A power conversion device capable of shortening the time required for acceleration of a motor and a metal processing device including the power conversion device are provided. Then, a power conversion device 10 includes a converter 100 configured to convert an AC voltage from outside to a DC voltage Vo and a converter controller 107 configured to control the converter 100. The converter 100 includes a voltage doubler circuit 104 configured to boost the DC voltage Vo when activated, and outputs the DC voltage Vo having a voltage value different in accordance with the activation and stop of the voltage doubler circuit 104. The converter controller 107 activates the voltage doubler circuit 104 at a first time that is earlier by a predetermined period than a second time at which a speed command value ω* of the motor 130 rises from a predetermined value.

In accordance with at least one aspect of this disclosure, a method for pulse width modulation control includes resolving a reference vector for any number of active space vectors to determine a voltage offset for the reference vector, adding the voltage offset to each active vector to determine a modified modulated signal to be added to a carrier signal, and controlling, with a control module, a switching circuit based at least in part on the modified carrier signal.

Examples include a method for controlling a variable speed drive driving an electric motor. The variable speed drive is connected to an electric power source and comprises a passive DC-link and an inverter stage controlled by a first controller of the variable speed drive. The passive DC-link is connected to the inverter stage. The method comprises running the electric motor to reach a steady-state operating point, measuring a plurality of values of current or voltage of the passive DC-link, and computing, by a second controller, a frequency spectrum of the DC-link based on the plurality of values of current or voltage measured. The method further comprises detecting a specific resonance frequency by comparing amplitudes of the frequency spectrum to a predetermined pattern, and modifying filter parameters of a digital filter of the DC-link or control parameters of a control law of the electric motor based on the specific resonance frequency.

To provide a control apparatus for AC rotary machine and an electric power steering apparatus which can reduce the error component of the current detection value close to the mechanical resonance period of AC rotary machine. A control apparatus for AC rotary machine detects currents which flow into three-phase windings at a current detection period which is a first natural number times of a carrier period; calculates current detection values, by performing a current addition processing which adds current detection values detected at this time, and current detection values detected before an addition period which is a second natural number times of the current detection period; and calculates the voltage command values of three-phase based on the current detection values after current addition processing, wherein the second natural number is set to a natural number that the addition period becomes the closest to the half period of the mechanical resonance period.

To provide a control apparatus for AC rotary machine and an electric power steering apparatus which can reduce the error component of the current detection value close to the mechanical resonance period of AC rotary machine. A control apparatus for AC rotary machine detects currents which flow into three-phase windings at a current detection period which is a first natural number times of a carrier period; calculates current detection values, by performing a current addition processing which adds current detection values detected at this time, and current detection values detected before an addition period which is a second natural number times of the current detection period; and calculates the voltage command values of three-phase based on the current detection values after current addition processing, wherein the second natural number is set to a natural number that the addition period becomes the closest to the half period of the mechanical resonance period.

A rotary electric machine control apparatus (1) suitably controls two inverters (10) connected to associated ends of open windings (8). The rotary electric machine control apparatus (1) performs target control involving: controlling a first one of the inverters (10), which is selected from a first inverter (11) and a second inverter (12), by rectangular wave control; and controlling a second one of the inverters (10) by special pulse width modulation control that is one type of pulse width modulation control. The special pulse width modulation control is a control method to produce a switching pattern (Su2+) that is based on a difference between a switching pattern resulting from the pulse width modulation control and a switching pattern (Su1+) resulting from the rectangular wave control when a target voltage is to be generated in the open windings (8).

A rotary electric machine control apparatus (1) suitably controls two inverters (10) connected to associated ends of open windings (8). The rotary electric machine control apparatus (1) performs target control involving: controlling a first one of the inverters (10), which is selected from a first inverter (11) and a second inverter (12), by rectangular wave control; and controlling a second one of the inverters (10) by special pulse width modulation control that is one type of pulse width modulation control. The special pulse width modulation control is a control method to produce a switching pattern (Su2+) that is based on a difference between a switching pattern resulting from the pulse width modulation control and a switching pattern (Su1+) resulting from the rectangular wave control when a target voltage is to be generated in the open windings (8).

According to one embodiment, a refrigeration cycle apparatus includes a motor which including a plurality of phase windings in a mutually unconnected state, a first inverter which controls application of electric power to one ends of the phase windings, a second inverter which controls application of electric power to the other ends of the phase windings, switches connected between the other ends of the phase windings, and a motor controller which selectively sets one of an open-windings mode and a star-connection mode. The motor controller sets, at the time of startup of the motor, the open-windings mode.

An electronic switch module for a power tool is provided including a housing, a trigger moveable relative to the housing, a magnet being moveable relative to the housing with the trigger along a movement axis, and a linear hall sensor fixed relative to the housing and intersecting the movement axis of the magnet. The linear hall sensor magnetically detects a linear position of the magnet along the movement axis and outputs a voltage signal based on the detected linear position.

An electronic switch module for a power tool is provided including a housing, a trigger moveable relative to the housing, a magnet being moveable relative to the housing with the trigger along a movement axis, and a linear hall sensor fixed relative to the housing and intersecting the movement axis of the magnet. The linear hall sensor magnetically detects a linear position of the magnet along the movement axis and outputs a voltage signal based on the detected linear position.