The scheme for the distribution of electric power of the tanker "Ligovsky Prospekt" containing three diesel generator sets with brushless three-phase synchronous generators with an active capacity of 750 kW, a total power of 937.5 kVA, a voltage of 440 V, a frequency of 60 Hz, a rated current of 1203 A, a power factor of 0 ,8. The main power quality indicators and the requirements for them of the IEC and the Russian Maritime Register of Shipping are given. The characteristics two devices "Energotester PKE-06" of domestic production are described with the help of which the main energy indicators (phase and line voltages, phase and linear currents, active, reactive and full power, load power factor, load factor) and power quality indicators (voltage deviation, frequency deviation, non-sinusoidal coefficient and others) on a tank with single operation of dieselgenerator sets (DGA) and with parallel (running, maneuvering, parking in the roadstead) in the electric circuits of generators and receivers (electric drives: electric drive of ballast pump No. 2, power 315 kW, electric drive of inert gas fan, power 126 kW, electric drive of ballast pump No. 1 , the power of 160 kW). The duration of the measurement for running, maneuvering and parking mode in the roadstead was at least 24 hours with 30 minutes averaging. The analysis of power quality indicators based on their measured values and graphical dependencies on time showed the compliance of the quality of electricity with the requirements of the IEC and the Russian Maritime Register of Shipping.
The article deals with partial discharge modeling based on gas inclusion (defect) in high-voltage electrical insulation on board ship. For modeling a sample of insulating material used in ship high-voltage equipment , has been taken. A sample of the insulating material is described by means of three capacitors. Based on the calculated capacitance values, a replacement circuit was constructed, and then a scheme for modeling partial discharges in Matlab / Simulink program was designed. While simulating the most common voltage values applied in ship high-voltage systems have been used. The gas inclusion (defect) of a cylindrical shape, located in the middle of the insulating material, has been taken as reference. Simulation of partial discharges is performed for three gas inclusion versions differing in size. The graphs show partial discharges for which the voltage across the capacitances and the apparent charges for each defect and voltage are calculated using a formula. Dependences of the apparent charge on the area of the defect in the insulation and on the amplitude of the partial discharges are presented for different voltages. Based on these graphs, conclusions are drawn regarding the dependence of partial discharges on the supply voltage and the size of the defect within the insulating material. Spectral analysis of the simulated signals corresponding to the defects considered by the fast Fourier transform method is made and the frequency distribution of the signal depending on its amplitude is presented diagrammatically. Found values of the apparent charge allow to calculate the average value of the current, which makes it possible to estimate the intensity of partial discharges and technical condition of electrical insulation. Another problem with constant monitoring of partial discharges in high-voltage powerequipment is,separating useful signal (partial discharges) from the noise component. This issue needs further detailed study.
The computer modeling of changes in the shape and amplitude of a high-frequency signal at its propagation in the ship high-voltage cables is considered in the paper. The computer simulation was carried out on the basis of the real parameters of the ship high-voltage electric power system of gas carrier vessel Corcovado LNG. On the basis of the ship's technical documentation, it was concluded that the overwhelming number of the electricity receivers are connected to high-voltage switchboards using cables of 60 meters long. Only cargo pumps for liquid natural gas have a cable length of 200 meters. Thus, the computer simulation of a high-frequency signal propagation is performed in the ship high-voltage cables of 60 and 200 meters long. A theoretical description of change in the shape and the amplitude of a high-frequency signal at its propagation is presented using mathematical equations. The simulation is produced in Matlab/Simulink program. The cables of 60 and 200 meters long are described by means of a quadripole (RLCG section). The cable parameters and other simulation parameters are set in the program dialog window. Based on the obtained simulation results, the additional mathematical calculations were performed to obtain the attenuation coefficient and the propagation constantan. The graphs show the dependence of the change in the shape and the amplitude of the high-frequency signal on its frequency, taking into account the influence of the cable length. As a result, on the basis of the computer simulation, it was concluded that a partial discharge with a frequency of 30 MHz can be successfully measured in the high-voltage cable of 60 m long and a partial discharge with the frequency of 10 MHz can be measured in the high-voltage cable of 200 m long.
Based on the analysis of requirements of normative documents and technical literature considers the characteristics of the three types of light sources: incandescent, fluorescent and led. The prospects of led light sources according to the main technical characteristics: luminous efficiency and lifetime.The main attention is paid to consideration of led lamps (DM), a typical scheme of power supply of SD. The issues associated with electromagnetic compatibility of SD. Noted that led light sources being non-linear loads distort the sine wave of the supply voltage and generate the network of higher harmonic (SH) components of a current that have a negative impact on supply mains, compromising the overall electromagnetic environment. To assess the possibility of functioning of the lighting systems of the courts on the basis of SD of the lamps were held the experimental research of power characteristics, which are listed in article a laboratory setting. The results of laboratory studies of SD showed the ability of electromagnetic compatibility of CD in marine power systems. It is indicated that for a number of SD lighting inrush current can reach ten values relative to the nominal that must be considered when selecting the switchgear and protective devices, especially in lighting systems with low power consumption. For ship characteristic network voltage fluctuation causes changes of luminous flux, which is negatively perceived by the person. Studies have shown that some SD lamps is constant luminous flux, regardless of the mains voltage and must be recommended for installation in networks of marine lighting.The lack of existing regulations and sanitary regulations and methods of control for SD lighting. Conclusions about the absolute prospects as led light sources for ships.
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