ENPNewswire-June 19, 2019--Adaptive LED Current Ripple
Suppressor from Diodes Incorporated Enables High Power Factor and Flicker-Free Professional LED Lighting
Also due to the current cancellation effect (interleaved mode with 90 degrees of phase shift) a significant drop of output current ripple
during heavy load can be achieved.
This is due to phase current ripple
, as magnetic circuit shapes were designed based on the assumption that their value was constant.
The low voltage ripple, low current ripple
plus a range of integrated safety features make it safe for batteries and the vehicles delicate electronic system.
2) and, therefore, are applicable up to a current ripple
level of ~50 % (when [I.sub.0] is selected in the middle part of this domain).
In addition, the newly developed optimized CMVRPWM strategies with the consideration of the current ripple
losses and switching losses minimizing have been proposed in .
where [DELTA][I.sub.I] is the desired current ripple
at the inductor, [f.sub.s] is the switching frequency of the inverter, [V.sub.L] is the voltage at the inductor, and D is the equivalent duty cycle of the inverter.
Converter parameters Parameters Notation Value Rated input voltage [V.sub.g] 30 V Rated output voltage [V.sub.C] 15 V Rated load current [I.sub.L] 15 A Inductor parasitic resistor [R.sub.L] 0.118 [OMEGA] MOSFET resistor(IRFZ44N) [r.sub.dson] 0.035 [OMEGA] Inductor current ripple
[DELTA][I.sub.L] 0.34 A Output voltage ripple [DELTA][V.sub.C] 0.3 mV Output capacitor C 1000[micro]F Output inductor L 142[micro]H Switching frequency [f.sub.s] 150 kHz Table 1.
Inductor Current Ripple
(peak to peak) (3) amplitude can determine the inductor current ripple
value between peak to peak
However, the analog 1 st-order RC filter does not completely reject the current ripple
due to PWM switching, so the final solenoid current signal is obtained after averaging several samples using logic embedded in the microcomputer.
The trapezoidal strategy relies its operation on a discrete trapezoidal linear approximation that more accurately determines the switching of the active filter for the one-step ahead current sample, such that three significant advantages are potentially exhibited: first, the trapezoidal predictive controller slightly increments the processing time without affecting the switching of the power converter; second, in contrast to the typical Euler approximation used in other works [6,7,13-20], the trapezoidal method generates lower AC current ripple
; and third, the convergence time and load operating performance are wider than those obtained using the typical predictive control strategy, which improves the reference current tracking and, therefore, the power quality.