Compensation for neutral current harmonics in a three-phase four-wire system by a synchronous machine

This paper presents a new method that passively reduces the neutral current harmonics in a three-phase four-wire system by a synchronous machine. Selecting 2/3 as the coil pitch of the armature winding can minimize the zero-sequence reactance of the synchronous machine. The proposed method utilizes such a characteristic, which allows harmonic compensation by the synchronous machine. For analysis and design, an equivalent circuit for the third harmonic component of the basic system is derived. Using this equivalent circuit, its harmonic compensation characteristics are theoretically analyzed, and design fundamentals are provided. Experimental results demonstrate the effectiveness of the proposed method and validate the theoretical analysis.

[1]  Prasad Enjeti,et al.  Analysis and design of a new active power filter to cancel neutral current harmonics in three phase four wire electric distribution systems , 1993, Conference Record of the 1993 IEEE Industry Applications Conference Twenty-Eighth IAS Annual Meeting.

[2]  Ned Mohan,et al.  Active filtering of harmonic currents in three-phase, four-wire systems with three-phase and single-phase nonlinear loads , 1992, [Proceedings] APEC '92 Seventh Annual Applied Power Electronics Conference and Exposition.

[3]  T. M. Gruzs.  A survey of neutral currents in three-phase computer power systems , 1989 .

[4]  Jih-Sheng Lai,et al.  Effectiveness of harmonic mitigation equipment for commercial office buildings , 1996 .

[5]  T. M. Gruzs,et al.  A survey of neutral currents in three-phase computer power systems , 1989, Conference Record. Industrial and Commercial Power Systems Technical Conference.