scholarly journals Sufficient Condition-Based Stability Analysis of a Power Converter Applied Switching Transient Waveform Modification Using Kharitonov’s Theorem

Electronics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 245
Author(s):  
Tongkai Cui ◽  
Qishuang Ma ◽  
Ping Xu
Keyword(s):  
Stability Analysis ◽  
Closed Loop ◽  
Power Converters ◽  
System Stability ◽  
Sufficient Condition ◽  
Small Signal ◽  
Design Guideline ◽  
Saturation Region ◽  
Kharitonov’S Theorem ◽  
Kharitonov's Theorem

The rapid switching action of power metal-oxide-semiconductor field-effect transistor (MOSFET) causes high-level electromagnetic interference (EMI) in power converters. The switching transient waveform modification method realized by closed-loop gate drive has been recognized as an effective high-frequency EMI reduction approach. However, feedback control of power MOSFET in the saturation region would introduce stability problems. This paper presents a sufficient condition-based stability analysis of all the operating points during turn-off using Kharitonov’s theorem. Firstly, a small-signal MOSFET model during turn-off was used to derive the closed-loop system transfer function. The nonlinear capacitances and the rest constant parameters of the small-signal model were determined based on the device characteristics and the expected outcome of the drain-source voltage. Then we split the turn-off switching transient into several subintervals, during which the system characteristic equation became an interval polynomial due to the nonlinear capacitances. Finally, Kharitonov’s theorem was applied in each subinterval to evaluate the stability, thereby achieving the overall system stability analysis during turn-off. Experiments were conducted to investigate the system’s stability and the results confirmed the validity of the proposed analysis. This work presents an implementable design guideline for the applied switching transient waveform modification of power converters via closed-loop gate drive.

Small Signal Stability Analysis Based on Multi-Band Parallel Technology in Henan Power Grid

2013 ◽  
Vol 441 ◽  
pp. 258-262
Author(s):  
Lin Lin Yu ◽  
Yu Fei Rao ◽  
Shi Qian Wang
Keyword(s):  
Stability Analysis ◽  
Power System ◽  
Power Grid ◽  
System Stability ◽  
Small Signal ◽  
Small Signal Stability ◽  
Work Efficiency ◽  
Signal Stability ◽  
Small Signal Stability Analysis ◽  
Multi Band

With the rapid growth in the size of Henan grid, in the context of UHV networking, Henan power grid operation is facing a more complex mechanism and operating characteristics. Risks affecting the security and stability will be more subtle. There are more and more problems in frequency oscillation. The power system has much more generators and dimension after interconnection. Small signal stability analyzing eigenvalue complex and longer, which greatly reduces the work efficiency. This paper which based on Henan power system stability diagnostic platform developed technology based on multi-band parallel algorithm for small signal stability analysis. The analysis of the small signal stability eigenvalue calculation is assigned to a different platform computing nodes simultaneously. Then this method is applied to Henan grid in the year of 2012. The results show that the small signal stability algorithm which based on the multi-band can ensure the correctness of calculations. Simultaneously, calculation time is greatly reduced and the work efficiency is improved. The practice has a strong role in the promotion.

scholarly journals Stability analysis of a phase-shifted full-bridge circuit for electric vehicles based on adaptive neural fuzzy PID control

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yan Liu ◽  
Yan Huang ◽  
He Zhang ◽  
Qiang Huang
Keyword(s):  
Mathematical Model ◽  
Stability Analysis ◽  
Electric Vehicles ◽  
Pid Control ◽  
Closed Loop ◽  
Loop System ◽  
Small Signal ◽  
Fuzzy Pid ◽  
Closed Loop System ◽  
Neural Fuzzy

AbstractIn the paper, adaptive neural fuzzy (ANF) PID control is applied on the stability analysis of phase-shifted full-bridge (PSFB) zero-voltage switch (ZVS) circuit, which is used in battery chargers of electric vehicles. At first, the small-signal mathematical model of the circuit is constructed. Then, by fuzzing the parameters of PID, a closed-loop system of the small-signal mathematical model is established. Further, after training samples collected from the fuzzy PID system by adaptive neural algorithm, an ANF PID controller is utilized to build a closed-loop system. Finally, the characteristics of stability, overshoot and response speed of the mathematical model and circuit model systems are analyzed. According to the simulation results of PSFB ZVS circuit, the three control strategies have certain optimizations in overshoot and adjustment time. Among them, the optimization effect of PID control in closed-loop system is the weakest. From the results of small-signal model and circuit model, the ANF PID system has highest optimization. Experiments demonstrate that the ANF PID system gives satisfactory control performance and meets the expectation of optimization design.

scholarly journals Small Signal Stability Analysis of Multi-Area Power System

2020 ◽  
Vol 9 (4) ◽  
pp. 1850-1855
Keyword(s):  
Fuzzy Logic ◽  
Steady State ◽  
Stability Analysis ◽  
Power System ◽  
System Stability ◽  
Small Signal ◽  
Small Signal Stability ◽  
Interconnected Power System ◽  
Signal Stability ◽  
Small Signal Stability Analysis

This paper focuses on methodologies for calculation and examination of oscillatory security of interconnected power system network against constant disturbances. For instance, voltage soundness, transient dependability and oscillatory behaviors are also the measure of power system stability, which must be evaluated. For that proposed strategies based on proportional integral and fuzzy logic controlling techniques are implemented. The integral controller-based technique provides the zero steady-state error and with adequate damping, time to reach steady state can be reduced, on the cost of oscillation in frequency and tie-line power. On the contrary, fuzzy logic has demonstrated that strategies of computational intelligence can alleviate the quick appraisal of oscillatory solidness with less time to reach steady state. Furthermore, Eigenvalues are constructed for small signal stability analysis, utilizing a parallel variation of Arnoldi technique, reducing the time essential for calculation of vast Multi-Area power frameworks. For exhibit purposes, models have been composed utilizing MATLAB/SIMULINK and with the assistance of the fuzzy logic.

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