Electrical Drives Systems Structure Evolution
26 June 2009 | Green Technology | No Comments
The first stage started from the middle of 19th century and consisted in the replacement of the group electrical drives with individual electrical drives. Every eqiupment was driven by at least one electrical motor an in this way the mechanical part of the drives was simplified and certain drives became more appropriate for work machines. Therefore the productivity was increased, the energy consumption of electrical drives reduced and the product quality was improved.
-The second stage is characterized by automation and has started in the period between two World Wars, but has become decisive in 1960 when power semiconductors have been discovered.The power electronics has been developed very fast so the unit power of industrial electrical drives is between fractions of W and several MW. In the majority of cases the driven variable is the machine revolution respectively the machine position, but in certain cases it is a variable regarding the technological process of the machine(for example pressure, quantity of transported material etc.)The spread of integrated circuits has completed efficiently power electronics circuits and has allowed that the circuits of logical command and drive to work at very low power. Consequently, new possibilities for producing control circuits appeared and the structure of control circuits has been modofied significantly.
-The third stage is the actual one, when important modifications take place in informational electronics of electrical drives (circuits for command, measurement, and control).The philosophy of electrical drive systems is changing due to the use of digital control, with microprocessors or with computers.The new systems are more elastic, could be programmed very easily, and coupled easier in a bigger system with independent functioning and adapted easier to certain loads or functioning regimes.
Tags: control circuits, efficiently power, electrical drives, electrical motor, electronics circuits, energy consumption, individual electrical drives, industrial electrical drives, informational electronics, microprocessors, power semiconductors