高压变频调速微机保护系统的研究

由于高压变频装置及其故障的特殊性,使得与高压变频调速系统相关的保护理论和保护装置亟待完善和提高。为此,在分析三电平高压变频装置主拓扑结构的基础上,针对该装置的特点及可能出现的故障情况,从保护系统的设计要求入手,着重分析了高压变频调速保护系统的要求、功能和基本原理;阐述了保护系统的硬件设计和特点,构建出系统的硬件整体结构;叙述了软件部分中断保护程序的设计方法、特点,介绍了基于"继电器功能模块"的保护逻辑判断方法以及为解决频率变化问题而提出的测频方法和改进的傅氏算法,力图解决目前国内高压变频调速系统在保护方面存在的不足。

Microcomputer Protection System of High Voltage Inverters

The three-level inverter is a kind of circuit that uses power electronic device to change AC from 50Hz to other frequencies which includes 3 parts as AC input circuit,DC circuit and AC output circuit,so the protection system include 3 parts as AC input protection,DC circuit protection and AC output protection.In each protection,based on the analysis of the corresponding circuit,aiming at the possible faults,the function demand and the realization method of the microcomputer relay protection system are studied and analyzed.The design of the hardware and the software of the protection system are particularly introduced.Under the design demands of the hardware configuration,the location of the sensors and the trait of the hardware circuit like AC,DC input circuits and the switch input circuit are introduced.In the end the protection software are introduced.The software includes the main program and the interrupt program.The interrupt program is different from traditional protection program and is designed as relay module mode to simulate electromagnetism relay so each logic judgment can be recorded conveniently for program writing,maintenance and later faults analysis.The frequency measurement and variational Fourier transform for variable frequency are also introduced.