According to some embodiments, AC chopping circuit includes a switching circuit, a synchronizing signal generating circuit, a switch driving circuit and an auxiliary power supplying circuit. In some examples, the switching circuit are coupled to an AC power source and a load. In certain examples, the synchronizing signal generating circuit provides a synchronizing signal which is related to a polarity of the AC power source. In some examples, the switching circuit is controlled based at least in part on the synchronizing signal.

A load protection and control apparatus (1) for protecting and controlling an electrical load connected to the load protection and control apparatus (1) comprising an overcurrent protection circuit (1A) having a power switch (5) through which the electrical load receives an electrical load current (I.sub.L) and having a sensor component (4) connected in series with the power switch (5) and adapted to generate directly a voltage drop (ΔU.sub.4) corresponding to the current rise speed of the electrical load current (I.sub.L) flowing from an input terminal (2) of the load protection and control apparatus (1) via the sensor component (4) and the power switch (5) to the output terminal (3) and having a driver circuit (6) adapted to detect an occurring overcurrent depending on the voltage drop (ΔU.sub.4) generated by the sensor component (4) and/or depending on a voltage drop (ΔU.sub.5) along the power switch (5) and adapted to switch off said power switch (5) upon detection of an overcurrent within a switch-off period of less than one millisecond; and/or comprising a power supply control circuit (10) having a sensor component (9) adapted to measure at the input terminal (2) a supply voltage (U) notified to a control unit (8) of the load protection and control apparatus (1) adapted to control an electrical power supplied to the electrical load, wherein each input terminal (2) is configured to establish an electrical connection with a busbar (14) of a busbar system or with a current carrying wire.

A power-conversion device and a ground-fault-location-diagnosis method for determining ground-fault locations on a motor and a cable are disclosed. The power-conversion device includes a ground-fault-current-measurement unit, an interphase short-circuit current-measurement unit, and a ground-fault-location-determination unit. The ground-fault-current-measurement unit turns on all switches of either upper arms or lower arms of three half-bridge circuits, and measures output current values of a plurality of phases generated during the ON period. The interphase short-circuit-current-measurement unit turns on a switch of an upper arm of one phase of the three half-bridge circuits and a switch of a lower arm of a phase different from the one phase, and measures output current values of a plurality of phases generated during a period of time both switches are ON. The ground-fault-location-determination unit determines a ground-fault location based on output-current values measured by the ground-fault-current-measurement unit and the output-current values measured by the interphase short-circuit current-measurement unit.

A current detection unit includes current detection elements provided to phases on a high potential side of an upper arm element or on a low potential side of a lower arm element. A detection target element is the upper arm element or the lower arm element to which the current detection elements are provided. A target duty is a duty ratio of the detection target element. The control unit includes a current acquisition unit, an energization control unit, and an abnormality determination unit. The current acquisition unit acquires a current detection value from the current detection unit. The abnormality determination unit performs an abnormality determination based on the current detection value. The abnormality determination unit varies a determination threshold, which is used for the abnormality determination based on the current detection value, according to the target duty.

A direct-current power supply device includes a reactor, a bridge circuit that converts alternating-current voltage output from an alternating-current power supply, which is connected to the reactor, into direct-current voltage, a capacitor that smoothes the output voltage of the bridge circuit, a current detector that detects a first current flowing as an alternating current between the alternating-current power supply and the bridge circuit, a current detector that detects a second current flowing as a direct current between the bridge circuit and the capacitor, an overcurrent determination unit that determines on the basis of a detected first current value whether or not the first current is an overcurrent, and an overcurrent determination unit that determines on the basis of a detected second current value whether or not the second current is an overcurrent. The bridge circuit stops operating when a determination result of either the overcurrent determination unit or the overcurrent determination unit indicates an overcurrent.

A drive circuit drives a power semiconductor element including a control terminal, a first main electrode, and a second main electrode. The drive circuit includes a first switching-off circuit and a second switching-off circuit each for turning off the power semiconductor element. The second switching-off circuit is lower in impedance than the first switching-off circuit. In a case where the power semiconductor element is turned off, only the first switching-off circuit operates when the power semiconductor element is in an unusual state, and the first switching-off circuit and the second switching-off circuit complementarily operate when the power semiconductor element is in a normal state.

A torque-limiting safety circuit servo drive for AC permanent magnet motors including a three-phase inverter bridge, a first current sensor in series with a first motor phase, a second current sensor in series with a second motor phase, a third current sensor in series with the DC bus, and a drive control circuit that controls the six pulse-width modulated gate drive signals for the three-phase inverter bridge. The drive circuit has first and second safety channel STO inputs whereby either channel can shut down the three-phase inverter bridge, emits a signal set to represent the switching state of the three-phase inverter bridge, and modifies the switching pattern of the PWM to ensure the dwell times of PWM is sufficiently long to allow a valid measurement of phase current using the bus current sensor. First and second safety processors controls the first and second safety channel STO inputs, respectively.

This application provides a power supply system of a motor control module and a vehicle. The power supply system includes a first current limiting unit and an isolation unit. An output end of a first direct current power supply is coupled to a first input end of the isolation unit to form a first power supply loop with the isolation unit. A first output end of a second direct current power supply is coupled to one end of the first current limiting unit. The other end of the first current limiting unit is coupled to a second input end of the isolation unit to form a second power supply loop with the isolation unit. The second power supply loop is connected in parallel to the first power supply loop.

To avoid the catastrophic failure of a drive, protection circuitry is configured to limit current in the DC bus capacitors. The drive may include an isolation circuit and a protection circuit having a comparator. The protection circuit may be configured to compare the voltage measured across a DC bus capacitor with a threshold voltage and activate the isolation circuit when the DC capacitor voltage exceeds the threshold voltage. The drive may also include a low voltage circuit coupled to the isolation circuit, where the low voltage circuit is configured to interrupt the bypass signal to disengage the bypass circuit and activate the precharge circuit when the isolation circuit is activated. Accordingly, the current in the drive and to the DC bus capacitors is limited by the precharge circuit when the voltage of a capacitor in the DC bus exceeds a threshold.

The present disclosure relates to a conversion circuit, an inverter, and a method of driving the inverter, wherein a switch is provided at an input terminal of a direct current (DC) link capacitor, so that power is charged in the DC link capacitor through a switching element at initial driving and charged in the DC link capacitor through a rectifier when a voltage level of the DC link capacitor is equal to or higher than a preset reference level, thereby limiting inrush current caused in the DC link capacitor through the switching element when the inrush current is caused.