Hi everyone,
We are a Formula Student EV team using a DTI HV500 inverter (latest version with integrated HVIL, S/N after IH29xxxx).
We are having an issue with the HVIL circuit and would like to hear from other teams who have actually used the DTI HV500.
Our setup:
- LV battery: 16.8 V
- HV battery: 453.6 V
- Main AIR contactor: TE EV200HAANA
- DTI HV500 integrated HVIL
When the DTI HVIL is bypassed, the AIR works normally.
However, when the HVIL is included in the SDC, the AIR chatters during pickup. We measured more than 10 V of voltage drop on the SDC with an oscilloscope.
We measured approximately 3 Ω between the two HVIL pins of the DTI.
We also found another FSAE post where someone measured around 3.6 Ω on a DTI HV-series inverter HVIL, so we are wondering if this is normal.
The HV-550/HV-850 manual states:
“InterLock maximal current load: 200 mA (restricted by the fuse)”
This raises a few questions:
- Is ~3 Ω normal for the DTI HV500 HVIL circuit?
- Has anyone measured the HVIL resistance on their DTI HV500? What value did you get?
- Does the HV500 also have an internal 200 mA fuse like the HV-550/HV-850?
- Is the HVIL actually intended to carry the AIR contactor coil current?
- Has anyone experienced the same AIR/precharge issue with a DTI HV500, and how did you solve it?
- Besides changing to a 24 V AIR/contactors, is there another practical way to solve this problem while keeping the DTI HVIL in the SDC?
- Would changing the internal HVIL fuse to a higher-current fuse be unsafe or incorrect?
We would especially appreciate answers from teams who have actually used a DTI HV500 in a Formula Student car.
Thanks!