Kinetic Energy Analysis for Smaller Systems |
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This analysis is intended for a system with fewer generators and with power supplies that have no inherent inertia, e.g., wind farms. Starting with individual power supplies, we develop the composite of all the sources.
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The stored energy for an individual “real” generator is expressed as follows: |
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Eg = Hg
* ( F / F0 )^2 * Sg |
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The stored energy for an individual conventional wind farm is expressed as follows: |
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Ew = Hw
* ( F / F0 )^2 * Sw |
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To get the system stored energy of the interconnected resources,
we add up the individual stored energies: |
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Es = ∑ Hg
* ( F / F0 )^2 * Sg + ∑
Hw * ( F / F0 )^2 * Sw |
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At this point we “remove” the wind farms since they have no stored energy, i.e., their “H” is zero: |
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Es = ∑ Hg
* ( F / F0 )^2 * Sg |
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This is where we can derive a composite “Hs” and a composite “Ss”. Notice that the system stored energy does not include the effect of wind farms:
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Es = Hs * ( F / F0 )^2 * Ss
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Note that:
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Hs * Ss =
∑ Hg * Sg
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This is an opinion for how to derive a “weighted average” for system “H” for simulation studies.
In conclusion, the inertia of the system does not change with the addition of conventional wind farms.
Consider a shaft with large heavy flywheels and some light thin disks.
Where will most of the stored energy reside?
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