Modeling, Control and Characterization of Aircraft Electric Power Systems

A study model of advanced aircraft electric power system (AAEPS) corresponding to B767 Aircraft is developed in the PSIM9 software environment. The performance characteristics of the system under consideration for large sharing of non-linear loads are studied. A comprehensive mathematical model describing system dynamics is derived where the GSSA technique is applied for reduced-order system approximation. The transient and steady-state performance of the hybrid PEM-FC/battery APU integrated to the aircraft electric network is analyzed while different loading scenarios are taken into account. In addition, dynamic bifurcation analysis is employed to characterize the systems stability performance under multi-parameters condition. Also, the power quality of the system is assessed under various loading configurations, and the effect of installing active/passive power filters (APF/PPF) on power quality of the system is investigated for a wide range of operating frequencies

Design and experimental implementation of voltage control scheme using the coefficient diagram method based PID controller for two-level boost converter with photovoltaic system

Introduction. Currently, in the solar energy systems and a variety of electrical applications, the power converters are essential part. The main challenge for similar systems is controller design. In the literature, the PID controller has proved its effectiveness in many industrial applications, but determining its parameters remains one of the challenges in control theory field. The novelty of the work resides in the design and experimental implementation of a two-level boost DC-DC converter controlled by a PID controller for photovoltaic (PV) maximum power extraction. Purpose. Analysis and control of the two-level boost topology with renewable energy source and design of the PID controller parameters using simple and accurate method. Methods. PID coefficients are optimized using Coefficient Diagram Method (CDM) in the MATLAB environment. Results. A mathematical model of a two-level boost converter with PID controller and PV energy source was developed and analyzed. The model allows to design the controller parameters of the proposed system. Practical value. A prototype steered by the proposed CDM-PID controller was tested using an Arduino embedded board. A comparison between the simulation results and the experimental one is presented. The obtained results illustrate that the experimental results match the simulation closely, and the proposed CDM-PID controller provides a fast and precise results.Вступ. В даний час перетворювачі потужності є невід’ємною частиною сонячних енергетичних систем та різних електричних пристроїв. Основною проблемою для таких систем є проектування контролера. У літературі ПІД-регулятор довів свою ефективність у багатьох промислових застосуваннях, але визначення його параметрів залишається однією з проблем у галузі теорії управління. Новизна роботи полягає у розробці та експериментальній реалізації дворівневого підвищувального перетворювача постійного струму, керованого ПІД-регулятором, для отримання максимальної потужності фотоелектричних пристроїв. Мета. Аналіз та управління дворівневою топологією підвищення з використанням відновлюваного джерела енергії та розрахунок параметрів ПІД-регулятора простим та точним методом. Методи. Коефіцієнти ПІД оптимізуються за допомогою методу діаграми коефіцієнтів (CDM) у середовищі MATLAB. Отримані результати. Розроблено та проаналізовано математичну модель дворівневого підвищувального перетворювача з ПІД-регулятором та фотоелектричним джерелом енергії. Модель дозволяє спроєктувати параметри контролера пропонованої системи. Практична цінність. Прототип, керований пропонованим контролером CDM-PID, протестували з використанням вбудованої плати Arduino. Наведено порівняння результатів моделювання з експериментальними даними. Отримані результати показують, що експериментальні результати близько відповідають моделюванню, а пропонований CDM-ПІД-регулятор забезпечує швидкі та точні результати

Design and Control of Power Converters 2020

In this book, nine papers focusing on different fields of power electronics are gathered, all of which are in line with the present trends in research and industry. Given the generality of the Special Issue, the covered topics range from electrothermal models and losses models in semiconductors and magnetics to converters used in high-power applications. In this last case, the papers address specific problems such as the distortion due to zero-current detection or fault investigation using the fast Fourier transform, all being focused on analyzing the topologies of high-power high-density applications, such as the dual active bridge or the H-bridge multilevel inverter. All the papers provide enough insight in the analyzed issues to be used as the starting point of any research. Experimental or simulation results are presented to validate and help with the understanding of the proposed ideas. To summarize, this book will help the reader to solve specific problems in industrial equipment or to increase their knowledge in specific fields

Dynamic modeling of pwm and single-switch single-stage power factor correction converters

The concept of averaging has been used extensively in the modeling of power electronic circuits to overcome their inherent time-variant nature. Among various methods, the PWM switch modeling approach is most widely accepted in the study of closed-loop stability and transient response because of its accuracy and simplicity. However, a non-ideal PWM switch model considering conduction losses is not available except for converters operating in continuous conduction mode (CCM) and under small ripple conditions. Modeling of conductor losses under large ripple conditions has not been reported in the open literature, especially when the converter operates in discontinuous conduction mode (DCM). In this dissertation, new models are developed to include conduction losses in the non-ideal PWM switch model under CCM and DCM conditions. The developed model is verified through two converter examples and the effect of conduction losses on the steady state and dynamic responses of the converter is also studied. Another major constraint of the PWM switch modeling approach is that it heavily relies on finding the three-terminal PWM switch. This requirement severely limits its application in modeling single-switch single-stage power factor correction (PFC) converters, where more complex topological structures and switching actions are often encountered. In this work, we developed a new modeling approach which extends the PWM switch concept by identifying the charging and discharging voltages applied to the inductors. The new method can be easily applied to derive large-signal models for a large group of PFC converters and the procedure is elaborated through a specific example. Finally, analytical results regarding harmonic contents and power factors of various PWM converters in PFC applications are also presented here

Rectifier power converter for marine applications with compensating capacitor and boost converter stage

Environmental concerns and new emissions regulations, as well as increasing power needs for marine electrical grids, are pushing the development of more efficient power converters for shipboard power systems (SPS). The priorities for SPS design are reliability and power density especially in harsh operating conditions. Safety, space, and weight are of paramount importance requirements on a ship. One factor affecting the design of SPS is the high inductive impedance presented by ac generators, which requires high voltage ratios to compensate for. Therefore, ac-dc converters, sitting as they do between ac generators and the dc bus of the SPS, are identified as a point of potential development to improve the form factor and efficiency of SPS. A novel series capacitor compensation technique is proposed and applied to an ac-dc boost rectifier. Time-averaged equations are derived and compared to simulated waveforms generated using MATLAB/Simulink. Total harmonic distortion (THD) and power factor (PF) are calculated and measured. THD is found to be the limiting factor in designing the proposed compensator. The circuit is simulated in one and three phases, and several input-to-output voltage ratios are compared. To verify the practicality of the compensation method, a single-phase 1 kW rated prototype is implemented and practical results are presented and compared with the simulated waveforms. It is found that the compensation method can control THD to acceptable levels for a large range of inductive impedances, suggesting that this solution should be further developed and investigated for application in SPS.Environmental concerns and new emissions regulations, as well as increasing power needs for marine electrical grids, are pushing the development of more efficient power converters for shipboard power systems (SPS). The priorities for SPS design are reliability and power density especially in harsh operating conditions. Safety, space, and weight are of paramount importance requirements on a ship. One factor affecting the design of SPS is the high inductive impedance presented by ac generators, which requires high voltage ratios to compensate for. Therefore, ac-dc converters, sitting as they do between ac generators and the dc bus of the SPS, are identified as a point of potential development to improve the form factor and efficiency of SPS. A novel series capacitor compensation technique is proposed and applied to an ac-dc boost rectifier. Time-averaged equations are derived and compared to simulated waveforms generated using MATLAB/Simulink. Total harmonic distortion (THD) and power factor (PF) are calculated and measured. THD is found to be the limiting factor in designing the proposed compensator. The circuit is simulated in one and three phases, and several input-to-output voltage ratios are compared. To verify the practicality of the compensation method, a single-phase 1 kW rated prototype is implemented and practical results are presented and compared with the simulated waveforms. It is found that the compensation method can control THD to acceptable levels for a large range of inductive impedances, suggesting that this solution should be further developed and investigated for application in SPS

Bidirectional Electric Vehicles Service Integration in Smart Power Grid with Renewable Energy Resources

As electric vehicles (EVs) become more popular, the utility companies are forced to increase power generations in the grid. However, these EVs are capable of providing power to the grid to deliver different grid ancillary services in a concept known as vehicle-to-grid (V2G) and grid-to-vehicle (G2V), in which the EV can serve as a load or source at the same time. These services can provide more benefits when they are integrated with Photovoltaic (PV) generation. The proper modeling, design and control for the power conversion systems that provide the optimum integration among the EVs, PV generations and grid are investigated in this thesis. The coupling between the PV generation and integration bus is accomplished through a unidirectional converter. Precise dynamic and small-signal models for the grid-connected PV power system are developed and utilized to predict the system’s performance during the different operating conditions. An advanced intelligent maximum power point tracker based on fuzzy logic control is developed and designed using a mix between the analytical model and genetic algorithm optimization. The EV is connected to the integration bus through a bidirectional inductive wireless power transfer system (BIWPTS), which allows the EV to be charged and discharged wirelessly during the long-term parking, transient stops and movement. Accurate analytical and physics-based models for the BIWPTS are developed and utilized to forecast its performance, and novel practical limitations for the active and reactive power-flow during G2V and V2G operations are stated. A comparative and assessment analysis for the different compensation topologies in the symmetrical BIWPTS was performed based on analytical, simulation and experimental data. Also, a magnetic design optimization for the double-D power pad based on finite-element analysis is achieved. The nonlinearities in the BIWPTS due to the magnetic material and the high-frequency components are investigated rely on a physics-based co-simulation platform. Also, a novel two-layer predictive power-flow controller that manages the bidirectional power-flow between the EV and grid is developed, implemented and tested. In addition, the feasibility of deploying the quasi-dynamic wireless power transfer technology on the road to charge the EV during the transient stops at the traffic signals is proven