OPERATION AND CONTROL OF ACTIVE DISTRIBUTION NETWORKS

Experiences of coordinated Volt/Var control algorithm for medium voltage networks with high

share of distributed Generation

Roman Schwalbe

Austria

PAPER #433 LISBON 2013

DG DEMONET PROJECT LISBON 2013

Objective:

Development, planning, implementation and validation of voltage control concepts allowing a cost-effective integration of very high shares of distributed generation in medium voltage networks,

• maintaining a high level of quality of supply

• achieving economic benefits in comparison to network reinforcement

• LevelController: Utilizes the tap-change-capability of the central MV-transformer to raise or lower the voltage in the whole MV-grid to keep all nodes in the grid within the allowed voltage-limits.

• RangeController: Utilizes the capability of generators to produce reactive power to keep the range between the highest and the lowest voltage in the grid within the allowed range.

110 kV

30 kV

DG

DG

Range

Control

Level

ControlAVC

UHVnTap

Pact,UDG

Pact,

UDG

UCN

Q,P

Q,P

Communication (PLC, Radio Link, WiMax)

OLTC

CVCU

Central Voltage

Control Unit

MV

Distribution

NetworkUset

Q,P

VOLTAGE CONTROL CONCEPT LISBON 2013

• Critical Nodes

– Nodes which have the highest or lowest voltage within a year

– Determined by offline power flow calculation

• Contribution Matrix

– Linearised model of the network

– Has to be determined via offline power flow sensivity analysis

VOLTAGE CONTROL CONCEPT LISBON 2013

0 5 10 15 20 25 30 0.98

0.99

1

1.01

1.02

83902

Distance (km)

Voltage(

p.u

.)

Voltage drop diagram of node 83902 at max_time 8.5.2005 | 03:15

Node Coritcal node Critical node hydropower

reduce

DG

P

DGCNDG

Q

DGCNCN

result

CN PAQAUU ,,

DG

CNP

DGCN

DG

CNQ

DGCN

P

UA

Q

UA

,

,

VOLTAGE CONTROL VALIDATION LISBON 2013

• Validation of control concept in two Austrian distribution grids ‘Lungau’ and ‘Nenzing’

substation ‘Lungau’

active / apparent

power Transformer 1 32 MVA Transformer 2 32 MVA DG 1 0,95 MW DG 2 2,50 MW DG 3 0,80 MW Peak Demand 24 MW Peak Generation 8 MW

Critical Nodes 9

substation ‘Nenzing’

active / apparent

power Transformer 1 40 MVA Transformer 2 40 MVA DG 1 0,82 MW DG 2 0,96 MW DG 3 0,60 MW Peak Demand 32 MW Peak Generation 33 MW

Critical Nodes 16

• Motivation

– Provide actual information which critical nodes are actually supplied by the controlled substation

– Contribution matrix values depend on the actual grid’s switching state

• Topology recognition systems:

– ‘Lungau’: .xml-file which contains topology information is provided and automatically updated by external topology extraction tool (part of process control system)

– ‘Nenzing’: Process variables contain information to which substation the critical nodes are connected

TOPOLOGY RECOGNITION LISBON 2013

SCADA INTEGRATION NENZING LISBON 2013

• Smooth decrease of HV grid voltage during 2min

VOLTAGE VARIATIONS LUNGAU LISBON 2013

• All process-variables invalid for ~20min

COMMUNICATION BLACKOUT LISBON 2013

• Refitting reactive power control for existing DGs is extremely time-consuming, costly, and does not lead to satisfying results

• Topology recognition system has to be improved / dependency of topology information has to be reduced

• Coordinated Voltage Control Concept works sucessfully

• Validation in progress until June 2013: Answer the question how much voltage band can be freed for the integration of renewables with Coordinated Voltage Control?

CONCLUSION LISBON 2013

Thank you for your attention!

Project partners:

Project supported by:

BSc Roman Schwalbe

Energy Department

Electric Energy Systems

AIT Austrian Institute of Technology

Giefinggasse 2 | 1210 Vienna | Austria

T +43(0) 664 73146308

roman.schwalbe@ait.ac.at | http://www.ait.ac.at

QUESTIONS? LISBON 2013

mailto:roman.schwalbe.fl@ait.ac.athttp://www.ait.ac.at/

BACKUP SLIDES LISBON 2013

Range Controller Aim:

BACKUP SLIDES LISBON 2013

Range Controller improvements for better solvability:

BACKUP SLIDES LISBON 2013

Real Process, Simulation and testing

BACKUP SLIDES LISBON 2013

COMSICAM

230

IEC 104MV

Network

OPCPower

FactoryCVCUOffline Sim ulation

Real Tim e Sim ulation Process Interface via SCADA

Telecontrol interface

SIMULATION

REAL PROCESS

VOLTAGE CONTROLLER

COM

OPC