The phenomenon of anti-symmetrical bifurcation of periodic solutionsoccurring near an integral manifold is the intrinsic cause resulting in harmonic resonanceover-voltage in power systems. Due to this discovery, the p...The phenomenon of anti-symmetrical bifurcation of periodic solutionsoccurring near an integral manifold is the intrinsic cause resulting in harmonic resonanceover-voltage in power systems. Due to this discovery, the principle of eliminating resonance byusing anti-bifurcation technique is presented, which makes that the theoretical bases of verymeasure to eliminate resonance are unified firstly from a point of view of basic theory. Ourdiscussion models depend on a class of nonlinear control model. Using the direct Lyapunov method, acomplete theoretical proof is given in accordance with the measure of eliminating resonance byconnecting nonlinear resistor in series to the neutral point of P. T., and the feedback control lawbeing applied. It comprises the action of parameters of resistor to eliminate resonance and theactual process of eliminating resonance, i.e., to go against bifurcation process which forces thebig harmonic solutions to retreat to the integral manifold gradually and disappear eventually, whichby using the nonlinear controllers. This makes it sure that the intrinsic cause of resonance iseliminated thoroughly. The obtained theory results and computing results are better than thepresented results.展开更多
The control of the stability of the filament tension is one of the crucial techniques ensuring the component quality of the composite materials. The open-loop tension control system, with industrial control computer a...The control of the stability of the filament tension is one of the crucial techniques ensuring the component quality of the composite materials. The open-loop tension control system, with industrial control computer as the core, magnetic particle clutch as the actuator, equipped with compensation technique is researched and manufactured. It can assure the tension control stability of the yarn in filament winding process and increase the control precision of the whole system.展开更多
An immune algorithm solution is proposed in this paper to deal with the problem of optimal coordination of local physically based controllers in order to preserve or retain mid and long term voltage stability. This pr...An immune algorithm solution is proposed in this paper to deal with the problem of optimal coordination of local physically based controllers in order to preserve or retain mid and long term voltage stability. This problem is in fact a global coordination control problem which involves not only sequencing and timing different control devices but also tuning the parameters of controllers. A multi-stage coordinated control scheme is presented, aiming at retaining good voltage levels with minimal control efforts and costs after severe disturbances in power systems. A self-pattem-recognized vaccination procedure is developed to transfer effective heuristic information into the new generation of solution candidates to speed up the convergence of the search procedure to global optima. An example of four bus power system case study is investigated to show the effectiveness and efficiency of the proposed algorithm, compared with several existing approaches such as differential dynamic programming and tree-search.展开更多
In order to resolve the problean of the unbalanced threephase and unstable voltage, intellectual economized technique on elec- tricity based on electromagnetic regulation and control is proposed in this paper. We choo...In order to resolve the problean of the unbalanced threephase and unstable voltage, intellectual economized technique on elec- tricity based on electromagnetic regulation and control is proposed in this paper. We choose the TMS320LF2407A as the control chip and stepper motor as the executing agency. The equipment controls the movable contact reaching to the assigned position on the magnetic coil quickly and accurately, and outputs the sine-wave voltage steadily along with the network voltage variation though the fuzzy Porportional Integral Derivative（PID） control algorithm of integral separation and incremental mode with setting dead area. The principle of work and the key technique on the electromagnetic regulation and control are introduced in detail in this paper. The experiment result gives a proof for all the algorithm mentioned in this paper.展开更多
A multi-channel active vibration controller based on a filtered-u least mean square （FULMS） control algorithm is analyzed and implemented to solve the problem that the vibration feedback may affect the measuring of ...A multi-channel active vibration controller based on a filtered-u least mean square （FULMS） control algorithm is analyzed and implemented to solve the problem that the vibration feedback may affect the measuring of the reference signal of the filtered-x least mean square （FXLMS） algorithm in the field of active vibration control. By analyzing the multi-channel FULMS algorithm, the multi-channel controller structure diagram is given, while by analyzing multi-channel FXLMS algorithm and its algorithmic procedure, the control channel model identification strategy is given. This paper also provides an easy but practical way to configure the actuators based on the maximal modal force rule. Taking the configured piezoelectric beam as the research object, an active vibration control experimental platform is established to verify the effectiveness of the identification strategy as well as the FULMS control scheme. Simulation and actual control experiments are done after the model parameters are obtained. Both the simulation and actual experiment results show that the designed multi-channel vibration controller has a good control performance with low order model and rapid convergence.展开更多
A predictive current control algorithm for the Buck-Boost DC-DC converter is presented in this paper. The continuous time model of the system is properly introduced, then, by imposing a proper PWM modulation pattern, ...A predictive current control algorithm for the Buck-Boost DC-DC converter is presented in this paper. The continuous time model of the system is properly introduced, then, by imposing a proper PWM modulation pattern, its discrete time model is achieved. This last one is successfully employed in determining the steady state locus of the Buck-Boost converter, both in CCM （continuous conduction mode） and DCM （discontinuous conduction mode）. A novel continuous time equivalent circuit of the converter is introduced too, with the aim of determining a ripple free representation of the state variables of the system, over both transient and steady state operation. Then, a predictive current control algorithm, suitable in both CCM and DCM, is developed and properly checked by means of computer simulations. The corresponding results have highlighted the effectiveness of the proposed modelling and of the predictive control algorithm, both in CCM and DCM.展开更多
An automated multi-range multipliers（range resistors）system is established for the AC voltage measurements by using a thermal voltage converter.It is performed automatically by selecting the appropriate multiplier w...An automated multi-range multipliers（range resistors）system is established for the AC voltage measurements by using a thermal voltage converter.It is performed automatically by selecting the appropriate multiplier whose voltage range contains the voltage to be measured without changing it manually through a new designed system.It consists of control part through a micro-controller controlled by specified prepared Lab-VIEW program and switching part through electronic relays in one circuit as clearly described in this work.It is used for measuring the ac voltage in the range from 1 V to 200 V.Also,it can be used for the voltage ranges up to 1 000 V by putting some factors into consideration.The AC-DC transfer differences for these multipliers combined with thermal voltage converter are determined automatically against another standard thermal voltage converter by using another Lab-VIEW program.展开更多
This paper proposes a parameter determination method of distribution voltage regulators load ratio control transformers （LRT） and step voltage regulators （SVR） considering the tap change and voltage profile. The m...This paper proposes a parameter determination method of distribution voltage regulators load ratio control transformers （LRT） and step voltage regulators （SVR） considering the tap change and voltage profile. The method takes two procedures in order to simplify the optimization problem and to reduce calculation time. One is to simultaneously determine the control parameters of LRT and SVR minimizing voltage violations and voltage variations. The algorithm is based on particle swarm optimization （PSO）, which is one of non-linear optimization methods by using a concept of swarm intelligence. Another is to determine the dead-band width of LRT and SVR on the basis of bi-evaluation of tap change and voltage margin. The concept of a Pareto optimal solution is used for the decision of the best dead-band width. As the results of numerical simulations using distribution network model, the validity of the proposed method has been affirmed.展开更多
An appropriate acquisition configuration in terms of signal quality can optimize the acquisition performance. In view of this, a new approach of acquisition assisted by the control voltage of automatic gain control(AG...An appropriate acquisition configuration in terms of signal quality can optimize the acquisition performance. In view of this, a new approach of acquisition assisted by the control voltage of automatic gain control(AGC) is proposed. This approach judges the signal power according to the AGC control voltage and switches the working modes correspondingly and adaptively. Non-coherent accumulation times and the detection threshold are reconfigured according to the working mode. Theoretical derivation and verification by simulation in typical situations are provided, and the algorithm is shown to be superior in terms of the mean acquisition time, especially in strong signal scenarios compared with the conventional algorithm.展开更多
In order to avoid the overcharge and overdischarge damages, and to improve the lifetime of the lithium-ion batteries, it is essential to keep the cell voltages in a battery pack at the same level,i.e., battery equaliz...In order to avoid the overcharge and overdischarge damages, and to improve the lifetime of the lithium-ion batteries, it is essential to keep the cell voltages in a battery pack at the same level,i.e., battery equalization. Based on the bi-directional modified Cuk converter, variable universe fuzzy controllers are proposed to adaptively maintain equalizing currents between cells of a serially connected battery pack in varying conditions. The inputs to the fuzzy controller are the voltage differences and the average voltages of adjacent cell pairs. A large voltage difference requires large equalizing current while adjacent cells both with low/high voltages can only stand small discharge/charge currents. Compared with the conventional fuzzy control method, the proposed method differs in that the universe can shrink or expand as the effects of the input changes. This is important as the input may change in a small range. Simulation results demonstrate that the proposed variable universe fuzzy control method has fast equalization speed and good adaptiveness for varying conditions.展开更多
文摘The phenomenon of anti-symmetrical bifurcation of periodic solutionsoccurring near an integral manifold is the intrinsic cause resulting in harmonic resonanceover-voltage in power systems. Due to this discovery, the principle of eliminating resonance byusing anti-bifurcation technique is presented, which makes that the theoretical bases of verymeasure to eliminate resonance are unified firstly from a point of view of basic theory. Ourdiscussion models depend on a class of nonlinear control model. Using the direct Lyapunov method, acomplete theoretical proof is given in accordance with the measure of eliminating resonance byconnecting nonlinear resistor in series to the neutral point of P. T., and the feedback control lawbeing applied. It comprises the action of parameters of resistor to eliminate resonance and theactual process of eliminating resonance, i.e., to go against bifurcation process which forces thebig harmonic solutions to retreat to the integral manifold gradually and disappear eventually, whichby using the nonlinear controllers. This makes it sure that the intrinsic cause of resonance iseliminated thoroughly. The obtained theory results and computing results are better than thepresented results.
文摘The control of the stability of the filament tension is one of the crucial techniques ensuring the component quality of the composite materials. The open-loop tension control system, with industrial control computer as the core, magnetic particle clutch as the actuator, equipped with compensation technique is researched and manufactured. It can assure the tension control stability of the yarn in filament winding process and increase the control precision of the whole system.
基金Project supported by the National Basic Research Program (973) of China (No. 2002CB312200) and City University of Hong Kong (No.9380026), China
文摘An immune algorithm solution is proposed in this paper to deal with the problem of optimal coordination of local physically based controllers in order to preserve or retain mid and long term voltage stability. This problem is in fact a global coordination control problem which involves not only sequencing and timing different control devices but also tuning the parameters of controllers. A multi-stage coordinated control scheme is presented, aiming at retaining good voltage levels with minimal control efforts and costs after severe disturbances in power systems. A self-pattem-recognized vaccination procedure is developed to transfer effective heuristic information into the new generation of solution candidates to speed up the convergence of the search procedure to global optima. An example of four bus power system case study is investigated to show the effectiveness and efficiency of the proposed algorithm, compared with several existing approaches such as differential dynamic programming and tree-search.
基金supported by Natural Science Foundation of Shandong Province(No.Z2007F08)
文摘In order to resolve the problean of the unbalanced threephase and unstable voltage, intellectual economized technique on elec- tricity based on electromagnetic regulation and control is proposed in this paper. We choose the TMS320LF2407A as the control chip and stepper motor as the executing agency. The equipment controls the movable contact reaching to the assigned position on the magnetic coil quickly and accurately, and outputs the sine-wave voltage steadily along with the network voltage variation though the fuzzy Porportional Integral Derivative（PID） control algorithm of integral separation and incremental mode with setting dead area. The principle of work and the key technique on the electromagnetic regulation and control are introduced in detail in this paper. The experiment result gives a proof for all the algorithm mentioned in this paper.
基金Supported by the National Natural Science Foundation of China （No. 90716027, 51175319）, and Shanghai Talent Development Fund （No.2009020）.
文摘A multi-channel active vibration controller based on a filtered-u least mean square （FULMS） control algorithm is analyzed and implemented to solve the problem that the vibration feedback may affect the measuring of the reference signal of the filtered-x least mean square （FXLMS） algorithm in the field of active vibration control. By analyzing the multi-channel FULMS algorithm, the multi-channel controller structure diagram is given, while by analyzing multi-channel FXLMS algorithm and its algorithmic procedure, the control channel model identification strategy is given. This paper also provides an easy but practical way to configure the actuators based on the maximal modal force rule. Taking the configured piezoelectric beam as the research object, an active vibration control experimental platform is established to verify the effectiveness of the identification strategy as well as the FULMS control scheme. Simulation and actual control experiments are done after the model parameters are obtained. Both the simulation and actual experiment results show that the designed multi-channel vibration controller has a good control performance with low order model and rapid convergence.
文摘A predictive current control algorithm for the Buck-Boost DC-DC converter is presented in this paper. The continuous time model of the system is properly introduced, then, by imposing a proper PWM modulation pattern, its discrete time model is achieved. This last one is successfully employed in determining the steady state locus of the Buck-Boost converter, both in CCM （continuous conduction mode） and DCM （discontinuous conduction mode）. A novel continuous time equivalent circuit of the converter is introduced too, with the aim of determining a ripple free representation of the state variables of the system, over both transient and steady state operation. Then, a predictive current control algorithm, suitable in both CCM and DCM, is developed and properly checked by means of computer simulations. The corresponding results have highlighted the effectiveness of the proposed modelling and of the predictive control algorithm, both in CCM and DCM.
文摘An automated multi-range multipliers（range resistors）system is established for the AC voltage measurements by using a thermal voltage converter.It is performed automatically by selecting the appropriate multiplier whose voltage range contains the voltage to be measured without changing it manually through a new designed system.It consists of control part through a micro-controller controlled by specified prepared Lab-VIEW program and switching part through electronic relays in one circuit as clearly described in this work.It is used for measuring the ac voltage in the range from 1 V to 200 V.Also,it can be used for the voltage ranges up to 1 000 V by putting some factors into consideration.The AC-DC transfer differences for these multipliers combined with thermal voltage converter are determined automatically against another standard thermal voltage converter by using another Lab-VIEW program.
文摘This paper proposes a parameter determination method of distribution voltage regulators load ratio control transformers （LRT） and step voltage regulators （SVR） considering the tap change and voltage profile. The method takes two procedures in order to simplify the optimization problem and to reduce calculation time. One is to simultaneously determine the control parameters of LRT and SVR minimizing voltage violations and voltage variations. The algorithm is based on particle swarm optimization （PSO）, which is one of non-linear optimization methods by using a concept of swarm intelligence. Another is to determine the dead-band width of LRT and SVR on the basis of bi-evaluation of tap change and voltage margin. The concept of a Pareto optimal solution is used for the decision of the best dead-band width. As the results of numerical simulations using distribution network model, the validity of the proposed method has been affirmed.
基金supported by the National Natural Science Foundation of China(Grant No.61401026)the National High Technology Research and Development Program of China(Grant No.2014AA1070)
文摘An appropriate acquisition configuration in terms of signal quality can optimize the acquisition performance. In view of this, a new approach of acquisition assisted by the control voltage of automatic gain control(AGC) is proposed. This approach judges the signal power according to the AGC control voltage and switches the working modes correspondingly and adaptively. Non-coherent accumulation times and the detection threshold are reconfigured according to the working mode. Theoretical derivation and verification by simulation in typical situations are provided, and the algorithm is shown to be superior in terms of the mean acquisition time, especially in strong signal scenarios compared with the conventional algorithm.
基金supported by the National Natural Science Foundation of China under Grant Nos.61433013 and 61621002
文摘In order to avoid the overcharge and overdischarge damages, and to improve the lifetime of the lithium-ion batteries, it is essential to keep the cell voltages in a battery pack at the same level,i.e., battery equalization. Based on the bi-directional modified Cuk converter, variable universe fuzzy controllers are proposed to adaptively maintain equalizing currents between cells of a serially connected battery pack in varying conditions. The inputs to the fuzzy controller are the voltage differences and the average voltages of adjacent cell pairs. A large voltage difference requires large equalizing current while adjacent cells both with low/high voltages can only stand small discharge/charge currents. Compared with the conventional fuzzy control method, the proposed method differs in that the universe can shrink or expand as the effects of the input changes. This is important as the input may change in a small range. Simulation results demonstrate that the proposed variable universe fuzzy control method has fast equalization speed and good adaptiveness for varying conditions.
