Pulsating characteristic of the hydraulic hybrid vehicle system with pipeline effect

The configuration and working principle of hydraulic hybrid vehicle (HHV) based on the hydraulic transformer (HT) were described to extend its energy-regenerated potential. The approximate algorithm of basic elements for pipeline distributed parameter model was summarized to simplify the pipeline model calculation, and the various basic elements of this method were proven to be used in the practical application by comparison with the experimentally validated Zhao and Hullender model. The pressure pulsation characteristics between the HT and accumulator of the HHV by considering Zhao model, Hullender model, and original pipeline approximate model was analyzed to optimize the system structure design by the method of the mathematical model, which mainly includes the series accumulator and parallel accumulator, respectively. The simulation result shows that the series accumulator was better than the parallel accumulator in terms of pulsation damping of hydraulic transformer with considering the pipeline effect. The test-rig result shows that the theoretical analysis of the pulsation between the HT and accumulator with pipeline was very close to the measurement data of the experiment in the curve trend, where the theoretical analysis results of pulsation characteristic for HHV were appropriate and reasonable.