Distributed power generation units and their impact on the power network
Download
1 / 19

Distributed Power Generation Units and Their Impact on the Power Network - PowerPoint PPT Presentation


Distributed Power Generation Units and Their Impact on the Power Network. ABB Switzerland Ltd. Christoph Haederli. Large scale DG interconnection. System parameters Protection Stability “Plug and Power”. “Virtual DG” in small European town . Case Study with Small European Town.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha

Download Presentation

Distributed Power Generation Units and Their Impact on the Power Network

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Distributed Power Generation Units and Their Impact on the Power Network

ABB Switzerland Ltd.

Christoph Haederli


Large scale DG interconnection

  • System parameters

  • Protection

  • Stability

  • “Plug and Power”

“Virtual DG” in small European town


Case Study with Small European Town

  • Study in CALPOS

  • Real network (ca. 1 km2)

  • “random” placing of DG

  • 5 MVA load / 7 MVA DG


Considered Network Configurations

Meshed network configuration

  • Three MV lines

  • MV transformers connected on LV level (All LV lines connected in selected area).

  • Redundancy for MV lines

Station to station (non meshed) network configuration

  • Three MV lines

  • No connection between MV transformers on LV level

  • No redundancy for MV lines


Voltage Profile

  • All these nodes are LV-nodes. In the MV-network, the voltage profile is in the admissible range for all calculated cases.

  • Load profiles applied

  • Admissible range: -10 / +6 % (Germany)


Voltage Rise in Station to Station LV-grid


Voltage Rise in meshed LV grid


Voltage Rise in Station to Station LV-grid


Loading of LV Network

  • All these lines are LV-lines.


Comparison of Network Configurations

  • Meshed LV grid with multiple MV strands

    • higher reliability

    • more balanced voltage profile

    • smaller voltage rise at load steps

    • lower equipment loading (in normal operation)

    • lower losses

    • can handle more DG without alterations in grid

  • Non-meshed LV grid with station to station supply

    • higher capacity with the same amount of resources

    • simple design, easier to plan and extend

    • Cheaper

    • No reverse power relays needed

    • Lower short circuit power


Impact on Protection

  • Qualitative

    • Reverse power flow

    • Additional functionality required (Loss of mains detection, etc.)

  • Quantitative

    • Relay parameter settings

    • Increased short circuit power

Selective tripping schedule of distance protection relays with infeed effect


Reverse Power Relays

MV Line 1

  • DG may trip reverse power relay under normal operating conditions

Reverse Power Relay

Meshed LV grid

Reverse Power Relay

MV Line 2


Ik” Indicators on MV Line (Small Town Study)

( Ik” = short circuit current )


Stability: Inverter Based DG Configuration

  • DG-power conditioner


Stability: Equivalent Network with Multiple DG

  • Paralleling of inverters in LV grid

  • Line parameters from small town case study


Robust Stability Analysis

  • Robust stability analysis


Stability Analysis, Parallel Units

  • Number of units allowed for stable operation (Generic 100kW DG model used for calculations)

  • Stability depends very much on filter and control

  • Other configurations may allow higher numbers of parallel units


Conclusions

  • “Plug and power” for small units and small aggregated power.

  • Limited “Plug and power” for intermediate Power

  • No “Plug and power” for large units and a lot of aggregated power.

    • Advanced planning

    • Economical barriers

  • Important factors

    • Network configuration

    • DG type

  • Stability depends strongly on network impedance, filter design and control of DG

  • A significant share of power can be supplied locally by DG without reverse power flow into the network


ad
  • Login