Bezkontaktu sinhronie dzinēji ar ārējo rotoru

Monogrāfijā aplūkotas bezkontaktu sinhrono ventiļdzinēju konstrukcijas, to teorijas pamatjautājumi un raksturlīknes. Piedāvātas sinhrono dzinēju ar pastāvīgajiem magnētiem un sinhrono reaktīvo dzinēju jaunas konstrukcijas ar ārējo rotoru, kas nodrošina augstu īpatnējo elektromagnētisko momentu. dzinēju konstrukciju optimizācijā izmantoti metamodeļi, kuru pamatā ir magnētisko lauku skaitlisko aprēķinu rezultāti. Aplūkotas dzinēju eksperimentālās izpētes metodes un rezultāti. Monogrāfija paredzēta elektroenerģētikas, elektronikas un elektrotehnoloģiju virzienu studentiem un speciālistiem

Elektriskās mašīnas

Grāmatā aplūkoti elektrisko mašīnu un transformatoru uzbūves principi un konstrukcijas, teorijas jautājumi stacionāros un pārejas procesos, kā arī analizēti to darba režīmi un ekspluatācijas īpašības. Grāmata paredzēta elektroenerģētikas, elektromehāniskas un elektrotehnoloģiju virzienu studentiem un speciālistiem

Development of Diagnostic Algorithm Based on Fault

The paper gives a short insight into the structure of Latvian high voltage transmission network. The situation in the field of power transformers’ diagnostics is analyzed, focusing mainly on the specific features of their maintenance in Latvia. Classification of the most commonly used dissolved gas analysis (DGA) data interpretation methods is given in this paper as well as causes for developing new methods are analyzed. Comparative diagnostic criterion is proposed which is based on typical gas concentration typical level

Metamodels for New Designs of Outer-Rotor Brushless Synchronous Electric Motors

The authors consider the possibilities to synthesise metamodels for the analysis and optimisation of brushless synchronous motors. The metamodels are presented for new designs of the outer-rotor permanent magnet synchronous motor and the outer-rotor reluctance motor. The metamodels are synthesised based on the results obtained by the numerical calculations of magnetic field taking into account magnetic saturation. Analysis of the results for the motor magnetic field and tests of the metamodels at the selected and intermediate points shows that these can be synthesised with acceptable accuracy using numerical calculations instead of expensive real experiments

Elektriskās mašīnas

Grāmatas otrajā papildinātajā izdevumā ietvertas tēmas par elektrisko mašīnu un transformatoru uzbūves principiem un konstrukcijām, teorijas jautājumiem stacionāros un pārejas procesos, kā arī analizēti to darba režīmi un ekspluatācijas īpašības. Grāmata paredzēta elektroenerģētikas, elektromehāniskas un elektrotehnoloģiju virzienu studentiem un speciālistiem

Power Transformer's Technical Condition Assessment by Dissolved Gas Analysis Considering Unit's Current Working Life Parameter

Classification of the most commonly used dissolved gas analysis (DGA) data interpretation methods is given in this paper as well as causes for developing new methods are analyzed. Comparative diagnostic criterion is proposed which is based on typical gas concentration typical level for separate groups of power transformers with varied current age. Transformers’ grouping principle and analysis of typical gas concentration of several representative DGA data samples are the main points of case study in which 224 power transformers with the voltage 110 kV in Latvian transmission network are reviewed

Comparison of Permanent Magnet Synchronous Motor and Synchronous Reluctance Motor Based on Their Torque per Unit Volume

The paper deals with comparative analysis and equivalence determination of the brushless synchronous motors based on their torque per unit volume in power range from 1 kW to 2.5 kW. Novel designs of external-rotor surfacemounted permanent magnet synchronous motors and externalrotor synchronous reluctance motor are analyzed in the comparative study. Two types of the permanent magnets are analyzed with the use in surface-mounted permanent magnet synchronous motor: ferrite magnets and neodymium magnets. The optimal designs of studied motors are found for correct comparison with the help of synthesized analytical relationships between torque per unit volume and main dimensions of the motor magnetic circuit (also known as metamodels). The calculation of studied motor torque is based on the results obtained with numerical calculations of the motor magnetic field. Comparative analysis shows that permanent agnets do not significantly reduce dimensions of the motor in comparison with studied synchronous reluctance motor in the considered power range