Feedforward layered perceptron neural networks seek to capture a system mapping inferred by training data. A properly trained neural network is not only capable of mimicking the process responsible for generating the training data, but the inverse process as well. Neural network inversion procedures seek to find one or more input values that produce a desired output response for a fixed set of synaptic weights. There are many methods for performing neural network inversion. Multi-element evolutionary inversion procedures are capable of finding numerous inversion points simultaneously. Constrained neural network inversion requires that the inversion solution belong to one or more specified constraint sets. In many cases, iterating between the neural network inversion solution and the constraint set can successfully solve constrained inversion problems. This paper surveys existing methodologies for neural network inversion, which is illustrated by its use as a tool in query-based learning, sonar performance analysis, power system security assessment, control, and generation of codebook vectors.

Inversion of feedforward neural networks : Algorithms and applications : Special issue on computational intelligence

The composite converter allows integrating the high-efficiency converter modules to achieve superior efficiency performance, becoming a prominent solution for electric transport power conversion. In this work, the versatile buck–boost dc–dc converter is proposed to be integrated into an electric vehicle composite architecture that requires a wide voltage range in the dc link to improve the electric motor efficiency. The inductor core of this versatile buck–boost converter has been redesigned for high voltage applications. The versatile buck–boost converter module of the composite architecture is in charge of the control stage. It provides a dc bus voltage regulation at a wide voltage operation range, which requires step-up (boost) and step-down (buck) operating modes. The PLECS thermal simulation of the composite architecture shows a superior power conversion efficiency of the proposed topology over the well-known classical noninverting buck–boost converter under the same operating conditions. The obtained results have been validated via experimental efficiency measures and experimental transient responses of the versatile buck–boost converter. Finally, a hardware-in-the-loop (HIL) real-time simulation system of a 4.4 kW powertrain is presented using a PLECS RT Box 1 device. The HIL simulation results verified the accuracy of the theoretical analysis and the effectiveness of the proposed architecture.

https://www.mdpi.com/1424-8220/22/14/5409/pdf?version=1658309134

A Composite DC–DC Converter Based on the Versatile Buck–Boost Topology for Electric Vehicle Applications

Rectifiers with power factor correction are key devices to supply DC loads from AC sources, guaranteeing a power factor close to one and low total harmonic distortion. Boost-based power factor correction rectifiers are the most widely used topology and they are formed by a power stage (diode bridge and Boost converter) and a control system. However, there is a relevant control problem, because controllers are designed with linearized models of the converters for a specific operating point; consequently, the required dynamic performance and stability of the whole system for different operating points are not guaranteed. Another weak and common practice is to design the power and control stages independently. This paper proposes a co-design procedure for both the power stage and the control system of a Boost-based PFC rectifier, which is focused on guaranteeing the system’s stability in any operating conditions. Moreover, the design procedure assures a maximum switching frequency and the fulfillment of different design requirements for the output voltage: maximum overshoot and settling time before load disturbances, maximum ripple, and the desired damping ratio. The proposed control has a cascade structure, where the inner loop is a sliding-mode controller (SMC) to track the inductor current reference, and the outer loop is an adaptive PI regulator of the output voltage, which manipulates the amplitude of the inductor current reference. The paper includes the stability analysis of the SMC, the design procedure of the inductor to guarantee the system stability, and the design of the adaptive PI controller parameters and the capacitor to achieve the desired dynamic performance of the output voltage. The proposed rectifier is simulated in PSIM and the results validate the co-design procedures and show that the proposed system is stable for any operating conditions and satisfies the design requirements.

/pdf/co-design-of-the-control-and-power-stages-of-a-boost-based-g02ca9u2.pdf

Co-Design of the Control and Power Stages of a Boost-Based Rectifier with Power Factor Correction Depending on Performance Criteria

Feedback linearization theory and symbolic computations nonlinear control of a simulated single evaporator process robustness study of nonlinear control theories robust controller synthesis using uncertainty vector adjustment Lyapunov function analysis of the uncertainty vector adjustment simulation and control of a triple effects evaporator implementation of input output linearization on an industrial evaporator process final comment and conclusions

Robust Nonlinear Control of Industrial Evaporation Systems: Implementation of Differential Geometric Techniques

Motivated by the important growth of VTOL vehicles research such as quadrotors and to a small extent autonomous flight, a quadrotor dynamical model is presented in this work. The purpose of this study is to get a better understanding of its flight dynamics. It is an underactuated system. So, a simplified and clear model is needed to implement controllers on these kind of unmanned aerial systems. In addition, a computational tool is used for validation purposes. For future works embedded or intelligent control systems can be developed to control them. Gyroscopic and some aerodynamics effects are neglected.

/pdf/mathematical-modelling-and-identification-of-a-quadrotor-2nd204wiyr.pdf

Mathematical Modelling and Identification of a Quadrotor

Evaporation is a process that is widely used in the chemical industry and aims to concentrate a solution consisting of a non-volatile solute and a volatile solvent. In this paper the design of robust control systems for a simple effect evaporation system is presented. Two controllers were designed, the first was based on the Algebraic Riccati Equations (ARE) solutions technique and the second was derived from the D-K iteration method. To show the potentiality of the control system proposed, we present the results of some tests carried out in simulation.

/pdf/robust-control-of-an-evaporator-through-algebraic-riccati-48lb34qasd.pdf

Robust control of an evaporator through algebraic Riccati equations and d-k iteration

Many electronic power distribution systems have strong needs for highly efficient AC-DC conversion that can be satisfied by using a buck-boost converter at the core of the power factor correction (PFC) stage. These converters can regulate the input voltage in a wide range with reduced efforts compared to other solutions. As a result, buck-boost converters could potentially improve the efficiency in applications requiring DC voltages lower than the peak grid voltage. This paper compares SEPIC, noninverting, and versatile buck-boost converters as PFC single-phase rectifiers. The converters are designed for an output voltage of 200 V and an rms input voltage of 220 V at 3.2 kW. The PFC uses an inner discrete-time predictive current control loop with an output voltage regulator based on a sensorless strategy. A PLECS thermal simulation is performed to obtain the power conversion efficiency results for the buck-boost converters considered. Thermal simulations show that the versatile buck-boost (VBB) converter, currently unexplored for this application, can provide higher power conversion efficiency than SEPIC and non-inverting buck-boost converters. Finally, a hardware-in-the-loop (HIL) real-time simulation for the VBB converter is performed using a PLECS RT Box 1 device. At the same time, the proposed controller is built and then flashed to a low-cost digital signal controller (DSC), which corresponds to the Texas Instruments LAUNCHXL-F28069M evaluation board. The HIL real-time results verify the correctness of the theoretical analysis and the effectiveness of the proposed architecture to operate with high power conversion efficiency and to regulate the DC output voltage without sensing it while the sinusoidal input current is perfectly in-phase with the grid voltage.

DC Voltage Sensorless Predictive Control of a High-Efficiency PFC Single-Phase Rectifier Based on the Versatile Buck-Boost Converter.

Palm oil industry is an important agricultural activity in Colombia. Agents of this industry have chosen associative strategies and vertical integrations to increase their efficiency. However, reducing logistics costs to compete with countries such as Thailand and Malaysia, is still a challenge, also due to the scarceness of applied research in the palm oil logistics processes. In this paper, we present a continuous-discrete simulation-based approach to evaluate and optimize the fresh fruit bunches unloading process at the mill. Two simulation models representing the current process and alternative process scenarios were developed and compared. The findings show that important improvements in waiting time and supplier satisfaction can be achieved without major investments.

Improving Fresh Fruit Bunches Unloading Process at Palm Oil Mills with Discrete-Event Simulation

This article shows the results obtained in the application of State Estimation to a case of fault detection and diagnosis in an osmotic dehydration process. The disturbances that affect the measurements on the system are unknown but it is known that they are bounded. The tools used for the development of this work were the EMV (Extended Mean Value) and SIVIA (Set Inversion Via Interval Analysis) algorithms, which allow obtaining the necessary boundaries for the fault detection and diagnosis algorithm. The paper presents simulations and validations.

/pdf/detection-of-faults-in-an-osmotic-dehydration-process-1vdc40ehwp.pdf

Detection of Faults in an Osmotic Dehydration Process Through State Estimation and Interval Analysis

Security assessment techniques are a tool that allows the operational personnel of electrical systems to categorize operating conditions in different labels. Nowadays, the large size of power grids and the operating conditions close to their operating limits require efficient, safe and fast procedures to assess the overall grid security, being one of the challenges posed by smart grids conception. In this paper, a supervised learning approach that allows to integrate all the concepts of safety of the electrical network: voltage, angle, frequency, etc., to give an overall assessment of the system in terms of security which may be applied according to the regulations and geographical contexts of each country.

/pdf/security-state-estimation-of-electrical-power-systems-a-1b3bwhu0vq.pdf

Fredy A. Sanz

Papers

Robust control of an evaporator through algebraic Riccati equations and d-k iteration

DC Voltage Sensorless Predictive Control of a High-Efficiency PFC Single-Phase Rectifier Based on the Versatile Buck-Boost Converter.

Improving Fresh Fruit Bunches Unloading Process at Palm Oil Mills with Discrete-Event Simulation

Detection of Faults in an Osmotic Dehydration Process Through State Estimation and Interval Analysis

Security-State Estimation of Electrical Power Systems: A Methodological Proposal