78 results about "Ac machine" patented technology

A low-cost sine-wave drive for a 3-phase permanent magnet synchronous AC machines (PMSM) in open-loop control is based on the measurements of two linear Hall sensors. The two Hall sensors are excited by a magnetic ring with the same pole number as the PMSM rotor magnet and sinusoidal flux distributions. The output signals of the Hall sensors are unified through a two-phase-type phase-lock-loop in order to reduce the impact of the sensor mounting non-uniformity during mass production. The peak torque and speed of motor is simply controlled by adjusting the amplitude of pulse-width-modulation carrier. Smooth torque control is achieved due to sinusoidal 3-phase currents. Such a simple sine-wave drive can be achieved with or without the assistance of a micro-controller unit (MCU). No current sensor is required for the motor phase current detection. This motor can be used in industrial applications where there is no strict requirement on torque response and constant speed control of PMSM machines.

A control system for an electric motor including an inverter for providing power to the electric motor, a controller for controlling the inverter, a first motor speed control block in the controller injecting a high frequency signal into the electric motor to determine the speed and position of the electric motor, a second motor speed control block in the controller detecting the back electromotive force to determine the speed and position of the electric motor, and a transition control block in said controller to vary operation between the first motor speed control block and the second motor speed control block.

The machine in accordance with the present disclosure is an AC machine whose pole numbers can be switched (from pole p₁ to pole p₂), and whose number of series turns per phase N can be switched say from N₀=N_rated to N₁=N₀/2. Furthermore, it employs an inverter so that the frequency can be changed from a low value (e.g., 5 Hz) to a high value (e.g., 200 Hz). Due to the combination of pole number and number of series turns switching/reconfiguration, a high torque at low speed (e.g., 0 rpm) and a high torque at high speed (e.g., 5,000 rpm) can be achieved, making mechanical gears obsolete. In addition, the output power of the motor can be increased at high speed in direct proportion to the speed increase.

A system is provided for controlling two alternating current (AC) machines via a five-phase PWM inverter module. The system comprises a first control loop, a second control loop, and a current command adjustment module. The current command adjustment module operates in conjunction with the first control loop and the second control loop to continuously adjust current command signals that control the first AC machine and the second AC machine such that they share the input voltage available to them without compromising the target mechanical output power of either machine. This way, even when the phase voltage available to either one of the machines decreases, that machine outputs its target mechanical output power.

A method of controlling an AC machine that includes a stator and a rotor. The method includes observing a stability parameter that is indicative of the stability of the AC machine and dependent on a current state of the AC machine; and controlling the AC machine based on the observed stability parameter so as to promote stable operation of the AC machine. The method may include controlling the AC machine to operate as a motor or as a generator. The AC machine may be a permanent magnet synchronous machine. A controller suitable for performing the method is also disclosed.

The present invention relates to control of an alternator-starter for a hybrid electric vehicle having a disconnected high-voltage battery. A hybrid powertrain system includes an electric motor/generator unit having a multiphase asynchronous AC machine electrically connected to a multiphase bridge inverter. A high-voltage capacitor is electrically connected between positive and negative sides of a high-voltage DC power bus. High-voltage DC bus pre-charge circuits are electrically connected between gate drive bias power supplies and the multiphase bridge inverter. A low-voltage battery electrically charges the high-voltage DC link capacitor via the gate drive bias power supplies and the high-voltage DC bus pre-charge circuits when the high-voltage energy storage system is disconnected from the high-voltage DC power bus.

A method of controlling a power converter (258) of a synchronous machine drive system (100) determines position and speed of a rotor (350) of the synchronous machine (300); regulates a current vector relative to a reference frame, having a direct-axis component and a quadrature-axis component, the regulating step selectively causing the current vector to lag a quadrature axis of the machine (300); and outputs a command signal to the power converter (258) as a function of the regulating step. According to one implementation, this process creates higher total torque and maintains supply voltage within a maximum level during a high speed range of the machine.

Method for providing current regulation and a current controller (10) for an electric machine (30) are provided. The method includes receiving a state vector time signal (36) indicative of a time interval when a switching state vector is activated and comparing the received state vector time signal to a commanded state vector time signal (38). The method further includes using the result of the comparison to regulate a direct axis current signal (42, 44) input to an electric machine controller. The current controller (10) includes a state vector error comparator for comparing a received state vector time signal to a commanded state vector time signal and generating a state vector time error. This error is processed by a PI controller, coupled to the state vector error comparator, for providing a direct axis current signal output responsive to the state vector time error to an electric machine.

The invention is a variable-frequency energy-saving control system of central air-conditioner, composed of main controller and temperature sampling controller, where the input end of the main controller is connected with 485 communication circuit, memory, analogue quantity input circuit and switching quantity input circuit, and the output end of the main controller is connected with relay output circuit and frequency inverter output control circuit; the input end of the temperature sampling controller is connected with three sampling chips and the output end of he temperature sampling controller is connected with the 485 communication interface of the main controller through 485 communication port. The main controller implements a compound control according to the temperature signal and the pressure signal of evaporator and condenser of the central air-conditioner, and controls a three-phase AC machine by the output of the frequency inverter and the relay to realize the speed change, able to realize the variable frequency switching of two frequency inverters controlling three electric machines, providing the optimum working state for variable-frequency control system and achieving the best energy-saving effect.

A method of starting a wind turbine generator of any type of polyphase AC machine, including, but not limited to, brushless DC or permanent magnet machines is disclosed. The machine starts from a dead stop or from low speed operation and is accelerated to the cut in speed for power production. The start-up is realized utilizing the common set of electrical conductors and the power converter also used for capturing the generated power. Under initial operation, the power converter executes a PWM modulation technique to drive the machine. Periodically, the PWM modulation is stopped to read the electrical position of the generator.

An electric AC machine with a primary section and a secondary section is disclosed. The primary section has a region facing the secondary section and a region facing away from the secondary section. The region facing the secondary section has windings adapted to receive an AC current. The winding of the primary section has at least one phase conductor which at least partially extends in or on the region of the primary section facing away from the secondary section, thereby producing a magnetic field that extends outside the secondary section. This arrangement can reduce overvoltages and eliminate voltage breakdowns at the star point of winding strands of a synchronous motor.

A power converter configured to improve power capture in a wind turbine during low wind speed operation is disclosed. The power converter converts the power generated by the alternator of the wind turbine into a suitable AC current for delivery to a utility grid or to an electric load independent of the utility grid. The power converter is configured to operate in multiple operating modes, utilizing both synchronous and non-synchronous control methods, to extend the operating range of the power converter. During non-synchronous operation, the power converter utilizes a modulation routine that may either vary the dead-time compensation period during a constant modulation period or vary the modulation period with a constant on-time. A seamless transfer between non-synchronous and synchronous control methods with low total harmonic distortion (THD) improves the range of power generation for wind generators.

A system is provided for controlling two AC machines. The system comprises a DC input voltage source that provides a DC input voltage, a voltage boost command control module (VBCCM), a five-phase PWM inverter module coupled to the two AC machines, and a boost converter coupled to the inverter module and the DC input voltage source. The boost converter is designed to supply a new DC input voltage to the inverter module having a value that is greater than or equal to a value of the DC input voltage. The VBCCM generates a boost command signal (BCS) based on modulation indexes from the two AC machines. The BCS controls the boost converter such that the boost converter generates the new DC input voltage in response to the BCS. When the two AC machines require additional voltage that exceeds the DC input voltage required to meet a combined target mechanical power required by the two AC machines, the BCS controls the boost converter to drive the new DC input voltage generated by the boost converter to a value greater than the DC input voltage.