Patent ID: 9692225
Date: 2017-06-27
CPC Classifications: H01H,H02H

Claim:
1. A hybrid DC breaker, comprising a main current circuit, a transfer current circuit, an over-voltage limiting circuit, a control system, and an first access terminal and an second access terminal of the system, the main current circuit, the transfer current circuit and the over-voltage limiting circuit being connected in parallel, wherein: (1) the main current circuit consists of a high-speed mechanical switch and a first power semiconductor device, which are connected in series, wherein: the first access terminal is connected with one end of the high-speed mechanical switch to realize the connection of the first access terminal with one end of the main current circuit; the other end of the high-speed mechanical switch is connected with one end of the first power semiconductor device; and the other end of the first power semiconductor device is connected with the second access terminal to realize the connection of the second access terminal with the other end of the main current circuit; (2) the transfer current circuit comprises a first circuit consisting of a second power semiconductor device, a second circuit consisting of an first inductor and a third power semiconductor device connected in series, a third circuit consisting of an second inductor and a fourth power semiconductor device connected in series, a fourth circuit consisting of a fifth power semiconductor device, and a pre-charged capacitor pre-charged with a certain voltage, the first circuit being connected with the fourth circuit in series, the second circuit being connected with the third circuit in series, wherein: (A) the first circuit is connected with the fourth circuit in series to form a first branch of the transfer current circuit, and the first branch is connected with the main current circuit in parallel, furthermore: the first access terminal is connected with one end of the second power semiconductor device to realize the connection with one end of the first branch; the other end of the second power semiconductor device is connected with one end of the fifth power semiconductor device to realize the connection in series of the first circuit with the fourth circuit; and the other end of the fifth power semiconductor device is connected with the second access terminal to realize the connection of the other end of the first branch with the second access terminal, in order to realize the connection in parallel of the first branch with the main current circuit; (B) the second circuit is connected with the third circuit in series to form a second branch of the transfer current circuit, and the second branch is connected with the main current circuit in parallel, furthermore: the first access terminal is connected with one end of the first inductor to realize connection with one end of the second branch; the other end of the first inductor is connected with one end of the third power semiconductor device; the other end of the third power semiconductor device is connected with one end of the second inductor to realize the connection in series of the second circuit with the third circuit; the other end of the second inductor is connected with one end of the fourth power semiconductor device; and the other end of the fourth power semiconductor device is connected with the second access terminal to realize the connection of the other end of the second branch with the second access terminal, in order to realize the connection in parallel of the second branch with the main current circuit; and (C) the pre-charged capacitor is connected between an endpoint between the first circuit and the fourth circuit and an endpoint between the second circuit and the third circuit; and (3) the control system measures the current flowing through the first or second access terminal, the current flowing through the main current circuit, the current flowing through the first circuit in the transfer current circuit, the current flowing through the over-voltage limiting circuit, the voltage at two ends of the high-speed mechanical switch and the displacement of the high-speed mechanical switch, and controls the high-speed mechanical switch and the second, third, fourth and fifth power semiconductor devices in the transfer current circuit to act by measuring the current amplitude and current rate of change of the main current circuit and the current amplitude and current rate of change of the first circuit in the transfer current circuit.