Real time application of an optimal power flow algorithm for reactive power allocation of the RWE energy control center

In the Federal Republic of Germany the very high voltage network is owned by 9 utilities which work together in the Deutsche Verbundgesellschaft. The very high-voltage systems (380/220 kV) are mutually interconnected and are linked to the systems of Austria, Belgium, France, Netherlands, Switzerland and to Denmark. Since 1984, the operation of the RWE 380/220 kV energy system has been supported by an optimal power flow algorithm for reactive power allocation. In this real-time optimization process the reactive power of 65 generators and 15 reactive compensation devices as well as tap ratios of 30 transformers 380/220 kV are used as control variables. The network losses are taken as the objective function which has to be minimized. The following types of operating limitations are considered as constraints: voltage range for all busses, and current limitations for all lines and transformers