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Stator Windings Currents Analysis Of The Ipm
Machine Under Short-Circuit Conditions
Knebl, Ladislav
The development of the synchronous motors with permanent magnets is, mostly thanks to the legislation pressure to achieve the highest efficiency in electric drives, experiencing raising interest. Since the number of motors used in the industry is growing year by year, it is reasonable to investigate the motor behavior under faulty conditions, such as short-circuit conditions. This paper deals with the stator current analysis of interior permanent magnet synchronous motor under the short-circuit condition, both short-circuit in one phase and symmetrical three-phase short-circuit.
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Analysis of parallel operation of nodal areas of 110 kV Krasikov and Neznasov transformers stations
Kostkan, Petr ; Kopička, Marek (referee) ; Ptáček, Michal (advisor)
Currently, the nodal areas of Neznášov substation and Krasíkov substation, which belong to ČEZd distribution network 110 kV – East, are operand as separate units. In the defined setting, each nodal area comprises of two 400/110 kV transformers. In the case of failure of the transformer T401 or T402, the criterion N-1 for twenty percent of the rated output is not met. Such problem can be solved by parallel operation of nodal areas of Neznášov substation and Krasíkov substation. The principal as well as practical aim of this thesis is to interconnect the bridge operated connection in separated areas into parallel/loop operation of nodal areas (supplied by 400/110 kV transformers). Computing software is used to calculate the steady state and short-circuit conditions in the distribution network 110 kV for separate and parallel operation of mentioned nodal areas. Power flow analysis is aimed at assessment and evaluation of voltage conditions, transformers loading (400/110 kV and 110/vn) as well as 110 kV lines loading. Obtained short-circuit indices is used to examine short-circuit, withstand capability of the 110 kV substation. Finally, benefits as well as drawbacks of the separate and parallel operation are compared and evaluated. If necessary, the technical arrangements are proposed/designed in order to allow parallel operation of nodal areas Neznášov substation and Krasíkov substation.
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Short Circuit Calculation of MV Grid
Knápková, Dagmar ; Topolánek, David (referee) ; Toman, Petr (advisor)
This bachelor’s thesis deals with the faults in the distribution networks, focusing on shortcircuits as the most common and the most signiĄcant types of faults. The thesis is divided into theoretical and practical part. In the theoretical introduction, describes the types of faults in distribution networks with a focus on the short-circiuts, their causes, and the impact on distribution networks. Follows a description of the time course of short-circuit currents, short-circuit calculation simpliĄcation assumptions, the formula for calculating the impedance of the various elements of the short-circuits schema and the calculation methods of short-circuit currents in accordance with ČSN EN 60909-0. In the practical part, there is an example of the calculation of simple network conĄguration. Follows an analysis of the real network, including the analysis of the method of operation and the selection of appropriate method for the calculation of the short-circuit. After that are carried out practical calculations short-circuit conditions in four places on the network, and three diferent types of short circuits. For one-phase short-circuit is subsequently carried out the distribution of currents in a parallel branch of the distribution lines. At the conclusion of the bachelor’s thesis is caried out evaluation the results and analysis of the data obtained by calculation.
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Optimal Design of a Low-Frequency Structural Wiring System
Balák, Dušan ; Slavata, Petr (referee) ; Kadlec, Radim (advisor)
This thesis is concerned with designing and optimizing of a low-frequency structural wiring system in office building. The thesis is divided into two parts, theoretical and practical. Theoretical part is describing factors of designing the low-frequency structural wiring system, with focusing on short-circuits and their consequences on wiring system. Mentioned are optimal economic diameter of electrical cables, purchase and running costs and other factors connected with the optimal designing and protection of electrical devices. In practical part is adjusted, CAD´s system program, assigned a site wiring diagram and allocation of switchboards in the office building. In programs by EATON Elektrotechnika company were developed another parts of project´s documentation. In the Spider program was drew the wiring diagram assigned building and suggested cables and circuit breakers by EATON for correct running in the whole building. In the M-Profil program are designed assigned switchboards and calculated their warming. The motion includes prepared projection documentation, means site wire diagram of the building, schema with evaluations of short-circuits and voltage loss, switchboards design and calculation of their warming.
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Calculation of HV line distance relay setings
Pustowka, Pavel ; Vaculík, Petr (referee) ; Toman, Petr (advisor)
This work is divided into practical and theoretical part. The first part deals with defective states on ehv lines, especially short-circuits and their calculation, further discusses about distance protections and the theory necessary for their correct adjustment. The second part contains practical calculation of short-circuit conditions and adjustment for distance protection on selected part of 110 kV network, belonging to EO.N company. The result of the work are values needed for adjustment all distance protection in entered part of the network.
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Load Flow Calculation and Design of Distance Protection Relay Settings of 110 kV Overhead Line
Jasenský, Filip ; Vaculík, Petr (referee) ; Toman, Petr (advisor)
Bachelor thesis load flow calculation and design of distance protection relay settings of 110 kV overhead line acquaints with the theory calculation of steady operation, short-circuit conditions and a proposal setting the distance protection. The theoretical part is made an example of a simple calculation to show leadership methods of calculation. The practical part is a calculation of steady operation and short-circuit conditions. Short-circuit ratios are calculated for a single operation and parallel operation of transformers in Otrokovice. Calculated using the initial shock symmetrical output from the calculation of short-circuit conditions is verified by short circuit resistance of substations. The practical section setting the distance protection ABB REL 316*4 and compensation earth faults. Calculation of steady state and short-circuit conditions designed basic operational state of the network, for which the design of a distance protection relay settings.
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The analysis of parallel operation variants of supply areas 110 kV Čebín and Sokolnice
Reiter, Martin ; Vaculík, Petr (referee) ; Toman, Petr (advisor)
The diploma thesis is focused on the analysis of parallel operation of Čebín and Sokolnice substations. Different variants of parallel operation are researched. A calculation of steady state by the iterative method is described in the theoretical part. The next part briefly mentions a short-circuit and dimensioning of conductors. The possibility of overloading of lines and transformers is discussed in the last chapter of the theoretical part. The current state of the situation is described in the practical part. Main goal of the practical part of the diploma thesis is to design a configuration capable to parallel operation. Also another configuration of supply of this area is designed. There must be no direct connection between Čebín and Sokolnice substations on 110kV level in this configuration. This configuration should eliminate a transit flow of power. Each configuration has to fulfill the requirements on the steady state and on short-circuit current capability. One of the last chapters is focused on the steps, that should by undertaken to prevent transit flow of power.
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Analysis of Static and Dynamic Stresses the Existing 110 kV Substation for Short Circuit Strength Increasing
Balák, Dušan ; Škapa, Milan (referee) ; Orságová, Jaroslava (advisor)
This thesis is concerned with static and dynamic stress calculation of busbar and wire conductors in HV and EHV substations according to standards ČSN EN 60865-1 ed. 2 and ČSN EN 50341-1 ed. 2. Calculations are done in program made in MS Excel with consideration to corporate regulations of energetics. In introduction is described the construction of HV substations and methodical step-by-step computation. Practical evaluation is applied to the substation R110 kV Dluhonice, where has to be checked up sufficient short-circuit resistance because of short-circuit strength increasing. At the end is analysed the influence of the spring structure constant on short-circuit strength forces in substation. Highly significant utility is the founded program for HV substations designations.
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Short-circuit Calculation of Local Distribution Network
Byrtus, Jiří ; Paar, Martin (referee) ; Topolánek, David (advisor)
This thesis deals with transient phenomena in the electricity grid - especially with short-circuits. First part describes short-circuit types, reasons for their commencement and also consequences of their functioning. The thesis further shows waveforms of short-circuit currents and its components. A method of calculating short-circuits currents, using the constituent systems and the basic equations for calculating short-circuit impedances are also mentioned here. Relations and methods are based on valid standards of IEC 60909 – 0. The second part indicates the calculation of two-phase and three-phase short-circuit currents for specific network of industrial building. This calculation aims to verify the dimensioning of substations for short-circuit currents after connecting a synchronous generator with given power to the main substation.
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Calculation of distance protection relay setting for 110kV line.
Bartoš, Petr ; Vaculík, Petr (referee) ; Toman, Petr (advisor)
This work deals with both the calculation of short circuit conditions of 110 kV network in the Czech Republic. This network is divided into two parts, each of which feeds a 400/110 kV substation and the calculation is performed for different locations of a short circuit. The second part deals with the calculation of distance protection settings for one part of this network. The result of this work are the values of network parameters needed to set up distance protection, which protects our individual lines of the network.
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