A measurement system and method for the effective power generation utilization hours of a photovoltaic power station

Abstract

The present invention discloses a measurement system and method for the effective power generation utilization hours of a photovoltaic power station. The system includes: a grid-connected power generation metering system for calculating the actual effective power generation utilization hours based on the power generated by the photovoltaic strings; an automatic cleaning system for cleaning the photovoltaic strings using the electric energy generated by the photovoltaic strings. The automatic cleaning system includes: an automatic cleaning electric control box for driving the cleaning device according to a control program; and a cleaning device for completing the cleaning of the photovoltaic strings. The grid-connected power generation metering system includes: a photovoltaic string for converting light energy into electric energy; and a photovoltaic distribution box for obtaining the electric energy, calculating the status parameters of the corresponding photovoltaic string, and calculating the actual effective power generation utilization hours of the photovoltaic string based on the status parameters. The system and method of the present invention are convenient for operation and maintenance, and the test data is more accurate and stable, and can be widely applied to the field of photovoltaic power generation technology.

Description

Technical Field

[0001] The present invention relates to the technical field of solar photovoltaic power generation, and in particular to a measurement system and method for the effective power generation utilization hours of a photovoltaic power station. Background Art

[0002] Photovoltaic power generation is a clean energy source that is inexhaustible. Photovoltaic power generation mainly relies on solar panels to convert light energy into direct current electricity, and then the direct current is inverted into alternating current by an inverter for users to use. The surface of the solar panel is glass, and the cleanliness of the glass surface directly affects the ability of the solar panel to absorb sunlight, thereby affecting the power generation capacity of the solar power station. Therefore, doing a good job in the cleaning and operation and maintenance of the surface of the solar panel is the key work of the photovoltaic power station and one of the important operation and maintenance tasks for the current operation and maintenance assessment of the photovoltaic power station. Regular cleaning of the components of the photovoltaic power station can increase the power generation by more than about 3%. At present, the assessment indicators for measuring the operation level of photovoltaic power stations in the photovoltaic industry are the system efficiency and the effective power generation utilization hours of the photovoltaic power station. Among them, the system efficiency is the most commonly used indicator, which is calculated by substituting the solar radiation value measured by the irradiance meter and the power generation of the photovoltaic power station into the theoretical formula. However, in actual applications, the irradiance meter sensor is unstable, has poor accuracy, and is greatly affected by environmental factors (cloudy, rainy, dusty), resulting in a large error in the finally measured system efficiency and unable to accurately measure the actual system efficiency. Therefore, the irradiance meter in the actual photovoltaic power station is useless and cannot serve the project well. In addition, at present, the industry also lacks a standard reference data measurement system and corresponding methods for the effective power generation utilization hours for reference in photovoltaic power stations. Summary of the Invention

[0003] In order to solve the above technical problems, the object of the present invention is to provide a measurement system and method for the effective power generation utilization hours of a photovoltaic power station, so as to facilitate the measurement of the standard reference data of the effective power generation utilization hours of the photovoltaic power station and serve as a means for assessing the operation and maintenance effect of the photovoltaic power station.

[0004] The technical solution adopted by the embodiments of the present invention is as follows:

[0005] On the one hand, the embodiments of the present invention provide a measurement system for the effective power generation utilization hours of a photovoltaic power station, including:

[0006] A grid-connected power generation metering system for calculating the actual effective power generation utilization hours according to the power generation generated by the photovoltaic string; an automatic cleaning system for cleaning the photovoltaic string by using the electric energy generated by the photovoltaic string.

[0007] The automatic cleaning system includes: an automatic cleaning electric control box for driving the cleaning device according to a control program; a cleaning device for completing the cleaning of the photovoltaic string.

[0008] Further, the grid-connected power generation metering system includes: a photovoltaic string for converting light energy into direct current electrical energy, which is selected from the same power station and is consistent with the characteristics of the on-site strings of the power station; a photovoltaic distribution box for obtaining the direct current electrical energy, calculating the state parameters of the corresponding photovoltaic string, and calculating the actual effective power generation hours of the photovoltaic string according to the state parameters; the photovoltaic string includes at least one photovoltaic module.

[0009] Further, the photovoltaic distribution box includes: a surge protection device for absorbing the common-mode surge voltage of the positive and negative lines; a metering device for calculating the state parameters of the corresponding photovoltaic string according to the direct current electrical energy, and calculating the actual effective power generation hours of the operation of the photovoltaic string according to the state parameters.

[0010] Further, the cleaning device includes: a driving motor for driving the cleaning trolley according to a control program; a cleaning trolley for cleaning the photovoltaic string; a cleaning trolley traveling track for restricting the traveling track of the cleaning trolley; a limit switch for restricting the traveling range of the cleaning trolley.

[0011] Further, the automatic cleaning electric control box includes: a protective circuit breaker for cutting off or connecting the circuit; a step-down transformer for converting high-voltage current into low-voltage current; an AC / DC power supply for converting alternating current into direct current and providing direct current power for the cleaning trolley control circuit unit and the driving motor; a cleaning trolley control unit for controlling the driving motor and monitoring the operating state according to a control program.

[0012] Further, the cleaning trolley control unit includes:

[0013] a DSP processor, a communication interface circuit, a status indication circuit, a motor A drive circuit, a motor B drive circuit, a motor A monitoring circuit, a motor B monitoring circuit, a limit switch detection circuit, a clock circuit, a power supply circuit, and an AC voltage on-line monitoring circuit;

[0014] The DSP processor is respectively connected to the communication interface circuit, and the output ends of the DSP processor are respectively connected to the input end of the status indication circuit, the input end of the motor A drive circuit, and the input end of the motor B drive circuit; the output end of the power supply circuit, the output end of the clock circuit, the output end of the AC voltage on-line monitoring circuit, the output end of the limit switch detection circuit, and the output ends of the motor A monitoring circuit and the motor B monitoring circuit are all connected to the input end of the DSP processor.

[0015] On the other hand, an embodiment of the present invention provides a method for measuring the effective power generation hours of a photovoltaic power station, which is used to detect the measurement system for the effective power generation hours of the photovoltaic power station, and includes the following steps:

[0016] Obtain the electrical energy generated by the photovoltaic string;

[0017] Using the electric energy generated by the photovoltaic string, the cleaning of the photovoltaic string is completed through an automatic cleaning system;

[0018] Obtain the electric energy generated by the photovoltaic string after cleaning, and measure the operation parameters of the photovoltaic string;

[0019] Calculate the actual effective power generation hours of the photovoltaic string according to the status parameters.

[0020] Further, the step of using the electric energy generated by the photovoltaic string to complete the cleaning of the photovoltaic string through the automatic cleaning system specifically includes: setting the control program for the cleaning action; obtaining the peripheral signals of the DSP processor; performing fault troubleshooting according to the peripheral signals; and controlling the driving motor to complete the cleaning action according to the fault troubleshooting results and the control program.

[0021] Further, the step of obtaining the electric energy generated by the photovoltaic string after cleaning and measuring the status parameters of the photovoltaic string specifically includes: obtaining the current of the electric energy through a shunt detection circuit, and obtaining the voltage in the circuit through a metering device; calculating the real-time power and power generation according to the current and voltage.

[0022] Further, the step of performing fault troubleshooting according to the peripheral signals specifically includes: generating a fault alarm according to the fault cause in the peripheral signals; reporting the fault alarm to the background; and performing operation control and parameter setting on the cleaning trolley control unit according to the fault alarm.

[0023] The beneficial effects of the present invention are:

[0024] In terms of the system: The present invention includes a grid-connected power generation metering system and an automatic cleaning system. By selecting similar photovoltaic strings in the power station and configuring an automatic cleaning system for the photovoltaic strings, the surface of the photovoltaic strings is always kept clean through the automatic cleaning system, which is convenient for operation and maintenance and has a high safety factor, and makes the measurement data more accurate.

[0025] In terms of the method: The present invention selects a photovoltaic string as a reference power generation device in the same photovoltaic power station, and forms a power generation system by configuring a metering device and a protection device for it. The system is connected to the power grid where the photovoltaic power station is located and the actual effective power generation hours are calculated through the output power. In order to improve the accuracy of the photovoltaic string power generation and reduce the influence of factors such as weather and dust, an automatic cleaning system is configured for the photovoltaic string, and the surface of the photovoltaic string is always kept clean through the automatic cleaning system, and the test data is more accurate and stable. Description of the Drawings

[0026] Figure 1Schematic diagram of the grid-connected power generation metering system of an effective power generation utilization hours measurement system for a photovoltaic power station according to a specific embodiment of the present invention;

[0027] Figure 2 Schematic diagram of the structure of an automatic cleaning device of an effective power generation utilization hours measurement system for a photovoltaic power station according to a specific embodiment of the present invention;

[0028] Figure 3 Schematic diagram of the structure of a cleaning device in the vertical installation state of a photovoltaic string of an effective power generation utilization hours measurement system for a photovoltaic power station according to a specific embodiment of the present invention;

[0029] Figure 4 Schematic diagram of the structure of a cleaning device in the horizontal installation state of a photovoltaic string of an effective power generation utilization hours measurement system for a photovoltaic power station according to a specific embodiment of the present invention;

[0030] Figure 5 Structure framework diagram of a cleaning trolley control unit of an effective power generation utilization hours measurement system for a photovoltaic power station according to a specific embodiment of the present invention;

[0031] Figure 6 Flowchart of steps of a method for measuring effective power generation utilization hours of a photovoltaic power station according to a specific embodiment of the present invention.

[0032] Reference numerals: 101, original photovoltaic string of the photovoltaic power station; 102, surge protection device; 103, current detection device; 104, DC meter; 105, circuit breaker; 201, circuit breaker; 202, step-down transformer; 301, motor A; 302, motor B; 303, proximal limit switch A; 304, proximal limit switch B; 305, distal limit switch A; 306, distal limit switch B; 307, cleaning trolley running track; 308, cleaning trolley running track; 309, cleaning trolley. Detailed implementation manners

[0033] The present invention will be further described in detail below in conjunction with the accompanying drawings of the specification and specific embodiments. For the step numbers in the following embodiments, they are only set for the convenience of elaboration and explanation, and no limitation is imposed on the order between the steps. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0034] Referring to Figure 1 , the present invention provides an effective power generation utilization hours measurement system for a photovoltaic power station, including:

[0035] A grid-connected power generation metering system for calculating the actual effective power generation utilization hours according to the generated power of the photovoltaic string;

[0036] An automatic cleaning system for cleaning a photovoltaic string by using electric energy generated by the photovoltaic string.

[0037] The automatic cleaning system includes: an automatic cleaning electric control box for driving a cleaning device according to a control program; and a cleaning device for cleaning the photovoltaic string.

[0038] Specifically, the embodiment of the present invention is composed of a grid-connected power generation metering system and an automatic cleaning system. The grid-connected power generation metering system is used to measure the real-time power and power generation amount based on parameters such as the voltage and current of the electric energy converted from light energy by the photovoltaic string, and finally calculate the corresponding actual effective power generation utilization hours. The calculation method of the effective power generation utilization hours: effective power generation utilization hours = power generation amount / rated power of a single string. For example, annual effective power generation utilization hours = annual power generation amount / rated power of a single string; monthly effective power generation utilization hours = monthly power generation amount / rated power of a single string; daily effective power generation utilization hours = daily power generation amount / rated power of a single string. In addition, referring to Figure 2 , the automatic cleaning system includes an automatic cleaning electric control box and a cleaning device. The automatic cleaning electric control box converts the alternating current generated by the photovoltaic distribution box into direct current as the power supply for the cleaning device. At the same time, the electric control box also has functions such as signal detection, fault warning, overload protection, and emergency power supply. The automatic cleaning system uses the electric energy generated by the photovoltaic string as the power supply to complete the cleaning of the photovoltaic string, so that the photovoltaic string remains clean and avoids the influence of environmental factors on the data measurement process. In the system, the photovoltaic string is the reference power generation component that converts light into electric energy and is the core component. As the reference component, the automatic cleaning system needs to clean and remove dust from it regularly according to the set program to keep the surface clean. In order to have higher credibility for the test data, the reference photovoltaic string is selected from the same power station and is consistent with the characteristics of the strings on the power station site.

[0039] Referring to Figure 1 , as an optional implementation manner, the grid-connected power generation metering system includes: a photovoltaic string for converting light energy into direct current electric energy, and the photovoltaic string is selected from the same power station and is consistent with the characteristics of the strings on the power station site; a photovoltaic distribution box for obtaining the direct current electric energy, calculating the state parameters of the corresponding photovoltaic string, and calculating the actual effective power generation utilization hours of the photovoltaic string according to the state parameters; the photovoltaic string includes at least one photovoltaic module.

[0040] Specifically, the grid-connected power generation metering system includes a photovoltaic string and a photovoltaic distribution box. The photovoltaic string is mainly used to convert light energy into electrical energy (direct current). The generated electrical energy is incorporated into the power grid through the string-type inverter of the photovoltaic power station and further provides power for the automatic cleaning system. The photovoltaic string is formed by connecting single photovoltaic modules in series, and the series connection methods include vertical installation and horizontal installation. The original photovoltaic string of the photovoltaic power station is a normally operating photovoltaic string selected from the already-operated photovoltaic power stations.

[0041] Refer to Figure 1 , as an optional implementation, the photovoltaic distribution box includes: a surge protection device for absorbing the common-mode surge voltage of the positive and negative lines; a metering device for calculating the state parameters of the corresponding photovoltaic string according to the direct current electrical energy and calculating the actual effective power generation utilization hours of the photovoltaic string operation according to the state parameters; and a circuit breaker 105 for cutting off the circuit to play a protective role when a fault current occurs.

[0042] Specifically, the grid-connected power generation metering system consists of a photovoltaic string 101 (the original photovoltaic string of the photovoltaic power station), a surge protection device 102, a metering device, and a circuit breaker 105. The direct current electrical energy generated by the photovoltaic string is incorporated into the low-voltage side of the box transformer of the photovoltaic power station and is converted into alternating current with the same direction and frequency as the power grid through the string-type inverter. The surge protection device 102 is composed of positive and negative surge arresters, mainly absorbing the common-mode surge voltage of the positive and negative lines and protecting the safety of the subsequent metering device and other equipment. The metering device is mainly used to measure the output power and power generation of the reference string. The device calculates the real-time power and power generation by detecting the direct current voltage and current. The metering device in this embodiment selects a direct current meter 104. The power supply of the direct current meter 104 in the metering system is taken from the electric control box of the cleaning trolley. At the same time, the meter adopts a high-precision sampling circuit and a high-speed data processing unit, which can realize high-precision and wide-range data analysis and monitoring, and is installed in a rail-mounted manner. And through the current detection device 103, finally the data generated by the direct current meter 104 is uploaded to the background of the photovoltaic power station management system through the RS485 communication method; the current detection device 103 uses a high-precision power resistor. When the current passes through the current detection device 103, a voltage signal is generated, and this signal is collected by the direct current meter 104 for calculating the loop current. In addition, for the operation safety of the grid-connected measurement system, the convenience of power-off maintenance, and the continuity of data, the circuit breaker 105 in this embodiment needs to have the functions of under-voltage release and automatic closing, which can prevent the grid-connected power generation metering system from islanding operation when the power grid is powered off, and at the same time can realize the automatic closing operation of the system without manual intervention after the power grid comes back on, without interrupting the operation.

[0043] As an optional implementation, the cleaning device includes: a driving motor for driving the cleaning cart according to a control program; a cleaning cart for cleaning the photovoltaic string; a cleaning cart traveling track for restricting the traveling track of the cleaning cart; and a limit switch for restricting the traveling range of the cleaning cart.

[0044] Specifically, referring to Figure 3 and Figure 4 , corresponding to the vertical and horizontal installation methods of the photovoltaic string, an automatic cleaning device is configured for the entire string. Through the automatic cleaning device, the surface of the entire string is always kept cleanest, so that the power generation of the photovoltaic string is in the optimal state. The cleaning device mainly consists of two driving motors (motor A 301 and motor B 302), a cleaning cart 309, cleaning cart traveling tracks 307, cleaning cart traveling tracks 308, and limit switches (proximal limit switch A 303, proximal limit switch B 304, distal limit switch A 305, and distal limit switch B 306). The motor is controlled by an electric control box to drive the track to move back and forth. The cleaning cart 309 is fixed to the track. The track is used to restrict the traveling track of the cleaning cart 309. The track and the cleaning cart 309 realize the function of cleaning the string with the forward and reverse rotation of the motor. The cleaning range of the cleaning cart 309 is realized by the limit switch, and the cleaning work is completed by the brush carried by the cleaning cart 309.

[0045] As an optional implementation, the automatic cleaning electric control box includes: a protective circuit breaker 201 for cutting off or connecting the circuit; an AC / DC power supply for converting alternating current into direct current and supplying power to the cleaning cart control circuit unit and the driving motor; and a cleaning cart control unit for controlling the driving motor and monitoring the operating state according to a control program.

[0046] Specifically, the main function of the cleaning cart electric control box is to convert alternating current into direct current, and at the same time be responsible for controlling the cleaning cart driving motor and related signal detection. It mainly consists of an input protective circuit breaker 201, a step-down transformer 202, an AC / DC power supply, a cleaning cart control unit, and a cleaning cart control unit. After taking power from the AC busbar box of the photovoltaic power station or the low-voltage side of the box transformer, it is input to the step-down transformer 202 through the circuit breaker 201. The original high AC voltage in the photovoltaic power station is stepped down to AC 220V low voltage through the step-down transformer 202. This 220V voltage supplies power to the metering system and the AC / DC power supply at the same time. The AC / DC power supply rectifies the AC 220V into direct current suitable for the use of the cleaning cart control unit (the DC output has 3 paths, one of which is the power supply for the cleaning cart control unit, and the remaining two are the driving power supplies for motor A 301 and motor B 302).

[0047] Referring to Figure 5 , as an optional implementation, the cleaning cart control unit includes:

[0048] A DSP processor, a communication interface circuit, a status indication circuit, a driving circuit for motor A and a driving circuit for motor B, a monitoring circuit for motor A and a monitoring circuit for motor B, a limit switch detection circuit, a clock circuit, a power supply circuit, and an on-line AC voltage monitoring circuit; the DSP processor is connected to the communication interface circuit, and the output terminals of the DSP processor are respectively connected to the input terminal of the status indication circuit, the input terminal of the driving circuit for motor A, and the input terminal of the driving circuit for motor B; the output terminals of the power supply circuit, the output terminal of the clock circuit, the output terminal of the on-line AC voltage monitoring circuit, the output terminal of the limit switch detection circuit, and the output terminals of the monitoring circuit for motor A and the monitoring circuit for motor B are all connected to the input terminal of the DSP processor. Specifically, the cleaning trolley control unit in the photovoltaic power station reference effective power generation utilization hour measurement system mainly consists of a DSP processor, a communication interface circuit, a status indication circuit, driving circuits for motor A and motor B, monitoring circuits for motor A and motor B, a limit switch detection circuit, a clock circuit, and a power supply circuit; after the cleaning trolley control unit is powered on, the DSP processor starts to detect peripheral signals and drives and controls the two motors according to a pre-set control program. The control system starts cleaning according to the set program, and the motors start to drive the cleaning trolley to move forward for cleaning. When the signals of the 305 far-end limit switch A and the 306 far-end limit switch B are detected, the cleaning trolley control unit considers that the cleaning trolley has reached the end point, and the motors stop working. Later, the controller controls the motors to run in reverse, and the cleaning trolley starts to clean in the reverse direction. During the reverse operation, if the signals of the 303 near-end limit switch A and the 304 near-end limit switch B are received again, the cleaning trolley control unit considers that the cleaning trolley has returned to its position, and the motors stop working. At this time, the control system completes a cleaning task of a photovoltaic string under an instruction. The two motors are equipped with running monitoring sensors, which are composed of a permanent magnet and a reed switch. The magnet rotates with the motor. During the rotation of the motor, the magnet approaches the reed switch once, and a dry contact signal is generated through the reed switch. This signal is connected to the cleaning trolley control unit. During the cleaning process, if the DSP processor does not detect the motor running signal, it is considered that the motor has a fault or is stuck, and a fault alarm will be generated. The fault alarm is reported to the background through the communication interface circuit. At the same time, the background can also perform running control and parameter setting on the cleaning trolley control unit through the communication interface circuit. In order to monitor the operation of the cleaning system, the cleaning trolley control unit has the functions of on-line AC voltage monitoring and lithium battery backup. When the AC 220V power supply is interrupted during the operation of the controller, the cleaning trolley control unit is powered by the lithium battery for backup, and at the same time, when no on-line AC voltage monitoring signal is detected, the alarm signal is uploaded to the background for processing, which can realize the functions of power outage and power-on notification, and greatly improve the reliability of the system operation.

[0049] Refer to Figure 6The embodiment of the present invention provides a method for measuring the effective power generation hours of a photovoltaic power station, which is used to detect the effective power generation hours measurement system of the photovoltaic power station, and includes the following steps:

[0050] S101, obtaining electric energy generated by photovoltaic strings;

[0051] Specifically, the photovoltaic strings of the same batch in the original power station are laid at the same angle, and their string outputs are connected to the photovoltaic distribution box and converted into AC power that complies with the grid. After being integrated into the grid, the generated electric energy is consumed, and at the same time, it is also connected to the input end of the metering device at the rear end of the string.

[0052] S102, using the electric energy generated by the photovoltaic strings to clean the photovoltaic strings through an automatic cleaning system;

[0053] Specifically, the electric energy generated by the photovoltaic strings also provides power for the automatic cleaning system. The electric energy is converted into direct current through the AC / DC power supply in the automatic cleaning electrical control box, and the DC output is three-way, one of which is the power supply for the cleaning trolley control unit, and the remaining two are the driving power supplies for motor 301 A and motor 302 B.

[0054] S103, obtaining the electric energy generated by the cleaned photovoltaic strings, and measuring and obtaining the operating parameters of the photovoltaic strings;

[0055] Specifically, the metering device accurately measures parameters such as voltage, current, and power generation of the electric energy converted by the photovoltaic string based on the acquired electric energy.

[0056] S104, calculating the actual effective power generation utilization hours of the photovoltaic string operation according to the state parameters;

[0057] Specifically, the various data measured by the metering device are uploaded to the background of the power station photovoltaic system for analysis and storage, and the actual effective power generation utilization hours of the photovoltaic strings of the device are calculated by the background system software. After obtaining the data, it can be used as a reference for evaluating the actual effective power generation utilization hours of the photovoltaic power station.

[0058] As a further preferred embodiment, the automatic cleaning system uses the electric energy generated by the photovoltaic strings to complete the cleaning action. This step S102 specifically includes:

[0059] S1021, setting a control program for the cleaning action;

[0060] S1022, obtaining DSP processor peripheral signals;

[0061] S1023, performing troubleshooting according to the peripheral signal;

[0062] S1024. Control the drive motor to complete the cleaning action according to the troubleshooting result and the control program.

[0063] Specifically, the control program is pre - set in the DSP processor of the cleaning trolley control unit. After powering on the cleaning trolley control unit, the DSP processor starts to detect and obtain the signals of the peripheral circuits. The peripheral circuits include a communication interface circuit, a status indication circuit, a drive circuit for motor A and motor B, a monitoring circuit for motor A and motor B, a limit switch detection circuit, a clock circuit, and a power supply circuit. When the DSP receives non - fault signals from each circuit, it drives and controls the two motors according to the pre - set control program. The control system starts the cleaning according to the set program. The two motors in the cleaning device are controlled by the electric control box to run synchronously. The motors drive the crawler to control the cleaning trolley to walk between the proximal end and the distal end. When the motors rotate forward, the cleaning trolley walks towards the distal end; when the motors rotate backward, the cleaning trolley walks towards the proximal end. When the cleaning trolley touches the 305 distal limit switch A and the 306 distal limit switch B during the process of walking towards the distal end, the two motors stop running, indicating that the distal position has been reached. When the cleaning trolley touches the 303 proximal limit switch A and the 304 proximal limit switch B during the process of walking towards the proximal end, the two motors stop running, indicating that it has returned to the initial position. At this time, the control system completes a photovoltaic string cleaning task under one instruction.

[0064] As a further preferred embodiment, the step S103 of obtaining the power generation amount of the photovoltaic string after cleaning and measuring to obtain the photovoltaic string status parameters specifically includes:

[0065] S1031. Obtain the current of the electric energy through a shunt detection circuit;

[0066] S1032. Obtain the voltage in the circuit through a metering device;

[0067] S1033. Calculate the real - time power and power generation amount according to the current and voltage.

[0068] Specifically, the metering device detects the voltage and current (DC) of the electric energy converted by the photovoltaic string in the circuit to calculate the real - time power, power generation amount, and effective power generation utilization hours. The metering device also includes a high - precision sampling circuit and a high - speed data processing unit, which can realize high - precision and wide - range data analysis and monitoring.

[0069] As a further preferred embodiment, the step S1023 of troubleshooting according to the peripheral signals specifically includes:

[0070] S10231. Generate a fault alarm according to the fault cause in the peripheral signals;

[0071] S10232. Report the fault alarm to the background;

[0072] S10233. Perform operation control and parameter setting on the cleaning trolley control unit according to the fault warning.

[0073] Specifically, before or during the cleaning operation, when the DSP processor does not detect the motor operation signal, it is considered that the motor fails or is stuck, and a fault warning will be generated. The fault warning is reported to the background through the communication interface circuit. At the same time, the background can also perform operation control and parameter setting on the cleaning trolley control unit through the communication interface circuit. In order to monitor the operation of the cleaning system, the cleaning trolley control unit also has the functions of AC voltage on-line monitoring and lithium battery backup. When the AC 220V power supply is interrupted during operation, the lithium battery provides backup power supply. At the same time, when the cleaning trolley control unit detects that there is no AC voltage on-line monitoring signal, it will upload the warning signal to the background for processing, which can realize the power outage and power-on notification functions and greatly improve the reliability of system operation.

[0074] Compared with the prior art, the photovoltaic power station effective power generation utilization hour measurement system and method of the present invention have the following advantages:

[0075] 1) The effective power generation utilization hours measured by the system of the present invention are more stable and closer to the actual operation of the photovoltaic power station. The pyranometers commonly used in photovoltaic power stations are affected by factors such as rainy days and dust, and the measurement data has large errors. At the same time, there is a large difference from the actual operation of the power station. The present invention uses the same batch of photovoltaic strings in the original power station as the measurement object, and the test data is closer to the power station operation data.

[0076] 2) The system of the present invention can achieve regular automatic cleaning. The pyranometers commonly used in photovoltaic power stations cannot achieve automatic cleaning due to the characteristics of the equipment itself. At the same time, other devices similar to using photovoltaic strings as the measurement object are not equipped with automatic cleaning devices, and dust will affect the accuracy of the measurement data.

[0077] 3) The electric energy of the photovoltaic string of the system of the present invention is connected to the low-voltage side of the photovoltaic power station box transformer for consumption, which is safe and reliable.

[0078] 4) The system of the present invention operates reliably and is convenient for operation and maintenance, and has the functions of on-line monitoring of commercial power and monitoring of the motor operation status.

[0079] 5) This technical solution evaluates the system efficiency, power generation capacity and operation and maintenance level of the photovoltaic power station through the effective power generation utilization hours. The effective power generation utilization hours are the ratio of the power generation amount to the rated power of the photovoltaic power station. The larger the power generation amount, the higher the effective power generation utilization hours. In this case, for the same photovoltaic power station, it represents a higher system efficiency and stronger power generation capacity. Therefore, the evaluation accuracy through the effective power generation utilization hours is much greater than the evaluation accuracy of the system efficiency of the photovoltaic power station.

[0080] Regarding the step numbers in the above method embodiments, they are only set for the convenience of elaboration and explanation, and no limitation is imposed on the order between steps. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0081] The above has specifically described the preferred embodiments of the present invention, but the present invention is not limited to the described embodiments. Those skilled in the art can also make various equivalent deformations or substitutions without departing from the spirit of the present invention, and these equivalent deformations or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A measurement system for the effective power generation hours of a photovoltaic power station, characterized in that Comprising: A grid-connected power generation metering system for calculating the actual effective power generation hours based on the power generation amount generated by a photovoltaic string and the real-time power of the photovoltaic string; An automatic cleaning system for cleaning the photovoltaic string by using the electric energy generated by the photovoltaic string; The automatic cleaning system includes: An automatic cleaning electric control box for driving a cleaning device according to a control program; the automatic cleaning electric control box includes a cleaning trolley control unit; the cleaning trolley control unit includes a DSP processor, a communication interface circuit, a status indication circuit, a motor A drive circuit, a motor B drive circuit, a motor A monitoring circuit, a motor B monitoring circuit, a limit switch detection circuit, a clock circuit, a power supply circuit, and an AC voltage on-line monitoring circuit; the DSP processor is connected to the communication interface circuit, and the output ends of the DSP processor are respectively connected to the input ends of the status indication circuit, the motor A drive circuit input end, and the motor B drive circuit input end; the output ends of the power supply circuit, the clock circuit, the AC voltage on-line monitoring circuit, the limit switch detection circuit, and the output ends of the motor A monitoring circuit and the motor B monitoring circuit are all connected to the input end of the DSP processor; A cleaning device for completing the cleaning of the photovoltaic string.

2. The measurement system for the effective power generation hours of a photovoltaic power station according to claim 1, wherein The grid-connected power generation metering system includes: A photovoltaic string for converting light energy into direct current electric energy, and the photovoltaic string is selected from the same power station and is consistent with the string characteristics on the power station site; A photovoltaic distribution box for obtaining the direct current electric energy, calculating the operating parameters of the corresponding photovoltaic string, and calculating the actual effective power generation hours of the photovoltaic string according to the operating parameters; The photovoltaic string includes at least one photovoltaic module.

3. The measurement system for the effective power generation hours of a photovoltaic power station according to claim 2, wherein The photovoltaic distribution box includes: A surge protection device for absorbing the common mode surge voltage of the positive and negative lines; A metering device for calculating the operating parameters of the corresponding photovoltaic string according to the direct current electric energy, and calculating the actual effective power generation hours of the operation of the photovoltaic string according to the operating parameters.

4. A measurement system for the effective power generation hours of a photovoltaic power station according to claim 1, characterized in that, The cleaning device includes: A driving motor for driving a cleaning trolley according to a control program; A cleaning trolley for cleaning the photovoltaic string; A cleaning trolley traveling track for restricting the traveling track of the cleaning trolley; A limit switch for restricting the traveling range of the cleaning trolley.

5. The measurement system for the effective power generation hours of a photovoltaic power station according to claim 1, wherein, The automatic cleaning electric control box includes: A protective circuit breaker for cutting off or connecting a circuit; A step-down transformer for converting high-voltage current into low-voltage current; An AC / DC power supply for converting alternating current into direct current and providing a DC power supply for the cleaning trolley control circuit unit and the driving motor; A cleaning trolley control unit for controlling the driving motor and monitoring the operating state according to a control program.

6. A method for measuring the effective power generation utilization hours of a photovoltaic power station, characterized in that, The method adopts the measurement system according to any one of claims 1 to 5, and includes the following steps: Obtaining the electric energy generated by the photovoltaic string; Using the electric energy generated by the photovoltaic string to complete the cleaning of the photovoltaic string through the automatic cleaning system; Obtaining the electric energy generated by the cleaned photovoltaic string and measuring to obtain the operating parameters of the photovoltaic string; the operating parameters of the photovoltaic string include the power generation amount generated by the photovoltaic string and the real-time power of the photovoltaic string; Calculate the actual effective power generation hours of the photovoltaic string operation based on the operating parameters.

7. A method for measuring the effective power generation hours of a photovoltaic power station according to claim 6, characterized in that, The step of using the electric energy generated by the photovoltaic string to complete the cleaning of the photovoltaic string through the automatic cleaning system specifically includes: Set the control program for the cleaning action; Obtain the peripheral signals of the DSP processor; Perform fault troubleshooting based on the peripheral signals; Control the drive motor to complete the cleaning action according to the fault troubleshooting results and the control program.

8. A method for measuring the effective power generation hours of a photovoltaic power station according to claim 6, characterized in that, The step of obtaining the operating parameters of the photovoltaic string by measuring the electric energy generated by the cleaned photovoltaic string specifically includes: Obtain the current of the electric energy through the shunt detection circuit; Obtain the voltage of the circuit through the metering device; Calculate the real-time power and power generation according to the current and voltage.

9. A method for measuring the effective power generation hours of a photovoltaic power station according to claim 7, characterized in that, The step of performing fault troubleshooting based on the peripheral signals specifically includes: Generate a fault alarm according to the fault cause in the peripheral signals; Report the fault alarm to the background; Perform operation control and parameter setting on the cleaning trolley control unit according to the fault alarm.

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