Investigation of the Teslaco method for islanding prevention.

摘要

Islanding of distributed generation systems can occur when a utility interactive distributed generation system, such as a photovoltaic system, lacks the ability to acknowledge the absence of the utility, which can lead to safety hazards to working personnel due to live lines and damage of equipment due to asynchronous reclosure. It is possible that the likelihood of formation of an island could be more problematic in the multi-inverter case. Several techniques have been investigated to prevent islanding and the effectiveness of some previously developed methods in the multi-inverter case is being explored. The Teslaco method, based on classical control theory, was developed in 1984. This study was designed to explore the effectiveness of the Teslaco method in multi-inverter applications. A computer model of the Teslaco method was built in MATLAB/Simulink and simulations were conducted to examine the performance of the model in the single inverter and multi-inverter cases. Verification of model performance was done by comparing the single-inverter results obtained from previous studies. The Teslaco method was compared to a recently developed method, Sandia Frequency Shift (SFS), to examine its effectiveness. The following findings were made: (1) The Teslaco behavior as a function of the quality factor of the local load is the opposite of that of most common methods; (2) Contrary to expectations, the Teslaco method does not lose effectiveness in the multi inverter case; in fact, it slightly improves.