Abstract: With the continuous development of computer technology and the widespread application of frequency conversion technology, traditional boiler water quality regulation methods are gradually being replaced by automatic dosing methods. The automatic dosing system of Panzhihua Iron and Steel Group Power Plant is mainly divided into an ammonia system, a hydrazine system, and a phosphate system. After receiving signals transmitted from the field, the system converts them into digital signals via an analog-to-digital converter (ADC). The CPU receives the digital signals and executes the corresponding control program according to the state of the control switches. The ADC output card sends the signal to the frequency converter, which changes the output power frequency according to the signal, thus changing the speed of the dosing pump to control the dosing amount. Keywords : In-furnace dosing; Automatic control; Conductivity; Frequency converter; pH value 1. Overview of the Dosing System The boiler water quality regulation at Panzhihua Iron and Steel Group Power Plant includes feedwater ammonia regulation, hydrazine regulation, and boiler water phosphate regulation. Since its commissioning, these have been manually regulated, and the steam and water quality of the unit has also relied entirely on manual analysis. Because manual analysis involves sampling and analyzing every 2 hours, it suffers from discontinuous monitoring of equipment operation, inconsistent reflection of changes in steam and water quality, and relatively delayed feedback of operating information. This fails to achieve the goal of preventing corrosion and scaling in the boiler thermal system and may even affect the safe and economical operation of the power plant. Therefore, conducting research on boiler chemical dosing stability and achieving automated control of feedwater ammonia, hydrazine, and boiler water phosphate dosing is of great significance. The widespread application of computer technology and AC variable frequency drives has led to the adoption of variable frequency speed control technology for automatic chemical dosing. Since it does not require pipeline modifications, the system is stable, reliable, and effective, gaining widespread acceptance. It has also significantly improved the data acquisition, analysis, and processing capabilities of computers and instruments, as well as the reliability of automatic control systems, making the control of the dosing pump more energy-efficient and the dosing more precise. 2 System Hardware Composition and Functions [b][align=center]For details, please click: Application of Variable Frequency Technology in Boiler Chemical Dosing Systems of Generator Units[/align][/b]