Hybrid Analyzing Technique for Active Islanding Detection Based on d-Axis Current Injection

Detection of islanded operation of distributed generators has become very important for ensuring the safety of the service personnel and electrical components. In this paper, a deliberate disturbance in the d-axis current of the generator is used for active island detection. A novel hybrid analyzing technique is proposed, which analyses the d-axis voltage component in two different ways to detect islanding accurately. It is shown that the proposed hybrid analyzing technique utilizes the time-tested d-axis current disturbance injection in an attempt to detect islanding faster without causing any threat to the stability of the distributed generator. It has also been established that the proposed technique avoids any malidentification of islanding and distinguishes accurately the switching and other transients from an islanded operation. MATLAB/Simulink platform has been used to validate the proposed method of islanding detection on various operating conditions.