CN114337499B - Illumination self-adaptive thermal-patch-prevention greenhouse type photovoltaic power generation device and method - Google Patents

Abstract

The invention provides an illumination self-adaptive heat-patch-prevention shed type photovoltaic power generation device and method, comprising a heat-patch-prevention photovoltaic array, a heat-patch-prevention driving module, a voltage and current sampler, an output interface, an angle regulator, a controller, an illumination angle sampling module, a power supply manager and a lithium battery; the hot spot prevention photovoltaic array is respectively and electrically connected with the hot spot prevention driving module and the voltage and current sampler, the voltage and current sampler is electrically connected with the electric energy output interface, and the hot spot prevention driving module, the voltage and current sampler, the power manager, the illumination angle sampling module and the angle regulator are respectively and electrically connected with the controller; the device can adaptively adjust the angle of the photovoltaic unit by taking heat energy as power according to the current illumination intensity and illumination angle; regulating the output voltage of the photovoltaic array to reach the maximum power point; meanwhile, the hot spot effect is prevented from affecting the photovoltaic power generation efficiency; compared with the existing illumination angle tracking, the invention uses heat as power, and avoids the problems of high power consumption and high maintenance cost of the motor.

Description

A light-adaptive, heat-spot-proof shed-type photovoltaic power generation device and method

Technical field

The invention belongs to the field of new energy technology, and specifically relates to an illumination-adaptive, heat-spot-proof shed-type photovoltaic power generation device and method.

Background technique

Due to the influence of the cosine effect, many fixed solar panel arrays currently cannot ensure vertical irradiation of sunlight, cannot fully utilize solar resources, and have low power generation efficiency. Applying tracking systems to flat-panel photovoltaic power generation arrays can improve power generation efficiency. Most of the current fixed solar tracking systems use motors to directly drive the photovoltaic panels to rotate or motors to drive hydraulics to drive the photovoltaic panels to rotate. This method not only increases the system maintenance cost, but also increases the power consumption. Therefore, a thermally adaptive light angle and light intensity anti-hot spot photovoltaic power generation device is studied. Under the control of electrical signals, it uses industrial The thermal expansion of the mass adjusts the position of the photovoltaic panels to meet the needs of tracking the maximum light intensity angle with low power consumption.

Due to the characteristics of photovoltaic panels, when the light is partially blocked, the output power of the entire photovoltaic panel will be greatly reduced. At the same time, the blocked area will generate a lot of heat, causing damage to the photovoltaic panel, which is the "hot spot effect". In order to combat the hot spot effect, most methods are to remove foreign objects on the surface of photovoltaic panels. However, this solution cannot deal with the shadows caused by distant obstacles and solve the problem of "hot spot effect" caused by shadow occlusion.

Since the output voltage and current of photovoltaic panels have a highly nonlinear relationship with external factors, there is a unique maximum power output point in a specific working environment. In order to ensure that the photovoltaic array can always work at the maximum power point, there is a problem of studying maximum power output point tracking (MPPT). However, the existing disturbance observation method, hysteresis comparison method, voltage increment optimization method, constant voltage method, admittance increment method, fuzzy control method, etc. cannot cope with the multi-peak shape of the P-U curve caused by factors such as local shadows. It is a problem to find the global optimum, and artificial intelligence algorithms often require complex hardware support.

Contents of the invention

Based on the above problems, the present invention proposes an illumination-adaptive anti-hot spot photovoltaic power generation device and method to solve the maximum power point tracking problem when the P-U curve of the photovoltaic array is in a multi-peak shape and the "hot spot effect" problem of the photovoltaic array. , as well as the problem of low-power adaptive lighting angle in complex urban environments.

The invention proposes an illumination-adaptive anti-hot-spot photovoltaic power generation device, which includes: an awning base, an anti-hot-spot photovoltaic array installed on the awning base, an anti-hot-spot driving module, and a voltage and current sampler. , output interface, angle regulator, controller, light angle sampling module, power manager, lithium battery; the anti-hot spot photovoltaic array is electrically connected to the anti-hot spot drive module and the voltage and current sampler respectively, and the voltage and current sampler is connected to the output interface Electrically connected, the anti-hot spot drive module, voltage and current sampler, power manager, light angle sampling module, and angle regulator are respectively connected to the controller.

The anti-hot spot photovoltaic array is installed on the upper surface of the awning base; the anti-hot spot photovoltaic array includes N power generation units connected in series and composed of monocrystalline silicon photovoltaic units and field effect tubes connected in parallel, N is a positive integer. ; The drain of the field effect tube of each power generation unit is connected to the positive electrode of the monocrystalline silicon photovoltaic unit, and the source of the field effect tube is connected to the negative electrode of the monocrystalline silicon photovoltaic unit; the port of the anti-hot spot photovoltaic array includes the output end of the anti-hot spot photovoltaic array And the anti-hot spot photovoltaic array control end, the anti-hot spot photovoltaic array output end is connected to both ends of the series circuit of the power generation unit, the gates of all field effect tubes are connected to the anti-hot spot photovoltaic array control end; the anti-hot spot photovoltaic array output end Connect the voltage and current sampler input.

The ports connecting the anti-hot spot drive module to other modules include the power end of the anti-hot spot drive module, the output end of the anti-hot spot drive module and the control end of the anti-hot spot photovoltaic array; the power end of the anti-hot spot drive module is connected to the power manager for stability. The output end of the anti-hot spot drive module is connected to the anti-hot spot photovoltaic array control end, and the anti-hot spot photovoltaic array control end is connected to the I/O port of the controller.

The voltage and current sampler includes a voltage collector and a current collector; the ports of the voltage and current sampler include a power end of the voltage and current sampler, an input end of the voltage and current sampler, an output end of the voltage and current sampler, and a feedback end of the voltage and current sampler. terminal; the input terminal of the voltage and current sampler has positive and negative terminals; the input terminal of the voltage and current sampler is connected to the output terminal of the anti-hot spot photovoltaic array; the power terminal of the voltage and current sampler is connected to the regulated output terminal of the power manager; the output terminal of the voltage and current sampler is connected Buck circuit input end; the feedback end of the voltage and current sampler is connected to the I/O port of the controller; the voltage and current sampler is composed of a voltage sampler and a current sampler; the voltage sampler is connected to the positive and negative poles of the input end of the voltage and current sampler, The positive wire of the input terminal of the voltage and current sampler passes through the magnetic ring of the current sampler. The voltage sampler and current sampler are powered by the power terminal of the voltage and current sampler. The feedback terminal of the voltage and current sampler outputs the voltage measured by the voltage sampler and current sampler. current information;

The power manager includes a DC bus, a battery manager, a battery voltage sampler, a voltage regulator, and a bus voltage sampler; the ports of the power manager include a battery terminal, a power input terminal, and a voltage regulator output terminal of the power manager; the battery terminal Connect the lithium battery, and the power input terminal is connected to the DC bus; the voltage-regulated output terminal of the power manager is connected to the voltage and current sampler power terminal, the angle regulator power terminal, the solenoid valve power terminal, the anti-hot spot drive module power terminal, and the controller power terminal. The power end of the illumination angle sampling module; the battery terminal in the power manager is connected to the battery manager and the battery voltage sampler; the DC bus connects the battery manager, the power input end, the bus voltage sampler and the voltage regulator; the voltage regulator The battery manager is connected to the regulated output terminal of the power manager; the battery manager is connected to the control terminal of the power manager; the battery voltage sampler and bus voltage sampler are connected to the feedback terminal of the voltage and current sampler.

The angle adjuster includes a frame and a solar collector tube, an energy storage cylinder, a two-way hydraulic cylinder, a solenoid valve, and a hydraulic cylinder installed on the frame; the two-way hydraulic cylinder consists of a cylinder body, a gas-liquid mixed working fluid pipe, and a hydraulic oil pipe. Composition; the solar collector tube is installed on the backlight surface of the anti-hot spot photovoltaic array and is connected to the energy storage cylinder; the energy storage cylinder contains a gas-liquid mixed working fluid, and the energy storage cylinder is connected to a bidirectional hydraulic cylinder; the bidirectional hydraulic cylinder is controlled to prevent the angle of the hot spot photovoltaic array. The solenoid valve is connected to the hydraulic cylinder; the power end of the solenoid valve is connected to the regulated output end of the power manager, and the control end of the solenoid valve is connected to the I/O port of the controller.

The illumination angle sampling module has a triangular prism structure; the bottom cylinder is close to the anti-heat spot photovoltaic array; the other two cylinders each have a set of photoresistor arrays composed of X photoresistors, X is a positive integer; illumination angle sampling The ports that the module connects to other modules include the power end of the illumination angle sampling module and the illumination angle sampling signal output end; the illumination angle sampling module power end is connected to the regulated output end of the power manager; the illumination angle sampling signal output end is connected to the I/O of the controller. Port O, the illumination angle sampling module and the heat spot prevention photovoltaic array are both installed on the upper surface of the shed base, and the illumination angle sampling module occupies the same area as a photovoltaic unit.

An illumination-adaptive heat-spot-proof shed-type photovoltaic power generation method, the method is implemented based on the illumination-adaptive heat-spot-proof shed-type photovoltaic power generation device, and includes:

Step 1: The illumination angle sampling module outputs the voltage reading U _ij of each photoresistor to the controller, i is the array number, i=1, 2; j is the array number, j=1, 2,...,X;

Step 2: The controller calculates and selects the maximum value U _MAX in U _ij and estimates the relative light intensity _PS = U _MAX ·K; when _PS is greater than the set value A, the maximum power angle adjustment strategy and power generation priority energy management are simultaneously executed. strategy, otherwise a low-power energy management strategy is implemented, where A is a set constant;

Step 3: The anti-hot spot photovoltaic array generates electricity when exposed to light, and delivers the power to the voltage and current sampler;

Step 4: The voltage and current sampler measures the anti-hot spot photovoltaic array port voltage and output current, and outputs the anti-hot spot photovoltaic array end voltage U(t) and current I(t) of the t-th sampling period to the controller, and calculates and Record the output power of the anti-hot spot photovoltaic array P(t)=U(t)I(t) in the t-th sampling period;

Step 5: The controller uses the MPPT algorithm to control the anti-hot spot photovoltaic array to generate electricity through the Buck circuit;

Step 6: The controller calculates the value V′ = P _S -P (t). If V′ > V ₀ , the controller enables the anti-hot spot self-check adjustment strategy to control the anti-hot spot drive module to adjust the anti-hot spot photovoltaic array. , where V ₀ is a constant; if V′ ≤ V ₀ , and the anti-hot spot self-checking adjustment strategy has been enabled for C sampling periods, the anti-hot spot self-checking adjustment strategy ends, and a low level is applied to the field effect tubes of all power generation units. Level, C is a constant;

Step 7: The Buck circuit inputs power into the DC regulator;

Step 8: The DC voltage regulator adjusts the output voltage value to U _h , and U _h is the set constant; it is output to the power end of the power manager and output to the outside through the output interface.

The maximum power angle adjustment strategy is specifically expressed as:

Step B1: Calculate the average voltage of each photoresistor in the t′th sampling period of the illumination angle sampling module The voltage value of each photoresistor in each array is the difference between its array average value/> If |ΔU _ij |<w, record the value as U _in , where w is the set constant, n is the record label, and n is increased by 1 for each value recorded in the array; calculate the average value of each array recorded value/>

Step B2: The controller calculates the subtraction of the average value of the recorded values of array 1 and array 2 in the t′th sampling period of the illumination angle sampling module.

Step B3: When |E ₁₂ (t′)|＜α, α is the set value, and the controller controls the solenoid valve flow FL＝K _P1 E ₁₂ (t′)+K _I1 ∑ _t′ E ₁₂ (t′) , add 1 to t′, and return to step B2; when |E ₁₂ (t′)|≥α, the maximum power angle adjustment strategy ends; where K _P1 and K _I1 are set constants;

The power generation priority energy management strategy is specifically expressed as:

Step D1: The power manager provides energy to the controller, light angle sampling module, angle regulator, and voltage and current sampler through the 5V output terminal; the DC voltage regulator outputs energy to the power manager and output interface at the same time;

Step D2: The battery voltage sampler in the power manager measures the terminal voltage of the lithium battery and outputs it to the controller through the feedback terminal of the power manager. The controller determines the battery status: If the battery voltage U _B is less than 4.2V, the power manager Charging the lithium battery through the battery terminal;

The low-power energy management strategy is specifically expressed as:

Step C1: The power manager and controller stop inputting energy and control signals to the angle regulator and voltage and current sampler; the DC voltage regulator outputs energy to the power manager and stops outputting energy to the output interface;

Step C2: The battery voltage sampler in the power manager measures the terminal voltage of the lithium battery and outputs it to the controller through the feedback terminal of the power manager. The controller determines the battery status: If the battery voltage U _B is greater than 3V, execute step C3, otherwise Execute step C4;

Step C3: The power manager supplies power to the light angle sampling module and controller through the voltage-regulated output terminal, and executes step C1; the controller outputs DC power with a voltage of U _h to the Buck circuit control terminal through the I/O port;

Step C4: The regulated output terminal of the power manager stops outputting and disconnects the lithium battery;

The specific description of the hot spot prevention self-check adjustment strategy is as follows:

Step E1: The voltage and current sampler obtains the output current i(0) of the current anti-hot spot photovoltaic array, and sets the integer variable p to 1;

Step E2: The controller controls the anti-hot spot driving module to apply a high level to the field effect transistor of the p-th power generation unit;

Step E3: The voltage and current sampler obtains the output current i(p) of the anti-hot spot photovoltaic array;

Step E4: Controller Comparison and the size of the constant q, if/> Then the anti-hot spot driving module applies a low level to the field effect tubes of all power generation units. When the variable p equals N, the anti-hot spot self-check adjustment strategy ends, otherwise n is increased by 1 and step E2 is executed; if/> Then keep applying a high level to the field effect transistor of the p-th power generation unit, and end the hot spot prevention self-test adjustment strategy.

The step 5 includes:

Step A1: The controller calculates the disturbance amount in the tth period K ₁ and b are constants;

Step A2: The controller calculates the expected voltage u(t) of the anti-hot spot photovoltaic array, and lets the expected voltage u(t) be the terminal voltage of the anti-hot spot photovoltaic array for the sampling period plus the step size corresponding to the period: u(t) )=U(t)+Δu(t);

Step A3: The controller converts the expected terminal voltage u(t) of the anti-hot spot photovoltaic array into the PWM wave duty cycle and updates the duty cycle value Where f=K _P′ ΔU′[x]+K _I ∑ _t ΔU′[x], x is the current number of executions, x increases by 1 for each execution; where K _P′ and K _I are set constants, ΔU′ [x _] =u(t ₎ -U Step A3, add 1 to the independent variable x; v is the set threshold;

Step A4: The controller obtains the current anti-hot spot photovoltaic array terminal voltage U′(t) and current I′(t); and calculates the output power P′(t)=U′(t)I′(t);

Step A5: The controller compares the size of P(t) and P′(t): if the power rises P′(t)>P(t), the initial terminal voltage of the next period is the initial terminal voltage of the original period plus the step size. U ₀ (t+1)=U ₀ (t)+Δu(t); if the power does not change P′(t)=P(t), then the initial terminal voltage of the next cycle does not change, that is, U ₀ (t +1)=U ₀ (t); if the power decreases P'(t)<P(t), it is accepted with probability p ₁ , that is, the initial terminal voltage of the next period is the initial terminal voltage of the original period plus the step size U ₀ (t+1)=U ₀ (t)+Δu(t) _; if not accepted, the initial terminal voltage of the next period will be the initial terminal voltage of the original period minus the step size U ₀ (t+ 1)=U ₀ (t)-Δu(t); where p ₂ =f·p ₁ , f is a constant; p ₁ =p′ ₁ +K ₁ ΔP _S -K ₂ T, p ₁ ′ is the last calculation In the value of p ₁ , K ₁ and K ₂ are constants, and T is the number of consecutive times when the power rises, that is, P'(t)>P(t). If it is discontinuous, it will be reset to zero.

The beneficial effects of the present invention are:

The present invention proposes an illumination-adaptive heat-spot-proof shed-type photovoltaic power generation device and method. The device can adaptively adjust the angle of the photovoltaic unit based on the current illumination intensity and illumination angle and use thermal energy as the driving force; and adjust the photovoltaic array. The output voltage reaches the maximum power point; at the same time, the hot spot effect is prevented from affecting the photovoltaic power generation efficiency; compared with the existing illumination angle tracking, the present invention uses heat as power to avoid the problems of high motor power consumption and high maintenance costs; the method is based on The maximum power angle adjustment strategy is implemented. Compared with the existing methods of direct motor drive or motor-driven hydraulic drive, it not only simplifies the control hardware and reduces costs, but also avoids motor failure and is more suitable for improving photovoltaic power generation efficiency over a long period of time; prevent The application of hot spot photovoltaic arrays solves the "hot spot effect" problem caused by shadow occlusion; the application of the differential adjustment variable step perturbation observation MPPT algorithm to find the optimal multi-peak conditions overcomes the photovoltaic array P-U curve caused by local shadows and other factors. When there are multiple peaks, the traditional MPPT algorithm falls into the local optimum problem; at the same time, compared with the existing MPPT algorithm based on neural network, particle swarm, ant colony and other algorithms, the multi-peak condition proposed by the present invention finds the optimal differential adjustment variable. The step size perturbation observation MPPT algorithm process is simpler, has lower hardware requirements, is easier to implement, and meets the needs of industrialization.

Description of the drawings

Figure 1 is an illumination-adaptive heat-spot-proof shed-type photovoltaic power generation device in the present invention;

Figure 2 is a schematic structural diagram of the hot spot photovoltaic array in the present invention;

Figure 3 is a schematic diagram of the circuit principle of the anti-hot spot photovoltaic array in the present invention;

Figure 4 is a schematic diagram of the circuit principle of the anti-hot spot driving module in the present invention;

Figure 5 is a schematic diagram of the internal connection method of the voltage and current sampler in the present invention;

Figure 6 is a schematic diagram of the internal connection method of the power manager in the present invention;

Figure 7 is a schematic structural diagram of the angle adjuster in the present invention;

Figure 8 is a flow chart of the illumination-adaptive heat-spot-proof shed-type photovoltaic power generation method in the present invention;

Figure 9 is a flow chart of the maximum power angle adjustment method in the present invention;

Figure 10 is a flow chart of the differential adjustment variable step size perturbation observation MPPT algorithm for finding the optimal multi-peak conditions in the present invention.

Detailed ways

The invention will be further described below in conjunction with the accompanying drawings and specific implementation examples.

The present invention proposes an illumination-adaptive anti-hot spot photovoltaic power generation device, as shown in Figure 1, including: an awning base, an anti-hot spot photovoltaic array installed on the awning base, and an anti-hot spot driving module. , voltage and current sampler, output interface, angle regulator, controller, light angle sampling module, power manager, lithium battery; the anti-hot spot photovoltaic array is electrically connected to the anti-hot spot drive module and the voltage and current sampler respectively, and the voltage and current The sampler is electrically connected to the output interface, and the anti-hot spot drive module, voltage and current sampler, power manager, light angle sampling module, and angle regulator are electrically connected to the controller respectively;

The awning base is a mechanical support frame for a thermally adaptive light angle and light intensity anti-heat spot photovoltaic power generation device, and is a mechanism for mechanical connection of various parts;

The anti-hot spot photovoltaic array is used to convert solar energy into electrical energy and deliver the electrical energy to the voltage and current sampler;

The anti-hot-spot driving module is used to drive the anti-hot-spot photovoltaic array to work according to the anti-hot-spot photovoltaic power generation method under the control of the controller;

The voltage and current sampler is used to obtain the voltage and current information of the hot spot prevention photovoltaic array and convert it into a level signal readable by the controller;

The angle adjuster is used to adjust the angle between the hot spot photovoltaic array and sunlight according to the maximum power angle adjustment strategy under the control of the controller;

The controller is used to receive the level information of the voltage and current sampler, the illumination angle sampling module and the power manager, and perform calculations and processing according to the illumination-adaptive anti-hot-spot photovoltaic power generation method, and to control the anti-hot-spot driving module and Power manager and angle adjuster for control;

The illumination angle sampling module is used to obtain the angle information of the sun-relative illumination-adaptive heat-proof shed-type photovoltaic power generation device, and convert it into a level signal readable by the controller;

The power manager is used to supply power to the light angle sampling module, anti-hot spot driving module, controller and angle regulator, and also has the function of controlling the charge and discharge of the lithium battery and protecting the battery;

The lithium battery is used for energy storage;

The circuit principle of the anti-hot spot photovoltaic array is shown in Figure 3. The anti-hot spot photovoltaic array is installed on the upper surface of the awning base; the anti-hot spot photovoltaic array includes N monocrystalline silicon photovoltaic units and fields connected in series. A power generation unit formed by parallel connection of effect tubes, N is a positive integer; the drain of the field effect tube of each power generation unit is connected to the positive electrode of the single crystal silicon photovoltaic unit, and the source of the field effect tube is connected to the negative electrode of the single crystal silicon photovoltaic unit; heat protection The ports of the spot photovoltaic array include the output end of the anti-hot spot photovoltaic array and the control end of the anti-hot spot photovoltaic array. The output end of the anti-hot spot photovoltaic array is connected to both ends of the series circuit of the power generation unit, and the gates of all field effect tubes are connected to the anti-heat spot photovoltaic array. Spot photovoltaic array control terminal; the output terminal of the anti-hot spot photovoltaic array is connected to the input terminal of the voltage and current sampler.

The circuit structure of the anti-hot spot drive module is shown in Figure 4. The ports include the power end of the anti-hot spot drive module, the output end of the anti-hot spot drive module and the anti-hot spot photovoltaic array control end; the power end of the anti-hot spot drive module is connected to the power supply. The voltage-stabilizing output end of the manager and the output end of the anti-hot spot drive module are connected to the control end of the anti-hot spot photovoltaic array, and the control end of the anti-hot spot photovoltaic array is connected to the I/O port of the controller.

The voltage and current sampler includes a voltage collector and a current collector, as shown in Figure 5; the ports of the voltage and current sampler include a voltage and current sampler power end, a voltage and current sampler input end, and a voltage and current sampler output end. and the feedback terminal of the voltage and current sampler; the input terminal of the voltage and current sampler has positive and negative terminals; the input terminal of the voltage and current sampler is connected to the output terminal of the anti-hot spot photovoltaic array; the power terminal of the voltage and current sampler is connected to the regulated output terminal of the power manager; voltage The output terminal of the current sampler is connected to the input terminal of the Buck circuit; the feedback terminal of the voltage and current sampler is connected to the I/O port of the controller; the voltage and current sampler is composed of a voltage sampler and a current sampler; the voltage sampler is connected to the voltage and current sampler The positive and negative poles of the input terminal, the positive wire of the input terminal of the voltage and current sampler pass through the magnetic ring of the current sampler, the voltage sampler and current sampler are powered by the power supply terminal of the voltage and current sampler, and the feedback terminal of the voltage and current sampler outputs the voltage sampler and current The sampler measures voltage and current information;

In order to output stabilized DC power, the output end of the voltage and current sampler is connected to the DC regulator through the Buck circuit, and the regulated DC power is output through the DC regulator. The input end of the Buck circuit is connected to the output end of the voltage and current sampler; the output of the Buck circuit The terminal is connected to the input end of the DC voltage regulator; the control terminal of the Buck circuit is connected to the I/O port of the controller; the Buck circuit is the core hardware of the differential adjustment variable step size disturbance observation MPPT algorithm to achieve optimal multi-peak conditions. The algorithm improves the power generation efficiency of the photovoltaic array by finding the voltage value corresponding to the maximum power point in the P-U curve of the photovoltaic array. The calculation result is a certain duty cycle, and the voltage value at the output end of the photovoltaic array is adjusted by the controller. The control end of the Buck circuit outputs a PWM wave with a specified duty cycle.

The ports of the DC voltage regulator include a DC voltage regulator control terminal, a DC voltage regulator input terminal and a DC voltage regulator output terminal; wherein the DC voltage regulator control terminal is connected to the I/O port of the controller; the DC voltage regulator The input terminal is connected to the output terminal of the Buck circuit; the output terminal of the DC voltage regulator is connected to the power input terminal and output interface of the power manager; the function of the DC voltage regulator is to convert the unstable voltage at the output terminal of the Buck circuit into a stable voltage output. And at the same time, the power is output to the output interface and power manager under the control of the controller. According to the low-power energy management strategy proposed by the present invention, the controller can enable and stop the DC voltage regulator to transmit power to the output interface.

As shown in Figure 6, the power manager includes a DC bus, a battery manager, a battery voltage sampler, a voltage regulator, and a bus voltage sampler; the ports of the power manager include a battery terminal, a power input terminal, and a power manager stabilizer. voltage output end; the battery end is connected to the lithium battery, and the power input end is connected to the DC bus; the voltage-stabilized output end of the power manager is connected to the voltage and current sampler power end, the angle regulator power end, the solenoid valve power end, and the anti-hot spot drive module power end. , controller power supply end, light angle sampling module power supply end; the battery terminal in the power manager is connected to the battery manager and battery voltage sampler; the DC bus connects the battery manager, power input end, bus voltage sampler and voltage regulator Connect together; the voltage regulator is connected to the regulated output end of the power manager; the battery manager is connected to the control end of the power manager; the battery voltage sampler and the bus voltage sampler are connected to the feedback end of the voltage and current sampler; the power manager is in the control It has a battery protection function under the control of the controller, and at the same time supplies power to the controller and angle regulator lighting angle sampling module with a stable voltage. The battery manager in the power manager is used to control the energy exchange between the lithium battery and the DC bus, and is also used to ensure the safe operation of the battery: it controls the operating current of the battery; it can stop the battery from continuing to charge after the battery is fully charged; it can stop charging when the battery is discharged to a certain level. The battery can then be stopped to continue discharging; the battery voltage sampler is used to monitor the battery voltage in real time; the bus voltage sampler is used to monitor the bus voltage in real time; the voltage regulator is used to supply power to other modules with a stable voltage through the voltage-regulated output terminal.

As shown in Figure 7, the angle adjuster includes a frame and a solar collector tube installed on the frame, an energy storage cylinder, a two-way hydraulic cylinder, a solenoid valve, a hydraulic cylinder, a gas-liquid mixed working medium and hydraulic oil; where two-way The hydraulic cylinder is composed of a cylinder body, a gas-liquid mixed working medium pipe and a hydraulic oil pipe; the solar collector pipe is installed on the backlight surface of the anti-hot spot photovoltaic array and is connected to the energy storage cylinder; the energy storage cylinder contains a gas-liquid mixed working medium, and the energy storage cylinder is connected The gas-liquid mixed working medium pipe of the two-way hydraulic cylinder; the hydraulic oil pipe of the two-way hydraulic cylinder is connected to the hydraulic cylinder through the solenoid valve that controls the angle of the anti-hot spot photovoltaic array; the power supply end of the solenoid valve is connected to the voltage-stabilizing output end of the power manager, and the control of the solenoid valve It is connected to the I/O port of the controller; the rack is a structure that plays a physical connection and supporting role, and all components are installed on the rack.

The port of the controller includes a controller power terminal and an I/O port; the controller power terminal is connected to the voltage-stabilizing output terminal of the power manager; the I/O port is connected to the DC voltage regulator control terminal, the power manager control terminal, and the power supply. The manager feedback end, the illumination angle sampling signal output end, the voltage and current sampler feedback end, the Buck circuit control end, and the solenoid valve control end are connected; the controller can use an STM32F103C6T6 microcontroller to sample the power manager and illumination angle The module processes the ADC information of the voltage and current sampler, and outputs the corresponding PWM wave to control the power manager, Buck circuit and angle regulator; the algorithm executed by the central control module in the present invention is illumination angle and light intensity adaptive photovoltaic Power generation methods, including multi-peak condition optimization differential adjustment variable step size disturbance observation MPPT algorithm, maximum power angle adjustment strategy, power generation priority energy management strategy, anti-hot spot self-checking adjustment strategy and low-power energy management strategy.

The illumination angle sampling module has a triangular prism structure, as shown in device 1 in Figure 2; the bottom cylinder is close to the anti-hot spot photovoltaic array; the other two cylinders each have a set of photoresistors composed of X photoresistors. Array, The voltage-stabilized output terminal of the power manager; the illumination angle sampling signal output terminal is connected to the I/O port of the controller. The illumination angle sampling module and the anti-hot spot photovoltaic array are both installed on the upper surface of the shed base. The illumination angle sampling module The same area as a photovoltaic unit.

In this embodiment, the lithium battery is a ternary lithium battery with a rated full-charge voltage of 4.2V: the positive and negative electrodes are connected to the battery terminals of the power manager.

An illumination-adaptive anti-heat-spot photovoltaic power generation method, as shown in Figure 8. The method is implemented based on the illumination-adaptive anti-hot-spot photovoltaic power generation device, and includes:

Step 1: The illumination angle sampling module outputs the voltage reading U _ij of each photoresistor to the controller, i is the array number, i=1, 2; j is the array number, j=1, 2,...,X;

Step 2: The controller calculates and selects the maximum value U _MAX in U _ij , and estimates the relative light intensity _PS = U _MAX ·K. The unit of _PS is W/m ² and K is a constant; when _PS is greater than the set value A Then execute the maximum power angle adjustment strategy (steps B1~B3) and the power generation priority energy management strategy (steps D1~D2) at the same time, otherwise execute the low-power energy management strategy (steps C1~C4), where A is a set constant;

Step 3: The anti-hot spot photovoltaic array generates electricity when exposed to light, and delivers the power to the voltage and current sampler;

Step 4: The voltage and current sampler measures the anti-hot spot photovoltaic array port voltage and output current, and outputs the anti-hot spot photovoltaic array end voltage U(t) and current I(t) of the t-th sampling period to the controller, and calculates and Record the output power of the anti-hot spot photovoltaic array P(t)=U(t)I(t) in the t-th sampling period;

Step 5: The controller uses the MPPT algorithm to control the power generation of the anti-hot spot photovoltaic array through the Buck circuit; the differential adjustment variable step size disturbance observation MPPT algorithm for finding the optimal multi-peak condition is shown in Figure 10, including:

Step A1: The controller calculates the disturbance amount in the tth period K ₁ and b are constants;

Step A2: The controller calculates the expected voltage u(t) of the anti-hot spot photovoltaic array, and lets the expected voltage u(t) be the terminal voltage of the anti-hot spot photovoltaic array for the sampling period plus the step size corresponding to the period: u(t) )=U(t)+Δu(t);

Step A3: The controller converts the expected terminal voltage u(t) of the anti-hot spot photovoltaic array into the PWM wave duty cycle and updates the duty cycle value Where f=K _P′ ΔU′[x]+K _I ∑ _t ΔU′[x], x is the current number of executions, x increases by 1 for each execution; where K _P′ and K _I are set constants, ΔU′ [x _] =u(t ₎ -U Step A3, add 1 to the independent variable x; v is the set threshold;

Step A4: The controller obtains the current anti-hot spot photovoltaic array terminal voltage U′(t) and current I′(t); and calculates the output power P′(t)=U′(t)I′(t);

Step A5: The controller compares the size of P(t) and P′(t): if the power rises P′(t)>P(t), the initial terminal voltage of the next period is the initial terminal voltage of the original period plus the step size. U ₀ (t+1)=U ₀ (t)+Δu(t); if the power does not change P′(t)=P(t), then the initial terminal voltage of the next cycle does not change, that is, U ₀ (t +1)=U ₀ (t); if the power decreases P'(t)<P(t), it is accepted with probability p ₁ , that is, the initial terminal voltage of the next period is the initial terminal voltage of the original period plus the step size U ₀ (t+1)=U ₀ (t)+Δu(t) _; if not accepted, the initial terminal voltage of the next period will be the initial terminal voltage of the original period minus the step size U ₀ (t+ 1)=U ₀ (t)-Δu(t); where p ₂ =f·p ₁ , f is a constant; p ₁ =p′ ₁ +K ₁ ΔP _S -K ₂ T, p ₁ ′ is the last calculation In the value of p ₁ , K ₁ and K ₂ are constants, and T is the number of consecutive times when the power rises, that is, P′(t)>P(t). If it is discontinuous, it will be reset to zero;

Step 6: The controller calculates the value V′ = P _S -P (t). If V′ > V ₀ , the controller enables the anti-hot spot self-check adjustment strategy to control the anti-hot spot drive module to adjust the anti-hot spot photovoltaic array. , where V ₀ is a constant; if V′ ≤ V ₀ , and the anti-hot spot self-checking adjustment strategy has been enabled for C sampling periods, the anti-hot spot self-checking adjustment strategy ends, and a low level is applied to the field effect tubes of all power generation units. Level, C is a constant;

Step 7: The Buck circuit inputs power into the DC regulator;

Step 8: The DC voltage regulator adjusts the output voltage value to U _h , and U _h is the set constant; it is output to the power end of the power manager and output to the outside through the output interface.

The maximum power angle adjustment strategy is shown in Figure 9 and is specifically expressed as:

Step B1: Calculate the average voltage of each photoresistor in the t′th sampling period of the illumination angle sampling module The voltage value of each photoresistor in each array is the difference between its array average value/> If |ΔU _ij |<w, record the value as U _in , where w is the set constant, n is the record label, and n is increased by 1 for each value recorded in the array; calculate the average value of each array recorded value/>

Step B2: The controller calculates the subtraction of the average value of the recorded values of array 1 and array 2 in the t′th sampling period of the illumination angle sampling module.

Step B3: When |E ₁₂ (t′)|＜α, α is the set value, and the controller controls the solenoid valve flow FL＝K _P1 E ₁₂ (t′)+K _I1 ∑ _t′ E ₁₂ (t′) , add 1 to t′, and return to step B2; when |E ₁₂ (t′)|≥α, the maximum power angle adjustment strategy ends; where K _P1 and K _I1 are set constants;

The power generation priority energy management strategy is specifically expressed as:

Step D1: The power manager provides energy to the controller, light angle sampling module, angle regulator, and voltage and current sampler through the 5V output terminal; the DC voltage regulator outputs energy to the power manager and output interface at the same time;

Step D2: The battery voltage sampler in the power manager measures the terminal voltage of the lithium battery and outputs it to the controller through the feedback terminal of the power manager. The controller determines the battery status: If the battery voltage U _B is less than 4.2V, the power manager Charging the lithium battery through the battery terminal;

The low-power energy management strategy is specifically expressed as:

Step C1: The power manager and controller stop inputting energy and control signals to the angle regulator and voltage and current sampler; the DC voltage regulator outputs energy to the power manager and stops outputting energy to the output interface;

Step C2: The battery voltage sampler in the power manager measures the terminal voltage of the lithium battery and outputs it to the controller through the feedback terminal of the power manager. The controller determines the battery status: If the battery voltage U _B is greater than 3V, execute step C3, otherwise Execute step C4;

Step C3: The power manager supplies power to the light angle sampling module and controller through the voltage-regulated output terminal, and executes step C1; the controller outputs DC power with a voltage of U _h to the Buck circuit control terminal through the I/O port;

Step C4: The regulated output terminal of the power manager stops outputting and disconnects the lithium battery;

The specific description of the hot spot prevention self-check adjustment strategy is as follows:

Step E1: The voltage and current sampler obtains the output current i(0) of the current anti-hot spot photovoltaic array, and sets the integer variable p to 1;

Step E2: The controller controls the anti-hot spot driving module to apply a high level to the field effect transistor of the p-th power generation unit;

Step E3: The voltage and current sampler obtains the output current i(p) of the anti-hot spot photovoltaic array;

Step E4: Controller Comparison and the size of the constant q, if/> Then the anti-hot spot driving module applies a low level to the field effect tubes of all power generation units. When the variable p equals N, the anti-hot spot self-check adjustment strategy ends, otherwise n is increased by 1 and step E2 is executed; if/> Then keep applying a high level to the field effect transistor of the p-th power generation unit, and end the hot spot prevention self-test adjustment strategy.

The maximum power angle adjustment strategy proposed in the present invention, compared with the existing method of direct motor drive or motor-driven hydraulic drive, not only simplifies the control hardware and reduces the cost, but also avoids motor failure and is more suitable for long-term use. Improve photovoltaic power generation efficiency. The invention proposes an anti-hot spot photovoltaic array and its control method. Compared with the existing optimized photovoltaic panel styles, the invention solves the problem of "hot spot effect" caused by shadow occlusion at the algorithm and hardware levels. The present invention proposes a differential adjustment variable step size perturbation and observation MPPT algorithm for optimal multi-peak conditions. Compared with traditional MPPT algorithms such as the fixed voltage method and the perturbation observation method, the multi-peak condition optimization proposed by the present invention The differential adjustment variable step size perturbation observation MPPT algorithm can overcome the problem that the traditional MPPT algorithm falls into local optimality when the photovoltaic array P-U curve is multi-peaked due to factors such as local shadows; at the same time, it is compatible with existing methods based on neural networks, particle swarms, Compared with the multi-peak condition optimal differential adjustment variable step size perturbation observation MPPT algorithm proposed by the present invention, the MPPT algorithm of the ant colony algorithm has a simpler process, has lower hardware requirements, and is easier to implement.

Claims (2)

1. An illumination-adaptive heat-spot-proof shed-type photovoltaic power generation method. The method is based on an illumination-adaptive heat-spot-proof shed-type photovoltaic power generation device. The device includes a sunshade base and a sunshade base installed on the sunshade. The anti-hot spot photovoltaic array, anti-hot spot drive module, voltage and current sampler, output interface, angle regulator, controller, light angle sampling module, power manager, and lithium battery on the base; the anti-hot spot photovoltaic array is respectively connected with The anti-hot spot drive module and the voltage and current sampler are electrically connected. The voltage and current sampler is electrically connected to the output interface. The anti-hot spot drive module, voltage and current sampler, power manager, light angle sampling module, and angle regulator are respectively connected to the controller. connected, characterized in that the method includes: Step 1: The illumination angle sampling module outputs the voltage reading U _ij of each photoresistor to the controller, i is the array number, i=1,2; j is the array number, j=1,2,...,X; Step 2: The controller calculates and selects the maximum value U _MAX in U _ij and estimates the relative light intensity _PS = U _MAX ·K; when _PS is greater than the set value A, the maximum power angle adjustment strategy and power generation priority energy management are simultaneously executed. strategy, otherwise execute the low-power energy management strategy; Step 3: The anti-hot spot photovoltaic array generates electricity when exposed to light, and delivers the power to the voltage and current sampler; Step 4: The voltage and current sampler measures the anti-hot spot photovoltaic array port voltage and output current, and outputs the anti-hot spot photovoltaic array end voltage U(t) and current I(t) of the t-th sampling period to the controller, and calculates and Record the output power of the anti-hot spot photovoltaic array P(t)=U(t)I(t) in the t-th sampling period; Step 5: The controller uses the MPPT algorithm to control the anti-hot spot photovoltaic array to generate electricity through the Buck circuit; Step 6: The controller calculates the value V′ = P _S -P (t). If V′ > V ₀ , the controller enables the anti-hot spot self-check adjustment strategy to control the anti-hot spot drive module to adjust the anti-hot spot photovoltaic array. , where V ₀ is a constant; if V′ ≤ V ₀ , and the anti-hot spot self-checking adjustment strategy has been enabled for C sampling periods, the anti-hot spot self-checking adjustment strategy ends, and a low level is applied to the field effect tubes of all power generation units. Level, C is a constant; Step 7: The Buck circuit inputs power into the DC regulator; Step 8: The DC voltage regulator adjusts the output voltage value to U _h , and U _h is the set constant; it is output to the power end of the power manager and output to the outside through the output interface; The maximum power angle adjustment strategy is specifically expressed as: Step B1: Calculate the average voltage of each photoresistor in the t′th sampling period of the illumination angle sampling module The voltage value of each photoresistor in each array is the difference between its array average value/> If |ΔU _ij |<w, record the value as U _in , where w is the set constant and n is the record label. Each time a value is recorded in the array, n will be increased by 1; the average value of each array record value is calculated/> Step B2: The controller calculates the subtraction of the average value of the recorded values of array 1 and array 2 in the t′th sampling period of the illumination angle sampling module. Step B3: When |E ₁₂ (t′)|<α, α is the set value, and the controller controls the solenoid valve flow FL＝K _P1 E ₁₂ (t′)+K _I1 ∑ _t′ E ₁₂ (t′) , add 1 to t′, and return to step B2; when |E ₁₂ (t′)|≥α, the maximum power angle adjustment strategy ends; where K _P1 and K _I1 are set constants; The power generation priority energy management strategy is specifically expressed as: Step D1: The power manager provides energy to the controller, light angle sampling module, angle regulator, and voltage and current sampler; the DC voltage regulator outputs energy to the power manager and output interface at the same time; Step D2: The battery voltage sampler in the power manager measures the terminal voltage of the lithium battery and outputs it to the controller. The controller determines the battery status: If the battery voltage U _B is less than the set value z ₁ , the power manager Charge; The low-power energy management strategy is specifically expressed as: Step C1: The power manager and controller stop inputting energy and control signals to the angle regulator and voltage and current sampler; the DC voltage regulator outputs energy to the power manager and stops outputting energy to the output interface; Step C2: The battery voltage sampler in the power manager measures the terminal voltage of the lithium battery and outputs it to the controller. The controller determines the battery status: If the battery voltage U _B is greater than the set value z ₂ , then execute step C3, otherwise execute step C3. C4; Step C3: The power manager supplies power to the light angle sampling module and controller, and executes step C1; the controller outputs DC power with a voltage of U _h ; Step C4: The power manager stops output and disconnects the lithium battery; The specific description of the hot spot prevention self-check adjustment strategy is as follows: Step E1: The voltage and current sampler obtains the output current i(0) of the current anti-hot spot photovoltaic array, and sets the integer variable p to 1; Step E2: The controller controls the anti-hot spot driving module to apply a high level to the field effect transistor of the p-th power generation unit; Step E3: The voltage and current sampler obtains the output current i(p) of the anti-hot spot photovoltaic array; Step E4: Controller Comparison and the size of the constant q, if/> Then the anti-hot spot driving module applies a low level to the field effect tubes of all power generation units. When the variable p equals N, the anti-hot spot self-check adjustment strategy ends, otherwise n is increased by 1 and step E2 is executed; if/> Then keep applying a high level to the field effect transistor of the p-th power generation unit, and end the hot spot prevention self-test adjustment strategy. 2. A light-adaptive heat-spot-proof shed-type photovoltaic power generation method according to claim 1, characterized in that the step 5 includes: Step A1: The controller calculates the disturbance amount in the tth period K ₁ and b are constants; Step A2: The controller calculates the expected voltage u(t) of the anti-hot spot photovoltaic array, and lets the expected voltage u(t) be the terminal voltage of the anti-hot spot photovoltaic array for the sampling period plus the step size corresponding to the period: u(t) )=U(t)+Δu(t); Step A3: The controller converts the expected terminal voltage u(t) of the anti-hot spot photovoltaic array into the PWM wave duty cycle and updates the duty cycle value Where f=K _P′ ΔU′[x]+K _I ∑ _t ΔU′[x], x is the current number of executions, x increases by 1 for each execution; where K _P′ and K _I are set constants, ΔU′ [x _] =u(t ₎ -U Step A3, add 1 to the independent variable x; v is the set threshold; Step A4: The controller obtains the current anti-hot spot photovoltaic array terminal voltage U′(t) and current I′(t); and calculates the output power P′(t)=U′(t)I′(t); Step A5: The controller compares the size of P(t) and P′(t): if the power rises P′(t)>P(t), the initial terminal voltage of the next period is the initial terminal voltage of the original period plus the step size. U ₀ (t+1)=U ₀ (t)+Δu(t); if the power does not change P′(t)=P(t), then the initial terminal voltage of the next cycle does not change, that is, U ₀ (t +1)=U ₀ (t); if the power decreases P'(t)<P(t), it is accepted with probability p ₁ , that is, the initial terminal voltage of the next period is the initial terminal voltage of the original period plus the step size U ₀ (t+1)=U ₀ (t)+Δu(t) _; if not accepted, the initial terminal voltage of the next period will be the initial terminal voltage of the original period minus the step size U ₀ (t+ 1)=U ₀ (t)-Δu(t); where p ₂ =f·p ₁ , f is a constant; p ₁ =p′ ₁ +K ₁ ΔP _S -K ₂ T, p ₁ ′ is the last calculation In the value of p ₁ , K ₁ and K ₂ are constants, and T is the number of consecutive times when the power rises, that is, P'(t)>P(t). If it is discontinuous, it will be reset to zero.