Asynchronous driving

The activation of these actuators can be simultaneous (synchronous driving) or selective/controlled (asynchronous driving), which can usually provide higher speed and smoother motion. 

The capacity of a motor is defined by the distance (mm) between its drive shaft and bed plate. This distance is termed its frame size. For asynchronous motors there is a standard (IEC standard) that defines frame size. For example, if a motor has a diameter of 800 mm, its frame size is 400. Motors produced according to this standard are termed standard motors. 

Asynchronous motors can operate directly on the AC network current. The resulting speed is constant and dependent on the number of pole pairs and network frequency. However, an extruder drive should at least have variable speed. For this, a frequency converter is used. 

With a frequency converter, stator voltage and frequency of the asynchronous motor can be varied infinitely. This transforms a standard motor into a variable speed drive system. An asynchronous motor equipped with a rotor position sensor, magnetization calculation, and the impression of the corresponding stator currents (vector regulation) has the properties of a servo drive. 

Asynchronous motors are the most widely used industrial motors. They can be plugged directly (with a motor starter) into AC network current, are very robust, and simple to build. Thanks to these desirable characteristics, this drive is internationally standardized and produced in large quantities all over the world. 

Nominal motor speed is an important parameter for configuring the drives of an extruder. Many contemporary extruders offer screw speeds of 1200 rpm. At 60 Hz mains network frequency, the synchronous speed of an asynchronous motor per number of pole pairs is... 

Continuous product flows under high-pressure conditions (p > 30 MPa) can only be achieved with hermetic centrifugal pumps. Although the two drive systems that can be used - the permanent magnet coupling and the asynchronous canned motor - have the same mode of operation, they differ in their applications and their safety ranges. 

The versatile drive system of the asynchronous canned motor has set fresh yardsticks for centrifugal pumps operating under high-pressure conditions. The operating limits for pressure, temperature and toxicity of the flow product have been extended by some orders of magnitude. This is the logical result of the response to heightened safety environment requirements, and means that technical processes can now be implemented for the manufacture of new products. 

The one simulator session they did receive was less than effective, partly because the computer tape provided by Boeing to drive the exercise was not current (another instance of asynchronous evolution). For example, the maps were out of date, and the rules of engagement used were different and much more restrictive than those currently in force in OPC. No Mode I codes were listed. The list of friendly participants in OPC did not include UH-60s (Black Hawks) and so on. The second simulation session was canceled because of a wing exercise. 

Main spindles can be classified as directly driven (motor spindles) or externally driven versions. In directly driven spindles, the power is generated via a motor integrated into the spindle housing, with the rotor seated on the spindle shaft. In contrast, the drive in the externally driven version is positioned outside of the housing and connected to the spindle shaft by a coupling or gear. Normally synchronous or asynchronous machines are used as drives. 

The synchronous drive motor (45 MW) at 3000 rpm showed a trouble-free operational behaviour. The same applieds to the asynchronous three-phase motor (4.5 MW) for the start-up. 

Drive harmonics are a function of the drive switching frequency and pattern, and will differ between suppliers. The TMEIC P30 source converter is a medium voltage, IGBT, PWM regenerative source converter using a 1,536-Hz modulation frequency that is asynchronous to the utihty frequency. Harmonics created by the source converter are sideband frequencies centered around integer multiples of this carrier frequency (i.e., when applied on a 60 Hz utihty, the sidebands with series that will be) ... 

The primary circuit blower consists of a single-stage radial compressor. A speed-controlled asynchronous motor is provided as drive. The motor is cooled with water. The blower with motor is installed in the blower pressure vessel section as a slide-in unit with vertical shaft and hanging impeller. A blower flap is located on the suction side of the blower. The blower increases the pressure of the helium sucked in from the steam generator outlet side by approx. 1.5 bar. 

The drive system has a frictionless asynchronous AC motor and inductive position sensor. The ranges are listed, accuracy is better than +10% at 0.00002 mN-m. 

In ASYNC IF I, if INIT is low then the register will be initialized to 1000, independent of the state of the clock. It will be held in this state while INIT remains low, regardless of the number of dock pulses received. The synchronous and asynchronous sections should not drive REG at the same time. To ensure this does not happen, a conditional statement within the synchronous section determines the state of INU before the bits in the register are shifted. This will require additional logic for its implementation. 

---