292results about "Polyphase induction motor starter" patented technology

A system for providing inrush current limiting for induction motor starting. The system utilizes a pre-start controller to initialize operation of a controller including multiple switches for controlling the voltage delivered to a motor having multiple phases. The pre-start controller activates each switch and determines whether a phase current flowing through the switches satisfies a threshold current. The switches are deactivated a phase current satisfies the threshold current. The pre-start controller determines an activation order for each phase and orders phases having higher phase currents higher in the order than lower phase currents, and determines an activation timing. Based on whether the highest phase current is positive or negative, the pre-start controller then activates, using a voltage at a corresponding angle and based on the activation order and activation timing, the phases to de-saturate the flux generated by the phase currents, thereby limiting an inrush current provided to the motor.

Adjustment of operational performance of an electric machine (e.g., using a computerized tool) is enabled. For example, a non-transitory computer-readable medium can comprise executable instructions that, when executed by a processor, facilitate performance of operations, comprising: deactivating a first sub-set of winding sectors, wherein the first sub-set of the winding sectors comprises at least one winding sector, and triggering an AC drive signal for a second sub-set of the winding sectors such that a rotor is rotated using the winding sectors of the second sub-set, wherein an electric machine comprises a stator and the rotor, wherein the stator comprises a set of N phase windings, wherein each N phase winding, of the set of N phase windings, forms p poles around a circumference of the stator, and wherein each p pole, of the p poles, is formed by the at least one winding sector.

The embodiment of the invention discloses a multiplex type three-stage starting power generation controller, and relates to the technical field of aviation three-stage starting power generators. In the starting stage, an H-bridge inverter in the starting power generation controller provides single-phase alternating-current exciting current for a main exciter stator exciting winding through SPWM modulation so as to establish a pulsating magnetic field to provide exciting current for a main motor, and a three-phase full-bridge inverter provides armature current for a main motor stator armature winding through SVPWM modulation. In a power generation stage, an anti-parallel diode of the three-phase full-bridge inverter is used as a rectification circuit of the auxiliary exciter, and the H-bridge inverter adopts a PWM chopping mode to operate as an asymmetric half-bridge circuit. A power generation controller and a starting controller are integrated into a whole, and by changing the modulation mode of a hardware circuit, the control function of the three-stage starting generator at different stages can be realized by only one controller, so that the structure of the starting power generation controller is simplified, the system integration degree of the three-stage starting generator is improved, and the volume and the weight of the system are reduced.

The invention relates to a starting and power generation integrated control method based on externally distributed bosses of a permanent magnet motor, and the method comprises the following steps: determining the initial position of a rotor of the permanent magnet motor relative to a stator through a pulse voltage injection method, and applying a drive signal to a stator coil, so that the motor reaches the rotating speed at which an ignition trigger can stably detect the signal; an ignition trigger is used for obtaining boss signals and conducting shaping processing, and the specific position of the rotor relative to the stator is determined; the stator coil is electrified by utilizing the relative position of the rotor and the stator, the motor is driven to rotate, and flux-weakening voltage regulation control is carried out; and when the power-assisted condition is met, a stator coil corresponding to the permanent magnet motor is electrified by utilizing the relative position of the rotor and the stator, so that switching control from power generation voltage regulation to power-assisted driving of the motor is realized, and power-assisted driving operation is executed. According to the control method, the boss on the rotor is used for starting and power generation voltage regulation control of the permanent magnet motor, and the method is simple and easy to implement.

A variable frequency starter generator (VFSG) system includes a VFSG having a start mode and a generate mode, a permanent magnet generator (PMG) and a main generator section and an exciter section. The system also includes a controller electrically connected to the VFSG. The controller flow start mode three phase electrical power from aircraft power to the exciter of the VFSG in the start mode and flows single phase electrical power to the exciter of the VFSG in the generate mode. The controller includes: an input active rectifier that receives input AC power and converts it to DC power and provides it to across a positive rail and negative rail; an output inverter coupled to an output of the input active rectifier; and one or more line inductors connected along one or both of the positive rail and negative rail between the input active rectifier and the output inverter.

An alternating current (AC) motor system includes an AC motor with a rotor and a stator with multi-phase AC stator windings. The system also includes a power inverter that generates a multi-phase AC voltage, an AC bus that connects the power inverter to the stator windings, an AC choke that surrounds the AC bus, and a current sensor with a coil wound on or surrounded by the AC choke. The current sensor measures common mode current in the AC bus, and is used in pulse width modulation or slew rate control of the power inverter, ensuring smooth operation and reducing the risk of damage due to common mode current.

The invention discloses a centralized control method for a frequency conversion starting and speed regulating system of a compressed air energy storage compressor, and belongs to the technical field of compressed air energy storage compressor control. When the controller in the frequency converter controls the starting of the motor and the variable-speed operation of the compressor, the controller in the frequency converter also controls the external excitation device to adjust the rotating speed of the motor; the rotating speed sensor samples the rotating speed value of the motor and transmits the rotating speed value to the controller, and the controller processes the received rotating speed value of the motor and transmits the processed rotating speed value to the liquid crystal screen for displaying, so that the rotating speed of the motor is monitored; the precision of the rotating speed value of the motor treated by the controller is efficiently improved, the rotating speed value of the motor is easy to treat, and finally monitoring of the rotating speed of the motor is improved.

The invention relates to a double-fed asynchronous motor debugging method and system based on a back-to-back converter, and belongs to the technical field of motor control. Comprising the following steps: supplying power to a three-phase alternating-current voltage regulator, and charging a direct-current bus capacitor by connecting a grid-side alternating-current contactor with a buffer resistor in parallel; when the DC bus capacitor is charged to a preset amplitude, the digital signal processor sends a closing signal to the AC contactor; after the alternating current contactor is switched on, pure open-loop debugging, current closed-loop debugging and rotating speed closed-loop debugging are respectively carried out on the rotor side; the upper computer controls the pulse width modulator to work, carries out excitation on the rotor, and monitors the voltage and phase of the stator end; when the voltage rises to a preset value and the phase is synchronized with the power grid, a closing signal is sent to the AC contactor at the stator side, and the motor stator is connected to the power grid. The problems that a traditional doubly-fed asynchronous motor is too large in starting current and complex in control link decoupling are solved, and the debugging reliability and efficiency are improved. In addition, debugging does not depend on additional prime mover dragging.

A current sourced control topology is provided for an AC motor controller that eliminates many of the problems associated with prior art motor controllers that use voltage source inverter (VSI) technologies. By controlling the output of AC current sources such as synchronously controlled down converters to directly drive each motor phase, significant efficiency gains and a reduction in electromagnetic interference is achievable.

A power converter is configured to measure an output current and to determine a multiphase voltage reference as a function of the output current. Within the same switching period the voltage reference is determined, a modulation routine determines a modulation index for each phase of the output voltage. In some instances, one or more phases must start modulation during the switching period before the new modulation index is determined. The modulation routine stores the value of the modulation index generated from the prior switching period and uses the stored value when a new value is not yet ready. An offset value for the phase voltage which used a modulation index from the prior switching period is determined in order to compensate the phase voltages of the other phases and to maintain a desired line-to-line voltage output from the power converter.

The present disclosure relates to an apparatus comprising a controller, an inverter, a load and a DC link. The DC link is coupled to the load and couplable to a power source. The load comprises an AC electrical component. The inverter is configured to provide an output voltage and an output current to the AC electrical component, the output voltage having an output frequency. The controller is configured to: evaluate a component startup criterion relating to whether the AC electrical component is performing a startup process; in response to a determination that the component startup criterion has been met, operate the inverter in a protected startup mode; and when operating the inverter in the protected startup mode, control the output frequency such that the output frequency increases with time until the output frequency reaches a predefined operating frequency.

The present invention provides a starting control device, system and method for an induction motor. The device is configured to: control a driving control device of the motor so that the rotating induction motor enters a DC braking state; receive a first parameter and a second parameter, the first parameter including a given value of an excitation current, a given value of a torque current and a given value of a stator electrical angle, and the second parameter including a phase current of the induction motor; based on the first parameter and the second parameter, calculate the feedback value of the excitation current and the feedback value of the torque current in a current closed-loop controller; determine the direction and frequency of the induction motor based on the change of the feedback value of the excitation current over time, the change of the feedback value of the torque current over time, and the relationship between the changes of the two; and determine a power supply scheme for the induction motor based on the determined direction and frequency, so that the induction motor enters a starting state from a DC braking state.

The application discloses a variable-frequency-power-frequency automatic switching energy-saving system and method, and belongs to the technical field of motor control, which comprises the following steps: in the variable-frequency starting stage, a motor is driven to run at variable speed by a frequency converter; when the motor reaches full frequency, high power and stable operation, a control device controls the output voltage of the frequency converter to be synchronous with the grid voltage, and the switching to the power-frequency grid is completed when the phases are consistent; when the load decreases and needs to be reduced, the control device starts the frequency converter to make the output voltage of the frequency converter synchronous with the counter electromotive force of the motor in the power-frequency operation, then performs a back switching operation, the motor in rotation is smoothly connected by the frequency converter, and speed reduction control is implemented, and finally the variable-frequency speed regulation operation state is returned; the application realizes automatic selection of the optimal operation mode according to the actual load, avoids energy loss of the frequency converter in the high-speed area, and ensures that the impact on the motor and the grid in the switching process is minimum.

The invention discloses a method for identifying a locked-rotor condition of a motor, a frequency converter and a storage medium. The method for recognizing the locked-rotor condition of the motor in the compressor comprises the steps that first preset detection voltage is applied to a stator of the motor, and first stator current flowing through the stator of the motor is detected; obtaining a first position angle of the rotor based on the first predetermined detection voltage and the first stator current; applying a predetermined DC voltage to a stator of the motor based on the first position angle; applying a second predetermined detection voltage to the stator of the motor, and detecting a second stator current flowing through the stator of the motor; obtaining a second position angle of the rotor based on the second predetermined detection voltage and the second stator current; and identifying a locked-rotor condition of the motor based on the first position angle and the second position angle.

A drive system (10) for an induction motor (200) is provided. The drive system (10) includes a drive unit (12) coupled to the induction motor (200), and a control unit (11). The control unit (11) is configured to control the drive unit (12) to provide a first magnetizing current to the induction motor (200) in response to a trigger signal such that the drive unit (12) is operated for magnetization of the induction motor (200) during a first time period. The control unit (11) is further configured to control the drive unit (12) to provide a torque current to the induction motor (200) such that the drive unit (12) is operated for acceleration of the induction motor (200) during a second time period after the first time period.

The invention relates to the technical field of motor control, and discloses an anti-locked-rotor starting control system. The system comprises a main control module, a dynamic rule base generation module, a phase compensation module, a pre-triggering module and a feedback correction module. The main control module monitors a three-phase current waveform and a rotor position signal of the motor and generates an instantaneous locked-rotor feature vector; the dynamic rule base generation module extracts a current waveform distortion mode of a historical locked-rotor event, and combines a rotor inertia parameter to construct a fuzzy rule set so as to initialize a dynamic rule base; the phase compensation module dynamically compensates the phase current waveform and constructs a stability evaluation function; the pre-triggering module triggers pre-access of the standby power supply according to the phase offset and verifies compatibility; and the feedback correction module generates a feedback parameter according to the locked-rotor risk index and the power supply verification result, and corrects the mapping relationship between the feature vector and the rule base. The system can accurately identify locked-rotor characteristics, dynamically adapt to operation parameters, actively prevent and control locked-rotor risks, and improve the starting stability of the motor.

The utility model discloses a machine frame of a mining vacuum electromagnetic starter, which relates to the technical field of machine frames and comprises a starter main body, a supporting plate is arranged at the lower end of the starter main body, a movable plate is arranged on one side of the supporting plate, a supporting column is attached to the lower end of the supporting plate, and a supporting frame is fixedly connected to the lower end of the supporting column. A sealing door is hinged to one side of the starter body, the lower end of the supporting plate is fixedly connected with a supporting screw rod, and one side of the supporting screw rod is in threaded connection with a rotating nut. The connecting block, the first fixing bolt and the movable plate are arranged to limit the position of the starter body, the supporting screw, the fixing rod and the rotating nut are arranged to enable the supporting plate to ascend and descend so as to drive the starter body to ascend and descend, the supporting column and the extending column are arranged to limit the supporting plate, and the adjusting bolt and the supporting block are arranged to adjust the position of the starter body. The angle of the support frame is adjusted.

One aspect of the present disclosure provides an electric power tool including a motor, a drive circuit, a voltage detector, a first calculator, and a second calculator. The drive circuit applies a power-supply voltage to the motor in accordance with a first duty ratio. The voltage detector detects a magnitude of the power-supply voltage. The first calculator calculates a desired duty ratio based on the magnitude of the power-supply voltage detected. The second calculator increases the first duty ratio from an initial value to the desired duty ratio in accordance with a lapse of time. The second calculator varies a rate of increase of the first duty ratio based on the magnitude of the power-supply voltage detected.

This invention discloses a forward / reverse control module based on zero-crossing detection control, comprising a power supply circuit, an interlock delay circuit, a drive circuit, a switching circuit, a detection circuit, and a control unit. The drive circuit is connected in series between the interlock delay circuit and the switching circuit, and the switching circuit is connected in series between the load power supply and the winding terminals of the motor. The signal input terminal of the detection circuit is connected to the switching circuit. The control unit is connected to the interlock delay circuit to detect the presence of a forward rotation signal and / or a reverse rotation signal. The control unit is connected to the drive circuit through the detection circuit, and outputs a braking signal to the drive circuit. The drive circuit drives the corresponding switch in the switching circuit to conduct according to the braking signal, thereby realizing forward / reverse control and braking control of the motor. This invention combines forward / reverse control and braking functions without the need for additional braking components. It allows for adjustment of braking time and force, and features a simple braking structure, excellent performance, and high reliability.

This application provides a motor controller, a powertrain, and an electric vehicle, to resolve a problem of current impact on a power transistor that exists during startup of the motor controller and therefore improve powertrain efficiency and vehicle endurance. The motor controller provided in this application includes a control apparatus and an inverter circuit. The control apparatus is configured to receive a first torque signal, at least one second torque signal, and a third torque signal in sequence. In response to the third torque signal, the control apparatus outputs a startup signal and a third control signal in sequence. The startup signal is used to control the inverter circuit to generate a startup voltage, to avoid current impact that exists when the power transistor is turned on. The inverter circuit receives the third control signal and controls an induction motor to output a torque based on a torque value indicated by the third torque signal . According to the motor controller, the powertrain, and the electric vehicle provided in embodiments of this application, a startup speed of the motor controller can be increased, and current impact that exists during startup of the motor controller can be eliminated.

Techniques are described to continuously calculate an inverter DC power of a synchronous machine, e.g., motor or generator, based on the individual phase currents, DC link voltage, and gate signals, which can be compared against the commanded mechanical power based of the estimated rotor speed and commanded torque. A controller can determine whether to shut down the inverter, such as the pulse width modulation (PWM), if the DC power is greater than a threshold value. Such a threshold can be defined to allow an acceptable position and speed estimation error margin.

Embodiments of the present disclosure relate to soft turn-off for motor controllers. A bidirectional switch for an induction motor is described. The bidirectional switch can include a first power semiconductor transistor having a first source, a first drain, and a first gate. The bidirectional switch can also include a second power semiconductor transistor having a second source, a second drain, and a second gate. The bidirectional switch can include the second source connected to the first source. The bidirectional switch can include a soft start device including a control circuit configurable to provide a first control signal to the first power semiconductor transistor and a second control signal to the second power semiconductor transistor.

The embodiment of the invention discloses a motor star-delta switching circuit and a motor. The motor star-delta switching circuit comprises a star-delta starting control circuit, a protection circuit, a star-shaped starting circuit and a delta starting circuit. When the motor is started in a star-delta mode, the operation time of the star-shaped starting circuit can be controlled through circuit setting in the star-delta starting control circuit based on parameters of a second resistor, a sixth resistor and a third capacitor and the voltage corresponding to the reverse end of a comparator. And the interval time for switching the star-shaped starting circuit to the triangular starting circuit is controlled based on the parameters of the fourth resistor and the sixth capacitor and the voltage corresponding to the reverse end of the comparator, so that star-delta mode starting of the motor is realized. In the star-delta starting process, only corresponding hardware circuit parameters need to be adjusted, software end control does not need to be introduced, the problem of software end system bug does not exist, and the motor star-delta switching circuit is high in stability and low in cost.

A solid-state controller for limiting startup current in an induction motor is provided. The solid-state controller includes a first comparator configured to generate a first comparison based on comparing a rotor speed of the induction motor with a rotor speed threshold. The solid-state controller includes a phase current limiter configured to generate a startup current limit based on the comparison received from the first comparator. The solid-state controller includes a second comparator configured to generate a second comparison based on comparing a startup current of the induction motor with the startup current limit. The solid-state controller includes a microprocessor configured to generate a firing phase angle based on the second comparison, where the firing phase angle is a phase angle at which the solid-state controller is turned on, and generate a stopping time at which the solid-state controller is turned off.

A motor control circuit is provided for connecting or disconnecting an AC voltage to an AC motor, having a switch having two switch contacts, configured to respond to a process variable and move between open and closed switch contact positions to connect or disconnect the AC voltage to the AC motor; and a snubber circuit arranged across the switch contacts in parallel with the AC motor, and configured to respond to motor inductance when the switch is moved between the open and closed switch contact positions, and provide arc suppression in the switch by dissipating energy stored in the motor inductance. The snubber circuit may include a network having a resistor connected in series with a capacitor, or a metal oxide varistor, or a transient voltage suppressor.

A solid-state controller for limiting startup current in an induction motor is provided. The solid-state controller includes a first comparator configured to generate a first comparison based on comparing a rotor speed of the induction motor with a rotor speed threshold. The solid-state controller includes a phase current limiter configured to generate a startup current limit based on the comparison received from the first comparator. The solid-state controller includes a second comparator configured to generate a second comparison based on comparing a startup current of the induction motor with the startup current limit. The solid-state controller includes a microprocessor configured to generate a firing phase angle based on the second comparison, where the firing phase angle is a phase angle at which the solid-state controller is turned on, and generate a stopping time at which the solid-state controller is turned off.

The present invention relates to the field of automatic control technology, and particularly relates to an autotransformer step-down control system based on a PLC. It includes a main power supply circuit and a control loop. The autotransformer step-down control system based on a PLC of the present invention is controlled based on a programmable logic controller (PLC) and a touch screen, and improves the control loop of the XJ01 autotransformer. A main circuit AC contactor KM4 is added to the main circuit. When the star point short-circuit AC contactor KM1, the step-down operation AC contactor KM2, and the contacts are adhered, the internal timer T38 of the PLC detects an abnormality, and the main circuit AC contactor KM4 issues an immediate trip command to protect the motor and the autotransformer. The design concept of this solution is advanced, and the use of the PLC and the touch screen is stable, safe and reliable; compared with the original wiring method, the connection is simple; it is convenient to maintain, and even if the internal data is lost, the data can be restored in only a few minutes.

The utility model relates to a large-scale three-phase asynchronous motor starting control device which comprises a coupling and an auxiliary motor. The large three-phase asynchronous motor is a double-output-shaft working motor, and a rear-end output shaft of the working motor is connected with a front-end output shaft of the auxiliary motor through a coupler; the coupler is a clutch type coupler; the working motor is connected to a working three-phase alternating current power supply sequentially through a thermal overload relay, a contactor, a first circuit breaker and an isolating switch which are connected in series; the auxiliary motor is connected to a three-phase alternating current power supply for starting through a soft start controller or a frequency converter and a second circuit breaker which are connected in series in sequence; starting and stopping of a working motor and an auxiliary motor are controlled through a control circuit, a starting button, a stopping button and a first intermediate relay in the control circuit are sequentially connected in series and then connected with a direct-current power source, and a second control switch, a normally-closed contact of a contactor and a second intermediate relay are sequentially connected in series and then connected with the direct-current power source. The normally open contact is connected in series with the third intermediate relay and then connected with the DC power supply.

Embodiments of the present disclosure relate to a method, apparatus for operating a conduction assembly, a start device, and a computer-readable medium. The conduction assembly is coupled between an AC power supply and an inductive load, and comprises a first switch device and a second switch device which are in anti-series connection, the first switch device comprises a first body diode in anti-parallel connection with the first switch device, and the second switch device comprises a second body diode in anti-parallel connection with the second switch device. The method comprises: conducting the conduction assembly at a first conduction angle in a first cycle; conducting the conduction assembly in a second cycle at a second conduction angle that is greater than the first conduction angle, wherein in the first cycle and second cycle, a turn-off timing of the first switch device or the second switch device in anti-parallel connection with the first body diode or second body diode having a conduction direction the same as a current direction is determined based on the current flowing through the conduction assembly. The method proposed here may reduce the power loss of the soft start circuit.