Scenario: Expanding SCADA System in an Electrical Power Distribution Facility


Initial Setup:

Imagine an electrical power distribution facility equipped with a SCADA (Supervisory Control and Data Acquisition) system. Initially, the facility uses an RTU (Remote Terminal Unit) to monitor basic electrical parameters such as voltage levels and current flow. The Common Address (CA) of the RTU is set to 1, and the initial data points (sensors and actuators) are connected as follows:


  • Voltage Sensor (IOA=101) measures the voltage at various points in the grid. Address: 1;9;101;20 (M_ME_NC for voltage, general interrogation)
  • Current Flow Sensor (IOA=102) monitors the current flowing through the main transmission lines. Address: 1;9;102;20 (M_ME_NA for current, general interrogation)


Expansion Phase 1: Adding Power Quality Monitoring

As the facility expands to focus on power quality, new parameters such as frequency and harmonic distortion are monitored. New sensors are installed and configured:


  • Frequency Sensor (IOA=103) to measure the frequency of the electrical supply. Address: 1;13;103;20 (M_ME_NC for frequency, general interrogation)
  • Harmonic Distortion Sensor (IOA=104) to monitor harmonic levels in the power system. Address: 1;11;104;20 (M_ME_NB for harmonic distortion, general interrogation)


Expansion Phase 2: Control Functions

With requirements for better control over the electrical grid, the facility adds automated control functions to the SCADA system:


  • Circuit Breaker (IOA=201) to manage load by disconnecting parts of the network during overload conditions. Address: 1;45;201;1 (C_SC_NA for circuit breaker, direct operate)
  • Capacitor Bank Control (IOA=202) to adjust the power factor based on real-time load conditions. Address: 1;50;202;1 (C_SE_NC for capacitor bank control, direct operate)


Expansion Phase 3: Advanced Monitoring and Reliability

To enhance reliability and operational safety, the facility integrates temperature monitoring within transformers and high-load alarms:


  • Transformer Temperature Sensor (IOA=105) to monitor temperature within key transformers. Address: 1;13;105;20 (M_ME_NC for temperature, general interrogation)
  • High-Load Alarm (IOA=106) to signal when current levels exceed safe thresholds. Address: 1;30;106;20 (M_SP_TB for high-load alarm, general interrogation)