An additional damping method for improving power angle stability of voltage source energy storage system

By introducing an additional damping element through an improved virtual synchronous generator control method, and combining voltage and current dual closed-loop and virtual impedance control, the power angle and frequency stability of the voltage source energy storage system are improved, thus solving the problem of frequency and power angle instability during grid faults in the existing technology.

CN116316824BActive Publication Date: 2026-07-24NORTHWEST BRANCH OF STATE GRID POWER GRID CO +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
NORTHWEST BRANCH OF STATE GRID POWER GRID CO
Filing Date
2023-02-23
Publication Date
2026-07-24

AI Technical Summary

Technical Problem

Existing technologies, while improving the power angle stability of voltage source energy storage systems, have failed to effectively consider the frequency stability of the system. This may lead to significant frequency deviations and rates of change during grid faults, affecting the system's stability.

Method used

An improved virtual synchronous generator control method is adopted. By introducing an additional damping element, the difference between the grid angular frequency and the virtual angular frequency is fed back by the active frequency control loop. Combined with voltage and current dual closed loop and virtual impedance control, a PWM signal is constructed to improve the power angle and frequency stability of the system.

Benefits of technology

During grid faults, it reduces power angle overshoot and frequency variation, improves system stability, and ensures inverter synchronization with the grid. It is suitable for voltage source energy storage systems under weak voltage-supported grids.

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Patent Text Reader

Abstract

The application discloses an additional damping method for improving power angle stability of a voltage source energy storage system, which introduces an additional damping link in an active frequency control loop; since the virtual angle frequency of the inverter is consistent with the grid angle frequency during stable operation, the method does not change the steady-state characteristics of the system; the introduction of the additional damping link can increase the system damping ratio, reduce the power angle overshoot during a fault, and thus improve the power angle stability of the system; increasing the additional damping gain K1 can reduce the maximum frequency change during the fault, and does not change the maximum frequency change rate at the fault moment, so as to adjust the system frequency stability. The application is suitable for various PWM-controlled three-phase inverter devices composed of various high-frequency switch self-turn-off devices represented by the voltage source energy storage system under a weak voltage support grid, and the method can improve the system frequency stability while improving the system power angle stability, and is beneficial to realize the stable operation of the grid-connected inverter under a large disturbance of the grid.
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