Project 2

Part A:

1. Design a DC power supply using a PFC circuit for general purpose applications with 350V dc output and load in the range of 0-7A. The supply should meet the harmonic standard limits for input power quality such that current THD limits are satisfied with input power factor >0.97 value. The input side is connected to a single phase grid with parameters as 230V and 50Hz.

Design the supply to give the following specifications:

1. Component selection and justification
2. Passive component designs including filters
3. Controller design
4. Simulation results
5. Validation with the design criterion

ANSWER:

Normally, the DC voltage is set to 10 to 20V higher than the expected maximum peak input voltage. Designing a universal input power supply (87-266Vrms at 47-63Hz) the DC output voltage from the PFC at the input to the DC-DC converter would be set at 386V to 396V

The active PFC circuit controls the current by turning the MOSFET on and off, synchronizes the power supply voltage and phase, and brings the input current waveform closer to a sine wave

The easy way would be to look at the label and look up the model's specs (or post it here) - chances are "no" since an active PFC circuit costs more to manufacture and typical cheap tax cases that have PSUs bundled typically have low price points.

PFC (power factor correction; also known as power factor controller) is a feature included in some computers and other power supply boxes that reduces the amount of reactive power generated by a computer. Reactive power operates at right angles to true power and energizes the magnetic field.

_______________________________________________________________________________________________________________

1. Redesign the above power supply with the PWM rectifier. Give the difference in both power supplies in terms of cost, control complexity, degrees of freedom, additional features and efficiency.

______________________________________________________________________________________________________________________

Part B:

Design a high-performance high voltage DC power supply for 15 kV dc output and load in the range of 0-10A. The supply should meet the harmonic standard limits for input power quality such that current THD limits are satisfied with input power factor >0.98 value. The input side is connected to a three-phase LV grid with parameters 11kV (line-line) and 50Hz.

Design the supply to give the following specifications:

1. Component selection and justification
2. Passive component designs including filters
3. Controller design
4. Simulation results
5. Validation with the design criterion

ANSWER:

Typical output voltages for high voltage power supplies are 1kV to 360kV, although ranges of 62V to 500kV are offered. Spellman's range of output power spans from less than a watt to over 200 kilowatts.

HVDC allows power transmission between AC transmission systems that are not synchronized. Since the power flow through an HVDC link can be controlled independently of the phase angle between source and load, it can stabilize a network against disturbances due to rapid changes in power.