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Topics - rezwan.eee

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Electric vehicle(EV) is a propitious engineering revolution to replace conventional motor vehicles to dismantle the current level of environmental pollution. Engineers are already focusing on developing its current state of efficiency and new ideas are emerging every now and then. One of the bigger challenges in such vehicles revolves around the control method adjustable speed drives used in conjunction.

The popular approach was to use a time-averaged torque control of the motor. The control of torque in dc commutator motors is based on the classical theory in which torque is proportional to the vector current of armature current and flux. Under sufficiently light load the commutator maintains the spatial orthogonality of these quantities so that the vector product becomes a scalar product. Since both the flux and the current are normally constant, the instantaneous torque is also constant. There is ideally no torque ripple and the torque is varied by changing the current or the flux or both. In ac sinusoidal machines the situation is similar. The actual phase currents and flux linkages are not constant, but can be made to appear constant by means of a reference-frame transformation that has appropriately been called the commutator transformation (e.g: Park's transformation). The instantaneous torque of an ideal ac sinusoidal machine is constant and is proportional to the vector product of current and flux linkages in the transformed reference frame. The transformation unifies the theory of the dc and ac systems for dc and ac drives that have closely similar structures when viewed from the appropriate reference frame. These principles are put into practice in the so-called "vector control" of ac motor drives.
As the dc commutator motors and ac sinusoidal motors have an instantaneous torque equal to their time-averaged torque in the steady state, the time-averaged control scheme is suitable for such machines. But the use of motors with varying instantaneous torque is increasing rapidly. As a consequence, instantaneous torque control is becoming a viable adaption for the upcoming future of this technology. The speed and functionality of the digital integrated circuits will have a further leap in adjustable control of speed drives through the prescribed instantaneous analysis. On the other hand it has the potential to provide a faster feedback response to the control unit. Also, it can remove the ripple torques over a wide spectrum of instabilities including shaft resonances with software controlled accuracy in principle. Hence engineers are shifting towards this innovative controlling method and research is progressing swiftly.

Time-averaged and instantaneous torque control both methods have their suitability to adjustable speed drives of modern electric vehicles. But which will dictate the next step of advancement in control mechanism remains a debate to be resolved for the future.

Latest Technology / Littelfuse Takes Majority Stake in Monolith Semi
« on: April 22, 2017, 02:13:20 AM »

Power control and sensing chip and component supplier increases stake in developer of silicon carbide chips.

Latest Technology / Cypress Sells Minnesota Fab for $30 Million
« on: April 22, 2017, 02:12:55 AM »

Deal enables firm to continue receiving supply from startup foundry while transitioning manufacturing to Texas.


Market watcher IC Insights expects semiconductor industry capital spending to grow by about 6 percent, led by increased spending from the top 11 spenders.

Latest Technology / Avnet, Arrow Drive into IoT
« on: April 22, 2017, 02:11:56 AM »

Rival electronics distributors Avnet and Arrow are both nurturing new IoT groups, but their targets in the Internet of Things are initially somewhat different

Latest Technology / Chip Sales Jump 14% in January
« on: April 22, 2017, 02:11:40 AM »

Semiconductor sales started the year off where 2016 left off, posting the largest annual increase in one month in six years.

Latest Technology / Startup Taps TSMC to Attack B’com
« on: April 22, 2017, 02:11:17 AM »

Using InFO packaging from TSMC, a startup spun out of Mediatek aims to attack Broadcom’s dominance in Ethernet switch chips.

Latest Technology / Competing Sensors Crave Human Contact
« on: April 22, 2017, 02:10:51 AM »

While CMOS imagers and infrared are well established as sensors in smartphones, today’s $64 million question is whether they will make room for radar and ultrasound inside IoT devices. And if yes, what roles will they play?

Latest Technology / AMD Describes Zen for Servers
« on: April 22, 2017, 02:10:28 AM »

AMD will announce at the annual Open Compute Project event that its Zen-based x86 Naples server processor will ship by June.

Latest Technology / X-Fab Files for IPO
« on: April 22, 2017, 02:10:07 AM »

German specialty chip foundry hopes to raise $530 million in two offerings, according to reports.

Latest Technology / Everspin Tips First System-level MRAM Offering
« on: April 22, 2017, 02:09:45 AM »

Storage accelerator harnesses MRAM technology to offer high-performance, low latency.

Latest Technology / Softbank to Sell 25% of ARM to Saudi-Backed Fund
« on: April 22, 2017, 02:09:19 AM »

Softbank is about to sell 25 percent of ARM into a new, Saudi-backed $100 billion investment fund. The Japanese decision appears to be driven by Mubadala -- which owns 100 percent of Globalfoundries -- who is interested in ARM.

Latest Technology / PowerVR Gets Graphics Refresh
« on: April 22, 2017, 02:08:51 AM »

Imagination Technologies unveiled Furian, its next-generation PowerVR graphics architecture, aimed to help claw back market share from ARM’s Mali.

Latest Technology / Low-End Oscilloscope Market Gets More Crowded
« on: April 22, 2017, 02:08:30 AM »

The sub-$1000 market for oscilloscopes just got pushed around with the entry of Keysight Technologies. The sub-low-end for makers and hobbyists hasn't changed

Latest Technology / Auto SoCs: Race to ASIL D
« on: April 22, 2017, 02:08:05 AM »

Where does the automotive industry stand today on the Automotive Safety Integrity Level (ASIL) of the SoCs in their current ADAS models or in the autonomous cars on their drawing boards?

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