The duty ratios of switches in each switching cycle can be directly obtained by simple calculation using two phases source currents and dc bus capacitor voltage.
只需检测两相电源电流和直流侧电容电压，通过简单计算就可直接求出每个开关周期内各开关的占空比。
2
On -board emission test system (OBS) is used to evaluate the emission level of a heavy duty hybrid bus to see whether the on -board energy recycle device could improve emission level.
This thesis studied certain light-dutybus, which analyzed braking process of this bus and built whole vehicle model, single wheel model, tire model and arrester model.