An energy storage system for use in a renewable energy power system is provided. More particularly, an energy storage system can be coupled to the DC bus of a power converter in a renewable energy power system. A switching power supply can be coupled between the energy storage device and the DC bus of the power converter. The switching power supply can include a bi-directional resonant DC to DC converter. The bi-directional resonant converter can include a plurality of switching elements, a resonant circuit coupled to the at least one switching element, and a filtering circuit coupled to the resonant circuit. The bi-directional resonant converter can be configured to accommodate power flow in at least two directions.

A method involves receiving, at an active clamp controller circuit, an active clamp switch current that passes through an active clamp switch. The active clamp switch is enabled using the active clamp controller circuit in response to determining, based on the active clamp switch current, body-diode conduction of the active clamp switch. The active clamp switch is disabled using the active clamp controller circuit in response to determining, based on the active clamp switch current, a first zero-crossing of the active clamp switch current and a second zero-crossing of the active clamp switch current.

A method of controlling first and second switches of a switching cell, including measuring a current flowing through the first switch when the first switch is controlled to the off state, and setting a switching dead time according to the measurement.

A control method for regulating the switching frequency of a resonant converter having an input terminal to receive an input voltage and an output terminal to output an output voltage. The control method is sensing the input voltage and adjusting the switching frequency based on the comparison of the input voltage with a reference threshold voltage. When the input voltage is less than the reference threshold voltage, the switching frequency is adjusted to decrease, and when the input voltage is higher than the reference threshold voltage, the switching frequency is adjusted to increase.

According to an aspect, a power supply system includes a power stage, a power supply controller configured to control operations of the power stage, a metering circuit configured to sense measured conditions of the power stage, and a system performance controller configured to be coupled to the power supply controller and the metering circuit. The system performance controller is configured to set or adjust a control parameter for the power stage based on standby power of the power stage. The system performance controller includes a standby power computation circuit configured to compute the standby power of the power stage based on the measured conditions, and a control manipulation module configured to modify the control parameter until the standby power achieves a threshold condition.

A system is described that includes a half-bridge, a first driver, a second driver, and a controller unit. The half-bridge includes a first switch coupled to a second switch at a switching node. The first driver is configured to drive the first switch and the second driver is configured to drive the second switch. The controller unit is configured to determine whether a hard commutation event is likely to occur at the half-bridge during a future switching cycle, and responsive to determining that the hard commutation event is likely to occur during the future switching cycle, control the first driver and the second driver to activate at least one hard commutation countermeasure.

The method of controlling power transmission to a load permits: to eliminate over-voltage in an electric circuit; to decrease energy losses and time of charging of an energy storing device; to increase service life of switches and provide very high reliability of power transmission to a load. The conception is following: controlling power transmission to a load from additional circuit so that current can be transferred from additional circuit to operating circuit (circuit with a load) and vice versa from operating circuit to additional circuit without interruption (without switching off) circuit of the load.

A zero-crossing detection circuit coupled to a power factor correction (PFC) controller of a power supply system includes a zener diode configured to generate a zener reference signal, and an operational amplifier coupled to the zener diode and configured to receive the zener reference signal and a feedback signal corresponding to an output current of the power supply system, and to generate a zero-crossing signal to a zero-crossing input of the PFC controller.

Various examples are directed to systems and methods for a multi-level inverter to convert direct current (DC) to alternating current (AC). The inverter may comprise first, second and third capacitors electrically coupled in series between a positive DC rail and a negative DC rail. A first pole switch bank of the inverter may comprise a plurality of first pole switches. A first pole may be electrically coupled to the first pole switch bank. A control circuit may comprise at least one processor that is programmed to alternately switch the first pole switch bank to a first state of the first pole switch bank in which the first pole is electrically coupled to the positive DC rail, a second state of the first pole switch bank in which the first pole is electrically coupled between the first capacitor and the second capacitor, a third state of the first pole switch bank in which the first pole is electrically coupled between the second capacitor and the third capacitor, a fourth state of the first pole switch bank in which the first pole is electrically coupled to the negative DC rail.

A converter includes a DC input; a transformer including first and second primary windings, first and second secondary windings, and first and second feedback windings; a first field-effect transistor; a second field-effect transistor; and a drive circuit connected to the first and second field-effect transistors. The drive circuit includes a bias circuit that applies a bias voltage to gates of the first and second field-effect transistors via the first and second feedback windings during start-up of the converter, wherein the bias voltage is reduced to zero or substantially zero after start-up of the converter; and a reset circuit that resets the bias circuit when the converter is turned off. The converter is a self-oscillating push-pull DC-DC converter.