OPEN V-Q for Power System Optimization

Achieve optimization and efficiency for power generation and transmission systems

BSI and Hitachi have joined forces to produce the Optimized Performance Enabling Network for Volt/Var (Q) platform (otherwise known as OPEN V-Q) that will forecast future power system conditions and optimize the voltage profile using AC-Optimal Power Flow (ACOPF) technology and online data. The goal is to bring “innovation in power grid operation by online optimization technology”.

The OPEN V-Q Platform seeks to:

  • Perform Volt-Var optimization
  • Handle renewable energy uncertainty
  • Forecast and manage future operating conditions
  • Determine optimal control adjustments to current system devices
  • Optimize Key Performance Indices (KPI)
    • Reduce operating costs by cutting transmission system losses via optimized control of shunt devices, transformer taps, and reactors
    • Save on capital expenditures
    • Enhance power transfer capability through improved voltage profile and system stability

Utility Cases

Tokyo Electric Power Company (TEPCO) – Power provider for Tokyo (Japan) and the surrounding region, and the largest investor-owned utility.

The OPEN V-Q Platform simulation on the TEPCO Power Grid

  • Operational KPIs: Transmission losses and load margin
  • Optimal Power Flow Conditions:
    • Objective function – minimize transmission losses
    • Constraints: voltage range, maximum reactive power output of generators, capacity, and available switchable devices


  • Voltage Security – Improved available transfer capability by 10%
  • Operational Expenses – 2% reduction in overall transmission line losses
  • Capital Expenses – No need for investment in capital as the system becomes more efficient

EGAT Thailand

Hitachi Ltd. and Bigwood Systems, Inc. teamed up with Tokyo Electric Power (TEPCO), Ernst & Young, and the Electricity Generating Authority of Thailand (EGAT) for a feasibility study on the northeastern area of the Thailand power grid.

Reactive Power Coordination Tool (RPCT)

In addition to OPEN V-Q, BSI offers RPCT for volt-var optimization, specifically to predict and remove future grid violations (voltage and thermal) through coordinated reactive power scheduling using optimal static and dynamic control options.

The RPCT integrated package is used in both on-line (near real-time) and off-line study modes. The coordinated reactive power scheduling is conducted through static and dynamic control options to mitigate expected hourly violations over a future time duration (12 hours to start but extended to 48 hours ahead of real time). The powerful engine behind RPCT prioritizes various control types, constraints (temporal, physical, reactive reserve, etc.), and user configurations to find the best and most efficient solutions. This means for a given time duration, the RPC tool will provide optimal control recommendations that will handle violations for several hours at once with minimal control adjustments.

This innovative tool is different from traditional segregated Volt/VAr tools and other look-up table control tools, which degrade overall performance due to changes in system configuration, renewable uncertainties, varying load profiles, etc. RPCT uses the most up-to-date information to make system condition calculations on-the-fly.