Stabilization of the load mode of the internal combustion engine of the tractor through the use of a hybrid power plant
It is known that the main costs in the operation of agricultural machinery are associated with fuels, lubricants and spare parts. The attempts are made to improve the performance of the machinery by reducing operating costs. This happens due to the increasing competitive requirements of the final product. For example, during daily operation of the MTZ-82 tractor, the most widespread tractor in the Eurasian Economic Union, when delivering feed and driving a feeder for a year of operation, just the fuel costs will amount to approximately 20 % of its initial cost (300 thousand Russian rubles). In addition, to ensure the tractor is in a working condition, it will require spare parts and other consumables for another hundreds of thousands of rubles in Russian currency. The diesel engine used in tractors idles most of the time and, as a result, is underloaded. In peak loads, on the contrary, more power is required and, accordingly, it is necessary to create a sufficient energy reserve. This in turn inevitably leads to increased fuel consumption. Hence, there is a need to stabilize the load mode of the engine, reduce its operation in underloaded modes and at maximum loads. This problem can be solved in various ways. One of them is a combination of a diesel engine and an electromechanical transmission. Such power plants are usually called combined or hybrid. Among several typical structural schemes in agricultural machinery, hybrid power plants of the mild hybrid type and full hybrid type were most widely used. The presented methodology will allow to analyze the proposed schemes of a hybrid power plant, assess possible losses and calculate the required engine power, and ultimately determine a more rational scheme for the given operating conditions. The authors also presented the results of a comparative calculation of the required power of an internal combustion engine of hybrid power plants.