共查询到20条相似文献,搜索用时 140 毫秒
1.
《Power Electronics, IEEE Transactions on》2009,24(8):1939-1950
2.
Detjen D. Jacobs J. De Doncker R.W. Mall H.-G. 《Power Electronics, IEEE Transactions on》2001,16(6):821-827
A new hybrid power filter is presented for three phase industrial power systems which include passive power factor correction equipment (PFC). The hybrid filter damps resonances occurring between line impedances and the PFC. In addition, the hybrid filter topology can be used to compensate harmonic currents. The capacitors of the PFC, which generally cause resonant problems in harmonic distorted networks, can be used for passive filtering by connecting a transformer with a low magnetizing inductance in series hence creating a single harmonic trap. The primary side of the transformer is connected to a low VA-rated three-phase current controlled inverter which builds the active part of the hybrid topology. Simulation results and experimental results are presented verifying the damping and harmonic compensation performance of the proposed topology 相似文献
3.
A three-phase ZVS PWM DC/DC converter with asymmetrical duty cycle for high power applications 总被引:1,自引:0,他引:1
This paper proposes the application of the asymmetrical duty cycle to the three-phase dc/dc pulse-width modulation isolated converter. Thus, soft commutation is achieved for a wide load range using the leakage inductance of the transformer and the intrinsic capacitance of the switches, as no additional semiconductor devices are needed. The resulting topology is characterized by an increase in the input current and output current frequency, by a factor of three compared to the full-bridge converter, which reduces the filters size. In addition, the rms current through the power components is lower, implying the improved thermal distribution of the losses. Besides, the three-phase transformer allows the reduction of the core size. In this paper, a mathematical analysis, the main waveforms, a design procedure, as well as simulation and experimental results obtained in a prototype of 6 kW are presented. 相似文献
4.
Jinn-Chang Wu Yung-Shan Wang Hurng-Liahng Jou Wei-Tso Lu 《International Journal of Electronics》2016,103(7):1236-1247
This study proposes a single-phase to three-phase power conversion interface which converts the power from a single-phase utility to three-phase power for a three-phase load. The proposed single-phase to three-phase power conversion interface comprises a bridge-type switch set, a set of three-phase inductors, a transformer set and a set of three-phase capacitors. A current-mode control controls the switching of bridge-type switch set, to generate a set of nonzero-sequence (NZS) currents and a set of zero-sequence (ZS) currents. The transformer set is used to decouple the NZS currents and the ZS currents. The NZS currents are used to generate a high-quality three-phase voltage that supplies power to a three-phase load. The ZS currents flow to the single-phase utility so that the utility current is sinusoidal and in phase with the utility voltage. Accordingly, only a bridge-type switch set is used in the single-phase to three-phase power conversion interface to simply the power circuit. A prototype is developed and tested to verify the performance of the proposed single-phase to three-phase power conversion interface. 相似文献
5.
A three-phase ZVS PWM DC/DC converter with asymmetrical duty cycle associated with a three-phase version of the hybridge rectifier 总被引:1,自引:0,他引:1
This paper proposes the use of a three-phase version of the hybridge rectifier in the three-phase zero-voltage switch (ZVS) DC/DC converter with asymmetrical duty cycle. The use of this new rectifier improves the efficiency of the converter because only three diodes are responsible for the conduction losses in the secondary side. The current in the secondary side of the transformer is half the output current. In addition to this, all the advantages of the three-phase DC/DC converter, i.e., the increased frequency of the output and input currents, the improved distribution of the losses, as well as the soft commutation for a wide load range, are preserved. Therefore, the resulting topology is capable of achieving high efficiency and high power density at high power levels. The theoretical analysis, simulation, and experimental results obtained from a 6-kW prototype, and also a comparison of the efficiency of this converter with the full-bridge rectifier are presented. 相似文献
6.
《Power Electronics, IEEE Transactions on》2008,23(6):2710-2718
7.
为了保障配电房能够安全、可靠地正常运行,文中针对配电房常见的3大故障:电房三相故障、变压器故障及保护装置故障,提出了对应每项故障发生状况及处理方法。 相似文献
8.
本文阐述配电变压器负荷三相不平衡带来的问题和隐患,并对常规的解决方法进行技术比较,在现有自动控制的基础上进行适当改良以达到有载调整三相负荷平衡的目的,有效的解决三相负荷不平衡给供电企业带来的困扰。 相似文献
9.
《Power Electronics, IEEE Transactions on》2009,24(2):358-368
10.
Ratanapanachote S. Han Ju Cha Enjeti P.N. 《Power Electronics, IEEE Transactions on》2006,21(1):124-130
High power telecommunication power supply systems consist of a three-phase switch mode rectifier followed by a dc/dc converter to supply loads at -48 V dc. These rectifiers draw significant harmonic currents from the utility, resulting in poor input power factor with high total harmonic distortion (THD). In this paper, a digitally controlled three-phase switch mode power supply based on a matrix converter is proposed for telecommunication applications. In the proposed approach, the matrix converter directly converts the low frequency (50/60Hz, three-phase) input to a high frequency (10/20kHz, one-phase) ac output without a dc-link. The output of the matrix converter is then processed via a high frequency isolation transformer to produce -48V dc. Digital control of the system ensures that the output voltage is regulated and the input currents are of high quality under varying load conditions. Due to the absence of dc-link electrolytic capacitors, power density of the proposed rectifier is expected to be higher. Analysis, design example and experimental results are presented from a three-phase 208-V, 1.5-kW laboratory prototype converter. 相似文献
11.
A new high-power-factor three-phase AC-DC converter: analysis,design, and experimentation 总被引:4,自引:0,他引:4
This paper proposes a new high-power factor three-phase AC-DC power converter, which is composed of a line interphase transformer (LIT) and two three-phase diode rectifiers, followed by a pulsewidth modulation (PWM) DC-DC boost power converter. The active switch of the boost converter is gated at a constant frequency such that the AC input current is discontinuous. This procedure provides an input current shaping without the third, fifth and seventh harmonics. The currents that flow through the LIT and boost inductors have such a high-switching frequency that ferrite cores with a small size can be utilized. In addition, the output voltage is regulated by PWM to compensate for line voltage variations and load change. Theoretical analysis, design procedure and example, along with experimental results taken from a 6 kW laboratory prototype are given 相似文献
12.
Zhuo Sun Xinjian Jiang Dongqi Zhu Guixin Zhang 《Power Electronics, IEEE Transactions on》2004,19(4):1036-1042
To improve the power quality of traction power system, a novel active power quality compensator (APQC) and a new compensating currents detection method are proposed. The APQC consists of a three-phase voltage source converter and a Scott transformer. The Scott transformer, taken as an isolation transformer, not only connects the three-phase converter to the traction power system, but also converts the traction power system to a nearly balanced three-phase power system. Therefore, a general three-phase converter could be used in APQC. Regarding the traction substation as a compensating object, the power quality of a traction substation can be improved integrally. Simulation and prototype experimental results show that the proposed APQC is able to compensate reactive power, harmonic, and negative-sequence currents in two feeders of a traction substation. 相似文献
13.
Sabahi M. Hosseini S.H. Sharifian M.B.B. Goharrizi A.Y. Gharehpetian G.B. 《Power Electronics, IEEE Transactions on》2009,24(3):830-837
This paper presents a single-stage bidirectional power electronic transformer (PET) for lighting systems as a three-phase electronic ballast. The lighting system supplies multilamp units that are controlled simultaneously by a bidirectional PET using a pulsewidth modulation scheme. The PET contains a single-input multioutput high-frequency isolating transformer to control the illumination of the lamps as well as providing galvanic isolation in each unit simultaneously. The high-frequency operation, direct ac to ac conversion, and bidirectional power flow capabilities help the PET to operate without any bulky storage elements. So good efficiency, and low weight, volume, and cost of the power conversion system can be achieved. The control strategy promotes the ballast performance to let fluorescent lamps operate free from both voltage flicker and disturbances. As a result, improved dimmable illumination, lamps protection, and increasing lifetime of lamps can be achieved. A design procedure based on equivalent circuit is presented to determine the resonant output circuit parameters. The experimental results of the prototype, which converts 110 V/3phi/50 Hz input voltage to 130 V/1phi/25 kHz and 70 V/1phi/25 kHz output voltages, show the practical aspects of the proposed PET. 相似文献
14.
A Three-Phase Current-Fed DC/DC Converter With Active Clamp for Low-DC Renewable Energy Sources 总被引:1,自引:0,他引:1
《Power Electronics, IEEE Transactions on》2008,23(6):2784-2793
15.
Hurng-Liahng Jou Jinn-Chang Wu Kuen-Der Wu Hong-Ren Shen 《International Journal of Electronics》2018,105(11):1962-1975
A conventional DC-AC inverter can only output either a single-phase AC voltage or a set of three-phase AC voltages. A new three-port DC-AC inverter which can simultaneously output a single-phase AC voltage and a set of three-phase AC voltages is proposed in this paper. This three-port DC-AC inverter is based on the three-port T-type multi-level power converter which is composed of three T-type power electronic legs, a decoupling transformer set, a filter inductor set, a single-phase filter capacitor, and a three-phase filter capacitor set. The DC port of the proposed power converter is connected to a DC power source to act as the input port, and the single-phase AC port and the three-phase AC port serve as two output ports to supply power to the single-phase load and the three-phase load, respectively. The zero-sequence transformer is used to decouple the single-phase and three-phase AC components, which are generated by the three T-type power electronic legs. The operation principle of this three-port DC-AC inverter is analyzed, and a hardware prototype is established to verify the performance of the proposed three-port DC-AC inverter. The experimental results are as expected. 相似文献
16.
三相四线制电路中由于非线性负载的大量使用,使得中线上累加了大量的零序谐波电流,给电网的安全运行带来隐患。为此本文提出了一种新的中线零序谐波治理方案,即采用Zigzag变压器与有源电力滤波器(Active Power Filter,APF)相结合的方法。Zigzag变压器因其接线简单、性价比高而在中线谐波治理方面倍受青睐。两者的结合使得目标装置具有较高的性价比和广阔的市场应用前景。经仿真验证,此方案滤波效果在三相负载对称和不对称时均较好,是解决目前日益严重的中线零序谐波污染问题的一种切实可行的方案。 相似文献
17.
18.
Mendes A. M. S Marques Cardoso A. J. 《Industrial Electronics, IEEE Transactions on》2006,53(6):1807-1817
This paper presents a comparative analysis involving several fault-tolerant operating strategies, applied to three-phase induction-motor drives, that intend to compensate for inverter faults. The results presented show the advantages and the inconveniences of several fault-tolerant drive structures, under different control techniques, such as the field-oriented control and the direct torque control. Experimental results concerning the performance of the three-phase induction motor, based on the analysis of some key parameters, like induction-motor efficiency, motor power factor, and harmonic distortion of both motor line currents and phase voltages, will be presented 相似文献
19.
Grandi G. Rossi C. Ostojic D. Casadei D. 《Industrial Electronics, IEEE Transactions on》2009,56(11):4416-4426
A novel scheme for three-phase grid-connected photovoltaic (PV) generation systems is presented in this paper. The scheme is based on two insulated strings of PV panels, each one feeding the dc bus of a standard two-level three-phase voltage-source inverter (VSI). The inverters are connected to the grid by a three-phase transformer having open-end windings on the inverter side. The resulting conversion structure performs as a multilevel power active filter (equivalent to a three-level inverter), doubling the power capability of a single VSI with given voltage and current ratings. The multilevel voltage waveforms are generated by an improved space-vector-modulation algorithm, suitable for the implementation in industrial digital signal processors. An original control method has been introduced to regulate the dc-link voltages of each VSI, according to the voltage reference given by a single maximum power point tracking controller. The proposed regulation system has been verified by numerical simulations and experimental tests with reference to different operating conditions. 相似文献
20.
A robust 12 kW rectifier with low THD in the line currents, based on an 18-pulse transformer arrangement with reduced kVA capacities followed by a high-frequency isolation stage is presented in this work. Three full-bridge (buck-based) converters are used to allow galvanic isolation and to balance the dc-link currents, without current sensing or current controller. The topology provides a regulated dc output with a very simple and well-known control strategy and natural three-phase power factor correction. The phase-shift PWM technique, with zero-voltage switching is used for the high-frequency dc-dc stage. Analytical results from Fourier analysis of winding currents and the vector diagram of winding voltages are presented. Experimental results from a 12 kW prototype are shown in the paper to verify the efficiency, robustness and simplicity of the command circuitry to the proposed concept. 相似文献