Don mahinda Vilathgamuwa

Queensland University of Technology | QUT

We are delighted to announce the upcoming 9th IEEE Southern Power Electronics Conference (SPEC) 2024 sponsored by the IEEE Power Electronics Society which is scheduled to take place in Brisbane, Australia from December 2-5, 2024. SPEC 2024 organizing committee is extending a sincere invitation to you to join and contribute to our conference by su...

The power capability of a lithium-ion battery signifies its capacity to continuously supply or absorb energy within a given time period. For an electrified vehicle, knowing this information is critical to determining control strategies such as acceleration, power split, and regenerative braking. Unfortunately, such an indicator cannot be directly m...

Along with the higher penetration of renewables, more frequent natural disasters/disturbing events, and increased level of interconnection between different industrial processes, higher-level flexibility and adaptability are demanded to address the intermittence, rising costs, and high uncertainty and vulnerability in energy supply and utilization....

In a dynamic distribution market environment, residential prosumers with solar power generation and battery energy storage devices can flexibly interact with the power grid via power exchange. Providing a schedule of this bidirectional power dispatch can facilitate the operational planning for the grid operator and bring additional benefits to the...

Lithium-ion battery energy storage systems are made from sets of battery packs that are connected in series and parallel combinations depending on the application’s needs for power. To achieve optimal control, advanced battery management systems (ABMSs) with health-conscious optimal control are required for highly dynamic applications where safe op...

In recent times, wireless power transfer systems have been identified as a reliable option to supply power to medical implants. Up to now, Wireless Power Transfer Systems (WPTS) have only been used to charge batteries of low-power medical implants. However, for medical implants requiring a relatively higher power, such as a ventricular assist devic...

A model-based battery power capability prediction method is reported to prevent the battery from moving into harmful situations during its operation for its health and safety. The method incorporates a high-fidelity electrochemical-thermal battery model, with which not only the external limitations on current, voltage, and power, but also the inter...

To unlock the promise of electrified transportation and smart grid, emerging advanced battery management systems (BMSs) shall play an important role in health-aware monitoring, diagnosis, and control of widely used lithium-ion (Li-ion) batteries. Sophisticated physics-based battery models incorporated in the advanced BMS can offer valuable battery...

A computationally efficient state estimation method for lithium-ion (Li-ion) batteries is proposed based on a degradation-conscious high-fidelity electrochemical-thermal model for advanced battery management systems. The computational burden caused by the high-dimensional nonlinear nature of the battery model is effectively eased by adopting an ens...

In this article, a new technique of synchronized sampling to estimate the transferred power in wireless power transfer (WPT) systems is proposed. Defining demand factor as a criterion linking unknown receiver parameters to the transferred power, it can be estimated by measuring the front-end variables of the transmitter LCC compensating network....

The transport sector is one of the leading contributors of anthropogenic climate change. Particularly, internal combustion engine (ICE) dominancy coupled with heavy private motor vehicle dependency are among the main issues that need to be addressed immediately to mitigate climate change and to avoid consequential catastrophes. As a potential solut...

Battery energy storage power stations (BESPS) play an important role in the power flow regulation in large-scaled micro-grids. It is proposed that the static Var compensator (SVC) be replaced by BESPS through activation of its dynamic voltage regulation (DVR) function so that the cost of SVC can be saved. An additional controller named energy stora...

Energy storage systems are essential for achieving transportation electrification and, at the same time, they are advocated to be fundamental assets if properly integrated into modern power systems hosting a large amount of stochastic distributed generation. Unlocking the potential of these systems in terms of performance and cost requires new devi...

The authors regret to request the corrigendum to the full manuscript to provide more accurate and complete content. The authors would like to apologise for any inconvenience caused. DOI of original article: 10.1016/j.electacta.2018.12.16.

The rapid growth in distributed energy sources on power grids leads to increasingly decentralized energy management systems for the prediction of power supply and demand and the dynamic setting of an energy price signal. Within this emerging smart grid paradigm, electric vehicles can serve as consumers, transporters, and providers of energy through...

In a typical wireless power transfer (WPT) system, the load, the mutual inductance and the required tuning frequency can vary in a particular range. Variation of each parameter can substantially impact the dynamic characteristics of the system. Thus, they can be considered as the sources of uncertainty in the system. To address this issue, robust c...

This paper proposes a new fast charging strategy for lithium-ion (Li-ion) batteries. The approach relies on an experimentally validated high-fidelity model describing battery electrochemical and thermal dynamics that determine the fast charging capability. Such a high-dimensional nonlinear dynamic model can be intractable to compute in real-time if...

This article proposes a novel model-based estimator for distributed electrochemical states of lithium-ion (Li-ion) batteries. Through systematic simplifications of a high-order electrochemical-thermal coupled model consisting of partial differential-algebraic equations, a reduced-order battery model is obtained that features an equivalent circuit f...

The potential of variable-speed dish-Stirling (VSDS) solar-thermal generating plant in providing grid frequency support is investigated. In the proposed VSDS frequency support control scheme, the reference speed of the Stirling engine is regulated to track a deloaded power curve which is governed by the solar insolation level. The gain of a supplem...

The detection and localization of dc arc faults is a major problem in large grid-connected photovoltaic systems. Hence, a time-domain technique based on the mathematical morphology called the decomposed open–close alternating sequence (DOCAS) is proposed in this article for the detection and localization of such fault conditions. The dc arc is usua...

Voltage multipliers (VMs) are widely used in applications with high-voltage-gain rectifiers and dc/dc converters with the capability of increasing voltage conversion ratio. Currently, all the existing VM circuits are designed with two input-terminals, while optimal design on voltage conversion ratio and voltage stress on semiconductor devices of th...

The rapid growth in distributed energy sources on power grids is leading to more decentralised energy management systems for the prediction of power supply and demand and the dynamic setting of an energy price signal. Within this emerging smart grid, electric vehicles can serve as consumers, transporters, and providers of energy through two-way cha...

Low voltage stress on the impedance source network devices is the main reason for the advent of DC-linked type quasi-switched boost inverters (DqSBIs). However, the DqSBI has become less attractive due to its low voltage gain. This paper presents a novel PWM control strategy for the DqSBI and its comparative performance evaluation to the convention...

A new approach to derive the equations of Multi-Coil Wireless Power Transfer (MCWPT) systems and to simplify and analyze them is proposed in this paper. By parametrically solving the equations governing MCWPT systems and mapping the resultant transfer functions into Graph Sets (GSs), a set of rules is developed to form the transfer function amongst...

This paper is the continuation of Graph Sets Method (GSM) proposed in the companion paper Part I for deriving equations and analyzing Multi Coil (MC) Wireless Power Transfer (WPT) systems. After explaining GSM, categorizing WPT coils into three different types, and proposing some approximation techniques in Part I, this article, as the second part...

The application of lithium-ion (Li-ion) battery energy storage system (BESS) to achieve the dispatchability of a renewable power plant is examined. By taking into consideration the effects of battery cell degradation evaluated using electrochemical principles, a power flow model (PFM) of the BESS is developed specifically for use in system-level st...

In this paper, an improved PWM scheme is proposed for an active quasi-Z source inverter (AqZSI). Compared to the quasi-Z-source inverter (qZSI), the AqZSI with improved PWM strategy can operate in a wide range of input voltage with a higher efficiency. Furthermore, the AqZSI can operate with a higher modulation index, a lower inductor current stres...

A single-switch high step-up boost converter based on a novel voltage multiplier (VM) has been proposed in this study. Compared to traditional boost converter, not only the voltage conversion ratio has been increased, but also voltage stress across semiconductor devices has been decreased. Moreover, the voltage conversion ratio and voltage stress o...

We present a one-dimensional, radial, coupled degradation-electrochemical-thermal (DET) model of a large format cylindrical lithium ion cell. The model consists of reduced order equations that describe the electrochemical phenomena, including that associated with degradation, coupled with an approximate model of thermal behavior. The reduced order...

Expandable and flexible wireless power transfer (WPT) systems have been in demand in numerous industry applications, especially for dynamic chargers in electric vehicles. Those systems, however, brings about certain technical issues such as modulation technique and topology of the transmitter-side, and transferred power profile of the transmitters....

Non‐linear rectifier loads usually cause heavy distortion in the output voltage of single‐phase inverters due to pulsating charging current of the rectifier direct current link capacitor. In this article, a predictive load current‐based digital feedforward (PCFF) compensation method is proposed to decrease the inverter voltage distortion associated...

A computationally-efficient and reliable method is developed to permit the simultaneous assessment of both the short- and long-term performance of lithium-ion battery in power system planning studies. Toward this end, a physics-based equivalent circuit model of the lithium-ion battery is derived in which side reaction-induced degradation of the bat...

The voltage conversion ratio of basic DC/DC converters is limited due to the influence of parasitic elements of circuits and components. In this paper, a family of passive circuits termed as “coat circuits” are proposed for conventional DC/DC converters. Not only voltage step-up capacity can be improved but also the voltage stress of components can...

Double switching frequency components of the input current in the isolated three‐port converter (TPC) can be effectively mitigated using an LC circuit at the input side of the converter. Although the LC circuit prevents the high‐frequency current flow into the system, there is a resonant peak in the port current control model that can degrade the c...

Electric vehicles (EVs), which are becoming increasingly popular, can be charged by either wired or wireless means. The latter, based on wireless power transfer (WPT) technology, is convenient and safe, but pad misalignment is one of the major concerns as it causes a reduction in charging power level, prolonging the charging process. Therefore, wir...

A bidirectional integrated bus voltage conditioner (IBVC) for an isolated phase shifted full bridge (PSFB) DC/DC converter is proposed to reduce the DC bus voltage oscillations in a cascaded power converter system where a load converter is controlled tightly with high control bandwidth. Unlike conventional DC bus voltage stabilization methods for w...

In this paper, a new optimal pulse-width modulation (PWM) scheme for a three-level quasi-switched boost T-type inverter (TL qSBT2I) under normal and failure modes is proposed. The proposed method reveals its semiconductor fault tolerance capability in open-circuit fault condition situations as described in the paper. The PWM control algorithm for t...

The modeling and control system design of high step-up DC/DC converters based on voltage multipliers (VMs) are difficult, due to the various circuit topologies and the presence of large number of capacitors in VMs. This paper proposes a generic approach to reduce the model order of such converters by replacing the VM capacitors with voltage sources...

Double-switch buck-boost converter is a distinctly suitable candidate for the front-end converter in two-stage power converter systems that can perform step-up/down power conversion. Several modulation schemes, such as synchronisation modulation (SM), interleaved modulation (IM) and combined control strategy have been proposed for this converter, a...

A non-isolated high-voltage gain dual-input DC/DC converter with a zero voltage turn-off (ZVT) auxiliary circuit has been presented. Two photovoltaic (PV) modules can be connected to the proposed converter with separate maximum power point tracking (MPPT). The cost of whole PV power generation system can be decreased significantly as a single conve...

This study presents a high step-up scalable voltage multiple cell (SVMC)-based DC/DC converters, which have the features of high gain, low and adjustable components stresses and automatic input-current sharing in each input phase. In virtue of the above features, the converter is applicable for the DC collection grids for offshore wind farms. In th...

A physics-based equivalent circuit model (ECM) is derived by applying finite volume method to a pseudo-two-dimensional (P2D) model of lithium-ion (Li-ion) batteries. Only standard passive components are used to construct the equivalent circuit, which reflects the fact that a Li-ion battery is an energy storage device. Voltages across and currents t...

The existence of the double grid frequency (100Hz) ripple current in DC/AC dual active bridge (DAB) power converters can degrade their performance and as such these ripples need to be compensated. An active power decoupling method is proposed in this paper to attenuate the 100 Hz current ripple in single phase DC/AC DAB converters. Compared to othe...

A computationally efficient reduced-order electrochemical-thermal model for small-format cylindrical lithium ion cells is developed, by applying the Padé approximation technique to the Pseudo-2-Dimensional battery model. Whence the amount of the total heat produced in the battery is obtained which in turn allows the evolution of the cell temperatur...

The high-power density and capability of three-port converters (TPCs) in generating demanded power synchronously using flexible control strategy make them potential candidates for renewable energy applications to enhance efficiency and power density. The control performance of isolated TPCs can be degraded due to the coupling and interaction of pow...

In single phase DC-AC systems, double-line-frequency power ripple appears at the DC side inherently. Normally a large electrolytic capacitor can be used to reduce the power ripple at the DC side. But there are several problems with this method as it decreases the power density and reliability of the converter. In addition, a double-line-frequency c...

The paper focuses on developing power flow control strategy for electricity end users installed with photovoltaic-battery systems. The control objective is to reduce the overall cost to the end users while meeting the users’ load demands. By taking into consideration the cost associated with the degradation of the battery, a nonlinear model predict...

The constant power load (CPL) property of a load converter with tight control results in DC bus voltage oscillations in interconnected power converter systems. In this paper, a disturbance observer (DOB) feedforward compensation scheme is proposed to stabilize the DC bus voltage of a cascaded power converter. An equivalent DC link voltage control m...

Power supplies with several paralleled DC/DC converters are usually used for high reliability purposes owing to their advantage in terms of redundancy and modularisation. However, current unbalance due to parameter deviations among the paralleled converters might deteriorate the whole system reliability and results in excessive thermal and device s...

We present a reduced order model for a lithium ion battery in which Padé approximants are used to simplify complex, transcendental, transfer functions associated with the linearized, pseudo 2-dimensional (P2D) electrochemical model of the battery. The resulting transfer functions take the form of simple, rational polynomial functions, which can be...

A control strategy is developed for lithium-ion (Li-ion) battery energy storage system used in conjunction with renewable generation. The strategy is based on a developed dynamic model of Li-ion battery cell derived from electrochemical principles. The major degradation behaviors, that of the battery storage capacity fading and the increase of its...