A power conversion apparatus includes: a reactor; a rectifier circuit that includes a first leg including switching elements connected in series and a second leg connected in parallel with the first leg, including switching elements connected in series; and a smoothing capacitor that smooths an output voltage of the rectifier circuit. The power conversion apparatus also includes an inverter that converts a direct-current voltage smoothed by the smoothing capacitor into a drive voltage for a motor and applies the drive voltage to the motor; a voltage detection unit that detects the direct-current voltage; and a control unit that controls operation of the rectifier circuit and the inverter. The control unit controls operations of the switching elements on the basis of an induced voltage induced in the motor and a detected value of the direct-current voltage.

A voltage doubling phase converter that converts single phase AC electric power to balanced three phase AC power. Two input terminals are connectable to a single-phase AC power source and connect directly to two output terminals of the converter. The phase converter has a storage capacitor, three active half-bridge modules connected to the storage capacitor, and a controller. Two modules connect to the input terminals and charge the storage capacitor. The other module connects to a third output terminal. The controller switches the module connected to the third output terminal and one of the other modules to generate and shape a second and a resultant third phase.

The invention relates to a method for operating a wind turbine which comprises a power generator, a generator side converter, a grid side converter, a DC link electrically connected to an output of the generator side converter and an input of the grid side converter. The method comprises monitoring a wind turbine signal for detection of an operational condition which requires an increase of an output voltage of the grid side converter, upon detection of the operational condition, initiate an over-modulation mode wherein the grid side converter is operated with a modulation index in an over-modulation range, and upon the detection of the operational condition, initiate a DC-voltage adjustment mode wherein the a DC-voltage of the DC link is increased from a first voltage level towards a second voltage level.

A powertrain for electric and plug-in hybrid vehicle applications with integrated three-phase AC charging featuring buck-boost operation and optional vehicle-to-grid (V2G) capability, along with corresponding methods and machine instruction sets for switch control. The powertrain can include of a three-phase current source converter (CSC) front-end with an associated input filter, a polarity inversion module, and in an embodiment, a dual-inverter motor drive. The dual-inverter drive is the source of both the back emf and requisite DC inductance for the CSC. A compact design is thus provided as no additional magnetics are required and the on-board cooling system required for traction mode can be re-deployed for charging and V2G mode. The powertrain is mode shifted between charging and V2G mode through an optional polarity inversion module.

A three-phase regenerative drive configured for operation from a single phase alternating current (AC) power source, the three-phase regenerative drive including a three-phase converter having inputs for connection to a single-phase AC source, the three-phase converter having three phase legs, a three-phase inverter for connection to a motor, the three phase inverter configured to provide three phase command signals to the motor, and a DC bus connected between the three-phase converter and the three-phase inverter. A first phase leg of the three-phase converter and a second phase leg of the three-phase converter are employed to direct current from the single-phase AC source to the DC Bus and a third phase leg of the three phase legs of the three-phase converter returns current to a return of the AC source.

The insulation deterioration monitoring apparatus comprises a computer on which software is installed. The software causes the computer to execute at least first to fourth processes. In the first process, during stopping of at least one inverter unit, the computer selects one inverter unit out of the stopped inverter units and causes the inverter corresponding to the selected inverter unit to generate a direct current voltage. In the second process, the computer measures the current value of the ground current while the corresponding motor driving inverter generates the direct current voltage. In the third process, the computer records the measured current value of the ground current for each inverter unit in association with the selected inverter unit. Then, in the fourth process, based on the measured current value of the ground current recorded for each inverter unit, the computer analyzes the tendency of insulation deterioration of each inverter unit.

A method for controlling an inverter-based resource (IBR) having a power converter and a generator connected to an electrical grid includes determining an available active power of the electrical grid. The method also includes determining an available active power of the IBR based on an effect of a speed and a rating of the generator. Further, the method includes determining a minimum available active power based on the available active power of the electrical grid and the available active power of the IBR. Moreover, the method includes determining an active power limit change for the IBR based on one or more thermal margins of the IBR. In addition, the method includes determining an active power estimation as a function of the minimum available active power and the active power limit change. The method further includes providing the active power estimation to a supervisory controller for controlling the IBR.

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.

A system and a method for power conversion. The system includes a rectifier; an inverter; a DC-link capacitor coupled between the rectifier and the inverter; and a controller. The controller is configured to obtain a current value at an output of the inverter and a voltage value across the DC-link capacitor, determine an average component and a fluctuating component of an output voltage of the inverter based on the obtained current value and the voltage value, and determine a current reference for controlling the rectifier based on the average component and the fluctuating component of the output voltage.

A frequency converter adapted to be connected to another frequency converter via a direct current bus is provided. The frequency converter comprises: a positive bus interface adapted to be interconnected with a positive bus interface of the other frequency converter; an external bleeder resistor interface adapted to be interconnected with an external bleeder resistor interface of the other frequency converter; and a first control logic which controls a parallel connection, between the frequency converter and the other frequency converter and realized by a direct current bus, to be turned on or off. A corresponding frequency converter assembly, a control method, and a computer readable storage medium are also provided.