[Abstract] The turbine governor is a crucial automation device for hydro-generator units and the entire power system. This paper introduces the performance, adjustment, characteristic testing, fault types, and problems encountered after commissioning of the main components of the TDBYWT-PLC stepper motor type high-pressure hydraulic governor at the Houlongxi Second-Stage Hydropower Plant in Fujian Province, as well as the corresponding handling measures. [Keywords] Houlongxi Second-Stage High-Pressure Hydraulic Governor, TDBYWT-PLC Governor, Adjustment and Testing, Existing Problems 0 Overview The Houlongxi Second-Stage Hydropower Plant is the second-stage power station in the Houlongxi cascade project. It is located 60 km from Zhouning County and approximately 24 km from Limen Township. The plant is 6.1 km downstream of the dam, and the dam is located 2.6 km upstream of Houlong Village. It is a seasonally regulated power plant. The plant is equipped with two 20 MW mixed-flow turbine generator units, with an average annual power generation of 140.45 million kWh. The governor of the Houlongxi Second-Level Hydropower Plant adopts the TDBYWT-PLC type stepper motor high-pressure governor developed and manufactured by Tianjin Electrical Transmission Research Institute. It consists of two parts: a control transmission device and a hydraulic device. The control cabinet, pressure tank, vertical oil pump, and valve group are all mounted on the return oil tank. The microcomputer regulator, with PLC as its core, is located at the top of the control cabinet. The lower part houses the stepper motor drive, main pressure distribution valve, one-way throttle valve, and emergency stop solenoid valve. The two generating units of the power plant were connected to the grid on January 24, 2006. Before grid connection, all governor commissioning tests met the requirements of the regulations. However, some problems arose after a period of operation. After taking measures, the governor basically returned to normal operation. 1. Performance and Main Technical Parameters of Main Components The microcomputer regulator consists of a programmable controller module (FX2N-32MR PLC module), a signal processing module, an A/D conversion module, a communication module, a positioning module, a stepper motor driver, a power supply module, and a touch screen display (GOT). This system enables automatic control, adjustment, and display functions for the speed controller. 1.1 Stepper Motor-Ball Screw Transmission Device The upper part consists of a transmission mechanism composed of a stepper motor and a ball screw; the lower part is the main pressure regulating valve. The stepper motor drives the ball screw to rotate, causing the nut of the ball screw to move up and down. The piston of the main pressure regulating valve is connected to the nut of the ball screw, causing the piston of the main pressure regulating valve to move up and down accordingly, achieving the purpose of switching the power supply unit. [b][align=center]For more details, please click: Application of High-Pressure Stepper Motor Speed ​​Controller in Houlongxi Second-Level Hydropower Plant[/align][/b]