H-bridge produces square wave output under heavy inductive load instead of sine wave

Question

I was Following this tutorial to make H-Bridge. I have first did some simulation and the following image shows the same.

I don't have schematic because I directly made the circuit by hand based of the simulation.

The problem that I am having is that without having any load the output of H-bridge is a square wave and not a sine wave as apposed to the simulation.

Infact, the person in the tutorial was also having the same problem but he solved that by connecting a load at the output (please visit the link to see the problem).

Can you explain why do we get square wave instead of sine wave

the following is the LTSPICE file

Version 4
SHEET 1 3732 1544
WIRE 336 48 -224 48
WIRE 528 48 336 48
WIRE 976 48 528 48
WIRE -224 96 -224 48
WIRE 336 144 336 128
WIRE 640 144 336 144
WIRE 688 144 640 144
WIRE 2256 144 1888 144
WIRE 336 160 336 144
WIRE 528 160 528 48
WIRE 288 176 -144 176
WIRE 976 192 976 48
WIRE 1008 192 976 192
WIRE 1888 192 1888 144
WIRE 2256 192 2256 144
WIRE -144 208 -144 176
WIRE 976 208 976 192
WIRE 1008 208 976 208
WIRE 1120 208 1072 208
WIRE 1248 208 1200 208
WIRE 288 224 240 224
WIRE 976 224 976 208
WIRE 1008 224 976 224
WIRE 640 240 640 144
WIRE 944 240 640 240
WIRE 1008 240 944 240
WIRE 1008 256 816 256
WIRE 528 272 528 240
WIRE 640 272 528 272
WIRE 688 272 640 272
WIRE -224 288 -224 176
WIRE -144 288 -224 288
WIRE 528 304 528 272
WIRE 976 304 976 224
WIRE 1008 304 976 304
WIRE 480 320 -16 320
WIRE 976 320 976 304
WIRE 1008 320 976 320
WIRE 1120 320 1072 320
WIRE 1248 320 1200 320
WIRE 976 336 976 320
WIRE 1008 336 976 336
WIRE 944 352 944 240
WIRE 1008 352 944 352
WIRE 640 368 640 272
WIRE 816 368 816 256
WIRE 816 368 640 368
WIRE 880 368 816 368
WIRE 1008 368 944 368
WIRE 1888 368 1888 288
WIRE 1952 368 1888 368
WIRE 2256 368 2256 288
WIRE 2256 368 2176 368
WIRE 240 400 240 224
WIRE 240 400 -176 400
WIRE 1888 432 1888 368
WIRE 2256 432 2256 368
WIRE -16 464 -16 320
WIRE -16 464 -128 464
WIRE 112 464 -16 464
WIRE 112 480 112 464
WIRE -16 560 -16 464
WIRE -176 576 -176 400
WIRE -128 576 -128 528
WIRE -128 576 -176 576
WIRE 1888 576 1888 528
WIRE 2256 576 2256 528
WIRE 2256 576 1888 576
WIRE 112 592 112 544
WIRE 224 592 112 592
WIRE 304 592 224 592
WIRE 336 592 336 240
WIRE 336 592 304 592
WIRE 528 592 528 384
WIRE 528 592 336 592
WIRE 880 608 800 608
WIRE -128 624 -128 576
WIRE 112 624 112 592
WIRE 1152 656 1072 656
WIRE 880 704 816 704
WIRE -128 736 -128 688
WIRE -16 736 -16 640
WIRE -16 736 -128 736
WIRE 112 736 112 688
WIRE 112 736 -16 736
WIRE -224 768 -224 288
WIRE 224 768 224 592
WIRE 224 768 -224 768
WIRE 304 768 304 592
WIRE -16 832 -16 736
WIRE 480 832 480 368
WIRE 480 832 -16 832
WIRE 880 848 800 848
WIRE 1856 880 1776 880
WIRE 1984 880 1936 880
WIRE 2224 880 1984 880
WIRE 2544 880 2304 880
WIRE 2608 880 2544 880
WIRE 2784 880 2688 880
WIRE 1152 896 1072 896
WIRE 1984 912 1984 880
WIRE 2544 912 2544 880
WIRE 880 944 816 944
WIRE -16 1024 -192 1024
WIRE 64 1024 -16 1024
WIRE -16 1104 -16 1024
WIRE 880 1104 832 1104
WIRE 1392 1104 1072 1104
WIRE 1152 1152 1072 1152
WIRE 1168 1152 1152 1152
WIRE -192 1200 -192 1024
WIRE 880 1200 832 1200
WIRE 1104 1200 1072 1200
WIRE 1392 1200 1392 1184
WIRE 1392 1200 1104 1200
WIRE 1104 1232 1104 1200
WIRE 1136 1232 1104 1232
WIRE -16 1248 -16 1184
WIRE 64 1248 -16 1248
WIRE -16 1296 -16 1248
WIRE 880 1344 832 1344
WIRE 1392 1344 1072 1344
WIRE 1152 1392 1072 1392
WIRE -192 1440 -192 1280
WIRE -96 1440 -192 1440
WIRE -16 1440 -16 1360
WIRE -16 1440 -96 1440
WIRE 64 1440 -16 1440
WIRE 880 1440 832 1440
WIRE 1104 1440 1072 1440
WIRE 1392 1440 1392 1424
WIRE 1392 1440 1104 1440
WIRE -96 1472 -96 1440
WIRE 1104 1472 1104 1440
WIRE 1136 1472 1104 1472
FLAG 304 768 0
FLAG 688 144 pwm
IOPIN 688 144 Out
FLAG 688 272 sq
IOPIN 688 272 Out
FLAG 528 592 CG
IOPIN 528 592 Out
FLAG 816 704 CG
IOPIN 816 704 In
FLAG 1232 656 O1_1
IOPIN 1232 656 Out
FLAG 1248 208 O1
IOPIN 1248 208 Out
FLAG 1248 320 O2
IOPIN 1248 320 Out
FLAG 800 608 O1
IOPIN 800 608 In
FLAG -96 1472 0
FLAG 64 1024 HV+
IOPIN 64 1024 Out
FLAG 64 1248 HVM+
IOPIN 64 1248 Out
FLAG 64 1440 HV-
IOPIN 64 1440 Out
FLAG 1072 608 HVM+
IOPIN 1072 608 In
FLAG 1072 704 HV-
IOPIN 1072 704 In
FLAG 816 944 CG
IOPIN 816 944 In
FLAG 1232 896 O2_1
IOPIN 1232 896 Out
FLAG 800 848 O2
IOPIN 800 848 In
FLAG 1072 848 HVM+
IOPIN 1072 848 In
FLAG 1072 944 HV-
IOPIN 1072 944 In
FLAG 832 1200 CG
IOPIN 832 1200 In
FLAG 832 1440 CG
IOPIN 832 1440 In
FLAG 832 1104 O1
IOPIN 832 1104 In
FLAG 832 1344 O2
IOPIN 832 1344 In
FLAG 1232 1152 O1_2
IOPIN 1232 1152 Out
FLAG 1232 1392 O2_2
IOPIN 1232 1392 Out
FLAG 1136 1232 U3G
IOPIN 1136 1232 Out
FLAG 1136 1472 U4G
IOPIN 1136 1472 Out
FLAG 1840 272 O1_2
IOPIN 1840 272 In
FLAG 1888 368 U3G
IOPIN 1888 368 In
FLAG 2304 272 O2_2
IOPIN 2304 272 In
FLAG 2256 368 U4G
IOPIN 2256 368 In
FLAG 1840 512 O2_1
IOPIN 1840 512 In
FLAG 2304 512 O1_1
IOPIN 2304 512 In
FLAG 1888 144 HV+
IOPIN 1888 144 In
FLAG 1888 576 HV-
IOPIN 1888 576 In
FLAG 1952 368 HOA
IOPIN 1952 368 Out
FLAG 2176 368 HOB
IOPIN 2176 368 Out
FLAG 1776 880 HOA
IOPIN 1776 880 In
FLAG 2784 880 HOB
IOPIN 2784 880 In
FLAG 1984 976 HV-
IOPIN 1984 976 In
FLAG 2544 976 HV-
IOPIN 2544 976 In
SYMBOL voltage -16 544 R0
WINDOW 3 24 96 Invisible 2
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR Value SINE(0 3.3 50)
SYMATTR InstName V1
SYMBOL voltage -144 192 R0
WINDOW 3 24 44 Invisible 2
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR Value PULSE(0 3 0 30u 30u 0 60u 17000)
SYMATTR InstName V2
SYMBOL diode -144 464 R0
SYMATTR InstName D1
SYMBOL diode 96 624 R0
SYMATTR InstName D2
SYMBOL diode 128 544 R180
WINDOW 0 24 64 Left 2
WINDOW 3 24 0 Left 2
SYMATTR InstName D3
SYMBOL diode -112 688 R180
WINDOW 0 24 64 Left 2
WINDOW 3 24 0 Left 2
SYMATTR InstName D4
SYMBOL sw 336 144 R0
SYMATTR InstName S1
SYMATTR Value ""
SYMATTR SpiceModel MYSW1
SYMBOL voltage -224 80 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V3
SYMATTR Value 5
SYMBOL res 320 32 R0
SYMATTR InstName R1
SYMATTR Value 1k
SYMBOL sw 528 288 R0
SYMATTR InstName S2
SYMATTR Value ""
SYMATTR SpiceModel MYSW2
SYMBOL res 512 144 R0
SYMATTR InstName R2
SYMATTR Value 1k
SYMBOL Digital\\and 1040 272 R0
WINDOW 3 16 52 Invisible 2
SYMATTR Value Vhigh=5
SYMATTR InstName A1
SYMBOL Digital\\and 1040 160 R0
WINDOW 3 16 52 Invisible 2
SYMATTR Value Vhigh=5
SYMATTR InstName A2
SYMBOL Digital\\inv 880 304 R0
WINDOW 3 8 60 Invisible 2
SYMATTR Value Vhigh=5
SYMATTR InstName A3
SYMBOL Optos\\TLP5702 976 656 R0
SYMATTR InstName U1
SYMBOL voltage -192 1184 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V4
SYMATTR Value 48
SYMBOL res -32 1088 R0
SYMATTR InstName R3
SYMATTR Value 2.2k
SYMBOL zener 0 1360 R180
WINDOW 0 24 64 Left 2
WINDOW 3 24 0 Left 2
SYMATTR InstName D5
SYMATTR Value EDZV15B
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL Optos\\TLP5702 976 896 R0
SYMATTR InstName U2
SYMBOL Optos\\TLP5702 976 1152 R0
SYMATTR InstName U3
SYMBOL Optos\\TLP5702 976 1392 R0
SYMATTR InstName U4
SYMBOL voltage 1392 1088 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V5
SYMATTR Value 15
SYMBOL voltage 1392 1328 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V6
SYMATTR Value 15
SYMBOL res 1216 192 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R5
SYMATTR Value 100
SYMBOL res 1216 304 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R6
SYMATTR Value 100
SYMBOL res 1248 640 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R7
SYMATTR Value 22
SYMBOL res 1248 880 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R8
SYMATTR Value 22
SYMBOL res 1248 1136 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R9
SYMATTR Value 22
SYMBOL res 1248 1376 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R10
SYMATTR Value 22
SYMBOL nmos 1840 192 R0
SYMATTR InstName M1
SYMATTR Value IRF510
SYMBOL nmos 1840 432 R0
SYMATTR InstName M2
SYMATTR Value IRF510
SYMBOL nmos 2304 192 M0
SYMATTR InstName M3
SYMATTR Value IRF510
SYMBOL nmos 2304 432 M0
SYMATTR InstName M4
SYMATTR Value IRF510
SYMBOL ind 1952 864 R90
WINDOW 0 5 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName L1
SYMATTR Value 10m
SYMBOL cap 1968 912 R0
SYMATTR InstName C1
SYMATTR Value 10µ
SYMBOL ind 2704 864 R90
WINDOW 0 5 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName L2
SYMATTR Value 10m
SYMBOL cap 2528 912 R0
SYMATTR InstName C2
SYMATTR Value 10µ
SYMBOL res 2320 864 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R4
    SYMATTR Value 48
    TEXT -464 216 Left 2 !.tran 50m
    TEXT -184 -48 Left 2 !.model MYSW1 SW(Vt=0, Vh=0, Ron=10meg, Roff=0.1)
    TEXT -184 -16 Left 2 !.mode

l MYSW2 SW(Vt=0, Vh=0, Ron=0.1, Roff=10meg)

A schematic is needed (not slightly needed or a bit nice to have; it is needed). — Andy aka, Nov 18 '20 at 10:58
Please add a schematic but NOT a raft of huge photos that create a major scrolling headache and a hard-to-follow question. — TonyM, Nov 18 '20 at 11:08
Voltage is square , but current is not. Try to connect resistive load and measure drop voltage. — user263983, Nov 18 '20 at 12:12
How are you generating the PWM control input? Make sure the schematic shows us that. If it's software, have you checked it independently of the 220V bridge? — , Nov 18 '20 at 14:53
@Sanmvegsaini Posting the source for the schematic is encouraging, but you're using custom libraries, in particular `TLP5702` (both symbol and subcircuit). People that don't have your files can't run the schematic. However, looking at the connections, it's difficult to decipher what you're doing, but judging from the looks of it, all you want is to see the effect of a filtered SPWM. In this case, maybe [this answer](https://electronics.stackexchange.com/a/372170/95619) will help you. — a concerned citizen, Nov 20 '20 at 14:56

H-bridge produces square wave output under heavy inductive load instead of sine wave

0 Answers0