Research And Application Of Regional Integrated Energy System Based On Distributed Low-Carbon Energy Station

Written by Guixiong He, Kaicheng Liu, Huaguang Yan, and Haoyong Chen

Under the background of China's four revolutions in energy consumption, supply, technology, and system, the form of energy system presents a new development trend. The state puts forward "guiding social forces to build a multi-energy collaborative and terminal integrated comprehensive energy service model." The energy demand of end users has changed from "power consumption" to "energy consumption", and the energy supply status options have changed from "yes or no" to "good or bad". There is an urgent need for more professional, intensive, and integrated high-quality, low-cost, and high-quality energy services. In urban load gathering areas, building distributed energy stations, coordinating the production, storage, transmission, and distribution of energy, making full use of load differences and energy complementarity, and providing integrated power supply, hot and cold energy supply has become a new idea for the comprehensive utilization of distributed energy. Compared with the traditional energy supply mode, the interconnected comprehensive energy system has better source load matching, multi-energy complementarity, better energy efficiency, and system robustness.

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Introduction

Regional multi integrated energy systems mainly include a power distribution system, gas distribution system, and regional thermal system. The schematic diagram of a typical regional multi integrated energy system is shown in Figure 1. In the urban load gathering area, the distributed energy stations are taken as the basic unit, and the energy stations in different areas are interconnected through pipelines for unified planning and coordinated operation^[1-3]. Multi-energy is coupled and interacted through distributed energy station to supply users' demand for electricity, heat, gas, and cooling load^[4-5]. The typical distributed energy station is shown in Figure 2, which is composed of transformer, cogeneration, electricity to gas, electric refrigerator, renewable energy, and other equipment^[6-7]. Through the coordination of energy production, storage, transmission, and distribution, the system can make full use of load difference and energy complementarity to provide an integrated power supply and a hot and cold energy supply^[8-9].

 

Figure 1: Schematic diagram of regional integrated energy system

 

Figure 2: Typical distributed energy station

 

 

Research and Demonstration Results

The demonstration project is Shanghai area B of the Shanghai World Expo. The central enterprise headquarters energy center in area B of the Shanghai World Expo mainly supplies cold and hot energy for the office building and affiliated commercial areas. The total aboveground energy supply area of the project is 597,288 square meters, including 571,188 square meters of office area and 26,100 square meters of commercial area. The area for underground businesses and an underpass is about 60,000 square meters. The main pieces of equipment used in this project are a gas turbine generator unit, lithium bromide refrigeration unit, gas boiler, electrically-driven refrigerator unit, and cold/heat storage device.

The owner realizes the quantifiable and comparable of multiple energy sources among energy stations, and seeks the best matching point. The key technologies of regional multi-energy station interconnection, mutual assistance, location, and capacity have been overcome, unified planning and coordinated operation have been realized, and the redundancy of energy station configuration capacity is less than 10%.

The multi-energy coupling control in the energy station is difficult and the system is complex. During the cooperative operation of the energy station, there are many control points, heavy traffic, and difficult-to-solve realtime optimization problems which limit the efficient and optimal operation of the energy station. The project puts forward the optimal operation method of interconnection and mutual assistance of multiple energy stations based on distributed control. Compared with independent operation, the safety and reliability of energy supply was improved from 95% to 97.6%.

All kinds of energy and equipment coupling make it difficult to participate in the modeling of power grid demand response, it is difficult to accurately describe the input and output characteristics as well as calculating the response parameters, so it is difficult to give full play to the regulation potential of energy stations. This project puts forward the equivalent load modeling method for energy stations to participate in power grid demand response, improves the interactive flexibility of energy system, overcomes the dynamic aggregation modeling technology of distributed low-carbon energy stations and their loads, carries out fine control of equipment and loads in energy stations, and reduces peak loads by more than 25%.

 

Conclusion

Facing the growing demand for multiple energy sources in smart cities, in urban load gathering areas, make full use of local renewable energy and source load space-time complementarity, and build an interconnected mutual aid comprehensive energy system with distributed low-carbon energy stations as the hub to meet the needs of users for electricity, heat and cold energy. Through the unified planning, coordination, mutual assistance, and interactive operation of the production, storage, transmission, and distribution of the regional comprehensive energy system, it has become a new idea for the comprehensive utilization of distributed energy. Compared with the traditional energy supply mode, the interconnected comprehensive energy system has better source load matching, multi energy complementarity, better energy efficiency, and system robustness.

This work was supported by the Key Program of the National Natural Science Foundation of China (51937005).

 

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This article was edited by Luis M. Fernandez-Ramirez

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