Direct current machine

FIELD: electrical engineering; direct current machines.

SUBSTANCE: direct current machine comprises a stator, an armature fixed on a rod, a contact device in the form of annular rings insulated from each other which contact with brush electrodes used for current feed and collecting from the start and the finish of the coil, end shields, a controlled solid-state switch which activates bipolar transistors and resistors between the electrodes of the emitter and the base and which is connected to its control device. The control device of a solid-state switch consists of brush electrodes which receive the control signal, a brush electrode giving the control signal, and two rings fixed on the rod and insulated from this electrode. One of these rings is made from a conductive material, while the second ring is cut into two sections, one section is made from a conductive material and connected with the solid ring of the control device, and the second section is made from insulating material. All brush electrodes are installed with the possibility to connect them with the sectioned ring and are connected with the control electrode of the semiconductor elements of the solid-state switch, while the brush electrode giving the control signal is installed with the possibility to connect with the solid ring of the control device and is connected with the brush electrodes receiving the signal at the moment of the connection of these brushes with the conductive part of the sectioned ring. Furthermore, the contact device is made in the form of four solid conductive rings. One of these rings is connected with the start of all armature coils, while all other rings are connected with the finish of the respective coils. The conductive section of the ring is made in the form of a 120° section, whereas there six electrode brushed that receive the control signal positioned with a 60° angle between them. In addition, the machine includes a relay with an option to switch the positive pole of the feeding line from the solid-state switch to the start of the coils.

EFFECT: prevention of sparking, radio interference and noise, improvement of adjusting characteristics, simplification of the device's manufacturing technique and increase of the direct current machine's efficiency.

3 cl, 10 dwg

The invention relates to electrical engineering, in particular to the electrical direct current, which can be used as motors and as generators. The motors are designed for operation in DC drives powered generators or static converters and can be used on electric, for driving of machines, fans, compressors, pumps, cranes and transport mechanisms, elevators, freight trucks. Generators can be used not only as Autonomous sources of electricity, but also as power sources in remote consumers. You can also use generators for radio stations, DC motors, battery charging, welding and electrochemical low-voltage electrical installations.

Known DC machine comprising a stationary field winding located on the frame, anchor, mounted on a shaft with laminated magnetic circuit in the form of a steel drum with grooves winding and the collector, on which are superimposed the brush (Katzman MM Electrical machines. - M.: Academy, 2008, s-370). The principle of operation of DC machines based on the interaction of the current in the coils of the windings of the armature and the magnetic field winding. As a result, the conductors of the armature winding are the electromagnetic force and the electromagnetic torque occurs. For continuous operation DC machine, you must change the direction of current in the conductors anchor winding when changing its position relative to the poles of the stator magnetic field. This switch in conventional machines of direct current is provided by the collector.

The collector consists of a split copper ring and slip ring brushes. Thus isolated between the segments of the split rings connected with the turns of the armature winding and rotating with the winding alternately in contact with the stationary slip ring brushes connected to the external circuit.

The presence of the collector in conventional machines of direct current causes they have some undesirable properties. First and foremost among them is the need for constant supervision and care of commutator-and-brush-node, as in the operation of the machine brush abraded, and the collector is polluted and burns. In addition, the inevitable sparking brush-collector apparatus creates interference that hinders the use of machinery in hazardous locations and environments. As the main disadvantage of brush-collector apparatus is its inability to handle large voltages, because the arcing on the surface of the collector depends on the voltage between adjacent its plates and it does not have revisit 18-22 Century Despite several advantages of using DC for power transmission over long distances, the restriction of DC machines voltage considerably complicates this task. This is due to the necessity of a large number of conversion of electricity to reduce its losses. Work commutator-brush Assembly also creates additional noise when the machine is in operation. The desire to eliminate mechanical commutator-and-brush the node and replace it with any contactless device with the same functions has led to the emergence of the so-called brushless machines.

Known brushless DC machine, called switched-reluctance machine (Ovshinnikov I.E. Brushless electric motors and drive on their basis. - SPb.: CROWN-century, 2007, C-27), consisting of a stationary armature winding, is placed on the frame, alternating EMF which is generated by semiconductor switch, and a rotor attached to the shaft and having windings. This machine is having the same characteristics as the machine with the usual collector, has higher reliability and simplicity of operation, no sparking and will not create in their work interference. Complete elimination of mechanical contact devices in these machines leads to the fact that the rotor runs without windings, i.e. assetsassets. The principle of operation of a valve of the machine is based on the interaction of the field winding of the armature with the poles of the rotor, made of a ferromagnetic material. Because you only use one armature winding, nearly the whole of the vehicle's energy is focused on this winding. This leads to the fact that the anchor winding machines of large capacity will be affected by significant electromagnetic, thermal and mechanical effects. Due to the large currents of the armature winding will overheat, resulting in reduced efficiency and premature failure of the insulation or the armature winding must be run from large-gauge wire and insulation with high thermal resistance, which leads to higher costs. When this alternating current in the armature winding creates a semiconductor switch, which commutes with all the current machines. Therefore, it is necessary semiconductor elements capable of operating with current values is somewhat higher than in machines with an active rotor with the winding. Used for a rotor of ferromagnetic material is very expensive, in addition to his magnetic properties deteriorate. The use of brushless machines is limited by the fact that the commutation of the windings of the armature leads to impulsive electromagnetic torque, which is unacceptable for a machine with low the speed and high torque, and to the strong vibration of the vehicle body, which leads to significant acoustic noise. Reducing impulsive moment is possible by increasing the number of windings of the armature. This leads to an increase in the number of semiconductor elements. Such machines have a very high cost. The vibration of the hull due to the location of armature winding. In collector cars DC armature winding is placed on a solid magnetic core and it is not the whole part of the power machine, so the vibration of the armature of these machines is negligible.

One of the main parts of the valve of the machine is a position sensor rotor that controls the switch, giving signals to each control electrode, depending on the angle of rotation of the rotor. This device has a complex performance and require considerable resources. In addition, the position sensor rotor sensitive to external electromagnetic influences. Thus, the brushless machine it is advisable to use only as machines of small and average capacity, requiring complex control of technological processes.

Known DC machine Ishibashi (RF Patent No. 2091966, H02K 23/38, publ. 27.09.1997), taken as a prototype, containing a stator, armature, brush mechanism, bearing, connecting device, performed in the de two conductive rings, separated by insulation, with one of them made a solid and the other with three sections that are offset relative to each other by 120°, the armature winding is made of three coils, each separated from each other by 120°, and the beginning of the coils are attached to a solid ring, and the ends of the coils to split. The contact device produces alternate enabling and disabling of the winding coils of the armature as it rotates, which creates a pulsating magnetic field of the armature, directed at an angle of 90° to the magnetic field of the stator, while the armature winding switch completely. In this case, the coils of the armature passes only DC current, i.e. the current conversion does not occur and, as a consequence, there is no hysteresis loss.

Switching the windings of the armature DC machine Ishibashi during the rotation of the armature at every 60° and their placement are presented in figures 1, 2, 3 of the supplemental material. The switching of the windings is produced by the mechanical contact of each segment CA, Cb and SS split ring with a fixed brush. Based on figure 1, 2 and 3 it can be noted that at any point in time involved only one winding, that is, the armature winding is used inefficiently. The result is a number of drawbacks:

1) the ability to use at any given time, only one armature winding of this coil is s leads to fluctuations of the electromagnetic torque and the inability to start the engine in the position of the anchor, corresponding to the moment of switching of windings, because the magnetic moment is almost zero, poor use of copper windings and, consequently, decrease efficiency;

2) the mechanical switch does not allow you to use a DC machine with high voltages (more than 1500);

3) arcing is not completely eliminated, because between the segment under the brush and adjacent segments of the split ring, there is a potential difference;

4) modes of operation of this machine is very limited.

The problem to which the invention is directed, is to increase the capability of DC machine, in order while maintaining all the positive qualities inherent in machines of direct current commutator type, it would ensure the achievement of the following technical results:

1) the ability to use DC machines of large capacity with high voltages;

2) complete elimination of the collector mechanism, and consequently, arcing, RFI, noise;

3) improving the regulating characteristics;

4) the ability to use the machine in different modes;

5) simplification of the manufacture of the armature of the machine;

6) improving the efficiency of DC machine.

The task is solved in that the stated DC machine, containing the I the stator, fixed on the shaft of the armature winding, the contact device made in the form of separated insulated conductive rings in contact with the brushes for the supply and withdrawal of current from the beginning and end of the windings of the armature and bearing shields, further comprises a semiconductor switch, comprising bipolar transistors and resistors between the electrodes of the emitter and base associated with the entered device management containing brushes, receiving the control signal, brush, feed control signal, and also attached to the shaft and electrically insulated from it two rings, one of which is made of solid conductive material, and the other with cuts dividing it into two parts, with one part of a split ring made of a conductive material and electrically connected with a solid ring control device, and the other of an insulating material, each of the devices receiving the control signal, is installed with the possibility of contact with the split ring and connected with a control electrode of the semiconductor switch elements, and brush applying a control signal which is installed with the possibility of contact with a solid ring control device and electrically connected to the receiving signal brushes at the moment of contact the conductive part of the split rings with these brushes, if e is ω pin device made in the form of four continuous conductive rings, one of which is connected to the start winding of the armature and each of the remaining solid rings connected to the ends of the respective windings. Part of the split ring of conductive material is made in the form of a segment of 120°, while the number of brushes, receiving the control signal, is six, and the angles between the brushes 60°. DC machine further comprises a switch that is installed with the possibility of switching the positive pole of the supply network from the semiconductor switch to the windings by means of a continuous conductive ring contact device and brushes for the supply and withdrawal of current from the beginning of the windings of the armature.

Currently, there are very powerful semiconductor device capable of switching circuits with a voltage up to 6.5 kV, while the collector of the conventional DC machines are able to operate with voltage only up to 1.5 kV. Therefore, the collector DC machine of large capacity are forced to work with very large values of current, which leads to significant power losses and expenses of conducting and insulating materials. The use of a semiconductor switch allows you to increase the value of the voltage supply line of the engine or the voltage at the terminals of the generator. Although the execution of the armature winding claimed the machines the color corresponds to the prototype, yet there is a difference, namely, that the current in the armature windings is variable. This allows the use of two armature windings simultaneously and, therefore, reduce the electromagnetic torque ripple. Moreover, this efficient use of the windings increases the efficiency of the machine, as supplied current at any point in time flows not one winding and two (less electrical losses).

Replacement collector, perform the function of a mechanical transducer that eliminates arcing, since the semiconductor switch does not cause absolutely no sparking. However, in the inventive machine is a device control switch, which, as a collector, performs switching by mechanical means, but it works with very low values of current and voltage supplied only to the control electrodes of semiconductor elements.

Currently developed electrical steel, which greatly reduce the saturation of the magnetic circuit, as in conventional machines of large capacity loss hysteresis are lower values on the capacity of machines than machines of small and medium capacities.

The improved regulating characteristics is achieved in that the semiconductor cell battery (included) which you can change the value of the supplied their signal when changing the firing angle of their control electrode.

Given in the invention of the bridge circuit allows the use of a DC motor as in intermittent modes, and long-term. Intermittent mode requires a more smooth increase in torque at start-up and its smooth descending when braking. In this mode, an invalid ripple torque and, therefore, it is necessary to involve the maximum number of windings to reduce miscomputation period. For continuous smooth it is necessary to provide only at start-up. After acceleration of the engine may increase miscomputation period off three transistors. As a result, the current in the windings of the armature is distributed similarly to the current in the armature windings of the prototype: in each moment of time involved only one winding and the current in it is always positive. Disconnect the three transistors in continuous mode leads to the elimination of hysteresis loss.

The simplification of the manufacture of the inventive machine is due to the fact that the technology for manufacturing of windings of the armature is much easier than making an annular armature winding traditional DC machines.

1 shows a DC machine, side view, with a slit upper parts; figure 2 - device control semiconductor switch, the view from the CMOS; figure 3 - cross section a-a in figure 2; figure 4 is a circuit diagram DC machine; figure 5, 6, 7 - change the direction of the current in the windings of the armature, when they pass through the poles of the field windings; Fig shows a graph of torque DC machine depending on the angle of rotation of the armature; figure 9 is a wiring diagram of the transistor using an independent source; figure 10 is a wiring diagram of the transistor with the positive pole of the supply network.

DC machine consists of a stationary and rotating parts (figure 1). The stationary part (stator) includes steel frame 1 on which are mounted the pole 2. At the poles 2 are coil 3 field windings, circuit connections are similar schemes in machines of direct current conventional designs. The rotating part of the machine consists of a attached to the shaft 4 of the armature 5 with the winding 6, the contact device 7 with three round rings 8 and one solid ring 9, separated by insulation 10, the control unit 11 of the semiconductor switch 12, containing the split ring 13 with two sections and a continuous ring 14. The shaft 4 anchor 5 is located at a bearing shields 15. The armature winding 5 is carried out by three winding coils according to the variant of a simple loop winding. On the machine casing also find the camping box 16 for placing the semiconductor switch 12.

The ring 14 of the device 11 controls the semiconductor switch 12 is made of solid conductive material, and the other ring 13 is divided into parts 17 and 18, with part 17 made of a conductive material, and the part 18 of an insulating material. Part 17 of conductive material split ring 13 is electrically connected with a solid ring 14 by means of a strap 19. Both rings 13 and 14 are insulated from the shaft 4 and fixed on it by means of the insulator 20. Figure 3 also shows the opening 21 to accommodate the shaft.

The electrical circuit (figure 4) includes a semiconductor switch 12, consisting of six transistors V_IV_IIV_iiiV_IVV_Vand V_VIn-p-n type resistors R_I, R_II, R_III, R_IV, R_Vand R_VIconnected between the emitter electrodes and base, brush 22 for feeding and removing current from the ends a', b' and C' of the windings 6 (a, b and C) armature 5 through continuous ring 8 of the contact device 7, the brush 23 for feeding and removing the current began with a, b and C windings 6 (a, b and C) armature 5 through a solid ring 9 of the contact device 7, the control device 11 of the semiconductor switch 12, the switch 24, which is designed to switch the positive pole of the network from the switch 12 to the windings 6 by means of a continuous conductive ring 9 and the brush 23 for feeding and removing the first current windings of the armature. The device 11 controls the semiconductor switch 12, in turn, consists of six brushes I, II, III, IV, V and VI, one brush VII and placed on the shaft 4 split 13 and solid 14 rings. Brush VII constantly in contact with the solid surface of the ring 14 and delivers the control signal to the switch 12 (schemes connections brushes VII with a control electrode of the transistor shown in Fig 9 and 10), and brushes (I, II, III, IV, V and VI in contact with the conductive part 17 split ring 13 take control signal and pass it through a wire (not shown) on the control electrode of the semiconductor switch element 12.

Changing the direction of the current in the windings 6 of the armature 5 when changing its position relative to the poles 2, due to the operation of the switch 12 in conjunction with the device 11 of his control, shown in figure 5, 6, 7.

The schedule change time machine depending on the angle of rotation of the armature 5 is presented on Fig, where the rotation of the armature 5 and, accordingly, the rotation of the conductive segment 17 split ring 13, at every 60° (miscomputation period) opens and closes a single transistor. However, any transistor remains open during the rotation of the armature 5 to 120°. Therefore, as shown in Fig, in each miscomputation period involved two transistors that are listed in the cells above the graph, and two ammo the key. For example, the open state of the transistors V_IIIand V_IVcorresponds to the work of the windings a and C.

Figure 5, above, presents the position of the anchor, which involved the brush IV, the input signal to the control electrode of the transistor V_IV. The wiring diagram and principle of the control transistor in this case is seen in figures 9 and 10. Figures 9 and 10 differ in that figure 9 shows a diagram of the connections of the transistor, where the source of the control transistor V_IVan independent power source with a voltage U_NETWORKand figure 10 the control signal is supplied from the mains through a limiting resistor R_Ogredesigned to reduce the capacity of the supply network. The second option scheme (figure 10) does not require any additional power source, however, this scheme may only be used for machines low voltage. This is due to the difficulty of obtaining the control signal with a low current from the high voltage source. In figures 9 and 10 is considered a transfer control signal when the conductive contact part 17 split ring 13 with brushed IV. When this control signal opens the transistor V_IVand through the winding And armature 5 passes current mains voltage u_network. After rotation of the armature 5 and, therefore, the control unit 11 of 60° with the PTO is the contact conductive portion 17 and brush V _IVconductive portion 17 of the split ring 13 is in contact with the brush III, thus opening the transistor V_III(not shown).

The work of the DC machine is as follows. When passing a conducting segment 17 split ring 13 of the device 11 of the control switch 12 under the same brush, receiving the control signal, opens the transistor switch 12, the control electrode of which is connected with this brush. As the angle conductive segment 17 split ring 13 is 120°, and the angles of arrangement of the brushes, the receiving signal is 60°, miscomputation period involved two transistors and, accordingly, two windings, circuit switched these transistors, the current flows in one coil flows from other flows. Through the resistors R_I, R_II, R_III, R_IV, R_Vand R_VI, each of which is placed between the electrodes of the emitter and base of the respective transistor, the control electrode (base) is the locking signal. For example, when the conductive contact segment 17 split ring 13 with brushes III and IV (figure 5) is opened transistors V_IIIand V_IV. Consequently, the current flows in the windings and is derived from a winding of A. In motor mode when passing these windings under the poles 2 of them on the force, the direction of which is determined by the rule of the left hand", and in the generator mode according to the rule of "right hand". When removing the control signal through the resistors R_III, R_IVthe base electrode is supplied locking signal and the transistors V_IIIand V_IVclosed. The principle of commutation of the windings 6 of the armature 5 in the generator mode is performed in the same way, when the switch 12 performs the function of the rectifier, that is, it rectifies the alternating current winding 6 of the armature 5. As in the winding 6 of the armature 5 always runs alternating current, electromagnetic conversion declared machine is similar to the traditional machines, DC. Open armature coil 6 5 (S=0) the magnetic field in the machine is created only MDS winding 3 of excitation at which current flows V During the rotation of the armature 5 in the winding 6 Indochinese variable EMF. When the machine is loaded and running in motor mode or generator (S≠0), the magnetic field is created by the joint action of MDS winding 3 excitation and MDS winding 6 of the armature 5. When operating in the motor mode, EDS inductively in the winding 6 of the armature 5 is less than the supply voltage, the constant current switch 12 is converted to AC and fed to the coils 6 of the armature 5, and the electric energy received from the network is converted into mechanical energy transmitted through the shaft 4 paired with the mechanism. When working generatorname mode EMF more than the supply voltage, the armature current 5 when this is rectified via a switch 12 and fed into the network, and the mechanical energy supplied through the shaft 4 of the machine, is converted into electrical energy.

In this machine diagram of the switch 12 is made with the possibility of switching transistors V_IV_IIV_IIIswitch 24. With a significant acceleration of the DC motor the switch 24 allows to obtain the distribution of the currents in the windings 6 of the armature 5 similarly, car DC Ishibashi and, consequently, to eliminate losses by hysteresis. This is done by switching the positive pole of the supply network from the switch 12 to the winding 6 by means of a continuous conductive ring 9 and the brush 23 for feeding and removing current from the beginning of the windings of the armature. In this case, no current flows through the first three transistor and miscomputation period winding is 120°.

The use of the claimed machine enables the use of direct current for transmission lines that transmit electricity over long distances, thus reducing the material used in the wires, as you only need two wires with a smaller effective cross-section.

1. DC machine containing a stator fixed on the shaft of the armature winding, the contact device made in the form of ustelennyh insulated conductive rings, in contact with the brushes for the supply and withdrawal of current from the beginning and end of the windings of the armature and bearing shields, characterized in that the machine further comprises a semiconductor switch, comprising bipolar transistors and resistors between the electrodes of the emitter and base associated with the entered device management containing brushes, receiving the control signal, brush, feed control signal, and also attached to the shaft and electrically insulated from it two rings, one of which is made of solid conductive material, and the other with cuts, divides it into two parts, with one part of the split rings made of conductive material and electrically connected with the solid ring control device, and the other of an insulating material, each of the devices receiving the control signal, is installed with the possibility of contact with the split ring and connected with a control electrode of the semiconductor switch elements, and brush applying a control signal which is installed with the possibility of contact with a solid ring control device and electrically connected to the receiving signal brushes at the moment of contact the conductive part of the split rings with these brushes, with the contact device is designed as four continuous conductive rings, one of which is connected to the start winding of the armature, and with each of the remaining continuous conductive rings are connected to the ends of the respective windings.

2. DC machine according to claim 1, characterized in that the number of brushes, receiving the control signal, is six, and the angles between the brushes 60°, while the portion of the split ring of conductive material is made in the form of a segment of 120°.

3. DC machine according to claim 1, characterized in that the machine further comprises a switch that is installed with the possibility of switching the positive pole of the supply network from the semiconductor switch to the windings by means of a continuous conductive ring contact device and brushes for the supply and withdrawal of current from the beginning of the windings of the armature.