Power processing and energy storage
A power conversion device may perform power processing for multiple power nodes coupled in parallel. The power conversion device includes interconnects that couple power nodes to power converters. The power converters include a dense tier of power converters sized to correct, using multiple corrective components, from varied power flow levels to interim power flows for parallel coupling of the multiple power nodes. The power converters also include a sparse tier. The sparse tier performs power processing to convert from the interim power flows generated by the dense tier to a uniform target flow.
1 . A device including:
multiple power sources coupled in parallel;
a dense tier of power converters coupled to the multiple power sources, a first number of power converters in the dense tier being proportional to a total number of the multiple power sources, the dense tier configured to:
apply a first power correction component to a first subset of the multiple power sources to generate a first target output determined for series coupling of the multiple power sources;
apply a second power correction component a second subset of the multiple power sources to generate a second target output determined for series coupling of the multiple power sources, the second target output having a difference in power level from the first target output; and
apply, via virtual tier operation, a third power correction component to the first subset of the multiple power sources and a fourth power correction component to the second subset of the multiple power sources to correct the first target output and second target output for parallel coupling; and
a sparse tier of power converters coupled to the multiple power sources through the dense tier, a second number of power converters in the sparse tier dependent on a model for estimating the difference in power level, the sparse tier configured to correct for the difference in power level for the multiple power sources coupled in parallel.
2 . The device of claim 1 , where the multiple power sources include batteries.
3 . The device of claim 1 , where the multiple power sources include a photovoltaic cell.
4 . The device of claim 1 , where sizes of the third and fourth power correction components are selected to equalize current in the first target output and the second target output.
5 . The device of claim 1 , where sizes of the third and fourth power correction components are determined based on a circuit duality transformation from series to parallel operation.
6 . The device of claim 1 , where the sparse tier power converters each have an individual conversion capacity that is greater than that of any individual one of the dense tier of power converters.
7 . The device of claim 1 , where the first number of power converters is one less than the total number of the multiple power sources.
8 . The device of claim 1 , where the first and second power correction components are determined based on a power source degradation model for the multiple power sources.
9 . The device of claim 8 , where the power source degradation model includes a model of degradation based on:
power source age;
power source type; and/or
power source charge-discharge cycle count.
10 . The device of claim 8 , where the power source degradation model includes a model of degradation an empirical distribution of battery degradation.
11 . A method including:
for multiple power sources coupled in parallel:
at a dense tier of power converters coupled to the multiple power sources, a first number of power converters in the dense tier being proportional to a total number of the multiple power sources:
applying a first power correction component to a first subset of the multiple power sources to generate a first target output determined for series coupling of the multiple power sources;
applying a second power correction component a second subset of the multiple power sources to generate a second target output determined for series coupling of the multiple power sources, the second target output having a difference in power level from the first target output; and
applying, via virtual tier operation, a third power correction component to the first subset of the multiple power sources and a fourth power correction component to the second subset of the multiple power sources to correct the first target output and second target output for parallel coupling; and
at a sparse tier of power converters coupled to the multiple power sources through the dense tier, a second number of power converters in the sparse tier dependent on a model for estimating the difference in power level:
correcting for the difference in power level for the multiple power sources coupled in parallel.
12 . The method of claim 11 , where the multiple power sources include batteries.
13 . The method of claim 11 , where the multiple power sources include a photovoltaic cell.
14 . The method of claim 11 , where sizes of the third and fourth power correction components are selected to equalize current in the first target output and the second target output.
15 . The method of claim 11 , where sizes of the third and fourth power correction components are determined based on a circuit duality transformation from series to parallel operation.
16 . The method of claim 11 , where the sparse tier power converters each have an individual conversion capacity that is greater than that of any individual one of the dense tier of power converters.
17 . The method of claim 11 , where the first number of power converters is one less than the total number of the multiple power sources.
18 . The method of claim 11 , where the first and second power correction components are determined based on a power source degradation model for the multiple power sources.
19 . A method including:
for multiple power node connection ports connected in parallel, the multiple power node connection ports including:
a first connection port to support a first power flow range, the first power flow range spanning one or more first expected power flow levels for a first defined portion of a group of power stores; and
a second connection port to support a second power flow range, the second power flow range spanning one or more second expected power flow levels for a second defined portion of the group of power stores:
executing a first stage of power processing at a dense converter tier coupled to the multiple power node connection ports, by:
at a first dense tier power converter coupled to at least the first connection port:
providing a first series power correction component from within the first power flow range to a first series interim power flow for series coupling of the multiple power node connection ports; and
providing, via virtual tier operation, a first duality correction component to convert the first series interim power flow to a first parallel interim power flow for flow for parallel coupling of the multiple power node connection ports; and
at a second dense tier power converter coupled to at least the second connection port:
providing a second series power correction component from within the second power flow range to a second series interim power flow for series coupling of the multiple power node connection ports; and
providing, via virtual tier operation, a second duality correction component to convert the second series interim power flow to a second parallel interim power flow for parallel coupling of the multiple power node connection ports; and
executing a second stage of power processing at a sparse converter tier coupled to the multiple power node connection ports via the dense converter tier, by converting a combined power flow to a uniform model-corrected target, the combined power flow including at least a portion of each of the first and second parallel interim power flows.
20 . The method of claim 19 , where sizes of the first and second duality correction components are selected to equalize current flow associated with the first and second parallel interim power flows.