Load and Frequency Control

Technical document presenting the fundamentals of load-frequency control in power systems, covering systems with single or multiple generating units, isolated systems, and interconnected systems. It addresses primary and secondary load-frequency regulation, Tie-Line Bias Control, Area Control Error, and their application to the Brazilian Interconnected Power System (SIN). The document also covers economic dispatch, its interaction with load-frequency control, and the challenges associated with variable renewable energy sources. It further presents criteria and parameters for adjusting generating-unit speed governors, with emphasis on permanent and transient droop, time constants, inertia, overspeed, transfer functions, and application examples. 

Document prepared by Eng. Sergio Carvalhaes Moreira. 

The document covers, among other topics:

• Fundamentals of load-frequency control; 
• Systems with a single generating unit; 
• Isolated systems with multiple generating units; 
• Load variation sharing among generating units; 
• Regulation characteristic and droop; 
• Primary load-frequency regulation; 
• Secondary or supplementary load-frequency regulation; 
• Joint control; 
• Area regulation characteristic; 
• Interconnected power systems; 
• Flat frequency control and supplementary frequency control; 
• Tie-Line Bias Control (TLB); 
• Area Control Error (ACE); 
• Economic dispatch and its interaction with load-frequency control; 
• The role of the Brazilian Independent System Operator (ONS) in operation of the Brazilian Interconnected Power System; 
• Economic dispatch with variable renewable energy sources; 
• Permanent and transient droop; 
• Accelerometric time constant; 
• Water inertia time constant; 
• Effective rotor inertia; 
• Overspeed and load rejection; 
• Transfer functions and time constants; 
• Gain and speed-governor adjustment criteria; 
• Specific example of speed-governor adjustment and performance analysis.

Electrical engineers, power system engineers, hydroelectric plant operators, consultants, researchers, electrical engineering students and professionals involved in the operation, control, automation and planning of electric power systems. 

•  Technical PDF Document.