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The three phase electrical motor contains three armature stator coils shifted in space from each other 120 degrees and one stator coil for excitation. Salient multi poles laminated rotor without coil. Rotor has reduced weight because it does not contain coil excitation and has reduced steel core weight. Each of the armature coils is controlled by the one phase H – transistor bridge circuit. DC shoulder of each bridge is connected to a battery. There is an optical sensor of rotor position which controls transistor bridges. Rotor speed may be controlled by change of the armature voltage or by change of current excitation. Current value in both cases is controlled by a pulse-width voltage modulation. In this type of machine, like in DC machines, it is possible to realize shunt, series and combinational methods of the excitation. It is known that series DC motors can develop very high torque at low speeds and therefore can serve very well in a vehicle applications.

The main feature of the described sensor is its contact-less construction. The lack of contacts on the moving rod increases reliability of the sensor. The sensor comprises the core with the short - circuited two - layer secondary winding. In addition, the sensor is provided with the two multilayer windings, the first being the long primary winding, the second one is the short output winding. The output signal is induced on the output winding. In order to produce the output signal, the alternating voltage with frequency of 20…50 kHz is applied to the primary coil. Depending upon the core position of the short-circuited winding, the current of various values will be induced, which causes various voltages to be induced on the output winding. The position of the core may vary in range 0...40 mm. The range can be modified in a particular construction. The output characteristics of the sensor are roughly linear.

The application of the induction electrical generator instead of the synchronous ones in the self-contained power diesel-generating plants is known to have a number of advantages. The induction generator is a simple and reliable non-contact electrical machine. The symmetric rotor possesses perfect damping features being of great importance with the asymmetric load. When operating with the frequency converter (amplifier) the generator is not loaded with the highest harmonics which makes it possible to lower the dimensions power by a factor of 1.5-2. The capacitor system is considered to be the simplest one among the available systems for voltage excitation and control. The paper considers the mathematical model of the two-phase induction machine. The model regards the residual magnetization of the magnetic circuit as well as its saturation in the nominal conditions.