Performance Assessment of the αβ0-Based Bus Differential Protection

This paper presents the experimental performance assessment of the αβ0-based bus differential protection (BDP). This protection is developed for buses that interconnect battery storage systems (BSSs). The tested BDP employs αβ0 components of the apparent powers flowing in all branches that are connected to the protected bus. The αβ0 components of apparent powers allow accommodating frequent changes in the direction of power flows due to the charging/discharging modes of the BSS operation. In each branch connected to the protected bus, the 3φ apparent powers are determined using the measured branch currents and voltage (at the protected bus). The αβ0-based BDP is implemented using a digital processing board for experimental testing for a laboratory setup. The test setup is composed of a bus that interconnects a 4 kW BSS, and feeds 3φ linear and dynamic loads. The performance of the αβ0-based BDP is assessed for responding to various internal and external faults occurring during the charging and discharging of the BSS. Experimental results reveal encouraging abilities of the tested BDP to initiate fast, accurate, and reliable responses to internal and external faults. Observed response features are complimented with a minor sensitivity to the BSS mode of operation, fault type, and/or fault location.