Improving the Accuracy of the Output Voltage of the Converter by Changing the Load Parameters

In the article on the basis of the theory of invariance the increase of accuracy of work of system with the converter for nuclear magnetic logging under condition of change of parameters of loading is considered. Based on the proposed functional scheme of two-channel control, formulas are given to determine the structural relationships and internal influences on the parameters of the control system components to reduce the impact of disturbances that occur both by changing load parameters and by changing the supply voltage. To maintain the required value of the carrier voltage amplitude, it is necessary to increase the reference voltage or decrease the amplitude of the sawtooth voltage, which is equivalent to increasing the gain of the feedback circuit. In this case, if you increase the gain of the feedback circuit, you must ensure that the stability of the system is maintained. The implementation of these proposals gives a more accurate formation of the bypass probing signal. The given functional scheme provides realization of regulation and stabilization of amplitude. The paper considers various options for reducing the effect of power supply perturbation on the output parameters of the converter. By changing the period of operation of the sawtooth voltage generator, which is determined by the frequency of the voltage-controlled generator and depends on the output frequency of the inverter, which varies depending on the parameters and properties of the rock during logging, the accuracy of stabilizing the amplitude of the probe signal increases. In the proposed two-channel control system, the first channel provides regulation and stabilization of the amplitude of the output voltage in accordance with the reference voltage. The second channel provides a change in the frequency of the sawtooth voltage generator by determining the period of the voltage-controlled generator from the phase detector, which determines the deviation of the real frequency from the frequency of the reference generator. The application of the above techniques allows to build circuit implementations of the system with transducers for nuclear magnetic logging, which meet the requirements for the accuracy of the formation of the bypass probing signal.

The experimental results of the geophysical pulse voltage generator

The paper is devoted to the development process of the geophysical pulse voltage generator. The peculiarity of the generator lies in the non-specific purpose of this type of construction. Its main function is the controlled effect on the active faults of seismically dangerous zones. The results of the field experiment with the constructed device from 2018 to 2020 are presented. During the experiments, estimations and theoretical analysis we have obtained the seismic noise recorded by means of molecular electronic instruments and determined the periods of the electrical pulses. Operational parameters of the generator were identified on the basis of experiment results. The software and hardware elements of the system were upgraded and, as a result, a new version of the geophysical pulse voltage generator was developed.

Modeling and Performance Assessment of the Split-Pi Used as a Storage Converter in All the Possible DC Microgrid Scenarios. Part II: Simulation and Experimental Results

Bidirectional DC/DC converters such as the Split-pi can be used to integrate an energy storage system (ESS) into a DC microgrid providing manifold benefits. However, this integration deserves careful design because the ESS converter must behave like a stiff voltage generator, a non-stiff voltage generator, or a current generator depending on the microgrid configuration. Part I of this work presented a comprehensive theoretical analysis of the Split-pi used as an ESS converter in all the possible DC microgrid scenarios. Five typical microgrid scenarios were identified. Each of them required a specific state-space model of the Split-pi and a suitable control scheme. The present paper completes the study validating the theoretical analysis based on simulations and experimental tests. The chosen case study encompassed a 48 V, 750 W storage system interfaced with a 180 V DC microgrid using a Split-pi converter. It can represent a reduced-power prototype of terrestrial and marine microgrids. A prototypal Split-pi converter was realized in the lab, and several experimental tests were performed to assess the performance in each scenario. The results obtained from the experimental tests were coherent with the simulations and validated the study.

Ozone Production with High Voltage in a Mixed Core Mesh Coil

The ozone is a gas composed by three molecules of oxygen which has a great oxidative capacity. This gas can be generated by a nucleus with two electrodes through high voltage in a phenomenon known as corona effect. Actually the conventional nucleus of ozone generators use plane electrodes with a dielectric in the middle of both. A nucleus composed by a mixed ionizador (coil and mesh) is presented as an alternative for an ozone machine in order to take advantage of the individual benefits of each electrode due to its shape and efficiency. A solenoid acts better without dielectric, reducing the consumption, and a mesh improves the air flux. As a result, there is a good production of ozone using this combination of electrodes. However, there are no studies that demonstrate that it is possible to use different types of electrodes in the same ionizador, for this reason in this study will be detected the production of ozone by corona effect in the proposed nucleus and will be approximated its concentration in a closed volume. Keywords: Ozone, corona effect, high voltage, generator, ionization. Resumen El ozono es un gas compuesto por tres moléculas de oxígeno que tiene una gran capacidad oxidativa. Este gas puede ser generado en un núcleo con dos electrodos mediante el uso de altos voltajes en un fenómeno conocido como efecto corona. Actualmente los núcleos de los generadores de ozono convencionales utilizan electrodos planos con un dieléctrico en medio de ellos. Un núcleo compuesto por un ionizador mixto (bobina y malla) se presenta como una alternativa para un ozonificador, con el fin de aprovechar las ventajas individuales de cada electrodo debido a su forma y eficiencia. Un solenoide actúa mejor sin dieléctrico, disminuyendo el consumo, y una malla mejora el flujo de aire. Lo que resulta en una buena producción de ozono utilizando esta combinación de electrodos. Sin embargo, no existen estudios anteriores que demuestran que se puede utilizar diferentes tipos de electrodos en un mismo ionizador, por esta razón en el presente estudio se detectará la producción de ozono por efecto corona en el núcleo mixto propuesto y aproximamos su concentración en un volumen cerrado. Palabras Clave: Ozono, efecto corona, alto voltaje, generador, ionización.

Selective Arcing Electrostatically Eradicates Rice Weevils in Rice Grains

We developed an arc discharge exposer (ADE) that kills rice weevils nesting in dried rice. The ADE features multiple identical metal plates, half of these are linked to a voltage generator and the others are grounded. The plates were arrayed in parallel and an electric field formed between them. Any insect entering the field was arced from the negatively charged plate and killed. The ADE was placed on a vessel containing pest-infested rice grains; the insects were lured out of the grains by mechanically vibrating the vessel. When rice grains move, insects tend to climb upward, thus, the weevils were effectively removed. Our electrostatic apparatus is easy to construct and could be used to control pests in stored rice.