Power supply system and apparatus
View Patent ↗The present invention relates to a switched mode power supply with programmable digital control and to a power supply system comprising a plurality of switched mode power supplies. The input terminals and the output terminals of the switched mode power supply system are separated by an insulation barrier, and the switched mode power supply comprises a conversion stage having at least one switching element. The switching element of the conversion stage, as well as any switching elements of a possible pre-regulator, is digitally controlled by a programmable digital circuit. In one embodiment of the switched mode power supply, the programmable digital circuit is located on the primary side of the insulation barrier.
1. A switched mode power supply having
input terminals for receiving electric power and output terminals for delivering output power having an output voltage and an output current;
wherein said input terminals are separated from said output terminals by an insulation barrier adapted to electrically insulate said input terminals from said output terminals so that said input terminals are provided on a primary side of the insulation barrier and said output terminals are provided on a secondary side of the insulation barrier;
said switched mode power supply comprising:
a converter stage coupled between the input terminals and the output terminals, said converter stage having at least one controllable first switching element for generating a converter stage duty cycle so as to cause said converter stage to generate said output power;
a pre-regulator coupled between the input terminals and the converter stage, the pre-regulator including a second switching element; and
a programmable digital circuit;
the switched mode power supply being characterized in that the programmable digital circuit is located on the primary side of the insulation barrier;
the programmable digital circuit is arranged to control said first switching element in dependence of at least one signal obtained on said primary side of the insulation barrier;
and the programmable digital circuit is further arranged to control said second switching element.
2. The switched mode power supply of claim 1 , wherein the programmable digital circuit is a single processor or a single held programmable gate array.
3. The switched mode power supply claim 1 , wherein said converter stage is a DC/DC converter stage.
4. The switched mode power supply of claim 1 , wherein said converter stage comprises four switching elements arranged in a full-bridge, said programmable digital circuit being adapted to control said four switching elements.
5. The switched mode power supply of claim 4 , wherein:
said programmable digital circuit is adapted to generating and sending one pulse width modulated signal to each of said four switching elements; and
said programmable digital circuit is further adapted to determine a phase shift in two of said four pulse width modulated signals with respect to the other two of said four pulse width modulated signals, said phase shift being determined based on a desired value of the duty cycle of said full-bridge.
6. The switched mode power supply of claim 4 , wherein the programmable digital circuit comprises a timer having a digital counter, and
wherein the sampling sequence in the pre-regulator and the converter stage is determined by means of said digital counter.
7. The switched mode power supply of claim 1 further comprising:
a converter stage output controller adapted to control the value of the converter stage duty cycle: said converter stage output controller being at least partly embodied by said programmable digital circuit.
8. The switched mode power supply of claim 1 , wherein said programmable digital circuit is adapted to use the mains frequency in determining timing of re-start attempts of the switched mode power supply.
9. The switched mode power supply of claim 1 , wherein said
switched mode power supply comprises:
means for measuring a quantity;
means for generating a reference value of said quantity;
means for generating the difference between the measured value and the reference value of said quantity; and
said programmable digital circuit comprises means for converting said difference between the measured value and the reference value of said quantity into digital representation.
10. The switched mode power supply of claim 9 , wherein said quantity is the output voltage of the switched mode power supply; and
said programmable digital circuit is further adapted to using said difference in the control of the first switching element.
11. A power supply system comprising:
a first switched mode power supply of claim 1 , said first switched mode power supply being adapted to deliver a first power output; and
a second switched mode power supply of claim 1 , said second switched mode power supply being adapted to deliver a second power output; and
a distribution unit having a distribution unit input being connected to receive said first power output and said second power output; and
at least one distribution unit output for supplying electric power to a load.