Right here, we'll establish a gain alternatives approach based on the volume effect of the system
Of Eq. (2.28) , it can be seen that the current-control attribute hinges on the fresh new performance of the latest control, and that's dependent on the brand new P and i gains chose for the PI control.
dos.6.step one Proportional–Built-in Current Control
A current control system with which has good PI operator is actually shown during the Fig. 2.thirty two . Here, think that the latest feedforward manage makes up the rear-EMF of one's DC engine really well.
in which T p i ( = K p c / K i c ) 's the built-in time ongoing of your PI latest controller and K we c 's the built-in gain.
There are many PI obtain tuning regulations for instance the well-known Ziegler–Nichols approach. Right here, we're going to follow the technique called the rod-zero cancellation method. Using the rod-zero termination, we could take away the current-control attribute of your own DC system by itself so that the PI operator will get influence the fresh efficiency of the modern handle.
If for example the zero ( ? K i c / K p c ) of PI controller is made to terminate this new rod ( ? Roentgen an excellent / L a beneficial ) of your own DC system by the pole-zero cancellation approach, i.age.
Fig. 2.33 reveals the new bode area of open-circle regularity impulse from Grams c o ( s ) . The fresh new phase try ?90° at the gain mix-more than regularity ? c c where in actuality the magnitude | Grams c o ( j ? ) | = 0 dB . Hence the new gain margin try positive and also the system might possibly be secure. And additionally, in this instance, the transfer purpose of Eq. (dos.32) becomes the computer away from sorts of=1 and you can, therefore, we sitios de citas ecológicas are able to predict the fresh new steady-state error to-be zero as the
New get mix-more volume ? c c of the open-circle regularity answer is equivalent to the fresh get reduce-off regularity of the romantic-loop volume impulse, hence suggests the data transfer of your own current-control program. Let's check the bandwidth associated with the current control program.
Their frequency answer is shown during the Fig. 2.34 . We are able to notice that the newest data transfer of the experience given once the ? c c by allowing | Grams c c ( j ? ) | comparable to step 1 / 2 (=?3 dB) as the
Along these lines, in case the no of your own PI controller was created to terminate the newest pole of the program, the current handle system is indicated merely while the an initial-acquisition program that have a cut right out-from volume ? c c , which is secure. In this situation, there will be no overshoot from the reaction in addition to time necessary for the solution to achieve the latest worth is from the fourfold the full time constant of your own system.
Based on the reason provided significantly more than, the latest proportional and you may integral gains of your most recent controller wanted to get to the needed data transfer are going to be determined the following.
Whether your needed control bandwidth is actually ? c c , then the proportional get K p c is obtainable from Eq. (2.34) as well as the built-in gain K i c is present out of Eq. (2.31) once the
You should note that the earnings of your own operator trust the latest engine variables L a and you can Roentgen an effective . Additionally the acquire thinking to truly have the same current-control efficiency ple, a system which have an enormous property value winding inductance, whoever newest is hard to evolve, means a larger proportional gain to acquire the same bandwidth of the current manage than simply by using a little value of winding inductance, whoever newest is easy adjust. Thus, accurate information about the latest motor variables is important to achieve the required current control abilities.
