Power drive circuit and method of controlling the same
AssigneeDelta Electronics, Inc.
InventorsYi-Wei Lin, Kai-Wei Hu, Lei-Chung Hsing
Life of this patent
Estimating the term…
Abstract
A power drive circuit includes a power conversion module, a plurality of gate drivers, a waveform processing unit, a control unit, a weighting unit, and a comparator. Each gate driver includes a drive resistance setting value. The waveform processing unit outputs a current absolute value waveform of an AC power. The weighting unit generates a trigger voltage. When the comparator determines that the current absolute value waveform is greater than the trigger voltage, the comparator outputs a slew rate control signal to each of the gate drivers. When the gate driver receives the slew rate control signal, each of the gate drivers decreases the drive resistance setting value of the gate driver.
Claims15
A power drive circuit comprising:
- a power conversion module comprising a plurality of switches, and the power conversion module configured to receive a DC power source and output an AC power,
- a plurality of gate drivers, each of the gate drivers correspondingly connected to a control end of each of the switches, and each of the gate drivers having a drive resistance setting value,
- a waveform processing unit coupled to an AC current signal of the AC power to output a current absolute value waveform of the AC current signal,
- a control unit configured to adjust a duty cycle of a first PWM signal according to the DC power source and an AC voltage signal of the AC power to output a second PWM signal,
- a weighting unit configured to acquire an average voltage of the second PWM signal and superimpose the average voltage and a trigger level signal to generate a trigger voltage, and
- a comparator configured to output a slew rate control signal to each of the gate drivers when the comparator determines that the current absolute value waveform is greater than the trigger voltage,
- wherein when each of the gate drivers receives the slew rate control signal, each of the gate drivers decreases the corresponding drive resistance setting value.
A control method applied to a power drive circuit, the power drive circuit comprising a power conversion module and a plurality of gate drivers, each of the gate drivers correspondingly connected to each of a plurality of switches of the power conversion module, and each of the gate drivers comprising a drive resistance setting value;
- the control method comprising steps of:
- converting, by the power conversion module, a DC power source into an AC power,
- executing an absolute value operation procedure to acquire a current absolute value waveform of an AC current signal of the AC power,
- adjusting a duty cycle of a first PWM signal to form a second PWM signal according to the DC power source and an AC voltage signal of the AC power,
- acquiring an average voltage of the second PWM signal,
- superimposing the average voltage and a trigger level signal to generate a trigger voltage, and
- comparing the current absolute value waveform and the trigger voltage,
- wherein when the current absolute value waveform is greater than the trigger voltage, outputting a slew rate control signal to each of the gate drivers,
- wherein when each of the gate drivers receives the slew rate control signal, decreasing the corresponding drive resistance setting value of each of the gate drivers.
Dependencies are inferred from the claim text.