Faculty of Ocean Engineering and Ship Technology，Gdansk University of Technology,
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In a motor or in a drive system the quantity of power increases in the direction opposite to the direction of power flow. Energy losses and energy efficiency of a motor or a drive system must be presented as functions of physical quantities independent of losses. Such quantities are speed and load of the driven machine or device. Nevertheless, the picture of the power stream in a motor or in a drive system is presented in the literature in the form of a traditional Sankey diagram of power decrease in the direction of power flow. The paper ”On Power Stream in Motor or in Drive System” refers to Matthew H. Sankey’s diagram in his the ”The Thermal Efficiency of Steam Engines” of 1898. Presented is also Paszota diagram of power increase in a motor or in a drive system in the direction opposite to the direction of power flow. The diagram, replacing the Sankey diagram, opens a new perspective of research into the power of energy losses and efficiency of motors and drive systems. Evaluation of the proposed novel idea presented by Paszota diagram, described in the paper” On Power Stream in Motor or in Drive System”. Assessment of the novel idea - discovery by taking into account its scientific and technical importance. A new perspective of research into energy losses and efficiency of motors and drive systems is presented in the book” Energy losses in hydrostatic drive. Drive investigation method compatible with diagram of power increase opposite to the direction of power flow”.