System Protection Technology

The objective of this module is to introduce and present the major features of static relaying, including analog-type solid-state relays and digital microprocessor relays. At this stage in the program, it is assumed that all participants are thoroughly familiar with the functions and characteristics of the different types of relays. This module focuses upon the differences between solid state and electromechanical relays.

After study of this tape and the associated workbook, participants should be able to understand the following overall concepts and apply them in their day-to-day work activities. They will also be able to answer related test questions on these subjects:

• Advantages and disadvantages of static relays
• Static relay solid state components: diode, transistor
• Transistor circuits
• Thyristors
• Integrated circuits; operational amplifier
• FETs and MOSFETs
• Basic relay circuits
• Signal level detector, timer
• Polarity detector, square wave generator
• Phase comparison circuits
• Amplitude comparison
• Logic circuits
• Switching circuits
• Relay power supplies, voltage regulation
• Examples of solid-state relays
• Overcurrent relays, directional relays
• Differential relays, distance relays
• Digital microprocessor relaying
• Signal sampling, analog-digital conversion
• Reference algorithms
• Function of printed circuit board modules
• Monitoring, remote and local
• Relay programming, remote and local
• Substation control systems