Astec International Limited

Edge Electrons Limited

Other

Power Quality Engineering Limited

Edge Electronics Limited

Wing Ling Cheng

Neal George Stewart

Man Keung Tse

Zhe Wang

Lin Wang

John M Groves

Huai Gang Jiang

Kevin Donald Wildash

Ying Qu

Shu Chung Wong

Wai Kin Chan

Zong Bo Hu

Jian Carlo Decena Zapata

Gordon Currie

Yuk Man Shing

Tai Keung Lee

Yi Cai

Steven Lee Willing

Chau Hon Yu

John Michael Groves

Conor Quinn

Rex William Whittle

Alastair Alexander Keir

Efren Ii Santos Cruzat

Xiao Fen Zhong

An example switched-mode power supply includes an input for receiving an input voltage from a voltage source, an output for providing an output voltage to a load, and a transformer having a primary winding, a secondary winding, and a conductive shield disposed between the primary winding and the secondary winding. The power supply also includes a neutralization signal generator circuit coupled to the conductive shield to apply a neutralization signal to the conductive shield to reduce a common mode noise between the primary winding and the secondary winding of the transformer. The neutralization signal has an adjustable amplitude and/or phase. Other example power supplies and methods are also disclosed.

Power supplies and methods for reducing common mode noise

Audio Frequency Load Control (AFLC) signal processing electronics added to a power factor correction (PFC) unit allowing the AFLC system to operate without the need of large and heavy passive bypass or blocking filters at the PFC installations. The AFLC signal processing electronics a first group of additional electronics tuned to the AFLC frequency for detecting the AFLC carrier signal; and a second group of additional electronics for driving an AFLC impedance switch that is connected in parallel with an AFLC impedance. The AFLC impedance is connected in series with the PFC capacitors, and is sufficiently large to offer significant impedance in series with the PFC capacitors that allows the AFLC signal to bypass the PFC unit.

Method and apparatus to solve PFC capacitor reduction of line AFLC ripple without passive filters

A high-efficiency system for conducting power factor (PF) and harmonics correction in an electrical network, comprising a controller; a digital PFC capacitor array comprising two or more passive PFC capacitors, providing fine steps increments in the PF correction; and linear PFC capacitor arrays, providing coarse steps increments in the PF correction. The PF correction in coarse steps increments and fine steps increments allow a total or near total PF correction without overcompensation. Optionally, the system further comprises a lower power active power filter (APF) configured to only target and eliminate or minimize harmonics in the electrical network.

System and method for high efficiency power quality correction

An energy saving alternate current (AC) series voltage regulator comprises an AC high frequency (HF) series voltage buck power regulator, a bypass contactor (K), a bidirectional AC semiconductor device (S) connected in parallel with the bypass contactor and a control circuitry. Under the condition of an input AC mains voltage (Vin) drops below a specified and set optimum energy savings voltage or a lower selected voltage point, the control circuitry transitions both the slow bypass contactor and the fast bidirectional AC semiconductor device, then the AC high frequency (HF) series voltage buck power regulator are switched out to save the AC high frequency (HF) series voltage buck power regulator internal power electronics usage. Under this condition, the lower input AC mains voltage is directly delivered to an electrical load by the contactor bypass system, hence achieving more energy savings.

Energy saving high frequency series buck AC voltage regulator system

Legacy automatic variable capacitor KVAR compensation systems typically use either electromechanical devices such as relays or contactors of various forms and types to switch the selected capacitors in and out of the electrical system under some form of electronic control. These systems are slow and discontinuous in their ability to closely regulate the exact value of compensatory capacitance needed to compensate the variable and rapidly changing reactive power KVAR in the electrical power transmission and distribution networks. The present invention provides a fast response active KVAR compensator based on a variable transimpedance topology.

Fast response active reactive power (KVAR) compensator

An AC voltage regulator that regulates the output AC voltage level regardless of the varying AC input voltage utilizing high frequency series inductors that only process a proportion of the total output power and uses unipolar semiconductor low loss switches in series with one or more rectifiers.

High frequency series AC voltage regulator

A control circuit for controlling a switching device having a first terminal, a second terminal, and a control terminal is disclosed. The control circuit includes a first diode for coupling to the first terminal of the switching device, a second diode for coupling to the second terminal of the switching device, a first transistor for coupling to the control terminal of the switching device, and a second transistor coupled to the second diode. The first transistor is coupled to the first diode. The control circuit is configured to allow current flow in only one direction between the first and second terminals of the switching device.

Control circuits and methods for controlling switching devices

A power supply includes a power circuit for converting an input voltage or current to an output voltage or current, at least one interface port for receiving signals from one or more external devices, and a control circuit coupled to the power circuit and the at least one interface port. The control circuit is adapted to operate the power circuit in response to control signals having a plurality of different control signal formats that are received by the at least one interface port.

Power supplies responsive to multiple control signal formats

A bidirectional AC series voltage regulator that regulates an output AC voltage level regardless of the varying AC input voltage utilizing high frequency series inductors that only process a proportion of the total output power. The AC series voltage regulator detects the power inductor current direction data signal and can generate power inductor current direction data signals for its control to determine the AC input voltage polarity at all time; wherein the determination of the AC input voltage polarity is unambiguous during the AC input voltage zero crossover and near zero points; and wherein the determination of the AC input voltage polarity allows normal switching sequence of the AC bidirectional switches during the AC input voltage zero crossover and near zero points to prevent power 'shoot-through.'

A resonant converter apparatus includes a plurality of resonant converters connected in parallel, and a control module outputting a pulse width modulation (PWM) control signal to the resonant converters. The control module includes a voltage control loop and a circuit control loop. The voltage control loop compares the sensed output voltage with a predetermined reference voltage, and outputs a PWM control signal to one of the resonant converters so the output voltage of the one converter is equal to the predetermined reference voltage. The current control loop uses the sensed output current of the one converter as a reference current, compares the reference current with the sensed output current from each of the other resonant converters, generates a frequency adjusting variable, and calculates the individual PWM control signal for each of the other converters so the output currents of the plurality of converters are the same.

Multiple resonant converter apparatus and control method

A method for detecting a performance degradation of a capacitor in a power converter is disclosed. The method includes monitoring a voltage across the capacitor, detecting the performance degradation of the capacitor based on the monitored voltage, and generating a warning signal after detecting the performance degradation of the capacitor. A power converter is including at least one capacitor and a processor operably coupled to the at least one capacitor for monitoring a voltage across the at least one capacitor is also disclosed. The processor is configured for detecting a performance degradation of the capacitor based, at least in part, on the monitored voltage, and for generating a warning signal after detecting the performance degradation of the at least one capacitor.

Health monitoring for power converter capacitors

A power converter including a processor, at least one component whose health in the power converter will degrade over time, and at least one alarm is disclosed. The processor is configured for monitoring the health of the component over time, and for activating the alarm when the monitored health of the component reaches a threshold level.

Power converter with degraded component alarm

A power converter including a processor and at least one component whose health in the power converter will degrade over time is disclosed. The processor is configured for monitoring the health of the component over time, and for generating a warning signal when the monitored health of the component reaches a threshold level. A method for monitoring the health of at least one component in a power converter is also disclosed. The method includes monitoring at least one performance characteristic of the power converter. The performance characteristic represents the health of the component. The method further includes comparing the monitored performance characteristic with stored data to determine whether the health of the component has reached a predetermined level, and generating a warning signal after determining the health of the component has reached the predetermined level.

Health monitoring for power converter components

A power supply having a control circuit for controlling an output of the power supply, and a voltage monitor circuit for detecting a voltage at a first location and providing the detected voltage to a second location in the control circuit independent of any difference in ground voltage between the first location and the second location. The control circuit is configured to control the output of the power supply in response to the detected voltage provided by the voltage monitor circuit.

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Hong Kong, China

Wing Ling Cheng