Power Electronics Assignment: Design Project - Power Supply Design

1. Overview

You work for a consumer electronics design company that is developing a Smart-device Docking Station capable of providing power to a range of smart devices (phones, tablets, music players, etc), audio amplifiers, as well as providing an auxiliary power supply. The docking station is required to be able to plug into any single-phase power outlet anywhere in the world, and should be compliant to applicable power quality standards. Your role at the company is to design and test a power supply system that is capable of supplying the various parts of the docking station with the necessary quantities of power at the required voltages.

Part 1 - Rectifier and Converters Designs

Diode-Bridge Rectifter + Stage 1 DC-DC Converter

Start by designing the Rectifier and Stage 1 DC-DC converter. Unlike the rectifiers mostly discussed in the notes, you won't have a large enough load to enable inductive filtering on its own to smooth the output (without using a very large inductor). And like the hardware labs, if you use too large a capacitive filter it will result in large amount of harmonic distortion on the input side. You should instead allow the rectifier output to have some capacitive ftltering but still fluctuate over a reasonable range, and rely upon the Stage 1 DC-DC converter to provide suitable regulation and a constant 24 V output.

Stage 2 DC-DC Converter(s)

You need to come up with a single converter design that will work for both loads. The converter should be also operate at the previous university ID determined switching frequency. (Note that it does not necessarily have to be at the same switching frequency as the stage 1 rectifier.)

Part 2 - Implement and Test Stage 2 Converters

Use LTSpice to build the Stage 2 converter with open loop control (unregulated), and then test the converter for all three load types and load ranges. Verify that the converter produces the required outputs and stays in continuous conduction. Measure the input power required in each load scenario and measure converter efficiency under a range of different load scenarios.

Optional: Implement closed loop/feedback PWM control to automatically manage the duty cycle to achieve the required output. Note: it can be harder to get this right than for the Stage 1 converter - in fact it is recommended to do stage 1 converter feedback control first.

Part 3 - Implement and Test Rectifier and Stage 1 Converter

Use LTSpice to build the Rectifier and Stage 1 converter, complete with closed loop PWM control of the DC-DC converter section (regulated supply). Validate that the circuit works for both maximum and minimum output loads and for the maximum and minimum AC voltages that it can experience. Check that the converter produces the required 24V output, that it stays in continuous conduction and also that there are no high current spikes in the circuit. Measure the input power required in each load/input scenario, identifying where the losses are, and calculate the Rectifier/Converter efficiency. Observe and comment on the AC supply current waveform.

Part 4 - Join Rectifier/Stage 1 and Three Stage 2 converters and Test

Connect the Rectifier/Stage 1 converter to two copies of the Stage 2 converter and test under all real conditions. Comment particularly on whether you are still able to achieve the desired output voltages and low ripple, and if required what you think might do to address that. Calculate the combined/overall efficiency of supply to the loads.

Comment on what you observe at start-up, that is when you first plug in the power supply and all output voltages are zero. Do some research and see what can be done in practice to address this.

Attachment:- Design-Project-Power-Supply-Design.pdf