Krasovskii

pp. 320-330

The paper considers the application features of traction induction electric motors in transmissions of vehicles. It shows that one of important stages in their designing is to choose the number of poles. The analysis of the initial multi-polar traction induction motor is given as a part of the traction electric drive. The paper presents results of its simulation characteristics in the structure with vector control and estimates their compliance with the given traction characteristic. It is established that because of increased alternating frequency of currents in the range of high speeds there is an excessive decrease in the torque and the requirement for constancy of the target capacity, corresponding to the typical traction characteristic is not fulfilled. Given calculation results of electromagnetic field distribution in a groove of the engine stator are used to establish a substantial growth of additional losses in the engine, and an extent of flow loss because of damping actions of eddy currents in the laminated steel of stator at increased frequencies is estimated. The traction induction motor alternative with the improved characteristics is proved.

Existing shock sensors for car protection using the sensitive elements (SE) of piezoelectric, microphone and electromagnetic types and the analogue circuits of signal processing, have a number of essential shortcomings, such as "false" operations, instable temperature characteristics, nonlinear adjusting characteristic, and inconvenient control via variable resistors. The article considers issues to design the two-zone digital shock sensors with a SE of electromagnetic type. It offers a SE design, a circuitry solution, and algorithms of signal processing, which allow a remote control of prevention and alarm zones (with 16 gradations of sensitivity) and an algorithm for self-adapting to repeating external impacts. The method has been developed to form the basic levels of digital comparators for each gradation of sensitivity. Using this method enables the sensor to have the straight-line adjusting characteristic. Prospects for using the 3-axial micromechanical accelerometers as a SE of the shock sensors are proved.

The existing analog circuit-based microwave sensors for car alarm systems have high power consumption and high level of intrinsic noise, causing "false" alarm of response sensors; non-stable temperature characteristics that require readjusting the sensor during the transition from the summer season to the winter one; adjusting the nonlinear characteristics and uneasy adjusting with variable resistors.The paper concerns the issues of designing the two-zone digital microwave sensors. It proposes a circuitry and algorithms for digital signals processing. This allows the 6-8 times reduction of power consumption, cut of noise level in half thereby increasing the sensor sensitivity and implementing a remote setting of warning and alarm zones (16 levels of sensitivity) and an algorithm of self-adaption to the repetitive external actions. The paper proposes a method for generating the reference levels of digital comparators at each gradation of sensitivity to linearize the output characteristic of the sensor.

In this article the author considers a step electric drive with power supply of the motor by a controlled current inverter in which the basic operation mode is movement with a constant or slowly varying speed. Relatively quick dynamic behavior is required in short periods of time. A control algorithm ensuring speeding at the expense of short-term increase in its torque at the corresponding multiplicity of increase in a phase current of the drive was proposed for the specified variant of the step electric drive. A simulation model of the electric drive was developed in MATLAB – SIMULINK; this software helped to verify  efficiency of the proposed steering mode. It was shown that the considered algorithm is not effective for electric drives with considerable external damping. Results of the simulation were presented in a polynomial shape convenient for practical use.

Features of architecture of an individual cycle of switching in a gated inductor motor were considered in this article. Existent control algorithms for the motor obtained on the basis of a simplified piecewise linear representation of its real magnetic characteristics were estimated. Simulation results of a cycle of phase switching of the motor with the use of its experimental nonlinear magnetic characteristics were presented; these results were used to formulate optimum, in terms of force and power indexes, conditions of turning on/off. Character of voltage variation on the drive’s phase with standard parameters for maintaining the presence of a current in the zone of overlap of interacting poles was determined.