CN2791552Y - sun tracking device based on tracking posture feedback - Google Patents

Abstract

The utility model discloses a sun tracking device based on trail gesture feedback, it includes singlechip, clock chip, keyboard, LCD controller, attitude sensor and through the direct current motor power of signal processing interface rather than the electricity be connected, and wherein the computer is the singlechip, and the signal processing interface comprises digital analog conversion interface. The sun tracking device based on tracking posture feedback calculates the sun direction, the sunrise and the sunset time of the day by using the date, the time and the latitude and longitude, and particularly considers the time difference and the nonuniformity of the solar declination change. The solar photovoltaic power generation system is simple in structure, small in maintenance amount, low in manufacturing cost, stable in working and suitable for the field of unattended solar development in natural environment.

Description

Sun Tracking Device Based on Tracking Attitude Feedback

Technical field The utility model relates to a sun tracking device, especially a sun tracking device based on tracking attitude feedback.

BACKGROUND OF THE INVENTION With the shortage of energy in the world and the high price of oil, solar energy has been paid more and more attention as an inexhaustible free green energy. In order to improve the utilization efficiency of solar energy, it is necessary to make the sunlight incident as vertically as possible. The scientific and technological community has done a lot of work on sun tracking, and developed two sun tracking methods: active tracking based on sensing the direction of sunlight and passive tracking based on the law of the earth's orbit around the sun.

Active tracking such as "solar radiation tracking control device" (patent number 01217140.9, authorized announcement number CN2472151Y), passive tracking representative such as "micro power consumption timing sun tracking device" (patent number 02222766.0, authorized announcement number CN2562135Y). The former "solar radiation tracking control device" uses a pyramid-shaped photoelectric sensor to receive sunlight. When the sunlight is not perpendicular to the center of the pyramid-shaped photoelectric sensor, the output voltages of the four photovoltaic panels will be unequal. By comparison, the azimuth of the sun can be calculated, and then the stepping motor is controlled to drive the tracking device to align with the sun. The advantages are high precision, but the disadvantages are complex structure, high cost, and large maintenance. Accuracy, using multiple modules such as heating wires, temperature sensors, optical radiation detectors, four-quadrant detectors, and positioning sensors; the latter "micro-power timing sun tracking device" is passive tracking, using the sun's azimuth angle of 15 degrees/hour According to the law, the azimuth angle of the sun panel is driven to rotate synchronously, and the single-axis tracking control is performed from 9:00 to 18:00. The structure is simple, but the disadvantage is that the tracking error is large and the utilization rate of solar energy is low. Dual-axis tracking, without considering longitude and latitude factors, is not suitable for large-scale promotion, has no day and night distinction function, and has low solar energy utilization efficiency. In addition, stepper motors are generally used for driving in the prior art, and photoelectric sensors are generally used for positioning devices, which are expensive and have poor ability to resist environmental interference.

The tracking efficiencies when the tracking error is 5 degrees, 7 degrees, 10 degrees, 12 degrees, 15 degrees, and 20 degrees are:

ρ ₅ =cos(5°)=99.62%, ρ ₇ =cos(7°)=99.25%, ρ ₁₀ =cos(10°)=98.48%,

ρ ₁₂ =cos(12°)=97.81%, ρ ₁₅ =cos(15°)=96.59%, ρ ₂₀ =cos(20°)=93.97%. It can be seen that the tracking efficiency begins to drop significantly after the tracking error is greater than 10 degrees. The field of civil solar energy is mainly hot water and power generation, as long as the tracking error is controlled within 10 degrees, it can meet the demand.

Although the tracking accuracy in the field of civil solar energy is lower than the scientific research requirements, it pursues a higher level of automation, less maintenance, and lower costs. The current active tracking is expensive because it involves photoelectric sensors, and it is easily affected by dust and light pollution. It requires a lot of maintenance and is not suitable for the field of civil solar energy; Tracking devices are all driven by stepping motors, using high-precision traditional systems, and the cost is high. At the same time, the time difference and the inhomogeneity of the sun's declination change (caused by the eccentricity of the earth's orbit around the sun), and the longitude and latitude are not considered. There is still a big gap from large-scale promotion.

Utility model content The purpose of this utility model is to propose a new type of passive tracking device for the defects of domestic and foreign solar trackers, so as to reduce the cost of the sun tracking device, reduce the amount of maintenance, and meet the needs of the civil solar field.

The principle of the utility model is: use the single-chip microcomputer to accurately calculate the time difference of the day (the difference between the true solar time and the average solar time) and the solar declination (the latitude of the direct sun point) according to the date, and then combine the local longitude and latitude to accurately calculate the current position of the sun. Altitude angle and azimuth angle, determine the sun position, and judge day and night, the algorithm of the utility model calculation sun altitude angle, azimuth angle is as follows:

The working day is the day D after counting from January 1. For convenience, let the middle amount X be

$\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; 365</span>}}$

Then the day's time difference δ and solar declination σ are respectively

$\mathrm{<span\; class="notranslate">\; \&delta;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 229.18</span>}<span\; class="notranslate">\; \&times;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 75</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 186.8</span>}\mathrm{<span\; class="notranslate">\; com</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 32077</span>}\mathrm{<span\; class="notranslate">\; sin</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 14615</span>}\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 40890</span>}\mathrm{<span\; class="notranslate">\; sin</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; 1000000</span>}}$

$\mathrm{<span\; class="notranslate">\; \&sigma;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 180</span>}}{\mathrm{<span\; class="notranslate">\; \&pi;</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6918</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 399912</span>}\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 70257</span>}\mathrm{<span\; class="notranslate">\; sin</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 6758</span>}\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 907</span>}\mathrm{<span\; class="notranslate">\; sin</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2697</span>}\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1480</span>}\mathrm{<span\; class="notranslate">\; sin</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; )</span>$

The angle through which the sunlight turns when it hits the longitude where the tracking device is located is called the solar hour angle Ω, and its magnitude is

Ω=(CT+CL+δ-12)×15°, where CT is the current moment, CL is longitude correction, 1 degree/4 minutes, and δ is the time difference of the day.

The latitude of the working point is , the north latitude is positive, the south latitude is negative, the sun altitude angle α is the angle between the sun’s rays and the ground plane, and the sun’s azimuth angle β is the angle starting from the true north and rotating clockwise to the sun’s rays , then for the vast area from the equator in the south to the Arctic Circle in the north, there is

sinα＝sinsinσ+coscosσcosΩ

In order to find the sunrise and sunset times of the local day, let the elevation angle α equal to zero, there is cos[(CT+CL+δ-12)×15°]=-tantanσ, CT has two solutions, and the one less than 12 It is the sunrise time, and the solution greater than 12 is the sunset time.

The single-chip microcomputer compares the expected position of the sun with the actual tracking position fed back by the attitude sensor, and obtains the tracking error. According to the control algorithm, the control signal is output to control the operation of the DC motor, and the error is reduced to zero under closed-loop control to realize dual-axis tracking. The single-chip microcomputer recalculates the sun's position every once in a while, and carries out a new round of tracking, and the length of the interval can be set by the keyboard circuit to the single-chip microcomputer. The attitude sensor is composed of capacitive sensors, in which the altitude angle is obtained by a differential capacitive sensor, and the azimuth is obtained by a three-lobed capacitive angle sensor. Tracking is performed during the day and stopped at night.

The purpose of this utility model is achieved in that:

A sun tracking device based on tracking attitude feedback, including a device structure and a circuit, the device includes a solar panel, an altitude adjustment rod, an altitude sensor, a column, and an azimuth sensor; the circuit includes a single-chip microcomputer and a signal interface; It is characterized by:

The device is a vertical tube structure. The solar panel is connected to the height angle adjustment rod and the support rod through two upper and lower hinges. The height angle adjustment rod can move up and down in the column to adjust the height angle of the solar panel. The pole plate and the fixed pole plate are respectively placed on the outer wall of the height adjustment rod and the inner wall of the column, and the capacitive dynamic plate of the azimuth sensor is placed on the bottom outer wall of the column;

The circuit includes single chip microcomputer, signal interface, LCD controller, clock chip, keyboard;

It is characterized in that: the signal interface is composed of two pieces of DAC0832, the data input terminals of two pieces of DAC0832 on the PB0~PB7 port of the single-chip computer, the chip selection signals of the two pieces of DAC0832 are respectively electrically connected with the PA0 and PA1 ports of the single-chip computer; the height angle drives the motor power to control the height angle Drive motor, azimuth drive motor power supply control azimuth drive motor; altitude sensor is electrically connected to PA2~PA3 port of single chip microcomputer with internal analog/digital conversion function, and azimuth sensor is electrically connected to PA4~PA6 of single chip microcomputer with internal analog/digital conversion function Port; /CS, /WR, and DATA of the LCD controller are electrically connected to the PD5~PD7 ports of the microcontroller; the RST, SCLK, and I/O ports of the clock chip are electrically connected to the PD2~PD4 ports of the microcontroller; the output port of the keyboard is electrically connected to the PC0 of the microcontroller ~PC7 port.

The single-chip microcomputer mentioned is single-chip microcomputer AT90LS8535, the clock chip is HT1380, the signal interface is composed of two pieces of DAC0832, and the LCD controller is HT1621.

Said altitude angle drive motor power supply is connected to control the altitude angle drive motor, and the azimuth angle drive motor power supply is connected to control the azimuth angle drive motor.

Said altitude sensor is a differential capacitive sensor, and the azimuth sensor is a three-lobed capacitive angle sensor.

The PD0-PD1 ports of said single-chip microcomputer are used for external serial communication interfaces of external devices.

The innovation of the utility model lies in: accurate calculation of time difference and solar declination, avoiding the calculation error caused by approximating the change of solar declination to a uniform speed in the existing passive tracking technology without considering the time difference; considering the geographical longitude and latitude Factors, suitable for promotion in various places; with day and night discrimination function; adopts capacitive sensor to realize device tracking attitude feedback, and uses DC motor to drive.

The utility model has the advantages of

1. Low cost, composed of single-chip microcomputer, capacitive sensor and DC motor, without photoelectric sensor and stepper motor.

2. Less maintenance. The single-chip microcomputer accurately calculates all the factors necessary to determine the sun's position: time difference, solar declination, longitude, and latitude. It can realize dual-axis tracking, has the ability to distinguish day and night, and can run fully automatically for a long time.

Description of drawings

Fig. 1 is the structural representation of the specific embodiment of the utility model;

Fig. 2 is the circuit diagram of the embodiment of the utility model;

Fig. 3 is the time difference variation curve of the specific embodiment of the utility model;

Fig. 4 is the variation curve of solar declination of the utility model embodiment;

Fig. 5 is a working principle diagram of a cylindrical capacitive sensor according to a specific embodiment of the present invention;

Fig. 6 is a structural diagram of a differential cylindrical capacitive sensor according to a specific embodiment of the present invention;

Fig. 7 is a structural diagram of a three-lobe capacitive angle sensor according to a specific embodiment of the present invention;

Fig. 8 is a schematic diagram of a circuit of a three-lobe capacitive angle sensor according to a specific embodiment of the present invention.

DETAILED DESCRIPTION In Figure 1, 1 is a hinge, 2 is a solar panel, 3 is an altitude adjustment rod, 4 is an altitude sensor, 5 is a column, 6 is an azimuth sensor, and 7 is a support rod.

In Fig. 2, 8 is the keyboard, 9 is the driving motor power supply for altitude angle, 10 is the driving motor power supply for azimuth angle, 11 is the single-chip microcomputer AT90LS8535, 12 is the LCD controller HT1621, 13 is the clock chip HT1380, and 14 is the serial number of the single-chip microcomputer 11 The communication interface PD0, 15 is the serial communication interface PD1 of the single-chip microcomputer string 11, and 16 is the signal interface, and the signal interface 16 is made up of two pieces of DAC0832.

Fig. 3 is a diagram of time difference change at noon at 120 degrees east longitude in 2004.

Figure 4 is a graph of solar declination variation. The variation of solar declination in a year is not uniform, and it is approximated as a linear variation in traditional technology, resulting in a large tracking error.

Figure 5 is a schematic diagram of the working principle of the cylindrical capacitive sensor, and the capacitance value is proportional to the relative area of the two plates.

Fig. 6 is a structural diagram of a differential cylindrical capacitive sensor. When the position of the height angle adjustment rod 3 changes, the two capacitors become larger/lower respectively, and the position of the height angle adjustment rod 3 relative to the column 5 can be calculated by using the ratio of the two capacitance values. The interference caused by weather changes can be resisted by using the differential capacitance ratio method.

Figure 7 is a three-lobed capacitive angle sensor. Three fixed plates form a circle in a symmetrical manner, and form three capacitors with the moving plate.

Fig. 8 is a circuit diagram of a three-lobe capacitive angle sensor. When the column 5 rotates, it drives the moving plate to rotate, causing the three capacitances to change. According to the ratio of the three capacitance values, the rotation angle of the column 5 can be calculated, that is, the azimuth angle of the solar panel 2 .

It works like this:

Utilize keyboard 8 through PC0～PC7 ports of single-chip microcomputer 11 to set the required data when the system starts: local longitude, latitude, date, dormancy period, RST, SCLK, I/O ports of clock chip 13 are electrically connected to PD2～PD4 of single-chip microcomputer 11 Port, after acquiring the time from the single-chip microcomputer 11, starts uninterrupted timing, and the device starts up and enters a fully automatic working state. After the device is started, the single-chip microcomputer 11 reads the timing of the clock chip 13, combines the longitude and latitude values stored in the memory, calculates the time difference and solar declination of the day, and then calculates the altitude and azimuth of the sun at that time, and calculates the local sunrise of the day Time and sunset time, if the current time is night, the program waits in a loop, if it is daytime, the system will track.

After the tracking starts, the single-chip microcomputer 11 reads the electrical signals of the altitude sensor 4 and the azimuth sensor 6, wherein the altitude sensor 4 uses a differential capacitance to sense the position of the altitude adjustment rod 3 relative to the column 5, and the azimuth sensor 6 passes through the three-lobe The fixed plate senses the azimuth angle of the column 5 attached with the moving plate, and the single-chip microcomputer 11 uses the A/D conversion function of the PA port to realize the analog/digital conversion of the electrical signal of the altitude angle and the azimuth angle; the single-chip microcomputer 11 calculates the sun and the solar panel 2 The difference between the altitude angle and the azimuth angle is calculated by the PID algorithm respectively, and the PB0-PB7 ports of the single-chip microcomputer 11 input the control signal to the signal interface 16 in time-sharing, and the single-chip microcomputer 11 is electrically connected to the signal interface 16 through PA0 and PA1 The two DAC0832 chip select signal/CS ports are used to perform D/A conversion on the altitude angle control signal and azimuth angle control signal in turn, and input the altitude angle drive motor power supply 9 and the azimuth angle drive motor power supply 10 respectively after conversion; The motor controls the altitude adjustment rod 3 to move to the corresponding position to realize the height angle adjustment of the solar panel 2; the azimuth drive motor controls the column 5 to rotate to the corresponding position to realize the azimuth adjustment of the solar panel 2.

The single-chip microcomputer 11 is electrically connected to the /CS, /WR, and DATA ports of the LCD controller 12 through the PD5-PD7 ports, and inputs the current clock, longitude, and latitude into the LCD controller 12 in time-sharing to realize external display.

The tracking device is maintained once every six months. During maintenance, the operator restarts the system through the keyboard 8, and resets the system clock and the local longitude and latitude.

Claims (5)

1, a kind of sun tracker based on tracking attitude feedback comprises apparatus structure and circuit, and described device comprises solar panels (2), elevation angle adjusting rod (3), elevation angle sensor (4), column (5), azimuth sensor (6); Described circuit comprises single-chip microcomputer (11) and signaling interface (16); It is characterized in that:

Described device is the vertical barrel structure, solar panels (2) is connected respectively on elevation angle adjusting rod (3) and the support bar (7) by two hinges (1) up and down, elevation angle adjusting rod (3) places in the column (5) and with it and is connected movingly, the electric capacity movable plate electrode of elevation angle sensor (4) and fixed plate place respectively on elevation angle adjusting rod (3) outer wall and column (5) inwall, and the electric capacity movable plate electrode of azimuth sensor (6) places the bottom outer wall of column (5);

Described circuit also comprises lcd controller (12), clock chip (13), keyboard (8);

Signaling interface (16) is made up of two DAC0832, and single-chip microcomputer PB0～PB7 port is electrically connected two DAC0832 data input pins, the chip selection signal of two DAC0832 respectively with single-chip microcomputer (11) PA0, the PA1 port is electrically connected; Dc motor power (9) is electrically connected with the elevation angle drive motors, and dc motor power (10) is electrically connected with the azimuth drive motors; Elevation angle sensor (4) is electrically connected PA2～PA3 port that single-chip microcomputer (11) has internal mode/number conversion function, and azimuth sensor (6) is electrically connected PA4～PA6 port that single-chip microcomputer (11) has internal mode/number conversion function; Lcd controller (12) /CS ,/WR, DATA be electrically connected the PD5～PD7 port of single-chip microcomputer (11); RST, the SCLK of clock chip (13), I/O port are electrically connected the PD2～PD4 port of single-chip microcomputer (11); The output port of keyboard (8) is electrically connected single-chip microcomputer (11) PC0～PC7 port.

2, according to claim 1 a kind of based on the sun tracker of following the tracks of the attitude feedback, it is characterized in that: said single-chip microcomputer (11) for single chip computer AT 90LS8535, clock chip (13) for HT1380, signaling interface (16) by two DAC0832 form, lcd controller (12) is HT1621.

3, according to claim 1 a kind of based on the sun tracker of following the tracks of the attitude feedback, it is characterized in that: said dc motor power (9) connects control elevation angle drive motors, and dc motor power (10) connects controlling party parallactic angle drive motors.

4, according to claim 1 a kind of based on the sun tracker of following the tracks of the attitude feedback, it is characterized in that: said elevation angle sensor (4) is a differential capacitance sensor, and azimuth sensor (6) is a three-clove style electric capacity angular transducer.

5, according to claim 1 a kind of based on the sun tracker of following the tracks of the attitude feedback, it is characterized in that: the PD0 of said single-chip microcomputer (11)～PD1 port is used for external external equipment serial communication interface (14) and (15).

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