A method for estimating the current flowing through a winding of an electric motor of the type having one winding controllable by a switching device, including the following steps: measuring a voltage at the input of the winding, correcting the measured voltage to produce a corrected voltage determining a resistance of the switching device, estimating the current flowing through the winding by dividing the difference between a control voltage used to control the switching device and the corrected voltage by the resistance. The use of such an estimating method for providing a diagnosis for a current sensor, and an estimating method for controlling an electric motor in fail-soft mode are also disclosed.

A battery state estimating apparatus as an embodiment includes a state estimator, a power estimator, and a determiner. The state estimator estimates a state of a battery. The power estimator estimates first power amount charged/discharged by the battery within a charging/discharging period, based on the state. The determiner compares the first power amount with second power amount inputted/outputted to/from the battery within the charging/discharging period and thereby determines validity of the state.

A closed-loop circuit is detected based on a short-circuit failure of a motor control switching element of a motor drive circuit and a cutoff switching element. A motor control device including a motor, a motor drive circuit (10a) that is connected to a power supply device and the motor and controls the output of the motor, and a processing unit for detecting a closed-loop circuit formed by the motor and the motor drive circuit (10a) based on a short-circuit failure of switching elements arranged in the motor drive circuit (10a).

A method for controlling circuitry of a softstarter arrangement to operate an electric motor for driving a pump is provided, wherein the softstarter circuitry electrically connects the motor to electric mains. The method includes: (i) controlling the circuitry of the softstarter arrangement to accelerate the motor up to full speed in a forward direction; (ii) controlling the circuitry of the softstarter arrangement to decelerate the motor when the motor has run at full speed in the forward direction for a first period of time; (iii) controlling the circuitry of the softstarter arrangement to accelerate the motor up a specified speed in a reverse direction; (iv) controlling the circuitry of the softstarter arrangement to decelerate the motor when the motor has run at the specified speed in the reverse direction for a second period of time; and (v) repeating the steps (i)-(iv) one or more times.

A method for controlling circuitry of a softstarter arrangement to operate an electric motor for driving a pump is provided, wherein the softstarter circuitry electrically connects the motor to electric mains. The method includes: (i) controlling the circuitry of the softstarter arrangement to accelerate the motor up to full speed in a forward direction; (ii) controlling the circuitry of the softstarter arrangement to decelerate the motor when the motor has run at full speed in the forward direction for a first period of time; (iii) controlling the circuitry of the softstarter arrangement to accelerate the motor up a specified speed in a reverse direction; (iv) controlling the circuitry of the softstarter arrangement to decelerate the motor when the motor has run at the specified speed in the reverse direction for a second period of time; and (v) repeating the steps (i)-(iv) one or more times.

A controller for controlling a multi-phase motor is described. The controller may be configured to drive a first virtual multi-phase motor in an active mode and drive a second virtual multi-phase motor in a passive mode. In the active mode, at least a portion of a reference torque is distributed to the first virtual multi-phase motor. In the passive mode, zero torque is distributed to the second virtual multi-phase motor.

In a diagnostic device and a diagnostic method for a motor unit of an electric vehicle, an oil degradation/others detection unit is provided which is configured to detect at least any one detection item of a contamination degree, a degradation degree, and an oil amount of an oil used for cooling a motor unit or a reduction gear unit during a non-traveling period when the vehicle is powered on. An abnormalities-time control unit is provided which is configured to send notice of abnormalities of an oil supply system or not permit start of rotation of the motor unit when a detection value detected by the oil degradation/others detection unit is out of a setting range.

A motor driving controller, comprising a rotary position detection device generating a position detection signal corresponding to a rotary position of a rotor of a motor; a control circuit selecting a first driving control signal for performing rectangular wave driving or a second driving control signal for performing driving with an overlapped energization period longer than an overlapped energization period in the rectangular wave driving, based on the position detection signal, thereby to output a driving control signal; and a motor driver outputting a driving signal to a stator coil of the motor based on the driving control signal, wherein the control circuit outputs the first driving control signal at time of starting, and the control circuit outputs the second driving control signal when a rotary state is detected on the basis of the position detection signal.

An inverter control apparatus and a control method thereof are provided. The inverter control apparatus and a control method thereof stably operate a three-phase motor using a capacitor having a small capacitance for a DC link. The inverter control apparatus includes a current sensor to sense an output current of the inverter, a voltage sensor to sense a DC-link voltage of the inverter, and a controller to generate an average of a periodically varying rotor based q-axis current boundary value based on the output current and the DC-link voltage to generate a current reference on the basis of the average of the rotor based q-axis current boundary value, and to drive a three-phase motor based on the current reference. Stabilized variable speed control of a motor by using a small-capacitance capacitor for a DC link of an inverter is performed and reliability of an inverter circuit improved.

A method for controlling a variable speed drive arranged for powering an electric motor, the variable speed drive comprising a power part and a control part. The method comprises a preliminary phase of storing a set of predetermined levels of flux of the electric motor. Then, during a current phase, the method comprises selecting a level of flux from among the set of predetermined levels of flux and controlling the power part of the variable speed drive based on the selected level of flux as reference value.