A New Half-Bridge Winding Compensation-Based Power Conditioning System for Electric Railway with LQRI

A New Integrated Hybrid Power Quality Control System for Electrical Railway

“…By selecting an appropriate value of y in the designing process of MPBT, the voltages in tapes U, V, and W can be adjusted. Byusing the Kirchhoff's law and the ampereturns balancing equations of MPBTin Fig.1, the basic current transforming relationship of HRPQC can be calculated as follows [8]: I I I I B B I I I (2) where: I A , I B , and I C are the primary currents, I α and I β are the two phase load currents, I U and I W are the currents absorbed from taps U and W; …”

“…Ignoring the zero sequence components in MPBT's primary side, we can get the following voltage and current equations: I I I I I I I I I I I I I I I I I 0 (7) where I a∆h , I b∆h , and I c∆h are the harmonic currents in ∆-filtering loop; Z Fh is the harmonic impendence of PPF; E a1h , E a2h , E c1h , E c2h and E bh are the induced electromotive forces of windings aU, UV, bW, WV, and ab, respectively. To offset the main harmonic magnetic flux in the iron-core of MPBT, Z Fh should satisfy (8) in the design process of PPF [23],…”

“…The relationship between γ com with y in the condition of different τ is shown in Fig.4, which is obtained by substituting (A.1) and (8) to (11), making τ as a fixed value, and yϵ(0,1). From Fig.4, it can be seen that, in the condition of τ=0, more than 56% harmonics are eliminated when y>0.4.…”

“…Various IGBT or IGCT based active compensating systems have been put forward in the last 20 years [8]- [20]. Among them, railway static power conditioner (RPC) [16]- [19] and active power quality compensator (APQC) [20] are the representative models.…”

“…But, RPC requires two large-capacity single-phase multi-winding step-down transformers; while a complex high power Scott transformer is also needed for APQC as the interface of its converter. All these bulky low-frequency auxiliary transformers are the major unfavorable factor in reducing the costs and improving the system's integration [8].…”