Consider the three-phase inverter in Figure 4. The battery is modeled by an electromotive force voltage...

 

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Consider the three-phase inverter in Figure 4. The battery is modeled by an electromotive force voltage source Vs and zero internal resistance. The three-phase load is modeled by three sources of sinusoidal currents phase shifted by 1200. Electronic switches are supposed to be perfect. Im designates the maximum value of the current absorbed by the load, Dhe phase shift of this current in relation to the simple voltage. We give f-200 Hz, Vs-600V, Im=12A and (p=0° This inverter is controlled with a 1800 type control at frequency f P i(t)= sin( cot To T4 i, (t)=1 sin(cot - Q) 2x i, (t)=1, sin( oot- (4) 3 vs) T1 d) 4x 3 Phase a T3 ToT6 Phase b Draw the curves of the three neutral phase voltages van(t), vbn(t) and vcn(t). b) Give the Fourier series decomposition of the voltage van(t): Calculate the harmonic distortion rate THD of the voltage van and the current ia. Calculate the conduction time of transistor T1 and diode D1 by taking the van voltage as a reference voltage. To T2 Charge Figure 4. Three-phase inverter supplying three sources of sinusoidal currents T5 Phase c ic Vs. e) Calculate the active power Pch absorbed per load. f) We now replace the previous one with a purely resistive load (R = 20 y): • Plot the waveform in the source is(t); • Calculate the average power consumed by the resistive load. g) We now replace the previous one with an inductive load (R = 5 ÿ, L = 12 mH) • Calculate the average power consumed by the load • Calculate the conduction time of transistors and diodes. h) If we keep the load only the resistive (R=52) but we do not control the transistor T5 and T2 (they are kept open) and the same signals are maintained control on other transistors as follows. O T/6 6 2T/6 3T/6 3 4T/6 5T/6 4 6 • What is the switching sequence? • Give the equivalent circuit of the load for all switching sequences. • Plot the waveform of the line voltage vab(t) and that of the current ia(t). t to s Consider the three-phase inverter in Figure 4. The battery is modeled by an electromotive force voltage source Vs and zero internal resistance. The three-phase load is modeled by three sources of sinusoidal currents phase shifted by 1200. Electronic switches are supposed to be perfect. Im designates the maximum value of the current absorbed by the load, Dhe phase shift of this current in relation to the simple voltage. We give f-200 Hz, Vs-600V, Im=12A and (p=0° This inverter is controlled with a 1800 type control at frequency f P i(t)= sin( cot To T4 i, (t)=1 sin(cot - Q) 2x i, (t)=1, sin( oot- (4) 3 vs) T1 d) 4x 3 Phase a T3 ToT6 Phase b Draw the curves of the three neutral phase voltages van(t), vbn(t) and vcn(t). b) Give the Fourier series decomposition of the voltage van(t): Calculate the harmonic distortion rate THD of the voltage van and the current ia. Calculate the conduction time of transistor T1 and diode D1 by taking the van voltage as a reference voltage. To T2 Charge Figure 4. Three-phase inverter supplying three sources of sinusoidal currents T5 Phase c ic Vs. e) Calculate the active power Pch absorbed per load. f) We now replace the previous one with a purely resistive load (R = 20 y): • Plot the waveform in the source is(t); • Calculate the average power consumed by the resistive load. g) We now replace the previous one with an inductive load (R = 5 ÿ, L = 12 mH) • Calculate the average power consumed by the load • Calculate the conduction time of transistors and diodes. h) If we keep the load only the resistive (R=52) but we do not control the transistor T5 and T2 (they are kept open) and the same signals are maintained control on other transistors as follows. O T/6 6 2T/6 3T/6 3 4T/6 5T/6 4 6 • What is the switching sequence? • Give the equivalent circuit of the load for all switching sequences. • Plot the waveform of the line voltage vab(t) and that of the current ia(t). t to s

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a What are the loads for which the conduction time of all the diodes is zero The conduction time of all the diodes is zero when the load is a capacitorThis is because the voltage across a capacitor ca... View the full answer