Analysis of electric city bus performance based on transient test of electric drive system considering real- world driving cycles

The performance characteristics of a newly developed electric city bus, including those of an advanced motor such as the permanent magnet synchronous motor drive system, were analyzed and evaluated using vehicle simulation and dynamometer-based motor testing. The electric city bus was modeled and simulated for obtaining the mechanical and electrical parameters of its motor drive system, such as speed, torque, mechanical power, voltage, current, and electrical power. The electric motor drive system, being the only highly effective propulsion system, was evaluated based on a dynamometer test for ensuring precise performance characteristics and controlling the accuracy. Static modeling of the electric motor system, simulation and testing, and motor dynamometer-based transient and chassis dynamometer tests were conducted and their results were analyzed for confirming the simulation accuracy and studying the correlation between them. The analysis revealed that both the results have exactly similar patterns. The study also demonstrated that it is possible to obtain fairly reliable performance and fuel efficiency characteristics for an electric bus without using the vehicle or chassis dynamometer equipment and instead, using only a motor dynamometer-based transient test, thereby eliminating the need for conducting the costly and time-consuming chassis dynamometer test.