TECHNICAL AND ECONOMIC ASPECTS OF DECARBONISATION PROSPECTS ASSESSING OF THE INTERCONNECTED POWER SYSTEM OF UKRAINE

Shot analysis of power systems decarbonisation problem to ensure a net-zero greenhouse gas emissions is given. The mathematical model of the power system capacity balancing, generating capacities of which are renewables and nuclear power plants (NPP) is proposed. For capacity balancing storage power plants (SPP) with specified efficiency indicators are used. By using the indicators of the operational conditions of the IPS of Ukraine in 2019 and mathematical modeling for various options of the NPP installed capacity in the decarbonised IPS of Ukraine, the needs in the renewables installed capacity and in the capacity and energy of various types of the SPP were estimated. References 10, figures 4, tables 2.

COMPARATIVE ANALYSIS OF MAGNETIC SYSTEMS OF PERMANENT MAGNET MOTORS FOR TRAM

A numerical study of eight configurations of magnetic systems of electric motors with permanent magnets for driving a tram was carried out. The permanent magnet electric motor can be used as a high-speed electric drive to replace the existing DC electric drive of a tram, and as a low-speed gearless electric drive of a new generation tram. The most promising configurations of magnetic systems of electric motors with permanent magnets for tram drive have been determined. By varying the geometrical and winding parameters of each of the investigated models of electric motors, the mechanical characteristics are determined, at which the given torque and power are achieved in the entire range of the rotor speed. Also, a thermal calculation was performed taking into account the urban driving cycle of high-speed electric motors with air cooling by a fan and low-speed ones in liquid cooling mode. The calculation of the characteristics of the investigated electric motors was carried out in the Simcentre MotorSolve software package. References 13, figures 8, tables 3.

EXPERIMENTAL STUDY OF A TEST SAMPLE OF A WIRELESS POWER TRANSFER FOR ELECTRIC VEHICLES

A prototype of a wireless charger of inductive type with serial resonance in the circuits of the transmitting and receiving coils has been developed and manufactured, and experimental studies of the efficiency of power transmission from an external source to a storage battery have been carried out. It is shown that the efficiency of the created sample takes values in the range 39% - 78 % and depends on the operating frequency and the distance between the coils. It is also shown that when using coils with an outer diameter of 500 mm, the positioning of these coils in the process of charging the battery at a distance of up to 10 cm does not lead to a significant decrease in efficiency. The experimental values of the efficiency are compared with the calculated ones obtained on a simplified model that takes into account only resistive losses in the coils, and it is shown that the experimental values of the efficiency are 15-20 % less than the calculated ones. References. 8, figures. 5, table 1.

ENERGY INDICATORS OF AXIAL INDUCTION DISK-SHAPED MOTOR FOR SHIP RADARS

The development of a reliable gearless electric drive for antennas of ship radars is an important problem. To solve the problem, this article proposes to use an axial induction motor (AIM) with a massive bimetallic disk-shaped rotor. The AIM model is presented, which consists of three computational domains with the boundary condition of symmetry. To calculate the electromagnetic field, a well-known analytical method of integral transformations is used taking into account the variable along the radial coordinate of the linear speed of the rotor. Ready-to-use expressions are presented for the development of a program for the numerical calculation of the magnetic field and energy characteristics of the motor. Algorithm is developed for calculating the dimensions of the AIM, operating at different speeds with a frequency converter. The numerical calculation program is used to calculate the dimensions AIM. It uses well-known recommendations for the parameters of the electromagnetic field in the magnetic core and in the air gap. The calculation of the dimensions of the AIM for ship radars “Mius” is performed. The dependence of the efficiency on the current frequency for different rotor’s frequencies is investigated. The energy indicators of the AIM are investigated at a variable torque on the shaft and at different rotor speeds. The parameters of the power source for the AIM of ship radars are established. References 20, figures 5, tables 3.

ASYNCHRONOUS ELECTRIC DRIVE WITH REACTIVE POWER CONTROL

The method of control of asynchronous electric drive, which based on measuring and control of reactive power of induction motor, is presented. It provides independence of magnetic flow of rotor from changes of induction motor parameters, uninterrupted diapason of regulation of speed including zero and fast regulation.

ANALYTICAL NONLINEAR-PROBABILISTIC MODEL OF THE EQUIVALENT ELECTRICAL RESISTANCE OF A LAYER OF METAL GRANULES

As a result of processing the experimental data, an analytical continuous nonlinear-probabilistic model of the equivalent electrical resistance of a layer of metal granules in the working liquid was created. It is described by four equations: the modified Gaussian distribution and the dependences on the instantaneous values of the discharge current in the layer of metal granules of the mathematical expectation, dispersion and correction coefficient of the range of its equivalent electrical resistance. Based on the form of the dependences obtained during the experiments and the physics of the processes that occur in this case, two main groups of analytical functions are considered that approximate the obtained dependences. Criteria and methods for finding the optimal values of their coefficients are described. The adequacy of the approximation of each of the three obtained dependences by several analytical functions was investigated, the optimal values of the coefficients of which were found by the described method. Analytical functions was compared, which approximate the dependence of the mathematical expectation of the equivalent electrical resistance of a layer of metal granules on the instantaneous values of the discharge current in it with the known nonlinear models of the resistance of such a medium. References 33, figures 3, tables 3.

SHUNT ACTIVE FILTER CONTROL OF A THREE-PHASE THREE-WIRE NETWORK IN THE COORDINATE SYSTEM OF THE TWO WATTMETERS METHOD

A combined control system for a shunt active filter in the coordinate system of the two-wattmeters method has been proposed, which, depending on the conditions of use, implements one of the four active filtration strategies, optimal according to a certain quality indicator. The most promising is the proposed integral strategy for active filtration control with the reference vector of line voltages of direct sequence, which provides symmetric sinusoidal currents of the network and the minimum pulsation of power consumption for the almost identical energy-saving effect as the concept of S. Fryze. New formulas for calculating the energy-saving effect and pulsations of the instantaneous power in a three-phase system of power in the case of the formation of an active current in the transmission line in the conditions of asymmetry of loading voltage and linear asymmetric load have been developed. Simulation studies have confirmed the adequacy of the proposed strategies and calculations. References 15, figures 5, tables 2.

MULTICHANNEL CONVERTION OF RANDOM DATA WITH THE PAIR-ELEMENTS OF ORDERED SAMPLES

The concept of multichannel parallel converting of probability density function (pdf) of random data was previously used for single-element pdf-converters. In development of this concept, here we investigate converting properties of spdf-converters channels formed by the sum of the ​​pairs of ordered sample elements (order statistics). The characteristics of the conversion results as dependencies on the size of the samples and the displacement of the channels relative to the median of the samples were obtained for data with a uniform distribution density. Also where excluded the areas of mutual dependence of the density functions of the summed elements, which further where normalized together with approximating them functions. Despite the apparent structural differences, the goal of this study still was to determine the closeness of the converted data with some standard functions of the probability distribution density, in particular, with the normal distribution law. As before, the estimates of the closeness of the spdf-converter channels were obtained using the chi-square criteria. The results of the research were used to determine the size and location of the statistical closeness windows, and to construct spdf-converters statistical model. References 20, figures 14.

LASER MEASURING SYSTEMS WITH FIBER-OPTICAL SENSORS FOR CONTROL OF LINEAR PARAMETERS OF MECHANICAL OBJECTS

A block diagram of a laser measuring system with a fiber-optical sensor for monitoring the air gap between the rotor and stator of a hydrogenerator has been developed and analyzed. The system uses an algorithm for alternating comparison of the investigated and reference light fluxes. This makes it possible to reduce the influence on the measurement result of the gap of the instability of the parameters of individual units and blocks of such a system. The analysis of the main measurement errors, which can affect the result of determining the gap, is carried out. References 16, figure 1.

AUTOMATED DEVICE FOR MONITORING THE STATOR CORE OF POWERFUL TURBOGENERATOR

A device for automated control by the stator core of a powerful turbine generator (TG) during assembly and pressing at the manufacturing plant is proposed. Using the device, places in the core with a weakened solidity are determined. For this, at N points evenly spaced along the cross section of the stator core, the specific pressing pressure of special plastic elements, which are installed in the control cells of the additional pressure ring of the press, on which the core is assembled, is measured. During pressing, the elements are deformed, and their deformation depends on the degree of core defect (decrease in solidity) in the zone of which they are located. The sample will be deformed less, located in the zone of the largest defect, and most of all - in the zone where the defect is minimal. The pressure is measured using a flat metal membrane with a rigid center on which strain gauges are located at selected points. It is shown that the relative deformations in a flat membrane, which are measured by strain gages, depend on the value of the specific pressing pressure. Analytical relationships between the relative radial and tangential deformations and the specific pressing pressure have been determined. References 20, figures 5.