MV Network Design Book With Exercises and Answers

MV Network Design

MV Network Design Book, prepared by Schneider Electric gives a great technical knowledge of MV network design and correct devices selection intended for medium voltage equipment and network designers.

This guide helps you to carry out the various calculations required to define and determine network characteristics, substation equipment dimensions and provides useful information enabling you to design your MV switchboard and other substation devices.

Exercise sections and answers //

1. MV substation architectures
2. MV substation architectures
3. Industrial C13-200 MV substation
4. Max. distance between surge arrester and MV equipment
5. Calculation of MV cable cross-section
6. Calculation of Isc
7. CT s for MV metering
8. CT s for MV protection
9. Earth-fault relay settings
10. Capacitors

Exercise 1 – MV substation architectures

To define //

1. Type of LV or MV metering
2. Architecture and choice of cubicles
3. Type and rating of fuse that protects the transformer

Inputs //

• Consumer substation on energy supplier loop: 20kV
• 1 800kVA transformer with 20kV/400V secondary
• Short-circuit power 250 MVA

Answers and chosen substation equipment //

• 800 kVA with 20 kV = 23A < 45A
  OK for LV metering

• 800 kVA with 410V = 1127A < 2000A
• 800 kVA < 1250 kVA
• MV Isc 20kV = 250MVA / 20kV / 1.732 = 7.2 kA rms
  OK for standard equipment 24 KV 12.5 kA

• 800 kVA 20 kV transformer, UTE standard,
  43A Solefuse chosen fuse rating