Small Signal Stability Analysis of VSC-MTDC with Hybrid Wind/Photovoltaic/Energy Storage System

Multi-terminal voltage source based flexible DC (VSC-MTDC) system has faster response speed, better controllability, and flexible operation modes. However, due to complex effect of many converters and parameters, the stable operation is threatened. Therefore, this paper investigates the small signal stability of VSC-MTDC with hybrid wind/photovoltaic generation system and energy storage system. First, the basic structure of the multi-terminal flexible system under typical control strategy is constructed. Then, the nonlinear algebraic differential equation models of different components are constructed, and all the component models are linked to construct a complete linearized state space model. And then, the eigenvalue analysis method is used to give the eigenvalue and participation factor calculation method of the system. Finally, based on the Simulink simulation model of the VSC-MTDC system, the effects of multiple system parameters are analyzed in detail. The experimental results show that, based on the relationship between the state variables and the oscillation decay modes, the energy storage converter control parameters, phase-locked loop control parameters, MPPT control parameters and grid-connected inverter control parameters are the main factors affecting the oscillation modes.