2021 ◽  
Vol 939 (1) ◽  
pp. 012014
Author(s):  
A Rakhmatov ◽  
N Rajabov ◽  
Kh Yakubova

Abstract This article describes the methods and means for determining the technical condition of electrical equipment in power supply systems, particularly in transformer substations. There are many ways to determine the technical condition of electrical equipment. However, their implementation requires complex and additional equipment and devices. In addition, these tests must be carried out when the power supply system is off. This will lead to a decrease in the quality of electrical energy. Determination of the technical condition of electrical equipment using thermal imagers is performed under the voltage and in operating modes, the measurement process does not affect the parameters of the power supply system. The results of research in energy enterprises of the Syrdarya region are presented.


2021 ◽  
Vol 288 ◽  
pp. 01019
Author(s):  
Vladimir Govorun ◽  
Oleg Govorun ◽  
Vadim Markovskiy ◽  
Aliya Zhumadirova

In this paper, on the basis of simulation modeling, an algorithm for studying the current resonance that occurs in the power supply system with a chaotic change of the load power and variation of reactive power compensation degree, in the presence of consumers with a nonlinear current-voltage characteristic is proposed. It is shown that overloading of capacitor banks can occur in a wide frequency range, close to the resonant frequency. The proposed algorithm determines all possible frequencies at which an increase of currents in capacitor banks can occur above the permissible values in parallel resonance. The purpose of the proposed work: to show in what operating modes of the enterprise power supply system an overload of capacitors by currents of higher harmonics can occur when the load power changes and the degree of reactive power compensation varies.


2021 ◽  
Vol 25 (5) ◽  
pp. 568-585
Author(s):  
Yu. N. Bulatov

The paper determines the effect of proposed joint voltage and frequency predictive controllers for distributed generation (DG) plants on quality indicators characterizing the control process in different operating modes of power supply systems. The studies are conducted in the MatLab environment (Simulink and SimPowerSystems simulation packages) employing control engineering methods. It is proposed to design and adjust joint predictive controllers by determining the resonant frequency of oscillations for the master generator rotor. This approach provides better quality indicators of voltage and frequency control in power supply systems while maintaining the same settings for the controllers of DG plants. With an additional load in an isolated power supply system, the maximum voltage sag is found to be 1.75 times lower than for local predictive control and 3.5 times lower as compared to the use of conventional controllers. For the specified mode, predictive controllers enable a threefold reduction in the transient time between rotor rotational speeds in a synchronous generator. In the start mode of a powerful electric motor, the predictive controllers of synchronous generators in the power supply system enable a 1.5 times reduction in voltage sag, with a 1.4 times reduction in overvoltage following its start. In the case of a short-term three phase short-circuit, joint predictive controllers allow a 1.5 times decrease in transient time and a 2.3 times decrease in the overshoot of power line frequency as compared to local control. In addition, frequency oscillation in the power system is also reduced. Similar effects are observed in other operating modes of the considered power supply systems equipped with DG plants. The performed dynamic simulation confirms the effectiveness of using joint voltage and frequency predictive controllers for DG plants, which consists in a positive impact on the quality of processes involved in controlling the parameters of power supply systems in various operating modes.


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