Search for dissertations about: "math"

Showing result 6 - 10 of 61 swedish dissertations containing the word math.

  2. 6. Propagation of Supraharmonics in Low-Voltage Networks

    Author : Angela Espin Delgado; Sarah Rönnberg; Math Bollen; Jos Knockaert; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; supraharmonics; waveform distortion; low-voltage; high-frequency harmonics; Electric Power Engineering; Elkraftteknik;

    Abstract : The need for measures towards a sustainable use of energy has incited the proliferation of devices and systems for the efficient use of electricity. Energy-efficient appliances, equipment for the electrification of transportation, electricity generators from renewable energy sources, and communication protocols, e.g. READ MORE

  4. 7. Multiple Aspects of Dynamic Rating in the Power System

    Author : Seyede Fatemeh Hajeforosh; Math Bollen; Sarah Rönnberg; Alfredo Vaccaro; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dynamic rating; Transmission lines; Overload Protection; Stochastic analysis; Hosting capacity; Transformers; Electric Power Engineering; Elkraftteknik;

    Abstract : Increased consumption and increased use of renewable energy make overhead lines and transformers more often congested. Dynamic rating (DR) uses a time-depending maximum permissible current instead of a long-term-fixed rating; it is an effective solution to upgrade the capacity of existing grid assets to minimize this congestion. READ MORE

  5. 8. Stability of Low-Frequency AC Railways : Models and Transient Stability

    Author : John Laury; Lars Abrahamsson; Math Bollen; Pablo Arboleya; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electric Power Engineering; Elkraftteknik;

    Abstract : Low-frequency AC railway grids are unique in the sense that a only few countries around the world uses them, still however, they are an important parts of their countries infrastructures. Due to the usage of a dierent frequency than the public grid of the country, conversion of frequency is needed for the interconnection. READ MORE

  6. 9. Managing uncertainties through efficient calculation of transients and harmonic propagation in power systems

    Author : Oscar Lennerhag; Math Bollen; Jan Lundquist; David Thomas; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Overvoltages; harmonics; uncertainties; stochastic methods; Electric Power Engineering; Elkraftteknik;

    Abstract : The electric power system is undergoing changes including large-scale introduction of renewable energy sources together with HVDC/FACTS, changes in the network such as increased amount of high voltage cables, industrial electrification, and changes in the load composition. These changes will impact the system in different ways and lead to challenges that must be addressed to facilitate planning, dimensioning, and operation of the system in a secure and economical way. READ MORE

  7. 10. Data analytics for weak spot detection in power distribution grids

    Author : Hassan Mashad Nemati; Sławomir Nowaczyk; Anita Pinheiro Sant'Anna; Math Bollen; Högskolan i Halmstad; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : This research aims to develop data-driven methods that extract information from the available data in distribution grids for detecting weak spots, including the components with degraded reliability and areas with power quality problems. The results enable power distribution companies to change from reactive maintenance to predictive maintenance by deriving benefits from available data. READ MORE