E ects of leakage inductance on the input current of double-star diode recti er with active inter-phase reactor

Transcription

1 Scientia Iranica D (017) (6), 19{0 Sharif University of Technology Scientia Iranica Transactions D: Comuter Science & Engineering and Electrical Engineering E ects of leaage inductance on the inut current of double-star diode recti er with active inter-hase reactor J. Wang and S. Yang School of Electrical Engineering and Automation, Harbin Institute of Technology, Harbin, China. Received 19 Setember 01; received in revised form May 016; acceted July 016 KEYWORDS Abstract. An Active Inter-Phase Reactor (AIPR) is often emloyed to inject triangle current to imrove the inut current quality of double-star diode recti er. Due to the existing leaage inductance of transformer, the inut current harmonics suression ability of the injected triangle current would be weaened. In this aer, the current commutation rocess of the double-star diode recti er with AIPR is analyzed initially. Then, according to the relation between the inut current and outut current of the double-star transformer, the relation between the leaage inductance and the inut line current of double-star diode recti er with AIPR is established. Such factors lie the inut current THD, the inut current lag angle, and ower factor of the double-star diode recti er with AIPR as well as their relations with the leaage inductance are also obtained. The theoretical analysis demonstrates that leaage inductance increases the inut current THD and lag angle. It indicates that leaage inductance decreases the dislacement factor and ower factor. To ensure the inut current THD is less than % and the ower factor is more than 0.99, the leaage inductance factor, KLS, should be less than 0.. Simulation results verify the theoretical analysis. 017 Sharif University of Technology. All rights reserved. 1. Introduction Volt Amere (VA) rating of auxiliary current injection circuit and excellent harmonic reduction ability, the method of active harmonic reduction at dc side is suitable for high ower alications and has drawn more and more attention [16-6]. In [1], the concet of Active Inter-Phase Reactor (AIPR) was roosed in 1-ulse diode recti er. The low-va (% Po) active auxiliary circuit injects a triangular current into the extra winding of the AIPR. The resulting system draws near sinusoidal inut currents with less than 1% THD. In [19], the method to reduce the ac-side harmonics of series-connected 1ulse diode recti er utilizing dc-side active auxiliary circuit formed by two buc-and-boost converters is resented. The auxiliary circuit is laced arallel to each six-ulse recti er bridge to inject current and shae the recti er outut current. The resulting THD Double-star diode recti er; Leaage inductance; Inut current THD; Active inter-hase reactor; The inut current lag angle. Diode recti ers are widely used due to their ruggedness, simlicity, and low rice [1,]. However, they draw distorted currents from the ac suly and do not meet the requirements of the harmonics standard [,]. Therefore, researchers have exlored a variety of methods to reduce the inut line current distortion of diode recti ers in recent decades [-6]. Comared with other harmonic reduction methods, because of the small ilo*. Corresonding author. Tel.: ; Fax: addresses: wjfyjs0@16.com (J. Wang); syyang@hit.edu (S. Yang) doi: 10.00/sci.017.

2 19 J. Wang and S. Yang/Scientia Iranica, Transactions D: Comuter Science &... (017) 19{0 is below % and the ilovolt amere rating of auxiliary circuit is less than 1% Po. In [0], an AIPR scheme to achieve near sinusoidal inut line currents for a -ulse converter is roosed. The roosed AIPT scheme consists of three IPTs and a current-controlled inverter with rating required to be only 1.16% of the system ower rating. In [1], a double-star diode rectier with an auxiliary PWM rectier is also resented. It draws near sinusoidal utility line currents with less than % THD. Besides the introduced dc-side active current injection schemes, the authors in [-6] also roosed diode rectiers with an auxiliary current injection circuit at dc-side. However, those dc-side active current injection schemes were not concerned with the eects of leaage inductance of transformer. In the high ower alications, the eects of the leaage inductance of transformer are more serious and should not be ignored. In order to clarify the eects of leaage inductance of transformer on the inut current, this aer sets the double-star diode rectier with AIPR as an examle and the eects of leaage inductance of transformer on the inut current are analyzed in deth. Due to the essence of the diode rectiers, the same active current injection reduction method is used; the analysis of the eects of leaage inductance of transformer on the inut current can be extended to other diode rectiers with active current injection circuit.. Theoretical analysis.1. The double-star diode rectier with AIPR Figure 1 shows the double-star diode rectier with AIPR. Comared with the conventional double-star diode rectier, the Inter-Phase Reactor (IPR) is relaced by the AIPR. The AIPR consists of the secic IPR with an additional secondary winding and a smallva active auxiliary circuit. The active auxiliary Figure 1. The double-star diode rectier with AIPR.

3 J. Wang and S. Yang/Scientia Iranica, Transactions D: Comuter Science &... (017) 19{0 19 circuit consists of the auxiliary PWM rectier and the buc conventer. The auxiliary PWM rectier injects the triangle current into the double-star diode rectier to shae the distorted inut line current as sine wave aroximately. The buc converter is used to feed the harmonic ower absorbed by single PWM rectier to the load. In Figure 1, the outut voltage reference of auxiliary PWM rectier is designed according to the inut voltage of auxiliary PWM rectier and the load current. The outut voltage control loo of the auxiliary PWM rectier is emloyed to maintain the outut voltage as the outut voltage reference, which hels the auxiliary PWM rectier to inject the required triangle current accurately. When the harmonic ower absorbed by single PWM rectier changes, the outut voltage of auxiliary PWM rectier changes; then, the outut signals of voltage simle and PI regulators change; the duty cycle of buc converter is adjusted corresondingly. It indicates that the harmonic ower fed to the load is changed. Finally, outut voltage of the auxiliary PWM rectier is adjusted and maintained as the outut voltage reference. The injected triangle current, i s, meets: i s = I d m I d I d m + I d m m I d I d m 0 I d m I d m + 7I d m m 9I d m I d m + 11I d m (1) where I d is the average outut current of the doublestar diode rectier, and m is the turn ratio between the secondary and rimary windings of the secic IPR. In Figure 1, L a1, L b1, L c1, L a, L b, and L c are the equivalent leaage inductances of double-star transformer. The values of leaage inductance are assumed to be the same. That is: L a1 = L b1 = L c1 = L a = L b = L c = L S : () The double-star diode rectier is sulied by a balanced three-hase voltage system: u a = U m sin() u b = U m sin( =) u c = U m sin( + =) () where U m is the amlitude of inut hase voltage. Assuming that the turn ratio of double-star transformer is 1:, the outut voltages of secondary-winding double-star transformer are: u a1 = U m sin( + =6) u b1 = U m sin( =) u c1 = U m sin( + =6) u a = U m sin( =6) u b = U m sin( + =) u c = U m sin( =6) () () According to the Kirchho's current law and the Amere-turns balance law of the transformer, the inut current of the double-star rectier is: i a = 1 (i a1 i a + i c i c1 ) i b = 1 (i b1 i b + i a i a1 ) i c = 1 (i c1 i c + i b i b1 ) (6).. Current commutation rocess of the double-star diode rectier with AIPR When the triangle current, i s, is injected into the additional secondary winding of the secic IPR, outut currents of two three-hase half-wave rectiers are: i d1 = i d = I d I d ( + 1) I I d 6 d + 1 I d ( + 1) (7) () where = 0; 1;. From Eqs. (7) and (), it is noted that as a result of the modulation of the triangle current, i s, outut currents of two three-hase halfwave rectiers are critical continuous, which mae the current commutation rocess of the double-star diode rectier with AIPR dierent from that of the conventional double-star diode rectier. Figure illustrates the main waveforms of the double-star diode rectier with AIPR under large inductive load. In Figure, due to the leaage inductance, L s, the current commutation of double-star diode rectier with AIPR has not been comleted instantaneously; this aects the inut line current. To analyze the

4 196 J. Wang and S. Yang/Scientia Iranica, Transactions D: Comuter Science &... (017) 19{0 Figure. Main waveforms of the double-star diode rectier with AIPR: (a) The injected triangle current, (b) outut currents of two three-hase half-wave rectiers, (c) inut voltages of three-hase half-wave rectiers, (d) inut currents of three-hase half-wave rectiers, and (e) inut line currents of double-star diode rectier with AIPR. eects of the current commutation on the inut current in details, we introduced the current commutation rocess of double-star diode rectier with AIPR stly. Figure illustrates the main waveforms of the new current commutation from diode D a1 to diode D b1. In Figure, when < =, the inut voltage u a1 is more than the inut voltage u b1, the diode D a1 has been conducted and own into the current i d1, current i a1 is equal to i d1, and current i b1 is zero. At = =, the inut voltage u a1 is equal to the inut voltage u b1, the currents i a1 and i d1 decrease to zero exactly, diode D a1 is switched o, and D b1 is conducted automatically. When > =, the inut voltage u a1 is less than the inut voltage u b1, the diode D b1 is conducted and own into the current i d1, and current i b1 is equal to i d1. The current i b1 builds u from zero through diode D b1 and a voltage dro is roduced by the current i b1 in L b1. Then, a forward-bias voltage aears across diode D a1 and diode D a1 is conducted again. Diode D a1 and diode D b1 are conducted simultaneously and current Figure. Main waveforms of new current commutation from diode D a1 to diode D b1 : (a) Inut voltages of three-hase half-wave rectier, (b) outut currents of three-hase half-wave rectier, (c) currents though diode D a1 and diode D b1, and (d) voltage across L a1 and L b1. commutation rocess is roduced. During the current commutation interval, diode D a1 and diode D b1 are conducted at the same time and the inut voltages u a1 and u b1 are shortened through L a1 and L b1. The current commutation rocess from diode D a1 to diode D b1 is comleted when current i b1 is equal to the outut current i d1. From the above analysis, it is noted that the time of commutation beginning is decided only by the inut voltages u a1, u b1 and the outut current i d1 ; thus, the voltage dros on diodes do not aect the time of commutation beginning. In Figure, during the current commutation interval, the double-star diode rectier with AIPR meets: < : di L a1 di a1 dt = u b1 L b1 b1 dt (9) i d1 = i a1 + i b1 u a1 From Eq. (9), it is noted that during the current

5 J. Wang and S. Yang/Scientia Iranica, Transactions D: Comuter Science &... (017) 19{0 197 commutation interval, the voltage dros on diodes do not aect the current wave. Solving Eq. (9), the currents i a1 and i b1 are obtained as: i a1 = I d 6U X s i b1 = I d + 6U X s (10) where U is the RMS value of inut hase voltage of three-hase half-wave rectier and X s =!L s is the leaage inductive reactance of transformer. Considering that current i b1 changes from 0 to i d1 in the current commutation interval, the relation between the overla angle and the circuit arameters can be obtained: X B I d = 6U (1 cos ): (11) In Eq. (11), the overla angle is roortional to the leaage inductance of transformer and dc outut current, but it is inversely roortional to the outut voltage of the double transformer... Eects of the leaage inductance on the inut current According to Eq. (6) and Figure 1, in order to establish the exression between the leaage inductive of transformer and inut current, the exression of outut currents of double-star transformer should be calculated rstly. From Eqs. (7) and (10), by combining the hase relation between the currents i a1 and i b1, the outut current i a1 of double-star transformer can be obtained as: i a1 = I d + 6U X s (1 cos()) 0 I d I d + I d I d 6U X s (1) Since the rincile of six times current commutation is identical in one-line eriod, according to the hase relation among outut currents of double-star transformer, which is shown in Figure, the outut currents of double-star transformer i a, i c1, and i c are calculated as: Figure. The hase relation among outut currents of double-star transformer. i a = i c1 = i c = 0 0 I d ( ) + 6U X s (1 cos( )) + I d ( ) + I d ( ) + I d I d 6U X s I d () 6U X s (1 cos()) 0 0 (1) I d + 6U X s + (1) I d + I d +Id 0 0 I d + 6U X s + I d + I d + Id I d ( ) 6U X s (1 cos( )) (1)

6 19 J. Wang and S. Yang/Scientia Iranica, Transactions D: Comuter Science &... (017) 19{0 Substituting Eqs. (1)-(1) into Eq. (6), the inut current, i a, is: i a = 6U X S (1 cos()) 0 I d I d + 6U X S + I d + I d I d I d( ) 6U X S + I d + + 6U X S (1 cos( )) + (16) K Ls = X s 6U : (1) I d Based on the relation between the overla angle and the circuit arameters shown in Eq. (11), the leaage inductance factor, K Ls, is equal to 1 when the overla angle is equal to the maximum value 60. According to the denition of the inut current THD, combing Eqs. (19), (0), and (11), the inut current THD of double-star diode rectier with AIPR has been calculated. Figure illustrates the inut current THDs of the conventional double-star diode rectier and the double-star diode rectier with AIPR when the leaage inductance factor, K Ls, changes from 0 to 1. In Figure, it is clear that the eects of leaage inductance on the inut current THDs of conventional double-star diode rectier and double-star diode rectier with AIPR are dierent. With the increase in I d ( ) I d + 6U X S + I d + I d + I d( ) + 6U X S + I d( ) I d + The Root-Mean-Square (RMS) value and the fundamental harmonic of the inut current i a are calculated as shown in Box I. 1 is the inut current lag angle, and it meets Relation (0) as shown in Box II. To establish the relation between the inut current and the leaage inductances of transformer in a general method, we dene the leaage inductance factor K Ls as: Figure. Relation between the inut current THD and the leaage inductance factor K Ls. 16 I arms = cos ( cos ) + sin (cos ) + 0 (1 cos ) + 76) 6 ; (17) (1 cos ) I a:1 = I a1rms sin( + 1 ); (1) where: q I a1rms = 1( + cos sin cos + cos ) + (1 cos ) (6 sin cos ) : (1 cos ) (19) Box I

7 J. Wang and S. Yang/Scientia Iranica, Transactions D: Comuter Science &... (017) 19{ = arctan 6 cos sin cos cos 6 sin + +! 6 + cos sin 1 cos + 6 cos : (0) Box II leaage inductance factor K Ls, the inut current THD of conventional double-star diode rectier decreases, but it increases in the double-star diode rectier with AIPR. It is noted that the inut current THDs of conventional double-star diode rectier and double-star diode rectier with AIPR are the same when leaage inductance factor, K Ls, equals 0.. It indicates that the double-star diode rectier with AIPR cannot reduce the inut current harmonics when the leaage inductance factor K Ls is more than 0.. To ensure that the inut current THD of doublestar diode rectier with AIPR meets the standards of IEEE-19 and IEC 1000-, it should be less than %. In Figure, the leaage inductance factor, K Ls, is equal to 0. when the inut current THD is %; thus, the design of double-star transformer should mae the leaage inductance factor, K Ls, less than 0.. Combing Eqs. (0) and (11), the relation between the inut current lag angle, 1, and the leaage inductance factor, K Ls, is obtained. Figure 6 shows the inut current lag angles of the conventional double-star diode rectier and the double-star diode rectier with AIPR when the leaage inductance factor K Ls changes from 0 to 1. In Figure 6, comared with the conventional double-star diode rectier, the inut current lag angle 1 roduced by the leaage inductance of transformer is reduced eectively by the AIPR. It indicates that the double-star diode rectier with AIPR has the smaller inut current lag angle, 1, and the higher dislacement factor. With the increase in leaage inductance factor K Ls, the inut current lag angle, Figure 6. Relation between the inut current lag angle, 1, and the leaage inductance factor, K Ls. Figure 7. Relation between the ower factor and the leaage inductance factor, K Ls. 1, of double-star diode rectier with AIPR increases. When the leaage inductance factor, K Ls, equals 0., the inut current lag angle, 1, is only 0:6. Figure 7 illustrates the ower factors of the conventional double-star diode rectier and the doublestar diode rectier with AIPR when the leaage inductance factor, K Ls, changes from 0 to 1. In Figure 7, with increase in leaage inductance factor K Ls, the ower factors of conventional doublestar diode rectier and double-star diode rectier with AIPR decrease. Comared with the conventional double-star diode rectier, the double-star diode rectier with AIPR has high ower factor. The ower factor of the double-star diode rectier with AIPR is more than 0.9 when leaage inductance factor, K Ls, changes from 0 to 1.. Simulation results In order to demonstrate the eects of leaage inductance on its inut current, the double-star diode rectier with AIPR is simulated in Saber software. The circuit arameters of double-star rectier with AIPR for simulation are given in Table 1. The simulation results are shown in Figures -1. Figure illustrates the inut voltages of the three-hase half-wave rectier, the outut current of the three-hase half-wave rectier, and the currents through diode D a1 and diode D b1 when the leaage inductance L s is 0 and 1.1 mh (corresonding leaage inductance factor K Ls = 0:), resectively. In Figure, it is clear that due to the leaage inductance L s, the current commutation of double-

8 00 J. Wang and S. Yang/Scientia Iranica, Transactions D: Comuter Science &... (017) 19{0 Table 1. Parameters of double-star diode rectier with AIPR for simulation. Symble Descrition Value Um Line-to-line utility voltage in RMS 0 V f Frequency of utility voltage 0 Hz Turns ratio of the rimary and the secondary windings of the doubel-star transformer T1 10:1 V D Voltage dro on diode 0.7 V L Load ltering inductance 1 mh I d Outut current 100 A f c Current injection circuit switching frequency 0 Hz L s Current injection circuit inut ltering inductance 100 H C 1 Current injection circuit outut ltering caacitance 170 F f b Buc converter switching frequency 0 Hz L f Buc converter outut ltering inductance 10 mh m Turns ratio of the rimary and secondary windings of the AIPR 1: Figure. The inut voltages of the three-hase half-wave rectier, the outut current of the three-hase half-wave rectier, and the currents through diode D a1 and diode D b1 : (a) The leaage inductance L s = 0, and (b) the leaage inductance L s = 1:1 mh. Figure 9. The inut voltage, the inut current, and the sectrum of inut current of double-star diode rectier with AIPR: (a) The leaage inductance L s = 0, and (b) the leaage inductance L s = 1:1 mh.

9 J. Wang and S. Yang/Scientia Iranica, Transactions D: Comuter Science &... (017) 19{0 01 Figure 10. The inut current THD of double-star diode rectier with AIPR under dierent leaage inductance conditions. Figure 11. The inut current lag angle 1 of double-star diode rectier with AIPR under dierent leaage inductance conditions. Figure 1. The ower factor of double-star diode rectier with AIPR under dierent leaage inductance conditions. star diode rectier with AIPR cannot be comleted instantaneously; the current commutation from diode D a1 to diode D b1 taes lace under new current commutation mode. Figure 9 illustrates the inut voltage, the inut current, and the sectrum of inut current of doublestar diode rectier with AIPR when the leaage inductance L s is 0 and 1.1 mh (corresonding leaage inductance factor K Ls = 0:), resectively. Comaring Figure 9(a) and Figure 9(b), it is obvious that the leaage inductance L s leads to increase in the inut current harmonics. The inut current THD increases from.6% to 10.%, which is consistent with the theoretical analysis. Due to the leaage inductance L s, the inut current lag angle 1 also increases from 0 to :. According to the denition of the leaage inductance factor K Ls, under the simulation arameters shown in Table 1, the relation between the leaage inductance, L s, and the leaage inductance factor, K Ls, is obtained as: L s = 1:9K Ls (mh): () From Eq. (), the leaage inductance, L s, changes from 0 to 1.9 mh when the leaage inductance factor, K Ls, changes from 0 to 1. To corresond to Figure, Figure 10 illustrates the inut current THD of double-star diode rectier with AIPR under dierent leaage inductance conditions. In Figure 10, it is clear that with increase in leaage inductance L s, the inut current THD increases. The simulation results are consistent with the theoretical analysis in Figure. When the leaage inductance L s is less than 7 uh (corresonding leaage inductance factor K Ls = 0:), the inut current THD is less than %. To corresond to Figure 6, Figure 11 shows the inut current lag angle 1 of double-star diode rectier with AIPR under dierent leaage inductance conditions. In Figure 11, it can be seen that the leaage inductance, L s, leads to increase in the inut current lag angle 1. It indicates that the leaage inductance L s reduces the dislacement factor of double-star rectier with AIPR. To corresond to Figure 7, Figure 1 shows the ower factor of double-star diode rectier with AIPR under dierent leaage inductance conditions. In Figure 1, with increase in leaage inductance L s, the ower factor of double-star diode rectier with AIPR decreases slightly; it is not less than 0.9 when the leaage inductance L s changes from 0 to 1.9 mh. Comared with conventional double-star diode recti- er, the double-star diode rectier with AIPR oerates under almost unity ower factor condition.

10 0 J. Wang and S. Yang/Scientia Iranica, Transactions D: Comuter Science &... (017) 19{0. Conclusion In this aer, the eects of leaage inductance of transformer on the inut line current of the doublestar rectier with AIPR are analyzed in deth. The theoretical analysis results indicate that the leaage inductance of transformer leads to increase in the inut current harmonics of the double-star rectier with AIPR, and the inut current THD is greater than % when the leaage inductance factor K Ls is more than 0.. The leaage inductance of transformer also increases the inut current lag angle of the doublestar rectier with AIPR. It indicates that leaage inductance of transformer decreases the dislacement factor. In order to ensure that the double-star diode rectier with AIPR meets the requirements of the harmonics limitation standard and oerates under almost unity dislacement factor and ower factor, the leaage inductance factor K Ls of the double-star transformer should be less than 0.. Owing to the essence of the diode rectiers, the same active current injection reduction method is used. The analysis method for the eects of leaage inductance of transformer on the inut current in this aer can be extended to analyze other diode rectiers with active current injection circuit, such as 1-ulse diode rectier with active current injection circuit. References 1. Siebert, A., Troedson, A. and Ebner, S. \Ac to dc ower conversion now and in the future", IEEE Transactions on Industry Alications, 1(1), (01).. Singh, B., Gairola, S., Singh, B.N., Chandra, A. and Al-Haddad, K. \Multiulse AC-DC converters for imroving ower quality: a review", IEEE Transactions on Power Electronics, (1), (00).. IEEE Guide for Recommended Control and Reactive Comensation of Static Power Converters, IEEE Standard 19 (199).. Limitation of Emission of Harmonic Currents in Low- Voltage Power Suly Systems for Equiment With Rated Current Greater Than 16 A, IEC (199).. Swamy, M., Kume, T.J. and Taada, N. \A hybrid 1- ulse rectication scheme for diode front-end rectiers with large DC bus caacitor", IEEE Transactions on Industry Alications, 6(6),. -9 (010). 6. Choi, S. \A three-hase unity-ower-factor diode rectier with active inut current shaing", IEEE Transactions on Industrial Electronics, (6), (00). 7. Maswood, AI. and Liu, FR. \A novel unity ower factor inut stage for AC drive alications", IEEE Transactions on Power Electronics, 0(),. 9-6 (00).. Tangtheerajaroonwong, W., Hatada, T. and Wada, K. \Design and erformance of a transformerless shunt hybrid lter integrated into a three-hase diode recti- er", IEEE Transactions on Power Electronics, (), (007). 9. Saidi, S., Abbassi, R. and Chebbi, S. \Virtual ux based direct ower control of shunt active lter", Scientia Iranica. Transaction D, Comuter Science & Engineering and Electrical Engineering, 1(6), (01). 10. Le Roux, A.D., Mouton, H. du T. and Aagi, H. \DFT-based reetitive control of a series active lter integrated with a 1-ulse diode rectier", IEEE Transactions on Power Electronics, (6), (009). 11. Aagi, H. and Isozai, K. \A hybrid active lter for a three-hase 1-ulse diode rectier used as the front end of a medium-voltage motor drive", IEEE Transactions on Power Electronics, 7(1), (01). 1. Villablanca, M.E., Nadal, J.I. and Bravo, M.A. \A 1- ulse AC-DC rectier with high-quality inut/outut waveforms", IEEE Transactions on Power Electronics, (), (007). 1. Fuuda, S., Ohta, M. and Iwaji, Y. \An auxiliarysuly-assisted harmonic reduction scheme for 1- ulse diode rectiers", IEEE Transactions on Power Electronics, (), (00). 1. Singh, B., Bhuvaneswari, G., Garg, V. and Gairola, S. \Harmonic mitigation in AC-DC converters for vector controlled induction motor drives", IEEE Transactions on Energy Conversion, (), (007). 1. Mino, K., Gong, G. and Kolar, J.W. \Novel hybrid 1- ulse boost-tye rectier with controlled outut voltage", IEEE Transactions on Aerosace and Electronic System, 1(), (00). 16. Biela, J., Hassler, D. and Schoenberger, J. \Closedloo sinusoidal inut-current shaing of 1-ulse autotransformer rectier unit with imressed outut voltage", IEEE Transactions on Power Electronics, 6(1),. 9-9 (011). 17. Araujo-Vargas, I., Forsyth, A.J. and Chivite-Zabalza, F.J. \High erfor-mance multi-ulse rectier with single transistor active injection", IEEE Transactions on Power Electronics, (), (00). 1. Lee, BS., Hahn, J. and Enjeti, PN. \A robust threehase active ower-factor-correction and harmonic reduction scheme for high ower", IEEE Transactions on Industry Electronics, 6(),. -9 (1999). 19. Choi, S., Enjeti, P.N., Lee, H.H. and Pitel, I.J. \A new active inter-hase reactor for 1-ulse rectiers rovides clean ower utility interface", IEEE Transactions on Industry Alications, (6), (1996). 0. Bai, S. and Luic, S.M. \New method to achieve AC harmonic elimination and energy storage integration

11 J. Wang and S. Yang/Scientia Iranica, Transactions D: Comuter Science &... (017) 19{0 0 for 1-ulse diode rectiers", IEEE Transactions on Industrial Electronics, 60(7),. 7- (01). 1. Young, C.M., Chen, M.H. and Lai, C.H. \A novel active interhase transformer scheme to achieve threehase line current balance for -Pulse converter", IEEE Transactions on Power Electronics, 7(), (01).. Wang, J., Yang, S., Yang, W. and Li, Y. \A low harmonic double star rectier with current injection at DC side", International Power Electronics and Alication and Exosition Conference, Shanghai, China, (01).. Meng, F., Yang, S., Yang, W. and Gao, L. \Active harmonic reduction for 1-ulse diode bridge rectier at DC side with two-stage auxiliary circuit", IEEE Transactions on Industrial Information, 11(1),. 6-7 (01).. Young, C.M., Wu, S.F. and Yeh, W.S. \A DCside current injection method for imroving AC line condition alied in the 1-ulse converter system", IEEE Transactions on Power Electronics, 9(1), (01).. Mao, L., Ren, X., Ruan, X. and Jiang, L. \Research of the current-injection-based P-tye 1-ulse ATRU", International Power Electronics and Motion Control Conference, Harbin, China,. 1-6 (01). 6. Wang, M. and Zhang, F. \1-ulse auto-transformer rectier with harmonic current injection for non-gridconnected wind ower alications", World Non-Grid- Connected Wind Power and Energy Conference, Nanjing, China,. 6-0 (009). Biograhies Jingfang Wang was born in Hebei, China, in 19. He received the BS degree in Automation from Yanshan University, Qinhuangdao, China, in 00 and the MS degree in Electrical Engineering from the Harbin Engineering University, Harbin, China, in 01. Since 01, he has been woring towards the PhD degree in Electrical Engineering at the Harbin Institute of Technology, Harbin, China. His research interests include high ower converters and harmonics comensation. Shiyan Yang was born in Heilongjiang, China, in 196. He received the BS and MS degrees in Electrical Engineering and the PhD degree in Welding Engineering from the Harbin Institute of Technology, Harbin, China, in 19, 199, and 199, resectively. He is currently a rofessor and suervisor of Doctoral Candidates at the Harbin Institute of Technology. He has ublished over 60 aers. His research interests include high-ower secial tye ower suly and its alication, energy storage system and its equilibrium, and fundamental theory of nity ower suly drive and ey commonsense roblem.