A power electronics based power shedding control for wind/diesel systems

Abstract

The use of power shedding (or dump load) control in wind-diesel systems represents a method to ensure stability of the electrical network or to maintain a minimum load on the diesel(s). One approach to dissipate excess power is the use of an electronically controlled electrical load. This paper describes a simple, effective, low cost, and reliable power shedding control system that was designed and built as part of the University of Massachusetts Wind/Diesel System Simulator. The power electronics design, which is based on pulse width modulation, requires only one active switching device, and a single resistive element. In its present form, the capacity of the device is 10kW. Scaling, however, to a larger capacity should not present significant problems. As described in the paper, tests undertaken with the dump load control show that it can successfully maintain grid frequency, has acceptable harmonic distortion, and can ensure a minimum load on a diesel generator. In addition, the dynamic response of the control has been found to be acceptable.