实时可编程双向模拟负载研究

Study on Real-time Programmable Bi-directional Simulation Load

各项研究往往需要进行试验用负载并希望它能具备实时动态模拟负载能力,在不同的应用场合往往采用不同的技术方案。进行电动汽车能量管理研究需要一款可实时变化的动态具备能量双向流动能力的负载以模拟各种工况的实际负载需求。利用二端口阻抗变换特性,可以将某一定值阻抗变换为期望阻抗,并采用实时控制得到实时变化的期望阻抗。采用电力电子技术构建了一款具备能量双向流动能力的复合模拟负载。实时可编程双向模拟负载分为两部分,纯耗能子系统与能量储存子系统。纯耗能子系统由定值功率电阻及其对应的DC-DC变换器构成,通过对DC-DC变换器的控制使功率电阻以一定的规律消耗能量,用以模拟汽车在运行过程中的消耗能量。能量储存子系统由超级电容和其相对应的双向DC-DC变换器构成,通过对双向DC-DC变换器的控制,使超级电容以一定的规律储存或释放电能,模拟汽车在运行过程中的动能变化。系统采用层级控制方案,控制器为上层,而两个子系统充当执行层为下层。两个子系统通过控制器的有序控制,有机结合构成了完整的具备能量双向流动能力的动态实时可编程电子负载。实时可编程双向模拟负载系统结构简洁、成本较低、控制灵活。最后通过试验验证表明此方案可很好地实时模拟电动汽车的负载,满足需求。

Researches always need some experiment loads to simulate the real-time dynamic loads. The different technical schemes are used to the different application situations. The research on energy management of electric vehicle requires an experiment load with real-time dynamic energy bidirectional flow capability to simulate the actual load demands of various working conditions. With the two-port＇s impedance transformation characteristics,fixed-value impedance can be transformed to expected-value impedance. And real-time variable expected impedance can be gotten by real-time control. Power electronic technology is introduced to construct a composite simulated load with energy bidirectional flow capability. The real-time programmable bidirectional simulation load is divided into pure energy consumption subsystem and energy storage subsystem. The pure energy consumption subsystem is composed of a fixed value power resistor and its corresponding DC-DC converter. The power resistor should consume energy with a certain rule by controlling the DC-DC converter,which simulates the energy consumption of the vehicle during operation.The energy storage subsystem is composed of an ultra capacitor and its corresponding bidirectional DC-DC converter. The ultra capacitor should store or release energy with a certain rule by controlling the bidirectional DC-DC converter. The subsystem simulates the changed kinetic energy of the vehicle during operation. Thesystem adopts layer control,the controller is the upper layer,and the 2 subsystems act as the lower layer（executive layer）. The 2 subsystems become a dynamic real-time programmable electronic load with energy bidirectional flow ability by the orderly control of the controller. The real-time programmable bidirectional simulation load system takes on a concise structure,low cost and flexible control. Experiment shows that the proposed scheme can well simulate EV dynamic load demands in real-time.