Synchronous self-excitation generator magnets. Synchronous generators with permanent magnets. Principle of operation of devices

Content:

IN modern conditions Permanent attempts are being made to improve electromechanical devices, reduce their mass and overall dimensions. One of these options is a generator on permanent magnets, which is sufficient simple design With a high efficiency. The main function of these elements is to create a rotating magnetic field.

Types and properties of permanent magnets

For a long time, permanent magnets obtained from traditional materials were known. In industry, the alloy, nickel and cobalt (Alnic) began to be used for the first time. This made it possible to apply constant magnets in generators, engines and other types of electrical equipment. Ferrite magnets received especially widespread.

Subsequently, Samary-cobalt hard magnetic materials were created, the energy of which has high density. Following them, the discovery of magnets based on rare earth elements - boron, iron and neodymium. The density of their magnetic energy is significantly higher than the samarium-cobalt alloy at a significantly low cost. Both types artificial materials Successfully replace the electromagnets and are used in specific areas. Ease elements relate to the materials of the new generation and are considered the most economical.

Principle of operation of devices

The main problem of the structure was considered the return of rotating parts in its original position without significant loss of torque. This problem was solved with the help of a copper conductor, according to which the electric current caused by attraction was passed. When the current is disconnected, the attraction action stopped. Thus, in devices of this type, a periodic switching on-shutdown was used.

The increased current creates an increased strength of attraction, and the one, in turn, is involved in the current exercise passing through the copper conductor. As a result of cyclic actions, device, except for mechanical work, Begins to produce an electric current, that is, perform the functions of the generator.

Permanent magnets in generator designs

In constructs of modern devices except permanent magnets Electromagnets are used in the coil. This function of combined excitation allows you to obtain the necessary adjusting characteristics of the voltage and speed of rotation at low excitation power. In addition, the magnitude of the entire magnetic system decreases, which makes such devices are much cheaper compared to the classic structures of electrical machines.

The power of the devices in which these elements can be only a few kilovolt amps. Currently, the development of permanent magnets with better indicators providing gradual power increases. Similar synchronous machines Used not only as generators, but also as engines of various purposes. They are widely used in the mining and metallurgical industries, thermal stations and other fields. This is related to the possibility of operation of synchronous motors with different reactive capacities. They themselves work with accurate and constant speed.

Stations and substations function together with special synchronous generators, which in idle mode provide only reactive power generation. In turn, ensures the work of asynchronous engines.

The generator on permanent magnets works on the principle of interaction of magnetic fields of the moving rotor and a fixed stator. Not to the end, the studied properties of these elements allow us to work on the invention of other electrical devices, up to the creation of illegal.

The present invention relates to the field of electrical engineering, namely to the unhealthy electric machines, in particular, electrical generators direct currentand can be used in any field of science and technology where autonomous power supplies are required. Technical result - the creation of a compact highly efficient electric generatorwhich allows you to preserve a relatively simple and reliable design to vary widely vary the output parameters of the electric current depending on the operating conditions. The essence of the invention is that a uncommunicative synchronous generator with permanent magnets consists of one or more sections, each of which includes a rotor with a circular magnetic circuit, on which an even number of permanent magnets is fixed with the same step, the stator carrying an even number of horseshoe electromagnets located in pairs is fixed. opposite each other and having two coils with a consistently counter direction of winding, a device for straightening the electric current. Permanent magnets are fixed on a magnetic lines in such a way that they form two parallel rows of poles with a longitudinally and transversely alternating polarity. The electromagnets are focused across the title poles so that each of the electromagnet coils is located above one of the parallel rows of the poles of the rotor. The number of poles in one row, equal to N, satisfies the relation: n \u003d 10 + 4k, where k is an integer taking values \u200b\u200bof 0, 1, 2, 3, etc. The number of electromagnets in the generator usually does not exceed the number (N-2). 12 Z.P. F-lies, 9 yl.

Patents to the Patent Patent 2303849

The present invention relates to undercoltor electric machines, in particular DC electric generators, and can be used in any area of \u200b\u200bscience and technology where autonomous power supplies are required.

Synchronous AC machines were widely distributed both in the field of production and in the sphere of electric power consumption. All synchronous machines have a property of reversibility, that is, each of them can work both in the mode of the generator and in the engine mode.

Synchronous generator It contains a stator, usually a hollow elevated cylinder with longitudinal grooves on the inner surface, in which the stator winding is located, and the rotor, which is the permanent magnets of the alternating polarity, located on the shaft, which can be driven in one way or another. In industrial high-power generators, an excitation winding located on the rotor is used to obtain an excitation magnetic field. In synchronous generators with respect to low power, constant magnets located on the rotor are used.

With the unchanged rotation frequency, the form of the EDC curve generated by the generator is determined only by the law of the distribution of magnetic induction in the gap between the rotor and the stator. Therefore, to obtain a voltage at the output of the generator of a certain form and to effectively convert the mechanical energy to the electrical use of various geometry of the rotor and the stator, and also select the optimal number of constant magnetic poles and the number of turns of the stator winding (US 5117142, US 5537025, DE 19802784, EP 0926806, WO 02/003527, US 2002153793, US 2004021390, US 2004212273, US 2004155537). The listed parameters are not universal, but are selected depending on the operating conditions, which often leads to the deterioration of other characteristics of the electric generator. In addition, the complex form of the rotor or stator complicates the manufacture and assembly of the generator and, as a result, increases the cost of the product. Rotor synchronous magnetoelectric generator may have various shapesFor example, when low power The rotor is usually performed in the form of "asterisks", with medium power - with clawing poles and cylindrical permanent magnets. The rotor with clawed poles makes it possible to obtain a generator with scattering of poles that limits the shock current with a sudden short circuit of the generator.

In permanent magnet generator, stabilization of the voltage is difficult when the load changes (since there is no reverse magnetic connection, such as, for example, in the excitation winding generators). To stabilize the output voltage and rectify current use various electrical circuits (GB 1146033).

The present invention is directed to the creation of a compact highly efficient electrical generator, which allows, while maintaining a relatively simple and reliable design, the output parameters of the electric current will vary widely depending on the operating conditions.

The electric generator, made in accordance with the present invention, is a bulk synchronous generator with permanent magnets. It consists of one or more sections, each of which includes:

The rotor with a circular magnetic core, on which an even number of permanent magnets is fixed with the same step,

The stator carrying an even number of horseshoe (P-shaped) electromagnets located in pairs opposite each other and having two coils with a consistently counter direction of the winding,

Electric current straightening device.

Permanent magnets are fixed on a magnetic lines in such a way that they form two parallel rows of poles with a longitudinally and transversely alternating polarity. The electromagnets are focused across the title poles so that each of the electromagnet coils is located above one of the parallel rows of the poles of the rotor. The number of poles in one row, equal to N, satisfies the relation: n \u003d 10 + 4k, where k is an integer taking values \u200b\u200bof 0, 1, 2, 3, etc. The number of electromagnets in the generator usually does not exceed the number N-2.

The current straightening device is usually one of the standard rectifier circuits performed on diodes: two-speech-free with a midwater or bridge connected to the windings of each electromagnet. If necessary, a different current straightening scheme can also be used.

Depending on the features of the operation of the electric generator, the rotor can be located both from the outer side of the stator and inside the stator.

The electric generator made in accordance with the present invention may include several identical sections. The number of such sections depends on the power of the mechanical energy source (drive motor) and the required parameters of the electric generator. Preferably, the sections are shifted by phase relative to each other. This can be achieved, for example, the initial shift of the rotor in adjacent sections at an angle lying in the range from 0 ° to 360 ° / N; or the corner shift of the stator electromagnets in adjacent sections relative to each other. Preferably, the electric generator also includes a voltage regulator unit.

The invention is illustrated by the following drawings:

figure 1 (a) and (b) shows the electrical generator scheme made in accordance with the present invention, in which the rotor is located inside the stator;

figure 2 shows the image of one section of the electric generator;

figure 3 presents the principal electrical circuit electric generator with two-speech-mode with an average point of current straightening circuit;

figure 4 shows the electrical circuit diagram of the electric generator with one of the bridges of the current straightening;

figure 5 presents a circuitral circuit diagram of an electric generator with another bridge scheme for rectifying current;

figure 6 presents the electrical circuitry of the electric generator with another bridge scheme for rectifying the current;

figure 7 presents a circuitral circuit diagram of an electric generator with a different bridge scheme for rectifying current;

figure 8 shows a diagram of an electric generator with an external execution of the rotor;

figure 9 presents the image of a multisective generator made in accordance with the present invention.

Figure 1 (a) and (b) shows the electric generator, made in accordance with the present invention, which contains a housing 1; Rotor 2 with circular magnetic pipe 3, on which the even number of permanent magnets 4 is fixed with the same step; Stator 5, carrying an even number of horseshoe electromagnets 6, located in front of each other, and the tool for straightening the current (not shown).

The housing 1 of the electric generator is usually cast from an aluminum alloy or cast iron or welded. Installation of the electric generator at the place of its installation is carried out by means of paw 7 or by means of a flange. Stator 5 has a cylindrical interior surfaceon which identical electromagnets 6 are attached with the same step. In this case, ten. Each of these electromagnets has two coils 8 with a successively counter direction of the winding located on a P-shaped core 9. The core of the core 9 is assembled from the peeled plates of the electrical steel on the adhesive or grips. The conclusions of the windings of electromagnets through one of the rectifier circuits (not shown) are connected to the output of the electric generator.

The rotor 3 is separated from the stator by the air gap and carries an even number of permanent magnets 4, arranged in such a way that two parallel rows of poles are formed equid to the axis of the generator and alternating along polarity in the longitudinal and transverse directions (Figure 2). The number of poles in one row satisfies the relation: n \u003d 10 + 4k, where k is an integer taking values \u200b\u200bof 0, 1, 2, 3, etc. In this case (Figure 1) n \u003d 14 (k \u003d 1) and, accordingly, the total number of permanent magnetic poles is 28. When the electric generator rotates, each of the coils of electromagnets passes over the corresponding number of alternating poles. Permanent magnets and electromagnet cores have the form such to minimize losses and achieve homogeneity (as far as possible) the magnetic field in the air gap during the operation of the electric generator.

The principle of operation of the electric generator made in accordance with the present invention is similar to the principle of operation of a traditional synchronous generator. The rotor shaft is mechanically connected to the drive motor (source of mechanical energy). Under the action of the rotating moment of the drive motor, the generator rotor rotates at some frequency. At the same time, in the winding of the coils of electromagnets in accordance with the phenomenon of electromagnetic induction, EMC is guided. Since the coils of an individual electromagnet have a different winding direction and are at any time in the area of \u200b\u200baction of various magnetic poles, the emf is in each of the windings.

In the process of rotating the rotor, the magnetic field of the constant magnet rotates at some frequency, so each of the windings of the electromagnets alternately turns out in the zone of the northern (N) magnetic pole, then in the zone of the southern (s) magnetic pole. At the same time, the change of pole is accompanied by a change in the direction of EDC in the windings of electromagnets.

The windings of each electromagnet are connected to the current straightening device, which is usually one of the standard rectifier circuits performed on diodes: two-floweriodic with an average point or one of the bridge circuits.

Figure 3 presents the conceptual electrical diagram of a two-speech rectifier with an average point for an electric generator with three pairs of electromagnets 10. FIG. 3, electromagnets are numbered from i to vi. One of the conclusions of the winding of each electromagnet and the output of the winding of the opposite electromagnet with it are connected to one generator output; Other conclusions of the windings of the named electromagnets are connected through diodes 11 to another generator output 13 (with this inclusion of diodes, the output 12 will be negative, and the output is 13 positive). That is, if the start of the winding (B) is connected to the negative bus for the electromagnet, then the end of the winding (E) is connected to the opposite electromagnet to it. Similarly for other electromagnets.

Fig. 4-7 presents different bridge circuits for rectifying current. The connection of bridges, straightening the current from each of the electromagnets, can be parallel, consistent or mixed. At all various schemes Used to redistribute the output current and potential characteristics of the electric generator. The same electric generator, depending on operating modes, can have one or another straightening scheme. Preferably, the electrical generator contains an optional switch to select the desired mode of operation (bridge connection scheme).

Figure 4 shows the electrical circuit diagram of the electric generator with one of the bridge schemes of the current straightening. Each of the electromagnets I-VI is connected to a separate bridge 15, which in turn are connected in parallel. The total tires are connected respectively to the negative output of 12 of the electric generator or to positive 13.

Figure 5 presents an electrical circuit with a serial connection of all bridges.

Fig. 6 shows an electrical circuit with a mixed compound. Bridges, straightening current from electromagnets: I and II; III and IV; V and VI are connected in pairwise. And the pairs in turn are connected in parallel through the total tires.

Figure 7 presents a circuit electrical circuit of an electric generator, in which a separate bridge straightens the current from the pair of diametrically opposite electromagnets. For each pair of diametrically opposite electromagnets, the conclusions (in this case "B") are electrically interconnected, and the remaining conclusions are connected to the straightening bridge 15. The total number of bridges is M / 2. Broadcast bridges can be connected in parallel and / or sequentially. Figure 7 shows a parallel connection of bridges.

Depending on the features of the operation of the electric generator, the rotor can be located both from the outer side of the stator and inside the stator. Figure 8 shows a diagram of an electric generator with an outer version of the rotor (10 electromagnets; 36 \u003d 18 + 18 permanent magnets (k \u003d 2)). The design and principle of the operation of such an electric generator are similar to those described above.

The electric generator made in accordance with the present invention may include several sections A, B and C (FIG. 9). The number of such sections depends on the power of the mechanical energy source (drive motor) and the required parameters of the electric generator. Each of the sections corresponds to one of the designs described above. The electric generator may include both identical sections and sections that differ from each other by the number of permanent magnets and / or electromagnets or straightening scheme.

Preferably, the identical sections are shifted by phase relative to each other. This can be achieved, for example, the initial shift of the rotor in adjacent sections and the angular shift of the stator electromagnets in the adjacent sections relative to each other.

Examples of implementation:

Example 1. In accordance with the present invention, an electric generator was made to supply electrical appliances to a voltage to 36 V. The electric generator was made with a rotating outer rotor, on which 36 permanent magnets were placed (18 in each row, k \u003d 2) made from FE-ND alloy -IN. The stator carries 8 pairs of electromagnets, each of which has two coils containing 100 turns of the PTTV wire with a diameter of 0.9 mm. The inclusion circuit is bridge, with a compound of the same conclusions of diametrically opposite electromagnets (Fig. 7).

outer diameter - 167 mm;

output voltage - 36 V;

maximum current - 43 A;

power - 1.5 kW.

Example 2. In accordance with the present invention, an electric generator was made to recharging power supplies (pair of batteries by 24 V) for urban electric vehicles. The electric generator is made with a rotating inner rotor, which contains 28 permanent magnets (14 in each row, k \u003d 1) made from the FE-ND-B alloy. The stator carries 6 pairs of electromagnets, each of which has two coils containing 150 turns wound by the PTTV wire with a diameter of 1.0 mm. The inclusion scheme is a two-speech-mode with an average point (figure 3).

The electric generator has the following parameters:

outer diameter - 177 mm;

the output voltage is 31 V (for charging 24 in the battery block);

maximum current - 35a,

maximum power - 1.1 kW.

Additionally, the electric generator contains an automatic voltage regulator by 29.2 V.

CLAIM

1. An electric generator containing at least one circular section comprising a rotor with a circular magnetic core, on which an even number of permanent magnets forming two parallel rows of poles with longitudinally and transversely alternating polarity are fixed, the stator carrying an even number of horseshoe electromagnets located pairwise opposite each other, a device for straightening the electric current, where each of the electromagnets has two coils with a consistently counter direction of the winding, while each of the coils of electromagnets is located above one of the parallel rows of the rotor poles and the number of poles in one row equal to N satisfies By relationship

n \u003d 10 + 4k, where k is an integer taking values \u200b\u200b0, 1, 2, 3, etc.

2. The electric generator according to claim 1, characterized in that the number of electromagnets of the stator M satisfies the ratio M n-2.

3. The electric generator according to claim 1, characterized in that the device for straightening the electric current contains diodes connected to, at least one of the terminals of the windings of electromagnets.

4. The electric generator according to claim 3, characterized in that the diodes are connected via a two-speech-mode with an average circuit.

5. The electric generator according to claim 3, characterized in that the diodes are connected along the pavement scheme.

6. The electric generator according to claim 5, characterized in that the number of bridges is M, and they are interconnected in series, or in parallel, or sequentially parallel.

7. The electric generator according to claim 5, characterized in that the amount of bridges is M / 2 and one of the same outputs of each pair of diametrically opposite electromagnets are connected, while others are connected to one bridge.

8. The electric generator according to any one of claims 1 to 7, characterized in that the rotor is located on the outside of the stator.

9. The electric generator according to any one of claims 1 to 7, characterized in that the rotor is located inside the stator.

10. The electric generator according to claim 1, characterized in that it contains at least two identical sections.

11. The electric generator according to claim 10, characterized in that at least two sections are shifted by phase relative to each other.

12. The electric generator according to claim 1, characterized in that it contains at least two sections that differ in the number of electromagnets.

13. The electric generator according to claim 1, characterized in that further contains the voltage regulator unit.

Synchronous machines with permanent magnets (magnetoelectric) do not have an excitation winding on the rotor, and the exciting magnetic flux is created by permanent magnets located on the rotor. The stator of these machines of the usual design with a two- or three-phase winding.

Apply these machines most often as low power engines. Synchronous permanent magnet generators are applied less often, mainly as autonomously working heightened frequency generators, small and medium power.

Synchronous magnetoelectric motors. These engines were distributed in two design versions: with radial and axial location of permanent magnets.

For radial location Permanent magnets The rotor package with a pad, made in the form of a hollow cylinder, is fixed on the outer surface of the express poles of the permanent magnet 3. In the cylinder make interpole slots that prevent the closure of the flow of a constant magnet in this cylinder (Fig. 23.1,).

For axial location Magnets The rotor design is similar to the design of the rotor asynchronous short-circuit engine. Ring constant magnets are pressed to the ends of this rotor (Fig. 23.1, ).

The axial arrangement of the magnet is used in low-diameter engines with power up to 100 W; The designs with the radial arrangement of magnets are used in larger diameter engines with a capacity of up to 500 W and more.

The physical processes occurring in the asynchronous start of these engines have some feature due to the fact that magnetoelectric motors are allowed in the excited state. The field of a permanent magnet in the process of overclocking the rotor brings in the winding of the stator EMF
, the frequency of which increases in proportion to the rotor rotation frequency. This EMF leads in the winding of the stator current, interacting with the field of permanent magnets and creating brakemoment
, directed to the rotation of the rotor.

Fig. 23.1. Magnetoelectric synchronous motors with radial (a) and

axial (b)location of permanent magnets:

1 - Stator, 2 - short-circuited rotor, 3 - permanent magnet

Thus, when the engine is accelerated with permanent magnets, two asynchronous moments act on its rotor (Fig. 23.2): Rotating
(from current , acting into the winding of the stator from the network) and brake
(from current induced in the winding of the constant magnet stator).

However, the dependence of these moments from the rotor speed (slip) is different: maximum torque
corresponds to a significant frequency (slightly slip), and maximum braking torque M. T. - low speed (big slide). The rotor acceleration occurs under the action of the resultant
which has a significant "failure" in the zone of small speed. From the curves shown in the figure, it can be seen that the influence of the moment
on the starting properties of the engine, in particular at the time of entry into synchronism M. vK , much.

To ensure reliable engine startup, it is necessary that the minimum resulting torque in asynchronous mode
and the moment of entry into synchronism M. vK , there were more points of load. The form of an asynchronous moment of magnetoelectric

Fig.23.2. Graphs asynchronous moments

magnetoelectric synchronous engine

the engine largely depends on the active resistance of the starting cell and on the degree of excitation of the engine characterized by the magnitude
where E. 0 - EMF of the phase of the stator, induced in idle mode when rotating the rotor with a synchronous frequency. With increasing "Failure" in the moment curve
increases.

Electromagnetic processes in magnetoelectric synchronous motors are in principle similar to processes in synchronous electromagnetic excitation engines. However, it is necessary to bear in mind that constant magnets in magnetoelectric machines are subject to demagnetizing the effect of the magnetic flow of the anchor reaction. The starting winding somewhat weakens this demagnetization, as shielding effects on permanent magnets.

The positive properties of magnetoelectric synchronous motors are increased stability of operation in synchronous mode and the uniformity of the speed of rotation, as well as the ability to simply rotate multiple engines included in one network. These engines have relatively high energy indicators (efficiency and
,).

The disadvantages of magnetoelectric synchronous motors are increased value compared with synchronous engines of other types, due to the high cost and complexity of treating permanent magnets performed from alloys with a large coercive force (Alni, Alnico, Magno et al.). These engines are usually made on low power and used in instrument making and automatic devices to drive mechanisms that require constancy of the rotational speed.

Synchronous magnetoelektrically generators. The rotor of such a generator is performed at low power as a "asterisk" (Fig. 23.3, but), with an average power - with clawed poles and a cylindrical permanent magnet (Fig. 23.3, b).The rotor with clawed poles makes it possible to obtain a generator with scattering of poles that limits the shock current with a sudden short circuit of the generator. This current is a greater danger to a permanent magnet due to a strong demagnetizing effect.

In addition to the disadvantages noted when considering magnetoelectric synchronous motors, permanent magnet generators have another disadvantage due to the lack of an excitation winding, and therefore the voltage adjustment in magnetoelectric generators is almost impossible. This makes it difficult to stabilize the voltage of the generator when the load changes.

Fig.23.3. Rotors of magnetoelectric synchronous generators:

1 - shaft; 2 - permanent magnet; 3 - Pole; 4 - Non-magnetic sleeve

Dmitry Levkin

The main difference between each synchronous engine with permanent magnets (SDPM) and lies in the rotor. Studies show that SDPM has about 2% more than highly efficient (IE3) asynchronous electric motor, provided that the stator has the same design, and the same is used to control. At the same time, synchronous electric motors with permanent magnets compared to other electric motors have better indicators: power / volume, moment / inertia, etc.

Constructions and types of synchronous electric motor with permanent magnets

The synchronous motor with permanent magnets, as any, consists of a rotor and a stator. The stator is a fixed part, the rotor is a rotating part.

Typically, the rotor is located inside the stator of the electric motor, there are also structures with an external rotor - trading electric motors.


Constructions of a synchronous engine with permanent magnets: the left is standard, the right is converted.

Rotor consists of permanent magnets. Materials with high coercive force are used as permanent magnets.

    By the design of the rotor, synchronous engines are divided into:

The electric motor with implicitly expressed poles has an equal inductance along the longitudinal and transverse axes L d \u003d L Q, while at the electric motor with explicitly pronounced poles, the transverse inductance is not equal to the longitudinal L Q ≠ L d.


The cross section of the rotors with a different attitude of LD / LQ. Black margins marked. In Figure D, E presented axially stratified rotors, in the figure B and s depicted rotors with barriers.

Synchronous Motor Rotor with Surface Installation of Permanent Magnets

Rotor synchronous motor with built-in magnets

Stator Consists of a hull and core with winding. The most common designs with a two- and three-phase winding.

    Depending on the stator design, the synchronous engine with permanent magnets happens:
  • with distributed winding;
  • with a concentrated winding.

Distributed They call such a winding, in which the number of grooves per pole and the phase Q \u003d 2, 3, ...., k.

Concentrated They call such a winding, in which the number of grooves per pole and the phase Q \u003d 1. In this case, the grooves are uniformly in the circumference of the stator. Two coils forming the winding can be connected both in succession and in parallel. The main disadvantage of such windings is the impossibility of influence on the form of the EDC curve.

Scheme of three-phase distributed winding


Scheme of three-phase concentrated winding

    Form of reverse EMF The electric motor can be:
  • trapezoidal;
  • sinusoidal.

The form of the EDC curve in the conductor is determined by the magnetic induction distribution curve in the gap in the circumference of the stator.

It is known that magnetic induction in the gap under a pronounced pole of the rotor has a trapezoidal form. The same form has a fit in EMF conductor. If it is necessary to create a sinusoidal EMF, then the pole tips attach such a form at which the induction distribution curve would be close to sinusoidal. This contributes to the squeaks of the pole rotor tips.

The principle of operation of the synchronous motor is based on the interaction of the stator and the constant magnetic field of the rotor.

Run

Stop

Rotating magnetic field of synchronous motor

The magnetic field of the rotor, interacting with the synchronous alternating current of the stator winding, according to, creates, forcing the rotor to rotate ().

Permanent magnets located on the Rotor SDPM create a constant magnetic field. With a synchronous rotor speed with a stator field, the rotor pole is unlocked with a rotating magnetic field of the stator. In connection with this, the SDPM cannot start when it is connected directly to the three-phase current network (current frequency in 50 Hz).

Control of the synchronous engine with permanent magnets

For the operation of a synchronous motor with permanent magnets, a control system is required, for example, or a servo. In this case, exists a large number of Methods of managing control implemented by control systems. Choice optimal method Management mainly depends on the task that is placed in front of the electric drive. Basic management methods synchronous electric motor With permanent magnets, are shown in the table below.

Control Benefits disadvantages
Sinusoidal Simple control scheme
With position sensor Smooth and accurate installation of the position of the rotor and speed of rotation of the engine, a large range of regulation Requires a rotor position sensor and a powerful control system microcontroller
Without position sensor No rotor position sensor is required. Smooth and accurate installation of the position of the rotor and the speed of rotation of the engine, a large range of regulation, but less than with a position sensor Dummy Pole-oriented Management in the entire speed range It is possible only for SDPM with a rotor with explicit poles, a powerful control system is required.
Simple management scheme, good dynamic characteristics, large range of regulation, no rotor position sensor High pulsations torque and current
Trapezdal Without feedback Simple control scheme Management is not optimal, not suitable for tasks, where the load changes, manageability is possible.
FROM feedback With position sensor (Hall sensors) Simple control scheme Wanted Hall Sensors. There are moment pulsations. Designed to control the SDPM with a trapezdinal reverse EMF, when controlling the SPMM with a sinusoidal reverse EDC, the average moment below is 5%.
Without sensor Need a more powerful control system Not suitable for working on low revs. There are moment pulsations. Designed to control the SDPM with a trapezdinal reverse EMF, when controlling the SPMM with a sinusoidal reverse EDC, the average moment below is 5%.

Popular Methods for Control Magnets Synchronous Engine

To solve uncomplicated tasks, trapestial controls on the Hall sensors are commonly used (for example - computer fans). To solve problems that require maximum characteristics from the electric drive, polyatentized control is usually selected.

Trapestial control

One of the simplest methods for controlling a synchronous engine with permanent magnets is trapezoidal control. Trapestial management is used to control the SDPM with a trapezdinal reverse EDC. In this case, this method also allows you to control the SPM with a sinusoidal reverse EMF, but then the average moment of the electric drive will be below 5%, and the moment pulsation will be 14% of the maximum value. There is a trapestial control without feedback and feedback on the position of the rotor.

Control without feedback Not optimally and can lead to the exit of the SDPM from synchronism, i.e. By loss of controllability.

    Control with feedback can be divided into:
  • trapestial control over the position sensor (usually - on the Hall sensors);
  • trapestial control without a sensor (dumbway trapezda).

As a rotor position sensor, three-phase SDPM trapezdal controls are commonly used three high-end sensors, which allow you to determine an angle with an accuracy of ± 30 degrees. With this control, the current vector of the stator takes only six positions per electric period, as a result of which there are moment pulsations at the output.


    There are two ways to determine the position of the rotor:
  • on the position sensor;
  • without a sensor - by calculating the angle, a real-time control system based on the available information.

Pole-oriented SDPM control over position sensor

    The following types of sensors are used as an angle sensor:
  • inductive: sinus-cosine rotating transformer (SKVT), Reducleosyne, Industosin et al.;
  • optical;
  • magnetic: magnetic sensors.


Pole-oriented SDPM control without position sensor

Due to the rapid development of microprocessors since the 1970s, desponsive vector methods for controlling brushless alternating current began to be developed. The first precipitative methods for determining the angle were based on the electric motor properties to generate a reverse EMF during rotation. The reverse EMF of the engine contains information about the position of the rotor, so the ratio of the reverse EDC in the stationary coordinate system can calculate the position of the rotor. But when the rotor is not moving, the reverse EMF is absent, and on low revs the reverse EMF has a small amplitude, which is difficult to distinguish from noise, therefore this method is not suitable for determining the position of the engine rotor at low revs.

    There are two common options for launching SDPM:
  • run as a scalar method - launch by a predetermined characteristic of the dependence of voltage from frequency. But scalar control greatly limits the capabilities of the control system and the parameters of the electric drive as a whole;
  • - It works only with the SDPM in which the rotor has explicitly pronounced poles.


Currently it is possible only for engines with a rotor with explicit poles.

Three-phase synchronous alternating current generator without magnetic sticking with excitation from constant neodymium magnets, 12 pairs of poles.

Very long ago soviet times In the magazine "Models designer" published an article dedicated to the construction of a rotary type windmill. Since then, I have a desire to build something like this on my cottage plot, but it did not reach real actions. Everything has changed with the advent of neodymium magnets. Asked a bunch of information on the Internet and what happened.
Generator device: Two steel Disc From low carbon steel with glued magnets is rigidly connected through a spacer sleeve. In the gap between the disks there are fixed flat coils without cores. EMF induction arising in the halves of the coil is opposite in the direction and is summed into the general EDC of the coil. EMF induction arising in the conductor moving in a constant homogeneous magnetic field is determined by the formula E \u003d b · v · L Where: B.-magnetic induction V.- Movement of movement L.-The extensive length length. V \u003d π · d · n / 60 Where: D.-diameter N.-rotational speed. The magnetic induction in the gap between the two poles is inversely proportional to the square of the distance between them. The generator is assembled on the lower support of the wind turbine.

The diagram of the three-phase generator, for simplicity is deployed to the plane.

In fig. 2 shows the scheme of the arrangement of coils when their number is twice again, the crosses between poles increase in this case. The coils overlap on 1/3 of the magnet width. If the width of the coils are reduced by 1/6, then they will stand in one row and the gap between the poles will not change. The maximum gap between the poles is equal to the height of one magnet.

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