A high-voltage system including a high-voltage battery and a DC/DC converter, the high-voltage system having two different galvanically connected voltage levels with enabled DC/DC converters. A first measuring device detects the voltage of the high-voltage battery and a second measuring device detects the voltage at the output of the DC/DC converter. An insulation resistance measuring device may be configured to carry out insulation resistance measurements only when the DC/DC converter is disabled. A third measuring device may detect a voltage between a positive high voltage line and the ground and a fourth measuring device and a voltage between a negative high-voltage line and the ground. An insulation monitoring device may monitor the insulation resistances from data of the first to fourth measuring device at least when the DC/DC converter is enabled.

Various embodiments provide a direct current (DC)-DC converter circuit. The DC-DC converter circuit includes a control circuit to switch the DC-DC converter circuit between a charge state, a discharge state, and a tri-state mode. As part of a first control loop, the control circuit may switch the DC-DC converter between the charge state and the discharge state based on the output voltage to provide the output voltage with the target voltage level. Additionally, as part of a second control loop, the control circuit may switch the DC-DC converter between the charge state and the discharge state based on the current through an inductor of the DC-DC converter. The second control loop may provide overcurrent protection for the DC-DC converter. Other embodiments may be described and claimed.

Disclosed is an overvoltage protection circuit and method thereof. The overvoltage protection circuit includes a charge/discharge circuit configured to be charged or discharged based on a source voltage of a first transistor included in a non-isolated converter and a comparison circuit, based on a voltage charged in the charge/discharge circuit exceeding a threshold voltage, turn off a power supply circuit supplying power to the non-isolated converter.

A power supply system includes first and second power supply lines to respectively connect positive and negative electrode terminals of a load with a main power supply. First and second voltage detection lines are respectively connected to the first and second power supply lines via first and second resistances. First and second inspection power supplies respectively supply power and provide potential differences to the first and second voltage detection lines from the first and second power supply lines. Occurrence of a short circuit in one of the first and second voltage detection lines is recognized when corresponding one of the first and second inspection power supplies supplies power and a difference between a preset voltage and a voltage caused between the first and second voltage detection lines is a threshold value or more.

A system topology may use intentional signal injection to monitor one or more power supply circuits that may supply electrical power to components of the system. The system topology may include voltage monitoring circuitry to monitor the output of the power supply. In some examples, a power supply rail fault may happen either inside or outside of the power supply circuit, but not be detectable by the voltage monitoring circuitry. Injecting a check signal in the presence of an actual fault, may cause oscillations at the output node of the power supply detectable by the voltage monitoring circuitry. Once the check signal, combined with the fault signal, at the output node reaches the monitoring threshold detectable by the voltage monitoring circuitry, the voltage monitoring circuitry may output an indication of the fault to processing circuitry of the system.

Even when one power conversion device among a plurality of power conversion devices connected in parallel experiences a short circuit, the other power conversion devices having experienced no short circuit can be promptly restarted. Each power conversion device includes: a short circuit occurrence determination unit configured to determine, on the basis of a current value at an output terminal, whether or not a short circuit has occurred; a short circuit elimination determination unit configured to determine, on the basis of a current value and a voltage value at the output terminal, whether or not the short circuit has been eliminated; and a current interruption unit configured to, on the basis of determination by the short circuit occurrence determination unit and determination by the short circuit elimination determination unit, interrupt current that flows from a power conversion unit to the output terminal or cancel the interruption.

A switching mode power supply preventing false triggering of an over current protection due to a surge pulse. The switching mode power supply has a switch and an inductor. An inductor current flows through the inductor. The switching mode power supply turns off the switch and meanwhile starts timing for a preset period of time when the inductor current is larger than a preset value. The switch is kept off during the preset period of time and is then turned on when the preset period of time expires.

A converter apparatus includes: an AC/DC converter; a DC link capacitor connected to the converter; a voltage detection unit detecting the DC link voltage; a switching unit connecting or disconnecting between a power supply and the converter; a switching operation unit detecting an abnormality in a motor drive device including the converter apparatus and an inverter, and control the switching unit; a power supply monitoring unit detecting a voltage inputted to the converter to monitor a connection state between the power supply and the converter; a threshold value setting unit setting a threshold value to determine the presence or absence of a short circuit failure; and a short circuit failure detection unit determining that a short circuit failure has occurred, when the voltage of the DC link capacitor, immediately after the power supply is disconnected from the converter, is equal to or less than the threshold value.

A reverse polarity protection device includes a protection unit, a detection unit, and a control unit electrically connected between a power supply device and a load device. The detection unit is electrically connected to the power supply device for detecting the polarity of an output signal of the power supply device, and the control unit is electrically connected to the detection unit and the protection unit. The detection unit outputs a detection signal to the control unit according to a detection result of the polarity of the output signal. If the detection signal shows that the polarity of the output signal is reverse, the control unit will control the protection unit to form an open circuit between the power supply device and load device to stop transmitting the output signal of the power supply device to the load device and achieve a reverse polarity protection effect of the load device.

A power converter capable of performing over-voltage protection and over-temperature protection converts an input voltage into an output voltage. A power switch is connected in series with a primary winding between the input voltage and an input ground. A power controller with a multi-function pin controls the power switch to control a winding current through the primary winding. The power converter has a multi-purpose circuit with first and second resistors, a rectifier and a thermistor. A connection node makes the first and second resistors connected in series between two ends of an auxiliary winding. The rectifier and the thermistor are connected in parallel between the multi-function pin and the connection node. The power controller can perform over-voltage protection and over-temperature protection via the multi-purpose circuit and the multi-function pin.