CN102841609A

CN102841609A - Method for solar tracking controller system

Info

Publication number: CN102841609A
Application number: CN2011101723150A
Authority: CN
Inventors: 杨际荣
Original assignee: ZHENJIANG HUAYANG INFORMATION TECHNOLOGY CO LTD
Current assignee: ZHENJIANG HUAYANG INFORMATION TECHNOLOGY CO LTD
Priority date: 2011-06-24
Filing date: 2011-06-24
Publication date: 2012-12-26

Abstract

The invention relates to a method for a solar tracking controller system. According to the method, a high-accuracy solar tracking controller is comprehensively implemented by adopting software algorithm control and sensor detection accuracy control; the software algorithm control is used for calculating the position of the sun in real time according to the operation law of a celestial body, so that a tracker is positioned in a certain range; the sensor detection control is used for searching and detecting the strongest point of the sunlight in the range and improving the utilization rate of the sunlight; the anti-interference capacity of the system can be improved by the software algorithm control; due to the complex and changeable outside natural environment, flying leaves in the air or household garbage and the movement of cloud layers can cause interference to the sensor detection to cause the tracker to generate a big tracking error, and thus, the tracking accuracy and the anti-interference capacity can be improved by adopting the high-accuracy solar tracking controller; the software algorithm control is mainly used for reading current time and calculating a horizontal angle and a pitch angle, by which a solar cell panel is to be rotated, by a DSP (Digital Signal Processor) according to a related algorithm; and the sensor detection control adopts a four-quadrant sensor, a signal amplification circuit, an absolute value circuit, a comparison circuit and the like.

Description

A kind of method of solar energy tracking controller system

Technical field

The present invention relates to the computed in software method in the solar energy tracking control system, the method is through the direction of the cell panel of the sunny ability of calculations of offset of the sun.

Background technology

The solar energy tracking controller is to keep solar panel at any time over against the sun, makes the mechanical driver unit of solar panel ability vertical irradiation, can significantly improve the capacity factor of solar photovoltaic device.Because change and rotation, every day, the irradiating angle of the sun all had difference all the time at all seasons in each fixed location, improve solar energy utilization rate, must guarantee that solar panel can rotate according to the difference of position of sun.At present, general solar energy tracking controller is different according to longitude and latitude, calculates per moment sun place elevation angle and deflection according to the rule of motion of celestial body.The calculating of motion of celestial body need apply to a large amount of floating-points, triangle, anti-triangle etc.

Complex calculations will guarantee the precision calculated, and common single-chip microcomputer needs the time of labor, calculating that can not be real-time.In addition, because the existence of astronomical refraction (atmospheric refraction), astronomical refraction changes along with the variation of conditions such as atmospheric density, temperature and pressure, can not realize solar tracking very accurately.On the market solar tracking device that adopts hardware detecting circuit to realize is arranged also now, it adopts photoelectric cell as sensor, realizes solar tracking.The precision of this tracker will be leaned on high-precision sensor, and accurate experimental circuit guarantees; And anti-interference is poor, easily with wrong target.

Summary of the invention

Have these shortcomings to existing solar energy tracking controller, the object of the invention is exactly to have designed the software algorithm of a kind of novel high-precision sun in can tracking control unit.This is mainly through reading the current time the horizontal angle and the angle of pitch that the sunny ability of the algorithm computation cell panel of being correlated with by D S P basis will rotate.Sensor control is made up of quadrant sensors, signal amplification circuit, absolute value circuit, comparator circuit etc.Concrete step is following: sun altitude and azimuthal calculating, calculate the value in altitude of the sun and orientation according to formula, and calculate the horizontal angle and the scope of the angle of pitch that solar panel will rotate according to elevation angle of calculating and position angle, control the motor rotation.

A kind of method of solar energy tracking controller system: comprised sun altitude and azimuthal computing formula, concrete formula is following:

(1) computing formula of sun altitude:

sinα＝sinφsinδ+cosφcosδcosω

In the formula, α is a sun altitude, and φ is local geographic latitude, and δ is a declination angle, and ω is a solar hour angle.Sun altitude α refers to the section of certain point on the earth and the angle of this point of certain moment and sun line.Declination angle δ is the angle of sunray and terrestrial equator, to the north of for just.In 1 year, declination angle is ± 23.Change between 271.Confirm the declination angle of some day, in the calculating that can utilize following formula to be similar to: δ=23.45sin (284+DAY/365*360 °) formula:: DAY arrives the fate of this day for from January 1.Solar hour angle ω: local solar time.360 ° of earth rotations in 24 hours in a day, the angle of rotation of each hour is 15 °.0 ° of the hour angle of the local positive period of the day from 11 a.m. to 1 p.m, the morning is for negative, and afternoon is for just.For example, at 10 o'clock in the morning, ω=-30 °, at 3 o'clock in afternoon, ω=30 °.

(2) computing formula of solar azimuth:

A＝arctan(sin(ω)/cos(ω)sinφ-tan(δ)cos(ω))

Wherein α φ δ implication is the same.

A is a solar azimuth: refer to that sunray projection and local its concrete steps of meridianal angle on ground level are following:

Because sun altitude and azimuthal real-time calculating need the clock period of labor,, adopt radix point scaling method and IQmath function library for speed and the precision that improves calculating.The IQmath function library of TI company has been collected height optimization and mathematical function library and the accurate operation part that on D S PTMS320C28X chip, floating-point arithmetic is converted to the point of fixity algorithm accurately for the C/C++ programmer.Use the IQmath function library can improve the precision and the speed of intensive real-time calculating.

The IQmath function library adopts the Q form to represent the calibration of number.Explaining for ease, is example with 16 DSP.When assumed decimal point (black circle is represented among Fig. 5) is positioned at the 0th right side, be Q0; When the right side that is positioned radix point the 15th, be Q15.The conversion formula of floating number and fixed-point number is following: when floating number Xf converts fixed-point number Xq into,

Xq＝(int)(Xf*2 ^-Q)

When fixed-point number Xq converts floating number Xf into,

Xf＝(float)(Xq?*2 ^-Q)

Can know that when radix point is scaled to 0 the scope of expression is maximum, is-32768≤X≤32767, but the precision of expression is minimum, is 1.When radix point was scaled to 15, the scope of expression was minimum, is-1≤X≤1, but the precision of expression is the highest, can reach 0.0003.

For the IQmath function library of using TI company to provide, need:

(1) comprises the IQmath.h file hereof;

(2) code is connected with IQmath.h;

(3) in program storage, place the IQmath code with correct CMD file;

(4) because the IQmath table comprises IQmath functional query table, be stored among the BOOTROM of DSP, therefore this section must be set to the NOLOAD type in the CMD file, can this section be written in the Target Board like this.IQmath CMD can write as follows:

Below since explanation IQmath function library how to use.Processor chips are selected 32 DSP tms320f28027, and the frequency of this processor is 40MHz.Suppose PI=3.14159, select for use IQ24 and two kinds of forms of IQ15 to calculate by precision and scope.Below be the C language description:

Through on CCS3.3, carrying out simulation run: floating-point operation is about 4709 clock period, and 24 calibration computings are about 126 clock period, and 16 calibration computings are about 127 clock period.Adopt calibration faster about 37.4 times than floating-point operation, the calibration computing clock period equates.Calculate f=0.3213938, IQ24_f=0.3213937, IQ15_f=0.3213501, visible, improve computational accuracy, select higher Q form as far as possible for use.Can prove through a large amount of experiments, can make the speed of calculating improve 8～40 times in utilization IQmath function library, can be under the prerequisite that guarantees computational accuracy, real-time calculating is controlled motor to appointed positions.

Claims

1. the method for a solar energy tracking controller system: it is characterized in that mainly through reading the current time, by D SP according to the sunny horizontal angle and the angle of pitch that can cell panel will rotate of relevant algorithm computation.Sensor control is made up of quadrant sensors, signal amplification circuit, absolute value circuit, comparator circuit etc.Concrete step is following: sun altitude and azimuthal calculating, calculate the value in altitude of the sun and orientation according to formula, and calculate the horizontal angle and the scope of the angle of pitch that solar panel will rotate according to elevation angle of calculating and position angle, control the motor rotation.

(1) computing formula of sun altitude:

sinα＝sinφsinδ+cosφcosδcosω

In the formula, α is a sun altitude, and φ is local geographic latitude, and δ is a declination angle, and ω is a solar hour angle.Sun altitude α refers to the section of certain point on the earth and the angle of this point of certain moment and sun line.Declination angle δ is the angle of sunray and terrestrial equator, to the north of for just.In 1 year, declination angle is ± 23.Change between 271.Confirm the declination angle of some day, in the calculating that can utilize following formula to be similar to: δ=23.45sin (284+DAY/365*360 °) formula:: DAY arrives the fate of this day for from January 1.Solar hour angle ω: local solar time.360 ° of earth rotations in 24 hours in a day, the angle of rotation of each hour is 15 °.0 ° of the hour angle of the local positive period of the day from 11 a.m. to 1 p.m, the morning is for negative, and afternoon is for just.

(2) computing formula of solar azimuth:

A＝arctan(sin(ω)/cos(ω)sinφ-tan(δ)cos(ω))

Wherein α φ δ implication is the same.

A is a solar azimuth: refer to projection and the local meridianal angle of sunray on ground level

According to the method for the said solar energy tracking controller system of claim 1, it is characterized in that according to the rule of the sun according to motion of celestial body, by LZT, geographic latitude, geographic longitude etc. are tried to achieve per moment sun altitude and position angle.Secondly calculate the horizontal angle and the scope of the angle of pitch that solar panel will rotate according to elevation angle of calculating and position angle, control the motor rotation.