System and load behaviour following loss of generation. Experimental results and evaluation

The paper describes tests involving sudden loss of generation on an isolated power system of more than 2000 MW installed capacity. Amounts of generation ranging from 3% to 27% of the system total were disconnected, causing voltage depression and frequency excursions. The maximum transient frequency drop recorded was 3.25 Hz. During the tests, measurements were made simultaneously at six different locations, five of which were concerned with load response, and the sixth with the (average) system frequency. Relatively homogeneous but different types of loads were selected, including residential, commercial, aluminum-plant mechanical-industry and electric furnace loads. The applied voltage and power flow to these loads were recorded during each system disturbance. Using data obtained from the tests, an attempt has been made to determine the characteristic parameters for the individual static loads. The test results and the experimental values of the characteristic parameters are presented and discussed.