Advertisement

# Half Bridge CVC-PWM Series Resonant Converter

• Ivo Barbi
• Fabiana Pöttker
Chapter
Part of the Power Systems book series (POWSYS)

## Abstract

This chapter studies a capacitor voltage clamped series resonant converter, regulated at constant frequency by pulse-width modulation (PWM-CVC-SRC). The principle of operation, topological states and relevant waveforms are described, after the presentation of the converter power stage diagram. Theoretical analysis is carried out, using the state-plane trajectory approach, which gives the static gain and output characteristics. In the subsequent sections, simplified design example and methodology are provided, along with simulation results. Proposed exercises with answers are included at the end of the chapter.

## Nomenclature

Vi

DC Bus voltage

V1

Half of the DC Bus voltage

Vo

Output DC voltage

Po

Output power

Po min

Minimum output power

Co

Output filter capacitor

Ro

Output load resistor

q

Static gain

D

Duty cycle

Dmax

Maximum duty cycle

Dmin

Minimum duty cycle

fs

Switching frequency

fs max

Maximum switching frequency

fs min

Minimum switching frequency

Ts

Switching period

fo

Resonant frequency [Hz]

ωo

Resonant frequency [rad/s]

μo

Frequency ratio

$${\text{V}}^{\prime}_{\text{o}}$$

Output DC voltage referred to the transformer primary side

io

Output current

$${\text{i}}^{\prime}_{\text{o}}$$

Output current referred to the transformer primary side

$${\text{i}}^{\prime}_{\text{o}} \left( {\overline{{{\text{I}}^{\prime}_{\text{o}} }} } \right)$$

Average output current referred to the transformer primary and its normalized value

Io min

Minimum average output current

$${\text{i}}^{\prime}_{{{\text{o}}\,\hbox{min} }}$$

S2—main switches

S3 and S4

Auxiliary switches

vg1, vg2, vg3 and vg4

Switches gate signals

$$\text{S}_{1} \text{and} \, \text{S}_{2}$$

main switches

DC1 and DC2

Clamping diodes

Cr

Resonant capacitors

Lr

Resonant inductor (may include the transformer leakage inductance)

z

Characteristic impedance

iLr

Resonant inductor current

vCr

Resonant capacitor voltage

$${\text{I}}_{1} \left( {\overline{{{\text{I}}_{1} }} } \right)$$

Inductor current at the end of the first step of operation and its normalized value

$${\text{I}}_{2} \left( {\overline{{{\text{I}}_{2} }} } \right)$$

Resonant inductor peak current and its normalized value

$${\text{I}}_{3} \left( {\overline{{{\text{I}}_{3} }} } \right)$$

Inductor current at the end of the third step of operation and its normalized value

vab

AC voltage, between points “a” and “b”

vS1, vS2, vS3 and vS4

Voltage across switches

iS1, iS2, iS3 and iS4

Switches currents

∆t1

Time interval of the first step of operation (t1−t0)

∆t2

Time interval of the second step of operation (t2–t1)

∆t3

Time interval of the third step of operation (t3–t2)

∆t4

Time interval of the fourth step of operation (t4–t3)

∆t5

Time interval of the fifth step of operation (t5–t4)

∆t6

Time interval of the sixth step of operation (t6–t5)

∆t7

Time interval of the seventh step of operation (t7–t6)

∆t8

Time interval of the eighth step of operation (t8–t7)

∆t9

Time interval of the ninth step of operation (t9–t8)

∆t10

Time interval of the tenth step of operation (t10–t9)

ϕ, θo, θr, θ

State plane angle

$$\overline{{{\text{r}}_{1} }} \,{\text{and}}\,\overline{{{\text{r}}_{ 2} }}$$

State plane radius

## Reference

1. 1.
Freitas Vieira, J.L., Barbi, I.: Constant frequency PWM capacitor voltage-clamped series resonant power supply. IEEE Trans. Power Electron. 8(2), 120–126 (1993)

## Copyright information

© Springer International Publishing AG, part of Springer Nature 2019

## Authors and Affiliations

1. 1.Federal University of Santa CatarinaFlorianópolisBrazil
2. 2.Department of ElectronicsFederal University of Technology—ParanáCuritibaBrazil