Analysis of Convergence of an Evolutionary Algorithm with Self-Adaptation using a Stochastic Lyapunov function

2003 ◽  
Vol 11 (4) ◽  
pp. 363-379 ◽  
Author(s):  
Mikhail A. Semenov ◽  
Dmitri A. Terkel

This paper analyses the convergence of evolutionary algorithms using a technique which is based on a stochastic Lyapunov function and developed within the martingale theory. This technique is used to investigate the convergence of a simple evolutionary algorithm with self-adaptation, which contains two types of parameters: fitness parameters, belonging to the domain of the objective function; and control parameters, responsible for the variation of fitness parameters. Although both parameters mutate randomly and independently, they converge to the floptimumfl due to the direct (for fitness parameters) and indirect (for control parameters) selection. We show that the convergence velocity of the evolutionary algorithm with self-adaptation is asymptotically exponential, similar to the velocity of the optimal deterministic algorithm on the class of unimodal functions. Although some martingale inequalities have not be proved analytically, they have been numerically validated with 0.999 confidence using Monte-Carlo simulations.

2018 ◽  
Vol 2 ◽  
pp. 9-16
Author(s):  
A. Al-Ammouri ◽  
◽  
H.A. Al-Ammori ◽  
A.E. Klochan ◽  
A.M. Al-Akhmad ◽  
...  

2019 ◽  
Vol 9 (2) ◽  
pp. 252 ◽  
Author(s):  
Ziqian Zhang ◽  
Cihan Gercek ◽  
Herwig Renner ◽  
Angèle Reinders ◽  
Lothar Fickert

This article presents an in-situ comparative analysis and power quality tests of a newly developed photovoltaic charging system for e-bikes. The various control methods of the inverter are modeled and a single-phase grid-connected inverter is tested under different conditions. Models are constituted for two current control methods; the proportional resonance and the synchronous rotating frames. In order to determine the influence of the control parameters, the system is analyzed analytically in the time domain as well as in the frequency domain by simulation. The tests indicated the resonance instability of the photovoltaic inverter. The passivity impedance-based stability criterion is applied in order to analyze the phenomenon of resonance instability. In conclusion, the phase-locked loop (PLL) bandwidth and control parameters of the current loop have a major effect on the output admittance of the inverter, which should be adjusted to make the system stable.


2015 ◽  
Vol 352 (3) ◽  
pp. 776-801 ◽  
Author(s):  
Liang Li ◽  
Yahui Zhang ◽  
Chao Yang ◽  
Xiaohong Jiao ◽  
Lipeng Zhang ◽  
...  

2017 ◽  
Vol 76 (5) ◽  
pp. 1225-1233 ◽  
Author(s):  
M. Schäfer ◽  
I. Hobus ◽  
T. G. Schmitt

In the future, an additional potential of control reserve as well as storage capacities will be required to compensate fluctuating renewable energy availability. The operation of energy systems will change and flexibility in energy generation and consumption will rise to a valuable asset. Wastewater treatment plants (WWTPs) are capable of providing the flexibility needed, not only with their energy generators but also in terms of their energy consuming aggregates on the plant. To meet challenges of the future in regard to energy purchase and to participate in and contribute to such a volatile energy market, WWTPs have to reveal their energetic potential as a flexible service provider. Based on the evaluated literature and a detailed analysis of aggregates on a pilot WWTP an aggregate management has been developed to shift loads and provide a procedure to identify usable aggregates, characteristic values and control parameters to ensure effluent quality. The results show that WWTPs have a significant potential to provide energetic flexibility. Even for vulnerable components such as aeration systems, load-shifting is possible with appropriate control parameters and reasonable time slots without endangering system functionality.


2019 ◽  
Vol 148 ◽  
pp. 157-172 ◽  
Author(s):  
Sriraj Gokarakonda ◽  
Christoph van Treeck ◽  
Rajan Rawal

2014 ◽  
Vol 644-650 ◽  
pp. 722-725
Author(s):  
Fan Wu

A large cement factory as an example, according to the requirements of process and control parameters of production line of raw mill, this paper researches and designs the automatic control system of cement raw mill production line based on PCS7 and PROFIBUS. The design of the whole system consists of three levels: field layer, control layer and operation layer which are connected by Ethernet and PROFIBUS implementation, and focus on the design of the feed flow includeing feed composition, feed machine speed loop control etc. Through the on-site operation, the system is stable and reliable, and has good application and promotion effect.


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