Research Of Online Insulation Monitoring System For The Power System Of Ship

Neutral ungrounded method is used the power system of ship. This system needn't protection's trip when the line have single-phase-to-ground fault. If we don't judge the fault, it will have more trouble, for example, fire or phase-to-phase fault. We can quickly find out the fault line via online insulation monitoring system, and it's important to improve the security of performance and reliability of supply of power system. Therefore, it's very meaningful thing to develop a new micro-computer protection with high reliability and high flexibility for the power system of ship.This paper introduce the working style of the power system of ship, and then the present status and development direction of online insulation monitoring system and the correlative relay protection are summarized. By analyzing the behavior of the power system of ship, this paper introduce a new method based on injecting single-frequency signal, and the simulation analysis confirmed its feasibility. And introduce the principle of the fault-phase for the online insulation monitoring system. The paper systematically expounds ensemble design project,design principles and function requirements of new online insulation monitoring system.According to the function demand of the protection system, the hardware is designed and layered hardware configuration is put forward. Super performance, general-purpose, economical, anti-jamming, expansibility are considered for hardware design. The system chooses DSP as it's CPU, and using mode of DSP+ARM to simplify hardware design. The design characteristic and circuit principle of the AC-input board, DC-input board, switch-input board and the switch-output board are especially expatiated.For satisfying measurement function, software design use special software framework. The software is organized by programming modules to simplify software design and improve expansibility. All kinds of protection principle are realized by the format of protection logical function, and protection logical functions are designed basing on the thought of protection logical framework.