Active electric filter device based on three close-loop control and three close-loop control method
Technical field
The present invention relates to a kind of active electric filter device based on three close-loop control, particularly relate to a kind of based on voltage outside
Ring, current inner loop and stablize active electric filter device based on three close-loop control and the three close-loop control method of corrector loop.
Background technology
Along with the development of Power Electronic Technique, various uses non-linear, impact equipment bring substantial amounts of to electrical network
Harmonic pollution, thus brings power factor low, and harmonic pollution is serious, and the series of problems such as system loss increasing.Along with electricity
The deterioration of energy quality, power quality awaits administering and improving.The quality of power supply refers to power supply from universal meaning and uses
Electricity quality, makes electrical equipment including voltage, the stable state of electric current and the deviation of transient state value, the degree of wave distortion, flickering etc.
Become power supply and the electrical problem of impact.And the pollution of electric energy quality harmonic at present is increasingly severe, some even has resulted in huge
Big economic loss.Additionally the effect between electric harmonic and capacitor is mutual, and it produces additionally the most in the capacitor
Power consumption, and serial or parallel connection resonance may be produced together with capacitor.Under the effect of capacitor, harmonic current can
To be exaggerated 2~5 times, and when resonance up to more than 30 times.Overvoltage and overcurrent that resonance causes can be greatly increased electric capacity
The loss of device and overheated, this often leads to the damage of capacitor.The impact of relay protection is mainly shown as making relay by harmonic wave
Acting characteristic distortion or effect reduce, and its consequence is often tripping or the malfunction of protection device.At present, metering uses electrostatic induction
Formula electric energy meter is manufactured and designed by power frequency (first-harmonic 50Hz) pure sinusoid exchange declared working condition.When there is electric harmonic, first-harmonic
Electric current and harmonic current all can produce eddy current on electric energy meter rotating disk, thus harmonic wave existence can affect the accuracy of metering.
Therefore the harmonic wave control product-active electric filter device for the harmonic pollution of electrical network arises at the historic moment.Current
Active electric filter device has been widely applied.The operation conditions of APF and compensation effect depend on that the control of APF itself is calculated
Method, traditional PI controls a large amount of uses along with active electric filter device, and its defect also begins to emerge, based on inner and outer ring
The control method of the PI load tracking weak effect to change, there is hysteresis in output phase place, so that the improvement effect of the quality of power supply
Fruit can not accomplish the end in view, and based on the active electric filter device that three close-loop control is theoretical, uses the Repetitive controller of predictability, right
Compensating output and have good tracking characteristics, compensation effect is good.
Summary of the invention
It is an object of the invention to overcome in prior art current inner loop control present in delayed phase, and provide a kind of
It is intended to optimize the active power filtering based on three close-loop control of tradition Double Loop Control System based on current inner loop and outer voltage
Device and three close-loop control method, increase prediction on the basis of tradition Double Loop Control System based on current inner loop and outer voltage
Property Repetitive controller link, to compensate output have good tracking characteristics, its performance is better than traditional double-loop control.
The object of the present invention is achieved like this:
A kind of active electric filter device based on three close-loop control, including system power supply USA, USB, USC, with system power supply
Smoothing reactor La, Lb, Lc that the three-phase output end of USA, USB, USC is connected, is connected with smoothing reactor La, Lb, Lc
The three phase full bridge inversion unit being made up of six insulated gate bipolar transistor IGBTs of S1, S2, S3, S4, S5, S6 and three-phase
The electric capacity C1 of the DC side of full-bridge inverting unit be connected two groups concatenation, C2, equalizing resistance in parallel on each group of electric capacity
R1, R2, it is characterised in that:
Being connected with between smoothing reactor La, Lb, Lc at system power supply USA, USB, USC and have voltage transformer, voltage is mutual
The outfan of sensor is connected to the systematic sampling port of master control borad;
Between smoothing reactor La, Lb, Lc and three phase full bridge inversion unit, it is installed with output current transformer, exports electric current
The outfan of transformer is connected to the output sample port of master control borad;
Each group of electric capacity of three phase full bridge inversion unit DC side connects and has DC voltage transformer, DC voltage mutual inductance
The outfan of device is connected to the DC side sample port of master control borad;
The insulated gate bipolar transistor IGBT of master control borad drives port to be directly connected to insulated gate bipolar transistor
The drive circuit of IGBT;Additionally load-side cross-under load current transformer, its secondary outfan is connected to the load electricity of master control borad
Stream sample port.
A kind of three close-loop control method of described active electric filter device based on three close-loop control, it is characterised in that: press
Carry out according to following steps:
Step 1), by through voltage transformer detection three-phase system power supply USA, USB, USC magnitude of voltage, through phaselocked loop
PLL obtains voltage-phase and carries out COS and the SIN sequence of park change;
Step 2), detect threephase load electric current ILA, ILB, ILC by load current transformer, and according in step 1
COS and SIN sequence converts through park, including C32Conversion and C convert, and are changed by threephase load electric current under three phase static coordinate system
Electric current under biphase rotating coordinate system dq coordinate, obtains threephase load fundamental current by filtering high-frequency harmonic (LPF), further according to
COS and SIN sequence in step 1, through park inverse transformation, is converted into three-phase and compensates target current iaf, ibf, icf;
Step 3), detected output current IO A, IOB, IOC by LEMA, LEMB, LEMC end of output current transformer, logical
Overcurrent internal ring PI regulation obtains interior circular current and controls output desired value;
Step 4), by DC side through direct current sampling transformer draw DC voltage value UDCA, UDCB, by summation after
And obtain DC side compensation energy target values through DC voltage outer shroud PI regulation;
Step 5), theoretical according to Repetitive controller, and according to load current repeat for foundation, mend through three-phase current
Repay desired value iaf, ibf, icfProofread with the phase place of three-phase output current IO A, IOB, IOC, and control to obtain Repetitive controller through PI
Desired value;Repetitive controller desired value is exported with step 3, step 4 desired value superpose through SVPWM, SVPWM be space vector
PWM regulates, and generates and triggers pulse train, controls insulated gate bipolar transistor IGBT turn-on and turn-off through IGBT drive circuit,
Thus control current transformer output and reach to compensate desired value.
Compared with existing active electric filter device, active power filtering based on three close-loop control proposed by the invention
Device has a following outstanding advantages:
1), the control to three-phase SVPWM current transformer DC voltage is achieved by outer voltage, it is ensured that DC voltage
Stable and control accuracy, and be kept stable at setting value;
2), by repeating the predictability control that electric current three close-loop control achieves the phase place of output electric current, improve compensation effect
Really, the interference produced because of phase problem and harmonic wave are decreased;
3), ensure that the stable, accurate, efficient of system by three close-loop control, it is to avoid cause because of the instability of device
Device failure.
Active electric filter device based on three close-loop control proposed by the invention, have output voltage control precision high,
The outstanding advantages such as compensation effect is good, system reliability is high.
Accompanying drawing explanation
Fig. 1 is the structural representation of the present invention.
Fig. 2 is the three close-loop control figure of the present invention.
Fig. 3 is the compensation effect figure of example A phase power network current.
Detailed description of the invention
Below in conjunction with the accompanying drawings be embodied as example the present invention be described in further detail: this embodiment is with this
Implement under premised on bright technical scheme, give embodiment and operating process, but protection scope of the present invention is not limited to
Following embodiment.
Fig. 1 is the structured flowchart of the active electric filter device based on three close-loop control that the present invention proposes, including for three
The inversion unit of phase SVPWM control output, the connection inductance La of grid side, Lb, Lc, system voltage transformer, load current are mutual
Sensor, output current transformer, direct current sampling transformer, for the drive circuit of three phase full bridge IGBT and be used for calculating and controlling
The governor circuit of system.The invention discloses a kind of active electric filter device based on three close-loop control, from improving conventional active electricity
The compensation tracking effect angle of power filter is set out, at outer voltage and the electric current of conventional Active Power Filter-APF (APF)
On the basis of the double-loop control algorithm of internal ring, it is additionally arranged predictability and repeats current control feedback correction link.And in design prediction
Property repeat the parameter of current control feedback correction link during, have employed and improve APF complete machine and compensate current tracking speed
Repeat PI and control technology, to seek the quick tracking effect of optimal system stability, constitute and meet the prediction that system stability requires
Property repeat current regulator joint, define and novel repeat current regulator based on outer voltage, current inner loop and predictability
The active electric filter device of three close-loop control.
As it is shown in figure 1, a kind of active electric filter device based on three close-loop control, including system power supply USA, USB, USC,
Smoothing reactor La, Lb, the Lc being connected with the three-phase output end of system power supply USA, USB, USC, with smoothing reactor La,
The three phase full bridge inversion being made up of six insulated gate bipolar transistor IGBTs of S1, S2, S3, S4, S5, S6 that Lb, Lc are connected
Electric capacity C1, the C2 of two groups of concatenations that unit is connected with the DC side of three phase full bridge inversion unit, in parallel on each group of electric capacity
Equalizing resistance R1, R2;
It is connected with between smoothing reactor La, Lb, Lc at system power supply USA, USB, USC and has system voltage transformer, electricity
The outfan of pressure transformer is connected to the system voltage sample port of master control borad;
Between smoothing reactor La, Lb, Lc and three phase full bridge inversion unit, it is installed with output current transformer, exports electric current
The outfan of transformer is connected to the output current sample port of master control borad;
Each group of electric capacity of three phase full bridge inversion unit DC side connects and has DC voltage transformer, DC voltage mutual inductance
The outfan of device is connected to the DC side sample port of master control borad;
The insulated gate bipolar transistor IGBT of master control borad drives signal port to be directly connected to insulated gate bipolar crystal
The drive circuit of pipe IGBT;Additionally load-side cross-under load current transformer, its secondary outfan is connected to the load of master control borad
Current sample port.
A kind of based on three close-loop control the active electric filter device of invention described above includes for three-phase SVPWM
Inversion unit, connect grid side inductance be La, Lb, Lc, system voltage transformer, load current transformer, output electric current
Transformer, direct current sampling transformer, for three phase full bridge IGBT drive circuit and for calculate and control governor circuit.
Governor circuit for calculating and control is arranged on master control borad.
As in figure 2 it is shown, the invention also discloses the three of a kind of described active electric filter device based on three close-loop control
Ring control method, it carries out in accordance with the following steps:
Step 1), by through voltage transformer detection three-phase system power supply USA, USB, USC magnitude of voltage, through phaselocked loop
PLL obtains voltage-phase and carries out COS and the SIN sequence of park change;
Step 2), detect threephase load electric current ILA, ILB, ILC by load current transformer, and according in step 1
COS and SIN sequence converts through park, including C32Conversion and C convert, and are changed by threephase load electric current under three phase static coordinate system
Electric current under biphase rotating coordinate system dq coordinate, obtains threephase load fundamental current by filtering high-frequency harmonic (LPF), further according to
COS and SIN sequence in step 1, through park inverse transformation, is converted into three-phase and compensates target current iaf, ibf, icf;
Step 3), detected output current IO A, IOB, IOC by LEMA, LEMB, LEMC end of output current transformer, logical
Overcurrent internal ring PI regulation obtains interior circular current and controls output desired value;
Step 4), by DC side through direct current sampling transformer draw DC voltage value UDCA, UDCB, by summation after
And obtain DC side compensation energy target values through DC voltage outer shroud PI regulation;
Step 5), theoretical according to Repetitive controller, and according to load current repeat for foundation, mend through three-phase current
Repay desired value iaf, ibf, icfProofread with the phase place of three-phase output current IO A, IOB, IOC, and control to obtain Repetitive controller through PI
Desired value;Repetitive controller desired value is exported with step 3, step 4 desired value superpose through SVPWM, SVPWM be space vector
PWM regulates, and generates and triggers pulse train, controls insulated gate bipolar transistor IGBT turn-on and turn-off through IGBT drive circuit,
Thus control current transformer output and reach to compensate desired value.
Described predictability is repeated the parameter of current control feedback correction link and is preferably obtained by the method for phase matched.Its
Basic thought assumes that the same time in next primitive period is repeated by the distortion occurred in the previous primitive period, controls
Device determines required correction signal, then in next primitive period according to the given error with feedback signal of each switch periods
This Signal averaging on original control signal, is distorted by the same time with the repeatability that will appear from each cycle after eliminating;
For correctness and the feasibility of the explanation present invention, the three-phase active filter operation system of a 50A is carried out
Checking.Parameter is: line voltage is 380V, and controlling output DC voltage is 750V, and switching frequency is 20kHz, and AC is filtered
Ripple device parameter is La=0.4mH, Lb=0.4mH, Lc=0.4 mH.Accompanying drawing 3 is the specific experiment waveform of this embodiment.