Abstract : This article introduces the basic principle of constant pressure water supply and the application of SIMOVERT MV high-voltage frequency converter in constant pressure water supply. Keywords : SIMOVERT MV high-voltage frequency converter, water pump, constant pressure, PID 1 Introduction The steel industry is a basic industry of the country. At the same time, its energy consumption is also a serious problem that plagues the steel industry. The steel industry uses a large amount of fans and water pumps for a long time. Their efficiency directly affects the benefits of enterprises. At present, the water pumps of China's steel enterprises generally have the following three problems in operation: (1) Low efficiency of single machine. The efficiency of domestic products is about 5%-10% lower than that of foreign products. This is a problem that manufacturers should improve the technical quality of products under market competition. (2) Low system operating efficiency. This is caused by improper selection and matching of single machines in the system, excessive coefficient margin and unreasonable adjustment method. (3) Most fans and water pumps rely on valves to throttle and pressurize, which wastes a lot of electrical energy. Furthermore, in the throttling and slack-down method, motors and pumps operate under high speed and heavy load for extended periods, resulting in high maintenance workload, short equipment lifespan, and significant noise pollution at the operating site. The best way to change this situation is to adopt advanced variable speed control technology and intelligent control technology widely used internationally in the field of constant pressure water supply, such as multi-level direct high-voltage frequency converters and fuzzy controllers, to achieve constant pressure water supply. [b][align=center]For details, please click: Application of High-Voltage Frequency Converters in Constant Pressure Water Supply[/align][/b]