Fault Analysis of 3 phase system in Simulink

Summary

This video demonstrates the simulation of faults in three-phase electrical systems using Simulink. It walks through the process of setting up a system with components like a three-phase source, circuit breaker, relay, fault mechanism, and load. The video focuses on how faults are introduced via step functions and how the relay acts to stop the flow of current when excessive values are detected. Although the simulation is more theoretical than practical, it provides valuable insights into the functioning of circuit breakers and fault detection in electrical systems.

Takeaways

• 😀 The video focuses on demonstrating faults in three-phase systems using a theoretical simulation tool called Simulink.
• 😀 The simulation setup uses blocks from the 'S Power System' library, including a three-phase source and a circuit breaker.
• 😀 A three-phase circuit breaker is included in the simulation, with inputs from the three-phase source and a relay that controls its operation.
• 😀 The relay is set to activate when the current exceeds a certain threshold, triggering the fault mechanism in the system.
• 😀 The voltage and current measurements are taken using specialized blocks, which allow for fault monitoring during simulation.
• 😀 The fault occurs at 0.1 seconds in the simulation, triggered by a step function that activates the fault mechanism.
• 😀 The fault induces a high current spike in the system, which is greater than the comparison value set in the relay, triggering its operation.
• 😀 The relay continues to operate until the current drops to zero, demonstrating the protective action taken against excessive current.
• 😀 The simulation runs for 0.3 seconds, with the fault occurrence at 0.1 seconds, and the system is observed through scopes showing voltage and current behavior.
• 😀 The results show a rapid voltage drop towards zero once the fault occurs, highlighting the impact of short circuits on system stability.
• 😀 While the simulation is theoretical and not based on real-world hardware, it provides a useful understanding of fault detection and protection in three-phase systems.

Q & A

What is the main focus of the video?

The main focus of the video is on simulating faults in a three-phase electrical system, using a theoretical simulation with blocks from the Simulink S-POWER system library.

What simulation software is being used in the video?

The simulation software used is Simulink, specifically utilizing blocks from the S-POWER system library for modeling electrical components.

How is the three-phase source modeled in the simulation?

The three-phase source is modeled with an RMS value of 11 kV, with no changes to the angles or frequency, and the voltages are also RMS values.

What role does the circuit breaker play in the simulation?

The circuit breaker in the simulation has four inputs and three outputs, with the main purpose of controlling the flow of current when a fault occurs. It is actuated by a relay.

How is the fault triggered in the system?

The fault is triggered by a step function at 0.1 seconds. When the step function is activated, it generates a pulse that induces a fault into the circuit.

What is the significance of the relay in the system?

The relay monitors the current and compares it to a predefined safe limit. When the current exceeds the threshold (30 kA), the relay activates and triggers the circuit breaker to disconnect the system.

How does the system detect when a fault occurs?

The system detects faults by measuring the current flow through the system. If the current exceeds the safe limit, the relay compares the values and triggers the circuit breaker to disconnect the faulted section.

What is the role of the logical operators used in the relay subsystem?

Logical operators like the AND gate are used to combine multiple conditions. For example, if all inputs to the AND gate are true (1), the system performs certain actions, such as triggering the relay.

What happens when the fault is induced at 0.1 seconds in the simulation?

When the fault is induced, the current spikes rapidly, exceeding the safe limit. The relay activates, disconnecting the system and causing the current and voltage to drop to zero after the fault occurs.

Why is the simulation run for 0.3 seconds?

The simulation runs for 0.3 seconds to allow the fault to develop and for the system to react. The fault is introduced at 0.1 seconds, and the system continues to respond until the end of the simulation.