Selection of parameters of a three-flow parallel electromechanical transmission of a tracked vehicle

One of the serious shortcomings of electromechanical transmissions, restraining their widespread use on tracked vehicles, is the large weight of electric motors and energy storage devices. The article provides a three-flow transmission scheme with the minimum number of electric machines necessary to ensure stepless acceleration and rotation with the obligatory use of an internal combustion engine and electric drive. Reducing the number of electric machines is achieved by using the same machines as traction motors and generators, depending on the mode of operation. This implies that when driving at speeds below average, electric machines should work as a generator, above average - as a traction motor. Transmission allows movement without the use of electric machines, but with reduced performance. The article discusses five modes of transmission, the specific traction and power characteristics for these modes. The features of the use of short-term and long-term characteristics of electric machines in the engine mode are taken into account. The use of the internal combustion engine is substantiated not only in the nominal mode, but also in the maximum power mode. A method for selecting transmission ratios, characteristics of the internal combustion engine and electric machines is presented and justified. The calculation is made for the track conveyor of the ultra-light mass category. A description of the regenerative braking modes available for transmission, as well as a description of the mode of charging the drive when parked are given. The scientific problems of evaluating the efficiency of the transmission, the need to study the rotation of the tracked vehicle where it is installed, the development of top-level algorithms for its control are indicated.