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An analysis of the transient processes of the oscillatory charge of the capacitive energy storage (CES) in the electric discharge installation (EDI) from the direct voltage source (DVS) of the UDVS was carried out under the condition of a non-zero voltage of the CES at the start time of the charge. The dependences of the maximum charging voltage of CES and energy characteristics (dosage of energy consumed from the DVS and one entered to capacitor, energy losses and efficiency) on the magnitude and sign (polarity) of the initial voltage CES and the Q factor of the charge circuit were obtained. It is shown that an increase in the absolute value of the negative initial voltage of the CES together with an increase in the Q factor of the charging circuit leads to an increase in the maximum voltage of the CES charge. The most energetically appropriate capacitor charge modes were determined. It is substantiated that increasing the initial voltage on the capacitor, as well as the Q factor of the charging circuit, leads to an increase in the charge efficiency. Analysis of the ratio between the dose of energy entering the capacitor during one charge cycle W* C and the energy losses W* losses showed that the ratio W* C / W* losses becomes larger with the change of the U0C voltage from –UDVS to + UDVS. References 15, figures 3. [ABSTRACT FROM AUTHOR]

It were analyzed the processes of charging the capacitive electro-technical storage (CES), which can be the electrical insulation of modern high -voltage equipment (in particular power cables) during the current monitoring of its technical condition by the value of leakage currents when applying high voltage to insulation. The transformerless electrotechnical system (ETS) of a resonance type, in which resonant inductive-capacitive circuit (ICС) with a high Q -factor carried out a multiple increase in AC voltage, was used to generate such voltage. Analytical expressions were obtained for the steady-state voltage on such CES and transient currents in the ETS circuit its charging. Simulation modeling of transient processes in the circuits of such ETS during CES charging was performed using the LTSpice software package. It is shown that the dependences of the output voltage and current of the ETS on time, obtained by analytical expressions, practically coincide with the results of simulation simulations. The influence of the ratio of the load capacitance and the resonant circuit capacitance on the relative load charging time and, accordingly, on the ETS power was studied. It was found that in order to increase the power of high -voltage transformerless ETS of the specified resonance type, it is necessary to increase the ratio of the CES capacity to the ICС capacity of the resonant circuit of the ETS. This approach can be used when using ETS with resonant ICCs to create powerful electric discharge installations (EDIs) for the implementation of technologies for obtaining electro-spark micro- and nano powders with unique operational properties. When creating powerful EDIs, it is suggested to use the value of the above-mentioned ratio at least 10. References 31, figures 5. [ABSTRACT FROM AUTHOR]

A new scientific concept has been developed for the creation of high-voltage electro-technical systems (ETS) of a resonant type based on the implementation in them of series high-quality inductive-capacitive circuits (ICC) and highfrequency (HF) resonant currents. This makes it possible to repeatedly increase the alternating voltage on the reactive elements of the ICC and on the load connected in parallel to one of the elements, and to ensure a significant decrease in the impulse energy of the ETS without changing their average power, as well as to increase the speed of control and parametric stabilization of the load modes of the ETS even with a rapid decrease in the electrical resistance of this load to almost zero, as in the case of electrical breakdown of its insulation. The generation of resonant currents with a frequency of up to 40 kHz in the ICC, which has a coil with an inductance of ~ 25 mH and a Q factor up to 270 (made of multi-core twisted copper wires of the " litzendraht " type) and a ceramic capacitor with a capacity of ~ 3.5 nF and a Q factor > 1000, ensures the realization of the QICC up to 260 and the corresponding increase in the ratio of the ETS output voltage to the input voltage without the use of step-up transformers. When connecting such an ETS to a source of alternating voltage of 220 V, a voltage of up to 40 kV can be generated at the output of the ETS. A significant increase in the frequency of currents leads to a significant decrease in the mass-dimensional characteristics of ETS and the possibility of creating their samples mobile (weighing up to 5 kg), and if necessary, autonomous, in particular with power supply from batteries. The new scientific concept is aimed at creating a resonance-type ETS for safe and reliable monitoring and diagnostics of the technical condition of high-voltage insulation of power cables, powerful electric machines and other energy objects of the critical infrastructure of Ukraine. Such ETS can also be effectively used for charging to high voltages capacitive energy storage (CES) in technological installations for the production of electro-spark microand nano-powders with unique properties, as well as for high-voltage electro-hydro-pulse processing of various materials and environments. It has been established that the power of these ETS increases with a decrease in the ratio of the capacitances of the capacitors ICC and CES. References 40, figures 4. [ABSTRACT FROM AUTHOR]

The paper analyzes the performance characteristics of the electrоtechnical system (ETS), built on the basis of a series high-Q resonant LC circuit and intended for diagnosing the isolation of high-voltage equipment. The frequency dependences of the parameters L and C elements of the resonant circuit were experimentally studied and it was shown that for both elements there is an optimal frequency at which the value of the element’s Q- factor reaches its maximum value. It was established that the Q-factor of the investigated circuit is determined mainly by the Q-factor of its inductance and reaches the maximum value QLC,max = 280 at the frequency f= 40 kHz. The Simulink model was developed for the analysis of the performance characteristics of the ETS in steady state. Graphical dependences are given, which allow to determine the level of voltage on the load for a given active resistance of this load, as well as the energy characteristics and the value of the efficiency of the ETS at the stage of its design. A Simulink model has also been developed to analyze the dynamic characteristics of the ETS when a breakdown of the diagnosed insulation occurs. It is shown that the breakdown of the insulation in the ETS, which has a series high-Q resonant circuit, will cause a rapid decrease in current by Q times, and not an increase in current to emergency values, as in an ETS based on high-voltage transformers. In this way, a fast-acting parametric stabilization of the output current is implemented in the ETS even in case of electrical breakdowns of the high-voltage insulation of the power equipment under diagnosis. Thus, the ETS implements high-speed parametric stabilization of the output current, which prevents the destruction of both the ETS and the diagnosed high-voltage insulation of power equipment even during its electrical breakdown. References 11, figures 9. [ABSTRACT FROM AUTHOR]

A method is proposed for stabilizing the transient discharge processes of capacitive energy storages (CESs) of electric discharge installations (EDIs) to a load whose electrical resistance can vary non-linearly and stochastically. The method is based on the use of one direct voltage generator (DVG) in the EDI, which carries out alternately an oscillatory charge of two CESs to the required voltage, as well as on the introduction of semiconductor switches into the charge circuit and discharge one of these CESs and the developed algorithms for switching them on, according to which bipolar discharge currents are formed alternately in the EDI load, regardless of the nature of the change in its electrical resistance. The frequency and duration of positive and negative discharge-pulse currents in the load can be the same or different, depending on the selected parameters of the elements of discharge circuits of the two CESs. The use of the developed method provides the formation of unipolar modes in the capacitors of each CES, which allows you to choose them for lower voltages, increase their life and reduce cost. In addition, with the same capacitance of the CESs, the total electric charge flowing in the load is practically zero after each even number of discharges. This significantly reduces the effect of electrochemical processes in the load, in particular the electrochemical destruction of the anode of the technological apparatus of the EDI, which inevitably occurs during the formation of unipolar pulse currents. The use of bipolar discharge currents in the EDI load also increases the stability of the discharge modes in the EDI due to the limitation of the duration of possible long aperiodic currents during the discharge of one of the CESs by the beginning of the counter current of the next discharge of the other CES. References 10, figures 3, table 1. [ABSTRACT FROM AUTHOR]

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Copyright of Technical Electrodynamics / Tekhnichna Elektrodynamika is the property of National Academy of Sciences of Ukraine, Institute of Electrodynamics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)