Intelligent integrated medium-voltage AC vacuum switchgear based on flexible switching-closing technology

An intelligent integrated medium-voltage alternating current (AC) vacuum switchgear based on a flexible switching-closing technology comprises a controller (24), and a vacuum switching tube (1), an insulator (9), and an switching-closing mechanism connecting piece (15), which are connected in sequence. A microprocessor is built in an intelligent circuit (23); a travel sensor is fixed to a movable contact connecting rod (5), and directly detects a motion state of a movable contact (4) and acquires accurate motion parameters of the movable contact (4); switching-closing operating parameters are obtained by comprehensively calculating arc light intensity detected by an arc light transmitter (20) and a temperature measured by an infrared temperature measuring transmitter (22), such that the switching-closing performance of switching on and switching off a medium-voltage power grid is greatly improved, switching-closing time points are accurately controlled, and “flexible” switching-closing is achieved.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an intelligent integrated medium-voltage alternating current (AC) vacuum switchgear applied to a medium-voltage power grid, and in particular, to an intelligent integrated medium-voltage AC vacuum switchgear based on a flexible switching-closing technology, which belongs to the technical field of electrical switches.

2. Description of Related Art

Patent No. ZL201410015050.7, entitled “integrated high-voltage alternating-current circuit breaker and a protective circuit operating method therefor” and Patent No. ZL201410017012.5, entitled “intelligent integration high-voltage alternating current contactor” both relate to intelligent integrated AC vacuum switchgears. Both the inventions are highly intelligent and integrated. However, in the inventions, a travel sensor or a travel detection circuit (for example, “10” in “ZL201410015050.7” or “9” in “ZL201410017012.5”) is mounted at a lower portion of an insulator (“8” in “ZL201410015050.7” or “6” in “ZL201410017012.5”), instead of being mounted on a movable contact or a movable contact leading terminal (for example, “6” in “ZL201410015050.7” or “13” in “ZL201410017012.5”) of a switch. Therefore, motion parameters of the movable contact cannot be accurately represented, and as a result, the movable contact of the switch cannot be accurately controlled. Despite being the most important and fundamental characteristic of a switch, the switching-closing performance of switching on and switching off a medium-voltage power grid cannot be greatly improved. A “flexibility” feature is unavailable. There are problems that a switching-closing time is long, three-phase synchronization is poor, time points are uncontrollable, the movable contact jumps during closing, and the movable contact bounces during switching. Therefore, in the switching and closing processes, the harmful impact on the power grid, loads and a switch is severe, and a demand on construction of a strong intelligent power grid cannot be met.

SUMMARY OF THE INVENTION

The object of the present invention is to provide an intelligent integrated medium-voltage AC vacuum switchgear which has a novel structure and performs accurate guide and control on a micro travel motion of a movable contact of a switch to achieve a “flexible” switching-closing performance. The intelligent integrated medium-voltage AC vacuum switchgear has features of good performance, high reliability, and low costs, and is suitable for construction of a strong intelligent power distribution grid.

A technical solution of the present invention provides an intelligent integrated medium-voltage AC vacuum switchgear based on a flexible switching-closing technology. The design points of the technical solution include:

a vacuum switching tube1, an insulator9, a switching-closing mechanism connecting piece15, and a controller24, the vacuum switching tube1, the insulator9, and the switching-closing mechanism connecting piece15being axially connected in sequence, wherein
the controller24includes an intelligent circuit23, a grating travel transmitter16, a switching control interface circuit17, and a closing control interface circuit18; a microprocessor is built in the intelligent circuit23, and is configured to calculate switching-closing operating parameters; and the grating travel transmitter16, the switching control interface circuit17, and the closing control interface circuit18are electrically connected to the intelligent circuit23;
a grating sheet6is disposed on a movable contact connecting rod5of the vacuum switching tube1, an emitting light guide7is disposed on one side of the grating sheet6, a receiving light guide8is disposed on the other side of the grating sheet6, and a light inlet of the receiving light guide8is opposite to a light outlet of the emitting light guide7; and the emitting light guide7and the receiving light guide8are connected to the grating travel transmitter16, and the grating travel transmitter16is electrically connected to the intelligent circuit23; and
the switching-closing mechanism connecting piece15includes a transmission piece12, a switching mechanism13, and a closing mechanism14, the switching mechanism13and the closing mechanism14are coaxially connected to one end of the transmission piece12, the other end of the transmission piece12is fixedly connected to the insulator9, and the switching mechanism13and the closing mechanism14are electrically connected to the switching control interface circuit17and the closing control interface circuit18, respectively.

In application, the present invention also has the following further optimized technical solutions.

Further, a cylinder having an opening at the top is disposed at an upper portion of the insulator9, an over-travel spring11and a piston10are sequentially disposed within the cylinder, one end of a piston rod penetrating the top opening of the insulator9is fixedly connected to the piston10, and the other end of the piston rod is fixedly connected to the movable contact connecting rod5of the vacuum switching tube1.

Further, the over-travel spring11is a compression spring or a disc spring.

Further, the vacuum switching tube1includes a housing, a fixed contact2, a fixed contact connecting rod3, a movable contact4, and the movable contact connecting rod5, one end of the fixed contact connecting rod3is fixedly connected to the fixed contact2and is located within the housing, and the other end of the fixed contact connecting rod3is fixed to the housing and extends out of the housing; one end of the movable contact connecting rod5is fixedly connected to the movable contact4and is located within the housing, and the other end of the movable contact connecting rod5penetrates the housing and is connected to the housing in a slideable and sealed manner; the fixed contact connecting rod3and the movable contact connecting rod5are coaxial; and a light transmission part used for light measurement is disposed on the housing.

Further, an infrared temperature measuring light guide21and an arc guide19are disposed on an outer side of the light transmission part of the vacuum switching tube1, and the infrared temperature measuring light guide21is electrically connected to an infrared temperature measuring transmitter22built in the controller24, and is configured to detect a temperature of the vacuum switching tube1in the switching and closing processes; the arc guide19is electrically connected to an arc light transmitter20built in the controller24, and is configured to detect arc light intensity generated in the vacuum switching tube1in the switching and closing processes; and the infrared temperature measuring transmitter22and the arc light transmitter20are electrically connected to the intelligent circuit23, and the intelligent circuit23performs calculation according to the detected temperature and arc light intensity to generate switching-closing parameters having a small arc and a small temperature rise.

Further, the infrared temperature measuring light guide21and the arc guide19are both formed of optical fiber bundles.

Further, the switching-closing mechanism connecting piece15includes a mechanism body, the transmission piece12, the switching mechanism13, and the closing mechanism14; the switching mechanism13and the closing mechanism14are located within the mechanism body and are fixed to one end of the transmission piece12, and the other end of the transmission piece12extends out of the mechanism body.

Further, the switching mechanism13includes a magnetic cylinder disposed within the mechanism body and a switching coil fixed to the transmission piece12, and the closing mechanism14includes a magnetic cylinder disposed within the mechanism body and a closing coil fixed to the transmission piece12.

Further, the emitting light guide7and the receiving light guide8are formed of optical fiber bundles having a photosensitive characteristic.

Further, a first light condensing device is disposed at the light outlet of the emitting light guide7, a second light condensing device is disposed at the light inlet of the receiving light guide8, and the first light condensing device and the second light condensing device are both formed of lenses or lens groups.

For the intelligent integrated medium-voltage AC vacuum switchgear based on a flexible switching-closing technology according to the present invention, in application, a vacuum switching tube is connected to a medium-voltage power grid circuit by using a lead. A travel sensor of the present invention is, for example, a grating sheet, and is directly mounted on and is fixed to a movable contact connecting rod of the vacuum switching tube, and directly detects a motion state of a movable contact of the vacuum switching tube, so that motion parameters of the movable contact can be accurately represented. A human-machine interaction device connected to a controller is used to set parameters, so that the switching-closing performance of switching on and switching off the medium-voltage power grid can be greatly improved. “Flexible” switching-closing is achieved, and switching-closing time points can be accurately controlled. An over-travel spring is disposed within an insulator, so that on one hand, in a closed state, high enough pressure is provided between the movable contact and the fixed contact of the vacuum switching tube, and on the other hand, quick bounce-free switching is achieved. In the switching and closing processes, the harmful impact on the power grid, loads and a switch is quite small, and a demand on construction of a strong intelligent power grid is met.

Beneficial Effects

A travel sensor is directly mounted and is fixed to a movable contact connecting rod of a vacuum switching tube, and directly detects a motion state of a movable contact of the vacuum switching tube, so that motion parameters of the movable contact can be accurately represented. A human-machine interaction device connected by using a controller is used to set parameters, so that the switching-closing performance is greatly improved. Switching-closing time points can be accurately controlled, and “flexible” switching-closing operations are achieved.

By means of an over-travel spring disposed in an insulator, on one hand, in a closed state, enough pressure is maintained between the movable contact and the fixed contact of the vacuum switching tube, and on the other hand, quick bounce-free switching is achieved during switching.

In the switching and closing processes, the harmful impact on the power grid, loads and a switch is quite small, and a demand on construction of a strong intelligent power grid is met.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

To illustrate the technical solutions and technical objectives of the present invention, the present invention is further described below with reference to the accompanying drawings and specific embodiments.

As shown inFIG. 1, an intelligent integrated medium-voltage AC vacuum switchgear based on a flexible switching-closing technology according to the present invention includes: a vacuum switching tube1, an insulator9, a switching-closing mechanism connecting piece15, and a controller24. The vacuum switching tube1, the insulator9, and the switching-closing mechanism connecting piece15are axially connected in sequence. The controller24includes an intelligent circuit23, a grating travel transmitter16, a switching control interface circuit17, a closing control interface circuit18, an arc light transmitter20, and an infrared temperature measuring transmitter22. A microprocessor is built in the intelligent circuit23, and is configured to calculate switching-closing operating parameters. The grating travel transmitter16, the switching control interface circuit17, the closing control interface circuit18, the arc light transmitter20, and the infrared temperature measuring transmitter22are all electrically connected to the intelligent circuit23. A grating sheet6is disposed on a movable contact connecting rod5of the vacuum switching tube1. An emitting light guide7is disposed on one side of the grating sheet6, and a receiving light guide8is disposed on the other side of the grating sheet6. An end face of a light inlet of the receiving light guide8is directly opposite to an end face of a light outlet of the emitting light guide7. The emitting light guide7and the receiving light guide8are connected to the grating travel transmitter16. The emitting light guide7and the receiving light guide8are formed of optical fiber bundles having a photosensitive characteristic. The optical fiber bundle is made of a high-voltage resistant material such as a quartz material, so that the voltage resistant strength between the two end faces of the emitting light guide7and the receiving light guide8exceeds a medium-voltage rated voltage by more than 2 times, so as to ensure that insulation safety is met. The switching-closing mechanism connecting piece15includes a transmission piece12, a switching mechanism13, and a closing mechanism14. The switching mechanism13and the closing mechanism14are connected to one end of the transmission piece12, and the switching mechanism13, the closing mechanism14, and the transmission piece12are coaxial. The other end of the transmission piece12is fixedly connected to the insulator9. The switching mechanism13and the closing mechanism14are electrically connected to the switching control interface circuit17and the closing control interface circuit18, respectively. A first light condensing device is disposed at the light outlet of the emitting light guide7and a second light condensing device is disposed at the light inlet of the receiving light guide8, in order to improve signal detection sensitivity. The first light condensing device and the second light condensing device are both formed of lenses or lens groups.

The intelligent circuit23, the switching control interface circuit17, the closing control interface circuit18, the switching mechanism13, the closing mechanism14, the switching-closing mechanism connecting piece15, the transmission piece12, the insulator9, a piston10, an over-travel spring11, and the movable contact connecting rod5form a switching-closing control system. During closing, the intelligent circuit23outputs a closing weak-current control electrical signal, and the signal is subjected to power amplification by the closing control interface circuit18, so as to drive the closing mechanism14connected to the switching-closing mechanism connecting piece15to move, and thus drive a movable contact4to move upwards through the transmission piece12, the insulator9, and the movable contact connecting rod5, to come into contact with a fixed contact2, thereby achieving a closing operation. During switching, the intelligent circuit23outputs a switching weak-current control electrical signal, and the signal is subjected to power amplification by the switching control interface circuit17, so as to drive the switching mechanism13connected to the switching-closing mechanism connecting piece15to move, and thus drive the movable contact4to move downwards through the transmission piece12, the insulator9, and the movable contact connecting rod5, to disengage from the fixed contact2, thereby achieving a switching operation.

Switching-closing operating parameters of the movable contact are directly measured. A travel sensor is directly mounted and is fixed to the movable contact connecting rod of the vacuum switching tube, and directly detects a motion state of a movable contact of the vacuum switching tube. During switching and closing, the movable contact connecting rod5carries the grating sheet6disposed thereon to move together. Detection light emitted by a light-emitting tube in the grating travel transmitter16passes through the emitting light guide7, is condensed by a light condensing device, and is directed to the grating sheet6. The receiving light guide8receives dynamic light which transmits through the grating sheet6and is related to motion parameters of the movable contact4. The grating travel transmitter16receives the dynamic light which is incident on the light guide8. The grating travel transmitter16processes the dynamic light and sends the processed light to the intelligent circuit23for processing such as analysis and calculation to obtain the motion parameters such as travel, over-travel, speed, and acceleration of the movable contact4. In the switching and closing processes, the intelligent circuit23directly monitors the motion parameters of the movable contact4, and adjusts driving parameters of the switching mechanism and closing mechanism, so that the switching and closing have “flexible” features in which a short time is required, time points can be controlled, and no bounce occurs in the processes.

An arc guide19, the arc light transmitter20, an infrared temperature measuring light guide21, the infrared temperature measuring transmitter22, and the intelligent circuit23form a flexible switching-closing monitoring system. A major objective of the flexible switching and closing is to achieve a small arc between the movable contact4and the fixed contact2in the switching and closing processes and a small temperature rise between the movable contact4and the fixed contact2during closing. The intelligent circuit23detects an arc degree in the switching and closing processes by means of the arc guide19and the arc light transmitter20, monitors a temperature rise during closing by means of the infrared temperature measuring light guide21and the infrared temperature measuring transmitter22, and performs comprehensive processing on the obtained motion parameters such as travel, over-travel, speed, and acceleration of the movable contact4, so as to obtain control parameters for accurate switching and closing, thereby achieving flexible switching and closing. Therefore, an arc is minimized in the switching and closing processes, and a temperature rise is minimized during closing, so as to meet a demand on construction of a strong intelligent power grid.

A cylinder having an opening at the top is disposed at an upper portion of the insulator9. The over-travel spring11and the piston10are sequentially disposed within the cylinder. One end of a piston rod penetrating the top opening of the insulator9is fixedly connected to the piston10. The other end of the piston rod is fixedly connected to the movable contact connecting rod5of the vacuum switching tube1. The piston10and the over-travel spring11enable, after the movable contact4is contacted with the fixed contact2in the closing process, the insulator9and the like to continue to move upwards by a travel (referred to as an over-travel). The over-travel spring11is a compression spring, or may be a disc spring. On one hand, in a closed state, enough pressure is maintained between the movable contact and the fixed contact of the vacuum switching tube, so that the movable contact and the fixed contact are in sufficient contact, thereby reducing a contact resistance. On the other hand, during switching, the movable contact4has certain acceleration before disengaging from the fixed contact2, so that the movable contact4rapidly accelerates during switching and reaches a certain movement speed, so as to achieve quick bounce-free switching and ensure switching quality.

The vacuum switching tube1includes a housing, the fixed contact2, a fixed contact connecting rod3, the movable contact4, and the movable contact connecting rod5. One end of the fixed contact connecting rod3is fixedly connected to the fixed contact2and is located within the housing, and the other end of the fixed contact connecting rod3is fixed to the housing and extends out of the housing. One end of the movable contact connecting rod5is fixedly connected to the movable contact4and is located within the housing, and the other end of the movable contact connecting rod5penetrates the housing and is connected to the housing in a slideable and sealed manner. The fixed contact connecting rod3and the movable contact connecting rod5are coaxially arranged, that is, are disposed on two opposite sides of the housing respectively. A light transmission part used for light measurement is disposed on the housing. The infrared temperature measuring light guide21and the arc guide19are disposed on an outer side of the light transmission part of the vacuum switching tube1. The infrared temperature measuring light guide21is electrically connected to the infrared temperature measuring transmitter22built in the controller24, and is configured to detect a temperature of the vacuum switching tube1in the switching and closing processes. The arc guide19is electrically connected to the arc light transmitter20built in the controller24, and is configured to detect arc light intensity generated in the vacuum switching tube1in the switching and closing processes. The infrared temperature measuring transmitter22and the arc light transmitter20are electrically connected to the intelligent circuit23. The intelligent circuit23performs calculation according to the detected temperature and arc light intensity to generate switching-closing parameters having a small arc and a small temperature rise. The infrared temperature measuring light guide21and the arc guide19are both formed of optical fiber bundles, and serve as optical channels for optical signal detection.

The switching-closing mechanism connecting piece15includes a mechanism body, the transmission piece12, the switching mechanism13, and the closing mechanism14. The switching mechanism13and the closing mechanism14are located within the mechanism body and are fixed to one end of the transmission piece12. The other end of the transmission piece12extends out of the mechanism body. The switching mechanism13includes a magnetic cylinder disposed within the mechanism body and a switching coil fixed to the transmission piece12. The closing mechanism14includes a magnetic cylinder disposed within the mechanism body and a closing coil fixed to the transmission piece12. The switching coil and the closing coil are electrically connected to the switching control interface circuit17and the closing control interface circuit18, respectively.

For the intelligent integrated medium-voltage AC vacuum switchgear based on a flexible switching-closing technology according to the present invention, in application, a vacuum switching tube is connected to a medium-voltage power grid circuit by using a lead. A travel sensor of the present invention is, for example, a grating sheet, and is directly mounted on and is fixed to a movable contact connecting rod of the vacuum switching tube, and directly detects a motion state of a movable contact of the vacuum switching tube, so that motion parameters of the movable contact can be accurately represented. A human-machine interaction device connected to a controller is used to set parameters, so that the switching-closing performance of switching on and switching off the medium-voltage power grid can be greatly improved. Switching-closing time points can be accurately controlled and “flexible” switching-closing is achieved. An over-travel spring is disposed within an insulator, so that on one hand, in a closed state, high enough pressure is provided between the movable contact and the fixed contact of the vacuum switching tube, and on the other hand, quick bounce-free switching is achieved. In the switching and closing processes, the harmful impact on the power grid, loads and a switch is quite small, and a demand on construction of a strong intelligent power grid is met.

Compared with the prior art, the present invention has the following technical advancement.

1) A travel sensor is directly mounted and is fixed to a movable contact connecting rod of a vacuum switching tube, and directly detects a motion state of a movable contact of the vacuum switching tube, so that motion parameters of the movable contact can be accurately represented. A human-machine interaction device connected to a controller is used to set parameters, so that the switching-closing performance is greatly improved. Switching-closing time points can be accurately controlled, and “flexible” switching-closing operations are achieved.

2) By means of an over-travel spring disposed in an insulator, on one hand, in a closed state, enough pressure is maintained between the movable contact and the fixed contact of the vacuum switching tube, and on the other hand, quick bounce-free switching is achieved during switching.

3) In the switching and closing processes, the harmful impact on the power grid, loads and a switch is quite small, and a demand on construction of a strong intelligent power grid is met.

The basic principles and main features of the present invention and the advantages of the present invention are shown and described above. A person skilled in the art should understand that the present invention is not limited to the foregoing embodiments. Only the principles of the present invention are described in the foregoing embodiments and the description. Various variations and modifications may further be made to the present invention without departing from the spirit and scope of the present invention. The protection scope of the present invention is defined by the appended claims, the description, and equivalents thereof.