This power conversion device has: a current measurement unit for measuring phase current; a current vector calculation unit for calculating a current vector by performing 3-phase to 2-phase conversion on the phase current; an amount-to-be-analyzed calculation unit for calculating, on the basis of the current vector, an amount to be analyzed; and a feature amount waveform extraction unit for extracting a waveform in a specific frequency range on the basis of the amount to be analyzed.

A circuit includes processing circuitry is sensitive to a regulated voltage at the output node and to a temperature of the circuit. The processing circuit is configured to provide voltage and temperature sensing signals indicative of the regulated voltage at the output node and the temperature of the circuit. The processing circuitry is configured to assume i) a first state, as a result of the voltage sensing signal reaching a voltage threshold, ii) a second state, as a result of the temperature detection signal reaching a temperature threshold, or iii) a third state, as a result of both the voltage and the temperature sensing signals failing to reach the thresholds. The circuit comprises a warning output coupled to a warning signal generation network controlled by the processing circuitry.

An electrical protection circuit breaker comprises a microprocessor chip part, a circuit breaker part connected between a power line and a power supply, a temperature detection part for detecting a temperature of the power line, a current detection part for detecting a current of the power line, and a voltage detection part for detecting a voltage of the power line. A memory of the microprocessor chip part stores a data collection S=f(temp, I, V, Δtime), wherein S represents a diameter of the power line, temp represents the temperature, I represents the current, V represents the voltage, and Δtime represents a set time period. The microprocessor chip part matches electronic data of real-time temperature changes, electronic data of an import current, and electronic data of a voltage with data sets in the data collection, and sets a corresponding safety protection current according to matching results.

Provided is a power conversion device capable of directly performing a protection operation according to the state of a cooler. A control unit includes: a semiconductor switching element loss calculation unit which calculates a loss in a semiconductor switching element with use of a switching state of the semiconductor switching element, and a current detection value or a voltage detection value; and a cooler state estimation unit which estimates a state of a cooler on the basis of a loss calculation value from the semiconductor switching element loss calculation unit and a temperature detection value from a temperature detector. The control unit limits current flowing to the semiconductor switching element on the basis of the state of the cooler.

An improved electric circuit structure for short circuit protection is applicable to examining a device under test, comprising a circuit breaking element, a thermistor, a filtering and rectifying module and a capacitor. A first end of the circuit breaking element is connected to a power source. The filtering and rectifying module is connected to a second end of the circuit breaking element, a ground, a first end of the thermistor and a first end of the capacitor. A second end of the capacitor is connected to a second end of the thermistor. The capacitor is connected in parallel with the device under test. The circuit breaking element disclosed in the present invention is a ceramic tube fuse and forms an open circuit when the device under test forms a short circuit. Meanwhile, the ceramic tube fuse withstands voltage between its first and second end without generating any physical damage.

Current absorption management for an electronic fuse coupled between an electrical supply source node and an electrical load node selectively controls a high current electronic switch and a low current electronic switch coupled in parallel between the electrical supply source node and the electrical load node. The high current and low current electronic switches are alternatively actuated: in a first mode where the high current electronic switch is turned on and the low current electronic switch is turned off, and in a second mode where the high current electronic switch is turned off and the low current electronic switch is turned on. Change to the second mode may be made in response to a standby state or a sensing of a lower current in the electrical load. Conversely, change to the first mode may be made in response to a sensing of a higher current in the electrical load.

A power supply system includes: a battery; a master device supplied with power from the battery; and a slave device supplied with power from the master device via a first power supply line. The slave device supplies power to a load via a second power supply line. The master device estimates a temperature of the second power supply line. When the estimated temperature of the second power supply line is higher than a second cutoff threshold, power supply via the second power supply line is cut off.

An improved electric circuit structure for short circuit protection is applicable to examining a device under test, comprising a circuit breaking element, a thermistor, a filtering and rectifying module and a capacitor. A first end of the circuit breaking element is connected to a power source. The filtering and rectifying module is connected to a second end of the circuit breaking element, a ground, a first end of the thermistor and a first end of the capacitor. A second end of the capacitor is connected to a second end of the thermistor. The capacitor is connected in parallel with the device under test. The circuit breaking element disclosed in the present invention is a ceramic tube fuse and forms an open circuit when the device under test forms a short circuit. Meanwhile, the ceramic tube fuse withstands voltage between its first and second end without generating any physical damage.

A semiconductor device includes a power semiconductor switch; a logic circuit connected to an input terminal; an overheat detection circuit that outputs to the logic circuit an overheat detection signal when a temperature of the power semiconductor switch exceeds an overheat detection threshold; and an overcurrent detection circuit that monitors a current that flows through the power semiconductor switch and that outputs to the logic circuit and to the overheat detection circuit an overcurrent detection signal when the current that flows through the power semiconductor switch exceeds a prescribed threshold, wherein in the overheat detection circuit, the overheat detection threshold values is changed from a first threshold value to a second threshold value that is lower than the first threshold value when the overheat detection circuit receives the overcurrent detection signal from the overcurrent detection circuit.

A fault detection apparatus includes a temperature detection unit, a current detection unit, a controller, and a breaking unit. The temperature detection unit is configured to detect temperatures of the plurality of filter capacitors and output the temperatures to the controller. The current detection unit is coupled to the plurality of filter capacitors and is configured to detect currents of the plurality of filter capacitors and output the currents to the controller. The controller is separately connected to the temperature detection unit, the current detection unit, and the breaking unit, and is configured to: when the received temperature exceeds a first threshold and the received current exceeds a second threshold, control the breaking unit to be disconnected. The breaking unit is connected between the output end of the grid-tied inverter and the plurality of filter capacitors and is configured to be disconnected or connected under control of the controller.