- Electric energy harvesting system
1.1. Overview of Electric Energy Harvesting System
The electric energy acquisition system is an automatic information acquisition system. By collecting the voltage, current, reactive power and other data of each electric energy meter in the power station, and analyzing and processing the information, it can monitor the electric power in real time. The composition of the power acquisition system is generally not very complicated, but many new technologies are applied in the process of forming the system. Macroscopically, the electric energy collection system includes three major parts: the main station system, the channel system and the user information collection terminal system.
The function realization of the main station system should include two aspects-software and hardware, which is the real core of the electric energy information acquisition system. The information collection terminal is located at the user’s location, and its main function is to collect power information. The channel system is the channel between the master station and the data acquisition terminal. In the system, it is responsible for the connection between the main station and the information collection terminal, the terminal and the electric energy meter. The collection terminal system is mainly composed of meters and electric energy collection terminal devices. It monitors the electricity generation and consumption information in real time and can provide meter reading data in a very short period of time. Understand the power generation and consumption status of each terminal through analysis. The terminal equipment also has the function of automatic reporting of abnormal conditions, which is helpful for the management of the system.
1.2. Specifications for operation and maintenance of electric energy harvesting system
The power station should conduct regular inspections of the electric energy collection system to check the correctness of the parameter settings and data. In addition, the following environmental detectors should also be checked:
(1) Check whether the appearance of the electric energy meter is damaged, and whether the backup battery alarms.
(2) Check whether the wiring of the electric energy meter is loose, and whether the cable is damaged, heated or yellowed.
(3) Check whether the communication between the electric energy meter and the acquisition terminal is normal.
(4) Check whether the voltage, current and other data displayed by the electric energy meter are consistent with the acquisition terminal, and whether there is any abnormality with the corresponding bus voltage and current data.
(5) Check whether the power supply of each device is normal.
(6) Check whether the communication of the electric energy collection terminal equipment is normal.
(7) Check whether the communication with the master station system is delayed or interrupted.
2.1. Overview of Environmental Monitor
The environmental monitoring instrument is usually composed of scattered sensor elements, including the collection of basic functional units such as environmental temperature, environmental humidity, wind speed, wind direction, atmospheric pressure, total radiation value, cumulative radiation value, instantaneous radiation value, and component temperature. The basic working process is to connect each sensor element to the data collector through the cable, the measured data can be displayed on the data collector, and the data is transmitted to the background through the 485 interface.
The data of the environmental monitor is mainly provided to the optical power prediction system, the stand-alone information upload system and the photometric data upload, which is convenient for the grid to calculate the peak load for unified deployment. Therefore, the accuracy of the data of the environmental monitor is particularly important.
The photovoltaic power station can record and monitor the data of the environmental monitoring instrument in real time through the computer background monitoring system, and use the computer system to make a report, which is convenient for the maintenance and query of the power station operation and maintenance personnel, estimate the theoretical power generation of the power station according to the radiation value, and use the statistical data to calculate the power generation. Analysis and comparison to improve quality and efficiency.
2.2. Installation and use of environmental monitor
Environmental monitors are generally installed on roofs or other uncovered places to avoid inaccurate monitoring due to external factors. Be careful not to damage components during installation.
There are generally two ways to supply power to the data collector of the environmental monitoring instrument: one is to connect the power line to the AC cabinet of the relay protection room, or to the uninterruptible power supply (UPS) to ensure the stable operation of the equipment. The second is that the environmental detector is equipped with batteries and solar panels to achieve self-sufficiency. According to the current relevant regulations, the point of the environmental monitoring instrument that needs to be uploaded to the grid-connected photovoltaic power station must meet the relevant specifications of the public power grid dispatching department.
2.3. Operation and maintenance specification of environmental monitoring instrument
The environmental monitoring instrument is an important reference for calculating the peak load of the power grid. Regular inspections are required to ensure the normal operation of the equipment and correct data collection. The main inspection items are:
(1) Check the correctness of the monitoring data.
(2) Check that the connection of each probe is not loose and the cable is not damaged.
(3) Check that the angle of the radiometer is correct, and that the fixed angle bolts are not loose or corroded.
(4) Check that the power supply of the environmental monitor is normal.
(5) Check the power supply components and show that they are clean and free of debris.
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