SPRIXIN’s Energy Storage Solution for Smart Microgrids

Time：2022-07-19 Source：SPRIXIN

Microgrids were formed under the need to reconcile the conflict between large power grids and distributed power sources and make full use of the value and benefits brought by distributed power sources to power grids and load. Energy storage in the microgrid efficiently enhances the stability of distributed energy, improves the quality of power for load consumption, and plays an important role in energy buffering in the microgrid through peak regulation.

What is a Microgrid?
Micro-Grid refers to a small power generation and transmission system composed of distributed power sources, energy storage systems, energy conversion devices, other power generation systems, loads, monitoring and safety devices, etc. New energy microgrids can be built into existing or new distribution networks; there could be either a single new energy microgrid or a microgrid group composed of multiple new energy microgrids in a certain area.

There are two common types of microgrids:
1 On-grid Microgrid
➩ Supported by the large power grid, self-generated and self-contained, the remaining electricity connected to the grid
➩ Can supply power for a short time during power failure
➩ Relatively low technical difficulty
➩ Promote new energy consumption and overall economic benefits
2 Off-grid Microgrids
➩ Without a large power grid, completely dependent on (new energy) power generator sets for power supply
➩ Large-scale off-grid systems are technically difficult (stable power supply and frequency regulation)
➩ Rigid demand for power supply in areas without electricity

It is substantial to the development of user-side power systems to perfectly take advantage of the microgrids to help ensure a reliable power supply, improve power quality, boost new energy consumption, achieve efficient operation, and reduce electricity costs. Most importantly, when the microgrid is disconnected from the grid and operates independently, the output power of distributed energy in the microgrid varies with the environmental factors, making it hard to provide stable output for the load. When there is energy storage in the microgrid, the EMS achieves coordination control of the distributed power generators, the energy storage system, and the power grid to stabilize the power output of the distributed power generators. SPRIXIN’s smart energy management solution includes system data collection and analysis, centralized monitoring, real-time control, intelligent operation, and maintenance, etc., which guarantees the safe, stable, and efficient operation of the microgrid, and reduces wind and solar power abandonment in a way that fosters overall resource utilization.

The working principle of a smart microgrid is shown in the figure below:

During the day: Load electricity is primarily supplied by new energy power generation, then the surplus power generated will be charged to batteries, and the rest can be sold to the grid. When the power generated in the microgrid is insufficient for load supply, the gap can be filled by the power grid or other power generation systems;
At night: Load electricity is primarily supplied by the battery energy storage system (BESS), and the power gap will be filled by the power grid or other power generation systems. When the system detects a grid fault or substandard power quality, the microgrid is automatically disconnected from the grid and enables off-grid operation mode.

Consequently, the EMS serves as the core and the brain in the smart microgrid, and SPRIXIN’s EMS is suitable for various business scenarios with multiple data processing algorithm models.

A Project Case: SPRIXIN’s EMS in a Smart Off-grid Microgrid of a High-tech Park for PV Storage and Charging
The project involves photovoltaic modules of 100kw installed on building roofs and sheds with a total area of 1,000 square meters. A BESS of 30kw/70kwh is also installed to maximize new energy consumption.

The microgrid EMS service provided by SPRIXIN, in this case, offers a variety of operation strategies:
①Economic Operation
Power supply prioritizes PV power generation, then the grid, and the remaining power will be stored in the BESS.
②Smoothing Photovoltaic Fluctuations
Quick adjustment of the power of PCS according to PV fluctuations and real-time load.
③Peak Shaving and Valley Filling
Supports the use of peak-to-valley spread arbitrage for greater returns.
④ Anti-reflux Strategy for Off-grid Mode
In case of low load demand during holidays when the high-tech park is most likely to be empty, a software + hardware strategy is adopted to prevent reflux.

Through the mixed power supply of mains power, PV power generation, and energy storage, the park realizes peak shaving and valley filling, charging piles increasing revenue, and optimal control of office load power. Currently, the self-sufficiency rate of power consumption of the park has reached 60%. The second phase of the project plans to extend the coverage of the microgrid to other commercial buildings in the industrial park, and the installed photovoltaic capacity will increase by about 900kW.

To Summarize
The smart microgrid is a promising development trend of new energy given that it multiplies new energy application forms. By utilizing distributed energy, the smart microgrid renders a more flexible solution of power supply than the traditional centralized power supply of the power grid. SPRIXIN’s Intelligent EMS is the guardian of the safe, stable, and efficient operation of smart microgrids, and further promotes the participation of microgrid energy storage in power grid peak regulation, power trading markets, and auxiliary service markets.