Optimal Power Flow

Design Features

PRISM OPF is a nonlinear optimization program for calculating secure system operating conditions and determining operating strategies which minimize a selected objective function while satisfying constraints.


OPF recognizes the following constraints:

  • Bus voltage limits
  • Branch flow limits
  • Limits on branch groups
  • Generator reactive power output


OPF suggests the following control actions:

  • Shifting generator real power outputs
  • Changing generator regulated voltages
  • Switching capacitors and reactors
  • Adjusting tap positions on voltage regulating and phase-shifting transformers
  • Adjusting DC line terminal voltage, tap ratios, and firing angles at the converter station
  • Bus load transfer


Objective functions minimize the following:

  • Generating cost
  • Transmission losses
  • User-defined objective function


Leveraging off of this stable field proven product suite, ACS offers this package supporting the IEC 61970 CIM and PSS/E industry standards.


Security Constrained OPF

Security constrained optimal power flow programs are important tools for ensuring correct dispatch of supply while respecting the many constraints imposed by the delivery system power grid. Current state-of-the art production-grade tools typically break the relevant optimization problems down into sequences of sub-problems, using DC approximations to model the transmission and replace voltage and adequacy requirements with corresponding proxy constraints. Given the deregulated power market, this approach can obscure real weakness in the power system. 


BSI offers a production-grade SuperOPF package equipped with a commercial power flow solver and a homotopy-based interior point based solver and supports industrial-grade static power system models such as 13,000-bus EMS models.  Standard data formats are supported including the Common Information Model (CIM) and the PSS/E data format. The current implementation of the SuperOPF package is equipped with a voltage stability solver capable of handling voltage stability analysis under a large set of contingencies and adjusting control variables for both real and reactive power. 



The SuperOPF commercial package has been validated on the California ISO and PJM networks, including handling of the voltage stability constraint for a large set of contingencies (2,500 contingencies.)

More Information

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