Two inverters (10) provided at respective both ends of open-end windings (8) are appropriately controlled. As control regions (R) of a rotating electrical machine (80), a first speed region (VR1) and a second speed region (VR2) in which the rotational speed of the rotating electrical machine (80) is higher than in the first speed region (VR1) for the same torque are set, and in the second speed region (VR2), a rotating electrical machine control device (1) controls both inverters (10), a first inverter (11) and a second inverter (12), by mixed pulse width modulation control in which control is performed such that a plurality of pulses with different patterns are outputted during a first period (T1) which is a half cycle of electrical angle, and an inactive state continues during a second period (T2) which is the other half cycle.

The present disclosure provides an optimization method, a unit, and an electronic device of a shifted frequency (SF)-based electromagnetic transient simulation, comprising: determining a current amplitude and a voltage frequency based on a node voltage and a branch current calculated from a shifted frequency on a basis of a current time step; determining an optimal shifted frequency of the current time step based on the current amplitude and the voltage frequency; and updating the shifted frequency by adopting the optimal shifted frequency of the current time step for calculating a node voltage and a branch current of the next time step. The method, the unit, and the electronic device provided in the present disclosure may gradually update and optimize the shifted frequency in the simulation process so to enable the shifted frequency to reach the best, thus ensuring the accuracy of output current and voltage simulation results.

Methods and apparatus for providing DC motor gate driver isolation. In embodiments, first and second DC input signals are received at a supply control module, which generates first and second control signals for controlling first and second switches. A first transformer has a primary winding having one end coupled to the first DC input signal and another end coupled to the first switch A second transformer has a primary winding having one end coupled to the second DC input signal and another end coupled to the second switch. The supply control module controls the first and second control signals so that a secondary winding of the first or second transformer energizes an isolated AC bus coupled to the first and second transformers. First and second gate drivers receive respective isolated AC signals from the isolated AC bus. Conversion of the isolated AC signals back to DC occurs at the point of use.

The present disclosure provides an optimization method, a unit, and an electronic device of a shifted frequency (SF)-based electromagnetic transient simulation, comprising: determining a current amplitude and a voltage frequency based on a node voltage and a branch current calculated from a shifted frequency on a basis of a current time step; determining an optimal shifted frequency of the current time step based on the current amplitude and the voltage frequency; and updating the shifted frequency by adopting the optimal shifted frequency of the current time step for calculating a node voltage and a branch current of the next time step. The method, the unit, and the electronic device provided in the present disclosure may gradually update and optimize the shifted frequency in the simulation process so to enable the shifted frequency to reach the best, thus ensuring the accuracy of output current and voltage simulation results.

Methods and apparatus for providing DC motor gate driver isolation. In embodiments, first and second DC input signals are received at a supply control module, which generates first and second control signals for controlling first and second switches. A first transformer has a primary winding having one end coupled to the first DC input signal and another end coupled to the first switch A second transformer has a primary winding having one end coupled to the second DC input signal and another end coupled to the second switch. The supply control module controls the first and second control signals so that a secondary winding of the first or second transformer energizes an isolated AC bus coupled to the first and second transformers. First and second gate drivers receive respective isolated AC signals from the isolated AC bus. Conversion of the isolated AC signals back to DC occurs at the point of use.

To provide a controller for a rotary electric machine capable of suppressing occurrence of an angle interval when the rotary electric machine cannot output torque, even if the ON angle interval of the switching devices is set smaller than 120 degrees in the rectangular wave control. A controller for a rotary electric machine performs a rectangular wave control to a rotary electric machine which has 2 groups of three-phase windings, with a phase difference between groups; and switches a first control mode and a second control mode according to a switching condition; wherein the first control mode is a mode which sets an ON angle interval to an angle within a range from 120 degrees to 180 degrees; and wherein the second control mode is a mode which sets the ON angle interval to an angle within a range from 90 degrees to 120 degrees.

A driving device is provided with an output unit, an input unit, a rectifier circuit, a switching circuit and a controller. The input unit inputs an AC in put. The rectifier circuit has a smoothing capacitor and converts the AC input into a rectified output. The switching circuit switches between an ON-state in which input impedance is low and an OFF-state in which input impedance is higher than that in the ON-state. The controller sets a start timing such that, when controlling the switching circuit to switch between the ON-state and the OFF-state, at least a portion of a period, in which the start timing of a power supply period becomes a second timing, is included in a period from a time when an input current inputted to the smoothing capacitor is generated to a time when the voltage of the smoothing capacitor reaches a maximum value.

The present invention relates to a fan motor driving circuit, a driving method, and a cooling device and an electronic machine using the same. The present invention provides a motor driving circuit capable of suppressing strain on coil current and/or reducing noise. A control circuit a control circuit switches an output phase of an H-bridge circuit based on a Hall signal, and in a soft switching duration (Tss) that starts before and ends after the output-phase switching, slowly varies a duty ratio (DUTY1) of an output voltage (V.sub.OUT1) of one leg of the H-bridge circuit over time, and meanwhile, varies a duty ratio (DUTY2) of an output voltage (V.sub.OUT2) of another leg of the H-bridge circuit in an opposite direction with respect to the duty ratio (DUTY1) of the output voltage (V.sub.OUT1) of the one leg.

API duty calculation unit of a microcomputer that performs control at a predetermined control period calculates a duty ratio of a voltage applied to a coil of a motor from a target rotation speed and an actual rotation speed calculated by a number-of-rotation information unit. The PI duty calculation unit generates a rectangular wave signal having a period according to one frequency selected from plural predetermined frequencies together with the start of one control period and indicating the calculated duty ratio, and outputs the rectangular wave signal to a PWM duty calculation unit. The PWM duty calculation unit generates a PWM signal for controlling an inverter circuit based on the rectangular wave signal output by the PI duty calculation unit and position information of a rotor of the motor calculated by an electrical angle position information unit.

Two inverters (10) provided at respective both ends of open-end windings (8) are appropriately controlled. As control regions (R) of a rotating electrical machine (80), a first speed region (VR1) and a second speed region (VR2) in which the rotational speed of the rotating electrical machine (80) is higher than in the first speed region (VR1) for the same torque are set, and in the second speed region (VR2), a rotating electrical machine control device (1) controls both inverters (10), a first inverter (11) and a second inverter (12), by mixed pulse width modulation control in which control is performed such that a plurality of pulses with different patterns are outputted during a first period (T1) which is a half cycle of electrical angle, and an inactive state continues during a second period (T2) which is the other half cycle.