Abstract: A power line conditioner includes an active filter coupled, in series, and a passive filter coupled, in parallel, to a three-phase power distribution network. The three-phase power distribution network includes a voltage source that induces three-phase input currents at a first end of the three-phase power distribution network. A load, circulating three-phase load currents, is positioned at a second end of the three-phase power distribution network. The active filter controller of the invention uses synchronous transformations to identify selected harmonic reference components corresponding to individual harmonics of the three-phase load currents. The selected harmonic reference components are multiplied by a predetermined factor corresponding to a permissible percentage of the individual harmonics that may be injected into the supply voltage. This results in active filter reference signal components that are applied to the active filter.

Abstract: A converter, for providing three phase power to a three phase induction motor from a single phase supply, includes an inverter connected to the single phase input power lines which has two switching devices, and a bi-directional switch connected between one of the single phase input power and one output line to the motor. The other two outputs provided to the motor are a direct connection from the other AC input line and the output of the inverter. In a first or start-up mode of operation, the bi-directional switch and the inverter are controlled to provide currents to the motor which are at a fundamental frequency lower than the single phase AC input frequency to provide controlled start-up of the motor with limited in-rush current. After the motor has started, the converter may be switched to a second mode wherein the bi-directional switch is turned off and the inverter provides single phase power at increasing frequency to the motor to drive the motor up in speed.

Abstract: A contactless recharging system and method for recharging a battery storage device onboard an electric vehicle has a primary converter station for converting power from a power source into high frequency power at a selected charging rate. The vehicle has a secondary converter for converting high frequency power into DC power to charge the battery. The converters are coupled together by a contactless coupling of a conductor loop and a coupling link forming a coaxial winding transformer. The coupled link and loop carry a communication indicating the selected charging rate of the battery. The link has a magnetic core and a core-mounted conductor at least partially surrounded by the core. The core-mounted conductor selectively at least partially surrounds a portion of the loop to transfer power therebetween. The core-mounted conductor is coupled to one of the converters, and the loop is coupled the other converter.

Abstract: A contactless power transfer system, especially for powering electric loads, hazardous loads or underwater loads and the like. A converter supplies high frequency power to a conductor loop. A coupling sheath or link has a core-mounted conductor at least partially surrounded by a magnetic core which slidably receives a portion of the conductor loop within the link. An optional secondary converter converts power from the core-mounted conductor to meet the load requirements. A contactless power distribution system delivers power to a variety of loads through clamped-on or captive links attached at any location along the conductor loop. Methods are also provided of powering a movable electric load, or a stationary load from a movable source, and of distributing power to a plurality of portable electric loads.

Abstract: A submersible contactless power transfer system, especially for powering underwater electric loads, including movable loads, such as underwater vehicles, elevators, or worksite equipment. A converter supplies high frequency power to a conductor loop. A coupling sheath or link has a core-mounted conductor at least partially surrounded by a magnetic core which slidably receives a portion of the conductor loop within the link. An optional secondary converter converts power from the core-mounted conductor to meet the load requirements. A contactless power distribution system is submersible to deliver power to underwater loads through clamped-on or captive links attached at any location along the conductor loop. Methods are also provided of powering loads submersed in water, including seawater, or other non-magnetic liquid mediums.

Abstract: An apparatus for converting single phase input power to three phase output power supplied to a motor includes a pair of input lines, and a pair of DC bus lines, a pair of capacitors, a pair of diodes, and a pair of controlled switching devices which are each connected between the DC bus lines. One of the input lines is connected to the node between the capacitors and the other input line is connected to the node between the diodes. Two output lines are connected to the input line and a third output line is connected to the node between the two switching devices, with the three output lines being connected to a motor to supply three phase power to the motor. The switching devices are switched in a pulse width modulated manner to provide a voltage between the third output line and the other two output lines which provides the three phase power. During motor startup, at least one startup capacitor is switched in between one or both of the input lines and the output lines to provide startup torque for the motor.

Abstract: A power converter integrates an input boost converter and an output forward converter into a single power stage utilizing only two active switches. AC input power is provided through a rectifier to an input inductor which supplies current to a main node. The diode is connected from a main node to a DC bus supply line and current is returned to the rectifier by DC bus return line. An energy storage capacitor and a series connected switching device and diode are connected across the DC bus lines. A second control switching device is connected from the main node to the DC bus return line. The primary of a high frequency transformer is connected between the main node and the junction between the first switching device and diode, and the secondary of the transformer is connected to an output circuit which includes a rectifier and an inductor and capacitor filter to provide a DC output voltage to a load.

Abstract: A contactless recharging system and method for recharging an energy storage device onboard an electric vehicle has a primary converter for converting power from a power source into high frequency power. A secondary converter on board the vehicle is coupled to the battery for converting high frequency power into charging power supplied to the energy storage device. The primary and secondary converters are coupled together by a contactless coupling of a conductor loop and a coupling link forming a coaxial winding transformer. The coupling link has a magnetic core and a core-mounted conductor at least partially surrounded by the magnetic core. The core-mounted conductor selectively at least partially surrounds a portion of the conductor loop to transfer power therebetween. The core-mounted conductor is coupled to either the primary or the secondary converter, with the conductor loop being mounted to the other of the primary and the secondary converters.

Abstract: A power conversion apparatus (20) circuit includes pairs of rectifying devices (48,49) connected together at a first node, a pair of capacitors (50, 51) connected together at a second node, and pairs of controllable switching devices (53,54) connected together at a third node, each of the pairs being connected in parallel by DC bus lines (58,59). The AC power source (21) is connected between the first and second nodes and the output voltage to a load (22) is provided between the first and third nodes. The switching devices (53,54) are controlled to switch on and off at proper times to provide a controllable output voltage to the load (22) which is at the same frequency as the input voltage and which may be controlled from zero to substantially twice the peak-to-peak input voltage. The output voltage waveform provided to the load can be filtered to provide a substantially sinusoidal waveform to the load.

Abstract: A DC/DC power converter suitable for high power applications has an input converter which converts the DC input voltage to an AC voltage and supplies this voltage to a transformer. The output of the transformer is provided to an output converter which converts the AC to a DC output voltage at a controlled level to a load. Both the input and output converters are composed of active gate controlled switching devices and are switched in a soft-switched manner to minimize switching losses and increase switching frequency. The converters can be implemented in single phase or polyphase configurations and can be controlled to closely maintain the output voltage provided to the load at a desired level.

Abstract: Power conversion apparatus for AC to DC to AC power conversion includes a rectifier bridge formed of rectifying devices (24,25) connected to an AC source (21) and providing a DC output to DC bus lines (27,28). A full bridge of active switching devices (30, 31, 34, 35) is connected across the DC bus lines to which a power source such as a battery (39) may also be connected. The load (36) and the AC power supply (21) share a common neutral line (33). The output of the bridge can provide AC output power to the load through a transformer (74). The power conversion apparatus allows full control of the currents on the load lines and AC input lines, even when the input and output are asynchronous. By providing an external DC power source such as a battery (39), uninterrupted power can be supplied to the load when the AC power source fails.

Abstract: A high efficiency power converter is achieved utilizing a resonant DC link between a DC source, such as a converter rectifying power from an AC power system, to a variable frequency voltage source inverter. A resonant circuit composed of an inductor and capacitor is connected to the DC power supply and to a DC bus supplying the inverter and is caused to oscillate stably at a high frequency to provide a uni-directional voltage across the DC bus which reaches zero volts during each cycle of oscillation of the resonant circuit. The switching devices of the inverter are controlled to switch on and off only at times when the DC bus voltage is zero, thereby eliminating switching losses in the inverter. The resonant circuit can be caused to oscillate utilizing pairs of switching devices in the inverter or a separate switching device across the capacitor, which again are caused to switch on and off only at times of zero voltage on the DC bus.

Abstract: An inverter has a resonant circuit composed of a parallel connected inductor and capacitor and a filter capacitor connected in series with the inductor which has a capacitance substantially greater than the resonant capacitor. A half bridge or full bridge switching circuit formed of pairs of gate controlled switching devices is connected to a DC power supply and to the resonant circuit and filter capacitor, with the switching devices being switched to provide a relatively high frequency, e.g., 20 KHz or higher, resonant current in the resonant circuit. The filter capacitor is of a size such that the high frequency component of the current flowing in the resonant circuit does not result in a substantial voltage at the switching frequency appearing across the filter capacitor.

Abstract: A high efficiency power converter is achieved utilizing a resonant DC link between a DC source, such as a converter rectifying power from an AC power system, to a variable frequency voltage source inverter. A resonant circuit composed of an inductor and capacitor is connected to the DC power supply and to a DC bus supplying the inverter and is caused to oscillate stably at a high frequency to provide a uni-directional voltage across the DC bus which reaches zero volts during each cycle of oscillation of the resonant circuit. The switching devices of the inverter are controlled to switch on and off only at times when the DC bus voltage is zero, thereby eliminating switching losses in the inverter. The resonant circuit can be caused to oscillate utilizing pairs of switching devices in the inverter or a separate switching device across the capacitor, which again are caused to switch on and off only at times of zero voltage on the DC bus.