Adaptively configured and autoranging voltage transformation module arrays
View Patent ↗A method and apparatus for adaptively configuring an array of voltage transformation modules is disclosed. The aggregate voltage transformation ratio of the adaptive array is adjusted to digitally regulate the output voltage for a wide range of input voltages. An integrated adaptive array having a plurality of input cells, a plurality of output cells, or a plurality of both is also disclosed. The input and output cells may be adaptively configured to provide an adjustable transformer turns ratio for the adaptive array or in the case of an integrated VTM, an adjustable voltage transformation ratio for the integrated VTM. A controller is used to configure the cells and provide digital regulation of the output. A converter having input cells configured as a complementary pair, which are switched out of phase, reduces common mode current and noise. Series connected input cells are used for reducing primary switch voltage ratings in a converter and enabling increased operating frequency or efficiency. An off-line auto-ranging power supply topology is disclosed. An auto-ranging converter module (“ACM”) includes 2 or more input cells magnetically coupled to an output cell providing auto-ranging, isolation, and voltage transformation. The ACM converts a rectified line voltage to a low DC bus voltage. The topology allows regulation and power factor correction to be provided at a low voltage increasing energy density and efficiency and reducing cost.
1. A method of converting power from an AC line at a line voltage for delivery to a load at a DC output voltage, where the line voltage may vary between a high line voltage and a low line voltage, comprising:
passing the AC line through a rectifier to produce a rectified line signal at a rectified voltage;
providing at least two input cells each having at least one switch for driving a primary winding for converting power received from the rectified line signal;
providing an output cell having a secondary winding magnetically coupled to the primary winding in each of the input cells, the output cell having rectification circuitry for delivering a unipolar output voltage;
connecting the input cells in series for operation at the high line voltage to divide the rectified voltage between the input cells.
2. The method of claim 1 further comprising providing capacitive energy storage between the unipolar output voltage and the load.
3. The method of claim 1 further comprising connecting the input cells in a parallel connection for operation at the low line voltage to divide an input power between the input cells.
4. The method of claim 2 further comprising providing regulation circuitry between the unipolar output voltage and the load.
5. The method of claim 2 further comprising providing a power factor correction circuit between the unipolar output voltage and the capacitive energy storage.
6. The method of claim 2 wherein the capacitive energy storage is provided at the output of the rectification circuitry.
7. The method of claim 4 or 5 wherein the capacitive energy storage is provided at the load.
8. The method of claim 3 further comprising providing a controller that senses the AC line voltage and configures the input cells in series when the AC line voltage is within an upper range and that configures the input cells in parallel when the AC line voltage is within a lower range.
9. The method of claim 8 wherein said sensing comprises sensing the peak value of the rectified AC line voltage.
10. The method of claim 9 further comprising comparing said peak value to a predetermined switchover threshold.
11. The method of claim 9 wherein the upper range is between 226 V PEAK and 388 V PEAK.
12. The method of claim 9 wherein the lower range is between 113 V PEAK and 195 V PEAK.
13. The method of claim 10 wherein the switchover threshold is greater than voltages within the lower range.
14. Apparatus for converting power from an AC line at a line voltage for delivery to a load at a DC output voltage, where the line voltage may vary between a high line voltage and a low line voltage, comprising:
a rectifier having an input connected to the AC line to produce a rectified line signal at a rectified voltage;
at least two input cells each having at least one switch for driving a primary winding for converting power received from the rectified line signal;
an output cell having a secondary winding magnetically coupled to the primary winding in each of the input cells, the output cell having rectification circuitry for delivering a unipolar output voltage;
wherein the apparatus is adapted to configure the input cells in series for operation at the high line voltage to divide the rectified voltage between the input cells.
15. The apparatus of claim 14 further comprising capacitive energy storage connected between the unipolar output voltage and the load.
16. The apparatus of claim 14 wherein the apparatus is further adapted to configure the input cells in a parallel connection for operation at the low line voltage to divide an input power between the input cells.
17. The apparatus of claim 15 further comprising regulation circuitry having an input connected to receive power from the unipolar output voltage and an output for delivering power to the load.
18. The apparatus of claim 15 further comprising a power factor correction circuit having an input connected to receive power from the unipolar output voltage and an output for delivering power to the capacitive energy storage.
19. The apparatus of claim 15 wherein the capacitive energy storage is connected across the output of the rectification circuitry.
20. The apparatus of claim 17 or 18 wherein the capacitive energy storage is connected across the load.
21. The apparatus of claim 16 further comprising a controller adapted to sense the AC line voltage and to configure the input cells in series when the AC line voltage is within an upper range and to configure the input cells in parallel when the AC line voltage is within a lower range.
22. The apparatus of claim 21 wherein the controller is adapted to sense the peak value of the rectified AC line voltage.
23. The apparatus of claim 22 wherein the controller is adapted to compare said peak value to a predetermined switchover threshold.
24. The apparatus of claim 22 wherein the upper range is between 226 V PEAK and 388 V PEAK.
25. The apparatus of claim 22 wherein the lower range is between 113 V PEAK and 195 V PEAK.
26. The apparatus of claim 23 wherein the switchover threshold is greater than voltages within the lower range.