An electric-motor driving apparatus is used to drive an electric motor including a plurality of winding groups constituting a three-phase winding. The electric-motor driving apparatus includes a switch that switches connection of windings of a first winding group and a second winding group, an inverter that drives an electric motor, and a controller that controls the inverter and the switch.

A heat pump apparatus, including: a two-cylinder compressor including: an electric motor; two compression units to be driven by the electric motor, the two-cylinder compressor being structured to switch between two operation modes including single operation in which one of the compression units is brought into a non-compression state, and parallel operation in which both the compression units are brought into a compression state; an inverter drive control device supplying drive power to the electric motor of the two-cylinder compressor; an operation mode detecting-determining unit determining a current operation mode based on an electric signal acquired from the inverter drive control device; and a capacity control device determining a rotating frequency of the electric motor so that a temperature of a target object is brought close to a set value, to thereby control the inverter drive control device based on a result of determination of the operation mode detecting-determining unit.

A synchronous motor control device includes a voltage detector, a current detector, an inverter main circuit, and an inverter control unit. The inverter control unit includes: a phase current reproduction unit that reproduces a direct current into phase currents flowing to a permanent magnet synchronous motor; a current coordinate transformation unit that transforms the reproduced phase current into current on a control coordinate axis of a rotating coordinate system; a current control unit that calculates a voltage command value of the permanent magnet synchronous motor in such a manner that the current on the control coordinate axis equals a specific value; and a limiter unit that limits the value of the voltage command value.

A power converter includes: a converter circuit converting an alternating current to a direct current; a reactor electrically connected to one of output terminals of the converter circuit; a capacitor electrically connected to the other output terminal of the converter circuit and the reactor; and an inverter circuit electrically connected to the capacitor converting the direct current to an alternating current. The capacitor is a film capacitor. The capacitor and the reactor are mounted on an identical circuit board.

A heat pump apparatus includes: a compressor including a motor; an inverter that applies a desired voltage to the motor; a current detector that detects current flowing to the motor; a drive-signal generation unit that generates a drive signal for the inverter; a magnetic-pole position estimation unit that changes a voltage phase of a voltage command value for a high-frequency voltage, and estimates a maximum-heat-amount acquisition magnetic-pole position when the generation unit applies the high-frequency voltage to the motor to heat the compressor; a steady heating control unit that determines an amplitude and voltage phase of the voltage command value from the maximum-heat-amount acquisition magnetic-pole position and a defined necessary amount of heat when the generation unit applies the high-frequency voltage to the motor to heat the compressor; and a control switching determination unit that causes one of the estimation unit and the heating control unit to operate.

An inverter module according to an embodiment of the present invention comprises: a high voltage circuit unit which generates an inverter control voltage and a motor driving voltage by using a first DC voltage; a high voltage circuit pattern which electrically connects the high voltage circuit unit; a low voltage circuit unit which communicates with an external device by using a second DC voltage having a smaller magnitude than the first DC voltage; and a low voltage circuit pattern which electrically connects the low voltage circuit unit. The high voltage circuit pattern and the low voltage circuit pattern are spaced apart from each other.

A fan drive circuit for a variable speed fan motor in a cooling system, includes an inverter configured to supply a current signal to stator windings of the variable speed fan motor, a frequency detection circuit coupled to an output stage of an inverter of a compressor motor of the cooling system and configured to detect a first frequency of a compressor current signal at the output stage of a variable speed compressor drive circuit and generate a frequency signal, and a digital signal processor (DSP) coupled to the inverter and the frequency detection circuit. The DSP is configured to receive the frequency signal corresponding to the first frequency from the frequency detection circuit, select a second frequency corresponding to the first frequency at which to operate the variable speed fan motor, and transmit control signals to the inverter to supply current to the stator windings at the second frequency.

A system for operational acoustic optimization of a variable speed compressor (2) includes a motor (6), a frequency inverter (3), and a control block (5). The frequency inverter (3) is electrically connected to the synchronous motor (6), an electrical network (4), and the control block (5). The control block (5) is configured to control the speed of the motor (6) and to establish a first switching frequency (F1) and a second switching frequency (F2) of the frequency inverter (3). The frequency inverter (3) is configured to start the variable speed compressor (2) by supplying motor (6) with a signal (9) with the first switching frequency (F1) for the duration of a time period (T1) corresponding to at least one alignment operation period of the motor (6) and to supply the motor (6) with a signal (9) with the second switching frequency (F2) after the time period (T1).

An electric motor includes: a permanent magnet; a rotor including a first rotor core having a first electrical steel sheet and a second rotor core having a second electrical steel sheet; and a stator including a stator core. The first electrical steel sheet is located outside the stator core. A relationship among a minimum width BL1 of a first left bridge, a thickness tL1 of the first left bridge, a minimum width BR1 of a first right bridge, a thickness tR1 of the first right bridge, a minimum width BL2 of a second left bridge, a thickness tL2 of the second left bridge, a minimum width BR2 of a second right bridge, and a thickness tR2 of the second right bridge satisfies (BL1?tL1+BR1?tR1)>(BL2?tL2+BR2?tR2).

An air conditioning apparatus includes an electric compressor, an inverter, a temperature detection element, and an ECU. The electric compressor compresses a refrigerant drawn from a refrigerant intake port and discharges the refrigerant from a refrigerant discharge port. The inverter is integrated with the electric compressor so as to be cooled by the drawn refrigerant, and operates the electric compressor according to a control signal. The temperature detection element detects a temperature of the inverter. The ECU outputs a control signal to control the inverter. The ECU performs any one or both of a control for reducing a self-cooling amount of the electric compressor and a control for increasing a self-heat generation amount of the inverter with respect to the inverter when the temperature detected by the temperature detection element is lower than a predetermined reference temperature.