Abstract : The dynamic model of the motorcycle chassis dynamometer was studied, and on this basis, a control method of the AC servo system composed of frequency converter and AC asynchronous motor was proposed. An energy feedback unit was designed to address the energy flow problem of the AC chassis dynamometer. At the same time, the overall design of the motorcycle AC digital chassis dynamometer was given, and the anti-interference measures of the system were studied. Keywords : motorcycle; AC chassis dynamometer; frequency converter; vehicle performance 0 Introduction The motorcycle chassis dynamometer is a large-scale device that simulates road driving conditions and attempts to transfer the road driving conditions to a bench to realize the indoor vehicle performance test. Compared with road test, bench test on the chassis dynamometer has the advantages of good safety, no weather influence, fast test speed, high accuracy, low cost, and good data stability, and can carry out test of exhaust pollutants by the working condition method [1]. Some research has been carried out on motorcycle chassis dynamometers at home and abroad, and a series of chassis dynamometers (hereinafter referred to as dynamometers) have been developed. Since the 1990s, countries such as Japan and Germany have begun using AC servo systems for motorcycle performance testing. Due to technical barriers and confidentiality reasons, detailed technical reports are scarce. Domestic research in this area is still in its early stages and development is relatively slow. This paper, based on an in-depth study of the basic principles, composition, and key technologies of AC variable frequency dynamometers, designs and implements a digital control system for a motorcycle AC chassis dynamometer. 1. Dynamic Principle of Simulating Road Resistance When testing a motorcycle on the dynamometer, the rear wheel is placed on rollers that represent the road surface, while the front wheel is clamped and fixed (Figure 1). To ensure that the dynamometer can accurately and effectively simulate real road driving conditions, a dynamic model should be analyzed and established. [b][align=center]For more details, please click: Design and Implementation of AC Digital Dynamometer[/align][/b]