Internal Voltage Phase-Amplitude Dynamic Analysis With Interface Friendly Back-To-Back Power Converter Average Model for Less Power Electronics-Based More-Electric Ship

Abstract

The advancement in power electronics techniques provides a strong impetus for the adoption of medium-voltage direct current (MVDC) shipboard power system (SPS). However, high fault protection difficulty and cost are the major challenges. In this paper, a partially power decoupled SPS based on the doubly fed induction machine (DFIM) propulsion load is presented to increase the system safety level by using less power electronics. Different from a grid-connected DFIM-based system, the on-board power of the proposed DFIM-SPS is supplied from standalone synchronous generators, and its system dynamics need to be further investigated. An interface friendly average model for the back-to-back power converter (BTBPC) in DFIM-SPS is proposed for system-level dynamic study, which reduces the simulation time and is easy for physical understanding. The stator and BTBPC of DFIM are regarded as separate voltage vectors in the system, and small-signal modeling is carried out in the electromechanical control timescale to analyze the internal voltage phase-amplitude dynamics. The control effects of rotor speed control (RSC), reactive power control (RPC), and phase-locked loop (PLL) are considered in the modeling process. The simulations are performed to study the control effects on DFIM-SPS in MATLAB/Simulink, with the effectiveness of the proposed BTBPC average model validated.