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180 results about "Dead-beat control" patented technology

In discrete-time control theory, the dead-beat control problem consists of finding what input signal must be applied to a system in order to bring the output to the steady state in the smallest number of time steps.

Current predictive control method of permanent magnet synchronous motor

The invention relates to a current predictive control method of a permanent magnet synchronous motor, which belongs to the electric control field. The dynamic response speed and the control accuracy for the stator current control of the permanent magnet synchronous motor are improved through stator current prediction and deadbeat control, and the system delaying is compensated, so that the noise and the torque ripple of the motor in operation are reduced. The method comprises the steps as follows: obtaining a three phase stator current signal, and the electrical angle and the electrical angular speed of the motor rotor through the technologies of sensor sampling and a photoelectric coded disc or position sensorless detection; carrying out Clarke transformation and Park transformation on the stator current signal to obtain the stator current in a synchronous revolution dq coordinate system; substituting the obtained stator current signal in the dq coordinate system into a control equation of a current predictive controller of the permanent magnet synchronous motor, carrying out deadbeat control according to the given value of the obtained stator current in the dq coordinate system in an outer ring controller to obtain a stator voltage vector in the dq coordinate system; carrying out Park inverse transformation on the obtained stator voltage vector in the dq coordinate system, to obtain a pulse-width modulation (PWM) control signal of an inverter by a space vector pulse width modulation (SVPWM) method, controlling the stator current through the inverter, and then implementing the current predictive control over the permanent magnet synchronous motor.
Owner:EAST CHINA ARCHITECTURAL DESIGN & RES INST

Robust dicyclic photovoltaic grid-connected control method based on power feedforward

The invention discloses a robust dicyclic photovoltaic grid-connected control method based on power feedforward, which mainly comprises three parts: proportion integration (PI) control of exocyclic voltage, dead-beat control of endocyclic robust predictive current and power feedforward control, wherein the exocyclic PI control of the voltage is used for stabilizing the capacitive voltage of a direct-current side; the dead-beat control of the endocyclic robust predictive current is used for carrying out linear prediction on the voltage of a power grid at a next control period and carrying out non-linear prediction on grid-connected current by advanced control so as to obtain the command value of the grid-connected current at the next period; and then, PWM (pulse-width modulation) and grid-connected control are realized by the dead-beat control. According to the robust dicyclic photovoltaic grid-connected control method based on the power feedforward, a photovoltaic grid-connected inverter has higher robustness, wider stability margin and quicker dynamic response, and the requirement of grid-connected running of an inverter is better met.
Owner:HUNAN UNIV

Grid-connected generation control method for photovoltaic power generation converter

The invention provides a grid-connected generation control method for a photovoltaic power generation converter. The method comprises the following steps of: grid voltage software phase lock, voltage outer loop establishment, current control and grid voltage orientated vector control, wherein the grid voltage software phase lock adopts a software three-phase phase-locked loop method; a phase-locked loop consists of a phase detector, a loop filter and an oscillator; the grid voltage orientated vector control adopts a double-closed-loop cascade control structure, namely a voltage outer loop and a current inner loop; the voltage loop controls a direct-current bus voltage; and the current loop controls an alternating-current side input current. By the method, the orientation is accurate, the direct-current bus voltage is controlled to be stable, and maximum power point tracking control is realized. Deadbeat control design is performed aiming at the current loop, so that the current loop controls the alternating-current side input current according to a current command given by the voltage loop and unit power factor operation is realized. By adopting a feedforward decoupling control method, stable grid-connected operation can be realized.
Owner:HARBIN JIUZHOU ELECTRIC TECHNOLOGY CO LTD

Vector screening and duty cycle combined motor model prediction control system and method

The invention discloses a vector screening and duty cycle combined motor model prediction control system and method. The method comprises the steps that a reference voltage vector is acquired according to the idea of no-beat control; the sector of the reference voltage vector is judged through the position angle of the reference voltage vector, and at the same time two effective non-zero voltage vectors are quickly selected; the comparison between the reference voltage vector and two quickly selected effective non-zero voltage vectors is used as a value function; a new value function is provided, and a duty cycle control method is used to calculate the action time of the non-zero voltage vectors; and based on the principle of switching loss minimization, the appropriate zero voltage vector is selected according to the non-zero voltage vectors, and the action time of the zero voltage vector is calculated. The switching state and action time of the non-zero voltage vectors and the switching state and action time of the zero voltage vector are applied on an inverter in turn. The inverter converts the switching state into voltage and outputs the voltage to a permanent magnet synchronous motor to drive a motor to run.
Owner:SOUTHEAST UNIV

Parallel cross operation method of critical continuous conducting mode power factor corrector

InactiveCN1599188ARealize parallel interleavingRealize parallel interleaved workEnergy industrySingle network parallel feeding arrangementsSwitched currentClosed loop
The parallel connection interleaving operational method of the power factor corrector in the critical and consecutive conducting mode belongs to the field of the control technology of the power converter. It chooses the method of digital dead beat control, adopts single DSP, confirms one of the several shunt-wound BCM Boost convertors as the master convertor, which is controlled in closed loop, and the rest as the appurtenant convertors, which are controlled in open loop. Under the condition of variable switch frequency and sampling frequency, make the inductive current of the appurtenant convertors follow the inductive current of the master convertors and realize the parallel connection interleaving operation of the BCM Boost APFC convertor. It only samples the input voltage and the output voltage, does not need to detect the peak value of the switched current in the hardware or to judge the crossover point of the inductive current, can get relatively high power and control it more simply.
Owner:TSINGHUA UNIV

Three-phase photovoltaic grid-connected inverting control method and device thereof

The invention aims at providing a three-phase photovoltaic grid-connected inverting control method and a device thereof, relating to the technical field of solar energy power generating. The method and device gather secondary side line voltages u<ab>, u<bc> and u<ca>, and currents i, i and i<c> of a grid-connected isolation transformer, DC voltage Ud and current i<dc> of a panel; magnitude of grid-connected command current is obtained according to maximum power point tracking (MPPT); switching time is calculated by adopting deadbeat predictive current control strategy; on and off of a main circuit switch element are controlled by a controller according to the calculated time, thereby realizing control of grid-connected current. The invention can ensure system current to track the variation of the command current in a control cycle (us level), realize controllable power factor, low harmonic grid-connected current and steady and astatic system and has the characteristics of fast response speed, high tracking accuracy and efficiency, good reliability, etc.
Owner:天威新能源系统工程(北京)有限公司

Controller of exciting power-supply net sided converter for double-feedback speed-variable frequency-constant wind-driven generator

The invention is concerned with a controller of side converter to excitation electrical source web of double fed variable speed constant frequency wind generator. It controls current by a deadbeat control based on predicted current control, turns the current command signal of dq coordinate to two-phase immobile coordinate to get positive and negative order current present value of alpha and beta axes. Get present value of current to two-phase immobile coordinate through addition operation and carry immobile coordinate commutation about current of power system to get alpha and beta component of actual current value. Make the difference of command and present value, and get inductance pressure drop according to change ratio of current to count the input voltage, and get impulse signal to control on-off tube through SVPWM (space voltage vector). It keeps the control precision of DC voltage, eliminates influence to rotor side converter of fluctuation to DC side voltage, restrains common-mode voltage and differential-mode voltage output by rotor side converter to reduce burden of processor under lopsided state of power system.
Owner:INST OF ELECTRICAL ENG CHINESE ACAD OF SCI

STATCOM unbalance compensation control method based on modular multilevel converter

The invention discloses a STATCOM unbalance compensation control method based on a modular multilevel converter (MMC). The method comprises a converter compensation current dead-beat control method and a converter interphase circular current active damping control method. A comprehensive compensation current dead-beat control part is used for compensating active loss in the MMC by controlling active current, reactive current and negative-sequence current which are output by the MMC so as to eliminate unbalance of the current of a power grid and compensate reactive power; the interphase circular current active damping control method is used for summing by detecting the bridge arm current of upper and lower bridge arms of each phase and multiplying by 0.5 to obtain the circular current of each phase, and superposing the output of three-phase current passing through an active damping controller to dead-beat control output so as to inhibit the alternating current component of the circular current, reduce the current stress of converter devices and reduce the loss of the converter. Through the adoption of the method provided by the invention, compensation of the negative-sequence current and reactive current of unbalanced load of the power grid is realized, inhibition of the interphase double frequency circular current of the MMC is simple, the response speed is high and the stability is high.
Owner:HUNAN UNIV

Permanent magnet synchronous motor quasi dead-beat model prediction flux linkage control method

The invention discloses a permanent magnet synchronous motor (PMSM) quasi dead-beat model prediction flux linkage control method comprising steps of: computing a stator flux linkage vector reference value at a next moment within a limited control framework, and obtaining a target voltage vector according to the reference value and a dead-model control idea; determining the sector of the target voltage vector in virtue of the position angle of the target voltage vector and selecting three valid voltage vectors by using the sector; predicting the stator flux linkage vector at the next moment according to the three valid voltage vectors; and obtaining the optimum on-off state of an inverter by optimizing a value function, wherein the inverter outputs voltage to a PMSM according to the optimum on-off state. The value function does not include weight calculation. When the value function is optimized, only the three valid voltage vectors are optimized so that algorithm operation time is shortened.
Owner:SOUTHEAST UNIV

Micro-grid multi-inverter parallel voltage unbalanced compensation method

The invention discloses a micro-grid multi-inverter parallel voltage unbalanced compensation method. The method relates to an unbalanced compensation ring, a power droop control ring and a voltage and current ring. On the basis of traditional power droop control, three-phase negative sequence voltages and currents are detected, the negative sequence reactive conductance Q-G unbalanced droop control ring is introduced, directive current reference values are synthesized and revised, and then unbalanced compensation of micro-grid voltage is achieved. Through P-f, Q-E and Q-G droop control, distributed power inverters can independently adjust and output fundamental wave frequency, voltage amplitude and unbalanced compensation conductance, and therefore active and reactive equilibrium distribution can be achieved among the inverters. Quasi-resonance PR control is adopted by the voltage and current control ring, astatic control of the voltage is achieved, dead-beat control is adopted, and then accurate control of currents in an inner ring is achieved. According to the method, the three-phase inverters in a micro-grid possess the unbalanced compensation capacity, and therefore micro-grid three-phase voltage balance is maintained.
Owner:HUNAN UNIV

Permanent magnet synchronous motor control method based on second-order terminal slip form

ActiveCN109560736ADecrease the value of switching gainSolve the problem of excessive speed changeElectronic commutation motor controlElectric motor controlVoltage vectorLoad torque
The invention discloses a permanent magnet synchronous motor control method based on a second-order terminal slip form. The method comprises the following steps that: S1: under a rotator coordinate system, obtaining dq shaft current id and iq; S2: obtaining a q shaft current given value iq'; S3: obtaining a load torque observation value; S4: after compensation, obtaining a q haft current given value iq<*>; S5: obtaining input voltage u[Alpha] and u[Beta] under an [Alpha] [Beta] coordinate system; and S6: adopting a space voltage vector pulse width modulation technology to convert the u[Alpha]and the u[Beta] obtained in S5 into an on-off signal used for controlling a three-phase inverter power device, and finally, driving the permanent magnet synchronous motor to operate. By use of the method, a current loop controller adopts a dead-beat controller, a speed loop adopts a two-order terminal slip form controller to realize the high-accuracy control of the permanent magnet synchronous motor, and therefore, the problem that the speed change range of the permanent magnet synchronous motor with small rotational inertia is large during load mutation or given revolving speed mutation can be solved.
Owner:SOUTHEAST UNIV

Smooth switching control method for operating mode of micro-grid inverter of different capacity micro sources

The invention relates to a smooth switching control method for an operating mode of a micro-grid inverter of different capacity micro sources. The method is applied to a micro-grid consisting of multiple different capacity micro sources. The method comprises the following steps: by virtue of switching among different switches, realizing smooth switching of an inverter control method under island/grid-connected operating modes, wherein the island operation is controlled by robust V-f based on capacitive equivalent output impedance so as to generate the voltage reference quantity, and the grid-connected operation is controlled by adopting PQ; adding a pre-synchronization link to be used for controlling the inverter output voltage to trace the power grid voltage when the inverter is switched from island operation to the grid-connected operation, and ensuring that the grid-connected operation is smoothly finished; introducing virtual impedance, designing the equivalent output impedance of the inverter to be capacitive, reducing loop current between parallel inverters, and well realizing power distribution among different capacity micro sources; and adopting double-loop control of the outer voltage loop and inner current loop, wherein the outer voltage loop is controlled by PI, and the inner current loop is controlled by dead beat. Therefore, the system is high in stability and high in dynamic response speed.
Owner:STATE GRID CORP OF CHINA +1

Large-power high-frequency switch eliminator power comprehensive control method

The invention discloses a large-power high-frequency switch eliminator power comprehensive control method which includes a front-stage three-phase voltage type rectifier control method and a back-stage high-frequency direct current / direct current (DC / DC) convertor control method. A parameter self-adaptation control dead beat control method based on power front feed is adopted in a front-stage three-phase voltage type rectifier, and quick response of a system and quick track of load change are achieved; and through parameter self-adaptation control, on-line dead beat controller parameter correction can be achieved, matching of control parameters and actual parameters can be achieved, bad influence on control performance because of parameter perturbation or drifting can be eliminated, and control robustness can be improved. A virtual impedance self-current-sharing control method based on output voltage feedback is adopted in a back-stage high-frequency DC / DC convertor, conflict between current-sharing control accuracy and load output voltage accuracy can be effectively solved, virtual impedance dereference can not influence output adjustment of load voltage, and adaptation capacity of the virtual impedance current-sharing method on occasions where accuracy demands on the output voltage are high is improved.
Owner:HUNAN UNIV

Controlling method for predicting direct power of three-phase voltage source type PWM converter

The invention discloses a controlling method for predicting direct power of a three-phase voltage source type PWM converter. The dead-beat controlling concept in predictive control is introduced into the direct power controlling strategy of the three-phase voltage source type PWM converter, two controllers, namely a voltage controlling ring and a dead-beat power controlling ring, finish power decoupling control and direct current voltage stabilizing control together, and a phase-locked loop is not needed. In addition, the space vector modulation manner is used so as to achieve switching frequency constancy controlled by direct power, and therefore an output filter is easy to design and engineering is easy to achieve. The controller is simple in design and good in performance of controlling and has the advantages of being fast in response speed, high in controlling precision and good in robustness.
Owner:湖南中聚福能源科技有限公司

Motor control method based on dead-beat optimization and double vector model prediction

The invention discloses a motor control method based on dead-beat optimization and double vector model prediction. The motor control method comprises the steps of: acquiring current, flux linkage and torque of a next moment according to model prediction control; calculating to obtain a reference voltage vector according to dead-beat control; utilizing rotor position information to obtain the reference voltage vector and a position angle in a stationary coordinate system; judging sectors of voltage vectors according to the position angle, and accordingly selecting the voltage vector for calculation to obtain a predicted voltage vector with a minimal target function value; and calculating to obtain action time of the predicted voltage vector and a zero vector, and acquiring pulse signals of 6-path PWM waves for driving an inverter to act. The motor control method obtains the position angle of the reference voltage vector through dead-beat control, thus 8 voltage vectors in model prediction control are reduced to 3, the calculation workload of a control system is reduced, the torque pulsation is further reduced through the double vector model, and the stability of a motor control system is further improved.
Owner:NORTH CHINA UNIVERSITY OF TECHNOLOGY

Dead-beat control system and method for permanent magnet synchronous motor with complex vector modeling in discrete domain

ActiveCN108768233AControl static difference improvementGood static controlTorque ripple controlVector control systemsMotor speedPermanent magnet synchronous motor
The invention discloses a dead-beat control system and a method for a permanent magnet synchronous motor with complex vector modeling in a discrete domain, which is characterized in that the system comprises a permanent magnet synchronous motor, an encoder, an abc-dq coordinate conversion unit, a speed outer loop PI controller, a current dead-beat controller, a dq-Alphabeta coordinate conversion unit, an SVPWM modulation module, and an inverter. The invention has the beneficial effects that: in the modeling process of the current prediction model, the inverter and the motor are regarded as a whole modeling, the delay action of the inverter is considered, and the established model is more accurate than the traditional current prediction model; a current error integral compensation module isadded to the dead-beat controller, the stator current control static error is greatly improved, and finally the purpose of no-beat control at low switching frequency is achieved. The results show that the motor speed and stator current are well controlled, the motor stator current control static error is small, and the output torque ripple is also improved.
Owner:ZHUZHOU ELECTRIC LOCOMOTIVE CO +1

Improved dead-beat control method for pulse width modulation (PWM) rectifier at unbalance of voltage of power grid

InactiveCN102891614ASuppress power pulsationGuarantee the output qualityAc-dc conversionBandpass filteringEngineering
The invention discloses an improved dead-beat control method for a pulse width modulation (PWM) rectifier at unbalance of voltage of a power grid. According to the technical scheme, the key point is that the improved dead-beat control method for the PWM rectifier at unbalance of voltage of the power grid comprises the following steps of: respectively obtaining an active power double-frequency voltage compensation item and a reactive power double-frequency voltage compensation item by a bandpass filter and a proportion and integration (PI) controller through compensation voltage calculation according to input active power and input reactive power; obtaining a reference value of input voltage of the converter by taking the voltage compensation items as inputs of a built voltage reference value calculation model; performing reversed Park conversion by taking the voltage position angle of the power grid as a conversion angle to obtain input voltage under a two-phase static coordinate system; and generating a switching signal for controlling a power device by performing space vector pulse width modulation on the voltage signal. By the method, the model of the PWM rectifier can be compensated in real time, the pulses of the input active power and the input reactive power of the PWM rectifier can be effectively suppressed, and the voltage fluctuation of a direct current bus can be reduced.
Owner:HENAN NORMAL UNIV

Two-vector predictive control system and method for permanent magnet synchronous motor based on geometric method

ActiveCN109039189AImprove steady-state control performanceSimplify analytical calculationsElectronic commutation motor controlVector control systemsTwo-vectorVoltage vector
The invention discloses a two-vector predictive control system and method for a permanent magnet synchronous motor based on a geometric method. The method of the invention comprises the following steps: 1, obtaining a reference voltage vector according to a deadbeat control idea; 2, quickly screening three voltage vectors, including two non-zero vectors and one zero vector, through the position angle of the reference voltage vector as an alternative vector; 3, selecting two voltage vectors from three candidate vector by using a geometric method, and calculating a corresponding duty cycle; and4, converting the selected two voltage vectors and duty cycle into corresponding switching sequence, and output the optimal voltage to the permanent magnet synchronous motor through the inverter. Theinvention can effectively improve the steady-state performance of the permanent magnet synchronous motor, and is easier to understand than the traditional two-vector model predictive control system based on the analytical method, and is easy to extend to the control of the multi-phase motor.
Owner:SOUTHEAST UNIV

Open-loop and/or closed-loop control system of a 3-phase power converter for the operation of an asynchronous machine

An open-loop and / or closed-loop control device for operating an asynchronous machine which is fed by a 3-phase power converter. The open-loop and / or closed-loop control structure has a stator flux controller and a pulse pattern generator for generating pulse signals based on mean values. An output of the stator flux controller is connected to an input of the pulse pattern generator, with the result that the pulse pattern generator can generate the pulse signals as a function of a manipulated variable which is generated by the stator flux controller. The stator flux controller is configured so as to generate the manipulated variable as a function of a desired value of the stator flux of the asynchronous machine and as a function of a desired value of the torque of the asynchronous machine. The stator flux controller has a dead-beat control response.
Owner:BOMBARDIER TRANSPORTATION GMBH

Multi-step model forecast control-based circulation control method of modular multilevel converter (MMC)

ActiveCN107147315ASmall amount of calculationRealize multi-step optimal controlAc-dc conversionHarmonicOptimal control
The invention discloses a multi-step model forecast control-based circulation control method of a modular multilevel converter (MMC). The circulation control method comprises the following steps of firstly, performing dead beat control by an AC output current of the MMC to obtain reference input module numbers of an upper bridge arm and a lower bridge; secondly, performing single-step circulation forecast by combining a circulation current discrete state equation; thirdly, selecting the input module number conforming to a single-step forecast effect, and performing multi-state circulation forecast; and finally, solving an optimal solution of the bridge arm input module number, and achieving multi-step optimal control of a circulation current so that a harmonic current in the circulation current is effectively suppressed. The circulation control method comprises AC dead beat control, circulation single-step forecast and circulation multi-step forecast. Aiming at the circulation harmonic current of the MMC, a multi-step forecast finite control set is built by a multi-step model forecast control method according to the optimal solution obtained by single-step forecast, the cycle forecast frequency required by multi-step forecast can be substantially reduced, and the calculation quantity of a controller is effectively reduced.
Owner:HUNAN UNIV

Lithographic apparatus, device manufacturing method, performance measuring method, calibration method and computer program

A controller for a pulsed radiation source is a closed-loop controller of minimum order, preferably first, to effect dead beat control. Performance indicators for a pulsed radiation source in a lithographic apparatus are based on moving averages (MA) and moving standard deviations (MSD) of the error between target and actual pulse energies. The normalized indicators are given by:MAE,n⁡(xk)=1∑i=k-(Nslit-e-1)k⁢⁢Epref⁡(i)·∑i=k-(Nslit-e-1)k⁢⁢Eperr⁡(i)⁢⁢(k=Nslit-e⁢⁢…⁢⁢Nscan),wherein Epref(i) and Eperr(i) indicate reference energy per pulse and energy error per pulse for point i andMSDE,n⁡(xk)=1Nslit-e-1⁢∑i=k-(Nslit-e-1)k⁢[Eperr⁡(i)Epref⁡(i)-MAE,n⁡(xk)]2⁢⁢(k=Nslit-e⁢⁢…⁢⁢Nscan).
Owner:ASML NETHERLANDS BV

Feedforward decoupling control method based on three-phase two-arm tri-level active power quality compensator

The invention discloses a feedforward decoupling control method based on a three-phase two-arm tri-level active power quality compensator. For the purpose of realizing reactive compensation, negative sequence compensation and harmonic compensation, one two-input and two-output coupling system is decoupled into two independent single-input single-output systems, thus quickly tracking current and improving reliability of the system; and a corresponding PWM (pulse width modulation) method is adopted to drive a switching tube to acquire an expected current. The feedforward decoupling deadbeat control method based on the three-phase two-arm tri-level active power quality compensator can be used to realize complete compensation and inhibition of the negative sequence and harmonic waves of the systems.
Owner:HUNAN UNIV

Equal power distribution control method of multiple parallel single-phase inverters for solar power generation

ActiveCN102437589AMeet the needs of parallel operationPower sharing controlSingle network parallel feeding arrangementsProportion integration differentiationDistribution control
The invention discloses an equal power distribution control method of multiple parallel single-phase inverters for solar power generation. In the invention, a parallel single-phase multi-inverter system for solar power generation is composed of a plurality of parallel inverters. The equal power distribution control method has the beneficial effects that by means of combination of a PID (proportion integration differentiation) control method and a deadbeat control method, the disadvantages of a voltage and current dual-loop PID control mode are overcome so as to achieve higher reliability, higher stability and faster dynamic response for equal power distribution control of the parallel inverters, thus better meeting the requirement for parallel operation of the inverters.
Owner:HUNAN UNIV

Field failure-considered robust fault-tolerant prediction control method and device

The invention discloses a field failure-considered robust fault-tolerant prediction control method and a device. The method comprises the following steps of firstly, designing a composite observer, wherein a voltage compensation amount and a current prediction value at the next moment are observed at the same time by the observer according to a motor stator current, a stator voltage and a motor rotating speed in two-phase rotating coordinate system; secondly, obtaining a robust fault-tolerant prediction control method through responding to a quick and accurate tracking command current based onthe non-differential-beat control principle. According to the method, the influence of system parameter perturbation and permanent magnet demagnetization on current vectors is eliminated through adding the voltage compensation amount. The sampling current value at the current moment is replaced by the current prediction value at the next moment, so that the one-beat delay compensation of the current can be realized. Finally, the space vector pulse width SVPWM modulation is carried out on an obtained new voltage command, so that a six-path PWM pulse signal for driving a motor to run is obtained. According to the invention, the current fast non-static tracking under the condition of motor parameter perturbation and permanent magnet demagnetization is realized. The harmonic current is reduced, and the control performance of a current loop is optimized. The method and the device can be widely applied to occasions wherein a permanent magnet synchronous motor is adopted as a driving system.
Owner:HUNAN UNIV OF TECH

Control method for three-phase PWM rectifier suitable for power grid waveform distortion

ActiveCN103944428ASuppression of Harmonic DistortionGuaranteed input power factorAc-dc conversionActive disturbance rejection controlVoltage distortion
The invention discloses a control method for a three-phase PWM rectifier suitable for power grid waveform distortion. The control method for the three-phase PWM rectifier suitable for the power grid waveform distortion mainly includes that extracting a current reference signal under input voltage distortion and unbalanced disturbance, and actively injecting negative-sequence current, improved dead-beat inner current loop which is forecast through combining with linear extrapolation, and outer direct voltage loop performed with active disturbance rejection control. The control method for the three-phase PWM rectifier suitable for the power grid waveform distortion plays roles of inhibiting the harmonic wave of the input current of the PWM rectifier, injecting proper negative-sequence current to eliminate the secondary power pulse of the output direct current voltage of the PWM rectifier, improving the transient response of the output direct current voltage, and compensating the influences of all kinds of delay on the dead-beat control. The control method for the three-phase PWM rectifier suitable for the power grid waveform distortion is capable of obviously reducing the secondary wave of the output direct current voltage under the disturbance of the input harmonic wave and unbalanced voltage, improving the transient response speed of the PWM rectifier, reducing the transient offset of the direct current voltage, and improving the system control precision.
Owner:HUNAN UNIV +1

Method for controlling parallel running of micro-grid multi-inverter combination on basis of capacitor voltage differentiation

The invention relates to a method for controlling parallel running of a micro-grid multi-inverter combination on the basis of capacitor voltage differentiation. The method is suitable for a micro-grid multi-inverter parallel control system consisting of a plurality of inverters connected to one another in parallel. Filtering capacitor voltage is differentiated to obtain filtering capacitor current, the filtering capacitor current can be acquired without the aid of a current transformer, and the designing amount of a hardware circuit is reduced; alternating quantity serves as the filtering capacitor voltage and filtering inductor current during power computing, and the outputting power of the inverters is reflected accurately; virtual complex impedance is guided in droop control, the output impedance of the inverters is ohmic, the inverters are suitable for a low-voltage micro-grid, and ring current among the inverters which are connected to one another in parallel is greatly reduced; and a dead-beat control method is used in current inner ring control, the filtering inductor current is controlled, the robustness of the system is high, the stability of the inverters which are connected to one another is high, and dynamic response is fast.
Owner:STATE GRID CORP OF CHINA +1

H-bridge cascading STATCOM dead-beat control method based on discrete state observer and discrete sliding-mode observer

The invention discloses an H-bridge cascading STATCOM dead-beat control method based on a discrete state observer and a discrete sliding-mode observer, and relates to the H-bridge cascading STATCOM control technology. The H-bridge cascading STATCOM dead-beat control method aims to solve the problem that an existing dead-beat control method must be matched with a good reference current prediction method and a common prediction method needs to be dependent on an accurate mathematical model, so that the existing dead-beat control method is seriously limited in actual application. According to the H-bridge cascading STATCOM dead-beat control method, the discrete state observer is constructed according to a simple mathematical model of an H-bridge cascading STATCOM, and a reference instruction current at a k+1 moment is obtained by means of calculation at a k moment by adopting the prediction function of the discrete state observer, so that dead-beat control is realized in a true sense; the discrete sliding-mode observer is constructed for conducting real-time observation on ud (k) and uq (k) of three-phase voltage values output by the STATCOM under a dq coordinate system. The H-bridge cascading STATCOM dead-beat control method based on the discrete state observer and the discrete sliding-mode observer is applied to reactive compensation and harmonic wave filtering of a power grid.
Owner:山东汉德自动化控制设备有限公司

Method for cooperating power/current mass of microgrid inverter and active power filter

The invention discloses a method for cooperating power / current mass of a microgrid inverter and an active power filter. The method is characterized in that under the condition of unbalanced power grid voltage, the certain contradiction exists between the fluctuating of the output power of the grid connecting of the microgrid inverter and the distortion of the current of the grid connecting, and a cooperative decision-making layer will set three parameters including the weighting coefficient, active power reference value and reactive power reference value, and transmit to a software layer, so as to cooperate the power / current mass of the microgrid inverter and the active power filter; the active power filter in the software layer uses current inner loop dead-beat control of voltage outer loop PI to control the size of the compensation current for the whole system, of the active power filter; the microgrid inverter uses current inner loop PR (proportional resonant) control of an alpha-beta coordinate system to control the output current of the microgrid inverter; a hardware execution layer produces expected control action to control the stable running of the microgrid inverter and the active power filter. The method has the advantage that the contradiction between the fluctuating of the output power of the microgrid inverter and the distortion of the current under the condition of unbalanced power grid voltage is balanced, so as to improve the running property of the whole system.
Owner:HUNAN UNIV

Improved specified sub-harmonic current compensation control method for active power filter

The present invention relates to an improved specified sub-harmonic current compensation control method for an active power filter. Based on the harmonic current control of a conventional shunt activepower filter with extracted each sub-harmonic current as a harmonic current command, the PI closed-loop control on each sub-harmonic current is carried out. At the same time, after a fundamental wavecurrent command value and a harmonic wave current command value are superimposed, a switch signal of a power switch tube is obtained through a deadbeat controller, the tracking of harmonic command current is achieved, thus the high accuracy compensation of specified sub-harmonic current can be ensured, and the dynamic performance of the system can be ensured.
Owner:华夏天信物联科技有限公司

High-efficiency stable photovoltaic single-phase grid connected control method with double MPPT functions

The invention provides a high-efficiency stable photovoltaic single-phase grid connected control method with double MPPT functions and belongs to the technical field of photovoltaic generating control. The method is characterized in that: a high-speed digital signal processor and a C-language dynamic fixed point algorithm are utilized for forming a high-performance high-reliability control algorithm for an overall photovoltaic single-phase grid connected control system; by using a two-stage type grid connected control structure, a maximum power point tacking strategy of double MPPT rapid smoothing, and a grid connected current prediction dead-beat control algorithm, multiple strings of photovoltaic arrays are enabled to be at optimization operation states and the maximum energy emitted by the photovoltaic arrays is transformed through a stable bipolar type structure for outputting to a local electrical network; and at the time when the multiple strings of photovoltaic arrays are provided with double MPPT maximum power point tacking and grid connected current prediction dead-beat control, photovoltaic grid connected current is enabled to be completely consistent with a local single-phase voltage phase. The advantages are as follows: the power factor is 1, and the grid connected current harmonic wave distortion rate is lower than 3%, thus the system operation is safe and reliable.
Owner:周德佳 +1
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