Lect-1_FrequencyControl - FREQUENCY CONTROL Lecture in...

Info icon This preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
1 FREQUENCY CONTROL Lecture in MJ2426 Applied Heat and Power Technology, Tuesday 27 January 2008 Mikael Amelin
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
2 POWER SYSTEMS Electricity has to be generated the instant it is used. Automatic control systems are necessary in all larger power systems. Electric energy cannot be stored!
Image of page 2
3 SYNCHRONOUS GRIDS A power system connected by AC lines and transformers constitutes a synchronous grid . There can only be one frequency in a synchronous grid. Analogy A synchronous machine can be compared to a trolley be- tween two locomotives—it must go at the same pace as the rest of the system, otherwise it will be crushed. 50 Hz 50 km/h
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
4 SYNCHRONOUS GRIDS - Nordel HVDC HVDC HVDC HVDC (220 kV) (220 kV) N N N N N N N N Krajnik Gdansk Rostock Lübeck Kiel Hamburg Flensburg Ringhals Helsing- borg Cøpen- hagen Gothen- burg Malmö Karlshamn Norrköping Oskars- hamn Biastystok Hasle Stavanger Bergen Rjukan Oslo Stockholm Enköping Nea Trondheim Tunnsjødal Umeå Sundsvall Røssåga Rana Melfjord Svartisen Salten Ofoten Kobbelv Narvik Loviisa Olkiluoto Tallin Tartu Riga Klaipeda Ignalina Latvia Kaunas Vilnius HVDC Kristiansand Paide Rauma Forsmark Kassø 0 100 200 km N Luleå The power transmission network in northwestern Europe Hydro power plant Thermal power plant (CHP) Transformer or switching station 750 kV line 400 kV line 300 kV line N Joint operation link for voltages below 220 kV 220 kV line Extend 2004 Cable Overhead line 275 kV AC 75 km 220 kV AC 4295 km 130 kV AC 7 km The Swedish grid, comprises mainly 220 and 400 kV lines, switchyards and transformer stations and foreign links for alternating (AC) and direct current (DC). 400 kV AC 4 km 10643 km Planned/under construction Sweden Norway Finland Poland Kaliningrad Estonia Lithuania Russia Belorussia Denmark Germany Rovaniemi Helsingfors Åbo Vasa Tammerfors Kemi Uleåborg HVDC (High Voltage DC) 459 km 115 km Liepaja Viborg Slupsk Teknikredaktörerna AB 2005 HVDC Sindi
Image of page 4
5 FREQUENCY RANGE The frequency of a large power system must be kept around the nominal value! Certain frequencies can harm important equipment in the power system. - Harmonic vibrations in turbine blades and shafts. - Heating of generators and transformers. Some loads might be disturbed.
Image of page 5

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
6 FREQUENCY RANGE Automatic control systems–primary control (In Sweden: 49.
Image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern