The invention relates to a method (19) for starting an electric single-phase induction motor (1), wherein during a start-up interval of the start-up cycle for starting said electric motor (1), the frequency (f.sub.ref) of the electric current for driving said electric motor (1) is set to a first frequency (f.sub.start), and later to the operating frequency (f.sub.run) of the electric motor (1), wherein the first frequency (f.sub.start) is higher than the operating frequency (f.sub.run).

An electrified vehicle includes a traction battery, an inverter coupled to the traction battery and operable to convert direct current (DC) power from the traction battery to three-phase alternating current (AC) power, a three-phase electric machine coupled to the inverter by associated cables, a sensor configured to generate a signal associated with rotational position of a rotor of the three-phase electric machine, a current sensor associated with each cable/phase of the three-phase electric machine, and a controller programmed to generate non-zero phase current at each of a plurality of predetermined regularly spaced rotational positions by either adjusting rotor angle or injecting q-axis current, command the inverter to inject a test current pulse to the electric machine, and generate a diagnostic signal in response to any one of the current sensor signals being less than an associated threshold to detect a cable or current sensor anomaly in a single phase.

A motor is connectable to a single-phase AC power supply and forms a hermetic compressor. The motor includes a main circuit connected in parallel with the auxiliary circuit, and a winding structure having a main winding arranged as part of the main circuit and an auxiliary winding arranged as part of the auxiliary circuit. The motor includes a rotor arranged to be rotated by a current in the winding structure. To provide a motor durable and cheap to manufacture and to ensure a suitable response to overload situations, the auxiliary circuit has a first section and a second section extending in parallel where an NTC is inserted in the first section. A PTC is inserted in the second section, and a relay is arranged to activate and deactivate current in the first section of the auxiliary circuit based on a current level in the main circuit.

The present invention provides a control system (100, 200, 300) for controlling a single phase induction motor (150, 250) with a main winding (151, 251) and with an auxiliary winding (152, 252), the control system (100, 200, 300) comprising a first bidirectional switching element (101) and a second bidirectional switching element (102), wherein the first bidirectional switching element (101) is arranged between a phase supply input (103, 203) of the single phase induction motor (150, 250) and the main winding (151, 251) and wherein the second bidirectional switching element (102) is arranged electrically parallel to the main winding (151, 251), and a control unit (105, 205) coupled to the first bidirectional switching element (101) and the second bidirectional switching element (102).

The present disclosure provides a control system (100, 200, 300) for controlling a single phase induction motor (150, 250) with a main winding (151, 251) and with an auxiliary winding (152, 252), the control system (100, 200, 300) comprising a first bidirectional switching element (101) and a second bidirectional switching element (102), wherein the first bidirectional switching element (101) is arranged between a phase supply input (103, 203) of the single phase induction motor (150, 250) and the main winding (151, 251) and wherein the second bidirectional switching element (102) is arranged electrically parallel to the main winding (151, 251), a control unit (105, 205) coupled to the first bidirectional switching element (101) and the second bidirectional switching element (102), wherein the control unit (105, 205) is configured to control in an alternating manner during a positive half-wave of a supply voltage of the single phase induction motor (150, 250) the first bidirectional switching element (101) to provide a positive current to the main winding (151, 251) and the second bidirectional switching element (102) to provide a freewheeling current path for the positive current through the main winding (151, 251), and wherein the control unit (105, 205) is configured to control in an alternating manner during a negative half-wave of a supply voltage of the single phase induction motor (150, 250) the first bidirectional switching element (101) to provide a negative current to the main winding (151, 251) and the second bidirectional switching element (102) to provide a freewheeling current path for the negative current through the main winding (151, 251). Further, the present disclosure provides a respective control method.

Starter system for an electric motor (M) supplied by an electrical network (1), the starter system comprising an electronic control circuit (7) and an electronic switch (10) for controlling one phase of the motor (M), the electronic switch (10) being controlled by the control circuit (7). The starter system comprises a sensor (3) intended to deliver an analog signal (4) that is representative of the derivative of a current flowing through the phase of the motor (M), a detection board (5) comprising means for transforming said analog signal (4) into a binary signal (6) that is representative of the changes in sign of said analog signal, and comprising means for transmitting said binary signal to the control circuit (7), so as to optimize the control of the electronic switch (10).

A method for controlling a switch that controls a power supply line of an electric motor from an alternating voltage source, including determination of a switch closing instant (t.sub.f) starting from a measurement of the derivative of the current carried on the power supply line. A starter system and a computer program product are capable of using this method.

Controller is provided for electromechanical actuator such as an electric brake actuator having a motor driven in response to motor drive signal generated by controller. Controller includes first current limiter and second current limiter. First current limiter limits current command to maximum current limit in response to detecting that current command at least one of exceeds maximum current limit setpoint or is less than minimum current limit setpoint. Second current limiter further limits current and to limited current command in response to detecting that current command exceeds topper current detection limit for specified time duration. Controller may further include intermediate current limiter between first and second current limiters for further limiting current command from first current limiter in response to detecting current command from first current limiter at least one of exceeds maximum power limit setpoint or is less than minimum power limit setpoint.

A control circuit for an induction motor operates to determine whether the inductor motor is of the three-phase type or single-phase type. If three-phase, a variable frequency drive operation is implemented. If single-phase, a closed loop current control process is implemented. The closed loop current control process includes an operation by the control circuit to measure winding resistances and determine a turns ratio for the main and auxiliary motor windings. The turns ratio is used in the closed loop current control process to scale a measurement of current in the auxiliary winding for the purpose of generating the control voltage for the auxiliary winding. Phase of the current in the windings is further processed to generate a phase control signal.

A system for measuring soft starter current includes a current monitoring system having a controller and a current transfer device that includes a first solid state switching device. A first current sensor is coupled to the first solid state switching device and the controller to sense off-state current of the first solid state switching device. The controller is configured to determine an operational status of the first solid state switching device.