The experimental source code has been uploaded to CSDN, you can download it directly if you need it, link: https://download.csdn.net/download/weixin_53129688/87694703
Purpose
The purpose of this experiment is to analyze the changes of δ%, Tp, and Ts through modeling and simulation, and deepen the understanding of the correction effect of the series correction device on the dynamic performance of the system.
Experimental content
1. serial lead correction
(1) The analog circuit diagram of the system is shown in Figure 5-1. In the figure, the switch S is turned off to correspond to the uncorrected situation, and turned on to correspond to the advanced correction.
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Figure 5-1 Lead correction circuit diagram
(2) System structure diagram as shown in Figure 5-2
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Figure 5-2 Structural diagram of the lead correction system
Referring to the experiment guide, the transfer function of G C ( S ) in the figure is:
Before correction: Gc1(s)=2
2（0.055s+1）
After correction: Gc2(s)=————————
0.005s+1
2. Series lag correction
- The analog circuit diagram is shown in Figure 5-3. The switch s is turned off corresponding to the uncalibrated state, and turned on corresponds to the hysteresis correction.
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Figure 5-3 Lag correction analog circuit diagram
(2) The system structure diagram is shown in Figure 5-4
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Figure 5-4 Structural diagram of hysteresis system
Referring to the experiment guide, the transfer function of G C ( S ) in the figure is:
Before correction: Gc1(s)=2
2（s+1）
After correction: Gc2(s)=——————
11s+1
3. Series lead-lag correction
- The analog circuit diagram is shown in Figure 5-5. The double-pole switch is turned off to correspond to the uncalibrated state, and turned on to correspond to the lead-lag correction.
Figure 5-5 Lead-lag correction analog circuit diagram
- The system structure diagram is shown in Figure 5-6.
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Figure 5-6 Structural Diagram of Lead-Lag Correction System
Referring to the experiment guide, the transfer function of G C ( S ) in the figure is:
Before correction: Gc1(s)=6
6（1.2s+1）（0.15s+1）
After correction: Gc2(s)=————————————
（6s+1）（0.05s+1）
Experimental steps:
- Open the simulink of matlab and select the library browser.
Lead correction:
- First of all, the first thing to do is lead correction. Find the step function in the library browser. The step function is located in the Sources in the library browser . Press and hold the left button to drag it to the model.
- First, build the model before correction according to the system structure diagram (in the experimental content), as shown in the figure:
- Some of the module parameters are set as follows (the first few experiments of module configuration are explained in detail, so I won’t go into details here):
- Click to run, and observe the waveform (the scope background change is also explained in detail before):
6. At this time, we found that the steady-state performance of the system is better but the dynamic performance is not ideal. At this time, we add advanced correction and make comparisons. After correction according to the experimental content:
2（0.055s+1）
Gc2（s）=————————
0.005s+1
So add it to the model, as shown in the figure:
The parameters are set to:
7. Click Run, and observe the system response waveform before and after calibration:
8. It can be observed that after adding advanced correction, the dynamic performance of the system has been improved. At this time, the before and after changes of δ%, Tp, Ts can be analyzed and recorded for analysis:
lag correction
9. The second is lag correction, copy and paste the lead correction model, and make changes according to the experimental content,
Gc1（s）=2
2（s+1）
Gc2（s）= —————
11s+1
As shown in the picture:
10. Click to run, and through waveform observation, it can be seen that the system performance has been improved through hysteresis correction. At this time, the before and after changes of δ%, Tp, Ts can be analyzed and recorded for analysis:
Lead-lag correction
11. The third is the lead-lag correction, as before, copy and paste the model, and then modify it according to the experimental content
Gc1（s）=6
6（1.2s+1）（0.15s+1）
Gc2（s）=——————————————
（6s+1）（0.05s+1）
As shown in the picture:
12. Click to run, and observe the waveform. It can be seen that the system performance has been improved through the lead-lag correction. At this time, the before and after changes of δ%, Tp, Ts can be analyzed and recorded for analysis:
Summary: When the open-loop gain of the system meets the requirements of its steady-state performance, its dynamic performance is generally not ideal, and even instability may occur. For this reason, it is necessary to connect a correction device in series in the system, which can not only keep the open-loop gain of the system unchanged, but also make the dynamic performance of the system meet the requirements.