1OTTO, Frank DE Session 2 – Block 4

Barcelona 12-15 May 2003

Tailor-made solutions in response

to increased demands on supply quality

… paper 2.66 by DREWAG – Stadtwerke Dresden GmbH (Germany)

2OTTO, Frank DE Session 2 – Block 4

Barcelona 12-15 May 2003

Dresden - capital of Saxony

also known as "Silicon Saxony"

DRESDENis a symbiosis of

high technology and baroque

Sachsen

3OTTO, Frank DE Session 2 – Block 4

Barcelona 12-15 May 2003

Fundamental statements

• The basic standard of supply quality is a balance between the customers’ quality demands and the acceptance of the resulting costs in general.

• Changes in the basic standard are only possible in the long term and at great expense.

• Increased requirements for supply quality call for customer-specific solutions.

4OTTO, Frank DE Session 2 – Block 4

Barcelona 12-15 May 2003

110 kV grid of Dresden

Elbe

Caption:110 kV overhead line110 kV underground line110 kV undergrond line (planned)

power plant with 110-kV/MV-substation

110-kV/MV-substation110-kV/MV-substation (planned)

380-kV/110-kV/MV-substationpumped-storage power station with 110 kV network node

Location of mask house

380 kV

380 kV

G

5OTTO, Frank DE Session 2 – Block 4

Barcelona 12-15 May 2003

Connection of switchgear to 20 kV grid Wilschdorf substation

C D

MV switchgear mask house

n.o.

n.o.

C

HQ

GQ

n.o.

n.o. n.o.

UPS 1 UPS 2 UPS 3 UPS 4

A B C

D E

Automatic transfer gear

Connection to customer

Klotzsche substation

auto

mat

ic

byp

ass

han

d b

ypas

s

6OTTO, Frank DE Session 2 – Block 4

Barcelona 12-15 May 2003

Commissioning tests – Power failure

Phase-to-earth voltage L1 (HQ busbar)

Current L1 (GQ busbar)

Current L1 (HQ busbar)

HQ

GQ

UPS 2 UPS 3 UPS 4

Measuring-point GQ

Measuring-point HQ

7OTTO, Frank DE Session 2 – Block 4

Barcelona 12-15 May 2003

Principal conclusions

1. Cooperation as partners is necessary already in the planning stage economic efficiency is the scale.

2. Simply configured customer plants for:• classification of consumption points• economical system management.

3. Desensitisation of plants and equipment sensitively to faults.