Photovoltaic solar power generation system control method

Abstract

A control method of a solar hierarchical voltage reduction controller belongs to roof photovoltaics and household photovoltaics, and comprises the following steps of: dividing a plurality of output circuits into priority levels, respectively adopting different voltage boosting and reducing methods for each circuit, limiting the load power of the circuit with low priority level when necessary, adjusting the power of each circuit at any time, selectively connecting a battery and connecting a mains supply; and the output power of the mains supply can reach more than 90% of the solar photovoltaic power generation power and is stable for a long time.

Description

Technical Field

[0001] The present invention relates to the field of solar photovoltaic power generation technology, and in particular to a photovoltaic power generation system, a photovoltaic controller and a method for controlling load power of photovoltaic power generation in multiple ways. Background Art

[0002] Existing solar photovoltaic controllers, PWM controllers, MPPT controllers and other controllers generally cannot operate without batteries, or have low efficiency when operated without batteries, and cannot directly adapt to household appliance loads, etc. Multiple products need to cooperate with each other to be used at home, and cannot be used alone or are not easy to use alone.

[0003] Take JinkoSolar's high-efficiency monocrystalline silicon single-sided N-type half-cell solar module 430-455w as an example. The best operating voltage is the highest power operating voltage at 1000 light intensity. The maximum power point is the maximum power point at different light intensities. The maximum power point of the solar cell is shown in Figure 1. Fig.11 Under different light intensities, the current changes greatly, the voltage changes very little, the maximum power point voltage is very close to the optimal working voltage, and the error between the optimal working voltage and the maximum power point voltage under different light intensities is very small.

[0004] Off-grid energy storage power generation or off-grid power generation is suitable for use in RVs or when there is no city electricity, but not for home, household and rooftop photovoltaics. Because there are no dedicated photovoltaic energy storage batteries, the energy storage cost is higher than the electricity price, and the maintenance cost remains high. It cannot be applied to daily electricity needs such as ordinary household, household and rooftop photovoltaics.

[0005] High-frequency inverter, generally high-frequency inverter will boost the battery voltage from about 12v-96v to 340v and then convert it into sinusoidal direct current through push-pull circuit or other circuits, and use independent products with batteries and photovoltaic controllers to form an off-grid photovoltaic system to meet daily electricity needs. Summary of the invention

[0006] The purpose of the present invention is to solve the problem of high-efficiency use of household rooftop photovoltaics in existing household or commercial rooftop photovoltaic systems, to solve the problem of operating at a higher efficiency after being separated from the energy storage system, to reduce the construction cost after being separated from the battery, and at the same time to improve the efficiency of photovoltaic power generation as much as possible and reduce the occurrence of power abandonment.

[0007] The control method of the solar energy graded buck controller is a rooftop photovoltaic system, which belongs to the household photovoltaic system. It divides the multi-channel output circuits into priority levels, and adopts different buck-boost methods for each circuit. When necessary, it limits the load power of the circuit with low priority, adjusts the power of each circuit at all times, does not connect the battery, and cooperates with the mains. The output power can reach more than 95% of the solar photovoltaic power generation power and is relatively stable for a long time.

[0008] The present invention overcomes the dependence of the photovoltaic controller on batteries, while improving the efficiency to near the theoretical maximum value and reducing the instability of photovoltaic power generation to a local area, so that the local output end with high priority obtains stable power output, reduces the influence of instability, and thus obtains a certain stability.

[0009] The solar buck-boost controller of the present invention is suitable for household or home use, and home photovoltaic is mainly suitable for household appliances and corporate electricity use. The solar buck-boost controller adopts synchronous buck-boost classification at the front and rear ends, limits the output power according to the priority, and limits the power of the low-priority power load in real time, thereby ensuring the stability of the high-priority power circuit.

[0010] Output priority classification

[0011] The control method of the solar energy graded buck controller prioritizes the output circuit, and the levels from high to low are: T0, T1, T2, ....

[0012] Output priority classification is very important for the control method of solar buck-boost controller. In order to ensure the stability of the entire circuit, in theory, the more classifications there are, the easier it is to control the output and the easier it is to ensure the stability of the entire circuit. However, in practice, there may be no classification for a single channel, two levels for two channels, or three levels for three channels, and 4-10 levels are rare, and rarely appear in these aspects of home use.

[0013] like Figure 2 As shown, 6, 7, 8 and ... are all the levels, and 9, 10, 11 ... are omitted here. All levels have a corresponding core power component, and this core power component (2) is linked to the control part (1), and the output end of the level is also connected to the load power port. Figures (3), (4), (5), (7), (8) and (9) all have multiple levels, many of which are omitted, and Figure 5 Figure 6 Figure 8 Fig. 9 There are two levels and three output terminals. It is normal that there is one more output terminal than the level. Figure 5 and Figure 8 There are three stages: front, middle and back. There is one more middle stage than other circuits, and also one more core power component. Each stage is equivalent to two core power components, and electric energy needs to pass through two core power components.

[0014] High priority can be called T0 level, medium priority is called T1, low priority is called T2, and enterprise or commercial users may have t3, t4, etc.

[0015] Priority loads The priority of household electricity is set by the user. Each user has different habits, and the final settings vary greatly. However, generally, electrical appliances can be installed. Computers, air conditioners, refrigerators and washing machines are considered high priority, rice cookers, electric fans, ventilation equipment, backup battery charging, freezers, mosquito repellent facilities, fish tank water pumps, etc. are considered medium priority, and water storage heaters, solar hydrogen production, etc. are considered low priority.

[0016] In daily use, if there are too many high-priority loads, the low-priority will be restricted, and then the medium-priority will be restricted. When necessary, the mains will be connected to maintain stability. The high-priority directly affects the user experience of using home appliances. Generally, its stability is fully guaranteed. The medium priority is second to the high priority and stronger than the low priority.

[0017] Low priority, also known as T2 level electricity, is the core of the high efficiency of the solar step-up and step-down controller control method. The water storage electric heater uses the high specific heat capacity of water to store the excess electricity generated during the day in water. As long as there is more water, a water tank with a length, width and height of 1 meter can store 1 ton of water, and 1 ton of water requires 116 degrees of electricity from 0 degrees to 100 degrees. A household can use multiple small water tanks, 500-liter water tanks, to be placed in multiple rooms. Each water tank can be simply modified to add a heating rod to become a water storage water heater. When no one is at home during the day, you can cover it with a thick cloth, and remove the cloth when you get off work or when someone is at home. Since the water tank is relatively large, it will continue to dissipate heat to maintain the heating effect inside the house in winter.

[0018] Solar hydrogen production and solar methanol production are a technical direction of current scientific research, a trend of low-carbon and environmental protection in the future, and a future direction for high efficiency of solar buck-boost controller control methods. Actively increasing high-power products that can use T2-level electricity is the core path to ensure high efficiency of solar buck-boost controller control methods, and enriching T2-level electrical appliances is the key to affecting the high efficiency of solar buck-boost controller control methods.

[0019] Modify various household appliances, such as living room air conditioners and other electrical appliances. After the modification, the appliances can directly use T2 electricity. By adding physical methods such as batteries or capacitors inside the appliances, and by modifying the software or control methods, many situations where T2 electricity cannot be used can be turned into using secondary electricity. At the same time, the ability to use normal electricity is also retained. This can also indirectly improve the use of T2 electricity. For example, in summer, the living room air conditioner can also have a certain working capacity when there are no guests. The application of T2 electricity can be increased, the waste of electricity can be reduced, and the efficiency of solar energy utilization can be improved.

[0020] There are relatively few electrical appliances that can be adapted to T2-level electricity now, but this is a question of which comes first, the chicken or the egg. Only after a usable household photovoltaic product is developed can a product that adapts to this household photovoltaic product be born. At present, the water storage electric heater is a way to implement the solar buck-boost controller control method. Only when it is full load, saturation and overloaded, the solar buck-boost controller control method can have a relatively high efficiency. At the same time, without the assistance of the battery, it is a way to achieve high-efficiency operation without the battery. In other words, photovoltaic power generation and batteries are not integrated, they are originally two unrelated things. In reality, most of the cost of many photovoltaic systems is batteries, which leads to excessively high operating and maintenance costs of photovoltaic systems, and the income output is less than the investment, resulting in no one paying attention to off-grid photovoltaics.

[0021] Core power components and circuit front and rear stages

[0022] The front end of the core power component is the input end, and the back end is the output end. The core power component is the part directly controlled by the control part. It is a component that can be controlled to affect the entire circuit. The core power component is composed of multiple components, generally power tubes, capacitors, inductors, diodes, transformers, etc., as shown in the figure. Figure 2 The component (2) represents the core power component part, and the core power component is connected to the control part (1) and the input and output ends. Figure 3 is a full magnetic circuit, where (q1), transformer, (ejg) and (d1) are a core power module component. Figure 4 is a semi-magnetic circuit, where (q1), (e), (g1) and (f) are a core power module component. Figure 5 It is a non-magnetic circuit, in which (q0) and (d1) are a core power module, and the front stage has two core power components in parallel, in which q1 and d3 are a core power component. Figure 3 Figure 4 Figure 5 The figure also includes other core power components. Flyback, forward, push-pull, full-bridge, half-bridge, bauk, boost and other switching power supply buck-boost circuits all contain core power components, which can be controlled and have a certain adjustment range, and are connected to the power input terminal and the load.

[0023] The core power component of the solar buck-boost controller control method, the circuit in front of the core power component is the front-stage circuit, and the circuit behind the core power component is the back-stage circuit. At the same time, the solar buck-boost controller control method will be divided into multiple priorities, each priority will be divided into a back-stage circuit, and in some cases there will be an extra back-stage circuit output terminal. During work, the front stage is connected to the solar photovoltaic panel, and the back stage is connected to the power output terminal and the electrical appliances. The voltage and power of the front and back stages change in real time, and the front stage is shared, while the back stage is controlled separately. When necessary, the output power of the back stage can be limited to keep the overall stability of the entire solar photovoltaic system.

[0024] And the front and back intermediate, such as Figure 5 and 8 There are three stages in the figure, namely front, middle and back. The middle stage is the neutral line which may be grounded, and the solar front stage is at the bottom of the figure. In a 330-volt photovoltaic power generation system, the negative pole of the front stage circuit may vary between 0 volts and negative 200+ volts. When it is idling, the negative value of the negative pole of the front stage will reach the maximum, and when it is fully loaded, saturated and overloaded, the negative pole is close to 0 volts. The circuit control end adjusts the voltage and power of the circuit to achieve the abandonment of the power generated by the solar photovoltaic panel of the front stage circuit, and the abandoned power will not enter the core part of the entire power generation system.

[0025] The non-magnetic, semi-magnetic and full-magnetic working modes are determined by whether the core power component has magnetic force converted into electrical energy, and the electrical energy is converted into magnetic energy when passing through the core power component, and then converted back into electrical energy.

[0026] 1. No magnetic force means that when electrical energy passes through the core power component, it passes through the core power component by switching on and off the electric current. There is no conversion of magnetic energy, nor is there any conversion of magnetic energy into electrical energy. Almost all of it is not converted and has nothing to do with magnetic energy.

[0027] 2. Semi-magnetic force will not be converted under certain conditions, and will pass through as electrical energy. According to the load and power generation conditions, the control part will be adjusted in real time. In some cases, it will work with a certain magnetic force and a certain amount of electrical energy will flow through. There are two situations of semi-magnetic force, one is that electrical energy passes through, and the other is that part of the electrical energy passes through and part is converted into magnetic energy, and the magnetic energy is converted into electrical energy to power the load. The last one is a small amount or no electrical energy, and almost all magnetic energy passes through.

[0028] 3. Full magnetic force means that all the electrical energy of the power part is converted into magnetic energy, and then the magnetic energy is converted into electrical energy again. All the electrical power is converted into magnetic energy and magnetic energy into electrical energy and transmitted to the back end.

[0029] The solar buck-boost controller adopts the synchronous buck-boost grading at the front and rear ends. The front and rear of the synchronous buck-boost at the front and rear ends can be divided into three parts when necessary, such as front, middle and back. Figure 5 Figure 8 Fig. 9 The circuit can be considered to be divided into three parts: front, middle and back.

[0030] The front and rear classification is based on the core power component circuits such as switch tubes or transformers. The circuits before or after are called front circuits or rear circuits. The front and rear ends are synchronously stepped up and down. The voltage of the front and rear circuits is unstable in real time during operation. The voltage will change at any time. The control circuit handles power abandonment, no load, light load, full load, saturation, and overload according to user requirements, and reacts to the voltages of the front and rear ends in real time. It also detects the power generation and power consumption of the circuit, and adjusts in real time to ensure the stability of the power supply while outputting power close to the theoretical maximum efficiency value to meet user requirements.

[0031] Control methods for no-load, light-load, full-load, saturation and overload The control method of solar buck-boost controller is to control power abandonment, no-load, light load, full load, saturation and overload. Power abandonment means that when the user consumes little electricity and the power generation is useless, and there is no possibility of reuse, the user is forced to abandon the power. Photovoltaic power generation is affected by the weather, and the power generation power changes in real time. When the load power is less than the full load power, when the load power becomes smaller, the control part reduces the proportion of the upgrade voltage, and the output end of the back end begins to reduce the power. Then after feedback to the front end, the front end will continue to increase the front end voltage because of the control to reduce the power of the back end. The control part detects that the front end continues to increase the voltage, and continues to control the back end to reduce the power... until it is adjusted in place, adjusted to a certain range, and can reach stability in a reasonable range. At the same time, after the front end voltage increases, the current becomes smaller. For photovoltaic panels, the power generation power decreases under high voltage, and the power becomes smaller under high voltage, thereby indirectly abandoning power. By reducing the power of the back end circuit, the front end photovoltaic naturally increases the voltage to abandon the unused power.

[0032] No-load, light-load and power abandonment are similar. No-load means no load. In this case, the back-end power is almost zero. Only the solar buck-boost controller controls its own power consumption. The voltage of the front-end photovoltaic panel is almost equal to the open-circuit voltage. The power at both ends is almost zero, so the whole circuit is in a stable state. The light-load situation is not much different. The voltage of the front-end photovoltaic panel will drop to a position between the open-circuit voltage and the optimal voltage. At this time, the power of the photovoltaic panel is relatively low, but this is when the whole circuit is relatively stable and it is an ideal state. The back-end power is also relatively low. The power at both ends is equal. The circuit enters a stable state and does not require too much external support or limit the output of some low-priority circuits. It can fully guarantee that all priority circuits are fully loaded and meet the requirements of all priority circuits.

[0033] When the load power is almost 0 watts, after going from light load to no load, the voltage of the photovoltaic panel group continues to rise in the no-load state, reaching 90%-99.999% of the open-circuit voltage value. If the photovoltaic power generation power is relatively low, not higher than 5kw, the photovoltaic power generation system itself has a high power consumption. After going from light load to no load, the voltage of the photovoltaic panel group continues to rise, reaching 85%-99% of the open-circuit voltage value.

[0034] Full load, saturation and overload are extreme, but also necessary conditions for the theoretical limit efficiency. Otherwise, the theoretical limit efficiency cannot be achieved. It is necessary to actively create such working conditions to allow solar photovoltaic panels to work at full load as much as possible, reduce power abandonment, and reduce the waste of electricity. Full load, saturation and overload refer to the entire power generation system. Generally, they refer to the full load and saturation of the photovoltaic panel. Overload means that even if the photovoltaic power generation reaches the theoretical maximum value, it cannot meet the load requirements. At this time, it is considered overloaded. The total power of the load electrical appliances exceeds the photovoltaic input power. Even in the super-power mode, overload means entering the super-power mode. Even if the photovoltaic works at 100%, it cannot meet the load requirements. At this time, the solar photovoltaic power generation glass can work continuously at nearly 100%. Under such circumstances, the economic benefits can reach the maximum value, and there is no need to use batteries to improve efficiency. The efficiency is completely determined by the load. The solar buck-boost controller controls multiple outputs. When the load is too much, it is connected to the load through multiple outputs. The output is graded according to priority. The output power with high priority is stable, and the output with low priority can also meet part of the demand. In this case, the solar buck-boost controller control method can continuously approach the theoretical limit power output to maximize the efficiency of photovoltaic system power generation and electricity use. Since no battery is required, the cost is also reasonable.

[0035] In the case of full load, saturation and overload, when the load changes from light load to full load, all the levels will be involved in the work when the load changes from light load to full load, and when the load changes from full load to full load, the control part will detect all the level circuits and input voltages, and if the output power becomes higher, it will adjust the level buck-boost ratio until the stable state is reached. When the buck-boost ratio reaches the limit, and the photovoltaic panel is not suitable for further adjustment at the optimal working voltage, it will enter the saturation state at this time. If it stabilizes at this place, it is the saturation state, and it is close to the limit efficiency of solar photovoltaic panels. In actual situations, this saturation is difficult to maintain. Photovoltaic glass is affected by weather or other factors, and the maximum power generation value is always changing, so overload can occur at any time. Therefore, full load, saturation and overload are in the state of switching with each other. In this state, to maintain the power generation efficiency, it is necessary to manage the output in a priority level. For loads with low priority, their power can be appropriately limited to reduce their power. When overload occurs, the output terminals and connected loads with high priority are fully protected to ensure their stability. It is necessary to introduce AC power to supplement the circuit to ensure the stability of the high priority circuit. The medium priority circuit will be determined according to the situation. If the medium priority circuit cannot maintain stability even when the low priority circuit has been turned off, the AC power will be introduced to supplement the circuit or limit its power according to the situation. In this way, even if the load is several times that of the solar photovoltaic glass, the circuit can be fully loaded to meet the stable needs of some electrical appliances.

[0036] The power consumption of users is also unstable. Sometimes they use a lot of electricity, and sometimes no one uses electricity. After the peak period of power consumption of users has passed, the medium and low priority loads can also use electricity to work during the low peak period. In this way, regardless of whether it is a peak period or a low peak period, it is fully loaded. It may not be able to meet the power demand of low priority in a short time, but in the long run, it can meet some low priority power requirements, and can meet all requirements of the high priority output load. In this way, the instability of solar photovoltaic panel power generation and the instability of user power consumption are limited, so that the impact of instability is reduced, and some important electrical appliances are still very stable. In this way, the solar buck-boost controller can meet the basic requirements of users, and can work continuously at full load, saturation and overload, so that the solar buck-boost controller control method can work continuously at the full load limit of solar panel power generation efficiency, and maximize efficiency benefits.

[0037] Step up or step down

[0038] Solar buck-boost controller control method, about the actual application of boost control, when users install solar photovoltaic glass, they are affected by the site and space, and there is not enough space to install enough photovoltaic glass. At this time, the number of photovoltaic glass is small and the voltage is relatively low. At this time, it is suitable for boost control. The solar buck-boost controller control method adopts boost operation when the voltage is relatively low, and the boost operation is generally done by full magnetic or semi-magnetic core power components.

[0039] Similarly, when the site is relatively large, the number of solar photovoltaic panels is relatively large, and the voltage after series connection is relatively high, it is more suitable to use step-down control at this time, and step-down control is more suitable for semi-magnetic and non-magnetic core power components to work. Generally, the voltage emitted by the photovoltaic power generation group is lower than 300v, and the boost control is used, and the full magnetic or semi-magnetic core power components are used to work, while the step-down control is used above 300v, and generally the full magnetic or semi-magnetic core power components are used to work. Doing so is easier to approach the theoretical limit of power output in practical applications, and it is also more reasonable.

[0040] Solar photovoltaic power generation is an unstable power source. In daily life, the open circuit power supply voltage of solar photovoltaic is relatively high, far higher than the working voltage. For example, Jinko Energy's 440w solar panel has an open circuit voltage of more than 50 volts, while the optimal working voltage is about 33 volts. As the power used increases, the output power of photovoltaic glass also increases. From more than 50 volts, the current is very small, and the power is the lowest at this time. When the load is too high, the current becomes larger and the voltage becomes smaller. When the voltage drops to the optimal working voltage, the current also increases to a suitable position. At this time, the theoretical power is the highest. In practice, weather and other factors must be considered. When the output voltage of photovoltaic glass reaches the optimal working voltage of about 33v, the photovoltaic glass has reached the vicinity of the optimal working voltage, and the power can no longer be increased. The power reaches the maximum value. The control part adjusts the voltage reduction ratio in time by checking the output voltage, from about 1.6:1 to 1:1 times. When the control part adjusts the voltage reduction ratio to 1:1, the power of the entire voltage reduction circuit also reaches the best and highest state. At this time, the output voltage of the power generation system of a single photovoltaic glass is 33v, and when the photovoltaic panels are connected in series to reach 10 solar panels, the voltage of the best output power of the entire system is 330v. At this time, using the semi-magnetic or non-magnetic solar voltage reduction control method, you can adjust the voltage reduction ratio to stabilize the output of 330v. The output voltage of 330v is equivalent to the power of about 230v of AC power, which can directly power electrical appliances with low power requirements, such as electric heaters, electric fans, electric blankets, electric hot pots, electric kettles, and even home computers.

[0041] In actual use, when it is impossible or inappropriate to use multiple solar photovoltaic panels due to space, site and other reasons, it is necessary to use a single or fewer panels to build a power generation system. In this case, full magnetic or semi-magnetic force must be used to boost the voltage by adjusting the boost ratio. For two solar panels with an optimal working voltage of 33v, the control part adjusts the voltage reduction ratio in time by checking the output voltage, with a maximum boost ratio of about 5 times, and boosts the voltage to about 320v. 320v is directly suitable for some household appliances to use electricity.

[0042] other

[0043] The control unit of the present invention can be a simple voltage regulator diode, chip or digital chip, such as Figure 6 In the figure, (w1) and (w2) are two voltage regulator diodes with different voltages. There are other components involved in the specific circuit. When necessary, the voltage regulator diode will be used to detect the circuit. At critical times, 220VAC will be rectified and then incorporated into the voltage regulator. Figure 7 That is, the digital chip controls the signal amplifying chip for indirect control, while other pictures are generally controlled by ordinary analog chips. The control part of the solar buck-boost controller can be either a simple voltage regulator diode or analog chip and digital chip control.

[0044] T2 level load safety energy storage heating water tank, the water tank can be of various shapes, even built into the wall, cabinet, bed, equipment, etc., can also be placed inside or outside the house with the support of insulation materials, and even the insulation materials can be removed when necessary to enhance heat dissipation when necessary. The safety energy storage water tank is connected to the ground wire, which can be guided to the ground in the event of leakage, and the water tank heating rod is added to the structure and placed at the top of the water tank, so that it can quickly break away from the water level line when a certain height of water leaks, reducing the problem of ground water and water tank water being charged when leaking, and reducing safety hazards.

[0045] Relative stability means that the power demand of important electrical equipment is met as much as possible, and the T0 proportion of important electrical equipment is preferably less than 50% of the total power generation power. When necessary, the AC power can be connected to supplement the T0 circuit to fully guarantee the power demand of important electrical equipment. At the same time, when there is a power shortage, the power of secondary electrical equipment such as electric heaters, electric hot pots, electric ovens, etc. is limited to ensure high-priority stability while achieving relative stability as a whole.

[0046] The solar buck-boost controller controls the system itself with power, usually using a flyback switch. To reduce costs, the resistor-capacitor method can be used to step down the system control system and components. The resistor-capacitor method has low efficiency and high power consumption, but the photovoltaic power generation system itself has abundant power, so there are many ways to step down the photovoltaic system itself, and the power consumption itself varies greatly. In the case of no-load, such as Figure 5As shown in the figure, when the load is unloaded, the actual power required by the load is 0 watts. If the photovoltaic system itself has high power consumption and the photovoltaic panel group GFB does not generate much power when unloaded, the photovoltaic panel group GFB voltage value will be a certain distance away from the open circuit voltage value.

[0047] Smart home, controlled by solar buck-boost controller, connects the load to the network through wifi or the Internet, coordinates the use of smart home appliances in real time, automatically reduces the power of smart home appliances when necessary, and digitally controls all loads through the network, using less electricity and providing more services.

[0048] like Figure 7 , a control method for a solar buck-boost controller, wherein (11) a digital detection circuit, (1) a control part and (10) a digital conversion circuit, the digital control part is connected to other smart home appliances through wifi, and the power consumption of the home appliances is understood in real time through the network. By delaying the start or reducing the power, the power is reduced in real time when the load power is too high, thereby reducing the peak power consumption and using more power during the off-peak period. The digital control part can understand the weather conditions through the network, and if necessary, through big data, it can predict the exact time when dark clouds block the sun, and advance or postpone the peak power consumption.

[0049] The optimal operating voltage of solar photovoltaic panels refers to the voltage value at the maximum power point of a single piece or a whole group of solar photovoltaic glass. Of course, there will be differences under different light intensities, but the current mainstream generally does not differ much. The middle value or average value of the voltage can be measured multiple times, which may vary depending on the habits of the installer.

[0050] When the input power is insufficient and the load is overloaded.

[0051] If necessary, AC can be added to any circuit, and ZL can be rectified to connect to the circuit when the power is insufficient.

[0052] If necessary, DC, battery, JHNBQ, simplified inverter can be added to any circuit to make the circuit function more perfect. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is a schematic diagram of the control structure of the solar buck-boost controller Figure 2 The schematic diagram of the control structure of the solar buck-boost controller is shown in Figure 1. Figure 3 A schematic diagram of the full magnetic field of the solar buck-boost controller Figure 4 A schematic diagram of a solar buck controller with semi-magnetic force Figure 5A schematic diagram showing the non-magnetic solar step-down controller Figure 6 A schematic diagram of the solar buck-boost controller without magnetic force and simplified control part Figure 7 The control part of the solar buck-boost controller is shown as a digital schematic diagram Figure 8 A schematic diagram of a solar buck controller with semi-magnetic force Fig. 9 A schematic diagram of a solar buck controller with semi-magnetic force Fig.10 A schematic diagram of a solar boost controller with semi-magnetic force Fig.11 Power curve of Jinko Energy solar photovoltaic modules Fig.12 The core power components of the solar boost controller adopt non-magnetic and semi-magnetic Fig.13 The core power components of the solar boost controller adopt non-magnetic and full magnetic Fig.14 Simplified diagram of push-pull inverter Figure numerals: 1, control part; 2, core power component; 3, photovoltaic power input; 4, battery chain end; 5, AC power input; 6, output end 1; 7, output end 2; 8, output end 3; 10, digital conversion element; 11, digital signal detection end; GFB, photovoltaic panel; Q00, power switch; Q1, power switch; Q2, power switch; Q3, power switch; Q4, power switch; F1, load 1; F2, load 2; F3, load 3; F4, load 4; F5, load 5; AC, AC power input; ZL, rectifier; D1, capacitor 1; D2, capacitor 2; D3, capacitor 3; EJG, diode; DC, battery; JHNBQ, simplified inverter; E, diode; G1, inductor 1; G2, inductor 2; W1, Zener diode 1; W2, Zener diode 2; Fig.14 The simplified diagram of the push-pull partial rear-stage inverter does not include the high-frequency inverter boost front-stage circuit, and only requires the simplified board of the high-frequency inverter rear-stage drive circuit. DETAILED DESCRIPTION

[0056] Household photovoltaic rooftop photovoltaics are generally installed on the top of the house and used in series. When solar energy shines on the photovoltaic glass, it generates electricity and is connected to photovoltaic control equipment or concentrators and other equipment through wires. It is prioritized and output in multiple channels to electrical equipment, and AC power is introduced to supplement it when necessary.

[0057] When there are relatively few solar panels, such as 2, the best working voltage is 66V, and the open circuit voltage is about 100V. According to Jinko New Energy's small photovoltaic panels, the actual best working voltage is about 66V, and household appliances are equivalent to 220V 311V DC, so it is necessary to increase the front end of the photovoltaic panel voltage to about 320V. Through the circuit of the full magnetic energy conversion core power component or the semi-magnetic core power component, the power is boosted to about 320V and output in priority levels. There are multiple loads in the chain. When the power is insufficient, the control unit control part can limit the power of some loads to stabilize the circuit, maximize the output power of the photovoltaic system with fewer cells, and maximize efficiency without batteries.

[0058] As shown Figure 3 and Fig.10 It is a full magnetic core power component and a semi-magnetic core power component, both of which can achieve a voltage boost from 66V to 320V. Figure 3 Take the boost control principle as an example, Figure 3 To simplify the circuit and make it easier to view, many components are omitted. Figure 3 In the circuit, the capacitor (D3) is charged, and the voltage starts to rise at the same time. Then the power supply supplies power to the control part. When the control part is ready, it starts to control the power switches (Q1) and (Q2). (Q1) and (Q2) are turned on respectively. After turning on, current flows through the transformer. At the same time, the primary coil of the transformer is charged. Later, (Q1) and (Q2) are disconnected respectively. The coil energy storage will release energy and conduct backward. Then the magnetic energy will be induced to the secondary coil of the transformer through the transformer coil. The secondary coil current flows out and flows from the transformer to the (EJG) diode. After flowing through the diode, it charges (D1) and (D2) in the two subsequent circuits respectively, and flows to the load for power supply. At the same time, the control part (1) detects the voltage and power at the front and rear ends, and adjusts the on and off time and frequency of (Q1) and (Q2) in real time to ensure the voltage and power at the front and rear ends. When the load is large, the control part (1) can adjust (Q1) or (Q2), which generally limits the low priority circuit, such as limiting the (Q2) power switch, not giving the opportunity to pass, so that it can be turned off. Figure 2 In the lower part of the circuit, the subsequent loads will be powered off after a short time. When necessary, the AC power can be controlled to flow into the rectifier ZL rectifier bridge and flow into the circuit for supplement. Through various methods, the circuit stability is guaranteed, the power stability is achieved, and the solar energy efficiency is maximized.

[0059] When there are more solar panels, such as 20, there are multiple options.

[0060] Solution 1: Non-magnetic solution, 10 photovoltaic panels in series with an optimal working voltage of 330V, 2 series in parallel.

[0061] like Figure 5This is a simplified diagram, with auxiliary components omitted. Figure 5 The core power components shown are non-magnetic. The core power components have power switches and capacitors, which are connected to the control part, photovoltaic panels and loads respectively. When the photovoltaic panel group (GFB) is connected to Figure 5 In the circuit, the capacitors (D2), (D1) and (D3) are charged first, and then the power supply supplies power to the (1) control part, and then the (1) control part turns on Q0, Q1 and Q2 respectively. Then the (1) control part detects the load power, photovoltaic panel power and voltage respectively. When the whole system is under full load, saturation or overload, the (1) control part will make Q0 fully turned on, making Q0 similar to a wire. At this time, the negative pole of the photovoltaic panel group (GFB) is very close to 0v, and the whole solar buck-boost controller will operate at the highest efficiency. When the entire system is in a no-load state, (1) the control part will make (Q0) almost in the disconnected state, and only in the conductive state for a very short time, which is almost equal to non-conductive. At this time, the negative pole of the photovoltaic panel group (GFB) will have a negative voltage close to more than 200V, and the positive pole of the photovoltaic panel group (GFB) will have a positive voltage of 330V. At this time, the total voltage of the photovoltaic panel group GFB is very close to the open-circuit voltage of more than 500V, and the output power of the photovoltaic panel is almost zero. At this time, it is in a completely no-load state, which is equivalent to reducing the open-circuit voltage of the photovoltaic panel group GFB to 330V in disguise, achieving voltage reduction while discarding most of the power.

[0062] (Q1) and (Q2) control the power of (F2) and (F3) respectively. Through square wave DC, capacitors and inductors can be added to the load circuit when necessary to make the current and voltage smoother. (Q0) is directly connected to the circuit. The (Q0) load has no power limit. When the load power is too large, it can be supplemented by the mains. By limiting the low priority power, the whole system is stable. When necessary, the (DC) battery and (JHNBQ) simplified inverter can be connected.

[0063] Solution 2: Semi-magnetic solution, 20 photovoltaic panels connected in series with an optimal working voltage of 660V.

[0064] Simplified as shown Fig.12 As shown, the core power components use non-magnetic and semi-magnetic forces, including power switches, (EJG0 diodes, capacitors and inductors, which are linked to the control part, photovoltaic panels and loads respectively. When the photovoltaic panel group (GFB) is linked to Fig.12In the circuit, the circuit immediately generates voltage, and then the power supply supplies power to the control part (1), and then (1) the control part turns on (Q1) and (Q2) respectively, and then (1) the control part detects the load power, photovoltaic panel power and voltage respectively. Among them, (F1) load is about 320V after voltage reduction, while F2 load is about 660V, and the output voltage of the two paths differs by about 2 times. Among them, (F1) uses the same principle as the buck buck circuit to reduce voltage, but the difference is that the voltage at the input end of the photovoltaic panel group (GFB) also changes, so the voltage reduction control is more difficult. The control part (1) must simultaneously detect and control the power and voltage at the front and rear ends, adjust the conduction time and switching frequency of (Q1) and (Q2) at any time, and limit the power of the output end with low priority at any time. It is necessary to connect the battery and AC power to supplement it, maintain the stability of the high priority of the entire circuit, and at the same time, when the circuit is rich, all power is transmitted to the low priority circuit. The circuit below this circuit is low priority, and it is also a square wave current circuit, which limits the load power through the PWM square wave.

[0065] Solution 3: non-magnetic part, fully magnetic part, 20 photovoltaic panels connected in series, the optimal working voltage is 660v.

[0066] If simplified Fig.13 As shown, the core power components use non-magnetic and full-magnetic forces, including power switches, (EJG) diodes, transformers and capacitors, which are connected to the control part, photovoltaic panels and loads respectively. Fig.13 In the circuit, the circuit immediately generates voltage to charge (D3), and then the power supply supplies power to the control part (1), and then (1) the control part turns on (Q1) and (Q2) respectively, and then (1) the control part detects the load power, photovoltaic panel power and voltage respectively. Among them, the F1 load is about 320v after voltage reduction, and the (F2) load is about 660v, and the two output voltages differ by about 2 times. Among them, (F1) is similar to the flyback switching power supply to reduce the voltage, and the flyback buck circuit is used to reduce the voltage. The difference is that the voltage at the input end of the photovoltaic panel group (GFB) is also changing, so the voltage reduction control is more difficult. The control part (1) must simultaneously detect and control the power and voltage at the front and rear ends, adjust the conduction time and switching frequency of (Q1) and (Q2) at any time, and limit the power of the output end with low priority at any time. It is necessary to connect the battery and AC power to supplement it to maintain the stability of the high priority of the entire circuit. At the same time, when the circuit is rich, all power is transmitted to the low priority circuit. The circuit below this circuit is of low priority and is also a square wave current circuit that limits the load power through a PWM square wave.

[0067] Plan 4: Household appliances include: computer 100w, light bulb 100w, electric hot pot 2000w, storage water heater 5000w.

[0068] A set of 10 500w33v photovoltaic panels in series are installed on the roof. The theoretical optimal power of the photovoltaic panels is 5000w. In winter, when no one is at home, the 5kw of electricity generated by the photovoltaic panels is all consumed by the T2 water storage electric heater. When the input is insufficient, its power is limited to ensure that the input end outputs at the maximum power. After get off work at noon, you need to cook. The electric hot pot is plugged into the output end of t1. When the electric hot pot starts to cook, 2kw will further limit the power of the t2 water storage electric heater to less than 3000w. At this time, the electric hot pot can just be fully opened at 2kw. Suddenly, the clouds cover the sunlight. At this time, the power generation power drops sharply, and there is only 1800w left. At this time, the t2 power will be limited to almost 0. At this time, it still cannot meet the t1 electric hot pot, so the t1 power will be limited. The electric hot pot drops to 1800w, but it can still cook, but the cooking heating speed drops by 10%. The weather changes from cloudy to overcast, and the photovoltaic power is increased to 2500w. At this time, the power of the electric hot pot is not limited and can be fully loaded with 2000w. The power of the t2 water storage electric heater is limited to 500w. The computer and the light are turned on. The computer and the light are both T0 level 100w. Their stability will be given priority. No matter how much photovoltaic power is generated, the t0 level power supply will be given priority. When necessary, it will be connected to the mains to ensure its stability.

[0069] Plan 5: New energy vehicle slow charging 4kw, water storage electric heater 10kw, electric hot pot 2kw, air conditioner 1kw*2, refrigerator 100w, freezer 100w, photovoltaic solar panel 10kw.

[0070] A set of 500w33v photovoltaic panels with 10 panels in series and 2 panels in parallel with a total of 10kw is installed on the roof. Theoretically, 18,000 kWh of electricity can be generated 365 days a year. During the installation, the high demand in winter and the large photovoltaic angle may cause power loss. During the day when no one is at home, except for the 200w power consumption of the refrigerator and freezer, almost all the generated power will be used to drive the 10kw water storage electric heater. About 50 degrees of electricity will be distributed every day. If it is not used at that time, it will be used for heating and stored in water. Covering it with a thick blanket can reduce the adjustment of fan heat. When needed, removing the blanket can appropriately increase heat dissipation and enhance winter heating.

[0071] When the output power exceeds 10kw, even if the photovoltaic power generation enters the full power state, it is impossible to meet the electricity demand. At this time, limiting t2 will then limit the power of t1 to maintain the power balance of input and output. This is an overload state for the photovoltaic system. At this time, the system efficiency can reach close to the maximum 100%. The full load situation determines the income of photovoltaics. The more full load scenarios, the higher the income. The centralized heating time is from November 15th to March 15th, about 120 days in 4 months. In spring, summer and autumn, if the water storage heating system is not used, the efficiency will decrease. The efficiency can be indirectly improved by slow charging of new energy vehicles and air conditioning in summer. In theory, the entire heating period will consume 6,000 degrees of electricity, calculated based on 120 days. For the remaining 245 days of the year, ordinary single workers consume about 4,000 degrees of electricity, and the abandoned electricity is 7-8k degrees of electricity. Theoretically, a single-income family or a dual-income family with elderly people using the household appliances during the day and having new energy vehicles with slow charging can consume about 10,000 kWh of electricity from a 10kw power generation system each year, and discard 7-8k kWh of electricity. A 10kw solar photovoltaic glass now costs only about 7,000 yuan, and it can be recovered in about 2 years, so the overall benefit is still considerable.

[0072] Solution 6: For users in Hainan Province or with small rooftop areas, 5kw photovoltaic panels can be used in a network. By connecting the solar panels of two independent photovoltaic systems of two independent households in parallel, the two households can share a 10kw solar photovoltaic panel. In this way, the two households can take turns to charge their new energy vehicles, and at the same time have extra electricity to use for air conditioning and other purposes.

[0073] Networking: Since the input voltage of photovoltaic power generation systems of the same model is not much different, they can be used in parallel. They can be used by multiple users in parallel, not limited to two. By sharing photovoltaic panels, costs can be reduced and efficiency can be improved.

[0074] Solution 7: Balcony photovoltaic household photovoltaic, 2 pieces of Jinko 500w solar panels are connected in series, and the photovoltaic group with the best working voltage of 66v can be obtained. Figure 3 or Fig.10 Similar boost core components can increase the voltage to around 320V to drive household appliances. Batteries can be properly connected and treated as a backup power source. Once there is a power outage at home, it can be used as an emergency power source to charge mobile phones or power refrigerators to ensure necessary daily electricity.

[0075] Balcony photovoltaics can also cooperate with photovoltaic manufacturers to produce photovoltaic glass with low power and high voltage. Only a few pieces can reach the optimal working voltage of 300-400v. By stepping up or down the voltage, it can also be used as a backup power supply.

[0076] The above is only a specific implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for controlling a photovoltaic power generation system, wherein the positive input terminal and the negative input terminal of the photovoltaic controller are respectively connected to the positive electrode and the negative electrode of the photovoltaic panel, and the positive output terminal and the negative output terminal of the photovoltaic controller are respectively connected to the positive electrode and the negative electrode of the load circuit; characterized in that: The photovoltaic controller uses boost, buck or duty cycle to achieve boost and buck, to control the output voltage and power, to achieve a relative balance between the power of the photovoltaic panel and the power of the electrical load, thereby maintaining relative stability. It is a control method for photovoltaic power generation systems.

2. A photovoltaic power generation system control method as claimed in claim 1, wherein the core power component uses one of the three methods of boosting, bucking or duty cycle to perform work, characterized in that: The photovoltaic power generation system control method adopts multiple outputs, each output has at least one core power component, and each core power component is controllable.

3. The photovoltaic control method according to claim 2, characterized in that: As described above, if the photovoltaic panel group outputs the best working voltage, the best working voltage is different, and the core power components of different models of products use different boost, buck or duty cycles. If the best working voltage of the panel group is lower than 250v, the core power component will use the boost method. If the best working voltage of the panel group is higher than 280v, the buck method or the duty cycle method will be used.

4. The photovoltaic control method according to claim 1, characterized in that: Each output will control and limit the power of one or more outputs in real time according to the input power of the photovoltaic panel and the load power output, according to the output priority level, so as to keep the power of the entire system relatively stable.

5. The photovoltaic control method according to claim 4, when the power generation is insufficient, is characterized in that: The highest priority circuit will be connected to the mains power input circuit, while the low priority and medium priority circuits will not be connected to the mains power input.

6. The photovoltaic control method according to claim 1, characterized in that: In the circuit described above, from light load to no-load, when the load power is almost 0 watts, it is in no-load state, the voltage of the photovoltaic panel group continues to increase, and the voltage of the photovoltaic panel group can reach 92%-99.999% of the open-circuit voltage value, but the voltage required by the photovoltaic system does not increase.

7. The photovoltaic control method according to claim 1, characterized in that: All the multiple outputs except T0, T1, T2, T3..., all work in the form of about 320V DC or pulse DC output to drive the load.

8. A water storage and heating water tank that can be adapted to a photovoltaic power generation system, characterized in that: It can be adapted to priority levels T1, T2, T3..., and used in conjunction with a photovoltaic power generation system for heating. The more water stored, the stronger the thermal insulation capacity. At the same time, the heating device in the water is an electric heating device, and this device is located in the water and near the top of the water tank. Once a leak occurs, when the water in the water tank leaks out to a certain height, the water is separated from the heating device, which can reduce the possibility of leakage of the heating device being transmitted to the ground.

9. The photovoltaic control method according to claim 1, characterized in that: The voltage and power of the solar photovoltaic panels change in real time, the power required at the output end also changes, and the electricity is used as it is, otherwise it will be discarded.

10. The photovoltaic control method according to claim 1, characterized in that: The control part can be either digitally controlled or analog chip controlled.

Images