DESIGN & IMPLEMENTATION OF SOFT SWITCHING DC-DC CONVERTER WITH HIGH VOLTAGE GAIN FOR HIGH POWER APPLICATION

Transcription

1 International Journal of Technoloy and Enineerin ystem(ijte) IN: Paper Reviewed by: 1. Prof.A. Arul Prakasam 2.Prof.. Manimalar EIGN & IMPLEMENTATION OF OFT WITCHING C-C CONVERTER WITH HIGH VOLTAGE GAIN FOR HIGH POWER APPLICATION *B..Manikandaprabu, **.Kirupakaran, Asst professor, epartment of Electrical Enineerin ri Lakshmi Ammal Enineerin Collee, Anna University, Chennai, India. Abstract - A zero voltae switchin (ZV) dc dc converter with hih voltae ain is proposed. It consists of a ZV boost switch cell converter stae and a ZV half-bride converter stae with resonant converter and all these staes are mered into a sinle stae. The ZV boost converter stae provides a continuous input current and ZV operation of the power switches. The ZV halfbride converter stae provides a hih voltae ain. The principle of operation and system analysis are presented. The desin of the half-bride converter stae can be focused on hih voltae ain. Therefore, hih voltae ain is easily obtained. ZV operation of the power switches reduces the switchin loss durin the switchin transition and improves the overall efficiency. Index Terms - Boost converter, coupled inductor, hih voltae ain, reverse recovery, zero-voltae switchin (ZV). I. INTROUCTION C C converters with hih voltae ain are required in many industrial applications such as the front-end stae for the renewable and reen enery sources includin the solar arrays and the fuel cells, the power systems based on battery sources and super capacitors. IN dc dc converters with hih voltae ain, there are several requirements such as hih voltae ain, low reverserecovery loss, and soft-switchin characteristic, low-voltae stress across the switches, electrical isolation, and continuous input current and hih efficiency. In order to meet these requirements, various topoloies are introduced. In order to extend the voltae ain, the boost converters with resonant circuit is proposed. The voltae ain is extended but continuous input current characteristic is lost and the efficiency is deraded due to hard switchin of power switches. Their switchin frequencies are limited due to the hard-switchin operation. In order to increase the efficiency in various soft-switchin techniques are suested. Generally, there are tradeoffs between soft-switchin characteristic and hih voltae ain. It is because an inductor that is related with soft-switchin limits the voltae ain. In order to solve these problems, a zero-voltae-switchin (ZV) dc dc converter with hih voltae ain is proposed. As shown in Fi. 1, it consists of a ZV boost converter stae to make the input current continuous and provide ZV functions and resonant circuit for impedance matchin between load and source and a ZV half-bride converter stae to provide hih voltae ain. ince sinle power processin stae can be a more efficient and cost-effective solution, the staes are mered and share power switches to increase the system efficiency and simplify the structure. ince both staes have the ZV function, ZV operation of the power switches can be obtained with wider load variation. Moreover, due to the ZV function of the boost converter stae, the desin of the half-bride converter stae can be focused on hih voltae ain. Therefore, hih voltae ain is easily obtained. ZV operation of the power switches reduces the switchin loss durin the switchin transition and improves the overall efficiency. The theoretical analysis is verified by a 100W experimental prototype with V conversion.. 51

2 International Journal of Technoloy and Enineerin ystem(ijte) IN: Paper Reviewed by: 1. Prof.A. Arul Prakasam 2.Prof.. Manimalar Conventional dc-dc converter circuit diaram auxiliary diode current ia arrives at its maximum value Ia. The current il has its maximum value IL 1. FUNCTIONAL BLOCK IAGRAM Fi convntional soft-switchin dc dc converter with hih voltae ain The equivalent circuit of the proposed converter is shown in Fi.. The ZV boost converter stae consists of a coupledinductor Lc, the lower switch Q1, the upper switch Q2, the auxiliary diode a, and the dc-link capacitor Cdc. The diodes Q1 and Q2 re present the intrinsic body diodes of Q1 and Q2. The capacitors CQ1 and CQ2 are the parasitic output capacitances of Q1 and Q2. The coupled inductor Lc is modeled as the manetizin inductance Lm1, the leakae inductance Lk1, and the ideal transformer that has a turn ratio of 1:n1 (n1 = Ns 1/Np 1 ). The ZV half-bride converter stae consists of a transformer T, the switches Q1 and Q2, the output diodeso1 ando2, the dcblockin capacitors CB1 and CB2, and the output capacitor Co. The transformer T is modeled as the manetizin inductance Lm2, the leakae inductance Lk2, and the ideal transformer that has a turn ratio of 1:n2 (n2 = Ns 2/Np 2 ). The theoretical waveforms of the proposed converter are shown in Fi. The switches Q1 and Q2 are operated asymmetrically and the duty ratio is based on the switchq1. The operation of the proposed converter in one switchin period Ts can be divided into seven as shown in Fi. 4. Just beforemode 1, the upper switch Q2, the auxiliary diode a, and the output diode o1 are conductin. The manetizin current im1 of Lc arrives at its minimum value Im12 and the Fi Proposed functional block diaram The input source is a C supply. Then the hybrid boost converter circuit are used to hih power voltae produced. But the switchin losses and voltae stress are reduced. The resonant circuit is produced by the hih frequency. o the isolation transformer is used to boost the voltae and hih frequency transformer. Next the half bride rectifier circuit, it is used to AC voltae into C voltae. The rectifier is improve the double of the voltae, the losses is reduced the filter. o the output is hih of the circuit. ince both staes have the ZV function, ZV operation of the power switches can be obtained with wider load variation. Moreover, due to the ZV function of the boost converter stae, the desin of the half-bride converter stae can be focused on hih voltae ain. Therefore, hih voltae ain is easily HYBRI BOOT CONVERTER Fi Hybrid boost converter 52

3 International Journal of Technoloy and Enineerin ystem(ijte) IN: Paper Reviewed by: 1. Prof.A. Arul Prakasam 2.Prof.. Manimalar The hybrid boost switchin blocks are inserted in a classical boost converter to ive the hybrid step-up power supplies respectively. For reducin the output current ripple, an output inductor is inserted after Voltae second balance on the inductors lead to, hybrid converters Hybrid dc dc PWM step-up converter with switchin structure. A dc ain (1=+) times bier than that of a classical boost converter is obtained. The circuit was studied in detailed. Where experimental results proved the expected performances. The input inductor in a classical boost converter was just replaced by the two inductors of in the new hybrid converter. A unified method for developin hybrid converters with a hih step-down/up conversion voltae ratio was proposed. The topoloies and formulas of the dc ain have been deducted, a detailed analysis and discussion of practical aspects of every one of the new converters bein left for other papers. The new present a similar complexity with available quadratic converters (or one element less for some of the new converters similar voltae stresses on the transistors and diodes, and similar conversion ratio as the quadratic converters (for some values of the duty cycle, some of the quadratic converters have the ede, for other values, the new hybrid converters have a steeper step-down/up dc voltae ratio). The main advantae of the new converters is their lower enery in the manetic elements, what leads to weiht, size and cost savin for the inductors, and thus for the power supply, and less conduction losses, what leads to a better efficiency. of the new converters bein left for other papers The new hybrid converters present a similar complexity with available quadratic converters (or one element less for some of the new converters), similar voltae stresses on the transistors and diodes, and similar conversion ratio as the quadratic converters (for some values of the duty cycle, some of the quadratic converters have the ede, for other values, the new hybrid converters have a steeper stepdown/up dc voltae ratio). The main advantae of the new converters is their lower enery in the manetic elements, what leads to weiht, size and cost savin for the inductors, and thus for the power supply, and less conduction losses, what leads to a better efficiency. Feature of proposed Hybrid C-c converter Hih efficiency. Reduced size & weiht. impler structure & control. Provide hih voltae ain with out entre switch duty cycle. Lower switchin stress on the semiconductor devices so as to reduce the cost switch conduction is turn on losses. Ripple free continuous output & input current. PROPOE CIRCUIT IAGRAM This paper consists of a ZV hybrid boost converter circuit, half bride LLC resonant circuit and half bride rectifier circuit are arraned by the soft switch C-C converter. ZV operation of the power switches. ZV hybrid boost stae to make the input current continuous and ZV half bride converter stae provide hih voltae ain. Fi. Propose oft witchin dc dc converter with hih voltae ain ince sinle power processin stae can be a more efficient and cost-effective solution, both staes are mered and share power switches to increase the system efficiency 53

4 International Journal of Technoloy and Enineerin ystem(ijte) IN: Paper Reviewed by: 1. Prof.A. Arul Prakasam 2.Prof.. Manimalar and simplify the structure. ince both staes have the ZV function, ZV operation of the power switches can be obtained with wider load variation. Moreover, due to the ZV function of the boost converter stae, the desin of the halfbride converter stae can be focused on hih voltae ain. Therefore, hih voltae ain is easily obtained. ZV operation of the power switches reduces the switchin loss durin the switchin transition and improves the overall efficiency. The boost converter produced a improve the output voltae, then the resonant switch are used to reduce the switchin losses but the frequency improved by this resonant switches. It consists of the isolation transformer used to ac-dc conversion, with actin the hih frequency transformer. The last stae is the half bride rectifier converter, it is used for secondary said transformer output is ac voltae. Therefore chane the ac voltae into the dc voltae because the output is the dc voltae. o rectifier are used. The capacitor are used to filter circuit, the output is filterin and reduces the losses of the output circuit. o the output side is improved with hih voltae ain and hih efficiency. The new hybrid converters present a similar complexity with available quadratic converters (or one element less for some of the new converters), similar voltae stresses on the transistors and diodes, and similar conversion ratio as the quadratic converters (for some values of the duty cycle, some of the quadratic converters have the ede, for other values, the new hybrid converters have a steeper stepdown/up dc voltae ratio). The main advantae of the new converters is their lower enery in the manetic elements, what leads to weiht, size and cost savin for the inductors, and thus for the power supply, and less conduction losses, what leads to a better efficiency. Comparision of conventional and proposed topoloy In order to extend the voltae ain, the boost converters with coupled inductors are proposed in the converter. The voltae ain is extended but continuous input current characteristic is lost and the efficiency is deraded due to hard switchin of power switches. In a stepup converter based on a chare pump and coupled inductor is suested. Its voltae ain is around 10 but its efficiency is not hih enouh due to the switchin loss. In a hih-step-up converter with coupled inductors is suested to provide hih voltae ain and a continuous input current. However, its operatin frequency is limited due to the hard switchin of the switches. The converters suested have a similar drawback. Their switchin frequencies are limited due to the hardswitchin operation. In order to increase the efficiency and power density, soft-switchin technique is required in dc dc converters. In arious soft-switchin techniques are suested. Generally, there is a tradeoff between soft-switchin characteristic and hih voltae ain. It is because an inductor that is related with soft-switchin limits the voltae ain. In order to solve these problems, a zero-voltae-switchin (ZV) dc dc converter with hih voltae ain is proposed. As shown in Fi, it consists of a ZV boost onverter stae to make the input current continuous and provide ZV functions and a ZV half-bride converter stae to provide hih voltae ain. ince sinle power processin stae can be a more efficient and cost-effective solution, both staes are mered and share power switches to increase the system efficiency and simplify the structure. Feature of the soft switchin C-C converter oft switchin characteristics Low-voltae stress across the switches Electrical isolation Low reverse recovery loss Continuous input current Hih efficiency Hih voltae ain Application of proposed C-C Converter C C converters with hih voltae ain are required in many industrial applications such as the front-end stae for the renewable and reen enery sources includin the solar arrays and the fuel cells, the power systems based on battery sources and super capacitors. In dc dc converters with hih voltae ain improved. imulation diaram and results for hybrid boost dc-dc converter The circuit diaram of half bride zero voltae hybrid boost converter C-C converter is shown below. In this circuit, the voltae and current waveforms are measured 54

5 m m m m International Journal of Technoloy and Enineerin ystem(ijte) IN: Paper Reviewed by: 1. Prof.A. Arul Prakasam 2.Prof.. Manimalar with voltae and current measurement block. Voltae is measured for input of the dc source. The dc output voltae is measured usin the discrete mean block. IMULATION IMULATION OF OPEN LOOP CONTROL OF THE C-C CONVERTER CIRCUIT 0.5 iscrete, Ts = 1e-008 s. a1 L1 V G1 a3 a From 4 VG2 Goto L a2 Operator imulation open loop output current waveform q2 <= V G2 Goto1 Cb1 VC 0.8 q3 Operator1 i + - Curre nt L2 From3 02 Operator2 VG1 Cout rload + - v Volta e q1 LM1 1 2 LK2 cb2 01 hih frequency Transformer3 IMULATION CLOE LOOP CONTROL OF THE C- C CONVERTER CIRCUIT aturation -K- du/dt imulation open loop input voltae waveform 393 Gain2 erivative VG1 Goto iscrete, Ts = 1e-007 s. -K- Operator a1 L1 Gain1 a3 a4 L a2 VG2 From 4 q2 Add -K- Gain 1 s Interator <= VG2 Goto1 Add1 Operator1 0.8 Operator2 q3 Cdc i + - Current V C 02 VG1 L2 Cout rload + - v From 3 Volta e q1 LK2 cb2 LM hih frequency Transformer3 IMULATION OPEN LOOP OUTPUT VOLTAGE WAVEFORM The circuit diaram of half bride zero voltae hybrid boost converter C-C converter is shown below. In this circuit, the voltae and current waveforms are measured with voltae and current measurement block. Voltae is 55

6 International Journal of Technoloy and Enineerin ystem(ijte) IN: Paper Reviewed by: 1. Prof.A. Arul Prakasam 2.Prof.. Manimalar measured for input of the dc source. The dc output voltae is measured usin the discrete mean block. imulation closed loop input voltae waveform frequency response of the boost converter usin frequency response technique. The simulated results shows that the only switch used in this converter is switched ON at zero current and switched OFF at zero voltae. The output voltae is boosted and it is constant. The output is hih voltae ain achieved It reaches the steady state vale within several micro seconds. REFERENCE IMULATION CLOE LOOP OUTPUT VOLTAGE WAVEFORM imulation closed loop output current waveform CONCLUION A new novel soft switchin scheme is desined and simulated with a feedback control. PI Controller is used for feedback control. We simulated the soft switchin technique and achieved the low stress and less switchin loss in the converter. The linear PI controller was desined based on [1] Q. Zhao, F. Tao, Y. Hu, and F. C. Lee, Active-clamp C/C converter usin manetic switches, in Proc. IEEE Appl. Power Electron. Conf 2001, pp [2]. A. Grant, Y. arroman, and J. uter, ynthesis of tapped-inductor switched-mode converters, IEEE Trans. Power Electron., vol. 22, no. 5,pp , ep [3] K. I. Hwu and Y. T. Yau, Voltae-boostin converter on chare pump and couplin inductor with passive voltae clampin, IEEE Trans. Ind. Electron., vol. 57, no. 5, pp , May [4]. V. Araujo, R. P. Torrico-Bascope, and G. V. Torrico-Bascope, Hihly efficient hih step-up converter for fuel-cell power processin based on three-state commutation cell, IEEE Trans. Ind. Electron., vol. 57, no. 6, pp , Jun [5] C.-T. Pan and C.-M. Lai, A hih-efficiency hih step-up converter with low switch voltae stress for fuel-cell system applications, IEEE Trans. Ind. Electron., vol. 57, no. 6, pp , Jun [6].-K. Chanchien, T. J. Lian, J.-F. Chen, and L.-. Yan, Novel hih step-up C-C converter for fuel cell enery conversion system, IEEE Trans. Ind. Electron., vol. 57, no. 6, pp , Jun [7] H. Chen, K. M. medley, anda.abramovitz, A wide-input-wideoutput (WIWO) C-C converter, IEEE Trans. Power Electron., vol. 25, no. 2, pp , Feb [8] Park and. Choi, oft-switched CCM boost converters with hih voltae ain for hih-power applications, IEEE Trans. Power Electron., vol. 25, no. 5, pp , May [9] E.-H. Kim and B.-H. Kwon, Zero-voltae- and zero-current-switchin full-bride converter with secondary resonance, IEEE Trans. Ind. Electron., vol. 57, no. 3, pp , Mar [10] H.-J. Chiu, Y.-K. Lo, H.-C. Lee,.-J. Chen, Y.-C. Yan, C.-Y. Lin, T.- H. Wan, and.-c. Mou, A sinle-stae soft-switchin flyback converter for power-factor-correction applications, IEEE Trans. Ind. Electron., vol. 57, no. 6, pp , Jun [11] E. Adib and H. Farzanehfard, Zero-voltae-transition PWM converters with synchronous rectifiers, IEEE Trans. Power Electron., vol. 25, no. 1, pp , Jan [12] X. Li and A. K.. Bhat, Analysis and desin of hih-frequency isolated dual-bride series resonant C/C converter, IEEE Trans. Power Electron., vol. 25, no. 4, pp , Apr [13] H.-L. o, A soft-switchin C/C converter with hih voltae ain, IEEE Trans. Power Electron., vol. 25, no. 5, pp , May [22] K.-B. Park, C.-E. Kim, G.-W. Moon, and M.-J. Youn, Threeswitch active-clamp forward converter with low switch voltae stress and wide ZV rane for hih-input-voltae applications, IEEE Trans. Power Electron., vol. 25, no. 4, pp , Apr