OPTIMAL REFERENCE POWER TRACKING OF DFIG CONVERTERS ANALYSIS AT LOW WIND SPEED AND GRID DISTURBANCES USING INTERNAL MODEL CONTROLLER

• Published in: I-Manager's Journal on Circuits & Systems Vol. 5; no. 2; p. 1
• Main Author: Ananth, D V N
• Format: Journal Article
• Language: English
• Published: Nagercoil iManager Publications 01.03.2017
• Subjects: Analysis; Converters; Disturbances; Electric potential; Energy management; Pitch (inclination); Reactive power; Rotor speed; Synchronism; Torque; Tracking; Turbines; Wind speed
• ISSN: 2321-7502; 2322-035X
• DOI: 10.26634/jcir.5.2.13661

A pitch angle control based MPPT for turbine is modeled and a sensor-less rotor speed and torque estimation are proposed in this paper. Rotor Side Converter (RSC) proposed helps to achieve optimal real and reactive power from generator, which keeps rotor to rotate at optimal speed and quickly vary current flow from rotor and stator terminals. Grid Side Converter (GSC) proposed helps to track grid reactive power demand or to setup synchronism when grid voltage changes with better response than earlier techniques. The RSC and GSC are designed based on characteristic look up table technique for identifying the grid and turbine operating conditions and give instructions accordingly. Here RSC and GSC control loops is designed depending on characteristic based lookup table techniques. These controllers are intended to maintain equilibrium in rotor speed, generator torque, and stator and rotor voltages. It is obtained using stator voltage, current and derived torque is used to track rotor speed. Moreover, it is desired to meet optimal reference real and reactive power during the turbulences like sudden change in voltage or reactive power with concurrently changing wind speed. The control of real and reactive powers is independent of the proposed technique. The sensorless controller can be connected or disconnected from running conditions. The Maximum Power Point Tracking (MPPT) algorithm with rotor converter is designed to improve mechanical power extraction from turbine - generator set. An internal model controller is used in place of conventional converters for better performance during disturbances. The performance of DFIG is compared to three cases, change from wind speeds, and alter in reactive power and in final case with variation in grid voltage.