Thyristor contactors for PFC

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The high response of the semiconductor switch allows one to connect the capacitor to the network exactly at the moment when the voltage on it becomes equal to the instantaneous mains voltage. This prevents switching inrush currents and the resulting overload of capacitors and other elements of PFC cabinet. In turn, the capacitor switches off at the moment when the current through the thyristor is close to zero, which suppresses overvoltages in the network that cause sparking and burning the contacts of ordinary contactors with their subsequent failure. These features of thyristor contactors allow switching PFC steps with a frequency of more than 10 times per second, which is two orders of magnitude higher than this parameter for a conventional installation with electromagnetic contactors. BMR has developed and manufactures thyristor contactors for switching capacitor steps rated from 15 to 72 kvar, as well as high-speed controllers for them