A first offset voltage which is added to voltage commands in a first three-phase voltage command calculated on the basis of a control command for an AC rotary machine, and a second offset voltage which is added to voltage commands in a second three-phase voltage command calculated on the basis of a control command for the AC rotary machine, are set in such a manner that a period during which one of a first power converter and a second power converter outputs an effective vector and the other thereof outputs a zero vector occurs during a carrier period of a first carrier wave signal and a second carrier wave signal.

An anti-pinch method for an apparatus for automatic movement of sliding windows including the steps of: receiving at least one electrical quantity (e.sub.a, i.sub.a) of the motor (M); counting (R.sub.c) oscillation periods (R.sub.d) of the at least one electrical quantity (e.sub.a, i.sub.a); calculating an angular position (θ(t)) of the motor (M) as a function of the number of periods (R.sub.c) of the electrical quantity (e.sub.a, i.sub.a); calculating a position of the window (F) as a function of said angular position (θ(t)) of the motor (M); and reversing the direction of rotation of the motor (M) if the position of the window (F) falls within an anti-pinch zone (APZ) and the movement of the motor (M) is at least partially blocked.

A fire suppression system includes a motor and a foam pump. The foam pump is driven by the motor to inject one or more chemical additives from an off-board additive container into a discharge conduit. A bypass valve is in fluid communication with the output of the foam pump. One or more sensors are configured to measure at least one operating condition of the foam pump. A controller is in communication with the one or more sensors and is operatively connected to the bypass valve. The controller is configured to determine, based on data received from the one or more sensors regarding the at least one operating condition of the foam pump, whether the foam pump is experiencing a loss of prime, and to open the bypass valve in response. The motor may also selectively operate in one of two modes depending on the rotational speed and torque required.

A fire suppression system includes a motor and a foam pump. The foam pump is driven by the motor to inject one or more chemical additives from an off-board additive container into a discharge conduit. A bypass valve is in fluid communication with the output of the foam pump. One or more sensors are configured to measure at least one operating condition of the foam pump. A controller is in communication with the one or more sensors and is operatively connected to the bypass valve. The controller is configured to determine, based on data received from the one or more sensors regarding the at least one operating condition of the foam pump, whether the foam pump is experiencing a loss of prime, and to open the bypass valve in response. The motor may also selectively operate in one of two modes depending on the rotational speed and torque required.

A control apparatus for driving a three-phase rotary electric machine that generates torque including magnet torque and reluctance torque is provided. AC current supplied to two winding groups of the rotary electric machine have the same amplitude and the mutually different phases defined as 30±60×n[deg]. The control unit calculates d-axis current and q-axis current of 6 (2k+1)th order component superposed on a fundamental wave component on dq coordinate, to reduce a peak of the first order component in the phase current, thereby controlling the three-phase rotary electric machine. The control unit calculates current such that an amplitude of the q-axis current of the 6 (2k+1)th order component is larger than an amplitude of the d-axis current of the 6 (2k+1)th order component.

A control apparatus for driving a three-phase rotary electric machine that generates torque including magnet torque and reluctance torque is provided. AC current supplied to two winding groups of the rotary electric machine have the same amplitude and the mutually different phases defined as 30±60×n[deg]. The control unit calculates d-axis current and q-axis current of 6 (2k+1)th order component superposed on a fundamental wave component on dq coordinate, to reduce a peak of the first order component in the phase current, thereby controlling the three-phase rotary electric machine. The control unit calculates current such that an amplitude of the q-axis current of the 6 (2k+1)th order component is larger than an amplitude of the d-axis current of the 6 (2k+1)th order component.

An electrical switching device for operating an electrical machine comprises an inverter circuit, an exciter circuit and a cooling device, wherein the exciter circuit is formed by at least one circuit module, wherein the circuit module is thermally coupled to the cooling device and comprises a discharge circuit, connected to the inverter circuit and adapted to discharge at least one energy accumulator of the inverter circuit.

An electrical switching device for operating an electrical machine comprises an inverter circuit, an exciter circuit and a cooling device, wherein the exciter circuit is formed by at least one circuit module, wherein the circuit module is thermally coupled to the cooling device and comprises a discharge circuit, connected to the inverter circuit and adapted to discharge at least one energy accumulator of the inverter circuit.

A system for simultaneously controlling a plurality of PM AC motors includes a single VFD operatively connected to a power source. The single VFD is programmable to have predetermined operating conditions. The plurality of PM AC motors is operatively connected to the single VFD. Each PM AC motor is free of a built-in VFD. Each PM AC motor is operated in accordance with the operating conditions of the single VFD.

A method for determining rotor characteristic of an alternating current (AC) electrical machine includes obtaining a reference voltage signal, one or more phase currents, and rotor data. The method includes determining orthogonal components of an extended back electromotive force (BEMF) model of the AC electrical machine based on the reference voltage signal, the one or more phase current characteristics, and the rotor data. The method includes determining a product of the orthogonal components of the extended BEMF model. The method includes determining a squared-magnitude of the orthogonal components of the extended BEMF mode. The method includes determining the rotor characteristic of the AC electrical machine based on the product of the orthogonal components and the squared-magnitude of the orthogonal components.