Smart dim fuse: electrical load flexibility controller using sub-circuit voltage modulation and load sensing
Improved control of electrical power consumption is provided with “Smart Dim Fuses” (SDF) which can alter their output voltage as provided to the load circuits they are connected to. SDF units can replace conventional circuit breakers in electrical panels. The voltage control capability provided by SDF units can lead to improved control of electrical power consumption, since many loads can smoothly operate at lower power consumption when the voltage they are driven with decreases. SDF units can comply with relevant safety requirements, such as uninterrupted neutral connections between electrical mains and load circuits. SDF units can also provide a current limiting function that can substitute for the protective action of conventional circuit breakers.
1. Apparatus for managing electrical power consumption, the apparatus comprising:
at least one local control unit configured to be connected between an electrical main and a load electrical circuit within a building;
wherein the local control unit includes an AC-AC converter configured to alter an output AC voltage it delivers to the load electrical circuit responsive to a control signal without interrupting power to the load electrical circuit;
wherein the output AC voltage can be set to any value in a predetermined voltage range according to the control signal; and
a controller configured to automatically set the output AC voltage of the local control unit in order to control electrical power consumption by the load electrical circuit;
wherein the load electrical circuit consumes electrical power but does not store electrical power or generate electrical power;
wherein the local control unit is configured as a replacement for a circuit breaker in an electrical panel.
2. The apparatus of claim 1 ;
wherein the local control unit includes an AC to AC buck converter having a first switching element, a second switching element, a capacitor and an inductor;
wherein the AC to AC buck converter includes a first node, a second node, a third node and a ground node;
wherein the electrical main is connected to the first node and the ground node;
wherein the load electrical circuit is connected to the third node and the ground node;
wherein the first switching element is connected to the first node and to the second node;
wherein the second switching element is connected to the second node and the ground node;
wherein the inductor is connected to the second node and to the third node; and
wherein the capacitor is connected to the third node and to the ground node.
3. The apparatus of claim 2 , wherein the AC to AC buck converter uses current hysteresis control with an outer control loop to set the output voltage.
4. The apparatus of claim 3 , wherein the AC to AC buck converter is configured to limit its output current if the load electrical circuit short circuits.
5. The apparatus of claim 1 , wherein the local control unit includes an unbroken neutral connection between a neutral of the electrical main and a neutral of the load electrical circuit.
6. The apparatus of claim 1 , wherein the local control unit includes a pass-through mode with no output voltage control.
7. The apparatus of claim 6 , wherein the local control unit is configured to limit its output current if the load electrical circuit short circuits.
8. A method for managing electrical power consumption, the method comprising:
connecting one or more local control units each between an electrical main and a corresponding load electrical circuit within a building;
wherein the local control units each include an AC-AC converter configured to alter output AC voltages they deliver to their corresponding load electrical circuits responsive to control signals without interrupting power to the load electrical circuits;
wherein the output AC voltages can be individually set to any value in a predetermined voltage range according to the control signals; and
automatically setting the output AC voltages of the local control units in order to control electrical power consumption by the load electrical circuits;
wherein the load electrical circuit consumes electrical power but does not store electrical power or generate electrical power;
wherein the local control unit is configured as a replacement for a circuit breaker in an electrical panel.
9. The method of claim 8 , further comprising communicating between the local control units and a building-level base station with a communication network.
10. The method of claim 8 , wherein a measurement sampling rate of current vs. voltage of load electrical circuits is 1 kHz or more.
11. The method of claim 8 , further comprising using a database of power controllability vs. electrical load circuit to improve building-level load control, wherein the database is constructed at least in part from real time data on current vs. voltage of the load electrical circuits from the local control units.
12. The apparatus of claim 1 , wherein the controller is configured to achieve a power consumption of the load electrical circuit according to an input set power command.
13. The method of claim 8 , wherein electrical power consumption by the load electrical circuits is controlled to achieve a power consumption of the load electrical circuits according to an input set power command.