Abstract: This paper discusses the significant energy-saving and process improvement effects achieved by adopting perfect harmonic-free high-voltage frequency converters for major auxiliary equipment such as fans and pumps in thermal power plants. Currently, thermal power accounts for approximately 74% of China's energy structure (80% of electricity generation). Improving energy conservation in thermal power units and their auxiliary equipment is crucial. In China's power equipment, large-capacity, high-parameter thermal power units constitute a small proportion, resulting in high overall energy consumption for thermal power generation, with plant power consumption consistently around 8%. Statistics show that the coal consumption for power generation in Chinese thermal power plants is 400-420 grams per kilowatt-hour, 80-90 grams per kilowatt-hour higher than in advanced countries. Water consumption in thermal power plants is also relatively high; generally, power plants with secondary circulating water consume 1 cubic meter per second per million kilowatts, while in other countries it is only 0.6-0.7 cubic meters per second. Furthermore, due to various reasons, equipment in thermal power plants, such as forced draft fans, induced draft fans, boiler feed pumps, circulating water pumps, coal mills, and slurry pumps, suffers from severe overcapacity. Moreover, currently, domestic power generation capacity temporarily exceeds demand, and most power plants cannot operate at full capacity; the operating load of the units must change according to the load requirements of the power grid. Accordingly, adjusting the operating status of the aforementioned auxiliary equipment, such as using variable frequency speed control technology to change the operating speed of the equipment to regulate the amount of water and air supplied, can both meet production requirements and save energy. It also reduces economic losses caused by frequent shutdowns for maintenance and damage to damper valves, pipe wear, and other issues. Therefore, promoting the adoption of variable frequency speed control technology on the main auxiliary equipment of thermal power plants can improve the reliability of power plant operation and power supply, save a significant amount of energy, and bring substantial economic and social benefits to thermal power plants. 1. Problems with Traditional Damper Valve Regulation The traditional method of regulating fans and pumps is to adjust the opening of inlet or outlet damper valves to regulate flow and pressure. The following problems exist with the use of baffle valves for regulation: A significant amount of energy is lost during the baffle valve's flow throttling process. Fans and pumps account for approximately 65% ​​of the plant's total electricity consumption. For fans and pumps, the most effective energy-saving measure is to regulate flow rate through speed control. Since fans and pumps are mostly square torque loads, their shaft power is essentially cubic with respect to speed. Therefore, when the fan/pump speed decreases, the power consumption drops significantly. Figure 1 shows the power consumption versus airflow curves for fans using various regulation methods. Curve 1 represents the motor input power when the output damper is controlled, curve 2 represents the motor input power when the input damper is controlled, curve 3 represents the motor input power when using slip speed control (using a slip motor and hydraulic coupling), curve 4 represents the inverter input power when using variable frequency speed control, and the bottom curve represents the required shaft input power of the fan, i.e., the motor shaft output power, when using speed control. It is evident that among the various regulation methods, variable frequency speed control offers the best energy-saving effect. The medium exerts a significant impact on the baffle valve, causing severe equipment damage. The damper valve operates slowly, making manual operation difficult and prone to causing fan vibration if not handled properly. The damper valve actuator is typically a high-torque electric actuator, prone to failure, unsuitable for frequent, long-term adjustments, difficult to implement in closed-loop automatic control, and exhibits unsatisfactory dynamic performance. The starting current of an asynchronous motor during direct starting is generally 6-8 times its rated current, causing significant impact on the power grid and motor heating. Furthermore, the strong impact torque negatively affects the mechanical lifespan of both the motor and the fan. 2. Advantages of Variable Frequency Speed ​​Control **Saving a significant amount of energy lost in the damper valve's flow control process:** Variable frequency speed control allows for soft starting, eliminating the impact on the power grid and load, and extending the lifespan of the motor and fan. With variable frequency speed control, the fan and pump frequently operate below their rated speed, greatly reducing wear on the pump impeller, fan fan, bearings, and seals. After adopting variable frequency speed control, closed-loop control can be easily formed for automatic adjustment. The 4-20mA signal output by the regulator is sent to the frequency converter (or controlled via a communication interface). By adjusting the motor speed through the frequency converter, air volume and flow rate can be smoothly and stably adjusted, enabling the unit to operate safely and stably in a more economical state. [b][align=center]For more details, please click: Application of Harmonic-Free High-Voltage Frequency Converters in Auxiliary Equipment of Thermal Power Plants[/align][/b]