1 Introduction In recent years, solar photovoltaic power generation technology has been widely used and developed rapidly at home and abroad. The world's solar photovoltaic industry develops at an average annual growth rate of more than 33%, and the growth rate in 2002 was more than 40%. At present, the installed capacity of photovoltaic systems worldwide has exceeded 2.0GW and will exceed 15GW by 2010. In the future, solar photovoltaic building integration and photovoltaic grid-connected systems will be the ultimate development direction of solar photovoltaic applications. However, the operation of photovoltaic grid-connected power plant systems is generally operated without supervision. Solar photovoltaic power plants are composed of scattered photovoltaic power generation subsystems. It is necessary to monitor and maintain a wide range of distributed photovoltaic systems in the region. It is very difficult and cumbersome, requiring a lot of manpower and material resources. The local and remote monitoring technology is used to monitor the photovoltaic power generation system in real time, so as to achieve centralized dispatch management of these decentralized energy systems, achieve the goals of peak shaving, distribution, measurement, and effective use of the large power grid. The decentralized solar photovoltaic grid-connected systems are connected to form a safe, intelligent and decentralized large-scale green energy dispatch management system. Therefore, it is of great significance to study the local and remote monitoring technology of photovoltaic systems. In particular, the upcoming energy shortage in China has important practical significance in accelerating the popularization of grid-connected solar photovoltaic power plants in urban and rural areas. The main content of this paper is to use Ethernet technology to build an embedded Web2Se ve r with DSP as the core and interconnect with Intenet to realize status monitoring, fault detection, data collection, energy scheduling and distribution of the photovoltaic system. , Measurement, etc. 2 System realization principle Figure 1 is a system block diagram of a photovoltaic power generation monitoring system. The most important part is the embedded Web2seve r with DSP as the core, electric energy measurement and related parameter monitoring, LCD display and other parts. Among them, the electric energy measurement part should not only measure the electric energy and harmonic amount converted by the inverter, but also collect solar sensor information to monitor solar radiation, solar panel temperature, solar cell array voltage, Battery voltage, solar cell array current, battery current. Therefore, it is no longer a traditional electrical energy measurement, but a fully functional data acquisition system. Therefore, advanced DSP measurement technology is adopted to ensure high accuracy and high stability of the energy meter. 3 System design 3. 1 choice of communication method This system adopts the communication method of Ethernet. Its advantages are that the Ethernet is widely used, the cost is low, the communication rate is high, and the hardware and software resources are very rich. Due to these advantages of Ethernet, there are many ways to use Ethernet technology as a network communication platform. Advantages, through Intenet access system, as long as you have a computer, PDA or mobile phone with Internet access, you can automatically monitor the equipment in the photovoltaic system anytime and anywhere, and optimize the management and control of energy. Application prospects. 3. 2 The design of network communication module based on ADSP2BF537 This system selects ADSP2BF537 as the main controller. The chip is a high-performance blackfin processor with a clock frequency of up to 600MHZ. It has 132KB full-speed SRAM on-chip, 10-stage R ISC MCU / DSP pipeline, and has the best code density. 32-bit ISA, powerful and flexible cache is very suitable for soft real-time control and industry standard systems, as well as hard real-time signal processing, and the chip is embedded in IEEE802. 3 compatible 10/100 Ethernet MAC, with a buffer oscillator output to A separate PHY is very suitable as an Ethernet controller, which simplifies the circuit design and saves design costs. The physical layer interface chip selects LAN83C185. The LAN83C185 chip is a low-power high-integration analog interface IC, including an encoder / decoder, scrambler / descrambler, transmitter with shaping and output driver, and chip Internal adaptive equalizer and baseline roaming (BLW) modified twisted pair receiver, clock and data recovery circuit and media separate interface (M II) part, integrated DSP with adaptive equalizer, supports automatic circulation and parallel detection , Working voltage 3. 3V, fully compatible with IEEE 802.12 / 802 / 3u standard, with full-duplex 10BASE2T / 100BASE2TX transceiver, supporting 10Mbps and 100Mbps unshielded twisted pair, complete power management features. 3. 3 Design of energy measurement module In the design, ADE7169 of American Analog Devices was used as the energy measurement chip. The energy measurement chip combines the mature energy measurement core of AD I with the microprocessor, on-chip flash memory, LCD driver, real-time clock and intelligent battery management circuit. Together, it not only reduces power consumption but also simplifies circuit design. After filtering, the voltage signal collected by the voltage sensor is sent to the energy measurement chip through pins 49 and 50, and the current signal is also obtained through the current sensor, and after filtering, it is sent to pins 52 and 53 of the energy measurement chip 7169. Perform energy calculations for active power, reactive power, and apparent power, as well as measurement of voltage RMS and current RMS. The circuit diagram of the energy measurement module with ADE7169 as the core is shown in Figure 2. 3. 4 Human-machine interface design The man-machine interface design includes a liquid crystal display module. The liquid crystal display module adopts TSG128128A series module. This series of liquid crystal display module is based on SMD technology, the display content is 128x128 dot graphic dot matrix, the connection module 22 pins, the pin spacing 2. 54mm. Typical operating voltage and current; contrast can be adjusted, The display effect is clear and the screen stability is good. This module is connected to pins 7-33 of ADE7169. 4 Software design and its workflow The RJ-45 of this system is the interface between the system and the local area network. Since most local area networks use Ethernet, the LAN83C185 here is used to process the Ethernet protocol (IEEE 802.3). The flow of data is that the request information comes from the local area network and is sent to the LAN83C185 through RJ-45. The processed data packets are sent to the protocol stack of the DSP system. The protocol stack analyzes the data packets to obtain the original request information. The request information is then processed by the DSP system to generate response information. The response information is transmitted to the user's browser through the local area network. The software flow of the entire system is shown in Figure 3. The software of the embedded Web server in this system is mainly composed of modules such as chip initial setting, implementation of lwip protocol stack, data acquisition and processing. Add user-defined data communication protocol based on lwip protocol to the program. In this way, the PC in the customer's local area network can communicate with the embedded Web server in a customized manner, such as sending data acquisition commands and acquisition parameter initialization commands. The network layer part has joined the address resolution protocol (ARP) to realize the mapping of IP addresses to physical addresses. The implementation of the protocol stack is mainly divided into the interpretation of receiving data packets and the packaging of sending data packets. Ethernet data is transmitted in frame format. If the value of the frame type field is 0x0806, it is an ARP packet; if it is 0x0800, it is an IP data packet. When receiving a frame, it is processed by different software modules according to different frame types. When sending data frames, they are also packaged by different programs according to different frame types. The receiving and sending of frames are based on the operation of the physical layer on the PHY, including reading the receiving buffer and writing the sending buffer. 5 Conclusion The innovation of this article lies in the use of Ethernet technology to build a small embedded Web server with DSP as the core and loaded with LW IP protocol stack that can be interconnected with the Internet to realize automatic monitoring of photovoltaic equipment and optimization of electrical energy Management and control functions. Experiments show that when you enter the address of the system http: / / 192. 168. 1. 36 / index. Htm, the monitoring web page will be displayed in the browser. By clicking each function button, you can get the current voltage, current, The size of the active power and reactive power, as well as the parameters of the ambient temperature of the equipment work, at present, the system can realize the remote monitoring of the photovoltaic system equipment in the local area network. The main pain points in obtaining customers in foreign trade are fierce market competition, high customer acquisition costs, low customer stickiness, and single marketing methods. With the changes in the market environment, traditional marketing methods Orange sample 2222Bossgoo(China)Tecgnology.
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