Power control device and method

1. A switch control device comprising:

a switch device comprising a first input terminal, a second input terminal, a first switch unit, a second switch unit, and an output terminal receiving a first input voltage from the first input terminal through the first switch unit or a second input voltage from the second input terminal through the second switch unit, each of the first and second switch units comprising a plurality of relays;

a control device comprising:

a detection unit coupled to the first and second input terminal and configured to detect a zero crossover signal of the first input voltage or the second input voltage;

a processor coupled to the detection unit, the first switch unit, and the second switch unit, wherein the processor is configured to:

receive the first or second input voltage and the zero crossover signal of the first or second input voltage;

detect a period of the first or second input voltage;

determine whether the first or second input voltage is normal or not;

when the first input voltage from the first input terminal is abnormal, compute a delay time according to the period of the first input voltage and a discharge time of relays of the first switch unit; and control the relays of the first switch unit to turn off according to the delay time and the zero crossover signal of the first zero crossover signal of the first input voltage; when the first switch unit is turned off, the processor controls the second switch unit coupled to the second input terminal to turn on;

wherein each of the first and second switch units comprises first to fourth relays, a first silicon controlled rectifier (SCR), and 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 first and second SCRs are coupled to the processor.

2. The switch control device of claim 1 , wherein the detection unit comprises a voltage sensor and a zero crossover signal sensor, both of the voltage sensor and the zero crossover signal sensor are coupled to the first input terminal, the second input terminal, and the processor, the voltage sensor is configured to receive the first or second input voltage, and to transmit the first or second input voltage to the processor.

3. The switch control device of claim 2 , wherein the zero crossover signal sensor comprises a first zero crossover signal sensor and a second zero crossover signal sensor, the first zero crossover signal sensor and the second zero crossover signal sensor are coupled to the first input terminal and the second input terminal respectively, the processor is configured to detect the zero crossover signal of the first input voltage through the first zero crossover signal sensor, or to detect the zero crossover signal of the second input voltage through the second zero crossover signal sensor.

4. The switch control device of claim 3 , wherein the voltage sensor comprises a first voltage sensor and a second voltage sensor, the first voltage sensor and the second voltage sensor are coupled to the first input terminal and the second input terminal respectively, the processor is configured to detect whether the period of the first input voltage is normal or not through the first voltage sensor, or to detect whether the period of the second input voltage is normal or not through the second voltage sensor.

5. The switch control device of claim 1 , wherein each of the relays is coupled to the processor.

6. A switch control device comprising:

a switch device comprising a first input terminal, a second input terminal, a first switch unit, a second switch unit, and an output terminal receiving a first input voltage from the first input terminal through the first switch unit or a second input voltage from the second input terminal through the second switch unit, each of the first and second switch units comprising a plurality of relays;

a control device comprising:

a detection unit coupled to the first and second input terminal, and configured to detect a peak of wave signal of the first input voltage or the second input voltage;

a processor coupled to the detection unit, the first switch unit, and the second switch unit, wherein the processor is configured to:

receive the first or second input voltage and the peak of wave signal of the first or second input voltage;

detect a period of the first or second input voltage;

determine whether the first or second input voltage is normal or not;

when the first input terminal from the first input terminal is abnormal, computes a delay time according to the period of the first input voltage and a discharge time of relays of the first switch unit, and controls the relays of the first switch unit to turn off according to the delay time and the peak of wave signal of the first zero crossover signal of the first, when the first switch unit is turned off, the processor controls the second switch unit coupled to the second input terminal to turn on;

wherein each of the first and second switch units comprises first to fourth relays, a first silicon controlled rectifier (SCR), and 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 first and second SCRs are coupled to the processor.

7. The switch control device of claim 6 , wherein the detection unit comprises a voltage sensor and a zero crossover signal sensor, both of the voltage sensor and the zero crossover signal sensor are coupled to the first input terminal, the second input terminal, and the processor, the voltage sensor is configured to receive the first or second input voltage, and to transmit the first or second input voltage to the processor.

8. The switch control device of claim 7 , wherein the peak of wave signal sensor comprises a first peak of wave signal sensor and a second peak of wave signal sensor, the first peak of wave signal sensor and the second peak of wave signal sensor are coupled to the first input terminal and the second input terminal respectively, the processor is configured to detect the peak of wave signal of the first input voltage through the first peak of wave signal sensor, or to detect the peak of wave signal of the second input voltage through the second peak of wave signal sensor.

9. The switch control device of claim 8 , wherein the voltage sensor comprises a first voltage sensor and a second voltage sensor, the first voltage sensor and the second voltage sensor are coupled to the first input terminal and the second input terminal respectively, the processor is configured to detect whether the period of the first input voltage is normal or not through the first voltage sensor, or to detect whether the period of the second input voltage is normal or not through the second voltage sensor.

10. The switch control device of claim 6 , wherein each of the relays is coupled to the processor.

11. A control method of a switch control device comprising:

a voltage sensor receiving a first input voltage from a first input terminal;

a signal sensor sensing a zero crossover signal or the peak of wave signal of the first input voltage;

a processor receiving the first input voltage and detecting the period of the first input voltage, and determining whether the first input voltage is normal or not, the processor computing a delay time according to the period of the first input voltage and a discharge time of relay of a first switch unit when the first input voltage is abnormal;

the processor determining when to output a control signal to turn off of the relays of the first switch unit, according to the delay time and the zero crossover signal or the peak of wave signal of the first input voltage;

when the first switch unit is turned off, the processor controlling the second switch unit coupled a second input terminal to turn on;

wherein the first switch unit comprises first to fourth relays, a first silicon controlled rectifier (SCR), and 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 first and second SCRs are coupled to the processor.