Protection Relay

Implement protection relay with definite minimum time (DMT) trip characteristics

• Library:

• Motor Control Blockset / Protection and Diagnostics

• 

Description

The Protection Relay block implements a protection relay for the hardware and the motor with definite minimum time (DMT) trip characteristics using the reference limit, feedback, and reset input signals. In the event of a fault, the block generates a latched fault signal that you can use to protect the hardware and the motor. You can reset the fault latch using an external reset signal.

Ports

Input

Imax — Upper limit for current

scalar

Upper limit for current in the feedback loop, so as to provide overcurrent protection. The block generates a latched fault signal when the current in the feedback loop (Ifb) exceeds this value.

Dependencies

To enable this port, set Select Protection to Overcurrent.

Data Types: single | double | fixed point

Ifb — Actual current in feedback loop

scalar

Actual current in the feedback loop at a given time.

Dependencies

To enable this port, set Select Protection to Overcurrent.

Data Types: single | double | fixed point

⍵m max — Rotor speed limit for overspeed protection

scalar

Speed limit of the rotor (in RPM). The block generates a latched fault signal when the rotor speed (⍵m fb) exceeds this value.

Dependencies

To enable this port, set Select Protection to Overspeed.

Data Types: single | double | fixed point

⍵m fb — Actual rotor speed

scalar

Actual rotor speed at a given time.

Dependencies

To enable this port, set Select Protection to Overspeed.

Data Types: single | double | fixed point

Vmax — Upper voltage limit for overvoltage protection

scalar

Upper limit for voltage across the feedback loop. The block generates a latched fault signal when the voltage across the feedback loop (Vfb) exceeds this value.

Dependencies

To enable this port, set Select Protection to Overvoltage.

Data Types: single | double | fixed point

Vmin — Lower voltage limit for undervoltage protection

scalar

Lower limit for voltage across the feedback loop. The block generates a latched fault signal when the voltage across the feedback loop (Vfb) is less than this value.

Dependencies

To enable this port, set Select Protection to Undervoltage.

Data Types: single | double | fixed point

Vfb — Actual voltage across feedback loop

scalar

Actual voltage across the feedback loop at a given time.

Dependencies

To enable this port, set Select Protection to either Overvoltage or Undervoltage.

Data Types: single | double | fixed point

Reset — External reset pulse

scalar

External pulse that resets the fault latch.

Data Types: single | double | fixed point

Output

y — Latched fault signal

scalar

Latched fault signal that the block generates during the overcurrent, overspeed, overvoltage, and undervoltage conditions to protect the hardware and the motor.

Data Types: single | double | fixed point

Parameters

Select Protection — Type of protection relay

Overcurrent (default) | Overspeed | Overvoltage | Undervoltage

Available protection types to configure block behavior during the overcurrent, overspeed, overvoltage, and undervoltage conditions.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Fixed-Point Conversion
Design and simulate fixed-point systems using Fixed-Point Designer™.

Version History

Introduced in R2020a