Developing a model for analysis of the cooling loads of a hybrid electric vehicle by using co-simulations of verified submodels

Abstract

The requirement for including the air-conditioning and the battery-cooling loads within the energy efficiency analyses of a hybrid electric vehicle is widely recognized and has promoted system-level simulations and integrated modelling, escalating the challenge of balancing the accuracy and the speed of simulations. In this paper, a hybrid electric vehicle model is created through co-simulation of the passenger cabin, the air conditioning, the battery cooling, and the powertrai. Calibration and verification of the submodels help determine their accuracy in representing the target vehicle and achieve a balance between the model fidelity and the simulation speed. The result is a model which has a higher accuracy and a higher speed than those of similar models developed previously and which provides a reliable tool for a thorough investigation of the cooling loads for different ambient conditions and different duty cycles.Keywords Vehicle simulations, system-level simulations, co-simulations, hybrid electric vehicle model, energy efficiency of a hybrid electric vehicle, cooling load Date

Modelling and Co-simulation of hybrid vehicles: A thermal management perspective

“…This reference can be a legislative drivecycle [41,42], real world logged data [43,44] or custom traces to simulate particular conditions such as vehicle acceleration or gradeability tests [45,46]. Vehicle powertrain models are generally separated into three categories; backward facing [47,48], forward facing [49][50][51] and acausal models [52][53][54].…”

“…This allows the same basic model to be used for both forward-facing and backward-facing simulations depending on the inputs given [54]. Acausal models tend to be slightly more complex and time-consuming to develop and validate, but there are a number of software packages such as openModelica [54,55], Dymola [52,53,65], Simscape Driveline [52], and AMESim [66][67][68] which are available with pre-defined interfaces, component models, and even example systems to alleviate this issue. The major advantage of this type of model is that systems and components can be re-used much more readily and for many different purposes.…”

“…Historically, vehicle powertrain models would consistent of relatively simplistic models (e.g., mapped engines [73]) so that they can be quickly created, parameterized, validated and simulated in a variety of configurations for component sizing and control optimisation exercises [74][75][76]. However, dynamic characteristics of the engine response have become much more important due to the events such as engine and transmission warm-up [53,77,78], engine stop-start [79,80], tipin [81], and power-on gearshifts occurring more frequently during the tests. These events can account for a substantial proportion of the emissions if not properly managed by the powertrain and vehicle supervisory control modules and therefore it is vital to include them in the vehicle powertrain model by using more advanced component models [78].…”

“…One way to achieve this is to use a 1D fluid modelling approach incorporating the major components in the engine coolant path. This already is typically performed by component design teams using software such as Dymola [53], KULI [102,103] or GT Suite [104,105]. In this way, the system dynamics of the coolant fluid flow and heat transfer paths can be captured in higher detail because these models are based on physical characteristics of the cooling circuit components.…”

Improving the Performance Attributes of Plug-in Hybrid Electric Vehicles in Hot Climates through Key-Off Battery Cooling

“…The layout of the model is shown in Figure 3. Details of the model and its experimental verification are explained in [52,53]. For completeness, a summary of the key attributes of the model pertinent to the problem considered here is provided below.…”