Grid-Forming BESS
Overview
With the integration of a high proportion of new energy sources and power-electronic devices, the power system experiences a reduction in inertia, a weakening of system strength, and a decline in the support and regulation capabilities of frequency and voltage, leading to increasingly severe stability issues. Constructing an energy storage converter with the characteristics of a voltage source, centered around the grid-forming technology, enhancing the stability of the power system. The grid-forming energy storage system is suitable for scenarios such as the grid connection and islanded operation of new energy in desert, gobi and wasteland areas.
Features
Flexible and Fast
- Supporting flexible switching between grid-following and grid-forming modes
- Charge-discharge transition time < 20ms
Safe and Reliable
- High protection level of IP65
- Software and hardware multi-protection
Efficient and Compact
- ANPC topology
- Maximum efficiency＞99.1%
- Industry-leading power density
Grid-friendly
- Good adaptability of relay protection
- Active frequency/voltage support
Benefits
Multi-scenario Support Capabilities
It possesses the multi-scenario grid-forming support capabilities including short-term 3-fold overload, inertia support and primary frequency regulation, voltage support and regulation, adaptability to weak systems, and black start of the entire station.
Parallel Operation and Black Start
It supports the parallel operation of large-scale centralized grid-forming energy storage systems, enabling the construction of grid-forming energy storage power plants at the scale of hundreds of megawatts. It also supports the black start of the entire station, and can ensure that there is no oscillation between each parallel energy storage converter, with the circulating current being less than 5%.
Enhancing Grid Strength
The grid-forming energy storage system exhibits the characteristics of a voltage source externally. This can enhance the short-circuit ratio of new energy power stations, improve the strength of the power grid, and support the connection of more new energy sources.
Power Sharing and Grid Stabilization
When there is a power change in the power grid, the grid-forming energy storage system can instantaneously and automatically share the unbalanced power of the grid, slow down the change rate of the grid voltage/frequency, and reduce the depth of the grid voltage/frequency drop.
Typical Cases
Zhejiang Huadian Jiande Dayang Photovoltaic Co-located Energy Storage Project
The installed capacity of this energy storage project is 15MW/15MWh, which includes two energy storage units. The charging and discharging power of each energy storage unit is 7.5MW, and they are respectively connected to two 35kV busbars in the 110kV substation. The grid-forming energy storage system possesses the characteristics similar to those of a synchronous generator and can actively provide voltage and frequency support for the power grid. When there are fluctuations in photovoltaic power output or grid faults occur, it can respond rapidly to maintain the power system stability. It can smooth the photovoltaic power output, enhance the reliability and stability of photovoltaic power generation, and improve the power quality. In the event of a grid fault, the grid-forming energy storage system can quickly reconstruct the local power grid and supply power to critical loads.
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