Current observer-based online open-switch fault diagnosis for voltage-source inverter.

Area of Science:

• Electrical Engineering
• Power Electronics
• Control Systems

Background:

• Voltage-source inverters (VSIs) are critical components in power electronic systems.
• System reliability and efficient post-fault maintenance are essential for inverters.
• Open-switch faults can compromise VSI performance and lead to system failures.

Purpose of the Study:

• To develop an online open-switch fault diagnosis method for VSIs.
• To enhance system reliability and improve post-fault maintenance efficiency.
• To provide a fast and reliable fault detection mechanism.

Main Methods:

• Utilizing a current observer-based approach to estimate phase currents.
• Analyzing the state-space model of VSIs during fault conditions.
• Generating a current residual vector by comparing estimated and measured currents.
• Employing the average value of current residuals and Clark transformation for vector angle acquisition.
• Normalizing the sum of absolute values of measured currents to indicate fault occurrence.

Main Results:

• The proposed method effectively diagnoses open-switch faults in VSIs.
• The current residual vector's amplitude and phase provide distinct fault signatures.
• On-line diagnosis is achieved with high reliability and speed.
• Simulation and experimental results validate the method's effectiveness.

Conclusions:

• The current observer-based method offers a robust solution for online open-switch fault diagnosis in VSIs.
• This approach enhances the operational reliability and maintainability of inverter systems.
• The technique demonstrates practical applicability through successful simulation and experimental validation.