A Monitoring System for Diesel Engine Driven Generators Based on Electric Power Output Oscillation Assessment

Diagnosis is a main concern in power systems with generators driven by internal combustion engines, especially by low- and medium-speed diesel engines. The purpose of this paper is to develop a new diagnostic method that avoids generator operation in dangerous torque imbalance conditions. Torque in internal combustion engines has a periodic oscillation due to variations in the combustion process and pressure development between cylinders. A defective combustion in one or more cylinders produces an imbalance in torque oscillation. Analyzing the harmonic order of the generator power output makes it possible to detect and identify the cylinder that is producing the imbalance. This method has been tested with satisfactory results in a 11.6-MVA/600-r/min/10-kV diesel engine driven generator.