Photovoltaic inverter bifurcation

What causes slow-scale bifurcation in a single-phase voltage source full-bridge inverter?

This paper focuses on analyzing the slow-scale bifurcation phenomenon of a single-phase voltage source full-bridge inverter with an LCL filter. The simulations show that the slow-scale instability phenomenon occurs when improper parameters of the system are selected.

What is slow-scale bifurcation in a digitally controlled inverter with an LCL filter?

The slow-scale bifurcation phenomenon of a digitally controlled inverter with an LCL filter under off-grid conditions was studied in ref. , considering the digital adoption delay, and it pointed out that the slow-scale instability of the system is actually Hopf bifurcation.

Why should bifurcation behavior be avoided in power electronic circuits?

Recently, studies on the nonlinear dynamics of power electronic circuits have indicated that bifurcation behavior in power electronic circuits can lead to significant noise and unstable behavior, which is very harmful in practical applications. Therefore, bifurcation behavior should be avoided as much as possible.

Does an LCL filter affect stability of a single-phase voltage source full-bridge inverter?

However, the effect on the stability of the system caused by an LCL filter due to its resonance characteristic cannot be ignored. This paper studies the stability of a single-phase voltage source full-bridge inverter with an LCL filter through the bifurcation theory as it is a nonlinear system.

What happens if a voltage source full-bridge inverter has an LCL filter?

The simulation results above indicate that the voltage source full-bridge inverter with an LCL filter will lose its stable operation and transition into the low-frequency oscillation state as the control parameter kp increases. Simultaneously, the THD value of the system rises obviously with the increasingly severe oscillation.

What is low-frequency oscillation in a full-bridge inverter?

The average model is derived to analyze the low-frequency oscillation; the theoretical analysis demonstrates that low-frequency oscillation is essentially a period in which doubling bifurcation occurs, which indicates the intrinsic mechanism of the instability of the full-bridge inverter with an LCL filter.