BOOK_CONTENT
From The Switching Function: Analysis of Power Electronic Circuits

5.1 Introduction

The analysis of the rectifier with capacitive load is a classical case of a 'circuit determined' switching function. The switching instances are circuit determined and they must be known before the application of the technique.

The analysis is based on the input loop equation. The voltage at the input of the bridge is made up from two components each at a different time slot: the input supply voltage and the 'reflection' of the output dc voltage. For this purpose two switching functions are introduced, both circuit determined (Fig. 5.1).


Figure 5.1: AC to DC diode converter capacitive load

The output voltage ripple is ignored when the line current is calculated; it makes the derivation simpler. This is justified for a practical system where large capacitors are used. The output ripple voltage itself is later calculated in terms of the output ripple current. The line current is derived as a function of the parameters of the two switching functions, the output dc voltage and the other circuit parameters.

The output dc voltage is calculated from the expression of the line current by considering the two points in time where it is zero.

5.2 Mathematical Modelling

The mathematical modelling of this circuit is a good candidate for the procedure outlined in Chapter 1 for the application of the switching function technique. The analysis of this circuit is based on the input loop voltage expression. The input loop comprises the input voltage V in( t), the voltage across the...

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DC Power Supplies
DC power supplies accept an input power and output the desired form of DC power. Common types of DC power supplies include linear power supplies, switching power supplies, DC-DC converters, and silicon controlled rectifier (SCR) type power supplies.
Power Supplies
Power supplies are electrical devices that deliver electric power to one or several loads. They generate the output power by converting an input signal into an output signal.
Switching Power Supplies
Switching power supplies are DC sources that use a switching element (normally a power transistor) to generate the desired voltage. Switching power supplies are also called switch-mode products or switching mode power supplies (SMPS).
Zener Diodes
Zener diodes are PN junction devices that are designed to operate in the reverse-breakdown region.  
Frequency-to-Current Converters
Frequency-to-current converters accept a frequency (an AC signal) and produce an output current whose value is a function of the input frequency.

Topics of Interest

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