Load Flow Studies

What are Load Flow Studies?

• Load flow is commonly referred to as power flow and it is one of the most common studies to assess the steady-state performance of the system under various operating conditions and configurations of equipment.

• The objective of load flow studies is to determine the voltage, current, real and reactive power flow, power factor, voltage drop, and real and reactive power losses for all the buses of the system.

What is the Importance of Load Flow Studies?

• Load flow studies are very important for power system planning, design, and operation. It can be used to determine the optimum size of the equipment in the system.

• To determine the steady state performance under different loading conditions (start-up, minimum, normal, and maximum), and various operating configurations (generator/transmission line/load outages, tie-breaker closed, etc.).

• Load flow studies are the initial condition for short circuit, transient stability, harmonic, protection coordination, and motor starting studies.

• To identify the requirement of capacitive or inductive VAR support to maintain the voltage within acceptable limits.

• To determine the transformer and load tap settings and voltage set points for the generator exciter/regulator.

How Do We Perform Load Flow Studies?

• Step-1: Data collection of the study system/substation such as single line diagram (SLD), guaranteed technical particulars (GTP), and datasheet of all the equipment needed.

• Step-2: Modeling the study system/substation in PSCAD/EMTDC software.

• Step-3: Preparation of simulation case studies with the study scenarios accepted by clients.

• Step-4: Preparation of technical report and submission to clients.

What Standards can be referred for Load Flow Studies?

• IEEE Std 3002.2™-2018 - IEEE Recommended Practice for Conducting Load-Flow Studies and Analysis of Industrial and Commercial Power Systems.

• IEEE Std 399-1997 - IEEE Recommended Practice for Industrial and Commercial Power Systems Analysis.