This project proposal describes the involvement of a wireless pager. It describes the possibility of realization, block diagrams of the receiver and transmitter controlprogram for their individual and flowcharts. In the theoretical design are taken intoaccount the ease of use, durability and endurance of the battery function. Was chosenfor the realization of a suitable wireless module, with a sufficient range. The goal is todesign a suitable wireless pager with sufficient range, durability and reasonable price that could be used within a department or a house to call for help.

The subject of this thesis is the proposal of constructional solution for pallet changer of the vertical machining center. This pallet changer serves for the manipulation with technological pallets between dilatory places of the machining center and charger of pallets. Thanks to this changer the machines share one workpieces´ base. Main accent is not put only on the function but also on the low price of this solution.

The thesis is focus on design solutions of automatic tool changer for CNC vertical milling machine SLV 300 in cooperation with the design company IMC/Engineering s. r. o. The main goal of theses is the creation of several design variants based on the critical research of similar machinery and the subsequent choice of the most appropriate solution. The assessment of the various options is done with amount of the changes caused on the existing design of the machine. It is essential the suitability of the solution from the perspective of the customer's company SolidVision s. r. o. Design solution is being designed for the possibility of a presentation device with unique features in its class, which is meant to be a simple maintenance free design with the possibility of easy service access For the chosen solution of the automatic tool changer are by calculation verified by the most exposed part of the device. In the thesis is also design documentation, for a better understand of the design solution.

Thesis (MEng (Electrical Engineering)--Cape Peninsula University of Technology, 2019 / The purpose of an electrical power system is to supply electrical energy to the customers. Power transformers are required to transform the system voltage from generation to transmission and distribution levels. Protection and control systems must ensure that power system high voltage equipment such as transformers operate and deliver save, reliable and secure electricity supply. The aim of the project research work is to develop and implement a strategy, methods and algorithms for monitoring, protection and voltage control of parallel power transformers based on IEC 61850-9-2 process bus standard. NamPower is a power utility in Namibia. The IEC 61850 protocol for electrical substation automation system is used for the protection and control of 5 power transformers operated in parallel in an existing substation system. The IEC 61850-9-2 process bus standard is however not used in regards of Sampled Values (SV). Protection and control devices are connected to a substation communication network, routers and switches using fibre optic linked Ethernet. Inductive Current Transformers (CTs) and Voltage Transformers (VTs) secondary circuits are hardwired to Intelligent Electronic Devices (IEDs) and fibre optic links are not used for this purpose at process level communication. The research focuses on the implementation of the IEC 61850 standard with Merging Units (MUs) and sampled values to improve the existing implemented protection and control system at NamPower. This includes substation communication networks and MUs used for transformer protection, voltage regulator control and cooling fan control. At the present the CTs located at the transformer bushings and switchgear and the VTs located at the switchgear are hardwired to the inputs on protection and control IEDs. The research focuses on issues with the copper wires for voltage and currents signals and how these issues can be eliminated by using the MUs and the SV protocol. The MUs which are considered in this Thesis is to improve the voltage regulator control and the control of the cooling fan motors. The voltage regulator control IED is situated at the tap change motor drive of the On-Load Tap Changer (OLTC). The IED of each transformer is required to regulate the voltage level of the secondary side bus bar it is connected to. All the regulating IEDs are required to communicate with each other and collectively to control the bus bar voltage depending on the switching configuration of the parallel transformers. The control circuit for controlling the cooling fan motors is hardwired. Temperature analogue signal input into a programmable automation controller IED can be used for controlling the transformer cooling fans. A strategy, methods and algorithms for transformer protection, voltage regulator control and cooling fan motor control of parallel power transformers need to be developed and implemented based on IEC 61850-9-2 process bus. Power utilities and distributors can benefit from interpretation of the IEC 61850-9-2 standard and implementing MUs and SV in substations. MUs can be included in the power transformer protection, automation and control systems. A cost reduction in high voltage equipment, substation installation and commissioning costs and better performance of protection and control system are anticipated.

This thesis focuses on a control system for theater scenes. The system is based on technology of industrial computers and can handle theatre scene equipment, such as slot. The asynchronous AC engines and computer controlled frequency changers are used along with various sensors. The control is done via CANopen protocol and the software was written using Control Web.

Este projeto de pesquisa propõe desenvolver um novo modelo e uma nova abordagem para a resolução do problema da otimização Volt/VAr em redes de distribuição de energia elétrica. A otimização Volt/VAr consiste em, basicamente, determinar os ajustes das variáveis de controle tais como bancos de capacitores chaveados, transformadores com comutação de tap sob carga e reguladores de tensão, de modo a satisfazer, simultaneamente, as restrições de carga e de operação para um dado objetivo operacional. Esse problema, matematicamente, foi formulado como um problema de programação não linear, multiperíodo, e com variáveis contínuas e discretas. Algoritmos de programação não linear foram utilizados com o intuito de aproveitar as vantagens das matrizes altamente esparsas montadas ao longo do método de solução. Para utilizar tais algoritmos, as variáveis discretas são tratadas como contínuas por meio da utilização de funções senoidais que penalizam a função objetivo do problema original enquanto estas não convergirem para algum dos pontos pré-definidos no seu domínio. O caráter multiperíodo do problema, contudo, refere-se à consideração de uma restrição que relaciona os ajustes das variáveis de controle para sucessivos intervalos de tempo na medida em que limita o número de operações de chaveamento desses dispositivos para um período de 24-horas. O estudo fundamenta-se, metodologicamente, em métodos do tipo Primal-Dual Barreira-Logarítmica. Para demonstrar a eficiência do modelo proposto e a robustez dessa abordagem, a partir de dados teóricos obtidos de levantamentos bibliográficos, testes foram realizados em sistemas-teste de 10, 69 e 135 barras, e em um sistema de 442 barras do noroeste do Reino Unido. As implementações computacionais foram feitas nos softwares MATLAB, AIMMS e GAMS, utilizando o solver IPOPT como método de solução. Os resultados mostram que a abordagem proposta para a resolução do problema de programação não linear é eficaz para tratar adequadamente todas as variáveis presentes em problemas de otimização Volt/VAr. / This work proposes a new model and a new approach for solving the Volt / VAr optimization problem in distribution systems. The Volt/VAr optimization consists, basically, to determine the settings of the control variables of switched capacitor banks, on-load tap changer transformers and voltage regulators, in order to satisfy both the load and operational constraints, to a given operational objective. The problem is formulated as a nonlinear programming problem, multiperiod, and with continuous and discrete variables. Nonlinear programming algorithms were used in order to take advantage of the highly sparse matrices built along the solution method. The discrete variables are treated as continuous along the solution method by means of the use of sinusoidal functions that penalize the original objective function while the control variables do not converge to any of the predefined discrete points in its domain. The multiperiod, or dynamic, characteristic of the problem, however, refers to the use of a constraint that relates the settings of the control variables for successive time intervals that limits the control devices switching operations number for a period of 24-hours. The study is based, methodologically, on Primal-Dual Logarithmic Barrier method. To demonstrate the effectiveness of the proposed model and the robustness of this approach, the data were obtained from theoretical literature surveys, and tests were performed on test-systems of 10, 69 and 135 buses, and in a 442 buses located in the Northwest of the United Kingdom. The computational implementation was accomplished in the softwares MATLAB, AIMMS and GAMS, using the IPOPT solver as solution method. The results have shown the approach for solving nonlinear programming problems is effective to appropriate cope with all the variables presented in Volt/VAr optimization problems.

Este projeto de pesquisa propõe desenvolver um novo modelo e uma nova abordagem para a resolução do problema da otimização Volt/VAr em redes de distribuição de energia elétrica. A otimização Volt/VAr consiste em, basicamente, determinar os ajustes das variáveis de controle tais como bancos de capacitores chaveados, transformadores com comutação de tap sob carga e reguladores de tensão, de modo a satisfazer, simultaneamente, as restrições de carga e de operação para um dado objetivo operacional. Esse problema, matematicamente, foi formulado como um problema de programação não linear, multiperíodo, e com variáveis contínuas e discretas. Algoritmos de programação não linear foram utilizados com o intuito de aproveitar as vantagens das matrizes altamente esparsas montadas ao longo do método de solução. Para utilizar tais algoritmos, as variáveis discretas são tratadas como contínuas por meio da utilização de funções senoidais que penalizam a função objetivo do problema original enquanto estas não convergirem para algum dos pontos pré-definidos no seu domínio. O caráter multiperíodo do problema, contudo, refere-se à consideração de uma restrição que relaciona os ajustes das variáveis de controle para sucessivos intervalos de tempo na medida em que limita o número de operações de chaveamento desses dispositivos para um período de 24-horas. O estudo fundamenta-se, metodologicamente, em métodos do tipo Primal-Dual Barreira-Logarítmica. Para demonstrar a eficiência do modelo proposto e a robustez dessa abordagem, a partir de dados teóricos obtidos de levantamentos bibliográficos, testes foram realizados em sistemas-teste de 10, 69 e 135 barras, e em um sistema de 442 barras do noroeste do Reino Unido. As implementações computacionais foram feitas nos softwares MATLAB, AIMMS e GAMS, utilizando o solver IPOPT como método de solução. Os resultados mostram que a abordagem proposta para a resolução do problema de programação não linear é eficaz para tratar adequadamente todas as variáveis presentes em problemas de otimização Volt/VAr. / This work proposes a new model and a new approach for solving the Volt / VAr optimization problem in distribution systems. The Volt/VAr optimization consists, basically, to determine the settings of the control variables of switched capacitor banks, on-load tap changer transformers and voltage regulators, in order to satisfy both the load and operational constraints, to a given operational objective. The problem is formulated as a nonlinear programming problem, multiperiod, and with continuous and discrete variables. Nonlinear programming algorithms were used in order to take advantage of the highly sparse matrices built along the solution method. The discrete variables are treated as continuous along the solution method by means of the use of sinusoidal functions that penalize the original objective function while the control variables do not converge to any of the predefined discrete points in its domain. The multiperiod, or dynamic, characteristic of the problem, however, refers to the use of a constraint that relates the settings of the control variables for successive time intervals that limits the control devices switching operations number for a period of 24-hours. The study is based, methodologically, on Primal-Dual Logarithmic Barrier method. To demonstrate the effectiveness of the proposed model and the robustness of this approach, the data were obtained from theoretical literature surveys, and tests were performed on test-systems of 10, 69 and 135 buses, and in a 442 buses located in the Northwest of the United Kingdom. The computational implementation was accomplished in the softwares MATLAB, AIMMS and GAMS, using the IPOPT solver as solution method. The results have shown the approach for solving nonlinear programming problems is effective to appropriate cope with all the variables presented in Volt/VAr optimization problems.

The purpose of this thesis is to develop a model to enhance the effectiveness of machining centers with multi-pallet automatic pallet changers (APCs). From critical literature review no existing theories within this field were found. The multi-pallet APC allows multi-setups and a more flexible sequencing of jobs. The model together with the developed heuristic scheduling algorithm with the objective to minimize the total weighted tardiness can be used to plan in n jobs on m pallets in a shop-floor. The right maintenance policy ensures a high availability, which together with the program guarantees a high level of utilization of the machinery. Consequently the effectiveness will be enhanced. A case study approach was used to test the model at Växjöfabriken in Sweden, which treats cast material. The results of this case study are a more effective utilization of the machines with decreased tardiness costs, increased customers’ satisfaction and goodwill of the company. The contribution of this thesis is a model with a flexible, adjustable and expandable heuristic scheduling algorithm, which can be applied in all manufacturing companies using machining centers with multi-pallet APCs. / Syftet med denna uppsats är att utveckla en modell för att förbättra effektiviteten av maskincentra med automatiska palletväxlare (APCs) för multi-palleter. När en kritisk litteratursökning genomfördes hittades inga relevanta teorier inom det aktuella området. Multi-pallet APC tillåter att många jobb kan förberedas samtidigt och gör planeringen av jobben mer flexibel. Modellen, tillsammans med den utvecklade heuristiska planeringsalgoritmen med målet att minimera den totala viktade förseningen, kan användas för att planera in n jobb med m palleter på ett verkstadsgolv. Rätt underhålls policy försäkrar en hög tillgänglighet vilket tillsammans med programmet garanterar en hög utnyttjandenivå av maskinerna. Som följd kommer effektiviteten att höjas. En fallstudie utfördes på Växjöfabriken i Sverige för att utvärdera modellen, på företaget efterbehandlas gjutgods. Resultatet från denna fallstudie blev ett effektivare utnyttjande av maskinerna, med minskade förseningskostnader, ökad kundtillfredställelse och goodwill för företaget. Denna uppsats bidrar med en modell och en flexibel, anpassningsbar och utvecklingsbar heuristisk planeringsalgoritm, vilken kan användas i alla industriföretag som använder maskincentra med multi-pallet APCs.

<p>The purpose of this thesis is to develop a model to enhance the effectiveness of machining centers with multi-pallet automatic pallet changers (APCs). From critical literature review no existing theories within this field were found. The multi-pallet APC allows multi-setups and a more flexible sequencing of jobs. The model together with the developed heuristic scheduling algorithm with the objective to minimize the total weighted tardiness can be used to plan in n jobs on m pallets in a shop-floor. The right maintenance policy ensures a high availability, which together with the program guarantees a high level of utilization of the machinery. Consequently the effectiveness will be enhanced. A case study approach was used to test the model at Växjöfabriken in Sweden, which treats cast material. The results of this case study are a more effective utilization of the machines with decreased tardiness costs, increased customers’ satisfaction and goodwill of the company. The contribution of this thesis is a model with a flexible, adjustable and expandable heuristic scheduling algorithm, which can be applied in all manufacturing companies using machining centers with multi-pallet APCs.</p> / <p>Syftet med denna uppsats är att utveckla en modell för att förbättra effektiviteten av maskincentra med automatiska palletväxlare (APCs) för multi-palleter. När en kritisk litteratursökning genomfördes hittades inga relevanta teorier inom det aktuella området. Multi-pallet APC tillåter att många jobb kan förberedas samtidigt och gör planeringen av jobben mer flexibel. Modellen, tillsammans med den utvecklade heuristiska planeringsalgoritmen med målet att minimera den totala viktade förseningen, kan användas för att planera in n jobb med m palleter på ett verkstadsgolv. Rätt underhålls policy försäkrar en hög tillgänglighet vilket tillsammans med programmet garanterar en hög utnyttjandenivå av maskinerna. Som följd kommer effektiviteten att höjas. En fallstudie utfördes på Växjöfabriken i Sverige för att utvärdera modellen, på företaget efterbehandlas gjutgods. Resultatet från denna fallstudie blev ett effektivare utnyttjande av maskinerna, med minskade förseningskostnader, ökad kundtillfredställelse och goodwill för företaget. Denna uppsats bidrar med en modell och en flexibel, anpassningsbar och utvecklingsbar heuristisk planeringsalgoritm, vilken kan användas i alla industriföretag som använder maskincentra med multi-pallet APCs.</p>

Voltage imbalance in low voltage (LV) networks is expected to deteriorate as low carbon technologies, e.g. electric vehicles (EVs) and heat pumps (HPs) are increasingly deployed. The new electrical demand attributable to EVs and HPs would increase the voltage magnitude variation, increasing the possibility of voltages moving outside the statutory LV magnitude limits. Moreover, the single-phase nature of EVs and HPs, which will be connected via a single-phase 'line &amp; neutral' cable to a 3-phase four-wire LV mains cable buried beneath the street, further entangles this voltage management problem; the non-balanced voltage variations in the three phases boost the levels of voltage imbalance. Excessive voltage imbalance and magnitude variation need to be mitigated to limit their adverse effects on the electric network and connected plant. The voltage imbalance in LV networks is conventionally reduced by reinforcing the network, generally at a high cost. Some modern methods for voltage imbalance mitigation have been introduced in recent years. The power electronic converter based methods are inadequate due to the generation of harmonics, significant power losses and short lifetime. Besides, automatic supply phase selection and smart EV charging rely on an advanced smart communication system, which currently is not available. This project aims to develop alternative solutions that mitigate the voltage imbalance seen in LV networks. A voltage balancing method based on Scott transformer (ST) is proposed. This method does not generate harmonics and is independent of the smart communication system. Computer simulations demonstrated the proposed method is able to convert a non-balanced 3-phase voltage into a balanced 3-phase voltage at either a point on the LV feeder or a 3-phase load supply point with the predefined voltage magnitude. Besides, a physical voltage balancing system was created based on the proposed method and it was tested in an LV network in the laboratory. The test results show the balancing system is capable of maintaining a low level of voltage imbalance on the LV feeder by rapidly compensating for the voltage rises and sags caused by single-phase load variations. This voltage balancing method is a potential solution for the network utilities to accommodate the significant penetration of low carbon technologies without breaching the network voltage limits. The impact of EVs and HPs on the LV network voltages is investigated based on a Monte Carlo (MC) simulation platform, which comprises a statistical model of EV charging demand, profiles generators of residential and HP electrical demand, and a distribution network model. The MC simulation indicates the impact of EVs and HPs is related to their distribution; when more than 21EVs and 13HPs are non-evenly distributed on a 96-customer LV feeder, the voltage limits are likely to be violated. Moreover, the effectiveness of the ST based voltage balancing method and the demand response based TOU tariff, implemented either alone or together, in mitigating the impact of EVs and HPs is investigated based on the established MC simulation platform. The results indicate the ST based balancing method alone is able to completely mitigate the voltage limit violations regardless of the penetration levels of EVs and HPs. Moreover, using both of the two investigated methods further enhances the balancing effectiveness of the ST based voltage balancing method.