Mppt photovoltaic maximum power point tracking control matlab simulation

MpptPhotovoltaic maximum power point tracking controlmatlab仿真

1 Photovoltaic cell modeling
Photovoltaic power generation principle for light born v effect,The vast majority of pv cells arePN结构的,When the sun in the cell surface of a certain intensity,Micro level equivalent as photon cell surface,The electrons in a semiconductor gain energy,From peripheral orbit,Inspire from the covalent bond formation electronic-空穴对,电子向带正电的NArea of mobile hole to the negatively charged at the same timePArea mobile form the internal electric field,The external produce voltage and can be generated through the external circuit current on both ends.

Light conversion efficiency not only by the light、Temperature factors influence,Semiconductor material properties can also affect the light conversion rate,Photovoltaic modules of materials is one of the determinants of photovoltaic power generation efficiency,A large number of companies are working to improve the photovoltaic conversion rate,At present the most commonly used material is silicon photovoltaic battery,Such as crystal secco energyNType of monocrystalline silicon unijunction battery efficiency has been achieved24.9%.Currently has a large amount of silicon replacement material research by people,如钙钛矿,This is a kind of extensive material,A large number of possible chemical combination can be used in the manufacture of the material,And silicon processing and manufacturing need persists for more than1000℃的高温,The perovskite can below200℃的条件下处理,此外,Many candidates perovskite relative to silicon, or some other substitute another major advantage is that,It can form a very thin layer,At the same time still can effectively capture the solar energy,Several orders of magnitude than conventional silicon light weight.Perovskite is eventually replace silicon as the material of choice for solar panels,They provide a low cost、Low temperature environment create ultra-thin lightweight flexible battery potential,But now they are the efficiency of converting sunlight into electricity is behind the silicon,还有很大的发展潜力.

1.1 The mathematical model of pv cells

When the sun to the surface of a photovoltaic cell,It can be seen as a current source.IphSaid photovoltaic cells in the light of light current raw,Its size is the battery material、The effects of light intensity and environment temperature.Single diode photovoltaic battery equivalent circuit diagram as shown in figure2-1.

图中Iph,ID,IshRespectively is light current、Diode reverse saturation current and parallel branch current,RshIs a jumper resistance,RsBy electrode conductor resistance、表面电阻、Body resistance equivalent series resistance of the.


Usually ignore the resistance in the process of actual modelingRsh和RS的影响.Get simplified model of the photovoltaic cell,See expression type2.6：

Regardless of the bleeder resistor and the series resistance of photovoltaic battery output power influence,This type can reflect and changeable environment photovoltaic cells along with the change of temperature light.In the process of photovoltaic system practical application,Small single photovoltaic battery capacity can not meet the actual demand of power rating,Need a series parallel combination of multiple single photovoltaic cell power generation.

1.2Photovoltaic cell engineering model
在实际应用中,Photovoltaic modules manufacturer will provideIm、Um、Isc和Uoc四个参数,This is four parameters in the standard test condition(Standard Test Condition,STC)下得到的.This paper adopts the following photovoltaic engineering application model,See output characteristic expression type2.8.

式2.8中：I和UOutput current and voltage of photovoltaic modules;Im和UmIs a current and voltage of maximum power point,Isc和UocIs the short circuit current and open circuit voltage,As photovoltaic cell manufacturer gives4A standard reference technology value.在实际运行过程中,Photovoltaic modules will be affected by light intensity and the influence of battery temperature,4The techniques of a standard reference value see type2.9.

式2.9中：Imb、Umb、Iscb、UocbIs any temperature light of the four coefficient of photovoltaic modules;SrefIs the light intensity reference(1kW/m2);Tref标准温度(25℃);S实际光照强度;TThe actual battery temperature;补偿系数a、b、c为常数,Given by the battery manufacturer,In the simulation generally takea=0.0025(℃)-1、b=0.5(W/m2)-1、c=0.0028(℃)-1.Through two type can be any light and temperature of photovoltaic components.

由上式可以看出,The output of the photovoltaic modules will change with the change of light intensity and temperature,If not controlled the output of the photovoltaic modules,The output will be very unstable,MPPTTo ensure the stability of photovoltaic power generation system power output.为了更加直观的理解MPPT原理,Need for photovoltaic output characteristic modeling simulation,重点分析MPPT的难点,The uneven illumination photovoltaic output complex situations.

2 算例仿真

T不变,S变;S不变,T变化时,进行仿真.

3 仿真结果

1）T不变,S变

2）S不变,T变化

4 仿真

1）主函数

clc
clear
close all
%% 

for S=400:200:1000
T=25;
sim('TWO_17.slx')

figure(1)
plot(V,P,'DisplayName',['S=',num2str(S)])
hold on
axis([0 50 0 400])
xlabel('U/W')
ylabel('P/W')
title('光照变化P-U特性曲线')
legend

figure(2)
plot(V,I,'DisplayName',['S=',num2str(S)])
hold on
axis([0 50 0 20])
xlabel('U/W')
ylabel('I/A')
title('光照变化I-U特性曲线')
legend
end

%% 
for T=25:15:70
S=1000;
sim('TWO_17.slx')
figure(3)
plot(V,P,'DisplayName',['T=',num2str(T)])
hold on
axis([0 50 0 400])
xlabel('U/W')
ylabel('P/W')
title('温度变化P-U特性曲线')
legend

figure(4)
plot(V,I,'DisplayName',['T=',num2str(T)])
hold on
axis([0 50 0 20])
xlabel('U/W')
ylabel('I/A')
title('温度变化I-U特性曲线')
legend
end

%% 

2）sinmulink仿真


5 The simulation full link：
https://mp.weixin.qq.com/s?__biz=Mzg4MTc1MjE2Mg==&mid=2247484441&idx=1&sn=41040f5b06aedcbea854032e42b76cbf&chksm=cf606514f817ec02fe18615d97af10078b56d667f75d00348949f525ac4fe0f25f3c175359f8&token=1293156571&lang=zh_CN#rd