Abstract
In this paper, a discrimination method is proposed for the interturn short-circuit and resistive unbalance faults of the synchronous condenser. The mathematical models of the synchronous condenser are established under these two faults. Especially, the zero-sequence voltage components (ZSVC) under two faults are analyzed. Due to the direct connection between the synchronous condenser and the power grid, the fundamental component of ZSVC under the interturn short-circuit fault is not affected by the stator currents, while the resistive unbalance fault is just the opposite. Hence, the amplitude of fundamental component in ZSVC is used to detect the fault occurrence. Then, the change of the fundamental component in ZSVC is observed by changing the excitation current to discriminate the fault type. The effectiveness of the proposed method is verified by the simulation and experimental results.
Highlights
Ultra-high voltage direct current (UHVDC) transmission system has the advantages of large capacity and long distance, and can realize efficient power transmission [1]
A discrimination method is proposed for the synchronous condenser with the interturn short-circuit or resistive unbalance faults
It is found that the fundamental component of zero-sequence voltage component (ZSVC) under the interturn short-circuit fault is not affected by the stator currents while that under the resistive unbalance fault will be affected by the stator currents
Summary
Ultra-high voltage direct current (UHVDC) transmission system has the advantages of large capacity and long distance, and can realize efficient power transmission [1]. In [28], the rotor demagnetization and interturn short-circuit faults of PMSMs are discriminated by the phase angle between stator current and q-axis. In [6], a wavelet-based index is proposed to discriminate interturn short-circuit fault and resistive unbalance faults of doubly fed induction generators. In [29], the zero-sequence voltage or negativesequence current are used to discriminate the interturn short-circuit fault and the resistive unbalance of induction machines. To the best of the authors’ knowledge, no existing literature has discussed the discrimination method of interturn shortcircuit and resistive unbalance faults for the synchronous condenser. The interturn short-circuit and resistive unbalance faults can be discriminated by adjusting the excitation current, which takes full advantage of the operation characteristics of the synchronous condenser.
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call