초록 ▼

The problem of providing an engine starting system from any one of a plurality of input power sources is solved with an engine start control apparatus operating a generator as a synchronous motor and employing input power limiting. The motor receives power from a main inverter and an excitation inve

The problem of providing an engine starting system from any one of a plurality of input power sources is solved with an engine start control apparatus operating a generator as a synchronous motor and employing input power limiting. The motor receives power from a main inverter and an excitation inverter. These inverters are controlled by a control unit which provides for input power limiting and also constant power characteristics in the field weakening range. The control unit includes a pulse width modulation (PWM) generator which is responsive to a voltage command and a commutation command to develop switching signals for controlling the switches in the start inverter. The voltage command is used to vary the duty cycle of the PWM signals. The commutation angle command is used to control the timing of the PWM signals. In addition to commutation angle control, the start control system employs field weakening control to obtain constant power characteristics.

대표청구항 ▼

A start control system for a brushless machine having a rotor and a stator having a stator coil which is controllably energized from a source of DC power defining a positive and a negative DC voltage for imparting rotation to the rotor, comprising means for sensing the rotational position of said ro

A start control system for a brushless machine having a rotor and a stator having a stator coil which is controllably energized from a source of DC power defining a positive and a negative DC voltage for imparting rotation to the rotor, comprising means for sensing the rotational position of said rotor; switching means coupled between the source of DC power and the stator coil for alternately applying the positive and negative voltage to the coil according to the rotational position of the rotor; means for developing a stator current reference signal representing a desired stator current level; means for generating an actual stator current signal representing actual current level through the stator coil; and control means coupled to s said developing means and said switching means for phase advancing the rotational position at which the positive and negative voltages are applied to the coil according to a difference between said desired and actual stator current level to provide constant current starting.