Development of Active Rectifier's Improved Control System with Stabilizing Effect for Voltage Sags Compensation

Modern main electric drives of rolling mills are performed (created) using asynchronous (synchronous) AC electric motors and three-level frequency converters with active rectifiers and autonomous voltage inverters. Semiconductor keys are controlled using the pulse width modulation method with orientation along the voltage vector of the supply network. AR control systems are sensitive to the quality of the mains voltage, the occurrence of voltage sags or overvoltage leads to emergency shutdowns of FC-AR. To increase the reliability of AR operation in case of asymmetric voltage sags and to compensate for voltage sags due to reactive power reserves SVC, it is proposed to combine electric steelmaking and rolling complexes for parallel operation. Therefore, the measures development to improve the reliability of the main electric drives of the mill in case of network voltage disturbances caused by the operation of the electric steelmaking complex is an urgent task. An improved AR control system with a stabilizing effect is developed in the article. This system compensates for the voltage deviation at the connection point of the frequency converter by controlling the reactive power flows.