A multistage voltage and power flow control of distribution systems in the presence of DGs

Abstract

With the rapid increase of distributed generation (DG) in distribution systems, voltage and power flow become more liable to violate. The generation of non dispatchable DG is un_ controlled so traditional controllers such as on load tap changer (OLTC) are unable to keep the distribution system operating all times without violations. As a result, voltage and power flow control should be adapted. This paper proposes a multistage method to control voltage and power flow in the system if any bus or line exceeds its voltage or thermal limit respectively. The first stage is the control of (OLTC) and then the reactive power control is applied and if the two last methods are insufficient to keep the system operating within accepted limits, active generated power curtailment is considered. The method proposed here considers the rated reactive power drawn from the transmission system that keeps the voltage of transmission buses within limits. This method is based on the Jacobian sensitivity matrix. This method is tested on IEEE 33 bus radial distribution system using matlab. The simulation is done using matpower5.1 package.