Started 25th Jul, 2022

Hysteresis Current Control

Dear All,
I am working on hysteresis current controller with the inputs are the reference sinusoidal currents for the three phases and the actual three phase currents. the output of the controller is the gate signal for inverter. when I change the switch on and switch off values in relay block parameters in Simulink, there was no change in the controller performance and gate signals!!! and this against the logic expectations of the change in switching pattern of inverter and then the controller performance. Does anyone help me to know the reasons for this issue and how to solve.
I am grateful in advance.

All replies (1)

28th Jul, 2022
Samer Saleh Hakami
Ajou University
I would suggest you check the hysteresis controller rules and the best way is by testing it when it is disconnected from the system. First, apply any value for the sensed current greater than the upper band, then another value less than the lower band. The expected output will be ON or OFF.
Once the hysteresis controller is giving you the desired output, then connect it back to the system for a closed-loop test. Please ensure the band size is correct (try 10% of the rated current) and make sure the sampling time is reasonable, i.e., try different sampling period settings.
Good luck!
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