In article ample opportunities of the converter of frequency are noted at work of the "small" mechanization applied in farmer and priusadebny farms, small workshops, etc.
The three-phase electric motor in capacity to 1,5 kW with the converter of frequency creates the universal electric drive practically for all "small" mechanization.
If there were problems with connection of three-phase electric motors to the single-phase power supply network and with selection of engines with necessary turns moreover and with possibility of their regulation – pay attention to modern electronic converters of frequency.
First, the converter of frequency allows without additional condensers, induktivnost, elements of resistance to connect to a single-phase network of an alternating current a voltage of 220 V three-phase electric motors with a short-circuited rotor in capacity from several watt to 1,5 kW (our power supply networks, as a rule, aren’t calculated on big capacity). But also this has enough for work over 70 names (not all at the same time!) "small" mechanization, namely: electrosprayers, electrocultivators, pumps, sharpened, woodworking machines, a zernodrobilok, mills, vegetable cutters, a medogonok, etc. It is not necessary to spend money for the device of the three-phase power supply network.
Secondly, the frequency converter smoothly or in steps regulates turns of any electric motor from nominal synchronous 3000, 1500, 750, 500 to 60 … 100 revolutions per minute.
Turns are regulated by pressing of buttons or handle-makhovichka turning. Thus the moment of torsion of a shaft of the engine decreases approximately by 15 %, i.e. power characteristics of the electric motor practically remain constants.
In order that the owner on the discretion didn’t undertake to regulate engine turns in a range technically impossible for the car or for the engine, designers provided special blocking of the bottom and top levels of frequencies of the converter.
At the expense of regulation of turns of a shaft of the electric motor it is possible to improve considerably technical and technological indicators of cars and mechanisms.
Thirdly, the converter "suffers" fluctuations of tension and frequency of the power supply network and "twists" an engine shaft at tension from 180 to 264 In and at frequency from 48 to 62 Hz.
Fourthly, the converter smoothly for some seconds starts or stops the electric motor. This important property at work with asynchronous electric motors which allows to avoid considerable loadings of a current in the power supply network.
Fifthly, the converter can change the direction of rotation of the electric motor.
Seventhly, in a design of the converter possibility of programmed control by means of the computer is put. All this allows to spend the electric power economically.
At all adjustments of the converter of frequency the capacity of the three-phase engine can decrease only by 20 % (compare, when using condensers for connection to a single-phase network the rated power of the electric motor decreases on 40-50 %).
Some words about possibility of wide use of converters of frequency in farmer and priusadebny farms, craft workshops. The asynchronous three-phase electric motor with a short-circuited rotor the cheapest of all engines, both electric, and internal combustion engines it also spends cheap electric energy. Its resource of work without repair – 20 thousand hours. For this period the electric motor won’t demand neither oils, nor replacement of any parts. For the comparison, the petrol engine of HONDA firm best on the indicators has a resource to 3 thousand hours, demands some oils and service and is more expensive more than in 4 times of the electric motor of similar capacity.
The three-phase electric motor in capacity to 1,5 kW with the converter of frequency creates the universal electric drive practically for all "small" mechanization.
It is necessary only instead of four bolts with which the electric motor and a working part of the car traditionally incorporate, to apply the quick disconnect adaptation which will allow to have only one electric drive on some working sites. And it is considerable economy of means.
The frequency converter on engine capacity has the sizes 150x150x150mm. It is expedient to establish it near the electric meter in the separate metal case with performance of electric installation work according to existing standards. Its working temperature from – 100S to +500S. In a non-working condition he isn’t afraid of low temperatures. From it there can be a cable eyeliner to cars and machines in length of 50 m. And, as well as it is necessary, management of the converter is established on a working part, i.e. on the machine or the mechanism.
P. Osipenko.