Static Operating Characteristics Research Articles

ASYNCHRONOUS ELECTRIC MOTOR WITH SINGLE-PHASE STATOR WINDING

The current standard considers the efficiency of electric motors only in terms of power efficiency and does not pay attention to the so-called economic efficiency - the power factor that affects the loss of electricity in the motor supply network and depends on its energy excellence.This ill-considered approach to establishing the energy efficiency class is a significant shortcoming of the European standard and requires its refinement. The single-phase power supply network in housing and communal services has led to the fact that modern motor compressor units of refrigerators, air conditioners, etc. are equipped with single-phase asynchronous electric motors. An innovative single-phase asynchronous AC motor for motor-compressor units of household appliances is considered in the paper. The stator winding of it is composed of two identical series-connected coils enclosed in half-slots of the stator with a spacious offset of 900.The phase shift of the currents in the coils is provided by a capacitor connected in parallel to one of the coils. The proposed motor is technological in production, has higher specific power and energy efficiency than existing models and meets the IE-3 class energy efficiency. Equivalent electrical circuit and vector diagram of currents for this motor have been developed and shown. They are intended for its mathematical simulation, calculation of static operating characteristics, analysis of dynamic properties at operation in the electric drive system, and also at the level of design work.

Preparation and analysis of single and hybrid metal-phthalocyanine organic phototransistors and comparison of their photoelectric properties

Vertical organic thin film transistors (VOTFT) in a five-layer structure of ITO/MPc/Al/MPc/Cu were prepared using a single phthalocyanine or two hybrid phthalocyanine material co-blended films as the active layer. The prepared single phthalocyanine device and the mixed phthalocyanine material device experimented with static operating characteristics. The threshold voltage of the device of ZnPc is 1 V, while the threshold voltage of the hybrid material is reduced, and the threshold voltage of the device of CuPc mixed with ZnPc can reach 0.4 V. The results of the photoelectric characteristics of the devices show that the light sensitivity of the hybrid material is significantly better than that of the single material. The light sensitivity of the 1:1 blend of PbPc mixed with ZnPc device has the greatest photosensitivity, 5.37 times that of ZnPc and 141.62 times that of PbPc. The device switching parameters for the hybrid materials are ton = 0.4 ms and toff = 0.44 ms, which switching characteristic times in the sub-millisecond range. The cut-off frequency of the hybrid materials has also increased, with the highest mobility VOTFT of ZnPc mixed with PbPc reaching a cut-off frequency of 4.6 kHz.

Preparation and Characterization of the Organic Thin Film Transistors by Adopting the ZnPc0.5-PbPc0.5 Co-Deposited Material as the Active Layer

The organic film co-deposited by Zinc Phthalocyanine (ZnPc) and Lead Phthalocyanine (PbPc) was used as the active layer of the vertical organic film diode, and we obtained the co-deposition ratio of the devices with the better performance of 1:1. We made the vertical organic thin film transistor (VOTFT) with the same process again, compared the co-deposited VOTFT with the VOTFT with a single organic material (ZnPc, PbPc) as the active layer and tested the static operating characteristics of the device. The results show that the carrier mobility of ZnPc-PbPc-VOTFT is more than three times higher than that of ZnPc-VOTF and PbPc-VOTFT. When [Formula: see text][Formula: see text]V and [Formula: see text][Formula: see text]V, the output current [Formula: see text] of ZnPc-PbPc-VOTFT is up to 0.2[Formula: see text]mA, which is 12 times that of ZnPc-VOTFT and 27 times that of PbPc-VOTFT. Overall, the electrical performance of ZnPc-PbPc-VOTFT is better than ZnPc-VOTFT and PbPc-VOTFT.

Switch‐mode rectifier fed switched‐reluctance motor drive with dynamic commutation shifting using DC‐link current

Adequate commutation instant setting and tuning in accordance with varied operating conditions are required for achieving good winding current and developed torque responses for a switched-reluctance motor (SRM) drive. This study presents a dynamic commutation shift controller (DCSC) based on DC-link current ripple minimisation for SRM drives. A single-phase bridgeless switch-mode rectifier (SMR) fed SRM drive is established for making the performance evaluation. The robust control schemes of the SMR and SRM drive are properly designed to yield satisfactory dynamic and static operation characteristics. The boosted and well-regulated DC-link voltage is established from the mains to enhance the SRM drive performance under high speeds. In addition, good line drawn power quality with high efficiency is obtained simultaneously by the bridgeless SMR front-end. In the developed DCSC, the observed DC-link ripple current is processed and used to determine the commutation shift angle automatically. Some measured results are provided to demonstrate the performance of the established SMR-fed SRM drive under the commutation using the proposed DCSC.

Robust multi-mode flight control design for an unmanned helicopter based on multi-loop structure

In this paper, a novel multi-mode flight control strategy for unmanned helicopter, in presence of model uncertainty, atmospheric disturbances and handling qualities specification requirements (as in ADS-33E), based on multi-loop control structure combining robust H-infinity and PI control is presented. In inner loop H-infinity optimal control technique is utilized ensuring the stability of flight control system in case of change of helicopter dynamics, model uncertainties and eliminates effect of gust disturbance on helicopter states and collective/cyclic inputs. PI control in outer loop is used to improve the dynamic and static operation characteristics. Attitude control and attitude holding flight mode with satisfactory command response and decoupling characteristics is designed using the proposed control strategy. Analysis and simulation results show that Level 1 handling requirements as defined in ADS-33E are accomplished even when helicopter is under constant wind circumstance.

Development of a Compact Switched-Reluctance Motor Drive for EV Propulsion With Voltage-Boosting and PFC Charging Capabilities

This paper presents a compact battery-powered switched-reluctance motor (SRM) drive for an electric vehicle with voltage-boosting and on-board power-factor-corrected-charging capabilities. Although the boost-type front-end DC/DC converter is externally equipped, the on-board charger is formed by the embedded components of SRM windings and converter. In the driving mode, the DC/DC boost converter is controlled to establish boostable well-regulated DC-link voltage for the SRM drive from the battery. During demagnetization of each stroke, the winding stored energy is automatically recovered back to the battery. Moreover, the regenerative braking is achieved by properly setting the SRM in the regenerating mode. The controls of two power stages are properly designed and digitally realized using a common digital signal processor. Good winding current and speed dynamic responses of the SRM drive are obtained. In addition, the static operation characteristics are also improved. In the charging mode, the power devices that were embedded in the SRM converter and the three motor-phase windings are used to form a buck-boost switch-mode rectifier to charge the battery from utility with good power quality. All constituted circuit components of the charger are placed on board, and only the insertion of power cords is needed.

Static and dynamic operating characteristics of a pericardial balloon

Previously, we developed a balloon transducer to measure the constraint of the pericardium (i.e., pericardial pressure) on the surface of the heart. It was validated physiologically in that it was shown to measure a pressure equal to the difference between the left ventricular end-diastolic pressure measured before and after pericardiectomy at the same left ventricular volume. To define its static operating characteristics, we loaded the balloon nonuniformly with weights that covered fractions of the balloon surface and found that the balloon accurately recorded the average stress if the stress was applied over at least 23% of its surface. To test its performance when curved, we placed it in large and small cylinders (minimum diameter 31 mm) and found that the balloon accurately recorded the stress. To define its dynamic operating characteristics, we applied sinusoidal stresses and found that its frequency response was limited only by that of the connecting catheter. When better dynamic response is required, we introduce a micromanometer-tipped catheter to obtain a unity-gain frequency response that is flat to 200 Hz.

Dynamic characteristics of level and two-axis attitude detector using magnetic fluid

Level and attitude detectors are required for the detection of level and angles, for instance, in controlling the attitude of underwater robots, to keep solar cell panels directed constantly toward the sun, and the parabola antenna constantly toward the manmade satellite in communication systems. The usual angle detector can detect angle in one axis only, but the detector described in this paper is able to detect the angles of orientation with the horizontal and the vertical planes with a single unit. In addition, the new detector uses levels, such as water levels, by itself. This detector has three tubes with the magnetic fluid placed inside and with three coils. Its structure is very simple, small, and robust. It is also a light unit. The output signals are sine waves. The static operating characteristics of this detector were shown previously. The dynamic characteristics are presented in this paper.

Characteristics of Level and Angle Detector Using Magnetic Fluid

The static operating characteristics of a new type of levelness and orientation sensor, using magnetic fluid and employing the principle of operation of differential transformer sensors, are described. Three output voltages from a single sensor unit enable accurate detection of the sensor angles of orientation within the horizontal and vertical planes over wide ranges.

Characteristics of level and two axis attitude detector using magnetic fluid

The static operating characteristics of a new type of level and two axis attitude detector using magnetic fluid are described. The usual angle detector can detect angle in one axis only, but this detector can do it in two axis with a single unit. In addition, the new detector using fluid can detect level like a water level by itself.

An Experimental and Theoretical Examination of the Static Characteristics of Three-Lobe Bearings

Nine symmetric three-lobe bearings with preloads ranging from 0.00 to 0.88 and L/D ratios from 0.33 to 0.67 were tested with a rigid rotor. The load angle was also varied for each bearing. In this paper, the static operating characteristics are presented and compared to a theoretical solution. The experimental and theoretical relationships between the eccentricity ratio and Sommerfeld number were found to agree best for small values of bearing preload. The experimental and theoretical loci of operating points within the bearing clearance circle were found to agree best for large values of bearing preload. For positive values of preload, the operating position of the shaft in the bearing clearance circle was also found to approach the oil grooves for small values of Sommerfeld number. Presented as an American Society of Lubrication Engineers paper at the ASME/ASLE Lubrication Conference in San Francisco, California, August 18–21, 1980.

Hierarchical Control of a Multimachine Power System Model

The power-frequency control of a multimachine power system model is investigated using combined boiler-turboalternator units interconnected with the general node equations of a transmission network. The boilers, represented by lumped energy storage elements, are combined with the turbine equations using flow- power relations associated with static operating characteristics. The alternators are represented by a linearized set of Park's equations in a form suitable for investigating the effects of voltage regulator action.

Dynamic optimisation of a boiler-turboalternator model

Optimal control of a combined boiler-turboalternator model is developed using a discrete linear representation of the interconnected system. The boiler model is assumed to consist of lumped energy-storage elements, and it is combined with the turbine using flow-power relations associated with static operating characteristics. The turbine model includes the effects of steam storage in the reheater and inlet-valve chest, and it is coupled with an alternator model based on a linearised form of Park's equations. Integrated control of fuel, feedwater, valve position and alternator-field excitation is developed, using the concept of dynamic programming to solve the single-point boundary problem. Integral action related to measurement of selected variables is also included within the optimal controller, and performance is compared with conventional three-term control of the overall model.