CN111313304A

CN111313304A - Power switch cabinet

Info

Publication number: CN111313304A
Application number: CN201811514146.2A
Authority: CN
Inventors: 吴长兰; 其他发明人请求不公开姓名
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-12-11
Filing date: 2018-12-11
Publication date: 2020-06-19

Abstract

The invention belongs to the field of switch cabinets, and particularly discloses a power switch cabinet which comprises a cable compartment, a bus compartment, a breaker compartment and a control compartment. The bus compartment is internally provided with a bus copper bar, an incoming line contact box, an outgoing line contact box and a current transformer. A1 st handcart and a circuit breaker are arranged in the circuit breaker compartment, the 1 st handcart is assembled with the circuit breaker compartment through a 1 st guide rail, the circuit breaker is fixed on the 1 st handcart, and an incoming line contact of the circuit breaker is matched with an incoming line contact box, and an outgoing line contact is matched with an outgoing line contact box. The breaker is internally provided with a switching-on and switching-off mechanism which is composed of an elastic damper, an electromagnetic driver, an insulating cylinder and a vacuum bulb which are fixedly connected in the axial direction. The controller is arranged in the control compartment and is electrically connected with the electromagnetic driver and the current transformer respectively. The elastic damper absorbs partial energy of the opening and closing mechanism before closing, inhibits the moving contact of the circuit breaker from generating closing bounce, avoids generating closing bounce arcing and explosion caused by arcing, and improves the closing performance and safety of the switch cabinet.

Description

Power switch cabinet

Technical Field

The invention relates to a switch cabinet, in particular to an electric switch cabinet suitable for reducing switch-on arcing, and belongs to the field of electric equipment.

Background

The switch cabinet is widely applied to industries such as power plants, petroleum, chemical engineering, metallurgy, textile, high-rise buildings and the like, and is used for power transmission, power distribution and electric energy conversion. The switch cabinet is internally provided with a circuit breaker used for controlling the on-off of the primary circuit. Switch cabinet is at the application, and its circuit breaker often takes place the combined floodgate bounce, leads to producing the arcing between circuit breaker moving contact, the static contact, and the switching-on bounce is arcing promptly, and the arcing ablation makes moving contact, the static contact of circuit breaker easily damaged, causes the life of circuit breaker short, need consume a large amount of manpowers, material resources to maintain the switch cabinet, and application, maintenance cost are higher. In addition, arcing is generated between a moving contact and a fixed contact of the circuit breaker, the internal temperature of the circuit breaker is rapidly increased, high temperature and high pressure are generated to cause explosion, major accidents are caused, and the safe operation of a power grid is influenced.

Disclosure of Invention

The invention mainly aims to provide a power switch cabinet, which aims to solve the technical problem that the power switch cabinet is easy to generate switching-on bounce and arcing during switching-on in the prior art.

In order to achieve the purpose, the invention provides a power switch cabinet, which is characterized in that: the switch cabinet comprises a cable compartment 10, a bus compartment 20, a breaker compartment 30 and a control compartment 50 which are enclosed by metal plates and are in a closed state, wherein the cable compartment 10 and the bus compartment 20 are positioned at the rear side of the switch cabinet, and the cable compartment 10 is positioned at the lower side of the bus compartment 20; the breaker compartment 30 and the control compartment 50 are positioned on the front side of the switch cabinet, the breaker compartment 30 is positioned in front of the bus compartment 20 and is adjacent to the bus compartment 20, and the control compartment 50 is positioned on the upper side of the breaker compartment 30; a bus copper bar 24, an incoming line contact box 23, an outgoing line contact box 22 and a current transformer 21 are arranged in the bus compartment 20, the bus copper bar 24 is electrically connected with the incoming line contact box 23, the outgoing line contact box 22 is electrically connected with an incoming line end of the current transformer 21, and an outgoing line end of the current transformer 21 is suitable for being electrically connected with an outgoing line cable 11 arranged in the cable compartment 10; the circuit breaker compartment 30 is internally provided with a 1 st handcart 31 and a circuit breaker 32, the 1 st handcart 31 is assembled with the circuit breaker compartment 30 through a 1 st guide rail, the circuit breaker 32 is arranged on the 1 st handcart 31 and is fixed, an incoming line contact of the circuit breaker 32 is matched with an incoming line contact box 23 in a coaxial line manner, an outgoing line contact is matched with an outgoing line contact box 22 in a coaxial line manner, the circuit breaker 32 is internally provided with a switching-on and switching-off mechanism, and the switching-on and switching-off mechanism at least comprises an elastic damper 100, an electromagnetic driver 323, an insulating cylinder 322 and a vacuum bubble 321 which are fixedly connected in an axial direction; the control compartment 50 is internally provided with a controller 52, and the controller 52 is electrically connected with the electromagnetic driver 323 and the current transformer 21 respectively and is suitable for controlling the breaker 32 to open and close and obtaining the load current of the switch cabinet.

In the application and implementation process, the invention also has the following optional technical scheme.

Optionally, a 1 st drive mechanism disposed within the circuit breaker compartment 30 is also included and adapted to drive the 1 st trolley 31 to reciprocate along the 1 st rail.

Optionally, the cable compartment 10 houses an arrester 13 and a grounding switch 14, wherein one end of the arrester 13 is electrically connected with a terminal of the grounding switch 14, and the other end is electrically connected with a grounding bar; the terminal of the grounding knife switch 14 is electrically connected with the outlet terminal of the current transformer 21.

Optionally, a voltage transformer compartment 40 is further included, the voltage transformer compartment 40 being adjacent to the cable compartment 10, below the circuit breaker compartment 30; a 2 nd handcart 41, a voltage transformer 42 and a pressure measuring contact box 43 are arranged in the voltage transformer compartment 40, and the pressure measuring contact box 43 is fixed in the voltage transformer compartment and is electrically connected with a wire outlet end of the current transformer 21; the No. 2 handcart 41 is assembled with a voltage transformer compartment through a No. 2 guide rail, a voltage transformer 42 is arranged on the No. 2 handcart 41 and is fixed, and a contact of the voltage transformer 42 is coaxially matched with a pressure measuring contact box 43.

Optionally, a 2 nd driving mechanism arranged in the voltage transformer compartment 40 is further included and is suitable for driving the 2 nd handcart 41 to reciprocate along the 2 nd guide rail.

Optionally, the bullet arrester 100 includes a cylinder 110, a piston mechanism 120 and a drainage mechanism 130 in a closed state; the piston mechanism 120 comprises a piston 121 arranged in the cylinder 110, and a piston rod 122 with one end extending into the cylinder 110 and fixed with the piston 121, wherein a damping hole 123 is arranged on the piston 121; the drainage mechanism 130 comprises a drainage hole 131, a drainage valve core 133, a 1 st return spring 134 and an end plate 135, which are arranged on the piston 121, wherein a drainage valve seat 132 on the rod cavity side is arranged in the drainage hole 131; the drain valve core 133 and the 1 st return spring 134 are assembled in the drain hole 131, the end plate 135 positioned on the rodless cavity side is fixed with the drain hole 131, the 1 st return spring is in a compressed state, and the drain valve seat 132 is in sealing fit with the drain valve core 133; the exhaust contact rod 1332 of the exhaust valve core 133 protrudes from the upper end face of the piston 121 and protrudes into the rod chamber.

Optionally, the bullet arrester 100 further includes a flow blocking mechanism 140 for preventing the damping valence from flowing in the opposite direction in the discharge hole 131, the flow blocking mechanism 140 includes a flow blocking hole 141, a flow blocking valve core 143, a 2 nd return spring 144 and a pressure plate 145 which are disposed in the end plate 135, an upper end portion of the flow blocking hole 141 is disposed on the valve core seat 142, the flow blocking valve core 143 and the 2 nd return spring 144 are assembled in the flow blocking hole 141, the pressure plate 145 and a lower end portion of the flow blocking hole 142 are fixed, the 2 nd return spring 144 is in a compressed state, and the flow blocking valve core 143 and the valve core seat 142 are in sealing engagement.

Optionally, the power switch cabinet further includes a high-voltage isolating switch, the high-voltage isolating switch is disposed in the bus compartment 10, the bus copper bar 24 is electrically connected to the incoming line end of the high-voltage isolating switch, and the outgoing line end of the high-voltage isolating switch is electrically connected to the incoming line contact box 23.

Optionally, a zero sequence current transformer 12 is further configured in the cable compartment 10, and is adapted to be sleeved outside the outgoing cable 11; the zero sequence current transformer 12 is fixed with the cable compartment 10 by a bracket.

Optionally, a 1 st temperature sensor adapted to detect the temperature of the incoming line contact box 23 and a 2 nd temperature sensor adapted to detect the temperature of the outgoing line contact box 22 are further included, and the 1 st temperature sensor and the 2 nd temperature sensor are electrically connected with the controller 52 respectively.

The power switch cabinet comprises a cable compartment, a bus compartment, a breaker compartment and a control compartment which are enclosed by metal plates and are in a closed state. The cable compartment and the bus compartment are positioned on the rear side of the switch cabinet, and the cable compartment is positioned on the lower side of the bus compartment. The circuit breaker compartment and the control compartment are located on the front side of the switch cabinet, the circuit breaker compartment is located in front of the bus compartment and is adjacent to the bus compartment, and the control compartment is located on the upper side of the circuit breaker compartment. The bus compartment is internally provided with a bus copper bar, an incoming line contact box, an outgoing line contact box and a current transformer, the bus copper bar is electrically connected with the incoming line contact box, the outgoing line contact box is electrically connected with an incoming line end of the current transformer, and an outgoing line end of the current transformer is suitable for being electrically connected with an outgoing line cable arranged in the cable compartment. The built-in 1 st handcart of circuit breaker compartment and circuit breaker, the assembly of 1 st handcart through 1 st guide rail and circuit breaker compartment, the circuit breaker setting is on 1 st handcart and fixed, and the inlet wire contact of circuit breaker cooperates with inlet wire contact box coaxial line, the contact of being qualified for the next round of competitions cooperates with the contact box coaxial line of being qualified for the next round of competitions, the built-in divide-shut brake mechanism of circuit breaker, this divide-shut brake mechanism constitute by bullet ware, electromagnetic drive ware, insulating cylinder and the vacuum bulb of hindering of axial fixity connection at least. The controller is arranged in the control compartment, is electrically connected with the electromagnetic driver and the current transformer respectively, and is suitable for controlling the opening and closing of the circuit breaker and obtaining the load current of the switch cabinet.

Compared with the prior art, the invention has the beneficial effects that: the switch cabinet is internally provided with the elastic damper, the elastic damper absorbs partial kinetic energy of a moving contact of the circuit breaker before switching on, the instantaneous speed of switching on is reduced, the moving contact of the circuit breaker is restrained from generating switching-on bounce, switching-on bounce arcing between the moving contact and the static contact is reduced, the service life of the circuit breaker is prolonged, explosion caused by arcing of the circuit breaker is avoided, and the switching-on performance and safety of the switch cabinet are improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive labor.

Fig. 1 is a schematic diagram of an embodiment of a power switchgear.

Fig. 2 is a schematic structural diagram of the circuit breaker.

Fig. 3 is a schematic structural diagram of the bullet arrester.

Fig. 4 is an enlarged view of the AA region in fig. 3.

The system comprises a 10-cable compartment, a 11-outgoing cable, a 12-zero sequence current transformer, a 13-lightning arrester, a 14-grounding disconnecting link, a 20-bus compartment, a 21-current transformer, a 22-outgoing line contact box, a 23-incoming line contact box, a 24-bus copper bar, a 25-insulating sleeve, a 30-circuit breaker compartment, a 31-1 st handcart, a 32-circuit breaker, a 321-vacuum bulb, a 322-insulating cylinder, a 323-electromagnetic driver, a 40-voltage transformer compartment, a 41-2 nd handcart, a 42-voltage transformer, a 43-pressure measuring contact box, a 50-control compartment, a 51-relay group, a 52-controller and a 53-touch screen; 100-damper, 110-cylinder, 111-cylinder, 112-1 st end cover, 113-2 nd end cover, 114-shaft pressure plate, 115-1 st sealing ring, 116-2 nd sealing ring, 120-piston mechanism, 121-piston, 122-piston rod, 123-damping hole, 124-3 rd sealing ring, 125-4 th sealing ring, 130-drainage mechanism, 131-drainage hole, 132-drainage valve seat, 133-drainage valve core, 1331-valve core part, 1332-drainage contact rod, 134-1 st return spring, 135-end plate, 140-flow blocking mechanism, 141-flow blocking hole, 142-valve core seat, 143-flow blocking valve core, 144-2 nd return spring, 145-pressure plate.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application. The directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship between the components, the movement, etc. in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indication is changed accordingly.

As described in the background art, when a switch cabinet is operated to be switched on in the prior art, a circuit breaker is often subjected to switching-on bounce, so that arcing is generated between a moving contact and a fixed contact of the circuit breaker, that is, the switching-on bounce is generated, the moving contact and the fixed contact of the circuit breaker are easily damaged due to arcing ablation, the service life of the circuit breaker is shortened, a large amount of manpower and material resources are consumed to maintain the switch cabinet in a daily use process, and the application and maintenance cost is high. In addition, arcing is generated between a moving contact and a fixed contact of the circuit breaker, the internal temperature of the circuit breaker rises rapidly, high temperature and high pressure are generated, the circuit breaker is exploded, major accidents are caused, and the safe operation of a power grid is influenced.

The inventor further researches and discovers that the main reason that the switch cabinet breaker generates the switching-on bounce arcing is that when the switch cabinet is closed, the speed of a moving contact of the breaker is very high, the energy is very large, the moving contact generates reverse bounce when colliding with a fixed contact, the reverse bounce speed is high, and in order to reduce or avoid the switching-on bounce generated by the moving contact of the breaker, the energy of the moving contact needs to be partially consumed before switching-on so as to reduce the energy at the moment of switching-on, inhibit the reverse bounce of the moving contact and further reduce the generation of the switching-on bounce arcing.

Based on above-mentioned research, the inventor provides a built-in power switch cabinet that has bullet-proof ware after many-sided analysis experiment, and when the cubical switchboard closed a floodgate, bullet-proof ware absorbed the circuit breaker moving contact, divide closing mechanism promptly, and partial energy reduces the instantaneous speed that the moving contact was closed a floodgate, and the suppression circuit breaker moving contact takes place the combined floodgate bounce, avoids taking place combined floodgate bounce and arcing, extension circuit breaker life to and avoid the circuit breaker to take place the arcing explosion. As an embodiment of the present invention, a power switchgear having a built-in damper includes a base frame serving as a structural support, and a cable compartment 10, a bus compartment 20, a breaker compartment 30, a voltage transformer compartment 40, and a control compartment 50 provided in the base frame, as shown in fig. 1. The cable compartment 10 and the bus compartment 20 are positioned at the rear side of the switch cabinet, and the cable compartment 10 is positioned at the lower side of the bus compartment 20; the breaker compartment 30 and the control compartment 50 are positioned on the front side of the switch cabinet, the breaker compartment 30 is positioned in front of the bus compartment 20 and is adjacent to the bus compartment 20, and the control compartment 50 is positioned on the upper side of the breaker compartment 30; the voltage transformer compartment 40 is provided on the lower side of the breaker compartment 3.

The base frame of the switch cabinet is a frame made of steel sectional materials, such as angle steel welded, plays a role in structural support and is a bearing foundation of the switch cabinet. The left side and the right side of the base frame are respectively fixed with a left metal plate and a right metal plate; the top end of the base frame is fixed with the cabinet top plate, and the bottom end of the base frame is fixed with the cabinet bottom plate; a front cabinet door is assembled on the front side of the base frame, and the front cabinet door comprises a control compartment cabinet door, a breaker compartment cabinet door and a voltage transformer compartment cabinet door; the rear side of the base frame is provided with a cable compartment cabinet door to enclose an inner space of the switch cabinet. The metal partition is provided to divide the internal space of the switchgear, is fixed to the inside of the switchgear, and sequentially divides the internal space of the switchgear into the above-described compartments, as described below. Alternatively, the left metal plate, the right metal plate and the metal partition plate for partitioning the compartment, which form the switch cabinet, are non-magnetic metal plates, such as aluminum, 200 stainless steel, 201 stainless steel, etc., to enhance the electromagnetic isolation effect.

The cable compartment 10 is a closed cavity structure formed by the metal plates fixed on the base frame, and the bus compartment 20 is a closed cavity structure formed by the metal plates fixed on the base frame, and the closed state can be a through hole suitable for communicating adjacent compartments in a physical structure, and electromagnetic waves in the compartments do not leak outwards in an electromagnetic structure, so that no electromagnetic interference influence exists between the adjacent compartments, and the robustness of the switch cabinet is improved. The cable compartment 10 and the bus compartment 20 are arranged on the rear side of the switch cabinet (the side of the switch cabinet with the operating panel, i.e. the side facing the user operating the switch cabinet, is the front side of the switch cabinet, see fig. 1, which is a left side view, the left side of fig. 1 is the rear side of the switch cabinet, and the right side is the front side of the switch cabinet, i.e. the side where the operating panel is located), and the cable compartment 10 is located on the lower side of the bus compartment 20; it is understood that the cable compartment 10, the bus bar compartment 20 are disposed at the rear side of the base frame, and the bus bar compartment 20 is disposed at the upper side of the cable compartment 10. The breaker compartment 30 is a closed cavity structure formed by the metal plates fixed on the base frame, and the control compartment 50 is a closed cavity structure formed by the metal plates fixed on the base frame; the closed state can be provided with a through hole suitable for communicating with adjacent compartments on a physical structure, and on an electromagnetic structure, the electromagnetic wave in the compartments does not leak outwards, so that no electromagnetic interference influence exists between the adjacent compartments. The breaker compartment 30, the control compartment 50 are arranged on the front side of the switchgear base frame, the breaker compartment 30 is arranged in front of the bus compartment 20 and adjacent to the bus compartment 20, it being understood that the breaker compartment 30 and the bus compartment 20 are at a corresponding height level with respect to the base frame, so that the two compartments are adapted. The control compartment 50 is disposed above the breaker compartment 30 and above the front side of the base frame, so that a user can conveniently check the operation parameters of the power switch cabinet and operate the switch cabinet, such as closing and opening operations.

As shown in fig. 1, the bus compartment 20 is provided with a bus copper bar 24, an incoming contact box 23, an outgoing contact box 22 and a current transformer 21. The current transformers 21 are three and are respectively used for detecting phase currents of three-phase power. The application field of the power switch cabinet is provided with three main bus copper bars, the three main bus copper bars correspond to three-phase three-wire systems of power transmission and are respectively used for transmitting three-phase electric energy outside the switch cabinet into the switch cabinet, for example, transmitting the electric energy at the low-voltage side of a transformer into the switch cabinet. The current transformer 21 is fixed within the bus bar compartment 20 and may be secured to a pedestal located at the bus bar compartment. The outgoing line contact box 22 and the incoming line contact box 23 are respectively fixed in the bus compartment 20 and close to one side of the breaker compartment. The outgoing line contact box 22 penetrates through a metal partition plate between the bus compartment 20 and the breaker compartment 30, an insulating sleeve is arranged between the outgoing line contact box 22 and the metal partition plate, the insulating sleeve protrudes out of two side faces of the metal partition plate, the insulating creepage distance is increased, and the electrical insulating property is improved; the incoming line contact box 23 penetrates through the metal partition plate, another insulating sleeve is arranged between the incoming line contact box 23 and the metal partition plate, and the another insulating sleeve protrudes out of two side faces of the metal partition plate, so that the insulating creepage distance is increased, and the electrical insulating property is improved. The corresponding rectangular wall through holes are formed in the wall through plate, which is suitable for the main bus copper bar to penetrate through, of the bus compartment 20. The main busbar copper bars extend into the busbar compartment 20 through the wall-passing holes. An insulating sleeve 25 is arranged between the main bus copper bar and the wall penetrating plate, the insulating sleeve 25 protrudes out of two side faces of the wall penetrating plate, the insulating creepage distance is increased, the electric insulating property is improved, and the main bus copper bar is electrically insulated and isolated from the wall penetrating plate. The bus copper bar 24 is three. One end of the bus copper bar 24 is fixed and electrically connected with the main bus copper bar, and the other end of the bus copper bar 24 is fixed and electrically connected with the three wiring ends corresponding to the incoming line contact box 23. The wire inlet end of the current transformer 21 and the wire connecting end of the wire outlet contact box 22 are respectively fixed and electrically connected through conductive copper bars.

The circuit breaker compartment 30, as shown in fig. 1, houses a first trolley 31 and a circuit breaker 32. The 1 st guide rail is fixed at the bottom of the breaker compartment 30, and the 1 st guide rail is arranged along the front-back direction of the switch cabinet, namely the left-right direction of fig. 1; the 1 st handcart 31 is matched with the 1 st guide rail, and the 1 st handcart 31 can reciprocate back and forth along the 1 st guide rail. The circuit breaker 32 is assembled and fixed on the first handcart 31 1, and the incoming line contact and the outgoing line contact of the circuit breaker 32, which are respectively positioned above and below, are respectively matched with the incoming line contact box 23 and the outgoing line contact box 22, that is, the incoming line contact of the circuit breaker 32 is matched with the contact hole of the incoming line contact box 23, which is suitable for the incoming line contact to be inserted, and the outgoing line contact is matched with the contact hole of the outgoing line contact box 22, which is suitable for the outgoing line contact to be inserted. And the 1 st trolley 31 is operated to reciprocate back and forth along the 1 st guide rail, so that the circuit breaker 32 is switched between a test position and a working position. The breaker 32 incorporates a switching mechanism, which is composed of at least a damper 100, an electromagnetic actuator 323, an insulating cylinder 322, and a vacuum bulb 321, as shown in fig. 2. The vacuum bulb 321 includes a vacuum chamber, and a moving contact and a static contact penetrating the vacuum chamber and disposed therein, wherein the static contact is electrically connected to the incoming line contact, and the moving contact is electrically connected to the outgoing line contact. An output shaft of the bullet arrester 100 is connected with one end shaft of an output shaft of an electromagnetic driver 323, the other end of the output shaft of the electromagnetic driver 323 is connected with one end shaft of an insulating cylinder 322, and the other end shaft of the insulating cylinder 322 is connected with a movable contact shaft of a vacuum bubble 321; it is understood that the bullet arrester 100, the electromagnetic driver 323, the insulating cylinder 322 and the vacuum bulb 321 are axially connected in sequence and fixed. The aforementioned arrester 100, the electromagnetic driver 323, the insulating cylinder 322, and the vacuum bulb 321 are respectively assembled and fixed with the base frame of the circuit breaker. In addition, in order to realize the automatic control of the switch cabinet, a 1 st driving mechanism is further arranged in the circuit breaker compartment 30 and is suitable for driving the 1 st trolley 31 to reciprocate back and forth along the 1 st guide rail, so that the 1 st trolley 31 is automatically switched between a test position and a working position, namely, the circuit breaker 32 is switched between the test position and the working position. The 1 st driving mechanism can be an electromagnetic driving mechanism, can also be a driving mechanism consisting of a motor and a screw rod mechanism, and can also be formed by an oil cylinder or an air cylinder.

In order to further monitor the contact state between the contact box and the contact and avoid arcing caused by poor contact, the bus compartment 10 is internally provided with a 1 st temperature sensor and a 2 nd temperature sensor. The 1 st temperature sensor and the 2 nd temperature sensor adopt infrared temperature sensors. Through holes penetrating through the side walls of the insulating sleeves sleeved outside the outgoing line contact box 22 and the incoming line contact box 23 are respectively arranged on the insulating sleeves to serve as temperature measuring windows so that the infrared temperature sensors can detect the temperature of the contact boxes. The 1 st temperature sensor faces the temperature measuring window of the insulating sleeve assembled on the incoming line contact box 23 and is suitable for detecting the temperature of the incoming line contact box 23, and the 2 nd temperature sensor faces the temperature measuring window of the insulating sleeve assembled on the outgoing line contact box 22 and is suitable for detecting the temperature of the outgoing line contact box 22. The 1 st temperature sensor and the 2 nd temperature sensor are respectively electrically connected with the controller 52, and are suitable for the controller to acquire the temperatures of the incoming line contact box 23 and the outgoing line contact box 22, and when the temperatures are abnormal, an alarm is triggered or the breaker is operated to open the brake, so that accidents are avoided.

The bullet arrester 100, as shown in fig. 3, includes a cylinder 110, a piston mechanism 120, and a discharge mechanism 130 in a closed state. The cylinder block 110 includes a cylindrical cylinder 111, a 1 st end cap 112, and a 2 nd end cap 113. The upper end and the lower end of the cylinder barrel 111 are provided with openings, and the 1 st end cover 112 covers the upper end opening of the cylinder barrel 111 and realizes sealing and fixing in an integrated forming mode; the 2 nd end cap 113 is fixed to the lower end opening of the cylinder 111, and the 1 st packing 115 seals between the 2 nd end cap 113 and the cylinder 111. The piston mechanism 120 includes a piston 121 and a piston rod 122. The piston 121 is arranged in the cylinder body 110, one end part of the piston rod 122 penetrates through a through hole in the middle of the 1 st end cover 112, extends into the cylinder body 110, and is fixed with the piston 121, and the piston rod 122 and the through hole in the middle of the piston 121 are sealed through a 3 rd sealing ring 124; the piston rod 122 is sealed with a through hole in the middle of the 1 st end cover 112 through a 2 nd sealing ring 116, and the shaft pressure plate 114 is sleeved on the piston rod 122 and fixed with the 1 st end cover 112 and used for extruding and limiting the 2 nd sealing ring 116 to ensure a good sealing effect; the piston 121 and the inner wall surface of the cylinder 111 are sealed by a 4 th seal ring 125. The piston 121 divides the inner space of the cylinder 110 into a rod chamber located above and a rod-less chamber located below, as shown in fig. 3. The piston 121 is provided with a damping hole 123, which is suitable for allowing damping medium in the rod cavity to flow into the rodless cavity and damping medium in the rodless cavity to flow into the rod cavity, so as to release energy stored by the damping medium compressed and generate damping force to absorb energy of the movable contact of the switch cabinet. The area of the damping hole 123 is 0.6-1.3%, preferably 0.8% of the area of the piston 121, and the effect of suppressing the closing bounce of the movable contact is good. The cylinder 110 is filled with a damping medium, preferably nitrogen, or other inert gas such as helium or neon. The cylinder 110 is filled with high pressure nitrogen gas having a pressure greater than one standard atmospheric pressure, and the pressure of the high pressure nitrogen gas is preferably 2 standard atmospheric pressures. The 2 nd end cap 113 is provided with a through hole extending in the axial direction thereof, and the through hole is fitted with an outside-in communication and inside-out blocking check valve. The design of the check valve facilitates the filling of the damping medium into the cylinder body 110 and prevents the leakage of the damping medium, i.e., facilitates the filling of the damping medium into the cylinder body 110. It should be noted that the damping medium may also be damping oil, and when the damping oil is selected as the damping medium, the area of the damping hole 123 is larger, and is 2-8%, preferably 5%, of the area of the piston.

When the switch cabinet is switched on, the switching-on and switching-off mechanism of the circuit breaker drives the piston of the damper 100 to move towards the direction of the rod cavity, the damping medium in the rod cavity is compressed by applying work, and the damping medium flows into the rodless cavity through the damping hole 123 to generate damping force and absorb partial energy of the switching-on and switching-off mechanism, namely partial energy of the vacuum bubble moving contact; the greater the speed of the piston 121, the greater the generated damping force, the greater the negative power applied to the switching-on and switching-off mechanism, and the greater the energy consumed by the switching-on and switching-off mechanism, the smaller the energy of the movable contact at the moment of switching-on, and the smaller the energy of the reverse bounce of the movable contact, which is beneficial to inhibiting the switching-on bounce of the movable contact. At the moment of closing the switch cabinet, the speed of the piston 121 is the largest, the generated damping force is the largest, and the elastic damper 100 effectively absorbs the energy of the opening and closing mechanism, namely the energy of the moving contact of the circuit breaker, so that the speed of the moving contact at the moment of closing the switch cabinet is reduced, the moving contact of the circuit breaker is restrained from generating reverse bounce when closing the switch cabinet, the occurrence of switch-on bounce arcing of the moving contact is reduced, and the service life of the circuit breaker is prolonged.

Wherein, the cable compartment 10 is internally provided with a zero sequence current transformer 12, a lightning arrester 13 and a grounding knife switch 14. The earthing switch 14 is fixed to the side of the cable compartment 10, on the rear side of the switchgear cabinet. The lightning arrester 13 is fixed to the bottom of the cable compartment 10 by means of a mounting bracket. One end of the lightning arrester 13 is electrically connected to the terminal of the grounding switch 14, and the other end is electrically connected to the ground bar. The wiring end of the grounding switch 14 is fixed and electrically connected with the wire outlet end of the current transformer 21 through a conductive copper bar, the conductive copper bar penetrates through a wall penetrating hole in the metal plate between the cable compartment 10 and the bus compartment 20, and an insulating sleeve is arranged between the conductive copper bar and the wall penetrating hole of the metal plate, so that the conductive copper bar is electrically insulated and isolated from the metal plate. In order to overhaul the switch cabinet more safely, a high-voltage isolating switch, which can be called a front isolating switch, can be connected in series between the front end side (i.e. the electric energy input end) of the circuit breaker and the bus copper bar 24. The high-voltage isolating switch is positioned in the bus compartment 20, the wire inlet end of the high-voltage isolating switch is electrically connected with the bus copper bar 24, and the wire outlet end of the high-voltage isolating switch is electrically connected with the wire inlet contact box 23. The outgoing cable 11 is a power cable for transmitting electric energy flowing through the switchgear to the outside. An outgoing cable 11 extends into the cable compartment 10 from an outgoing hole at the bottom of the switch cabinet, as shown in fig. 1, the outgoing cable 11 and a terminal of the grounding disconnecting link 14 are fixed and electrically connected, that is, the outgoing cable 11 and a conductive copper bar fixed at an outgoing end of the current transformer 21 are fixed and electrically connected; the outgoing cable 11, the lightning arrester 13 and the grounding bar are electrically connected in sequence; the outgoing cable 11, the current transformer 21 and the outgoing contact box 22 are electrically connected in sequence. The zero sequence current transformer 12 is sleeved outside the outgoing cable 11. The zero sequence current transformer 12 is fixed by a bracket and cable compartment 10 and is electrically connected with the controller 52. The controller 52 obtains the zero sequence current value detected by the zero sequence current transformer 12, and when the zero sequence current value is not zero, the controller 52 triggers an abnormal alarm.

The control compartment 50 houses a relay set 51, a controller 52 and a touch screen 53. The circuit breaker 32 and the current transformer 21 are respectively electrically connected with the controller 52; the touch screen 53 is electrically connected to the controller 52. The controller 52 is suitable for operating the 1 st driving mechanism to automatically switch the 1 st handcart 31 between a test position and a working position; is suitable for controlling the switching-on and switching-off of the breaker 32 and controlling the on and off of the primary loop; the controller 52 is adapted to obtain the open and closed states of the circuit breaker 32 and the phase currents of the three-phase power and display them on the touch screen 53. Alternatively, the controller 52 is electrically connected to the 1 st driving mechanism via the relay set 51 and is adapted to operate the 1 st driving mechanism to move. The controller 52 may be formed by a PLC module, such as a PLC module of siemens S7-300 model available from siemens corporation. In this example, the controller 52 is specifically configured by a CPU 315-2DP processor module, an SM321 digital input module, an SM322 digital output module, an SM 331 analog input module, an SM 332 analog output module, an S7307 power supply module, and a CP 340 communication interface module.

Compared with the prior art, the power switch cabinet of the embodiment has the following beneficial technical effects: the built-in bullet ware that hinders of cubical switchboard absorbs the partial kinetic energy of circuit breaker moving contact before the combined floodgate, reduces the moving contact instantaneous speed of closing a floodgate, reduces the energy of the reverse bounce of moving contact, restraines the circuit breaker moving contact and takes place the combined floodgate bounce, reduces the moving contact and takes place combined floodgate bounce arcing, extension circuit breaker life-span to and avoid the circuit breaker to take place the arcing explosion, improve the combined floodgate performance and the security of cubical switchboard.

Further, the above described power switchgear is also provided with a voltage transformer compartment 40. The voltage transformer compartment 40 is a closed cavity structure surrounded by metal plates. This closed state can be understood as: the voltage transformer compartment can be provided with a through hole suitable for communicating with the adjacent compartment on the physical structure, and the electromagnetic structure means that electromagnetic waves in the compartment do not leak outwards, so that the adjacent compartment is free from electromagnetic interference influence. The voltage transformer compartment 40 is arranged in the lower part of the switchgear cabinet on the front side of the switchgear cabinet, as shown in fig. 1, the voltage transformer compartment 40 adjoining the cable compartment 10 below the circuit breaker compartment 30. The voltage transformer compartment 40 is internally provided with a 2 nd handcart 41, a voltage transformer 42 and a pressure measuring contact box 43. The pressure measuring contact box 43 penetrates through the rear side wall of the voltage transformer compartment 40 through an insulating sleeve and extends into the cable compartment 10, and the pressure measuring contact box 43 and the voltage transformer compartment 40 are fixed. The pressure measuring contact box 43, which projects into the cable compartment 10, is electrically connected to the connection terminal of the earthing switch 14. A No. 2 guide rail is arranged in the voltage transformer compartment 40, and the No. 2 guide rail is arranged along the front-back direction of the switch cabinet and fixed at the bottom of the voltage transformer compartment 40. The 2 nd handcart 41 is matched with the 2 nd guide rail, the 2 nd handcart 41 can move back and forth relative to the 2 nd guide rail, and the 2 nd handcart 41 is understood to be assembled with the voltage transformer compartment through the 2 nd guide rail. The voltage transformer 42 is arranged on the 2 nd handcart 41 and fixed, and the pressure measuring contact of the voltage transformer 42 is matched with the pressure measuring contact box 43, namely the pressure measuring contact of the voltage transformer 42 is matched with the contact hole of the pressure measuring contact box 43 which is suitable for inserting the pressure measuring contact coaxially. In addition, a 2 nd driving mechanism is also arranged in the voltage transformer compartment 40 and is suitable for driving a 2 nd handcart 41 to reciprocate back and forth along a 2 nd guide rail so as to automatically switch the 2 nd handcart 41 between a test position and a working position. The 2 nd driving mechanism can be an electromagnetic driving mechanism, can also be a driving mechanism consisting of a motor and a screw rod mechanism, and can also be formed by an oil cylinder or an air cylinder. The controller 52 is electrically connected to the 2 nd driving mechanism via the relay set 51 and is adapted to operate the 2 nd driving mechanism to reciprocate along the 2 nd guiding rail.

The voltage transformer 42 and the 2 nd driving mechanism are electrically connected to the controller 52, respectively. The controller 52 is suitable for operating the 2 nd driving mechanism to automatically switch the 2 nd handcart 41 between a test position and a working position; and acquiring the voltage detected by the voltage transformer 42, wherein the voltage comprises the line voltage and the phase voltage, displaying the voltage on the touch screen 53 for the user to check, analyzing the abnormal condition of the voltage, and generating an alarm by the controller 52 when the voltage is abnormal.

Although the aforementioned damper 100 can effectively reduce the occurrence of switch-on arcing in the switch cabinet, the damper is instantaneously closed, i.e., the damperThe piston (100) is close to the stroke end, the speed of the piston (or the moving contact) is the highest, the damping force is the largest, the energy stored in the damping medium in the rod cavity is higher, the piston after being switched on is driven to move in the reverse direction, namely the moving contact is driven to bounce in the reverse direction, and then the generation of switching-on bounce arcing is promoted. In order to solve the problem, the inventor improves the bullet arrester 100: the piston 121 is provided with the drainage mechanism 130, and the drainage mechanism 130 is triggered to drain before closing so that the damping medium in the rod cavity flows into the rodless cavity, and the energy stored by the damping medium in the rod cavity is released, so that the damping medium in the rod cavity is prevented from driving the moving contact to bounce reversely at the stroke end. The exhaust mechanism 130, as shown in fig. 3 and 4, includes an exhaust hole 131 provided in the piston 121, an exhaust spool 133, a 1 st return spring 134, and an end plate 135. The center portion of the end plate 135 is provided with a through hole adapted for the flow of a damping medium. The discharge hole 131 is a through hole penetrating the upper and lower end faces of the piston 121, and is a circular hole adapted to communicate the rod chamber and the rodless chamber. An exhaust valve seat 132 is provided in the exhaust hole 131, and the exhaust valve seat 132 is located on the rod chamber side, i.e., on the upper end face side of the piston 121. The drain spool 133 includes a spool portion 1331 and a drain stem 1332 that are axially fixed in sequence, with the spool portion 1331 and the drain stem 1332 alternatively co-axially mated. The drain valve 133 is inserted into the drain bore 131, and a drain contact rod 1332 of the drain valve 133 protrudes from an upper end face of the piston 121, and the height of the drain contact rod protruding from the upper end face of the piston 121 is denoted by H₀It is understood that the outlet stem 1332 of the outlet valve spool 133 projects from the upper end face of the piston 121 and projects into the rod chamber; the 1 st return spring 134 is then inserted into the discharge hole 131, and the end plate 135 is fixed to the lower end of the discharge hole 131, and the end plate 135 is located on the rodless chamber side, that is, the end plate 135 is fixed to the lower end surface of the piston 121. The exhaust valve seat 132, the exhaust valve spool 133, the 1 st return spring, and the end plate 135 are sequentially engaged. The 1 st return spring is in a compressed state and the exhaust valve seat 132 is in sealing engagement with the exhaust spool 133.

When the switch cabinet is operated to be switched on, the switching-on and switching-off mechanism of the circuit breaker 32 drives the moving contact of the vacuum bubble to move towards the fixed contact, the piston of the damper 100 is driven to move towards the side of the rod cavity, the damping medium in the rod cavity flows towards the rodless cavity through the damping hole on the piston to generate damping force, partial energy of the moving contact of the circuit breaker is absorbed, and the speed of the moving contact before switching-on is reduced, i.e., the energy is reduced, at the end of the stroke, the exhaust stem 1332 of the piston 121 strikes the first end cap 112, the exhaust mechanism 130 is triggered to exhaust, that is, the discharge valve element 133 moves away from the discharge valve seat 132, the damping medium in the rod chamber flows into the rodless chamber through the discharge hole 131, the energy stored in the damping medium in the rod chamber at the stroke end is released, the damping medium in the rod cavity can not promote the piston 121 to move reversely after the breaker is switched on, that is, the moving contact of the breaker can not be promoted to bounce after the breaker is switched on; it can be understood that the drainage mechanism 130 is adopted to effectively overcome the problem that the damping medium in the rod cavity promotes the switch cabinet moving contact to generate the switch-on bounce and the arcing, and further reduce the switch-on bounce and the arcing of the contact.

After the bullet arrester 100 disposes the drainage mechanism 130, when the cubical switchboard was closed, the closing temperature rise of the vacuum bubble of placing the circuit breaker in was compared and is reduced by a wide margin before, but its temperature is still too high, and to this abnormal phenomenon, the inventor has studied and found that drainage mechanism 130 makes bullet arrester 100 again can't absorb the reverse energy of bouncing of moving contact after the circuit breaker was closed, leads to the moving contact still can take place the closing bounce of less stroke, and this is because: the piston 121 of the bullet arrester 100 moves in the opposite direction from the end of its stroke (i.e. the closing moment), during the initial stage of its movement in the opposite direction, in particular during the stroke H₀During the reverse bounce, the drainage mechanism 130 is in a state of being triggered to drain the rod cavity and the rodless cavity, that is, the damping medium in the rodless cavity mainly flows into the rod cavity through the drainage mechanism 130, and the damping medium in the rodless cavity cannot generate a damping force to absorb the energy of the reverse bounce of the closing of the moving contact. To solve this problem, a choke mechanism 140 is provided in the flow path of the drain mechanism 130 through which the damping medium flows. When the piston 121 moves in the opposite direction from the end of the closing stroke, the flow blocking mechanism 140 prevents the damping medium from flowing from the rodless cavity to the rod cavity through the drainage mechanism 130, and then the damping medium can only flow from the rodless cavity to the rod cavity through the damping hole 123, so that a damping force is generated to absorb the energy of the reverse bounce of the moving contact after closing, the reverse bounce of the moving contact is further suppressed, the occurrence of the arc burning of the closing bounce is avoided, and the switch is improvedThe closing performance of the cabinet. The end plate 135 is sealingly fixed to the lower end of the drain hole 131. As shown in fig. 3 and 4, the choke mechanism 140 includes a choke hole 141 disposed in the end plate 135, a choke spool 143, a 2 nd return spring 144, and a pressure plate 145. The pressure plate 145 is provided with a through hole adapted for the passage of a damping medium. The baffle hole 141 is a through hole provided in the end plate 135, such as provided in the middle of the end plate 135 and extending in the axial direction thereof. Alternatively, the orifice 141 is coaxially aligned with the discharge orifice 131. Disposed within the choke bore 141 is a valve seat 142, the valve seat 142 being located on an upper end side of the end plate 135, as shown in FIG. 4, the valve seat 142 sealingly engaging the choke valve core 143. The choke valve core 143 and the 2 nd return spring 144 are sequentially fitted into the choke hole 141, and the pressing plate 145 is fixed to the lower end portion of the choke hole 141, that is, to the lower end surface of the end plate 135. The valve core seat 142, the choke valve core 143, the 2 nd return spring 144 and the pressure plate 145 are sequentially attached, the 2 nd return spring 144 is in a compressed state, the choke valve core 143 is in sealing fit with the valve core seat 142, and the damping medium can only flow from the rod cavity side to the rodless cavity side through the drainage hole 131.

The above-mentioned flow blocking means 140, which is adapted to the outlet means 130, is arranged on the piston 121, the flow blocking means 140 allowing the damping medium to flow only from the rod chamber to the rodless chamber via the outlet opening 131. At the moment that the switch cabinet is operated to be switched on, the moving contact of the circuit breaker generates switching-on reverse bounce to drive the piston 121 of the elastic damper 100 to reversely move from the tail end of the switching-on stroke, in the process of the reverse movement, the piston 121 moves towards the direction of the rodless cavity, under the action of the 2 nd return spring 144, the flow blocking mechanism 140 is immediately reset to block circulation, damping media are prevented from flowing from the rodless cavity to the rod cavity through the drainage mechanism 130, the damping media in the rodless cavity only can flow towards the rod cavity through the damping holes 123 to generate damping force, the damping force absorbs the energy of the switching-on reverse bounce of the moving contact of the vacuum bubble, and the reverse bounce generated after the moving contact of the circuit breaker is switched on is further inhibited. By adopting the three technical means, the switch-on bounce of the moving contact of the circuit breaker is inhibited, so that the switch-on bounce arcing between the moving contact and the static contact of the vacuum bulb is effectively avoided, the service life of the circuit breaker is prolonged, and the switch cabinet can work safely and a power distribution network can run safely.

Compared with the prior art, the invention has the following beneficial technical effects.

The switch cabinet is internally provided with the elastic damper, the elastic damper absorbs partial energy of a moving contact of the circuit breaker before switching on, the instantaneous switching-on speed of the moving contact is reduced, the moving contact of the circuit breaker is restrained from generating switching-on bounce, switching-on bounce arcing is avoided even between the moving contact and the fixed contact, the service life of the circuit breaker is prolonged, explosion caused by arcing of the circuit breaker is avoided, and the switching-on performance and the safety of the switch cabinet are improved.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the foregoing description only for the purpose of illustrating the principles of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined by the appended claims, specification, and equivalents thereof.

Claims

1. An electric power switch cabinet which characterized in that: the switch cabinet comprises a cable compartment (10), a bus compartment (20), a breaker compartment (30) and a control compartment (50) which are enclosed by metal plates and are in a closed state, wherein the cable compartment (10) and the bus compartment (20) are located on the rear side of the switch cabinet, and the cable compartment (10) is located on the lower side of the bus compartment (20); the breaker compartment (30) and the control compartment (50) are positioned on the front side of the switch cabinet, the breaker compartment (30) is positioned in front of the bus compartment (20) and is adjacent to the bus compartment (20), and the control compartment (50) is positioned on the upper side of the breaker compartment (30); the bus compartment (20) is internally provided with a bus copper bar (24), an incoming line contact box (23), an outgoing line contact box (22) and a current transformer (21), the bus copper bar (24) is electrically connected with the incoming line contact box (23), the outgoing line contact box (22) is electrically connected with an incoming line end of the current transformer (21), and an outgoing line end of the current transformer (21) is suitable for being electrically connected with an outgoing line cable (11) arranged in the cable compartment (10); the circuit breaker is characterized in that a 1 st handcart (31) and a circuit breaker (32) are arranged in the circuit breaker compartment (30), the 1 st handcart (31) is assembled with the circuit breaker compartment (30) through a 1 st guide rail, the circuit breaker (32) is arranged on the 1 st handcart (31) and fixed, an incoming line contact of the circuit breaker (32) is matched with an incoming line contact box (23) in a coaxial line manner, an outgoing line contact is matched with an outgoing line contact box (22) in a coaxial line manner, and a switching-off and switching-on mechanism is arranged in the circuit breaker (32) and at least comprises a damper (100), an electromagnetic driver (323), an insulating cylinder (322) and a vacuum bulb (321) which are fixedly connected in an axial direction; the control compartment (50) is internally provided with a controller (52), and the controller (52) is respectively and electrically connected with the electromagnetic driver (323) and the current transformer (21) and is suitable for controlling the breaker (32) to open and close and acquiring the load current of the switch cabinet.

2. The power switch cabinet of claim 1, wherein: the first driving mechanism 1 is arranged in the circuit breaker compartment (30), and the first driving mechanism 1 is suitable for driving the first trolley (31) to reciprocate along the first guide rail 1.

3. The power switch cabinet of claim 1, wherein: a lightning arrester (13) and a grounding disconnecting link (14) are arranged in the cable compartment (10), one end of the lightning arrester (13) is electrically connected with a wiring end of the grounding disconnecting link (14), and the other end of the lightning arrester is electrically connected with a grounding bar; the terminal of the grounding disconnecting link (14) is electrically connected with the outlet terminal of the current transformer (21).

4. The power switch cabinet of claim 1, wherein: the transformer substation further comprises a voltage transformer compartment (40), wherein the voltage transformer compartment (40) is adjacent to the cable compartment (10) and is positioned below the circuit breaker compartment (30); a 2 nd handcart (41), a voltage transformer (42) and a pressure measuring contact box (43) are arranged in the voltage transformer compartment (40), and the pressure measuring contact box (43) is fixed in the voltage transformer compartment and is electrically connected with a wire outlet end of the current transformer (21); the 2 nd handcart (41) is assembled with the voltage transformer compartment through the 2 nd guide rail, the voltage transformer (42) is arranged on the 2 nd handcart (41) and is fixed, and the contact of the voltage transformer (42) is matched with the pressure measuring contact box (43) in a coaxial line mode.

5. The power switch cabinet of claim 4, wherein: the second driving mechanism is arranged in the voltage transformer compartment (40), and the second driving mechanism 2 is suitable for driving the second hand truck (41) to reciprocate along the second guide rail 2.

6. The power switch cabinet of claim 1, wherein: the bullet arrester (100) comprises a cylinder body (110) in a closed state, a piston mechanism (120) and a drainage mechanism (130); the piston mechanism (120) comprises a piston (121) arranged in the cylinder body (110) and a piston rod (122) with one end extending into the cylinder body (110) and fixed with the piston (121), and a damping hole (123) is formed in the piston (121); the drainage mechanism (130) comprises a drainage hole (131) arranged on the piston (121), a drainage valve core (133), a 1 st return spring (134) and an end plate (135), wherein a drainage valve seat (132) positioned on the rod cavity side is arranged in the drainage hole (131); the drainage valve core (133) and the 1 st return spring (134) are assembled in the drainage hole (131), an end plate (135) positioned on the side of the rodless cavity is fixed with the drainage hole (131), the 1 st return spring is in a compressed state, and the drainage valve seat (132) is in sealing fit with the drainage valve core (133); the drainage contact rod (1332) of the drainage valve core (133) protrudes out of the upper end surface of the piston (121) and extends into the rod cavity.

7. The power switch cabinet of claim 6, wherein: the bullet arrester (100) further comprises a flow blocking mechanism (140) for preventing the damping valence in the drainage hole (131) from flowing in the opposite direction, wherein the flow blocking mechanism (140) comprises a flow blocking hole (141) arranged in the end plate (135), a flow blocking valve core (143), a 2 nd return spring (144) and an annular pressing plate (145), the upper end part of the flow blocking hole (141) is provided with a valve core seat (142), the flow blocking valve core (143) and the 2 nd return spring (144) are assembled in the flow blocking hole (141), the pressing plate (145) and the lower end part of the flow blocking hole (142) are fixed, the 2 nd return spring (144) is in a compression state, and the flow blocking valve core (143) and the valve core seat (142) are in sealing fit.

8. An electric power switchgear, according to any of claims 1-7, characterized in that: the power switch cabinet further comprises a high-voltage isolating switch, the high-voltage isolating switch is arranged in the bus compartment (10), a bus copper bar (24) is electrically connected with the wire inlet end of the high-voltage isolating switch, and the wire outlet end of the high-voltage isolating switch is electrically connected with the wire inlet contact box (23).

9. The power switch cabinet of claim 8, wherein: a zero sequence current transformer (12) is also arranged in the cable compartment (10) and is suitable for being sleeved outside the outgoing cable (11); the zero sequence current transformer (12) is fixed with the cable compartment (10) through a bracket, and the zero sequence current transformer (12) is electrically connected with the controller (52).

10. The power switch cabinet of claim 9, wherein: the temperature detection device is characterized by further comprising a 1 st temperature sensor and a 2 nd temperature sensor, wherein the 1 st temperature sensor is suitable for detecting the temperature of the incoming line contact box (23), the 2 nd temperature sensor is suitable for detecting the temperature of the outgoing line contact box (22), and the 1 st temperature sensor and the 2 nd temperature sensor are respectively and electrically connected with the controller (52).