Power_Electronics-10.ppt

ECE 364 – Power ElectronicsSession 10 – Regulation Examples, Equivalent Sources, “Power Filtering” Analysis P. T. Krein Department of Electrical and Computer Engineering University of Illinois at Urbana-Champaign Power Electronics Regulation examples Equivalent sources “Power filtering” analysis The method of “ideal action” Regulation Examples Example: DC supply with 0.1% line regulation. Input: 120 Vrms 60 Hz. Output: 5 V. Assume input = 120 V ± 10% (108 V to 132 V) Regulation Examples With input variation as allowed, the output change will not exceed 5 mV. Ripple (which is about 50 mV), is not included in the line regulation definition. Regulation Examples Example: Input: 85 to 265 Vrms 60 Hz Output: Vout,nom=12 V Regulation Examples Load Regulation Load Regulation Example Example: Output: 5 V, 10 to 100 W Load Regulation Example Regulation Some power supplies are called regulators, if their main function is to prevent change at the output. Control is required to achieve good regulation. Regulation Examples Kelvin connection: Sense wires have  I=0 or I=constant. Regulation Temperature regulation: Ex. Office: 0.04% per °C. Range: 20°C to 35°C (15°C change)  Output change ? 0.6% Regulation Ex. Automotive: Range: -20°C to +35°C (70°C change)  Output change less than  (0.04%) x (70°) = 2.8% Equivalent Sources When a switch matrix operates to satisfy KVL and KCL, many of the waveforms become well defined. Example: Matrix 2x2 ac voltage  to dc current converter.  The output must be  +vin, -vin, or zero. Equivalent Sources Equivalent Sources If switch action is specified, the output waveform becomes fully determined. We can treat the waveform as an ideal source (with an unusual sh