# PID tuning of a classic voltage controlled three-phase rectifier

I have a three-phase synchronous active rectifier

I need to control it with a voltage oriented scheme like this:

But I have no idea of how to tune multiple PIs, I'm trying to do it by trial but I need a "systematic" method.

This question is much too broad to answer properly; the "best" approach depends on system properties, available controller architecture, available control design tools,...

Assuming you have a MIMO system (i.e. the inputs/outputs of the system are coupled and the controllers can therefore not be considered as independent) the general approach would be to:

1. Characterize the properties of the system to be controlled. This is usually done by either building a model of the plant to be controlled or, if the plant is available, by measuring the frequency response functions between its inputs and outputs (including cross terms).

2. Design a controller based on the measured or modeled plant characteristics and a MIMO control design technique of your choice. There are many possible choices here; in case a loop-shaping like approach is preferred sequential loop closing might be an option. In case a more formal approach is needed $H_\infty$ control might be an option.

3. Apply the designed controller to your actual system (but only after you are certain that stability and performance requirements are met).

A good reference, explaining many of the details related to MIMO control design, is:

Multivariable Feedback Control: Analysis and Design, 2nd Edition Sigurd Skogestad, Ian Postlethwaite

• This is the right way to think about this situations. For all but the most basic systems, it is best to think about designing a controller based on a system model rather than "tuning" a controller with some adjustable parameters.
– Max
Jul 6 '17 at 20:26
• @Max The problem is right here, i have to use that control architecture. Jul 7 '17 at 15:35