Permanent Magnet Actuator Research Articles

Design and comparison of a novel 3-DOF deflection type permanent magnet actuator

Design and comparison of a novel 3-DOF deflection type permanent magnet actuator

Research on Classification Performance of Circuit Breaker Vibration Signal Based on Fuzzy C-Means Clustering Analysis

With permanent magnetic actuator monostable circuit breaker as the research object, it gets three different running status signal data, normal circuit breaker closing state , break-brake spring single loss and Institutions unsmooth Through constructing data acquisition platform. The performance of the three methods of feature extraction is compared, short-time Fourier transform, wavelet packet energy entropy and Hilbert huang transform, through fuzzy c-means clustering analysis algorithm. Through the comparative study, it is concluded that adopt wavelet packet transform method to get the best classify performance of time-frequency entropy vector .

Optimal design of permanent magnet actuator for vacuum circuit breakers using response surface methodology

Recently, permanent magnetic actuator (P.M.A.) is widely used to drive the mechanism of vacuum circuit breaker (V.C.B.). This paper deals with the optimal design of P.M.A. for V.C.B. using the response surface method (R.S.M.). First, the dynamic characteristics of the initial P.M.A. mod el, such as the holding force, exciting current, and action complete time, are calculated by coupled electrical-mechanical problem based on finite element method (F.E.M.). In order to verify the validity of numerical results obtained from finite element analysis (F.E.A.), the calculated dynamic characteristics of the initial P.M.A. model are compared with no-load test results. Next, using the R.S.M., the initial P.M.A. model is optimized to improve the dynamic characteristics. Finally, in order to verify the validity of the P.M.A. model optimized by using the R.S.M., the dynamic characteristics of the optimized P.M.A. model are calculated by using F.E.A. and compared with those of the initial P.M.A. model.

A Low-Wear Onload Tap Changer Diverter Switch for Frequent Voltage Control on Distribution Networks

This paper presents a fast mechanical diverter switch design suitable for new “arcless” hybrid onload tap-changing systems. In such systems, arcing at contact separation and contact closure is almost completely eliminated by the inclusion of alternate current paths incorporating semiconductor devices. This allows the use of compact, air-insulated mechanical contacts that do not need to withstand significant arc erosion or provide arc quenching. As a result, the moving mass and the drive system for the switch may be dramatically reduced in size, leading to low inertia of the moving parts and resulting in very rapid operation times. An integrated, high-torque, low-mass permanent-magnet actuator is presented that provides detent (unpowered) contact force coupled with a cantilever spring contact system sized for an 11-kV 2-MVA onload tap changer. The design delivers operation times of under 20 ms and is capable of sustaining more than 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> operations. The complete design is experimentally verified under representative electrical conditions, and contact wear levels comparable to pure mechanical (zero current) operation are demonstrated.

A Permanent Magnetic Actuator for 126 kV Vacuum Circuit Breakers

Permanent magnetic actuators (PMAs) have been widely used in medium-voltage vacuum circuit breakers (VCBs) due to their high reliability and controllability. However, a conventional bistable PMA cannot be adopted in power equipment for the transmission voltage level such as 126 kV VCBs directly because of its low-velocity characteristics. The objective of this paper is to propose a multimagnetic circuit PMA to satisfy the high-velocity requirements for 126 kV VCBs. The novel PMA is a bistable and axisymmetric structure, including holding and driving components whose magnetic circuits are separated. Air gaps are specifically designed in the magnetic circuits to improve the velocity performance of the novel PMA. Both static and dynamic characteristics of the novel PMA model have been calculated through finite-element software coupled with multi-body dynamics software. Furthermore, a prototype of the PMA has been developed according to the calculation results. The experimental results on the prototype have shown that the velocity characteristics of the PMA are able to meet the requirements of a 126 kV VCB and agree well with the simulation results.

Optimal Design of a Novel Permanent Magnetic Actuator using Evolutionary Strategy Algorithm and Kriging Meta-model

The novel permanent magnetic actuator (PMA) and its optimal design method were proposed in this paper. The proposed PMA is referred to as the separated permanent magnetic actuator (SPMA) and significantly superior in terms of its cost and performance level over a conventional PMA. The proposed optimal design method uses the evolutionary strategy algorithm (ESA), the kriging meta-model (KMM), and the multi-step optimization. The KMM can compensate the slow convergence of the ESA. The proposed multi-step optimization process, which separates the independent variables, can decrease time and increase the reliability for the optimal design result. Briefly, the optimization time and the poor reliability of the optimum are mitigated by the proposed optimization method.

Static Characteristics of Novel Air-Cored Linear and Rotary Halbach Permanent Magnet Actuator

This paper investigates the static characteristics of a novel air-cored linear and rotary permanent magnet actuator (LRPMA) with a Halbach permanent magnet array. By the given magnetization distributions and boundary conditions in the cylindrical coordinate system, the magnetic field distributions of the actuator are analytically analyzed using the magnetic scalar potential and the modified BESSEL functions. A 3-D finite-element (FE) model is established to validate the correctness of the analytical results. Analytical linear electromagnetic force and rotary electromagnetic torque, respectively, are derived and verified using the FE method for the characterization and optimization design of the air-cored Halbach LRPMA.

Structure Optimization on High-Speed Electromagnetic Repulsion Mechanism

High speed mechanical switches are gradually becoming a research hotspot in power systems, for its fast switching speed, large conduction flow and voltage-withstanding. Among them, the core design of the switches focuses on optimal design of the structure of repulsion actuator. Besides traditional factors like coil turns, capacitance, voltage, which affect the output power, the material and structure of coil frame, the enclosure of repulsion mechanism are found to be important factors in this paper. Based on finite element analysis and simulation of repulsion mechanism, a novel prototype was designed, and the simulation results were verified by experiments. Moreover, during opening process of switch, the repulsion mechanism coupled with either assistant spring or assistant opening coil in permanent magnetic actuator (PMA) are compared by experiments. The results show that the switch has smaller opening oscillation and simpler structure through using assistant opening coil. This paper has provided a better guidance for the development of high-speed repulsion mechanism in interrupters.

Cascaded loops control of DC motor driven joint including an acceleration loop

The aim of this paper is to transform easily, a three cascaded loops controller toward a four cascaded loops controller which includes an acceleration loop. A state space analysis with pole placement is proposed for the gains calculation of the acceleration loop. The method is implemented on an experimental DC permanent magnet actuator. The position error and velocity are compared when torque disturbances are performed on the actual machine.

An Optimal Design for New Electromagnetic Valve in Camless Engines

Some previous studies have demonstrated that electromagnetic valve (EMV), which uses permanent magnet and electromagnetic coil (PM/EM) hybrid actuator, has some benefits about actuator control, energy consumption, time response compared with conventional EMVs. In this paper, a new EMV with PM/EM actuator, which significantly differs from existing EMVs, has been proposed. The EMV design has been examined and analyzed by finite element. The results conclude that the EMV satisfies the requirement of dimension space limit. Moreover, the optimal EMV design meets the requirements of transition time and holding force. The holding force can reach about 719 N and drop 42.22% for valve releasing if desired current is supplied to the coils. Therefore, the EMV can fully control the closed and open of valve timings at maximum speed in SI engines.

Design, Optimization, and Intelligent Control of Permanent-Magnet Contactor

This paper presents the design method of a permanent-magnet (PM) actuator and an intelligent control module for the associated PM contactor. The original design parameters of the PM actuator are obtained using magnetic circuit method. The optimization model for the PM actuator is solved by genetic algorithm and simulated annealing algorithm. A monostable cylindrical 140-A PM contactor is designed, and the corresponding intelligent control module of the actuator is developed. A dedicated control technique based on voltage feedback is proposed to realize the intelligent dynamic adjustment of the making process for the PM contactor. The electromagnetic force calculation model, the dynamic making model of the iron core and contact, the buffering model for the iron core, and the contact bounce model are all built using MATLAB. Experimental results are reported to showcase the correctness of the simulation method and the effectiveness of the feedback control technique to decrease the closing velocities of both the movable contact and the moving iron core that, in turn, will reduce the first and the second contact bounces significantly to lengthen the life span of the device.

A Method of Impact Simulation in Permanent Magnetic Field

To simulate the impact response of the moving body in the permanent magnetic actuator, this paper takes the magnetic force of the moving body at different positions as one of the input loads for the impact simulation, which avoids the coupling calculation of the magnetic and impact problem. The static and transient analysis of the magnetic field in the permanent magnetic actuator are implemented respectively to compute the magnetic flux density and their relative errors, results show the moving body in this magnetic field exerts little influence on the magnetic intensity and the influence can be neglected. The force of the moving body with respect to its position can be calculated in the static analysis and then be imported into the impact calculation to obtain the velocity and displacement. By comparing these results with the ones from the magneto-mechanical coupling transient analysis, the difference is small which proves the feasibility and accuracy of the proposed method.

Experimental Research on Speed Control of Vacuum Breaker

For phase-controlled vacuum breakers, the acting time of the actuator should be precise. The variation of capacitor voltage, capacitance, and environmental temperature impact the dispersion of closing time seriously. A new technology has been put forward in this paper. It is the speed control of the vacuum breaker. This technology can be used for phase-controlled operation of vacuum breakers. By using this technology, the deviation of displacement can be corrected in real time. So the permanent-magnetic actuator (PMA) can move along with the given displacement curve. Also, the closing time is stable when the external factors, such as capacitor voltage, capacitance, and environment temperature change. The closed-loop system has been established in this paper. The proportion-differentiation (PD) algorithm and fuzzy algorithm are used in the system. The PD algorithm adjusts the coil current to ensure that different actuators have the same excitation time. And the fuzzy algorithm is used to adjust actuator displacement. With the use of the algorithm, the closing time of the breaker is stable, and mechanical properties are optimal. Based on the aforementioned theory, many experiments have been performed when external factors change, such as environment temperature, capacitance, and so on. The results prove that the displacement deviation can be corrected using this method and the closing time can be stabilized within ±0.5 ms. Therefore, not only can the accuracy of phase-controlled operation can be ensured, but the lifespan of the circuit breaker can also be prolonged.

Fast Component Placement with Optimized Long-Stroke Passive Gravity Compensation Integrated in a Cylindrical/Tubular PM Actuator

Applications such as vibration isolation, gravity compensation, pick-and-place machines, etc., would benefit from (long-stroke) cylindrical/tubular permanent magnet (PM) actuators with integrated passive gravity compensation to minimize the power consumption. As an example, in component placing (pick-and-place) machines on printed circuit boards, passive devices allow the powerless counteraction of translator including nozzles or tooling bits. In these applications, an increasing demand is arising for high-speed actuation with high precision and bandwidth capability mainly due to the placement head being at the foundation of the motion chain, hence, a large mass of this device will result in high force/power requirements for the driving mechanism (i.e. an H-bridge with three linear permanent magnet motors placed in an H-configuration). This paper investigates a tubular actuator topology combined with passive gravity compensation. These two functionalities are separately introduced, where the combination is verified using comprehensive three dimensional (3D) finite element analyses.

The Research for the Energy Saving Effect of Permanent Magnetic Drive Technology in Pumping Systems

The purpose of this article is to analyze the energy savings of drive technology for permanent magnet in pumping systems applications. Studied the system structure and working principle of permanent magnetic actuator, according to the production parameters of pumping system collected before and after installation, drew the superimposed slip torque characteristic curve for the motor, analyzed the movement of rod load and the crank shaft, and to study the changes for rod power and active power of pumping system. did data comparison and analysis, showed that the magnet actuator improves the dynamic performance of pumping system, decrease the fluctuations of load and torque and reduced installed power of drag motor, theoretical analysis matched experimental results, confirmed the drive technology for permanent magnet in pumping system applications have a good energy saving effect.

Comparison Study of Tubular Linear Surface-Mounted Permanent Magnet Actuator with Different Fractional Slot Winding

There are many slot/pole combinations may be selected for the fractional slot tubular linear surface-mounted motors (TLSPM) used as actuators for high voltage breakers, such as 15/8, 15/4, 15/2, 12/8. Compared with integral slot winding, the fractional slot winding has more advantages. Since the winding arrangement will be changed due to the different slot/pole numbers. The characteristics of the TLSPM with different fractional slot, such as detent force, back EMF, are analyzed and compared in this paper. It is shown that good performance may be achieved by selecting appropriate fractional slot design.

3-D Analytical Linear Force and Rotary Torque Analysis of Linear and Rotary Permanent Magnet Actuator

This paper presents a 3-D analytical study of the linear electromagnetic force and rotary electromagnetic torque of a novel linear and rotary permanent magnet actuator (LRPMA). The 3-D analytical magnetic distribution of the LRPMA is established using the magnetic scalar potential and modified BESSEL functions in the cylindrical coordinate system. Linear electromagnetic force and rotary electromagnetic torque, respectively, are derived and verified using finite element method (FEM) for the characterization and optimization design of the LRPMA being examined by experiments in this paper.

Contact Parameter Computation and Analysis of Air Circuit Breaker with Permanent Magnet Actuator

An air circuit breaker (ACB) with novel double-breaker contact and permanent magnet actuator (PMA) is presented. Three-dimensional (3-D) finite element method (FEM) is employed to compute the electro-dynamic repulsion forces, including the Holm force and Lorentz force, which are acting on the static and movable contacts. The electro-dynamic repulsion forces of different contact pieces are computed, illustrating there is an optimal number of contact pieces for the ACB being studied. The electro-dynamic repulsion force of each contact, which varies from the outer position to the inner position, is also computed. Finally, the contacts of the double-breaker are manufactured according to the analyzed results to validate the simulations.

Design and Analysis of a New Permanent Magnet Actuator for Medium Voltage Vacuum Circuit Breakers

This paper proposes a bi-stable permanent magnetic actuator (PMA) for medium voltage vacuum circuit breaker. The structure of the proposed PMA is discussed and the optimization of the structure is carried out. The model of finite element analysis (FEA) is constructed where the flux distributions, electromagnetic force under different structure parameters are analyzed. The feasibility and correctness of the PMA are verified by the FEA simulation results and the optimal size for movable plunger and stationary iron ring is obtained.

Characteristic analysis and design of a novel permanent magnetic actuator for a vacuum circuit breaker

In this study, a novel permanent magnetic actuator (PMA) termed a separated permanent magnetic actuator (SPMA) is proposed. The efficiency of the proposed SPMA is significantly higher than a conventional PMA because of its innovative structure, with which the magnetic flux path is efficient and the holding forces can be designed independently taking the unique values of each load into consideration. Hence, the SPMA is smaller in size and lower in cost than the conventional PMA. For the SPMA, a characteristic analysis and design method using a two-dimensional finite element method, an equivalent circuit, an equation of motion and a time difference method is suggested in this study to save time and reduce the costs incurred because of the experimental trial and error deign. The SPMA was designed and prototyped such that the usefulness of the SPMA for application to a vacuum circuit breaker and the reasonableness of the suggested characteristic analysis and design method were confirmed by the experimental data.