Photovoltaic power generation system and power generation adjusting method

Abstract

The invention relates to the technical field of photovoltaic power generation, and discloses a photovoltaic power generation system and a power generation adjusting method, and the system comprises a photovoltaic module which is used for converting the radiation energy of the sun into electric energy; the storage battery is used for storing electric energy; the inverter is used for converting direct current into alternating current. The proportion of the output power of the photovoltaic power generation system meeting the frequency regulation requirement of the photovoltaic power generation system in the maximum output power of the photovoltaic power generation system is obtained by converting the named value of the total required power into the power permillage, and then the output power of each inverter is regulated according to the power permillage, so that the frequency regulation requirement of the photovoltaic power generation system is met. The output power of the inverter is the product of the power permillage and the rated power of the inverter, and it is guaranteed that the actual output power of the whole photovoltaic power generation system is the total demand power, so that the purpose of adjusting the frequency of the photovoltaic power generation system is achieved. And when the frequency of the photovoltaic power generation system is adjusted, the data collector cannot convert the form of the power issued by the rapid frequency modulation device into the form of the power which can be received by the inverter.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic power generation, and in particular to a photovoltaic power generation system and a power generation regulation method. Background Art

[0002] As a sustainable, renewable and clean energy, solar energy has huge potential for development and application. The continuous increase in photovoltaic installed capacity has brought good economic and social benefits to our country.

[0003] However, photovoltaic power is an intermittent renewable energy source and is greatly affected by external weather changes. With the continuous development and commissioning of my country's ultra-high voltage transmission lines, the operating characteristics of my country's power grid have also undergone major changes. The most obvious change is that the volatility and uncertainty of the power grid have significantly increased, frequency disturbances have continued to increase, and transient overvoltages often occur. Therefore, the operational safety risks of the power grid have increased significantly. The large-scale grid connection of new energy sources has led to a downward trend in the primary frequency regulation capacity of the entire power grid system, and the frequency regulation ability of the power grid has been reduced, which can easily lead to frequency over-limit or even low-frequency load reduction. In order to ensure the safe operation of the power grid, the realization of rapid frequency response of photovoltaic power stations has become a matter with a huge impact on the entire power grid.

[0004] Most of the existing data acquisition devices that cooperate with the fast frequency modulation technology of photovoltaic power stations use IEC104 communication to access the fast frequency modulation device, collect photovoltaic inverters through the MODBUS protocol, and only have data acquisition and forwarding functions. The existing technology cannot meet the rapid response required by the current fast frequency modulation, and there is no power regulation algorithm, which cannot adapt to the power regulation methods of inverters from different manufacturers. Summary of the invention

[0005] In view of the deficiencies of the prior art, the present invention provides a photovoltaic power generation system and a power generation regulation method to solve the above-mentioned problems.

[0006] The present invention provides the following technical solution: a power generation regulation method, comprising a data collector, a fast frequency regulation device and an inverter, wherein: a total required power, the number of inverters in normal operation and a total installed capacity are obtained, wherein the total required power is the output power of the photovoltaic power generation system that meets the frequency regulation requirements of the photovoltaic power generation system;

[0007] When the total required power is a nominal value, the power per thousand is calculated according to the total required power, the number of the inverters in normal operation and the total installed capacity, and the power per thousand is the per thousandth of the ratio of the total required power to the maximum output power of the photovoltaic power generation system;

[0008] The inverter is controlled to output a required power to adjust the frequency of the photovoltaic power generation system, wherein the required power is the product of the rated power of the inverter and the power per thousand, and the power per thousand is calculated according to the total required power, the number of the inverters in normal operation and the total installed capacity, including: calculating the ratio of the number of the inverters in normal operation to the total number of the inverters to obtain the operation ratio; calculating the product of the total installed capacity and the operation ratio to obtain the maximum output power; calculating the ratio of the total required power to the maximum output power to obtain the power ratio; calculating the power The power thousandth is obtained by multiplying the power ratio by 1000. Before obtaining the total required power, the number of the inverters in normal operation and the total installed capacity, the method further includes: obtaining the operating status of all the inverters, the operating status of the inverter including the normal operation status and the fault status; determining the number of the inverters in the normal operation status according to the operating status of all the inverters. Before controlling the inverter to output the required power to adjust the frequency of the photovoltaic power generation system, the method further includes: sending the power thousandth to the inverter in a serial communication manner.

[0009] Preferably, before obtaining the total required power, the number of the inverters in normal operation and the total installed capacity, the method also includes: receiving a first goose message sent by the fast frequency modulation device, the first goose message including the total required power, the format of the first goose message being a 61850 model file format; parsing the first goose message to obtain the total required power.

[0010] Preferably, receiving the first goose message sent by the fast frequency modulation device includes: receiving an original goose message sent by the fast frequency modulation device, the original goose message being a message transmitted using a physical layer protocol or a data link layer protocol; when the original goose message is a message transmitted using the physical layer protocol, determining that the original goose message is the first goose message.

[0011] Preferably, before calculating the power per thousand based on the total required power, the number of the inverters in normal operating state and the total installed capacity, the method also includes: triggering an internal interrupt instruction to stop the ongoing internal work of the data collector.

[0012] Preferably, after controlling the inverter to output the required power to adjust the frequency of the photovoltaic power generation system, the method also includes: obtaining the operating status and output power of the inverter; assembling the operating status and the output power of the inverter into a second goose message, the second goose message is in the 61850 model file format; and sending the second goose message to the fast frequency modulation device.

[0013] A photovoltaic power generation system includes a photovoltaic module for converting solar radiation energy into electrical energy; a storage battery for storing electrical energy; an inverter for converting direct current into alternating current; and a control module for controlling the operation of the photovoltaic power generation system.

[0014] Wherein, a cleaning module is arranged on the photovoltaic component and is operated by the control module to clean impurities from the surface of the photovoltaic panel.

[0015] Preferably, it also includes a protection module arranged on the photovoltaic component, which covers and protects the photovoltaic component after the cleaning module cleans the photovoltaic panel.

[0016] Preferably, it also includes an environmental monitoring module for detecting the weather environment when the photovoltaic components are working. In rainy and snowy weather conditions, the control module pre-controls the protection module to operate to cover and protect the photovoltaic components.

[0017] Preferably, the control system is capable of varying according to the time of day and night to ensure that the solar panels receive sunlight during the day and protect the storage at night.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The power generation regulation method converts the nominal value of the total power demand into a power per thousand, and obtains the proportion of the output power of the photovoltaic power generation system that meets the frequency regulation demand of the photovoltaic power generation system to the maximum output power of the photovoltaic power generation system. Then, according to the power per thousand, the output power of each inverter is adjusted. The output power of the inverter is the product of the power per thousand and the rated power of the inverter, ensuring that the actual output power of the entire photovoltaic power generation system is the total power demand, so as to achieve the purpose of adjusting the frequency of the photovoltaic power generation system. This method solves the problem in the prior art that the data collector cannot convert the form of the power sent by the fast frequency modulation device into the form of power that the inverter can receive when adjusting the frequency of the photovoltaic power generation system.

[0020] 2. In the photovoltaic power generation system, the cleaning module is operated through the control module to clean impurities on the surface of the photovoltaic panel to ensure the power generation efficiency of the photovoltaic module; the protection module protects the photovoltaic module when it is idle and not in use to ensure the cleanliness of the photovoltaic module when it is used again. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a flow chart of the power generation regulation method of the present invention;

[0022] Figure 2 is a structural diagram of the photovoltaic power generation system of the present invention;

[0023] Figure 3 The figure is a flow chart of the photovoltaic power generation system of the present invention. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] See also Figure 1-Figure 3 , a power generation regulation method, including a data collector, a fast frequency regulation device and an inverter, characterized in that: : a total required power, the number of inverters in a normal operating state and a total installed capacity are obtained, the total required power is the output power of the photovoltaic power generation system that meets the frequency regulation requirements of the photovoltaic power generation system;

[0026] When the total power demand is a nominal value, the power per thousand ratio is calculated based on the total power demand, the number of inverters in normal operation and the total installed capacity. The power per thousand ratio is the ratio of the total power demand to the maximum output power of the photovoltaic power generation system in thousandths.

[0027] Control the inverter to output the required power to adjust the frequency of the photovoltaic power generation system. The required power is the product of the rated power of the inverter and the power per thousand. The power per thousand is calculated according to the total required power, the number of inverters in normal operation and the total installed capacity, including: calculating the ratio of the number of inverters in normal operation to the total number of inverters to obtain the operation ratio; calculating the product of the total installed capacity and the operation ratio to obtain the maximum output power; calculating the ratio of the total required power to the maximum output power to obtain the power ratio; calculating the product of the power ratio and 1000 to obtain the power per thousand. Before determining the number and total installed capacity of inverters in normal state, the method further includes: obtaining the operating state of all inverters, the operating state of the inverter includes normal operating state and fault state; according to the operating state of all inverters, determining the number of inverters in normal operating state; before controlling the inverter to output the required power to adjust the frequency of the photovoltaic power generation system, the method further includes: using serial communication to send the power per thousand to the inverter. Most of the inverters used in the current photovoltaic power generation system can only receive the total required power in the form of per thousand, that is, receiving the power instruction in the form of per thousand, and the total required power sent to the data collector under the fast frequency modulation device. When the power is in the form of a nominal value, the data collector will calculate the power per thousand according to the total installed capacity of the current zone, the number of operating inverters and the total required power received, that is, convert the total required power in the form of a nominal value into the total required power in the form of a per thousand. The calculation formula for the power per thousand is as follows, where the total required power is the total required power of the current zone, the total installed capacity is the total installed capacity of the current zone, the number of operating units is the number of inverters in normal operation in the current zone, the total number of inverters is the total number of inverters in the current zone, the total required power issued by the fast frequency modulation device in the current zone is 500kW, and the total installed capacity of the current zone is 1000k W, the number of inverters in operation in the current zone is 10, and the total number of inverters in the current zone is 15. The power per thousand formula above can be used to calculate that the power per thousand of the current zone is 750‰, that is, when the total output power of the photovoltaic power generation system in the current zone reaches 750‰ of the maximum output power of the current zone, the frequency regulation demand of the photovoltaic power generation system in the current zone can be met. After calculating the power per thousand sent to the inverter, the power per thousand is displayed on the operation and maintenance tool to facilitate analysis and debugging by on-site debugging engineers. When the total required power sent to the data collector by the fast frequency modulation device is in the form of per thousand, the total required power in the form of per thousand can be directly sent to the inverter.

[0028] Furthermore, before obtaining the total required power, the number of inverters in normal operation and the total installed capacity, the method also includes: receiving a first goose message sent by the fast frequency modulation device, the first goose message including the total required power, and the format of the first goose message is the 61850 model file format; parsing the first goose message to obtain the total required power.

[0029] Furthermore, receiving a first goose message sent by the fast frequency modulation device includes: receiving an original goose message sent by the fast frequency modulation device, the original goose message being a message transmitted using a physical layer protocol or a data link layer protocol; when the original goose message is a message transmitted using a physical layer protocol, determining that the original goose message is a first goose message.

[0030] Furthermore, before calculating the power per thousand based on the total required power, the number of inverters in normal operation and the total installed capacity, the method also includes: triggering an internal interrupt instruction to stop the ongoing work inside the data collector.

[0031] Furthermore, after controlling the inverter to output the required power to adjust the frequency of the photovoltaic power generation system, the method also includes: obtaining the operating status and output power of the inverter; assembling the operating status and output power of the inverter into a second goose message, the second goose message is in the 61850 model file format; sending the second goose message to the fast frequency modulation device, after the data collector in the current zone calculates the power thousandths that need to be sent to the inverter, the data collector in the current zone immediately assembles the power thousandths into a broadcast message according to the modbus communication protocol, and sends it to each inverter in the current zone through the serial port 485 bus or the power carrier device, and each inverter in the current zone quickly responds to the power after receiving the broadcast message, that is, each inverter in the current zone quickly outputs the required power according to the adjustment instruction to meet the needs of fast frequency modulation of the photovoltaic power generation system.

[0032] A photovoltaic power generation system includes a photovoltaic module for converting solar radiation energy into electrical energy; a storage battery for storing electrical energy; an inverter for converting direct current into alternating current; and a control module for controlling the operation of the photovoltaic power generation system; wherein a cleaning module is provided on the photovoltaic module, and is operated by the control module to clean impurities on the surface of the photovoltaic panel; a protection module is provided on the photovoltaic module, and covers and protects the photovoltaic module after the cleaning module cleans the photovoltaic panel; and an environmental monitoring module is provided to detect the weather environment when the photovoltaic module is working. In rainy and snowy weather, the control module controls the protection module to operate in advance to cover and protect the photovoltaic module. The control system can change according to the time of day and night to ensure that the solar panel receives sunlight during the day and is protected and stored at night. The protection module is provided in consideration of the fact that the photovoltaic module cannot receive sunlight at night or in rainy and snowy weather, that is, the photovoltaic module is exposed, which will only increase the risk of impurities accumulating. Therefore, the protection module is provided to cover and protect the photovoltaic module, and the protection module is operated after the cleaning module is operated, so as to ensure the cleanliness of the photovoltaic module when it is used again.

[0033] Working principle,.

[0034] In the description of the present invention, it is necessary to understand that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0035] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0036] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] In the present invention, unless otherwise clearly specified and limited, the first feature "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. In the description of this specification, the description with reference to the terms "one scheme", "some schemes", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the scheme or example are included in at least one scheme or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same scheme or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more schemes or examples in a suitable manner.

[0038] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A power generation regulation method, comprising a data collector, a fast frequency modulation device and an inverter, characterized in that: The method comprises: obtaining a total power demand, the number of inverters in normal operation and a total installed capacity, wherein the total power demand is the output power of the photovoltaic power generation system that meets the frequency regulation requirements of the photovoltaic power generation system; When the total required power is a nominal value, the power per thousand is calculated according to the total required power, the number of the inverters in normal operation and the total installed capacity, and the power per thousand is the per thousandth of the ratio of the total required power to the maximum output power of the photovoltaic power generation system; The inverter is controlled to output a required power to adjust the frequency of the photovoltaic power generation system, wherein the required power is the product of the rated power of the inverter and the power per thousand, and the power per thousand is calculated according to the total required power, the number of the inverters in normal operation and the total installed capacity, including: calculating the ratio of the number of the inverters in normal operation to the total number of the inverters to obtain the operation ratio; calculating the product of the total installed capacity and the operation ratio to obtain the maximum output power; calculating the ratio of the total required power to the maximum output power to obtain the power ratio; calculating the power The power thousandth is obtained by multiplying the power ratio by 1000. Before obtaining the total required power, the number of the inverters in normal operation and the total installed capacity, the method further includes: obtaining the operating status of all the inverters, the operating status of the inverter including the normal operation status and the fault status; determining the number of the inverters in the normal operation status according to the operating status of all the inverters. Before controlling the inverter to output the required power to adjust the frequency of the photovoltaic power generation system, the method further includes: sending the power thousandth to the inverter in a serial communication manner.

2. A power generation regulation method according to claim 1, characterized in that: Before obtaining the total required power, the number of inverters in normal operation and the total installed capacity, the method also includes: receiving a first goose message sent by the fast frequency modulation device, the first goose message including the total required power, the format of the first goose message being a 61850 model file format; parsing the first goose message to obtain the total required power.

3. A power generation regulation method according to claim 1, characterized in that: Receiving the first goose message sent by the fast frequency modulation device, including: receiving the original goose message sent by the fast frequency modulation device, the original goose message is a message transmitted using a physical layer protocol or a data link layer protocol; when the original goose message is a message transmitted using the physical layer protocol, determining that the original goose message is the first goose message.

4. A power generation regulation method according to claim 1, characterized in that: Before calculating the power per thousand based on the total required power, the number of the inverters in normal operation and the total installed capacity, the method further includes: triggering an internal interrupt instruction to stop the ongoing work inside the data collector.

5. A power generation regulation method according to claim 1, characterized in that: After controlling the inverter to output the required power to adjust the frequency of the photovoltaic power generation system, the method also includes: obtaining the operating status and output power of the inverter; assembling the operating status and the output power of the inverter into a second goose message, the second goose message is the 61850 model file format; and sending the second goose message to the fast frequency modulation device.

6. A photovoltaic power generation system, characterized in that: It includes photovoltaic components for converting solar radiation into electrical energy; batteries for storing electrical energy; inverters for converting direct current into alternating current; and control modules for controlling the operation of the photovoltaic power generation system. Wherein, a cleaning module is arranged on the photovoltaic component and is operated by the control module to clean impurities from the surface of the photovoltaic panel.

7. A photovoltaic power generation system according to claim 6, characterized in that: It also includes a protection module arranged on the photovoltaic component, which covers and protects the photovoltaic component after the cleaning module cleans the photovoltaic panel.

8. A photovoltaic power generation system according to claim 6, characterized in that: It also includes an environmental monitoring module for detecting the weather environment when the photovoltaic components are working. In rainy and snowy weather conditions, the control module pre-controls the protection module to operate and cover the photovoltaic components for protection.

9. A photovoltaic power generation system according to claim 6, characterized in that: The control system is able to change according to the time of day and night to ensure that the solar panels receive sunlight during the day and protect the storage at night.

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