CN106787871A - A kind of LC code converters of multivariable feedback controller - Google Patents

Abstract

The invention discloses the LC code converters and method of a kind of multivariable feedback controller, including first adder, second adder, the 3rd adder, the 4th adder, d axis controllers, q axis controllers, d axles compensator and q axle compensators；The input of d axis controllers is connected to the output end of first adder, and the first input end of the 3rd adder is connected to the output end of d axis controllers, and the second input is connected to the output end of d axle compensators, the input connection status amount of d axle compensators；3rd adder is output as d axle modulated signals；The input of q axis controllers is connected to the output end of second adder, and the first input end of the 4th adder is connected to the output end of q axis controllers, and the second input is connected to the output end of q axle compensators, the input connection status amount of q axle compensators；4th adder is output as q axle modulated signals.The present invention has that good stability, stable state accuracy be high, dynamic response fluctuation is small and fireballing feature.

Description

A kind of LC code converters of multivariable feedback controller

Technical field

The invention belongs to LC code converters field, more particularly, to a kind of LC code converters of multivariable feedback controller And method.

Background technology

The application of three phase supply power supply is relatively broad and demand increasingly increases in power equipment, while being proposed more to power quality High target requirement.In order to be respectively controlled to active component and reactive component, three-phase inverter more selects to be sat in rotation Mark system is lower to implement control, and the direct current instruction that conventional PI control device is intrinsic under rotating coordinate system possesses DAZ gene energy Power.But the coupling terms that coordinate transform is introduced between rotatable coordinate axis will cause the system cannot be to active component and reactive component reality Now real independent control, and the output performance of converter can be reduced.The Mathematical Modeling of three-phase LC code converters is in rotational coordinates There are two pairs of coupling terms between axle, thus dq decoupling problems are faced when control is implemented.Additionally, single-phase LC code converters can also lead to Construction two-phase rest frame is crossed to realize being controlled under dq axle rotating coordinate systems, because now regulation is DC quantity, therefore Can be implemented with simple PI controllers.However, Mathematical Modeling and three-phase LC the types conversion under the dq axle rotating coordinate systems for being constructed Device can equally introduce two pairs of coupling amounts, cause output performance to reduce.Therefore, dq axles coupled problem is not limited to three phase inversions Device.For convenience of stating, involved converter is still illustrated by taking three-phase inverter as an example.

For the problem of LC code converters uneoupled control under rotating coordinate system, existing document uses filtered electrical electrification mostly Stream is sampled to form inner ring to improve outer voltage control object characteristic.On the basis of current inner loop, by inductive current and electric capacity Passing ratio feeds back to current regulator output end and voltage regulator output to realize decoupling voltage respectively.But this method Have at following 2 points：Inductive current must be sampled first to form double -loop control, increase hardware cost；Secondly, capacitance voltage coupling Close item can passing ratio feedback to realize that decoupling is based on inductive current inner ring gain be that 1 assumed condition is just set up, but actually Current inner loop gain can not possibly whole frequency ranges all close to 1, thus decoupling effect is influenceed larger by electric current loop.

The content of the invention

For the defect of prior art, it is an object of the invention to provide a kind of LC types conversion of multivariable feedback controller Device, it is intended to solve in the prior art due to LC code converters exist itself damping it is weak caused by stability it is not strong, and due to Dq axles rotating coordinate system is implemented to introduce output voltage problem of low quality caused by coupling during control.

The invention discloses the LC code converters and method of a kind of multivariable feedback controller, including first adder, second Adder, the 3rd adder, the 4th adder, d axis controllers, q axis controllers, d axles compensator and q axle compensators；First adds The first input end connection capacitance voltage d axle specified rates of musical instruments used in a Buddhist or Taoist mass, the second input connection capacitance voltage d axles of first adder are defeated Output, the input of d axis controllers is connected to the output end of first adder, and the first input end of the 3rd adder is connected to d The output end of axis controller, the second input of the 3rd adder is connected to the output end of d axle compensators, d axle compensators it is defeated Enter end connection d, q Spindle Status amount；3rd adder is output as d axle modulated signals；The first input end connection electricity of second adder Hold voltage q axle specified rates, the second input connection capacitance voltage q axle output quantities of second adder, the input of q axis controllers The output end of second adder is connected to, the first input end of the 4th adder is connected to the output end of q axis controllers, and the 4th adds Second input of musical instruments used in a Buddhist or Taoist mass is connected to the output end of q axle compensators, input connection d, q Spindle Status amount of q axle compensators；4th Adder is output as q axle modulated signals.

Further, the d axis controllers and the q axis controllers are PI controllers.

Further, the PI controllersWherein, K_pRepresent proportionality coefficient, K_iIt is integral coefficient, s It is complex variable.

Further, it is characterised in that the d axles compensator G_com,dIncluding：Feedback function-G_N1And feedback function G_N2, Wherein G_N1=g₀+sg₁、G_N2=sq₁, g₀And g₁Represent correspondence G_N1Coefficient, q₁Represent correspondence G_N2Coefficient, s is complex variable.

Further, it is characterised in that the q axles compensator G_com,qIncluding：Feedback function G_N2And feedback function G_N1, Wherein G_N1=g₀+sg₁、G_N2=sq₁, g₀And g₁Represent correspondence G_N1Coefficient, q₁Represent correspondence G_N2Coefficient, s is complex variable.

Present invention also offers a kind of multivariable feedback controller method based on above-mentioned LC code converters, including following steps Suddenly：

Capacitance voltage d, q axle output quantity is sent into d axle compensators, capacitance voltage d axle specified rates u_c,d ^*With capacitance voltage d axles Output quantity u_c,dThe margin of error be sent to the input of d axis controllers, by the feedback function of flexible modulation d axle compensators, then The output quantity of d axis controllers is added with the output quantity of d axle compensators, obtains final product d axle modulation wave signals；At the same time, capacitance voltage D, q axle output quantity send into q axle compensators, capacitance voltage q axle specified rates u_c,q ^*With capacitance voltage q axle output quantities u_c,qThe margin of error The input of q axis controllers is sent to, by the feedback function of flexible modulation q axle compensators, the then output quantity of q axis controllers Output quantity with q axle compensators is subtracted each other, and obtains final product q axle modulation wave signals.

Further, closed loop of capacitance voltage d, q axle specified rate of LC code converters to capacitance voltage d, q axle output quantity Transmission function and characteristic equation are as follows：

WhereinBy the physical quantity plural number of dq axles Form represents that d axles represent real part, q axles represent imaginary part；If expecting, configuration system closed loop dominant apices are And non-dominant limit is p₃=-m ξ ω_n, closed-loop zero is z₁=-h ξ ω_n.According to the pole of state space theory knowledge distribution closed loop zero Point, can all undetermined parameters expression formula.Specially:g₁=L₁C [(m+2)ξω_n]/G_inv；q₁=-2 ω₀L₁C/G_inv。

The present invention has advantages below compared with prior art：

(1) the multivariable feedback controller structure for being proposed can significantly improve the damping characteristic of LC code converters, realize dq axles Full decoupled and zero pole point flexible configuration.System can be made has stability very high, control bandwidth very wide, so that Obtain rapid dynamic response speed, oscillation amplitude small；Using the synergic adjustment of controller and compensator in multivariable feedback controller structure Effect, makes output voltage quality high.

(2) the multivariable feedback controller Parameters design for being proposed can be while take into account the stability of LC code converters, control Parameter designing is controlled in the case of the requirement such as bandwidth processed, stable state accuracy, it is easy to ensure that system has superior sound state Performance.

(3) the multivariable feedback controller structure and Parameters design for being proposed can guarantee that systematic parameter is becoming in a big way Still there is very strong robustness during change, therefore significantly improve the Ability of Resisting Disturbance of LC code converters, when operating condition is mutated Output voltage remains to obtain preferable response wave shape.

(4) the multivariable feedback controller Parameters design for being proposed can be while obtain controller, compensator multiple parameters Design result, therefore design procedure is convenient succinct.

Brief description of the drawings

Fig. 1 is the multivariable feedback controller structured flowchart of LC code converters

Fig. 2 is the main circuit diagram of LC code converters

Fig. 3 is the multivariable feedback controller block diagram of LC code converters

Fig. 4 is the block diagram of d axles compensator and q axle compensators in multivariable feedback controller

Specific implementation method

In order to make the purpose , technical scheme and advantage of the present invention be clearer, it is right below in conjunction with drawings and Examples The present invention is further elaborated.It should be appreciated that the specific embodiments described herein are merely illustrative of the present invention, and It is not used in the restriction present invention.

The present invention utilizes complex vector analysis method for LC code converters, it is proposed that a kind of multivariable feedback controller structure. On this basis, it is proposed that the Parameters design of multivariable feedback controller structure.The multivariable feedback controller strategy can change It is apt to damping capacity, realizes the full decoupled of rotational coordinates between centers and dynamic is significantly improved due to the flexible configuration of zero pole point Energy.

For the LC code converters of further description multivariable feedback controller provided in an embodiment of the present invention, in conjunction with Details are as follows for drawings and Examples：

Fig. 1 is the multivariable feedback controller structured flowchart of LC code converters, including d axis controllers, q axis controllers, d axles are mended Repay device, q axle compensators, LC code converters equivalent gain and LC mode filters (control object).The control of LC code converters is in rotation Turn to implement under coordinate system, detect that (LC types are converted for capacitance voltage d, q axle output quantity and d, q Spindle Status amount first from control object Capacitance voltage d, q axle output quantities are also quantity of state in device).Secondly, by capacitance voltage d axle specified ratesIt is defeated with capacitance voltage d axles Output x_dThe margin of error be sent to d axis controllers (can be PI controls, Repetitive controller or resonance control etc.) input；Together Reason, by capacitance voltage q axle specified ratesWith capacitance voltage q axle output quantities x_qThe margin of error to be sent to q axis controllers (can be PI Control, Repetitive controller or resonance control etc.) input.Again, quantity of state (a_d,a_q...) and being sent to d axles compensator (can be with It is a feedback function, may also be multiple feedback functions) after, by the feedback function of flexible modulation d axle compensators, then by d The output quantity of axis controller is added with the output quantity of d axle compensators, and the value of gained is the d axle modulated signals of LC code converters； Similarly, quantity of state (a_d,a_q...) and it is sent to q axles compensator (can be a feedback function, may also be multiple feedback functions) Afterwards, by the feedback function of flexible modulation q axle compensators, then by the output quantity of q axis controllers and the output quantity of q axle compensators Subtract each other, the value of gained is the q axle modulated signals of LC code converters.D, q axle modulated signal are to obtain LC respectively through amplifier Corresponding d, q shaft voltage u of bridge arm midpoint output voltage of code converter_inv,dAnd u_inv,q.This multivariable feedback controller structure can To be effectively improved the damping characteristic of LC code converters, full decoupled and arbitrary disposition system the zero pole point of dq axles is realized.

Fig. 2 gives the main circuit diagram of LC code converters.L_1a、L_1bAnd L_1cRespectively transducer side A, B, C three-phase filtered electricals Sense, R_1a、R_1bAnd R_1cRespectively transducer side A, B, C three-phases consider the equivalent series resistance of inductance, conversion bridge PWM dead bands effect Should, the comprehensive equivalent resistance of the damping factor such as switching tube conduction voltage drop and line resistance.C_ab、C_bcAnd C_caIt is the phase transformation of A, B, C tri- The triangular form structure filter capacitor of parallel operation.u_dcIt is DC terminal voltage, u_inv,a、u_inv,bAnd u_inv,cIt is A, B, C three-phase bridge arm midpoint phase Voltage, u_C,a、u_C,bAnd u_C,cRespectively A, B, C three-phase filter capacitor phase voltage, i_1,b、i_1,bAnd i_1,cThe respectively phase transformation of A, B, C tri- The filter inductance phase current of parallel operation side, i_C,a、i_C,bAnd i_C,cRespectively A, B, C three-phase filter capacitor phase current, i_o,a、i_o,bAnd i_o,c Respectively A, B, C threephase load electric current.

As shown in Fig. 2 obtaining the main circuit equation expression formula under ABC coordinate systems using KVL and KCL theorems, then pass through After CLARK and PRAK conversion, LC code converters circuit equation such as formula (1) is shown under can obtaining dq rotating coordinate systems：

Wherein, u_inv,dq=[u_inv,d,u_inv,q]^TIt is expressed as corresponding d, q axle electricity of LC code converter bridge arms midpoint phase voltage Pressure, i_1,dq=[i_1,d,i_1,q]^TIt is expressed as corresponding d, q shaft current of LC code converters side inductive current, u_c,dq=[u_c,d,u_c,q]^T It is expressed as corresponding d, q shaft voltage of filter capacitor phase voltage (i.e. capacitance voltage d, q axles output quantity) of LC code converters, i_o,dq= [i_o,d,i_o,q]^TIt is expressed as corresponding d, q shaft current of load current of LC code converters.ω₀Fundamental wave angular frequency is expressed as, j is represented It is the imaginary axis.Generally A, B, C three-phase LC code converters main circuit parameter are consistent, therefore can simply remember：L_1a=L_1b=L_1c= L₁, C_ab=C_bc=C_ca=C/3, R_1a=R_1b=R_1c=R₁。

Fig. 3 is the multivariable feedback controller block diagram of LC code converters, it is contemplated that the stability problem of LC code converters, therefore Ignore stray resistance R₁To represent a kind of worst situation of damping.At the same time, the resonant frequency of LC mode filters isD axis controllers and q axis controllers are G in multivariable feedback controller block diagram_u, d axles compensator and q axles Compensator is respectively G_com,dAnd G_com,q.By capacitance voltage d, q axle output quantity [u_c,d,u_c,q]^TFeeding d axle compensators, capacitance voltage d Axle specified rate u_c,d ^*With capacitance voltage d axle output quantities u_c,dThe margin of error be sent to the input of d axis controllers, by flexibly tune The feedback function of d axle compensators is saved, then the output quantity of d axis controllers is added with the output quantity of d axle compensators, obtain final product d axles tune Ripple signal processed；At the same time, capacitance voltage d, q axles output quantity [u_c,d,u_c,q]^TFeeding q axle compensators, capacitance voltage q axles give Amount u_c,q ^*With capacitance voltage q axle output quantities u_c,qThe margin of error be sent to the input of q axis controllers, mended by flexible modulation q axles The feedback function of device is repaid, then the output quantity of q axis controllers is subtracted each other with the output quantity of q axle compensators, obtain final product q axles modulating wave letter Number.Although only with capacitance voltage feedback control, being equally applicable to introduce that other Variable feedback controls combine is many Individual Variable feedback control, therefore can be collectively referred to as multivariable feedback controller structure.

Fig. 4 gives the block diagram of d axles compensator and q axle compensators in multivariable feedback controller structure.D axle compensators Input is capacitance voltage d, q axle output quantity, and-G is multiplied by successively_N1And G_N2, their sums are the output end of d axle compensators；Together Reason, the input of q axle compensators is capacitance voltage d, q axle output quantity, and G is multiplied by successively_N2And G_N1, their sums be q axles compensation The output end of device.

Under dq rotating coordinate systems, PI controller energy DAZ gene DC quantities, so most of selection PI controllers. On the basis of this, required controller and compensator parameter can be directly obtained from whole system close_loop zero pole arrangement angles Method for designing.That is proposition is applied to the control parameter method for designing of the multivariable feedback controller structure of LC code converters.

By Fig. 3, with complex vector modeling method in motor control, the physical quantity in dq axles is represented with plural form, its Middle d axles represent real part, and q axles represent imaginary part.Can obtain capacitance voltage d, q axle specified rate of LC code converters to capacitance voltage d, q The closed loop transfer function, of axle output quantity is：

U in above formula_C,dq ^*=[u_C,d ^*,u_C,q ^*]^TCorresponding d, q axle specified rate of LC code converter capacitance voltage specified rates is represented, G_invIt is LC code converter equivalent gains.D axis controllers and q axis controllers are G_u, and be：

Wherein K_pRepresent proportionality coefficient, K_iIt is integral coefficient, s is complex variable.

Because LC code converters itself damping is weak, while two pairs of coupling amounts are introduced under rotating coordinate system again, so that carrying The damping of LC code converters high, and realize that dq axles are full decoupled.When two penalty functions are assumed to be G_N1=g₀+sg₁And G_N2= sq₁, the damping of LC code converters can be improved and the full decoupled control of dq axles is realized.The closed loop of LC code converters can be obtained by arranging Transmission function and characteristic equation are as follows：

WhereinLC is represented respectively The real part of code converter closed loop transform function and imaginary part part.

If expecting, configuration system closed loop dominant apices areAnd non-dominant limit is p₃=-m ξ ω_n, closed-loop zero is z₁=-h ξ ω_n.Wherein ξ represents the system damping ratio for expecting configuration, ω_nRepresent the system angle for expecting configuration Frequency, m then represents multiple of the non-dominant limit with dominant pole with a distance from the imaginary axis with a distance from the imaginary axis, and h represents closed-loop zero from void Wheelbase is from the multiple with dominant pole with a distance from the imaginary axis.According to state space theory knowledge distribution close_loop zero pole, can own The expression formula of undetermined parameter, it is specific as follows：

Actual main circuit parameter and expectation configuration parameter are substituted into according to formula (6) and successively, the control of LC code converters can be obtained Device and all parameters of compensator.

As it will be easily appreciated by one skilled in the art that the foregoing is only presently preferred embodiments of the present invention, it is not used to The limitation present invention, all any modification, equivalent and improvement made within the spirit and principles in the present invention etc., all should include Within protection scope of the present invention.

Claims (7)

1. LC code converters of a kind of multivariable feedback controller, it is characterised in that including：First adder, second adder, Three adders, the 4th adder, d axis controllers, q axis controllers, d axles compensator and q axle compensators；

The first input end of the first adder is used to connect capacitance voltage d axle specified rates, the second of the first adder Input is used to connect the capacitance voltage d axle output quantities of LC code converters；The input of the d axis controllers is connected to described The output end of one adder, the first input end of the 3rd adder is connected to the output end of the d axis controllers, described Second input of three adders is connected to the output end of the d axles compensator, and the input of the d axles compensator is used to connect D, q Spindle Status amount of LC code converters；The output end of the 3rd adder is used to export d axle modulated signals；

The first input end of the second adder is used to connect capacitance voltage q axle specified rates, the second of the second adder Input is used to connect the capacitance voltage q axle output quantities of LC code converters；The input of the q axis controllers is connected to described The output end of two adders, the first input end of the 4th adder is connected to the output end of the q axis controllers, described Second input of four adders is connected to the output end of the q axles compensator, and the input of the q axles compensator is used to connect D, q Spindle Status amount of LC code converters；The output end of the 4th adder is used to export q axle modulated signals.

2. LC code converters as claimed in claim 1, it is characterised in that the d axis controllers and the q axis controllers are PI controllers.

3. LC code converters as claimed in claim 2, it is characterised in that the PI controllersWherein, K_pTable Show proportionality coefficient, K_iIt is integral coefficient, s is complex variable.

4. LC code converters as described in claim any one of 1-3, it is characterised in that the d axles compensator G_com,dIncluding：Instead Feedback function-G_N1And feedback function G_N2, wherein G_N1=g₀+sg₁、G_N2=sq₁, g₀And g₁Represent correspondence G_N1Coefficient, q₁It is right to represent Answer G_N2Coefficient, s is complex variable.

5. LC code converters as described in claim any one of 1-3, it is characterised in that the q axles compensator G_com,qIncluding：Instead Feedback function G_N2And feedback function G_N1, wherein G_N1=g₀+sg₁、G_N2=sq₁, g₀And g₁Represent correspondence G_N1Coefficient, q₁Represent correspondence G_N2Coefficient, s is complex variable.

6. a kind of multivariable feedback controller method of the LC code converters based on described in claim 1, it is characterised in that including under State step：

Capacitance voltage d, q axle output quantity is sent into d axle compensators, capacitance voltage d axle specified rates u_c,d ^*Exported with capacitance voltage d axles Amount u_c,dThe margin of error be sent to the input of d axis controllers, by the feedback function of flexible modulation d axle compensators, then d axles The output quantity of controller is added with the output quantity of d axle compensators, obtains final product d axle modulation wave signals；At the same time, capacitance voltage d, q Axle output quantity sends into q axle compensators, capacitance voltage q axle specified rates u_c,q ^*With capacitance voltage q axle output quantities u_c,qThe margin of error feeding To the input of q axis controllers, by the feedback function of flexible modulation q axle compensators, the then output quantity and q of q axis controllers The output quantity of axle compensator is subtracted each other, and obtains final product q axle modulation wave signals.

7. multivariable feedback controller method as claimed in claim 6, it is characterised in that capacitance voltage d, q of LC code converters The closed loop transfer function, and characteristic equation of axle specified rate to capacitance voltage d, q axle output quantity are as follows：

$\frac{u_{C,dq}}{u_{C,dq}}=\frac{G_{inv}({\mathrm{sK}}_p+K_i)}{s^3{L}_{1}C+s^2(2{\mathrm{j\ω}}_0{L}_{1}C+{\mathrm{jq}}_1{G}_{inv}+g_1{G}_{inv})+s(1-{\mathrm{\ω}}_0^2{L}_{1}C+K_p{G}_{inv}+g_0{G}_{inv})+K_i{G}_{inv}};$

$\begin{array}{c}{D}_C{|}_{LC}\left(s\right)=s^3{L}_{1}C+s^2\left(g_1{G}_{inv}\right)+s(1-{\mathrm{\ω}}_0^2{L}_{1}C+K_p{G}_{inv}+g_0{G}_{inv})+K_i{G}_{inv}\\ +j\left\{s^2(2{\mathrm{\ω}}_0{L}_{1}C+q_1{G}_{inv})\right\}\\ =D_{C\_r}{|}_{LC}\left(s\right)+j\·D_{C\_i}{|}_{LC}\left(s\right)\end{array};$

WhereinBy the physical quantity of dq axles plural number shape Formula represents that d axles represent real part, q axles represent imaginary part；If expecting, configuration system closed loop dominant apices areAnd Non-dominant limit is p₃=-m ξ ω_n, closed-loop zero is $g_0=L_{1}C\[{\mathrm{\ω}}_0^2+{\mathrm{\ω}}_n^2-{{\mathrm{\ω}}_r}^2+(2{\mathrm{\ξ}}^2-1/h){\mathrm{m\ω}}_n^2\]/G_{inv};q_1=-2{\mathrm{\ω}}_0{L}_{1}C/G_{inv}.$