skip to main content


Title: A 100kW SiC Switched Tank Converter for Transportation Electrification
This paper compares three different dc-dc topologies, i.e. boost converter, three-level flying capacitor multilevel converter (FCMC) and one-cell switching tank converter (STC) for a 100 kW electric vehicle power electronic system. This bidirectional dc-dc converter targets 300 V - 600 V voltage conversion. Total semiconductor loss index (TSLI) has been proposed to evaluate topologies and device technologies. The boost converter and one-cell STC have been fairly compared by utilizing this index. The simulation results of a 100 kW one-cell STC working at zero current switching (ZCS) mode have been provided. A 100 kW hardware prototype using 1200 V 600 A SiC power module has been built. The estimated efficiency is about 99.2% at 30 kW, 99.13% at half load, and 98.64% at full load. The power density of the main circuits is about 42 kW/L  more » « less
Award ID(s):
1810428
NSF-PAR ID:
10109863
Author(s) / Creator(s):
; ; ; ;
Date Published:
Journal Name:
IEEE Transportation Electrification Conference and Expo 2019
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. A 300 V to 600 V 100 kW SiC MOSFET based one-cell switched tank converter (STC) is developed as a bidirectional dc-dc power transfer stage between the vehicle battery and the DC-link side of the vehicle dc-ac inverter. A continuous half-load 50 kW and short-period full-load 100 kW operation is targeted. Working principles of the proposed topology are analyzed. Design of the key components such as SiC MOSFET power modules, AC resonant capacitor and inductor is presented. A 100 kW prototype has been assembled and tested. An energy-efficient test platform is designed. The power density of the main power processing part is around 41.7 kW/L. The tested peak and full-load efficiencies are about 98.7% and 97.35%, respectively. The thermal performance has also been evaluated. Both the tested electrical and thermal results are consistent with the theoretical design. 
    more » « less
  2. This paper presents a 100kW one-cell switched-tank converter (STC) for electric vehicle (EV) application. A new evaluation method that evaluates different converter topologies has been proposed in this paper to show the advantages of the STC over the boost converter and 3-level flying capacitor multilevel (FCML) converter. Both non-interleaved (1-phase) and interleaved (2-phase and 3-phase) operation of the STC have been analyzed. The analytical study shows that it is difficult to achieve the optimum design of the passive components such as input and output capacitors in 1-phase converter because of the high RMS current flowing through them. This means the passive components need to be over-designed in order to meet the current stress requirement. For instance, the designed capacitance of input capacitor is several times of the required value, which leads to bulky capacitor size. Therefore, this paper evaluates the potentials of using 2-phase and 3-phase interleaved operation to address this issue. Two operation modes, zero-voltage switching (ZVS) mode and zero-current switching (ZCS) mode, are evaluated to show the ZCS operation mode is more suitable for the presented converter with interleaved operation. By using the interleaving concept, the predicted 100kW 3-phase interleaved converter can achieve 60% size reduction based on the 1-phase converter design. And the predicted power density of the 3-phase interleaved STC can achieve 115kW/L power density. Simulation results are provided to validate the theoretical analysis. Both 1-phase and 3-phase 100kW prototypes under developing are shown in this paper. 
    more » « less
  3. This paper proposes a generalized Gallium Nitride (GaN) based modular multiport multilevel flying capacitor architecture. In other words, the attractive flying capacitor multilevel (FCML) design and the full-bridge unfolding circuit are employed to develop a multiport multilevel converter architecture that fits various applications. Each module can be designed to contain any combination of AC and DC ports connected through DC-to-DC and DC-to-AC power conversion paths. These conversion paths are FCML topologies that can be designed with any number of levels; the DC-to-AC paths incorporate the full-bridge unfolding circuit. Two example prototypes with open-loop control, three-port and four-port, have verified this generalized architecture. A single module 3 kW three-port four-level prototype with two DC ports and an AC port has achieved a compact size of 11.6 in 3 (4.8 in ×4.3 in × 0.56 in) and a high power density of 258.6 W/in 3 . The three ports are connected through DC-to-AC and DC-to-DC paths that have achieved peak efficiencies of 98.2% and 99.43%, respectively. The total harmonic distortion (THD) of the AC port's voltage and current are 1.26% and 1.23%, respectively. It operates at a high switching frequency of 120 kHz because of the GaN switches and has an actual frequency (inductor's ripple frequency) of 360 kHz thanks to the frequency multiplication effect of the FCML. The four-port prototype contains three DC ports and an AC port and achieved similar high figures of merit. These experimental results of the two prototypes of high efficiency, power density, and compact size are presented in this article and highlight this architecture's promising potential. The choice of the number of modules, ports, and levels depends on the application and its specification; therefore, this proposed generalized structure may serve as a reference design approach for various applications of interest. 
    more » « less
  4. This paper demonstrates a high-efficiency modular multilevel resonant DC-DC converter (MMRC) with zero-voltage switching (ZVS) capability. In order to minimize the conduction loss in the converter, optimizing the root-mean-square (RMS) current flowing through switching devices is considered an effective approach. The analysis of circuit configuration and operating principle show that the RMS value of the current flowing through switching devices is closely related to the factors such as the resonant tank parameters, switching frequency, converter output voltage and current, etc. A quantitative analysis that considers all these factors has been performed to evaluate the RMS current of all the components in the circuit. When the circuit parameters are carefully designed, the switch current waveform can be close to the square waveform, which has a low RMS value and results in low conduction loss. And a design example based on the theoretical analysis is presented to show the design procedures of the presented converter. A 600 W 48 V-to-12 V prototype is built with the parameters obtained from the design example section. Simulation and experiments have been performed to verify the high-efficiency feature of the designed converter. The measured converter peak efficiency reaches 99.55% when it operates at 200 kHz. And its power density can be as high as 795 W/in 3 . 
    more » « less
  5. null (Ed.)
    This paper presents the integration of an AC-DC rectifier and a DC-DC boost converter circuit designed in 180 nm CMOS process for ultra-low frequency (<; 10 Hz) energy harvesting applications. The proposed rectifier is a very low voltage CMOS rectifier circuit that rectifies the low-frequency signal of 100-250 mV amplitude and 1-10 Hz frequency into DC voltage. In this work, the energy is harvested from the REWOD (reverse electrowetting-on-dielectric) generator, which is a reverse electrowetting technique that converts mechanical vibrations to electrical energy. The objective is to develop a REWOD-based self-powered motion (such as walking, running, jogging, etc.) tracking sensors that can be worn, thus harvesting energy from regular activities. To this end, the proposed circuits are designed in such a way that the output from the REWOD is rectified and regulated using a DC-DC converter which is a 5-stage cross-coupled switching circuit. Simulation results show a voltage range of 1.1 V-2.1 V, i.e., 850-1200% voltage conversion efficiency (VCE) and 30% power conversion efficiency (PCE) for low input signal in the range 100-250 mV in the low-frequency range. This performance verifies the integration of the rectifier and DC-DC boost converter which makes it highly suitable for various motion-based energy harvesting applications. 
    more » « less