A system for controlling an electric motor by implementing a synchronized bidirectional rotary dual active bridge, comprising a rotary transformer having a primary side and a secondary side; a first inverter being a first full active bridge, connected between an AC power source and the primary side; a second inverter being a second full active bridge, connected to the secondary side and feeding current to the rotor of the electric motor via the secondary side; a control circuit, for continuously transmitting, via the rotary transformer, synchronization pulses at the switching frequency of the inverters, to operate the second full active bridge independent of the first full active bridge; processing the synchronization pulses to obtain an essentially square wave signal that independently operates the second full active bridge to feed the rotor with predetermined current originated from passing power from the AC power source to the second full active bridge, via the rotary transformer; At the primary side, controlling the phase and the operating duty cycle of the first full active bridge, being in synchronization with the synchronization pulses, to thereby vary the current provided by the second full active bridge to the rotor.

A system for controlling an electric motor by implementing a synchronized bidirectional rotary dual active bridge, comprising a rotary transformer having a primary side and a secondary side; a first inverter being a first full active bridge, connected between an AC power source and the primary side; a second inverter being a second full active bridge, connected to the secondary side and feeding current to the rotor of the electric motor via the secondary side; a control circuit, for continuously transmitting, via the rotary transformer, synchronization pulses at the switching frequency of the inverters, to operate the second full active bridge independent of the first full active bridge; processing the synchronization pulses to obtain an essentially square wave signal that independently operates the second full active bridge to feed the rotor with predetermined current originated from passing power from the AC power source to the second full active bridge, via the rotary transformer; At the primary side, controlling the phase and the operating duty cycle of the first full active bridge, being in synchronization with the synchronization pulses, to thereby vary the current provided by the second full active bridge to the rotor.

Provided is a motor control system. The motor control system include an inverter connected to a DC link, including both ends which a DC link voltage value is applied across, and including switch groups connected in parallel and applying a three-phase current to a motor according to a switching operation, based on PWM control, of each of the switch groups, a current converter converting voltage values, applied across both ends of shunt resistors included in the switch groups, into DC current values according to an ADC gain, an adder estimating a current value, obtained by summating the DC current values, as a DC link current value, and a PI control unit outputting a voltage value for controlling a field current of the motor to the motor by using the estimated DC link current value according to a PI control method, for controlling a generated power of the DC link.

Provided is a motor control system. The motor control system include an inverter connected to a DC link, including both ends which a DC link voltage value is applied across, and including switch groups connected in parallel and applying a three-phase current to a motor according to a switching operation, based on PWM control, of each of the switch groups, a current converter converting voltage values, applied across both ends of shunt resistors included in the switch groups, into DC current values according to an ADC gain, an adder estimating a current value, obtained by summating the DC current values, as a DC link current value, and a PI control unit outputting a voltage value for controlling a field current of the motor to the motor by using the estimated DC link current value according to a PI control method, for controlling a generated power of the DC link.

An electrical machine (1) comprises a rotor (20), a stator (10), a rotor power supply (50), at least one sensor (70) and a rotor magnetization control arrangement (60). The rotor has rotor windings (22) for controlling magnetization of rotor magnetic poles (24). The sensor is arranged to measure a parameter associated with a relative force between the stator and the rotor. The rotor magnetization control arrangement is communicationally connected to the sensor for receiving a signal representing the measured parameter. The rotor magnetic poles are divided into at least two groups (23). The rotor magnetization control arrangement is arranged for controlling the magnetization of the groups individually by providing a respective individually controllable rotor current. The rotor magnetization control arrangement is arranged to individually control the rotor currents in dependence of the signal representing the measured parameter. A method for controlling such an electrical machine is also disclosed.

Disclosed is a method for detecting motor parameters, comprising: injecting a first direct current signal; receiving a first d-q axis feedback current corresponding to the first direct current signal and a first d-q axis voltage output by a current regulation module; injecting a second direct current signal different from the first direct current signal; receiving a second d-q axis feedback current corresponding to the second direct current signal and a second d-q axis voltage output by the current regulation module; and determining motor parameters based on the first d-q axis feedback current, the first d-q axis voltage, the second d-q axis feedback current and the second d-q axis voltage. Also disclosed is an apparatus for detecting motor parameters, a computer program product and an air conditioner compressor system.

Disclosed is a method for detecting motor parameters, comprising: injecting a first direct current signal; receiving a first d-q axis feedback current corresponding to the first direct current signal and a first d-q axis voltage output by a current regulation module; injecting a second direct current signal different from the first direct current signal; receiving a second d-q axis feedback current corresponding to the second direct current signal and a second d-q axis voltage output by the current regulation module; and determining motor parameters based on the first d-q axis feedback current, the first d-q axis voltage, the second d-q axis feedback current and the second d-q axis voltage. Also disclosed is an apparatus for detecting motor parameters, a computer program product and an air conditioner compressor system.

The invention relates to an energy efficient induction motor comprising a stator, a main winding of the stator for generating a rotating magnetic field (RMF), and a rotor disposed to rotate relative to the main winding due to the RMF. The stator comprises additional winding(s) for producing an alternating EMF which is induced in the one or more additional windings due to the rotation of the rotor. The alternating EMF produced in the one or more additional windings is fed back simultaneously to the main winding throughout the complete rotation cycle of the rotor through an electronic control unit coupled to the stator, producing a resultant AC output power that is fed continuously to the main winding.

The invention relates to an energy efficient induction motor comprising a stator, a main winding of the stator for generating a rotating magnetic field (RMF), and a rotor disposed to rotate relative to the main winding due to the RMF. The stator comprises additional winding(s) for producing an alternating EMF which is induced in the one or more additional windings due to the rotation of the rotor. The alternating EMF produced in the one or more additional windings is fed back simultaneously to the main winding throughout the complete rotation cycle of the rotor through an electronic control unit coupled to the stator, producing a resultant AC output power that is fed continuously to the main winding.

A motor system includes a motor, first and second power rails connected to a DC voltage input terminal, and a DC bus capacitor connected between the first and second power rails. An inverter circuit has a first inverter leg, a second inverter leg and a third inverter leg, each of which includes first and second power switches connected in series between the first and second power rails. The inverter circuit is configured to selectively output energization signals to phase windings of the motor. A DC link discharge circuit is configured to monitor a voltage level of the DC bus capacitor, and a bus switching circuit is configured to selectively output one of a first DC voltage level or a second DC voltage level to the DC voltage input terminal in response to an output of the DC link discharge circuit.