UNIFIED POWER FLOW CONTROLLER FOR DOUBLE-CIRCUIT LINE

摘要

An unified power flow controller for a double-circuit transmission line comprises at least one parallel-connection transformer (1), three current converters (4), at least two series-connection transformers (8), a parallel-connection side switching circuit (3), a series-connection side switching circuit (6) and a direct current common bus (5). At least one side of the series-connection transformers is connected with at least one set of by-pass switches (9, 10) in parallel. The alternating current sides of the three current converters are connected to each loop line in series after being connected with at least one series-connection transformer through the series-connection side switching circuit (6). The alternating current sides of the three current converters are connected to an alternating current system after being connected with at least one parallel-connection transformer (1) through a parallel-connection side switching circuit starting circuit (2). The direct current sides of the three current converters are connected to the direct current common bus (5) through a transfer switch. With the unified power flow controller, various operating modes can be realized, and when one current converter is in fault, power flow control of the double-circuit transmission line can still be achieved. The unified power flow controller is small in occupied space, low in cost, and excellent in economy, flexibility and reliability.