A kind of asynchronous motor vector controller
Technical field
The present invention relates to a kind of asynchronous motor vector controller, is a kind of AC speed regulating equipment, belongs to the electric machines control technology field.
Background technology
In the design of asynchronous motor vector controller, the algorithm of controller is its core, in at present general Vector Control System of Induction Motor algorithm, observation to the rotor magnetic linkage is very important, directly influence asynchronous machine control effect and motor runnability, rotor flux observation can be by realizing indirectly that to the amplitude of stator magnetic linkage and the observation of phase place the observation procedure of stator magnetic linkage mainly contains following 3 kinds:
1) direct computing method, this method is simple, dynamic response is fast, but the parameter of electric machine that relies on is more, and uncompensated for open loop, cause result of calculation to become inaccurate easily with the motor operating condition;
2) based on the method for various observers, when the estimating system state, for making system's overall situation stable, the observer of different operational speed range need be taked different gain matrixs. and this method is subjected to the influence of the parameter of electric machine very big, extra presence observer need be set estimate the parameter of electric machine in real time, increase the complexity of system configuration;
3) based on the method for back-emf integration, this method only relies on the motor stator resistance parameter, realizes very simply, but low-speed performance is bad.
Summary of the invention
The objective of the invention is to, overcome the shortcoming of prior art, provide a kind of and make the reliable precision operation of asynchronous machine control, improve back-emf integration initial value and direct current offset, also improve the integrate phase offset issue simultaneously, improve asynchronous machine magnetic linkage control effect, improve the accuracy of observation of stator magnetic linkage and the asynchronous motor vector controller of the stability of motor when nominal load.
Technical scheme of the present invention is: a kind of asynchronous motor vector controller, it comprises a DSP control board with Vector Control System of Induction Motor algorithm of integrator, an I/O plate that is used for IO amount and rate signal observing and controlling, one is used for the fibre optic plate that PWM drives and braking drives, a conditioning plate that is used for DC bus-bar voltage and output current signal observing and controlling; Described integrator is in asynchronous machine model observation module, form by feedforward part and feedback fraction two parts, comprise integration orthogonality detection module, quadrature compensation PI adjustment module, cartesian coordinate is tied to the polar coordinates modular converter, polar coordinate system is to the cartesian coordinate modular converter, magnetic linkage amplitude amplitude limit module.
Further technical scheme is:
Described asynchronous motor vector controller, its integration orthogonality detection module are α by obtaining behind calculating back-emf and its integration, the detection module of the orthogonality error-detecting of β axle stator magnetic linkage component; Adding the quadrature detection compensation rate in the integrator is stator magnetic linkage amplitude compensation amount, is used for that the stator magnetic linkage component is calculated the phase deviation that produces and compensates.
Described asynchronous motor vector controller, its quadrature detection compensation rate is smaller or equal to 0.02 times of rated value.
Described asynchronous motor vector controller, its DSP control board comprises the DSP digital signal processor, preserve data and fault message (NVRAM) nonvolatile memory that extends out, the input of monitoring I/O plate the switching signal state and notify (CPLD) programmable logic device that DSP in time handles, analog to digital converter, and (PLC) (RS485) serial communication device of programmable logic controller (PLC) communication, also have (ADC) analog to digital converter, (PWM) pulse-width signal processor.
Described asynchronous motor vector controller, its I/O plate comprises photoelectric encoder, input state signal detector, and the isolation and the level conversion processing apparatus of output switch actuating signals.
Described asynchronous motor vector controller, its fibre optic plate comprises the fiber optic connector spare between control loop and the power cell, and control unit powers on and the protection device of power down process.
Described asynchronous motor vector controller, the connecting relation of its DSP control board, I/O plate, fibre optic plate, conditioning plate is: the I/O plate connects with (CPLD) programmable logic device in the DSP control board, (PWM) pulse-width signal processor output in fibre optic plate and the DSP control board connects, and conditioning plate connects with (ADC) analog to digital converter in the DSP control board.
Described asynchronous motor vector controller, its conditioning plate comprise isolation, filtering device and the level conversion to output current and DC bus-bar voltage analog signal, possess the device of current/voltage protection merit simultaneously; Described integration quadrature compensation PI adjustment module is that an orthogonality detection error that is used for obtaining by detection computations is carried out the module that the PI adjusting obtains magnetic linkage amplitude compensation value.
Described asynchronous motor vector controller, its cartesian coordinate are tied to the polar coordinates modular converter and are one and realize α, β axle stator magnetic linkage to the magnetic linkage amplitude with the module of magnetic linkage angular transition; Described polar coordinate system is one to the cartesian coordinate modular converter and realizes stator magnetic linkage amplitude and magnetic linkage angle to α, the module of β axle stator magnetic linkage component conversion; Described magnetic linkage amplitude amplitude limit module is one and realizes stator magnetic linkage amplitude amplitude limit, eliminates the module of stator magnetic linkage integral offset and integration initial value influence.
Technique effect of the present invention is: improved back-emf integration initial value and direct current offset, also improved simultaneously the integrate phase offset issue, also improve asynchronous machine magnetic linkage control effect, improved the accuracy of observation and the stability of motor when nominal load of stator magnetic linkage.The present invention has done corresponding improvement on prior art, relatively simple for structure, does not relate to the quantity of parameters of asynchronous machine, is easy to realize.
Description of drawings
Fig. 1 is a controller architecture theory diagram of the present invention;
Fig. 2 is the DSP control board vector control system structured flowchart of one embodiment of the invention;
Fig. 3 is the amplitude compensation integrator schematic diagram of prior art;
Fig. 4 is integrator structure figure of the present invention;
Fig. 5 is the magnetic linkage control design sketch of prior art;
Fig. 6 is an one embodiment of the invention magnetic linkage control design sketch;
Fig. 7 is one embodiment of the invention asynchronous machine nominal load electric current and voltage figure.
The name of each mark is called among the figure: the 1-DSP control board; 1.0-DSP digital signal processor; 1.1-analog to digital converter; 1.2-digital to analog converter; 1.3-static random access memory; 1.4-nonvolatile memory; 1.5-serial communication device; 1.6-lan controller; 1.7-programmable logic device; 1.8-pulse-width signal processor; The 2-I/O plate; The 3-fibre optic plate; The 4-conditioning plate; The 5-programmable logic controller (PLC); The 6-man-machine interface; 7-integration orthogonality detection module; 8-quadrature compensation PI adjustment module; The 9-cartesian coordinate is tied to the polar coordinates modular converter; The 10-polar coordinate system is to the cartesian coordinate modular converter; 11-magnetic linkage amplitude amplitude limit module.
Embodiment
It is as follows that the invention will be further described in conjunction with the accompanying drawings and embodiments:
As shown in the figure, a kind of asynchronous motor vector controller of the present invention, it has a DSP control board 1 with Vector Control System of Induction Motor algorithm of integrator, an I/O plate 2 that is used for IO amount and rate signal observing and controlling, one is used for PWM and drives and brake the conditioning plate 4 that 3, one of fibre optic plates that drive are used for DC bus-bar voltage and output current signal observing and controlling; As shown in Figure 4, described integrator is in asynchronous machine model observation module, form by feedforward part and feedback fraction two parts, an integration orthogonality detection module 7 is arranged, quadrature compensation PI adjustment module 8, cartesian coordinate is tied to polar coordinates modular converter 9, and polar coordinate system is to cartesian coordinate modular converter 10, magnetic linkage amplitude amplitude limit module 11.Described integration orthogonality detection module 7 is the α by obtaining behind calculating back-emf and its integration, the detection module of the orthogonality error-detecting of β axle stator magnetic linkage component; Adding the quadrature detection compensation rate in the integrator is stator magnetic linkage amplitude compensation amount, is used for that the stator magnetic linkage component is calculated the phase deviation that produces and compensates.Described quadrature detection compensation rate is smaller or equal to 0.02 times of rated value, and present embodiment quadrature detection compensation rate is 0.02 times of rated value (rated value is 1), can elect 0.01 times as required as, can also uncompensation.Described DSP control board 1, its composition comprises DSP digital signal processor 1.0, preserve data and fault message (NVRAM) nonvolatile memory 1.4 that extends out, the input of monitoring I/O plate the switching signal state and notify (CPLD) programmable logic device 1.7 that DSP in time handles, analog to digital converter 1.1, and (PLC) (RS485) serial communication device 1.5 of programmable logic controller (PLC) 5 communications, also has (ADC) analog to digital converter 1.1, PWM pulse-width signal processor 1.8.Described I/O plate 2, its composition comprises photoelectric encoder, input state signal detector, and the isolation and the level conversion processing apparatus of output switch actuating signals.Described asynchronous motor vector controller, its fibre optic plate 3 comprises the fiber optic connector spare between control loop and the power cell, and control unit powers on and the protection device of power down process.The connecting relation of described DSP control board 1, I/O plate 2, fibre optic plate 3, conditioning plate 4 is: I/O plate 2 connects with (CPLD) programmable logic device 1.7 in the DSP control board 1, (PWM) pulse-width signal processor 1.8 outputs in fibre optic plate 3 and the DSP control board 1 connect, and conditioning plate 4 connects with (ADC) analog to digital converter 1.1 in the DSP control board 1.Described conditioning plate 4, its composition comprise isolation, filtering device and the level conversion to output current and DC bus-bar voltage analog signal, possess the device of current/voltage protection merit simultaneously; Described integration quadrature compensation PI adjustment module 8 is that an orthogonality detection error that is used for obtaining by detection computations is carried out the module that the PI adjusting obtains magnetic linkage amplitude compensation value.Described cartesian coordinate is tied to polar coordinates modular converter 9, be one and realize α, β axle stator magnetic linkage to the magnetic linkage amplitude with the module of magnetic linkage angular transition; Described polar coordinate system is one and realizes stator magnetic linkage amplitude and magnetic linkage angle to α, the module of β axle stator magnetic linkage component conversion to cartesian coordinate modular converter 10; Described magnetic linkage amplitude amplitude limit module 11 is one and realizes stator magnetic linkage amplitude amplitude limit, eliminates the module of stator magnetic linkage integral offset and the influence of integration initial value, adopted this improvement integrator the magnetic field observation technique guarantee accurate surveying in asynchronous machine rotor magnetic field.
Be described further as follows to principle of the present invention, technical scheme and good effect:
Asynchronous motor vector controller of the present invention, the calculating of integrating detector is realized the integrate phase compensation as closed loop feedback, in integrator, add the quadrature detection compensation rate, realized the complete quadrature of stator magnetic linkage vector and back-emf, improved the flux observation precision.Asynchronous motor vector controller of the present invention adopts algorithm structure as shown in Figure 2, obtain asynchronous machine given rotating speed and non-synchronous motor parameter by man-machine interface 6, calculate α by the Clarke conversion module, β shaft current component, in conjunction with reconstruct the rotor field of asynchronous machine is observed the controller output voltage, thereby obtain the decoupling zero that the rotor field angle realizes exciting current and torque current, carry out the PI computing in conjunction with given rotating speed and asynchronous machine actual speed and obtain the given of torque current, it is given that the given and actual magnetic linkage amplitude of magnetic linkage amplitude PI computing obtains exciting current, it is given that control by electric current loop calculates output voltage, obtain the pwm control signal of asynchronous machine control at last by space vector modulation algorithm, realize accurate control asynchronous machine.
As shown in Figure 1, it is the control principle block diagram of a kind of asynchronous motor vector controller of the present invention, DSP control board 1 its algorithmic system block diagram as shown in Figure 2, algorithm of the present invention is the vector control algorithm that adopts the integrator improved, and controlling object is the 300KW asynchronous machine, and load is a 300KW AC self-exciting synchronous generator unit, rated voltage is 380V during asynchronous machine triangle shape connection, rated current is 526A, and rated voltage was 658V when asynchronous machine had been adopted star connection, and rated current is 304A.As shown in Figure 3 be that the integrator of prior art amplitude compensation carries out stator magnetic linkage and calculates, the motor run with load is when 30hz, it is relatively poor that the rotor flux circle is controlled effect as shown in Figure 5.Effect behind the improved integrator that adds the integration quadrature compensation of the present invention shown in Figure 4, under same operating mode, rotor flux is controlled effect as shown in Figure 6 very big improvement.As shown in Figure 7, during stator magnetic linkage calculates, back-emf and stator magnetic linkage integration quadrature have very big deviation when adopting the improvement integrator of amplitude compensation, and along with the increase of output frequency, it is big more that quadrature phase detects skew, the operation of frequency converter band simulator, band carries output frequency integration quadrature phase deviation when 30hz, maximum deviation is near 8, after adopting the present invention to add the improvement integrator of integration quadrature compensation, under the same operating mode, back-emf and stator magnetic linkage integration orthogonality are greatly improved, and are converged in substantially near the null value; Aspect the motor band carries, when adopting the integrator of amplitude compensation, the constant inadequately and integrate phase deviation effects of rotor flux amplitude control as shown in the figure, increase along with the motor running frequency, magnetic linkage amplitude fluctuations and integrate phase deviation are increasing, and cause that finally output current fluctuation is excessive, and causing the output current overcurrent, motor can not reach the rated condition operation; After adopting the present invention to add the improved integrator of integration quadrature compensation, the frequency converter output voltage current waveform when motor operates in rated condition as shown in Figure 7; Adopt integrator of the present invention not only to have its intrinsic effect of improving integration initial value and direct current offset, also improved simultaneously the integrate phase offset issue, guaranteed the complete orthogonality of back-emf integration, improve asynchronous machine magnetic linkage control effect, improved the accuracy of observation and the stability of motor when nominal load of stator magnetic linkage.