Power oscillation suppression strategy of VSG based on finite-time Hamiltonian method

In order to improve the stability of the virtual synchronous generator (VSG) system and suppress the power oscillation, a power oscillation suppression strategy of VSG based on the finite-time Hamiltonian method is proposed in this paper. Firstly, based on the traditional VSG control, the port-controlled Hamiltonian with dissipation model for the active power closed-loop circuit of the VSG grid-connected inverter is established by considering additional control inputs. Secondly, a Hamiltonian finite-time controller design method based on interconnection and damping assignment passivity-based control is proposed to achieve finite-time stability of the system. The Hamiltonian function is designed as a fractional power form by energy shaping, and the convergence speed of the system is accelerated by damping injection so that the system can quickly stabilize at the expected balance point. Then, the designed Hamiltonian function is taken as the Lyapunov function to analyse the system stability and calculate the convergence time of the VSG system. Finally, the simulation and hardware in the loop verification results show the effectiveness and great potential of this proposed controller in shortening the power oscillation time.