Increasing DG Capacity of Existing Networks through Reactive Power Control and Curtailment
Author
Summary, in English
Renewable energy sources (RES), especially wind turbines, have become more important
during the last years. An increasing number of distributed generation (DG) units are
connected to weak medium voltage distribution networks in rural areas where they have a large
influence on the voltage and the line losses. Voltage rise is in this case often a limiting factor for
the maximum amount of DG capacity. Already current wind turbines with a capacity of 2 MW
can often not easily be connected to existing 10 kV feeders.
To increase the DG capacity of existing networks without reinforcement DG units can be
controlled. This paper proposes abandoning unity power factor used today and letting the converters
used as network interface of many new wind turbine generators absorb reactive power
to reduce the voltage level. Since reactive power has great influence on losses in the network
the use of reactive power is limited. Line losses due to the transfer of reactive power are taken
into account in this study. Furthermore the use of curtailment is analysed.
Simulations of voltage change and line losses when using reactive power control by the connected
wind turbines and curtailment in a simple test system are presented. Without reinforcement
of the network it was possible to increase the DG capacity from 2;7MW to more than
4MW in the test network without violating voltage limits. Line losses increase but to a reasonable
extent and lost energy due to curtailment is insignificant.
during the last years. An increasing number of distributed generation (DG) units are
connected to weak medium voltage distribution networks in rural areas where they have a large
influence on the voltage and the line losses. Voltage rise is in this case often a limiting factor for
the maximum amount of DG capacity. Already current wind turbines with a capacity of 2 MW
can often not easily be connected to existing 10 kV feeders.
To increase the DG capacity of existing networks without reinforcement DG units can be
controlled. This paper proposes abandoning unity power factor used today and letting the converters
used as network interface of many new wind turbine generators absorb reactive power
to reduce the voltage level. Since reactive power has great influence on losses in the network
the use of reactive power is limited. Line losses due to the transfer of reactive power are taken
into account in this study. Furthermore the use of curtailment is analysed.
Simulations of voltage change and line losses when using reactive power control by the connected
wind turbines and curtailment in a simple test system are presented. Without reinforcement
of the network it was possible to increase the DG capacity from 2;7MW to more than
4MW in the test network without violating voltage limits. Line losses increase but to a reasonable
extent and lost energy due to curtailment is insignificant.
Department/s
Publishing year
2010
Language
English
Full text
Document type
Conference paper
Topic
- Other Electrical Engineering, Electronic Engineering, Information Engineering
Conference name
The 9th Nordic Electricity Distribution and Asset Management Conference (NORDAC 2010)
Conference date
2010-09-06
Conference place
Aalborg, Denmark
Status
Published