Fast and secure angular-based detection algorithm for reverse power occurrence in synchronous generators

Reverse power (RP) phenomenon in synchronous generators may lead to severe damage to the generator prime mover due to motoring action of the generator. The operation of the usual technique, which detects RP on the basis of current direction, is too slow because of utilization of intentional time delay in the relay structure. The deliberate time delay helps the relay to avoid tripping during unwanted disturbances. This paper proposes a novel angular-based scheme to detect RP in synchronous generators. For this, the proposed technique uses the load angle (δ) and the phase difference between voltage and current (θ), as the angular quantities of the generator. Furthermore, other electrical parameters of the generator such as current and voltage are also utilized as the supplementary parameters for RP detection. Ultimately, this contribution uses the analysis of vertical component of E_A (E_A Sinδ) and also the tangential component of I_A on V (I_A Cosθ) in the generator phasor diagram for making the final decision. To verify the performance of the angular-based technique, extensive simulations are carried out on two sample systems (single machine and three machines infinite bus), under different conditions and the final results show the satisfactory performance of the proposed algorithm.