Synthetic Internal Voltage Phase-Amplitude Dynamics Investigation for Electric Drivetrain Small-Signal Model in Electromechanical Control Timescale for a Wound Rotor Induction Machine-Based Shipboard Power System

With less fragile power electronics integrated, the overall shipboard power system (SPS) safety level is prone to increase. In this article, the motion equation concept of a less power electronics-based more-electric ship is proposed to study the SPS dynamics. A wound rotor induction machine (WRIM) acts as the propulsion load, whose stator and power converter are regarded as a synthetic internal voltage vector (SIVV). The small-signal model of a WRIM-based electric drivetrain (WRIM-ED) is established in the electromechanical control timescale. Besides, the external dynamic behaviors of the propulsion load are investigated in detail according to the phase and amplitude of SIVV. The control effects of phase-locked loop (PLL), rotor speed control (RSC), and reactive power control (RPC) are taken into account. In addition, the control schemes by applying the traditional PLL-based vector control (PLL-VC) and an emulated stator voltage-oriented VC (ESVO-VC) for WRIM-ED are described. Moreover, with ESVO-VC, the expression of equivalent inertia for WRIM-ED is much simplified, and there is no need to tune the PLL controller gains. MATLAB/Simulink is applied to carry out simulations to investigate the control effects of both PLL-VC and ESVO-VC on the system dynamic performance.