Volt/Var control using inverter-based distributed energy resources

Inverter-based distributed energy resource (DR) systems have been designed to provide constant, close to unity power factor and thus do not provide voltage support by producing non-active power in the form of reactive power. Oak Ridge National Laboratory (ORNL) has been working on control schemes to provide variable reactive power which is summarized here. The Distributed Energy Communications & Controls Laboratory (DECC) at ORNL is a unique facility for studying dynamic voltage, active power/non-active power and power factor control from inverter-based DR. DECC interfaces with the ORNL campus distribution system to provide actual power system testing. Using mathematical software tools and DECC, ORNL is developing and testing local, autonomous and adaptive controls for local voltage control and active/non-active power control for inverter-based DR. These control algorithms are being tested using a real-time software and processor system interface to our computer controls interface at DECC. The control aspects of voltage regulation and active/non-active power control using inverter-based DR are discussed and simulation and experimental results from testing are presented.