To improve the performance of chaotic secure communication,three simplified chaotic systems with one variable parameter were investigated.Basic properties were analyzed including symmetry,dissipation and topological s...To improve the performance of chaotic secure communication,three simplified chaotic systems with one variable parameter were investigated.Basic properties were analyzed including symmetry,dissipation and topological structure.Complex dynamical behaviors of the systems including chaos and periodic orbits were verified by numerical simulations,Lyapunov exponents and bifurcation diagrams.Interestingly,the three systems were integrated in a common circuit,and their dynamical behaviors were easily observed by adjusting regulable resistors R28,R14 and R17,respectively,and the relations between the variable resistor and the system parameter were deduced.The circuit experiment results agree well with the simulation results.Finally,a secure communication scheme based on chaos shift keying(CSK) was presented,which lays an experiment foundation for chaotic digital secure communication.展开更多
Routes to chaos in power systems are studied. Using a three-bus simple system, three routes that can lead power system to chaos are presented, illustrated and discussed. They are cascading period doubling bifurcation,...Routes to chaos in power systems are studied. Using a three-bus simple system, three routes that can lead power system to chaos are presented, illustrated and discussed. They are cascading period doubling bifurcation, torus bifurcation and route directly initiated by a large disturbance. Period doubling bifurcation is caused by a real Floquet multiplier going out of the unit circle from point (-1,0), while torus bifurcation is caused by a couple of conjugated Floquet multipliers going out of the unit circle with a non-zero imaginary part in the complex plane. Cascading period doubling bifurcation and torus bifurcation are two typical routes to chaos in dynamic systems, which have been investigated in the previous studies. The last route, i.e. directly initiated by a large disturbance, is reported and studied. This phenomenon reveals that chaos is caused by external disturbances in power systems.展开更多
基金Projects(611061006,61073187) supported by the National Nature Science Foundation of China
文摘To improve the performance of chaotic secure communication,three simplified chaotic systems with one variable parameter were investigated.Basic properties were analyzed including symmetry,dissipation and topological structure.Complex dynamical behaviors of the systems including chaos and periodic orbits were verified by numerical simulations,Lyapunov exponents and bifurcation diagrams.Interestingly,the three systems were integrated in a common circuit,and their dynamical behaviors were easily observed by adjusting regulable resistors R28,R14 and R17,respectively,and the relations between the variable resistor and the system parameter were deduced.The circuit experiment results agree well with the simulation results.Finally,a secure communication scheme based on chaos shift keying(CSK) was presented,which lays an experiment foundation for chaotic digital secure communication.
基金Supported by the Foundation for the Author of National Excellent Doctoral Dissertation(No.200439)Key Project of Chinese Ministryof Education (No.105047)+2 种基金Program for New Century Excellent Talents in University,Fok Ying Tung Education Foundation(No.104019)Innovation Fund of Tianjin Municipal(No.06TXTJJC13700),Natural Science Foundation of China(No.50595413) theSpecial Fund of the National Fundamental Research (2004CB217904)of China.
文摘Routes to chaos in power systems are studied. Using a three-bus simple system, three routes that can lead power system to chaos are presented, illustrated and discussed. They are cascading period doubling bifurcation, torus bifurcation and route directly initiated by a large disturbance. Period doubling bifurcation is caused by a real Floquet multiplier going out of the unit circle from point (-1,0), while torus bifurcation is caused by a couple of conjugated Floquet multipliers going out of the unit circle with a non-zero imaginary part in the complex plane. Cascading period doubling bifurcation and torus bifurcation are two typical routes to chaos in dynamic systems, which have been investigated in the previous studies. The last route, i.e. directly initiated by a large disturbance, is reported and studied. This phenomenon reveals that chaos is caused by external disturbances in power systems.
