Hardware-in-the-Loop Testing of Electric Traction Drives with an Efficiency Optimized DC-DC Converter Control
Konstantin Etzold, René Scheer, Timm Fahrbach, Shuang Zhou, Rafael Goldbeck, Daniel Guse, Fabian Frie, Dirk Uwe Sauer, Rik W. De Doncker and Jakob Andert
WCX SAE World Congress Experience, April 14, 2020, ISSN: 0148-7191, e-ISSN: 2688-3627
In order to reduce development cost and time, frontloading is now an established methodology for automotive development programs. With this approach, certain development tasks are shifted to earlier program phases. In particular, Hardware-in-the-Loop is a common frontloading tool and it has already been applied to conventional as well as electrified powertrains for various driving scenarios. Regarding driving performance and energy demand, the electrified powertrains are highly dependent on the DC link voltages. However, there is a particular shortage of studies of Hardware-in-the-Loop tests considering a variable DC link voltage control. This article is intended to be a first step towards closing this gap. Thereto, a battery electric vehicle with a virtual HV DC-DC converter is tested in a Hardware-in-the-Loop setup. The starting point for the DC-DC converter control implementation is a loss analysis of the traction drive consisting of an inverter, an interior permanent magnet synchronous machine and a HV DC-DC converter. The loss analysis is conducted for varying DC link voltages, and for each operation point, the optimum DC link voltage is identified and implemented into the DC-DC converter control system. In addition, a battery electric vehicle real-time simulation including a battery model and a DC-DC converter model is developed and verified based on measurement data. The vehicle simulation is combined with the inverter and the permanent magnet synchronous machine on a laboratory test bench to form a Hardware-in-the-Loop setup that meets real-time operating conditions. The entire setup is tested for various driving scenarios and the results are analyzed and discussed in terms of energy consumption and driving performance. The investigated use case demonstrates how Hardware-in-the-Loop tests can support and accelerate the virtual control development of HV DC-DC converters for electric traction drives.