WO2013082857A1

WO2013082857A1 - Centralized-distributed hybrid new energy power generation system and maximum power point tracking control method

Info

Publication number: WO2013082857A1
Application number: PCT/CN2012/000588
Authority: WO
Inventors: 吴红飞; 高峰; 常东升; 邢岩
Original assignee: 上海康威特吉能源技术有限公司
Priority date: 2011-12-09
Filing date: 2012-05-02
Publication date: 2013-06-13
Also published as: CN103166239B; CN103166239A

Abstract

The present invention relates to the technical field of new energy power generation. A centralized-distributed hybrid new energy power generation system and a maximum power point tracking control method. The new energy power generation system consists of a plurality of distributed serially connected new energy power generation modules (100) and a centralized transformer (200). The new energy power generation module (100) consists of power generation equipment (101) and a direct current transformer (102). The maximum power point tracking control method comprises: the distributed power generation modules (100) and the centralized transformer (200) performing maximum power point tracking on the power generation equipment (101) at the same time, the new energy power generation modules (100) and the centralized transformer (200) performing maximum power point tracking on different parts of the output characteristic curve of the power generation module, respectively. The control method can enable the centralized transformer (200) and the power generation module (100) to work stably and reliably without communication present therebetween, the centralized transformer (200) automatically works in the optimal direct current bus voltage point, and the new energy power generation modules (100) at the same time enable each set of power generation equipment (101) to work at respective maximum power point, so that the system automatically implements the maximum power output.

Description

Centralized-distributed hybrid new energy power generation system and maximum power point tracking control method

The invention belongs to the field of new energy power generation technology, and particularly relates to a series module structure new energy power generation system and a corresponding centralized-distributed hybrid maximum power point tracking control method of the system, and the invention is particularly suitable for a photovoltaic power generation grid-connected power generation system and Thermoelectric power generation systems, etc. Background technique

The development and utilization of new energy generation technologies such as solar energy and thermal power are important measures to deal with the energy and environmental crisis. Due to the high cost of new energy power generation equipment and low energy conversion efficiency, the power generation cost is greatly increased, which limits the promotion and application of new energy power generation technology. The application background of the present invention will be described below by taking a solar photovoltaic power generation system as an example.

Photovoltaic grid-connected power generation is the most important way of solar power generation applications. According to statistics, the world exceeds

90% of photovoltaic power generation equipment installation capacity is grid-connected, because grid-connected applications have the advantages of low cost and maintenance-free compared to independent photovoltaic systems. According to the way of PV module's Maximum Power Point Tracking (MPPT), PV grid-connected power generation systems are divided into centralized and distributed types. The distributed MPPT system can ensure that each PV module works at its own maximum power point, and eliminates the voltage or current coupling existing when the components are directly connected in series and parallel, eliminating the inconsistency of the characteristics of the PV modules or the inconsistent environmental conditions. The problem of lower power generation, improved system power generation efficiency, and higher system reliability have attracted wide attention.

At present, photovoltaic grid-connected power generation systems based on distributed MPPT include: (1) AC modular system based on micro-inverter; (2) Photovoltaic grid-connected power generation system based on parallel connection of output side of high-voltage DC module; (3) Based on low-voltage DC Photovoltaic grid-connected power generation system connected in series on the output side of the module. Due to the low output power and low output voltage of PV modules, micro-inverters or high-voltage DC modules usually need to achieve high boost ratios by means of transformers or coupled inductors to meet grid voltage requirements, resulting in complex converter topology, reduced efficiency and reliability. Reduced sex and increased costs. In the distributed series photovoltaic grid-connected power generation system, the output side of a plurality of new energy power generation modules form a high-voltage direct current in series, and the DC-DC converter in the new energy power generation module does not need high boosting itself, so basic Buck, Boost or The Buck/Boost converter is implemented with high efficiency and high reliability. But basic Buck, The conversion efficiency of the Boost or Buck/Boost converter is related to the difference between the input and output voltages. The greater the difference between the input and output voltages, the lower the efficiency. In order to obtain the optimal power generation efficiency of the whole system, it is necessary to pass the grid-connected inverter in real time. Adjust the input side DC bus voltage to make the input and output voltage of the DC-DC converter in the new energy power generation module close. However, the grid-connected inverter cannot directly obtain the output voltage value of each new energy power generation module, and it is impossible to determine the appropriate input side DC bus voltage value. By adding all new energy power generation modules and grid-connected inverters to the communication system, the grid-connected inverter can obtain the output voltage of all DC modules, thus setting the appropriate DC bus voltage value, but the system cost is high, and the system Operation needs to rely on communication, and the reliability is poor. Summary of the invention

The invention provides a concentrated-distributed hybrid new energy power generation system for the problems of high cost and low energy conversion efficiency of the existing new energy power generation system, and also provides a concentration of the distributed series modular new energy power generation system - Distributed hybrid maximum power point tracking control method. The invention combines the centralized maximum power tracking control of the centralized converter with the distributed maximum power tracking control of the new energy power generation module, so that the centralized converter automatically sets the optimal input side DC bus voltage value to improve the new energy source. The system efficiency of the power generation system achieves the goal of increasing power generation.

In order to achieve the above object, the present invention adopts the following technical solutions:

A centralized-distributed hybrid new energy power generation system comprising at least one DC module string and a centralized converter, wherein the output terminals of all DC module strings are connected in parallel to form a high voltage DC bus and connected to the input of the centralized converter The DC module string includes a plurality of new energy power generation modules, and the output ends of the plurality of new energy power generation modules are connected in series to form a DC module group; the new energy power generation module includes a new energy power generation device and a DC-DC converter. The output of the new energy power generation device is connected to the input end of the DC-DC converter, and the output end of the DC-DC converter is the output end of the new energy DC module.

In a preferred embodiment of the power generation system described above, the new energy power generation device may be a photovoltaic component, a thermal battery.

Further, the DC-DC converter in the new energy power generation module is a buck converter or a buck-boost converter.

Further, the centralized converter may be a DC-DC converter or a grid-connected inverter. When the centralized converter is a DC-DC converter, the output of the centralized converter may be connected to an electrical load or stored. The pool is connected. When the centralized converter is a grid-connected inverter, the output of the centralized converter is connected to the grid. In view of the above new energy power generation system, the present invention provides a centralized-distributed hybrid maximum power point tracking control method in which a DC-DC converter in a new energy power generation module is only connected to the DC-DC converter. The new energy power generation equipment performs maximum power tracking, and the centralized converter performs maximum power tracking for all new energy power generation equipment at the same time.

In a preferred embodiment of the above control method, when the DC-DC converter performs maximum power tracking on the new energy power generation device and the input voltage of the DC-DC converter is equal to the maximum power point voltage of the new energy power generation device (C/W, DC- The maximum output voltage of the DC converter is equal to the maximum power point voltage of the new energy power generation module and less than the open circuit voltage (U _oc ) of the new energy power generation module. The DC-DC converter can use any maximum power point tracking strategy to realize new energy generation. The maximum power tracking of the module, and the centralized converter uses the following control strategy to achieve maximum power tracking of all new energy generation modules:

(1) The centralized converter changes the input side bus voltage (t/^:) and simultaneously detects the input power before and after the centralized converter changes the bus voltage;

(2) If the input power becomes smaller after increasing the bus voltage value (C/^), reduce the bus voltage value (U _Bus ). If the input power becomes larger after increasing the bus voltage value (1⁄4 _s ), continue to increase the bus. Voltage value

(u _Bus y,

(3) If the input power becomes smaller after reducing the bus voltage value (1⁄4„ _s ), increase the bus voltage value (U _Bus ). If the input power becomes larger after reducing the bus voltage value (1⁄2„ _s ), continue to decrease. Small bus voltage value (U _Bus );

(4) If the input power is constant after reducing the bus voltage value, increase the bus voltage value (U _Bus ). If the input power is unchanged after increasing the bus voltage value (1⁄4„ _s ), continue to increase the bus voltage value in the above control. In another preferred embodiment of the method, when the DC-DC converter performs maximum power tracking on the new energy generation module and the input voltage of the DC-DC converter is equal to the maximum power point voltage of the new energy generation module (i/Mm, DC-DC) The lowest output (i/. _TO „) voltage of the converter is less than or equal to the maximum power point (i/Mw) voltage of the new energy generation module and greater than 0, and the highest output voltage of the DC-DC converter (ί/.„«„ ) Larger than the open circuit voltage of the new energy power generation module ( _c ), the DC-DC converter can use any maximum power point tracking strategy to achieve maximum power tracking of the new energy power generation module, and the centralized converter uses the following control strategy to achieve all new energy sources. The maximum power of the power generation module Trace:

(1) The centralized converter changes the input side bus voltage (^/^), and simultaneously detects the input power before and after the centralized converter changes the bus voltage;

(2) If the input power becomes smaller after increasing the bus voltage value (1⁄4„ _s ), reduce the bus voltage value (U _Bus ). If the input power becomes larger after increasing the bus voltage value, continue to increase the bus voltage value (U _Bus) );

(3) If the input power becomes smaller after reducing the bus voltage value, increase the bus voltage value (U _Bus ). If the input power becomes larger after reducing the bus voltage value, continue to reduce the bus voltage value.

(u _Bus ,

(4) If the input power is constant after reducing the bus voltage value (t/^), continue to reduce the bus voltage value {U _Bus ). If the input power is unchanged after increasing the bus voltage value, reduce the bus voltage value according to The invention obtained by the cedar scheme enables the centralized converter and the power generation module to work stably and reliably without communication, and the centralized converter automatically operates at the optimal DC bus voltage point, and the new energy power generation module simultaneously makes each power generation device work. At their respective maximum power points, the system automatically achieves maximum power output.

At the same time, the present invention has the following advantages compared with the prior art:

(1) The centralized converter and the distributed series of new energy power generation modules do not need communication, and the system can work stably and reliably to achieve maximum power output;

(2) The centralized converter performs centralized maximum power tracking control on all new energy power generation equipment, which can automatically set the DC bus voltage at the input of the centralized converter to make the input and output voltages of the DC-DC converter in the new energy power generation module similar. The bus voltage value improves the operating state of the DC-DC converter, improves the conversion efficiency of the DC-DC converter, and increases the system power generation;

(3) The DC-DC converter in the new energy power generation module respectively performs maximum power tracking on the new energy power generation equipment connected to each other, which can ensure that each new energy power generation equipment works at its respective maximum power point, avoiding photovoltaic components. The interaction between the characteristics and the environmental conditions is inconsistent, and the system power generation efficiency is maximized. DRAWINGS

The invention is further described below in conjunction with the drawings and specific embodiments. 1 is a schematic diagram of a new energy power generation system according to the present invention;

Figure 2 is a schematic diagram of a new energy power generation module;

Figure 3 is a schematic diagram of a photovoltaic DC module;

Figure 4 is a power-voltage characteristic curve of a photovoltaic module;

Figure 5 is a power-voltage characteristic curve of a conventional photovoltaic DC module;

6 is a schematic diagram of a tracking area of distributed maximum power tracking and centralized maximum power tracking when using control strategy 1;

Figure 7 shows the power-voltage characteristic curve of the photovoltaic DC module when the control strategy 1 is adopted;

8 is a schematic diagram of a tracking area of distributed maximum power tracking and centralized maximum power tracking when using control strategy 2;

Figure 9 shows the power-voltage characteristics of the PV DC module when Control Strategy 2 is used.

Symbols in the figure: PV—photovoltaic module; DC-DC—DC-DC converter; DC/AC—grid inverter; “(^ grid-connected inverter DC input side bus voltage; ^ Factory PV module output voltage; "PV module output power; Γ "PV module maximum power point power; PV module maximum power point voltage; c^" PV module open circuit voltage; w. A PV DC module output voltage; / 7. A photovoltaic DC module output power; ^ one PV module maximum output voltage; _W. ^ a photovoltaic DC module minimum output voltage.

In order to make the technical means, the authoring features, the achievement of the object and the effect of the present invention easy to understand, the present invention will be further described below in conjunction with the specific drawings.

Referring to Figure 1, the present invention provides a centralized-distributed hybrid new energy power generation system comprising N new energy power generation modules 100 and a centralized converter 200.

Referring to FIG. 2, each new energy power generation module 100 is mainly composed of a new energy power generation device 101 and a DC-DC converter 102, wherein an output end of the new energy power generation device 101 is connected to an input terminal of the DC-DC converter 102, DC The output of the -DC converter is the output of the new energy DC module. The output terminals of the N new energy power generation modules 100 are sequentially connected in series to form a DC module string 300. The output terminals of the DC module string 300 form a high voltage DC bus and are then connected to the input of the centralized converter 200.

In the present invention, the new energy power generating apparatus 101 may be a photovoltaic module, a heat battery, or the like. The centralized converter 200 can be a DC-DC converter or a grid-connected inverter. When the centralized converter is a DC-DC converter, the output of the centralized converter 200 can be connected to an electrical load or battery 400. When the device 200 is a grid-connected inverter, the output of the centralized converter is connected to the grid 400.

As another variation of the new energy power generation system of the present invention, the new energy power generation system is composed of a plurality of DC module strings 300 and a centralized converter 200, and the output terminals of the plurality of DC module strings 300 are connected in parallel to form a high voltage DC bus, and then It is then connected to the input of the centralized converter 200.

According to the above scheme, the new energy power generation module and the centralized converter in the new energy power generation system simultaneously perform maximum power tracking on the new energy power generation equipment, wherein the DC-DC converter in the new energy power generation module only pairs the DC-DC converter The connected new energy power generation equipment performs maximum power tracking, and the centralized converter simultaneously performs maximum power tracking on all new energy power generation equipment.

Based on the above principle, the centralized-distributed hybrid maximum power point following control method provided by the present invention specifically includes two control schemes.

Control plan 1 :

In this scheme, the DC-DC converter in the new energy power generation module can adopt a buck converter or a buck-boost converter, and the DC-DC converter performs maximum power tracking on the new energy power generation device and the DC-DC converter When the input voltage is equal to the maximum power point voltage of the new energy power generation equipment ([/ _MW :), the maximum output voltage of the DC-DC converter is greater than or equal to the maximum power point (ί/Λ^/ ) voltage of the new energy power generation module and is less than the new one. The open circuit voltage (i/ _oc ) of the energy generation module, the DC-DC converter can use any maximum power point tracking strategy to achieve the maximum power tracking of the new energy generation module, and the centralized converter uses the following control strategy to achieve all new energy generation. Maximum power tracking of the module:

(1) The centralized converter changes the input side bus voltage (1⁄4) and detects the input power before and after the centralized converter changes the bus voltage;

(2) If the input power becomes smaller after increasing the bus voltage value, reduce the bus voltage value ( U _BUS ). If the input power becomes larger after increasing the bus voltage value (1⁄4 _s ), continue to increase the bus voltage value.

(3) If the input power becomes smaller after reducing the bus voltage value (1/^), increase the bus voltage value ( U _BUS ). If the input power becomes larger after reducing the bus voltage value (1⁄4 _s ), continue to decrease. Small bus voltage value (U _BUS ); (4) If the input power is constant after reducing the bus voltage value, increase the bus voltage value (U _Bus ). If the input power is unchanged after increasing the bus voltage value, continue to increase the bus voltage value control scheme 2:

In this scheme, the DC-DC converter in the new energy power generation module can use a boost converter or a buck-boost converter, and the DC-DC converter performs maximum power tracking and DC-DC conversion on the new energy power generation module. When the input voltage of the device is equal to the maximum power point voltage (C/W) of the new energy generation module, the lowest output (t/. _TO „) voltage of the DC-DC converter is less than or equal to the maximum power point of the new energy generation module (i/Mm). The voltage is greater than 0, and the maximum output voltage ( ) of the DC-DC converter is greater than the open circuit voltage of the new energy generation module ([/ _oc ). The DC-DC converter can implement the new energy generation module by using any maximum power point tracking strategy. The maximum power tracking, and the centralized converter uses the following control strategy to achieve maximum power tracking of all new energy generation modules:

(1) The centralized converter changes the input side bus voltage (1⁄4J, and simultaneously detects the input power before and after the centralized converter changes the bus voltage;

(2) If the input power becomes smaller after increasing the bus voltage value, reduce the bus voltage value (U _Bus ). If the bus voltage value is increased (1⁄4, the input power becomes larger, continue to increase the bus voltage value).

(3) If the input power becomes smaller after reducing the bus voltage value, increase the bus voltage value {U _Bus ). If the input power becomes larger after reducing the bus voltage value, continue to reduce the bus voltage value.

(4) If the input power is constant after reducing the bus voltage value (1⁄4„ _s ), continue to reduce the bus voltage value (U _Bus ). If the input power is unchanged after increasing the bus voltage value, reduce the bus voltage value ( 1⁄4" ).

The working principle of the centralized-distributed hybrid maximum power point tracking control method of the distributed tandem photovoltaic grid-connected power generation system of the present invention will be described below by taking the control scheme 1 as an example. In order to simplify the analysis, the following assumptions are made: (1) The new energy power generation equipment in the new energy power generation system is a solar photovoltaic module, and the centralized converter is a grid-connected inverter; (2) The new energy composed of the photovoltaic module and the DC-DC converter The power generation module is referred to as the photovoltaic DC module, as shown in Figure 3; (3) The DC-DC converter in the PV DC module performs maximum power tracking on the PV module and the input voltage of the DC-DC converter is equal to the maximum power point of the PV module. At voltage, the highest output voltage of the DC-DC converter ((7.) is equal to light The maximum power point voltage of the volt component.

For the traditional photovoltaic grid-connected power generation system, only the grid-connected inverter can be used for centralized maximum power tracking control of all PV modules, or only for the PV modules by the DC-DC converter in the PV DC module. Distributed maximum power tracking control, ie centralized maximum power tracking control and distributed maximum power tracking control cannot be performed simultaneously, because the maximum power tracking of the two will conflict, the specific reasons are as follows: Output power-voltage of traditional photovoltaic components The characteristic curve is shown in Figure 4. There is a unique maximum power point (ί/ >/ , τ τ) in the characteristic curve. The output power-voltage characteristic curve of the multiple photovoltaic components after series and parallel connection is shown in Figure 4 The output power-voltage characteristic curve of the PV module is similar, that is, there is still a unique maximum power point in the system. When the grid-connected inverter performs centralized maximum power tracking for all PV modules at the same time, it can change the grid-connected inverter. Input voltage, that is, change the output voltage of the PV module, and compare the output power of the PV module The way to automatically search for the maximum power point, thus stable operation, but the centralized maximum power tracking can not take into account the output characteristics of each photovoltaic module, to ensure that each component can work at the maximum power point; when the PV module and DC- After the DC converters are connected to form a PV DC module, the DC-DC converter performs distributed maximum power tracking for each PV module, which ensures that each PV module operates at its respective maximum power point, since the DC-DC converter has always been The maximum power tracking of the PV module, the output power of the DC-DC converter always maintains the power of the maximum power point of the PV module, and the output power-voltage characteristic curve of the PV DC module thus formed is independent of the output voltage of the DC-DC converter. As shown in FIG. 5, the curve is a smooth straight line. When a plurality of photovoltaic DC modules are connected in series and in parallel, the output characteristic curve is still a smooth straight line, that is, there is no maximum power point in the output characteristic curve, because all The output power corresponding to the voltage point is the same, if the grid-connected inverter continues When the PV DC module performs centralized maximum power tracking, the maximum power point corresponding to the fixed voltage point cannot be detected, that is, the centralized maximum power tracking of the grid-connected inverter will fail. In this case, the grid-connected inverter input The terminal DC bus voltage will fluctuate randomly, which affects the stable operation of the system.

For the distributed series photovoltaic grid-connected power generation system, only the distributed maximum power tracking control by the PV DC module can ensure that each PV module works at its respective maximum power point, but the DC-DC conversion in the PV DC module The efficiency has a great relationship with the input and output voltage. For a PV DC module using a basic Buck, Boost or Buck-Boost converter, the closer the input and output voltage of the converter is, the higher the conversion efficiency of the DC-DC converter is. The closer the output voltage of the DC-DC converter is to the maximum power point voltage of the photovoltaic module, the higher the conversion efficiency of the DC-DC converter, and the higher the power generation efficiency of the grid-connected power generation system. In order to make the output voltage of the DC-DC converter close to the maximum power point voltage of the photovoltaic panel, it is necessary to adjust the value of the DC bus voltage at the input of the grid-connected inverter through the grid-connected inverter in real time, so that the output of the DC-DC converter is made. The voltage is close to the maximum power point voltage of the photovoltaic module. However, the grid-connected inverter cannot obtain the output voltage information of each PV DC module, so the optimal DC bus voltage value cannot be automatically selected.

In order to solve the above problems, the present invention employs a centralized-distributed hybrid maximum power tracking control strategy, including two control schemes. The basic principle of the control scheme 1 is as shown in Fig. 6: The output power-voltage characteristic curve of the photovoltaic DC module is centered on the maximum power point and is divided into two parts, so that the photovoltaic DC module is only in the left half plane of the photovoltaic module. Distributed maximum power tracking control is performed, while grid-connected inverters focus on centralized maximum power tracking control for the right half of all PV modules. Based on the above method, the photovoltaic DC module performs maximum power tracking control only when the output voltage is less than or equal to the maximum power point voltage, and thus the output characteristic curve of the photovoltaic DC module is as shown in FIG. According to FIG. 7, when the output voltage of the photovoltaic DC module is lower than the maximum power point voltage of the photovoltaic module, the photovoltaic DC module performs maximum power tracking control, and the output power-voltage curve of the photovoltaic DC module is a smooth straight line, and when the photovoltaic When the output voltage of the DC module is higher than the maximum power point voltage of the PV module, the PV DC module does not perform maximum power tracking control, and the output characteristics of the PV DC module are consistent with the original characteristics of the PV module. When multiple PV DC modules are connected in series, their output characteristics are still similar to the power-voltage characteristics shown in Figure 7, ie the power-voltage characteristic curve is no longer a smooth straight line, when the grid-connected inverter is all When the photovoltaic module performs centralized maximum power tracking, the control strategy described in the present invention can automatically track the vicinity of the maximum power point voltage of the photovoltaic component, and the voltage can automatically ensure the output voltage of the DC module and the photovoltaic module itself. The maximum power point voltage is close, so as to ensure that the photovoltaic DC module has high conversion efficiency and achieve the purpose of improving the power generation efficiency of the grid-connected power generation system.

The implementation principle of the control scheme 2 is similar to that of the control scheme 1, and the output characteristic curve of the photovoltaic module is still divided into two planes centered on the maximum power point voltage, as shown in FIG. 8, wherein the photovoltaic DC module is only for the photovoltaic component. The right half-plane performs distributed maximum power tracking control, and the output power-voltage characteristic curve of the obtained photovoltaic DC module is as shown in FIG. 9. The grid-connected inverter further performs centralized operation on the left half plane of the photovoltaic module. Maximum power tracking control, capable of automatically tracking the maximum power point voltage of the photovoltaic component under the control strategy of the present invention In the vicinity, the output voltage of the photovoltaic DC module is close to the maximum power point voltage of the photovoltaic module itself, thereby ensuring high conversion efficiency of the photovoltaic DC module and achieving the purpose of improving the power generation efficiency of the grid-connected power generation system.

The basic principles, main features and advantages of the present invention are shown and described above. It should be understood by those skilled in the art that the present invention is not limited by the foregoing embodiments, and that the present invention is only described in the foregoing embodiments and the description of the present invention, without departing from the spirit and scope of the invention. Various changes and modifications are intended to fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and their equivalents.

Claims

Rights request

1. A concentrated-distributed hybrid new energy power generation system, characterized in that: the new energy power generation system comprises at least one DC module string and a centralized converter, and the output terminals of all DC module strings are connected in parallel to form a high voltage DC bus, and Connected to the input end of the centralized converter, the DC module string includes a plurality of new energy power generation modules, and the output ends of the plurality of new energy power generation modules are connected in series to form a DC module string; the new energy power generation module includes a new energy source The power generation device and the DC-DC converter, the output end of the new energy power generation device is connected to the input end of the DC-DC converter, and the output end of the DC-DC converter is the output end of the new energy DC module.

2. The centralized-distributed hybrid new energy power generation system according to claim 1, wherein the new energy power generation device is a photovoltaic module or a heat battery.

3. The concentrated-distributed hybrid new energy power generation system according to claim 1, wherein the DC-DC converter in the new energy power generation module is a buck converter or a buck-boost converter.

4. The concentrated-distributed hybrid new energy power generation system according to claim 1, wherein the centralized converter is a DC-DC converter or a grid-connected inverter, and when the centralized converter is a DC-DC In the case of a converter, the output of the centralized converter can be connected to an electrical load or a battery. When the centralized converter is a grid-connected inverter, the output of the centralized converter is connected to the grid.

5. A centralized-distributed hybrid maximum power point tracking control method, characterized in that: in the control method, a DC-DC converter in a new energy power generation module performs only on a new energy power generation device connected to the DC-DC converter. Maximum power tracking, centralized converters simultaneously perform maximum power tracking for all new energy generation equipment.

6. The centralized-distributed hybrid maximum power point tracking control method according to claim 5, wherein when the DC-DC converter performs maximum power tracking on the new energy power generation device and the input voltage of the DC-DC converter is equal to When the maximum power point voltage (ί/^ ) of the new energy power generation equipment, the maximum output voltage of the DC-DC converter is equal to the maximum power point (i / ) voltage of the new energy power generation module and less than the open circuit voltage of the new energy power generation module (1⁄4c) The DC-DC converter can use any maximum power point tracking strategy to achieve maximum power tracking of the new energy generation module, and the centralized converter uses the following control strategy to achieve maximum power tracking of all new energy generation modules: (1) The centralized converter changes the input side bus voltage while detecting the input power before and after the centralized converter changes the bus voltage;

(2) If the input power becomes smaller after increasing the bus voltage value, reduce the bus voltage value.

{ U _BUS ), if the input power becomes larger after increasing the bus voltage value, continue to increase the bus voltage value (U _BUS );

(3) If the input power becomes smaller after reducing the bus voltage value, increase the bus voltage value (U _BUS ). If the input power becomes larger after reducing the bus voltage value, continue to reduce the bus voltage value (U _BUS );

(4) If the input power is constant after reducing the bus voltage value, increase the bus voltage value (U _BUS ). If the input power is unchanged after increasing the bus voltage value (1⁄4„ _s ), continue to increase the bus voltage value (U _BUS ) ₀

7. The centralized-distributed hybrid maximum power point tracking control method according to claim 5, wherein when the DC-DC converter performs maximum power tracking on the new energy power generation module and the input voltage of the DC-DC converter is equal to When the maximum power point voltage (ί/Μ^ζ) of the new energy generation module is used, the minimum output (^) voltage of the DC-DC converter is less than or equal to the maximum power point ([/ / ) voltage of the new energy generation module and greater than 0, The maximum output voltage of the DC-DC converter (C/. _Wi „) is greater than the open circuit voltage (i/ _oc ) of the new energy generation module. The DC-DC converter can implement the new energy generation module using any maximum power point tracking strategy. The maximum power tracking, and the centralized converter uses the following control strategy to achieve maximum power tracking of all new energy generation modules:

(2) If the bus voltage value is increased (the input power becomes smaller after 1⁄4J, the bus voltage value (U _BUS ) is decreased. If the input power becomes larger after increasing the bus voltage value, the bus voltage value continues to increase.

(3) If the input power becomes smaller after reducing the bus voltage value, increase the bus voltage value ( U _BUS ). If the bus voltage value is reduced (the input power becomes larger after 1⁄4J, continue to reduce the bus voltage value (U _BUS )).

(4) If the input power is constant after reducing the bus voltage value (1⁄4„ _s ), continue to reduce the bus voltage value (U _BUS ). If the input voltage is unchanged after increasing the bus voltage value (C/^), subtract Small bus voltage value ( U _BUS ) ₀