2006 Volume 126 Issue 10 Pages 994-1002
The connection of a large number of the dispersed generators induces voltage deviations beyond a statutory range in distribution systems. Therefore, a hierarchically cooperative control system has been developed for voltage regulation under the consideration of reactive power application of dispersed generators. In the hierarchically cooperative control, a distribution system is divided into blocks and each block with an on-load tap changing transformer is controlled under a cooperative control algorithm. A distribution system with a tap-changing substation transformer, step voltage regulators, and multiple dispersed generators connected to each feeder has been simulated in an analogue simulator; the hierarchically cooperative control has been demonstrated on the simulator and compared with independent control. The demonstration has experimentally confirmed the successful operation and high voltage regulation ability of the hierarchically cooperative control.