High performance position control of permanent magnet synchronous drives

In the design and test of electric drive control systems, computer simulations provide a useful way to verify the correctness and efficiency of various schemes and control algorithms before the final system is actually constructed, therefore, reducing development time and associated costs. Nevertheless, the transition from the simulation stage to the actual implementation has to be as straightforward as possible. This paper presents the design and implementation of a position control system for permanent magnet synchronous drives using the dsPIC33FJ32MC204 microcontroller as the target processor to implement the control algorithms. The overall system is simulated and tested in Proteus VSM software which is able to simulate the interaction between the firmware running on the microcontroller and the analogue circuits connected to it. The electric drive model is developed using elements present in the Proteus VSM library. As in any high-performance AC electric drive system, field oriented control is applied. The complete control system is distributed in three control loops, namely torque, speed and position. A standard PID control system, and a hybrid control system based on fuzzy logic, are implemented and tested. The natural variation of motor parameters, such as winding resistance and magnetic flux, are also simulated. Comparisons between the two control schemes are carried out for speed and position control using different error measurements, such as, integral square error, integral absolute error and root mean squared error. Comparison results show a superior performance of the fuzzy-logic-based controller when coping with parameter variations, and by reducing torque ripple, but the results are reversed when periodical torque disturbances are present.N/

Study of the Energy Efficiency of an Urban E-Bike Charged with a Standalone Photovoltaic Solar Charging Station and its Compliance with the Ecuadorian Grid Code No. ARCERNNR – 002/20

E-bikes are an emerging sustainable means of transportation, if adopted massively, they can help face the challenges of human mobility in urban centers worldwide. In Cuenca, Ecuador, the local government built cycle routes (13.47 km) connecting strategic points to facilitate and encourage sustainable mobility. However, the effective implementation of the electromobility strategies at a large scale entails impacts on the power grid, like the increase in the energy demand and the possible decrease of the energy quality due to the harmonic distortion that characterizes the battery's charging current. This research aims to obtain a primary input to evaluate such impacts through an energy efficiency study of an urban e-bike charged by a standalone solar photovoltaic charging station implemented in the Microgrid Laboratory of Universidad de Cuenca. The methodology includes the experimental characterization of the battery's charging regime, the vehicle's energy efficiency calculation, and the evaluation of its compliance with Ecuadorian grid code No. ARCERNNR – 002/20. Results show that the battery's charger performs a charging regime standardized by German regulations, delivering 92% of charge in 4.82 hours. The e-bike's calculated average energy efficiency is 2.18 kWh/100 miles or 73.77 m/Wh, and a fuel economy of 1545.1 MPGe. Finally, the magnitude of the first four odd harmonic components and the total harmonic distortion of the charging current exceeds the limits established by the grid code in force

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

High performance position control of permanent magnet synchronous drives

In the design and test of electric drive control systems, computer simulations provide a useful way to verify the correctness and efficiency of various schemes and control algorithms before the final system is actually constructed, therefore, reducing development time and associated costs. Nevertheless, the transition from the simulation stage to the actual implementation has to be as straightforward as possible. This paper presents the design and implementation of a position control system for permanent magnet synchronous drives using the dsPIC33FJ32MC204 microcontroller as the target processor to implement the control algorithms. The overall system is simulated and tested in Proteus VSM software which is able to simulate the interaction between the firmware running on the microcontroller and the analogue circuits connected to it. The electric drive model is developed using elements present in the Proteus VSM library. As in any high-performance AC electric drive system, field oriented control is applied. The complete control system is distributed in three control loops, namely torque, speed and position. A standard PID control system, and a hybrid control system based on fuzzy logic, are implemented and tested. The natural variation of motor parameters, such as winding resistance and magnetic flux, are also simulated. Comparisons between the two control schemes are carried out for speed and position control using different error measurements, such as, integral square error, integral absolute error and root mean squared error. Comparison results show a superior performance of the fuzzy-logic-based controller when coping with parameter variations, and by reducing torque ripple, but the results are reversed when periodical torque disturbances are present. © 2017 IEEE.In the design and test of electric drive control systems, computer simulations provide a useful way to verify the correctness and efficiency of various schemes and control algorithms before the final system is actually constructed, therefore, reducing development time and associated costs. Nevertheless, the transition from the simulation stage to the actual implementation has to be as straightforward as possible. This paper presents the design and implementation of a position control system for permanent magnet synchronous drives using the dsPIC33FJ32MC204 microcontroller as the target processor to implement the control algorithms. The overall system is simulated and tested in Proteus VSM software which is able to simulate the interaction between the firmware running on the microcontroller and the analogue circuits connected to it. The electric drive model is developed using elements present in the Proteus VSM library. As in any high-performance AC electric drive system, field oriented control is applied. The complete control system is distributed in three control loops, namely torque, speed and position. A standard PID control system, and a hybrid control system based on fuzzy logic, are implemented and tested. The natural variation of motor parameters, such as winding resistance and magnetic flux, are also simulated. Comparisons between the two control schemes are carried out for speed and position control using different error measurements, such as, integral square error, integral absolute error and root mean squared error. Comparison results show a superior performance of the fuzzy-logic-based controller when coping with parameter variations, and by reducing torque ripple, but the results are reversed when periodical torque disturbances are present.Würzbur

Peak control current in boundary conduction mode and discontinuous conduction mode for inverter with flyback topology

This paper proposes a hybrid control scheme peak current, applied to a single-phase micro inverter with flyback topology coupled to a LC filter, the proposed scheme allows the inverter to operate by boundary conduction mode when the output current exceeds a predetermined value. Otherwise, it operates in the discontinuous conduction mode, limiting the switching frequency. To set the control system in both modes of operation, the inverter is identified by averaging the model state and small signal, the control scheme used, presents a classic PI control and is tuned by pole placement. The proposed control scheme is verified through computer simulation.Bogot

Micro red de laboratorio como una herramienta para la investigación sobre la no - convencionales de energía de fuentes en Ecuador

This article presents to the scientific community technical and management issues taken into account for the implementation of the Micro Grid Laboratory, which will be part of “Balzay” Scientific, Technological and Research Center of the University of Cuenca. The paper describes the components that integrate the generation, storage and consumption of electrical energy from a combination of renewable and non-renewable sources that allow the emulation of a distributed generation network with the possibility of establishing technical criteria to recreate an intelligent network (Smart grid). The generation, storage and consumption components of the laboratory can interact through a control, monitoring and data acquisition system (SCADA) that allows automation of energy management for teaching and research purposes, as well as the possibility of interconnection with the local grid.Ixtap

Electrical energy conversion system design with single-phase inverter and H5 transformerless topology

This paper presents the design of an electrical energy conversion system (EECS) for the use of solar energy and its conditioning for injection of energy to the commercial power grid. A single-phase full-bridge inverter with transformerless H5 topology coupled to an LCL filter is used. The system is identified using an averaged small-signal state space model; while the used cascade control scheme is tuned by pole placement and includes a maximum power disturb-observe tracking type algorithm of that increases efficiency by operating the system at the optimum operating point of the solar panel. This design describes essential technical aspects in the components sizing and selection for experimental development, as well as the control structure design for a good performance to face systems perturbations

Local recorder of electrical parameters for determining the behavior of the residential demand in the city of Cuenca

En esta investigación se presenta un instrumento electrónico, desarrollado localmente, para registrar datos de los parámetros eléctricos relacionados al consumo energético de las viviendas de la ciudad de Cuenca-Ecuador, con el fin de conocer el comportamiento de la demanda y corroborar que el equipo de mayor consumo dentro de los domicilios es la refrigeradora. Mediante las mediciones en tiempo real, se puede conocer valores de primera mano de los parámetros eléctricos a nivel de abonado, lo cual todavía no ha sido realizado en el sector residencial del país. Para ello, se desarrolla un equipo electrónico, que mediante un software de programación entrega los datos de tensión y corriente RMS, así como el factor de potencia y la potencia activa que contabiliza o registra el equipo continuamente en periodos de un segundo. Este aparato fue desarrollado con recursos económicos relativamente bajos por lo que podría ser difundido y usado masivamente. La importancia de tener los parámetros eléctricos en tiempo real, inicia con la eliminación definitiva de la especulación de consumos en base a estimaciones y allana el camino para controlar la demanda desde el usuario. Mediante el análisis de los resultados y las curvas de consumo energético, se proponen además criterios de consumo de electricidad dentro del sector residencial, propendiendo al cambio de comportamientos de dicho consumo. De la misma forma, con los análisis realizados es posible aportar con recomendaciones de eficiencia energética para un adecuado dimensionamiento de los equipos que componen el sistema de distribución en el sector residencial de Cuenca.The aim of this research is to present an electronic instrument, developed locally, which allows to log electrical data and to model energy consumptions of homes in the city of Cuenca-Ecuador. This hands-on research is carried out in order to identify the energy behavior of the electrical demand and to corroborate that the refrigerator is the electric appliance with the most energy consumption inside the homes. By means of real-time measurements it is possible to get first-hand values of electrical parameters at the subscriber level, which has not yet been done in the residential sector of the country. For this reason, an electronic device is developed, which, through firmware programming, delivers RMS voltage, RMS current, power factor and the active power. The equipment records the parameters continuously in periods of one second. This device was developed with relatively low economic resources so it could be disseminated and used massively. The importance of having the electrical parameters in real time begins with the final elimination of consumption speculation based on estimations and paves the way to control the demand from the user side. Through modeling and analysis of the results and the energy consumption curves, energy consumption policies are also proposed within the residential sector, suggesting to change the behavior of the electric energy consumption. In the same way, based on the analysis of the results, it is possible to contribute with technical criteria of energy efficiency for an adequate dimensioning of electrical equipment that conform the distribution system in the residential sector of Cuenca

Use of supercapacitors for providing frequency-support in an island-mode microgrid

Este artículo presenta la implementación práctica de una técnica de control de frecuencia (inercia virtual) en un sistema de almacenamiento energético basado en el uso de supercondensadores (SAE-SC). La propuesta estuvo diseñada para brindar soporte de frecuencia a una microrred eléctrica aislada real que integra fuentes de generación renovable (solar fotovoltaica, 15 kWp), generación síncrona convencional (térmico diésel, 44 kVA) y sistemas de almacenamiento energético (SAE-SC, 30 kW). Tomando como caso base la operación en condiciones normales de una microrred híbrida solar-diésel (una situación típica de sistemas insulares), se comprobó la efectividad de las labores de soporte de frecuencia provisto por el SAE-SC y se evaluó la resiliencia de la microrred en términos de esta variable. Los resultados experimentales mostraron que la implementación de la propuesta permitió reducir las fluctuaciones de frecuencia de la microrred en un 30%, representando una mejora significativa en la calidad del suministro eléctrico. Los experimentos se llevaron a cabo en el Laboratorio de Micro-Red del Centro Científico, Tecnológico y de Investigación Balzay (CCTI-B) de la Universidad de Cuenca.This article presents the practical implementation of a frequency control technique (virtual inertia) in an energy storage system based on supercapacitors (ESS-SC). The design of this proposal provides frequency support to a real isolated microgrid that integrates renewable generation sources (solar photovoltaic, 15 kWp), conventional synchronous generation (diesel thermal, 44 kVA), and energy storage systems (ESS-SC, 30 kW). The base case is a hybrid solar-diesel microgrid (typical situation of insular systems) operating in normal conditions. Frequency support tasks' effectiveness provided by the SAE-SC checks out, and the resilience of the microgrid are evaluated in terms of this variable. The experimental results show that the implementation of the proposal allows reducing the frequency fluctuations of the microgrid by 30%, representing a significant improvement in the quality of the electricity supply. The experiments were carried out in the Microgrid Laboratory of the Centro Científico, Tecnológico y de Investigación Balzay (CCTI-B) of the Universidad de Cuenca