Non-contact measurement method of busbar voltage phase of substation arrester

Abstract

• The non-contact measurement method of busbar voltage phase for substation arresters is studied. • The principles of phase measurement are derived by formulas. • Three typical spatial models of arresters are established. • The optimal locations of double detection points are recommended under different conditions. The resistive current of metal oxide arrester (MOA) is an important parameter for evaluating the aging condition of arrester. To extract the resistive component from the full current, the phase angle between the full current and the busbar voltage must be known. In conventional measurement, the voltage signal needs to be acquired from the secondary side of the capacitor voltage transformer (CVT), so there is a risk of short circuit to trigger equipment damage. To solve the above problems, a non-contact measurement method for the busbar voltage phase of substation arrester is proposed. By placing suitable electric field probe under the arrester, the busbar voltage phase is derived from the electric field information. Moreover, models of ultra-high voltage (UHV) substation arresters based on actual operation are constructed to verify this method, and the optimal placement of probes is given. The results show that the error is relatively minimum when the electric field probe is placed between the arrester and the CVT and is 1.3 m – 2 m away from the arrester. In addition, the arrangement of double detection points proposed can not only obtain the phase sequence of the three-phase voltage of the power grid, but also average the measurement errors.