CN102591359B - Solar tracking controller - Google Patents

Abstract

The invention discloses a sun tracking controller. The output end of the sunlight sensor is connected to the input end of a modulus replacement device, the output end of the modulus replacement device is connected to the input end of a main controller, and the main controller outputs The terminal is connected to the driving circuit, and the output terminal of the driving circuit is connected to the pan-tilt control device, and the main controller is also connected to a power input interface, a button display interface and a serial communication interface; the sunlight sensor collects the sunlight position and converts it into an electrical signal , after analog-to-digital conversion, the digital signal is sent to the Atmega32 single-chip microcomputer, the single-chip microcomputer calculates the sun position according to the deviation signal, and outputs the corresponding control signal, and controls the pan-tilt through the driving circuit to ensure that the pan-tilt panel is always perpendicular to the sun, thus realizing For the purpose of sun tracking, the battery stores the electric energy generated by the solar panel, and provides power for the whole system at night, and the button display interface is connected to the button debugging module for installation, debugging and maintenance.

Description

A sun tracking controller

technical field

The invention relates to a controller, in particular to a sun tracking controller. the

Background technique

Solar energy is a renewable and clean energy. At present, the utilization of solar energy in my country is mainly in the primary application stage of non-tracking solar power generation, solar cells, and solar water heaters. The solar conversion efficiency of monocrystalline silicon cells used in solar power stations is only It is about 12%, which does not reflect the advantages of solar power generation. the

An effective way to improve the efficiency of solar power generation is to use tracking concentrating power generation - that is, equipped with a sun tracking system, which can directly increase the efficiency of solar power generation by 92.2%; for the new solar power generation material gallium arsenide, using tracking Concentrating power generation, solar power generation efficiency can be increased to more than 36%. However, the sun tracking system currently on the market has disadvantages such as high price, tracking accuracy of only 0.3°, and poor reliability, which restricts the practical application of the sun tracking system. Promotion in . the

Contents of the invention

In order to overcome the above-mentioned shortcoming of the prior art, a kind of solar tracking controller is provided, combined with the sunlight sensor, the tracking accuracy of the system can reach 0.1°. The angle between the cloud platform and the sunlight is 90°, so as to increase the effective light-receiving area of the platform and improve the utilization efficiency of solar energy. It has low cost and good stability. It can be applied to solar concentrated power generation, solar thermal power generation, and solar energy in the photovoltaic industry. Seawater desalination, sunlight conveyors, etc. need to use sun tracking, especially the occasions that require high-precision tracking of the sun. the

In order to achieve the above object, technical scheme of the present invention is:

A sun tracking controller, which is composed of a sunlight sensor, an analog-to-digital conversion device, a main controller, a drive circuit, a key display interface, a serial communication interface, and a power input interface, and the output end of the sunlight sensor is connected to the input of an analog-to-digital replacement device end, the output end of the modulus replacement device is connected to the input end of the main controller, the output end of the main controller is connected to the drive circuit, and the output end of the drive circuit is connected to the pan-tilt control device, and the main controller is also connected to the Power input interface, key display interface and serial communication interface;

The sunlight sensor is used to collect sunlight signals;

The analog-to-digital conversion conversion device is used to complete the analog-to-digital conversion of the sunlight sensor voltage signal;

The main controller circuit is used to complete input and output control and data calculation;

The drive circuit is used to increase the drive capability of the output signal;

The key display interface is connected to the key display module for installation, debugging and maintenance;

The serial port communication interface is connected to the host computer to realize the serial port communication function;

The power input interface is used to connect the power supply to provide power for the system;

Described master controller adopts Atmega32 single-chip microcomputer;

The sunlight sensor collects the position of the sun and converts it into an electrical signal. After the analog-to-digital conversion, the digital signal is sent to the Atmega32 single-chip microcomputer. The single-chip microcomputer calculates the sun position according to the deviation signal, and outputs the corresponding control signal, which is controlled by the drive circuit. , to ensure that the gimbal panel is always perpendicular to the sunlight, so as to achieve the purpose of sun tracking. The power supply part is composed of a battery and a solar panel. The battery stores the electric energy generated by the solar panel and provides power for the entire system at night. The button display interface is connected to the button debugging module. , for installation, commissioning and maintenance.

Description of drawings

Fig. 1 is the structure schematic diagram of the present invention. the

Figure 2(a) is the front view of the sunlight sensor, and Figure 2(b) is the top view of the sunlight sensor. the

Figure 3 is a connection diagram of the analog-to-digital conversion device. the

Figure 4 is the main controller connection diagram. the

FIG. 5 is a schematic diagram of the circuit connection of the drive circuit. the

Figure 6 is a flow chart of the system software. the

Figure 7 is a flow chart of the core algorithm software for tracking the sun. the

Detailed ways

The structural principle and working principle of the present invention will be briefly described below in conjunction with the accompanying drawings. the

The sunlight sensor is described below in conjunction with the accompanying drawing 2. The sunlight sensor is composed of 8 photoresistors with basically the same parameters and a black cylinder with a convex lens;

8号四个光敏电阻的1/4～1/3，在半径为R2圆周内并对称分布，螺纹连接管10上端通过与透镜固定台12以螺纹方式将平凸透镜9水平固定，下端通过与基准板11一体的调节内螺母连接于基准板11上，因为螺纹连接管10通过与透镜固定台12以螺纹方式将平凸透镜9水平固定后成为一个整体部件，所以还能够通过在内螺母11中旋转螺纹连接管10达到调节焦点的位置。 The specific design of the sunlight sensor is as follows: to realize the "coarse adjustment" of the sunlight signal acquisition part 1 The four photoresistors of No. 4 are respectively circumscribed and symmetrically distributed with the circle with a radius of R1, respectively representing the four directions of "North, East, South, and West"; and realizing "fine adjustment" signal acquisition part 5

1/4 to 1/3 of the four photoresistors of No. 8 are distributed symmetrically within a circle with a radius of R2. The upper end of the threaded connection pipe 10 is threaded with the lens fixing table 12 to fix the plano-convex lens 9 horizontally, and the lower end is passed through the base The integral adjustment inner nut of the plate 11 is connected to the reference plate 11, because the threaded connection pipe 10 becomes an integral part after the plano-convex lens 9 is horizontally fixed with the lens fixing table 12 in a threaded manner, so it can also be rotated in the inner nut 11 The threaded connection pipe 10 reaches the position for adjusting the focus.

In fact, the circumference whose radius is R2 is exactly the circular area where the plano-convex lens 9 gathers sunlight, and after the 5-8 four photoelectric sensors are installed and fixed, the size of R2 can be changed by rotating the threaded connecting pipe 10 in the inner nut 11, Therefore, the purpose of adjusting the light-receiving areas of the four photoelectric sensors according to needs is realized. the

The circuit connection of the 8 photoresistors on the sunlight sensor is shown in Figure 2(a). In the figure, R1~R8 are photoresistors, and Rf is a variable resistor; when the sun shines on the photoresistors, the voltage at AIN0~AIN7 will changes, the potential at this point satisfies the following relationship:

Connect these 8 signals to the 8 analog-to-digital conversion channels of the analog-to-digital conversion chip to complete the signal input. Since the parameters of the photoresistors are not completely the same, the variable resistor Rf is used to ensure that under the same lighting conditions The parameters of the 8 photoresistors are consistent.

The analog-to-digital conversion chip used by the analog-to-digital conversion device is a 12-bit parallel high-speed analog-to-digital conversion chip MAX197, which has 8 analog input channels. the

The analog-to-digital conversion chip MAX197 takes only 5us to perform an analog-to-digital conversion, which can meet the real-time requirements in system design. If the cost is sensitive, you can directly use the analog-to-digital conversion module in ATmega32 without using this chip. At this time, you only need to short-circuit AIN0~AIN7 and PA0~PA7 respectively. the

Described master controller finishes the input of signal, output control and data operation, and processor adopts the ATmega32 single-chip microcomputer of low power consumption, single instruction cycle, and accompanying drawing 4 is the signal input and output connection diagram of master controller, including analog signal data input The channel (PA0~PA7) is its circuit connection diagram, the analog-to-digital conversion chip control line (PD4~PD7), the serial port communication line (PD0, PD1), the ISP program download line (PB5, PB6, PB7), the JTAG debugging port (TDI , TDO, TMS, TCK), drive control lines (PB4, PB5, PB6, PB7), etc.; in addition, the main controller also includes an oscillation circuit and a reset circuit. The oscillation circuit is composed of a 12MHz crystal oscillator and two 20pF capacitor connections. the

The driving circuit is used to increase the driving ability of the signal. The driving chip adopts the integrated chip L298. The L298 can drive two two-phase motors, and can also drive a relay. The output voltage can reach up to 50V, and the output voltage is determined by the input power supply; The single-phase output current of the L298 can reach 2.5 A, which can drive inductive loads. the

Table 1 L298N logic control table

The driving circuit principle of ATmega32 single-chip microcomputer and L298 is that PB4, PB5, PB6 and PB7 of the single-chip microcomputer are respectively connected to pins 5 (IN1), 7 (IN2), 10 (IN3), and 12 (IN4) of L298N, which are control signals. The work of the motors in the horizontal direction and the vertical direction is stopped. Pin 4 (Vss) of L298N is directly connected to the positive pole of the solar panel. Pins 2 (OUT1), 3 (OUT2), 13 (OUT3), and 14 (OUT4) are output terminals, which are respectively connected to the positive and negative poles of the two motors. Diodes D6~D9, D13~D16 are freewheeling diodes, light emitting diodes D10, D11, D12, D17 are used to display the forward and reverse of the motor, P4 is the output interface, the output interface is two-way, P4 pin 1 and 2 The pin is one way, and the 3-pin and 4-pin are one way, which drive the east-west direction and north-south direction motors of the gimbal respectively. Both of these two ways can directly drive the DC motor with the motor power below 10W; if it needs to be applied to a higher power For the motor, these two signals can be used to control the relay, and then the relay is connected to the high-power motor.

The key display interface is connected to a specific key display module for installation, debugging and maintenance of the system. The button display module includes two parts: 12864 liquid crystal display and keyboard control. the

The serial communication module can be connected to the upper computer to realize the serial communication function; in order to make the system easy to upgrade, the system is equipped with a serial communication module, through which the system can be directly controlled and monitored by the computer. In addition, this module can realize the centralized management of some specific occasions, and can form a field bus (such as Profibus, Interbus, P-NET) with certain specifications through protocol conversion, so as to realize the digital monitoring and management of the system. the

In addition, in the sun tracking controller, other modules are added, mainly: ① EEPROM chip AT24C02 is added to save the relevant parameters set; ② clock chip DS1302 is also added, so that the system can use two Modes to realize tracking, namely: sensor mode and sensor and clock combination mode; ③ 4 limit switch signal interfaces are reserved for specific applications; ④ wind speed sensor interfaces are reserved, and the wind speed sensor can be connected to realize the strong wind protection function. the

The above part is the hardware design part of the system, and the software design of a high-precision sun tracking controller is described below. The system design is written in C language, the programming environment is ICCAVR, and the debugging environment is AVR studio. The overall flow of the system software is shown in Figure 7. After the single-chip microcomputer is powered on and reset, the parameters are set and initialized first, and the system is performing AD conversion, and then the single-chip microcomputer detects the current lighting conditions through the sensor, and then performs external adjustment, strong wind protection, abnormal detection, and internal adjustment according to the program. the

The sun tracking core algorithm control program consists of an external rough adjustment program and an internal fine adjustment program. The program flow is shown in Figure 7. The specific workflow of the program is as follows in conjunction with Figure 7:

1. ATmega32 outputs the corresponding control signal to start the analog-to-digital conversion chip MAX197 and starts to collect the 8-way AD input signal of the sunlight sensor;

2. Store the AD values corresponding to the 8 input signals into 8 registers respectively. The data stored in the first register represents the east direction inside the black tube of the sensor sunlight sensor (hereinafter referred to as the photoresistor in the east, south, west and north directions) Similar to the east direction) the AD value corresponding to the photoresistor, the data stored in the second register represents the AD value corresponding to the photoresistor in the south direction inside the black tube of the sunlight sensor, the data stored in the third register and the fourth register represent the inner west direction, The AD value of the photoresistor in the inner north direction; the data stored in the 5th, 6th, 7th, and 8th registers respectively represent the AD value of the photoresistor in the external east direction, external south direction, external west direction, and external north direction of the sunlight sensor black tube ;

3. The ATmega32 processor compares the values of the 5th and 7th registers. If the value of the 5th register is larger than the 7th, it means that the approximate position of the sun is in the east direction; then compare the values of the 6th and 8th registers , if the value of the 6th register is greater than the 8th, it means that the sun is roughly in the south direction; combining these two, it can be determined that the sun is roughly in the southeast direction. Similarly, when the fifth register is smaller than the seventh register, and the value of the sixth register is smaller than the value of the eighth register, several other states can be determined, namely: east, south, southwest, west, northwest, north, northeast;

4. After confirming the general direction, judge the difference between the fifth register and the seventh register, that is, outer east and outer west. If the difference is greater than 15, the ATmega32 single-chip microcomputer will drive the motor chip L298 to make the motor move eastward; The output signal is that the PB4 pin of the microcontroller is high level 1, and PB5 is low level 0;

For other situations, refer to Flowchart 7;

5. After the external adjustment is completed, turn to the internal adjustment. The internal adjustment is similar to the external adjustment, but due to the effect of light concentration and fine adjustment, the direction of the internal adjustment drive motor is opposite to the external one, and the difference is also changed to 8;

6. Judge the difference between the first register and the third register, that is, inner east and inner west. If the difference is greater than 8, the ATmega32 microcontroller will drive the motor chip L298 to make the motor move westward; the specific signal given is the microcontroller's PB4 pin is low level 0, PB5 is high level 1;

For other situations, refer to Flowchart 7;

7. Repeat steps 1 to 6 above until the system is adjusted to align with the sun.

Claims (3)

1. A solar tracking controller is made up of a sunlight sensor, an analog-to-digital conversion device, a main controller, a drive circuit, a button display interface, a serial port communication interface, and a power input interface, and is characterized in that the output terminal of the sunlight sensor is connected with The input end of the analog-to-digital conversion device, the output end of the analog-to-digital conversion device is connected to the input end of the main controller, the output end of the main controller is connected to the drive circuit, and the output end of the drive circuit is connected to the pan-tilt control device. The device is also connected with a power input interface, a button display interface and a serial communication interface; The operation steps of the sun tracking controller are as follows. In the first step, the main controller outputs the corresponding control signal to start the analog-to-digital conversion device and starts to collect the 8-way AD input signal of the sunlight sensor; The second step is to store the AD values corresponding to the 8 input signals into 8 registers respectively. The data stored in the first register represents the AD value corresponding to the photoresistor in the east direction inside the black tube of the sensor sunlight sensor, hereinafter referred to as Inner East, South The photoresistors in the west and north directions are similar to the east direction. The data stored in the second register represents the AD value corresponding to the photoresistor in the south direction inside the black tube of the sunlight sensor. The data stored in the third register and the fourth register represent the inner west direction respectively. , the AD value of the photoresistor in the inner north direction; the data stored in the 5th, 6th, 7th, and 8th registers represent the photoresistor AD of the external east direction, external south direction, external west direction, and external north direction of the sunlight sensor black tube respectively value; Step 3: The main controller processor compares the values of the 5th and 7th registers. If the value of the 5th register is larger than the 7th, it means that the approximate position of the sun is in the east direction; then compare the 6th and 8th The value of the first register, if the value of the sixth register is greater than the eighth, it means that the sun is roughly in the south direction; combining these two, it can be determined that the sun is roughly in the southeast direction; similarly, when the fifth register is greater than the first There are 7 registers, and the value of the 6th register is smaller than the value of the 8th register to determine several other states, namely: East, South, Southwest, West, Northwest, North, Northeast; Step 4: After determining the general direction, judge the difference between the fifth and seventh registers, that is, outer east and outer west. If the difference is greater than 15, the main controller MCU drives the motor chip L298 to drive the motor to the east. Movement; the specific signal given is that the PB4 pin of the microcontroller is high level 1, and PB5 is low level 0; Step 5. After the external adjustment is completed, turn to the internal adjustment. The internal adjustment is similar to the external adjustment, but due to the effect of light concentration and fine adjustment, the direction of the internal adjustment drive motor is opposite to the external one, and the difference is also changed to 8; Step 6. Determine the difference between the first and third registers, that is, inner east and inner west. If the difference is greater than 8, the main controller MCU drives the motor chip L298 to make the motor move westward; the specific given The signal is the PB4 pin of the microcontroller is low level 0, and PB5 is high level 1; Step 7: Repeat the first to sixth steps above until the system is adjusted to align with the sun. 2. A kind of sun tracking controller according to claim 1, characterized in that, the sunlight sensor is used for collecting sunlight signals; The analog-to-digital conversion device is used to complete the analog-to-digital conversion of the sunlight sensor voltage signal; The main controller circuit is used to complete input and output control and data calculation; The drive circuit is used to increase the drive capability of the output signal; The key display interface is connected to the key display module for installation, debugging and maintenance; The serial port communication interface is connected to the host computer to realize the serial port communication function; The power input interface is used to connect the power supply to provide power for the system. 3. A kind of sun tracking controller according to claim 1, characterized in that, said main controller adopts Atmega32 single-chip microcomputer.

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