Right here, we’re going to expose a gain choice method in line with the volume reaction of one’s system
Out-of Eq. (dos.28) , it can be viewed that the current-control attribute hinges on new efficiency of newest operator, that’s dependent on the brand new P and i also gains chose for the PI control.
2.6.1 Proportional–Inbuilt Latest Controller
A current handle program that has a PI controller is actually found inside the Fig. dos.thirty two . Here, assume that the new feedforward manage compensates the back-EMF of DC system really well.
in which T p we ( = K p c / K i c ) is the built-in day lingering of your PI latest operator and you will K we c is the integrated gain.
There are some PI obtain tuning laws and regulations including the popular Ziegler–Nichols method. Right here, we will embrace the process called the pole-no cancellation method. Using the pole-no termination, we can get rid of the current-control attribute of DC engine itself so that the PI control will get dictate the newest overall performance away from the modern manage.
In case your no ( ? K i c / K p c ) of one’s PI operator is designed to cancel the fresh new pole ( ? Roentgen good / L a beneficial ) of DC system of the pole-no termination strategy, we.elizabeth.
Fig. 2.33 shows the fresh bode area of one’s open-cycle regularity effect regarding G c o ( s ) . The stage is ?90° on get cross-over frequency ? c c where magnitude | G c o ( j ? ) | = 0 dB . Thus the new get margin was positive therefore the system could be steady. Together with, in such a case, the latest transfer intent behind Eq. (2.32) gets the machine off sorts of=1 and, hence, we can expect the brand new constant-county mistake as no just like the
The latest get get across-over frequency ? c c of discover-cycle volume answer is equivalent to new get slash-from frequency of your own close-loop volume effect, and this suggests the fresh bandwidth of current control program. Let us check the bandwidth of current-control program.
Its frequency answer is shown during the Fig. dos.34 . We are able to note that the bandwidth from the system is considering as ? c c by allowing | Grams c c ( j ? ) | equivalent to 1 / 2 (=?step three dB) since the
Like this, in the event your no of PI controller was designed to cancel the fresh new pole of your program, the modern control method is shown just since a primary-purchase system having a cut right out-of regularity ? c c , that’s stable. In this instance, there won’t be any overshoot throughout the impulse therefore the go out needed for the answer to achieve the finally worth was on the four times the amount of time lingering of system.
According to the explanation given more than, brand new proportional and you may integral increases of your own most recent control necessary to reach the necessary data transfer will likely be determined as follows.
In the event your required manage bandwidth was ? c c , then your proportional gain K p c can be found out of Eq. (dos.34) additionally the built-in gain K we c is obtainable from Eq. (2.31) as the
It is important to observe that the gains of one’s controller depend on https://www.datingranking.net/es/420-citas/ the system details L an excellent and you may R good . Together with gain values to truly have the exact same current-control abilities ple, an engine having a large property value wandering inductance, whose latest is difficult to evolve, requires more substantial proportional acquire to find the same bandwidth from the modern control than by using a little value of wandering inductance, whose newest is straightforward to improve. For this reason, precise information about the system parameters is very important to truly have the needed current control efficiency.