Application of DC/DC Ćuk converter as a soft starter for battery chargers based on double‐loop control strategy

Abstract

utilization of a transformer and passive snubbers in isolated converters increases the losses, volume, and cost. The second category is nonisolated converters, which are used for low or medium power levels. These have simple structure, low weight and high efficiency. Most of nonisolated converters are obtained by development of the boost and buckboost topologies. 7,8 It should be noticed that the boost and buck-boost converters are an unsuitable choice for DC/DC energy conversion, because of the pulsating output current. 9 Furthermore, the single-ended primary-inductor converter (SEPIC) normally presents an unbalanced output current. This deteriorated current may be undesirable for electronic systems. To overcome this drawback, Zeta converter has been introduced in many studies. 9-11 It produces a continuous output current. But, the input current of the Zeta converter is discontinuous, resulting in high losses and efficiency reduction. Hence, Ćuk converter has been proposed for industrial applications such as photovoltaic plants, 12 wind energy, 13 electrical vehicles, 14 compressor, 15 and fuel cell systems. 16 This converter can operate in a wide range of the output voltage, input voltage, and load. 17 The first goal of this paper is to show that a Ćuk converter can be well employed in battery charger applications as a soft starter to prevent the system from large current oscillations.So far, many researches have been focused on modelling and control of DC/DC converters. Small signal analysis of power converters is performed in a previous study 18 by considering the effects of parametric resistances and double-loop proportional-integral (PI) controller based on classical methods is proposed in another study. 19 Generally, traditional proportional-integral-derivative (PID)-type or PI-type controllers are common control methods in industrial systems, because of the unsophisticated design, simple control scheme, and effortless implementation. 20,21 The design theory of classical controllers is based on local linearization of the plant model to predict the system response in the frequency domain. However, these are inappropriate for large-signal models, which are subjected to significant variations. Also, it is necessary that the gains of classical methods is repeatedly adjusted to guarantee a favorable performance, because of the changes of controlled system parameters and the effects of uncertainties. In an existing work, 22 an automatic procedure is applied for optimal design of PI and PID controllers. Although this strategy brings more flexibility in design and provides a better response, the proposed control scheme looks to be more complicated as compared with nonadaptive design methods. Contrary to the aforementioned traditional approaches, some nonlinear control techniques have been offered for DC/DC converters in last decades. In the other research, 23 a particular linearized method around the equilibrium point of power converters is utilized to estimate the complete nonlinear system. Moreover, the analogue...

Sliding-mode controller for a step up-down battery charger with a single current sensor

“…Therefore, Fakham et al [17] was proposed a voltage control oriented (VOC) where the decomposition of direct and quadrature components allows to correct the power factor and avoid the total harmonic distortion, also controlling the DC voltage bus. Other non-linear controllers were proposed in the literature to provide a voltage regulation in battery chargers, such as fuzzy controllers [6], [19], [20] model predictive controllers (MPC) [21] and sliding mode controllers (SMC) [5], [15], [22]. In particular, the surface of the SMC used for battery chargers, based on high-order converters, frequently requires the measurement of two voltages and two currents to ensure bus stability in both charging and discharging modes, which is the case of the charger controller presented in [23].…”

“…Moreover, the Zeta converter has an inductor at the output port connected to the DC bus [6], [28]- [31], which makes possible to control the bus voltage with high precision and, at the same time, this enables the converter to provide a continuous current to the DC bus, reduces the harmonic components present in the microgrid; this is an advantage over battery chargers based on converters with discontinuous output current, e.g. buck and buck-boost based solutions [15], [32]- [34]. The proposed battery charger is regulated using sliding-mode theory, which provides robustness to changes on the electrical parameters and operation conditions [35].…”

A battery integrated three‐port bidirectional charger/discharger for light electric vehicles with G2V and V2G power flow capability

“…Unidirectional dc‐dc converters such as boost, cuk, and sepic are reported in the literature for the direct charging of LEV from RES, 11–13 but these are only suitable to meet the battery charging requirement which is generally termed as grid‐to‐vehicle (G2V) operation. However, the vehicle‐to‐grid (V2G) operation is highly desirable when the LEVs are interfaced with RES fed LVDDS.…”

Modeling and implementation of a new boost converter with elimination of right‐half ‐plan zero

“…For more enhancement of the voltage gain, the inverting ultra‐lift Luo converter has been designed and analyzed in References 19 and 20. In addition, various types of dc/dc step‐up topologies with a high voltage transfer gain have been proposed in References 21–30 during the last decades.…”

“…The conventional dc/dc boost converters presented in References 9–30 suffer from a slow dynamic response in continuous‐conduction mode (CCM) operation, because of existence of at least a RHPZ in their dynamic transfer function. Moreover, this RHPZ moves to the right hand of the complex S‐plane, when operating point of the power converters changes.…”