DEPARTMENT OF ELECTRICAL POWER ENGINEERING

COLLEGE OF ENGINEERING

POWER ELECTRONICS

| Home | Topics | Summary of Topics | Examples | Test Your Understanding | Survey |
Topics Covered - DC To DC Converters - Converter Design Consideration

TOPICS COVERED:

DC TO DC CONVERTER

•  Introduction

Buck (Step Down) Converter

•  Assumptions Made for Analysis of the Buck Converter

•  *Circuit Operation Switching Modes

•  Output Voltage Average

•  The Inductor Current Ripple

•  The Load and the Capacitor Current

•  Continuous Conduction Condition

•  The Capacitor Voltage Ripple

Boost (Step Up) Converter

•  Assumptions Made for Analysis of the Boost Converter

•  *Circuit Operation Switching Modes

•  Output Voltage Average

•  The Inductor Current Ripple

•  The Inductor Current

•  Continuous Conduction Condition

•  The Diode and Capacitor Currents

•  The Capacitor Voltage Ripple

Designing DC-DC Converters

•  Converter Design Consideration

PULSE WIDTH MODULATED INVERTERS

•  Introduction

•  Inverter Types

•  Basic Inverter

•  Performance Parameters

•  Fourier Series

•  Total Harmonic Distortion

Single Phase Inverter

•  Single Phase Half Bridge Inverter

•  Single Phase Full Bridge Inverter

•  Square-wave Inverter

•  Square-wave Inverter with RL Load

•  Pulse-Width Modulation (PWM) Control Strategy

•  Amplitude & Harmonics Control

•  Sinusoidal Pulse Width Modulation (SPWM)

•  PWM Definitions & Considerations

Bipolar Switching (Single Phase)

•  PWM Outputs

•  PWM Harmonics

Unipolar Switching (Single Phase)

•  PWM Outputs

•  PWM Harmonics

Three Phase Inverter

•  Introduction

•  Switch State for Six Step Inverter

•  Six Step Inverter (continue)

•  Three Phase SPWM

 

Converter Design Consideration

  1. If switching frequency increases, the size of minimum inductor for continuous current and minimum capacitor to limit output ripple are reduced.
  2. Hence, High switching frequencies are preferable to reduce th size of both the inductor and capacitor.
  3. But, High switching frequency will cause power losses to increase in the switch (heat is produced). Then, the efficiency of converter will be reduced.
  4. In general, switching frequency is chosen to be 20kHz to 300kHz.
  5. L is designed to be 25% greater or 10 times larger than the calculated minimum inductor value. (for allowing continuous current)
  6. The inductor wire must be rated at rms current and the core should not saturate for peak inductor current.
  7. The capacitor must be selected to limit the output ripple to the design specifications to withstand peak output voltage. and carry required rms current.
  8. The selected switch (e.g. IGBT, MOSFET, BJT, etc.) must withstand maximum voltage stress when off and minimum current when on.
  9. The temperature rating must not be exceeded.

 

Click to go to PREVIOUS page

Click to go to EXAMPLE page

 

 

 

Go To TOP Page

| Home | Topics | Summary of Topics | Examples | Test Your Understanding | Survey |