Hello,
I want to check DC Link stability connected before inverter and 3ph Induction motor.
If i change Torque and Speed of Motor and check DC Link, there might be some variation in DC Link. Am i right ?
Question is: How to check stability of DC Link ? Any method ? Mathematics ? Plots ?
Hi, I do have a question for you: are you controlling the DC-link voltage?
The question is because analyzing the DC-link stability only makes sense when you are operating the system in closed-loop mode.
If you don't have any controller to regulate the DC-link voltage, yes, some variations in the voltage level appear when you change either the velocity or the torque.
Hi Jorge
I am talking in terms of AC Traction system. Yes DC link is controlled in terms of to maintain constant DC voltage and it also accepts regenerative braking.
So how to check the stability ?
Hi, torque and speed are related to the current and frequency supplied by the 3p inverter, respectively. There is a linear relationship between the d current and the torque of the machine for a given constant rotor flux operation in the linear region of operation (max torque region). Consequently, it is the change in the torque how is translated into a disturbance to the DC-link controller. You have two options: first, to model the whole system (inverter + motor) and derive the transfer function which relates the torque to the DC-link or, second, finds an empirical transfer function Gvdc/id. Thus, using this transfer function evaluates the closed-loop system stability which will depend on the controller you are using too.
- Badges
- Science topic
- Similar topics
- Correction