General topological properties of switching structures

Investigation of a wide variety of switching converter topologies culminates in the establishment of the most general correlation between the converter topologies--the duality relationships. The recognition of this general law leads to a number of new results: new converter topologies generated by the application of the duality transformation to the existing converter configurations, the discovery of the new mode of converter operation (discontinuous capacitance voltage mode) as well as significantly improved understanding of the existing converters and their equivalent circuit models

High Power Density and High Efficiency Converter Topologies for Renewable Energy Conversion and EV Applications

This dissertation work presents two novel converter topologies (a three-level ANPC inverter utilizing hybrid Si/SiC switches and an Asymmetric Alternate Arm Converter (AAAC) topology) that are suitable for high efficiency and high-power density energy conversion systems. The operation principle, modulation, and control strategy of these newly introduced converter topologies are presented in detail supported by simulation and experimental results. A thorough design optimization of these converter topologies (Si/SiC current rating ratio optimization and gate control strategies for the three-level ANPC inverter topology and component sizing for the asymmetric alternate arm converter topology) are also presented. Performance comparison of the proposed converter topologies with other similar converter topologies is also presented. The performance of the proposed ANPC inverter topology is compared with other ANPC inverter topologies such as an all SiC MOSFET ANPC inverter topology, an all Si IGBT ANPC inverter topology and mixed Si IGBT and SiC MOSFET based ANPC inverter topologies in terms of efficiency and cost. The efficiency and cost comparison results show that the proposed hybrid Si/SiC switch based ANPC inverter has higher efficiency and lower cost compared to the other ANPC inverter topologies considered for the comparison. The performance of the asymmetric alternate arm converter topology is also compared with other similar voltage source converter topologies such as the modular multilevel converter topology, the alternate arm converter topology, and the improved alternate arm converter topology in terms of total device count, number of switches per current conduction path, output voltage levels, dc-fault blocking capability and overmodulation capability. The proposed multilevel converter topology has lower total number of devices and lower number of devices per current conduction path hence it has lower cost and lower conduction power loss. However, it has lower number of output voltage levels (requiring larger ac interface inductors) and lacks dc-fault blocking and overmodulation operation capabilities. A converter figure-of-merit accounting for the hybrid Si/SiC switch and converter topology properties is also proposed to help perform quick performance comparison between different hybrid Si/SiC switch based converter topologies. It eliminates the need for developing full electro-thermal power loss model for different converter topologies that would otherwise be needed to carry out power loss comparison between different converter topologies. Hence it saves time and effort

Efficient power-electronic converters for electric vehicle applications

This paper introduces advanced power-electronic converter topologies for Electric Vehicles (EVs) using a four-phase DC/DC interleaved boost converter (FP-IBC) and a five-level T-type DC/AC multilevel converter. A comparison between the proposed topologies and other converter topologies is performed and discussed. The simulation results are analysed to evaluate the converters based on power loss calculations and harmonic analysis. The converters are studied at different switching frequencies and various loading conditions to reflect their effects on the converter losses. The results highlight the proposed converters' higher efficiency compared to other studied converter topologies in electric vehicle applications

Review of Power Converter Topologies for Electrochemical Impedance Spectroscopy of Lithium-Ion Batteries

Frequency domain impedance of Li-ion batteries contains valuable information about the state of charge (SOC) and state of health (SOH). Normally, electrochemical impedance spectroscopy (EIS) is performed during the relaxation of battery cells. However, performing EIS during the batteries operation has been achieved through switching power converters. This paper reviews the power converter topologies for both online and offline Electrochemical Impedance Spectroscopy (EIS) characterization of batteries. The information that can be extracted from EIS Nyquist plots are discussed. Comparative analysis between converter topologies is presented. Finally, challenges are identified and new converter topologies are proposed for further consideration in online/offline EIS characterization

Medium voltage-high power converter topologies comparison procedure for a 6.6kV Drive Application using 4.5kV IGBT Modules

This paper presents a general comparison procedure for medium voltage - high power multilevel converter topologies and semiconductors, which is mainly based on analyzing the performance limits of the converters output characteristics such as the output voltage, current, active power, efficiency, etc. Afterwards, the general procedure is applied to compare some of the most relevant converter topologies oriented to a 6.6 kV drive application supplying quadratic torque loads and using 4.5 kV IGBT modules. The paper concludes evaluating the comparison factors of the different converter topologies and selected semiconductors obtained by the proposed procedure. The proposed procedure can potentially be extrapolated to any desired application framework

Converter topologies for alternative energy

2004-2005 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

Efficiency Improvement of Fault-Tolerant Three-Level Power Converters

Fault-tolerant power converters play a critical role in the transportation electrification. However, fault-tolerant operation, high efficiency, and low cost usually result in design criteria that have conflicting constraints and goals. The majority of the fault-tolerant power converter topologies presented in the literature confirm these conflicts. In this paper, three types of fault-tolerant neutral-point clamped (NPC) converters are investigated. Various modulation strategies are explored to reduce the losses of the redundant phase leg. The simulation and experimental results show that the Switching Frequency Optimal Phase opposition Disposition modulation strategy is the most effective approach in minimizing the losses in the redundant phase leg

One-Quadrant Switched-Mode Power Converters

This article presents the main topics related to one-quadrant power converters. The basic topologies are analysed and a simple methodology to obtain the steady-state output-input voltage ratio is set out. A short discussion of different methods to control one-quadrant power converters is presented. Some of the reported derived topologies of one-quadrant power converters are also considered. Some topics related to one-quadrant power converters such as synchronous rectification, hard and soft commutation, and interleaved converters are discussed. Finally, a brief introduction to resonant converters is given.Comment: 25 pages, contribution to the 2014 CAS - CERN Accelerator School: Power Converters, Baden, Switzerland, 7-14 May 201

Critical review of converter topologies for switched reluctance motor drives

This paper represents an overall literature review of SRM convenient drive circuit topologies with the proposal of a new topology utilizing switched capacitance circuit. The known topologies of SRM drive circuits were critically reviewed and compared. The main configurations and classifications of SRM and the principle of switched capacitance circuit with double capacitors, double switches are reviewed as well

Impact of converter interface type on the protection requirements for DC aircraft power systems

The utilization of converter interfaces has the potential to significantly alter the protection system design requirements in future aircraft platforms. However, the impact these converters will have can vary widely, depending on the topology of converter, its filter requirements and its control strategy. This means that the precise impact on the network fault response is often difficult to quantify. Through the analysis of example converter topologies and literature on the protection of DC networks, this paper tackles this problem by identifying key design characteristics of converters which influence their fault response. Using this information, the converters are classified based on their general fault characteristics, enabling potential protection issues and solutions to be readily identified. Finally, the paper discusses the potential for system level design benefits through the optimisation of converter topology and protection system design