LLC resonant converter based on PFM and secondary‐side short‐circuit control for on‐board charger

Zhu

et al. 2023

SummaryResonant converters have been widely applied in many fields, such as electric vehicles, renewable energy sources, and switch‐mode power supply. Conventional resonant converters generally adopt pulse frequency modulation (PFM), which would cause an extremely wide frequency variation range under wide output applications. However, it would lead to high electromagnetic interference (EMI), low utilization of magnetic components, and loss of soft switching features. For catering to wide output range applications, this paper proposes a self‐adaptive narrow frequency range PFM and asymmetrical voltage‐cancelation hybrid modulation strategy to solve the above problem. The advantages of the proposed strategy include (1) narrow frequency variation range; (2) self‐adaptive shift frequency; and (3) full process achievement of zero voltage switch. The modulation strategy and operational principle and performance analysis of the proposed method are given. Eventually, a series resonant converters–based experimental platform was implemented to verify the proposed strategy.

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

Frequency‐adapted hybrid modulation strategy of resonant converter with narrow frequency range

Zhu

et al. 2023

“…Pulse frequency modulation is used in LLC converter to regulate the output voltage of battery charging. This topology has the additional advantage that the output voltage can be regulated for a wide range of input voltage and load current with small variations in switching frequency 22 . Hence, LLC topology is adopted in this proposed scheme.…”

Section: Introductionmentioning

confidence: 99%

Design and analysis of reconfigurable sensorless brushless DC motor drive for regenerative braking and battery charging in electric vehicle

M U

Bindu

2023

SummaryThe expected depletion of fossil fuels has brought in an increased demand for electric vehicles with better performance in terms of easiness of control and reliability of operation and hence is a fertile area of research. In the present scenario, motoring, regenerative braking, and charging operations are performed in electric vehicles by separate converters. In this paper, an integrated scheme is developed, wherein the same voltage source inverter is employed to obtain all the three modes of operation, which in turn reduces the number of switching devices. Further, a sensorless control used in the proposed scheme improves the operational reliability. This novel approach adopts a simple switching scheme for voltage source inverter to operate as a dual‐boost DC‐DC converter during the regenerative braking period. This switching scheme enables reconfiguring voltage source inverter to a dual‐boost rectifier in conjunction with a LLC resonant converter in the charging mode. A comparison is also provided between the performance of single switch boost and dual‐boost converters used for braking operation. The performance of a prototype brushless DC (BLDC) motor drive with Li‐ion battery pack is evaluated in motoring, regenerative braking, and battery charging modes. This paper presents a detailed design of the scheme, the simulation of which is done on a MATLAB/SIMULINK platform and validated experimentally.

“…This change reduces the number of active switches on the secondary side and the corresponding drive circuit while retaining the original SPS control. This modification of the secondary-side structure has also been studied in literature [15][16][17] for DBSRC circuits; however, the converters all operate in discontinuous current mode (DCM) during the boost time, which generates a higher circulating current. In addition, the converters proposed in these papers all operate under a fixed frequency, which makes the soft-switching operating region narrower.…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, Jong‐Woo and Gun‐Woo 15 use the equivalent circuit analysis method for the gain analysis of the converter, which has a large error. Tang et al 16 use a phase‐shift modulation (PSM) control method on the secondary side to achieve boost operation. Unlike this method, the boosting method in this paper uses a frequency modulation plus phase shifting control strategy, and the derivation process and the selection of frequency and phase shifting values are analyzed in detail in the paper to achieve higher efficiency.…”

Section: Introductionmentioning

confidence: 99%

A secondary‐side semi‐active series resonant converter employing hybrid modulation scheme for on‐board chargers

Liu,

Tang,

Zhao

et al. 2023

This paper proposes a secondary‐side semi‐active series resonant converter with hybrid control. Compared with the traditional series resonant converter (SRC), the converter only replaces two diodes with metal oxide semiconductor field effect transistors (MOSFETs) on the secondary side of the transformer, without adding any auxiliary components. By employing hybrid modulation scheme, the proposed converter can achieve a wide output voltage range in a narrow switching frequency range with high efficiency and has excellent soft‐switching performance. Due to the large magnetizing inductor and narrow switching frequency range, the proposed converter can achieve energy delivery with high efficiency and high power density. This paper provides a detailed introduction to the working principle, circuit characteristics, and design process of the converter. Finally, a 3.3 kW SiC‐based experimental prototype with 400 V input, 250–430 V output, and a switching frequency of 120–140 kHz is built to verify the theoretical analysis, and the peak efficiency reaches 97.82%.