Search Results

The results of theoretical and experimental investigations of the special synchronous machine and the electrical drive on its base are submitted. This paper covers the principle of operation the brushless synchronous machine, its experimental characteristics, comparison with other types of motors, technique of account of the electromagnetic torque, functional circuits of the electric drive with the independent excited synchronous reactive motor (FRRM - Field Regulated Reluctance Machine). It is the most favorable application of the considered electric drive in the vehicles with heavy conditions of operation, where such are urgent it advantages, as: brushless, high rigidity of the shaft, large overloads on the torque. It can be used in the regular cars for starter generators, in pure-electrical and hybrid-electrical vehicles for power drive, in independent power generating installations with high-speed of the gas turbine engine and so on.

In this paper we consider the questions of increasing the between-charge mileage (range) of electric vehicles and other vehicles with independent electrochemical power supplies. These are classified as hybrid vehicles, and can have various combinations of energy sources installed, such as: storage battery and electrical generator, driven by the engine, storage battery and solar panel, capacitor and electrical generator with engine, and others. The priorities for the development of the combined power supplies used now are considered and analyzed. On the basis of the power analysis of the combined power supply of the hybrid electro-mobile with a solar battery - of which the basic source of energy is the storage battery - the technique of defining the length of between-charge mileage of the vehicle is developed, depending on a combination of a set of parameters: both the components of the combined power supply, and the parameters of the electrical vehicle.

A two-phase alternator consists of two one-phase generators. The phase of the two output voltages of the alternator is shifted 90 degrees. The alternator rotor has a salient pole configuration without coils. Two generators are mounted in the stator slots inside the alternator stator. Each of the generators consists of one winding for excitation and one output winding for voltage generation. For generator excitation, DC or AC current may be used. For AC excitation, the direction of current flow is changed as a function of the rotor position. If three one phase generators are used with a 120 degree output voltage phase shift, then a three-phase alternator can be built. The two-phase alternator has simpler construction and less parts than a three-phase alternator and is consequently easier to fabricate and maintain. This paper presents experimental and the field circuit calculation results of two-phase alternators with DC and AC stator excitation.

The use of alternating current machines of a simple construction with the squirrel cage rotor or the soft iron salient pole rotor as a car generator allows to increase a reliability of a generator and the maximum rotor rotation frequency as well in comparison with synchronous machines. The main feature of a car generator operation is a wide range of a rotation frequency change (five or six times). The use of alternating current machines aforementioned with the capacitor excitation is impossible, because it requires a capacitance value change in a wide range. In the paper presented the rotor excitation by passing current impulses through the stator winding over necessary periods of time is considered. The possibility of such an excitation is confirmed by the experiment. The single-phase generator with external rotor excitation is analysed on the basis of a digital model.

The electrical power consumption in automobiles continues to increase thereby demanding higher power capability of the alternator. The standard alternator today is a claw-pole synchronous machine. The claw-pole alternators have brushes which are maintenance issue; it is not possible to increase power output by increasing the stack length; and the rotor inertia is large due to the steel core and rotor excitation coil. Despite these disadvantages, the claw-pole alternator is still used because of its low cost and ease of manufacturing. An alternator with DC stator excitation, has a laminated salient pole rotor with no excitation coil. Therefore the weight and inertia is less than in the claw-pole alternator. The excitation coil is located in the stator and therefore there are no brushes needed. In this type of alternator, the stator has three-phase output coils evenly shifted in space 120 degrees.

The performance and property of brush-less car alternator with gap flux controlled by DC stator coil is discussed in this paper. This type of alternator is more dependable, has reduced weight and dimension of rotor compared with traditional alternators. Reduction of the rotor weight is obtained by elimination of rotor coil and reduction of steel core weight. The stator steel core is laminated and exactly like ordinary stator core, but coils are different. There are three phase stator coils and coil for DC excitation. Salient multi poles rotor is laminated and does not contain any coils This paper presents theoretical discussion of principle of operation of this type of machine. Traditional alternator was modified for physical modeling. Results of this modeling are presented as well.

The operation of electric vehicles in urban conditions, especially in limited spaces, frequently imposes increased requirements on maneuverability. For electric vehicles operating on roads up to 30-40 km/hour, one of the most practical methods of increasing maneuverability is the use of completely independent drawing mono-blocks. These blocks are self-contained units each consisting of a draw wheel, electric motor, power supply, storage battery, and an electronic power converter. The blocks allow the vehicle to rotate 360 degrees around center axis, turn at any radius, and move in any direction, including straight to the left and to the right. The authors have developed and patented an increased maneuverability electro-cycle vehicle which consists of two mechanically connected block modules. In addition to increased maneuverability, such a design also increases reliability-failure of one block module does not prevent vehicle operation.

This generator is a new simplified design version of an alternator with DC stator excitation that was published by the authors in the SAE 2003 and SAE 2004 World Congresses. [7, 8] In automotive applications, this type of electrical machine may be useful for regular cars, hybrid and fuel cell electrical vehicles with an electrical power source system of 12 VDC, 24, and higher. Brushless car alternators with DC stator excitation have less rotor inertia because the excitation windings are located in the stator. Smaller rotor inertia eliminates drive belt slippage. This generator is more reliable in view of the absence of contact rings and graphite brushes in a rotor circuit, which exist in a standard claw-pole alternator [9]. The laminated salient pole rotor of the alternator is very simple in construction and has low cost of production. The two-phase alternator is simpler than the three-phase, as it has only two output windings instead of three.

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.

It is known, that the alternator self-excitation is possible at capacitor loading [1]. From this follows, that the alternator excitation by means of capacitors connected to one or several stator windings, as from simple excitation winding is located on a rotor, is possible. In the report the excitation of the automobile alternator with claw pole rotor by means of capacitors connected to stator windings at rotor open excitation circuit is considered. Thus, for comparison the alternator idle characteristics are received both at excitation by means capacitors, and by means of a simple excitation winding. Besides the other electrical parameters of the alternator with claw pole rotor by experimental way are determined. On the basis of the received data the alternator digital model was developed, it takes into account the magnetic circuit saturation, by using of the received experimental idle characteristics.