ÚJV Řež, a. s. Power Flow Problem in a Smart Grid with ... · Ohm´s Law Two Kirchhoff´s...

ÚJV Řež, a. s.

Power Flow Problem in a Smart Grid with

Hydrogen Storage Systems

Michal Morte04.04.2014

HydrogenDays

Essential Questions

How does power engineering look at hydrogen storage systems?

Could be hydrogen storage systems easy involved in all kinds of electrical grid (especially smart)?

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Power Flow Problem

Ohm´s LawTwo Kirchhoff´s circuits laws

Current LawVoltage Law

Non – linear problemComplex Impedance

ResistanceCapacityInductance

PowerActive P (W)Reactive Q (var)Complex S (VA)

Power Factor = P / S

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Power Flow Problem

Generally Non – linear set of equationsf (x, u, p) = 0

x is vector containing the state variablesu is a vector with known control outputsp is a vector of parameters

Mathematical methodsGauss – SeidelNewton – Raphson

Four VariablesVoltage MagnitudeVoltage AngleActive PowerReactive Power

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Power Flow Problem

Transmission and Distribution Network

NodesThree kind of nodes

Voltage controlled nodePU

Load nodePQ

Slack nodeUθ

BranchesTopology

Admittance matrix

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Power Flow Problem

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Load Profile - Today

Only in generalOTE, a.s.

Regions

Temperature involvedDailyMonthlySeasonlyYearly

Typified load profilesVarious groups

FactoriesResidentials

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Load Profile – Smart Grid

ExampleCity

Two districtsWorkers´Academic

Different load profiles for both districtsStudents live their days differently than workers

Power engineersCould with a smart grid optimize power flow in different parts of

CityRegionCountry???

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Hydrogen Storage as a Node

Fuel cellLinearized polarization curveResistance

Only ohmic losses

No problem with reactive power and power factor

But power engineer needs reactive power for regulation of voltage!

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Hydrogen Storage as a Node

Ordinary power flow problem becomes more complexIn each node the load profile must be involved

Each time interval a new instance of power flow problemStability of the system must be guaranteed for the worst scenarios

Storage systems - and more complex again PQ nodeSometime as a load, sometime as a generator

Minus - loadPlus - generator

Very powerful IT technology must be used!

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Conclusion

It will not be easy to build a completely new and fully functional national smart grid with storage systemsDeeper and more complex real – time calculations are needed!Such systems will be very vulnerable

DestructionHacking

They will cost a lot of moneyTrillions of euro in the course of the next half of century!

But if all goes well, they will be a small step to paradiseBut if all went well, they would be a small step to paradiseWhich conditional do you prefer?

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THANK FOR YOUR ATTENTION

Ing. Mgr. Michal MorteHydrogen Technologies DepartmentNuclear Safety and Reliability Department

UJV Řež,a.s.Hlavní 130, 250 68, Husinec-ŘežCzech RepublicTel. +420 266 173 564Email: michal.morte@ujv.cz

www.ujv.cz

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