Provided are an inverter device deterring PWM voltage error even if high inverter output frequencies are used for overmodulation driving and an electric vehicle equipped with the inverter device. In an angular section where the output voltage from an inverter device is linearly approximated with the zero cross point as the center thereof, a PWM generator in the inverter device changes either the time interval between the centers of PWM ON pulses or the time interval between the centers of PWM OFF pulses depending on the inverter operation state. An electric vehicle is equipped with the inverter device, which drives a motor.

A power transmission system can include a transformer and compensator circuit(s), each coupled between a node of the transformer and a ground connection. The compensator circuit(s) can each be configured to counteract a DC signal component of an AC signal at the transformer. The compensator circuit(s) can include a converter circuit having an AC side and a DC side and configured to convert a DC voltage on the DC side to an AC signal at the AC side. The compensator circuit(s) can include a DC link coupled to the DC side of the converter circuit. The compensator circuit(s) can include a controller configured to measure a DC signal component between the load and the ground; to determine, based at least in part on the DC signal component, a compensating signal configured to counteract the DC signal component; and to inject, by the converter circuit, the compensating signal to counteract the DC signal component.

A system and method for an interleaved inverter including a set of module circuits and an inverter controller. The module circuits include multiple switches. The inverter controller is configured to assign a first phase shift value to each of the module circuits during a normal mode of operation and assign a second phase shift value to at least one of the module circuits during a failure mode of operation. The second phase shift value is greater than the first phase shift value.

An electronic device may include an inverter. The inverter may convert direct current (DC) power to alternating current (AC) power. The inverter may use a clock signal at a given frequency to output corresponding alternating current signals at the given frequency. The inverter may receive a dithered clock signal that is frequency dithered using a modulating signal. The dithered clock signal may have at least three different frequency levels during a repeated cycle of the modulating signal. The at least three different frequency levels may include a fundamental frequency, a first frequency that is lower than the fundamental frequency, and a second frequency that is higher than the fundamental frequency. The dithered clock signal may be, during the repeated cycle of the modulating signal, at the fundamental frequency for fewer total periods than at the first frequency and for fewer total periods than at the second frequency.

A power conversion device includes a first bridge circuit, a second bridge circuit, and an inductance element connected between a first AC terminal of the first bridge circuit and a second AC terminal of the second bridge circuit. The controller calculates a passing current passing through the inductance element based on a difference between a first alternating current flowing between the first AC terminal and the inductance element and a second alternating current flowing between the second AC terminal and the inductance element, and detects a first DC component included in the passing current. The controller changes a duty in at least one of the first AC voltage and the second AC voltage to cancel the detected first DC component, the duty being a ratio of a positive potential period and a negative potential period.

A power conversion device, including: a voltage detector that detects a common mode voltage generated upon a switching operation of a power semiconductor device; a voltage superimposer that superimposes the common mode voltage detected by the voltage detector onto an output of the power conversion device to cancel the common mode voltage having a frequency greater than or equal to a switching frequency generated upon the switching operation of the power semiconductor device; and a residual voltage detector that detects the common mode voltage of the power conversion device superimposed by the voltage superimposer. The voltage superimposer includes a feedback mechanism for adding and superimposing the common mode voltage detected by the residual voltage detector onto the output of the power conversion device. The voltage detector includes a first choke coil and a first capacitor.

A multi-phase power converter with current matching is provided. The apparatus may include a control circuit to control a first phase of a power converter having a plurality of phases, and a phase matching circuit. The phase matching circuit may remove a DC component from an output ripple voltage of the converter, detect when respective ones of the plurality of phases begins generating its respective phase current and output a phase detector signal, extract a signal proportional to the first phase current and a signal proportional to either the remaining or total phase currents, output first and second voltages respectively proportional to the average of the first phase current and the remaining or total phase current, and output a corrective signal based on the difference between the first and second voltage. The control circuit may control the first phase based on the corrective signal.

A setting unit sets a duty ratio of a PWM signal based on a target voltage value, and outputs the duty ratio to a voltage conversion circuit. An estimated value calculation unit cyclically calculates an estimated duty ratio value based on the detected input voltage value and the detected output voltage value. An abnormality detection unit cyclically calculates, as a difference value, a difference between an updated estimated value and a comparison reference value, and detects abnormality of a voltage detection unit based on a change in calculated difference value. The updated estimated value is a newly calculated estimated duty ratio value. The comparison reference value is a value based on the estimated duty ratio value calculated in a cycle prior to a cycle in which the updated estimated value is calculated.

The presence of injected DC has harmful consequences for a power grid system. A piecewise sinusoidal ripple voltage wave at the line-frequency that rides on the main capacitor bank of the power converter is observed. This observation leads to a new detection method and mitigation method. A two-stage control circuit is added to the operation of a power converter that controls power line impedance in order to mitigate the injected DC and to block DC circulation. This control computes a correction angle to adjust the timing of generated pulsed square waves to counter-balance the ripple. A functional solution and the results of experiments are presented. Furthermore, an extraction method and three elimination methods for this ripple component are presented to allow dissipation of DC energy through heat and/or electronic magnetic wave, or to allow transformation of this energy into usable power that is fed back into the power grid.

The presence of injected DC has harmful consequences for a power grid system. A piecewise sinusoidal ripple voltage wave at the line-frequency that rides on the main capacitor bank of the power converter is observed. This observation leads to a new DC detection elimination method. Three DC elimination methods for this ripple component are disclosed to allow dissipation of DC energy through heat and/or electromagnetic wave, or to allow transformation of this energy into usable power that is fed back into the power grid.