Therefore, it is necessary to do a good job in the standardized management of photovoltaic power plant operation, scientific data analysis, and intelligent remote monitoring to promote the better development of the photovoltaic power generation industry
Status quo of operation and maintenance management of distributed photovoltaic power plants
Main features of distributed photovoltaic power plants
There are four characteristics of distributed photovoltaic power plants:
1) The construction scale of the power station is small. Compared with the installed capacity of centralized photovoltaic power plants reaching hundreds of megawatts, the modular design of distributed photovoltaic power plants determines its size. Conditional restrictions are adjusted, and the general installed capacity is below 50MW.
2) A notable feature of distributed photovoltaic power generation is that it can convert a steady stream of solar energy resources in nature into green and clean electricity, and does not generate noise or emit harmful gases during the entire power generation process.
3) As an important supplement to the power source of the local power grid, it can effectively alleviate the problem of insufficient local power supply. The photovoltaic power generation system has the highest power during the daytime during the peak period of the user's electricity consumption, which is consistent with the peak and valley characteristics of the local power grid company, and can minimize the user's electricity bill.
4) The installation locations of distributed photovoltaic power station equipment are scattered and independent, and the components can be designed according to the area, location and structure of the roof, the installation scale and location of the inverter, and the installation methods are flexible and changeable.
Operation and maintenance management methods of distributed photovoltaic power plants
There are generally two types of operation and maintenance modes for photovoltaic power plants:
Adopt the mode of entrusting a third party to carry out power station operation and maintenance management.
Establish the operation and maintenance mode of the operation and maintenance team by yourself.
Problems in the operation and maintenance management of photovoltaic power plants
01: The number of power station operation and maintenance personnel is small and the professional quality of employees is low
Under normal circumstances, in order to reduce operation and maintenance management costs and improve project economics, most power stations adopt the mode of unattended and remote centralized monitoring, which makes it difficult to effectively implement the management requirements of manned stations and "two votes and three systems" at the same time. Quickly release the alarm of the power station and eliminate the defects of the power station.
Also out of cost-saving considerations, the threshold for operation and maintenance management practitioners is low, lack of systematic professional technical training and power station maintenance experience after employment, lack of basic on-site emergency handling capabilities, and it is difficult to quickly solve difficult equipment failures Response, thereby increasing the safety risk of power station operation and maintenance.
02: Lack of information management and control on the power station site
Due to the multifaceted characteristics of distributed photovoltaic power stations, in the operation and maintenance management of power stations, it is difficult to do daily inspections of power station equipment. The on-site situation can only be inferred through the background monitoring system equipment alarm monitoring, and the on-site situation cannot be accurately grasped. It is impossible to judge whether the alarm information is a false alarm, and when an equipment failure alarm is found, it is difficult to quickly eliminate the equipment failure on site, resulting in the delay in eliminating the equipment failure and then causing the expansion of the equipment failure.
At the same time, because the operation and maintenance personnel are far away from the power station site, it is difficult to judge the degree of dirt on the surface of the components. The cleaning of the components is only arranged through the analysis of the system efficiency, and the system efficiency is a variable parameter coupled by multiple factors. Therefore, the components are often not cleaned in time, and the system Economic losses caused by reduced efficiency.
03: The complexity of roof equipment makes equipment inspection and component cleaning difficult
In order to maximize the utilization of roof space, photovoltaic power plants are designed to arrange the modules in a relatively dense way, and maintenance channels and maintenance platforms are not properly set up, which will easily lead to difficult cleaning of components, inconvenient disassembly and assembly of equipment, and broken or cracked components caused by trampling on components. .
In addition, the components laid on the roof of color steel tiles are usually laid on the slope and close to the roof. Although this method reduces the impact of wind, frost, rain and snow, it brings many difficulties to the operation and maintenance personnel. For example, the DC cables on the back of the components cannot be observed during the on-site inspection. And the operation of the MC4 plug, at the same time, the operating environment of the module is not well ventilated, and the temperature of the back is high, which reduces the system efficiency and power generation.
04: The background monitoring platform is not unified
At present, the background monitoring platform of most photovoltaic power plants adopts the monitoring platform provided free of charge by inverter equipment manufacturers such as Sungrow, Huawei, Goodway, and Jinlong. Operation and maintenance managers can remotely monitor through the web version and mobile app version System for centralized management and remote monitoring of power plants.
Information such as daily and weekly reports needs to be extracted, summarized, and analyzed from different platforms. The efficiency of operation and maintenance management is low and centralized monitoring and management is difficult.
Power station operation and maintenance management improvement methods:
01: The allocation of sufficient professional and technical personnel is the guarantee for the long-term safe and stable operation of photovoltaic power plants. Combined with the characteristics of the power station and the staffing situation, scientifically and rationally establish rules and regulations, timely grasp the operation status of the power station and eliminate potential safety hazards, so as to ensure the safe and stable operation of photovoltaic power stations.
02: Remote centralized management of power station operation and maintenance + on-site entrusted technicians to manage
With the help of digital and information technology platforms, the unified management of information collection, transmission, processing and communication of photovoltaic power plants can be realized, and the power plant equipment information management system, status monitoring management system and automatic protection system can be effectively integrated to realize the data network of photovoltaic power plants Shared and remote centralized monitoring. The operation and maintenance management personnel can log in to the remote server for real-time remote access to data, and perform data query through web client, smart phone or tablet computer.
03: Design scheme for optimizing equipment layout
When carrying out the design of the power station, it should be aimed at possible component problems such as loose components, hot spot cracks, and poor contact of DC cables after the power station is put into operation, as well as inverter failures caused by aging modules, poor ventilation and heat dissipation, and poor string grounding , Cable insulation damage and aging, line short circuit, instantaneous overcurrent protection and other DC cable faults, it is necessary to choose equipment models and design methods reasonably to reduce the frequency of faults.
The arrangement of components, inverters, cables, and bridges should be rationally optimized based on the location of the existing equipment on the roof, the location of the power distribution room to be connected, and the shadow of the building, and the necessary operation and maintenance inspection channels and equipment maintenance platforms should be set up. , arrange as many components as possible on the premise of avoiding shadow occlusion and facilitating operation and maintenance.
The components laid on the color steel tile roof should reasonably raise the height of the bracket guide rails, leaving enough ventilation space, and at the same time remove the sundries blocking the air duct, reduce the temperature of the back of the components and improve the system efficiency.
04: Optimize the background centralized monitoring platform
After optimization, the monitoring platform should generally have the following functions:
Statistical analysis of data.
Intuitively compare the core indicators of each power station in multiple dimensions, grasp the overall operation level in real time, and provide a theoretical basis for management decision-making analysis.
Single power station analysis and multi-power station comparison.
Conduct multi-angle comparative analysis of data such as on-grid electricity of each power station, comprehensive system efficiency, failure frequency, and system efficiency of each matrix, and provide data support for power station evaluation and evaluation, decision analysis and scientific evaluation of operation and maintenance managers.
Count the operation status of each power station within a certain period of time, conduct in-depth analysis of each evaluation index year-on-year and month-on-month, and provide detailed and reliable operation data.
Integrate the monitoring platform data of different inverter manufacturers into one information system. The information system should have functions such as automatic classification and summary, intelligent comparison and analysis, and the information of all power station projects can be displayed on a large screen.
When the operation and maintenance management personnel find a fault through the remote monitoring system, they can directly send the operation instructions to the on-site operators through the monitoring platform, and update the fault elimination process on the platform in real time. The relevant data can be stored for a long time for easy reference. Through technical means, when a fault alarm occurs, the alarm information can be received in time.