Diesel locomotives is the most up-to-date wheel equipment at mining companies and for new powerful mines, their application is efficient and economically feasible. Introduction of diesel locomotives at the functioning mines requires careful feasibility study, and with regard to great length of courses and dispersion of mining and production faces, it is often unreasonable to use them.
Acid storage batteries have a range of advantages compared to the alkaline accumulators; the prices are about the same. Disadvantages of acid storage batteries are also known and require improvement of electric locomotives АМ-8D. Wide application of acid storage batteries at the Ukrainian mines is more reasonable when organizing production of acid accumulators at one of domestic plants with regard to experience of foreign manufacturers.
The abovementioned permits stating that the electric locomotive АМ- 8D with accumulator battery ТNSh-350-U-5 is the most widely-spread wheel transport of coal mines, and trolley locomotives К-10 и К-14 fit for the quarries and some of anthracite mines. In this respect it is necessary to upgrade the electric locomotives, which is an effective means for improving the wheel transport operation. There are 4 diesel locomotives, 178 trolley locomotives, 241 inertia-type locomotives and 1232 accumulator locomotives operated in Ukraine, 1178 of them are of АМ-8D (2АМ-8D) mark.
In May 2001, at Lutugina mine of the Integrated Mining and Chemical Plant “Torez-antracite” the tests of motor DRT-14 for electric locomotives finished, which made a good showing. With the price being the same as for DRT-13М, it has a range of essential advantages, the main of which is a service life and error-free running time that makes the engine competitive compared to the analogous foreign samples. Production of DRT-14 is planned for the year 2001 by Kharkov plant “Elektromashyna”.
Besides, the plant will produce an updated controller KRV-3 equipped with nonstop resistor step while braking with enhanced parameters of arc blowout and blocking to eliminate control out of cabin. The new breaker VRV-160 with electric control unit of battery charge, automatic circuit-breaker under deep discharge of accumulator battery and under current overload will enable to adapt the electric locomotive АМ- 8D to acid batteries and improve their operation at alkaline ones.
The specified equipment upgrading are half-measures compared to those represented by the modern developments of CJSC “Amplituda” and SKB OJSC “Elektomashyna”. There is being developed a transistor and pulse control system of electric locomotive АМ-8D in mine explosion-proof version RV-ZV, protection level Р54 according to GOST 14254—80, which will enable to realize smooth adjustment of voltage at railway motors and their reversing, maximum motor current limitation in different modes, electric motor thermal state control.
Disadvantages of standard rheostatic locomotive control systems:
-heavy electric losses in rheostatic starters (up to 50% of total power consumption) due to frequent starts and necessity to work with underspeeds on rheostatic characteristics;
-sharp (sudden) change of current and traction effort when transfer from one speed to another due to small quantity of stages and resulted thereof inefficient use of electric locomotive adhesive weight within the period of start that forcedly increases the accelerating period and reduces the average speed, and results in increased wear of the locomotive truck;
– heavy wear of commutation and contactor equipment of electric locomotive.
Application of pulse control cardinally improves tractive, operational and economical characteristics of electric locomotives. The main advantages of pulse control system are:
– power consumption reduction by 30—50% (depending on special peculiarities of electric locomotive operational conditions) due to eliminating losses in rheostatic starters and increasing the operation time at one charge of accumulator battery, as well as essential extension of its service life;
-increase of starting tractive effort due to smooth starting enabling to increase by 10 – 20 % the service load to the electric locomotive rolling equipment and average travelling speed of rolling equipment;
-stepless speed regulation and possibility of long-term travelling at any speed without overload to traction motors that allows to optimize the speed mode and increase the average travelling speed of rolling equipment;
– eliminating of those related to locomotive maintenance expenses associated with repair and maintenance of mechanical power commutation and contactor machines, because non-wearable electronic commutators are used for commutation of power circuits;
– increase of reliability of electrical equipment and overhaul life of electric locomotive operation at the account of eliminating the contactor commutation and start-control devices;
– increase of electrical operation safety, because the main controller in the operator’s cabin is connected only to low-voltage (12 V) and weak-current (50 mA) electric circuits.
Application of transistor-pulse control system will significantly extend the general service life of electric motors and locomotives. Given that cost of electric equipment АМ-8D will be increased by 20% maximum, and of the whole electric locomotive – by 10%, this control system is economically feasible. It should be accounted that it is applicable also for trolley electric locomotives К-10 and К-14. Testing of engineering sample of transistor and pulse control unit is planned at the end of 2001, and starting from 2002 there already will be electric locomotives at mines of Donbass with new improved electric equipment.
One of directions of further upgrading the electric locomotives planned for development by PRJSC “Amplituda” and SKB “Elektromashyna” is a frequency-regulated asynchronous drive of explosion-proof version. The salary at underground transport site in Ukraine is significantly lower that at the others. Due to it just some mines managed to retain qualified staff.
By no means unimportant reason of unsatisfactory condition of electric locomotives is a lack of spare parts for current repairs. Hence, if overhaul maintenance of any electric locomotive may be made by the mine based upon PrJSC “Amplituda”, the preventive measures and current repairs lack the most needed things. Analysis of coming for repair electric locomotives and fault detection in their units for 6 operational years of PrJSC “Amplituda” allows determining the details requiring replacement within the period between overhaul maintenances to extend the service life of electric locomotive. As for electrical part – these are controller contacts, its individual units, wiring, couplings and electric motors. As for mechanical part – these are block springs, bearings, inserts, reducer group and on rare occasions – mounted wheels bands.
At present time the manufacturers do not sell spare parts for individual units of electric locomotives, and mines, when they buy them, do it at unreasonably high prices and of questionable quality. PrJSC “Amplituda” offers those mines, to which it carries out overhaul maintenance, supply of all spare parts for current repair, and also it is willing to render consultation services of different kinds and assistance in any repair.