Network as automation platform for collaborative E-car charging at the residential premises
A system and method are provided for the collaborative charging of electric vehicles. The collaborative charging manages the disbursement of power from a neighborhood transformer so as to increase the efficiency of electric vehicle charging at the residences without significantly altering the existing power distribution and residential infrastructures. Time-flexible loads are shed in order to efficiently allocate energy distribution without compromising the comfort or security of the user. The identities of individual residential power demands can be concealed to protect the user's privacy or made available to further optimize power allocation. The power allocation negotiation may be performed in a residential local demand management client separate from the residential charging station.
1. A method for charging a plurality of electric vehicle batteries connected to a step-down transformer powering a plurality of residences, the method comprising:
identifying a plurality of residential power demands, wherein:
at least one of the residential power demands is a charging of an electric vehicle battery, and
a summation of the residential power demands is greater than an upper power limit of the transformer;
identifying a time-critical subset of the residential power demands and a time-flexible subset of the residential power demands, wherein the time-flexible subset includes the charging of the electric vehicle batteries;
allocating, at a beginning of a time slot, power from the transformer among all time-critical residential power demands and a portion of the time-flexible residential power demands so as not to exceed the upper power limit of the transformer for a duration of the time slot;
charging the electric vehicle batteries according to the allocating for the duration of the time slot; and
repeating the above for subsequent time slots until the upper power limit of the transformer is sufficient for simultaneous operation of all residential power demands;
wherein schedules allocating the power from the transformer are independently computed by each of a plurality of local demand management clients for each of the plurality of residences, and further wherein a voting process among the local demand management clients is used to decide which of the schedules is used in the allocating, at a beginning of a time slot, of power from the transformer.
2. A method as in claim 1 , wherein the allocating the portion of the time-flexible residential power demands comprises lowering an amperage supply to at least one electric vehicle battery.
3. A method as in claim 1 , wherein the allocating the portion of the time-flexible residential power demands comprises shedding at least one time-flexible residential power demand from the residential power demands.
4. A method as in claim 1 , wherein no residence is deprived of power for consecutive time slots.
5. A method as in claim 1 , wherein at least one of the time-flexible residential power demands is operation of an HVAC system.
6. A method as in claim 1 , wherein the allocating prioritizes a shedding of the charging of the electric vehicle batteries over a shedding of the remaining time-flexible residential power demands.
7. A method as in claim 1 , wherein the allocating maximizes a number of the electric vehicle batteries being charged simultaneously.
8. A method as in claim 1 , wherein the allocating minimizes demand peaks to the transformer.
9. A method as in claim 1 , wherein no electric vehicle battery is starved by the allocating.
10. A method as in claim 1 , wherein the identifying the residential power demands, the identifying the time-flexible residential power demands and the time-critical residential power demands, and the allocating power are performed by each of the plurality of local demand management clients, the local demand management clients synchronized at the beginning of each of the time slots.
11. A method as in claim 1 , wherein the identifying the residential power demands, the identifying the time-flexible residential power demands and the time-critical residential power demands, and the allocating power are performed by a master local demand management client, the master local demand management client selected from a plurality of local demand management clients.
12. A method as in claim 1 , wherein the allocating further comprises:
issuing a signal from a utility control center to the plurality of residences, wherein the signal is a utility-specific demand response signal or a pricing signal;
receiving the signal at the plurality of residences;
selecting an at least one preferred charging schedule at an at least one corresponding one of the plurality of residences based on the signal;
communicating the at least one preferred charging schedule to the utility control center; and
modifying the upper power limit according to the at least one preferred charging schedule.