In induction motors, efficiency is improved and a maximum torque is increased. For a magnetic flux density of the stator pole for each phase of an induction motor, a circumferential magnetic flux density distribution is controlled to any distribution state, from a trapezoidal wave-like distribution close to a square wave to a sinusoidal distribution. In particular, motor efficiency in a range of low to medium rotations is improved. The motor structure is designed to reduce the leakage inductance of the rotor windings, and the motor and control thereof are optimized for each other. This increases the maximum torque of the motor more effectively. In addition, the high efficiency of the motor makes it possible to reduce the size of the drive circuit.

The invention concerns a method for measuring a power (Pe, Pm) of an electric motor, that involves measuring a real current (I) of the motor, by means of a measurement sensor (11), the invention being characterised in that it involves inputting, on an interface (20), at least one piece of nominal power data (Pn), one piece of nominal speed data (Wn), one piece of nominal current data (In), one piece of nominal voltage data (Un), one piece of power factor data (cos φ) and the real current (I) of the engine, calculating, in the computer, a no-load current of the motor according to a first stored function depending on at least the data (Pn, In, Un, cos φ), calculating, in the computer, the active power (Pe) and/or the mechanical power (Pm) and/or the active energy and/or the mechanical energy according to at least one second stored function depending on at least the data (Pn, In), the real current (I) and the no-load current that has been calculated, and providing the power that has been calculated on an output interface (24).

The invention concerns a method for measuring a power (Pe, Pm) of an electric motor, that involves measuring a real current (I) of the motor, by means of a measurement sensor (11), the invention being characterised in that it involves inputting, on an interface (20), at least one piece of nominal power data (Pn), one piece of nominal speed data (Wn), one piece of nominal current data (In), one piece of nominal voltage data (Un), one piece of power factor data (cos φ) and the real current (I) of the engine, calculating, in the computer, a no-load current of the motor according to a first stored function depending on at least the data (Pn, In, Un, cos φ), calculating, in the computer, the active power (Pe) and/or the mechanical power (Pm) and/or the active energy and/or the mechanical energy according to at least one second stored function depending on at least the data (Pn, In), the real current (I) and the no-load current that has been calculated, and providing the power that has been calculated on an output interface (24).

A motor includes a shaft presenting a shaft lead end, a switch assembly including a switch arm shiftable between a first position and a second position, and shield structure. The shaft lead end and the switch assembly are disposed axially outward of an endhsield. The shield structure is disposed axially outward of the switch arm to at least substantially restrict direct tool access to the switch arm from an axially outward position relative to the switch arm. The shield structure at least in part defines first and second tool access channels each extending radially inwardly to the shaft lead end, such that the shield structure enables direct tool access to the shaft lead end via the tool access channels but prevents or at least substantially restricts direct tool access to the switch arm via the tool access channels.

A motor includes a shaft presenting a shaft lead end, a switch assembly including a switch arm shiftable between a first position and a second position, and shield structure. The shaft lead end and the switch assembly are disposed axially outward of an endhsield. The shield structure is disposed axially outward of the switch arm to at least substantially restrict direct tool access to the switch arm from an axially outward position relative to the switch arm. The shield structure at least in part defines first and second tool access channels each extending radially inwardly to the shaft lead end, such that the shield structure enables direct tool access to the shaft lead end via the tool access channels but prevents or at least substantially restricts direct tool access to the switch arm via the tool access channels.

An improved built-in capacitor motor structure includes a housing, a stator portion, an insulating member and a rotor portion. The housing includes a front cover and a rear cover for receiving the stator portion. The stator portion includes a core frame provided with an annular insulating frame body to which the insulating member connects. A plurality of circularly arranged docking units extend from the periphery of one side of the insulating frame body. A plurality of corresponding docking units are provided at the bottom side edge of the insulating member. These corresponding docking units are engaged with the docking units of the insulating frame body, respectively. The rotor portion is received in the stator portion. A capacitor is combined inside an accommodating space of the insulating member in communication with the outside, such that the capacitor is assembled inside the motor. In this way, assembly is easy while electromagnetic field of the motor is less easily affected.

A generator, in particular of a wind power installation, for generating electric current, comprising a rotor and a stator having stator teeth and grooves arranged between said stator teeth for receiving at least one stator winding, wherein a measuring device is provided to determine the deflection of at least one stator tooth of the stator in connection with the generator, wherein the measuring device is connected to at least one measuring unit, which is embodied as a strain gauge.

A generator, in particular of a wind power installation, for generating electric current, comprising a rotor and a stator having stator teeth and grooves arranged between said stator teeth for receiving at least one stator winding, wherein a measuring device is provided to determine the deflection of at least one stator tooth of the stator in connection with the generator, wherein the measuring device is connected to at least one measuring unit, which is embodied as a strain gauge.

An electronic control unit includes two inverters, a magnetic sensor, a failure detection unit, an inverter driving unit, a signal examination unit, and a failed element identification unit. The magnetic sensor detects a magnetic flux generated around a winding. The failure detection unit detects an ON-state failure of the inverter. When the ON-state failure is detected, the inverter driving unit stops driving the inverter to which the ON-state failure has been detected, and continues driving the other inverter. The signal examination unit examines a presence or absence of a special signal. When there is a signal appearing according to a special magnetic flux, the failed element identification unit identifies a failed switching element based on a motor electric angle generated by the signal.

An electronic control unit includes two inverters, a magnetic sensor, a failure detection unit, an inverter driving unit, a signal examination unit, and a failed element identification unit. The magnetic sensor detects a magnetic flux generated around a winding. The failure detection unit detects an ON-state failure of the inverter. When the ON-state failure is detected, the inverter driving unit stops driving the inverter to which the ON-state failure has been detected, and continues driving the other inverter. The signal examination unit examines a presence or absence of a special signal. When there is a signal appearing according to a special magnetic flux, the failed element identification unit identifies a failed switching element based on a motor electric angle generated by the signal.