LLC Resonant Half Bridge Converter

Gain
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
Impacts of Circuit Parameters
0
0.1 1 10
fn, (Ln =1)
L n =1
Qe=0.1
Qe=0.2
Qe=0.5
Qe=0.8
Qe=1
Qe=2
Qe=5
Qe=8
Qe=10
ZCS/ZVS
Gain
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
0.1 1 10
fn, (Ln =5)
L n =5
Qe=0.1
Qe=0.2
Qe=0.5
Qe=0.8
Qe=1
Qe=2
Qe=5
Qe=8
Qe=10
ZCS/ZVS
Gain
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
L n =10
Qe=0.1
Qe=0.2
Qe=0.5
Qe=0.8
Qe=1
Qe=2
Qe=5
Qe=8
Qe=10
ZCS/ZVS
0
0.1 1
fn
10
Gain Change with Ln and Qe
- Ln increase with Qe constant (designed Lr, Cr, and operational RL),
- flat,
- magnitude shift-up,
- frequency value at peak-gain moving towards more left,
- less “frequency-selective”
- wide frequency variation from no load to full load (more discussion later)
Ln somewhere 3 to 5 look best balance between peak gain and frequency
change – can be initially pick-up