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Static converters generate current harmonics in power grids. For numerous studies, analytical frequency modeling is preferred to carry out their harmonic modeling in the context of sizing by optimization. However, a design by optimization has to consider other constraints, e.g. modeling constraints and operating constraints. In this way, this paper aims to focus on applying an analytical frequency modeling on the sizing by optimization of an aircraft electrical power channel.

The paper aims to size a multiphysical system by optimization. In this way, the sizing of an aircraft electrical power channel by optimization has been carried out. The models of all the channel components are analytical. Specifically, the frequency model of the power electronics is based on Tran et al. (2016) and is made of equalities and inequalities. Due to this modeling choice, the optimization satisfies hundreds of constraints, such as modeling constraints and static converter operating constraints. Furthermore, transient constraints are only verified after optimization.

The difficulty is the modeling of the system by taking into account nonlinear implicit equations having several solutions. A solution is the addition of inequality constraints to the model to guide the implicit solving. Furthermore, this greatly helps the optimization algorithm to find the good operating mode of the static converter, at steady state. This aspect is indispensable to validate the sizing model.

The number of the configurations per operating period of the static converters is defined a priori and limited.

The analytical model for the sizing is formulated as a constrained optimization problem. Its solving and the sizing by optimization are carried out by the same optimization algorithm.

The purpose of this paper is to study the conceptual design and optimisation of a compound gyroplane. A study of a compound gyroplane configuration and its characteristics was performed to develop a sizing program.

The vertical takeoff and landing capabilities of a helicopter are particularly important. The need for efficient hover and the effectiveness of forward flight in the helicopter can cause conflicts within the design process. The designers usually wish to increase the helicopter's maximum forward speed. Recently, the compound aircraft is one of the concepts considered for the purpose of expanding the flight envelope of rotorcraft. The study of the compound gyroplane showed its advance capabilities for this purpose. Understanding its characteristics, a number of calculations are conducted to implement a sizing program for compound gyroplanes based on the conventional helicopter sizing process.

The results of the sizing program were validated using existing aircraft data such as the Challis Heliplane, Carter Copter, FB‐1 Gyrodyne, and Jet Gyrodyne. The program is appropriate to size a compound gyroplane at the conceptual design phase. An optimisation study was also performed to enhance sizing results. The compromise between the rotor lift sharing factor and the ratio of the wing span (Bw) to rotor diameter (D) was solved by choosing the total gross weight (TOGW) as the objective function, while the design variables are compromising factors. The optimum results showed that the TOGW of all four kinds of compound gyroplanes was considerably reduced.

A conceptual sizing program for unconventional compound aircraft was developed. The study showed that an optimum design process is necessary to enhance the sizing results.

The purpose of this study is to examine state-of-the-art in hybrid-electric propulsion system modeling and suggest new methodologies for sizing such advanced concepts. Many entities are involved in the modelling and design of hybrid electric aircraft; however, the highly multidisciplinary nature of the problem means that most tools focus heavily on one discipline and over simplify others to keep the analysis reasonable in scope. Correctly sizing a hybrid-electric system requires knowledge of aircraft and engine performance along with a working knowledge of electrical and energy storage systems. The difficulty is compounded by the multi-timescale dynamic nature of the problem. Furthermore, the choice of energy management in a hybrid electric system presents multiple degrees of freedom, which means the aircraft sizing problem now becomes not just a root-finding exercise, but also a constrained optimization problem.

The hybrid electric vehicle sizing problem can be sub-divided into three areas: modelling methods/fidelity, energy management and optimization technique. The literature is reviewed to find desirable characteristics and features of each area. Subsequently, a new process for sizing a new hybrid electric aircraft is proposed by synthesizing techniques from model predictive control and detailed conceptual design modelling. Elements from model predictive control and concurrent optimization are combined to formulate a new structure for the optimization of the sizing and energy management of future aircraft.

While the example optimization formulation provided is specific to a hybrid electric concept, the proposed structure is general enough to be adapted to any vehicle concept which contains multiple degrees of control freedom that can be optimized continuously throughout a mission.

The proposed technique is novel in its application of model predictive control to the conceptual design phase.

This paper deals with the collaborative design of electromagnetic devices over the internet network. The design is made by both mechanical and electrical engineers. So, the paper tries to show the importance but also constraints to size such a system using a collaborative optimisation process.

The paper compares two approaches in order to size an electromechanical actuator between mechanical and electrical engineers. In the first one, each profession designs its part, and only common constrained are negotiated. This can result in a design process with many iterations. In the second one, electrical and mechanical engineers built together a common model of the structure and a common list of specifications: this allows a global optimisation that is more efficient.

The main result of the paper is that the second approach in which a global model is built between electrical and mechanical engineers is more efficient.

The originality of the paper is to explore the problems and difficulties of an optimisation of an electromechanical device between engineers of different culture working together over the internet network.

In this article, a practical design methodology is proposed for discrete sizing optimization of high-rise concrete buildings with a focus on large-scale and real-life structures.

This framework relies on a computationally efficient approximation of the constraint and objective functions using a radial basis function model with a linear tail, also called the combined response surface methodology (RSM) in this article. Considering both the code-stipulated constraints and other construction requirements, three sub-optimization problems were constructed based on the relaxation model of the original problem, and then the structural weight could be automatically minimized under multiple constraints and loading scenarios. After modulization, the obtained results could meet the discretization requirements. By integrating the commercially available ETABS, a dedicated optimization software program with an independent interface was developed and details for practical software development were also presented in this paper.

The proposed framework was used to optimize different high-rise concrete buildings, and case studies showed that material usage could be saved by up to 12.8% compared to the conventional design, and the over-limit constraints could be adjusted, which proved the feasibility and effectiveness.

This methodology can therefore be applied by engineers to explore the optimal distribution of dimensions for high-rise buildings and to reduce material usage for a more sustainable design.

The purpose of this paper is to deal with the design of passive filter for power electronics voltage inverters used in aircraft electrical drives (a permanent magnet synchronous machine fed by a six-phase voltage inverter with PMW control), using optimization for both sizing and sensibility analyses.

The approach is generic. An aid allows to modify easily the frequency model and so to check various study cases, and to carry out the filter optimization for different topologies or control strategies.

The approach is generic. An aid allows to modify easily the frequency model and so to check various study cases, and to carry out the filter optimization for different topologies or control strategies.

The power electronics load is supposed to be a set of predefined harmonic sources, obtained by experiment or time simulation plus fast fourier transformation before the optimization process.

The problem has numerous constraints on the components, mainly technological constraints. The volume is minimized, respecting electromagnetic standards and an electro magnetic interference filter prototype has been made.

The frequency model is automatically generated. A complex aircraft application has been studied thanks to the approach. Several sensibility analyses have been carried out. An EMC filter has been sized and an experimental prototype has been made, comforting the sizing by optimization.

Topology optimization and conventional structural sizing optimization procedures are used together to obtain optimum designs for plate structures. A three‐layer, Mindlin‐Reissner plate model is first used with topology optimization to determine optimal stiffening zones. The central layer represents the unstiffened plate and the symmetrically located upper and lower layers are potential stiffening zones. A stiffening volume is specified and the objective is to minimize the strain energy. From these stiffening zones, a set of centre lines of equivalent stiffening Timoshenko beam elements is selected. A sizing optimization procedure is then used to optimize the stiffener dimensions. The objective of the design in the final sizing optimization stage is to minimise the strain energy keeping the total stiffened plate volume constant. The efficiency and accuracy of the proposed strategy is illustrated through several applications.

The paper deals with the sizing of a flyback converter. The approach proposes to use symbolic calculation to perform sizing times, the accuracy and the number of parameters to size. So, it presents a symbolic model to size a flyback converter using optimisation techniques. Such an approach is preferred to a simulation approach thanks to the flexibility of symbolic models and their possibility to treat a great set of criteria in few seconds or minutes. The expressions of a great part of the criteria are made by an automatic symbolic process – model builders – and the others are carried out by the designer. Such a model is used in a gradient optimisation process well known for its convergence properties. From this model, a builder carries out automatically the building of a dedicated sizing tool, by automatically transforming it into an optimisation problem and by automatically giving the corresponding sizing tool with its GUI.

In most applications the active power filters (APFs) are used to reduce harmonic distortion of a nonlinear load which is located near the APF installation point. This classic approach allows to reduce the distortion introduced to the power system but do not guarantee that the cost of the APFs installation is optimal. The purpose of this paper is to compare the classic approach to harmonic compensation with an optimization method of sizing and placement of the APFs in an existing distributed power network.

An exemplary real-life power system with distributed nonlinear loads was modeled using PCFLO power analysis software. Next, Matlab was used to implement the classic method and the optimization algorithm. Between Matlab and PCFLO a specially written Java middleware was used to provide a seamless workflow integration.

It was shown that the presented optimization method may lead to superior results in comparison with the classic approach. Simulation results clearly showed that the APFs installation cost can be significantly reduced when the optimization algorithm is used. Moreover, the proposed optimization method can overcome some problems connected with the nonlinearity and discontinuity of the APF's price/current function.

There are two main limitations of the presented method. First, the method needs much more computing power then the classic approach. Second, according to the authors’ knowledge, currently there are no commercially available APFs, which allow to directly apply the optimization method in industrial applications.

The presented results showed that the approach, which is the most popular in the industry, is far from being optimal from the cost perspective. As it has been shown in the investigated example, it might be possible to significantly reduce the total cost of APFs installed in the power system.

The optimization method presented in the paper as well as all simulation results are the original authors work. It was shown that the existing harmonic compensation strategies can be significantly upgraded and the proposed optimization method may be a basis and a reference point for future commercial solutions.

Most apparel sizing systems are based on one or two body dimensions and rely on assumptions about proportional body relationships to project other dimensions necessary to design the garment pattern. Garments from these systems will not fit a population with large variations in body proportions. Using nonlinear optimization methods and anthropometric data of US Army women three multidimensional sizing systems were derived that are designed to provide improved fit for women from the USA, a population with much variation. These systems range from an optimized linear system with a regular grade to an unconstrained optimized system with a grade break at each size. The optimized sizing systems compare favorably with D5585‐94 in their ability to accommodate variation in the population based on a mathematical test of the aggregate loss of each system. Issues related to pattern grading, size selection, and calculation of stock keeping units are discussed.