A power conversion device and a motor system according to the present disclosure comprises an inverter circuit which is connected to a motor, a switch circuit, and a control circuit. The power conversion device and the motor system are characterized in that the inverter circuit and the switch circuit are capable of two-level operation and three-level operation, and the control circuit switches between the two-level operation and the three-level operation on the basis of the motor torque command and the rotational speed command. As a result, it is possible to reduce the total loss in the power conversion device and the motor.

In a power conversion system, a power converter includes a power conversion circuit connected to a direct current (DC) source via a DC distribution line and converts and supplies received DC power to a load, and a power conversion control unit. A power stabilizing device is disposed between the DC distribution line and the power converter and stabilizes a DC voltage applied from the DC power source. A control power source of the power stabilizing device performs current control of the current transformer to suppress DC magnetization caused by a DC current component of the primary current while compensating for a varying component of the DC voltage. The control power source acquires current information or voltage information calculated from control information used by the power conversion control unit for control operations related to energization of the load and uses it as control information for the power stabilizing device.

An AC-DC converter includes three phase terminals, first and second DC terminals, a first converter stage for converting between the AC signal and a first signal at first and second intermediate nodes, a second converter stage to convert between a second signal at third and fourth intermediate nodes and the DC signal at the first and second DC terminals. The second converter stage has a first active switch. A link connects the first and third intermediate nodes and the second and fourth intermediate nodes. A current injection circuit has second active switches. In a first mode, the first active switch and the second active switches are operated through PWM. In a second mode, the third and fourth intermediate nodes are continuously connected to the first and second DC terminals such that the second converter stage is inoperative and the second active switches are operated through PWM.

A three-phase AC to DC converter includes a first converter stage for converting between three phase voltages at three phase terminals and a first signal at a first intermediate node and a second intermediate node. A phase selector is configured to selectively connect the three phase terminals to a third intermediate node. The converter includes a second converter stage, a DC link connecting the first and second converter stages, and a galvanically isolated DC/DC converter stage having a first side connected to output nodes of the second converter stage and a first common node. A second side of the DC/DC converter stage is galvanically isolated from the first side. The first common node is connected to the third intermediate node. The difference of a first current applied to the DC/DC converter at output nodes of the second converter stage is provided at the third intermediate node.

A first node of converter circuit receives an input, provides an output at a second node, and has a third node coupled by an inductance to ground. A first switch has a current path between the first and third nodes and a second switch has a current path between the third and second nodes. The converter circuit operates in a first state (with the first switch conductive and the second switch non-conductive) and a second state (with the first switch non-conductive and the second switch conductive). Current flowing through the first switch is sensed during the first state to produce a sensing signal indicative of inductance current. The sensing signal is averaged to produce an averaged sensing signal indicative of an average value of the current. The averaged sensing signal is then weighted by a time during which the second switch is conductive to produce a weighted signal.

A power conversion device includes a filter circuit unit between a power conversion unit and a smoothing capacitor for smoothing a pulsating flow accompanying power conversion in the power conversion unit to absorb at least a part of a high-frequency component of the pulsating flow.

Method and apparatus include a first stage converter configured to generate a half sine wave, and a second stage converter in electrical communication with the first stage converter and configured to transform the half sine wave into a power signal. The second stage converter may further supply the power signal to an electrical grid. In one example, the second stage converter may include an isolated, unregulated, resonant direct current/alternating current (DC/AC) converter.

This application provides a switching conversion circuit, including: a power module, supplying power to a switching conversion module and an IC controller; and the switching conversion module is an asymmetrical half-bridge flyback structure and includes at least a first switching transistor, a second switching transistor, a first capacitor, and a transformer. The transformer includes a first secondary-side winding and a second secondary-side winding, and the first secondary-side winding of the transformer is coupled to a load. The IC controller turns on the first switching transistor or the second switching transistor based on a value of a first voltage, so that the switching conversion module enters an operating state to supply power to the load; and turns off the first switching transistor and the second switching transistor based on a value of a second voltage, so that the switching conversion module stops supplying power to the load.

An apparatus includes a controller. The controller controls a main power supply to produce an output signal to power multiple dynamic loads such as disposed in series or other suitable configuration. The controller detects a transient power consumption condition associated with a first dynamic load of the multiple dynamic loads. The controller then adjusts control of the main power supply and generation of the output signal based on the detected transient power consumption condition.

A power supply may include a power converter circuit may be configured to control a magnitude of an output voltage, and generate a signal indicative of the magnitude of the output voltage. The power supply may include an over-power protection circuit that is configured to receive a feedback signal indicative of a magnitude of an input current of the power converter circuit. The power supply may include a control circuit that is configured to determine a magnitude of a requested power based on the signal indicative of the magnitude of the output voltage, and disable the power supply (e.g., control the magnitude of the output voltage to be zero volts) when the magnitude of the requested power is greater than a second threshold and the magnitude of input power indicated by the first feedback signal is less than a third threshold.