Power supply system and power supply apparatus
A power supply system includes at least two power supply apparatuses that supply current to one load. Each power supply apparatus includes a converter that supplies current to the load, a FET connected in series between the converter and the load, a current detection unit that detects current flowing between the converter and the load, and a droop characteristic controller that causes output voltage of the converter to droop at a droop rate determined based on the magnitude of load current flowing from the converter towards the load. The droop rate is greater when the load current is included in a first current section than when the load current is included in each of a second current section and a third current section. The second current section includes smaller current than the first current section. The third current section includes larger current than the first current section.
1. A power supply system comprising:
at least two power supply apparatuses configured to supply current to a load;
wherein each power supply apparatus comprises:
a converter configured to supply current to the load;
a FET connected in series between the converter and the load;
a current detection unit configured to detect current flowing between the converter and the load; and
a droop characteristic controller configured to cause output voltage of the converter to droop at a droop rate determined based on a magnitude of load current flowing from the converter towards the load;
wherein the droop rate when the load current is included in a first current section is greater than the droop rate when the load current is included in each of a second current section and a third current section;
wherein the second current section includes current that is smaller than current included in the first current section; and
wherein the third current section includes current that is larger than the current included in the first current section.
2. The power supply system of claim 1 , wherein each power supply apparatus further comprises a reverse current limitation unit configured to limit, based on a reverse current reference limit, a reverse current flowing from the load towards the converter.
3. The power supply system of claim 2 , wherein the reverse current limitation unit comprises a separation unit configured to input, to a gate of the FET, a signal based on a result of comparing the reverse current as detected by the current detection unit with the reverse current reference limit.
4. The power supply system of claim 2 , wherein the reverse current limitation unit includes a voltage monitor configured to input, to a gate of the FET, a signal based on a result of comparing a potential of a drain of the FET with a sum of a potential of a source of the FET and a monitoring offset voltage.
5. The power supply system of claim 3 , wherein the reverse current limitation unit includes a voltage monitor configured to input, to a gate of the FET, a signal based on a result of comparing a potential of a drain of the FET with a sum of a potential of a source of the FET and a monitoring offset voltage.
6. The power supply system of claim 2 ,
wherein the converter has a rated current; and
wherein the rated current is set to a larger value than a sum of a maximum load current and the reverse current reference limit.
7. The power supply system of claim 3 ,
wherein the converter has a rated current; and
wherein the rated current is set to a larger value than a sum of a maximum load current and the reverse current reference limit.
8. The power supply system of claim 4 ,
wherein the converter has a rated current; and
wherein the rated current is set to a larger value than a sum of a maximum load current and the reverse current reference limit.
9. The power supply system of claim 5 ,
wherein the converter has a rated current; and
wherein the rated current is set to a larger value than a sum of a maximum load current and the reverse current reference limit.
10. The power supply system of claim 1 , wherein a resistance element is connected in series in at least one of paths short-circuiting between a current path from the converter towards the load and a ground point.
11. The power supply system of claim 1 , wherein the first current section includes a current that is 50% of a maximum load current.
12. The power supply system of claim 1 ,
wherein the droop rate when the load current is included in a fourth current section is greater than the droop rate when the load current is included in each of a fifth current section and the third current section;
wherein the fourth current section includes current that is larger than the current included in the third current section;
wherein the fifth current section includes current that is larger than the current included in the fourth current section;
wherein the first current section includes current represented by a product of a maximum load current and an inverse of a first predetermined number; and
wherein the fourth current section includes current represented by a product of the maximum load current and an inverse of a second predetermined number yielded by subtracting one from the first predetermined number.
13. A power supply apparatus comprising:
a converter configured to supply current to a load;
a FET connected in series between the converter and the load;
a current detection unit configured to detect current flowing between the converter and the load; and
a droop characteristic controller configured to cause output voltage of the converter to droop at a droop rate determined based on a magnitude of load current flowing from the converter towards the load;
wherein the droop rate when the load current is included in a first current section is greater than the droop rate when the load current is included in each of a second current section and a third current section;
wherein the second current section includes current that is smaller than current included in the first current section; and
wherein the third current section includes current that is larger than the current included in the first current section.
14. The power supply apparatus of claim 13 , further comprising a reverse current limitation unit configured to limit, based on a reverse current reference limit, a reverse current flowing from the load towards the converter.
15. The power supply apparatus of claim 14 , wherein the reverse current limitation unit comprises a separation unit configured to input, to a gate of the FET, a signal based on a result of comparing the reverse current as detected by the current detection unit with the reverse current reference limit.
16. The power supply apparatus of claim 14 , wherein the reverse current limitation unit includes a voltage monitor configured to input, to a gate of the FET, a signal based on a result of comparing a potential of a drain of the FET with a sum of a potential of a source of the FET and a monitoring offset voltage.
17. The power supply apparatus of claim 14 ,
wherein the converter has a rated current; and
wherein the rated current is set to a larger value than a sum of a maximum load current and the reverse current reference limit.
18. The power supply apparatus of claim 13 , wherein a resistance element is connected in series in at least one of paths short-circuiting between a current path from the converter towards the load and a ground point.
19. The power supply apparatus of claim 13 , wherein the first current section includes a current that is 50% of a maximum load current.
20. The power supply apparatus of claim 13 ,
wherein the droop rate when the load current is included in a fourth current section is greater than the droop rate when the load current is included in each of a fifth current section and the third current section;
wherein the fourth current section includes current that is larger than the current included in the third current section;
wherein the fifth current section includes current that is larger than the current included in the fourth current section;
wherein the first current section includes current represented by a product of a maximum load current and an inverse of a first predetermined number; and
wherein the fourth current section includes current represented by a product of the maximum load current and an inverse of a second predetermined number yielded by subtracting one from the first predetermined number.