RU2627489C1 - Electric drive - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: electric drive of pipeline valves contains a voltage switch, an electric motor, an output shaft, an electrical network, an external control system. The electric drive additionally contains a gear reducer, the first, second and third position sensors, a power reducer, a manual branch, a torque sensor, a temperature sensor mechanically mounted on an electric motor. The control unit additionally includes a phase sequence analyzer, an output position and speed calculating module, first, second, third and fourth digitizing modules, a control module, a control panel, a digital interface controller, and an analog interface controller. Moreover, the power reducer is mechanically connected to the electric motor on one side, and on the other side - to the instrument gearbox, the torque sensor, the manual branch and the output shaft. At the same time, the instrument gearbox is made in the form of a multistage cylindrical gearbox with mechanically mounted first, second and third position sensors, the shafts of which are respectively mechanically connected to each of the three separate stages of the instrument gearbox. In this case, the first, second and third position sensors are electrically coupled to the first, second and third digitizing modules, respectively, and the torque sensor is electrically coupled to the fourth digitizing unit. In turn, the first, second and third digitizing modules are electrically connected to the output position and speed calculating module, which in turn is electrically connected to the control module. In this case, the control module is electrically connected to a phase sequence analyzer of the supply voltage, a voltage switch, fourth digitizing module, a temperature sensor, a control panel, a digital interface controller, an analog interface controller. Moreover, the digital interface controller and the analog interface controller are electrically connected to the external control system, and the phase sequence analyzer of the supply voltage is electrically connected to the electrical network and the voltage switch electrically connected to the motor.

EFFECT: invention makes it possible to increase the reliability of the electric drive, to provide the possibility of remote control, to unify the design of the electric drive, to improve the accuracy of positioning the electric drive output shaft.

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Description

The invention relates to electric drives, in particular to combined controls for valves (valves, valves, etc.), and can be used on pipelines for the transport of oil, petroleum products, in the chemical and petrochemical industries.

Known electric drive for valves of electric drives (US Pat. No. 2154219, 06/03/1999), consisting of a housing with an electric motor, gearbox, manual backup and torque limiting coupling, consisting of spring-loaded coupling halves, additionally equipped with a converter kinematically connected to the coupling half and connected to the recording device.

The disadvantage of this electric drive is the lack of an output shaft position sensor in its design, which can lead to incomplete closure of the pipe fittings when the torque limit clutch is triggered.

Known electric valve (Pat. No. 2285182, 10/22/2003) containing a three-phase asynchronous motor with a squirrel-cage rotor, a transmission mechanism, a torque unit, configured to calculate the torque as a function of the stator current of an asynchronous electric motor, rotor speed, current frequency, and also with the possibility of setting the maximum torque having a first input connected to the stator winding of the induction motor through a current sensor, a second input connected to an optomechanical sensor floor the output link of the gear mechanism, and the output. The positioner of the output link of the transmission mechanism has a first input for setting the end position, a second input connected to the optomechanical position sensor, and an output. The electric drive is configured to determine the rotational speed of the rotor of the asynchronous electric motor for the torque unit according to the reading of the optomechanical position sensor. This drive is the closest analogue of the claimed drive and is taken as a prototype.

The electric drive operates as follows. In the positioner, the values of the signals corresponding to the open and closed position of the valve are stored in advance. In the torque calculation unit, the limit values of the torque are set at various valve positions. When a command to open or close the valve is received, a command is issued to the proximity switch, which turns on the electric motor (ED) and drives the transmission mechanism. The optomechanical position sensor 3 associated with the transmission mechanism determines the position of the output link of the transmission mechanism taking into account the gear ratio along its entire path of movement and provides information about the current position in the form of signal codes to the positioner and to the torque calculation unit.

When the output link of the transmission mechanism of the installed open or closed position of the valve, the signal from the optomechanical position sensor enters the positioner. The positioner compares it with the set signal stored in it and transmits the resulting signal to its output when it reaches the set position. The position transmitter transmits a signal from its output to the contactless voltage switch, which smoothly brakes and disables the electric motor (ED).

The limit torque set in the torque block by software is compared with the current torque calculated in the same block, calculated from the signal from the current sensor. A signal about the excess of the calculated maximum torque over a given one is supplied to the contactless voltage switch and disconnects the asynchronous motor (ED) from the power supply network.

The disadvantages of the above electric drive are:

- low reliability associated with the lack of control over the temperature of the motor and the possible disappearance of the phases of the supply voltage;

- limited remote control capabilities;

- the need to select the gear ratio of the gearbox, depending on the maximum speed required to close the shutoff valves;

- a drop in the accuracy of positioning the output link with an increase in the gear ratio of the gearbox.

The technical objectives of the claimed invention are:

- improving the reliability of the electric drive;

- providing the possibility of remote control of the electric drive via analog and digital interfaces;

- unification of the design of the electric drive;

- improving the accuracy of positioning of the output shaft of the electric drive.

In order to achieve the indicated technical result, a well-known electric drive comprising a voltage switch, an electric motor, an output shaft, an electric network and an external control system according to the invention are additionally introduced:

- instrument gear;

- first, second, third position sensors (DP 1), (DP 2), (DP 3);

- power reducer;

- manual branch;

- moment sensor;

- a temperature sensor mechanically mounted on an electric motor,

in addition, in the control unit, additionally introduced:

- phase sequence analyzer;

- a module for calculating the position and speed of the output shaft;

- the first, second, third and fourth digitization modules (MO 1), (MO 2), (MO 3), (MO 4);

- control module;

- control Panel;

- digital interface controller;

- analog interface controller,

moreover, the power reducer on the one hand is mechanically connected with the electric motor, and on the other hand, with the instrument gear, torque sensor, hand branch and output shaft, while the gear gear is made in the form of a multi-stage cylindrical gear with the first, second and third sensors mechanically mounted on it positions whose shafts are respectively mechanically connected to each of the three separate stages of the instrument gearbox having predetermined gear ratios determined by its construction,

wherein the first, second and third position sensors are electrically connected respectively to the first, second and third digitization modules, and the moment sensor is electrically connected to the fourth digitization module, in turn the first, second and third digitization modules are electrically connected to the output position and speed calculation module shaft, which in turn is electrically connected to the control module, while the control module is electrically connected to the analyzer of the phase sequence of the supply voltage, the voltage switch, four a digital digitization module, a temperature sensor, a control panel, a digital interface controller, an analog interface controller, the digital interface controller and analog interface controller are electrically connected to an external control system, and the phase-voltage analyzer is electrically connected to an electric network and a voltage switch electrically connected with electric motor.

Comparative analysis with the prototype shows that new components have been introduced into the inventive electric drive, namely:

- instrument gear;

- first, second, third position sensors (DP 1), (DP 2), (DP 3);

- power reducer;

- manual branch;

- moment sensor;

- temperature sensor;

- a control unit into which:

- analyzer of the phase sequence of the supply voltage,

- a module for calculating the position and speed of the output shaft,

- the first, second, third and fourth digitization modules (MO 1), (MO 2), (MO 3), (MO 4),

- control module,

- control Panel,

- digital interface controller,

- analog interface controller.

A comparison of the proposed solutions with other technical solutions shows that the newly introduced elements are quite well known in the art, but their introduction in this connection into the inventive electric drive allows you to:

- to increase the reliability of the electric drive by introducing temperature control of the electric motor using a temperature sensor and monitoring the correct sequence of alternation and phase failure of the supply voltage in the corresponding analyzer of the control unit;

- to provide the possibility of remote control due to the existing communication with an external control system via analog and digital interfaces;

- to unify the design of the electric drive through the use of one instrument gear for a certain range of revolutions of closing the valve;

- to improve the accuracy of positioning of the output shaft of the electric drive through the use of three position sensors located on the steps of the instrument gear, made in the form of a multi-stage cylindrical gear.

The device and operation of the claimed invention are illustrated in graphic materials.

The drawing shows a structural diagram of the inventive electric drive.

Abbreviations adopted in the text and in the drawing:

DM - torque sensor;

DP1, DP2, DP3 - the first, second, third position sensors;

DT - temperature sensor;

MO1, MO2, MP3, MO4 - the first, second, third and fourth digitization modules;

ED - electric motor.

An electric drive consists of the following elements: an electric motor (ED) 1, a power reducer 2 mechanically connected to it, to which output valves 3 are connected to the output shaft 3.

The power gearbox has an input to the instrument gearbox 4 and a manual backup branch 5.

The instrument gearbox 4 has potentiometric position sensors (DP 1) 6, (DP 2) 7, (DP 3) 8 located at different stages.

A potentiometric torque sensor (DM) 9 is installed in the power reducer.

The signals from the position sensors (DP 1) 6, (DP 2) 7, (DP 3) 8 and the torque sensor (DM) 9 are received respectively through the digitizing modules (MO 1) 10, (MO 2) 11, (MO 3) 12 , (MO 4) 13.

Information on the presence and correct phase sequence of the supply voltage is processed in the phase sequence analyzer 14.

In the module for calculating the position and speed of the output shaft 15, a corresponding calculation of the current position and speed of the output shaft takes place.

The control signals are supplied to the control module 16 from the control panel 17, and also through the digital interface controller 18 and the analog interface controller 19 of the control unit 20 from the external control system 21. The output of the control module 16 is electrically connected to a voltage switch 22, which in turn is connected to one the side is connected to the electric network 23 and the phase sequence analyzer 14, and on the other hand, to the electric motor (ED) 1.

Information about the temperature of the electric motor from the temperature sensor (DT) 24 is transmitted to the control module 16 of the control unit 20.

The electric drive operates as follows.

Using the control panel 17, the positions of the sensors (ДП 1) 6, (ДП 2) 7, (ДП 3) 8 corresponding to the open and closed position of the valve, as well as the limiting values of the torques on the output shaft for opening and closing reinforcement.

When giving a command to open or close valves from the control panel 17 or from an external control system 21 through the analog interface controller 19 or digital interface 18, the control module 16 analyzes the sequence of alternating phases of the mains and, in accordance with it, connects the electric motor (ED) 1 to the mains 23 through the voltage switch 22 in a forward or reverse circuit. An electric motor (ED) 1 drives the output shaft 3 through a power reducer 2, while the rotation is also transmitted to the instrument gear 4 with position sensors installed on it (DP 1) 6, (DP 2) 7, (DP 3) 8. Signals from position sensors (DP 1) 6, (DP 2) 7, (DP 3) 8 through the digitizing modules (MO 1) 10, (MO 2) 11, (MO 3) 12 are transmitted to the module for calculating the position and speed of the output shaft 15 The calculated position and speed of the output shaft 3 are transmitted to the control module 16, where they are compared with the stored values corresponding to the closed positions or "open" shutoff valves. When the corresponding values are reached, the electric motor (ED) 1 is disconnected from the electrical network 23.

During the operation of the electric motor (ED) 1, a continuous analysis of the signal from the torque sensor (DM) 9, which is transmitted through the digitizing module (MO 4) 13 to the control module 16 of the control unit 20, and if the signal exceeds the preset limits, the electric motor (EM) switches off ) 1 from the electric network 23.

The control module also controls the temperature of the electric motor (ED) 1 using a temperature sensor (DT) 24 mechanically mounted on it. In case of overheating, the control module blocks the operation of the electric drive until the temperature drops to a safe level.

When the valve reaches the “open” or “closed” position, a signal about this is output to the control panel 17 and to the external control system 21 through the controllers of the analog interface 19 and digital interface 18.

Separate new elements of the inventive electric drive are implemented as part of the software of the control module of the control unit, while the processing of the received and transmitted data is carried out by modules, such as analog-to-digital conversion modules, digitization (MO) and digital-to-analog conversion modules, and an analog interface controller.

(See the book edited by Bogner R. and Konstantinidis A. "Introduction to Digital Filtering", translated from English. - M .: Mir, 1976.)

(See the book by Horowitz P., Hill W. "The Art of Circuit Engineering", trans. From English. - 4th ed., Revised and enlarged. - M.: Mir, 1993.)

(See Oppenheim A., Schafer R. Digital Signal Processing. M .: Technosphere, 2006. 856 pp.)

Thus, the claimed as an invention electric drive allows you to:

- to increase the reliability of the electric drive by introducing temperature control of the electric motor using a temperature sensor and monitoring the correct sequence of alternation and phase failure of the supply voltage in the corresponding analyzer of the control unit;

- to provide the possibility of remote control due to the existing communication with an external control system via analog and digital interfaces;

- to unify the design of the electric drive through the use of one instrument gear for a certain range of revolutions of closing the valve;

- to improve the accuracy of positioning of the output shaft of the electric drive through the use of three position sensors located on the steps of the instrument gear, made in the form of a multi-stage cylindrical gear.

The technical advantages presented in the description, the feasibility and reliability of the electric drive, implemented according to the claimed structural scheme, are confirmed by tests on the test base of OJSC SKB PA, OJSC KEMZ in Kovrov and as part of shut-off valves at the consumer.

Claims (1)

An electric actuator for pipe fittings comprising a voltage switch, an electric motor, an output shaft, an electric network, an external control system characterized in that it additionally includes an instrument gearbox, a first, second and third position sensors, a power gearbox, a manual branch, a torque sensor, a temperature sensor, mechanically mounted on an electric motor, in addition, a phase sequence analyzer, a module for calculating the position and speed of the output shaft, the first, second, third and fourth digitization modules, a control module, a control panel, a digital interface controller and an analog interface controller, the power reducer on the one hand mechanically connected to the electric motor, and on the other hand, to the instrument gear, torque sensor, hand branch and output shaft, with this instrument gearbox is made in the form of a multistage cylindrical gearbox with mechanically mounted first, second and third position sensors on it, the shafts of which are respectively mechanically connected to Each of the three separate stages of the instrument gear, the first, second and third position sensors are electrically connected to the first, second and third digitization modules, and the torque sensor is electrically connected to the fourth digitization module, in turn the first, second and third digitization modules connected to the module for calculating the position and speed of the output shaft, which in turn is electrically connected to the control module, while the control module is electrically connected to the sequence analyzer with a supply voltage, a voltage switch, a fourth digitization module, a temperature sensor, a control panel, a digital interface controller, an analog interface controller, the digital interface controller and analog interface controller are electrically connected to an external control system, and the phase sequence analyzer of the supply voltage is electrically connected to an electric a network and a voltage switch electrically connected to the electric motor.

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