KR20080067329A - System and method for array and string level monitoring of a grid-connected photovoltaic power system - Google Patents

Abstract

A grid-connected photovoltaic electrical power system with both array level and string level remote monitoring and production and efficiency analysis capabilities. The inventive system includes an array level monitoring component, software for recording and analyzing data obtained through the array level monitoring component, and a string level monitoring component.

Description

System and Method For Array And String Level Monitoring Of A Grid-Connected Photovoltaic Power System}

The present invention relates to a grid-connected photovoltaic energy system. More specifically, the present invention relates to grid-connected photovoltaic energy power systems having both array-level and string-level monitoring and production and efficiency analysis capabilities.

As by rapidly-minute Earth's remaining stockpile depletion on oil, CO as evidence of global warning on _two levels rise, and the need and suitability for clean energy and increase the awareness of the responsible preservation of natural resources, the people of Electrical Transitioning to new and reliable sources of power. It is now commonly said that the ultimate source of all energy on earth is the sun. Rather, it is said that the most promising of the proposed solutions to future energy supply problems is the direct use of sunlight. Because direct use of sunlight is the safest and most reliable means of generating energy. However, there are considerable issues regarding the economic viability of solar power systems, and the only economic factor that remains a problem for most potential users in some parts of the world, which are rich in solar energy. Nevertheless, with the design and development of buildings that optimize the use of sunlight for heating, lighting and hot water supply, the installation of photovoltaic systems continues to increase. Therefore, the performance of photovoltaic systems continues to be important.

Photovoltaic power systems generally include a number of interconnected photovoltaic modules, mounted on a large planar surface (typically, the roof of a powered building or home) and sometimes on a site surface adjacent to such a structure. The modules are connected in series to form a string, and these interconnected strings are called arrays (or panels). Each photovoltaic module in the array includes photovoltaic cells, which convert solar energy into DC power, and the DC power from each module is coupled and carried through a DC / AC power inverter. DC / AC power inverters are mounted adjacent to electrical power supplies from commonly used power suppliers. The inverter converts direct current into alternating current that is compatible with the alternating current provided by the utility provider (i.e., utility grid), so that the AC output of the photovoltaic system, through the building distribution panel, powers the load. It is combined with AC power from a utility (or public service) provider that supplies it. This kind of device is described as a grid-tied photovoltaic power system (hereinafter referred to as GCPV).

As already demonstrated, the power supplied by the GCPV system reduces the cost of the consumer by reliably reducing utility power consumption in an environmentally friendly manner. In addition, tax and financial incentives and solar rebate programs are provided by public policy and law, offsetting installation and operating costs and contributing to savings.

Standalone-There are several advantages of GCPV over GCPV systems, including the fact that most can be obtained at night or during harsh weather and dark winter days, without having to have an excess battery bank to store power. Furthermore, at the peak solar power generation time, excess power can be moved back to utilities. The disadvantage is that GCPV systems can only be installed where they are powered from the utility grid.

The critical step to lowering energy costs is to reduce electricity consumption. An informed approach to selecting and operating a suitable PV system requires preliminary and ongoing energy checks to determine actual needs, power consumption and power waste. This audit prevents consumers from purchasing too large a PV system and prevents subsequent waste due to system installation. Preliminary inspection involves identifying the main sources of electricity consumption, after which energy reduction and efficiency solutions represent problems such as lighting, refrigeration, air cooling, motor starting and optimization. Upgrading devices, applications, structural insulation, etc. is practical, and when combined with PV systems, reduces and potentially eliminates the energy consumption of public utility grids. In fact, in a net meter environment, PV power users can purchase power from utilities and send the surplus power generated back to the distribution grid for credit. Indeed, on bright days, electricity meters (or meters) rotate backwards, and solar systems receive a deduction for energy from the utility's retail energy bill. Utilities need to deduct fees to solar energy producers at retail rates on the date and time the energy was sent to the grid.

Once installed, the operation and efficiency of the GCPV system needs to collect, monitor, and evaluate large amounts of data. Several factors affect the efficiency of the GCPV system, which is the power output of the PV system and the power provided by the utility provider (as a contributing or exclusive source), the user's power consumption and ambient temperature, wind speed and direction. Operating environment data such as solar illuminance and solar insolation.

The same for the GCPV system applies equally to power generated and sold under a power purchase agreement.

Many institutions, industries and governments are moving toward "green power" procurement as one of their energy policies. The terminology indicated by quotation marks, of course, refers to several new energy sources, including wind, in addition to the sun. The government and industry or individuals may optionally purchase all or part of the power under a long and short term power purchase agreement, either directly from the green power producer or from a utility provider that procures power from the green power producer. Exchangeable credits and public goodwill associated with the use of new energy are strong incentives for green power purchases, improving green power joy energy infrastructure reliability and potentially caused by fossil fuel shortages, production plant accidents or terrorism Reduces concerns about potential supply disruptions. However, power purchase contracts are often contracts that fix prices or limited price ranges, so they need a party that anticipates the future for the best deal. This becomes increasingly difficult. Therefore, it is desirable to be flexible in creating such a contract and to include execution conditions that affect the purchase price. However, system performance must be carefully monitored, and it is desirable that the system monitor is for independent power producers and utility providers, not for retail buyers (consumers).

Thus, users and / or providers can collect, collate, and remotely analyze new power generation system data in real time and determine whether power is being generated by the sun, biomass (plant and animal waste), geothermal, wind, or hydro evening systems. You need a monitor system to monitor. The system of the present invention focuses on this need.

A method and system for an array and string level monitor of a grid-tied PV system according to the invention, comprising: an array level monitor component; Software for recording and analyzing data acquired through the array level monitor system; And a string level monitor system.

The first component is an array level system that provides a means for remotely monitoring the performance of a PV system. This allows you to monitor up to four kinds of information in real time. This information includes (a) the electrical power output of a solar array; (b) electrical power consumption of users (buildings, dwellings, factories, etc.); And (c) electrical power provided by the power utility, and optionally (d) selected weather and solar insolation data. The system preferably enables remote verification of system performance, energy cost savings, and return on investment, both internet-based and available online. Many other suitable communication systems may be used for data transmission, including portable communication systems, satellite systems, RF systems, infrared systems, wireless LANs and WANS, and other or existing systems that are not yet developed.

The monitor system according to the present invention combines proprietary software and hardware developed by the present invention. In operation, in real time solar energy data may be obtained by a revenue-grade ANSI electrical meter and may be obtained by a selectable spectrum, silicon photometer, or other temperature sensor. Data is delivered simultaneously to the online and / or on-site touchscreen. Data for power flow, cumulative energy use, solar insolation rate, and selected weather conditions—solar irradiation rate, wind speed, and ambient temperature—are updated and stored every 15 minutes. Access to stored data via the Internet is not blocked for 24 hours a day, 365 days a year, for both system providers and users. Spreadsheet formats known for data download, date, month and year data adders are provided. All data is logged to a secure server that is owned, supported and protected by the vendor.

Using an array level monitor system in accordance with the present invention, PV system users can log in to a secure server to recover a report on system performance. Because the monitor measures actual solar power generation and building electricity consumption, it indicates whether energy is being transferred to the utility grid in the net metering process or whether energy is drawn from the utility. And it adds a layer of information and record keeping that is not currently available in the solar industry.

The second component of the system according to the invention is the record analysis software associated with the array level monitor system. This enables the user to log in to perform an analysis on the data obtained by the monitor system.

A third component of the system according to the invention is the PV string level monitor system, which lowers the monitor for a wide range of sun rays to string level.

Other novel features relating to tissues and methods of operation, which are features of the present invention, will be better understood by the following description of the accompanying drawings, together with their objects and effects. The embodiments of the invention herein are for illustration only. However, it will be readily understood that the drawings are for illustrative purposes only and are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In order for the present invention to be fully understood and to have substantial effect, preferred embodiments of the present invention, but not limited thereto, are described below with reference to the accompanying drawings.

1 shows a typical grid-connected PV system structure.

2 is a diagram illustrating a back end of an array level monitor component of a system and method for an array and string level monitor of a grid tied photovoltaic power system, in accordance with the present invention.

3 is a block diagram illustrating a string level monitor component, in accordance with the present invention.

4 is a wiring and functional block diagram illustrating a string level sensing device of a string level monitor component.

5 shows a preferred embodiment of a sensor board, in accordance with the present invention.

6 shows a preferred embodiment of a micro-controller board in accordance with the present invention.

Hereinafter, the present invention will be described in detail with the accompanying drawings and examples.

1 through 6, like reference numerals in the various drawings indicate like components (components), showing new and improved methods and apparatus for array and string level monitors of grid-tied PV systems. 1 shows a general configuration of a GCPV system 10, which is a utility power provider or grid 12, a messenger transmission line 14 connecting the grid to a user building power supply 16, and inserted therebetween. A current converter 18. The system also includes a PV power system or array 20, a power transmission line 22 extending from the PV system to a junction or meter 24 (the junction or meter being connected to the power transmission line 14 from the grid). Connection), and a current converter 26 for the PV system.

In the previously described GCPV system architecture, the monitor system according to the invention comprises three preliminary components. This component (component) includes an array level monitor component, a computer component including a programmable computer for acquiring, recording and analyzing data acquired through the array level monitor component, and a string level monitor component.

2, the solar power array level monitor component 100 of a grid-tied system according to the present invention comprises three basic devices. (1) back-end hardware devices, (2) server-side back-end software, and (3) server-side front-end software.

6200 전력 미터기(130, 140)와 전기적으로 연결된 리눅스 커널 동작 시스템을 구동한다. (ION

은 캐나다, 브리티시 콜롬비아, 사니치톤에 위치한, 파워 메저먼트사(Power Measurement LTD.)의 등록 상표이다.) 슈퍼로직 8520 RS-232 - RS-485 컨버터(150)가 리눅스 시스템 치 전력 미터기 사이에 삽입된다. 제 1 전력 미터기(130)가 PV 시스템의 출력을 측정하고, 제 2 전력 미터기(140)가 유틸리티 회사에 의해 제공되는 전력을 측정한다. 측정된 미터기의 출력이 사용자/빌딩의 소비량을 표시한다.The back-end hardware is mounted in a closed housing 110. This housing includes, among other devices, a microprocessor for a small embedded Linux-based computer 120 (eg, as an open brick platform, preferably using small flash memory for reliability). Flash is Import Grade ION

Runs the Linux kernel operating system electrically connected to the 6200 power meters (130, 140). (ION

Is a registered trademark of Power Measurement LTD., Located in Sanchiton, Canada, British Columbia.) The SuperLogic 8520 RS-232 to RS-485 converter (150) is used between the Linux system's power meter. Is inserted. The first power meter 130 measures the output of the PV system, and the second power meter 140 measures the power provided by the utility company. The measured meter output shows the consumption of the user / building.

The Linux computer periodically checks the meter every 5 seconds to obtain readings from both the PV system meter and utility meter and the cumulative daily power output of the PV system and utility provider. The computer also receives field measurement data collected in an operating environment. This data is collected by atmospheric temperature data (collected by Type-J thermocouples 160 installed in shaded positions) and insolation data (solar rate sensors (LI-200 SZ all-in-one solar sensor 170) mounted on the plane of the array module. Collected) One or more AD converters (or converters) 180, 190 may comprise computer and analog data sources (preferably a SuperLogic 8019R data acquisition interface and / or a SuperLogic 8520 RS-232 to RS-485 converter). (Included)).

Thus, a Linux system obtains real-time data from two power meters and pyranometers through an AD converter, and creates a simple ASCII file with a data stamp. As a result, information about the photovoltaic system output (PVKW), PV meter system total KWH (measured from the time the meter was started), PVKWH of the day, total PVKWH of the month, and PVKWH of the year are stored and analyzed. In addition, it provides maximum power output for PV systems. Other fields in the ASCII file include utility power output (in KWH), total utility output of KWH, and other parameters (including temperature and insolation rate).

The ASCII file described above is logged in the event of a network error, thereby preserving history records that can be filed. Next, the file is transferred to the secure server using the file transfer protocol. In addition, log files are sent to the server regularly and automatically.

2000 서버이다. (윈도우즈

2000은 미국, 워싱턴, 레드몬트에 위치한 마이크로소프트 사의 등록 상표이다.) 백-앤드 서버가 자동으로 업로드 된 파일을 가지는 모든 GCPV 설치 파일을 데이터 디렉토리에 저장하고 판독하는 백-앤드 프로세스를 시행한다. 이는 이후에 프론트 앤드에 대해 XML 포맷의 파일을 만든다. 또한, 시간 동기화 파일을 제공하고, 에러를 확인하며, 데이터 파일 하우스키핑 기능을 수행한다.The back-end server is located in a security facility and communicates with the Linux system described above and the Internet 210 or other suitable means of communication.

2000 server. (Windows

2000 is a registered trademark of Microsoft Corporation in Redmont, Washington, USA.) The back-end server implements a back-end process that saves and reads all GCPV installation files in the data directory that have automatically uploaded files. This later creates a file in XML format for the front end. It also provides time synchronization files, checks for errors, and performs data file housekeeping.

The front end of the software is the GUI 220, which allows a user to log in to a computer provided to a general personal computer 230 or PV vendor kiosk 240. After login, the user can review a number of animated pages based on the XML file generated by the back-end software. The first animation provides a real time screenshot showing the amount of power currently provided by the utility company (how much power is provided by the PV system and how much is consumed by the facility). The animations are shown in the urban utility grid, power lines from the grid to the building, utility power consumption (or power credit if the PV system provides more power than is consumed by the building), PV solar panels (solar array) Graphics, extending from PV array systems, include power lines connected to utility-to-building power lines, and largely enlarged power meters between utilities and facilities that explicitly represent the graphics of the building. These animation simulations can be found at http://www.SPGsolar.com/net_metering.html.

The next device in the system according to the invention is the report software. Like the Beck-and-Engine, front-end report software includes a user interface that allows a user to log in using a password. After logging in, the user can view the real-time data described above, or specify a data range for performing usage analysis. The software generates a report divided into time intervals covering this range. For example, if the range is one day, the time interval is divided into hours. If the report is surveyed, the time interval is in days. If an annual report is surveyed, the analysis is based on monthly data. Fixed sub-sections are in days. When a report is requested, the report software sends a request to the server, which is processed by the back-end engine. The back-end engine generates data and all the data to show specific time periods such as kilowatt hours for the utility, kilowatt hours at the peak, part peak, and off-peak. Download it. These are based on the utility provider rate schedule. On the report page, the user is given the option to review graphs and spreadsheet forms showing all the data divided by time intervals. The user can collect two different parameters that make up three different building PVs or utilities, two basic parameters of power KW and use or energy KWH.

The third component of the system according to the invention is a string level monitor component (component). String monitors (or monitors) are important because array-level monitors are typically limited to monitoring energy generation as a function of solar time, ambient temperature, solar insolation, and so on. However, because there are many effect factors at the array level, as low as 1-3% in devices such as combiner box fuses, recombiner box fuses or individual modules at individual string levels , It is difficult to detect small device defects. The string monitor component enables monitoring at this small scale level. Maximum power is generated by detecting and correcting string errors.

Referring to FIG. 3, the string monitor device 300 is in a state of being in electrical communication with the PV array 310 through a positive lead 320 and a negative lead 330 connected to individual ends of each of a series of strings. have. Leads are coupled at the box level, preferably in a PCB10 PV array combiner box 340 in a NEMA 3R case 350. The outputs of the various PV source circuits are combined and current is routed through the additional combiner box 340. Next, all of the combiner boxes are attached to the recombiner box 350 until the output is routed through the inverter 370.

CLN-25 FW Bell 폐쇄-루프 전류 센서(380)를 사용한다.(SYPRIS

는 미국, 켄터키, 루이스빌의 사이프리스 솔루션 주식회사의 등록상표이다.) 이는 고 감도 DC 홀-효과 전류 측정 장치(200분의 1(0.5%)의 정확도를 가짐)이며, 1000V DC.까지 정해진다. 이는 여러 요인(factor)에 의해 전류를 단계적으로 낮추는 변압기로 기능 한다. 출력(390)은 11-채널 아날로그- 디지털 변환기를 가지는 간단한 마이크로 컨트롤러(400)로 라우트 된다. 마이크로 컨트롤러가 C 코 드( RS485 랜(410)에 대해 "Your Ask It"의 쿼리 언어를 지원함)를 동작시킨다. 각 채널 상의 전류가 개개의 스트링 상의 전류에 대응하며, 채널(420) 중 하나가 전압 기준이 부착된 레지스터(430)를 포함한다. 따라서, 결합기 박스가 스트링의 전류뿐 아니라, 이를 동작하는 전압도 전자적으로 측정한다. 따라서, 시스템이 전류뿐 아니라 모든 단일 포인트에서의 전력도 측정한다. 이는 어레이 전체의 전력 밸런스를 맞추는 수단을 제공한다. 결합기 박스의 스트링 모니터 장치가 RS-485 랜(440)을 통해, 같은 장소에 위치한, 구형 중앙 컴퓨터와 통신하며, 이는 실드(sealed) 장치이다. 중앙 컴퓨터(110)(바람직하게는 위에 설명한 바와 같이, 케이스(enclosure) 또는 하우징(110) 내에 배치됨)가 컴퓨터 박스 각각을, 어드레스 가능함에 따라, 조사한다. 이들 각각은 0-999에 걸친, 고유 어드레스로 설정된 회전 스위치를 포함한다(스위치 선택 회로에 대한 도 5 참조). 컴퓨터는 "What is your string current now?", "What is your voltage now?", "What is your power on this little string?"과 같은 종류의 쿼리(queries)로 각각의 결합기 박스와 통신한다. 따라서 스트링이 개별적으로 측정되고, 소프트웨어가 분석적인 비교를 수행한다. 스트링이 수용 범위 외에서 동작하는 경우에, 프론트 앤드 소프트웨어가 알람(450)을 울린다. 이러한 방법으로, 모듈 및 퓨즈 내 매우 작은 오류가 필요에 따라 검출 및 검토된다.As can be seen in Figure 4, in the first embodiment, the string level monitor component is a series of SYPRIS.

CLN-25 FW Bell closed-loop current sensor 380 is used. (SYPRIS

Is a registered trademark of Cypris Solutions, Inc. of Louisville, Kentucky, USA.) This is a high sensitivity DC Hall-effect current measurement device (with accuracy of 1/2200 (0.5%)) and is rated up to 1000V DC. . It acts as a transformer that lowers the current by several factors. The output 390 is routed to a simple microcontroller 400 with an 11-channel analog-to-digital converter. The microcontroller runs the C code (which supports the query language of "Your Ask It" for the RS485 LAN 410). The current on each channel corresponds to the current on an individual string, and one of the channels 420 includes a resistor 430 with a voltage reference attached. Thus, the coupler box electronically measures not only the current in the string, but also the voltage at which it operates. Thus, the system measures not only the current but also the power at every single point. This provides a means of balancing the power across the array. The string monitor device of the combiner box communicates via an RS-485 LAN 440 with an older central computer located in the same place, which is a sealed device. A central computer 110 (preferably disposed within enclosure or housing 110 as described above) illuminates each of the computer boxes, as addressable. Each of these includes a rotary switch set to a unique address, spanning 0-999 (see Figure 5 for a switch select circuit). The computer communicates with each combiner box in a variety of queries such as "What is your string current now?", "What is your voltage now?", And "What is your power on this little string?" Thus the strings are measured individually and the software performs an analytic comparison. If the string is operating outside the acceptable range, the front end software sounds an alarm 450. In this way, very small errors in modules and fuses are detected and reviewed as needed.

In an alternative embodiment for a string monitor device, a sensor board 500 is provided and consists of a 10DC Hall effect current sensor 510, a power supply 520, and a voltage divider 530. Current from the string 540 passes through the current sensor during measurement. The measurement signal is then sent to the micro-controller board 550. Similarly, the array voltage is passed to a high-impedance voltage divider, in which the voltage is stepped down to 0-5 VDC and transferred to the microcontroller board.

A unique feature of the string array monitor system is that a general microcontroller is powered by the array and therefore does not require an independent power supply. The power supply supplies +15 VDC, converted from the array voltage, to the measurement electronics (current sensor and microcontroller board), which is typically between 300-500 VDC. The power supply section consists of a series-pass linear FET 560 represented by two zener diodes 750, which maintains the FET output at about 300 VDC, which is the maximum of the V-high performance AC-DC converter 580. The output supplies +15 VDC power to the microcontroller board.

In the board according to the preferred embodiment, the microcontroller board 600 is comprised of an expandable 8051-based microcontroller 610, an ADC, RS-485 and other chips and components for power regulation. The microcontroller digitizes the signals from the ten current sensors 620 on the sensor board to obtain the signals from the ten string currents and voltage dividers. This specifies the string voltage level. These values are stored in memory and output as ASCII byte values for the query via the RS-485 interface chip 630. Green and red LEDs 640 indicate proper and unstable behavior, respectively. The red LED flashes to indicate a specific kind of problem. As described above, the microcontroller communicates with the combiner box via an addressable combiner box ID selection switch circuit 650.

The above-described embodiments of the present invention are for illustration and description only, and are not intended to limit the present invention to the described form. Accordingly, various changes and modifications can be made to those skilled in the art to which the present invention pertains. In addition, the detailed description of this specification does not limit the scope of the present invention.

For example, it will be apparent to those skilled in the art that the first two devices of the system described above can be used to monitor any type of grid-connected new electrical energy generating device. Thus, the previous discussion is centered on grid-linked PV systems, but the present invention provides for all types of independent new energy production systems, including solar, biomass, wind, geothermal, fossil fuels, and hydroelectricity. Obviously, it is intended to provide a means of monitoring (or monitoring) and analyzing performance and contribution.

Therefore, the above description and drawings should not be construed as limiting the scope of the invention but as defined by the appended claims below.

Claims (27)

A system for a string level monitor of a grid-tied photovoltaic system having a photovoltaic solar panel, the system comprising: Array level monitor components; A computer system in electronic communication with an array level monitor device, the computer comprising software, the computer system characterized by obtaining, recording and analyzing data from the array level monitor system; And String level monitor component in electronic communication with the array and the computer system String level monitor system comprising a. The method of claim 1, Wherein the array level monitor component comprises back-end hardware, a back-end server with server-side back-end software, and a front-end server with server-side front-end software. system. The method of claim 2, The back-end hardware includes a microprocessor, first and second imported grade power meters in electrical communication with the computer, and an AD converter inserted between the computer and the power meter, The first power meter measures the output of the PV system, And said second power meter measures the power provided by the utility energy provider. The method of claim 3, wherein And a housing surrounding the computer. The method of claim 3, wherein And the computer is programmed to periodically inspect the power meter at regular intervals of time for reading data from the first and second power meters. The method of claim 3, wherein And one or more analog data sources for providing real-time environmental data to the computer. The method of claim 6, And the analog data source comprises a temperature sensor. The method of claim 6, And said analog data source comprises a solar rate sensor. The method of claim 6, And at least one AC converter disposed between the computer and the analog data source. The method of claim 6, And the computer is programmed to obtain real-time data from the power meter and the analog data source and create a file with a data stamp. The method of claim 10, The computer is further programmed to store, analyze, and create a data file relating to data from the output of the photovoltaic system, The output of the photovoltaic system is the total output of the photovoltaic meter system measured from the time the meter is turned on, the output of the photovoltaic system for the current date, the output of the photovoltaic system for the last month, the output of the photovoltaic system for the year and And a maximum power output for the photovoltaic system. The method of claim 10, The computer is further programmed to obtain, analyze, and create a file related to data from the output of the utility power system, the overall utility output for a specified time interval, and the temperature and solar insolation rate. . The method of claim 10, The computer is programmed to transfer the data file to a secure server using a file transfer protocol. The method of claim 13, And said back-end server is disposed in a security facility and is in electronic communication with said computer. The method of claim 14, The back-end server includes software, and the back-end software stores and reads all files of a plurality of grid-connected photovoltaic systems with files that are automatically uploaded to a data directory and in a file in markup language format. String level monitoring system, providing time synchronization files, checking for errors, and performing data file housekeeping functions. The method of claim 15, The front end software provides a graphical user interface through which a user logs on to a computer to inspect a screen based on markup language files created by the back-end software, which screen is provided by a utility company. And a real-time screenshot that indicates the amount of power currently provided and indicates how much power is provided by the photovoltaic system and how much power is consumed by the facility. The method of claim 16, The front-end software includes means for specifying a data range over which the user undergoes energy usage analysis, and the front-end software generates a report divided into time intervals containing the range. Level monitor system. The method of claim 2, And the string level monitor component is in electronic communication with the array via a positive lead and a negative lead connected to an individual end of each series of strings. The method of claim 18, A plurality of combiner boxes, The positive and negative leads are coupled to a first array combiner box, the outputs of the plurality of PV source circuits are connected, and current is routed through the additional combiner box. The method of claim 19, Further includes an inverter, And all of the combiner boxes are attached to a re-coupler box, and current output from the re-coupler box is routed through the inverter. The method of claim 18, And a transformer for stepping down the current output from the array. The method of claim 21, And said transformer comprises a series of closed-loop current sensors. The method of claim 21, And the output current of the transformer is routed to the microcontroller. The method of claim 23, The microcontroller comprises a multi-channel analog-to-digital converter, The current in each channel corresponds to the current in the individual strings, One of the channels includes a resistor to which a voltage reference is attached, whereby the first combiner box measures the current in the string and the voltage at which it operates to measure power at every single point, in this way throughout the array. Providing a means for balancing power over a string level monitor system. The method of claim 19, The combiner box can be addressed using a switch, The combiner box communicates with the combiner box using a query regarding string level power output data, And said front-end software includes a program for outputting an alarm signal when the string is performed outside of a predetermined range. The method of claim 18, And said string level monitor component comprises a sensor board having a plurality of current sensors, a power supply and a voltage divider. The method of claim 18, And the microcontroller is powered by the array.

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