Linear electromagnetic actuators develop directly thrust and thus linear motion. In principle rotary motion electromagnetic motors may be turned into their linear counterparts by cutting them axially and spreading them in a plane. Rotary electromagnetic motors are predominant in industry but linear electromagnetic motors (actuators) are increasingly getting ground for linear industrial motion control. Typical applications are related to people movers (Fig. 1) whose acceleration and deceleration rates are freed from adherence and thus have lower deadweight per passenger; also they are almost maintenance free and easy to control them from on ground station; lower kWh per passenger and kilometer is obtained due to also full regenerative braking. Recent applications are related to industrial linear motion control with or without integrated magnetic suspension. While they are as many types of linear electromagnetic actuators as rotary ones, their control is also similar. So vector control and DTC is used for AC progressive motion linear electromagnetic actuators. Flux control may be used for suspension control. Fast action solenoids with or without PMs are proposed for valves actuation in internal combustion motors while conventional solenoids represent a mature and dynamic technology. Finally, oscillatory linear motion is used in linear generators and motors. Linear generators are driven by Stirling engines for space or home electricity generation and linear oscillomotors are proposed for small compressor drives. The paper reviews the principles, performance characteristics, design, control and recent applications of linear electric actuators.
| Filename: | EPE Journal 14-1 - 7 - Boldea |
| Filesize: | 409.2 KB |
