AUTOMATIC SYNCHRONIZATION OF "ISLANDS" AT RESTORATION OF POWER SUPPLY SYSTEMS WITH DISTRIBUTED GENERATION
The PURPOSE of the paper is to develop an operation algorithm of the automatic synchronization system under the restoration of the power supply system after emergency cut-off from the main power source (MPS) and breaking of the power supply system into separate “islands”. METHODS. Some operation stages of the synchronization system use reachability matrices, for the construction of which the Floyd-Warshall algorithm is used. RESULTS AND THEIR DISCUSSION. The operation of the synchronization system using the proposed algorithm is demonstrated on the test scheme of the power supply system. The execution of the algorithm is triggered in case of emergency shutdown of current breakers (CB); the algorithm identifies the structure of the “islands” formed as a result of the accident and forms a definite order of the synchronization process; the error signals determined by the algorithm are applied to automatic speed regulators (ASR) and automatic voltage regulators (AVR) of distributed generators (DG); when the synchronism is achieved the algorithm generates the commands to switch on the current breakers. CONCLUSIONS. The proposed algorithm of the synchronization system allows to reconnect the “islands” formed as a result of the accident between each other and with the main power source. When the power supply system is disconnected from the main power source it is necessary to switch the automatic speed regulators of distributed generators to a floating response to eliminate the frequency deviation from the nominal one. In order to exclude an arbitrary load distribution between the distributed generators when the automatic speed regulators are switched to a floating response it is necessary to use a group control of active and reactive power.