| 摘要 |
<p>PURPOSE:To prevent a brake from failing by connecting a resistor to a DC circuit when a power source voltage is eliminating during a power regenerative braking and the DC side output voltage of a converter rises. CONSTITUTION:Energy is returned from an induction motor IM side through a pulse width control converter having an inverter INV, a DC condenser CO, gate turn OFF thyristors TH1-TH4 and diodes D1-D4 to an AC side at power regenerative time. When the power source voltage is eliminated at this time, it is detected by an AC input voltage detector 1, and a pulse width controller stops. When the voltage of the condenser CO reaches the prescribed value in this state, a generating resistance controller 5 operates to close a switch S1, a resistor R1 is connected to a DC circuit, and the energy from the motor IM side is consumed by the resistor R1 to continue the brake force.</p> |
