CN106786647B - A kind of non-linear composite control method of three-phase four-wire system parallel connection APF two close cycles - Google Patents
A kind of non-linear composite control method of three-phase four-wire system parallel connection APF two close cycles Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
- H02J3/1821—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators
- H02J3/1835—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators with stepless control
- H02J3/1842—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators with stepless control wherein at least one reactive element is actively controlled by a bridge converter, e.g. active filters
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/01—Arrangements for reducing harmonics or ripples
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- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
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- Y02E40/20—Active power filtering [APF]
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Abstract
A kind of non-linear composite control method of three-phase four-wire system parallel connection APF two close cycles, outer voltage use sliding formwork PI composite non-linear control algolithm, and current inner loop is using repetition PI nonlinear control algorithm.This method uses synchronous rotating angle first, establish the lower order system model of dq coordinate system, PI feedforward decoupling controller is designed according to dq DC Model, PI repetitive controller is designed based on internal model control, establishes the control output function of current inner loop PI repetitive controller；For the current reference value for accurately and quickly obtaining current inner loop, the novel sliding formwork PI nonlinear control algorithm of invention DC voltage establishes out the control function of outer voltage sliding formwork PI controller according to exponential approach rate form design sliding-mode surface switching function.Outer ring sliding formwork PI complex control algorithm of the present invention can improve the steady-state performance and response speed of DC voltage, effectively reduce voltage fluctuation；Repeating PI nonlinear control algorithm can be realized the DAZ gene of current signal, improve the tracing control precision of harmonic compensation current instruction.
Description
Technical field
The invention belongs to active filter control field more particularly to a kind of three-phase four-wire system parallel connection APF two close cycles are non-thread
Property composite control method.
Background technique
Shunt (Active Power Filter, APF) is as a kind of solution harmonic pollution in electric power net
Effective means, it can realize accurate, effective in real time mend to harmonic wave, negative-sequence current existing for network system and reactive power
It repays.The output compensation characteristic of active filter depends primarily on the control method to Current Voltage, and used converter plant
Main circuit topological structure.Applying the control strategy on Active Power Filter-APF earliest is that electric current loop is controlled using list PI, directly
Flow the additional independent power supply unit of side voltage.At present to the research of active filter topological structure comparative maturity, now
Substantially do not had to independent DC source to go to power to DC side, but use outer voltage current inner loop double-loop control strategy.
Most of active filters use conventional three-phase PWM converter structure, and Shunt compensation performance improves thus
Depend on used control method.
Currently, having for the primary method of control of APF DC voltage: conventional PI control algorithm, fuzzy controller, adaptive
Control methods should be waited.When conventional PI control device is used for DC voltage control, though it can finally meet DC voltage stability, electricity
The response speed of pressure is slow, and there are overshoot, is unable to satisfy needs in load sudden change and when reference voltage jumps.Fuzzy control
Device does not depend on system, and convenient for transplanting, robust performance is stronger；However its control accuracy difference, DC voltage fluctuation cause to damage greatly
Consumption increases and reduces the compensation performance of APF.It is complex based on the realization of voltage adaptive control method, in control algolithm operation
Occupancy Resources on Chip is more, and DC voltage dynamic property is undesirable.There is traditional PI control for APF current inner loop control method
The control methods such as algorithm processed, Hysteresis control.Conventional PI control algorithm can be realized good tracking when reference signal is direct current
Control, but DAZ gene cannot be realized for the harmonic wave command signal changed constantly.Hysteresis control is a kind of transient feedback
Control system can obtain preferable tracking performance, its switching frequency wave though having many advantages, such as precision height, fast response time
Move larger, output filter design difficulty.
Summary of the invention
The purpose of the invention is to improve deficiency existing for above-mentioned control method, for three-phase four-wire system active electricity in parallel
Force filter, provides a kind of non-linear composite control method of three-phase four-wire system parallel connection APF two close cycles, and this method can improve direct current
Stable state accuracy of the side voltage when load sudden change and reference voltage jump, response speed, effectively reduce voltage fluctuation, and without quiet
Difference tracking changing currents with time command signal, mentions high control precision.
The technical scheme adopted by the invention is that:
A kind of non-linear composite control method of three-phase four-wire system parallel connection APF two close cycles, includes the following steps:
Step 1: detection supply voltage Us(abc), source side electric current Is(abc), load-side electric current IL(abc), APF compensate electric current
If(abc)With capacitance voltage U above and below DC sidedc1、Udc2；
Step 2: by the sum of capacitance voltage above and below DC side Udc(Udc=Udc1+Udc2) and DC side reference voltage value Udc_ref
It makes comparisons, obtains error signal, this error signal obtains current inner loop instruction current I by sliding formwork PI controllerref(dq0)；
Step 3: the load-side electric current I that will be detected in step 1L(abc)Through ip-iqCurrent Detection Algorithm obtains under dq coordinate system
Harmonic wave instruction current Ih(dq0), by harmonic wave instruction current Ih(dq0)With current inner loop instruction current I is obtained in step 2ref(dq0)Cooperation,
Obtain final instruction currentBy instruction currentPAF compensates electric current I under dq coordinate system in matching step 1f(dq0)
Input repeats PI controller and obtains output voltage instruction signal Udq0；
Step 4: by capacitance voltage U above and below the DC side detected in step 1dc1、Udc2Input neutral-point potential balance PI control
Device obtains balance of voltage factor f；
Step 3: the supply voltage detected in step 1 being obtained into system phase information by phase-locked loop systems, then by gained
The voltage command signal U exported in phase information, step 3dq0SVPWM mould is sent into balance of voltage factor f obtained in step 4
Block generates switching pulse signal, controls APF device, exports compensation harmonic electric current；
Step 6: whether subsequent work cycle detection mains input side current harmonic content is 0, if current harmonics contains at this time
Amount is not 0 return step 1, repeats step 1.
In step 1, Usk(k=a, b, c) is three-phase access point voltage；UkN(k=a, b, c) is each bridge arm midpoint electricity of three-phase
Position；Isk(k=a, b, c), Ilk(k=a, b, c), Ifk(k=a, b, c) is respectively mains input current, load current and compensation electricity
Stream；R is the equivalent resistance of route and inductance；L is flat wave inductance；C1、C2For capacitor above and below DC side, C1=C2=C capacitor both ends
Voltage is Udc1And Udc2；R1、R2For equalizing resistance, R1=R2=Rc。
Ignore the influence of switch parameter if switch is in perfect condition for the design for simplifying parallel connection APF control system；Together
Close coupling high order system model under abc coordinate system is transformed to the low order of dq0 coordinate system by Shi Caiyong synchronous rotating angle
System model.If Usi(i=d, q, 0) is access point voltage under dq0 coordinate system, Si(i=d, q, 0) is in parallel under dq0 coordinate system
Switch function, I is connected in APF bridge armfi(i=d, q, 0) is that parallel connection APF compensates electric current under dq0 coordinate system, then the mathematics of parallel connection APF
Model are as follows:
In step 2, C1、C2For capacitor above and below DC side, Udc1(s) and Udc2It (s) is the Lars shape of upper and lower capacitor both end voltage
Formula；IdIt (s) is Laplce's form of d shaft current；R1=R2=RcFor equalizing resistance above and below DC side.
Harmonic current and reactive current are compensated only in APF normal operating conditions, to simplify derivation process, enables the q shaft current be
Zero, then the transmission function of active filter DC voltage is derived using d shaft current are as follows:
According to the mentality of designing of current transformer tradition double-closed-loop control device, enabling current closed-loop transmission function is Gic(s).Due to electricity
It presses outer ring response speed to be much smaller than current inner loop response speed, current inner loop is replaced to simplify DC voltage PI with constant
The design process of controller then obtains outer voltage open loop Transmission Function are as follows:
T in formulav=RcC, the system are a typical second-order systems, and the design for eliminating zero pole point simplified control device obtains
Closed loop transfer function:
τ=C/K in formulap。
The realization of conventional PI control device is fairly simple, but control parameter is fixed；Change in load sudden change and with reference to given voltage
When, PI controller is not able to satisfy requirement of the system to steady-state performance and dynamic property, and DC voltage cannot timely stability contorting
The problems such as will cause the compensation effect of active filter reduces.
To overcome the above disadvantages, the present invention uses novel sliding formwork PI controller, control principle and biography in DC voltage
PI control of uniting is similar, the difference is that: the control parameter of sliding formwork PI controller is joined with system change, the control of PI controller
Number is by sliding mode controller come positive definite, and PI control parameter can be adjusted according to the variation of DC side in real time by doing so, to meet
Requirement of the system to DC voltage dynamic and steady-state performance.Current reference of the output of sliding formwork PI controller as current inner loop
Value ifd_ref, next main research sliding formwork PI controller, mainly includes the design of sliding-mode surface and the accessibility of sliding mode controller.
Mainly there are two purposes for the design of sliding formwork PI controller: 1) when load sudden change and reference voltage jump, DC side
Voltage is able to maintain enough response speeds；2) energy can be had good robustness in DC-side Voltage Stabilization control.APF is straight
The controller of stream side is mainly used for the stability contorting of voltage, and control freedom degree variable uses Direct Variable DC side total voltage
Udc, directly control amount can be controlled in this way；According to the principle for choosing sliding-mode surface, the sliding formwork control of DC voltage can define
Face processed are as follows:
K is normal number in formula.
For determining PI controller parameter, form is similar with conventional PI control device for the output of sliding mode controller, based on biography
System PI controller can immediately arrive at the PI controller based on sliding formwork control:
K in formulasp, ksiFor the parameter of PI controller, they are to be determined by sliding mode controller according to designed sliding-mode surface
The size of its value is mainly characterized by the variation according to system and obtains appropriate PI control parameter.Utilize formula DC side electricity
The transmission function of pressure and the Dynamic Closed Loop function of the available DC voltage of sliding formwork PI controller expression formula:
Wherein a=1/RdcC, b=1/C.
For guarantee DC voltage stability contorting, according to the available ShiShimonoseki of the Dynamic Closed Loop function of DC voltage
It is formula:
For formula (8) establishment, the control parameter output function of PI controller is designed according to sliding-mode surface (5):
Control parameter k in formulap+、kp-、ki+、ki-It is all positive number, these control parameters are in the case where meeting PI control output characteristics
Adjusting as a result, they can be adjusted according to the method for standard PI controller, for example, by using root-locus technique etc.；It is simultaneously
The DC voltage fluctuation that elimination system generates near sliding formwork control face is added in the differential and integral parameter of PI controller respectively
Positive parameter kav_p、kav_i, the fluctuation problem for causing DC voltage is buffeted by sliding-mode surface from eliminating, wherein sgn (s) is saturation letter
Number:
In the sliding-mode surface neighborhood of sliding mode controller, the system based on sliding mode controller will reach switching in finite time
Face then means that sliding formwork mode exists, and sliding mode is in the presence of the premise for being Sliding Mode Controller application, Lee usually chosen
Ya Punuofu function are as follows:
And time derivation is obtained:
K is normal number in formula, andGreater than zero, set up permanent less than zero of above formula then demonstrates the steady of designed sliding mode controller
It is qualitative.
Buffeting of the sliding mode controller in sliding-mode surface field is difficult to avoid that, to eliminate system in sliding formwork control face field
The DC voltage fluctuation of generation adds positive parameter k in the differential and integral parameter of PI controller respectivelyav_p、kav_i, from eliminate by
Sliding-mode surface buffets the fluctuation problem for causing DC voltage.As S > 0, ksp=2kp++kav_p, ksi=2ki++kav_i；When S < 0
When, ksp=2kp-+kav_p, ksi=2ki-+kav_i。
In step 3, the inner ring complex controll based on digital PI control and Repetitive controller is mainly composed in parallel by two parts: 1)
PI controller.Difference between harmonic wave instruction value and actual value is modulated, the dynamic property of APF system is improved.2) it repeats to control
Device processed.Elimination system periodicity tracking error improves the control precision of harmonic compensation current instruction.Since PI adjusting is to be based on opening
It closes the period, and Repetitive controller is to be based on the primitive period, therefore the two is decoupling in time.
The control expression formula of PI controller used by electric current loop are as follows:
In formula, KpFor proportional control factor, TiFor integration time constant, e is error signal.In PI control system, ratio
Partial effect is the error for the system that timely responds to, and the effect of integral part is the static error of elimination system, improves system
Static characteristic.But PI control is difficult to accomplish DAZ gene to the current command signal in APF, and control is not achieved and requires.
By deriving, we are it can be concluded that the transmission function of dq0 shaft voltage to electric current is；
Below by taking d shaft current as an example, the design of the current loop controller using PI control is introduced.It is expressed according to PI controller
Formula and voltage can obtain open loop and the closed loop transfer function, of continuous domain PI control electric current loop to the transmission function of electric current:
By closed loop transfer function, it is found that closed-loop current control is a typical second-order system, eliminates zero pole point and simplify control
The design of device processed can obtain simplified electric current loop open loop and closed loop transfer function:
τ=L/K in formulap。
Repetitive controller is the high stable state accuracy control method based on internal model principle, be widely used in it is various need to realize it is high-precision
Spend the occasion of control.The design difficulty of repetitive controller is that the design of compensator, the effect of compensator are to carry out school to system
Just, system is made to decay to 0 in low-frequency range, in high band energy rapid decay.If compensator are as follows:
S (z)=krzkF1(z)F2(z) (19)
Wherein krFor Repetitive controller gain, it is set as 1.F1It (z) is averaging filter, expression formula are as follows:
F2It (z) is second-order low-pass filter；zkFor differentiation element, k=3 is taken.
In step 4, capacitor voltage difference is only related to zero-axis current up and down for DC side, by the way of controlling zero-axis current
Reach the control requirement for controlling capacitor voltage balance up and down.Transmission function of the capacitor voltage difference to zero axle above and below DC side are as follows:
Because there are divider resistance and upper and lower capacitor it is equal in magnitude, upper and lower capacitor voltage difference very little, using simple PI control
System can reach the requirement of neutral-point potential balance.Enabling current inner loop closed loop transfer function, is Gic(s), then pole zero cancellation method is used
Capacitor voltage balancing control open-loop transfer function above and below simplified DC side are as follows:
In step 5, space vector modulation (SVPWM) is based on average equivalent principle, to substantially electric in a switch periods
Pressure vector is combined, and keeps its average value equal with given voltage vector.By command voltage signal Udq0Through coordinate transform, obtain
To the command signal U containing phase informationαβ, according to command signal UαβSector where decision instruction space vector determines switch week
Fundamental space vector used in phase, and then determine fundamental space vector action time and switching point time, modulate SVPWM
Switching pulse signal controls APF device, exports compensation harmonic electric current.
A kind of non-linear composite control method of three-phase four-wire system parallel connection APF two close cycles of the invention, technical effect are as follows:
1: being directed to three-wire system split capacitor formula Active Power Filter-APF, determine that PI controller is joined by sliding mode controller
Number improves stable state accuracy and response speed when load sudden change and reference voltage jump, reduces DC side power loss to guarantee
The compensation ability of parallel active filter；Low stable state accuracy caused by system low bandwidth, realization pair are made up by repetitive controller
The DAZ gene of time-varying command signal improves the tracing control precision of harmonic compensation current instruction.
2: the outer ring sliding formwork PI complex control algorithm in the novel non-linear composite control method of two close cycles can improve direct current
The steady-state performance and response speed of side voltage, effectively reduce voltage fluctuation.
3: repeating PI nonlinear control algorithm can be realized the DAZ gene of current signal, improves harmonic compensation current and refers to
The tracing control precision of order.
Detailed description of the invention
Fig. 1 is the non-linear composite control method flow chart of the novel two close cycles of three-phase four-wire system parallel connection APF.
Fig. 2 is three-phase and four-line split capacitor formula parallel connection type APF main circuit topology figure.
Fig. 3 is the non-linear composite control method overall control figure of the novel two close cycles of three-phase and four-line parallel connection APF.
Fig. 4 is outer voltage sliding formwork PI complex controll block diagram.
Fig. 5 is that current inner loop repeats PI complex controll block diagram.
Fig. 6 is neutral-point potential balance PI control block diagram.
Fig. 7 is space vector sector distribution map.
Fig. 8 (a) is the dynamic process experimental waveform figure of PI controller.
Fig. 8 (b) is the dynamic process experimental waveform figure of sliding formwork PI controller.
Fig. 9 (a) is the steady-state current waveform figure of PI controller.
Fig. 9 (b) is the steady-state current waveform figure for repeating PI controller.
Figure 10 (a) is the frequency analysis figure of PI controller.
Figure 10 (b) is the frequency analysis figure for repeating PI controller.
Specific embodiment
Below with reference to examples and drawings, the present invention is done and is further described in detail, but embodiments of the present invention are not
It is limited to this.
The non-linear composite control method flow chart of the novel two close cycles of Fig. 1 three-phase four-wire system parallel connection APF.
A kind of non-linear composite control method of three-phase four-wire system parallel connection APF two close cycles, specific steps are as follows:
Step (1): detection supply voltage Us(abc), source side electric current Is(abc), load-side electric current IL(abc), APF compensate electric current
If(abc)With capacitance voltage U above and below DC sidedc1、Udc2。
Step (2): by the sum of capacitance voltage above and below DC side Udc(Udc=Udc1+Udc2) and DC side reference voltage value
Udc_refIt makes comparisons, obtains error signal, this error signal obtains current inner loop instruction current by sliding formwork PI controller
Iref(dq0)。
Step (3): the load-side electric current I that will be detected in step (1)L(abc)Through ip-iqCurrent Detection Algorithm obtains dq coordinate
It is lower harmonic wave instruction current Ih(dq0), by harmonic wave instruction current Ih(dq0)Current inner loop instruction current is obtained with step (2)
Iref(dq0)Cooperation, obtains final instruction currentBy instruction currentPAF under dq coordinate system in matching step (1)
Compensate electric current If(dq0)Input repeats PI controller and obtains output voltage instruction signal Udq0。
Step (4): by capacitance voltage U above and below the DC side detected in step (1)dc1、Udc2Input neutral-point potential balance PI
Controller obtains balance of voltage factor f.
Step (5): the supply voltage detected in step (1) is obtained into system phase information by phase-locked loop systems, then will
The voltage command signal U exported in gained phase information, step (3)dq0It is sent into balance of voltage factor f obtained in step (4)
SVPWM module generates switching pulse signal, controls APF device, exports compensation harmonic electric current.
Step (6): whether subsequent work cycle detection mains input side current harmonic content is 0, if current harmonics at this time
Content is not 0 return step (1), is repeated step (1).
Fig. 2 is three-phase and four-line split capacitor formula parallel connection type APF main circuit topology figure.
U in figuresk(k=a, b, c) is three-phase access point voltage；UkN(k=a, b, c) is each bridge arm midpoint potential of three-phase；Isk
(k=a, b, c), Ilk(k=a, b, c), Ifk(k=a, b, c) is respectively mains input current, load current and compensation electric current；R
For route and the equivalent resistance of inductance；L is flat wave inductance；C1、C2For capacitor above and below DC side, C1=C2=C, capacitor both ends electricity
Pressure is Udc1And Udc2；R1、R2For equalizing resistance, R1=R2=Rc。
Ignore the influence of switch parameter if switch is in perfect condition for the design for simplifying parallel connection APF control system；Together
Close coupling high order system model under abc coordinate system is transformed to the low order of dq0 coordinate system by Shi Caiyong synchronous rotating angle
System model.If Usi(i=d, q, 0) is access point voltage under dq0 coordinate system, Si(i=d, q, 0) is in parallel under dq0 coordinate system
Switch function, I is connected in APF bridge armfi(i=d, q, 0) is that parallel connection APF compensates electric current under dq0 coordinate system, then the mathematics of parallel connection APF
Model are as follows:
In formula, Ifd、Ifq、If0To compensate electric current under dq0 coordinate system；Usd、Usq、Us0For supply voltage under dq0 coordinate system；
Udc1、Udc2For capacitance voltage above and below DC side, C1=C2=C；Sd、Sq、S0For parallel connection APF bridge arm conducting switch under dq0 coordinate system
Function；R1、R2For DC side equalizing resistance；R is the equivalent resistance of route and inductance；L is flat wave inductance.
Fig. 3 is the non-linear composite control method overall control figure of the novel two close cycles of three-phase and four-line parallel connection APF.
As shown in figure 3, a kind of novel two close cycles of three-phase four-wire system split capacitor formula parallel connection APF proposed by the present invention are non-thread
Property composite control method is respectively applied to outer voltage control and current inner loop control.Outer voltage is controlled using novel sliding formwork PI
Device, control principle is similar to conventional PI control, the difference is that: the control parameter of sliding formwork PI controller is with system change
, by sliding mode controller come positive definite, do so to adjust according to the variation of DC side the control parameter of PI controller in real time
PI control parameter, to meet requirement of the system to DC voltage dynamic and steady-state performance.The output of sliding formwork PI controller is made
For the current reference value I of current inner loopref(dq0), current inner loop is using novel repetition PI controller, control principle and inner ring biography
PI control of uniting is similar, the difference is that: system can be corrected through row by repeating the compensator in PI controller, make system low
Frequency range decays to 0, in high band rapid decay, to realize the DAZ gene to time-varying command signal, improves harmonic compensation
The tracing control precision of current-order.Pass through the appearance of detection network voltage, source side electric current, load-side electric current and APF output
The signals such as capacitance voltage above and below electric current and DC side, using the novel non-linear complex controll side of two close cycles proposed by the present invention
Method obtains the trigger signal of each control device in APF device, drives each control device, and then controls APF device and export the phase
The harmonic compensation current of prestige, while maintaining DC capacitor voltage to balance, and stablize in setting value.In figure, Us(abc)For three-phase
Supply voltage；R is the equivalent resistance of route and inductance；L is flat wave inductance；C1、C2For capacitor above and below DC side, capacitor both ends electricity
Pressure is Udc1And Udc2；Udc_refFor DC voltage reference value；R1、R2For equalizing resistance；If(dq0)It is exported for APF under dq coordinate system
Compensate electric current；Iref(dq0)For the current inner loop current reference value of outer voltage output；Udq0For the voltage instruction of current inner loop output
Signal.
Fig. 4 is the sliding formwork PI complex controll block diagram of DC voltage.
Harmonic current and reactive current are compensated only in APF normal operating conditions, to simplify derivation process, enables the q shaft current be
Zero, then the transmission function of active filter DC voltage is derived using d shaft current are as follows:
In formula, GdcIt (s) is the transmission function of DC side d shaft voltage；Udc1(s) and Udc2It (s) is upper and lower capacitor both end voltage
Lars form；IdIt (s) is Laplce's form of d shaft current；R1=R2=RcFor equalizing resistance above and below DC side.
DC bus capacitor C1=C2=C=4000 μ F, resistance Rc=10 Ω, then:
According to the mentality of designing of current transformer tradition double-closed-loop control device, enabling current closed-loop transmission function is Gic(s), DC side
The sliding formwork PI complex controll block diagram of voltage is as shown in Figure 4.Since outer voltage response speed is much smaller than current inner loop response speed,
Current inner loop is replaced to simplify the design process of DC voltage PI controller with constant, then obtains outer voltage open loop biography
Delivery function are as follows:
T in formulav=RcC；Gv1oFor outer voltage open-loop transfer function；PI (s) is the control function of outer voltage；
GicIt (s) is current closed-loop transmission function；Gv1It (s) is the transmission function of active filter DC voltage；RcIt is straight
Flow equalizing resistance；C is DC bus capacitor；S is the Laplace variable factor；KpFor outer voltage control parameter.
The system is a typical second-order system, and the design for eliminating zero pole point simplified control device obtains closed loop transmitting letter
Number:
τ=C/K in formulap, Gv1cFor for outer voltage closed-loop drive function；Gv1oFor outer voltage open loop Transmission Function；KpFor
Outer voltage control parameter；C is DC bus capacitor；S is the Laplace variable factor.
Outer loop control parameter is Kp=1.5, KI=3, DC bus capacitor C1=C2=C=4000 μ F, resistance Rc=10 Ω,
Then:
For determining PI controller parameter, form is similar with conventional PI control device for the output of sliding mode controller, based on biography
System PI controller can immediately arrive at the PI controller based on sliding formwork control:
C in formulaSMC_PIIt (s) is the transmission function of the PI controller based on sliding formwork control；S is the Laplace variable factor；
ksp, ksiFor the parameter of PI controller, they are the sizes for determining its value according to designed sliding-mode surface by sliding mode controller,
It is mainly characterized by the variation according to system and obtains appropriate PI control parameter.Using DC voltage transmission function and
The Dynamic Closed Loop function of the available DC voltage of PI controller based on sliding formwork control:
In formula, UdcIt (s) is Laplce's form of DC voltage；Udc_refIt (s) is the La Pula of DC side reference voltage
This form；S is the Laplace variable factor；ksp, ksiFor the parameter of PI controller；A=1/RcC, b=1/C, a are resistance RcWith
The inverse of capacitor C product, b are the inverse of capacitor C, and C is DC bus capacitor.
For guarantee DC voltage stability contorting, according to the available ShiShimonoseki of the Dynamic Closed Loop function of DC voltage
It is formula:
In formula, ksp, ksiFor the parameter of PI controller；A=1/RcC, b=1/C, a are resistance RcWith falling for capacitor C product
Number, b are the inverse of capacitor C, and C is DC bus capacitor.
To set up above formula, the control parameter output function of PI controller is designed according to sliding-mode surface:
K in formulasp, ksiFor the parameter of PI controller；kp+、kp-、ki+、ki-It for control parameter, and is all positive number；kav_p、kav_i
For the positive parameter added in the differential of PI controller and integral parameter.
Control parameter based on sliding formwork PI Compound Control Strategy is k=100, kp+=0.035, kp-=0.027, ki+=
3.125 ki-=0.92, kav_p=0.23, kav_i=3.25, then:
The realization of conventional PI control device is fairly simple, but control parameter is fixed；Change in load sudden change and with reference to given voltage
When, PI controller is not able to satisfy requirement of the system to steady-state performance and dynamic property, and DC voltage cannot timely stability contorting
The problems such as will cause the compensation effect of active filter reduces.
Fig. 5 is that current inner loop repeats PI control block diagram.
Inner ring complex controll based on digital PI control and Repetitive controller is mainly composed in parallel by two parts: 1) PI is controlled
Device.Difference between harmonic wave instruction value and actual value is modulated, the dynamic property of APF system is improved.2) repetitive controller.Disappear
Except system periodicity tracking error, the control precision of harmonic compensation current instruction is improved.Since PI adjusting is based on switch periods
, and Repetitive controller is to be based on the primitive period, therefore the two is decoupling in time.
The control expression formula of PI controller used by electric current loop are as follows:
In formula, KpFor proportional control factor, TiFor integration time constant, e is error signal.In PI control system, ratio
Partial effect is the error for the system that timely responds to, and the effect of integral part is the static error of elimination system, improves system
Static characteristic.But PI control is difficult to accomplish DAZ gene to the current command signal in APF, and control is not achieved and requires.
Below by taking d shaft current as an example, the design of the current loop controller using PI control is introduced.It is expressed according to PI controller
Formula and voltage can obtain open loop and the closed loop transfer function, of continuous domain PI control electric current loop to the transmission function of electric current:
In formula, GioIt (s) is open current loop function, Gic(s) current closed-loop function, L are input side equivalent inductance, and R is route
Equivalent resistance, s are the Laplace variable factor, TIFor integration time constant, KPFor differential parameter.
By closed loop transfer function, it is found that closed-loop current control is a typical second-order system, using PI controller zero point
With the pole zero cancellation method of control object pole, K is enabledP/(KP+KIHigh order system depression of order can be two levels by)=0.9902
System.ξ=0.707, ratio and the integral coefficient difference of digital pi regulator are taken according to optimal second-order model and inner ring bandwidth requirement
It is set as KP=1.55, KI=0.025 is converted into the electric current loop open loop behind the domain z and closed loop transfer function:
Repetitive controller is the high stable state accuracy control method based on internal model principle, be widely used in it is various need to realize it is high-precision
Spend the occasion of control.In Fig. 5, Q (z)=0.98 is taken.The design difficulty of repetitive controller is the design of compensator, compensator
Effect is corrected to system, and system is made to decay to 0 in low-frequency range, in high band energy rapid decay.If compensator S (z) are as follows:
S (z)=krzkF1(z)F2(z)
Wherein krFor Repetitive controller gain, it is set as 1；zkFor differentiation element, k=3 is taken；F1It (z) is averaging filter,
Its expression formula are as follows:
F2It (z) is second-order low-pass filter, system cut-off frequency is 2KHz, damping ratio ξ=0.707, system in the design
Sample frequency is 9.6KHz, keeps discretization to obtain using zeroth order:
Fig. 6 is neutral-point potential balance PI control block diagram.
Capacitor voltage difference is only related to zero-axis current up and down for DC side, reaches control by the way of controlling zero-axis current
The control requirement of upper and lower capacitor voltage balance.Transmission function of the capacitor voltage difference to zero axle above and below DC side are as follows:
Because there are divider resistance and upper and lower capacitor it is equal in magnitude, upper and lower capacitor voltage difference very little, using simple PI control
System can reach the requirement of neutral-point potential balance.Enabling current inner loop closed loop transfer function, is Gic(s), then pole zero cancellation method is used
Capacitor voltage balancing control open-loop transfer function above and below simplified DC side are as follows:
In formula, Gv20It (s) is capacitor voltage balancing control open-loop transfer function above and below DC side；G0(s) for above and below DC side
Transmission function of the capacitance voltage difference to zero axle, Gic(s) current closed-loop function, PI (s) controller function；KpFor control parameter；s
For the Laplace variable factor；C is DC bus capacitor.
Neutral-point potential balance PI control is similar to outer voltage PI control, compares the two closed loop transmitting it is found that need to will only control
The K of neutral-point potential balance processedP、KITake outer voltage control parameterIt can reach control to require, that is, take: KP=0.866,
KI=1.732, then have:
Fig. 7 is space vector sector distribution map.
Space vector modulation (SVPWM) swears fundamental voltage in a switch periods according to nearest Vector modulation principle
Amount is combined, and keeps its composite value equal with reference to given voltage vector.By command voltage signal Udq0Through coordinate transform, obtain
To the command signal U containing phase informationαβ, according to command signal UαβSector where decision instruction space vector determines switch week
Fundamental space vector used in phase, and then determine fundamental space vector action time and switching point time, modulate SVPWM
Switching pulse signal controls APF device, exports compensation harmonic electric current.
According to experimental result comparative analysis, from Fig. 8 (a) and Fig. 8 (b), it can be concluded that, Fig. 8 (b) is using based on sliding formwork PI
The APF in parallel of controller not only makes DC voltage control have good dynamic property, but also still in system stable operation
It can guarantee good stable state compensation performance, dynamic cannot be combined by overcoming traditional preset parameter PI DC voltage control device
With the deficiency of steady-state performance, sliding formwork PI device structure is simple, realizes that easy and calculation amount is small, and rapidity is good, strong robustness, realizes simultaneously
Join the optimal control of APF system.
Electric current after the compensation under two kinds of control methods is measured using oscillograph and is compared such as Fig. 9 (a) and Fig. 9 (b) institute
Show, Fig. 9 (b) is the compensation current waveform of compound PI controller, and having for the compensation electric current based on compound PI controller is preferable
Stable state compensation performance, compared to the compensation electric current of PI controller, current sinusoidal degree is high after compensation, and waveform is more smooth；From benefit
The experimental result for repaying rear electric current can analyze, and the tracking accuracy of harmonic wave instruction current can be significantly improved using compound PI controller,
The effective compensation harmonic electric current of energy, reduces the THD of source current.
Further to analyze the three-phase compensation current harmonic content using two kinds of controllers, given using power quality analyzer
Compensation current harmonic content under two kinds of controllers out, Figure 10 (a) are that the three-phase of PI controller compensates current harmonics analysis, are mended eventually
Source current THD value minimum 14.80% after repaying；Figure 10 (b) is that the three-phase of compound PI controller compensates current harmonics analysis,
Compensated source current THD value is up to 5.21% eventually；By comparing it follows that can significantly be mentioned using compound PI controller
The tracking accuracy of higher harmonics instruction current, the effective compensation harmonic electric current of energy, reduces the THD of source current.
Claims (3)
1. a kind of non-linear composite control method of three-phase four-wire system parallel connection APF two close cycles, it is characterised in that include the following steps:
Step 1: detection supply voltage Us(abc), source side electric current Is(abc), load-side electric current IL(abc), APF compensate electric current If(abc)
With capacitance voltage U above and below DC sidedc1、Udc2；
Step 2: by the sum of capacitance voltage above and below DC side Udc, Udc=Udc1+Udc2, with DC side reference voltage value Udc_refMake ratio
Compared with obtaining error signal, this error signal obtains current inner loop instruction current I by sliding formwork PI controllerref(dq0)；
Step 3: the load-side electric current I that will be detected in step 1L(abc)Through ip-iqCurrent Detection Algorithm obtains harmonic wave under dq coordinate system
Instruction current Ih(dq0), by harmonic wave instruction current Ih(dq0)With current inner loop instruction current I is obtained in step 2ref(dq0)Cooperation, obtains
Final instruction currentBy instruction currentAPF compensates electric current I under dq coordinate system in matching step 1f(dq0)Input
It repeats PI controller and obtains output voltage instruction signal Udq0；
Step 4: by capacitance voltage U above and below the DC side detected in step 1dc1、Udc2Neutral-point potential balance PI controller is inputted, is obtained
To balance of voltage factor f；
Step 5: the supply voltage detected in step 1 being obtained into system phase information by phase-locked loop systems, then by gained phase
The voltage command signal U exported in information, step 3dq0It is sent into SVPWM module with balance of voltage factor f obtained in step 4, is produced
Raw switching pulse signal, controls APF device, exports compensation harmonic electric current；
Step 6: whether subsequent work cycle detection mains input side current harmonic content is 0, if current harmonic content is not at this time
For 0 return step 1, step 1 is repeated.
2. a kind of non-linear composite control method of three-phase four-wire system parallel connection APF two close cycles, feature exist according to claim 1
In: in step 1, Usk(k=a, b, c) is three-phase access point voltage；UkN(k=a, b, c) is each bridge arm midpoint potential of three-phase；Isk
(k=a, b, c), Ilk(k=a, b, c), Ifk(k=a, b, c) is respectively mains input current, load current and compensation electric current；R
For route and the equivalent resistance of inductance；L is flat wave inductance；C1、C2For capacitor above and below DC side, C1=C2=C capacitor both end voltage
For Udc1And Udc2；R1、R2For equalizing resistance, R1=R2=Rc；
Ignore the influence of switch parameter if switch is in perfect condition for the design for simplifying parallel connection APF control system；It adopts simultaneously
With synchronous rotating angle, the close coupling high order system model under abc coordinate system is transformed to the lower order system of dq0 coordinate system
Model, if Usi(i=d, q, 0) is access point voltage under dq0 coordinate system, Si(i=d, q, 0) is parallel connection APF bridge under dq0 coordinate system
Switch function, I is connected in armfi(i=d, q, 0) is that parallel connection APF compensates electric current under dq0 coordinate system, then the mathematical model of parallel connection APF
Are as follows:
3. a kind of non-linear composite control method of three-phase four-wire system parallel connection APF two close cycles, feature exist according to claim 1
In: in step 5, space vector modulation SVPWM is based on average equivalent principle, adds in a switch periods to basic voltage vectors
With combination, keep its average value equal with given voltage vector；By command voltage signal Udq0Through coordinate transform, obtain containing phase
The command signal U of position informationαβ, according to command signal UαβSector where decision instruction space vector, determines that switch periods are used
Fundamental space vector, and then determine fundamental space vector action time and switching point time, modulate SVPWM switching pulse
Signal controls APF device, exports compensation harmonic electric current.
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| CN107968580B (en) * | 2017-12-25 | 2020-06-30 | 三峡大学 | One-way hybrid three-phase three-level rectifier |
| CN108599202B (en) * | 2018-05-08 | 2021-05-04 | 河北万博电器有限公司 | Three-phase unbalanced voltage suppression method for power distribution network |
| CN108899907B (en) * | 2018-07-11 | 2021-05-25 | 太原科技大学 | LCLCL type active power filter control method based on repeated sliding mode control |
| CN109358502B (en) * | 2018-10-20 | 2022-02-25 | 台州学院 | Discrete multi-period sliding mode repetitive control method for motor servo system |
| CN110190791B (en) * | 2019-05-30 | 2021-06-25 | 大连海事大学 | Independent operation double-fed direct current motor control system adopting sliding mode controller |
| CN110829863A (en) * | 2019-11-15 | 2020-02-21 | 天津航空机电有限公司 | Rectifier control method and control device and rectifier |
| CN112290820A (en) * | 2020-10-16 | 2021-01-29 | 中车永济电机有限公司 | Composite detection and control method for load sudden change of locomotive four-quadrant converter |
| CN113131767B (en) * | 2021-03-19 | 2022-11-04 | 上海电力大学 | Vienna rectifier RBF neural network outer ring voltage sliding mode control method |
| CN113065296B (en) * | 2021-03-30 | 2022-07-01 | 杭州申昊科技股份有限公司 | Different-modal stable switching control algorithm based on order reduction |
| CN115036929A (en) * | 2022-06-09 | 2022-09-09 | 国网河北省电力有限公司电力科学研究院 | Parallel APF control method and device |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103516249A (en) * | 2013-10-15 | 2014-01-15 | 哈尔滨工程大学 | Single-phase inverter and waveform control method thereof |
| CN104052059A (en) * | 2014-06-19 | 2014-09-17 | 国家电网公司 | Active power filter control method based on fuzzy neural network PID |
| CN104242313A (en) * | 2013-06-18 | 2014-12-24 | 无锡乐华自动化科技有限公司 | Three-phase three-line parallel type active power filter current control method |
-
2016
- 2016-12-27 CN CN201611228690.1A patent/CN106786647B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104242313A (en) * | 2013-06-18 | 2014-12-24 | 无锡乐华自动化科技有限公司 | Three-phase three-line parallel type active power filter current control method |
| CN103516249A (en) * | 2013-10-15 | 2014-01-15 | 哈尔滨工程大学 | Single-phase inverter and waveform control method thereof |
| CN104052059A (en) * | 2014-06-19 | 2014-09-17 | 国家电网公司 | Active power filter control method based on fuzzy neural network PID |
Non-Patent Citations (2)
| Title |
|---|
| Shunt active power filter with enhanced dynamic performance using novel control strategy;Zhenfeng Xiao et al.;《IET Power Electronics》;20141215;第3169-3181页 |
| 基于PI和重复控制三相并网逆变器的设计;赵涛等;《电力电子技术》;20150120;第49卷(第1期);第20-22页 |
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