.png)
Power plant generators are important components of an electrical energy system. They should be constantly monitored and protected in order to maintain the quality and reliability of the power supply. Otherwise, generators may occur in case of faults or incorrect operation. One of them is reverse power condition. Reverse power flow can be cause important problems if it is not considered in the protection system design.
The objective of this study is to investigate of the reverse power condition of the power plants generators. For this purpose, reverse power data are collected from a cogeneration power plant generators protection relays. The relays are able to detect disturbances and when these occurs, all digital and analogical signals are stored in its memory, including the pre-fault, fault and post-fault intervals. Hence, the reverse power data, which are collected during the transition case from abnormal condition of the generators to motoring mode, present current, voltage, active and reactive power data as well as frequency variations, are analyzed for two generators.