A converter controller configured to control a firing phase of a converter includes an integral element integrating a deviation of DC current from a current command value and generates a voltage command value of output voltage of the converter by performing control calculation of the deviation. In a first mode of performing commutation of an inverter by intermittently setting DC current to zero, the converter controller sets DC current to zero for a predetermined pause time by narrowing a phase control angle simultaneously with a commutation command for the inverter. When the control calculation is resumed immediately after the pause time, the converter controller uses a control amount calculated in control calculation immediately before the pause time as a preset value of the integral element immediately after the pause time.

A converter controller configured to control a firing phase of a converter includes an integral element integrating a deviation of DC current from a current command value and generates a voltage command value of output voltage of the converter by performing control calculation of the deviation. In a first mode of performing commutation of an inverter by intermittently setting DC current to zero, the converter controller sets DC current to zero for a predetermined pause time by narrowing a phase control angle simultaneously with a commutation command for the inverter. When the control calculation is resumed immediately after the pause time, the converter controller uses a control amount calculated in control calculation immediately before the pause time as a preset value of the integral element immediately after the pause time.

Provide is a power conversion device capable of avoiding a power outage even if reference AC power is lost. A power conversion device 1 includes a phase detector 31 calculating a voltage phase based on the phase of AC power supplied to an electric power system 9, a waveform controller 35 generating a control signal designating the frequency and phase of the AC power based on the voltage phase calculated by the phase detector 31, a power conversion circuitry 12 which converts power supplied from a power supply source 15 into the AC power based on the control signal generated by the waveform controller 35, and which outputs the converted power to the electric power system 9, and a determination block 44 which detects the frequency of the AC power supplied to the electric power system 9, and which determines that the AC power that becomes the reference for the frequency is not supplied to the electric power system 9 when the detected frequency is not within a preset first frequency range. When the determination block 44 determines that the AC power that becomes the reference for the frequency is not supplied to the electric power system 9, the waveform controller 35 executes a control on the power conversion circuitry 12 so as to supply the AC power that becomes the reference for the frequency to the electric power system 9.

Provide is a power conversion device capable of avoiding a power outage even if reference AC power is lost. A power conversion device 1 includes a phase detector 31 calculating a voltage phase based on the phase of AC power supplied to an electric power system 9, a waveform controller 35 generating a control signal designating the frequency and phase of the AC power based on the voltage phase calculated by the phase detector 31, a power conversion circuitry 12 which converts power supplied from a power supply source 15 into the AC power based on the control signal generated by the waveform controller 35, and which outputs the converted power to the electric power system 9, and a determination block 44 which detects the frequency of the AC power supplied to the electric power system 9, and which determines that the AC power that becomes the reference for the frequency is not supplied to the electric power system 9 when the detected frequency is not within a preset first frequency range. When the determination block 44 determines that the AC power that becomes the reference for the frequency is not supplied to the electric power system 9, the waveform controller 35 executes a control on the power conversion circuitry 12 so as to supply the AC power that becomes the reference for the frequency to the electric power system 9.

This invention proposes a single-vector-based finite control set model predictive control for two parallel power converters, which adopts a centralized control structure to achieve accurate control of overall performance. It establishes predictive models for line currents and three phase-circulating currents and constructs a novel cost function that uses these currents as performance indices to implement the predictive control algorithm based on the proposed predictive models. The invention proposes dynamic weighting coefficients and adjustment principles to improve system control performance. A finite set output signal matrix containing important characteristic information of all alternative vectors is constructed to avoid redundant calculations in each control horizon, reducing computation time during practical implementation. This invention addresses the limitations of existing one-vector-based FCS-MPC for two paralleled power converters, which controls each sub-converter individually with a set of available eight control actions and cannot effectively regulate the overall performance of the two paralleled power converters.

An overcurrent detection reference compensation system of a switching element for an inverter and an overcurrent detection system using the same can correct an overcurrent detection reference used to detect an overcurrent of a switching element according to a temperature of the switching element.

An overcurrent detection reference compensation system of a switching element for an inverter and an overcurrent detection system using the same can correct an overcurrent detection reference used to detect an overcurrent of a switching element according to a temperature of the switching element.

An electrical converter with at least two output phases includes a rectifier and a thyristor-based inverter interconnected by a DC link with an inductor, wherein the thyristor-based inverter includes a half-bridge with at least two half-bridge arms for each output phase of the electrical converter and each arm being provided by a thyristor. A method for switching the electrical converter includes: cyclically switching the thyristors of the inverter, such that at least one time instant, two thyristors of different half-bridge arms are switched on simultaneously, such that a pulse number, which determines at how many time instants thyristors of the inverter are switched during one stator voltage period, is lower than the number of half-bridge arms of the inverter.

An electrical converter with at least two output phases includes a rectifier and a thyristor-based inverter interconnected by a DC link with an inductor, wherein the thyristor-based inverter includes a half-bridge with at least two half-bridge arms for each output phase of the electrical converter and each arm being provided by a thyristor. A method for switching the electrical converter includes: cyclically switching the thyristors of the inverter, such that at least one time instant, two thyristors of different half-bridge arms are switched on simultaneously, such that a pulse number, which determines at how many time instants thyristors of the inverter are switched during one stator voltage period, is lower than the number of half-bridge arms of the inverter.

A converter controller configured to control a firing phase of a converter includes an integral element integrating a deviation of DC current from a current command value and generates a voltage command value of output voltage of the converter by performing control calculation of the deviation. In a first mode of performing commutation of an inverter by intermittently setting DC current to zero, the converter controller sets DC current to zero for a predetermined pause time by narrowing a phase control angle simultaneously with a commutation command for the inverter. When the control calculation is resumed immediately after the pause time, the converter controller uses a control amount calculated in control calculation immediately before the pause time as a preset value of the integral element immediately after the pause time.