An adjustable HVDC power supply using integrated high voltage transformer with some protective & controlling features

We can produce variable/adjustable HVDC with a little arrangement using Fly back Transformer (IHVT), Tesla coil, car ignition coil & other type of step-up auto transformer found in microwave oven, X-ray units & in similar devices. This arrangement of circuitry is very reliable & light weight. In our experiment we made a power supply using Integrated High Voltage Transformer & try to give it several protective & controlling features to its driver circuitry to increase the longevity of the power supply. As far as the general run of small-scale electronics is concerned, EHT (extra high tension)/HVDC power supplies are used mainly for cathode ray tube (CRT) anodes and for some specialized purposes such as Geiger-Muller counters and photomultipliers. None of these applications calls for a large current drain. As an example, X-ray equipment may require 100 kVDC at a current of less than 1 A. Some of these EHT supplies such as those used for radio transmitters or particle accelerators demand very substantial currents. As an example, large radio transmitters may call for a 20 kVDC supply at several amperes of current

Energy Saving Analysis and Simulation for Home Electricity

This paper presents the energy saving method by applying the voltage control technique on a single-phase AC source to a thyristor rectifier and an IGBT inverter with LC filter. Based on the LC filter parameter, the values of the gain for the controller are obtainable. The proposed controller structure consists of two loops arranged in a cascaded model. The output of the first loop is the capacitor current. This current is added to the load current in order to obtain the current reference. This reference current value will be compared with the inverter current which produces the error signal to be fed into the second loop in the cascade system. The output of the second loop is the inverter voltage. This voltage is added to the load voltage to produce the voltage reference. This reference is fed to the pulse width modulation generator via the controller and compared with the triangular wave. This energy-saving circuit is designed in blocks using MATLAB Simulink

New approach on development a dual axis solar tracking prototype

To track the sun in two directions that is elevation and azimuth, a dual-axis tracking prototype is developed to capture the maximum sun rays by tracking the movement of the sun in four different directions. One axis is azimuth which allows the solar panel to move left and right. The other axis is elevation and allows the panel to turn up and down. The result of this new development provides the solar panels with extensive freedom of movement. This new approach will make use of the Light Depending Resistor (LDR) which is important to detect the sun light by following the source of the sun light location. AutoCAD software is being used to design the draft in 2-dimension (2D) for the hardware dual axis solar tacker. Sketch Up software is being used to sketch the drawing to be more real in 3-dimension (3D). Proteus software is being used to design the circuit for the Arduino UNO microcontrollers and H-BridgeIC chip. This implemented system can save more energy and probably offers more reduction in cost. The paper discusses the process of hardware development and the control process of tracking the sun, as well as the circuit design

Installation of high resistance grounding system on the ungrounded system at offshore platform

Single line to earth fault usually can be seen in the ungrounded system. The ungrounded system is used widely in offshore platforms due to its advantages over the overvoltage whenever a fault occurs in the power systems. Continuous production with less interruption is vital in the oil and gas industry to achieve the production rate target. The grounding system has evolved for the past years and improvements have been made to the ungrounded system that has been around the years in the industry. The ungrounded system has been the best grounding system when the power system needs to maintain its operation with the presence of tolerable fault such as the single line to earth fault. Some facilities have included the feature of tripping the main circuit breaker whenever there is ground fault on the non-critical equipment. This has been unproductive to the operation and time consuming in restarting the plant facility after power failure or shutdown. Kikeh offshore platform is having the same situation whenever the ground fault occurs the main circuit breaker tripped and affects the operation badly. The High Resistance Grounding (HRG) design has proved to be able to sustain the fault and at the same time allows the plant to continue operating without any unnecessary shutdown. This improves the downtime and increases productivity. Furthermore, arc hazards to personnel and the classification flammable gas area can be minimized

Workload prediction of wireless sensor network based on linear prediction

Wireless Sensor Network has been widely used in remote monitoring application. However, energy efficiency of sensor nodes is an important issue, as they are powered by batteries. And most of the cases, sensor nodes are inaccessible once they have been deployed. So a good energy saving scheme of sensor nodes will provide long operational life (2-3 years). In this paper, Dynamic Voltage Scaling (DVS) is proposed to reduce the CPU energy by adjusting the voltage level based on its workload prediction. The workload prediction is based on Linear Prediction model

A fuzzy cost function optimization in product mix selection problem

Dimirovski, Georgi M. (Dogus Author) -- Conference full title: 2006 World Automation Congress, WAC'06; Budapest; Hungary; 24 June 2006 through 26 June 2006The modern trend in industrial application problem deserves modeling of all relevant vague or fuzzy information involved in a real decision making problem. In this paper the usefulness of the proposed S-curve membership function is established using a real life industrial production planning of a chocolate manufacturing unit. The unit produces 8 products using 8 raw materials, mixed in various proportions by 9 different processes under 29 constraints. A solution to this problem establishes the usefulness of the suggested membership function for decision making in industrial production planning. The objective of this paper is to find the optimal cost to produce 8 products using modified S-curve membership function as a methodology. The fuzzy linear programming approach is used to solve this problem. The optimal cost function is obtained respect to two major factors of degree of satisfaction and vagueness