In an electric system for an electric vehicle, DC power of a main battery is converted into AC power by an inverter which has a power regenerative function. At startup, the system charges an input smoothing capacitor on the DC side of the inverter through an initial charging circuit with an initial charging switch and resistor. A main circuit switch that can stop current is connected between the main battery and the inverter. A rheostatic braking circuit with a rheostatic braking switch and a braking resistor is connected to the DC input side of the inverter for rheostatic breaking when required. Rheostatic braking takes over after regenerative braking when the main battery loses its power absorption capability, with the main circuit switch off. Semiconductors can be used as switches, and can be placed on a cooling body or modularized. Low-noise wires can be used to reduce noise.
A startup circuit for starting a power converter for converting an input voltage to an output voltage includes a switch connected in series with a resistive element. The startup circuit is connected in parallel with a trigger switch in the power converter for enabling the power converter to generate the output voltage. When closed or activated, the switch in the startup circuit charges an energy storing device in the power converter. The energy storing device activates the trigger switch as the charge is released.
In a control device for a small-scale series-type hybrid automobile using an electric motor and an internal combustion engine as power sources, energy generated by the drive motor is applied to a motor/generator through a generator inverter so that the motor/generator drives the internal combustion engine to apply a braking force thereto. In this way, energy generated during regenerative braking which cannot be absorbed by a saturated battery (for example, when the vehicle is travelling downhill) can be used to help brake the vehicle.
The objective of providing a circuit arrangement for the control of at least one electric machine (1), which is suitable for also enabling operating conditions of the electric machine (1) that demand high power-peaks of short duration, is essentially achieved in that the electric machine (1) can be connected via a DC/AC converter (2) and at least one switching device (3) to at least two different electrical energy storage devices (I, II), one storage device (I) being designed as a storage device for comparatively long-lasting power demands and the other storage device (II) as a storage device for short and high power-peaks.
A PWM speed regulating apparatus for DC elevator comprises a rectifier-filter (1), voltage suppressor (2), chopper voltage regulator (3), system controller (4) and a driving protector (5). The speed of DC motor is regulated by a pulse width modulating mode so that the current of the motor is maintained continuously and the ripple of current and torque is lower, and which ensures a good riding quality and a high floor arrival accuracy.
A driving force transmission unit consists of a gear unit engaging with the motor axes of two AC motors, and a bevel gear for transmitting the driving forces of the two AC motors to an axle. Wheels are installed on both ends of the axle. The output voltage of a battery of low voltage is transformed to AC voltage by a DC/AC transformer, and the transformed voltage is supplied to the two AC motors. Then, the driving forces of the two AC motors are synthesized to be transmitted to the axle.
