Superconducting magnet control system for single crystal furnace

Abstract

The utility model relates to a superconducting magnet control system for a single crystal furnace. The superconducting magnet control system comprises a control circuit, the control circuit comprises at least one control branch, and the control branch is connected with the superconducting coil; the control branch comprises a circuit breaker, a power supply and a demagnetization module which are connected in series; and the demagnetization module is connected with the superconducting coil. According to the utility model, the programmable power supply is adopted, the magnetic module is added in the power supply and the superconducting magnet, and the demagnetization module adopts a plurality of demagnetization loops, so that the demagnetization speed of the superconducting magnet is accelerated through the on-off control of the multi-stage demagnetization loops, and the working efficiency of field application is improved. A temperature sensor and a current sensor are adopted, the temperature of a superconducting magnet coil and the current of a superconducting magnet can be fed back, and rapid excitation demagnetization of the superconducting magnet is achieved through a PLC. And a control panel is adopted, so that a user can directly read temperature and current data records during operation of the superconducting magnet through the control panel.

Description

TECHNICAL FIELD

[0001] The utility model relates to superconducting magnet equipment technical field especially relates to a superconducting magnet control system for single crystal furnace. BACKGROUND

[0002] At present, most of the single crystal silicon is produced by the Czochralski method. The magnetic field with certain strength and uniformity attached to the growth system of the Czochralski single crystal silicon can effectively suppress the thermal convection in the silicon melt and control the transportation of impurities in the molten silicon. The properly distributed magnetic field can reduce the entry of oxygen, boron, aluminum and other impurities from the quartz crucible into the melt, thereby improving the quality of the single crystal silicon.

[0003] The superconducting magnet can provide higher magnetic field strength, greatly suppress the Si melt convection and suppress the oxygen content of the silicon wafer. In the preparation process, the excitation demagnetization speed of the superconducting magnet affects the on-site production efficiency, and slow excitation demagnetization speed will increase the time cost during use and reduce the production efficiency.

[0004] In the existing superconducting magnet control technology, superconducting power supply and programmable power supply are generally used to excite and demagnetize the magnet. The superconducting power supply is relatively expensive, and the programmable power supply does not have the function of adjusting the speed of current drop during demagnetization, resulting in slow demagnetization speed of the superconducting magnet, prolonging the time used for single crystal pulling and reducing the production efficiency of the single crystal furnace. UTILITY MODEL CONTENTS

[0005] The application provides a superconducting magnet control system for a single crystal furnace to solve the problem of low integration and slow excitation demagnetization speed in the industrial application of the superconducting magnet in the prior art.

[0006] The utility model adopts the following technical scheme: a superconducting magnet control system for a single crystal furnace, comprising a control circuit;

[0007] The control circuit comprises at least one control branch, and the control branch is connected with the superconducting coil.

[0008] The control branch comprises a circuit breaker, a power supply and a demagnetization module connected in series; the demagnetization module is connected with the superconducting coil and the PLC.

[0009] A superconducting magnet control system for a single crystal furnace further comprises a main circuit, and the main circuit comprises a plurality of branches, each branch being connected with a certain refrigeration equipment; the branch comprises a main circuit circuit breaker and a thermal relay connected in series; the thermal relay is connected with the refrigeration equipment.

[0010] The refrigeration equipment comprises one of a water chiller, a first refrigerator and a second refrigerator.

[0011] The power supply is a programmable power supply.

[0012] The demagnetization module comprises a switch S1 and a plurality of demagnetization circuits connected in series.

[0013] The switch S1 is arranged between the positive output end and the negative output end of the power supply, the positive output end of the power supply is connected to one end of the superconducting coil through the plurality of demagnetization circuits connected in series, and the negative output end of the power supply is connected to the other end of the superconducting coil.

[0014] The demagnetization circuit comprises a DC contactor KMn normally open point, a DC contactor KMn normally closed point and a resistor Rn; the resistor Rn is connected in series with the DC contactor KMn normally open point and is connected in parallel with the DC contactor KMn normally closed point.

[0015] The DC contactor KMn main contact is connected in series with a control end to form a demagnetization branch, and the demagnetization branch is connected to a DC power supply; the control end is connected to a PLC; and the demagnetization branch is connected in parallel with a fan branch, the fan branch comprises a fan and a fan control end connected in series with the fan, and the fan control end is connected to the PLC.

[0016] The demagnetization branch is connected in parallel with a temperature detection module, and the detection end of the temperature detection module is arranged in the same space as the demagnetization module.

[0017] A diode V1 is connected between the positive output end of the power supply and the switch S1.

[0018] The superconducting magnet control system for a single crystal furnace further comprises a feedback module, the feedback module comprises a temperature sensor and a current sensor, and the temperature sensor and the current sensor are connected to a PLC; wherein the temperature sensor is arranged beside a coil of the superconducting magnet; and the current sensor is arranged at a wiring end of the superconducting magnet.

[0019] The utility model produces following beneficial effects and advantages:

[0020] 1. The utility model discloses a programmable power supply, and a magnetic module is added in the power supply and the superconducting magnet, and a plurality of demagnetization circuits are adopted in the demagnetization module. The on-off control of the multi-stage demagnetization circuits accelerates the demagnetization speed of the superconducting magnet and improves the work efficiency of the field application.

[0021] 2. The utility model discloses a temperature sensor and a current sensor, which can feed back the temperature of the superconducting magnet coil and the current of the superconducting magnet to realize the rapid excitation and demagnetization of the superconducting magnet through the PLC. A control panel is adopted, and the user can directly read the temperature and current data record of the superconducting magnet during operation through the control panel. DRAWINGS

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A connection diagram of the superconducting magnet control system for a single crystal furnace provided in this embodiment of the present invention;

[0024] Figure 2 The main circuit diagram of the superconducting magnet control system for a single crystal furnace provided in this embodiment of the utility model;

[0025] Among them, QF1 to QF5 are the first to fifth circuit breakers; FR1 to FR3 are the first to third thermal relays; M1 is the water chiller; M2 is the first chiller; M3 is the second chiller; M4 is the control cabinet fan and lighting.

[0026] Figure 3 Circuit diagram of excitation and demagnetization circuit of superconducting magnet control system for single crystal furnace provided in this embodiment of the present invention;

[0027] Among them, QF6 to QF9 are the sixth to ninth circuit breakers; T1 is the first power supply, T2 is the second power supply; A1 is the first coil of the superconducting magnet, and A2 is the second coil of the superconducting magnet.

[0028] Figure 4 The demagnetizing module circuit of the superconducting magnet control system for single crystal furnace provided in this embodiment of the utility model Figure 1 ;

[0029] Figure 5 The demagnetizing module circuit of the superconducting magnet control system for single crystal furnace provided in this embodiment of the utility model Figure 2 . Detailed Implementation

[0030] The technical solutions of the present invention will be further described in detail below with reference to the accompanying drawings of the embodiments of the present invention.

[0031] Reference Figure 1The application provides a superconducting magnet control system for a single crystal furnace, wherein a water cooling machine is connected with a first refrigerator and a second refrigerator, and is used for cooling the first refrigerator and the second refrigerator; the first refrigerator and the second refrigerator are connected with an end cooling head of the superconducting magnet through a helium pipe, and are used for cooling the superconducting magnet; a control cabinet is provided with a PLC, a main circuit and a control circuit; the main circuit is connected with the water cooling machine, the first refrigerator and the second refrigerator, and is used for controlling start and stop of the water cooling machine, the first refrigerator and the second refrigerator; the PLC is connected with the control circuit and a feedback module; the superconducting magnet is controlled to be excited and demagnetized through the control circuit according to the feedback signal of the feedback module.

[0032] The two superconducting coils are a first superconducting coil A1 and a second superconducting coil A2.

[0033] With reference to Figure 2 The main circuit comprises a first branch, a second branch, a third branch and a fourth branch, the first branch, the second branch, the third branch and the fourth branch are connected in parallel, and the first branch, the second branch, the third branch and the fourth branch are connected with a power supply end through a first circuit breaker QF1.

[0034] Further, the first branch is connected in series with a second circuit breaker QF2 and a first thermal relay FR1, the first thermal relay FR1 is connected with the water cooling machine M1; the second branch is connected in series with a third circuit breaker QF3 and a second thermal relay FR2, the second thermal relay FR2 is connected with the first refrigerator M2; the third branch is connected in series with a fourth circuit breaker QF4 and a third thermal relay FR3, the third thermal relay FR3 is connected with the second refrigerator M3; and the fourth branch is connected in series with a fifth circuit breaker QF5, the fifth circuit breaker QF5 is connected with a fan and lighting of the control cabinet.

[0035] With reference to Figure 3 In the application, a sixth circuit breaker QF6, a seventh circuit breaker QF7 and an uninterruptible power supply UPS are connected in series, an eighth circuit breaker QF8 is connected with a first power supply T1, and a ninth circuit breaker QF9 is connected with a second power supply T2. The first power supply T1 and the second power supply T2 are respectively coupled with a demagnetization module, and then are coupled with the first superconducting coil A1 and the second superconducting coil A2; wherein the first power supply T1 and the second power supply T2 are used for exciting the superconducting magnet; and the demagnetization module is used for demagnetizing the superconducting magnet.

[0036] The application further provides a feedback module, the feedback module comprises a temperature sensor and a current sensor, and the temperature sensor and the current sensor are connected with the PLC; wherein the temperature sensor is arranged beside a coil of the superconducting magnet, and is used for detecting the temperature of the superconducting magnet; and the current sensor is arranged at a wiring end of the superconducting magnet, and is used for detecting the current value when the superconducting magnet is excited and demagnetized.

[0037] The detected temperature and current value are fed back to the PLC, and the data are processed by the PLC (prior art) to obtain the voltage output of the first power supply T1 and the second power supply T2, so as to control the current change speed of excitation demagnetization.

[0038] Further, in the embodiment of the application, the PLC is connected with the first communication module, the second communication module and the third communication module respectively; the data collected by the temperature sensor are transmitted to the temperature monitor, the power supply of the temperature monitor is provided with 220V alternating current by the uninterruptible power supply UPS, and the temperature monitor is in communication connection with the first communication module; the temperature monitor value is read by the first communication module and transmitted to the PLC for data processing and judgment; the first power supply T1 and the second power supply T2 are in communication connection with the second communication module and the third communication module respectively, and the state information and data value of the first power supply T1 and the second power supply T2 are read by the second communication module and the third communication module.

[0039] Specifically, in the embodiment of the application, the PLC is connected with a control panel and coupled with a switching power supply, and the switching power supply is used for power supply of the control panel; the control panel is provided with temperature data display, peripheral device state information, alarm information and parameter adjustment buttons; in the local mode, the user can directly read the peripheral device state and set and debug the output parameters by the control panel, thereby improving the operation convenience.

[0040] In the demagnetization module, the following technical solutions are adopted:

[0041] As shown in Figure 4 , Figure 5 , a superconducting magnet demagnetization module is connected to both ends of the superconducting magnet to accelerate the demagnetization rate of the superconducting magnet. The demagnetization module comprises a demagnetization main circuit and a demagnetization control circuit, wherein the demagnetization main circuit comprises a diode V1, resistors R1, R2, R3 and R4, the demagnetization control circuit comprises DC contactors KM1, KM2, KM3 and KM4, and a temperature detection module H1. The superconducting magnet demagnetization module is used for accelerating the demagnetization speed of the superconducting magnet, and the voltage value and current value of the superconducting coil can be measured and displayed in real time through a DC voltmeter PV1 and a DC ammeter PA1.

[0042] The main contact of the DC contactor KM1 is coupled to a control end through a terminal, the main contact of the DC contactor KM2 is coupled to a control end through a terminal, the main contact of the DC contactor KM3 is coupled to a control end through a terminal, and the main contact of the DC contactor KM4 is coupled to a control end through a terminal. The four control ends are connected with the PLC.

[0043] The diode V1 is connected in series with the first DC contactor normally open point KM1, the first resistance R1, the second DC contactor KM2, the second resistance R2, the third DC contactor KM3, the third resistance R3, the fourth DC contactor KM4, and the fourth resistance R4.

[0044] The first resistance R1 is connected in series with the first DC contactor normally open point KM1 and then connected in parallel with the first DC contactor normally closed point KM1, forming a first loop; the second resistance R2 is connected in series with the second DC contactor normally open point KM2 and then connected in parallel with the second DC contactor normally closed point KM2, forming a second loop; the third resistance R3 is connected in series with the third DC contactor normally open point KM3 and then connected in parallel with the third DC contactor normally closed point KM3, forming a third loop; and the fourth resistance R4 is connected in series with the fourth DC contactor normally open point KM4 and then connected in parallel with the fourth DC contactor normally closed point KM4, forming a fourth loop.

[0045] As shown in Figure 4 For each coil A1 of the superconducting magnet, a magnet loop is formed between IN+ and IN-, and OUT+ and OUT-, and the superconducting magnet demagnetization module is connected to the power supply and the magnet loop. IN+ and IN- are respectively connected to the positive and negative output terminals of the programmable power supply, and OUT+ and OUT- are respectively connected to the positive and negative terminals of the superconducting magnet.

[0046] When the magnet is excited and maintained, the manual switch S1 is opened, the main contacts of the first DC contactor, the second DC contactor, the third DC contactor, and the fourth DC contactor do not perform actions, and the current flows from the positive terminal of the power supply through the diode, the normally closed point of the first DC contactor, the normally closed point of the second DC contactor, the normally closed point of the third DC contactor, the normally closed point of the fourth DC contactor, and then flows into the superconducting magnet, exciting the superconducting magnet.

[0047] As shown in Figure 5 When receiving a demagnetization instruction, the 1 and 2 terminals are closed, the normally closed point of the first DC contactor KM1 is opened, and the first resistance R1 is connected to the magnet loop.

[0048] In the demagnetization process, the demagnetization module and the magnet have the same current value, and since the current flowing through the magnet and the demagnetization module is always attenuated in the demagnetization process, the terminal voltage across the resistor in the demagnetization module is only the highest when the current just enters the demagnetization module, and then the voltage is getting smaller and smaller in the demagnetization process. If the resistance value of the resistor in the demagnetization module can be appropriately increased with the attenuation of the current in the demagnetization process, not only the demagnetization speed can be increased, but also the current attenuation rate can be maintained at a relatively stable value. Therefore, in the demagnetization process, the resistance value of the resistor in the demagnetization module is continuously adjusted with the attenuation of the current, the number of resistors connected in series in the demagnetization module is increased according to the adjustment of the on-off number of the DC contactor, so as to increase the total resistance value of the demagnetization module, and the purpose of stabilizing the voltage is achieved.

[0049] By controlling the closure of the corresponding terminal of the nth DC contactor KMn, n = 1, 2, 3, 4, the second loop, the third loop and the fourth loop are increased to increase the voltage across the demagnetization module in the current attenuation process, thereby accelerating the demagnetization speed.

[0050] In the demagnetization process, the heat released on the demagnetization module will cause the temperature of the demagnetization module to rise, and the whole module needs to be cooled, and if the temperature cannot be lowered in time, it may cause other components to burn out.

[0051] As shown in Figure 5 The demagnetization cooling system is composed of cooling fan F1 and cooling fan F2; when receiving the demagnetization instruction, the control end is closed, and the cooling fan starts to work to exchange heat with the whole demagnetization module. The temperature detection module H1 is arranged in the demagnetization module for monitoring the temperature value in the module. In the heat exchange process, the temperature detection module H1 continuously detects the temperature, and according to the different cooling capacity of the fan, the detected temperature can be set (such as 65℃), and if the temperature continues to exceed this temperature, the demagnetization module will alarm and feedback to the main control system.

[0052] Finally, it should be noted that: obviously, the above embodiments are only examples for clearly illustrating the utility model, and are not limited to the implementation. For ordinary skilled persons in the art, other different forms of changes or variations can be made on the basis of the above description. Here, it is not necessary and impossible to enumerate all the implementation. The obvious changes or variations derived therefrom are still within the protection scope of the utility model.

Claims

1. A superconducting magnet control system for a single crystal furnace, characterized in that, Including control circuitry; The control circuit includes at least one control branch, which is connected to the superconducting coil. The control branch includes a circuit breaker, a power supply, and a demagnetizing module connected in series; the demagnetizing module is connected to a superconducting coil and a PLC. The demagnetizing module includes a switch S1 and multiple demagnetizing circuits connected in series; The switch S1 is located between the positive and negative output terminals of the power supply. The positive output terminal of the power supply is connected to one end of the superconducting coil through multiple demagnetizing circuits connected in series, and the negative output terminal of the power supply is connected to the other end of the superconducting coil.

2. The superconducting magnet control system for a single crystal furnace according to claim 1, characterized in that, It also includes a main circuit, which includes multiple branches, each of which is connected to a refrigeration device; each branch includes a main circuit breaker and a thermal relay connected in series; the thermal relay is connected to the refrigeration device.

3. The superconducting magnet control system for a single crystal furnace according to claim 2, characterized in that, The refrigeration equipment includes one of a water chiller and a refrigeration unit.

4. The superconducting magnet control system for a single crystal furnace according to claim 1, characterized in that, The power supply is a programmable power supply.

5. A superconducting magnet control system for a single crystal furnace according to claim 1, characterized in that, The demagnetizing circuit includes a normally open contact of DC contactor KMn, a normally closed contact of DC contactor KMn, and a resistor Rn; The resistor Rn is connected in series with the normally open contact of the DC contactor KMn, and then in parallel with the normally closed contact of the DC contactor KMn.

6. A superconducting magnet control system for a single crystal furnace according to claim 5, characterized in that, The main contacts of the DC contactor KMn are connected in series with the control terminal to form a demagnetizing branch, which is then connected to a DC power supply. The control terminal is connected to a PLC. A fan branch is connected in parallel with the demagnetizing branch. The fan branch includes a fan and a fan control terminal connected in series with it. The fan control terminal is connected to a PLC.

7. A superconducting magnet control system for a single crystal furnace according to claim 6, characterized in that, The demagnetizing branch is connected in parallel with a temperature detection module, and the detection end of the temperature detection module is located in the same space as the demagnetizing module.

8. A superconducting magnet control system for a single crystal furnace according to claim 1, characterized in that, A diode V1 is connected between the positive output terminal of the power supply and the switch S1.

9. A superconducting magnet control system for a single crystal furnace according to claim 1, characterized in that, It also includes a feedback module, which includes a temperature sensor and a current sensor, both of which are connected to the PLC; The temperature sensor is located next to a coil of the superconducting magnet; the current sensor is located at the terminal of the superconducting magnet.

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