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 compressor control apparatus includes a rectifier configured to rectify AC power to DC power; an inverter including a plurality of switching elements, configured to convert the DC power into a three-phase voltage according to a pulse width modulation (PWM) signal applied to the plurality of switching elements; a motor configured to receive a three-phase current based on the three-phase voltage; a current detector configured to detect a sum of a first phase current, a second phase current, and a third phase current supplied to the motor; and a controller configured to differently determine a duty ratio of the PWM signal applied to each of the plurality of switching elements, and to determine the first phase current, the second phase current, and the third phase current, respectively, based on the determined duty ratio and the sum of the currents detected from the current detector.

A frequency converter, includes: a DC link, wherein the DC link has a first connection pole at which a positive link potential is present during operation of the frequency converter, and a second connection pole at which a negative link potential is present during operation of the frequency converter; an inverter, wherein the inverter has a first connection pole at which a positive inverter potential is present during operation of the frequency converter, and a second connection pole at which a negative inverter potential is present during operation of the frequency converter; a resistive shunt which is looped in between the first connection pole of the DC link and the first connection pole of the inverter; a differential amplifier which is designed to generate a test voltage from a potential difference across the resistive shunt; and an evaluation unit which is designed to detect a ground fault based on the test voltage.

A power converter for transforming electrical power between direct current power and alternating current power is provided, as well as related methods and systems. The power converter comprises: a half-bridge inverter, a switching cell, and a connection branch connecting the half-bridge inverter to the switching cell. The half-bridge inverter comprises: first and second switches connected in parallel, and a first capacitor connected between the first and second switches. The switching cell comprises: a first pair of switches forming a first branch, a second pair of switches and a second capacitor forming a second branch; and a third capacitor connected between the first and second branches. The connection branch is coupled to the half-bridge inverter at a first point intermediate the first capacitor and the second switch, and coupled to the switching cell at a second point intermediate the first branch and the second capacitor.

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.

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.

A motor drive control device capable of reliably acquiring currents of coils of two phases by a one-shunt current detection system is provided. The motor drive control device includes: a motor drive unit including an inverter circuit; a single current detection circuit connected to a direct current line of the inverter circuit, and detecting a current flowing through the direct current line; and a control circuit unit performing analog-to-digital conversion processing of the current to take in the current, and performing PWM control on the motor drive unit. The control circuit unit acquires, from the current detection circuit, a detection result of a first current and a second current being currents of coils of two phases among coils of three phases in a half cycle of one PWM cycle, and, when the A/D conversion processing of at least one of the first current and the second current is unsuccessful, reacquires, in the same PWM cycle or a next or subsequent PWM cycle, a detection result of only the current unsuccessful in the A/D conversion processing, and performs the A/D conversion processing of the reacquired detection current.

A motor control device drives first and second motors for outputting torque in braking or non-braking direction in a vehicle brake device, includes: an electric power converter that includes first to third legs having positive and negative switch elements; and a control unit. When the control unit energizes from the positive switch element of the first or third leg to the negative switch element of the second leg, the first and second motors output the torque in a same direction. When an absolute value of current flowing or estimated to flow in at least one of the first motor and the second motor exceeds a current threshold, the control unit drives the positive and negative switch elements of the second leg.

A motor control device drives first and second motors for outputting torque in braking or non-braking direction in a vehicle brake device, includes: an electric power converter that includes first to third legs having positive and negative switch elements; and a control unit. When the control unit energizes from the positive switch element of the first or third leg to the negative switch element of the second leg, the first and second motors output the torque in a same direction. When an absolute value of current flowing or estimated to flow in at least one of the first motor and the second motor exceeds a current threshold, the control unit drives the positive and negative switch elements of the second leg.