An electric circuit device includes: a first electric component; a first case that accommodates the first electric component and has a cooling channel for cooling the first electric component and a discharge port of the cooling channel; a second case that accommodates a second electric component and has a communication channel that communicates with a discharge port of the cooling channel; a first seal portion that is provided in a peripheral edge part of a discharge port of the cooling channel and seals the first case and the first electric component; a second seal portion that is provided outside the first seal portion with respect to a discharge port of the cooling channel and seals the first case and the first electric component; a through hole that is provided in the first case between the first seal portion and the second seal portion of and penetrates the first case from the first electric component side to the second case side; and a wall that is provided on one of the first case and the second case to surround a periphery of a discharge port of the cooling channel, and the through hole is provided outside the wall.

A bus bar for a plurality of capacitor elements having an equal impedance includes a positive electrode bus bar and a negative electrode bus bar. The positive electrode bus bar and the negative electrode bus bar each includes a main bus bar and branch bus bars. The main bus bar is electrically connected to an electric circuit having a switching element. First ends of the branch bus bars are connected to the main bus bar at different positions, and second ends of the branch bus bars are connected to the capacitor elements. The branch bus bars are configured so that an impedance between the first end and the second end reduces as an impedance between a connecting portion of the main bus bar to the electric circuit and a connecting portion of the first end of the branch bus bar to the main bus bar increases.

A power converter includes an inverter, a converter, an electrical-machine busbar, an electrical-machine sensor, an electrical-machine-sensor housing, a converter, a converter busbar, a converter-sensor housing. The inverter supplies a three-phase alternating current to a rotating electrical machine. The converter converts a voltage between a direct current power supply and the inverter. The electrical-machine busbar passes a current between the inverter and the rotating electrical machine. The electrical-machine sensor detects the current flowing through the electrical-machine busbar based on a magnetic field. The electrical-machine-sensor housing accommodates the electrical-machine sensor and the electrical-machine busbar together. The converter sensor detects the current flowing through the converter based on a magnetic field. The converter-sensor housing is disposed apart from the electrical-machine-sensor housing, and accommodates the converter sensor and the converter busbar together.

A gate drive circuit according to an embodiment includes: a voltage detector that detects a voltage between a first terminal and a second terminal of a switching device; a delay circuit that outputs, with a delay for a predetermined time, a detected value of the voltage obtained from the voltage detector; and a first off-mode drive circuit and a second off-mode drive circuit that apply a control signal to a control terminal of the switching device for turning off the switching device, wherein the first off-mode drive circuit turns off the switching device faster than the second off-mode drive circuit, and stops its operation to turns off the switching device when the delayed voltage value output from the delay circuit exceeds a predetermined threshold value.

The invention relates to an inverter (110) comprising: a power module (116.sub.1-3) having at least one semiconductor switch (Q, Q′), and a control device (120) configured to control the power module (116.sub.1-3) and to estimate an internal temperature (T.sub.J) of the at least one semiconductor switch (Q, Q′) by means of a temperature model (122) being a polynomial of order three or more having, as arguments, operating parameters including: a switching frequency (F.sub.SW), a temperature (T.sub.S) of the power module (116.sub.1-3), an AC current (I) outputted by the power module (116.sub.1-3), and the DC voltage (Udc).

Disclosed in various embodiments of the present invention are an electronic device for adjusting a voltage and an operating method therefor. The electronic device comprises: at least one first converter for supporting a plurality of operating modes for changing voltage; a second converter supporting the plurality of operating modes and connected with the at least one first converter in series; and at least one processor, wherein the processor can be configured to determine an intermediate voltage between the at least one first converter and the second converter on the basis of an input voltage of the at least one first converter and an output voltage of the second converter, and control an operating mode of each of the at least one first converter and the second converter on the basis of the determined intermediate voltage. Other embodiments are also possible.

Provided is a power conversion device capable of observing a chip temperature with high accuracy without increasing a cost of the power conversion device mounted with a current sense element for observing a main current of a power device. A main control MOSFET 11, a current MOSFET 12, and a diode 13 connected to a source electrode 8 of the main control MOSFET 11 and a source electrode 9 of the current MOSFET 12 are mounted in a chip of a power device, a temperature measurement circuit 3 is connected to the source electrode 9 of the current MOSFET 12, and when the main control MOSFET 11 is in an off state, a forward current (I.sub.f) is caused to flow through the diode 13, and an anode potential is observed to measure the chip temperature.

A motor control device of the present invention is connected to a power converter for converting power from direct current power to alternating current power, and controls the drive of an alternating current motor that is driven using said alternating current power, and the motor control device is provided with: a carrier wave generator; a carrier wave frequency adjuster that adjusts the frequency of the carrier wave; and a gate signal generator that uses the carrier wave to pulse width modulate a voltage command according to a torque command, and generates a gate signal for controlling operation of the power converter, wherein the carrier wave frequency adjuster adjusts the voltage command and carrier wave phase difference to reduce eddy current loss generated in rotor magnets of the alternating current motor according to a d-axis current flowing to the alternating current motor and the rotational speed of the alternating current motor.

A power system may comprise a plurality of power sources, each connected to a corresponding power regulator. The power regulators may be connected in series or in parallel, and may form a string. Each power regulator may comprise input terminals connected to the corresponding power source, output terminals, and a power converter that may be configured to convert input power from the corresponding power source to output power. The power regulator may further comprise a regulator communications module that may be configured to receive a power regulation indication relating to regulating an operational characteristic of the power regulator. The regulator controller may be configured to instruct the power converter to increase or decrease the regulator operational characteristic based on the power regulation indication, and based on power production characteristics of the power regulator.

Controller and method for a power converter. For example, a controller for a power converter includes: a first terminal configured to receive a first terminal voltage; a second terminal configured to receive a second terminal voltage; a comparator configured to receive a first threshold voltage and the second terminal voltage and to generate a comparison signal based at least in part on the first threshold voltage and the second terminal voltage; and a switch configured to receive the first terminal voltage and the comparison signal, the switch being further configured to be closed to allow a current to flow out of the second terminal through the switch if the comparison signal is at a first logic level; wherein the comparator is further configured to: receive a first reference voltage as the first threshold voltage if the first terminal voltage is smaller than a second threshold voltage.