| 摘要 |
PURPOSE:To suppress surge voltage efficiently by lowering the gate voltage of the main element in an inverter when the battery voltage increases due to regenerative brake operation thereby delaying voltage rise. CONSTITUTION:A controller 20 provides a battery voltage detection signal to a control relay 32, and only the transistor 28a is turned ON if the battery voltage Vb is relatively low. When the battery voltage Vb increasers, the control relay 32 turns only a transistor 28b ON. Consequently, a resistor 30a is connected between points A and B in the drawing and the gate voltage of an inverter main element 16 drops thus delaying voltage rise of the inverter main element 16 correspondingly when it is turned OFF. When the battery voltage Vb increases furthermore, the control relay 32 turns only a transistor 28c ON. When the battery voltage Vb increases furthermore, the control relay 32 turns only a transistor 28d ON to connect resistors 30a, 30b, 30c, in series, between the points A and B thus delaying voltage rise of the inverter main element 16. |
