Fuel Consumption Test Procedure for Hybrid Electric Vehicles - Test Procedure to Ensure Resultant Accuracy in Actual Linear Regression Method

摘要

Energy efficiency evaluation test of HEVs is important to classify the vehicles by efficiency or to confirm the efficiency level to pass the certain level such as the threshold level for green tax. HEVs that need no external charge (not-OVC HEVs) have been expected to be spread due to their low additional cost on conventional vehicles and their enough efficiency improvement in practical use. Effect of energy from or to on-board energy storage system makes it difficult to evaluate the fuel economy of the HEVs. To compasated the effect of SOC change in on-board energy storage system during the test period, some test procedures have already been proposed. One of the most promising procedures is to estimate the energy efficiency in no SOC change using energy efficiency data set corresponding to various SOC changes. Even by this procedure, it is difficult to ensure or confirm the accuracy by few data sets. Moreover, the accuracy has the tendency to depend on types of HEV system and/or the driving schedule to be tested. Final target of this study is to find the uniform test procedure that is independent on the system configuration of the test HEVs and/or driving schedule for testing. In the last report, the factors that affect the accuracy of test results were discussed, referring the numbers of resultant data obtained by repeated experimental scheduled driving tests. And some algorithm to improve the test results was also proposed. In this paper, we propose the procedure that can ensure the accuracy of the result obtained by small number of tests, and the reference by which one can judge if each resultant fuel consumption (FC) vs. SOC change data set is acceptable or not.