Robust vector control of induction motors using full-order observer in consideration of core loss

This paper proposes a method for designing a robust full-order observer for vector-controlled induction motors taking core loss into account. Although conventional research focuses on parameter identification, global stability of the identification remains questionable. Therefore, robustness against some parameters is required. This paper describes the design of a robust full-order observer which takes core loss into account, using both the gain-scheduled H/sub /spl infin// control and the linear matrix inequality technique. This design always results in a stable controller. The robustness of the proposed method against variations of resistances is evaluated by experiments.     

A neural network compensator for uncertainties of roboticsmanipulators

A neural network controller for trajectory control of robotic manipulators that is used not to internalize the inverse dynamic model of the controlled object but to compensate only the uncertainties of the robotic manipulator is presented. Its performance is compared with that of the conventional adaptive scheme. The results show the ability of the neural network controller to adapt to unstructured effects. A learning method for the neural network compensator with true teaching signals is shown. The tracking error of the robotic manipulator was greatly reduced when this controller was used     

Sensorless control of synchronous reluctance motors using on‐line parameter identification method not affected by position estimation accuracy

This paper presents a novel on‐line parameter identification method for sensorless control of Synchronous Reluctance Motors (SynRMs). Although conventional sensorless control methods based on mathematical models usually need some complex measurements of motor parameters in advance, the proposed identification method does not require them and can be realized on‐line. The proposed method identifies motor parameters under sensorless control, so rotor position and velocity cannot be used to identify these parameters. However, the proposed method does not need rotor position and velocity, and identified parameters are not affected by these estimation errors. The sensorless control using identified motor parameters is realized, and the effectiveness of the proposed method is verified by experimental results. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 155(3): 62–69, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20258     

A multiplexer with coupled quarter wave distributed lines in highdielectric ceramics

A multiplexers available several purposes such as for mobile communications, CATV systems and multimedia systems in future, are propped and trially made by authors. This paper present the results the design concept and experimental results. The design principle was based on the theoretical concept proposed by us     

Direct-linked-type frequency changer based on DC-clamped bilateralswitching circuit topology

This paper describes a direct-linked-type frequency changer (DLT-FC) proposed by the authors. The DLT-FC is a converter circuit with a new configuration for direct frequency change. The DLT-FC does not require a DC-link circuit, nor bilateral switches. In addition, DC snubber circuits can be applied without the need for a regenerative circuit of snubber energy. Therefore, the DLT-FC can be designed to be compact and lightweight, and have a long life. The authors made a prototype of the DLT-FC and experimentally checked its operation. The results indicate that the performance of the DLT-FC makes it suitable for industrial use     

Brain histamine mediates the bombesin-induced central activation of sympatho-adrenomedullary outflow

Intracerebroventricular (i.c.v.) administration of bombesin (0.3 nmol) increased plasma levels of both adrenaline and noradrenaline in urethane anesthetized rats. These bombesin-induced increases were inhibited by i.c.v. pretreatment with pyrilamine, an H1-receptor antagonist. Ranitidine, an H2-receptor antagonist also inhibited the increase of adrenaline, however, its effective dose was much larger than that of pyrilamine. Furthermore, the bombesin-induced increase of noradrenaline was not effectively inhibited by ranitidine. In the next series, turnover of histamine was assessed by measuring accumulation of tele-methylhistamine (t-MH), a major metabolite of brain histamine. I.c.v. administration of bombesin (0.3-3 nmol) increased turnover of hypothalamic histamine, while its intravenous administration was without effect. The present results suggest that the bombesin-induced central activation of sympatho-adrenomedullary outflow is probably, at least in part, mediated through brain histaminergic neurons.     

Slip-frequency type and flux-feedback type vector controls indiscrete-time system

In this paper, we evaluate the difference between the slip-frequency type and the flux-feedback type in discrete time. Both vector control systems in discrete time, designed equivalently in continuous time, have different discretization errors. In a large sampling time region, the slip-frequency type (using the induction motor rotor-flux frame model) is less influenced by the discretization error than the flux-feedback type (using the stator frame model). In this sense, the slip-frequency type is superior to the flux-feedback type, but the stator frame model is linear and the rotor-flux frame model is nonlinear. With the flux-feedback type using the stator frame, it is easier to design the controller and the observer. Therefore, we believe that the vector controller and the observer should be designed using the stator frame model and that, after it is transformed to the rotor-flux frame model, it should be implemented