Aspects of the invention overcome a monolithic approach to conventional low-frequency LPTs by using a high-frequency solid-state alternating current ac/ac modular powerconversion approach. Embodiments of the invention enable the ability to incorporate new technologies without in all cases redoing a LPT design from scratch. Furthermore, given that LPTs are for the long term, aspects of the invention ensure that they are durable, efficient, and fault tolerant with overloading capability.

Controller and method for a power converter. For example, a controller for a power converter includes: a feedback detector configured to receive a feedback voltage, sample the feedback voltage, and generate a sampled voltage based at least in part on the feedback voltage, the sampled voltage being associated with one or more fluctuations in magnitude; a resistor selector configured to receive the sampled voltage and generate one or more control signals based at least in part on the one or more fluctuations associated with the sampled voltage; a variable resistor network configured to receive the one or more control signals, determine a network resistance based at least in part on the one or more control signals, and output a compensation voltage based at least in part on the network resistance; and a voltage generator connected to the variable resistor network and configured to receive the compensation voltage.

Operating an electrical load controller includes, in one aspect, detecting zero-crossings of an AC waveform, determining periods each corresponding to a full cycle of the AC waveform, determining a frequency of the AC waveform based on the determined periods, and controlling a supply of AC power to a load based thereon using the determined frequency to fire a switching circuit of the electrical load controller. In another aspect, a method includes maintaining a minimum on-time for which a control signal to the switching circuit is to remain in an ON state to fire the switching circuit; based on a desired load level setting of the electrical load controller, setting a corresponding control signal turn-on time to turn the control signal to the ON state to conduct the supply of AC power to the load, the control signal turn-on time corresponding to a firing angle of half cycles of the AC power; selecting a control signal turn-off time to turn the control signal to the OFF state, where the selecting is made between (i) a first turn-off time equal to the set turn-on time plus the minimum on-time, and (ii) a second turn-off time equal to a default turn-off time for turning the control signal to the OFF state, the control signal turn-off time corresponding to a second angle of half cycles of the AC power; and controlling the supply of AC power to the load by selectively controlling the switching circuit to conduct the supply of AC power to the load, the controlling the supply of AC power to the load including: based on turning the control signal to the ON state during a half cycle of the AC power at the set control signal turn-on time, holding the control signal in the ON state until the selected control signal turn-off time during the half cycle.

Aspects of the invention overcome a monolithic approach to conventional low-frequency LPTs by using a high-frequency solid-state alternating current ac/ac modular power-conversion approach. Embodiments of the invention enable the ability to incorporate new technologies without in all cases redoing a LPT design from scratch. Furthermore, given that LPTs are for the long term, aspects of the invention ensure that they are durable, efficient, and fault tolerant with overloading capability.

A switched-mode neutral forming device is provided herein and comprises one or more windings coupled to (i) a plurality of line terminals via a plurality of switches and (ii) a neutral terminal, wherein each switch of the plurality of switches is a native four quadrant bi-directional switch and a controller, coupled to the plurality of switches, for driving the switches at a frequency orders or magnitude greater than an AC mains frequency.

An apparatus includes a DC-to-AC converter comprising a first output terminal and a second output terminal. The apparatus also includes a DC-to-DC converter comprising a third output. The DC-to-AC converter is configured to receive a DC input voltage from a DC power source, and to produce a first alternating output voltage at the first output terminal, and a second alternating output voltage at the second output terminal. The DC-to-DC converter is configured receive a DC input voltage from the DC power source, and to step down the DC input voltage at the third output.

A power transmission unit includes an alternating-current power source that outputs alternating-current power, a clock generation unit that generates a clock signal higher in frequency than the alternating-current power, and a power transmission antenna that wirelessly transmits the power. A power reception unit includes, a power reception antenna that receives wirelessly the power from the power transmission antenna, and a rectification circuit that rectifies a voltage output from the power reception antenna and outputs the alternating-current power. A control system includes a correction unit that estimates a property change in one or more passive elements included in at least one of the power transmission unit or the power reception unit, and corrects a phase of the clock signal or the alternating-current power output from the alternating-current power source to maintain linearity between the alternating-current power output from the alternating-current power source and the alternating-current power output from the rectification circuit.

An AC-AC converter can include a stack of four switches. An input of the converter can be coupled across the stack of four switches, and an output of the converter can be taken from first terminal coupled to a connection point of first and second switches of the stack and a second terminal coupled to a connection point of third and fourth switches of the stack. The converter can further include a controller that operates the switches such that during a positive half cycle of an AC input voltage, the first and second switches are operated with an alternating 50% duty cycle and the third and fourth switches are constantly on, and during the negative half cycle of the AC input voltage, the third and fourth switches are operated with an alternating 50% duty cycle and the first and second switches are constantly on.

Operating an electrical load controller includes, in one aspect, detecting zero-crossings of an AC waveform, determining periods each corresponding to a full cycle of the AC waveform, determining a frequency of the AC waveform based on the determined periods, and controlling a supply of AC power to a load based thereon using the determined frequency to fire a switching circuit of the electrical load controller. In another aspect, a method includes maintaining a minimum on-time for which a control signal to the switching circuit is to remain in an ON state to fire the switching circuit; based on a desired load level setting of the electrical load controller, setting a corresponding control signal turn-on time to turn the control signal to the ON state to conduct the supply of AC power to the load, the control signal turn-on time corresponding to a firing angle of half cycles of the AC power; selecting a control signal turn-off time to turn the control signal to the OFF state, where the selecting is made between (i) a first turn-off time equal to the set turn-on time plus the minimum on-time, and (ii) a second turn-off time equal to a default turn-off time for turning the control signal to the OFF state, the control signal turn-off time corresponding to a second angle of half cycles of the AC power; and controlling the supply of AC power to the load by selectively controlling the switching circuit to conduct the supply of AC power to the load, the controlling the supply of AC power to the load including: based on turning the control signal to the ON state during a half cycle of the AC power at the set control signal turn-on time, holding the control signal in the ON state until the selected control signal turn-off time during the half cycle.

A power converter includes an unfolder connected to a three-phase source and has an output connection with three output terminals. A three-input converter connected to the unfolder produces a quasi-sinusoidal output voltage across converter output terminals. Switches of the converter selectively connect each of the three output terminals across the converter output terminals. A pulse-width modulation controller controls a first duty ratio and a second duty ratio for the converter based on a phase angle of the source and a modulation index generated from an error signal related to a control variable. The duty ratios are time varying at a rate related to a fundamental frequency of the source. The modulation index relates to output voltage of the converter, peak voltage or current of the source and/or peak current at the output terminals.