Phase Lag Compensator
In the frequency domain, the goal of phase lag compensator design is typically to meet requirements for phase margin and steady-state accuracy. Additionally, a closed-loop bandwidth or gain crossover frequency specification might exist. A phase margin specification can indicate a need for relative stability because of a system’s pure time delay, or it can indicate properties of the intended transient response that have been converted from the time domain to the frequency domain.
- The phase angle of this compensator is negative which is used to provide the phase lag in the system. It helps in the refining of the transient response of the system which results in reducing the peak overshoot.
Process for Designing the Phase Lag Compensator
The process for designing the phase lag compensator in order to meet phase margin and steady-state error requirements is described in the following sections. The sections that follow will provide a detailed description of each stage.
1) Ascertain whether the steady-state error specification can be satisfied by increasing System Type N, and if
If necessary, add as many poles to the plant as needed at s = 0. To satisfy the steady-state error, compute Kc.
2) Create the G(s) = KcGp(s)/s(Nreq−Nsys) Bode graphs.
3) Create the compensator’s lag section:
Finding the frequency where G(jω) would satisfy the phase margin specification if it were the gain crossover frequency is step one. Step two is calculating the amount of attenuation needed to bring the magnitude of G(jω) down to 0 db at that frequency and corresponding α. Step three is computing the lag compensator’s zero zc and pole pc using the selected gain crossover frequency and α.
4) Select the right resistor and capacitor values if needed to put the compensator design into practice.
Lag Compensator
Compensators, which have a wide range of functionality and variants, are an essential component of Control Systems. The compensator is an electrical system that is used to obtain the desired performance of the system. It is used to stabilize the unstable system.
There are various types of compensators such as cascaded, feedback, and cascaded with feedback compensator. Furthermore, the control system is an important subject in the engineering curriculum, and it incorporates many important electronics components. There are some other types of compensators like lead, lag, lag-lead, and lead-lag compensators. The lag compensator eliminates high-frequency noise and improves stability. In this article, we will study lag compensators in detail.
Table of Content
- Compensator
- Lag Compensator
- Characteristic
- Advantages and Disadvantages
- Applications
- Conclusion
- FAQs