Space Elevator To Mars Using IGBT Application Technology

One day we may need a space elevator to visit Mars using the IGBT technology. People heading into space in the near future could be travelling by elevator rather than rocket if Obayashi Corporation has its way. The company announced two years ago that it has the capacity to build a space elevator — and have it up and running by the year 2050.

The company said that the elevator would reach 96,000km (59,652 miles) into space and use robotic cars powered by magnetic linear motors (maglev, as seen in high-speed rail lines around Asia and Europe) to ferry cargo and humans to a new space station.

Great switching speed is required for PWM VFD operation which can be achieved by using IGBT (insulated gate bipolar transistor). IGBTs are susceptible of switching on and off several thousand times a second. A VFD IGBT can turn on in less than 400 nanoseconds and off in approximately 500 nanoseconds. A VFD IGBT consists of a gate, collector and an emitter. When a positive voltage (typically +15 VDC) is applied to the gate the IGBT will turn on. This is similar to closing a switch. Current will flow between the collector and emitter. A VFD IGBT is turned off by removing the positive voltage from the gate. During the off state the IGBT gate voltage is normally held at a small negative voltage (-15 VDC) to prevent the device from turning on.

All recent VFDs use IGBTs as power devices. These devices make it feasible to reduce annoying audible noise by using switching frequencies beyond the audible range. Unfortunately, VFDs using IGBTs, present a high potential for generating RFI – Radio Frequency Interference. Fast switching in these devices generates sharp-edged waveforms with high frequency components that generate more RFI. The most likely complaint is interference with AM band radios 500-1600 Khz. Nonetheless, sensitive computers, medical equipment and other noise-sensitive devices sharing the same power buss could experience serious interference.

In ultimate cases, the VFD itself can experience electrical noise interference. If elevator machine room equipment is not correctly laid out and properly wired, the electrical noise preached by the elevator VFD system can interfere with the elevator controller.