Static Testing
1. Test the rectifying circuit; upon checking the results, an anomaly in the circuit can be identified: A. Connect the multimeter to the P and N terminals of the internal DC power supply of the aviation power source, set it to the X10 resistance range, and connect the red probe to P, the black probe to R, S, and T respectively. Normally, there should be several tens of ohms of resistance, and it should be relatively balanced. Conversely, if the black probe is connected to P, and the red probe is connected to R, S, and T in turn, there should be a resistance approaching infinity. Repeat the above steps with the red probe connected to N, and the same results should be obtained. If there is an imbalance in the resistance among the three phases, it indicates a fault in the rectifier bridge. B. When the red probe is connected to P, if the resistance is infinite, it can be concluded that there is a fault in the rectifier bridge or the starting resistor. 2. Test the inverting circuit; connect the red probe to P, and the black probe to U, V, and W respectively. There should be several tens of ohms of resistance, and the resistance of each phase should be relatively similar. When the black probe is connected to N, the reverse should be infinite. Repeat the above steps, and the same results should be obtained; otherwise, it can be determined that there is a fault in the inverter module.
Dynamic Testing
Following normal static test results, dynamic testing, i.e., power-on testing, can proceed. The following points must be noted before and after powering on: 1. Before powering on, ensure the input voltage is correct; connecting a 380V power source to a 220V-grade inverter will result in a failure (such as exploded capacitors, voltage-sensitive resistors, modules, etc.). 2. Check that all 400Hz power source connectors are properly connected and not loose, as abnormal connections may sometimes cause power supply failures, leading to situations where the equipment does not function properly. 3. After powering on, inspect the fault display content and initially determine the fault and its cause. 4. If no fault is displayed, first check for any abnormal parameters, reset them, and then start the aviation power supply under no-load conditions (without connecting the motor) to test the U, V, W phase output voltage values. If phase loss or unbalanced three-phase conditions occur, there may be a fault with the module or driver board. 5. Under normal output voltage conditions (no phase loss, balanced three phases), perform load testing, aiming for full-load testing. Ensure meticulous and patient troubleshooting with the 400Hz power source to accurately and error-free start the aircraft and conduct electrical testing.
