Pressure transformation ratio characteristics of kidney-shaped holes variable four-port hydraulic transformer

Aiming at the pressure control of hydraulic transformer (HT), the fractional order PID (FOPID) controller is proposed for the control of the position of the valve plate. The assignment system of the HT is carefully modeled. To optimally determine the parameters of the FOPID controller, a self-adapting differential evolution algorithm is employed. Numerical simulation is conducted to investigate the proposed control strategy. Both step response and sinusoidal command signal tracking of the servo system is assessed, and the results demonstrate that the proposed control strategy is obviously superior to the conventional PID, Fuzzy Logic Controller (FLC) and fuzzy-PID control strategy, and can afford precise tracking performances. It is suitable for the precise adjustment of the output pressure of the HT.

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Parameters and design optimization of the ring piezoelectric ceramic transformer

Journal of Advanced Dielectrics ◽

10.1142/s2010135x15500228 ◽

2015 ◽

Vol 05 (03) ◽

pp. 1550022 ◽

Cited By ~ 4

Author(s):

Jiří Erhart

Keyword(s):

High Efficiency ◽

Strong Electric Field ◽

Resistive Load ◽

Optimum Load ◽

Aspect Ratios ◽

Transformation Ratio ◽

Ring Segment ◽

New Type ◽

Transformation Parameters ◽

Piezoelectric Ceramic Transformer

Main aim of the presented paper is the theoretical analysis and experimental verification of the transformation parameters for the new type of nonhomogeneously poled ring transformer. The input part is poled in the thickness direction and output part in the radial direction. Two transformer geometries are studied — the input part is at inner ring segment, or it is at the outer ring segment. The optimum electrode size aspect ratios have been found experimentally as [Formula: see text] for the ring with aspect ratio [Formula: see text]. The fundamental as well as higher overtone resonances were studied for the transformation ratio, the optimum resistive load, efficiency and no-load transformation ratio. Higher overtones have better transformation parameters compared to the fundamental resonance. The new type ring transformer exhibits very high transformation ratios up to 200 under no-load and up to 13.4 under a high efficiency of 97% at the optimum load conditions of 10 [Formula: see text]. Strong electric field gradient at the output circuit is applicable for the electrical discharge generation.

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Field-circuit modelling of an advanced welding transformer with two parallel rectifiers

Archives of Electrical Engineering ◽

10.1515/aee-2015-0021 ◽

2015 ◽

Vol 64 (2) ◽

pp. 249-257 ◽

Cited By ~ 7

Author(s):

Lyudmila Sakhno ◽

Olga Sakhno ◽

Simon Dubitsky

Keyword(s):

Arc Welding ◽

Power Efficiency ◽

Power Conversion ◽

Fea Model ◽

Welding Arc ◽

Transformation Ratio ◽

Manual Arc Welding ◽

Bridge Rectifier ◽

Circuit Modelling ◽

Secondary Winding

Abstract The new topology of three-winding welding transformer is proposed. Each secondary winding is connected in parallel through the separate bridge rectifier to the welding arc. The main feature of the proposed device is parallel working of two secondary windings with different rated voltage. The advantage is nonlinear transformation ratio of current that provides unprecedented power efficiency. The self- and mutual leakage inductances, which are important in power conversion, are calculated by 2D FEA model. The operational current of the device is modelled numerically via P-Spice simulator. The proposed topology is up to 30% more power effective than conventional welding transformer provided that the leakage inductances of primary and secondary windings are correctly fitted. This transformer is used for manual arc welding

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