System control by use of phase rotation signaling
View Patent ↗A load distribution and management system (LDMS) has a source of multi-phase power and multiple power lines. A separate power line is associated with each phase of power. These power lines connect the power source to a plurality of outlets. A threshold compare circuit is effective to compare power drawn through the plurality of outlets to a preset power limit and signal a phase rotation control if the power drawn exceeds the threshold power. The phase rotation control effective to interchange the power line associated with two of said multi-phases in response to said signal and a rotation detector disables those outlets not in use in response to the interchange of power and power lines. Conversely, when the power drawn is less than the preset threshold power, the phase rotation control returns the power phase to its associated power line signaling the rotation detector to enable disabled outlets. The LDMS is particularly useful where there is a limited supply of power, for example to provide power to passenger laptop computers and personal entertainment devices on a commercial aircraft.
1. A load distribution and management system (LDMS), comprising:
a single source of multi-phase power;
multiple power lines, one associated with each respective phase of said multi-phase power, interconnecting said single source with a plurality of outlets;
a threshold compare circuit effective to compare power drawn through said plurality of outlets to a preset power limit and signal a phase rotation control if said power drawn exceeds said threshold power;
said phase rotation control effective to interchange the power line associated with two of said multi-phases in response to said signal; and
a rotation detector that disables ones of said plurality of outlets not in use in response to an interchange of said power lines.
2. The LDMS of claim 1 wherein said multi-phase power consists of three phases, each separated from the other two by a 120-degree phase difference.
3. The LDMS of claim 2 wherein said source of multi-phase power is a generator driven by an aircraft engine.
4. The LDMS of claim 2 wherein each of said three phases, A, B, C, is conducted over a separate power line, respectively AL, BL, CL when said power drawn is less than said threshold power.
5. The LDMS of claim 4 wherein each of said three phases, A, B, C, is conducted over a separate power line, respectively AL, CL, BL when said power drawn is equal to or exceeds said threshold power.
6. The LDMS of claim 5 wherein a plurality of switches are effective to switch said B phase from power line BL to power line CL and said C phase from power line CL to power line BL in response to said signal from said threshold compare circuit.
7. A method to manage a load distribution comprising the steps of:
providing, from a single power generator, multi-phase power having at least three phases, A, B, C over separate power lines, respectively AL, BL and CL from a power source to a plurality of outlets;
comparing the total power conducted through said outlets to a preset threshold power; and
transferring said B phase to said CL power line and said C phase to said BL power line if said total power is equal to or exceeds said preset threshold power.
8. The method of claim 7 including disabling outlets not in use if a phase rotation is detected.
9. The method of claim 8 wherein said multi-phase power has three phases generated by a generator driven by an aircraft engine.
10. The method of claim 8 wherein said B phase is returned to said BL power line and said C phase is returned to said CL line when said total power is less than said preset threshold line and disabled outlets are enabled when reverse phase rotation is detected.
11. The method of claim 9 wherein a group of said outlets are provided power through a common power unit mounted under a seat of said aircraft.