D-STATCOM The distribution static synchronous compensator (D-STATCOM) has the characteristics of nonlinearity, multivariable and strong coupling. Based on the analysis of the D-STATCOM mathematical model, in order to improve the performance of the linear active disturbance rejection controller (LADRC), solve the coupling problem between the d-axis and q-axis current and improve the dynamic tracking response speed and anti-interference ability. A controller with LADRC that compensates the error of the total disturbance is proposed, and the stability of the improved first-order LADRC is proved by the Lyapunov stability theory.
Then the output of the full interference channel is corrected to improve the anti-interference ability of the system and the interference observation ability of the linear extended state observer (LESO) to high frequency noise. Through the analysis of the Bode diagram in the frequency domain, compared with the traditional LADRC, the improved LADRC proposed in this paper has better anti-interference performance. Finally, the improved first-order LADRC is used to replace the traditional D-STATCOM control strategy for current inner loop control, which effectively reduces the disturbance observation error of LESO. The experimental results show that the improved LADRC control performance is better than the proportional integral (PI) controller, and it has better tracking performance and anti-interference performance.
- Distribution static synchronous compensator (D-STATCOM)
- Total disturbance
- Linear active disturbance rejection control (LADRC)
- Linear extended state observer (LESO)
- Anti-interference performance.
Figure 1. Overall Control Structure Of Voltage Type D-Statcom Device.
EXPECTED SIMULATION RESULTS:
Figure 2. Comparison Of Reactive Current Tracking Curves Under The Control Of Pi And Improved Ladrc Under Low Voltage Ride-Through.
Figure 3.Comparison Of Reactive Current Tracking Under Pi And Improved Ladrc Control With Increasing And Decreasing Load.
Figure 4. Comparison Of Reactive Power And Active Power Under The Control Of Pi And Improved Ladrc Under Low Voltage Ride-Through.
Figure 5. Comparison Of Reactive Power And Active Power Under Pi And Improved Ladrc Control With Increasing And Decreasing Load.
D-STATCOM Aiming at the nonlinear, multivariable and strong coupling characteristics of D-STATCOM, this paper proposes an improved first-order LADRC for the internal current loop of the D-STATCOM system. The key to LADRC performance is whether the extended state observer can accurately estimate the state variables of the system. The innovation of this paper is to propose a linear active disturbance rejection controller that compensates the total disturbance error to improve the control performance of the entire control system.
And through the rigorous mathematical derivation of the Lyapunov stability theory, the stability of the improved first-order LADRC is proved, and the asymptotic stability conditions are given. Then correct the output of the total disturbance channel. Finally, the experiment proved the correctness and feasibility of the improved first-order LADRC. In addition, this article only considers the situation of balanced load and symmetrical grid voltage failure. Future work will focus on the study of the D-STATCOM control method of the LADRC under unbalanced load and distorted grid voltage.
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