Assumption University Thailand EE4503 Electrical Systems Design Short-circuit Current 1

Assumption University Thailand Topics Term & Definition Equivalent Circuits –Voltage Source –Impedance Short-circuit Calculation 2

Assumption University Thailand Terms & Definition Short Circuits in Power Systems IEC Far-from-generator Short Circuit –Usually in transmission systems / end-users –Impedance is constant Near-to-generator Short Circuit –System Impedance changes when the short circuit occurred. 3

Assumption University Thailand Terms & Definition Types of Short Circuits Three-phase short-circuit Double-phase short-circuit without earth/ground connection Double-phase short-circuit with earth/ground connection Line-to-earth (line-to-ground) short-circuit 4

Assumption University Thailand Terms & Definition Types of Short Circuits 5 systems

Assumption University Thailand Terms & Definition Components: DC & AC 6

Assumption University Thailand Terms & Definition Components of Short Circuit Currents 7

Assumption University Thailand Terms & Definition Components of Short Circuit Currents 8

Assumption University Thailand Equivalent Circuits 9

Assumption University Thailand Equivalent Circuits Impedance: Network Feeder 10

Assumption University Thailand Equivalent Circuits Impedance: Network Feeder 11

Assumption University Thailand Equivalent Circuits Impedance: Cable 12

Assumption University Thailand Equivalent Circuits Impedance: Cable (calculation) 13

Assumption University Thailand Equivalent Circuits Impedance: table for PVC cables Electrical Systems Design: ประสิทธิ์ พิทยพัฒน์

Assumption University Thailand Equivalent Circuits Impedance: table for Busway Aluminium Electrical Systems Design: ประสิทธิ์ พิทยพัฒน์ Copper

Assumption University Thailand Equivalent Circuits Impedance: Transformer 16

Assumption University Thailand Short-circuit Calculation Example from CoE 17

Assumption University Thailand Short-circuit Calculation Example from CoE 18

Assumption University Thailand Short-circuit Calculation Example from CoE 19

Assumption University Thailand Short-circuit Calculation Example from CoE 20

Assumption University Thailand Short-circuit Calculation Example from CoE 21

Assumption University Thailand Electrical Systems Design: ประสิทธิ์ พิทยพัฒน์ Circuit_Calculation Calculation of short-circuit currents: Schneider Electric Reference 22

Assumption University Thailand Equivalent Circuits Impedance: Transformer (multi-tap***) 23