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Bài giảng ngành Điện: Giải các bài toán trong mạch điện điện thế thấp một pha và ba pha (Phần B) gồm các chủ đề sau Solve problems in single and threephase low voltage circuits Part B Content Topic 1: AC power and power factor Topic 23: Multiphase systems Topic 4: Threephase STAR connection Topic 5: Threephase, Fourwire systems Topic 6: Threephase DELTA connection Topic 7 Interconnected Star and Delta Devices Topic 8 Energy and Power Requirements of AC Systems Topic 9: Harmonics
Solve problems in single and three-phase low voltage circuits Topic 4: Three-Phase STAR Connections; and Topic 6: Three-Phase DELTA Connections Three-Phase Connections Three-Phase STAR Connection Three-Phase Connections: STAR 12/01/24 Nathan Condie Three-Phase Connections: STAR Formed by connecting the three similar ends of the windings together This connection point is called the STAR-POINT Star Point 12/01/24 The junction that remains at zero potential, and is often connected to a neutral conductor Nathan Condie Three-Phase Connections: STAR Line Voltage (VL) Phase Voltage (VP) The voltage measured between the start and finish of any phase winding Line Current (IL) The voltage measured from Phase-to-Phase The current flowing in any main supply conductor Phase Current (IP) 12/01/24 The current flowing in the phase winding (conductor loop) Nathan Condie Three-Phase Connections: STAR Phasor Diagram Star-Connection: PHASOR Diagram VC IC IA 1200E IB VA (Reference) 1200E VB 12/01/24 Nathan Condie Star-Connection: PHASOR Diagram 12/01/24 Nathan Condie Star-Connection: PHASOR Diagram V is ‘reversed’ to create an opposite VC B +VB VAB VCA 300E LEAD VA (Reference) VA is ‘reversed’ to create an opposite VC is ‘reversed’ to create an opposite VB VBC 12/01/24 Nathan Condie STAR Connection Formulae Star-connected System VL = √3 VP IL = I P VL LEADS VP by 300E 12/01/24 Nathan Condie 10 .. .Three- Phase Connections Three- Phase STAR Connection Three- Phase Connections: STAR 12/01/ 24 Nathan Condie Three- Phase Connections: STAR Formed by connecting the three similar ends... value? 12/01/ 24 VP = 19 kV Nathan Condie 11 UEENEEG002B Solve problems in single and threephase low voltage circuits Topic 6: Three- Phase DELTA Connections Three- Phase Connections: DELTA Formed... these junctions A Delta- connection does not create a junction where a neutral can be connected 12/01/ 24 Nathan Condie 13 Three- Phase Connections: DELTA 12/01/ 24 Nathan Condie 14 Delta- Connection: