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内容記述 |
Taking advantage of the wide dynamic range feature of diamond quantum sensor, a prototype battery monitor for electric vehicles (EVs) with a measurement range of ±1000 A and an accuracy of 10 mA has been developed1 using HPHT-Ib diamond irradiated with 3✕1018 cm-2 electron beam (EB). A battery monitor prototyped with a 150 μm thick 2✕1018 cm-3 nitrogen doped layer grown on a 150 μm thick heteroepitaxial (111) CVD substrate, has also confirmed 10 mA accuracy2,3. In this presentation, we demonstrate that these battery monitors can track the current in actual EV. The current was measured as the resonance frequency difference (RH-RL) on the ODMR spectrum . The current from the battery to the motor was supplied to the busbar. Electronics and optics were within cooler-box size and could be placed on the rear seat of the EV enabling the measurement during driving. The EV was driven in the WLTC (World-wide Light vehicle Test Cycle) mode on a chassis dynamometer and the whole mode could be correctly tracked by both sensors. For more abrupt current changes than in WLTC mode, HPHT-Ib monitor showed better trackability. Improving the trackability of the heteroepitaxial monitor, increasing the NV concentration and enhancing fluorescence intensity should certainly be effective. |
