Modular Multilevel Converter With Sensorless Diode-Clamped Balancing Through Level-Adjusted Phase-Shifted Modulation

Tashakor, Nima; Kilictas, Muhammet; Bagheri, Ehsan; Goetz, Stefan M.

doi:10.1109/tpel.2020.3041599

Cited by 29 publications

(10 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We adapted previous work allowing individual module balancing in cascaded double H bridges using phase-shifted carriers for ac and dc output [91]- [93]. For reconfigurable batteries based on cascaded modules in general, battery balancing can be achieved without additional hardware or losses by superimposing small dc values Δmx,k to the modulation indices [94], [95].…”

Section: Topology and Operating Principlementioning

confidence: 99%

A Rapidly Reconfigurable DC Battery for Increasing Flexibility and Efficiency of Electric Vehicle Drive Trains

Li¹,

Yang²,

Gerry³

et al. 2024

IEEE Trans. Transp. Electrific.

View full text Add to dashboard Cite

This paper proposes a drive train topology with a dynamically reconfigurable dc battery, which breaks hard-wired batteries into smaller subunits. It can rapidly control the output voltage and even contribute to voltage shaping of the inverter. Based upon the rapid development of low-voltage transistors and modular circuit topologies in the recent years, the proposed technology uses recent 48 V power electronics to achieve higher-voltage output and reduce losses in electric vehicle (EV) drive trains. The fast switching capability and low loss of low-voltage field effect transistors (FET) allow sharing the modulation with the main drive inverter. As such, the slower insulated-gate bipolar transistors (IGBT) of the inverter can operate at ideal duty cycle and aggressively reduced switching, while the adaptive dc battery provides an adjustable voltage and all common-mode contributions at the dc link with lower loss. Up to 2 /3 of the switching of the main inverter is avoided. At high drive speeds and thus large modulation indices, the proposed converter halves the total loss compared to using the inverter alone; at lower speeds and thus smaller modulation indices, the advantage is even more prominent because of the dynamically lowered dc-link voltage. Furthermore, it can substantially reduce the distortion, particularly at lower modulation indices, e.g., down to 1 /2 compared to conventional space-vector modulation and even 1 /3 for discontinuous pulse-width modulation with hardwired battery. Other benefits include alleviated insulation stress for motor windings, active battery balancing, and eliminating the vulnerability of large hard-wired battery packs to weak cells. We demonstrate the proposed motor drive on a 3-kW setup with eight battery modules.

show abstract

Section: Topology and Operating Principlementioning

confidence: 99%

A Rapidly Reconfigurable DC Battery for Increasing Flexibility and Efficiency of Electric Vehicle Drive Trains

Li¹,

Yang²,

Gerry³

et al. 2024

IEEE Trans. Transp. Electrific.

View full text Add to dashboard Cite

show abstract

“…The high number of individually governable transistors in reconfigurable batteries challenges the control but provides the degrees of freedom to optimize additional objectives, such as active balancing of the module charge [67][68][69][70][71][72]. While online-optimizing model-predictive approaches can trade off all degrees of freedom but suffer from the high computational load, phase-shifted carrier control, for instance, is a rather simple way to manage the complexity and can further use the parallel mode to maximize utilization of the modules [37,41,46,[73][74][75][76]. Other methods range in between.…”

Section: Previous Control Of Battery-integrated Power Electronicsmentioning

confidence: 99%

Bandwidth-Increased Ripple-Mitigating Scheduling Algorithm for Dynamically Reconfigurable Batteries

Kacetl

Tashakor

et al. 2022

IEEE Access

Self Cite

View full text Add to dashboard Cite

Modular cascaded circuits offer attractive qualities in reconfigurable battery applications, including improved fault tolerance and flexibility. In contrast to conventional hard-wired dc battery packs, however, cascaded topologies, such as modular multilevel circuits (MMC) with serial or serial and parallel connectivity, load modules with substantial low-frequency current ripple, which generates additional loss and can accelerate battery aging. Recent studies reveal that low-frequency ripple can cause noticeable battery aging, whereas high frequencies are insignificant, presumably mainly as they can be absorbed by the dielectric electrode capacitance, and reduce heating associated with lower high-frequency battery impedance. Previous MMC-battery control methods solely focus on state-of-charge and thermal balancing of individual modules, while the few existing methods for suppressing ripple tend to form low-frequency patterns in the modules' load, which increase battery cycling as well as loss. This paper presents a rippleoriented high-bandwidth control technique that minimizes low-frequency components in the module load spectrum and improves battery treatment, while maintaining the average switching frequency. The control method takes limitations related to module data acquisition into account and enhances the feedback bandwidth using observers. It works with a wide range of topologies including modules with series connectivity only as well as series/parallel. The measurements in the laboratory verify the shift of the module load from the 10 -100 Hz range to ~5 kHz and a reduction of battery losses by up to 20 %.INDEX TERMS Modular battery, modular multilevel converter, cascaded bridge converter, reconfigurable battery, battery ageing model, ripple suppression, influence of ripple current, second harmonic, scheduling, battery energy storage systems (BESS), electric vehicle drive trains.

show abstract

“…Recent studies attempt to control MMC without sensors by using various Subs structures and modulation methods. [34][35][36] These new control methods effectively eliminate all of the arm's sensors from the MMC, but they are unable to detect Subs' open-circuit faults.…”

Section: Introductionmentioning

confidence: 99%

An improved method to sub‐module voltage balancing in modular multilevel converters with two voltage sensors

Hashkavayi

Barakati

Torabi

et al. 2023

Circuit Theory & Apps

View full text Add to dashboard Cite

Summary The modular multilevel converter (MMC) is an innovative structure that has expanded the usage of multilevel converters (MLCs) in the electrical industry. Since the MMC initially required a large number of sensors to manage the capacitor voltages, various studies have been done to reduce their number to improve the converter's reliability and reduce construction costs. In this paper's proposed method, merely two voltage sensors are used to balance the converter's capacitor voltages, and voltages are estimated using the exponentially weighted recursive least square (RLS) method in each sampling time. Also, the estimated voltages are sorted according to the capacitor current sign determined by the voltage sensors, and the current sensors are entirely eliminated. Furthermore, three cases for compensating the capacitor estimated voltages are presented, and the last case proposes the sub‐module force algorithm (SFA) for system protection. The efficacy of the proposed method has been assessed via simulation and experimental implementations.

show abstract

Modular Multilevel Converter With Sensorless Diode-Clamped Balancing Through Level-Adjusted Phase-Shifted Modulation

Cited by 29 publications

References 46 publications

A Rapidly Reconfigurable DC Battery for Increasing Flexibility and Efficiency of Electric Vehicle Drive Trains

A Rapidly Reconfigurable DC Battery for Increasing Flexibility and Efficiency of Electric Vehicle Drive Trains

Bandwidth-Increased Ripple-Mitigating Scheduling Algorithm for Dynamically Reconfigurable Batteries

An improved method to sub‐module voltage balancing in modular multilevel converters with two voltage sensors

Contact Info

Product

Resources

About