Smart electrical distribution panel for dual split-phase power system
A DC to AC converter for solar energy installations is configured to convert DC input power at a first voltage from a floating DC source to a desired AC output power waveform. The converter is configured to cause an AC output waveform at a first repetition frequency and having a voltage relative to one of at least one ground, neutral, or reference potential terminals to appear with a unique phase at each of a number N at least equal to one of a set of live AC output terminals; and a common-mode voltage waveform at a second repetition frequency to appear relative to one of the ground, neutral, or reference potential terminals and in the same phase on both of positive and negative DC input terminals, varying alike in voltage while maintaining a substantially constant differential voltage between them, the variation in voltage having substantially the same common waveform on both the positive and negative DC input terminals and transitioning between a greatest negative and a greatest positive value at a frequency equal to N times the output AC waveform first repetition frequency.
1 . An electrical power distribution panel configured to supply power to a plurality of load circuits through an associated plurality of single pole or double pole circuit breakers, selectively, for each load circuit, from one of a primary split-phase power source and a secondary split-phase power source, comprising:
a plurality of controlled switches, each in series connection with one pole of an associated circuit breaker providing overcurrent protection to an associated load circuit;
a corresponding plurality of current sensors, each configured to measure a current momentarily flowing through the associated controlled switch to the associated circuit breaker;
analog to digital conversion circuitry connected to the plurality of current sensors and configured to provide digital codes indicative of the current measurements;
processing circuitry configured to receive user-designated load circuit priorities and maintain a list of the load circuits that are allowed to receive power from the secondary split-phase power source, the processing circuitry further configured to monitor a number of conditions and control, based on the conditions, the controlled switches associated with the load circuits that are allowed to receive power from the secondary split-phase power source, the conditions comprising:
the momentary current flow through the controlled switches;
the load circuit priorities received from the user terminal;
a power capacity of the secondary split-phase power source; and
indicators of whether the primary or secondary split-phase sources are available;
the electrical power distribution panel being configured such that:
adjacent breaker slots receive opposite phases of the selected split-phase power to provide double voltage to double pole circuit breakers; and
power flows to any load circuit through the same circuit breaker, whether the power is selected from the primary or secondary split-phase source;
wherein the processing circuitry is further configured to ensure that a total power allowed to flow to load circuits from the secondary split-phase power source never overloads a capacity of the secondary split-phase power source based on the measured currents, and to update the list and the state of associated controlled switches based on changes in the measured currents and the load circuit priorities in order to prevent overloading the capacity of the secondary split-phase power source.
2 . The electrical distribution panel of claim 1 wherein the processing circuitry has a wired or wireless communication with a user terminal device, from which it receives at least the user-designated load circuit priorities.
3 . The electrical distribution panel of claim 1 wherein a load circuit comprises one of a branch circuit and an appliance.
4 . The electrical distribution panel of claim 1 wherein the electrical distribution panel is configured to supply power to all of the load circuits when the primary split-phase power source is available and to supply power only to a selectable subset of the load circuits when only the secondary split-phase power source is available.
5 . The electrical distribution panel of claim 1 wherein the controlled switches comprise electromechanical relays.
6 . The electrical distribution panel of claim 1 wherein the controlled switches comprise electromechanical relays configured to perform a single-pole, double throw switching function.
7 . The electrical distribution panel of claim 1 wherein a group of the current sensors are multiplexed to the single analog to digital conversion circuitry.
8 . The electrical distribution panel of claim 1 wherein the processing circuitry comprises a software-controlled microprocessor.
9 . The electrical distribution panel of claim 8 wherein the processing circuitry further comprises a software controlled process running on the user terminal device and configured to provide additional functionality unconstrained by memory limitations of the software-controlled microprocessor.
10 . The electrical distribution panel of claim 1 wherein the secondary split-phase power source comprises a DC-to-AC inverter powered by a rechargeable battery.
11 . The electrical distribution panel of claim 10 wherein the processing circuitry is further configured to ascertain the power capacity of the DC-to-AC inverter.
12 . The electrical distribution panel of claim 10 wherein the processing circuitry is further configured to ascertain a charge state of the battery.
13 . The electrical distribution panel of claim 10 wherein the processing circuitry is configured to communicate with the DC-to-AC inverter.
14 . The electrical distribution panel of claim 1 wherein the processing circuitry further comprises a real-time clock.
15 . The electrical distribution panel of claim 1 wherein the user-designated load circuit priorities comprise a daytime load circuit priority and a nighttime load circuit priority.
16 . The electrical distribution panel of claim 2 wherein the wired or wireless communication between the processing circuitry and the user terminal device comprises at least one of a BLUETOOTH™ wireless protocol, a WiFi wireless protocol, and an Internet connection.
17 . The electrical distribution panel of claim 1 wherein the processing circuitry updates the list of the load circuits that are allowed to receive power from the secondary split-phase power source and the state of associated controlled switches based on changes in the momentary load circuit currents and the user-designated load circuit priorities in order to prevent overloading the capacity of the secondary split-phase power source by progressively disallowing power flow to load circuits in the user-designated load circuit priority order starting from the lowest priority.
18 . The electrical distribution panel of claim 1 wherein the processing circuitry is further configured to provide power from the secondary split-phase power supply to load circuits not on the list of allowed load circuits, in reverse user-designated load circuit priority order starting from the highest priority, as long as the capacity of the secondary split-phase power supply is not exceeded.