KR100354699B1 - Main Circuit Breaker - Google Patents

Abstract

The present invention relates to a main power circuit breaker for use in high speed trains and electric locomotives. The main power circuit breaker according to the present invention is designed to be electrically and mechanically opened and closed by transferring the potential energy stored in the spring of the mechanical mechanism operated by air to the vacuum interrupter of the breaker in the form of kinetic energy when the input / trip signal is applied. The configuration is composed of a control unit, a cylinder, a solenoid valve, a movable flange, an insulated rod, a three-partly arranged blocking spring, a wipe spring, a lever, and a vacuum interrupter. In addition, the present invention provides an ideal material for the electrode of the vacuum interrupter. This main circuit breaker has been developed by our own technology, it has excellent insulation performance, it is safe and easy to open and close the main circuit, it is also very durable and insulation performance.

Description

Main Circuit Breaker

Field of invention

The present invention relates to a main power circuit breaker for use in high speed trains and electric locomotives. More specifically, in the present invention, the potential energy stored in the spring of the mechanical mechanism operated by air is transferred to the vacuum interrupter of the breaker in the form of kinetic energy when the input / trip signal of the main circuit is applied, so that it can be electrically and mechanically opened and closed. To one mains breaker.

Background of the Invention

The Gyeongbu high-speed railway, which is under construction as part of the national project, is intended to solve traffic problems in Korea. It is an opportunity for revival in the domestic railway industry, and is becoming a new electricity for railway technology development. The cost of the project alone is 18,437 billion won, an astronomical amount. According to the announcement, the high-speed train technology development project lasted six years from December 1996 to October 2002, and was divided into two phases. In 2002, seven prototype trains were completed and 350km / h was completed. Commissioning will be performed at speed.

In addition, there has been a demand for development from the Korea Railroad Administration to compensate for the aging and lack of performance of imported main power circuit breakers mounted in domestic electric locomotives.

Accordingly, the present inventors have developed a main circuit breaker having excellent safety and insulation ability that is expected to take much time in the future without relying on foreign countries, so that the present invention can be used for high-speed trains and electric locomotives.

An object of the present invention to obtain the energy required for the contact by using the air pressure when connecting the main circuit, and to block the main circuit to provide a main power circuit breaker operated by using the force stored in the spring in the connection operation .

Another object of the present invention is to provide a main power circuit breaker that can solve the problem of arc discharge light generated less than the energy required when forming a contact in a vacuum interrupter.

Another object of the present invention is to provide a main power circuit breaker that can solve the instability of the trip time (Trip Time) that can be generated when performing the opening and closing operation with air pressure.

It is another object of the present invention to provide an excellent contact material structure capable of guaranteeing short circuit breakage of 20 kA and 1000 A load current breaking life performance.

It is another object of the present invention to provide a mechanism of a main power circuit breaker capable of guaranteeing short circuit breaking performance.

Another object of the present invention is to provide an excellent mechanical durability capable of guaranteeing 300,000 no-load opening and closing life.

Another object of the present invention is to provide excellent structural performance that can guarantee the vibration test of KS R 9144 Class 2 B.

Another object of the present invention is to provide an airtight performance that can protect the moisture penetration as outdoor equipment.

The above and other objects of the present invention can be achieved by the present invention described below.

Figure 1 shows the overall appearance of the main power circuit breaker according to the present invention.

2 schematically shows an operation unit of a main power circuit breaker constructed in accordance with the present invention.

3 shows the appearance of a vacuum interrupter according to the present invention.

4 is a schematic cross-sectional view of the main power circuit breaker according to the present invention.

5 is a circuit diagram of a controller for controlling the operation of the main power circuit breaker according to the present invention.

Figure 6 shows in detail the relay used in the control unit according to the present invention.

7 is a diagram showing the change in force of the open distance of the vacuum interrupter.

8 shows the characteristic curve in the case of interrupting the vacuum interrupter.

9 is a graph showing a lightning impulse wave (Lightning Impulse Wave) according to the brain impulse withstand voltage test.

10 is a graph according to the results of the temperature rise test.

Figure 11 is a curve fit (Curve Fit) by analyzing the results of the breaking capacity test.

12 is a graph showing an excitation signal in each direction when the resonance is not performed according to the vibration resistance test.

* Brief description of the major symbols in the drawings *

10: Vacuum Interrupter

11: Fixed lead piece electrode 12: Movable lead piece electrode

13: fixed lead 14: movable lead

15: Bellows 16: insulation container

17: Getter 18: Shield

19: Plate 20: Insulator

21: Bracket 37: connection box

30: support insulator 35: blocking spring

40: lever 45: wipe spring

50: insulated rod 62: movable flange

70 solenoid valve 71 fastening bolt

73: fixed flange 80: switch

81: input pressure switch 82: cutoff pressure switch

90: air tank

Summary of the Invention

The present invention relates to a main power circuit breaker for use in high speed trains and electric locomotives. The main power circuit breaker according to the present invention is delivered to the vacuum interrupter of the breaker in the form of kinetic energy when the input energy stored in the spring of the mechanical mechanism operated by air is applied to the trip / trip signal, electrically and mechanically open and close the operation The configuration is a control unit for controlling the overall operation by adjusting the air flowing into the cylinder, the single-acting type piston outer diameter is 125 mm, the stroke distance is 25 mm cylinder for generating air pressure to open and close the main circuit according to the signal of the control unit, the control unit A solenoid valve connected to a solenoid valve for supplying air introduced into the cylinder according to a signal of the controller, a movable flange connected to an upper surface of the cylinder to transfer a force transmitted from the cylinder to an insulating rod, and to one side of the flange It is connected by fastening with a bolt and connected to the lever on the other side of the cylinder Insulating rod that transfers the power transmitted from the vacuum interrupter to the vacuum interrupter, and is connected to the movable flange and the flange that connects the insulating rod to store the force transmitted from the cylinder during the operation of connecting the main circuit to interrupt the main circuit. A blocking spring to be used, a wipe spring which is located in the center of the flange and connected to the insulating rod to store the force when the contact is formed in the vacuum interrupter, and connected to the insulating rod on one side and the movable lead of the vacuum interrupter on the other side. A lever that is connected to transfer the force transmitted from the cylinder to change the vertical motion to a horizontal motion, by connecting to one side of the lever to form a contact between the primary side and the secondary side by the force provided from the cylinder It consists of a vacuum interrupter that connects the circuit.

Detailed description of the invention

The opening and closing operation of the main power circuit breaker according to the present invention is to be operated at a rated voltage of DC 72V and a rated operating pressure of 4.0kg · medium / cm ² . If the input air pressure is less than the allowable pressure 3.4kg · m / cm ² , the pressure sensor detects this and disables the operation. If a pneumatic leak occurs and the rated operating pressure decreases to 4.0kg · m² / cm ² , and there is a risk that the input contact may be opened, the pressure sensor may detect it at 3.4kg · m² / cm ² and shut off automatically. do.

Hereinafter, with reference to the accompanying drawings will be described in detail the contents of the present invention.

Figure 1 shows the overall appearance of the main power circuit breaker according to the present invention. The present invention is largely applied to the high voltage circuit vacuum interrupter 10, insulator 20, support insulator 30, lever 40 , An insulating rod 50 and the like, and a main part of the main power circuit breaker is operated when the input and interruption is composed of an operation unit operating by the air supplied from the compressor.

Hereinafter, a part of the blocking unit will be described.

The vacuum interrupter 10 is a vacuum interrupter that seals both ends of the ceramic cylinder with a metallic plate and has a fixed electrode, a movable electrode, a shield, bellows, and a high vacuum. This vacuum interrupter will be described in detail later.

The insulator 20 has a vacuum interrupter inside thereof, secures an insulation distance between the primary terminal and the secondary terminal of the main circuit, and protects the vacuum interrupter from external shock, vibration, and moisture. Was designed with uneven structure and molded with special cement. The surface leakage distance of the insulator is to be at least 750 mm.

The support insulator 30 has a primary support insulator 31 and a secondary support insulator 32 as a part supporting the insulator.

The shutoff lever 40 serves to transfer the force transmitted from the cylinder to the vacuum interrupter and changes the vertical operation to the horizontal operation. One side of the blocking lever is connected to the movable lead 14 of the vacuum interrupter, and the other side is connected to the insulating rod 50 to transfer the force transmitted from the operation unit to the vacuum interrupter 10 to open and close the contact.

The insulating rod 50 connects the cylinder 60 and the blocking lever 40 to a portion for transmitting a force transmitted from the cylinder 60 that opens and closes the contact point of the vacuum interrupter. The insulating rod used in the present invention is made of FRP material with a tensile load of 20 times the safety factor than the input force (280kg · F) required for the vacuum interrupter, and external creepage (Creepage) to 440 mm or more for electrical insulation. Designed to withstand 200 kV of impulse.

In addition to the above configuration, the insulator insulator 20 and the support insulator 30 are connected at the primary terminal side of the main circuit, and the bracket 21 is mounted at the primary terminal, and the insulator 20 is supported at the secondary side of the main circuit. The insulator 30 is connected to and has a connection box 23 including a blocking lever therein.

Hereinafter, an operation unit for inducing the inflow of air to the blocking unit will be described. 2 schematically shows an operation unit according to a preferred embodiment of the present invention. Reference numeral 60 shows a cylinder for opening and closing the main circuit, which is a single-acting type, having a piston outer diameter of 125 mm and a stroke distance of 25 mm. Air introduced into the cylinder 60 from the solenoid valve 70 pushes up the piston of the cylinder 60 to connect the main circuit. In addition, the mechanical spring necessary for blocking the blocking spring 35 and the wipe spring 45 is stored. When the main circuit is shut off, the air in the cylinder 60 is discharged by shutting off the power supply of the solenoid valve 70, and the main circuit is cut off by the mechanical energy stored in the springs 35 and 45.

Reference numeral 70 shows a solenoid valve. The solenoid valve 70 induces air in and out into the cylinder 60 according to the selection of the controller described below.

Two kinds of pressure sensors are used in the present invention. When the air pressure supplied to the main power circuit breaker is not sensed and the pressure required for the input is not reached, the input pressure switch 81 operates to cut off the circuit of the main power circuit breaker so that the input is impossible, and the initial setting value of the input pressure switch is 4.0 kg. ² When the air pressure supplied to the main power circuit breaker does not overcome the force of the wipe pressure contact force, a cutoff pressure switch 82 for blocking the main power circuit breaker is used. The initial setting value of the cutoff pressure switch is 3.4 kg · middle / cm ² . This pressure switch can be used by resetting the set value of the pressure in accordance with the selection of the switching pressure adjusting screw provided in the switch (81, 82).

Reference numeral 90 shows an air tank. In order for the cylinder 60 to operate at a high speed, it is necessary to secure a certain amount of air at a position close to the cylinder 60. Therefore, in this invention, an air tank is provided and used. In addition, in order to prevent the foreign substances and moisture in the air flowing from the regulator (unsigned) is used by connecting a filter between the air tank 90 and the regulator is connected.

Reference numeral 62 shows the auxiliary contact. The auxiliary contact transmits the open / close signal of the main circuit breaker to the outside. When opening and closing the contact of the vacuum interrupter by the operation of the breaker, an auxiliary contact which is mechanically directly connected by a link to the movable flange 62 is operated. When the axis of the auxiliary contact 62 rotates according to the operation of the movable flange 62, the contacts (a contact, b contact) of the auxiliary contact are attached and fall. An example of such an auxiliary contact will be described by way of example. When the auxiliary motor of the locomotive is connected to any one of the auxiliary contacts, the auxiliary contact is turned on or off according to the operation of the operation unit. May cause the operation of the auxiliary motor. In the present invention, it is possible to selectively configure the auxiliary contact. In addition, an electrical counter (not shown) that counts the number of times of disconnection of the main power circuit breaker may be added and installed.

3 shows a cross section of a vacuum interrupter according to the invention. As shown, the vacuum interrupter has two electrodes. One is the fixed lead piece electrode 11 connected to the primary side power supply of the main circuit and the other is the movable lead piece electrode 12 connected to the secondary side power source.

Reference numeral 17 shows a getter that absorbs when a small amount of gas is generated inside the vacuum interrupter and maintains the vacuum inside the interrupter.

Reference numeral 18 shows a shield for cooling by attaching metal vapor on the contact surface generated by the arc.

Reference numeral 19 shows a plate that seals both ends of the vacuum interrupter to maintain the vacuum therein.

The inside of the vacuum interrupter 10 is to open and close the contacts to open and close the current of the main circuit in a state of maintaining a vacuum state.

The main circuit as used herein refers to a circuit in which a current is opened and closed by a vacuum interrupter. In the state in which the fixed lead 13 is fixed, the movable lead 14 moves horizontally in accordance with the operation of the breaker to open and close the current of the main circuit.

Reference numeral 15 denotes a bellows, which is provided for the operation of the movable lead in a vacuum state and is a kind of corrugated pipe. Bellows used in the present invention uses a material of stainless steel (Stainless Steel). In addition, the movable lead 14 and the fixed lead 13 is manufactured using oxygen-free copper for the purpose of conducting current.

In the present invention, three factors are needed, which are the current interruption capability, the breakdown voltage characteristic, and the fusion resistance, which influence the basic performance of the vacuum interrupter. However, the additives are required because the copper single metal cannot satisfy the above three conditions. In the present invention, the electrodes 11 and 12 are formed by selecting Cu: Cr = 75: 25 having excellent blocking performance. Changes in physical properties depending on the content of chromium will be published in more detail through the examples below.

The insulating container 16 uses a ceramic container made of 94% of aluminum oxide (Al ₂ O ₃ ) having excellent dielectric strength.

4 is a schematic cross-sectional view of the main power circuit breaker according to the present invention. Hereinafter, the operation of the main power circuit breaker will be described with reference to the drawings.

When the signal for introducing air is transmitted from the controller to the solenoid valve 70, the valve is opened, and air is introduced into the cylinder 60 from the air tank. The introduced air pushes up the movable flange 62 connected to the upper surface of the cylinder by operating the cylinder. At this time, energy is primarily stored in the blocking spring 35 which is divided in three directions between the movable flange 62 and the fixed flange 73. In addition, the insulating rod 50 connected to the movable flange 62 and the adjustment bolt 71 pushes the lever 60 connected to the other side. At this time, the lever is transferred to the movable lead 14 connected to the other side of the lever by changing the horizontal force in the vertical direction transmitted through the insulating rod 50 through the cylinder 60 in the horizontal direction. The movable lead 14 which receives the transmitted force comes into contact with the fixed electrode 11 of the fixed lead side to form a contact.

When the contact is formed in the vacuum interrupter 10, the wipe spring 45, which is located at the center of the movable flange 62 and connects the movable flange 62 and one side of the insulating rod 50, is pressed to store energy secondarily. The input to form the contact is completed. The wipe spring decompresses the compressive energy so as to be the driving force of the rapid interruption when the main circuit is interrupted.

The blocking operation occurs in the reverse of the closing operation as described above, and when the blocking signal is transmitted to the solenoid valve 70, the valve is closed to cut off the inflow of air, and the air of the cylinder 60 is discharged. Accordingly, the springs 35 and 45 which have been compressed are returned to operate the insulating rod 50 downward. At this time, since the spring constant of the wipe spring 45 is greater than the constant of the blocking spring 35, the wipe spring 45 operates first. The blocking spring 35 is operated so that the contact point of the vacuum interrupter is dropped, and thus the main circuit is interrupted.

The main power circuit breaker according to the present invention, which operates as described above, is designed to perform six functions such as current conduction function, fault current interruption function, insulation function, vibration resistance function, airtight function, and current input function to be provided with the circuit breaker. Made according to the characteristics. This fact will be fully verified through the following examples.

5 is a circuit diagram of a controller for controlling the operation of the main power circuit breaker according to the present invention. C2 in the figure shows the input pressure switch 81, and T2 shows the cutoff pressure switch 82. And 52C shows solenoid valve 70 providing air to the cylinder. In addition, R1, R2, and R3 show relays, which are shown in detail separately in FIG.

As shown, 2-7 is the coil of the relay, and when 2-7 is energized, contacts A (1-3, 6-8) of the relay are connected and contacts B (1-4, 5-8) are disconnected. . When the signal is input through On switch which is connected to the connection switch of the train, it is energized to 2-7 of relay R1 only.

At this time, contacts 1-3 of this relay R1 are connected according to the energization of the relay R1. Then, 2-7 of relay R3 are energized. Continuously, contacts 1-3 of relay R3 are connected so that contacts 6-8 are also connected. After that 2-7 of R2 are connected and the signal is input to 52C, the cylinder is operated and the main circuit is connected.

After 2-7 contacts of relay R2 are connected, 6-8 contacts of R2 are connected and 1-4 contacts are dropped. In this case, even if the On switch is dropped, once the power is applied, the 52C is continuously energized by the contacts of 6-8 of R2 and 6-8 of R3.

If the circuit is cut off by pressing the Off switch, the 52C signal is cut off and the main circuit is closed.

In addition, the switch of C2 and T2 checks the air pressure flowing into the cylinder and blocks the main circuit by blocking the signal flowing into the 52C according to the initial setting value.

Standard operation responsibility of main circuit breaker shall be O (blocking) -0.3 seconds after -CO (breaking operation without delay following closing operation) -CO operation after 3 minutes in case of high speed switching method. In order to supply or cut off current according to the regulations, the movable contact inside the vacuum interrupter must be moved on the highway. Therefore, in order to obtain a very large acceleration, sufficient force is required, and this acceleration is instantaneously transferred to the moving contact of the vacuum interrupter of the breaker as kinetic energy within a short time. In addition, since the operation force is large during the blocking operation, the shock transmitted to the operation shaft is also large, and thus a device for absorbing such an impact is required.

The main power circuit breaker for the high-speed train according to the present invention was immediately put into the pneumatic using a pneumatic cylinder 60, and when shut off by the return force of the blocking springs (35, 45) compressed at the time of closing.

As the opening and closing distance of the main circuit breaker, the impulse insulation performance shall be satisfied under the condition that the breaking capability is guaranteed. This main circuit breaker satisfies the performance at stroke distances of 16 mm or more when verifying the performance of the vacuum interrupter. Therefore, the stroke distance of the cylinder 60 is adopted for 25 mm, which satisfies 21 mm, which is the sum of the vacuum interrupter S / T of 17 mm and the wipe S / T of 4 mm.

In addition, the required input speed of the vacuum interrupter was 1.0 ± 0.2 m / s, and the input speed of the operation part operating in accordance with the present invention maintained the measurement result 1.1 m / s.

In order to design a circuit breaker that meets the requirements of a vacuum interrupter, the calculation of the force required to open and close the circuit breaker must be preceded. For this purpose, FIG. 7 shows a change diagram of the force for each opening distance of the vacuum interrupter.

As can be seen in FIG. 7, the energy of the pressing force by the wipe spring 45 and the energy of the blocking spring 35 are combined as the blocking energy until the contact of the injected vacuum interrupter is dropped. From the point of contact dropping, it appears as the blocking energy except for the attenuation force caused by the vacuum pressure difference of the vacuum interrupter and the decrease in energy amount caused by the friction force.

In addition, since the change in the breaking speed is represented by the repulsion energy of the shaft springs 35 and 45, the main power circuit breaker is designed in the present invention to have a linear change value. FIG. 8 shows characteristic curves when the vacuum interrupter is interrupted, and the inclination value of the change diagram of the blocking spring of FIG. 7 is determined by V ₀ and V ₀₁ of FIG. 8.

Example A

Table 1a below shows the physical properties of the electrode used in the vacuum interrupter of the present invention according to the chromium content. In the present invention, Cu (copper): Cr (chromium) = 75: 25 having excellent blocking performance was selected. Table 1b compares the physical properties of Cu: Cr = 75: 25 and Cu: Cr = 80: 20.

Sample Sintered specific gravity (g / cm ³ ) Brinell hardness (HB) LACS% Remarks Cr 15wt% 8.36 81-89 51-57% 1070。C Sintered Cr 20wt% 8.28 79-90 45-50% 1070。C Sintered Cr 25wt% 8.06 76 to 88 38-42% 1000。C Sintered Cr 30wt% 7.98 71-82 30 to 37% 1000。C Sintered Cr 40wt% 7.85 67-81 27 to 31% 1000。C Sintered

Classification characteristics unit Cu: Cr = 75: 25 Cu: Cr = 80: 20 Remarks density g / cm ³ 7.90 8.10 Hardness HB10 70 70 conductivity IACS% 45 51 m / Ωcm3 28 30

Example B

Table 2 below shows the results of the power frequency withstand voltage test. The commercial frequency withstand voltage test is a test for verifying dielectric strength by applying a specified voltage for earth, phase, and pole to check whether a specimen is tolerated. The results showed very good results as shown in the table.

Test status Test voltage application part dry Test frequency (Hz) Judgment Test voltage (kV) Authorization time (sec) Main Circuit-Land to Land 1.5 60 60 Good Incest 75 60 60 Good Frostbite terminal 75 60 60 Good

Example C

Table 3 below shows the results of the Lightning Impulse Withstand Voltage Test. 9 also shows a Lightning Impulse Wave.

As shown in Table 3 and FIG. 9, very good results were obtained when the reference value of 170 kV was applied. For reference, a voltage of 170 kV or more was applied to check the limit of the dielectric strength of the brain impulse withstand voltage. As a result, dielectric breakdown occurred at 200 kVp when applied to ground, and dielectric breakdown occurred at 210 kVp at positive and 220 kVp at negative.

Test status Test voltage application part Polar sex dry Wave form (μs) Judgment Test voltage Examination Land government 170 kV 3rd time 1.2 × 50 Good Interstitial 170 kV 3 Good

Example D

Table 4 below shows the results of a simple measurement of the DC insulation resistance test with a MEGGER portable insulation resistance meter. This test reads insulation resistance after 1 minute by applying 1000V. As can be seen in Table 4, the test results show very good results.

(Measurement device: 1000V 2000MΩ use) Classification measure Main circuit (MΩ) Ground to Control Circuit (MΩ) Land Interstitial Reference value More than 1000 More than 1000 500 or more Measurement result Good Good Good

Example E

Insulation breakdown, one of the major accidents of power equipment, often involves partial discharge as its predecessor. Therefore, if partial discharge is performed, an insulation abnormality can be detected in the slight state which does not reach breakdown.

Partial discharges within the equipment produce pulsed currents and sound waves with a broad frequency distribution from the audible frequency to the ultrasonic wave. For this reason, there are an electric signal detection method for detecting a pulse current and a mechanical signal detection method for detecting an ultrasonic wave propagated through an insulator weight.

Partial discharge generated inside the insulator deteriorates the insulator, so the partial discharge test is conducted for the purpose of detecting defects or evaluating long life in high voltage equipment.

Test status Test voltage (kV) Regulation Measurement (pc) Judgment Between breakers A Less than 10pc Corona free Good B Corona free Good C Corona free Good Challenge Zone A Corona free Good B Corona free Good C Corona free Good

Example F

The main circuit resistance is measured to prevent serious accidents of the power equipment by checking the disconnection state or the contact state of the contact inside the vacuum interrupter, and the measuring method is to supply a current of 5 amperes (A) or more. The resistance between the terminals is measured by the direct current drop method.

In this sample, the resistance between the poles was measured by the voltage drop method after applying a current of 100 A using a contact resistance meter, and the results are shown in Table 6 below. In this test, it satisfies the condition within 20% of the change rate of the main circuit resistance, which is a standard test standard, and was judged to be a good characteristic.

Before the test After the test Measurement result 32 33

Example G

In order to guarantee the short circuit breaker performance of the main power circuit breaker, the time and speed at which the breaker is inserted and tripped together with the excellent contact material structure are very important. If the input speed is considerably fast, chattering or shock is large, whereas if the input speed is slow, an arc is generated just before the fixed electrode and the movable electrode contact each other. In order to test the opening and closing operation characteristics of the main power circuit breaker according to the present invention was tested using an operating characteristic analyzer (Breaker Analyzer System: TM-1600 / MA-31 PROGRAMMA (Sweden)) was as follows.

As a result of measuring the input time and the average input speed, it was determined that the characteristics were good at 58 ms (injection time) and 1.0 to 1.1 m / s (injection speed). The input time refers to a time from a time point at which a signal is applied to the input coil to a time point at which a contact is generated.

As a result of measuring the trip time and average trip speed, it was judged as a favorable characteristic with 43 ms (trip time) and 1.6-1.7 m / s (trip speed). The trip time refers to the time from the time when a signal is applied to the cylinder to the time when the contact is opened.

As a result of measuring the trip free (CO), it was determined to be a good characteristic, and the trip free is an operation of applying an inflow signal again immediately after the inflow signal of air is input, which means CO of the duty of blocking operation. It should be the same as the result obtained in each operation of the inflow and the blocking measured.

Example H

In all power equipments, the load current flows during use, and the maximum load current is much smaller than the short-circuit current. Rather, since the rise time is very long, fever caused by joule loss or stray load loss is a problem. The conductive part shall be designed so as not to exceed the allowable temperature rise limit when the rated current is continuously energized, and a temperature rise test is performed to verify this. The result of this temperature rise test is shown in Table 7 below. As can be seen from the table, when the rated current was flowed through the EUT, the temperature rise limit did not exceed the IEC56 standard, and good conduction performance was obtained. And FIG. 10 is a graph of the temperature rise of the article accordingly.

Example I

Fig. 11 is a graph of curve fit by analyzing the results of the breaking capacity test.This test is conducted by the Korea Railroad Research Institute, a domestic accredited test institute, conducted by the Korea Electrical Research Institute on August 29, 2000 and September 1 It was.

The test was conducted 30 times with the KERI's power equipment, and the electrical life test was performed with 1000A for 30,000 times, taking the long time and the load of the KERI test equipment into consideration. After the comparative analysis, the test was conducted in 20kA units.

Example J

12 is a photograph of vibration resistance test. This test was conducted from September 5, 2000 to September 6, 2000 by the Korea Institute of Machinery and Materials. The test was performed in accordance with the methods and procedures specified in the Vibration Testing Method of Railroad Vehicle Parts (KS R 9144) and was designed to withstand the resonant frequencies and to withstand the dynamic vibration stresses expected when handling, transporting and operating the equipment. The purpose is to verify the vibration resistance and to evaluate the vibration durability.

FIG. 13 shows the shape of the aluminum flange of the shielding part, and when the aluminum flange and the insulator are molded with cement, durability can be ensured to pass the vibration test.

Example K

Figure 14 shows the results of 300,000 consecutive opening and closing tests. The test was carried out in the presence of the Korea Railroad Research Institute on September 19, 2000 to October 10, 2000. The breaker was inspected approximately every 10,000 times and the bolts tightened, air leaks, mechanical damage and electrical damage were checked. No serious problems on the breaker's performance were found during the test, and the breaker's characteristics remained almost unchanged after the test.

The main power circuit breaker according to the present invention has been developed by its own technology, and has excellent insulation performance and easily operates to open and close the main circuit. In addition, as can be seen from the embodiment has shown excellent performance that satisfies all the requirements and safety requirements for the main power breaker.

Simple modifications and variations of the present invention can be readily used by those skilled in the art, and all such variations or modifications can be considered to be included within the scope of the present invention.

Claims (8)

A control unit for controlling the overall operation by adjusting the air flowing into the cylinder; A cylinder having a single-acting piston having an outer diameter of 125 mm and a stroke distance of 25 mm, generating a pneumatic pressure for opening and closing the main circuit according to the signal of the controller; A solenoid valve connected to the controller for supplying air introduced into the cylinder according to a signal of the controller; A movable huren connected to an upper surface of the cylinder and transmitting a force transmitted from the cylinder to an insulating rod; An insulation rod which is connected to one side by fastening with an adjustment bolt to the flange and connected to a lever on the other side to transmit a force transmitted from the cylinder; A blocking spring that is connected to the fixed flange that connects the movable flange and the insulating rod to store the force transmitted from the cylinder during the operation of connecting the main circuit and to use the power to cut off the main circuit; A wipe spring positioned at the center of the flange and connected to the insulating rod to store a force of the excitation when a contact is formed in the vacuum interrupter; A lever connected to the insulating rod on one side and connected to a movable lead of a vacuum interrupter on the other side to transfer a force transmitted from the cylinder to change a vertical motion to a horizontal motion; And A vacuum interrupter connected to one side of the lever to form a contact point between the primary side and the secondary side of the main circuit by a force provided from the cylinder; Main circuit breaker, characterized in that consisting of. The main power circuit breaker of claim 1, wherein the control unit senses the air pressure supplied to the cylinder and stops the operation of the solenoid valve when the air pressure is less than the pressure required to form a contact point of the vacuum interrupter. The main power circuit breaker of claim 1, wherein the control unit senses an air pressure of air supplied to the cylinder, and blocks the main circuit if the air pressure is less than a force of a wipe pressure contact force. The main power circuit breaker of claim 1, wherein the blocking spring is three. 2. The main power circuit breaker of claim 1, wherein the wipe spring has a spring constant greater than a constant of the shutoff spring. The main power circuit breaker according to claim 1, wherein the material of the fixed lead electrode and the movable lead electrode of the vacuum interrupter is copper (Cu): chromium (Cr) = 75: 25. The main power supply according to claim 1, further comprising an auxiliary contact which is mechanically connected to the movable flange by a link and opens and closes the contacts a and b according to the operation of the flange. breaker. The main power circuit breaker of claim 1, wherein the insulating rod is made of FRP material and manufactured with an outer creepage of 440 mm or more.