0 Introduction Since the 1990s, the technical performance of frequency converters has greatly improved, and the conditions for their widespread application are mature. Many successful examples and experiences have been gained in the cement industry in China. Variable frequency speed control technology has a series of advantages such as wide speed range, high transmission efficiency, and significant energy saving, and has been widely used in various industries. Its application in cement plants has yielded significant economic benefits. However, its application in rotary kilns, especially high-power rotary kilns with two motor drives, is a first in China. This article introduces the selection, installation, and commissioning of the main drive frequency converter for the 10,000 t/d kiln at Tongling Conch Cement Co., Ltd. 1 Equipment Introduction The rotary kiln for the 10,000 t/d clinker production line project at Tongling Conch Cement Co., Ltd. was supplied by S.A. Smith of Denmark, with specifications of 0.6m × 9.5m. Its drive system consists of two 915kW AC variable frequency motors, with dual drive. Model: HXR500LL6. The main parameters of the motor are: rated voltage 660V; frequency 45.2～76.1Hz; speed 899.8～1514.7r/min; rated current: 1006～935A. 2. Configuration of control equipment (1) A transformer with a capacity of 2500kVA and a voltage of 6.0/0.69kV is provided for two sets of variable frequency drive devices. (2) Two sets of variable frequency drive devices, the inverter model is ACS607-2540-6; power: 1000kW; voltage: 3x690V. [b][align=center]For details, please click: Application of variable frequency technology in rotary kiln of 10000t/d cement plant[/align][/b]