Energy storage device voltage regulation

What is energy management system?

The energy management system maintains the SOC of a battery within a predetermined range, ensuring the safe and reliable operation of the energy storage system. The authors of achieved battery charging and discharging control by regulating the output reference power of the inverter Pref and the photovoltaic power Ppv.

Why is virtual impedance used in VSG control?

Virtual impedance offers advantages such as reshaping the output impedance of the inverter, reducing power coupling, improving system dynamic characteristics, and enhancing system stability, making it widely used in VSG control . In , virtual inductance was introduced to reduce system power coupling.

Can VSG power and frequency droop control achieve SFM?

The authors of introduced an integrator to VSG power and frequency droop control to achieve SFM. However, when the system load changes, its control parameters need to be readjusted. In general, existing control methods combining virtual impedance and secondary frequency modulation still have room for further improvement.

Does VSG modulation reduce power oscillations based on integer-order pi?

When compared to traditional primary frequency modulation and VSG control based on integer-order PI, the proposed strategy was shown to significantly improve both the speed and stability of the VSG frequency recovery process, and effectively suppresses power oscillations.

What are the main parameters of a PV system?

The main parameters of the system are presented in Table 1. PV power generation is significantly affected by environmental illumination and temperature, leading to fluctuations in the power output of the PV system. Prolonged fluctuations can easily induce oscillations in the system, and in severe cases, destabilize the system.

What is the reference output power of an inverter?

At the start of the system, the reference output power of the inverter was Pref = 300 W. At 1.0 s, the reference output power of the inverter was stepped up to Pref = 400 W. Without virtual impedance, power oscillations are prone to occur at system start-up and when sudden changes occur in the power.