Simulation studies on the boot shape injection of a giant magnetostrictive injector

Giant magnetostrictive injector using giant magnetostrictive material acting an electronic controlled injector may be one new promising injector to acquire adjustable injection rates while maintaining large injection quantity. An electronic controlled injector driven by a giant magnetostrictive actuator was designed through combining the driving requirement and output characteristics of the material. To promote responding speed of the coil current, the driving voltage with open-hold-fall type waveform was employed just like using in an electromagnetic injector. Simulation model for the injection characteristic of the injector was established using AMEsim software and verified using experimental results collected by the single injection meter. From simulation and experimental results, designed giant magnetostrictive injector showed good performances as maximum spray rate of 4.5 L/min and minimum spray pulse width of 0.21 ms, and realized the boot shape injection when generated by the designed voltage wave. Furthermore, duration time and amplitude of the pilot spray part in a boot shape injection were respectively adjusted through changing the dwell time and opening time. The boot shape injection reached by the giant magnetostrictive injector can reach quite accurate control of fuel injection and then promote fuel efficiency effectively.

Modeling of Memristors under Periodic Signals of Different Parameters

In this paper, the problem of modeling memristors is studied. Two types of memristors with carbon and tungsten doping fabricated by the Knowm Inc. are tested. The memristors have been examined with either sinusoidal or triangle voltage wave periodic excitation. Some different frequencies, amplitudes and signal shapes have been applied. The collected data have been averaged and subjected to high frequency filtering. The quality of measurement data has also been discussed. The averaged measurement has been modeled using three popular memristor models: Strukov, Biolek and VTEAM. Some additional feathers to the considered models have been proposed and tested. Memristor is usually modeled by a set of algebraic-differential equations which link both electrical values (i.e., voltage and current) and the internal variable(s) responsible for the element dynamics. The interior-point with box constrains optimization method has been used to obtain the optimal parameters of the memristor model that fit best to the collected data. The results of the optimization process have been discussed and compared. The sensitivity to the different frequency range has been also examined and reviewed. Some conclusions and future work ideas have been postulated.

Investigation of overvoltage in electrical networks.

The paper considers the processes that occur in power lines and power transformers at atmospheric and switching overvoltages. Atmospheric overvoltages are divided into two types: direct, which occur due to a direct lightning strike; and induction - occur at any switching. Direct overvoltages reach values sufficient to cover the insulation of any voltage class. Protection of power transmission lines from them - suspension of grounded lightning protection cables, protection of substation equipment - installation of lightning rods. It is important to study the wave processes in power lines that occur when switching, which occurs when the power supply is turned on, when disconnected from the power supply, in the event of short circuits, when power lines are struck by lightning. In addition, it is important to study the wave processes in power transformers, the effect of the pulse corona, the effect of overvoltage on the transformer windings. In a more detailed analysis of the processes, the following conclusions were made: 1) under the condition of the same mains voltage, the voltage wave will be higher in the cable transmission line than in the air, due to the difference in impedance. 2) in the XX mode, the load current will drop to zero, and the load voltage will double. The voltage of the reflected wave will keep the sign. In short-circuit mode, the load voltage will drop to zero and the load current will double. The voltage of the reflected wave will change the sign. Thus, when the substation equipment is under a voltage close to XX, there is a probability of equipment damage during atmospheric overvoltages. 3) For substations that are powered by overhead power lines, it is advisable to use a tank to smooth the slope of the refracted wave, and for substations that are powered by cable transmission lines, it is advisable to use inductance to smooth the slope of the refracted wave. 4) Inductance and capacitance can have a significant effect on the amplitude of the voltage wave, provided that. 5) Capacitance performs protective functions in all directions, both refracted and reflected wave, and inductance only smooths the refracted wave. The obtained relations can be used to study the overvoltage in the connection nodes of node substations.

Response Times of Metal-Oxide Chemiresistors: Comparison Between the Isothermal and Temperature Modulation Modes

The response time is one of the main functional parameter for gas sensors, including metal oxide chemiresistors. This parameter is widely investigated for devices working in isothermal mode but it is much less investigated for gas sensors working in temperature modulation mode. In this work, considering ethanol as target gas, we compare the response times of a metal oxide chemiresistor working according to these two modes. In order to compare them, we worked with nearly the same average temperature in both cases, supplying a constant voltage to the heater in the isothermal mode and a squared voltage wave in temperature modulation. Our results show that, depending on the average working temperature, one mode or the other may be faster. At high average working temperature, the response time recorded with the isothermal mode is shorter than the thermal-period of the temperature modulation mode. Lowering the average working temperature, the response time increases for both modes, but the increase is more marked for the isothermal mode, which become slower than the temperature modulation one.

Kinetic Generator from Footstep Using Piezoelectric

Nowadays, the development of renewable energy resource technology is increase. There is a lot of research being done to find solutions to increasing energy needs while the energy resources are getting more and more of a concern. There are several types of energy plants with renewable power such as micro hydro, photo voltage, wave energy, footstep, and others. Foot step is a renewable energy resource that has only recently been glimpsed by the world. Therefore, the footstep will be applied on board the passenger ship. It is hoped that the use of this renewable energy source can replace the source of fuel energy to drive ship engines. In this researdh, piezoelectric was used as a energy resources. Piezoelectric will be placed on tiles, when the piezo is stepped on, there will be a voltage came out from piezo. Voltage from piezo will be colect and stored. Each piezoelectric produces a voltage that varies from 0.7 volts to 3.7 volts. If on an average, one piezoelectric can produce 2 volts. The size of the voltage issued by the piezo depends on the size of the pressure on the piezo.

Multi-level inverter for driving PV water pumps

In this research, we have developed a system for driving PV water pumps based on multi-level inverters, where cascaded H-Bridge-MLI was studied to improve conversion efficiency, by testing three different strategies to generate pulses for electronic elements and determining the best strategy between them, then compare it with the traditional 2-LEVEL inverter circuit. The results showed the superiority of Phase Disposition (PD-PWM) strategy, where the THD Ratio of the voltage and current wave was minimal compared to the other strategies at different carrier wave frequencies in addition to studying the effect of the number of voltage levels on THD Ratio, and when we simulated a three phase (Cascaded H-Bridge 7 level) inverter circuit based on PD-PWM strategy at 3000 Hz carrier wave frequency, the THD Ratio of voltage wave has not exceed 11%, While in the traditional 2-LEVEL inverter, the THD Ratio of voltage wave is about 66%, which shows the importance of MLI to improve conversion efficiency. The proposed driving system operates according to the v / f control system to control the pump speed in proportion to the intensity of the solar radiation while maintaining a constant torque, and also works to track the maximum power point MPPT according to P&O algorithm, and when we simulated the system by MATLAB / SIMULINK the results showed the effectiveness and reliability of the proposed system

SYNCHRONOUS MOTOR WITH INCREASED ROTOR SPEED

Development of the design of a synchronous electric motor with six C-shaped stator teeth, the rotor axis of rotation of which is displaced relative to the axis of rotation of the output shaft. The rotational speed of the output shaft is equal to twice the rotational speed of the stator magnetic flux. Determination of the phase shifts of the supply voltages in time and the spatial position of the stator windings. Visualization of the principle of operation of the electric motor under consideration, namely, step-by-step observation of the position of the rotor in space, when the sinusoidal voltage wave changes by an angle equal to π, with a step of π/6. Mathematical description of the engine under consideration, with all the structural features of the stator-rotor magnetic circuit. In the course of the work, analytical calculation methods were applied. As a result of the study, the basic laws of operation were determined, as well as the design and principle of operation of the considered electric motor with a suspended rotation speed.

Design the encoder inspection system based on the voltage wave form using finite impulse response (FIR) filter

Encoder is the measurement device that plays an important role in the electronic industry. In the process of manufacturing, the current mechanical testing methods are not of very high accuracy or are having problems in data processing algorithms. In this paper, the author represents a method for the testing mechanical work of an encoder product by measuring the torque induced by rotating the encoder. The advantages of this method are the high accuracy, stability and low cost. The accuracy of this method can go upto 95–98%. The measurement system uses LabView software as the data processing application and NI instruments as the data acquisition tools.