 12,000 MW capacity)

– 360 substations– 10,000 MW of peak load– Long transmission lines

from Remote generating facilities to Load center

– Controls against Voltage Stability, Transient Stability are part of operations

– Voltage control is important

BC ELECTRIC NETWORK OVERVIEW

3

System Voltage Control Approach, Supporting tool OPF

System Voltage Control

UI driven by OPF

Control Recommendations

4

OPF (Voltage Var Dispatch) in Real Time Sequence

- Runs with SE (RTNET) solution as base case every 2 minutes - 2200 Buses system of base case power flow- Typically examines 80 controls to satisfy 25 voltage constraints- Recommends controls to correct voltage violations / save MW losses- Controls :

– Shunt reactors / capacitors switching– Sync condensers, SVCs MVARs– Generating Unit MVARs

- Takes 2-4 seconds to complete the run

5

SAMPLE RESULTS– Voltage Correction example – PI Plot of MW

losses– Loss Minimization Example – PI Plot of MW

losses

6

IMPLEMENTATION ACTIVITIES– Requirements– Prototyping to cover one Region of controls– Modeling, tracking the solution– UI Development, Refinements– Enhancement to cover full system– Validation by Control room – Real Time validation– Operating order– Training– Handover to Control Room– Ongoing Support

7

Control Room involvement,Test/Maintenance Facilities, Vendor Support

– Control room supervisor involvement from prototyping unto handing over to control room

– Dispatchers feedback during validation phase– Study environment with direct access to real

time data and SE solution– Study environment modified to copy snap shot

of SE solution and to run at chosen cycle– A layer on UI for Analysts to try enhancements

and also for quick trouble shooting – Vendor support with direct access to developer

8

UI, Validation of results, Tracking the results, Outcome

– UI, Validation, Tracking the results• Selection of Controls, Voltage constraints• A Study display for evaluating effectiveness of a control• A high level box for validity results ( Green >Good, Red >

Reject)• Quality tracking and improvements of SE solution• Validation of tool running in real time over 2 years • Every cycle of OPF Recommendations, etc., tracked

– Outcome• Recommendations match close to expectations • Potential savings : 60-100 MWh a day ( Average 3-5 MW out

of 300-450 MW transmission losses) • Operating order developed for using OPF for system voltage

control• Tool formally taken into service in February 2011

9

HAND-OVER TO CONTROL ROOMTraining and familiarization–1st level of training on interpretation of VVD results to encourage looking at VVD results and to enable providing feedback by one-on-one discussions–Introduction of the tool to dispatchers in the form of seminars, presented by Manager/supervisor involved in the project to train and / or to collect more feedback and to encourage using the toolOperating Order–Distinguishing output produced by the tool as guideline recommendations to support dispatchers while following operating orders that are typically mandatoryOngoing Support

10

Issues Being Pursued– VVD not to recommend tagged devices for

control – to be pursued– Improve quality of state estimate in a few

pockets of network – mostly done– VVD to provide priority of shunt recommendation

in switching out a device over switching in any device modeled in VVD with in the Station – to be pursued

– VVD to honor some unique control constraints such as : to keep at least 1 shunt reactor connected all the times in chosen stations – to be pursued

11

CONCLUSIONS• Implemented OPF for Voltage control

recommendations in real time for Control room use• Recommended controls match with control

practices by dispatchers• Newer control practice opportunities observed• Quality of SE solution is critical• Control Room involvement is corner stone for

acceptance of tool• Timely vendor support is important for successful

implementation• Refinements to Loss minimization are in progress

12

THANK YOUVEERA.RAJU.VINNAKOTA@BCHYDRO.COM

DJORDJE.ATANACKOVIC@BCHYDRO.COM