Capacitor banks used in substations cause a maintenance problem, which consume time for technicians to identify the root cause of the problem which can result in voltage control issues. Therefore, aim of this p. 487E SEL transformer Protection Relay87ATP Differential. The literature review part is sub-divided into five sections, namely (i) Review on theory of Shunt capacitor bank protection methods,,,,,, (ii) Study on shunt capacitor elemen. The typical SEL application guide provides the detailed description of the case study consider in this paper. The system is shown in Fig. 1, provides voltage differential protec. The differential voltage comparators, compare the measured phase differential voltage (dV) magnitude to the respective pickup settings (87kPnP, n = 1, 2). The pickup settings al. The stem-based testing for voltage differential protection function for shunt capacitor banks is introduced in this paper. The lab-scale test bench setup shown in Fig. 4 is impleme.