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Capacitor ac circuit models:(a) series capacitor ac model and (b) equivalent ac capacitor model using transformer coupling.
Source publication
Of the single-switch dc-to-dc converters, those with the buck-boost voltage transfer function offer most potential for transformer coupling, hence isolation, at the kilowatt level. This paper highlights the limitations of the traditional magnetic coupled, buck-boost topology. Then four split-capacitor transformer-coupled topologies (specifically th...
Contexts in source publication
Context 1
... core volume is utilized differently if electrical energy transfer is through magnetic transformer action rather than core intermediate energy storage. If converter energy is transferred from the source to the load via ripple current (energy change) through a series capacitor, as in Figure 2(a), then that capacitor can be split so as to facilitate an interposed high magnetizing inductance shunt current transformer, as shown in Figure 2(b), and as with the Cuk converter, topology C5 in Table 1. AC-wise, if the output in Figure 2 is to be the same in both circuits, the secondary capacitor must electrically mirror the primary capacitor, so both are equal valued, if the transformer turns ratio Ns / Np = ηT is unity. ...
Context 2
... core volume is utilized differently if electrical energy transfer is through magnetic transformer action rather than core intermediate energy storage. If converter energy is transferred from the source to the load via ripple current (energy change) through a series capacitor, as in Figure 2(a), then that capacitor can be split so as to facilitate an interposed high magnetizing inductance shunt current transformer, as shown in Figure 2(b), and as with the Cuk converter, topology C5 in Table 1. AC-wise, if the output in Figure 2 is to be the same in both circuits, the secondary capacitor must electrically mirror the primary capacitor, so both are equal valued, if the transformer turns ratio Ns / Np = ηT is unity. ...
Context 3
... converter energy is transferred from the source to the load via ripple current (energy change) through a series capacitor, as in Figure 2(a), then that capacitor can be split so as to facilitate an interposed high magnetizing inductance shunt current transformer, as shown in Figure 2(b), and as with the Cuk converter, topology C5 in Table 1. AC-wise, if the output in Figure 2 is to be the same in both circuits, the secondary capacitor must electrically mirror the primary capacitor, so both are equal valued, if the transformer turns ratio Ns / Np = ηT is unity. The secondary capacitor is needed for supporting any dc bias associated with the secondary dc circuit conditions. ...
Context 4
... circuit reactance can be transferred to the primary for ac analysis according to the turns ratio, squared. Examination of the thirty-three known single-switch, single-diode, dc-to-dc converters [23] reveals that the Cuk C5, sepic G6, zeta G5, and new buck-boost P5 converters, as shown in Table 1, all with a buck-boost magnitude transfer function, fulfill the series energy transfer capacitor requirement, shown in Figure 2(a). Although the transformer plus split-capacitor buffering approach is commonly used to isolate the Cuk converter output, its possible use on the sepic and zeta converters [24] has been virtually unexploited, with the coupled magnetic circuit with flux bias replacement of an inductor approach favored for these two converters, as in Figure 1. ...
Context 5
... the Cuk, sepic and zeta converter cases, the split-capacitor mirroring pair in Figure 2(a) must fulfill the important function of buffering, specifically blocking, a dc voltage component from the magnetic coupling element. Table 1 shows the dc component (the input and/or output voltage) each of the series split capacitors, Cp and Cs, must block, hence support. ...
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Citations
... Cuk converters are a good option for this application, since they provide continuous input current; however, Cuk has a higher component count, in standard version and with increase of cells, as shown in Faistel et al. 17 Hence, iSEPIC is a very good choice, with low-component count, and significantly reducing the DC magnetizing current with the appropriate choice of VMCs, allowing to use a transformer instead of coupled inductor, 18 besides increasing voltage gain. Therefore, this paper proposes an isolated single-switch DC-DC converter achieving high-voltage gain and high efficiency using a transformer for galvanic isolation without using a snubber circuit, which significantly reduces volume and cost of the whole system. ...
Generating sources of renewable systems, like photovoltaic module or fuel cell, have a low-output voltage that has to be boosted for most of applications, such as grid-tie inverters. To accomplish this, an isolated DC–DC high step-up single-ended primary-inductor converter (SEPIC) with a Greinacher voltage doubler cell is presented. It has the advantage of continuous input current, high efficiency, and high-voltage gain and isolation and demands a single switch, being suitable for low-power grid-tie photovoltaic systems. The operating principles and steady-state analysis are presented, including the detailed analysis of resonant stage, and the effects of transformer winding capacitances on converter operation are investigated. Moreover, the effects of resonance frequency variations on converter efficiency are experimentally investigated.
Experimental results on a 50 kHz and 200 W prototype are presented to validate the proposed concept.
... (1) (2) Conventionally, for isolation purposes, coupled magnetic circuit was employed in buck-boost topology. However, the stored energy in the coupled winding core constrains the maximum WPT [48]. ...
By increasing concerns about global warming, air pollution, and fossil fuel cost, most countries have regulated laws to reduce the exploitation of fossil fuels and to replace green energy resources. Electric vehicles (EVs) and hybrid EVs are mainly considered as the best alternatives for conventional internal combustion vehicles. These vehicles use electricity, which is extracted from the stored energy in their batteries, fuel cells (FC), and supercapacitors (SC). Since these energy storages can be charged using renewable energy resources, EVs are typically considered as green vehicles. However, charging these kinds of vehicles requires additional power electronics facilities because the voltage and frequency of the electricity network are not the same as the voltage and frequency demanded by EVs. Therefore, power electronic converters are of the highest importance as obligatory interfaces between electricity networks and EVs. In addition to financial requirements, obligatory standards force manufacturers to produce high‐efficiency productions. Thus, advanced technologies must be used to improve EVs and their charging systems. Specifically, high‐power density converters and WBG technologies are expected to be utilized in EV‐related industries extensively. Developed converters have to provide proper energy for EVs’ batteries from the grid and green energy resources and convert the energy in the batteries in a way that the EVs’ motors can work in their best mode, with the least power loss and the highest quality. For this sake, various power electronic converters are required to perform different tasks. In this regard, in this chapter, some of the main challenges are reviewed and the main solutions for them are introduced. Specifically, this chapter discusses existent technology and recent advances in the area of power electronic devices used in EVs and wireless charging.
... Within the last 5 years a new candidate for reduced converter design in WPT systems has emerged. The work in [15] shows new isolated converter topologies for single switched Buck-Boost converters. The paper describes how the standard procedure has been to use a high frequency transformer or a pair of coupled inductors in place of one of the existing circuit inductors. ...
... This balanced operation can be seen in more traditional WPT circuits that use full or half wave rectifiers in conjunction with a resonant circuit to output a sine wave for optimized power transfer. The work in [15] also showcases a new P5 topology, this topology benefits from a reduction in the size of the split capacitors plus no DC bias on the primary or secondary side. ...
... By substituting (8) and (16) into (15) and rearranging for L1 the desired range of values can be found for L1 so that CCM is maintained: ...
This paper presents three DC-DC converter topologies, P5, Cuk and a class E 2 converter to compare their performance in the context of wireless power transfer for electric vehicle battery charging. The comparisons use MATLAB simulation to explore the abilities of the system to produce the desired outputs, efficiency, and ability to operate under changing load and coupling factor conditions. The paper highlights current issues with resonant DC-DC converters for wireless electric vehicle battery charging. It also serves to draw parallels between the new application of Cuk and P5 converters for WPT, and that of the Class E 2 topology which is better understood within the context of wireless power transfer. The promising feature of Buck-Boost DC-DC converters for wireless power transfer is the ability to control output voltage from the duty cycle. This controllability opens new avenues for creating robust systems under varying coupling factors and loads. The Buck-Boost converter-based systems also benefit from a reduction in overall converters needed and a lower operating frequency than that of Class E 2 converters.
... There are several Buck-Boost configurations such asĆuk, Zeta, SEPIC and P5. Several configurations are speculated upon in [48][49][50][51], where the consensus is that topologies with split capacitor configurations are better for isolated systems. This is due to their ability to operate with transformer action. ...
... There are several Buck-Boost configurations such as Ćuk, Zeta, SEPIC and P5. Several configurations are speculated upon in [48][49][50][51], where the consensus is that topologies with split capacitor configurations are better for isolated systems. This is due to their ability to operate with transformer action. ...
... 2016 [48] First instance of preposing split capacitor with sinlge switch converter topologies. Presents a new P5 buck-boost topolgy with reduced split capacitor size. ...
This article classifies, describes, and critically compares different compensation schemes, converter topologies, control methods, and coil structures of wireless power transfer systems for electric vehicle battery charging, focusing on inductive power transfer. It outlines a path from the conception of the technology to the modern and cutting edge of the technology. First, the base principles of inductive coupling power transfer are supplied to give an appreciation for the operation and design of the systems. Then, compensation topologies and soft-switching techniques are introduced. Reimagined converter layouts that deviate from the typical power electronics topologies are introduced. Control methods are detailed alongside topologies, and the generalities of control are also included. The paper then addresses other essential aspects of wireless power transfer systems such as coil design, infrastructure, cost, and safety standards to give a broader context for the technology. Discussions and recommendations are also provided. This paper aims to explain the technology, its modern advancements, and its importance. With the need for electrification mounting and the automotive industry being at the forefront of concern, recent advances in wireless power transfer will inevitably play an essential role in the coming years to propel electric vehicles into the common mode of choice.
... Accordingly, several SM circuit topologies have emerged from such constraints. Employing HFTs in these SMs, while operating at high switching frequency (<20 kHz), will reduce their total size considerably and, hence, higher power density is obtained [87]. There is always a trade-off between these requirements and the SM cost, losses, and complexity. ...
... Several papers have evaluated the progress of the SM designs of isolated converter topologies for PV systems [27,85,[87][88][89][90][91]. Reference [27] presented a general structure for modular energy conversion system suitable for the large-scale PV systems, which is shown in Figure 15. ...
The use of photovoltaic (PV) systems as the energy source of electrical distributed generators (DG) is gaining popularity, due to the progress of power electronics devices and technologies. Large-scale solar PV power plants are becoming the preferable solution to meet the fast growth of electrical energy demand, as they can be installed in less than one year, as compared to around four years in the case of conventional power plants. Modular multilevel inverters (MMIs) are the best solution to connect these large-scale PV plants to the medium-voltage (MV) grid, due to their numerous merits, such as providing better power quality, having higher efficiency, providing better reliability, and their scalability. However, MMIs are still progressing and need some improvement before they can be implemented safely in the industrial, medium, and high voltage networks. The main purpose of this paper is to review the present MMIs topologies when used in PV applications. The review aims to present a comprehensive study of the various recent submodule circuits associated with MMI topologies. Maximum power point tracking (MPPT) control schemes for PV inverters will be explored extensively. Then, the different control strategies of PV MMIs will be presented and compared to give a holistic overview of the submodules balancing techniques, ranges, and capabilities under balanced and unbalanced grid conditions. In addition, the paper will discuss the future of PV MMIs systems in electricity networks.
... The core volume is utilized more effectively if the magnetic energy transfer is through instantaneous transformer action rather than transfer with intermediate magnetic energy storage. The other three converters address this limitation by transferring electrical energy through magnetic transformer action [35]. The results of SEPIC and Zeta converters have been reported previously in BLDC ceiling fan drives, but the isolated Cuk converter is not reported to have been tested in such an application. ...
The usage of BLDC motors in the low-power range is increasing rapidly in home appliances such as ceiling fans. This has necessitated the development of reliable, compact and efficient AC-DC power supplies for motor drive circuitry. This paper presents a power supply design consisting of an AC-DC isolated PFC Cuk converter with integrated magnetics that supplies a single-shunt voltage source inverter for the sensorless drive of the BLDC fan motor. The proposed power supply design is comprised of an integrated magnetics structure in which the two inductors and the transformer windings share the same core. The zero input and output ripple current conditions have been derived from the reluctance model of the magnetic assembly. Smooth operation of the motor by minimizing the motor torque ripples is evident from the results. The Cuk converter operates in continuous conduction mode (CCM), employing the current multiplier method. The CCM-based current multiplier control loop ensures a near-unity power factor as well as low total harmonic distortion in the supply current. The current loop also provides over-current protection, enhancing reliability of the system. Moreover, the speed of the BLDC motor is controlled by the field oriented control (FOC) algorithm, which enables direct operation with alternate energy sources such as batteries and solar photovoltaic panels. The performance of the proposed supply is validated: motor torque ripple is reduced to only 2.14% while maintaining 0.999 power factor and only 4.72% THD at full load. Failure modes analysis has also been performed through software simulations, using the PLECS simulation environment. Due to the reliable power supply design with low ripples, it is well suited for low-power BLDC motors in home appliances and small power tools, in addition to ceiling fans.
... Basic single-switch isolated topologies are: flyback, ZETA, SEPIC and Ćuk. Among these options, isolated SEPIC converter is a very good choice for this application with low input voltage and low output power, since it provides continuous input current and can significantly reduce the dc magnetizing current with the appropriate choice of voltage multiplier cells (VMCs), allowing to use a transformer instead of coupled inductor [2]. ...
... The portion of iD1 and iD3 during the stage I is neglected, since the duration of this stage is considerably smaller than the duration of stage IV and, therefore, it does not affect the RMS current evaluation. Dk of segment uk of iD2 and iD4 is equal to 0.5Tr/Ts, resulting in a RMS equation given by 2 1( ) ...
High step-up converters are required and used in photovoltaic applications, due to low voltage of photovoltaic modules. In this paper, an isolated dc-dc high step-up SEPIC with a Greinacher voltage quadrupler cell is presented. It has the advantage of continuous input current, high efficiency, high voltage gain, isolation and demands a single switch, being suitable for low power grid-tie photovoltaic systems. The operating principles and steady-state analysis are presented, including the detailed analysis of resonant stage, where the value of primary side capacitor is taken into account and plays an important role in the design of the converter, since it directly affects the resonance frequency and RMS current values. Simulation results are presented to validate the analysis and design.
... The conventional coupled SEPIC and Zeta converters involve turning a shunt inductor into a coupled transformer which always has a core dc bias current. Alternatively, a transformer-coupled with a splitcapacitor that are utilized in the Ćuk converter family employs the transformer without a dc flux bias [1,2]. This paper proposes converter topologies with buck-boost transfer functions that can be utilized for wireless power transfer without a dc flux bias. ...
... Non-isolated and isolated versions of Ćuk and SEPIC converter have been used in the literature [25][26][27][28][29][30]. Magnetically coupled single-switch buck-boost converters (namely isolated Ćuk, Zeta, SEPIC, and P5) have been presented in [1]. Four DC-to-DC converters shown in Fig. 3 that utilize the resonant compensation networks without additional resonant tank components are proposed. ...
