Mathematical modeling of a system for monitoring the insulation resistance of a high-voltage power grid of a hybrid vehicle

The paper presents mathematical models and computational and analytical dependences, which make it possible to implement a system for monitoring the insulation resistance of a high-voltage power grid of a hybrid vehicle and make it possible to formulate requirements for the physical and simulation model of the software and hardware complex of laboratory tests. The purpose of the work is to determine the main functions and characteristics of the insulation monitoring system, its features, the principle of operation and methods of monitoring the insulation resistance, drawing up requirements for the simulation system. The introduction justifies the importance of monitoring insulation resistance and provides references to standards that regulate the requirements for the measurement and determination of mains failure. The block diagram of the vehicle power supply and the role of the insulation resistance monitoring system in this diagram are presented, the features of insulation monitoring are explained. The principle of operation of the insulation monitoring system and the use of the most common schemes are considered. The calculated dependencies for each of the presented schemes are given. These allow calculating the insulation resistance. The procedure for measuring the insulation resistance according to the ISO standard is described and the corresponding equations are given. For the presented circuit, a graph that explains the principle of the system's operation, when one of the keys is closed, the voltage across the measuring resistor changes with the normal insulation state of the positive and negative power supply bus of the high-voltage system is given. The conclusions provide a generalization of the presented mathematical model and formulate the requirements for the software and hardware complex, which allows simulation and mathematical modeling of electrical systems and their components in various operating modes. The paper explains the features of the software and hardware complex that allows to simulate changes in the insulation resistance and faults of the high-voltage power supply network for a vehicle with a hybrid power plant.

power supply system, insulation resistance, hardware and software complex, hybrid power plant