Switch control device and method for power

A switch control device comprising:

• at least one switch device comprising at least one input terminal, at least one switch unit coupled to a corresponding one of the at least one input terminal, and an output terminal, wherein each of the at least one switch unit comprising a first relay unit, a second relay unit, and a silicon controlled rectifier (SCR) coupled to the second relay unit in parallel;
• a control device comprising:
• a detection unit coupled to the at least one input terminal and configured to detect a zero crossover signal of an input voltage from the at least one input terminal;
• a processor coupled to the detection unit and the at least one switch unit, wherein the processor is configured to:
• receive the input voltage and the zero crossover signal of the input voltage;
• detect a period of the input voltage, and
• determine whether the input voltage is normal or not;
• wherein when the input voltage from the at least one input terminal is abnormal, the processor computes a delay time according to the period of the input voltage and a charge time of relays of one switch unit coupled to one input terminal from at least one input terminal and controls the relays to turn on according to the delay time and the zero crossover signal of the first zero crossover signal of the input voltage;
• and
• each of the switch unit further comprises third and fourth relays, a first SCR, and a second SCR;
• the first and second relays are coupled in series, and are coupled between a live wire of the first or second input terminal and the output terminal;
• the third and fourth relays are coupled in series, and are coupled between a neutral wire of the first or second input terminal and the output terminal;
• a first terminal of the first SCR is coupled to a node between the first relay and the second relay, a second terminal of the first SCR is coupled to the output terminal;
• a first terminal of the second SCR is coupled to a node between the third relay and the fourth relay, a second terminal of the second SCR is coupled to the output terminal;
• controls terminal of the each SCR is coupled to the processor.