A hydraulically regulated water electrode photovoltaic power generation and thermal storage system and control method

Abstract

This invention discloses a hydraulically controlled water-electrode photovoltaic power generation and thermal storage system and control method. Targeting the abundant wind and solar energy resources in high-altitude, high-latitude regions where the load is primarily for heating and water is sourced from glacial meltwater with low temperatures, this invention utilizes thermal storage to locally absorb excess photovoltaic power, improving local living standards and reducing carbon emissions. Simultaneously, flexible load control enhances grid stability, and the system can also be applied to industrial heat loads. The thermal storage system mainly includes a thermal storage tank, a water-electrode system, a photovoltaic power supply system, and a monitoring system. This invention solves the problems of water electrode polarization and photovoltaic maximum power point tracking in photovoltaic array heating of water-electrode boilers, achieving efficient utilization of photovoltaic power generation.

Description

Technical Field

[0001] This invention belongs to the fields of new energy and heating, specifically relating to a hydraulically regulated water electrode photovoltaic power generation and heat storage system and control method. Background Technology

[0002] The rapid development of solar photovoltaic (PV) power generation, coupled with its inherent instability and frequent curtailment, necessitates a high proportion of local renewable energy consumption. This addresses both grid stability and line losses, as well as local load demand. However, the key to successful local consumption lies in its grid-friendly nature and load controllability. For businesses and regions with heating and gas supply needs, hydroelectric boiler thermal storage offers a relatively ideal and controllable load option.

[0003] In high-altitude and high-latitude regions, where solar energy resources are abundant and the load characteristics are mainly for heating, water is sourced from glacial meltwater, which is at a low temperature. Therefore, photovoltaic power generation can be utilized locally through thermal storage, improving the local quality of life, reducing carbon emissions, and improving the stability of the power grid by flexibly controlling the load.

[0004] The current principle of electrode hot water boilers is based on the release of a large amount of heat energy through a three-phase voltage and current passing through water with a set conductivity, directly converting electrical energy into heat energy and generating steam. The heating power can be steplessly adjusted. Due to the direct heating via water resistance, 100% of the electrical energy is converted into heat, resulting in high efficiency with almost no heat loss. It is a highly efficient heating method.

[0005] The water electrode hot water boiler is powered by AC. The photovoltaic power generation is output through the inverter to meet the power supply requirements of the water electrode hot water boiler. However, the inverter's efficiency is greatly reduced when operating at low power, making it impossible to achieve high-efficiency utilization of photovoltaic power generation, and the cost is relatively high.

[0006] If photovoltaic power generation is directly applied to thermal storage in hydroelectric boilers, efficiency and cost can be improved. However, two major problems remain:

[0007] When the DC output power of photovoltaic power generation is applied to a water electrode, a polarization reaction occurs. If the water contains other minerals, impurities such as calcium carbonate will form on the cathode. This phenomenon does not occur with AC voltage. Therefore, it is necessary to solve the problem of high-efficiency, lossless photovoltaic polarization conversion.

[0008] Due to the characteristics of photovoltaic power generation, the question arises of how to match the load characteristics with the characteristics of photovoltaic power generation, i.e., the maximum power point tracking problem of photovoltaic power generation. Summary of the Invention

[0009] To address the aforementioned technical problems, this invention provides a hydraulically controlled water electrode photovoltaic power generation and heat storage system and control method, which mainly solves the problems of water electrode polarization and photovoltaic maximum power tracking during the process of photovoltaic array heating water electrode boiler, thereby achieving efficient utilization of photovoltaic power generation.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] A hydraulically controlled water electrode photovoltaic power generation and thermal storage system includes a thermal storage tank, a water electrode system, a photovoltaic power supply system, and a monitoring system. The water electrode system, except for a reversing valve, a metering plunger pump, a fixed water electrode fine-tuning rod, and some hydraulic pipelines, is located inside the thermal storage tank. The photovoltaic power supply system is located around the perimeter of the thermal storage tank. The thermal storage tank is equipped with an inlet, an outlet, an exhaust pipe, and a pressure reducing valve. The inlet is located above the thermal storage tank; the outlet is located below the thermal storage tank; the exhaust pipe is located on the upper side of the thermal storage tank; and the pressure reducing valve is located above the thermal storage tank near the inlet.

[0012] The water electrode system includes a hydraulically controlled water electrode, a hydraulically controlled water electrode connecting rod, a left piston, a right piston, hydraulic pipes, a reversing valve, a metering plunger pump, a fixed water electrode, a fixed water electrode fine-tuning rod, and a water electrode fixing slide rail. The two ends of the water electrode fixing slide rail are fixed to the tank wall of the thermal storage tank. A first hole is opened in the middle of the fixed water electrode, and a second hole is opened in the middle of the hydraulically controlled water electrode, through which the water electrode fixing slide rail passes. The fixed water electrode is placed on one side of the water electrode fixing slide rail, and the hydraulically controlled water electrode is located in the middle area of ​​the water electrode fixing slide rail and can move left and right. The fixed water electrode fine-tuning rod passes through the tank wall and connects to the fixed water electrode. The hydraulic... The pipeline has a C-shaped structure, with a reversing valve connected in series in the middle of the C-shape. The input end of the reversing valve is connected to a metering plunger pump. A left piston and a right piston are respectively placed at both ends of the C-shape, and the left and right pistons are fixedly mounted on the hydraulic control water electrode connecting rod. A hydraulic control water electrode is fixedly mounted in the middle of the hydraulic control water electrode connecting rod. The reversing valve is used to control the liquid flow direction. The metering plunger pump directly draws in and discharges the working medium in the hydraulic pipeline through the reciprocating motion of the plunger. Each reciprocating motion drives the left and right pistons through the reversing valve to push the hydraulic control water electrode connecting rod, causing the hydraulic control water electrode to move by one step, thus adjusting the distance between the hydraulic control water electrode and the fixed water electrode.

[0013] The photovoltaic power supply system includes a photovoltaic array and a power electronic square wave commutator;

[0014] The monitoring system includes a controller, a water electrode current sensor, a water electrode voltage sensor, and a temperature sensor for the thermal storage tank.

[0015] Furthermore, both the liquid-controlled water electrode and the fixed water electrode are made of metal conductive plate material, and have several holes on them to facilitate water flow and avoid disturbance caused by bubbles generated during the heating process.

[0016] Furthermore, the water electrode fixing slide rail is made of cylindrical insulating material.

[0017] Furthermore, by manually adjusting the stroke of the fixed water electrode fine-tuning rod, the distance between the fixed water electrode and the liquid-controlled water electrode is changed, which is used to determine the point of maximum photovoltaic output power.

[0018] Furthermore, the positive and negative output power of the photovoltaic array is connected to the input terminal of the power electronic square wave commutator. The power electronic square wave commutator switches the positive and negative output power of the photovoltaic array through a power electronic switch to convert it into a square wave output power that alternates between positive and negative. The square wave output terminal of the power electronic square wave commutator is connected to the fixed water electrode and the liquid-controlled water electrode through two cables respectively, providing the water electrode with a periodically changing positive and negative power.

[0019] Furthermore, the controller is placed around the thermal storage tank and is connected to the water electrode current sensor, water electrode voltage sensor, and thermal storage tank temperature sensor via communication cables. It is also connected to all controlled units and the metering plunger pump via control cables. The controller reads sensor data in real time and controls the controlled units according to algorithms, models, and control strategies.

[0020] The present invention also provides a control method for the above-mentioned hydraulically regulated water electrode photovoltaic power generation and thermal storage system, comprising the following steps:

[0021] Step 1: Initialization settings, specifically including:

[0022] Step 1.1: Input photovoltaic array parameters: installed capacity, array tilt angle, array orientation, horizontal diffuse reflection coefficient, open circuit voltage, short circuit current, photovoltaic power generation, total solar irradiance and typical photovoltaic maximum power point table;

[0023] Step 1.2: Determine the maximum displacement step size of the liquid-controlled water electrode to the left and right. max And the corresponding maximum power point of photovoltaic power generation;

[0024] Step 1.3: Considering the response speed of mechanical photovoltaic maximum power point tracking, segmented photovoltaic maximum power point tracking is adopted;

[0025] Step 2: Quickly locate the section with the maximum photovoltaic power generation;

[0026] Step 3: Perform refined photovoltaic power generation maximum power tracking control.

[0027] Further, step 1.2 specifically includes:

[0028] Step 1.2.1: Fine-tuning and fixing the water electrode. First, place the middle point of the hydraulic control electrode connecting rod. The hydraulically controlled water electrode is pushed by the metering plunger pump reversing valve in steps of several steps. n | n＝max =Step max Move right to reach the right end point of the liquid-controlled water electrode That is, liquid-controlled water electrode Minimum distance between the point and the fixed water electrode At this position, the water resistance is at its minimum. in accordance with By manually adjusting the travel of the fixed water electrode fine-tuning rod, the distance between the fixed water electrode and the liquid-controlled water electrode is finely adjusted, thereby increasing the power P applied by the photovoltaic power generation to the heating water resistor. water The maximum power point of photovoltaic power generation with the maximum local irradiance. Equal, that is Where δ d S is the electrical conductivity of water. g To fix the area of ​​the water electrode, L n Let n be the relative distance between any point on the liquid-controlled water electrode and the fixed water electrode, where n∈[min,max]; The midpoint of the liquid-controlled water electrode connecting rod; This is the right end point of the liquid-controlled water electrode; This is the left end point of the liquid-controlled water electrode.

[0029] Step 1.2.2, Determine The step size of the hydraulic electrode is increased by the reversing valve of the metering plunger pump. n | n＝max =Step max Move left to reach the left end point of the liquid-controlled water electrode That is, the distance between the liquid-controlled water electrode and the fixed water electrode is at its maximum. At this position, the heating water resistance is at its maximum, according to and Using a table of typical photovoltaic maximum power points, find the power P applied to the heating water resistor by shifting the liquid-controlled water electrode to the left. water The maximum power point of photovoltaic power generation corresponding to the local lower irradiance. Right now

[0030] Among them, S g To fix the area of ​​the water electrode; R w The resistance value of the heating water; ΔR w The displacement of the liquid-controlled water electrode is one step size Step1 = Step n | n＝1 This corresponds to an increase or decrease in the heating water resistance; ΔL is the resistance of the liquid-controlled water electrode M. wA displacement length is also the distance that the hydraulically controlled water electrode is driven per unit step; P water The load power on the water resistor; Step n The number of steps in which the reciprocating motion of the plunger pump drives the hydraulic control water electrode to move is also called the number of steps in the hydraulic control water electrode displacement. Step is the number of steps for the displacement of the liquid-controlled water electrode. n The point of maximum photovoltaic power generation; Step is the number of steps for the displacement of the liquid-controlled water electrode. n Maximum power output and voltage of point photovoltaic power generation; Step is the number of steps for the displacement of the liquid-controlled water electrode. n The maximum power point current of point-volt generator.

[0031] Furthermore, step 1.3 specifically includes:

[0032] First, based on the input photovoltaic array parameters and irradiance, a table for quickly locking the maximum power points of segmented photovoltaic power generation under different illumination conditions is established; since the length ΔL of the displacement of the liquid-controlled water electrode per unit step is the maximum distance L between the fixed water electrode and the liquid-controlled water electrode. max Minimum distance L from the liquid-controlled water electrode min The difference, divided by the sum of the absolute values ​​of the maximum left and right displacement steps of the liquid-controlled water electrode, is 2Step. max ,Right now

[0033] To achieve rapid location of the photovoltaic power generation maximum power point, the maximum step size will be doubled to 2Step. max Quantified in units of 10, that is

[0034] At the point of maximum photovoltaic power generation with the maximum local irradiance. and the maximum power point of photovoltaic power generation at lower local irradiance. Range, divided by the quantification result The number of segments for quickly locking the maximum power point of photovoltaic power generation under different illumination conditions is obtained, i.e.:

[0035]

[0036] And the maximum power points of photovoltaic power generation corresponding to the segment endpoints:

[0037]

[0038] Right now Therefore, the maximum photovoltaic power point value at each segment point is determined by looking up a table. Including the step size when the liquid-controlled water electrode is in the middle position: Step0 = Step n |n＝0 Corresponding maximum power point value of photovoltaic power generation

[0039] Therefore, the difference in maximum power output between adjacent photovoltaic power generation segments is a constant α, i.e.:

[0040]

[0041] Where mp is the number of segments at the maximum power point of photovoltaic power generation; Step0 = Step n | n＝0 This is the step size when the liquid-controlled water electrode is in the middle position; The maximum power point value of photovoltaic power generation is the step size Step0 when the liquid-controlled water electrode is in the middle position. The maximum power point value of photovoltaic power generation is the maximum irradiance in the local area; ΔL is the displacement distance of the liquid-controlled water electrode driven by a unit step size; Step n The number of reciprocating strokes of the plunger pump is also the number of steps in the displacement of the hydraulic control water electrode; Step is the number of steps for the displacement of the liquid-controlled water electrode. n The point of maximum photovoltaic power generation; Step is the number of steps for the displacement of the liquid-controlled water electrode. n The maximum power output of photovoltaic power generation at a given point and the voltage at that point; Step is the number of steps for the displacement of the liquid-controlled water electrode. n The maximum power of photovoltaic power generation at a point; α is a constant value for the difference in maximum power generation at each adjacent photovoltaic segment. For each segment point, n represents the point where the photovoltaic power generation reaches its maximum. m =1,2,3,…,mp;

[0042] Take Step0 = Step n | n＝0 The resistance of the heating water between the time-controlled water electrode and the fixed water electrode is R0, and the maximum number of steps for the time-controlled water electrode to move to the right is Step. max =Step n | n＝max The corresponding heating water resistance obtained is:

[0043] R w =R0-ΔR w ×Step max

[0044] The minimum number of steps required for the liquid-controlled water electrode to move to the right is Step1 = Step2. n | n＝1 The corresponding heating water resistance R obtained w =R0-ΔR w ;

[0045] The maximum number of steps for the liquid-controlled water electrode to shift to the left is -Step max =-Step n | n＝max The corresponding heating water resistance obtained

[0046] R w =R0-ΔR w ×(-Step max )=R0+ΔR w ×Step max

[0047] The minimum number of steps required for the liquid-controlled water electrode to move to the right is -Step1 = -Step n | n＝1 The corresponding heating water resistance R obtained w =R0+ΔR w ;

[0048] Based on this and The change in the number of steps for each liquid-controlled water electrode corresponds to a change in the resistance of the heating water, and also corresponds one-to-one with the maximum power point of photovoltaic power generation within the local maximum and minimum irradiance range.

[0049] Furthermore, step 2 specifically includes:

[0050] The controller reads the photovoltaic power generation current I in real time. pv and photovoltaic power generation voltage U pv The photovoltaic power output P was calculated. pv Based on the output power P pv Compared with the previous moment's maximum photovoltaic power generation The difference is calculated between the points, that is:

[0051]

[0052] Step 2.1, when This indicates that the directional valve's action causes the hydraulic control electrode to shift to the right:

[0053] When ΔP pv When the value is greater than 0, it indicates an increase in photovoltaic power generation and confirms that the directional valve's action causes the liquid-controlled water electrode to shift to the right, thereby increasing the photovoltaic power output P. pv Divide by the constant α of the maximum power difference point of photovoltaic power generation in each adjacent segment, that is:

[0054]

[0055] The result of the divisor is rounded to one decimal place, and the modulo function is used to determine its value.

[0056] mod(P pv ,α)≥0.5

[0057] in, This represents the point at which photovoltaic power generation reaches its maximum power at the previous moment; Step n-1 The point at which photovoltaic power generation reaches its maximum power at the previous moment. Number of displacement steps for the liquid-controlled water electrode; I pv U represents the current photovoltaic power generation current. pv P represents the current photovoltaic power generation voltage. pv This represents the current output power of photovoltaic power generation;

[0058] Step 2.1.1: Use the modulo modulo function to determine mod(P) pv If α)≥0.5, then according to the floor function:

[0059]

[0060] Using the principle of rounding up to the nearest whole number, determine the maximum power point of photovoltaic power generation in a certain segment. And determine the maximum power point of photovoltaic power generation. Falling and Between these, the number of displacement steps of the liquid-controlled water electrode is obtained as Step. n =n m ×10, according to Step n =n m ×10 times the displacement step size of the liquid-controlled water electrode minus the maximum power point of photovoltaic power generation at the previous moment. Number of displacement steps for the liquid-controlled water electrode n-1 The increase or decrease in the displacement step size ΔStep of the liquid-controlled water electrode is obtained. n Each step, i.e., ΔStep n =10n m Step n-1 .

[0061] Where, n m The point where the maximum photovoltaic power generation is known for a certain segment. The number of displacement steps for the liquid-controlled water electrode is set during initialization; L n Let n be the relative distance between any point on the liquid-controlled water electrode and the fixed water electrode, where n∈[min,max];

[0062] At this time, the controller adjusts the increment / decrement ΔStep. n The step-size control of the metering plunger pump causes the hydraulically controlled water electrode to shift to the right, reducing the distance L between the hydraulically controlled water electrode and the fixed water electrode. n This reduces the resistance R of the heating water.w Quickly pinpoint the maximum power point of segmented photovoltaic power generation Simultaneously, the controller reads the photovoltaic power generation current I in real time. pv and voltage U pv The photovoltaic power output P was calculated. pv Step 3 involves refining the maximum power point tracking control of photovoltaic power generation.

[0063] Step 2.1.2: Use the modulo modulo function to determine mod(P) pv If α) < 0.5, then according to the floor function... Using the principle of rounding up to the nearest whole number, determine the maximum power point of photovoltaic power generation in a certain segment. And determine the maximum power point of photovoltaic power generation. Falling and Between these points, the displacement step size of the liquid-controlled water electrode is obtained, based on the Step... n =n m ×10 times the displacement steps of the liquid-controlled water electrode minus the maximum power point of photovoltaic power generation at the previous moment. Number of displacement steps for the liquid-controlled water electrode n-1 The change in displacement ΔStep of the liquid-controlled water electrode was obtained. n Each step, i.e., ΔStep n =10n m Step n-1 , where n m The point where the maximum photovoltaic power generation is known for a certain segment. The number of displacement steps for the hydraulically controlled water electrode is set during initialization; at this time, the controller adjusts the displacement based on the increment / decrement ΔStep. n Each step controls the rightward displacement of the liquid-controlled water electrode, reducing the distance L between the liquid-controlled water electrode and the fixed water electrode. n This reduces the resistance R of the heating water. w Quickly pinpoint the maximum power point of segmented photovoltaic power generation Simultaneously, the controller reads the photovoltaic power generation current I in real time. pv and voltage U pv The photovoltaic power output P was calculated. pv Step 3 involves refining the maximum power point tracking control of photovoltaic power generation.

[0064] in, For n m The maximum power point of segmented photovoltaic power generation; For n m The maximum power point of photovoltaic power generation in the +1 segment; Step is the number of displacement steps for the liquid-controlled water electrode. n The point at which photovoltaic power generation reaches its maximum power; ΔStepn To increase or decrease the number of displacement steps of the volumetric water control electrode;

[0065] Step 2.2, when With ΔP pv When the value is less than 0, the photovoltaic power generation decreases, indicating that the directional valve's hydraulic control electrode has shifted to the left, reducing the current photovoltaic power output P. pv Divide by the constant α of the maximum power difference point of photovoltaic power generation in each adjacent segment, i.e. The result of the divisor is rounded to one decimal place, and the modulo (P) function is used to determine the modulo (P) result. pv ,α)≥0.5;

[0066] Step 2.2.1: Use the modulo modulo function to determine mod(P) pv If α)≥0.5, then according to the floor function... Using the principle of rounding up to the nearest whole number, determine the maximum power point of photovoltaic power generation in a certain segment. And determine the maximum power point of photovoltaic power generation. Falling and Between these, we obtain Step n =n m ×10 liquid-controlled water electrode displacement steps, based on the photovoltaic power generation maximum power point at the previous moment. Number of displacement steps for the liquid-controlled water electrode n-1 Subtract Step n =n m The displacement increment / decrement ΔStep of the liquid-controlled water electrode is obtained by multiplying the displacement step by 10. n Each step, i.e., ΔStep n =Step n-1 -10n m , where n m The point where the maximum photovoltaic power generation is known for a certain segment. The number of displacement steps for the hydraulically controlled water electrode is set during initialization. At this time, the controller adjusts the displacement based on the increment / decrement ΔStep. n Each step controls the displacement step of the liquid-controlled water electrode, increasing the distance L between the liquid-controlled water electrode and the fixed water electrode. n This increases the resistance R of the heating water resistor. w Quickly pinpoint the maximum power point of segmented photovoltaic power generation Simultaneously, the controller reads the photovoltaic power generation current I in real time. pv and voltage U pv The photovoltaic power output P was calculated. pv Step 3 involves refining the maximum power tracking control of photovoltaic power generation.

[0067] Step 2.2.2: Use the modulo modulo function to determine mod(P) pv If α) < 0.5, then according to the floor function... Using the principle of rounding up to the nearest whole number, determine the maximum power point of photovoltaic power generation in a certain segment. And determine the maximum power point of photovoltaic power generation. Falling and Between these, we obtain Step n =n m ×10 liquid-controlled water electrode displacement steps, based on the photovoltaic power generation maximum power point at the previous moment. Number of displacement steps for the liquid-controlled water electrode n-1 Subtract Step n =n m The displacement increment / decrement ΔStep of the hydraulically controlled water electrode is obtained by multiplying the displacement steps by 10. n Each step, i.e., ΔStep n =Step n-1 -10n m ; where n m The point where the maximum photovoltaic power generation is known for a certain segment. The number of displacement steps for the hydraulically controlled water electrode is set during initialization; at this time, the controller adjusts the displacement based on the increment / decrement ΔStep. n Each step controls the number of displacement steps of the liquid-controlled water electrode, increasing the distance L between the liquid-controlled water electrode and the fixed water electrode. n This increases the resistance R of the heating water resistor. w Quickly pinpoint the maximum power point of segmented photovoltaic power generation Simultaneously, the controller reads the photovoltaic power generation current I in real time. pv and voltage U pv The photovoltaic power output P was calculated. pv Step 3 involves refining the maximum power point tracking control of photovoltaic power generation.

[0068] Furthermore, step 3 specifically includes:

[0069] Step 2 quickly identifies the section with the maximum power output of the photovoltaic power generation, and the controller reads the photovoltaic power generation current I in real time. pv and voltage U pv The photovoltaic power output P was calculated. pv and the maximum power point of segmented photovoltaic power generation Compare and judge separately or

[0070] Step 3.1: Determine ΔP based on equation (20). pvWhen ≥0, the photovoltaic power generation increases, and the maximum power point of photovoltaic power generation is known in segments. Compare, judge hour:

[0071] Step 3.1.1: Determine mod(P) based on the mod modulo function. pv If α)≥0.5, then according to the floor function... And the principle of rounding up or down.

[0072] Step A: The controller adjusts the increment / decrement ΔStep based on the previous time step. n-1 Subtracting one disturbance step from each step size controls the displacement step size of the liquid-controlled water electrode, thereby changing the resistance value R of the heating water resistor. w At this point, the current increment / decrement step size is ΔStep. n =ΔStep n-1 -1; At the same time, the controller continues to read the photovoltaic power generation current I. pv and voltage U pv The output power of photovoltaic power generation was calculated. And compared with the photovoltaic power generation at the previous moment Compare;

[0073] Among them, when This indicates that the directional valve's hydraulic control electrode is displaced to the right, with an increase or decrease of ΔStep. n The step size is positive, according to R w =R0-ΔR w ×Step max Change the resistance R of the heating water w ;when This indicates that the directional valve's hydraulic control electrode is displaced to the left, with an increase or decrease of ΔStep. n If the step size is negative, according to R w =R0-ΔR w ×(-Step max )=R0+ΔR w ×Step max Change the resistance R of the heating water w ;

[0074] When judging The controller repeats step A.

[0075] When judging At that time, the distance between the current liquid-controlled water electrode and the fixed water electrode is determined, and the resulting heating water resistance R is calculated. w Adapted to the maximum power point of photovoltaic power generation

[0076] in, This represents the current output power of photovoltaic power generation; The photovoltaic power generation at the previous moment; ΔStep n-1 ΔStep represents the step size for the increase or decrease in the displacement of the hydraulically controlled water electrode at the previous moment. n This represents the step size for the current displacement increment / decrement of the liquid-controlled water electrode;

[0077] Step 3.1.2: Determine mod(P) based on the mod modulo function. pv If α) < 0.5, then according to the floor function... The principles of rounding up and down are:

[0078] Step B, the controller adjusts the increment / decrement ΔStep based on the previous time step. n-1 A step size plus a perturbation step size controls the displacement of the liquid-controlled water electrode, thereby changing the resistance value R of the heating water resistor. w At this point, the current increment / decrement step size is ΔStep. n =ΔStep n-1 +1; At the same time, the controller continues to read the photovoltaic power generation current I. pv and voltage U pv The output power of photovoltaic power generation was calculated. And compared with the photovoltaic power generation at the previous moment Compare;

[0079] Among them, when This indicates that the directional valve's hydraulic control electrode is displaced to the right, with an increase or decrease of ΔStep. n The step size is positive, and the resistance R of the heating water is changed according to formula (18). w ;when This indicates that the directional valve's hydraulic control electrode is displaced to the left, with an increase or decrease of ΔStep. n The step size is negative, and the resistance R of the heating water is changed according to formula (19). w ;

[0080] When judging The controller repeats step B.

[0081] When judging At that time, the distance between the current liquid-controlled water electrode and the fixed water electrode is determined, and the resulting heating water resistance R is calculated. w Adapted to the maximum power point of photovoltaic power generation

[0082] Step 3.2, based on Determine ΔP pv When the value is less than 0, the photovoltaic power generation decreases, and the known maximum power point of photovoltaic power generation is segmented. Compare, judge hour:

[0083] Step 3.2.1: Determine mod(P) based on the mod modulo function.pv If α)≥0.5, then according to the floor function... The principles of rounding up and down are:

[0084] Step A: The controller adjusts the increment / decrement ΔStep based on the previous time step. n-1 Subtracting one disturbance step from each step size controls the displacement step size of the liquid-controlled water electrode, thereby changing the resistance value R of the heating water resistor. w At this point, the current increment / decrement step size is ΔStep. n =ΔStep n-1 -1;

[0085] At the same time, the controller continues to read the photovoltaic power generation current I. pv and voltage U pv The output power of photovoltaic power generation was calculated. And compared with the photovoltaic power generation at the previous moment Compare;

[0086] Among them when This indicates that the directional valve's hydraulic control electrode is displaced to the right, with an increase or decrease of ΔStep. n The step size is positive, according to R w =R0-ΔR w ×Step max Change the resistance R of the heating water w ;when This indicates that the directional valve's hydraulic control electrode is displaced to the left, with an increase or decrease of ΔStep. n If the step size is negative, according to R w =R0-ΔR w ×(-Step max )=R0+ΔR w ×Step max Change the resistance R of the heating water w ;

[0087] When judging The controller continues to execute step A;

[0088] When judging At that time, the distance between the current liquid-controlled water electrode and the fixed water electrode is determined, and the resulting heating water resistance R is calculated. w Adapted to the maximum power point of photovoltaic power generation

[0089] in, This represents the current output power of photovoltaic power generation; The photovoltaic power generation at the previous moment; ΔStep n-1 ΔStep represents the increment or decrement of the liquid-controlled water electrode at the previous moment; n The increment or decrement of the current liquid-controlled water electrode is determined by the step size.

[0090] Step 3.2.2: Determine mod(P) based on the mod modulo function. pv If α) < 0.5, then according to the floor function... The principles of rounding up and down are:

[0091] Step B, the controller adjusts the increment / decrement ΔStep of the liquid-controlled water electrode based on the previous moment. n-1 A step size plus a perturbation step size controls the displacement of the liquid-controlled water electrode, thereby changing the resistance value R of the heating water resistor. w At this point, the step size for increasing or decreasing the liquid-controlled water electrode is ΔStep. n =ΔStep n-1 +1; At the same time, the controller continues to read the photovoltaic power generation current I. pv and voltage U pv The output power of photovoltaic power generation was calculated. And compared with the photovoltaic power generation at the previous moment Compare;

[0092] Among them, when This indicates that the directional valve's hydraulic control electrode is displaced to the right, with an increase or decrease of ΔStep. n The step size is positive, according to R w =R0-ΔR w ×Step max Change the resistance R of the heating water w ;

[0093] when This indicates that the directional valve's hydraulic control electrode is displaced to the left, with an increase or decrease of ΔStep. n If the step size is negative, according to R w =R0-ΔR w ×(-Step max )=R0+ΔR w ×Step max Change the resistance R of the heating water w ;

[0094] When judging The controller continues to execute step B;

[0095] When judging At that time, determine the distance between the current liquid-controlled water electrode and the fixed water electrode, and based on R w =R0-ΔR w ×(-Step max )=R0+ΔR w ×Step max The generated heating water resistance R w Adapted to the maximum power point of photovoltaic power generation

[0096] This invention has the following characteristics: relatively low cost compared to inverters; adaptable to 100% fluctuations in wind and photovoltaic power generation, with high efficiency; low switching losses, such as the loss of a second-level switching time switch being much less than the 50Hz switching loss; simple controller structure and high reliability; and high maximum power point tracking accuracy for photovoltaic power generation. Attached Figure Description

[0097] Figure 1 Structural diagram of the hydraulically regulated water electrode photovoltaic power generation and thermal storage system of the present invention;

[0098] Figure 2 A schematic diagram of the electrical connection of the hydraulically controlled water electrode photovoltaic power generation and thermal storage system of the present invention;

[0099] Figure 3 The flowchart of the control process of the hydraulically regulated water electrode photovoltaic power generation and thermal storage system of the present invention. Detailed Implementation

[0100] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0101] like Figure 1 and Figure 2 As shown, the hydraulically controlled water electrode photovoltaic power generation and heat storage system of the present invention mainly includes a heat storage tank 1, a water electrode system, a photovoltaic power supply system, and a monitoring system. The water electrode system, except for the reversing valve 11, the metering plunger pump 10, the fixed water electrode fine-tuning rod 8, and some hydraulic pipes, is located inside the heat storage tank 1. The photovoltaic power supply system is located around the periphery of the heat storage tank 1. The heat storage tank 1 is equipped with an inlet 19, an outlet 12, an exhaust pipe 21, and a pressure reducing valve 20. The inlet 19 is located above the heat storage tank 1; the outlet 12 is located below the heat storage tank 1; the exhaust pipe 21 is located on the upper side of the heat storage tank 1; and the pressure reducing valve 20 is located above the heat storage tank 1 near the inlet 19.

[0102] The water electrode system includes a hydraulically controlled water electrode 2, a hydraulically controlled water electrode connecting rod 9, a left piston 5, a right piston 6, a hydraulic pipeline 7, a reversing valve 11, a metering plunger pump 10, a fixed water electrode 3, a fixed water electrode fine-tuning rod 8, and a water electrode fixing slide rail 4. The hydraulically controlled water electrode 2 and the fixed water electrode 3 are made of conductive metal plates with several holes to facilitate water flow and prevent disturbance from bubbles generated during the heating process. The water electrode fixing slide rail 4 is made of cylindrical insulating material, fixed at both ends to the tank wall of the heat storage tank 1. A first hole 23 is located in the middle of the fixed water electrode 3, and a second hole 22 is located in the middle of the hydraulically controlled water electrode 2, through which the water electrode fixing slide rail 4 passes. When the fixed water electrode 3 and the hydraulically controlled water electrode 2 move, they act as a stable mirror image; the fixed water electrode 3 is placed on one side of the water electrode fixing slide rail 4, and the hydraulically controlled water electrode 2 is located in the middle area of ​​the water electrode fixing slide rail 4 and can move left and right. The fixed water electrode fine-tuning rod 8 passes through the tank wall and connects to the fixed water electrode 3. By manually adjusting the stroke of the fixed water electrode fine-tuning rod 8, the distance between the fixed water electrode 3 and the liquid-controlled water electrode 2 is changed, mainly for determining the maximum power point of photovoltaic output. The hydraulic pipeline 7 has a C-shaped structure, with a reversing valve 11 installed in series in the middle of the C-shaped structure. The input end of the reversing valve 11 is connected to the metering plunger pump 10. A left piston 5 and a right piston 6 are respectively placed at both ends of the C-shaped structure. The left piston 5 and the right piston 6 are fixedly installed on the liquid-controlled water electrode connecting rod 9. The liquid-controlled water electrode 2 is fixedly installed in the middle of the liquid-controlled water electrode connecting rod 9. The reversing valve 11 is a valve that controls the direction of liquid flow. The metering plunger pump 10 directly draws in and discharges the working medium in the hydraulic pipeline 7 through the reciprocating motion of the plunger. Each reciprocating motion drives the left piston 5 and the right piston 6 through the reversing valve 11 to push the liquid-controlled water electrode connecting rod 9, thereby moving the liquid-controlled water electrode 2 by one step and adjusting the distance between the liquid-controlled water electrode 2 and the fixed water electrode 3.

[0103] The photovoltaic power supply system includes a photovoltaic array 13 and a power electronic square wave commutator 16. The photovoltaic array 13 is connected to the power electronic square wave commutator 16 via its positive output terminal 14 and negative output terminal 15. The power electronic square wave commutator 16, through a power electronic switch, converts the power output from the positive terminal 14 and negative terminal 15 of the photovoltaic array 13 into an alternating positive and negative square wave output. The square wave output of the power electronic square wave commutator 16 is connected to a fixed water electrode 3 via a second cable 18, and to a liquid-controlled water electrode 2 via a first cable 17, providing the water electrode with a periodically alternating positive and negative power supply. If the power electronic square wave commutator 16 switches its square wave output at a frequency on the order of seconds, the switching loss time of its power electronic devices is negligible at the nanosecond level. This significantly reduces losses compared to the inverter's switching frequency of 5KHz to 20KHz.

[0104] The monitoring system includes a controller 24, a water electrode current sensor, a water electrode voltage sensor, and a temperature sensor for the thermal storage tank 1. The controller 24 is located around the thermal storage tank 1 and is connected to the water electrode current sensor, water electrode voltage sensor, and temperature sensor for the thermal storage tank 1 via communication cables. It is also connected to all controlled units and the metering plunger pump 10 via control cables. The controller 24 reads sensor data in real time and controls the controlled units based on algorithms, models, and control strategies.

[0105] The thermal storage principle of the water electrode of this invention is as follows:

[0106] Based on the heating principle of electrode hot water boilers, a technology that directly converts electrical energy into heat energy and generates steam by using three-phase voltage and current to release a large amount of heat energy through water with a set conductivity. The heating power can be steplessly adjusted.

[0107] Because water resistance heats the water directly, electrical energy is 100% converted into heat, resulting in high efficiency and almost no heat loss.

[0108] Mathematical expression based on the principle of electrical work:

[0109]

[0110] It can be seen that at the same voltage U water Below, heating water resistance R w The smaller the value, the larger the current flowing through it, based on the mathematical expression of Joule's law:

[0111]

[0112] and

[0113] It can be seen that the voltage U within the same time t water or current I water Changes in heat Q water The voltage U changes exponentially with square root. water or current I water The larger the heat Q generated water The larger.

[0114] And the current I water The size of the heating element is related to the resistance of the heating water, which in turn is related to the size of the electrode area and the distance between the two electrodes. The larger the electrode area, the smaller the equivalent parallel resistance and the larger the current; the closer the distance between the two electrodes, the smaller the water resistance and the larger the current. Therefore, the heating power of the water electrodes can be changed by adjusting the area and spacing of the water electrodes.

[0115] The relative position of the area of ​​the liquid-controlled water electrode to the fixed water electrode is analyzed as follows:

[0116] Due to the liquid-controlled water electrode M w With fixed water electrode G w Mirror mounting, equal area. Due to the liquid-controlled water electrode M w Located at point C, the middle of the hydraulically controlled water electrode connecting rod. The metering plunger pump drives the hydraulic control electrode M via a reversing valve. w Left and right displacement, shifting to the right to the endpoint B. Liquid-controlled water electrode M w With fixed water electrode G w The minimum relative distance at position O is:

[0117]

[0118] Displace to the left to the endpoint A The maximum relative distance is:

[0119]

[0120] Liquid-controlled water electrode M w At the left end of the hydraulic pipeline With the right end point any point between With fixed water electrode G w The relative distance is:

[0121]

[0122] Midpoint of the hydraulically controlled water electrode connecting rod The maximum right displacement distance L max With minimum relative distance L min The difference divided by 2 is the position, that is

[0123] Because the hydraulic pipeline has a C-shaped structure, a reversing valve is connected in series in the hydraulic pipeline to control the direction of hydraulic propulsion and change the relative distance L between the hydraulically controlled water electrode and the fixed water electrode. n Due to the liquid-controlled water electrode M w With fixed water electrode G w Mirror mounting, fixing the area S of the water electrode g It equals the area of ​​the liquid-controlled water electrode. The heating water resistance is concentrated between the mirror projections of the fixed water electrode and the liquid-controlled water electrode. Without considering the fixed water electrode G... w With liquid-controlled water electrode M w Under the conditions of the surrounding electric field distribution and the reduced area of ​​the holes on the water electrodes, the heating water resistance R w It should be: the distance L between the fixed water electrode and the involute water electrode n With water conductivity δ d The product of the fixed water electrode area S gThe ratio, that is:

[0124]

[0125] Due to the electrical conductivity δ of water d and fixed water electrode G w area S g It is a constant, fixed water electrode G w The positions are relatively fixed, and the relative distance L between the liquid-controlled water electrode and the fixed water electrode is... n That is, the liquid-controlled water electrode M w The displacement distance. From equation (7), it can be seen that the resistance R of the heating water... w The value is related to the relative distance L between the liquid-controlled water electrode and the fixed water electrode. n Proportional to the distance L between the liquid-controlled water electrode and the fixed water electrode n Increase the resistance of the heating water R w Increase, conversely, the relative distance L between the liquid-controlled water electrode and the fixed water electrode decreases. n Reduce the resistance of the heating water (R). w Reduce, based on the principle of electrical work:

[0126]

[0127] Substituting equation (7) into equation (8), we obtain the relative distance L between the liquid-controlled water electrode and the fixed water electrode. n Relationship with power:

[0128]

[0129] Equation (9) shows that when the resistance U of the heating water is applied... water Under constant voltage conditions, the liquid-controlled water electrode M w Each displacement step corresponds to a load power P. water .

[0130] Therefore, a metering plunger pump is used to complete one step with one reciprocating cycle. n | n＝1 =Step 1 movement, and outputs standard hydraulic pressure to drive the piston to push the hydraulically controlled water electrode M w A displacement of one length ΔL corresponds to a heating water resistance ΔR. w The increase or decrease, and the corresponding load power P water The increase or decrease of [the value] is used to obtain the liquid-controlled water electrode M under arbitrary step size. w Displacement distance:

[0131] L n =ΔL×Step n +L min (10)

[0132] Substituting equation (10) into equation (9) yields the corresponding power P at any step size. water :

[0133]

[0134] Substituting equation (10) into equation (7) yields... Therefore, any step size Step n The heating water resistance R w Load power P water :

[0135]

[0136] Due to the liquid-controlled water electrode M w Located at the midpoint of the hydraulically controlled water electrode connecting rod Therefore, the middle position of the liquid-controlled water electrode is defined. Zero displacement step size Step n | n＝0 =Step0, when shifting to the left it is -Step max ~Step0, when shifting to the right: Step0~Step max n = 0, 1, 2…max;

[0137] The metering plunger pump drives the hydraulic control electrode M via a reversing valve. w Displace to the left, until reaching the endpoint on the left side of the liquid-controlled water electrode. Time and fixed water electrode G w Maximum distance L max According to formula (10), the metering plunger pump is measured in steps: -Step n | n＝max =-Step max ;

[0138] Driven liquid-controlled water electrode M w Displacement; Liquid-controlled water electrode M w Displace to the right to the end point Time and fixed water electrode G w Minimum distance L min According to formula (10), the metering plunger pump is used in steps of a number of steps. n | n＝max =Step max Driven liquid-controlled water electrode M w Displacement.

[0139] Because the photovoltaic power generation is applied to the water resistance between the liquid-controlled water electrode and the fixed water electrode, the displacement of the liquid-controlled water electrode changes from one step under the action of the reciprocating motion of the metering plunger pump. n | n＝1 =Step 1 to n steps Stepn The process of change, namely Step 1 to Step 2 n From equations (11) and (12), it can be seen that the change in each step size affects the load power P applied by the photovoltaic power to the water resistor. water Each one corresponds to the maximum power point of photovoltaic power generation. That is, the voltage at the maximum power point of photovoltaic power generation. With the maximum power point current of photovoltaic power generation The product of, i.e.:

[0140]

[0141] The maximum power point of this photovoltaic power generation Maximum power point voltage of photovoltaic power generation With the maximum power point current of photovoltaic power generation The ratio is equal to the heating water resistance R. w :

[0142]

[0143] Among them, S g To fix the area of ​​the water electrode; R w The resistance value of the heating water; ΔR w The displacement of the liquid-controlled water electrode is one step size Step1 = Step n | n＝1 This corresponds to an increase or decrease in the heating water resistance; L n To fix the relative distance between the water electrode and the liquid-controlled water electrode; δ d ΔL is the electrical conductivity of water; ΔL is the liquid-controlled water electrode M. w A displacement length is also the distance that the hydraulically controlled water electrode is driven per unit step; P water The load power on the water resistor; Step n The number of steps in which the reciprocating motion of the plunger pump drives the hydraulic control water electrode to move is also called the number of steps in the hydraulic control water electrode displacement. Step is the number of steps for the displacement of the liquid-controlled water electrode. n The point of maximum photovoltaic power generation; Step is the number of steps for the displacement of the liquid-controlled water electrode. n Maximum power output and voltage of point photovoltaic power generation; Step is the number of steps for the displacement of the liquid-controlled water electrode. n The maximum power output and point current of a point-volt generator;

[0144] like Figure 3 As shown, the control method of the hydraulically regulated water electrode photovoltaic power generation and thermal storage system of the present invention includes the following steps:

[0145] Step 1, Initialization settings:

[0146] 1.1 Input photovoltaic array parameters: installed capacity, array tilt angle, array orientation, horizontal diffuse reflection coefficient, open circuit voltage, short circuit current, photovoltaic power generation, total solar irradiance and typical photovoltaic maximum power point table;

[0147] 1.2 Determine the maximum left and right displacement step size of the liquid-controlled water electrode. max And the corresponding maximum power point of photovoltaic power generation.

[0148] 1.2.1 Fine-tuning and fixing the water electrode

[0149] First, place the liquid-controlled water electrode M w Midpoint of the connecting rod The hydraulic control electrode M is pushed by the reversing valve of the metering plunger pump. w Step size n | n＝max =Step max Move right to reach the right end point of the liquid-controlled water electrode That is, liquid-controlled water electrode Minimum distance between the point and the fixed water electrode At this position, the water resistance is at its minimum. According to equation (9), by manually adjusting the stroke of the fixed water electrode fine-tuning rod, the distance between the fixed water electrode and the liquid-controlled water electrode is finely adjusted, so that the power P applied by photovoltaic power generation to the heating water resistor is increased. water The maximum power point of photovoltaic power generation with the maximum local irradiance. Equal, that is

[0150] Where, δ d S is the electrical conductivity of water. g To fix the area of ​​the water electrode, L n Let n be the relative distance between any point on the liquid-controlled water electrode and the fixed water electrode, where n∈[min,max]. The midpoint of the liquid-controlled water electrode connecting rod; This is the right end point of the liquid-controlled water electrode; This is the left end point of the liquid-controlled water electrode.

[0151] 1.2.2 Determine

[0152] The step size of the hydraulic electrode is increased by the reversing valve of the metering plunger pump. n | n＝max =Step max Move left to reach the left end point of the liquid-controlled water electrode That is, the liquid-controlled water electrode M w Maximum distance from fixed water electrode At the position where the heating water resistance is at its maximum, based on equations (12), (13), and (14) and the typical photovoltaic maximum power point table, find the power P applied to the heating water resistance by shifting the liquid-controlled water electrode to the left. water The maximum power point of photovoltaic power generation corresponding to the local lower irradiance. Right now

[0153] Among them, R w The resistance value of the heating water; ΔR w The displacement of the liquid-controlled water electrode is one step size Step1 = Step n | n＝1 This corresponds to an increase or decrease in the heating water resistance; ΔL is the resistance of the liquid-controlled water electrode M. w A displacement length is also the distance that the hydraulically controlled water electrode is driven per unit step; P water The load power on the water resistor; Step n The number of steps in which the reciprocating motion of the plunger pump drives the hydraulic control water electrode to move is also called the number of steps in the hydraulic control water electrode displacement. Step is the number of steps for the displacement of the liquid-controlled water electrode. n The point of maximum photovoltaic power generation; Step is the number of steps for the displacement of the liquid-controlled water electrode. n Maximum power output and voltage of point photovoltaic power generation; Step is the number of steps for the displacement of the liquid-controlled water electrode. n The maximum power point current of point-volt generator.

[0154] 1.3 Considering the response speed of mechanical photovoltaic maximum power point tracking, segmented photovoltaic maximum power point tracking is adopted.

[0155] First, based on the input photovoltaic array parameters and irradiance, a table for quickly locking the maximum power point of segmented photovoltaic power generation under different illumination conditions is established. Since the length ΔL of the displacement of the liquid-controlled water electrode per unit step is the maximum distance L between the fixed water electrode and the liquid-controlled water electrode... max Minimum distance L from the liquid-controlled water electrode min The difference, divided by the sum of the absolute values ​​of the maximum left and right displacement steps of the liquid-controlled water electrode, is 2Step. max ,Right now

[0156] To achieve rapid location of the photovoltaic power generation maximum power point, the maximum step size will be doubled to 2Step. max Quantified in units of 10, that is

[0157] At the point of maximum photovoltaic power generation with the maximum local irradiance. and the maximum power point of photovoltaic power generation at lower local irradiance. Range, divided by the quantification result The number of segments for quickly locking the maximum power point of photovoltaic power generation under different illumination conditions is obtained, i.e.:

[0158]

[0159] and the maximum power point of photovoltaic power generation corresponding to the segment endpoints

[0160]

[0161] Right now Therefore, the maximum photovoltaic power point value at each segment point is determined by looking up a table. Including the step size when the liquid-controlled water electrode is in the middle position: Step0 = Step n | n＝0 Corresponding maximum power point value of photovoltaic power generation

[0162] Therefore, the difference in maximum power output between adjacent photovoltaic power generation segments is a constant α, i.e.:

[0163]

[0164] Where mp is the number of segments at the maximum power point of photovoltaic power generation; Step0 = Step n | n＝0 This is the step size when the liquid-controlled water electrode is in the middle position; The maximum power point value of photovoltaic power generation is the step size Step0 when the liquid-controlled water electrode is in the middle position. The maximum power point value of photovoltaic power generation is the maximum irradiance in the local area; ΔL is the distance of driving the liquid-controlled water electrode per unit step; Step n The number of reciprocating strokes of the plunger pump is also the number of steps in the displacement of the hydraulic control water electrode; Step is the number of steps for the displacement of the liquid-controlled water electrode. n The point of maximum photovoltaic power generation; Step is the number of steps for the displacement of the liquid-controlled water electrode. n The maximum power output of photovoltaic power generation at a given point and the voltage at that point; Step is the number of steps for the displacement of the liquid-controlled water electrode. n The maximum power of photovoltaic power generation at a point; α is a constant value for the difference in maximum power generation at each adjacent photovoltaic segment. For each segment point, n represents the point where the photovoltaic power generation reaches its maximum. m =1,2,3,…,mp;

[0165] Take Step0 = Step n | n＝0The resistance of the heating water between the time-controlled water electrode and the fixed water electrode is R0, and the maximum number of steps for the time-controlled water electrode to move to the right is Step. max =Step n | n＝max The corresponding heating water resistance obtained is:

[0166] R w =R0-ΔR w ×Step max (18)

[0167] The minimum number of steps required for the liquid-controlled water electrode to move to the right is Step1 = Step2. n | n＝1 The corresponding heating water resistance R obtained w =R0-ΔR w ;

[0168] The maximum number of steps for the liquid-controlled water electrode to shift to the left is -Step max =-Step n | n＝max The corresponding heating water resistance obtained

[0169] R w =R0-ΔR w ×(-Step max )=R0+ΔR w ×Step max (19)

[0170] The minimum number of steps required for the liquid-controlled water electrode to move to the right is -Step1 = -Step n | n＝1 The corresponding heating water resistance R obtained w =R0+ΔR w .

[0171] Therefore, based on equations (13) and (14), it can be seen that the change in the number of steps of each liquid-controlled water electrode corresponds to the change in the resistance of the heating water, and at the same time, it corresponds one-to-one with the maximum power point of photovoltaic power generation within the local maximum and minimum irradiance range.

[0172] Step 2: Quickly locate the section with the maximum photovoltaic power generation:

[0173] The controller reads the photovoltaic power generation current I in real time. pv and photovoltaic power generation voltage U pv The photovoltaic power output P was calculated. pv Based on the output power P pv Compared with the previous moment's maximum photovoltaic power generation The difference is calculated between the points, that is:

[0174]

[0175] 2.1 When This indicates that the directional valve's action causes the hydraulic control electrode to shift to the right:

[0176] When ΔP pv When the value is greater than 0, it indicates an increase in photovoltaic power generation and confirms that the directional valve's action causes the liquid-controlled water electrode to shift to the right, thereby increasing the photovoltaic power output P. pv Divide by the constant α of the maximum power difference point of photovoltaic power generation in each adjacent segment, that is:

[0177]

[0178] The result of the divisor is rounded to one decimal place, and the modulo function is used to determine its value.

[0179] mod(P pv ,α)≥0.5 (22)

[0180] in, This represents the point at which photovoltaic power generation reaches its maximum power at the previous moment; Step n-1 The point at which photovoltaic power generation reaches its maximum power at the previous moment. Number of displacement steps for the liquid-controlled water electrode; I pv U represents the current photovoltaic power generation current. pv P represents the current photovoltaic power generation voltage. pv This represents the current output power of photovoltaic power generation;

[0181] 2.1.1 The modulo modulo function is used to determine mod(P) pv If α)≥0.5, then according to the floor function:

[0182]

[0183] Using the principle of rounding up to the nearest whole number, determine the maximum power point of photovoltaic power generation in a certain segment. And determine the maximum power point of photovoltaic power generation. Falling and Between these, the number of displacement steps of the liquid-controlled water electrode is obtained as Step. n =n m ×10, according to Step n =n m ×10 times the displacement step size of the liquid-controlled water electrode minus the maximum power point of photovoltaic power generation at the previous moment. Number of displacement steps for the liquid-controlled water electrode n-1 The increase or decrease in the displacement step size ΔStep of the liquid-controlled water electrode is obtained. n Each step, i.e., ΔStepn =10n m Step n-1 .

[0184] Where, n m The point where the maximum photovoltaic power generation is known for a certain segment. The number of displacement steps for the hydraulically controlled water electrode is set during initialization. At this time, the controller adjusts the displacement based on the increment / decrement ΔStep. n The step-size control of the metering plunger pump causes the hydraulically controlled water electrode to shift, reducing the distance L between the hydraulically controlled water electrode and the fixed water electrode. n This reduces the resistance R of the heating water. w Quickly pinpoint the maximum power point of segmented photovoltaic power generation Simultaneously, the controller reads the photovoltaic power generation current I in real time. pv and voltage U pv The photovoltaic power output P was calculated. pv Step 3 involves refining the maximum power tracking control of photovoltaic power generation.

[0185] Where mod is the modulo function; INT is the integer function; For n m The maximum power point of segmented photovoltaic power generation; For n m The maximum power point of photovoltaic power generation in the -1 segment; Step is the number of displacement steps for the liquid-controlled water electrode. n The point at which photovoltaic power generation reaches its maximum power; the point at which photovoltaic power generation reached its maximum power at the previous moment; Step n-1 The point at which photovoltaic power generation reaches its maximum power at the previous moment. The number of displacement steps of the liquid-controlled water electrode; ΔStep n To increase or decrease the number of displacement steps of the volumetric water control electrode; L n Let n be the relative distance between any point on the liquid-controlled water electrode and the fixed water electrode, where n∈[min,max];

[0186] 2.1.2 The modulo modulo function is used to determine mod(P) pv If α) < 0.5, then according to the floor function... Using the principle of rounding up to the nearest whole number, determine the maximum power point of photovoltaic power generation in a certain segment. And determine the maximum power point of photovoltaic power generation. Falling and Between these points, the displacement step size of the liquid-controlled water electrode is obtained, based on the Step... n =n m ×10 times the displacement steps of the liquid-controlled water electrode minus the maximum power point of photovoltaic power generation at the previous moment. Number of displacement steps for the liquid-controlled water electrode n-1 The change in displacement ΔStep of the liquid-controlled water electrode was obtained. n Each step, i.e., ΔStep n =10n m Step n-1 , where n m The point where the maximum photovoltaic power generation is known for a certain segment. The number of displacement steps for the hydraulically controlled water electrode is set during initialization. At this time, the controller adjusts the displacement based on the increment / decrement ΔStep. n Each step controls the displacement of the liquid-controlled water electrode, reducing the distance L between the liquid-controlled water electrode and the fixed water electrode. n This reduces the resistance R of the heating water. w Quickly pinpoint the maximum power point of segmented photovoltaic power generation Simultaneously, the controller reads the photovoltaic power generation current I in real time. pv and voltage U pv The photovoltaic power output P was calculated. pv Step 3 involves refining the maximum power tracking control of photovoltaic power generation.

[0187] in, For n m The maximum power point of segmented photovoltaic power generation; For n m The maximum power point of photovoltaic power generation in the +1 segment; Step is the number of displacement steps for the liquid-controlled water electrode. n The point at which photovoltaic power generation reaches its maximum power; ΔStep n To increase or decrease the number of displacement steps of the volumetric water control electrode;

[0188] 2.2 When With ΔP pv When the value is less than 0, the photovoltaic power generation decreases, indicating that the directional valve's hydraulic control electrode has shifted to the left, reducing the current photovoltaic power output P. pv Divide by the constant α of the maximum power difference point of photovoltaic power generation in each adjacent segment, i.e. The result of the divisor is rounded to one decimal place, and the modulo (P) function is used to determine the modulo (P) result. pv ,α)≥0.5.

[0189] 2.2.1 Using the modulo modulo function to determine mod(P) pv If α)≥0.5, then according to the floor function... Using the principle of rounding up to the nearest whole number, determine the maximum power point of photovoltaic power generation in a certain segment. And determine the maximum power point of photovoltaic power generation. Falling and Between these, we obtain Step n =n m ×10 liquid-controlled water electrode displacement steps, based on the photovoltaic power generation maximum power point at the previous moment. The number of displacement steps of the liquid-controlled water electrode is Stepn-1, minus Step n =n m The displacement increment / decrement ΔStep of the liquid-controlled water electrode is obtained by multiplying the displacement step by 10. n Each step, i.e., ΔStep n =Step n-1 -10n m , where n m The point where the maximum photovoltaic power generation is known for a certain segment. The number of displacement steps for the hydraulically controlled water electrode is set during initialization. At this time, the controller adjusts the displacement based on the increment / decrement ΔStep. n Each step controls the displacement step of the liquid-controlled water electrode, increasing the distance L between the liquid-controlled water electrode and the fixed water electrode. n This increases the resistance R of the heating water resistor. w Quickly pinpoint the maximum power point of segmented photovoltaic power generation Simultaneously, the controller reads the photovoltaic power generation current I in real time. pv and voltage U pv The photovoltaic power output P was calculated. pv Step 3 involves refining the maximum power tracking control of photovoltaic power generation.

[0190] 2.2.2 The modulo modulo function is used to determine mod(P) pv If α) < 0.5, then according to the floor function... Using the principle of rounding up to the nearest whole number, determine the maximum power point of photovoltaic power generation in a certain segment. And determine the maximum power point of photovoltaic power generation. Falling and Between these, we obtain Step n =n m ×10 liquid-controlled water electrode displacement steps, based on the photovoltaic power generation maximum power point at the previous moment. Number of displacement steps for the liquid-controlled water electrode n-1 Subtract Step n =n m The displacement increment / decrement ΔStep of the hydraulically controlled water electrode is obtained by multiplying the displacement steps by 10. n Each step, i.e., ΔStep n =Step n-1 -10n m Where n m The point where the maximum photovoltaic power generation is known for a certain segment. The number of displacement steps for the hydraulically controlled water electrode is set during initialization. At this time, the controller adjusts the displacement based on the increment / decrement ΔStep. n Each step controls the number of displacement steps of the liquid-controlled water electrode, increasing the distance L between the liquid-controlled water electrode and the fixed water electrode. n This increases the resistance R of the heating water resistor. w Quickly pinpoint the maximum power point of segmented photovoltaic power generation Simultaneously, the controller reads the photovoltaic power generation current I in real time. pv and voltage U pv The photovoltaic power output P was calculated. pv Step 3 involves refining the maximum power tracking control of photovoltaic power generation.

[0191] Step 3: Perform refined photovoltaic power generation maximum power point tracking control.

[0192] Step 2.1 quickly identifies the section with the maximum power output of the photovoltaic power generation, and the controller reads the photovoltaic power generation current I in real time. pv and voltage U pv The photovoltaic power output P was calculated. pv and the maximum power point of segmented photovoltaic power generation Compare and judge separately or

[0193] 3.1 Determine ΔP based on equation (20) pv When ≥0, the photovoltaic power generation increases, and the maximum power point of photovoltaic power generation is known in segments. Compare, judge hour:

[0194] 3.1.1 Determine mod(P) based on the mod modulo function pv If α)≥0.5, then according to the floor function... And the principle of rounding up or down.

[0195] Step A: The controller adjusts the increment / decrement ΔStep based on the previous time step. n-1 Subtracting one disturbance step from each step size controls the displacement step size of the liquid-controlled water electrode, thereby changing the resistance value R of the heating water resistor. w At this point, the current increment step size is ΔStep. n =ΔStep n-1 -1. Meanwhile, the controller continues to read the photovoltaic power generation current I. pv and voltage U pv The output power of photovoltaic power generation was calculated. And compared with the photovoltaic power generation at the previous moment Compare.

[0196] Among them, when This indicates that the directional valve's hydraulic control electrode is displaced to the right, with an increase or decrease of ΔStep. n The step size is positive, and the resistance R of the heating water is changed according to formula (18). w ;

[0197] when This indicates that the directional valve's hydraulic control electrode is displaced to the left, with an increase or decrease of ΔStep. n The step size is negative, and the resistance R of the heating water is changed according to formula (19). w ;

[0198] When judging The controller repeats step A.

[0199] When judging At that time, the distance between the current liquid-controlled water electrode and the fixed water electrode is determined, and the resulting heating water resistance R is calculated. w Adapted to the maximum power point of photovoltaic power generation

[0200] in, This represents the current output power of photovoltaic power generation; The photovoltaic power generation at the previous moment; ΔStep n-1 ΔStep represents the step size for the increase or decrease in the displacement of the hydraulically controlled water electrode at the previous moment. n This represents the step size for the current displacement increment / decrement of the liquid-controlled water electrode;

[0201] 3.1.2 Determine mod(P) based on the mod modulo function pv If α) < 0.5, then according to the floor function... And the principle of rounding up or down.

[0202] Step B, the controller adjusts the increment / decrement ΔStep based on the previous time step. n-1 A step size plus a perturbation step size controls the displacement of the liquid-controlled water electrode, thereby changing the resistance value R of the heating water resistor. w At this point, the current increment / decrement step size is ΔStep. n =ΔStep n-1 +1. Meanwhile, the controller continues to read the photovoltaic power generation current I. pv and voltage U pv The output power of photovoltaic power generation was calculated. And compared with the photovoltaic power generation at the previous moment Compare.

[0203] Among them, when This indicates that the directional valve's hydraulic control electrode is displaced to the right, with an increase or decrease of ΔStep. n The step size is positive, and the resistance R of the heating water is changed according to formula (18). w ;when This indicates that the directional valve's hydraulic control electrode is displaced to the left, with an increase or decrease of ΔStep. n The step size is negative, and the resistance R of the heating water is changed according to formula (19). w ;

[0204] When judging The controller repeats step B.

[0205] When judging At that time, the distance between the current liquid-controlled water electrode and the fixed water electrode is determined, and the resulting heating water resistance R is calculated. w Adapted to the maximum power point of photovoltaic power generation

[0206] 3.2 Determine ΔP based on equation (20) pv When the value is less than 0, the photovoltaic power generation decreases, and the known maximum power point of photovoltaic power generation is segmented. Compare, judge hour:

[0207] 3.2.1 Determine mod(P) based on the mod modulo function pv If α)≥0.5, then according to the floor function... And the principle of rounding up or down.

[0208] Step A: The controller adjusts the increment / decrement ΔStep based on the previous time step. n-1 Subtracting one disturbance step from each step size controls the displacement step size of the liquid-controlled water electrode, thereby changing the resistance value R of the heating water resistor. w At this point, the current increment / decrement step size is ΔStep. n =ΔStep n-1 -1.

[0209] At the same time, the controller continues to read the photovoltaic power generation current I. pv and voltage U pv The output power of photovoltaic power generation was calculated. And compared with the photovoltaic power generation at the previous moment Compare.

[0210] Among them, when This indicates that the directional valve's hydraulic control electrode is displaced to the right, with an increase or decrease of ΔStep. n The step size is positive, and the resistance R of the heating water is changed according to formula (18). w ;when This indicates that the directional valve's hydraulic control electrode is displaced to the left, with an increase or decrease of ΔStep. n The step size is negative, and the resistance R of the heating water is changed according to formula (19). w ;

[0211] When judging The controller continues to execute step A.

[0212] When judging At that time, the distance between the current liquid-controlled water electrode and the fixed water electrode is determined, and the resulting heating water resistance R is calculated. w Adapted to the maximum power point of photovoltaic power generation

[0213] in, This represents the current output power of photovoltaic power generation; The photovoltaic power generation at the previous moment; ΔStep n-1 ΔStep represents the increment or decrement of the liquid-controlled water electrode at the previous moment; n The increment or decrement of the current liquid-controlled water electrode is determined by the step size.

[0214] 3.2.2 Determine mod(P) based on the mod modulo function pv If α) < 0.5, then according to the floor function... The principles of rounding up and down are:

[0215] Step B, the controller adjusts the increment / decrement ΔStep of the liquid-controlled water electrode based on the previous moment. n-1 A step size plus a perturbation step size controls the displacement of the liquid-controlled water electrode, thereby changing the resistance value R of the heating water resistor. w At this point, the step size for increasing or decreasing the liquid-controlled water electrode is ΔStep. n =ΔStep n-1 +1. Meanwhile, the controller continues to read the photovoltaic power generation current I. pv and voltage U pv The output power of photovoltaic power generation was calculated. And compared with the photovoltaic power generation at the previous moment Compare.

[0216] Among them when This indicates that the directional valve's hydraulic control electrode is displaced to the right, with an increase or decrease of ΔStep. n The step size is positive, and the resistance R of the heating water is changed according to formula (18). w ;when This indicates that the directional valve's hydraulic control electrode is displaced to the left, with an increase or decrease of ΔStep. n The step size is negative, and the resistance R of the heating water is changed according to formula (19). w ;

[0217] When judging The controller then continues to execute step B.

[0218] When judging At that time, the distance between the current liquid-controlled water electrode and the fixed water electrode is determined, and the heating water resistance R is generated according to equation (19). wAdapted to the maximum power point of photovoltaic power generation

[0219] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A hydraulic control water electrode photovoltaic power generation and heat storage system, characterized in that: The system includes a thermal storage tank, a water electrode system, a photovoltaic power supply system, and a monitoring system. The water electrode system, except for the reversing valve, metering plunger pump, fixed water electrode fine-tuning rod, and some hydraulic pipelines, is located inside the thermal storage tank. The photovoltaic power supply system is located around the perimeter of the thermal storage tank. The thermal storage tank is equipped with an inlet, an outlet, an exhaust pipe, and a pressure reducing valve. The inlet is located at the top of the thermal storage tank; the outlet is located at the bottom; the exhaust pipe is located on the upper side of the thermal storage tank; and the pressure reducing valve is located at the top of the thermal storage tank near the inlet. The water electrode system includes a hydraulically controlled water electrode, a hydraulically controlled water electrode connecting rod, a left piston, a right piston, hydraulic pipes, a reversing valve, a metering plunger pump, a fixed water electrode, a fixed water electrode fine-tuning rod, and a water electrode fixing slide rail. The two ends of the water electrode fixing slide rail are fixed to the tank wall of the thermal storage tank. A first hole is opened in the middle of the fixed water electrode, and a second hole is opened in the middle of the hydraulically controlled water electrode, through which the water electrode fixing slide rail passes. The fixed water electrode is placed on one side of the water electrode fixing slide rail, and the hydraulically controlled water electrode is located in the middle area of ​​the water electrode fixing slide rail and can move left and right. The fixed water electrode fine-tuning rod passes through the tank wall and connects to the fixed water electrode. The hydraulic... The pipeline has a C-shaped structure, with a reversing valve connected in series in the middle of the C-shape. The input end of the reversing valve is connected to a metering plunger pump. A left piston and a right piston are respectively placed at both ends of the C-shape, and the left and right pistons are fixedly mounted on the hydraulic control water electrode connecting rod. A hydraulic control water electrode is fixedly mounted in the middle of the hydraulic control water electrode connecting rod. The reversing valve is used to control the liquid flow direction. The metering plunger pump directly draws in and discharges the working medium in the hydraulic pipeline through the reciprocating motion of the plunger. Each reciprocating motion drives the left and right pistons through the reversing valve to push the hydraulic control water electrode connecting rod, causing the hydraulic control water electrode to move by one step, thus adjusting the distance between the hydraulic control water electrode and the fixed water electrode. The photovoltaic power supply system includes a photovoltaic array and a power electronic square wave commutator; The monitoring system includes a controller, a water electrode current sensor, a water electrode voltage sensor, and a temperature sensor for the thermal storage tank.

2. The hydraulic regulated water electrode photovoltaic power generation and heat storage system according to claim 1, characterized in that: Both the liquid-controlled water electrode and the fixed water electrode are made of metal conductive plate material, and have several holes on them to facilitate water flow and avoid disturbance caused by bubbles during the heating process.

3. The hydraulic regulated water electrode photovoltaic power generation and heat storage system according to claim 1, characterized in that: The water electrode fixing slide rail is made of cylindrical insulating material.

4. The hydraulic regulated water electrode photovoltaic power generation and heat storage system according to claim 1, characterized in that: The distance between the fixed water electrode and the liquid-controlled water electrode is changed by manually adjusting the stroke of the fixed water electrode fine-tuning rod, which is used to determine the point of maximum photovoltaic output power.

5. The hydraulic regulated water electrode photovoltaic power generation and heat storage system according to claim 1, characterized in that: The positive and negative output power of the photovoltaic array is connected to the input terminal of the power electronic square wave commutator. The power electronic square wave commutator switches the output power of the photovoltaic array positive and negative to a square wave output power that alternates between positive and negative through a power electronic switch. The square wave output terminal of the power electronic square wave commutator is connected to the fixed water electrode and the liquid-controlled water electrode respectively through two cables, serving as the power output terminal of the power electronic square wave commutator and providing the water electrode with a periodically changing positive and negative power.

6. The hydraulic regulated water electrode photovoltaic power generation and heat storage system according to claim 1, characterized in that: The controller is placed around the heat storage tank, connected with the water electrode current sensor, water electrode voltage sensor and temperature sensor of the heat storage tank through communication cable, and connected with all controlled units and metering plunger pump through control cable; the controller reads sensor data in real time, and controls the controlled units according to algorithm, model and control strategy.

7. The control method of the hydraulic regulated water electrode photovoltaic power generation and heat storage system according to any one of claims 1-6, characterized in that, The method comprises the following steps: Step 1, initialization setting, specifically comprising: Step 1.1, inputting photovoltaic array parameters: installed capacity, array inclination, array orientation, horizontal diffuse reflection coefficient, open-circuit voltage, short-circuit current, photovoltaic power generation, total solar radiation intensity and typical photovoltaic maximum power point table; Step 1.2, determining the maximum displacement step number of the hydraulic water electrode to the left and to the right max corresponding to the maximum power point of photovoltaic power generation; Step 1.3, considering the mechanical photovoltaic maximum power tracking response speed, adopting segmented photovoltaic maximum power tracking; Step 2, quickly locking the photovoltaic maximum power point section: Step 3, performing fine photovoltaic maximum power tracking control.

8. The control method according to claim 7, characterized by, The step 1.2 specifically comprises: Step 1.2.1, fine adjustment of fixed water electrode determination First, the middle point of the hydraulic water electrode connecting rod is The hydraulic water electrode is pushed by the metering plunger pump reversing valve by Step n | n＝max = Step max Right to the right end of the hydraulic water electrode That is, the position of the hydraulic water electrode The distance between the points and the fixed water electrode is the smallest At this time, the heating water resistance is the smallest, in accordance with By manually adjusting the travel of the fixed water electrode fine-tuning rod, the distance between the fixed water electrode and the liquid-controlled water electrode is finely adjusted, thereby increasing the power P applied by the photovoltaic power generation to the heating water resistor. water The maximum power point of photovoltaic power generation with the maximum local irradiance. Equal, that is Where δ d S is the electrical conductivity of water. g To fix the area of ​​the water electrode, L n Let n be the relative distance between any point on the liquid-controlled water electrode and the fixed water electrode, where n∈[min,max]; The midpoint of the liquid-controlled water electrode connecting rod; This is the right end point of the liquid-controlled water electrode; This is the left end point of the liquid-controlled water electrode; Step 1.2.2, determining Push the hydraulic control water electrode by the metering plunger pump reversing valve for Step steps n n＝max = Step max Move left to the left end of the hydraulic control water electrode That is, the distance between the hydraulic control water electrode and the fixed water electrode is the largest At this time, the heating water resistance is the largest, according to And the typical photovoltaic maximum power point table, find the power P applied to the heating water resistance by the left movement of the hydraulic control water electrode water And the maximum power point of photovoltaic power generation corresponding to the smaller local irradiance ​​​ Wherein, S g is the area of the fixed water electrode; R w is the heating water resistance value; ΔR w is the displacement of the hydraulic control water electrode, which is one step Step1=Step n | n＝1 , corresponding to an increased or decreased heating water resistance; ΔL is the displacement length of the hydraulic control water electrode M w , which is also the unit step length of the driving hydraulic control water electrode distance; P water is the load power on the water resistance; Step n is the number of steps of the displacement of the hydraulic control water electrode driven by the reciprocating motion of the metering plunger pump, also known as the number of steps of the displacement of the hydraulic control water electrode; is the number of steps of the displacement of the hydraulic control water electrode Step n point photovoltaic power generation maximum power point; is the number of steps of the displacement of the hydraulic control water electrode Step n point photovoltaic power generation maximum power point voltage; is the number of steps of the displacement of the hydraulic control water electrode Step n point photovoltaic power generation maximum power point current.

9. The control method according to claim 8, characterized by, The step 1.3 specifically comprises: First, based on the input photovoltaic array parameters and irradiance, a table for quickly locking the maximum power points of segmented photovoltaic power generation under different illumination conditions is established; since the length ΔL of the displacement of the liquid-controlled water electrode per unit step is the maximum distance L between the fixed water electrode and the liquid-controlled water electrode. max Minimum distance L from the liquid-controlled water electrode min The difference, divided by the sum of the absolute values ​​of the maximum left and right displacement steps of the liquid-controlled water electrode, is 2Step. max ,Right now In order to achieve fast positioning of the maximum power point of photovoltaic power generation, the maximum step number 2Step max is quantized in units of 10, i.e. In the range of local maximum irradiance intensity photovoltaic power generation maximum power point And local smaller irradiance intensity photovoltaic power generation maximum power point Range, divided by the quantitative result Get fast lock different light photovoltaic power generation maximum power point segmentation, that is: And the photovoltaic maximum power point corresponding to the segmented end point: That is The photovoltaic power generation maximum power point value at each segment point is determined by table lookup method Including the number of steps Step0 = Step when the hydraulic control water electrode is in the middle position n | n＝0 The corresponding photovoltaic power generation maximum power point value Thus, the photovoltaic maximum power point difference of each adjacent section is constant α, that is: Where mp is the number of segments at the maximum power point of photovoltaic power generation; Step0 = Step n | n＝0 This is the step size when the liquid-controlled water electrode is in the middle position; The maximum power point value of photovoltaic power generation is the step size Step0 when the liquid-controlled water electrode is in the middle position. The maximum power point value of photovoltaic power generation is the maximum irradiance in the local area; ΔL is the distance of driving the liquid-controlled water electrode per unit step; Step n The number of reciprocating strokes of the plunger pump is also the number of steps in the displacement of the hydraulic control water electrode; Step is the number of steps for the displacement of the liquid-controlled water electrode. n The point of maximum photovoltaic power generation; Step is the number of steps for the displacement of the liquid-controlled water electrode. n The maximum power output of photovoltaic power generation at a given point and the voltage at that point; Step is the number of steps for the displacement of the liquid-controlled water electrode. n The maximum power of photovoltaic power generation at a point; α is a constant value for the difference in maximum power generation at each adjacent photovoltaic segment. For each segment point, n represents the point where the photovoltaic power generation reaches its maximum. m =1,2,3,…,mp; Take Step0 = Step n | n＝0 The heating water resistance between the liquid control water electrode and the fixed water electrode is R0, and the maximum step number of the right displacement of the liquid control water electrode is Step max = Step n | n＝max , the corresponding heating water resistance R w = R0-ΔR w × Step max ; The minimum number of steps of the liquid-controlled water electrode displacement to the right is Step1 = Step n | n＝1 , the corresponding heating water resistance R w = R0- ΔR w ; The maximum number of step for the left displacement of the liquid-controlled water electrode is -Step max = -Step n | n＝max The corresponding heating water resistance R w = R0-ΔR w ×(-Step max ) = R0+ΔR w ×Step max ; The minimum number of steps for the liquid-controlled water electrode to shift right is -Step1 = -Step n | n＝1 , the corresponding heating water resistance R w = R0 + ΔR w ; Thus, according to and The change of the number of steps of each liquid-controlled water electrode corresponds to the change of the heating water resistance, and one-to-one corresponds to the maximum power point of photovoltaic power generation in the local maximum and minimum irradiance range 10. The control method according to claim 9, characterized by The step 2 specifically comprises: The controller reads the photovoltaic power generation current I in real time. pv and photovoltaic power generation voltage U pv The photovoltaic power output P was calculated. pv Based on the output power P pv Compared with the previous moment's maximum photovoltaic power generation The difference is calculated at the points, that is: Step 2.1, when the reversing valve is in action, the hydraulic control water electrode is displaced to the right direction: When ΔP pv > 0, it indicates that the photovoltaic power generation power increases, and the reversing valve acts on the hydraulic control water electrode to displace to the right direction, thereby increasing the photovoltaic power generation output power P pv Divided by the maximum power point difference constant α of each adjacent section, that is: The divisor result is kept to one decimal place, and the remainder is judged according to the mod remainder function: mod(P pv ,α)≥0.5 wherein, is the maximum power point of photovoltaic power generation at the previous moment; Step n-1 is the maximum power point of photovoltaic power generation at the previous moment is the number of displacement steps of the liquid control water electrode; I pv is the current photovoltaic power generation current; U pv is the current photovoltaic power generation voltage; P pv is the current photovoltaic power generation output power; Step 2.1.1, if mod(P pv ,α)≥0.5, then according to the rounding function: Using the principle of rounding up to the nearest whole number, determine the maximum power point of photovoltaic power generation in a certain segment. And determine the maximum power point of photovoltaic power generation. Falling and Between these, the number of displacement steps of the liquid-controlled water electrode is obtained as Step. n =n m ×10, according to Step n =n m ×10 times the displacement step size of the liquid-controlled water electrode minus the maximum power point of photovoltaic power generation at the previous moment. Number of displacement steps for the liquid-controlled water electrode n-1 The increase or decrease in the displacement step size ΔStep of the liquid-controlled water electrode is obtained. n Each step, i.e., ΔStep n =10n m Step n-1 ; wherein, n m is the maximum power point of the photovoltaic power generation known for a certain segment The number of displacement steps of the liquid control water electrode, which is set in the initialization; L n is the relative distance between any point of the liquid control water electrode and the fixed water electrode, wherein n ∈ [min, max]; At this time, the controller controls the action of the metering plunger pump by ΔStep n steps to make the liquid control water electrode displace to the right, reducing the distance L between the liquid control water electrode and the fixed water electrode n , thereby reducing the resistance R of the heating water resistance w , quickly locking the maximum power point of the segmented photovoltaic power generation At the same time, the controller reads the photovoltaic power generation current I pv and voltage U pv in real time, calculates the photovoltaic power generation output power P pv , and performs step 3 fine photovoltaic power generation maximum power tracking control; Step 2.1.2: Use the modulo modulo function to determine mod(P) pv If α) < 0.5, then according to the floor function... Using the principle of rounding up to the nearest whole number, determine the maximum power point of photovoltaic power generation in a certain segment. And determine the maximum power point of photovoltaic power generation. Falling and Between these points, the displacement step size of the liquid-controlled water electrode is obtained, based on the Step... n =n m ×10 times the displacement steps of the liquid-controlled water electrode minus the maximum power point of photovoltaic power generation at the previous moment. Number of displacement steps for the liquid-controlled water electrode n-1 The change in displacement ΔStep of the liquid-controlled water electrode was obtained. n Each step, i.e., ΔStep n =10n m Step n-1 , where n m The point where the maximum photovoltaic power generation is known for a certain segment. The number of displacement steps for the hydraulically controlled water electrode is set during initialization; at this time, the controller adjusts the displacement based on the increment / decrement ΔStep. n Each step controls the displacement of the liquid-controlled water electrode, reducing the distance L between the liquid-controlled water electrode and the fixed water electrode. n This reduces the resistance R of the heating water. w Quickly pinpoint the maximum power point of segmented photovoltaic power generation Simultaneously, the controller reads the photovoltaic power generation current I in real time. pv and voltage U pv The photovoltaic power output P was calculated. pv Step 3 involves refining the maximum power point tracking control of photovoltaic power generation. wherein, n is an integer; m Segmented Photovoltaic Power Generation Maximum Power Point; n is an integer; m Segmented Photovoltaic Power Generation Maximum Power Point; n is an integer; n Segmented Photovoltaic Power Generation Maximum Power Point; ΔStep n n is an integer; Step 2.2, when ΔP pv <0, the photovoltaic power is reduced, indicating that the reversing valve acts on the hydraulic control water electrode to displace to the left direction, and the current photovoltaic power P pv is divided by the maximum power point difference constant α of each adjacent section, that is, The result of the divisor is kept to one decimal place, and mod(P pv , α) ≥ 0.5 is judged according to the mod remainder function. Step 2.2.1: Use the modulo modulo function to determine mod(P) pv If α)≥0.5, then according to the floor function... Using the principle of rounding up to the nearest whole number, determine the maximum power point of photovoltaic power generation in a certain segment. And determine the maximum power point of photovoltaic power generation. Falling and Between these, we obtain Step n =n m ×10 liquid-controlled water electrode displacement steps, based on the photovoltaic power generation maximum power point at the previous moment. Number of displacement steps for the liquid-controlled water electrode n-1 Subtract Step n =n m The displacement increment / decrement ΔStep of the liquid-controlled water electrode is obtained by multiplying the displacement step by 10. n Each step, i.e., ΔStep n =Step n-1 -10n m , where n m The point where the maximum photovoltaic power generation is known for a certain segment. The number of displacement steps for the hydraulically controlled water electrode is set during initialization; at this time, the controller adjusts the displacement based on the increment / decrement ΔStep. n Each step controls the displacement step of the liquid-controlled water electrode, increasing the distance L between the liquid-controlled water electrode and the fixed water electrode. n This increases the resistance R of the heating water resistor. w Quickly pinpoint the maximum power point of segmented photovoltaic power generation Simultaneously, the controller reads the photovoltaic power generation current I in real time. pv and voltage U pv The photovoltaic power output P was calculated. pv Step 3 involves refining the maximum power point tracking control of photovoltaic power generation. Step 2.2.2, if mod(P pv ,α)<0.5, then determine the certain segment photovoltaic maximum power point according to the rounding function and the principle of rounding off 5 for 4, and determine the certain segment photovoltaic maximum power point falls between and , thus obtaining Step n =n m ×10 liquid control water electrode displacement steps, according to the number of liquid control water electrode displacement steps Step n-1 of the photovoltaic maximum power point at the previous moment, subtract Step n =n m ×10 liquid control water electrode displacement steps, to obtain the liquid control water electrode displacement increment ΔStep n number of steps, i.e. ΔStep n =Step n-1 -10n m ; wherein n m is the number of liquid control water electrode displacement steps of the known photovoltaic maximum power point in a certain segment, which is set in initialization; at this time the controller controls the number of liquid control water electrode displacement steps according to the increment ΔStep n number of steps, increases the distance L n between the liquid control water electrode and the fixed water electrode, thereby increasing the resistance R w of the heating water resistance, and quickly locks the segment photovoltaic maximum power point At the same time, the controller reads the photovoltaic current I pv and voltage U pv in real time, calculates the photovoltaic output power P pv , and performs step 3 fine photovoltaic maximum power tracking control.

11. The control method according to claim 10, characterized by, The step 3 specifically comprises: Step 2 quickly identifies the section with the maximum power output of the photovoltaic power generation, and the controller reads the photovoltaic power generation current I in real time. pv and voltage U pv The photovoltaic power output P was calculated. pv and the maximum power point of segmented photovoltaic power generation Compare and judge separately or Step 3.

1. Determine ΔP according to formula (20) pv when ≥ 0, the photovoltaic power is increased, and the segmented known photovoltaic maximum power point is compare, determine when: Step 3.1.1: Determine mod(P) based on the mod modulo function. pv If α)≥0.5, then according to the floor function... And the principle of rounding up or down. Step A, controller according to the previous time increment ΔStep n-1 one step minus a disturbance step, control the hydraulic water electrode displacement step, change the resistance R of the heating water resistance w , the current increment step is ΔStep n = ΔStep n-1 -1; at the same time, the controller continues to read the photovoltaic power generation current I pv and voltage U pv , the output power of photovoltaic power generation is calculated and compared with the photovoltaic power generation power of the previous time ; Wherein when means that the reversing valve acts on the hydraulic control water electrode to displace to the right, and the increment / decrement ΔStep n is positive, according to R w = R0- ΔR w × Step max changes the resistance R of the heating water resistance w ; when means that the reversing valve acts on the hydraulic control water electrode to displace to the left, and the increment / decrement ΔStep n is negative, according to R w = R0- ΔR w × (-Step max ) = R0+ ΔR w × Step max changes the resistance R of the heating water resistance w ; When the judgment is repeated by the controller; When judging , the distance of the current hydraulic control water electrode relative to the fixed water electrode is determined, and the generated heating water resistance R w , adapted to the maximum power point of photovoltaic power generation wherein, is the current photovoltaic power output; is the photovoltaic power output at the previous time; ΔStep n-1 is the displacement increment step of the previous hydraulic control water electrode; ΔStep n is the current displacement increment step of the hydraulic control water electrode; Step 3.1.2, if mod(P pv ,α) < 0.5, then according to the rounding function and the principle of rounding off 5, there is: Step B, the controller increases or decreases the amount ΔStep according to the previous time n-1 one step plus a disturbance step, the hydraulic control water electrode displacement, change the value of the heating water resistance R w , the current increase or decrease step is ΔStep n n-1 +1; at the same time, the controller continues to read the photovoltaic power generation current I pv and voltage U pv , the output power of photovoltaic power generation is calculated and compared with the photovoltaic power generation power at the previous time ;​ wherein, when means that the reversing valve acts on the hydraulic control water electrode to displace to the right, and the increment / decrement ΔStep n is a positive number, and the resistance R of the heating water resistance is changed according to formula (18) w ; when means that the reversing valve acts on the hydraulic control water electrode to displace to the left, and the increment / decrement ΔStep n is a negative number, and the resistance R of the heating water resistance is changed according to formula (19) w ; The controller repeats step B when it judges that the battery is not fully charged. When judging , the distance of the current hydraulic control water electrode relative to the fixed water electrode is determined, and the generated heating water resistance R w , adapted to the maximum power point of photovoltaic power generation Step 3.2, depending on ΔP is determined pv <0: the photovoltaic power is reduced, and the segment known photovoltaic maximum power point is divided comparison, determination : Step 3.2.

1. Determine mod(P pv ,α)≥0.5, then according to the rounding function and the principle of rounding off 5, we have: Step A, the controller according to the previous time increment ΔStep n-1 one step minus a disturbance step, control the hydraulic water electrode displacement step, change the resistance value R of the heating water resistance w At this time, the current increment step is ΔStep n = ΔStep n-1 -1; At the same time the controller continues to read the photovoltaic power generation current I pv and voltage U pv , calculates the photovoltaic power generation output power and compares it with the photovoltaic power generation power of the previous moment; When , it means that the reversing valve acting liquid controls the water electrode to move to the right, and the increment / decrement ΔStep n is positive, according to R w = R0- ΔR w × Step max , the resistance value R of the heating water resistance is changed w ; when , it means that the reversing valve acting liquid controls the water electrode to move to the left, and the increment / decrement ΔStep n is negative, according to R w = R0- ΔR w × (-Step max ) = R0+ ΔR w × Step max , the resistance value R of the heating water resistance is changed w ; When the determination is made, the controller proceeds to step A; When judging , the distance of the current hydraulic control water electrode relative to the fixed water electrode is determined, and the generated heating water resistance R w , adapted to the maximum power point of photovoltaic power generation wherein, is the current photovoltaic power output; is the photovoltaic power output at the previous time; ΔStep n-1 is the previous hydraulic control water electrode increment / decrement step size; ΔStep n is the current hydraulic control water electrode increment / decrement step size; Step 3.2.

2. If mod(P pv ,α) < 0.5, then according to the rounding function and the principle of rounding off 5, we have: Step B, the controller according to the previous time liquid control water electrode increase or decrease amount ΔStep n-1 one step plus a perturbation step, control the displacement of the liquid control water electrode, change the resistance value R of the heating water resistance w At this time, the current liquid control water electrode increase or decrease step is ΔStep n n-1 +1; at the same time, the controller continues to read the photovoltaic power generation current I pv and voltage U pv , calculate the photovoltaic power generation output power and compare it with the photovoltaic power generation power of the previous time​ When , it means that the reversing valve acting liquid controls the water electrode to move to the right, and the increment / decrement ΔStep n is positive, and according to R w = R0- ΔR w × Step max , the resistance value R of the heating water resistance is changed w ; when , it means that the reversing valve acting liquid controls the water electrode to move to the left, and the increment / decrement ΔStep n is negative, and according to R w = R0- ΔR w × (-Step max ) = R0+ ΔR w × Step max , the resistance value R of the heating water resistance is changed w ; When the determination is made, the controller proceeds to step B; When judging , the distance of the current hydraulic control water electrode relative to the fixed water electrode is determined, and according to R w = R0- ΔR w × (-Step max ) = R0+ ΔR w × Step max The generated heating water resistance R w is adapted to the maximum power point of photovoltaic power generation

Images