In ship systems, diesel power generators are used in various systems of autonomous power plants to ensure power supply security. This article presents an autonomous hybrid system of a ship power plant with a diesel generator with a permanent magnet synchronous generator and electricity storage in parallel topology (the permanent magnet synchronous generator is connected directly to the receiving network). The electricity storage through the active converter is connected to the receiving network in parallel with the permanent magnet synchronous generator. The decoupled control of the reactive and active power in the active converter enables stabilization of the voltage in the ship’s electrical power grid while ensuring the possibility of obtaining different operating regimes of the power plant at various stages of the ship’s operation. The innovative method of voltage stabilization presented in this article is based on the compensation of the unfavorable reaction of the permanent magnet synchronous generator armature through the optimal transmission of negative inductive reactive power from the active converter to the generator using the electromagnetic properties of the synchronous generator. The active converter controls the direction of the active power transmission between the DC source, the grid, and the permanent magnet synchronous generator. This paper proposes a hybrid autonomous power plant system using battery storage in place of a single diesel generator set against the commonly used two diesel generator sets, working in parallel, to increase the energy efficiency of the power plant by minimizing the specific fuel consumption of the diesel generator set. The article examines the possibilities of such a mechatronic system design based on analytical research and analysis of electromagnetic and energy characteristics using the Matlab-Simulink program.