Gapon D. Methods and means of power supply quality analysis and electromagnetic compatibility of electrical complexes and systems

Українська версія

Thesis for the degree of Doctor of Science (DSc)

State registration number

0520U101583

Applicant for

Specialization

  • 05.09.03 - Електротехнічні комплекси та системи

29-10-2020

Specialized Academic Board

Д 64.050.04

National Technical University "Kharkiv Polytechnic Institute"

Essay

The paper contains the solution of the actual scientific problem of the analysis of quality of power supply and electromagnetic compatibility of electrotechnical complexes and systems. This problem is the lack of a mathematical basis and, accordingly, a regulatory framework for assessing the impact of a particular electrical complex or consumer system on the quality of electricity. The paper proposes an assessment of the quality of power supply by comparing the mode of power consumption of the existing electrical complex with the reference consumer in the form of numerical coefficients of power and losses. Calculation formulas for single-phase, three-phase three-wire and four-wire power supply systems are obtained. The paper proposes to build an assessment of the contribution of a separate electrical complex or consumer system in the deterioration of power supply on the basis of power values specified in the contract and the establishment of normalized resistance of the power supply system. Based on these values, a mathematical apparatus is proposed, which allows not only to determine the fact of violation of the limits of electromagnetic compatibility but also to quantify the amount of electricity that has been damaged. It is proposed to determine the coefficient of losses from asymmetry using a reference consumer. This coefficient is calculated as the ratio between the power loss of three independent single-phase reference consumers to the losses of the reference three-phase consumer. This solution avoids the influence of such factors as nonlinearity and reactivity. In addition, the device of symmetrical components is not used, which is inconvenient in the case of non-sinusoidal voltages and currents. It is proposed to select individual coefficients of losses from reactivity and nonlinearity, which are calculated by dividing the harmonic components of the distortion current by the power direction. The method of calculation of losses from nonstationarity is calculated, which is calculated as the ratio of total losses of reference consumers on several "short" intervals, and losses of the reference consumer on a long interval that includes all "short". The method of estimation of infringement by the consumer of norms of consumption on size of power and harmonic components which are potentially capable to cause an exit of indicators of quality of electric energy beyond admissible limits is offered. The basics of the method of construction of penalties against the consumer in case of exceeding the allowable parameters of electricity consumption, as well as penalties against the supplier of electricity in case of low quality of electricity and the absence of violations by the consumer. Also in the work the hardware realization in the form of the electric energy meter taking into account its quality is offered.

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