CN105259753A - Optimization method, parameter update module and controlling apparatus - Google Patents

Abstract

The embodiment of the invention, which relates to the grid-connected control field, provides an optimization method, a parameter update module and a controlling apparatus, wherein the optimization method, the parameter updating module and the controlling apparatus are applied to a photovoltaic grid-connected inversion system. The system consists of an inverter, a controller and a parameter updating module. The method comprises: a plurality of new parameter values are established according to an initial parameter value, the parameter updating module carries out processing on all new parameter values according to a genetic algorithm to obtain a new parameter value meeting a preset standard, wherein a fitness function of the genetic algorithm contains a mathematic model of a three-phase alternating-current phase voltage of the inverter; and the parameter updating module sends the new parameter value meeting the preset standard to the controller, so that the controller replace the initial parameter value with the received new parameter value. According to the invention, with the optimization method, the parameter updating module and the controlling apparatus, the human cost of parameter selection of the existing PID control algorithm can be reduced effectively and the existing PID control algorithm performance can be effectively improved.

Description

A kind of optimization method, parameter update module and control device

Technical field

The present invention relates to the cutting-in control field of new forms of energy, in particular to a kind of optimization method, parameter update module and control device.

Background technology

Photovoltaic generation, as a kind of important form of distributed power generation, progressively moves to maturity in technical field of new energies.And inverter is the important component part in photovoltaic generating system, the whether excellent performance index quality directly having influence on system of the control strategy that inverter adopts.Most photovoltaic combining inverter adopts voltage PWM converter topological structure, and this structure has good control performance.In grid-connected photovoltaic system, because maximum power point of photovoltaic array has time variation by the impact of environment, and the existence of the factors such as the interference of external environment, require that combining inverter must have good system dynamic-static character.

The mathematical model of combining inverter is nonlinear characteristic, how coming to carry out effective control to it is the problem that we pay close attention to jointly, in working control, due to proportional-integral-differential (proportion-integration-differentiation, PID) control algorithm involved by it and control structure simple and be employed, but when using it for the control of photovoltaic grid-connected inverting system, also there are some problems, saturation integral phenomenon is there will be in control procedure, just antisaturation control algolithm can be adopted in order to solve saturation integral phenomenon, and when carrying out antisaturation and controlling, in order to obtain good performance, its key is kp, choosing and rationality of these 3 parameters of ki and kd, therefore, optimize antisaturation PID controller parameter significant.At present, its parameter is mainly gathered by artificial adjustment and examination, and this method is not only time-consuming, and can not ensure to obtain best performance.

Summary of the invention

The object of the present invention is to provide a kind of optimization method, parameter update module and control device, effectively to reduce the human cost of the Selecting parameter of existing pid control algorithm and effectively to improve the performance of existing pid control algorithm.

First aspect, a kind of optimization method that the embodiment of the present invention provides, be applied to photovoltaic grid-connected inverting system, described system comprises inverter, controller and parameter update module, initial parameter value is preset with in described controller, described controller is used for controlling described inverter according to described initial parameter value, and meet pre-set level with the current value making described inverter export, described method comprises:

Described parameter update module obtains described initial parameter value;

Described parameter update module generates multiple new parameter value according to default first algorithm based on described initial parameter value;

Described parameter update module is according to being provided with the genetic algorithm of default fitness function to all described new parameter value process, to obtain the new parameter value meeting described preset standard, wherein, described default fitness function calculates according to the output valve of described inverter and obtains;

The described new parameter value meeting preset standard is sent to described controller by described parameter update module, to make described controller, described initial parameter value is replaced with received described new parameter value.

In conjunction with first aspect, the embodiment of the present invention additionally provides the first of first aspect may embodiment, and wherein, the expression formula of described fitness function is: F=1/J, wherein, the expression of J be for:

$J={\∫}_0^{\mathrm{\∞}}t\left|e\left(t\right)\right|dt;$

In the expression formula of described J, e (t) represents the difference of the effective value of the instruction current of the t of described controller and the output current effective value of described inverter.

In conjunction with the first possibility embodiment of first aspect, the embodiment of the present invention additionally provides the second possibility embodiment of first aspect, wherein, described parameter update module generates multiple new parameter value according to default first algorithm based on described initial parameter value, comprising:

Described parameter update module for testing site, generates multiple new parameter value by Uniform ity Design Method with described initial parameter value in default trial stretch.

In conjunction with first aspect or first aspect the first may embodiment or the second may embodiment, the embodiment of the present invention additionally provides the third possibility embodiment of first aspect, wherein, described controller is antisaturation PID controller, and described parameter value comprises scale-up factor, integration time constant and derivative time constant.

Second aspect, embodiments provide a kind of parameter update module, be applied to the photovoltaic grid-connected inverting system comprising described parameter update module, described system also comprises inverter and controller, initial parameter value is preset with in described controller, described controller is used for controlling described inverter according to described initial parameter value, and meet pre-set level with the current value making described inverter export, described parameter update module comprises:

Acquiring unit, for obtaining described initial parameter value;

Population productive unit, for generating multiple new parameter value according to presetting the first algorithm based on described initial parameter value;

Search unit, the genetic algorithm of default fitness function is provided with to all described new parameter value process for basis, to obtain the new parameter value meeting described preset standard, wherein, described default fitness function calculates according to the output valve of described inverter and obtains;

Updating block, for the described new parameter value meeting preset standard is sent to described controller, replaces with received described new parameter value to make described controller by described initial parameter value.

In conjunction with second aspect, the embodiment of the present invention additionally provides the first of second aspect may embodiment, and wherein, the expression formula of described fitness function is: F=1/J, wherein, the expression of J be for:

$J={\∫}_0^{\mathrm{\∞}}t\left|e\left(t\right)\right|dt;$

In the expression formula of described J, e (t) represents the difference of the effective value of the instruction current of the t of described controller and the output current effective value of described inverter.

In conjunction with second aspect the first may embodiment, the embodiment of the present invention additionally provides the second possibility embodiment of second aspect, wherein, described population generation unit specifically for: with described initial parameter value for testing site, in default trial stretch, generate multiple new parameter value by Uniform ity Design Method.

In conjunction with second aspect or second aspect the first may embodiment or the second may embodiment, the embodiment of the present invention additionally provides the third possibility embodiment of second aspect, wherein, described controller is antisaturation proportional-integral derivative controller, and described parameter value comprises scale-up factor, integration time constant and derivative time constant.

The third aspect, embodiments provides a kind of control device, is applied to the photovoltaic grid-connected inverting system comprising described control device, and described system also comprises inverter, and described control device comprises signal processing chip;

Described signal processing chip is used for the conducting controlling the switching tube in described inverter according to the output signal passing ratio-Integrated Derivative algorithm of described inverter, the output of described inverter is made to meet pre-set level, wherein, the parameter update mode of described proportional-integral-differential algorithm adopts presets optimization method, stores the initial parameter value of described proportional-integral-differential algorithm in described signal processing chip;

Described default optimized algorithm comprises: based on described initial parameter value, generate multiple new parameter value according to default first algorithm, described parameter update module is according to being provided with the genetic algorithm of default fitness function to all described new parameter value process, to obtain the new parameter value meeting described preset standard, wherein, described default fitness function calculates according to the output valve of described inverter and obtains, and described initial parameter value is replaced with the new parameter value meeting described preset standard.

In conjunction with the third aspect, the embodiment of the present invention additionally provides the 4th kind of possibility embodiment of second aspect, wherein, also comprises: signal conditioner and analog-to-digital conversion module;

The electric current that described signal conditioner exports for receiving described inverter, to received Current amplifier and filtering process;

Described analog-to-digital conversion module is used for that the analog electrical signal that described signal conditioner exports is converted to digital signal and inputs to described signal processing chip.

The embodiment of the present invention, first pass through the first default algorithm and generate multiple new parameter value based on described initial parameter value, namely be built into a population, the PID that such as Z-N method can be adopted to adjust controls to utilize Uniform ity Design Method to produce the initial population of certain scale near 3 parameter values; Then, then according to genetic algorithm to all described new parameter value process, to obtain the new parameter value meeting described preset standard.Such as, by the k of PID _p, k _iand k _d3 parameter combinations are together individual as each in genetic algorithm group, the fitness value of each group parameter is calculated according to fitness function, then, colony is selected, crossover and mutation operation, continuous evolution, until find optimal objective in colony individual, obtain the optimized parameter of PID controller.Wherein, the fitness function of described genetic algorithm comprises the mathematical model of the three-phase alternating current phase voltage of described inverter, also based on the mathematical model of the three-phase alternating current phase voltage of described inverter, namely build the fitness function of described genetic algorithm, therefore, can the parameter of continuous optimize PID algorithm, compared with the adjustment manually of prior art, genetic algorithm can upgrade automatically, effectively to reduce the human cost of the Selecting parameter of existing pid control algorithm and effectively to improve the performance of existing pid control algorithm.

Other features and advantages of the present invention are set forth at instructions subsequently, and, partly become apparent from instructions, or understand by implementing the embodiment of the present invention.Object of the present invention and other advantages realize by structure specifically noted in write instructions, claims and accompanying drawing and obtain.

Accompanying drawing explanation

In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment below, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.Shown in accompanying drawing, above-mentioned and other object of the present invention, Characteristics and advantages will be more clear.Reference numeral identical in whole accompanying drawing indicates identical part.Deliberately do not draw accompanying drawing by physical size equal proportion convergent-divergent, focus on purport of the present invention is shown.

Fig. 1 shows the three-phase photovoltaic grid-connected topology diagram of prior art;

Fig. 2 shows the structural drawing that antisaturation PID controls;

Fig. 3 shows the method flow diagram of the embodiment of a kind of optimization method that the embodiment of the present invention provides;

Fig. 4 shows the module frame chart of the embodiment of a kind of parameter update module that the embodiment of the present invention provides;

Fig. 5 shows the module frame chart of the embodiment of a kind of control device that the embodiment of the present invention provides.

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, carry out clear, complete description to the technical scheme in the embodiment of the present invention, obviously, described embodiment is only the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.

Photovoltaic generation, as a kind of important form of distributed power generation, progressively moves to maturity in technical field of new energies.And inverter is the important component part in photovoltaic generating system, the whether excellent performance index quality directly having influence on system of the control strategy that inverter adopts.Most photovoltaic combining inverter adopts voltage PWM converter topological structure, and this structure has good control performance.In grid-connected photovoltaic system, because maximum power point of photovoltaic array has time variation by the impact of environment, and the existence of the factors such as the interference of external environment, require that combining inverter must have good system dynamic-static character.

The mathematical model of combining inverter is nonlinear characteristic, how coming to carry out effective control to it is the problem that we pay close attention to jointly, in working control, due to proportional-integral-differential (proportion-integration-differentiation, PID) control algorithm involved by it and control structure simple and be employed, but when using it for the control of photovoltaic grid-connected inverting system, also there are some problems, saturation integral phenomenon is there will be in control procedure, just antisaturation control algolithm can be adopted in order to solve saturation integral phenomenon, and when carrying out antisaturation and controlling, in order to obtain good performance, its key is kp, choosing and rationality of these 3 parameters of ki and kd, therefore, optimize antisaturation PID controller parameter significant.At present, its parameter is mainly gathered by artificial adjustment and examination, and this method is not only time-consuming, and can not ensure to obtain best performance.

Be illustrated in figure 1 existing three-phase photovoltaic grid-connected topological structure, if ignore the internal resistance of three-phase alternating current electrical network, if the resistance of out put reactor L and inversion system internal resistance are equivalent to R, DC side busbar voltage is u _dc, D is anti-return diode, i _pvfor the DC current that photovoltaic array provides, ic is the electric current flowing into DC bus capacitor, and idc is the electric current flowing into inverter, and T1-T6 is gated bipolar transistors (InsulatedGateBipolarTransistor, IGBT) switching tube, Sa, S _b, Sc is upper brachium pontis switching drive signal, S' _a, S' _b, S' _cfor lower brachium pontis switching drive signal, u _a, u _b, u _cfor inverter side three-phase alternating current phase voltage, i _a, i _b, i _cfor inversion exports triple-phase line electric current, u _ea, u _eb, u _ecfor grid side three-phase alternating current phase voltage.

In three-phase equilibrium line voltage situation, the mathematical model of photovoltaic combining inverter in three-phase abc coordinate system is:

$\left\{\begin{array}{c}L\frac{{\mathrm{di}}_a}{dt}=-{\mathrm{Ri}}_a+u_{dc}(S_a-\frac{1}{3}\underset{j=a,b,c}{\Σ}{S}_j)-u_{ea}=-{\mathrm{Ri}}_a+u_a-u_{ea}\\ L\frac{{\mathrm{di}}_b}{dt}=-{\mathrm{Ri}}_b+u_{dc}(S_b-\frac{1}{3}\underset{j=a,b,c}{\Σ}{S}_j)-u_{eb}=-{\mathrm{Ri}}_b+u_b-u_{eb}\\ L\frac{{\mathrm{di}}_c}{dt}=-{\mathrm{Ri}}_c+u_{dc}(S_c-\frac{1}{3}\underset{j=a,b,c}{\Σ}{S}_j)-u_{ec}=-{\mathrm{Ri}}_c+u_c-u_{ec}\\ C\frac{d_{\mathrm{dc}}}{dt}=-i_{pv}-S_a{i}_a-S_b{i}_b-S_c{i}_c\end{array}\right.---\left(1\right)$

In formula (1), S _a, S _b, S _cfor the switch function of inverter.S _jbe defined as unipolarity two-valued function switch function, S _jduring (j=u, v, w)=1, upper brachium pontis conducting, lower brachium pontis turns off, S _jwhen=0, upper brachium pontis turns off, lower brachium pontis conducting.

The three phase sine alternating voltage become during owing to existing in the mathematical model of three-phase abc coordinate system.For the ease of the design of controller, pass through transformation matrix:

$Q_{abc/dq0}=\frac{2}{3}\left[\begin{array}{ccc}\cos \mathrm{\ω}t& \cos (\mathrm{\ω}t-2\mathrm{\π}/3)& \cos (\mathrm{\ω}t+2\mathrm{\π}/3)\\ \sin \mathrm{\ω}t& \sin (\mathrm{\ω}t-2\mathrm{\π}/3)& \sin (\mathrm{\ω}t+2\mathrm{\π}/3)\\ 1/2& 1/2& 1/2\end{array}\right]---\left(2\right)$

Transformed in two-phase synchronous rotary dq coordinate system, can be obtained

$\left\{\begin{array}{c}L\frac{{\mathrm{di}}_d}{dt}=-{\mathrm{Ri}}_d+{\mathrm{\ωLi}}_q+u_d-u_{ed}\\ L\frac{{\mathrm{di}}_q}{dt}=-{\mathrm{Ri}}_q-{\mathrm{\ωLi}}_d+u_q-u_{eq}\\ \frac{2}{3}C\frac{{\mathrm{du}}_{de}}{dt}=-\frac{2}{3}{i}_{pv}-i_{dc}=-\frac{2}{3}{i}_{pv}-S_d{i}_d-S_Q{i}_q\\ u_d=S_d{u}_{de},u_q=S_q{u}_{de}\end{array}\right.---\left(3\right)$

In formula (3), S _d, S _qfor the component of switch function on dq axle.

In the control system of photovoltaic grid-connected inversion, can by instruction current effective value as control objectives, definition error the online calculating voltage of design PID controller:

$u\left(t\right)=K_{P}e\left(t\right)+K_I{\∫}_{0}e\left(t\right)dt+\frac{K_{D}de\left(t\right)}{dt}---\left(4\right)$

In formula (4): K _pfor scale-up factor, K _ifor integration time constant, K _dfor derivative time constant.

Thus A phase current i _athe fundametal compoment i of (t) _a1(t), I ₁t () is i _a1the effective value of (t), A phase instruction current for effective value.

If Fig. 2 is an antisaturation PID Control system architecture figure, he is on the basis of traditional PID control principle, carry out integration to the saturated error of control inputs (in-is in Fig. 2), and be loaded in the integration item in PID control by adaptation coefficient adjustment, its adaptive change rule is

$\mathrm{\φ}=\left\{\begin{array}{cc}-\mathrm{\α}(i_n-i_s)/k_i,i_n\≠i_s,& e(i_n-\stackrel{\‾}{i})>0\\ e& i_n=i_s\end{array}\right.---\left(5\right)$

In formula (5), α >0, imin and imax are the max min of control inputs signal.

Antisaturation PID control method:

u(t)＝k _pe(t)+k _ii∫φdt+k _dde(t)/dt(6)

Therefore, as can be seen from formula (6), the optimization problem of antisaturation PID controller is exactly determine one group of suitable parameter kp, ki and kd, index is made to reach optimum, conventional error performance index has ISE, IAE, ITAE, ISTE etc., in the embodiment of the present invention, adopts ITAE index, i.e. integral time and absolute error index, its expression formula is:

$J={\∫}_0^{\mathrm{\∞}}t\left|e\left(t\right)\right|dt---\left(7\right)$

Reach best to make the control of system, as shown in Figure 3, embodiments provide a kind of optimization method to upgrade the parameter of PID controller, described optimization method is applied to photovoltaic grid-connected inverting system, the structure of described photovoltaic grid-connected inverting system as shown in Figure 1, in addition, described system comprises inverter, controller and parameter update module, initial parameter value is preset with in described controller, described controller is used for controlling described inverter according to described initial parameter value, pre-set level is met with the current value making described inverter export, such as, described pre-set level can be that the output current of described inverter meets satisfactory sinusoidal ac.

As shown in Figure 3, described method comprises:

S31: controller sets an initial parameter value;

In the embodiment of the present invention, the mode of the setting of described initial parameter value can be: set the initial parameter value that meets industry mark, or set an initial parameter value according to the empirical value in industry.

The setting of described initial parameter value can also adopt Ziegler-Nichols method to adjust acquisition.

Traditional PID experience regulates and is substantially divided into the following steps:

1. I and the D element of closing controller, strengthens P element, generation is vibrated.

2. reduce P, make PID system find threshold oscillation point.

3. strengthen I, make system reach setting value.

4. re-power, observe overshoot, vibration and whether meet system requirements stabilization time.

5. the situation for hyperharmonic vibration suitably increases differential term.

In above five steps, find suitable I and D parameter, more difficult, and Ziegler-Nichols method a kind ofly " to be adjusted " to pid loop, namely refers to the counteractive aggressiveness level that controller produces the error between actual value and setting value.If just at the right time control procedure relatively talks about slowly, as long as so pid algorithm can be arranged to a random interference when changing process variable or operation change setting value, quick and significant action just can be taked.

On the contrary, if control procedure is sensitive especially and controller is used to operating process variable to actuator, so pid algorithm must apply more conservative calibrated force within long a period of time.The essence adjusted in loop be exactly determine to controller action produce the counteractive aggressiveness level of process and pid algorithm to elimination error great help can be provided.

Ziegler-Nichols method is divided into following two steps:

1. build close loop control circuit, determine stability limit.

2. according to formulae discovery controller parameter.

Stability limit is determined by P element.This limit is just reached when there is steady oscillation.Create critical coefficient Kpcrit and critical period of the oscillation Tcrit.

After determining critical coefficient Kpcrit and critical period of the oscillation Tcrit, according to the formula of following table, calculate other parameters.

S32: parameter update module sets up the population of parameter value;

With described initial parameter value for radix, stochastic generation array, forms a population, concrete can in the following way:

With described initial parameter value for testing site, in default trial stretch, generate multiple new parameter value by Uniform ity Design Method.Described multiple new parameter value forms population.Described parameter value is these 3 parameters of kp, ki and kd, and therefore, preferably, the total quantity of these 3 parameters of described kp, ki and kd is consistent.

S33: parameter update module finds the optimal value of the parameter in described population by genetic algorithm;

Each individuality in described population is by a kp parameter, a ki parameter and a kd parameter composition, and calculate the fitness value of each individuality, the fitness function wherein calculating fitness value is the inverse of above-mentioned formula (7).

Genetic algorithm is a kind of algorithm based on space search, and it passes through the theory of the operations such as natural selection, heredity and variation and Darwin's survival of the fittest, and simulating nature evolutionary process, problem of implementation solves.Its basic step is as follows:

1, initialization colony;

2, the fitness value of each individuality in colony is calculated;

3, follow-on individuality will be entered by certain rules selection determined by ideal adaptation angle value;

4, cross selection is carried out by probability;

5, mutation operation is carried out by probability;

If 6 do not meet certain stop condition, then turn the 2nd step, otherwise enter next step;

7, the chromosome exporting fitness value optimum in colony is as the satisfactory solution of problem or optimum solution.

Wherein, individual fitness function larger, then individual performance is better, and possibility of existence is larger; Otherwise if the fitness function value of individuality is less, then individual performance is poorer, is more likely eliminated.Selection forms new population with certain probability selection defect individual from old colony, obtains individuality of future generation to breed.Individual selected probability is relevant with fitness value, and ideal adaptation angle value is higher, and selected probability is larger.Can adopt the selection strategy based on fitness ratio, the selected probability of individual i is f in formula _ifor the fitness value of individual i, N is population number.

Therefore, in the embodiment of the present invention, generate after population through step S32, the fitness of each individuality in population is calculated again according to the inverse of formula (7), wherein, each individuality has a kp parameter, a ki parameter and a kd parameter composition, carry out genetic manipulation again, namely select, crossover and mutation operates, produce new population, again fitness calculating is carried out to each individuality in population, whether inspection meets end condition, if meet, then parameter value corresponding for the fitness value meeting end condition is judged to be optimum parameter value, wherein, end condition is the kp set according to application demand, ki, kd parameter.

S34: the parameter value of controller is replaced with optimal value of the parameter by parameter update module.

Parameter value corresponding for the fitness value meeting end condition is exported to described PID controller, the parameter value that the fitness value initial parameter value of described PID controller being replaced with meet end condition is corresponding.

Therefore, compared with the adjustment manually of prior art, the embodiment of the present invention is when the parameter value that setting one is initial, described initial parameter value is made to trend towards optimal value of the parameter according to the fitness function that described PID controller sets, described optimal value of the parameter is applied in described PID controller, increase the performance of described PID controller, therefore, the embodiment of the present invention effectively reduces the human cost of the Selecting parameter of existing pid control algorithm and effectively improves the performance of existing pid control algorithm.

As shown in Figure 4, the embodiment of the present invention additionally provides a kind of parameter update module, be applied to the photovoltaic grid-connected inverting system comprising described parameter update module, described system also comprises inverter and controller, initial parameter value is preset with in described controller, described controller is used for controlling described inverter according to described initial parameter value, and meet pre-set level with the current value making described inverter export, described parameter update module comprises:

Acquiring unit 401, for obtaining described initial parameter value;

Population productive unit 402, for generating multiple new parameter value according to presetting the first algorithm based on described initial parameter value;

Search unit 403, for according to genetic algorithm to all described new parameter value process, to obtain the new parameter value meeting described preset standard, wherein, the fitness function of described genetic algorithm comprises the mathematical model of the three-phase alternating current phase voltage of described inverter;

Updating block 404, for the described new parameter value meeting preset standard is sent to described controller, replaces with received described new parameter value to make described controller by described initial parameter value.

Those skilled in the art can be well understood to, and for convenience and simplicity of description, the specific works process of the system of foregoing description, device and unit, with reference to the corresponding process in preceding method embodiment, can not repeat them here.

As shown in Figure 5, a kind of control device that the embodiment of the present invention provides, be applied to the photovoltaic grid-connected inverting system comprising described control device, described system also comprises inverter 501, described control device comprises signal conditioner 502, analog-to-digital conversion module 503, signal processing chip 504, the electric current that described signal conditioner exports for receiving described inverter, to received Current amplifier and filtering process, before gathered signal enters analog-to-digital conversion module, need the pre-service such as filtering, Simulation scale-up carrying out signal.Be provided with analog channel between described signal conditioner and described analog-to-digital conversion module, described analog channel mainly comprises voltage current transducer.Its major function is isolation and the conversion of settling signal.It utilizes accurate voltage current transformer by completely isolated to low voltage electric network signal and sample circuit below, and signal is converted to the analog quantity that analog-to-digital conversion module can accept.

Described signal processing chip is used for the conducting being controlled the switching tube in described inverter according to described analog-to-digital conversion module output signal by pid algorithm, the output of described inverter is made to meet pre-set level, wherein, the parameter update mode of described pid algorithm adopts presets optimized algorithm, stores the initial parameter value of described pid algorithm in described signal processing chip.

Described default optimized algorithm comprises:

Obtain described initial parameter value; Based on described initial parameter value, multiple new parameter value is generated according to default first algorithm; According to genetic algorithm to all described new parameter value process, to obtain the new parameter value meeting described preset standard, wherein, the fitness function of described genetic algorithm comprises the mathematical model of the three-phase alternating current phase voltage of described inverter; Described initial parameter value is replaced with received described new parameter value.

Single-chip microcomputer due to routine is difficult to competent so heavy calculation task, and the DSP that therefore signal processing chip of the embodiment of the present invention adopts arithmetic capability stronger is good selection.In general, single-chip microcomputer is compared with DSP, and Single-chip Controlling ability is stronger, and travelling speed is slow; And DSP arithmetic capability is strong, controlling functions is more weak.In the invention process, signal processing chip selects the dual core processor OMAP5912 hardware platform of TI company.OMAP5912 is highly integrated hardware, a software platform, it has unique dual-core architecture, and a risc processor realizing the band TI enhanced arm 926EJ kernel of controlling functions and one realize the high-performance of data processing function, the TMS320C55xDSP core of low-power consumption.It is equipped with multiple functional peripheral interface, greatly meets the demand of user to function.

Therefore, in the embodiment of the present invention, described signal processing chip controls conducting and the cut-off of the switching tube of described inverter according to the output current of described inverter by pid control algorithm, thus it is pre-conditioned that the output signal of described inverter is met.

Therefore, the present invention is on the basis that the PID antisaturation of prior art controls, propose the antisaturation control strategy based on genetic algorithm on-line optimization pid parameter, and be applied in photovoltaic combining inverter control device, the function of described control device is mainly realized by dsp chip, such as genetic algorithm is all integrated in described dsp chip to the optimization method of the parameter of pid control algorithm and pid control algorithm, by measured signal through signal conditioning circuit, deliver to AD data acquisition module, the middle conducting through DSP processing controls switching tube obtains good output.Method of the present invention and device not only solve saturation integral phenomenon, ensure that the Optimality of PID control performance simultaneously, effectively reduce the human cost of the Selecting parameter of existing pid control algorithm and effectively improve the performance of existing pid control algorithm.

Those skilled in the art can be well understood to, and for convenience and simplicity of description, the specific works process of the system of foregoing description, device and unit, with reference to the corresponding process in preceding method embodiment, can not repeat them here.

In addition, the process flow diagram in accompanying drawing and block diagram show system according to multiple embodiment of the present invention, the architectural framework in the cards of method and computer program product, function and operation.In this, each square frame in process flow diagram or block diagram can represent a part for module, program segment or a code, and a part for described module, program segment or code comprises one or more executable instruction for realizing the logic function specified.Also it should be noted that at some as in the realization of replacing, the function marked in square frame also can be different from occurring in sequence of marking in accompanying drawing.Such as, in fact two continuous print square frames can perform substantially concurrently, and they also can perform by contrary order sometimes, and this determines according to involved function.Also it should be noted that, the combination of the square frame in each square frame in block diagram and/or process flow diagram and block diagram and/or process flow diagram, can realize by the special hardware based system of the function put rules into practice or action, or can realize with the combination of specialized hardware and computer instruction.

In several embodiments that the application provides, should be understood that disclosed system, apparatus and method can realize by another way.Device embodiment described above is only schematic, such as, the division of described unit, be only a kind of logic function to divide, actual can have other dividing mode when realizing, again such as, multiple unit or assembly can in conjunction with or another system can be integrated into, or some features can be ignored, or do not perform.Another point, shown or discussed coupling each other or direct-coupling or communication connection can be by some communication interfaces, and the indirect coupling of device or unit or communication connection can be electrical, machinery or other form.

The described unit illustrated as separating component or can may not be and physically separates, and the parts as unit display can be or may not be physical location, namely can be positioned at a place, or also can be distributed in multiple network element.Some or all of unit wherein can be selected according to the actual needs to realize the object of the present embodiment scheme.

In addition, each functional unit in each embodiment of the present invention can be integrated in a processing unit, also can be that the independent physics of unit exists, also can two or more unit in a unit integrated.

If described function using the form of SFU software functional unit realize and as independently production marketing or use time, can be stored in a computer read/write memory medium.Based on such understanding, the part of the part that technical scheme of the present invention contributes to prior art in essence in other words or this technical scheme can embody with the form of software product, this computer software product is stored in a storage medium, comprising some instructions in order to make a computer equipment (can be personal computer, server, or the network equipment etc.) perform all or part of step of method described in each embodiment of the present invention.And aforesaid storage medium comprises: USB flash disk, portable hard drive, ROM (read-only memory) (ROM, Read-OnlyMemory), random access memory (RAM, RandomAccessMemory), magnetic disc or CD etc. various can be program code stored medium.

It should be noted that, in this article, the such as relational terms of first and second grades and so on is only used for an entity or operation to separate with another entity or operational zone, and not necessarily requires or imply the relation that there is any this reality between these entities or operation or sequentially.And, term " comprises ", " comprising " or its any other variant are intended to contain comprising of nonexcludability, thus make to comprise the process of a series of key element, method, article or equipment and not only comprise those key elements, but also comprise other key elements clearly do not listed, or also comprise by the intrinsic key element of this process, method, article or equipment.When not more restrictions, the key element limited by statement " comprising ... ", and be not precluded within process, method, article or the equipment comprising described key element and also there is other identical element.

The above; be only the specific embodiment of the present invention, but protection scope of the present invention is not limited thereto, is anyly familiar with those skilled in the art in the technical scope that the present invention discloses; change can be expected easily or replace, all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should described be as the criterion with the protection domain of claim.

Claims (10)

1. an optimization method, it is characterized in that, be applied to photovoltaic grid-connected inverting system, described system comprises inverter, controller and parameter update module, initial parameter value is preset with in described controller, described controller is used for controlling described inverter according to described initial parameter value, and meet pre-set level with the current value making described inverter export, described method comprises:

Described parameter update module obtains described initial parameter value;

Described parameter update module generates multiple new parameter value according to default first algorithm based on described initial parameter value;

Described parameter update module is according to being provided with the genetic algorithm of default fitness function to all described new parameter value process, to obtain the new parameter value meeting described preset standard, wherein, described default fitness function calculates according to the output valve of described inverter and obtains;

The described new parameter value meeting preset standard is sent to described controller by described parameter update module, to make described controller, described initial parameter value is replaced with received described new parameter value.

2. method according to claim 1, is characterized in that, the expression formula of described fitness function is: F=1/J, wherein, the expression of J be for:

$J={\∫}_0^{\mathrm{\∞}}t\left|e\left(t\right)\right|dt;$

In the expression formula of described J, e (t) represents the difference of the effective value of the instruction current of the t of described controller and the output current effective value of described inverter.

3. method according to claim 2, is characterized in that, described parameter update module generates multiple new parameter value according to default first algorithm based on described initial parameter value, comprising:

Described parameter update module for testing site, generates multiple new parameter value by Uniform ity Design Method with described initial parameter value in default trial stretch.

4., according to arbitrary described method of claim 1-3, it is characterized in that, described controller is antisaturation proportional-integral derivative controller, and described parameter value comprises scale-up factor, integration time constant and derivative time constant.

5. a parameter update module, it is characterized in that, be applied to the photovoltaic grid-connected inverting system comprising described parameter update module, described system also comprises inverter and controller, initial parameter value is preset with in described controller, described controller is used for controlling described inverter according to described initial parameter value, and meet pre-set level with the current value making described inverter export, described parameter update module comprises:

Acquiring unit, for obtaining described initial parameter value;

Population productive unit, for generating multiple new parameter value according to presetting the first algorithm based on described initial parameter value;

Search unit, the genetic algorithm of default fitness function is provided with to all described new parameter value process for basis, to obtain the new parameter value meeting described preset standard, wherein, described default fitness function calculates according to the output valve of described inverter and obtains;

Updating block, for the described new parameter value meeting preset standard is sent to described controller, replaces with received described new parameter value to make described controller by described initial parameter value.

6. parameter update module according to claim 5, is characterized in that, the expression formula of described fitness function is: F=1/J, wherein, the expression of J be for:

$J={\∫}_0^{\mathrm{\∞}}t\left|e\left(t\right)\right|dt;$

In the expression formula of described J, e (t) represents the difference of the effective value of the instruction current of the t of described controller and the output current effective value of described inverter.

7. method according to claim 6, is characterized in that, described population generation unit specifically for: with described initial parameter value for testing site, in default trial stretch, generate multiple new parameter value by Uniform ity Design Method.

8. the parameter update module according to claim 5-7, is characterized in that, described controller is antisaturation proportional-integral derivative controller, and described parameter value comprises scale-up factor, integration time constant and derivative time constant.

9. a control device, is characterized in that, is applied to the photovoltaic grid-connected inverting system comprising described control device, and described system also comprises inverter, and described control device comprises signal processing chip;

Described signal processing chip is used for the conducting controlling the switching tube in described inverter according to the output signal passing ratio-Integrated Derivative algorithm of described inverter, the output of described inverter is made to meet pre-set level, wherein, the parameter update mode of described proportional-integral-differential algorithm adopts presets optimization method, stores the initial parameter value of described proportional-integral-differential algorithm in described signal processing chip;

Described default optimized algorithm comprises: based on described initial parameter value, generate multiple new parameter value according to default first algorithm, described parameter update module is according to being provided with the genetic algorithm of default fitness function to all described new parameter value process, to obtain the new parameter value meeting described preset standard, wherein, described default fitness function calculates according to the output valve of described inverter and obtains, and described initial parameter value is replaced with the new parameter value meeting described preset standard.

10. control device according to claim 9, is characterized in that, also comprises: signal conditioner and analog-to-digital conversion module;

The electric current that described signal conditioner exports for receiving described inverter, to received Current amplifier and filtering process;

Described analog-to-digital conversion module is used for that the analog electrical signal that described signal conditioner exports is converted to digital signal and inputs to described signal processing chip.