A switching mode power supply including: a power input unit configured to receive an input alternating current (AC) voltage; a rectification unit configured to rectify the input AC voltage; a condenser configured to smooth the rectified input AC voltage; a current detection unit configured to detect a surge current flowing in the condenser; and a converter including switching elements, the converter being outputting a direct current (DC) voltage based on a voltage applied to first and second ends of the condenser and on/off duty ratios of the switching elements. The switching elements are configured to be turned off based on the surge current being detected by the current detection unit.

An electronic circuit comprises a power switch circuit and a fault detection circuit. The power switch circuit includes a transistor. The fault detection circuit includes a first comparator circuit configured to compare a monitored voltage of the transistor to a detection threshold voltage and produce an indication of a circuit fault according to the comparing, and a delay circuit configured to delay the comparing by the first comparator circuit according to slew rate of the monitored voltage.

A method and a circuit for complying with specified maximum values for output parameters a power supply unit includes at least a non-floating switch converter, an output voltage control unit, a current limiter and a switch element, wherein actual values of the current and voltage outputs of the power supply unit are measured continuously, where an evaluation unit calculates actual output power values of the power supply unit from the actual measured values of the output current and voltages, and subsequently compares at least the respective actually measured values of the output current and the respective actually calculated output power values with specified maximum values such that if at least one of the specified maximum values is exceeded by an actually measured value of the output current and/or by an actually calculated output power value, a current flow in the power supply unit is then interrupted by the evaluation unit.

An electronic circuit comprises a power switch circuit and a fault detection circuit. The power switch circuit includes a transistor. The fault detection circuit includes a first comparator circuit configured to compare a monitored voltage of the transistor to a detection threshold voltage and produce an indication of a circuit fault according to the comparing, and a delay circuit configured to delay the comparing by the first comparator circuit according to slew rate of the monitored voltage.

The present invention discloses a bypass thyristor valve group inspection method and control apparatus for inspecting sub-modules in a bypass thyristor valve group, and in particular, including: dividing the bypass thyristor valve group into N sub-modules, where N is greater than or equal to 2, N is a natural number, and each sub-module is formed by connecting one or more thyristors in series; under the condition that the bypass thyristor valve group bears a normal forward voltage, sequentially triggering, by the bypass thyristor valve group control apparatus, the sub-modules according to a certain time period; detecting whether the sub-modules are capable of operating normally or not; and if not, sending an alarm signal. According to the bypass thyristor valve group inspection method and control apparatus, the problem of thyristor performance monitoring under the condition that the bypass thyristor valve group does not operate for a long time is effectively solved, and safety in operation of a protected voltage source current converter is guaranteed.

A power converter monitor having built-in fault tolerance and containment including a plurality of voltage inputs operatively connected to a pulse timing device, a respective comparator electrically connected to each of the voltage inputs, an and-gate electrically connected in series to each of the comparators and wherein the pulse timing device is operatively connected by the and-gate and a-not gate to each of the voltage inputs configured to reset a detected voltage output fault and provide a converter inhibit pulse if the voltage output fault is detected.

A monitoring apparatus has a control apparatus for monitoring a cooling apparatus for a power electronics arrangement. The control apparatus has an input and an output, which input is configured to receive a temperature signal from a temperature sensor, and to determine a temperature value depending on the temperature signal, and which output is configured to output an output signal. The control apparatus performs the following steps: ascertaining at least twice a temperature value and a time value assigned to the temperature value, ascertaining a difference quotient of the change in the temperature values to the change in the assigned time values, determining the state of the cooling apparatus of the power electronics arrangement depending on the ascertained difference quotient, outputting the output signal depending on the state in order to influence the power electronics arrangement.

An apparatus includes a pulsed-width modulation signal corresponding to a cutoff voltage, a periodic signal generation circuit, a comparator, and logic. The comparator is configured to compare a voltage input with an output of the periodic signal generation circuit and, based on a comparison of the voltage input with the output of the periodic signal generation circuit, generate another pulsed-width modulation signal. The logic is configured to compare the pulsed-width modulation signal and the other pulsed-width modulation signal to determine whether the voltage input has reached the cutoff voltage.

A circuit for measuring temperature of an external switch is disclosed. The circuit includes a variable resistor, a switch coupled to the variable resistor in series, a fixed value resistor coupled to the variable resistor and a comparator coupled between the variable resistor and the fixed value resistor. The circuit is configured to compare voltage drop between a drain and a source of the external switch when the external switch is in ON state with voltage drop at the variable resistor and output a signal to indicate an overtemperature based on the comparing.

An overcurrent detection circuit includes a di/dt detection circuit to detect di/dt of a current Ie that flows in an emitter of an IGBT, a control circuit to detect whether the current Ie is an overcurrent based on di/dt and to output a detection result to a driving circuit, and a mask circuit to set a mask period in which an operation of overcurrent determination in the control circuit is masked.