Purpose

We will undertake advanced power system studies to determine the feasibility of generator connection to the distribution network. The modelling process will include several types of simulation. Each simulation will be used to test the generator performance against a different group of requirements as outlined in the Technical Rules (NER). Depending on the size of the generator we will undertake the following studies:

  • Load flow study to assess over/under voltage, overloading, adequate active and reactive power reserves, operational constraints and precautions required;
  • Short circuit study to confirm fault rating of connected equipment and determine if the rating will be adequate or exceeded;
  • Stability study to determine how the power system operates during different disturbances, in particular how fast the protective devices will clear the fault before the generator and surrounding power system become unstable;
  • Power quality study to ensure that distorting loads do not cause unacceptable power quality in the power system.
  • Network black start study to ensure that the plant can be reinstated from system black out and demonstrating if it’s capable of doing this automatically without the grid or diesel generator supply.
  • Under-voltage ride through study to demonstrate that the renewable plant, when supplying the normal load, can ride through a 3-Phase fault at specific terminals on the reticulation network, such as at MV/LV main board terminals of step down transformer.
  • Generator reactive capability study to confirm that the reactive power requirements of the generator are not excessive or if switched capacitor banks need to be provided at the generator terminals.
  • Frequency control study to conform that the power plant governor droop settings are coordinated with existing generator governor droop settings and demonstrate that the plant block load acceptances and rejections occur in a stable manner. This study investigates frequency stability issues that may arise with different generator combination: Wind, Solar, Diesel generator and Battery systems.