Power supplying system
A power supplying system that includes a power supplying mechanism, an electric load, a power line, and a storage pack. The power supplying mechanism supplies a DC power. The electric load is connected to the power supplying mechanism by the power line. The storage pack is connected to the power line. The charging/discharging curve of the storage pack has a step difference that passes through the rated voltage of the power supplying mechanism. An average discharging voltage on a lower-SOC side of the start point of the step difference is −20% or more of the rated voltage. An average charging voltage on a higher-SOC side of the end point of the step difference is +20% or less of the rated voltage.
1. A power supplying system comprising:
a power supplying mechanism that supplies a DC power;
an electric load;
a power line connecting the power supply to the electric load; and
a storage pack connected to the power line, wherein
a charging/discharging curve of the storage pack has a step difference that passes through a rated voltage of the power supplying mechanism,
an average discharging voltage on a lower-SOC side of a start point of the step difference is −20% or more of the rated voltage, and
an average charging voltage on a higher-SOC side of an end point of the step difference is +20% or less of the rated voltage.
2. The power supplying system according to claim 1 , wherein
the average discharging voltage on the lower-SOC side of the start point of the step difference is −2% or less of the rated voltage, and
the average charging voltage on the higher-SOC side of the end point of the step difference is +2% or more of the rated voltage.
3. The power supplying system according to claim 1 , wherein the storage pack comprises one of a lithium ion secondary battery and a nickel hydrogen secondary battery.
4. The power supplying system according to claim 3 , wherein
the storage pack comprises a lithium ion secondary battery having a positive electrode, and
the positive electrode comprises at least one positive electrode active material selected from Li[Ni x Mn (2−x) ]O 4 (0.05≤x≤0.45), Li[Co x Mn (2−x) ]O 4 (0.1≤x≤1), Li[Fe x Mn (2−x) ]O 4 (0.05≤x≤0.45), LiFe a Mn b Co c Ni d PO 4 (0≤a≤1, 0≤b≤1, 0≤c≤1, 0≤d≤1, a+b+c+d=1),and Li 3 V 2 (PO 4 ) 3 .
5. The power supplying system according to claim 3 , wherein
the storage pack comprises a lithium ion secondary battery having a positive electrode, and
the positive electrode comprises a plurality of kinds of positive electrode active materials.
6. The power supplying system according to claim 3 , wherein
the storage pack comprises a lithium ion secondary battery having a negative electrode, and
the negative electrode comprises a plurality of kinds of negative electrode active materials.
7. The power supplying system according to claim 1 , wherein the storage pack comprises a plurality of storage modules connected in parallel, and each of the plurality of storage modules comprises a plurality of storage devices connected in series, and
each of the plurality of storage modules are different from each other in a number of connected storage devices.
8. The power supplying system according to claim 1 , wherein the storage pack comprises a plurality of kinds of storage modules having different kinds of storage devices.
9. The power supplying system according to claim 1 , wherein, in the storage pack, a ratio of a first capacity on the lower-SOC side of the start point of the step difference to a second capacity on the higher-SOC side of the end point of the step difference is within a range of 10: 90 to 90:10.
10. A power supplying system comprising:
a power supplying mechanism that supplies a DC power;
an electric load;
a power line connecting the power supplying mechanism and the electric load; and
a storage pack connected to the power line, wherein
a charging/discharging curve of the storage pack has a step difference that passes through a rated voltage of the power supplying mechanism,
a voltage of a peak top on a curve (dQ/dV curve) obtained by differentiating the discharging curve of the storage pack with respect to the voltage on a lower-SOC side of a start point of the step difference is −20% or more of the rated voltage, and
a voltage of a peak top on a curve (dQ/dV curve) obtained by differentiating the charging curve of the storage pack with respect to the voltage on a higher-SOC side of an end point of the step difference is +20% or less of the rated voltage.
11. The power supplying system according to claim 10 , wherein
the voltage of the peak top on the curve (dQ/dV curve) obtained by differentiating the discharging curve of the storage pack with respect to the voltage on the lower-SOC side of the start point of the step difference is −2% or less of the rated voltage, and
the voltage of the peak top on the curve (dQ/dV curve) obtained by differentiating the charging curve of the storage pack with respect to the voltage on the higher-SOC side of the end point of the step difference is +2% or more of the rated voltage.
12. The power supplying system according to claim 10 , wherein the storage pack comprises one of a lithium ion secondary battery and a nickel hydrogen secondary battery.
13. The power supplying system according to claim 12 , wherein
the storage pack comprises a lithium ion secondary battery having a positive electrode, and
the positive electrode comprises at least one positive electrode active material selected from Li[Ni x Mn (2−x) ]O 4 (0.05≤x≤0.45), Li[Co x Mn (2−x) ]O 4 (0.1≤x≤1),Li[Fe x Mn (2−x) ]O 4 (0.05≤x≤0.45), LiFe a Mn b Co c Ni d PO 4 (0≤a≤1, 0≤b≤1, 0≤c≤1, 0≤d≤1, a+b+c+d=1), and Li 3 V 2 (PO 4 ) 3 .
14. The power supplying system according to claim 12 , wherein
the storage pack comprises a lithium ion secondary battery having a positive electrode, and
the positive electrode comprises a plurality of kinds of positive electrode active materials.
15. The power supplying system according to claim 12 , wherein
the storage pack comprises a lithium ion secondary battery having a negative electrode, and
the negative electrode comprises a plurality of kinds of negative electrode active materials.
16. The power supplying system according to claim 10 , wherein
the storage pack comprises a plurality of storage modules connected in parallel, and each of the plurality of storage modules comprises a plurality of storage devices connected in series, and
each of the plurality of storage modules are different from each other in a number of connected storage devices.
17. The power supplying system according to claim 10 , wherein the storage pack comprises a plurality of kinds of storage modules having different kinds of storage devices.
18. The power supplying system according to claim 10 , wherein, in the storage pack, a ratio of a first capacity on the lower-SOC side of the start point of the step difference to a second capacity on the higher-SOC side of the end point of the step difference is within a range of 10:90 to 90:10.