9 · v0.1 · draft · 2026-08-09
| Doctype | Test Report |
|---|---|
| Product line | openvvvf |
| Applies to | openvvvf-control-module, chassis-size-2 |
| Version | 0.1 |
| Date | 2026-08-09 |
| Status | draft |
| Description | Repeated forward/reverse direction changes at 180 VDC and ±60 Hz on the TECO MAX-IE3 induction motor to stress-test switching and current control. |
| Test id | 9 |
| Nav order | 356 |
| Normative refs | OV-TEST-HW-INDUCTION-180V-BRINGUP, OV-TEST-HW-INDUCTION-CAL-INDEX, OV-TEST-HW-INDEX |
Induction Motor 180 V 20-Minute Reversal Test
This report records a 20-minute reversal endurance run of the TECO MAX-IE3 induction motor on the C2 power stage at 180 VDC. The motor was commanded to alternate between +60 Hz and −60 Hz every ~45 s to exercise direction-change sequencing, DC-link regulation, and current control under repeated inrush conditions.
Test setup
- Motor: TECO Westinghouse MAX-IE3 3-phase induction motor, 10 HP / 7.5 kW, 208 V, 60 Hz
- Inverter: OpenVVVF C2 chassis with 200 V DC-link capacitors
- Cooling: Power stage baseplate passively cooled (no active cooling)
- Control: V/Hz open-loop excitation, commanded ±60 Hz, reversing every ~45 s
- Instrumentation: Controller telemetry, Klein Tools TI250 thermal imager
Test conditions
| Parameter | Value |
|---|---|
| DC bus voltage | ~182 VDC |
| Commanded frequency | +60 Hz / −60 Hz, alternating |
| Reversal interval | ~45 s |
| Mechanical load | None (free spinning shaft) |
| Duration | ~21 min (1263 s) |
| Ambient temperature | ~25 °C |
Electrical observations
The plot below shows the full 20-minute run. The bus voltage remained stable near 182 V throughout. Phase-current spikes appear at each reversal as the inverter re-magnetizes the motor in the opposite direction while the rotor is still spinning the other way.
Key metrics from the log:
| Quantity | Value |
|---|---|
| Reversals completed | 26 |
| Average reversal interval | 45.0 s |
| Average peak phase current at reversal | ~35.6 A |
| Maximum observed phase current | ~40.9 A |
| Maximum observed DC bus voltage | ~183.2 V |
| Average DC bus voltage | ~182.3 V |
Open telemetry log: View the reversal test in the Telemetry Viewer
Thermal results
Thermal spot-checks at the end of the run with no active cooling:
| Location | Steady-state temperature |
|---|---|
| Power stage baseplate | ~33 °C |
| Motor frame | ~31 °C |
Ambient temperature was ~25 °C, so the temperature rise was modest under the repeated reversal stress.
Results
- The C2 power stage completed 26 consecutive reversals at 180 VDC without fault.
- DC bus regulation remained stable; voltage sagged only slightly during reversal current spikes.
- Peak reversal currents averaged ~35.6 A and stayed below ~41 A.
- Direction-change sequencing behaved consistently across all 26 cycles.
- Steady-state temperatures stayed low with only passive cooling on the power stage.
Conclusion
The power stage and V/Hz control tolerate repeated full-speed reversals at 180 VDC on an unloaded induction motor. This validates direction-change robustness for 200 V-class operation and provides a baseline before adding mechanical load.
Artifacts
Notes
- The full-rate telemetry log is ~62 MB; the linked file is decimated to 0.2 samples per second for the repository.
- This test used an unloaded motor; loaded reversals will produce higher inrush currents and should be validated separately.