CN104699166A - Multipath MPPT device based on particle swarm optimization - Google Patents

Abstract

A plurality of boosting branches are connected in parallel, a particle swarm algorithm is restarted by a self-adaptive linear regulator, and each building photovoltaic array is promoted to run at respective maximum power point through selecting proper switch tube ON time, so that group power optimal control is realized, and the power generating efficiency of a BIPV system is exerted to an utmost extent. As the boosting branches share the same controller, the length of a DSP code is reduced, the number of detection circuits such as sensors in the system is also greatly reduced, the system cost is effectively reduced, the device size is reduced, too-high cost caused by a transformer is avoided, and an effective thought is provided for the further design of a photovoltaic MPPT device lower in cost, smaller in size and higher in reliability.

Description

A kind of multichannel MPPT device based on particle group optimizing

Technical field

Patent of the present invention relates to technical field of photovoltaic power generation, particularly relates to a kind of many building photovoltaic array collective control maximum power point tracking devices.

Background technology

Along with photovoltaic generation is rapidly close to " par online ", sun power becomes the main power of reconstruct future source of energy structure just day by day.And an investigation from Chinese Research Institute for Building Sciences shows, current China building energy consumption accounts for 1/3 of whole society's total energy consumption.Therefore, BIPV (BIPV) is trend of the times, not only can reduce floor area, ensure self building electricity consumption, also save the investment of power station pushing electric network, reduce transmission of electricity, distribution loss, take into account economy and practicality, there is great Social and economic benef@.But multiple extreme points that under condition of locally sheltering from heat or light, photovoltaic array P-V characteristic causes make conventional MPPT maximum power point tracking (MPPT) algorithm lose efficacy; Secondly, exist towards inconsistent problem between different photovoltaic array; Moreover blocking mutually between buildings peripheral facility, causes shade in various degree on photovoltaic array, makes each photovoltaic array work in different maximum power points.Traditional series and parallel centralized configuration is difficult to realize good MPPT maximum power point tracking under complex environment.

Under complex environment, the output of photovoltaic array presents serious nonlinear characteristic, especially under shadowed condition, multi-peak phenomenon is presented, traditional MPPT maximum power point tracking algorithm was lost efficacy, as conventional constant voltage process, disturbance observation, conductance increment method etc., these methods are simply easy to realize, and are applicable to the photovoltaic generation occasion that accuracy requirement is not high

North China Electric Power University's application number is the patent of invention " a kind of device for controlling MPPT of multi-channel photovoltaic power systems " of 201020679406.4, can obviously reduce photovoltaic generation cost, it is made up of single-chip microcomputer and multiple photo-voltaic power supply control module, the electrical energy inputs of each photo-voltaic power supply control module connects one group of photovoltaic cell, and output terminal connects load or grid-connected system by backbone point bus.Advantage uses same single-chip microcomputer to control the photo-voltaic power supply on diverse location, them are made all to be traceable to maximum power point, avoid the energy loss that same time different location is caused due to the condition difference such as intensity of illumination, temperature, when shortcoming is environment acute variation, MPPT maximum power point tracking may lose efficacy, be absorbed in local optimum, photovoltaic efficiency is difficult to realize maximizing.Middle electricity electric group application number be 201010223784.6 patent of invention a kind of double-peak maximum power point tracking is proposed, whole scan method is carried out in timing, cycle whole scan is added in general MPPT maximum power point tracking algorithm, effectively shorten sweep time according to solar energy system connection in series-parallel feature, avoid system works at secondary maximum power point; Application number be 201010018319.9 patent of invention then propose respectively from the left and right sides search find global maximum power point.Although above-mentioned two kinds of methods all can find real maximum power point, inevitably make the output power of photovoltaic array produce unnecessary significantly shaking for a long time, thus produce extra power loss and impact is produced to electrical network.

Particle group optimizing (PSO) algorithm has good performance in multi-objective optimization and Multiple hump function optimization.Therefore, how particle cluster algorithm is applied to photovoltaic colony MPPT optimization problem, the maximum power point realizing each photovoltaic array and overall photovoltaic array runs, and to give full play to the characteristic of BIPV, tool is of great significance.

Summary of the invention

The technical matters that patent of the present invention will solve is: under how solving complex environment, each building photovoltaic array runs on respective maximum power point problem simultaneously.

A kind of multichannel MPPT device based on particle group optimizing that patent of the present invention proposes, comprises hardware circuit and dsp software programming.Described hardware circuit comprises n (n >=1) individual photovoltaic array [1] and corresponding booster circuit [3], one piece of dsp controller [6] and peripheral circuit thereof, a filter capacitor [4] is respectively provided with between described photovoltaic array [1] and booster circuit [3], between described booster circuit [3] and inverter [5], the peripheral circuit of described dsp controller [6] is connected with protection and control circuit, sampling modulate circuit and level shifting circuit, and described level shifting circuit is connected with I/O information module and driver module; The software programming part of described dsp controller [6] comprises the dutycycle calculating section of MPPT algorithm and Boost circuit switching tube.

Accompanying drawing explanation

Fig. 1 is the circuit theory diagrams of apparatus of the present invention;

Fig. 2 is the data acquisition and procession structured flowchart of apparatus of the present invention;

Fig. 3 is the team control particle swarm optimization algorithm schematic diagram of apparatus of the present invention;

Fig. 4 is the team control particle swarm optimization algorithm program flow diagram of apparatus of the present invention.

In figure: 1, photovoltaic array, 2, electric capacity of voltage regulation, 3, booster circuit, 4, filter capacitor, 5, inverter, 6, dsp controller.

Embodiment

[1] PV1, PV2 ..., PVn is n road photovoltaic array, provides multichannel to input to inverter; Because Boost circuit can bring voltage ripple, so suitably add filtering circuit, the voltage ripple of front end can be filtered.

[2] main circuit adopts two-stage type topological structure, can expand the scope of cell panel input voltage.Prime booster circuit adopts traditional Boost circuit, cell panel input voltage is elevated to the high voltage meeting inverter requirement, completes the tracking to cell panel maximum power point simultaneously, so whole inverter is not containing isolating transformer, reduces system cost.

[3] described device adopts 32 floating type TMS320F28335DSP processors that TI company releases, and can perform floating-point operation at a high speed, saves code execution time and storage space.Comprise the sampling of analog quantity kept and carry out analog to digital conversion, MPPT maximum power point tracking calculates, I/O port data acquisition.

[4] the suitable population of described team control MPPT method choice carries out optimizing, and each particle dimension is determined by photovoltaic array number, and each particle contains the control information of each photovoltaic array.Each particle rapidity more new formula and location updating formula is respectively $v_i^{k+1}={\mathrm{wv}}_i^k+c_1{r}_1(p_i^k-x_i^k)+c_2{r}_2({\mathrm{pg}}^k-x_i^k)$ With $x_i^{k+1}=x_i^k+v_i^{k+1},$ Wherein $v_i^k=[v_1^k,v_2^k......{,v}_N^k],$ $x_i^k=[x_1^k,x_2^k......,x_N^k],p_i^k=[p_1^k,p_2^k......,p_N^k],{\mathrm{pg}}^k=[{\mathrm{pg}}_1^k,{\mathrm{pg}}_2^k,......,{\mathrm{pg}}_N^k].$ In formula: w is inertia weight, c ₁and c ₂it is the aceleration pulse between 0 ~ 2; r ₁and r ₂be the separate random number between 0 ~ 1, i is i-th particle, and k is iterations, and N is each particle dimension; for the speed of i-th particle in kth time circulation, the position of i-th particle in kth time circulation; Pg ^kfor the global optimum of kth time circulation; for the individual optimal value of kth time circulation.

[5] when $f\left(x_i^{k+1}\right)\≥f\left(p_i^k\right)$ Time, $p_i^{k+1}=x_i^{k+1},$ When $f\left(x_i^{k+1}\right)\≤f\left(p_i^k\right)$ Time, $p_i^{k+1}=p_i^k.$ Wherein, f is the fitness function of iteration each time.

[6] when $f\left(x_i^{k+1}\right)\≥f\left({\mathrm{pg}}^k\right)$ Time, ${\mathrm{pg}}^{k+1}=x_i^{k+1},$ When $f\left(x_i^{k+1}\right)\≤f\left({\mathrm{pg}}_g^k\right)$ Time, ${\mathrm{pg}}^{k+1}={\mathrm{pg}}^k.$

[7] when environment temperature, intensity of illumination are undergone mutation, or between buildings produce shelter from heat or light phenomenon time, if system meets stable state Rule of judgment simultaneously | Δ v ^k|=| U ₁(k)-U ₁(k-1), U ₂(k)-U ₂(k-1), U ₃(k)-U ₃(k-1) | < Δ V and environmental change Rule of judgment in time, restarts initialize routine and finds new maximum power point.

[8] by realtime power variation delta P=P _old.MPP-P, linear gradient 1/K ₁(K ₁for peak power and maximum power point voltage ratio) and old maximum power point operating voltage X _oldthe maximum power point voltage that approximate treatment makes new advances namely position range when reinitializing is reduced with adaptive line adjuster, the K as Δ P>0 ₁=K ₁, the K as Δ P<0 ₁=K ₁/ 2, introduce Discontinuous Factors K simultaneously ₂the disturbance of positive and negative direction is carried out to reference voltage, disturbance formula

[9] by formula calculate dutycycle required when each building photovoltaic array runs on respective maximum power point.

[10] above embodiment is only for illustration of the present invention, not limitation of the present invention.The staff of relevant technical field is not when departing from the present invention's spirit and essence, and can make a variety of changes and modification, therefore all equivalent technical schemes also belong to category of the present invention, and scope of patent protection of the present invention should be defined by the claims.

Claims (4)

1. the multichannel MPPT device based on particle group optimizing, it is characterized in that, it is made up of a MPPT controller and multiple building photovoltaic array, the electrical energy inputs of each photovoltaic array connect one group or string or and photovoltaic cell (PVn), electric energy output end connects respective booster circuit, the switching tube (Vn) of booster circuit connects the control signal output terminal of DSP, and the total voltage electric current after each photovoltaic array boosting connects the corresponding signal input end of DSP after sensor detects.

2. booster circuit according to claim 1, by IGBT (Vn), inductance (L), diode (Dn) composition, the input termination electric capacity of voltage regulation [2] of booster circuit, export termination filter capacitor [4], the output termination DC bus of each filter capacitor [4].

3. the MPPT group control method of device described in claim 1, its feature comprise following some:

1) only need detect two-way input signal just can the needs of complete cost apparatus input signal, i.e. DC bus side voltage and current signal, greatly reduces number of sensors and sampled signal circuit.

2) when external environment changes, the maximum power point that system re-initialization program looks is new need meet stable state Rule of judgment simultaneously | Δ v ^k|=| U ₁(k)-U ₁(k-1), U ₂(k)-U ₂(k-1), U ₃(k)-U ₃(k-1) | < Δ V and environmental change Rule of judgment $\frac{|P^k-P^{k-1}|}{P^{k-1}}>\mathrm{\&Delta;P}.$

3) adaptive line adjuster is used for the position range that reduces when reinitializing.New maximum power point voltage is by realtime power variable quantity (Δ P=P _old.MPP-P), linear gradient 1/K ₁and old maximum power point operating voltage X _oldapproximate treatment $X_{\mathrm{new}}=X_{\mathrm{old}}-\frac{1}{K_1}(P_{\mathrm{old}.\mathrm{MPP}}-P).$

4) K when illumination strengthens ₁=K ₁, K when illumination weakens ₁=K ₁/ 2; Introduce Discontinuous Factors K simultaneously ₂the disturbance of positive and negative direction is carried out to reference voltage, makes at least one particle near new MPP, disturbance formula

5) by the open-circuit voltage U of each photovoltaic array _pVnwith DC bus side voltage U _dCderive each booster circuit dutycycle formula each building photovoltaic array is made to run on respective maximum power point place.

4. MPPT group control method according to claim 3, adopt 32 TMS320F28335DSP processors to realize, can perform floating-point operation at a high speed, save code execution time and storage space, reliability is strong.