A three-phase (3φ) multi-functional battery energy storage system (BESS) is designed and implemented in this paper. When the utility power is in normal condition, the proposed BESS can be arranged to shave the peak l...
详细信息
A three-phase (3φ) multi-functional battery energy storage system (BESS) is designed and implemented in this paper. When the utility power is in normal condition, the proposed BESS can be arranged to shave the peak load or charge the battery bank. In either case, since the load unbalanced, harmonic and reactive powers can be compensated through the proposed active power filtering control, the power factor is maintained nearly unity and the line currents drawn from the utility are balanced and sinusoidal with very low distortion. As the utility power failure happens, the proposed BESS can immediately supply uninterruptible power to the loads. In this case, an instantaneous control technique is developed to yield good three-phase voltage waveforms. the determination of reactive components, the dynamic modeling, and the design of controllers for the proposed BESS are made. Some experimental results are provided to demonstrate the effectiveness of the proposed BESS.
We propose a methodology of genetic algorithms (GAs) for the rules searching of Model Reference Fuzzy Adaptive Control system (MRFACS). We choose a second order reference model as an ideal output, then adjust the prop...
详细信息
We propose a methodology of genetic algorithms (GAs) for the rules searching of Model Reference Fuzzy Adaptive Control system (MRFACS). We choose a second order reference model as an ideal output, then adjust the proportional sensitivity by using fuzzy adaptive controller to make the plant's output follows the reference signal. We apply Modified GAs for rules searching because that the rules set constructed by cut and try works unsatisfactory. In our study, we offer two types of fuzzy controllers (one is constructed with state error Ε & change rate of error Δ Ε and the other is constructed with state error Ε & plant output yp). the conclusions we get from simulation results are: (1) Modified GAs can find population with higher fitness values since it select better populations by multiple-point crossover and multiple-point mutation, (2) Fuzzy controller with Ε & yp(t) shows higher performance indices than that with Ε & Δ Ε for the reason that the front controller can avoid using same rules for different time delay constants, and (3) system remains controllable when the time delay constants exceed the expected margin, it proves that our fuzzy controller contains the characteristic of robustness.
the class of Petri nets denoted as timed event graphs can be used to represent a wide class of manufacturing systems. this fact allows one to apply analytical techniques for performance evaluation of such Petri nets. ...
详细信息
the class of Petri nets denoted as timed event graphs can be used to represent a wide class of manufacturing systems. this fact allows one to apply analytical techniques for performance evaluation of such Petri nets. this, in turn, permits to state mathematical programming problems whose objective is the optimization of manufacturing system performances. In this paper, the optimization of the systemthroughput is considered, with respect to the definition of the lot sizes in a cyclic manufacturing process. As a secondary optimization objective, the minimization of the work-in-progress, while keeping the system working at its maximum productivity, is considered.< >
In control system design, trial and error method can not be avoided. Accordingly, we have developed an optimizationsystemthat aids the designer in deciding optimal controller parameters to match the designer's s...
详细信息
In control system design, trial and error method can not be avoided. Accordingly, we have developed an optimizationsystemthat aids the designer in deciding optimal controller parameters to match the designer's specification. the system treats the design problem via two approaches: 1) if the designer has quantitative specifications, the problem is mathematically formulated and solved by optimization method; and 2) if the designer's specifications can only be described in qualitative form, decision-making is efficiently facilitated withthe graphic tools. We show examples in which the system is applied to the PID parameters for SISO control systems, and the weights of the linear quadratic regulator for MIMO control systems.< >
作者:
N. FujiiDaito
Osaka Sangyo University Osaka Japan
Deals with a class of shape optimization problems with a boundary integral as an objective functional. these shape optimization problems arise in various industrial applications such as minimum drag designs in fluid m...
详细信息
Deals with a class of shape optimization problems with a boundary integral as an objective functional. these shape optimization problems arise in various industrial applications such as minimum drag designs in fluid mechanics, designs of plasma shapes in tokamak devices. Deriving second order variations of the objective functionals, the author gives a set of the second order necessary conditions of Kuhn-Tucker-Fujii type. To this end, the author used also the second order variation of a solution of a boundary value problem that is a constraint to the optimization problems. As a byproduct of these analyses, the author obtains a numerical method for the solutions of the optimization problems.< >
A new slab heating control system was developed to reduce energy consumption and improve slab heating quality in continuous reheating furnaces. the new control system is characterized mainly by: 1) online optimization...
详细信息
A new slab heating control system was developed to reduce energy consumption and improve slab heating quality in continuous reheating furnaces. the new control system is characterized mainly by: 1) online optimization of the reference trajectory of slab temperature through online simulations with a physical model of the plant (nonlinear, parameter-distributed model); 2) some speeding-up techniques for optimization processing. the control has been verified effective through simulations and actual operations at a commercial plant.< >
this paper addresses the problem of multi-objective optimization of the hydropower generation versus irrigation releases applied to the Egyptian network. A linear programming-based multicriteria model is developed bas...
详细信息
this paper addresses the problem of multi-objective optimization of the hydropower generation versus irrigation releases applied to the Egyptian network. A linear programming-based multicriteria model is developed based on the described system constraints. Two objective functions are considered in the analysis. the first is to maximize the total sum of potential hydropower production of the whole system. the second is to minimize the total water release to the system, while satisfying the different demands imposed at various nodes. Using the generation technique for solution, the results have revealed several tradeoff curves of both hydropower and irrigation uses.< >
A new coupled-inductor structure that achieves zero current ripple without need for turns ratio adjustment is presented. Its residual ripple performance is as good as conventional structures, it is easier to design an...
详细信息
A new coupled-inductor structure that achieves zero current ripple without need for turns ratio adjustment is presented. Its residual ripple performance is as good as conventional structures, it is easier to design and has much less radiated noise. three different gap arrangements of practical interest are considered and closed-form design equations are given for each of them. As a practical example, coupled inductor design for a 50 W Cuk converter is performed with all three gap arrangements and relative circuit performance is compared.< >
Many optimizationsystems are individually optimized, however, they are closely related to each other at various levels. It is, therefore, necessary to integrate those systems if necessary, viewing from the standpoint...
详细信息
Many optimizationsystems are individually optimized, however, they are closely related to each other at various levels. It is, therefore, necessary to integrate those systems if necessary, viewing from the standpoint of the optimization of the whole company. the performance of an individual optimizationsystem largely depends upon the accuracy of the input information. It is, however, difficult to obtain the accurate present values of the input information when they are time variant and are observed with noises. the authors propose the pretreatment of input information withthe Kalman filter and the applications of it are introduced. this method is also effective for meeting one of the requirements of the ISO 9000 series in the calibration of the instruments.< >
A prototype robust controller for variable reluctance motor is proposed. A three-level cascade control structure is adopted for this highly nonlinear system. the three control levels are all described but a particular...
详细信息
A prototype robust controller for variable reluctance motor is proposed. A three-level cascade control structure is adopted for this highly nonlinear system. the three control levels are all described but a particular emphasis is put on the torque-sharing compensator, designed with nonlinear optimization techniques to resolve redundancy in the torque generation of VR motor. the proposed controller is first verified by means of extensive simulation experiments. the architecture of the laboratory prototype controller is presented and experimental results on NSK-Megatorque motor are reported too. Presented results prove feasibility and good performance of the proposed controller, suitable for a very simple and rather inexpensive fully hardware implementation.< >
暂无评论