The invention relates to a control device for an inverter which includes three half-bridges each having a first power switching element connected to a first DC voltage potential and a second power switching element connected to a second DC voltage potential. The control device is arranged for driving the power switching elements for converting a DC voltage present between the DC voltage potentials into a polyphase AC current in a normal operating mode and for transferring the inverter from the normal operating mode into a safe operating mode. The control device is further set up to alternately drive the power switching elements in the safe operating mode for switching single-phase active short circuits and for switching two-phase active short circuits.

A position control method for a servo, includes: receiving, from a control terminal, a motion control command that comprises a motion planning parameter about position of an output shaft of the servo; acquiring speed information or time information indicated by the motion planning parameter, and determining a constant parameter control duration according to the speed information or time information; determining a control parameter corresponding to a constant parameter control stage according to the constant parameter control duration and a preset constant parameter; performing a transient adjustment to the servo when the constant parameter control stage ends, and changing the control parameter to an adaptive operation parameter when the transient adjustment ends; and controlling a rotation angle of the output shaft of the servo to perform a position control of the servo, based on duration values and control parameters corresponding to each of a plurality of control stages.

Modulated pulse control of electric machines to deliver a desired output in a more energy efficient manner by either (a) operating the electric machine in a continuous mode when a requested torque demand is greater than the peak efficiency torque of the electric machine or (b) in a pulsed modulation mode when the requested torque demand is less than the peak efficiency torque of the electric machine. When operating in the pulsed modulation mode, the inverter may be deactivated to further improve the system efficiency when field weakening is not required to mitigate or eliminate generation of a retarding torque in situations when Back Electromagnetic Force (BEMF) exceeds a supply voltage for the inverter of the machine.

A thyristor starter is configured to accelerate a synchronous machine from a stop state to a predetermined rotation speed by sequentially performing a first mode of performing commutation of an inverter by intermittently setting DC output current of a converter to zero and a second mode of performing commutation of the inverter by induced voltage of the synchronous machine. The thyristor starter is further configured to raise induced voltage in proportion to the rotation speed of the synchronous machine by keeping field current constant and to suppress rise of the induced voltage by reducing the field current after the induced voltage reaches a first voltage value, in the first mode.

A motor control system includes a multi-phase motor, a multi-phase inverter circuit, a plurality of controllable switches, a plurality of sensors, and a monitor circuit. Each controllable switch is coupled in series between a second terminal of the motor and a common winding node and is responsive to switch commands to operate in either a first switch mode or a second switch mode. The monitor circuit is responsive to sensor signals to determine when one or more of the sensed motor state variables attains a predetermined threshold magnitude and when one or more of the sensed motor state variables attains the predetermined threshold magnitude, to supply a switch command to one or more of the controllable switches that causes the one or more controllable switches to operate in the second switch mode.

An electric motor control device includes an electronic control unit configured to perform switching control of a switching element of an inverter in PWM control mode when a modulation degree is less than a first predetermined value, perform switching control of the switching element in square wave control mode when the modulation degree is greater than or equal to a second predetermined value, and perform switching control of the switching element in intermediate control mode when the modulation degree is greater than or equal to the first predetermined value and less than the second predetermined value. The intermediate control mode uses a switching pattern in which, in a pulse pattern in the square wave control mode, a slit or a short pulse having the same width as the slit is formed according to whether a pulse is present at the time when a phase current crosses zero.

Modulated pulse control of electric machines to deliver a desired output in a more energy efficient manner by either (a) operating the electric machine in a continuous mode when a requested torque demand is greater than the peak efficiency torque of the electric machine or (b) in a pulsed modulation mode when the requested torque demand is less than the peak efficiency torque of the electric machine. When operating in the pulsed modulation mode, the inverter may be deactivated to further improve the system efficiency when field weakening is not required to mitigate or eliminate generation of a retarding torque in situations when Back Electromagnetic Force (BEMF) exceeds a supply voltage for the inverter of the machine.

A dual motor system includes a first motor providing a lower speed range and a second motor providing a higher speed range, wherein the motors are coaxially arranged and aligned on and drive a common shaft, and a motor control system controlling the speed of the first motor and engaging the second motor as needed. The first motor is a variable speed motor providing a lower two-thirds of a full speed range, and the second motor is an induction motor providing the upper one-third in the form of one or more discrete fixed speeds. The system may include a transformer including a first winding tap which provides a first higher speed, and a second winding tap which provides a second higher speed. The system may also include a flow control system for automatically controlling the speed of the motors for particular applications, such as flow control in a pool.

An electric motor control device includes an electronic control unit configured to perform switching control of a switching element of an inverter in PWM control mode when a modulation degree is less than a first predetermined value, perform switching control of the switching element in square wave control mode when the modulation degree is greater than or equal to a second predetermined value, and perform switching control of the switching element in intermediate control mode when the modulation degree is greater than or equal to the first predetermined value and less than the second predetermined value. The intermediate control mode uses a switching pattern in which, in a pulse pattern in the square wave control mode, a slit or a short pulse having the same width as the slit is formed according to whether a pulse is present at the time when a phase current crosses zero.

A system for controlling a motor includes a controller module comprising a controller portion, a regulator portion and an integrator portion. The regulator portion includes a set of regulator modules communicatively coupled in a sequence. Each regulator module configured to receive a respective input signal, indicative of a target or selected value, from the controller portion or the immediately preceding regulator module in the sequence, determine a respective selectable value; select one of the respective selectable value and the value indicated by the received input signal; and provide the selected value as an output signal to the next regulator module in the sequence or the integrator module. The integrator module is configured to receive the output signal from the last regulator module in the sequence, calculate a final demand value based on the received signal, and provide an output signal indicative of the final demand value.