Summary:Under the dual carbon goals of "peak carbon dioxide emissions" and "carbon neutrality," to avoid climate change caused by the direct combustion of fossil fuels, new energy will serve as the main power supply for the new power system. To ensure the reliable operation of the new power system, the configuration of microcomputer protection devices and online monitoring devices for power quality effectively monitors the operation status of the power system, and records in real-time the location and nature of any faults, thereby providing effective reference information for rapid fault handling. The anti-islanding protection devices and online power quality monitoring devices introduced in this article can provide corresponding protection for different objects in the Gaobeidian biogas power generation project, significantly enhancing the reliability, safety, and power supply quality of substation operations. This is conducive to achieving comprehensive automation of substations and realizing unmanned or minimally staffed operations.
Keywords:New Energy; Biogas Power Generation; Island Protection Device; Online Power Quality Monitoring Equipment
Project Overview
Gaobeidian Sewage Treatment Plant is located inBeijing, Chaoyang DistrictGao Beidian Town is home to one of Beijing's largest wastewater treatment plants, which is also the third largest in China. The initial phase of the Gao Beidian Wastewater Treatment Plant was completed and put into operation on October 24, 1993, with a treatment capacity of 500,000 cubic meters per day. The second phase was completed and launched by the end of 1999, increasing the capacity to 1 million cubic meters per day. Beijing generates over 2.5 million tons of wastewater daily, with nearly half being treated at this facility. The wastewater system covers an area of 96 square kilometers.Service Population2.4 million people, covering 68 hectares, and gathering most of the southern region of Beijing.Wastewater from Residential SourcesAll wastewater from Dongjiao Industrial Zone, Embassy District, and Chemical Road.
The project is located within the Gao Beidian Sewage Treatment Plant, No. 1 Xiaojiao亭 Village, Xiaojiao亭 Community, Gao Beidian Town, Chaoyang District, Beijing. The plant houses three main power distribution rooms, namely the Gao Beidian Sewage Main Power Distribution Room, Gao Beidian Reclaimed Water Plant Main Power Distribution Room, and Gao Beidian Waterworks Main Power Distribution Room. The cable entry and exit method is underground entry and overhead exit.
Product Requirements
The integration of this biogas power generation system into the local distribution network may affect the quality of electricity, including harmonics, voltage deviation, voltage fluctuations, and voltage unbalance. Additionally, the power station of this project should be capable of quickly detecting islanding and disconnecting from the grid. Moreover, when a 10kV line experiences a short-circuit fault, the line protection should act swiftly to meet the requirement for rapid and reliable fault removal during an outage.
The project is a biogas power generation system, which operates on a "self-generated, self-used, excess not fed into the grid" principle. Therefore, an AM5SE-IS anti-islanding protection device is configured in the incoming line cabinet to provide reverse power and voltage loss protection functions, and to achieve electrical interlock with the local grid connection cabinet. An APView500 power quality online monitoring device is also installed to monitor the power quality on the grid side, including voltage flicker, interruptions, and dips. In the grid connection cabinet, an AM5SE-F line protection device is configured to provide overcurrent and zero current protection functions, and to achieve electrical interlock with the incoming line and busbar cabinets. An APView500 PV power quality online monitoring device is installed in the generator cabinet to monitor the power quality on the generation side, such as harmonics, voltage deviation, and frequency deviation. The protection devices and power quality monitoring devices will promptly provide feedback when faults such as reverse power, voltage loss, overcurrent, and abnormal power quality occur in the power supply system.
3 Product Solutions
The biogas power generation project consists of three main distribution centers: Total Transformer 1 and 2 in the reclaimed water area, and Total Transformer 2 in the sewage area. A total of four internal combustion power generation sets are installed, connected through four connection points to the customer's internal system via a single busbar segmented system at the 10kV voltage level. The power supply system diagram and configuration are as follows:
Figure 1:再生水区总变一电气总接线图
Figure 2: Total Electrical Main Wiring Diagram of the Reclaimed Water Zone's Second Transformer Substation
Figure 3: Total Electrical Wiring Diagram for the Second Transformer in the Sewage Area
4 On-site Installation Photos
The installation of the online power quality monitoring system for the gas-powered generator set has been completed, along with the installation of the device panel for the secondary incoming line cabinet in the wastewater area. The remaining products are installed locally and dispersed on high-voltage switchgear cabinets, as shown in the installation photo. The project was energized and put into use in 2023, and it is operating normally.
Figure 4: On-site installation of the unit and group screen
5 Conclusion
With the rapid industrialization and urbanization worldwide, a significant amount of greenhouse gas emissions are produced, leading to continuous global temperature rise. To address climate change, "carbon peaking" and "carbon neutrality" have become the primary goals and pathways for countries to achieve emissions reduction and combat climate change. As the main power supply for the new power system, the reliable operation of the system is crucial. Microcomputer protection devices and online monitoring systems for power quality can effectively monitor the operational status of the power system, and in real-time record the location and nature of any faults, providing effective reference information for rapid fault handling. The microcomputer protection devices and online power quality monitoring systems introduced in this article offer corresponding guarantees for different objects in the Gaobeidian biogas power generation project. Not only do they enhance the reliability of power supply, achieving comprehensive automation for the entire distribution engineering, but they also effectively reduce the labor intensity of the staff.
References
Ankorri Enterprise Microgrid Design and Application Manual. June 2020 Edition
Ankorri's 35KV and below substation intelligent distribution system design and product secondary circuit diagram set. October 2020 edition.
[3] Ankerui User Substation Integrated Automation and Operation & Maintenance Solution. November 2021 Edition
