WO2018209696A1

WO2018209696A1 - Distributed photovoltaic power generation method

Info

Publication number: WO2018209696A1
Application number: PCT/CN2017/085113
Authority: WO
Inventors: 孟晓华; 张津; 林立
Original assignee: 欧贝黎新能源科技股份有限公司
Priority date: 2017-05-17
Filing date: 2017-05-19
Publication date: 2018-11-22
Also published as: CN107171358A

Abstract

A solar photovoltaic distributed power generation method, comprising a detection apparatus sending a control signal to a pre-connected photovoltaic combiner box according to the relationship between a luminous flux index and a preset index. A power generation system for implementing the method comprises a controller for discharging electrical energy stored in a storage battery to an inverter, and the inverter converting direct current into alternating current for use by a load. The function of the controller is to control the operation state of the entire system, and to provide over-charge and over-discharge protection for the storage battery. The system further comprises a glass vacuum tube solar photovoltaic device, and a hexagonal external cavity is further provided outside the cylindrical vacuum glass tube. For low temperature applications, non-tracking solar energy collection can be employed. For medium temperature applications, trough-type line-focus solar energy collection can be employed. For high temperature applications, dish-Stirling or solar tower tracking technologies can be employed. In this way, integrated utilization of photovoltaic and optothermal energy can be realized.

Description

Distributed photovoltaic power generation method

Technical field

The present invention relates to the field of power technology, and more particularly to a photovoltaic power generation method.

Background technique

A photovoltaic cell is a semiconductor device with optical and electrical conversion characteristics. It directly converts solar radiant energy into direct current, which is the most basic unit of photovoltaic power generation. The unique electrical characteristics of photovoltaic cells are based on the incorporation of certain silicon crystals. Elements (such as phosphorus or boron, etc.), causing a permanent imbalance in the molecular charge of the material, forming a semiconductor material with special electrical properties, which can generate free charges in semiconductors with special electrical properties under sunlight, these free charges Directional movement and accumulation, so that when both ends are closed, electrical energy is generated. This phenomenon is called "photovoltaic effect" and is referred to as photovoltaic effect.

Photovoltaic power generation refers to the way of generating electricity directly from solar radiation into electricity. Photovoltaic power generation is the mainstream of solar power generation today. Therefore, solar power generation is often referred to as photovoltaic power generation.

Photovoltaic distributed generation is a new type of comprehensive utilization of power generation and energy with broad development prospects. It advocates the near-generation power generation, the nearest grid connection, the nearby conversion, and the principle of near use, which can not only effectively increase the power generation capacity of photovoltaic power plants of the same scale. At the same time, it also effectively solves the problem of power loss in boosting and long-distance transportation. However, distributed power generation also imposes strict requirements on how to maximize solar power generation and how to ensure grid safety. The functionality and stability of photovoltaic inverters are also extremely critical.

Summary of the invention

In order to solve the above technical problem, the present invention provides a photovoltaic power generation method, comprising: a detecting device acquiring a luminous flux index of a current sunlight; and a detecting device transmitting a control signal to a pre-connected photovoltaic combiner box according to the relationship between the luminous flux index and a preset index. After receiving the control signal sent by the detecting device, the photovoltaic combiner box controls a plurality of internal switches according to the control signal to adjust the connection manner between the plurality of sets of photovoltaic modules; the output end of the photovoltaic combiner box is pre-connected through the DC cabinet The inverter outputs direct current, so that the inverter performs power adjustment on the direct current and outputs it.

The power generation method is implemented by a system including a battery, an inverter, a photovoltaic panel, and a controller.

The photovoltaic panel is used to convert solar energy into electrical energy.

The controller is configured to store electrical energy generated by the photovoltaic panel in the battery.

The controller is further configured to discharge the electrical energy stored in the battery to the inverter, and the DC through the inverter The electric power is converted into AC power for the load. The function of the controller is to control the working state of the whole system and to protect the battery from over-charge protection and over-discharge protection.

The controller should also be provided with a temperature compensation function, that is, a temperature sensor and a temperature adjustment unit are provided, the temperature sensor can sense the temperature of the controller, and the temperature adjustment unit can control the controller according to the sensed temperature. Heat or cool to keep the controller at a safe temperature.

The system also includes a vacuum glass tube solar photovoltaic device.

A hexagonal outer cavity is also provided on the outside of the cylindrical vacuum glass tube.

A solar lens is disposed at a sunlight incident portion of the vacuum glass tube, and the heat exchanger on the vacuum glass tube is a stainless steel cylindrical device, and a coating layer of solar energy converted into electric energy is disposed on the vacuum layer of the vacuum glass tube.

The heat exchange device is disposed inside the vacuum glass tube, and at the same time, an inlet and an outlet are disposed on the heat exchange device, and the fluid enters from the inlet and flows out from the outlet.

The embodiment has the following beneficial effects: adjusting the connection mode between the plurality of sets of photovoltaic modules according to the control signal, thereby adjusting the output of the photovoltaic combiner box; since the control signal is sent according to the relationship between the luminous flux index and the preset index, the photovoltaic combiner box is The output can be adjusted according to the luminous flux index, so that when the luminous flux is low, the output voltage of the photovoltaic combiner box is increased, thereby increasing the voltage input to the inverter, and the inverter is in a working state to realize photovoltaic power generation. For low temperature applications, non-tracking solar energy harvesting can be used. For medium temperature applications, trough-line focusing solar energy harvesting can be used. For high temperature applications, butterfly or tower solar tracking technology can be used. This can achieve the comprehensive utilization of photovoltaic and light heat.

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

This embodiment provides a photovoltaic power generation method, including:

The detecting device acquires the luminous flux index of the current sunlight. In this embodiment, the luminous flux index may be a direct current photovoltaic component voltage or a direct current photovoltaic component current. Wherein, during the daytime, the detecting device can obtain the voltage of the DC photovoltaic module; when the light is weak in the morning or evening, the detecting device can obtain the current of the DC photovoltaic component.

The detecting device transmits a control signal to the pre-connected photovoltaic combiner box according to the relationship between the luminous flux index and the preset index. In this embodiment, the method may include: determining whether the luminous flux index is greater than a preset index; if greater than, sending a shutdown control signal to the photovoltaic combiner box; if equal to, transmitting a dimension to the photovoltaic combiner box Control signal held; if less than, send a high-potential control signal to the PV combiner box.

After receiving the control signal sent by the detecting device, the photovoltaic combiner box controls a plurality of switches therein according to the control signal to adjust the connection manner between the plurality of sets of photovoltaic modules. In this embodiment, the input ends of the photovoltaic combiner boxes are respectively connected to the plurality of sets of photovoltaic modules, and the series and parallel relationship between the plurality of sets of the photovoltaic modules can be adjusted through the plurality of switches therein. In this embodiment, the step includes: if a control signal of the shutdown sent by the detecting device is received, controlling a plurality of switches inside the switch according to the turned off control signal, reducing the number of series of the plurality of sets of photovoltaic components, and adding multiple groups The number of parallel branches of the photovoltaic module; if receiving the maintained control signal sent by the detecting device, maintaining the state of the plurality of switches therein according to the maintained control signal; if receiving the control signal of the high potential sent by the detecting device, according to The high-potential control signal controls multiple switches inside, increases the number of series of multiple PV modules, and reduces the number of parallel branches of multiple PV modules.

The output end of the photovoltaic combiner box outputs DC power to the pre-connected inverter through the DC cabinet, so that the inverter performs power adjustment on the DC power and outputs it. In this embodiment, after the DC cabinet receives the DC power outputted from the output end of the PV combiner box, the DC power may be merged, and the DC power after the convergence is output to the inverter; the inverter receives the convergence of the DC cabinet output. After the subsequent DC power, the DC power after the convergence is adjusted and output.

The embodiment has the following beneficial effects: adjusting the connection mode between the plurality of sets of photovoltaic modules according to the control signal, thereby adjusting the output of the photovoltaic combiner box; since the control signal is sent according to the relationship between the luminous flux index and the preset index, the photovoltaic combiner box is The output can be adjusted according to the luminous flux index, so that when the luminous flux is low, the output voltage of the photovoltaic combiner box is increased, thereby increasing the voltage input to the inverter, and the inverter is in a working state to realize photovoltaic power generation.

A photovoltaic power generation system based on the above power generation method includes a battery, an inverter, a photovoltaic panel, a controller for converting solar energy into electrical energy, and the controller for storing electrical energy generated by the photovoltaic panel in the battery The controller is further configured to discharge the electrical energy stored in the battery to the inverter, and convert the direct current into an alternating current for the load through the inverter, the function of the controller is to control the working state of the entire system, and the battery It plays the role of over-charge protection and over-discharge protection. The controller should also be provided with a temperature compensation function, that is, a temperature sensor and a temperature adjustment unit are provided, the temperature sensor can sense the temperature of the controller, and the temperature adjustment unit can control the controller according to the sensed temperature. Heat or cool to keep the controller at a safe temperature.

The above photovoltaic power generation system also includes a vacuum glass tube solar photovoltaic power generation device, a vacuum in a cylinder The outside of the glass tube is also provided with a hexagonal external cavity, and a solar lens is disposed at a sunlight incident portion of the vacuum glass tube, and the heat exchanger on the vacuum glass tube is a stainless steel cylindrical device in a vacuum glass tube vacuum layer A coating that converts solar energy into electrical energy is provided. The heat exchange device is disposed inside the vacuum glass tube, and at the same time, the heat exchange device is provided with an inlet and an outlet, the fluid enters from the inlet and flows out from the outlet; for the low temperature application, the non-tracking solar energy collection can be used, and for the medium temperature application, Slotted line-focused solar harvesting can be used, and for high temperature applications, butterfly or tower solar tracking technology can be used. This can achieve the comprehensive utilization of photovoltaic and light heat.

The above description shows and describes a preferred embodiment of the present invention. As described above, it should be understood that the present invention is not limited to the form disclosed herein, and should not be construed as being Combinations, modifications, and environments are possible, and can be modified by the teachings of the above teachings or related art within the scope of the inventive concept described herein. All changes and modifications made by those skilled in the art are intended to be within the scope of the appended claims.

Claims

A solar photovoltaic distributed power generation method includes the following steps: the detecting device acquires a luminous flux index of the current sunlight; and the detecting device sends a control signal to the pre-connected photovoltaic combiner box according to the relationship between the luminous flux index and the preset index; the photovoltaic combiner box receives After the control signal sent by the detecting device, the plurality of switches inside the control device are controlled according to the control signal, and the connection manner between the plurality of groups of photovoltaic modules is adjusted; the output end of the photovoltaic combiner box outputs DC power to the pre-connected inverter through the DC cabinet. The inverter is configured to output power by adjusting the power of the direct current.
The power generation method according to claim 1, wherein the power generation method is implemented by a system including a battery, an inverter, a photovoltaic panel, and a controller.
The method of power generation according to claim 1, wherein said photovoltaic panel is used to convert solar energy into electrical energy.
The power generation method according to claim 3, wherein the controller is configured to store electrical energy generated by the photovoltaic panel in the battery.
The power generation method according to claim 4, wherein the controller is further configured to discharge the electrical energy stored in the battery to the inverter, and convert the direct current into an alternating current for the load through the inverter, the controller The function is to control the working state of the whole system and to protect the battery from over-charge protection and over-discharge protection.
The power generation method according to claim 5, wherein the controller is further provided with a temperature compensation function, that is, a temperature sensor and a temperature adjustment unit are provided, and the temperature sensor can sense the temperature of the controller. The temperature adjustment unit may heat or cool the controller according to the sensed temperature to bring the controller into a safe temperature.
The power generation method according to claim 6, wherein the system further comprises a vacuum glass tube solar photovoltaic power generation device.
The power generation method according to claim 7, characterized in that a hexagonal outer cavity is further provided outside the cylindrical vacuum glass tube.
The power generation method according to claim 8, wherein a solar lens is disposed at a sunlight incident portion of the vacuum glass tube, and the heat exchanger on the vacuum glass tube is a stainless steel cylindrical device on the vacuum glass tube vacuum layer. A coating that converts solar energy into electrical energy.
The power generation method according to claim 9, wherein the heat exchange device is disposed inside the vacuum glass tube, and at the same time, the heat exchange device is provided with an inlet and an outlet, and the fluid enters from the inlet and flows out from the outlet.