The Technical Session - Three-Phase AC-DC Converters Track: AC-DC Converters will be Wednesday, March 19, from 2 p.m. to 5:30 at APEC 2014:
Title: A New Interleaved Three-Phase Single-Stage PFC AC-DC Converter with Flying Capacitor
Abstract: A new interleaved three-phase PFC ac-dc single-stage multilevel is proposed in this paper. The proposed converter uses flying capacitor structure with standard phase-shift PWM to improve efficiency of the converter particularly at light load conditions. In the paper, the operation of the converter is explained, the steady-state characteristics of the new converter are determined and its design is discussed. The feasibility of the new converter is confirmed with experimental results obtained from a prototype converter and its efficiency is compared to that of another multilevel converter of similar type
Presenters:
Mehdi Narimani, University of Western Ontario
Gerry Moschopoulos, University of Western Ontario
Title: High Efficiency Paralleled Three-Phase Current Source Front-End Rectifiers for Data Center Power Supplies with Current Balancing and Hot-Swap
Abstract: This paper develops a 19 kW three-phase front-end power conversion stage for data center power supplies based on 400 Vdc power delivery architecture. The front-end stage is based on three paralleled three-phase current source rectifiers (CSRs), which have several benefits for this application. A control method will be introduced for paralleled CSRs to achieve balanced output power and individual rectifier module hot-swap, which are required by power supply systems. By using SiC devices, the power conversion efficiency of front-end stage is improved and the whole efficiency of the data center power supply system can be further increased too.
Presenters:
Fan Xu, University of Tennessee
Ben Guo, University of Tennessee
Zhuxian Xu, University of Tennessee
Leon M. Tolbert, University of Tennessee
Fred Wang, University of Tennessee
Benjamin J. Blalock, University of Tennessee
Title: Power Distribution in a 13 kW Three-Phase Rectifier System: Impact on Weight, Volume and Efficiency
Abstract: The impact of using distributed or centralized power processing to supply isolated loads on weight or efficiency is not clear. This paper addresses the evaluation of these metrics on an aircraft application consisting on seven isolated DC loads to be supplied from the AC grid. Additionally the rectifier switching frequency has to be synchronized with an external frequency clock to minimize the interference of the converter harmonics with the loads
Presenters:
Jose Maria Molina, Universidad Politécnica de Madrid
Sisi Zhao, Universidad Politécnica de Madrid
Marcelo Silva, Universidad Politécnica de Madrid
Jesús Angel Oliver, Universidad Politécnica de Madrid
Pedro Alou, Universidad Politécnica de Madrid
Javier Torres, INDRA
Fernando Arévalo, INDRA
Oscar García, Universidad Politécnica de Madrid
José Antonio Cobos, Universidad Politécnica de Madrid
Title: Input Impedance Improvement by Using Digital Compensation Strategy for High Power Density Rectifiers with Wide Load Operation
Abstract: In this paper, an improved control loop based on feedforward is proposed to reduce the total harmonic distortion of the input current (THDi), realizing power factor correction (PFC) in MCM. The frequency responses of the input impedance for a wide frequency range are improved and unified by adding feedforward duty-ratio to the output of the original current-loop. A 5 kW experimental prototype is built to verify the validity of this strategy. The experimental results show that the system has close to unity power factor (PF), and THDi is significantly reduced.
Presenters:
Shengbao Geng, Shanghai Jiao Tong University
Fei Wang, Shanghai Jiao Tong University
Lijun Hang, Shanghai Jiao Tong University
Yong Wang, Shanghai Jiao Tong University
Title: Design and Experimental Verification of a Third Harmonic Injection Rectifier Circuit Using a Flying Converter Cell
Abstract: The proposed active three-phase rectifier circuit utilizing a Flying Converter Cell (FCC) based on the concept of third harmonic injection allows the extension of a passive three-phase diode bridge rectifier to a low-harmonic input stage (THDi < 5%) for applications where dc-link voltage control is not required. In this work the design and experimental verification of a 10 kW laboratory prototype using the proposed concept is addressed. Based on the analysis of the rectifier system a control concept is developed which is implemented in a digital signal processor. It is shown that the proposed rectifier system shows several degrees of freedom which can be used for system optimization. Several implementation details are discussed and experimental results taken from the constructed 10 kW laboratory prototype demonstrate the good performance of the proposed rectifier system and verify the proper operation of the developed control concepts.
Presenters:
Michael Hartmann, Schneider Electric
Rudolf Fehringer, Schneider Electric
Markus Makoschitz, Technische Universität Wien
Hans Ertl, Technische Universität Wien
Title: Three-Phase Unidirectional Buck-Type Third Harmonic Injection Rectifier Concepts
Abstract: This work introduces three-phase unidirectional buck-type unity power factor rectifiers. The proposed rectifiers are assembled by incorporating auxiliary circuit branches into standard three-phase buck-type PFC topologies, each comprising an active switch and three diodes. These circuits can operate as active third harmonic current injection PFC systems. The characteristics of the buck-type converters, including their operation principle, appropriate modulation strategy and control structure, are described. The proposed converters are compared to state-of-the-art buck-type rectifiers. According to the results, the proposed rectifiers can achieve the highest efficiency and thus are the topology of choice for a 2.5 kW three-phase buck-type PFC rectifier.
Presenters:
Thiago Soeiro, ABB Switzerland Ltd.
Gean de Sousa, Universidade Federal de Santa Catarina
Márcio Ortmann, Universidade Federal de Santa Catarina
Marcelo Heldwein, Universidade Federal de Santa Catarina
Title: Performance Comparison of PI and P Compensation in Average-Current-Controlled Three-Phase Six-Switch Boost PFC Rectifier
Abstract: In this paper it is shown that in the three-phase six-switch boost PFC rectifier with average-current control and mismatched input-voltage and/or input-current sensing gains, the current controller with proportional (P) compensation exhibits better performance, i.e., lower THD and higher PF, compared with that of the proportional and integral (PI) compensation. It is also shown that the P compensation with the input-voltage feedforward is effective in improving output-voltage transient response with respect to input-voltage changes only if the duty-cycle feedforward is also implemented. The operation of the three-phase six-switch boost PFC rectifier with average current control implemented with PI and P compensation is illustrated with Matlab/Simulink simulation waveforms. Experimental results, which are in good agreement with the simulation results, are also provided.
Presenters:
Laszlo Huber, Delta Products Corporation
Misha Kumar, Delta Products Corporation
Milan Jovanovic, Delta Products Corporation
Title: Three-Level TAIPEI Rectifier
Abstract: A new low-cost, three-phase, four-switch, three-level, zero-voltage-switching (ZVS), discontinuous-current-mode (DCM), power-factor-correction (PFC) boost rectifier, for short named the three-level TAIPEI rectifier, that achieves a low input-current total-harmonic-distortion (THD) and features ZVS of all the switches is introduced. In the proposed rectifier, the voltage stress of the four switches is equal to one-half of the output voltage. Consequently, the rectifier can utilize switches with a lower voltage rating, which, generally, have lower conduction losses. The performance was evaluated on a three-phase 6-kW prototype for the line-to-line voltage range from 340 V to 520 V. The proposed rectifier exhibits efficiency in the 96-98% range, achieves less than 5% input-current THD over the entire input and above 10% load range.
Presenters:
Yungtaek Jang, Delta Products Corporation
Milan Jovanovic, Delta Products Corporation
Juan Ruiz, Delta Products Corporation
Title: Isolated Swiss-Forward Three-Phase Rectifier for Aircraft Applications
Abstract: A new trend of DC distribution is emerging employing a 270 Vdc grid. This yields the need for high-efficiency and high power-density AC-DC converters, connecting the two grids while providing galvanic isolation. This paper presents a new isolated single-stage PWM rectifier system, based on the recently presented non-isolated Swiss rectifier topology, called the Swiss-Forward rectifier. The principle of operation of this converter topology is presented together with detailed design guidelines and experimental validation on a 3.3kW 115Vac to 270Vdc prototype.
Presenters:
Marcelo Silva, Universidad Politécnica de Madrid
Nico Hensgens, Universidad Politecnica de Madrid
Jesús Angel Oliver, Universidad Politécnica de Madrid
Pedro Alou, Universidad Politécnica de Madrid
Oscar García, Universidad Politécnica de Madrid
José Antonio Cobos, Universidad Politécnica de Madrid