An Improved Model of Unified Power Flow Controller

In order to adapt the unified power flow controller UPFC to the power system analysis software package (PSASP) without adding or changing the bus, UPFC's power flow control model is based on the node injection power method. The model achieves UPFC's power control goal by changing the injection power between UPFC and power system, the injected power of the bus of two access points is controlled by the horizontal and vertical components of the series converter injected voltage and the horizontal components of the shunt side injected current. and finally, by using WSCC-9 bus system to verify that the proposed model can effectively and quickly track the power flow target and has high convergence. The results have a certain reference value for the control modeling of other flexible AC transmission system (FACTS) devices and the establishment of interfaces embedded in PSASP simulation software.