Renewable Energy Sources (RES) showed enormous growth in the last few years. In comparison with the other RES, solar power has become the most feasible source because of its unique properties such as clean, noiseless, eco-friendly nature, etc. During the extraction of electric power, the DC–DC converters were given the prominent interest because of their extensive use in various applications. Photovoltaic (PV) systems generally suffer from less energy conversion efficiency along with improper stability and intermittent properties. Hence, there is a necessity of the Maximum power point tracking (MPPT) algorithm to ensure the maximum power available that can be harnessed from the solar PV. In this paper, the most important features of the DC/DC converters along with the MPPT techniques are reviewed and analyzed. A detailed comprehensive analysis is made on different converter topologies of both non-isolated and isolated DC/DC converters. Then, the modulation strategies, comparative performance evaluation are addressed systematically. At the end, recent advances and future trends are described briefly and considered for the next-generation converter’s design and applications. This review work will provide a useful structure and reference point on the DC/DC converters for researchers and designers working in the field of solar PV applications.

https://www.mdpi.com/2079-9292/9/1/31/pdf

A Comprehensive Review of DC–DC Converter Topologies and Modulation Strategies with Recent Advances in Solar Photovoltaic Systems

This paper presents an active power filter based on a digital signal processing (DSP) controller with enhanced current control performance. A novel predictive current control method is introduced to compensate the phase error of harmonic components caused by discrete sampling and finite nonnegligible execution time delay. The concept of average current control is also introduced that is adequate for digital current control. With a close coordination between the reference current prediction, PWM pattern generation, and control timing, a high performance control is achieved. Experimental results show that the developed system gives satisfactory performance in harmonic and reactive power compensation.

DSP-Based Active Power Filter with Predictive Curent Control

With the increasing use of rechargeable lithium-ion battery packs in numerous applications, it calls for an effective evaluation of active battery cell equalization to enhance the whole battery pack's capacity and performance. Plenty of work has focused on cell equalizing circuit and control algorithm design. Still, none of them is devoted to a comprehensive analysis and comparison of cell balancing methods from the topology level. In this article, a review of the state-of-the-art active battery cell equalization methods is conducted, where it is classified as adjacent-based, nonadjacent-based, direct cell-cell, and mixed topologies. This classification can provide a comprehensive way to analyze and compare the existing active cell balancing methods’ performance. Subsequently, the mathematical models of these balancing structures are developed, and extensive simulation results are provided to compare the performance of these equalization topologies in terms of equalization speed. It then comes up with an inclusive economic comparison between them, followed by a discussion.

Active Cell Equalization Topologies Analysis for Battery Packs: A Systematic Review

Recently, the use of electric batteries has reached great heights due to the invention of electric vehicles (EVs). Many lithium-ion battery cells are usually connected in series to meet the voltage requirements. The voltages of the entire series-connected battery cells in a battery pack should be equal. However, such result is impossible due to some unavoidable reasons in real life. Unbalanced battery cell voltages can reduce storage capacities and may cause explosions or fires in the worst case which is a major obstacle for safe and optimum operations of battery-driven appliances, such as EVs. Therefore, battery cell voltage equalizations have become an important research topic. Many studies have been conducted to develop and improve techniques to equalize battery cell voltages by incorporating various remarkable features. This study makes a comprehensive and systematic review of these cell equalization techniques. The importance and research prospect of battery cell voltage equalizers are discussed. A critical analysis of recent techniques, particularly on construction, operation, and control strategy of equalization circuits, is also presented. Moreover, recent studies are compared based on circuit designs, sizes, costs, complexities, system efficiencies, applications, control strategies, balancing speeds, and voltage/current stresses of different equalizers. Commonly used two different types of control strategies/algorithms in software system of battery cell equalizers are briefly described. The recent research trend of different equalizers is also discussed in detail. Simulation results of few equalization approaches and performance evaluation techniques are analyzed.

Advancement of lithium-ion battery cells voltage equalization techniques: A review

A comprehensive review on inconsistency and equalization technology of lithium‐ion battery for electric vehicles

This paper presents the concept of active cell balancing mechanism for Lithium Ion (Li-ion) batteries for Electrical Vehicles (EV) based on inductor balancing method It equalizes eight number of cells in a series Voltage differences always exist between cells, therefore a battery management system (BMS) is required to ensure that all cells are equally charged or discharged and it increases the life cycle of the battery An equalizing method is essential to achieve the best performance A number of cell balancing method have been presented Among them, inductor based balancing is faster compared to other methods such as Switched Capacitor Converter (SCC) The problem of conventional inductor based balancing method occurs when the energy transfers from the first cell to the last one and causes long time equalization, because the energy transfer is cell by cell An alternative topology is proposed in this paper to improve the equalization time and the simulation results are performed to verify the feasibility of the system

An Active Cell Equalization Technique for Lithium Ion Batteries Based on Inductor Balancing

This article developed a coupled inductor balancing method to overcome cell voltage variation among cells in series, for Lithium Ion (Li-ion) batteries in Electrical Vehicles (EV). For an "eight cells in series" example, the developed balance circuit has four inductors, one magnetic circuit with one winding per two cells, and one control switch per cell, as compared to the traditional inductor-based equalizer that needs N-1 inductors and magnetic circuits for N number of cells and more switches. Therefore, ultimately, a more efficient, cost-effective circuit and low bill of materials (BOM) will be built up. All switches are logic-level N-Channel metal-oxide-semiconductor field-effect transistors (MOSFETs) and they are controlled by a pair of complementary signals in a synchronous trigger pattern. In the proposed topology, less components and fast equalization are achieved compared to the conventional battery management system (BMS) technique for electrical vehicles based on the inductor balancing method. This scheme is suitable for fast equalization due to the inductor-based balancing method. The inductors are made with a well-chosen winding ratio and all are coupled with one magnetic core with an air gap. Theoretical derivation of the proposed circuit was well-presented, and numerical simulation relevant to the electrochemical storage devices was conducted to show the validity of the proposed balance circuit. A complete balance circuit was built to verify that the proposed circuit could resolve imbalance problems which existed inside battery modules.

https://biblio.ugent.be/publication/8598811/file/8598813.pdf

An efficient equalizing method for lithium-ion batteries based on coupled inductor balancing

In this paper, a cuk converter balancing method by using a coupled inductor for lithium based batteries is investigated. The proposed circuit is an active balancing circuit that will equalize eight battery cells in a series. In electrical vehicles (EV), a battery management system (BMS) is a vital task to achieve the best performance of the batteries and longer lifetime. The problem of voltage difference in a battery pack is an important issue to be improved. To overcome the voltage differences in battery string, an equalizing method is mandatory. The conventional cuk converter requires 2(n-1) switches to balance n cells, while the proposed circuit requires only n switches for n cells in series. In addition, the proposed developed topology uses coupled inductors instead of un-coupled inductors, unlike the traditional cuk converter balancing method. Since the cuk balancing transfers the energy among two adjacent cells, it requires a proportionately long equalization time particularly for long string battery packs, but the coupled inductor cuk converter type overcomes this problem. The switches are N-channel metal-oxide field-effect transistor (MOSFET) to achieve lower drain-source on-resistance, RDS(on), and less voltage drop as compared to the P-channels. The switches are triggered by complementary signals. The coupled inductor is made in such a way to hold the same magnetizing inductance. It can be done by using five wires in one hand. The circuit contains five inductors, one magnetic core, with five winding for eight cells, and one capacitor for two cells. Therefore, the overall circuitry and complexity of the circuit are reduced, resulting in a more cost-effective and easy to implement circuit. The system also does not demand complicated control for battery equalizing. The experimental circuit was implemented and simulation results were obtained to confirm the validity of the proposed system.

https://www.mdpi.com/1996-1073/12/15/2881/pdf

A Ćuk Converter Cell Balancing Technique by Using Coupled Inductors for Lithium-Based Batteries

This paper presents the concept of a cell balancing method for Lithium Ion (Li-ion) batteries for Electrical Vehicles (EV), based on Resonant Switched Capacitor Converter (RSCC) balancing technique It equalizes eight number of cells in a series In Li-ion batteries, voltage differences always exist between cells due to charging and discharging process, therefore a battery management system (BMS) is required to ensure that all cells are equally charged or discharged and it also increases the life cycle of the battery An equalizing method is essential to achieve the best performance A number of cell balancing method have been presented Among them, Switched Capacitor Converter (SCC) is more effective compared to other methods because it can be implemented easily Low volume, low cost, high power density are its features However, low balancing speed is an important problem of the SCC In this paper, a resonant switching capacitor is proposed to reduce the balancing time and reduce the energy loss The simulation results are performed to verify the feasibility of the system

A Cell Equalization Method Based on Resonant Switched Capacitor Balancing for Lithium Ion Batteries

The concept of active cell equalizing method based on multi-winding transformer balancing for Lithium Ion (Li-ion) batteries is presented in this paper. In a battery pack, voltage differences exist between cells due to charging and discharging process thus, a battery management system (BMS) is required to ensure that all battery cells are equally charged or discharged. An equalizing method is essential to achieve the best performance. A number of cell balancing method have been presented. Among them multi-winding transformer balancing method has fast equalization time, and is easy to control. As compared to the conventional multi-winding transformer (Fly back structure) that uses diodes and requires air gap, this method (Forward) uses MOSFETs as a switch in the output and uses single phase inverter in the input. Fast equalization, easy to control, high efficiency and easy isolation are some of its features. The simulation results are accomplished to demonstrate the viability of the system.

Ali Farzan Moghaddam

Papers

An Active Cell Equalization Technique for Lithium Ion Batteries Based on Inductor Balancing

An efficient equalizing method for lithium-ion batteries based on coupled inductor balancing

A Ćuk Converter Cell Balancing Technique by Using Coupled Inductors for Lithium-Based Batteries

A Cell Equalization Method Based on Resonant Switched Capacitor Balancing for Lithium Ion Batteries

Multi-Winding Equalization Technique for Lithium Ion Batteries for Electrical Vehicles