Dynamic performance improvement of an ultra-lift Luo DC–DC converter by using a type-2 fuzzy neural controller

© 2018 Due to the uncertainty associated with the structure and electrical elements of DC–DC converters and the nonlinear performance of these modules, designing an effective controller is highly complicated and also technically challenging. This paper employs a new control approach based on type-2 fuzzy neural controller (T2FNC) in order to improve the dynamic response of an ultra-lift Luo DC–DC converter under different operational conditions. The proposed controller can rapidly stabilize the output voltage of converter to expected values by tuning the converter switching duty cycle. This controller can tackle the uncertainties associated with the structure of converters, measured control signals and measuring devices. Moreover, a new intelligent method based on firefly algorithm is applied to tune the parameters of T2FNC. In order to demonstrate the effectiveness of the proposed control approach, the proposed controller is compared to PI and fuzzy controllers under different operational conditions. Results validate efficiency of proposed T2FNC

Design And Implementation Of A Digital Controller With Dsp For Half-br

DC-DC power converters play an important role in powering telecom and computing systems. With the speed improvement and cost reduction of digital control, digital controller is becoming a trend for DC-DC converters in addition to existed digital monitoring and management technology. In this thesis, digital control is investigated for DC-DC converters applications. To deeply understand the whole control systems, DC-DC converter models are investigated based on averaged state-space modeling. Considering half-bridge isolated DC-DC converter with a current doublers rectifier has advantages over other topologies especially in the application of low-voltage and high-current DC-DC converters, the thesis take it as an example for digital control modeling and implementation. In Chapter 2, unified steady-state DC models and small-signal models are developed for both symmetric and asymmetric controlled half-bridge DC-DC converters. Based on the models, digital controller design is implemented. In Chapter 3, digital modeling platforms are established based on Matlab, Digital PID design and corresponding simulation results are provided. Also some critical issues and practical requirements are discussed. In Chapter 4, a DSP-based digital controller is implemented with the TI\u27s DSP chip TMS320F2812. Related implementation methods and technologies are discussed. Finally the experimental results of a DSP-based close-loop of HB converter are provided and analyzed in Chapter 5, and thesis conclusions are given in Chapter 6

Emerging Power Electronics Technologies for Sustainable Energy Conversion

This Special Issue summarizes, in a single reference, timely emerging topics related to power electronics for sustainable energy conversion. Furthermore, at the same time, it provides the reader with valuable information related to open research opportunity niches

Emerging Power Electronics Technologies for Sustainable Energy Conversion

This Special Issue summarizes, in a single reference, timely emerging topics related to power electronics for sustainable energy conversion. Furthermore, at the same time, it provides the reader with valuable information related to open research opportunity niches

Design and Control of Power Converters 2019

In this book, 20 papers focused on different fields of power electronics are gathered. Approximately half of the papers are focused on different control issues and techniques, ranging from the computer-aided design of digital compensators to more specific approaches such as fuzzy or sliding control techniques. The rest of the papers are focused on the design of novel topologies. The fields in which these controls and topologies are applied are varied: MMCs, photovoltaic systems, supercapacitors and traction systems, LEDs, wireless power transfer, etc

Robust Power Interface for Smart Grid with Renewable Energy Source-to-Grid Functionality

Many renewable energy companies design wind turbine generators, solar panels, or electrical car batteries with different specifications according to their management philosophy. And typical commercial power converters are not universally designed for all different types of renewable energy systems. Because of this lack of flexibility and interoperability, a universal and scalable smart grid power converter design is desirable. Designing a robust controlled bi-directional power converter is the motivation for this thesis as the first step to develop a more universal converter topology connecting renewable energy sources and the electrical smart-grid of the future. Renewable energy such as wind or solar power are promising alternatives with many advantages to traditional energy sources but they cannot provide a constant power flow due to the inherent variability of weather. For example, wind speed fluctuates depending on its elevation and solar irradiance fluctuates when moving clouds cover the sun. These example scenarios can be considered as uncertainty and one can assume that uncertainty is time varying as well. For these reasons, it is clear that wind turbine generators and solar panels cannot generate constant power levels and it may result in malfunctions in the converter and instability in the grid

High-Performance Isolated Bidirectional DC-DC Converter

Conversores DC-DC bidireccionais têm vindo a ganhar atenção na área da eletrónica de potência devido ao aumento da necessidade de um fluxo de potência controlado entre dois barramentos DC. Aplicações típicas podem ser facilmente listadas, indo desde unidades de produção de energia renovável até veículos elétricos e híbridos. Estes conversores podem apresentar funcionalidades como elevada densidade energética e performance, assim como isolamento galvânico entre cada porto. Desta forma, a AddVolt requisitou que tal conversor fosse incluído na sua solução de travagem regenerativa. Com esta dissertação, um conversor DC-DC bidireccional e isolado é proposto, sendo que todos os aspetos desde revisão bibliográfica, modelação, design, simulação, implementação, teste e validação são abrangidos. Um conversor Dual-Active Bridge (DAB) de média potência e alta frequência é a topologia escolhida. Após validação de quer a topologia como a malha de controlo desenhada num ambiente computacional, um protótipo experimental é assemblado e testado com sucesso. O isolamento galvânico é garantido e atingido através de um transformador de alta frequência desenhado e enrolado pelo autor.Bidirectional DC-DC converters have been gaining attention in the field of power electronics due to the increasing need of a controlled power flow between two DC buses. Typical applications can be easily listed, ranging from renewable energy production units to electric and hybrid vehicles. Such converters can feature characteristics as high power density and performance as well as isolation between each port. As a result, AddVolt has commissioned that such a converter should be included in its regenerative breaking solution. Within this dissertation, a bidirectional isolated DC-DC converter is proposed, and all aspects from literature review, modelling, design, simulation, implementation, testing and validation are deeply covered. A medium-power high frequency Dual-Active Bridge (DAB) converter is the chosen topology. After validation of both the topology and control structure in a computational environment, an experimental prototype is assembled and successfully tested. Galvanic isolation is granted and achieved by a self-designed and in-house wound high frequency transformer

Design and Implementation of Control Techniques of Power Electronic Interfaces for Photovoltaic Power Systems

The aim of this thesis is to scrutinize and develop four state-of-the-art power electronics converter control techniques utilized in various photovoltaic (PV) power conversion schemes accounting for maximum power extraction and efficiency. First, Cascade Proportional and Integral (PI) Controller-Based Robust Model Reference Adaptive Control (MRAC) of a DC-DC boost converter has been designed and investigated. Non-minimum phase behaviour of the boost converter due to right half plane zero constitutes a challenge and its non-linear dynamics complicate the control process while operating in continuous conduction mode (CCM). The proposed control scheme efficiently resolved complications and challenges by using features of cascade PI control loop in combination with properties of MRAC. The accuracy of the proposed control system’s ability to track the desired signals and regulate the plant process variables in the most beneficial and optimised way without delay and overshoot is verified. The experimental results and analysis reveal that the proposed control strategy enhanced the tracking speed two times with considerably improved disturbance rejection. Second, (P)roportional Gain (R)esonant and Gain Scheduled (P)roportional (PR-P) Controller has been designed and investigated. The aim of this controller is to create a variable perturbation size real-time adaptive perturb and observe (P&O) maximum power point tracking (MPPT) algorithm. The proposed control scheme resolved the drawbacks of conventional P&O MPPT method associated with the use of constant perturbation size that leads to a poor transient response and high continuous steady-state oscillations. The prime objective of using the PR-P controller is to utilize inherited properties of the signal produced by the controller’s resonant path and integrate it to update best estimated perturbation that represents the working principle of extremum seeking control (ESC) to use in a P&O algorithm that characterizes the overall system learning-based real time adaptive (RTA). Additionally, utilization of internal dynamics of the PR-P controller overcome the challenges namely, complexity, computational burden, implantation cost and slow tracking performance in association with commonly used soft computing intelligent systems and adaptive control strategies. The experimental results and analysis reveal that the proposed control strategy enhanced the tracking speed five times with reduced steady-state oscillations around maximum power point (MPP) and more than 99% energy extracting efficiency.Third, the interleaved buck converter based photovoltaic (PV) emulator current control has been investigated. A proportional-resonant-proportional (PR-P) controller is designed to resolve the drawbacks of conventional PI controllers in terms of phase management which means balancing currents evenly between active phases to avoid thermally stressing and provide optimal ripple cancellation in the presence of parameter uncertainties. The proposed controller shows superior performance in terms of 10 times faster-converging transient response, zero steady-state error with significant reduction in current ripple. Equal load sharing that constitutes the primary concern in multi-phase converters has been achieved with the proposed controller. Implementing of robust control theory involving comprehensive time and frequency domain analysis reveals 13% improvement in the robust stability margin and 12-degree bigger phase toleration with the PR-P controller. Fourth, a symmetrical pole placement Method-based Unity Proportional Gain Resonant and Gain Scheduled Proportional (PR-P) Controller has been designed and investigated. The proposed PR-P controller resolved the issues associated with the use of the PI controller which are tracking repeating control input signal with zero steady-state and mitigating the 3rd order harmonic component injected into the grid for single-phase PV systems. Additionally, the PR-P controller has overcome the drawbacks of frequency detuning in the grid and increase in the magnitude of odd number harmonics in the system that constitute the common concerns in the implementation of conventional PR controller. Moreover, the unprecedented design process based on changing notch filter dynamics with symmetrical pole placement around resonant frequency overcomes the limitations that are essentially complexity and dependency on the precisely modelled system. The verification and validation process of the proposed control schemes has been conducted using MATLAB/Simulink and implementing MATLAB/Simulink/State flow on dSPACE Real-time-interface (RTI) 1007 processor, DS2004 High-Speed A/D and CP4002 Timing and Digital I/O boards

Design and analysis of a novel multi-input multi-output high voltage DC transformer model

a novel Multi-Input Multi-Output (MIMO) step-up DC transformer for applications in high voltage renewable energy sources is designed and presente