SU752644A1

SU752644A1 - Syncronous electric motor

Info

Publication number: SU752644A1
Application number: SU782652460A
Authority: SU
Inventors: Николай Николаевич Голиков; Игорь Михайлович Черкасов
Priority date: 1978-08-07
Filing date: 1978-08-07
Publication date: 1980-07-30

Description

Изобретение относится к электрическим машинам, а именно к синхронным электродвигателям с устройством контроля частоты вращения и зашиты и может найти применение в различных областях народного хозяйства, например, в приводе исполнительных механизмов постоянной частоты вращения.The invention relates to electric machines, namely to synchronous motors with a speed control and protection device, and can find application in various fields of the national economy, for example, in the drive actuators of constant speed.

Известны электродвигатели, содержащие' устройство контроля частоты вращения в вице постоянного магнита, геркона и электронной схемы [1J. .Known electric motors containing 'rotational speed control device in vice permanent magnet, reed switch and electronic circuit [1J. .

Недостатком такой конструкции¹ является наличие постоянного магнита и геркона, который является недостаточно надежным элементом, с ограниченным числом циклов коммутаций.The disadvantage of this design ¹ is the presence of a permanent magnet and a reed switch, which is not a reliable element, with a limited number of switching cycles.

Наиболее близкими к предлагаемому являются синхронные электродвигатели, содержащие ротор с зубцами, статор с полюсами, на· внутренней поверхности которых выполнены зубцы, и многофазными обмотками,, фазы которых содержат параллельные ветви, выполненные из отдельных катушек, размещенных на одноименных и диаметрально противоположных полюсах и соединенных последовательно между собой и вентилем, причем вентили в параллельных ветвях включены встречно {2].Closest to the proposed are synchronous motors containing a rotor with teeth, a stator with poles, on the inner surface of which teeth are made, and multiphase windings, the phases of which contain parallel branches made of separate coils placed on the same and diametrically opposite poles and connected sequentially between themselves and the valve, and the valves in parallel branches are turned on counter {2].

Недостатком такой конструкции является то, что она не позволяет контролировать частоту вращения и защиты непосредственно в двигателе, а требует установки специальных. устройств, которые выполняют эту функцию раздельно, что ограничивает функциональные возможности двигателя.The disadvantage of this design is that it does not allow controlling the speed and protection directly in the engine, but requires the installation of special ones. devices that perform this function separately, which limits the functionality of the engine.

Нель изобретения - расширение функциональных возможностей путем обеспечения получения сигнала отклонения частоты вращения от синхронной, а также повышение надежности и упрощение конструкции,Nel invention - the expansion of functionality by providing a signal of the deviation of the speed from the synchronous, as well as improving reliability and simplifying the design,

Поставленная цель достигается тем, что параллельные ветви фаз с вентилем одного направления соединены в две звезды, между общими точками которых, включен резисторный шунт..This goal is achieved in that the parallel branches of the phases with a valve of the same direction are connected into two stars, between the common points of which a resistor shunt is connected ..

При этом, с целью обеспечения температурной защиты двигателя, резисторный шунт выполнен в виде моста, в плечи которого включены термосопротивления, например, позисторы. ₅ At the same time, in order to ensure thermal protection of the engine, the resistor shunt is made in the form of a bridge, in the shoulders of which thermistors are included, for example, posistors. ₅

Кроме того, с целью повышения чувствительности температурной защиты, термосопротивления включены в противоположные плечи моста, при этом термосопротивления выполнены с температурным 10 коэффициентом противоположного знака.In addition, in order to increase the sensitivity of thermal protection, thermal resistances are included in the opposite shoulders of the bridge, while the thermal resistances are made with a temperature coefficient of 10 opposite sign.

На фиг. 1 представлена электрическая схема включения обмоток двигателя и резисторного шунта; на фиг. 2 - электрическая схема шунта в виде моста, а на фиг. 3 - электрическая схема электродвигателя и устройства измерения частоты вращения.In FIG. 1 shows a wiring diagram for motor windings and a resistor shunt; in FIG. 2 is a circuit diagram of a shunt in the form of a bridge, and in FIG. 3 is a circuit diagram of an electric motor and a speed measuring device.

Синхронный электродвигатель содержит .обмотку, каждая фаза 1, 2 и 3 которой , содержит параллельные ветви 4 и 5, в каждой из которых включены катушки 6 и 7 и вентили £ и 9, включенные встречно. Параллельные ветви 4 и 5 фаз 1,2 и 3 с вентилями 8 и 9 одного направления соединены в две звезды с нулевыми точками 10 и 11, между которыми включен шунт 12. Шунт 12 может быть выполнен в виде моста 13 (фиг. 2), в плечи которого включены термосопротивления 14.The synchronous electric motor contains a winding, each phase 1, 2 and 3 of which contains parallel branches 4 and 5, each of which includes coils 6 and 7 and valves £ and 9, included in the opposite direction. Parallel branches 4 and 5 of phases 1,2 and 3 with valves 8 and 9 of the same direction are connected in two stars with zero points 10 and 11, between which a shunt 12 is included. Shunt 12 can be made in the form of a bridge 13 (Fig. 2), whose shoulders include thermal resistance 14.

Термосопротивления 14 могут быть включены в противоположные плечи моста 13 и выполнены антиподными, т.е. с противоположно изменяющимся сопротивлением при изменении температуры.Thermal resistance 14 can be included in the opposite shoulders of the bridge 13 and made antipodal, i.e. with oppositely changing resistance with temperature.

Для выявления отклонения частоты вращения от заданной может быть использована схема контроля, содержащая усилитель 15, стабилитрон 16; транзисторный ⁴⁰ключ 17, реле 18 с контактом 19, выпрямитель 20, переменное сопротивление 21, инерционное звено из сопротивления 22 и конденсатора 23, источник 24.To detect deviations of the rotational speed from the predetermined one, a control circuit containing an amplifier 15, a zener diode 16; transistor ⁴⁰ key 17, relay 18 with contact 19, rectifier 20, variable resistance 21, inertial link from resistance 22 and capacitor 23, source 24.

При работе электродвигателя с синхронной скоростью на. измерительном шунте 12 имеется постоянная составляющая напряжения с пульсацией с частотой 300 Ш. При выходе ротора электродвигателя на жесткий упор (выход из синхронизма) на измерительном шунте 12 выделяется переменная составляющая напряжения, которая имеет явно выраженную частоту 50 Гц. Увеличение переменной составляющей на шунте 12 происходит в связи с тем, что в синхронном электродвигателе всегда имеется пространственная асимметрия, а вследствие этого и магнитная, так как выполнить электродвигатель полностью симметричным практически не удается.When operating an electric motor with a synchronous speed on. the measuring shunt 12 has a constant voltage component with a pulsation with a frequency of 300 W. When the electric motor rotor reaches a hard stop (out of synchronism), the alternating voltage component is allocated to the measuring shunt 12, which has a pronounced frequency of 50 Hz. The increase in the variable component on the shunt 12 occurs due to the fact that the synchronous motor always has a spatial asymmetry, and therefore magnetic, since it is practically impossible to complete the motor completely symmetrical.

При выходе ротора электродвигателя на жесткий упор, токи в параллельных ветвях 4 и 5 из-за различного сопротивления магнитных цепей, имеют некоторое отличие, причем проводимость магнитной цепи каждого полюса изменяется по закону, определяемому колебаниями ротора, амплитуда которых зависит от жесткости упора и суммарного момента инерции нагрузки и ротора.When the rotor of the electric motor reaches a hard stop, the currents in parallel branches 4 and 5, due to the different resistance of the magnetic circuits, have some difference, and the conductivity of the magnetic circuit of each pole changes according to the law determined by the oscillations of the rotor, the amplitude of which depends on the stiffness of the stop and the total moment inertia of load and rotor.

При выходе ротора электродвигателя на жесткий упор (момент нагрузки превышает максимальный синхронный момент двигателя) на измерительном шунте 12 появляется переменная составляющая, по величине в два-три раза большая, чем при нормальной работе электродвигателя и при асимметрии сетевого напряжения в пределах допустимых в эксплуатации величин.When the rotor of the electric motor reaches a hard stop (the load moment exceeds the maximum synchronous motor torque), a variable component appears on the measuring shunt 12, which is two to three times larger in magnitude than during normal operation of the electric motor and with asymmetry of the mains voltage within the limits allowed for in operation.

При коротком замыкании на землю, межфазном замыкании и при обрыве одной фазы питания двигателя, на измерительном шунте 12 Также появляется значительная переменная составляющая напряжения.In the event of a short circuit to ground, an interphase short circuit, and when one phase of the motor power supply is interrupted, a significant alternating voltage component also appears on the measuring shunt 12.

Необходимость .выключения электродвигателя при выходе его из синхронизма (в приводе электрического исполнительного механизма) вызвана тем, что в режиме с заторможенным ротором, т.е. при нагрузке на валу, превышающей максимальный синхронный момент, развиваемый электродвигателем, возникает знакопеременный момент, который приводит к повышенному механическому износу элементов редуктора привода, и как следствие -к уменьшению его срока службы. Следует также отметить, что в данной схеме формируется аварийный сигнал не только при выходе электродвигателя из синхронизма, но и при других аварийных ситуациях, таких как обрыв фазы 1, 2 и 3 и· коротких замыканиях на землю и междуфазных.The need to turn off the electric motor when it is out of synchronism (in the drive of the electric actuator) is due to the fact that in the mode with a locked rotor, i.e. when the load on the shaft exceeds the maximum synchronous moment developed by the electric motor, an alternating moment occurs, which leads to increased mechanical wear of the elements of the drive gearbox and, as a result, to a decrease in its service life. It should also be noted that in this circuit an alarm is generated not only when the motor goes out of synchronism, but also in other emergency situations, such as a phase failure of 1, 2 and 3 and short circuits to the earth and interphase.

С целью обеспечения температурной защиты электродвигателя, в качестве измерительного шунта 12 может быть использован мост 13, составленный из сопротивлений, причем в одно или в два противоположных плеча моста 13 введены термосопротивления 14 (фиг. 2).In order to ensure thermal protection of the electric motor, a bridge 13 composed of resistances can be used as a measuring shunt 12, and thermal resistance 14 is introduced into one or two opposite shoulders of the bridge 13 (Fig. 2).

В исходном состоянии, т.е. при работе электродвигателя в нормальном режиме, мост 13 сбалансирован и величина выходного сигнала усилителя 15 меньше уровня стабилитрона 16. Выходной тран5 зисторный ключ 17 находится в закрытом состоянии и сигнал отключения электродвигателя отсутствует. При увеличении температуры в обмотках или подшипниках электродвигателя сверх допустимой, ве- s личина термосопротивлений 14 изменяется, вследствие чего разбалансируется равновесие моста 13 и напряжение на выходе усилителя 15 достигнет уровня пробоя стабилитрона 16. <0In the initial state, i.e. when the electric motor is operating in normal mode, the bridge 13 is balanced and the output signal of the amplifier 15 is less than the level of the zener diode 16. The output transistor switch 17 is in the closed state and the motor shutdown signal is absent. When the temperature in the windings or bearings of the electric motor rises above the permissible value, the value of thermal resistance 14 changes, as a result of which the balance of bridge 13 is unbalanced and the voltage at the output of amplifier 15 reaches the breakdown level of zener diode 16. <0

Выходной транзисторный ключ 17 переходит в открытое состояние и реле 18 срабатывает, отключая электродни?* гатель..The output transistor switch 17 goes into the open state and the relay 18 is activated, disconnecting the electrode? * Gatel ..

Аналогичное разбалансирование схемы ¹⁵производится при установке термосопротивлений 14 в противоположные плечи моста 13, при этом термосопротивления 13 должны быть антиподны.A similar imbalance of the circuit ^{15 is} carried out when installing the thermal resistance 14 in the opposite shoulders of the bridge 13, while the thermal resistance 13 should be antipodal.

Для выключения электродвигателя, при ³⁰выходе его из синхронизма, контакт 19 реле 18 может быть включен последовательно с измерительным шунтом 12.To turn off the electric motor, when it is ³⁰ out of synchronism, the contact 19 of the relay 18 can be connected in series with the measuring shunt 12.

При размыкании контакта 19 обмотки электродвигателя обесточиваются. ³⁵ When contact 19 is opened, the motor windings are de-energized. ³⁵

Предлагаемое устройство позволяет получить сигнал выхода из синхронизма электродвигателя, причем простым переключением обмоток, а также получить сигнал при обрыве фазы электродвигателя ³⁰и при коротких замыканиях на землю и междуфаэных.The proposed device allows you to get the exit signal from the synchronism of the electric motor, moreover, by simply switching the windings, as well as to obtain a signal when the phase of the motor ^{30 is} cut off and during short circuits to the ground and interfacial.

Предлагаемый электродвигатель позволяет расширить функциональные возможности за счет объединения его с устрой- 35 ством контроля частоты вращения и защиты, а также упростить надежность ее.The proposed electric motor allows you to expand the functionality by combining it with a speed control and protection device, as well as simplify its reliability.

Claims

The invention relates to electric machines, namely, synchronous electric motors with devices for controlling rotation frequency and protection, and can find application in various areas of the national economy, for example, in driving constant speed actuators. Electrocelliators are known to contain a rotational speed monitoring device in a vice permanent magnet, a reed switch and an electronic circuit i. The disadvantage of this design is the presence of a permanent magnate, which is not a sufficiently reliable element, with a limited number of switching cycles. Closest to the present invention are synchronous electric motors containing a rotor with teeth, a stator with poles, the inside surface of which is made teeth, multiphase windings, the phases of which contain parallel branches made of separate coils placed on the same poles and diametrically opposite poles and connected sequentially between the singular and the valve, and the valves in parallel veggies are connected in opposite 2. The disadvantage of such a coxchangement is that it often does not allow to control That is, the protection and protection are directly in the engine, and the installation requires special devices that perform this function separately, which limits the functionality of the engine. The purpose of the inventive 5 is to make the functionality clearer by ensuring that the rotational frequency deviation from synchronous is obtained, and the reliability is improved and the design is simplified. The set goal is sputtered, because steam # 1 is a smooth branch of the phases with a branch of one direction connected to two zedyedy, between the common points of which the resistor shunt is turned on. At the same time, in order to provide thermal protection of the engine, the resistor shunt is designed as a bridge, the shoulders of which include thermal resistances, for example, posistors. In addition, in order to increase the temperature protection sensitivity, thermal resistances are included in the opposite shoulders of the bridge, while thermal resistances are made with a temperature coefficient of opposite sign. Fig. 1 is an electrical circuit for connection of the motor and resistor shunt windings; in fig. 2 is an electrical diagram of a bridge shunt, and in FIG. 3 is an electrical circuit of an electric motor and a device for measuring rotational speed. The soliton electrode contains a winding, each phase 1, 2 and 3 of which contains paralap branches 4 and 5, each of which includes coils 6 and 7 and valves and 9, which are connected in opposite. Parallel branches 4 and J5 of phases 1,2 and 3 with valves 8 and 9 of the same direction are connected into two stars with zero points 10 and 11, between which shunt 12 is turned on. Shunt 12 can be made in vice bridge 13 (Fig 2) , the shoulders of which include thermal resistances 14. Thermal insulation 14 may be included in the opposite shoulders of the bridge, 13 and made anti-slide, i.e. with oppositely varying resistance when the temperature varies, To detect a deviation of the rotational frequency from the control circuit can be used, containing amplifier 15, zener diode 16; a transistor switch 17, a relay 18 with a contact 19, a rectifier 20, a variable resistance 21, an inertial element from resistance 22 and a capacitor 23, a source 24. When the electric motor operates at low speed on. measuring shunt 12 has a constant voltage component with a pulsation with frequency ZOO W When the rotor of the electric motor comes to a hard stop (out of synchronism) on the measuring shunt 12, an alternating voltage component has a pronounced frequency of 50 Hz . The increase of the variable component on the shunt 12 occurs due to the fact that there is always a spatial asymmetry in the synchronous electric motor, and SicnetscTB e of this is also mattatnous, since the EMPTY electric motor is almost completely imperfect. When the rotor of the electric motor comes out, the hard stop, the currents in parallel вв x 4 and 5, due to the different resistance of the magnetic circuits, have some difference, and the conductivity of the magnetic field of each pole varies in terms of the magnitude of the rotor, the magnitude of which depends on the rigidity time and total moment of inertia of the load and the rotor. When the rotor of the electric motor reaches a rigid stop (the load torque exceeds the maximum synchronous motor torque), measuring component shunt 12 appears to have a variable component that is two to three times larger than during normal operation of the electric motor and with asymmetry of the mains voltage within permissible in operation velit1n. When there is a short circuit to earth, an interfacial circuit, and if one motor phase is broken, the measuring voltage on the measurement shunt 12 also appears to be significant. The need to turn off an electric motor when it is out of synchronicity (B is driven by an electric actuator) is caused by the fact that in the mode with a decelerated rotor, t, e, prk a shaft load exceeding the maximum synchronous torque developed by an electrical device, an alternating moment occurs, which leads to increased mechanical wear of the drive gearbox components, and as a result, a reduction in its duration. It should also be noted that in this scheme an alarm signal is generated not only when the electric motor is out of synchroism, but also in other emergency situations, such as phase failure 1, 2 and 3 And short circuits to ground and phase-to-phase. motor protection, a bridge 13 composed of resistances can be used as a measuring shunt 12, and a thermal resistance 14 is inserted in one or two opposite arms of the bridge 13 (FIG. 2). In the initial state, i.e. when the motor is operating in normal mode, the bridge 13 is balanced and the output signal of amplifier 15 is less than the level of the zener diode 16. The output granisator key 17 is in the closed state and there is no signal to turn off the electric motor. When the temperature in the windings or bearings of the motor exceeds the permissible, the thermal resistance 14 changes, the equilibrium of the bridge 13 is unbalanced and the output voltage of the amplifier 15 reaches the level of the Zener diode 16. The output transistor switch 17 goes to the open state and the relay 18 operates, disconnect electrics. gatel A similar imbalance of the circuit is made when the thermistors 14 are installed on the opposite shoulders of mth 13, while the thermistors of 13 must also be anti-subsurface. To turn off the motor, when it goes out of sync, contact 19 of relay 18 may be connected in series with measuring shunt 12. When contact 19 of the motor is open, the motor windings are de-energized. The proposed device allows & T to obtain an output signal from the synchronism of the electric motor, and by simple switching of the windings, as well as receive. signal at the break of the phase of the electric motor and at short circuits x on the green and interfacial. The proposed electric motor allows the functionality to be expanded by combining it with a rotational speed monitoring device to protect, as well as simplifying its reliability. Claim 1, a synchronous electric motor containing a rotor with teeth, a stator with a pol | psAMI, on the inner surface of which teeth are made, and multiphase windings, the phases of which contain parallel branches made of individual coils placed on the same and diametrically opposite poles and connected in series with each other and the valve, and the valves in the pariplel branches x are turned on oppositely, in order to extend the functionality by providing a signal deviations of the rotational frequency from the synchronous one, as well as increase of the reliability and simplification of the design, parallel phases of the valve with the valve of the single direction of the connection to two stars, between which the points of the switch are connected to the mountain-mount shunt. 2, the motor according to claim 1, wherein the. in order to ensure the intestinal protection of the engine, the resistor shunt is designed as a bridge, in the plei of which thermal resistance is included, for example, posistor. 3, The electric motor according to claim 2. about a TONj that, in order to increase the sensitivity of the temperature protection, the thermoprotector is connected to the protruding shoulders of the bridge, while the thermoprotection is performed with a temperature coefficient: the opposite of the opposite energy efficiency. Sources of information taken into account in the examination 1.Patent of France NP 230644G, cl. G 01 P 3/56, 1S76.

2. Patent Franzni number 2272519, cl. n 02 to 19/24, 1975.