4.1.2  Comparison: Simulation / Measurement Data

Figure 4.3 is the simulated voltage at a load of 14W (V_power_1 = 50V), Figure 4.4 the corresponding oscilloscope-diagram. Slope (a) is caused by turn-off IGBT2+3, (b) by turn-on IGBT1+4, (c) by turn-off IGBT1+4 and (d) by turn-on IGBT2+3. The overshoots in Figure 4.4 are caused by parasitic inductances in the pins and tracks of the real circuit.

Figure 4.3: Simulated voltage at a load of 14W, V_power_in = 50V.

Figure 4.4: Measurement data according to Figure 4.3

Figure 4.5 is a magnification in time of (a) and (b) in Figure 4.3, Figure 4.6 the according measurement data.

Figure 4.5: Simulation data: magnification of (a) and (b) in Figure 4.3

Figure 4.6: Measurement data according to Figure 4.5

Figure 4.7 shows the turn-off of both IGBT2 and IGBT3 in series ((a) in Figure 4.3). The measured fall time is 126ns. Figure 4.8 shows the turn-on of both IGBT1 and IGBT4 in series ((b) in Figure 4.3). The rise time is 265ns.

Figure 4.7: Measurement Data: magnification of (a) in Figure 4.3

Figure 4.8: Measurement Data: magnification of (b) in Figure 4.3

Figure 4.9 shows the simulated voltage at the gate of IGBT2, Figure 4.10 is the corresponding measured signal (load = 14W, V_power_in = 50V). In the measurement diagram are noise-spikes (arrows in Figure 4.10) caused by the switching of the other channel. These noise-spikes are lower in the simulated diagram, but also visible (arrows in Figure 4.9). Since the noise-level is at about 1V it does not cause problems in this mode of operation, the trigger level of a IGBT is at about V_GE = 5V.

Figure 4.9: Simulated voltage: gate-signal at IGBT2

Figure 4.10: Measured voltage: gate-signal IGBT2

This page is part of a Frameset: Electrodynamic Sculpture: A Thesis by Rafael Bräg.