Delta Electronics, Inc.

Ping-Heng Wu

Kai-Wei Hu

Lei-Chung Hsing

Mitradatta Misra

A switch short-circuited diagnosis method includes steps of: determining an initial voltage interval of multiple voltage intervals according to voltage relationships between voltages of a first phase wire, a second phase wire, and a third phase wire; performing a switch short-circuited diagnosis of a first bidirectional switch module in the three consecutive voltage intervals from the initial voltage interval, and including steps of: turning on a first switch branch, a second switch branch, or a third switch branch of the first bidirectional switch module according to the voltage relationships between the voltages of the first, second and third phase wires, determining whether an overcurrent occurs to diagnose whether the first switch branch, the second switch branch, or the third switch branch of the first bidirectional switch module is in a short-circuited state, and performing the switch short-circuited diagnosis for the next voltage interval.

Switch short-circuited diagnosis method

A method of clamping an output current of a three-phase power converter is provided. The three-phase power converter includes three switching bridge arms and provides a three-phase output voltage command, and each switching bridge arm has an upper switch and a lower switch connected in series. The method includes steps of: determining that the output current is greater than a first current threshold to activate a current clamping control procedure, comparing a carrier signal with the three-phase output voltage command to turn on the lower switches by a first zero vector when the carrier signal is rising and turn on the upper switches by a second zero vector when the carrier signal is falling, determining that the output current is greater than a second current threshold to activate an overcurrent protection procedure, wherein the second current threshold is greater than the first current threshold.

Method of clamping output current of three-phase power converter

A matrix power conversion device including a plurality of three-phase switching modules and a controller is provided. Each three-phase switching module includes a plurality of bidirectional switches connected to the input phase voltages of the three-phase input power respectively and outputs a corresponding output phase voltage of the three-phase output power. The controller determines a maximum voltage, an intermediate voltage and a minimum voltage among all the input phase voltages to acquire a waveform of a control carrier wave in a switching cycle. The controller acquires output expected values corresponding to all output phase voltages and compares them with the waveform of the control carrier wave for acquiring a turning-on time of each of the plurality of bidirectional switches. Accordingly, the controller controls the matrix power conversion device to switch the three-phase input power so as to change the three-phase output power for driving the motor.

Matrix power conversion device and control method thereof

A method of controlling a power converter is provided. The power converter generates a three-phase output power by switching an input power through a plurality of switches. The method includes steps of: acquiring a three-phase output command corresponding to the three-phase output power; comparing the three-phase output command with a control carrier to acquire a voltage phase angle corresponding to the three-phase output command; acquiring a three-phase current value of the three-phase output power; detecting the voltage phase angle and a positive/negative change of the three-phase current value to decide a zero-sequence voltage; composing the zero-sequence voltage and the three-phase output command to acquire a three-phase output expected value; comparing the three-phase expected values with the control carrier to acquire a turned-on time of each switch; and switching the input power to adjust the three-phase output power according to the turned-on time of each switch.

Method of controlling power converter and power converter

A power system includes a pulse width modulation device. The pulse width modulation device outputs first, second, third and fourth driving signals. The pulse width modulation device receives a control signal. The control signal is divided into a positive periodic signal and a negative periodic signal. A portion of the positive periodic signal higher than or equal to a maximum threshold voltage is clamped as the maximum threshold voltage to generate a first comparison waveform. The positive periodic signal is clamped as the reference voltage level to generate a second comparison waveform. According to the first comparison waveform, a first ramp signal is generated. According to the second comparison waveform, a first pulse width modulation signal is generated. The first, second, third and fourth driving signals are adjusted according to the first ramp signal and the first pulse width modulation signal.

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Taoyuan, Taiwan

Ping-Heng Wu