SLYY234 December 2024 AMC0106M05 , AMC0106M25 , AMC0136 , AMC0311D , AMC0311S , AMC0386 , AMC0386-Q1 , AMC1100 , AMC1106M05 , AMC1200 , AMC1200-Q1 , AMC1202 , AMC1203 , AMC1204 , AMC1211-Q1 , AMC1300 , AMC1300B-Q1 , AMC1301 , AMC1301-Q1 , AMC1302-Q1 , AMC1303M2510 , AMC1304L25 , AMC1304M25 , AMC1305M25 , AMC1305M25-Q1 , AMC1306M05 , AMC1306M25 , AMC1311 , AMC1311-Q1 , AMC131M03 , AMC1336 , AMC1336-Q1 , AMC1350 , AMC1350-Q1 , AMC23C12 , AMC3301 , AMC3330 , AMC3330-Q1
In this simulation, the dual active bridge with phase shift control is running at a switching frequency of 100 kHz and is configured as constant current source output that drives a fixed current of 20 A into a pure resistive 10-Ω load (that results in a 200-V DC output, representing a 4-kW load).
At time t1 = 2ms, the load is changed from 10 Ω to 20 Ω. This results in an immediate current change down to 10 A (since voltage is 200 V at that time). After some time, the control loop starts to regulate back to the 20-A constant current which forces the output voltage to increase to 400-V DC when settled (resulting in a load change from 4 kW to 2 kW). Figure 97 shows the transient response of the output current.
Figure 97 shows the response to the same load step for different bandwidth settings or the current sensor in the control loop. With a current sensor bandwidth of only 1 kHz, there is a long settling time of 1.6 ms. Increasing the bandwidth to 10 kHz and 100 kHz, brings the settling time (90% of end value) down to 0.6ms and 0.3ms, respectively. A further increase of current-sensor bandwidth does not improve the transient response significantly because the settling time is limited by the control-loop bandwidth of the current loop which was set to 10 kHz.
In conclusion, a current sensor at point E or F with a bandwidth lower than 100 kHz is sufficient to keep the settling time < 1ms for any load step change at the converter output.