A circuit is disclosed. The circuit includes a current detecting FET, configured to generate a current signal indicative of the value of the current flowing therethrough, an operational transconductance amplifier (OTA) configured to output a current in response to the voltage of the current signal, and a resistor configured to receive the current and to generate a voltage in response to the received current, where the generated voltage is indicative of the value of the current flowing through the current detecting FET. The current detecting FET is configured to become nonconductive in response to the generated voltage indicating that the current flowing through the current detecting FET is greater than a threshold.

A var compensator circuit is provided. The var compensator circuit includes a gas tube switch and a reactive impedance. The gas tube switch is configured to be coupled to a transmission line. The transmission line is configured to deliver real power and reactive power to a load at an alternating current (AC) line voltage. The reactive impedance is configured to be coupled to the transmission line at the AC line voltage through the gas tube switch. The reactive impedance is configured to modify the reactive power configured to be delivered to the load.

An improved power converter produces power through a power switch in response to an activation signal that has an on-time and a switching frequency. An on-time signal has a constant on-time and controls the on-time of the activation signal. An error signal indicates that the switching frequency is not equal to a reference frequency. A step up signal and a step down signal are based on the error signal. A count signal is increased in response to the step up signal and decreased in response to the step down signal. An on-time pulse has a duration that is related to a value of the count signal. The on-time pulse controls the constant on-time of the on-time signal and maintains the switching frequency at about the reference frequency.

A switched power circuit to control a common-mode signal. The switched power circuit includes a first switch and a second switch configured to generate switch mode voltage between a first node and a second node. The switched power circuit further includes a feedback circuit that is configured to detect common-mode voltage generated between the first node and the second node by a first signal generated by the first switch and a second signal generated by the second switch, and incrementally adjust a timing parameter of the first signal to adjust the common-mode signal.

A power electronics system, comprising a first inverter configured to receive DC power from a power source and a second inverter configured to receive DC power from the power source is provided. The system includes a first output inductor connected in series to an output of the first inverter, a second output inductor connected in series to an output of the second inverter, a coupling inductor configured to receive current from the first output inductor and the second output inductor, and an AC power output.

An improved power converter produces power through a power switch in response to an activation signal that has an on-time and a switching frequency. An on-time signal has a constant on-time and controls the on-time of the activation signal. An error signal indicates that the switching frequency is not equal to a reference frequency. A step up signal and a step down signal are based on the error signal. A count signal is increased in response to the step up signal and decreased in response to the step down signal. An on-time pulse has a duration that is related to a value of the count signal. The on-time pulse controls the constant on-time of the on-time signal and maintains the switching frequency at about the reference frequency.

A method includes providing a transformer with primary and current injection windings, a primary switch connected to the primary winding, a parasitic capacitance reflected across the primary switch, a secondary rectifier means, and a current injection circuit including a current injection switch connected to the current injection winding, and a unidirectional current injection switch connected to the current injection winding. The method includes switching on the current injection switch to start a current injection flowing from a controlled voltage source, through the unidirectional current injection switch and further through the current injection winding. The current injection reflects into the primary winding, thereby discharging the parasitic capacitance reflected across the primary switch. The method includes turning on the primary switch with a delay time after the current injection switch turns on and turning off the current injection switch after the current injection reaches zero amplitude.

A direct current (DC)-DC converter includes a transformer and a gas tube-switched inverter circuit. The transformer includes a primary winding and a secondary winding. The gas tube-switched inverter circuit includes first and second inverter load terminals and first and second inverter input terminals. The first and second inverter load terminals are coupled to the primary winding. The first and second inverter input terminals are couplable to a DC node. The gas tube-switched inverter circuit further includes a plurality of gas tube switches respectively coupled between the first and second inverter load terminals and the first and second inverter input terminals. The plurality of gas tube switches is configured to operate to generate an alternating current (AC) voltage at the primary winding.

A method of operating a power protection system coupled between a power source and a power converter includes producing, by a controller of the power protection system, a driving signal to a cut-off switch of the power protection system to electrically couple the power source to the power converter; detecting, by the controller of the power protection system, a fault condition of the power converter while the power converter is in operation, where the detecting includes detecting, by the controller of the power protection system, that a current flowing through the cut-off switch is above a pre-determined threshold while a gate control signal from the power converter indicates an OFF state for a first current path of the power converter; and in response to detecting the fault condition, turning off, by the controller of the power protection system, the cut-off switch to isolate the power source from the power converter.

A circuit is disclosed. The circuit includes a current detecting FET, configured to generate a current signal indicative of the value of the current flowing therethrough, an operational transconductance amplifier (OTA) configured to output a current in response to the voltage of the current signal, and a resistor configured to receive the current and to generate a voltage in response to the received current, where the generated voltage is indicative of the value of the current flowing through the current detecting FET. The current detecting FET is configured to become nonconductive in response to the generated voltage indicating that the current flowing through the current detecting FET is greater than a threshold.