Abstract: A driving device includes a driving primary circuit, an isolating transforming circuit, and at least one driving secondary circuit. The isolating transforming circuit is coupled to the driving primary circuit. The at least one driving secondary circuit is coupled to the isolating transforming circuit. The driving primary circuit receives a control signal and a power signal. The driving primary circuit generates a driving pulse signal according to the control signal and generates a power pulse signal according to the power signal. The driving primary circuit transmits the driving pulse signal and the power pulse signal to the at least one driving secondary circuit through the isolating transforming circuit. The at least one driving secondary circuit receives the driving pulse signal so as to generate a driving signal, and the at least one driving secondary circuit drives a power semiconductor switch unit according to the driving signal.

Abstract: A voltage sampling system is provided. The voltage sampling system includes a voltage sampling device, two optic-fiber transmission lines and a control device. The voltage sampling device includes a voltage-dividing resistor module, a common mode rejection circuit and an analog-to-digital converter. The voltage-dividing resistor module generates a first and a second divided voltages according to a voltage source. The common mode rejection circuit receives the first and the second divided voltages to perform a common-mode noise rejecting process to generate an output voltage. The analog-to-digital converter converts the output voltage to generate a digital data signal. The two optic-fiber transmission lines transmit the digital data signal and a clock signal respectively. The control device receives the digital data signal from the analog-to-digital converter and the clock signal to perform a digital data processing.

Abstract: A voltage sampling system is provided. The voltage sampling system includes a first and a second input paths and a signal-processing module. The first input path includes a first input voltage-dividing resistor unit, a second input voltage-dividing resistor unit and a first DC voltage-dividing resistor unit to generate a first input divided voltage and a first DC bias voltage to further generate a first sampled voltage signal according to a first input voltage and a DC voltage source. The second input path includes a third input voltage-dividing resistor unit, a fourth input voltage-dividing resistor unit and a second DC voltage-dividing resistor unit to generate a second input divided voltage and a second DC bias voltage to further generate a second sampled voltage signal according to a second input voltage and the DC voltage source. The signal-processing module receives the first and the second sampled voltage signals to perform signal processing.

Abstract: The present disclosure provides a voltage-adjusting device applied in a power conversion system including a Vienna rectifier, a direct current (DC) bus, and an inverter. The voltage-adjusting device includes a grid voltage sampling module for sampling a grid voltage, a given bus voltage calculation module, a voltage-adjusting module, a current control module and a pulse width modulation module. The given bus voltage calculation module calculates a given value of the DC bus voltage based on the grid voltage. The current control module receives a three phase AC current from the grid, the active current given signal and the reactive current given signal to output a three phase control voltage. The pulse width modulation module outputs a pulse control signal to the Vienna rectifier.

Abstract: A method for detecting a short circuit fault in a multi-level inverter circuit is provided. The multi-level inverter circuit includes a plurality of single phase branches each including of switches. The method includes steps outlined below. At least one detecting pulse sequence is transmitted to the switches of each of the single phase branches. Whether a conducting path is formed in any of the single phase branches is determined according to the detecting pulse sequence. When the conducting loop is formed, respective position of one or more malfunctioned switch in the single phase branches is located according to a path of the conducting loop. A short-circuit detection device and a three-phase three-level inverter circuit are also disclosed herein.

Abstract: A variable frequency speed control system having a low voltage ride through function that includes a variable frequency drive having a rectifier, a DC bus and an inverter is provided. The variable frequency speed control system includes a voltage drop detecting module, a frequency control module, an operation mode selecting module and an inverter control module. The voltage drop detecting module generates a voltage drop coefficient according to a grid voltage and a rated grid voltage and generates an operation mode switching signal. The operation mode selecting module receives a target frequency signal and a frequency decreasing amount and generates an output frequency signal according to the operation mode switching signal. The inverter control module generates a three phase modulating signal according to the output frequency signal, which is used to control the operation of the inverter.

Abstract: A converter circuit is provided. The converter circuit includes a capacitor module, bridge arms, a voltage measuring module and an open-circuit detection module. Each bridge arm is connected to the capacitor module in parallel and includes an upper arm and a lower bridge arm connected at a middle point. The voltage measuring module measures voltage differences between each two bridge arms. The open-circuit detection module transmits test impulse signals to the bridge arms to activate at least one upper-conducted bridge arm and at least one lower-conducted bridge arm. The open-circuit detection module retrieves the voltage differences of each pair of the upper-conducted and lower-conducted bridge arms to make comparison with a reference value to determine an operation state thereof, and makes comparison of the operation state determined according to the different groups of test impulse signals to determine whether the upper and the lower bridge arms are actually open circuit.

Abstract: The disclosure provides a power converter including a cabinet, a first converter circuit module, a second converter circuit module, and a DC capacitor module. The first converter circuit module includes at least one first bridge arm. The second converter circuit module includes at least one second bridge arm. The first converter circuit module, the second converter circuit module, and the DC capacitor module are disposed in the cabinet. The second bridge arm and the first bridge arm are arranged side by side in parallel. The DC capacitor module is electrically connected between the first bridge arm and the second bridge arm, so that the first bridge arm and the second bridge arm share the DC capacitor module.

Abstract: A direct-current capacitor module is disclosed in this disclosure. The direct-current capacitor module includes a plurality of direct-current capacitors and a laminated busbar structure. The direct-current capacitors are grouped into a first portion and a second portion. The laminated busbar structure is electrically connected to capacitor binding posts of the direct-current capacitors. The laminated busbar structure has a positive terminal and a negative terminal. The laminated busbar structure includes a first busbar layer, a second busbar layer and an insulation layer. The first busbar layer includes a first sub-busbar layer, which is electrically connected between at least two direct-current capacitors of the first portion. The second busbar layer includes a second sub-busbar layer, which is electrically connected between at least two direct-current capacitors of the second portion. The insulation layer is disposed between the first busbar layer and the second busbar layer.

Abstract: A three-level rectifier includes at least one phase bridge arm that includes an upper-half and a lower-half bridge arm circuit modules. The upper-half bridge arm circuit module includes a first diode unit and a second diode unit that are in series connection, and a first power semiconductor switch unit. The lower-half bridge arm circuit module includes a third diode unit and a fourth diode unit that are in series connection, and a second power semiconductor switch unit. These first and second power semiconductor switch units are connected to the neutral point of the capacitor unit; the second diode unit and the third diode unit are connected to the alternating-current terminal; the first diode unit and the fourth diode unit are respectively connected to the positive terminal and negative terminal of the direct-current bus. The two circuit modules are disposed side by side and facing each other.

Abstract: A control circuit, control method used in a PFC circuit and the power source system thereof are disclosed herein. The control circuit comprises: a zero current detection circuit having a polarity detection circuit for outputting a first and a second digital signals and a signal conversion circuit for generating an analog signal; a feedback circuit for generating a driving pulse signal; and a pulse distribution circuit for distributing the driving pulse signal to a first and a second switches according to the first and the second digital signal. After a switch cycle, one of the first and the second switch performs an ON operation for the next switch cycle when the current flowing through the inductor decreases to a predetermined threshold value, wherein an ON time of the first switch is equal in each switch cycle, and an ON time of the second switch is equal in each switch cycle.

Abstract: A control circuit, control method used in a PFC circuit and the power source system thereof are disclosed herein. The control circuit comprises: a zero current detection circuit having a polarity detection circuit for outputting a first and a second digital signals and a signal conversion circuit for generating an analog signal; a feedback circuit for generating a driving pulse signal; and a pulse distribution circuit for distributing the driving pulse signal to a first and a second switches according to the first and the second digital signal. After a switch cycle, one of the first and the second switch performs an ON operation for the next switch cycle when the current flowing through the inductor decreases to a predetermined threshold value, wherein an ON time of the first switch is equal in each switch cycle, and an ON time of the second switch is equal in each switch cycle.

Abstract: A three-level converter includes at least one phase bridge arm, each including an upper-half and a lower-half bridge arm circuit modules. The upper-half bridge arm circuit module includes a first and a second switch units that are in series connection, and a first diode unit. The lower-half bridge arm circuit module includes a third and a fourth switch units that are in series connection, and a second diode unit. The first and second diode units are connected to the neutral point of the capacitor unit; the second and third switch units are connected to the alternating-current terminal; The first and the fourth switch unit is respectively connected to the positive terminal and negative terminal of the direct-current bus; the capacitor unit is connected to the direct-current bus between the positive and negative terminals. The two modules are disposed side by side and facing each other.

Abstract: Disclosed herein is a five-level rectifier that includes first, second, third, fourth power semiconductor switches, first and second DC bus capacitors, a phase capacitor, and first, second, third and fourth diode modules. The first, second, third and fourth diode modules are connected in series, the first and second DC bus capacitors are connected in series, and the second and third power semiconductor switches are connected in series. The first diode module is connected to the first DC bus capacitor and the first power semiconductor switch, and the fourth diode module is connected to the second DC bus capacitor and the fourth power semiconductor switch. The phase capacitor has a terminal connected to the first and second power semiconductor switches, and another terminal connected to the third and fourth power semiconductor switches.

Abstract: The present invention provides a high-power medium-voltage drive power cell, which comprises: a rectifier module for rectifying the three-phase AC input voltage to get a DC voltage; an IGBT (Insulated Gate Bipolar Transistor) inverter bridge connected to capacitors for converting the DC voltage into an AC voltage of which the frequency, the amplitude and the phase are adjustable; a bypass module connected to the IGBT inverter bridge for providing the bypass function when the IGBT inverter bridge works in an abnormal state; and a heat pipe heat sink having a base plate on both sides of which power elements of the high-power medium-voltage drive power cell are disposed.

Abstract: A power factor correction (PFC) circuit includes an AC power, a first bridge arm and a second bridge arm. The first bridge arm includes first and second switches connected in series with each other. A second terminal of the first switch is connected to a first terminal of the second switch, and coupled to a first end of the AC power via a first inductor. The second bridge arm includes third and fourth switches connected in series with each other. A second terminal of the third switch is connected to a first terminal of the fourth switch and a second end of the AC power. The third and fourth switches operate in ON/OFF states by use of a control signal having an operation frequency consistent with that of the AC power. The on-state resistance of the third and fourth switches is lower than that of the first or second switch.

Abstract: A DC/DC converter, a power converter and a control method thereof are disclosed, wherein the DC/DC converter includes an output circuit, a rectangular wave generator, a resonant tank, a detection unit and a control unit. The output circuit has a load. The rectangular wave generator converts an input voltage into driving pulses. The resonant tank provides a first voltage based on the driving pulses for the output circuit. The detection unit detects a signal related to a state of the load. When the state of the load is a light-load or a no-load, the control unit controls the rectangular wave generator in a hiccup mode to reduce a ratio of a work period to a stop period, or makes that number of the driving pulses within the current work period is less than the number of the driving pulses when a duty ratio is 50%.

Abstract: A DC/DC converter, a power converter and a control method thereof are disclosed, where the DC/DC converter includes an output circuit having a load, a rectangular wave generator having a bridge arm, a resonant tank, a detection unit and a control unit. The bridge arm includes a first and a second switches connected each other. The detection unit detects a signal related to a state of the load. When the state of the load is a light-load or a no-load, the control unit controls ON/OFF state of the first and second switches by pulse width modulation mode to convert an input voltage into at least one rectangular wave for the resonant tank. A duty ratio of the first switch is within a first or second predetermined range, and a duty ratio of the second switch is complementary to the duty ratio of the first switch, whereby a voltage gain of the DC/DC converter is greater than 1.

Abstract: A switch-driving circuit suitable for driving a full-controlled power switch combination is disclosed. The switch-driving circuit includes a first pulse-width modulator, a high-voltage isolation pulse transformer module and a plurality of output modules. The high-voltage isolation pulse transformer module includes a magnetic core connected to multiple output modules in a one-to-many way, or includes multiple magnetic cores connected to multiple output modules in a one-to-one way. Each output module includes a second pulse-width modulator and a driving-power amplifier. The full-controlled power switch combination includes a plurality of full-controlled power switches. The driving-power amplifier is coupled between the second pulse-width modulator and one of the full-controlled power switches.

Abstract: The present invention provides a power switch series circuit and its control method. The power switch series circuit includes a plurality of series modules, a control module and a drive module. At least one series module has a power switch and a detection module, and the detection module includes a detection unit and an isolation unit, so as to detect the overvoltage and output a voltage detection signal based on the detected voltage. The control module receives the voltage detection signal and outputs the corresponding control signal. The drive module amplifies the control signal to drive each power switch to turn ON or turn OFF. The control module outputs the corresponding control signal to turn off each power switch when the overvoltage happens.