RU2719544C1 - Drive device for pipeline valves, equipped with energy accumulator, with function of switching pipeline valves into safe position - Google Patents

Abstract

FIELD: electrical engineering.SUBSTANCE: drive device for pipeline valves with a function of converting pipeline valves into a safe position comprises a capacitive energy accumulator in form of one or more high-capacitance capacitors. Drive of actuating mechanism with controlled electric motor. Bi-directional voltage converter configured to lower voltage for capacitor bank of energy accumulator at serviceable network, or increasing voltage for discharging of capacitive energy accumulator to electric motor at faulty network in order to drive electric motor to move valve to safe position. Bi-directional voltage converter is made in the form of three-winding transformer. First winding of which is used as the primary winding in the mode of voltage reduction and secondary one in the mode of voltage increase is connected to the first bridge converter. Second winding of the transformer is used as the primary one in the mode of voltage increase and is connected to the second bridge converter. Third winding of the transformer is used as secondary winding of the transformer and is connected to the energy accumulator through the switch and is made with number of turns exceeding the number of turns of the second winding. As a result, the drive in the voltage reduction mode operates at a wide range of the input voltage of the network with provision of a stable charging current of the required value for the energy accumulator charge to the maximum voltage. In voltage increase mode it operates at wide range of charge voltage at energy accumulator with provision of stable voltage at output of such value, which is sufficient for actuation of powerful electric motor and, consequently, movement in safety position of pipeline valves, for which large torque moments are required.EFFECT: technical result consists in improvement of operational characteristics, providing in case of faulty network considerable torque moments on drive shaft.5 cl, 2 dwg

Description

The invention relates to electrical engineering, in particular, to an electric drive device for pipe fittings equipped with a means of protection against accident. The invention can be used on pipelines in the transport of oil, gas and other products, in the chemical and petrochemical industries.

Actuators are widely used to control valves in pipelines. To ensure reliable operation, the drive devices are equipped with energy storage devices designed to operate in a fault-tolerant mode, i.e. to move the pipe fittings to a safe position in the event of a power failure or voltage drop below the permissible value.

From the patent of the Russian Federation 2461039 (G05B 19/39, publ. 09/10/2012), a drive device for a valve is known. The drive unit is equipped with an energy storage device including at least one high-capacity capacitor, which in the event of a main power failure ensures the valve moves to a safe position. The drive device contains a step-down voltage converter, which, when a network is working properly, lowers the voltage to charge the energy storage device, and a step-up voltage converter, which, when the network is faulty, supplies power from the drive to the electric motor and control system to move the valve to a safe position.

A swap controller is used as a boost converter. The swap output voltage is such that it is less than the normal supply voltage.

With a working network, the voltage is supplied to a pulsed power supply (IIP) of direct / alternating current (DC / AC), which generates the voltage necessary for the traction motor and electronic circuits.

A disadvantage of the known drive device is that the boost converter does not provide a multiple (more than 4 times) voltage increase. This is because the maximum gain of the swap controller is not more than 4. Otherwise, if the gain exceeds 4, then the efficiency. boost converter will drop sharply to 0.1.

Because the pumping output voltage is less than the normal supply voltage, the boost converter does not provide power to electric motors with a rated voltage of 380 V and is designed for use with relatively small valves or gate valves.

In addition, to power the boost converter, a stable voltage is required produced by the switching power supply (IIP), due to the impossibility of operation of the boost converter in a wide range of input mains voltage. As a result, equipping the device with an additional unit - a power source (IIP), increases the power loss of the drive device, which leads to low energy efficiency of the device and increases its overall dimensions.

From the patent of the Russian Federation 2442924 (F16K 31/00, F16K 31/04, H02J 9/06, H02H 7/09, H02M 7/527, publ. 02.20.2012) a drive device for pipe fittings made with the possibility of transferring the valves to safe is known malfunctioning position through emergency protection circuit. This device contains a capacitive energy storage device, an actuator with a controlled electric motor, a bi-directional voltage converter, configured to either lower the voltage to charge the capacitive energy storage device with a working network, or increase the voltage to discharge the capacitive energy storage device to the electric motor when the network is faulty, to bring the electric motor into action.

With a working network, the electric current, which is used to power the electric motor and charge the capacitive energy storage, is converted to a relatively low potential by means of a voltage converter operating in the reduction mode, and the energy is stored in the capacitive energy storage. In the event of a voltage drop below the limit value or a power failure, the electric energy stored in the capacitive energy storage device containing at least one high-capacity capacitor is converted by means of the same voltage converter to a relatively high potential and is used in boost mode to ensure that the engine runs until until you reach the set position for safety.

The voltage converter is made in the form of an inductor L1 connected between two switches. In voltage boost mode, the microcontroller sends a PWM signal to the first key. If the first switch is closed, current flows through inductor L1 and charges capacitor C1. If the first switch is open, free current passes through the diode D2 and inductor L1, and the capacitor C1 is charged additionally. Similarly, in the undervoltage mode, the microcontroller sends a PWM signal to the second key for the discharge of capacitor C1.

The device operates on mains with a specific AC or DC voltage, for example, either 24 VAC, or 110 VAC, or 230 VAC, or 24 VDC, or 72 VDC. The power source stabilizes the mains voltage and supplies the circuit of the device 10 with the voltage of the same value of 24 VDC.

The energy storage device is made in the form of one or more high-capacity capacitors. Each of the series-connected capacitors is shunted by a normally open switch S3 and a resistor.

A disadvantage of the known device is the implementation of the voltage Converter in the form of an inductor L1, because the inductor does not provide a multiple increase / decrease in voltage during its conversion. Otherwise, to repeatedly increase / decrease the voltage, it will be necessary to significantly increase the dimensions of the inductor, which will lead to a large increase in power loss.

Another disadvantage is the presence in the device of a constantly working power source, which increases the loss of electricity and device power due to the heating of the power supply elements. This reduces the efficiency of the device. In addition, the presence of a power source increases the overall dimensions of the device.

Another disadvantage of the device is that capacitors C1 are shunted by normally open switches S3, for the closure of which requires the presence of power. When the capacitor C1 is discharged, the voltage decreases to the minimum acceptable value, after which the key S3 opens again, i.e. it is not possible to discharge the capacitor to zero. Due to the danger of working with a capacitor that is not discharged to zero, the maintenance of the device is difficult. In addition, the constant presence of a charge on capacitor C1 does not allow opening the power unit casing in the explosive zone if it is necessary to replace a failed capacitor.

Thus, the problem of creating an energy-efficient drive device with improved operating characteristics, which, when the network is faulty, provides significant torques on the drive shaft connected to the pipeline valve, remains relevant.

The technical result achieved by the proposed drive device:

- when lowering the voltage, work with a wide range of input voltage to ensure that the energy storage charge has a stable charging current;

- repeated decrease / increase of voltage by a voltage converter;

- with increasing voltage, work with a wide voltage range of the energy storage device providing the voltage converter with a stable voltage of such a value that is sufficient to drive the electric motor.

The invention is illustrated using the drawings. FIG. 1 is a functional diagram of a drive device. FIG. 2 is a functional diagram of a bi-directional voltage converter with an attached energy storage device.

In FIG. 1, the drive device 1 contains an energy storage circuit 2 and an actuator drive circuit 3. The energy storage circuit 2 comprises a bi-directional voltage converter 4, a microcontroller 5, an energy storage 6, an energy storage balancing and monitoring unit 7, as well as a resistor (R) and a key 9, preferably made in the form of a relay. Energy storage 6 includes one or more series-connected supercapacitors 8 with a capacity of 30 F or more.

In FIG. 2, a bi-directional voltage converter 4 includes a three-winding transformer 10 connected between two bridge converters 11 and 12. Each of the bridge converters 11, 12 is made in the form of a full bridge circuit (H-shaped bridge). The first bridge converter 11 contains electronic keys 13-1 13-4, the second bridge converter 12 contains electronic keys 13-5 13-8. In the three-winding transformer 10, one of the windings, conventionally named the first, is used as primary in the mode of undervoltage and secondary in the mode of increasing voltage. The first winding 15 is connected to the first bridge converter 11. The other of the windings, tentatively named the second, is used as primary in the voltage boost mode. The second winding 16 is connected to the second bridge converter 12. The next of the windings, conventionally called the third, is used as a secondary in the mode of undervoltage. To the third winding 17 is connected a rectifier 14 connected to the energy storage device 6 through an electronic switch 13-9. All three windings 15, 16, 17 of the transformer 10 are located on one core, for compactness. The winding data of the transformer 10 can provide a large ratio of lowering and increasing voltage. The third winding 17 is made with the number of turns exceeding the number of turns of the second winding 16.

In FIG. 1 actuator drive circuit 3 includes a frequency converter 18, a microcontroller 19, an auxiliary power supply 20, an electric motor 21, an actuator (gear) 22, pipe fittings 23. An auxiliary power supply 20 is connected to the microcontroller 5 via a galvanic isolation unit 24. The shown functional diagram shows an external AC network, in this case, circuit 3 contains a rectifier 25.

The notation in FIG. 1 and 2: + DC - DC bus with positive potential; SGND is a power bus, the potential of which is conditionally taken as zero.

The drive device for pipe fittings operates as follows.

With a working network, the rectifier 25 (Fig. 1) receives a supply voltage (U network) of direct / alternating current, which has a wide range of values, for example, in the range from (Un - 50%) to (Un + 47%), where Un is the rated voltage network. The rectifier 25 converts the alternating voltage of the network into constant voltage or transmits a constant voltage. This voltage is supplied to the actuator drive circuit 3 and to the energy storage circuit 2.

In the circuit 3 of the actuator actuator, the voltage from the output of the rectifier 25 is supplied to the frequency converter 18 to provide power to the electric motor 21 and to the auxiliary power source 20 to power the device’s own needs.

In the power storage circuit 2, the first bridge converter 11 (Fig. 2), by the control signal of the microcontroller 5 (Fig. 1), converts the constant voltage into alternating voltage and adjusts the duty cycle of the current pulses. The first bridge converter 11 (Fig. 2) controls the duty cycle of the pulses with keys 13-1 ÷ 13-4 of its diagonals depending on the magnitude of the mains voltage, changing the duty cycle of the pulses to a certain value necessary to obtain a stable charging current at the output of the voltage converter 4. In this case, according to the signal of the microcontroller 5, the keys 13-5 ÷ 13-8 of the second bridge converter 12 are open, and the key 13-9 is closed. The alternating voltage from the output of the first bridge converter 11 is lowered by the first 15 and third 17 windings of the transformer, operating as respectively the primary and secondary windings, with a transformation coefficient k1, the value of which provides the necessary voltage reduction ratio.

Then the diode bridge 14 rectifies the reduced alternating voltage, and the DC voltage through a closed electronic switch 13-9 is supplied to the capacitive energy storage 6 to charge it to the maximum operating voltage. The microcontroller 5 (Fig. 1) stops the charge when the maximum operating voltage at the power storage device 6 is reached and resumes charging when the voltage decreases by a predetermined amount.

When the voltage Converter 4 (Fig. 2) in the voltage lowering mode, the voltage ratio of the voltage Converter 4 is equal to:

Unets / Usp1 = S1⋅k1, where

Unets is the mains voltage, Uzar1 is the voltage to ensure the charge of the energy storage device 6, k1 is the step-down transformation coefficient of the transformer 10, S1 is the pulse ratio regulated by the first bridge converter 11.

Knowing the value of the transformation coefficient k1 and the measured value of the network voltage, by regulating the duty cycle of the transformer 10, they maintain such a voltage (Uzar1) that ensures that the energy store 6 is charged with a stable charging current, with a wide input voltage range of the network. Moreover, the value of the transformation coefficient k1 provides a large fold of voltage reduction.

Due to the fact that the first bridge converter 11 controls the duty cycle of the pulses by alternating the polarity of the first 15 windings, the magnetization characteristic of the core of the transformer 10 is fully used. This helps to ensure the compactness of the transformer 10, and therefore, reduce energy losses.

The charge is stored in the energy storage device 6. The monitoring and balancing unit 7 (Fig. 1) periodically checks the operability of at least one of the indicated high-capacitor 8 by measuring its capacitance and internal resistance.

An example of the implementation of a technical solution in the mode of lowering the DC voltage. With a rated voltage of the network Un = 536 VDC to ensure the maximum voltage of the energy storage Umax = 42VDC, the ratio of the voltage of the Converter 4 depending on the magnitude of the network voltage is:

- when the mains voltage is below the nominal by 50%, i.e. for U network = 268 VDC,

Networks / Umax = 268VDC / 42VDC = 6.38. The maximum voltage of the energy storage 6 is achieved by the fact that the keys of the first bridge converter 11 provide a duty cycle of 2 pulses (duty ratio 50%). In this case, the voltage ratio of the converter 4 is equal to the transformation coefficient k1 of the transformer, i.e. U networks / Uzar1 = 6.38 = k1;

- at a network voltage equal to the nominal, i.e. for U network = 536 VDC,

Networks / Umax = 536VDC / 42VDC = 12.76. The maximum voltage of the energy storage device 6 is achieved by the fact that the keys of the first bridge converter 11 provide a duty cycle of 4 equal to (duty cycle 25%). In this case, the voltage ratio of the converter 4 is equal to twice the transformation ratio k1 of the transformer, i.e. U networks / Uzar1 = 12.76 = 2 k1;

- when the mains voltage is above the nominal by 47%, i.e. for Uvx = 788VDC,

Networks / Umax = 788VDC / 42VDC = 18.76. The maximum voltage (Umax) of the energy storage device 6 is achieved by the fact that the first bridge converter 11 changes the duty cycle of the pulses to a value equal to 8 (duty cycle 12.5%). In this case, the ratio of the voltage of the converter Unet / Uzar1 = 18.76 = 2.94 k1.

Thus, in the mode of lowering the DC voltage, the drive device 1 operates with a wide range of input mains voltage from (Un - 50%) to (Un + 47%), the voltage ratio of the converter 4 is relatively large, i.e. voltage converter 4 can repeatedly reduce the voltage, for example, 18.76 times with Uset = 788VDC.

Similarly, in the mode of lowering the AC voltage, the voltage converter 4 operates at a wide input voltage range, providing a maximum charge of the energy storage device 6 with a stable charging current.

The operation of the voltage Converter 4 in the mode of lowering the voltage with a wide range of voltages at its input, ensuring a stable charging current at its output, eliminates the stabilizing power source at the input of the drive device 1, which reduces the power loss of the drive device. This ultimately improves energy efficiency and improves the overall dimensions of the drive unit.

In case of a faulty network (as a result of a power failure or voltage drop below the permissible value), the bidirectional voltage converter 4 operates in a voltage increase mode.

The microcontroller 5 (Fig. 1) opens the key 13-9 (Fig. 2), and the voltage from the capacitive energy storage 6 (Fig. 1) is supplied to the second bridge converter 12 (Fig. 2), which, according to the control signal of the microcontroller 5 (Fig. 1), 1) converts direct voltage to alternating current and regulates the duty cycle of current pulses. The second bridge converter 12 (Fig. 2) regulates the duty cycle of the pulses by closing and opening the keys 13-5 ÷ 13-8 depending on the voltage value of the energy storage 6, changing the duty cycle of the pulses to a certain value necessary to obtain a stable voltage at the output of the converter 4. For example, when the voltage of the energy storage device 6 is 50% lower than the maximum and equal to the maximum, the required voltage value is obtained with a pulse duty cycle of 2 and 4, respectively. In this case, the switch 9, which shunts the chain of series-connected capacitors 8, is made normally closed, i.e. in the absence of power supply, the key 9 is closed and shunts the capacitors 8, which ensures safe maintenance of the drive device 1 in explosive conditions.

Further, the alternating voltage from the output of the second bridge converter 12 (Fig. 2) rises the second 16 and first 15 windings of the transformer, operating as respectively the primary and secondary windings. The second 16 and the first 15 windings of the transformer increase the voltage with a transformation coefficient k2, the value of which provides a large increase in voltage.

Then, the first bridge converter 11, this time performing the function of a rectifier, rectifies the increased alternating voltage. And the DC voltage having a stable value is supplied to the actuator drive circuit 3.

In the circuit 3 (Fig. 1) of the actuator actuator, the voltage is supplied to the frequency converter 18 to provide power to the electric motor 21, to actuate the electric motor 21 and move the valve 23 to a safe position while maintaining the ability to control torque / axial force, and to the service source power 20 to power the auxiliary needs of the device 1.

When the voltage Converter 4 in the mode of increasing voltage, the voltage ratio of the voltage Converter 4 is equal to: Uzar2 / Uout = S2⋅1 / k2, where

Uзар2 - voltage of energy storage 6; Uout is the voltage at the output of the voltage converter 4, which ensures the operation of the actuator circuit 3 with a faulty network; k2 - increasing the transformation ratio of the transformer; S2 - duty cycle of the pulses, regulated by the second bridge Converter 12.

Knowing the value of the transformation coefficient k2 and the measured value of the energy storage voltage (Uzar2), by regulating the duty cycle (S2) of the transformer 10, a stable voltage (Uout) is maintained at the output of the voltage converter 4, which guarantees the activation of the electric motor 21 even with a significant decrease in the energy storage voltage 6. At the same time the value of the transformation coefficient k2 provides a large multiplicity of voltage increase.

Due to the fact that the second bridge converter 12 (Fig. 2) regulates the duty cycle of the pulses by alternating the polarity of the second 16 windings, the magnetization characteristic of the core of the transformer 10 is fully used. This helps to ensure the compactness of the transformer 10, and therefore, reduce energy losses.

An example of the implementation of a technical solution in the mode of increasing DC voltage. The voltage ratio of the Converter 4 depending on the voltage (Uzar2) of the energy storage 6 is equal to:

- when the energy storage voltage 6 is below the maximum by 50%, i.e. for Uzar2 = 0.5Umax = 21 VDC, Uzap2 / Uout = 21 VDC / 536 VDC = 1 / 25.52. The voltage at the output of the voltage converter 4, equal to the nominal, Uout = 536 VDC is achieved by the fact that the keys of the second bridge converter 12 provide a duty cycle of 2 pulses (50% duty cycle). In this case, Uзар2 / Uout = k2;

- when the energy storage voltage 6 is equal to the maximum, i.e. for Uzar2 = Umax = 42 VDC, Uzar2 / Uout = 42VDC / 536VDC = 1 / 12.75. This is achieved by the fact that the second bridge converter 12 changes the duty cycle of the pulses to a value equal to 4 (duty cycle 25%).

Thus, in the mode of increasing the DC voltage, voltage converter 4 operates with a wide range of energy storage voltage from (Uzar2 = Umax) to (Uzar2 = 0.5U max), voltage converter 4 can repeatedly increase the voltage, for example, by 25.52 times ( with Uzar2 = 0.5U max).

Similarly, in the mode of increasing the AC voltage, the voltage converter 4 operates with a wide voltage range of the energy storage device 6, providing a multiple increase in voltage.

Due to the multiple increase in voltage, the voltage converter 4 provides the activation of electric motors with a nominal voltage of 380V, and therefore, the movement of the pipe fittings to a safe position, which requires large torques.

The use of a three-winding transformer 10 makes it possible to obtain a magnitude of the voltage increase ratio that is different from the magnitude of the voltage decrease ratio, for example, exceeds the voltage reduction ratio by a predetermined number of times. Therefore, both necessary conditions can be fulfilled: both to ensure the maximum voltage of the energy storage device 6, and to provide a voltage sufficient to drive a powerful electric motor 21. This is achieved by the fact that the third winding 17 of the transformer is made with the number of turns exceeding the number of turns of the second winding 16 to a predetermined number time. So, in the above implementation example, the number of turns of the third winding 17 exceeds the number of turns of the second winding 16 by 4 times, therefore, the voltage increase ratio of 25.52 with a low charge of the energy storage device exceeds the voltage decrease ratio of 6.38 with a low network voltage 4 times. Due to the fact that in a bidirectional bi-winding transformer, the voltage increase ratio is equal to the voltage decrease ratio, only one of the two above conditions can be fulfilled. The use of a four-winding transformer or two double-winding transformers would lead to an increase in the overall dimensions of the transformer.

Thus, the implementation of a bi-directional voltage converter 4 in the form of a three-winding transformer 10, the pulse ratio of which is regulated by bridge converters 11 and 12, while the third transformer winding 17, used as secondary in the voltage reduction mode, is connected to the energy storage device 6 through a key 13-9 and made with the number of turns exceeding the number of turns of the second winding 16, used as primary in the voltage boost mode, allows the drive device 1:

- in the mode of undervoltage operation with a wide range of input voltage of the network to ensure a stable charging current of the required value for charging energy storage 6 to a maximum voltage. In turn, the operation of the voltage Converter 4 with a wide range of input voltage eliminates the energy-consuming power source at the input of the device 1, which improves energy efficiency and increase the efficiency of the drive device 1;

- in the mode of increasing voltage to work with a wide range of voltage of the charge on the energy storage device 6 providing the voltage converter 4 with a stable voltage of such a value that is sufficient to drive the electric motor 21;

- in the mode of lowering / increasing voltage, repeatedly lowering / increasing voltage by a bidirectional voltage converter 4 (unlike the swap controller in the analogue patent No. 2461039 and the inductor in the prototype patent No. 2442924).

At the same time, the implementation of a bidirectional voltage converter 4 in the form of a three-winding transformer (in contrast to the four-winding transformer or two double-winding transformers) allows to reduce the overall dimensions of the voltage converter 4, which increases the energy efficiency of the drive device 1.

Claims (5)

1. An actuator for pipe fittings equipped with an energy storage device, configured to transfer the pipe fittings to a safe position, containing a capacitive energy storage device, an actuator with a controlled electric motor, a bi-directional voltage converter configured to lower the voltage to charge the capacitive energy storage device with a working network or increase voltage for discharging a capacitive energy storage device to an electric motor with a faulty network, th to actuate the electric motor to move the valve to a safe position, while the energy storage device is made in the form of one or more high-capacity capacitors, characterized in that the bi-directional voltage converter is made in the form of a three-winding transformer, the first winding of which is used as the primary in the voltage reduction mode and secondary in voltage boost mode, connected to the first bridge converter, the second transformer winding used as the primary minutes in boost mode voltage coupled to the second bridge transducer, and the third winding of the transformer, used as a secondary voltage lowering mode, is connected to energy storage through the key and is adapted to the number of turns greater than the number of turns of the second coil. 2. The drive device according to claim 1, characterized in that a rectifier is connected to the third winding of the transformer. 3. The drive device according to claim 1, characterized in that the transformer is made with winding data, which allows for a multiple voltage reduction and increase. 4. The drive device according to claim 1, characterized in that each of the bridge converters is made in the form of a full bridge circuit (H-shaped bridge). 5. The drive device according to claim 1, characterized in that a key is inserted that shunts a series of high-capacity capacitors connected in series, made normally closed.

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