Abstract:
Prior generating systems utilizing electrically-compensated constant speed drives (ECCSD) have typically required a separate starter motor for starting a prime mover which supplies motive power to the ECCSD, thereby increasing the size and weight of the system. In order to overcome this problem, a generating system is provided with circuitry coupled to the electrical power windings of a permanent magnet machine (PMM) forming a part of the ECCSD for causing the PMM to develop motive power which causes an output shaft of a differential of the ECCSD to rotate at increasing speeds. When the output shaft of the differential reaches a predetermined speed, a generator (12) coupled to the output shaft of the differential is supplied external or ground power which in turn causes the generator (12) to operate as a motor and return motive power (16) through the differential to the prime mover to start same and bring it up to operating speed.
Abstract:
Prior generating systems utilizing electrically-compensated constant speed drives (ECCSD) have typically required a separate starter motor for starting a prime mover which supplies motive power to the ECCSD, thereby increasing the size and weight of the system. In order to overcome this problem, a generating system is provided with circuitry coupled to the electrical power windings of a permanent magnet machine (PMM) forming a part of the ECCSD for causing the PMM to develop motive power which causes an output shaft of a differential of the ECCSD to rotate at increasing speeds. When the output shaft of the differential reaches a predetermined speed, a generator (12) coupled to the output shaft of the differential is supplied external or ground power which in turn causes the generator (12) to operate as a motor and return motive power (16) through the differential to the prime mover to start same and bring it up to operating speed.
Abstract:
A bi-directonal DC/DC converter includes a first power switch coupled to a first input/output of the converter, an energy storage element coupled to the first power switch, a second power switch coupled between the energy storage element and a second input/output of the converter and means for controlling the first and second power switches so that one of the power switches is opened while the other power switch is alternately opened and closed to transfer power from one input/output to the other input/output.
Abstract:
A bi-directonal DC/DC converter includes a first power switch coupled to a first input/output of the converter, an energy storage element coupled to the first power switch, a second power switch coupled between the energy storage element and a second input/output of the converter and means for controlling the first and second power switches so that one of the power switches is opened while the other power switch is alternately opened and closed to transfer power from one input/output to the other input/output.
Abstract:
A bi-directional DC/DC converter includes a first switch coupled to a first input/output of the converter, a first input/output energy storage element coupled to the first input/output of the converter, a second input/output energy storage element coupled to a second input/output of the converter, an intermediate energy storage element coupled between the second input/output and the first switch and a second switch coupled to the intermediate energy storage element and to the first switch. A pulse width modulator operates the first switch between on and off states while the second switch is maintained in an off state to operate the converter as a buck converter, during which time the power is transferrred from the first input/output to the second input/output. A further pulse width modulator operates the second switch between on and off states while the first switch is maintained in the off state to operate the converter as a boost converter, during which time power is transferred from the second input/output to the first input/output.
Abstract:
A bi-directional DC/DC converter includes a first switch coupled to a first input/output of the converter, a first input/output energy storage element coupled to the first input/output of the converter, a second input/output energy storage element coupled to a second input/output of the converter, an intermediate energy storage element coupled between the second input/output and the first switch and a second switch coupled to the intermediate energy storage element and to the first switch. A pulse width modulator operates the first switch between on and off states while the second switch is maintained in an off state to operate the converter as a buck converter, during which time the power is transferrred from the first input/output to the second input/output. A further pulse width modulator operates the second switch between on and off states while the first switch is maintained in the off state to operate the converter as a boost converter, during which time power is transferred from the second input/output to the first input/output.
Abstract:
A bi-directional DC/DC converter includes a first switch coupled to a first input/output of the converter, a first input/output energy storage element coupled to the first input/output of the converter, a second input/output energy storage element coupled to a second input/output of the converter, an intermediate energy storage element coupled between the second input/output and the first switch and a second switch coupled to the intermediate energy storage element and to the first switch. A pulse width modulator operates the first switch between on and off states while the second switch is maintained in an off state to operate the converter as a buck converter, during which time the power is transferrred from the first input/output to the second input/output. A further pulse width modulator operates the second switch between on and off states while the first switch is maintained in the off state to operate the converter as a boost converter, during which time power is transferred from the second input/output to the first input/output.
Abstract:
A bi-directonal DC/DC converter includes a first power switch coupled to a first input/output of the converter, an energy storage element coupled to the first power switch, a second power switch coupled between the energy storage element and a second input/output of the converter and means for controlling the first and second power switches so that one of the power switches is opened while the other power switch is alternately opened and closed to transfer power from one input/output to the other input/output.
Abstract:
Electrically-compensated constant speed drive, CSD, (10) which includes a speed summer (18) having first and second input shafts (20, 36) and one output shaft (22). The first input shaft (20) is coupled to a variable speed prime mover (16) and the output shaft (22) develops a constant speed motive power. A speed-compensating permanent magnet machine (PMM2) couples to the second input shaft (36) of the speed summer (18). A control permanent magnet machine (PMM1) couples to the first input shaft (20) of the speed summer (18). A power converter (30) interconnects the power windings (70, 72) of these two permanent magnet machines (PMM1, PMM2). The power converter (30) comprises first and second bi-directional AC/DC converters (54, 56), a bi-directional DC/DC converter (58), and a circuit (44) for controlling the converters (54, 56, 58) so as to maintain the output shaft (22) of the speed summer (18) at a constant, desired speed.