CN102355165B - Photovoltaic power generation device with global maximum power output function - Google Patents

Abstract

The invention discloses a photovoltaic power generation device with a global maximum power output function, which includes a photovoltaic cell array and a main converter. The photovoltaic cell array includes a plurality of series-connected photovoltaic cells. converter, the input end of the auxiliary converter is connected to the DC bus of the photovoltaic cell array, the power regulation array includes a power regulation unit corresponding to the photovoltaic cells one by one, the power regulation unit is connected in parallel with the corresponding photovoltaic cell, and the power regulation unit The input terminal is connected to the output terminal of the auxiliary converter. The invention has simple structure and low cost, can automatically compensate the reduced output current under partial shadow conditions, and realize the maximum power output of a single photovoltaic cell.

Description

Photovoltaic power generation device with global maximum power output function

technical field

The invention relates to the field of photovoltaic power generation, in particular to a photovoltaic power generation device with a global maximum power output function.

Background technique

With the gradual depletion of fossil fuels, the energy issue has become a major issue of increasing concern to the world, and it is also a frontier scientific and technological issue of strategic significance that our country has vigorously researched and urgently needs to be solved. At the same time, problems such as environmental degradation and climate warming have prompted countries to vigorously develop clean, safe, and low-carbon renewable energy technologies, such as wind energy, solar energy, tidal energy, geothermal energy, fuel cells, and hybrid technologies. The next came into being. Among the utilization of many renewable energy sources, the solar photovoltaic power generation system is the second largest power generation method after the wind power generation system in installed capacity, and has broad application prospects. Research on solar photovoltaic power generation systems has always been a research hotspot in the academic circles. Scholars from the fields of materials, construction, power systems, electronics, and control have devoted themselves to research in the field of photovoltaic power generation, promoting its development and application. As an interdisciplinary subject spanning the three major fields of electricity, electronics, and control, power electronics technology is the core supporting technology for power conversion and control, and plays a decisive role in the field of renewable energy including solar photovoltaic power generation systems. At present, the main research directions of power electronics technology in the field of solar photovoltaic power generation include grid-connected inverter technology, maximum power tracking, power quality control, islanding detection, etc. The sub-problem of maximum power tracking includes the design of the power regulation unit of photovoltaic cells.

V_PVcell＝V_D-R_SI_PV；图3是光伏电池模块输出特性曲线。光伏电池的输出特性由材料的物理特性以及光照、温度、湿度等环境因素决定。受光照强度变化而产生的输出特性变化尤为明显；图4是不同光照强度下的光伏电池输出特性曲线，由图3的特性曲线可看出：短路电流随光照强度增加而增加，最大输出功率随光照强度增加而增加。鉴于此，光伏电池最大功率跟踪问题的研究就成为提升能量转换效率的最重要的问题。所谓的最大功率点(Maximum Power Point，MPP)即在一定的太阳辐照度和环境温度下，光伏电池运行在最大输出功率状态，而最大功率点跟踪(Maximum Power Point Tracking，MPP)即为充分利用光伏电池，实时调整光伏电池的负载电阻，使得光伏电池运行始终工作在最大功率点附近的过程。实际应用中，光伏电池往往不是单独使用的，而是多块光伏电池模块串、并联后形成光伏阵列，作为整体对外供电。每一个串联支路的支路电流必须是相同的，此时若各光伏电池模块特性不一，串联支路电流将被最小的光伏模块电流限制住，使得光伏阵列整体不能发挥最大作用。对于串联结构的光伏电池而言，局部阴影是一个很现实的问题，即光照被环境中的其他物体遮挡，导致光伏阵列各光伏模块接收的光照强度不同。此时各模块特性产生明显的离散型，特性曲线如图5和图6所示，功率-电压曲线出现多个极值点。当前的软、硬件措施均无法解决局部阴影条件下光伏阵列最大功率输出问题。As shown in FIG. 1 , a photovoltaic cell array of an existing photovoltaic power generation device generally includes a plurality of photovoltaic cells connected in series. As we all know, the physical characteristics of photovoltaic cells are determined by semiconductor materials, and its basic working principle is the photovoltaic effect, that is, when a certain energy of light irradiates a photovoltaic cell, the semiconductor material absorbs energy and undergoes electronic transitions, and the distribution of carriers that can conduct current inside it Changes in state and concentration result in electromotive forces and currents. Figure 2 is the equivalent circuit of the photovoltaic cell. According to the physical characteristics of the photovoltaic cell and its equivalent circuit, the mathematical model of the photovoltaic cell can be established, as shown in the following formula:

V _PVcell =V _D -R _{S IPV} ; Fig. 3 is the output characteristic curve of the photovoltaic cell module. The output characteristics of photovoltaic cells are determined by the physical properties of materials and environmental factors such as light, temperature, and humidity. The change of output characteristics caused by the change of light intensity is particularly obvious; Fig. 4 is the output characteristic curve of photovoltaic cells under different light intensities. From the characteristic curve of Fig. 3, it can be seen that the short-circuit current increases with the increase of light intensity, and the maximum output power increases with the increase of light intensity. increases with increasing light intensity. In view of this, the research on the maximum power tracking problem of photovoltaic cells has become the most important issue to improve the energy conversion efficiency. The so-called maximum power point (Maximum Power Point, MPP) means that under a certain solar irradiance and ambient temperature, the photovoltaic cell operates at the maximum output power state, and the maximum power point tracking (Maximum Power Point Tracking, MPP) is sufficient Using photovoltaic cells to adjust the load resistance of photovoltaic cells in real time, so that the photovoltaic cells always work near the maximum power point. In practical applications, photovoltaic cells are often not used alone, but multiple photovoltaic cell modules are connected in series and parallel to form a photovoltaic array, which supplies power to the outside world as a whole. The branch current of each series branch must be the same. At this time, if the characteristics of each photovoltaic cell module are different, the series branch current will be limited by the minimum photovoltaic module current, so that the photovoltaic array as a whole cannot play its maximum role. For photovoltaic cells with a series structure, partial shadowing is a very real problem, that is, the light is blocked by other objects in the environment, resulting in different light intensity received by each photovoltaic module of the photovoltaic array. At this time, the characteristics of each module are obviously discrete, and the characteristic curves are shown in Figure 5 and Figure 6, and there are multiple extreme points in the power-voltage curve. None of the current software and hardware measures can solve the problem of maximum power output of photovoltaic arrays under partial shadow conditions.

Contents of the invention

The technical problem to be solved by the present invention is to provide a photovoltaic power generation device with a global maximum power output function that has a simple structure, low cost, can automatically compensate for the reduced output current under partial shadow conditions, and realize the maximum power output of photovoltaic cells.

In order to solve the above technical problems, the technical solution adopted by the present invention is: a photovoltaic power generation device with a global maximum power output function, including a photovoltaic cell array and a main converter, and the photovoltaic cell array includes a plurality of photovoltaic cells connected in series , the photovoltaic power generation device also includes a power regulation array and an auxiliary converter, the input end of the auxiliary converter is connected to the DC bus of the photovoltaic cell array, and the power regulation array includes one-to-one correspondence with the photovoltaic cells A power adjustment unit, the power adjustment unit is connected in parallel with the corresponding photovoltaic cell, and the input end of the power adjustment unit is connected with the output end of the auxiliary converter.

As a further improvement of the above-mentioned technical scheme of the present invention:

The power conditioning unit includes an electronic power conversion circuit, a control module and a sampling unit, the input end of the electronic power conversion circuit is connected to the output end of the auxiliary converter, and the output end of the electronic power conversion circuit is connected to the corresponding photovoltaic cell The poles of the electronic power conversion circuit are connected in parallel, the control terminal of the electronic power conversion circuit is connected to the output terminal of the control module, the sampling unit includes an output current acquisition module, an output voltage acquisition module and a battery current acquisition module, and the output current acquisition module The input end is connected to an output end of the electronic power conversion circuit, the input end of the output voltage acquisition module is connected to the output end of the electronic power conversion circuit, and the input end of the battery current acquisition module is connected in series with the input end or output end of the photovoltaic cell terminal, the output terminal of the output current collection module, the output terminal of the output voltage collection module and the output terminal of the battery current collection module are respectively connected to the input terminal of the control module.

The electronic power conversion circuit includes a transformer, a switcher, a drive module and a rectification filter module, the input side of the transformer is connected in series with the switcher and connected with the output terminal of the auxiliary converter, and the control terminal of the switcher is driven by The module is connected to the output end of the control module, and the output side of the transformer is connected in parallel with the two poles of the corresponding photovoltaic cell through the rectification and filtering module.

The main converter includes a control drive unit, a boost module, a full-bridge inverter module and a voltage transformation output module, the input terminals of the boost module are respectively connected to the DC bus of the photovoltaic cell array, The input terminals of the variable module are respectively connected with the output terminals of the boost module and the DC bus of the photovoltaic cell array, the control terminals of the boost module and the full-bridge inverter module are respectively connected with the output terminals of the control drive unit, and the full-bridge The output terminal of the inverter module outputs electric energy through the voltage transformation output module.

A high-frequency ripple filtering module is provided between the full-bridge inverter module and the voltage transformation output module, and the high-frequency ripple filtering module includes an inductor and an inductor connected in series to an output end of the full-bridge inverter module Capacitors respectively connected to the two electrodes of the output terminal of the full-bridge inverter module.

The auxiliary converter includes an auxiliary control drive module, an auxiliary full-bridge inverter module, an auxiliary voltage transformation output module, and a rectifier module. The input end of the auxiliary full-bridge inverter module is connected to the DC bus of the photovoltaic cell array. The control end of the auxiliary full-bridge inverter module is connected to the output end of the auxiliary control drive module, and the output end of the auxiliary full-bridge inverter module is connected to the power adjustment unit through the auxiliary voltage transformation output module and the rectification module in sequence.

An auxiliary high-frequency ripple filtering module is provided between the output end of the rectifying module and the power adjustment unit, and the auxiliary high-frequency ripple filtering module includes an inductor connected in series to one output end of the rectifying module and connected to the rectifying module respectively. The capacitor connected to the two electrodes of the output terminal of the module.

The present invention has the following advantages:

1. The photovoltaic power generation device of the present invention includes a power regulation array and an auxiliary converter, the input end of the auxiliary converter is connected to the DC bus of the photovoltaic cell array, and the power regulation array includes power regulation units corresponding to the photovoltaic cells one by one , the power adjustment unit is connected in parallel with the corresponding photovoltaic cells, compensating the reduced output current of the photovoltaic cells under partial shading conditions, and realizing the maximum power output of the photovoltaic cells through the main converter. The characteristics are not uniform, especially in the case of partial shading, the automatic energy balance between each photovoltaic cell is realized to ensure the maximum power output of any photovoltaic cell under its own environmental conditions, so as to obtain the maximum power generation efficiency.

2. The input terminal of the power regulation unit is connected to the output terminal of the auxiliary converter. From the perspective of power transmission, the power output from the photovoltaic array is output to the power regulation bus through the auxiliary converter, and then returned to the photovoltaic array through the power regulation unit. Modules, thus forming a power closed-loop feedback mechanism, this energy closed-loop structure can quickly and evenly compensate the unbalanced photovoltaic modules according to the real-time output of the photovoltaic array, so as to achieve the maximum power output, this structure omits the traditional way of energy storage The structure eliminates the trouble of finding an external energy source, considering the response speed of the energy storage link, performance indicators, and service life. It has the advantages of compact structure, small size, convenient maintenance, and strong reliability. Moreover, since the system has designed a closed-loop feedback on the power output link, the power adjustment unit only needs to use a unidirectional DC-DC circuit instead of a complicated bidirectional DC-DC circuit, thereby simplifying the circuit design and reducing the system cost.

3. The control method of the present invention is flexible, and has good engineering operability, universal applicability and versatility. Under the premise of maintaining the original photovoltaic system structure, the user only needs to add a common auxiliary converter and connect a power adjustment unit in parallel to each photovoltaic cell to realize the above functions. The universality and versatility are also reflected in the fact that the use of the present invention is not limited by the number of photovoltaic arrays, spatial layout, etc., and is theoretically applicable to any number of photovoltaic arrays with any layout, plug and play, and the number is between Unlimited expansion within a reasonable range.

4. The present invention can reduce the grid-connected power generation cost of the photovoltaic system. On the basis of improving the energy conversion efficiency through the auxiliary converter and the power adjustment unit, it can indirectly reduce the cost of power generation and effectively reduce the grid-connected electricity price, so that the grid-connected power generation of the photovoltaic system becomes easier. more feasible.

5. The present invention can prolong the service life of photovoltaic cells. The unbalanced energy output not only limits the energy conversion efficiency of the photovoltaic cell, but also further reduces the service life of the unbalanced part of the photovoltaic cell module. Especially for the part of the photovoltaic cell array covered by partial shadows, if there are no effective protection measures, it may cause adverse effects such as current backflow and heat damage. After paralleling power electronic converter power modules and using advanced control algorithms, related concerns can be effectively avoided.

6. The invention can be transformed on the basis of the traditional photovoltaic power generation system, and the engineering installation is simple, the cost is low, and the use and later maintenance are convenient.

Description of drawings

FIG. 1 is a schematic diagram of a frame structure of an existing photovoltaic power generation device.

Figure 2 is the equivalent circuit of a photovoltaic cell.

Fig. 3 is the output characteristic curve of the photovoltaic cell module.

Fig. 4 is the output characteristic curve of the photovoltaic cell under different light intensities.

Fig. 5 is an output characteristic curve of a photovoltaic array under a partial shade condition.

Fig. 6 is another output characteristic curve of the photovoltaic array under partial shading conditions.

Fig. 7 is a schematic diagram of the frame structure of the embodiment of the present invention.

Fig. 8 is a schematic diagram of a frame structure of a power adjustment unit according to an embodiment of the present invention.

FIG. 9 is a schematic structural diagram of a circuit principle of a power adjustment unit according to an embodiment of the present invention.

Fig. 10 is a schematic diagram of the circuit principle structure of the main converter of the embodiment of the present invention.

Fig. 11 is a schematic diagram of the circuit principle structure of the auxiliary converter according to the embodiment of the present invention.

Legend: 1. Photovoltaic cell array; 11. Photovoltaic cell; 2. Main converter; 21. Control drive unit; 22. Boost module; 23. Full bridge inverter module; 24. Voltage transformation output module; 25 . High-frequency ripple filtering module; 3. Power adjustment array; 31. Power adjustment unit; 311. Electronic power conversion circuit; 312. Control module; 313. Output current acquisition module; 314. Output voltage acquisition module; 315. Battery Current acquisition module; 316, transformer; 317, switch; 318, drive module; 319, rectification and filtering module; 4, auxiliary converter; 41, auxiliary control drive module; 42, auxiliary full-bridge inverter module; 43, auxiliary Voltage transformation output module; 44. Rectification module; 45. Auxiliary high-frequency ripple filtering module.

Detailed ways

As shown in Figure 7, the photovoltaic power generation device with the global maximum power output function in the embodiment of the present invention includes a photovoltaic cell array 1 and a main converter 2, the photovoltaic cell array 1 includes a plurality of photovoltaic cells 11 connected in series, and the photovoltaic power generation device also It includes a power regulation array 3 and an auxiliary converter 4. The input end of the auxiliary converter 4 is connected to the DC bus of the photovoltaic cell array 1. The power regulation array 3 includes a power regulation unit 31 corresponding to the photovoltaic cell 11. The power regulation The unit 31 is connected in parallel with the corresponding photovoltaic cell 11 , and the input end of the power adjustment unit 31 is connected with the output end of the auxiliary converter 4 .

The power adjustment unit 31 of this embodiment is connected to the auxiliary converter 4 through the power adjustment bus. The power adjustment bus can be in the form of DC or AC. The power adjustment unit 31 has the output characteristic of a current source and is connected in parallel with the photovoltaic cell 11. For energy compensation, the power adjustment unit 31 extracts energy from the output DC bus of the photovoltaic array through the auxiliary converter 4, which is used for energy balance and compensation of photovoltaic cells. The power adjustment unit 31 performs distributed maximum power tracking with high real-time performance, which is The corresponding photovoltaic module compensates the electric energy to achieve the maximum power output of the module, the main converter 2 performs global maximum power tracking, and realizes the global maximum power output on the basis of the mechanism that the power adjustment unit 31 balances the unbalanced modules, even in the photovoltaic array When the characteristics of each photovoltaic module are not uniform, especially in the case of local shadows, the energy balance between each photovoltaic module can be realized automatically to ensure the maximum power output of any photovoltaic module under its own environmental conditions, so as to realize the global maximum power output of the photovoltaic array; and realize each At the same time as the maximum power output of a photovoltaic module and the global maximum power output of the photovoltaic array, the converter only processes the unbalanced part of the output power, which minimizes the energy loss caused by the power conversion link. In this embodiment, the photovoltaic cell 11 may be a monocrystalline silicon photovoltaic cell, a polycrystalline silicon photovoltaic cell or an amorphous silicon photovoltaic cell, and the output end of each photovoltaic cell is connected to the output end of the power adjustment unit 31 .

As shown in Figure 8, the power adjustment unit 31 includes an electronic power conversion circuit 311, a control module 312 and a sampling unit, the input terminal of the electronic power conversion circuit 311 is connected with the output terminal of the auxiliary converter 4, and the output terminal of the electronic power conversion circuit 311 terminals are connected in parallel with the two poles of the corresponding photovoltaic cell 11, the control terminal of the electronic power conversion circuit 311 is connected with the output terminal of the control module 312, and the sampling unit includes an output current acquisition module 313, an output voltage acquisition module 314 and a battery current acquisition module 315, output The input end of the current acquisition module 313 is connected to an output end of the electronic power conversion circuit 311, the input end of the output voltage acquisition module 314 is connected to the output end of the electronic power conversion circuit 311, and the input end of the battery current acquisition module 315 is connected to a photovoltaic cell in series The input end or output end of 11, the output end of the output current acquisition module 313, the output end of the output voltage acquisition module 314 and the output end of the battery current acquisition module 315 are respectively connected to the input end of the control module 312. The electronic power conversion circuit 311 is a DC/DC converter in which energy flows in one direction.

The electronic power conversion circuit 311 can adopt different circuit topologies such as flyback, forward, push-pull, half-bridge, and full-bridge. The control module 312 samples the output voltage and output current of the power regulation unit, as well as the output current of the corresponding photovoltaic cell, through The algorithm adjusts the output current so that the output power of the photovoltaic module connected in parallel with the power regulation unit reaches the maximum, or the net output power of the power regulation unit and the parallel connected photovoltaic module (that is, the output power of the photovoltaic module plus the output power of the power regulation unit minus the power regulation unit input power) to the maximum.

As shown in FIG. 9, the electronic power conversion circuit 311 includes a transformer 316, a switcher 317, a drive module 318 and a rectification filter module 319. The input side of the transformer 316 is connected in series with the switcher 317 and connected with the output end of the auxiliary converter 4. , the control end of the switch 317 is connected to the output end of the control module 312 through the drive module 318 , and the output side of the transformer 316 is connected in parallel with the two poles of the corresponding photovoltaic cell 11 through the rectification and filtering module 319 .

As shown in Figure 10, the main converter 2 includes a control drive unit 21, a boost module 22, a full-bridge inverter module 23 and a voltage transformation output module 24, and the input terminals of the boost module 22 are respectively connected to the photovoltaic cell array 1 The DC bus is connected, the input end of the full-bridge inverter module 23 is respectively connected with the output end of the boost module 22 and the DC bus of the photovoltaic cell array 1, and the control terminals of the boost module 22 and the full-bridge inverter module 23 are respectively connected with the control drive The output terminals of the unit 21 are connected, and the output terminal of the full-bridge inverter module 23 outputs electric energy through the voltage transformation output module 24 . The main converter 2 adopts a grid-connected inverter or an independent inverter or a DC/DC power supply with the maximum power tracking output function. The main converter is the only device that supplies electric energy to the outside in this system, and uses maximum power tracking internally. (MPPT) algorithm to obtain the maximum output power. The main converter 2 realizes the global maximum power point tracking of the photovoltaic array module, and the power regulation unit 31 realizes the maximum power point tracking and energy output of each photovoltaic cell. The global MPPT algorithm of the main converter 2 and the distributed power regulation unit 31 The MPPT algorithms operate independently and the control strategies cooperate with each other, so that each photovoltaic cell 11 works at the maximum power point, thereby realizing the global maximum power output. In this embodiment, the control driving unit 21 is composed of a controller U1, a driving circuit U2, and a driving circuit U3. The controller U1 adopts TMS320F2812 or TMS320F28035 of TI Company, the driving circuit U2 adopts IR2110 of IR Company, and the driving circuit U3 adopts MC34152 of ONSEMICONDUCTOR Company. The boost module 22 forms a boost circuit for L1, D1, and T5, which is used to boost the input voltage to a certain range. The full-bridge inverter module 23 constitutes a full-bridge inverter circuit for T1, T2, T3, and T4, and the voltage transformation output module 24 is a transformer Tx1. A high-frequency ripple filtering module 25 is arranged between the full-bridge inverter module 23 and the voltage transformation output module 24. The high-frequency ripple filtering module 25 includes an inductor L2 and The capacitor C2 connected to the two electrodes of the output end of the full-bridge inverter module 23 respectively. The current output by the full-bridge inverter module 23 filters high-frequency ripples through L2 and C2, and finally merges into the power grid through the transformer Tx1.

The auxiliary converter 4 is a DC/DC converter with unidirectional energy flow. As shown in Figure 11, the auxiliary converter 4 includes an auxiliary control drive module 41, an auxiliary full-bridge inverter module 42, an auxiliary voltage transformation output module 43 and a rectifier module 44, and the input terminal of the auxiliary full-bridge inverter module 42 is connected to the photovoltaic The DC bus of the battery array 1 is connected, the control end of the auxiliary full-bridge inverter module 42 is connected to the output end of the auxiliary control drive module 41, and the output end of the auxiliary full-bridge inverter module 42 passes through the auxiliary voltage transformation output module 43, rectifier Module 44 is connected to power conditioning unit 31 . The auxiliary converter 4 converts part of the energy output by the photovoltaic cell array 1 into low-voltage direct current or alternating current electric energy, so as to simplify the design of the power adjustment unit. The main circuit of the auxiliary converter 4 can adopt a unidirectional DC/DC circuit or a unidirectional DC/AC circuit, and the output voltage is kept constant. In this embodiment, the auxiliary control driving module 41 is composed of a driving circuit U1 and a controller U2, the controller U2 adopts TMS320F28035 of TI Company, the driving circuit U1 adopts IR Company IR2110 of IR Company, and the auxiliary full-bridge inverter module 42 is T1, T2, T3 , T4 form a full-bridge inverter circuit, the auxiliary voltage transformation output module 43 is implemented by a high-frequency transformer Lm, and the rectification module 44 is a full-wave rectification circuit composed of D1 and D2. An auxiliary high-frequency ripple filtering module 45 is provided between the output end of the rectifying module 44 and the power adjustment unit 31, and the auxiliary high-frequency ripple filtering module 45 includes an inductor L1 connected in series to an output end of the rectifying module 44 and connected to A capacitor C1 connected to two electrodes at the output end of the rectification module 44 . The current output by the auxiliary full-bridge inverter module 42 is isolated by the high-frequency transformer Lm, rectified by D1 and D2 and filtered by L1 and C1 to output a DC isolated power supply.

The above descriptions are only preferred implementations of the present invention, and the scope of protection of the present invention is not limited to the above-mentioned implementations. All technical solutions belonging to the principle of the present invention belong to the scope of protection of the present invention. For those skilled in the art, some improvements and modifications made without departing from the principles of the present invention should also be regarded as the protection scope of the present invention.

Claims (5)

1. A photovoltaic power generation device with a global maximum power output function, comprising a photovoltaic cell array (1) and a main converter (2), and the photovoltaic cell array (1) includes a plurality of series-connected photovoltaic cells (11) , characterized in that: the photovoltaic power generation device also includes a power regulation array (3) and an auxiliary converter (4), and the input end of the auxiliary converter (4) is connected to the DC bus of the photovoltaic cell array (1) , the power adjustment array (3) includes a power adjustment unit (31) corresponding to the photovoltaic cell (11) one by one, the power adjustment unit (31) is connected in parallel with the corresponding photovoltaic cell (11), and the power The input end of the regulating unit (31) is connected to the output end of the auxiliary converter (4); The power adjustment unit (31) includes an electronic power conversion circuit (311), a control module (312) and a sampling unit, and the input end of the electronic power conversion circuit (311) is connected to the output end of the auxiliary converter (4) , the output terminal of the electronic power conversion circuit (311) is connected in parallel with the two poles of the corresponding photovoltaic cell (11), the control terminal of the electronic power conversion circuit (311) is connected with the output terminal of the control module (312), The sampling unit includes an output current acquisition module (313), an output voltage acquisition module (314) and a battery current acquisition module (315), and the input terminal of the output current acquisition module (313) is connected to the electronic power conversion circuit (311) One output end is connected, the input end of the output voltage acquisition module (314) is connected to the output end of the electronic power conversion circuit (311), the input end of the battery current acquisition module (315) is connected in series with the photovoltaic cell (11) The input terminal or the output terminal, the output terminal of the output current collection module (313), the output terminal of the output voltage collection module (314) and the output terminal of the battery current collection module (315) are respectively connected with the control module (312) connected to the input; The electronic power conversion circuit (311) includes a transformer (316), a switch (317), a drive module (318) and a rectification and filtering module (319), and the input side of the transformer (316) is connected in series with the switch (317) connected to and connected to the output terminal of the auxiliary converter (4), the control terminal of the switch (317) is connected to the output terminal of the control module (312) through the drive module (318), and the transformer (316) The output side of the solar cell is connected in parallel with the two poles of the corresponding photovoltaic cell (11) through a rectification and filtering module (319). 2. The photovoltaic power generation device with global maximum power output function according to claim 1, characterized in that: the main converter (2) includes a control drive unit (21), a boost module (22), a full bridge An inverter module (23) and a voltage transformation output module (24), the input ends of the boost module (22) are respectively connected to the DC bus of the photovoltaic cell array (1), and the full-bridge inverter module (23) The input terminals of the boost module (22) and the DC bus of the photovoltaic cell array (1) are connected respectively, and the control terminals of the boost module (22) and the full-bridge inverter module (23) are respectively connected with the control drive The output ends of the units (21) are connected, and the output ends of the full-bridge inverter module (23) output electric energy through the voltage transformation output module (24). 3. The photovoltaic power generation device with the global maximum power output function according to claim 2, characterized in that: there is a high-frequency ripple between the full-bridge inverter module (23) and the voltage transformation output module (24) Ripple filtering module (25), the high-frequency ripple filtering module (25) includes an inductor connected in series to an output end of the full-bridge inverter module (23) and connected to the full-bridge inverter module (23) ) The capacitor connected to the two electrodes of the output terminal. 4. The photovoltaic power generation device with global maximum power output function according to claim 1, characterized in that: the auxiliary converter (4) includes an auxiliary control drive module (41), an auxiliary full-bridge inverter module (42 ), an auxiliary voltage transformation output module (43) and a rectifier module (44), the input end of the auxiliary full-bridge inverter module (42) is connected to the DC bus of the photovoltaic cell array (1), and the auxiliary full-bridge inverter The control end of the variable module (42) is connected to the output end of the auxiliary control drive module (41), and the output end of the auxiliary full-bridge inverter module (42) passes through the auxiliary voltage transformation output module (43), the rectification module ( 44) Connect with the power adjustment unit (31). 5. The photovoltaic power generation device with global maximum power output function according to claim 4, characterized in that: an auxiliary high-frequency ripple is provided between the output terminal of the rectification module (44) and the power adjustment unit (31) Filtering module (45), the auxiliary high-frequency ripple filtering module (45) includes an inductor connected in series to an output end of the rectification module (44) and a capacitor connected to two electrodes of the output end of the rectification module (44) respectively .

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