An improved low-voltage ride-through performance of DFIG based wind plant using stator dynamic composite fault...

Area of Science:

• Electrical Engineering
• Power Systems Engineering
• Renewable Energy Integration

Background:

• Grid-connected doubly fed induction generators (DFIGs) are crucial for renewable energy but susceptible to grid faults.
• Maintaining grid stability during faults requires robust protection mechanisms for DFIGs.
• Existing protection schemes like dynamic rotor current limiters (RCL) have limitations in fully mitigating fault impacts.

Purpose of the Study:

• To propose and evaluate an enhanced low-voltage ride-through (LVRT) strategy for grid-connected DFIGs.
• To introduce a novel stator dynamic composite fault current limiter (SDCFCL) for improved fault tolerance.
• To demonstrate the superiority of the SDCFCL over conventional methods in managing fault conditions.

Main Methods:

• Development of a stator dynamic composite fault current limiter (SDCFCL) circuit.
• The SDCFCL incorporates a series resistor-inductor combination and a parallel bidirectional semiconductor switch.
• Simulation studies using a grid-integrated 2.0MW DFIG model to validate the proposed SDCFCL performance.

Main Results:

• The SDCFCL effectively reduces rotor induced open circuit voltage by increasing stator inductance.
• The SDCFCL concurrently increases rotor impedance, limiting rotor circuit overcurrent and overvoltage.
• Simulation results show the SDCFCL provides more secure protection compared to conventional RCL during various fault scenarios.

Conclusions:

• The proposed SDCFCL significantly enhances the LVRT performance of grid-connected DFIGs.
• The SDCFCL offers a more effective and secure solution for mitigating rotor overcurrent and overvoltage during grid faults.
• The SDCFCL is a promising protection strategy for improving the reliability of DFIG-based power systems.