Xuzhou Xixin Photovoltaic Power Station

Xuzhou City, Jiangsu Province, China

Project Description

Executive Summary

December 30, 2009, GCL-Xuzhou Xixin PV power plant was formally connected to the grid and the largest ground-based photovoltaic power plant. In 2013, Pixel View Solar PV Energy DC String Monitoring System was adapted in the case to monitor the renovation project. Between 2013 and 2014, 5.5MWp was further built, including Zigbee transmission (3MW) and RS-485 transmission (2.5MW).

 

Background

On December 30, 2009, Xuzhou Xixin power plant, a 20MWp solar power station was built in Xuzhou City, Jiangsu Province, Jia Wang Qu Ainshan town. The facility was constructed as solar energy demonstration site and also regarded as the largest solar power station in China.

 

As national new energy demonstration project, the solar plant not only highlighted the improvement of economy and environment but also showed that GCL-Poly Energy Holdings Ltd had integrated the upstream and downstream of the solar industry by combining polysilicon and silicon module manufacturing to the construction of photovoltaic power plants. The project represented the formation and integration of the solar energy industry chain, and escalate the level of photovoltaic industry regarding the scale and technology.

 

The challenges

Xuzhou Xixin photovoltaic power plant is a large solar power station, which is installed on remote mountain area in Xingning, Guangdong, covering 678 acres in and is divided into six districts with a total of 38 inverters and nearly 10 million solar modules. Except for fixed PV system, it contains both single-axis & dual-axis solar trackers that personnel can only rely on the information of the inverter to conduct operation and maintenance process which was not easy and time-consuming. However, the information of relevant regulations and norms were not complete after the station construction was finished, which leads to negligence inspection. After several years of operation, GCL New Energy Holdings Limited expected to install monitoring tools to assist the air O&M personnel to immediately overview the operation status of the power plant, to maximize power plant economic benefits.

 

Solution

Billion Watts provides solar PV string management system. By integrating DC string meter (SG3212S), intelligent IoT gateway, and cloud management system, Billion Watts Pixel View transmits the front-end monitoring data to the backend system through the communication gateway by adopting ZigBee-wireless communication technology. Data will be stored on memory card even if the network is disconnected; Once the network is recovered, data will be re-uploaded to the cloud which can reduce information fault problems.

 

The administrator can monitor the power generation information of the whole power station via Pixel View, a user-defined monitoring platform. When the system detects the abnormal events such as low power efficiency, PR value, or even high module temperature, the system will display the remote troubleshooting of the unusual solar strings and pinpoint the string locations on the embedded station mapping in different colors, eliminating the need of manual inspection.

 

In the first phase, the 0.5MWp station was built for testing; After a year of testing, the O&M personnel found a lot of wiring problems and line anomalies in the station by utilizing Pixel View. In 2014, the 5MWp solar plant was built in the second phase; it was worth mentioning was that both Wireless ZigBee and wired RS-485 were applied for each 2.5MWp installation in cope with different terrains. After all the solar stations were completed, the installation of both phases was integrated together into one system. According to IEC 104 code of PRC Electric Power Industry Standard, the power station sends data to the headquarter system, so that the headquarters can understand the power plant real-time status and power efficiency evaluation.

 

Result

In the past, the O&M personnel of the solar power station used the information from the inverter to carry out operation and maintenance. When the situation was detected, due to the steep mountain slope, only one of the areas was thoroughly inspected. Sometimes, many snakes were found in the mountain that the personnel were bitten by them and hospitalized for two months. By using the system, Pixel View, O&M personnel could quickly figure out specific problems in the site, such as birds excreta, the diode burned, the fuse burned or line damage, etc. Initially, it took 1 to 2 days of inspection; by using Billion Watts’s system, time of inspection could be shortened to 1 to 2 hours only to check the maintenance is complete. The problem-solving efficiency and the lower risk of the inspection process to operation and maintenance personnel, which significantly increased the power generation efficiency.

Project Details

Project Type: Ground Mounted
Nominal Power: 5.5MWp
Monitoring Equipment:
  • DC String Meters: Billion SG3212 | 110 pc
  • Inverters: 11p c
  • Solar Panels: 28,200 pc

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