CN205721474U

CN205721474U - Photovoltaic cell capable of generating power maximum power point tracking device

Info

Publication number: CN205721474U
Application number: CN201620696083.7U
Authority: CN
Inventors: 吴德广
Original assignee: Shaoyang University
Current assignee: Shaoyang University
Priority date: 2016-07-05
Filing date: 2016-07-05
Publication date: 2016-11-23
Anticipated expiration: 2026-07-05

Abstract

Photovoltaic cell capable of generating power maximum power point tracking device, the output of photovoltaic battery panel connects the input of BUCK circuit, voltage, the input of current acquisition module connect load battery, output connects the A/D input of singlechip controller, the output of temperature sensor connects the signal input part of singlechip controller, the PWM output of singlechip controller connects the switch element control end of BUCK circuit, and the output of BUCK circuit connects load battery.The change of ambient temperature monitored in real time by temperature sensor, by being calculated maximum power point voltage, again by traditional little step-length MPPT method, solve the contradiction between existing maximum power point tracking device speed and vibration, accelerate to follow the trail of speed, reduce concussion, strengthen the adaptation ability of environmental change to external world, and collection ambient temperature every few minutes is set to temperature sensor, recalculate maximum power point voltage, realize the real-time capture to maximum power point, improve photovoltaic efficiency.

Description

Photovoltaic cell capable of generating power maximum power point tracking device

Technical field:

The utility model relates to photovoltaic solar generating, especially photovoltaic cell capable of generating power maximum power point tracking device.

Background technology

Solar energy has inexhaustible, nexhaustible, cleanliness without any pollution, the advantage such as renewable, and Application of Solar Energy has non- Often extensive prospect.The states such as American-European Japan are all greatly developing photovoltaic solar generating, and achieve very good effect.But The bottleneck problem that photovoltaic generation runs into is the conversion ratio of solar panel, the monocrystaline silicon solar cell conversion in testing at present Rate can reach 21%, and polysilicon is 18%, and has 17% just highly desirable at last in actual production.Photovoltaic cell is that system supplies The source of energy, plays the effect of photovoltaic cell to greatest extent, most important for whole electricity generation system.By photovoltaic cell Volt watt linearity curve understand, power output is a nonlinear curve, is affected by environmental factor, and at Maximum Power Output When operating point, we are referred to as the maximum power point (be called for short MPP) of photovoltaic cell.Difference according to external environmental factor or load Regulating the operating point of photovoltaic cell so that it is Maximum Power Output, this process is referred to as MPPT maximum power point tracking (Max Power Point Tracking, is called for short MPPT).This tracking is particularly important than when relatively low at conversion ratio.

Environmental factor has cannot be among intervention, such as temperature and illumination be in and be continually changing, it is desirable to photovoltaic cell work Make, always at maximum power point, must detect in real time due to the U under extraneous factor change_pvAnd I_pvReal-time sampling value is inputted by value MPPT controller, calculates according to the algorithm of controller, changes operating voltage or the electric current of MPPT in real time.At present, photovoltaic Battery MPPT maximum power point tracking (MPPT) controls technology, has had a certain degree of research both at home and abroad, has also developed and propose various Control method, again to intelligent algorithm from basic algorithm to innovatory algorithm, conventional persevering voltage-tracing method, interference observation, Conductance method increments etc., its purpose is to realize that maximum power of photovoltaic cell point is followed the tracks of.Current various MPPT algorithm is respectively arranged with excellent lacking Point, constant voltage process can only well realize MPPT at a certain temperature, it is impossible to adapts to the temperature occasion of change, and its advantage is control System simply easily realizes that tracking velocity is fast；The advantage of interference observation is to always search for this maximum power point, and its shortcoming is to produce Raw concussion, if step-length is little, follows the trail of speed slow；If step-length is big, concussion is acutely；Conductance increment method fast response time, to hardware requirement High；Other intelligent algorithms, can well realize the tracking of maximum power point in theory, but owing to its algorithm is complicated, to entirely System Hardware Requirement is high especially, is difficult to realize in real world applications.

Utility model content

The technical problems to be solved in the utility model is to provide the tracking dress of a kind of photovoltaic cell capable of generating power maximum power point Put, can preferably adapt to the change of environment, in the case of keeping rationally vibrating, improve the speed following the trail of maximum power point, improve The efficiency of photovoltaic generation.

Technology contents of the present utility model is: photovoltaic cell capable of generating power maximum power point tracking device, photovoltaic battery panel defeated Going out end and connecting the input of BUCK circuit, voltage acquisition module, current acquisition module output connect the letter of singlechip controller Number input, the output of temperature sensor connects the signal input part of singlechip controller, the PWM output of singlechip controller End connects the control end of the switch element of BUCK circuit, and the output of BUCK circuit connects load battery, measure voltage & current The input of circuit connects load battery.

Voltage acquisition module selects Hall voltage sensor CHV-20L；Current acquisition module selects Hall current sensor CHB-25NP；DS18B20 digital temperature sensor selected by temperature sensor, is directly driven by single-chip microcomputer pin；Single-chip Controlling Device uses STC12C5A60S2, receives the voltage and current that detection comes, a road PWM output respectively with two-way A/D input, connects The control end of BUCK circuit.

The utility model has the positive effect that: owing to temperature sensor detects ambient temperature, the extraneous ring of monitoring in real time The change in border, can obtain maximum power point voltage by calculating, thus quickly realize MPPT, but there is certain error, then Use little step-length MPPT, it is to avoid the oscillatory condition that big step-length is brought, solve original maximum power point tracking device speed and shake Contradiction between swinging.Temperature sensor arranges and gathers ambient temperature every few minutes, recalculates maximum power point voltage, strengthens The adaptation ability of the utility model environmental change to external world, improves photovoltaic efficiency.

Brief description

Fig. 1 is the utility model structured flowchart.

The utility model is described in further detail with embodiment below in conjunction with the accompanying drawings for detailed description of the invention.

As it is shown in figure 1, the structured flowchart of photovoltaic maximum power tracker, including singlechip controller, voltage acquisition Module, current acquisition module, temperature sensor, BUCK circuit and load battery.

The main circuit of photovoltaic generation: the output of photovoltaic cell connects the input of BUCK circuit, the output of BUCK circuit End connects the input of load battery.

Control circuit: the input of voltage acquisition module and current acquisition module connects load battery, output connects The data input pin of the controller of single-chip microcomputer, temperature sensor gathers the temperature of environment, and output connects the controller of single-chip microcomputer Data input pin, the PWM output of controller connects the control input of BUCK circuit.

Device of the present utility model selects: voltage acquisition module can use the form of simple electric resistance partial pressure to obtain electricity Pressure, but it is noted that gather voltage and can be accepted by single-chip microcomputer.For requiring the high system of comparison, voltage acquisition module uses Hall electricity Pressure sensor CHV-20L；Current acquisition module uses Hall current sensor CHB-25NP；DS18B20 selected by temperature sensor Digital temperature sensor, can directly be driven by single-chip microcomputer pin, thus reduce peripheral circuit；Singlechip controller uses STC12C5A60S2, with 2 road A/D inputs, receives the voltage and current that detection comes, a road PWM output respectively, connects BUCK electricity The control end on road.

Concrete control process is as follows: first passes through temperature sensor and gathers the temperature of environment, from pertinent literature, High-power point voltage U_mApproximate 0.75 times of U_oc, wherein U_ocFor (T=25 DEG C) open-circuit voltage values under normal temperature, the product of photovoltaic cell Specification can be given.Reduced rate further according to open-circuit voltage is-0.003mV/ DEG C, can calculate corresponding maximum power point voltage U_m, then by the PWM output of singlechip controller, adjust the dutycycle of BUCK circuit, quick Maximum Power Output point Voltage U_m.But output now there is also certain error, need the reality that voltage acquisition module and current acquisition module collection come Border voltage x current value, realizes MPPT by the interference observation of little step-length.And when external environment changes, can be by control The timer of device, such as 2-5 minute produces an interruption, according to the temperature of real-time detection, calculates the dutycycle of BUCK circuit Change output voltage, then realize MPPT by the interference observation of little step-length again.Thus strengthen system to environmental change Adaptability, improves the efficiency of photovoltaic generation.

Claims

1. photovoltaic cell capable of generating power maximum power point tracking device, the output of photovoltaic battery panel connects the input of BUCK circuit, It is characterized in that: voltage acquisition module, the input of current acquisition module connect load battery, and output connects single-chip microcomputer control The A/D input of device processed, the output of temperature sensor connects the signal input part of singlechip controller, singlechip controller PWM output connects the control end of the switch element of BUCK circuit, and the output of BUCK circuit connects load battery.

2. photovoltaic cell capable of generating power maximum power point tracking device according to claim 1, is characterized in that, voltage acquisition module Select Hall voltage sensor CHV-20L；Current acquisition module selects Hall current sensor CHB-25NP；Temperature sensor selects Use DS18B20 digital temperature sensor, directly driven by single-chip microcomputer pin；Singlechip controller uses STC12C5A60S2, band Having two-way A/D input to receive the voltage and current that detection comes respectively, a road PWM output connects the control end of BUCK circuit.