Three phase delta connected inverter
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Three phase inverters in 180 o conduction mode with the delta connected Load Presented by:- Gom Dorji Tenzin Dorji Tshering Choden Ugyen Wangchuk
description
Inverter is DC to AC converter. Its working is similar to the single phase inverter. We uses three pairs of switches, all are controllable switch. We can also use uncontrollable switch. Only differences is the use of gate pules in case of controllable switch. The conduction period is 120 degree.
Transcript of Three phase delta connected inverter
Three phase inverters in 180o conduction mode with the delta connected Load
Presented by:- Gom DorjiTenzin Dorji
Tshering ChodenUgyen Wangchuk
VR= VS (T1ON)
VR= -VS(T4ON)
VY= VS (T5ON)
VY= -VS(T2ON)
VB= VS (T3ON)
VB= -VS (T6ON)
Delta connected load
Load R=R1=R2
• Each thyristor conducts for 180 degrees.• There are VI mode of operations in a complete
time period with the duration of 60 degrees in a sequence.
• Three thyristors conduct at any instant of time (two in one half and one in other)
• For delta connected line voltage is equal to phase voltage.
• From phase voltage phase current can be determined.
Input waveforms for 180 Conductions
T1
T5
T6
T1
T2
T6
T1
T2
T3
T2
T3
T4
T3
T4
T5
T4
T5
T6
T1
T5
T6
Mode 1 operationsSCR T1ON, T5ON, T6ON
03
t
For Delta connectedVL=Vph, IL=3Iph
Output voltagesVR= VRY=0VY= VYB=Vs VB=VBR= -Vs
Output currentsIR= 3IRY= 0 IY= 3IYB= 3Vs/R IB= 3IBR= -3VS/R
Mode 2 operationsSCR T1ON, T2ON, T6ON
2
3 3t
Output voltagesVR= VRY=Vs VY= VYB=0VB=VBR= -Vs
Output currentsIR= 3IRY= 3Vs/RIY= 3IYB= 0IB= 3IBR= -3VS/R
2
3t
Mode 3 operationsSCR T1ON, T2ON, T3ON
Output voltagesVR= VRY=Vs VY= VYB=-Vs VB=VBR= 0
Output currentsIR= 3IRY= 3Vs/R IY= 3IYB= -3VS/R IB= 3IBR= 0
Mode 4 operationsSCR T2ON, T3ON, T4ON 𝜋≤𝜔𝑡≤4𝜋 /3
Output voltagesVR= VRY=0 VY= VYB=-Vs VB=VBR= Vs Output currentsIR= 3IRY=0 IY= -3IYB= -3VS/R IB= 3IBR= 3Vs/R
Mode 5 operationsSCR T3ON, T4ON, T5ON
4𝜋 /3≤𝜔𝑡≤5𝜋 /3
Output voltagesVR= VRY=-Vs VY= VYB=0 VB=VBR= Vs
Output currentsIR= 3IRY=3VS/R IY= 3IYB= 0 IB= 3IBR= 3Vs/R
Mode 6 operationsSCR T4ON, T5ON, T6ON
5𝜋 /3≤𝜔𝑡≤2𝜋
Output voltagesVR= VRY=-Vs VY= VYB= Vs VB=VBR= 0Output currentsIR= 3IRY=3VS/R IY= 3IYB= 3Vs/R IB= 3IBR= 0
Parameters Mode 1 Mode 2 Mode 3 Mode 4 Mode 5 Mode 6
VR=VRY 0 VS VS 0 -VS -VS
VY=VYB VS 0 -VS -VS 0 VS
VB=VBR -VS -VS 0 VS VS 0
IPHASE
IRY 0 VS/R VS/R 0 -VS/R -VS/R
IYB VS/R 0 -VS/R -VS/R 0 VS/R
IBR -VS/R -VS/R 0 VS/R VS/R 0
ILINE
IR 0 3Vs/R 3Vs/R 0 -3Vs/R -3Vs/R
Iy 3Vs/R 0 -3Vs/R -3Vs/R 0 3Vs/R
IB -3Vs/R -3Vs/R 0 3Vs/R 3Vs/R 0
Voltage waveform
Current waveform
Mathematical expressionThe instantaneous line to line voltage in fourier series can
be express as:
From the output voltage waveform ao and an =0
VRY =
VRY
VYB =
VRY
Therefore line voltage is,VRY
VBR =
VRY
Thank You Any
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