Experiment
DC-AC Inverter: Single-phase Square Wave Inverter
Part 1: To get acquainted with the simulation environment for Single-phase Square wave inverter
Graphically model and simulate the single-phase square wave inverter (dc-ac converter) using ORCAD 10.5 and PSpice. Study the dc source (input) current and ac load (output) voltage and current waveforms. Compare the same with the results obtained from the analytical expressions.
Objective:
Part 1:
Graphically model the square wave inverter shown in Fig. 1 using the graphical front end of ORCAD. The nominal values for the inverter are as follows:
Vs = 120 V L= 20 mH R = 5 ohms F= 50 Hz
Figure 1 Part 2:
1. Observe and plot the load voltage and current waveforms from time 0 to 0.1sec (Output voltage across R & L), (Current through L).
2. Observe and plot supply current and voltage for the same duration.
3. Observe and plot the FFT of the input and output voltage and current waveforms from fundamental frequency to 1000 Hz.
Part 3:
Repeat the above for R = 10 ohms.
Part 4:
Repeat the above experiment for a purely inductive load of L = 10 mH.
Tools required:
1. Software simulator ORCAD 2. Calculator
Software modules and settings
1. Add all the available libraries to the project
2. Add MOSFETs IRF450, Resistor, Inductor, VDC, VPULSE and 0/Ground 3. Set VDC = 120V
4. Set Vpulse1: V1=0, V2=15 TR=10u, TF=10u TD=0 PW=={0.5*T} PR = {T}
5. Set Vpulse2: V1=0, V2=15 TR=10u, TF=10u TD={0.5*T} PW=={0.5*T} PR = {T}
6. Set Vpulse3: V1=0, V2=15 TR=10u, TF=10u TD={0.5*T} PW=={0.5*T} PR = {T}
7. Set Vpulse4: V1=0, V2=15 TR=10u, TF=10u TD=0 PW=={0.5*T} PR = {T}
8. Set load inductance and resistance as given above.
5. Arrange the components as shown in the figure 1 6. Set the values of the components as required
7. Place ‘PARAM’ in the schematic page and add the variables ‘frequency’ and
‘T’ and assign values as 50 and {1/frequency}.
8. Make a new simulation profile PSpice>New Simulation Profile> Give any name>Set the simulation time to 0.1sec and other parameters according to requirements
9. Place the voltage and current marker across the load.
Frequency Spectrum of load voltage and current
Experiment
DC-AC Inverter: Three-phase Square Wave Inverter
Part 1: To get acquainted with the simulation environment for three-phase Square wave inverter
Graphically model and simulate the three-phase square wave inverter (dc-ac converter) using ORCAD 10.5 and PSpice. Study the dc source (input) current and ac load (output) voltage and current waveforms. Compare the same with the results obtained from the analytical expressions.
Objective:
Part 1:
Graphically model the square wave inverter shown in Figure using the graphical front end of ORCAD. The nominal values for the inverter are as follows:
Vs = 400 V L= 10 mH R = 2 ohms F= 50 Hz
Part 2:
1. Observe and plot the phase voltage and current waveforms from time 20ms to 100ms (Output voltage across R & L), (Current through L).
2. Observe and plot the line to line voltage waveforms from time 20ms to 100ms 3. Observe and plot supply current and voltage for the same duration.
4. Observe and plot the FFT of the input and output voltage and current waveforms from fundamental frequency to 1000 Hz.
Part 3:
Repeat the above for R = 10 ohms.
Part 4:
Repeat the above experiment for a purely inductive load of L = 10 mH.
Tools required:
1. Software simulator ORCAD 2. Calculator
Software modules and settings
1. Add all the available libraries to the project
8. Set VG5: V1=0, V2=15 TR=10u, TF=10u TD={T*(2/3)} PW= {0.5*T} PR = {T}
9. Set VG6: V1=0, V2=15 TR=10u, TF=10u TD={T*(5/6)} PW= {0.5*T} PR = {T}
10. Set load inductance and resistance as given above.
Procedure
1. Start ORCAD 10.5
2. Make a new project with the name ‘three_phase_square_inverter’ and select the option of analog and mixed A/D.
3. Add all the libraries to the project
4. Place components in the schematic page
5. Arrange the components as shown in the figure 6. Set the values of the components as required
7. Place ‘PARAM’ in the schematic page and add the variables ‘frequency’, ‘T’,
‘Rload’ and ‘Lload’ and assign values.
8. Make a new simulation profile PSpice>New Simulation Profile> Give any name>Set the simulation time to 0.1sec and other parameters according to requirements
9. Place the voltage and current marker across the load.
• Load current waveforms for R=2 ohm and L=10mH
• Phase A voltage
• Line to Line Voltage Vab
