Proposal of a Method to Estimate the Operating Status of the Distributed Generators

Along with widespread distributed generators that use natural energy, power flow control of the distribution systems has become complicated. In particular, when a system failure occurs, distributed generators are disconnected and power flow changes rapidly. This causes concerns about supply voltage deviation from its regulated value, distribution line overload, etc. To meet this, it is required to have an operational control technology that allows rapidly taking measures for the power flow change in the event of a system failure while successively catching up with the generated output of distributed generators.The authors indicate a future concept that allows for distribution system operational management considering distributed generators, and propose, as a technology to achieve this concept, a method to estimate the operating status (whether in operation or shutdown) of co-generating systems. With this method, the operating status of a co-generating system installed by a consumer is estimated based on the power flow value measured at the consumer's inlet. The proposed method has two estimation methods, i.e. one is a “power factor method” for consumers without power factor correction capacitors and the other is a “power factor/total power method” for consumers with power factor correction capacitors. This has led to estimating the operating status of a co-generating system, which was impossible thus far, with a percentage of correct estimations of almost 90%.