Skip to content

301 - Diode Rectifier

Single-phase and three-phase diode bridge rectifiers for AC-DC conversion.

Overview

Diode rectifiers are the simplest form of AC-DC power conversion, using uncontrolled diodes to convert AC voltage to pulsating DC.

Topics Covered

  • Single-phase half-wave rectifier
  • Single-phase full-wave bridge
  • Three-phase diode bridge
  • Ripple calculation and filtering
  • Power factor considerations

Single-Phase Full-Wave Bridge

Circuit Configuration

     D1      D3
AC+ ─┤►├─┬──┤►├─ DC+
         │
        Load
         │
AC- ─┤◄├─┴──┤◄├─ DC-
     D2      D4

Key Equations

Average DC Voltage: $\(V_{DC} = \frac{2V_m}{\pi} \approx 0.637 \cdot V_m\)$

RMS Voltage: $\(V_{rms} = \frac{V_m}{\sqrt{2}}\)$

Ripple Factor: $\(\gamma = \sqrt{\left(\frac{V_{rms}}{V_{DC}}\right)^2 - 1} \approx 0.483\)$

Three-Phase Diode Bridge

Circuit Configuration

Six-diode bridge configuration for three-phase input.

Key Equations

Average DC Voltage: $\(V_{DC} = \frac{3\sqrt{2}}{\pi} V_{LL} \approx 1.35 \cdot V_{LL}\)$

Ripple Frequency: 6× line frequency (300 Hz for 50 Hz input)

Simulation Parameters

Parameter Single-Phase Three-Phase
Input Voltage 230V RMS 400V L-L
Frequency 50 Hz 50 Hz
Load 100Ω 50Ω
Filter Cap 1000µF 470µF