Switch device, control method of the same, and control method of transfer switch system using the same

A control method for controlling a switch device, the switch device including:

• a first input terminal;
• a second input terminal;
• a first output terminal;
• a second output terminal;
• a first switch unit coupled between said first input terminal and said first output terminal;
• a second switch unit coupled between said second input terminal and said second output terminal;
• each of said first and second switch units including a plurality of diodes and at least one semiconductor-controlled rectifier (SCR), wherein at least one of said diodes and one of said at least one SCR cooperatively permit a current to flow therethrough from a corresponding one of said first and second input terminals to the corresponding one of said first and second output terminals when each thereof operates in an ON state, and wherein at least one of said diodes and one of said at least one SCR cooperatively permit a current to flow therethrough from a corresponding one of said first and second output terminals to the corresponding one of said first and second input terminals when each thereof operates in an ON state;
• and
• a first relay coupled between said first input terminal and said first switch unit, a second relay coupled between said second input terminal and said second switch unit, and each of said first and second switch units including a third relay coupled between a corresponding one of said first and second relays and the corresponding one of said first and second output terminals;
• the first and second input terminals of the switch device being coupled to an alternating current (AC) power source for receiving an AC voltage therefrom;
• said control method comprising:
• a first procedure that is performed when the AC voltage has an amplitude which equals a predetermined value greater than zero, and that includes:
• at a first time point, controlling each of the first and second relays to transition from an OFF state to an ON state;
• at a second time point after the first time point, controlling the at least one SCR of each of the first and second switch units to be operable between an ON state and an OFF state based on a voltage thereacross;
• at a third time point after the second time point, controlling the third relay of each of the first and second switch units to transition from an OFF state to an ON state;
• and
• at a fourth time point after the third time point, controlling the at least one SCR of each of the first and second switch units to disable transitioning of the at least one SCR from the OFF state to the ON state.

A control method for controlling a transfer switch system that includes a first switch device and a second switch device, each of the first and second switch devices including:

• a first input terminal;
• a second input terminal;
• a first output terminal;
• a second output terminal;
• a first switch unit coupled between said first input terminal and said first output terminal;
• a second switch unit coupled between said second input terminal and said second output terminal;
• each of said first and second switch units including a plurality of diodes and at least one semiconductor-controlled rectifier (SCR), wherein at least one of said diodes and one of said at least one SCR cooperatively permit a current to flow therethrough from a corresponding one of said first and second input terminals to the corresponding one of said first and second output terminals when each thereof operates in an ON state, and wherein at least one of said diodes and one of said at least one SCR cooperatively permit a current to flow therethrough from a corresponding one of said first and second output terminals to the corresponding one of said first and second input terminals when each thereof operates in an ON state;
• and
• a first relay coupled between said first input terminal and said first switch unit, a second relay coupled between said second input terminal and said second switch unit, and each of said first and second switch units including a third relay coupled between a corresponding one of said first and second relays and the corresponding one of said first and second output terminals;
• the first and second input terminals of the first switch device being coupled to a first alternating current (AC) power source for receiving a first AC voltage therefrom, the first and second input terminals of the second switch device being coupled to a second AC power source for receiving a second AC voltage therefrom, the first and second output terminals of the second switch device being coupled respectively to the first and second output terminals of the first switch device;
• said control method comprising:
• a first procedure that is performed when the first AC voltage has an amplitude which equals a predetermined value greater than zero, and that includes:
• at a first time point, controlling each of the first and second relays of the first switch device to transition from an OFF state to an ON state;
• at a second time point after the first time point, controlling the at least one SCR of each of the first and second switch units of the second switch device to be operable between an ON state and an OFF state based on a voltage thereacross;
• at a third time point after the second time point, controlling the third relay of each of the first and second switch units of the second switch device to transition from an ON state to an OFF state;
• at a fourth time point after the third time point, controlling the at least one SCR of each of the first and second switch units of the second switch device to disable transitioning the at least one SCR from the OFF state to the ON state;
• at a fifth time point after the fourth time point, controlling the at least one SCR of each of the first and second switch units of the first switch device to be operable between an ON state and an OFF state based on a voltage thereacross;
• at a sixth time point after the fifth time point, controlling the third relay of each of the first and second switch units of the first switch device to transition from an OFF state to an ON state;
• and
• at a seventh time point after the sixth time point, controlling the at least one SCR of each of the first and second switch units of the first switch device to disable transitioning of the at least one SCR from the OFF state to the ON state.