204results about How to "Improve voltage utilization" patented technology

Disclosed is a high-speed control method for a permanent magnet synchronous motor-compressor system, including the following steps: initial design is carried out; a motor is detected through DSP, including detecting the two-phase current of the stator of the motor, the voltage Udc of a DC generatrix; the voltage of a d-p shaft is calculated; faults of overcurrent, overpressure and undervoltage are detected; if any fault exists, the PWM pulse signals are blocked and then the control program is paused; if no fault exists, the following steps will be carried out; the rotating speed of the motor and the position of the rotor are identified in the process of speed-position estimation; the current and the voltage of the reference d-q shaft of the motor are calculated; switching signals of an inverter are acquired through haplotype over-modulation; the data are recorded and waveforms are displayed; judgment of whether to pause the control program is carried out; if not, the second step is carried out again; if yes, the control program will be paused. The control method applies haplotype over-modulation method into the permanent magnet synchronous motor-compressor system, realizing sensorless over-modulation to the synchronous motor-compressor vector control system.

The present invention provides a method for controlling a permanent magnet synchronous motor used in electric vehicles such as hybrid vehicles, fuel cell vehicles, and the like. The method for controlling the permanent magnet synchronous motor preferably includes detecting an absolute angular position of a permanent magnet synchronous motor; calculating a rotational speed of the permanent magnet synchronous motor based on the detected absolute angular position; detecting a voltage of a battery as a power source; calculating a compensated speed, for which a battery voltage variation is compensated, from the rotational speed of the permanent magnet synchronous motor based on a torque command, the rotational speed of the permanent magnet synchronous motor, and the battery voltage; generating a d-axis current command and a q-axis current command corresponding to the torque command and the compensated speed using a predetermined current command map; converting three-phase currents flowing into the permanent magnet synchronous motor into a d-axis feedback current and a q-axis feedback current based on the detected absolute angular position; calculating a d-axis voltage command and a q-axis voltage command based on the d-axis current command, the q-axis current command, the d-axis feedback current, and the q-axis feedback current; converting the d-axis voltage command and the q-axis voltage command into three-phase voltage commands based on the detected absolute angular position; and controlling the operation of the permanent magnet synchronous motor based on the three-phase voltage commands.

The invention provides a zero-sequence current suppression method of open type permanent magnet synchronous motor with double-inverter power supply, belongs to the technical field of motor control, and aims at solving the problem of zero-sequence current of the open type permanent magnet synchronous motor with the double-inverter power supply. The method is characterized in that the closed loop control for zero-sequence current i0=0 is added on the basis of a vector control system, so as to realize the suppression of the zero-sequence current; the zero-sequence current is calculated by detecting the three-phase current of the motor and is treated as the feedback quantity to build the closed loop control of the zero-sequence current; the output of a zero-sequence current ring is specified by zero-sequence voltage, and the zero-sequence current is suppressed by adjusting the zero-sequence voltage produced by the double inverters. The method is applied to the suppression of the zero-sequence current in the open type permanent magnet synchronous motor with double-inverter power supply.

In an apparatus, a norm setter sets, based on a request torque for a rotary machine and a rotational velocity of a rotor, a norm of a vector of an a output voltage in a two-phase rotating coordinate system defined in the rotor. A phase setter sets, based on a deviation between a generated torque and the request torque, a phase of the vector of the output voltage of the power converter in the two-phase rotating coordinate system. A drive signal determiner determines, based on the norm set by the norm setter and the phase set by the phase setter, a drive signal, and applies the drive signal to a switching member to thereby drive the switching member such that the generated torque is adjusted to the request torque.

Provided is an apparatus for operating interior permanent magnet synchronous motor by receiving a first current command of a flux weakening control region I in a system including a detector measuring a position and a speed of a rotor of an IPMSM, the apparatus including a feedback unit transmitting over-modulated voltage information to a correction unit, the correction unit using the rotor speed and the over-modulated voltage information to correct the first current command to a second current command of a flux weakening control region II, a control unit controlling the second current command to output a voltage, a first limit unit limiting an output of the control unit to a maximum voltage synthesizable by an inverter unit, and the inverter unit applying a 3-phase voltage command for following a command torque to the IPMSM using an output of a voltage limit unit.

The invention relates to an electric current reconstructing and over-modulating device of an air conditioning frequency converter, which is characterized by comprising an electric current reconstructing device, a vector controller, a pulse width modulation (PWM) frequency converter, a direct current side electric current sensor, an electric motor and a coder. The electric current reconstructing device comprises an SVPWM over-modulating module, a pulse width modulation (PWM) signal adjusting module, a direct current sampling module and an alternating current reconstructing module. An electric current reconstructing and over modulating method of the air conditioning frequency converter comprises the steps: sampling the direct current side electric current of the pulse width modulation (PWM)frequency converter at twice by the electric current reconstructing device; counting an approach vector switch action time which meets a minimum sampling time request according to the two sampling values; sampling the direct current side electric current at twice again in the approach vector switch action time; and reconstructing three phase alternating current according to the sampling values ofthe direct current at twice, thereby realizing the closed loop control of the pulse width modulation (PWM) frequency converter. The modulating method can be widely used for the field in reconstructingand over-modulating the electric current of the frequency converter in air conditionings and electric vehicles.

Synchronous motor controlling apparatus and method controls power applied to minimize or eliminate speed variations of a synchronous motor due to variations in load imposed the motor. The rotational position of a rotor of the synchronous motor based on the input terminal voltages and currents to the synchronous motor, and the power applied to the motor is adjusted accordingly. Higher harmonics of the input voltages and currents may also be used to detect the position of the rotor. In addition, the apparatus and method also accounts for the varying speed command inputs.

In an apparatus, a phase setter sets, based on a deviation between a generated torque and a request torque for a rotary machine, a phase of a vector of a variable output voltage of a power converter in a two-phase rotating coordinate system defined in a rotor of the rotary machine. A norm setter sets, based on the phase set by the phase setter and a rotational velocity of the rotor, a norm of the vector of the output voltage in the two-phase rotating coordinate system. A drive signal determiner determines, based on the phase set by the phase setter and the norm set by the norm setter, a drive signal, and applies the drive signal to the switching member to thereby drive the switching member such that the generated torque is adjusted to a request torque.

The invention discloses a short-circuit fault-tolerant vector control method for an embedded hybrid magnetic material fault-tolerant cylindrical linear motor. The short-circuit fault-tolerant vector control method comprises the following steps: building a five-phase embedded hybrid magnetic material fault-tolerant cylindrical linear motor model; compensating normal thrust missing caused by a short-circuit fault phase and suppressing a thrust ripple caused by phase short-circuit current with non-fault phase current of the motor; and obtaining expected phase voltage by adopting a series of coordinate conversion and voltage feed-forward compensation strategies, and achieving a fault-tolerant vector control after the phase short-circuit fault of the motor by a zero-sequence voltage harmonic injection-based CPWM modulation mode. According to the short-circuit fault-tolerant vector control method, the motor can suppress the thrust ripple of the motor under the condition of a phase short-circuit fault-tolerant operation; more importantly, the dynamic property, the steady-state performance and the properties in a normal state are consistent; the switching frequency of a voltage source inverter is constant; a CPU is low in overhead; and a natural coordinate system only needs to counterclockwise rotate a certain angle in any phase short-circuit fault, so that the motor fault-tolerant operation can be achieved.

The invention discloses a one-phase open-circuit fault-tolerant direct thrust control method for a five-phase permanent magnet linear motor. Firstly, a Clark transform matrix and an inverse matrix thereof are derived based on fault-tolerant phase current. On the above basis, a stator flux linkage on alpha-beta is derived, a stator virtual flux linkage is defined according to the requirements of acircular stator flux linkage trajectory, and thus the voltage compensation on alpha-beta is derived. The stator actual voltage on the alpha-beta is derived by a modulation function of a voltage sourceinverter, and voltage is combined with voltage compensation and stator current, and a stator virtual flux linkage and thrust are observed by a stator flux observer and a thrust observer. Then statorvirtual target votlage is calculated according to given thrust, a given stator flux linkage amplitude and the observed stator virtual flux linkage and thrust. Finally, the stator actual voltage is calculated by the voltage and the voltage compensation, and the motor is controlled by the voltage by the voltage source inverter. According to the method, a thrust fluctuation caused by a motor failureis suppressed, and more importantly, the dynamic performance and steady state performance are consistent with that in a normal condition.

The invention discloses a five-phase inverter random SVPWM modulation method, and belongs to the technical field of multi-phase inverter drive control. In every sampling cycle, the sampling cycle is kept constant, a PWM pulse is delayed randomly, to achieve random change of a switch cycle, at the same time, two vector action time obtained through an NFV-SVPWM algorithm are randomly allocated, and double-random of switch frequency and zero vector action time is achieved. According to the five-phase random SVPWM modulation method, on the condition of not influencing low frequency-band harmonic performance, the amplitude of higher harmonic is drastically lowered, harmonic originally concentrated on the switch frequency and around the integral multiple switch frequency is dispersed into a wider frequency spectrum range, thus a more consecutive and even frequency spectrum is obtained, electromagnetic interference and high frequency noise are effectively inhibited, and the electromagnetic compatibility of the system is improved.

The invention discloses a voltage converter which is used for converting direct-current voltage output by a direct-current power supply into alternating voltage provided for an alternating-current load. The voltage converter comprises a bypass unit, a boosted circuit, a first energy-storage filtering unit, a voltage-reduction circuit and an inverter circuit. The boosted circuit, the first energy-storage filtering unit, the voltage-reduction circuit and the inverter circuit are sequentially parallelly connected between the direct-current power supply and the alternating-current load. The bypass unit is used for bypassing the boosted circuit when the direct-current voltage is not smaller than the absolute value of an instantaneous value of the power grid voltage. The inverter circuit actuates at power frequency in each work cycle of the alternating-current voltage. The booster circuit operates only when the direct-current voltage is smaller than the absolute value of instantaneous value of the power grid voltage. Compared with the prior art, the voltage converter is wide in direct-current voltage working range, high in converting efficiency and low in cost.

The invention relates to an improved-overmodulation based method for improving the alternating current motor torque output capacity. The method comprises: a current PI regulator outputting voltage vectors Ud and Uq of d and q axes according to id*, iq*, id, and iq; when the alternating current motor is operating in a non-weak magnetic region, obtaining voltage vectors Ualpha and Ubeta of alpha and beta axes by performing coordinate transformation on Ud and Uq; when the alternating current motor is operating in a weak magnetic region, obtaining optimized voltage vectors Udn and Uqn of the d and q axes by applying a voltage optimization method to Ud and Uq, and obtaining Ualpha and Ubeta by performing coordinate transformation on Udn and Uqn; setting different modulation regions according to the magnitude of Ualpha and Ubeta, and outputting corrected voltage vectors Ud* and Uq* of the d and q axes according to Ualpha and Ubeta; and finally, performing spatial voltage vector modulation to generate a switch action signal for on/off control of an IGBT in an inverter. Compared with the prior art, the method of the invention has the advantages that the bus voltage is high in utilization rate, the increase of output torque is large, and the current response is quick.

The invention relates to an SVPWM (Space Vector Pulse Width Modulation) control method for a Z-source inverter, belongs to the technical field of inverter control and solves the problem of generation of a larger inductive current ripple caused by the existing SVPWM control method for the Z-source inverter. The states of three switching tubes of an upper bridge arm are represented by eight vectors, and the eight vectors divide a control interval into six sectors. For taking the third (III) sector as an example, the vectors taking actions in Ts in each SVPWM period are allocated sequentially from left to right as 111, 110, 100, 000, 000, 100, 110 and 111, wherein the total acting time of a traditional zero vector is set as T0; the total acting time of a direct-through zero vector is set as t0 which is greater than 0 and less than or equal to T0; and the total acting time t0 of the direct-through zero vector is divided into four sections inserted between the acting times of the traditional zero vector and an adjacent effective vector, thereby realizing SVPWM control of the Z-source inverter. The SVPWM control method is suitable for the SVPWM control of the Z-source inverter.

A motor controller and an electric power steering system including the motor controller are provided. The motor controller has a microcomputer. When the on time of one of the lower potential-side FETs corresponding to the respective phases in a drive circuit becomes shorter than the detection time for detecting the phase current value, the microcomputer estimates the phase current value of the electric current undetectable phase based on the phase current values of the two phases other than the electric current undetectable phase corresponding to the relevant FET (blind estimation). When electric current detection is performed in the blind estimation, motor control signals are output, by which the switching state of the switching arm of the electric current undetectable phase is maintained and the power loss caused by the switching operation of the FETs in the two phases other than the electric current undetectable phase is compensated for.

The invention discloses an inverter for two-phase orthogonal electromagnetic blender, adopting a six-leg structure and an orthogonal vector control method to complete the decoupling control for the current and frequency of the two-phase electromagnetic blender so as to make the phase difference of two-phase low-frequency output currents be 90 deg., the third phase is connected with the midpoint of the two-phase electromagnetic blender, and the AC of the third phase is radical sign 2 times as great as those of the other two phases. The method adopts a current- frequency double closed-loop control. The current sensor collects two-phase current signals and PI regulation sections control the frequency of the output pulse by orthogonal transform, PWM drive, etc., thus controlling the amplitudes and frequencies of the two-phase orthogonal low-frequency voltages that are outputted by the inverter, and thus the invention implement the vector control of the magnetic force of blending of the electromagnetic blender. The invention improves the reliability of the electromagnetic blending system and reduces reactive compensating equipment and filtering equipment, saving the space and reducing the cost of the electromagnetic blender.

The invention discloses a digital controlling method of a three-phase voltage type grid inverter. The controlling method for the three-phase voltage grid inverter is based on the thought of a traditional dead beat technology, and comprises the steps of voltage predication, current predication, dead-time compensation and zero-sequence current injection improvement. The controlling method for the three-phase voltage grid inverter solves the problem that digital achievement of traditional dead-time controlling is poor in stability and tracing accuracy, wherein the problem is caused by the sampling channel and the delay of the calculation process and 'one-step-delay' control.

The invention discloses an enhanced VSVPWM (virtual space vector pulse-width modulation) method. The method comprises steps as follows: space vectors are converted into virtual vectors through PWM, and the action time duty ratio of each virtual vector is calculated; duration per unit values of three-phase output voltage at states P and N are figured out according to the correspondence between the virtual vectors and actual space vectors; the duration per unit values of the three-phase output voltage at the states P and N are used as modulating waves respectively, and a three-phase switch state is obtained; small vector action time is adjusted according to the difference between voltage of two direct-current capacitors or the fluctuation magnitude of midpoint potential, and PWM output of an inverter is obtained. With the adoption of the method, the problem of virtual vector PWM midpoint potential cumulative deviation is solved, midpoint potential balance control can be realized within any modulation degrees, the low-frequency fluctuation of the midpoint potential can be completely eliminated, the anti-interference performance of a system is improved, sizes of the direct-current capacitors are reduced, and the output waveform quality is improved.