为了探明电动增压器响应规律,开展了动态工况下电动增压器电学参数、转速及进出口压力变化规律的试验研究。试验结果表明:电动增压器电流响应时间为毫秒级,目标转速突变时相电流有效值呈阶跃变化;转速和压力的响应时间均为秒级。升速情况下,不同转速变化范围时相电流有效值的响应规律近似,因而相电压、转速、压力等参数的变化曲线均部分重合。转速升高范围较大时转速和压力出现超调现象,说明电动增压器应视为二阶或高阶非线性系统。降速工况下,转速变化范围会影响相电流的动态变化规律,且同样转速变化范围下降速工况的响应时间明显长于升速工况,这体现出升速和降速工况下不同的控制策略。针对电动增压器喘振工况这一特殊不稳定工况开展了动态试验研究,发现相电流有效值、转速、压力均存在显著的喘振频率分量,而相电流的瞬时值没有喘振频率分量。
In order to explore the response characteristics of electric supercharger, the changing laws of electric parameter, speed and inlet and outlet pressure were researched under dynamic conditions. The test results proved that the phase current could change with the order of millisecond and showed the step response while the target speed abruptly increased. Besides, speed and pressures changed with the order of second. The effective values of phase currents had similar response laws under different speed ranges so that the partial coincidence of phase voltage, speed and pressure variation curve occurred during the acceleration. The speed and pressure would overshoot when the speed increase range is large, which indicated that the electric supercharger should be regarded as a second-order or high-order nonlinear system. The speed change range would affect the dynamic changing laws of phase current during the deceleration. The response time of deceleration was significantly larger than that of acceleration in the same speed change range, hence different control strategies should be adopted under the two conditions. In addition, a dynamic experimental study was carried out under the special unstable working condition of electric supercharger and significant surge frequency components could be found within the effective value of phase current, the speed and the pressure. However, it could not be found within the instantaneous value of phase current.