Reduction furnace power supply control method and device and reduction furnace

Abstract

The invention discloses a reduction furnace power supply control method and device and a reduction furnace, and the method comprises the steps: collecting the operation voltage and grounding current of a first silicon rod group which is any one of N silicon rod groups; determining a fault judgment threshold value of the first silicon rod group according to the operation voltage, wherein the fault judgment threshold value is a power supply trip protection threshold value corresponding to a preset voltage interval to which the operation voltage belongs; performing fault analysis on the first silicon rod group according to the fault judgment threshold and the grounding current to obtain a fault analysis result, the fault analysis result being used for indicating whether the first silicon rod group has a fault; and under the condition that the fault analysis result indicates that the first silicon rod group breaks down, executing a power supply control measure on the first silicon rod group. By using the reduction furnace power supply control method, the accuracy of reduction furnace power supply control can be improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of polysilicon production, and in particular relates to a reduction furnace power supply control method and device, and a reduction furnace. Background Art

[0002] In the production process of polysilicon, short-circuit protection is set for the power supply of the reduction furnace to prevent equipment damage, fire hazards and personal injury caused by short circuits, and to maintain the continuity and stability of production. However, in actual production, when the silicon rods in the outer ring of the reduction furnace are tilted and tilted, they will lean against the wall, causing the operating current to flow from the silicon rods to the furnace barrel to form a loop, causing continuous discharge damage to the furnace barrel.

[0003] The existing technology uses a unified power-off protection threshold as the reduction furnace power short-circuit protection threshold. However, the fixed threshold will result in the inability to accurately detect whether the silicon rod has a fault when the operating voltage of the silicon rod changes, resulting in equipment damage and safety hazards. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a reduction furnace power supply control method, device and reduction furnace in view of the above-mentioned deficiencies in the prior art. The method can accurately detect whether a silicon rod in the reduction furnace has a fault, thereby timely controlling the power supply corresponding to the silicon rod.

[0005] In a first aspect, an embodiment of the present invention provides a reduction furnace power supply control method.

[0006] The reduction furnace includes N silicon rod groups in its furnace body, each silicon rod group includes a plurality of rod pairs, and N is a positive integer. The method includes:

[0007] collecting an operating voltage and a grounding current of a first silicon rod group, where the first silicon rod group is any group among the N silicon rod groups;

[0008] Determine a fault judgment threshold of the first silicon rod group according to the operating voltage, wherein the fault judgment threshold is a power supply trip protection threshold corresponding to a preset voltage interval to which the operating voltage belongs;

[0009] Performing a fault analysis on the first silicon rod group according to the fault judgment threshold and the grounding current to obtain a fault analysis result, wherein the fault analysis result is used to indicate whether a fault occurs in the first silicon rod group;

[0010] When the fault analysis result indicates that a fault occurs in the first silicon rod group, power supply control measures are performed on the first silicon rod group.

[0011] Optionally, before determining the fault judgment threshold of the first silicon rod group according to the operating voltage, the method further includes:

[0012] Divide the operating voltage range of the first silicon rod group into partitions to obtain P voltage partitions, where P is a positive integer;

[0013] A fault judgment threshold of the first silicon rod group in each voltage partition is determined according to the lowest voltage within each voltage partition, the grounding resistance of the first silicon rod group, and the number of pairs of silicon rods in the first silicon rod group.

[0014] Optionally, determining a fault judgment threshold of the first silicon rod group in each voltage partition according to the lowest voltage within each voltage partition range, the grounding resistance of the first silicon rod group, and the number of pairs of silicon rods of the first silicon rod group specifically includes:

[0015] The fault judgment threshold of each voltage partition is calculated by the following formula (1):

[0016] Fault judgment threshold = minimum voltage / ground resistance / number of silicon rod pairs (1)

[0017] The minimum voltage is the minimum voltage within the voltage partition range, the grounding resistance is the resistance of the grounding resistance cabinet of the silicon rod group, and the number of silicon rod pairs is the number of pairs of rods in the first silicon rod group.

[0018] Optionally, performing fault analysis on the first silicon rod group according to the fault judgment threshold and the ground current to obtain a fault analysis result specifically includes:

[0019] When it is detected that the grounding current at the first moment is greater than or equal to the first threshold, a first continuous grounding current of the first silicon rod group from the first moment to the second moment is obtained, and the time interval between the first moment and the second moment is a first preset unit time;

[0020] When the first continuous grounding current is greater than or equal to a first threshold, obtaining a second continuous grounding current of the first silicon rod group from the second moment to a third moment, wherein the first threshold is a fault judgment threshold corresponding to the operating voltage of the first silicon rod group at the first moment, and the time interval between the third moment and the second moment is a second preset unit time;

[0021] When the second continuous grounding current is greater than or equal to the first threshold, it is determined that the fault analysis result is that the first silicon rod group has a wall-hitting fault.

[0022] Optionally, when the fault analysis result indicates that the first silicon rod group has a fault, executing power control measures on the first silicon rod group specifically includes:

[0023] When the fault analysis result indicates that the first silicon rod group has a fault and the operating voltage is greater than a preset voltage, powering off the first silicon rod group;

[0024] When the fault analysis result indicates that the first silicon rod group has a fault and the operating voltage is less than or equal to a preset voltage, fault warning information is output.

[0025] Optionally, after collecting the operating voltage and grounding current of a first silicon rod group, where the first silicon rod group is any group of silicon rods in the N groups of silicon rods, the method further includes:

[0026] When it is detected that the grounding current of the first silicon rod group at a fourth moment is greater than or equal to a preset threshold, a third continuous grounding current of the first silicon rod group from the fourth moment to a fifth moment is obtained, the time interval between the fourth moment and the fifth moment is a third preset unit time, and the preset threshold is determined according to historical detection data of the reduction furnace;

[0027] When the third continuous grounding current is greater than or equal to the target threshold, it is determined that a short circuit fault occurs in the first silicon rod group.

[0028] In a second aspect, an embodiment of the present invention provides a power supply control device for a reduction furnace, wherein the furnace body of the reduction furnace includes N silicon rod groups, each silicon rod group includes a plurality of rod pairs, and N is a positive integer. The device includes:

[0029] A collecting mechanism, used for collecting the operating voltage and grounding current of a first silicon rod group, where the first silicon rod group is any group of silicon rods among the N groups of silicon rods;

[0030] A first determination module, connected to the acquisition mechanism, is used to determine a fault judgment threshold of the first silicon rod group according to the operating voltage, wherein the fault judgment threshold is a power supply trip protection threshold corresponding to a preset voltage interval to which the operating voltage belongs;

[0031] an analysis module, connected to the determination module, and configured to perform a fault analysis on the first silicon rod group according to the fault judgment threshold and the ground current to obtain a fault analysis result, wherein the fault analysis result is used to indicate whether a fault occurs in the first silicon rod group;

[0032] A control module is connected to the analysis module and is used to execute power supply control measures on the first silicon rod group when the fault analysis result indicates that the first silicon rod group has a fault.

[0033] In a third aspect, a reduction furnace is provided, the reduction furnace comprising:

[0034] Reduction furnace body;

[0035] N groups of silicon rods are arranged in the reduction furnace body, each group of silicon rods includes a plurality of pairs of rods, and N is a positive integer;

[0036] The above-mentioned reduction furnace power supply control device is used to control the power supply of the N groups of silicon rods.

[0037] The reduction furnace power supply control method of the present invention can realize accurate monitoring and adaptive protection of the reduction furnace power supply system by real-time acquisition of the operating voltage and grounding current of each group of silicon rods and dynamically determining the fault judgment threshold according to the current operating voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 : is a flow chart of a reduction furnace power supply control method according to Example 1 of the present application;

[0039] Figure 2 : A 40-pair rod reduction furnace chassis provided by an embodiment of the present invention;

[0040] Figure 3 : A schematic diagram of the grounding principle of a reduction furnace provided in an embodiment of the present invention;

[0041] Figure 4 : A structural diagram of a reduction furnace power supply control method device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0043] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0044] At present, the reduction furnace in the reduction workshop uses the fourth-generation power supply for reducing polysilicon. Although the new power supply has many advantages, serious safety hazards and efficiency problems have emerged in actual operation. The main problem is that the power protection mechanism is imperfect and cannot effectively identify and respond to faults such as silicon rods hitting the wall, resulting in damage to the furnace barrel, furnace overturning and other accidents, increasing non-online time and reducing production. The existing grounding protection mechanism is not sufficient to distinguish between various fault types, especially when operating at low voltage, there is almost no protection. These problems not only affect production efficiency and product quality, but also seriously threaten the safety of operators, and urgently need to be improved and resolved.

[0045] The study found that for Figure 2 In the 40-pair rod reduction furnace shown, the outer ring of the reduction furnace chassis is A1 and C1 phases. If the inner ring silicon rods tilt or fall, the reduction power supply will provide short-circuit protection. However, if the outer ring silicon rods tilt or fall, they will lean against the wall. The operating current will flow from the silicon rods to the furnace barrel to form a loop, causing continuous discharge and damage to the furnace barrel. Because the existing power supply provides grounding protection with a trip value of 1000mA and a delay of 3S, there is no protection at all below the operating voltage of 1000V, and it is impossible to distinguish between ignition in the furnace, silicon powder deposition, and silicon rods leaning against the wall.

[0046] Based on the above findings, the current characteristics of ignition, silicon powder deposition, and silicon rods against the wall in the sub-furnace are analyzed:

[0047] Ignition in the furnace: The grounding current increases suddenly but lasts for a short time, generally 1S to 10S;

[0048] Silicon powder deposition: ground current increases slowly and fluctuates;

[0049] Silicon rod against the wall: the ground current increases suddenly and remains constant, and then decreases as the operating voltage decreases;

[0050] The reduction furnace transformer, power cabinet, PLC control cabinet and furnace chassis are grounded at the same point. When grounding or wall contact occurs in the furnace, the grounding current is detected by the current transformer in the grounding cabinet.

[0051] For example: When a ground fault occurs in phase A1 of the reduction furnace, the ground voltage flows from the grounding wire into the grounding bus to the grounding cabinet and generates a voltage difference with phase A1 N1, which is transmitted to the power control cabinet through the secondary side of the current transformer. The power control cabinet alarms or shuts down.

[0052] The grounding current calculation formula is: operating voltage / grounding resistance / number of silicon rod pairs (8 pairs of rods, 6 pairs of rods, 4 pairs of rods, etc.) = grounding current.

[0053] Due to the particularity of the reduction power supply, the operating voltage will change with the change of silicon rods (load). It is known that the grounding current also fluctuates with the operating voltage (the greater the operating voltage, the greater the grounding current). Assuming that the reduction furnace wall-hitting grounding trip value is a fixed threshold of 1000mA, if a grounding or wall-hitting fault occurs below the operating voltage of 1000V, the single-phase will not be tripped.

[0054] In summary, the current grounding protection trip value is set to a fixed value such as 1000mA, and the delay is 3 seconds. This may be effective when operating at high voltage, but when operating at low voltage (below 1000V), the grounding current does not reach the tripping threshold, resulting in failure to trigger the protection. The operating voltage of the reduction furnace will change with the change of the silicon rod (load) condition, but the protection mechanism fails to dynamically adjust the tripping threshold and fails to adapt to the actual operating conditions. The grounding protection mechanism fails to distinguish different fault types such as ignition in the furnace, silicon powder deposition, and silicon rods against the wall based on the characteristics of the grounding current (such as the rate of change and duration), resulting in untimely or inaccurate response.

[0055] Embodiment 1:

[0056] Based on the above research, in order to solve the existing technical problems, such as Figure 1 As shown, this embodiment provides a reduction furnace power control method, which is applied to polysilicon production, wherein the reduction furnace includes N silicon rod groups, each silicon rod group includes multiple pairs of rods, N is a positive integer, and includes the following steps 101 to 104.

[0057] S101, collecting the operating voltage and grounding current of a first silicon rod group, where the first silicon rod group is any group among N silicon rod groups;

[0058] Specifically, the key electrical parameters of each group of silicon rods in the reduction furnace are monitored in real time. By collecting the operating voltage and grounding current, the current working status information of any group of silicon rods can be obtained. These data are the basis for fault detection and analysis, and help to detect abnormal situations in a timely manner.

[0059] S102, determining a fault judgment threshold of the first silicon rod group according to the operating voltage, where the fault judgment threshold is a power supply trip protection threshold corresponding to a preset voltage interval to which the operating voltage belongs;

[0060] Specifically, the operating voltage will affect the magnitude of the grounding current, so the fault judgment threshold needs to be dynamically adjusted according to the actual operating voltage. By dividing the operating voltage into different preset voltage intervals and setting a corresponding trip protection threshold for each interval, it can be ensured that under different voltage conditions, the fault judgment threshold can adapt to the actual situation and improve the accuracy of fault detection.

[0061] S103, performing a fault analysis on the first silicon rod group according to the fault judgment threshold and the grounding current to obtain a fault analysis result, where the fault analysis result is used to indicate whether a fault occurs in the first silicon rod group;

[0062] Specifically, the working state of the silicon rod group can be determined by comparing the real-time collected ground current with the fault judgment threshold determined according to the operating voltage. If the ground current exceeds the threshold, it indicates that there may be a fault, such as silicon rods leaning against the wall, sparks in the furnace, etc. The fault analysis results provide a basis for subsequent control decisions.

[0063] In practical applications, each silicon rod group can be monitored or fault analyzed as needed, or only some important silicon rod groups can be detected, which is not limited in this application.

[0064] S104, when the fault analysis result indicates that the first silicon rod group has a fault, executing power supply control measures on the first silicon rod group.

[0065] Specifically, when a fault is detected, timely power control measures (such as tripping the power supply) can prevent the fault from further expanding, avoiding equipment damage and safety accidents. Power control measures for specific silicon rod groups help reduce the impact on the operation of the entire reduction furnace and improve production safety and reliability.

[0066] The embodiments of the present application realize effective monitoring and protection of the silicon rod group of the reduction furnace by real-time collection of electrical parameters, dynamic adjustment of fault judgment thresholds, accurate fault analysis, and timely power supply control measures, thereby solving the shortcomings of the traditional fixed threshold protection mechanism and improving the operating safety and production efficiency of the equipment.

[0067] Optionally, before the above S102, the following steps may also be included:

[0068] Divide the operating voltage range of the first silicon rod group into partitions to obtain P voltage partitions, where P is a positive integer;

[0069] The fault judgment threshold of the first silicon rod group in each voltage partition is determined according to the lowest voltage within each voltage partition, the grounding resistance of the first silicon rod group and the number of pairs of silicon rods in the first silicon rod group.

[0070] Specifically, when it is detected that the grounding current at the first moment is greater than or equal to the first threshold, a first continuous grounding current of the first silicon rod group from the first moment to the second moment is obtained, and the time interval between the first moment and the second moment is a first preset unit time;

[0071] When the first continuous grounding current is greater than or equal to the first threshold, a second continuous grounding current of the first silicon rod group from the second moment to the third moment is obtained, the first threshold is a fault judgment threshold corresponding to the operating voltage of the first silicon rod group at the first moment, and the time interval between the third moment and the second moment is a second preset unit time;

[0072] When the second continuous grounding current is greater than or equal to the first threshold, it is determined that the fault analysis result is that the first silicon rod group has a wall-touching fault.

[0073] Specifically, the entire possible operating voltage range of the first silicon rod group is first divided into several continuous voltage intervals; for each voltage partition, the lowest operating voltage within the partition range is taken, and the corresponding fault judgment threshold is determined according to the lowest operating voltage in the interval. By setting the corresponding fault judgment threshold in different voltage partitions, the system can dynamically adjust the threshold according to the actual operating voltage, improve the accuracy of fault detection, especially when operating at low voltage, to avoid missing faults due to excessively high thresholds.

[0074] In this embodiment, appropriate fault judgment thresholds can be used for different operating voltage intervals to adapt to fluctuations in the operating voltage; the problem that a fixed threshold cannot detect faults at low voltage is avoided, and the sensitivity and accuracy of fault detection are improved.

[0075] Optionally, according to the minimum voltage within each voltage partition range, the grounding resistance of the first silicon rod group and the number of pairs of silicon rods in the first silicon rod group, determining the fault judgment threshold of the first silicon rod group in each voltage partition specifically includes the following steps:

[0076] The fault judgment threshold of each voltage partition is calculated by the following formula (1):

[0077] Fault judgment threshold = minimum voltage / ground resistance / number of silicon rod pairs (1)

[0078] Among them, the grounding resistance is the resistance of the grounding resistance cabinet of the silicon rod group, the minimum voltage is the minimum voltage within the voltage partition range, and the number of pairs of rods in the first silicon rod group.

[0079] Specifically, first, the operating voltage range of the first silicon rod group is divided into multiple voltage partitions to obtain P voltage partitions, so that corresponding fault judgment thresholds can be set for different voltage intervals; for each voltage partition, the fault judgment threshold is calculated using formula (1). The purpose of using the lowest voltage in formula (1) is that when operating at low voltage, the fault current may be small. Using the lowest voltage calculation can ensure that the fault judgment threshold will not be too high in the entire voltage range, thereby avoiding missed faults. Further considering the voltage, grounding resistance and number of silicon rods, the fault judgment threshold is accurately calculated, so that the protection device can maintain appropriate sensitivity under different operating conditions.

[0080] In this embodiment, the fault judgment threshold is calculated by the minimum voltage, grounding resistance and silicon rod logarithm of each voltage partition, so as to realize dynamic adjustment of the fault detection threshold and adapt to the requirements under different voltage operating conditions. In particular, when operating at low voltage, the fault judgment threshold is dynamically lowered, so that the grounding protection can be activated in time when the grounding current is low, avoiding the missed fault judgment caused by the fixed high threshold, thereby improving the safety and reliability of the reduction furnace operation, avoiding equipment damage and ensuring the continuity of production.

[0081] Optionally, the above S102 may specifically include the following steps:

[0082] When it is detected that the grounding current at the first moment is greater than or equal to the first threshold, a first continuous grounding current of the first silicon rod group from the first moment to the second moment is obtained, and the time interval between the first moment and the second moment is a first preset unit time;

[0083] When the first continuous grounding current is greater than or equal to the first threshold, a second continuous grounding current of the first silicon rod group from the second moment to the third moment is obtained, the first threshold is a fault judgment threshold corresponding to the operating voltage of the first silicon rod group at the first moment, and the time interval between the third moment and the second moment is a second preset unit time;

[0084] When the second continuous grounding current is greater than or equal to the first threshold, it is determined that the fault analysis result is that the first silicon rod group has a wall-touching fault.

[0085] Here, the second continuous grounding current being greater than or equal to the first threshold value means that the grounding current of the first silicon rod group from the second moment to the third moment is continuously greater than or equal to the first threshold value.

[0086] Specifically, first, when it is detected that the ground current at a certain moment is greater than or equal to a preset threshold, the continuous ground current of the first silicon rod group from this moment to the next moment is obtained, and the time interval between these two moments is a preset unit time. By continuously monitoring for a period of time, it can be determined whether the abnormality of the ground current continues to avoid misjudgment due to short-term fluctuations.

[0087] Second, if the ground current continues to be greater than or equal to the threshold value during the first continuous monitoring time, the continuous ground current from the second moment to the third moment is obtained. The time interval between these two moments is the second preset unit time. The threshold here is still consistent with the fault judgment threshold corresponding to the operating voltage at the starting moment. If the ground current is always greater than or equal to the threshold value during the first preset time, the anomaly may persist and require further confirmation; during this period of time, the ground current is continuously monitored and recorded again to form the second continuous ground current data, which can more accurately determine whether the ground current anomaly persists and prevent false alarms caused by occasional interference or short-term faults.

[0088] Third, if the ground current is still greater than or equal to the threshold value during the second continuous monitoring period, the fault analysis result is determined to be a wall-hitting fault of the first silicon rod group. Then, according to the fault analysis result, corresponding power control measures are implemented on the first silicon rod group, such as cutting off the power supply, triggering a protective circuit breaker, and issuing an alarm signal, to prevent the fault from further expanding.

[0089] In this embodiment, the combination of the continuity of the ground current and the dynamic threshold can effectively distinguish temporary interference from continuous wall faults, avoiding misjudgment and missed judgment. This is of great significance for ensuring the safe operation of the reduction furnace, extending the life of the equipment, and improving production efficiency. In practical applications, it is necessary to optimize and adjust the threshold and time interval according to specific working conditions and equipment parameters to ensure the optimal performance of the fault detection system.

[0090] Optionally, the above S104 may specifically include the following steps:

[0091] When the fault analysis result indicates that the first silicon rod group has a fault and the operating voltage is greater than a preset voltage, power is tripped on the first silicon rod group;

[0092] When the fault analysis result indicates that a fault occurs in the first silicon rod group and the operating voltage is less than or equal to a preset voltage, fault warning information is output.

[0093] Specifically, when the fault analysis result indicates that the first silicon rod group has a fault and the operating voltage is higher than the preset voltage, the power tripping operation is performed on the first silicon rod group. When the voltage is higher than the preset voltage, the current and power of the silicon rod group are large, and the fault may lead to more serious consequences, such as equipment damage, fire and other safety hazards. Timely execution of the power tripping operation can quickly cut off the power supply to the fault point, prevent the fault from expanding, and protect the safety of equipment and personnel.

[0094] When the fault analysis results indicate that the first silicon rod group has a fault and the operating voltage is less than or equal to the preset voltage, a fault warning message is output. At a lower voltage, the power of the silicon rod group is smaller, and the impact of the fault may be relatively small, leaving the operator with time to deal with it. Continuing to run can provide technicians with opportunities for on-site observation and testing, and better locate and analyze the cause of the fault. The system can feedback fault information to the operator through displays, warning lights or sound prompts.

[0095] In this embodiment, by distinguishing the fault handling methods according to the operating voltage, this method improves the flexibility and effectiveness of fault handling while ensuring safety. The power supply is quickly cut off at high voltage to prevent the accident from expanding; and an early warning is provided at low voltage to facilitate timely intervention and maintenance. This strategy effectively balances safety and production continuity, and improves the operating reliability and efficiency of the reduction furnace.

[0096] Optionally, after the above S101, the following steps may also be included:

[0097] When it is detected that the grounding current of the first silicon rod group at the fourth moment is greater than or equal to the preset threshold, a third continuous grounding current of the first silicon rod group from the fourth moment to the fifth moment is obtained, the time interval between the fourth moment and the fifth moment is a third preset unit time, and the preset threshold is determined based on historical detection data of the reduction furnace;

[0098] When the third continuous grounding current is greater than or equal to the preset threshold, it is determined that a short circuit fault occurs in the first silicon rod group.

[0099] The preset threshold is determined based on historical detection data of the reduction furnace. A reasonable preset threshold can be determined by using ground current data during normal operation of the reduction furnace and historical fault data.

[0100] Here, the third continuous grounding current being greater than or equal to the preset threshold value means that the grounding current of the first silicon rod group from the fourth moment to the fifth moment is continuously greater than or equal to the preset threshold value.

[0101] Specifically, when the ground current exceeds the preset threshold at the fourth moment, it may indicate that there is an abnormality in the equipment and further monitoring is required; by continuously collecting ground current data within the third preset unit time, it can be determined whether the abnormality persists. Short-term current fluctuations may be caused by transient interference. Continuous monitoring can avoid misjudgment of faults due to transient interference; if the third continuous ground current continues to be greater than or equal to the preset threshold, it is determined that a short circuit fault has occurred in the first silicon rod group.

[0102] Once a short circuit fault is confirmed, protective measures must be taken immediately, such as cutting off the power supply, to prevent equipment damage or safety accidents. At the same time, the early warning information characteristics can also be used to enable relevant personnel to conduct maintenance, identify the cause of the fault, and prevent it from happening again.

[0103] In this embodiment, adding a detection step for short-circuit faults significantly improves the safety and reliability of the reduction furnace operation. By using threshold setting based on historical data and continuous grounding current monitoring, short-circuit faults can be accurately identified and emergency measures can be taken quickly to prevent accidents from expanding and equipment damage.

[0104] In practical applications, such as Figure 2 The 40 pairs of rod reduction furnace chassis shown in the figure have a total of 6 phases (i.e. 6 groups of silicon rods), namely A1, A2, B1, B2, C1, and C2, among which the outermost ring is the A1 and C1 phases. If B1, B2, C1, and C2 fall over or tilt, they will touch the silicon rods of other phases around them, and the reduction furnace power supply will have short-circuit protection to disconnect the reduction furnace power supply. There are no silicon rods on the outside of A1 and C1. If they tilt, they will rely on the wall of the reduction furnace drum to run.

[0105] For phases A1 and C1, if the inner ring silicon rods tilt or fall over, the restoration power supply will provide short-circuit protection. However, if the outer ring silicon rods tilt or fall over, they will lean against the wall. The operating current will flow from the silicon rods to the furnace barrel to form a loop, causing continuous discharge to the furnace barrel and causing damage. In the prior art, the grounding protection tripping value provided by the restoration power supply manufacturer is 1000mA with a delay of 3S, resulting in no protection at all for operating voltages below 1000V and inability to distinguish between ignition in the furnace, silicon powder deposition, and silicon rods leaning against the wall.

[0106] First, analyze different operating failures:

[0107] Ignition in the furnace: The grounding current increases suddenly but lasts for a short time, generally 1S to 10S.

[0108] Silicon powder deposition: The ground current increases slowly and fluctuates.

[0109] Silicon rod against the wall: the ground current increases suddenly and remains constant, then decreases as the operating voltage decreases.

[0110] Based on this, the following control method can be used for the power supply of the 40 pairs of rod reduction furnaces:

[0111] 1. Reduction furnace grounding setting

[0112] Specific as Figure 3 As shown, the reduction furnace transformer, power cabinet, PLC control cabinet, and furnace chassis are grounded at the same point. When grounding or hitting the wall occurs in the furnace, the reduction furnace will introduce the grounding current into the grounding point through the two grounding wires of the furnace chassis. At this time, a voltage difference will be generated between the grounding point and the zero row in the cabinet. Finally, the grounding current is detected by the current transformer in the grounding cabinet. After the grounding current is detected, it will be fed back to the power cabinet. The power controller determines whether to continue the protection action based on the trip value.

[0113] For example: when a grounding fault occurs in phase A1 of the furnace, the grounding voltage flows from the grounding wire into the grounding bus to the grounding cabinet and generates a voltage difference with phase A1 N1, which is transmitted to the power control cabinet through the secondary side of the current transformer, causing the power control cabinet to alarm or shut down.

[0114] 2. Divide the voltage into zones and determine the power trip threshold corresponding to each voltage zone.

[0115] The power trip threshold is determined by the following formula:

[0116] Operating voltage / grounding resistance (resistance of grounding resistance cabinet) / number of silicon rod pairs (8 pairs of rods, 6 pairs of rods, 4 pairs of rods) = grounding current = DCS wall trip value,

[0117] Based on the formula:

[0118] In the 2200V-2000V range (first partition), set the threshold to 250mA;

[0119] In the range of 1999V-1551V (second partition), set the threshold to 193.6mA;

[0120] In the range of 1550V-1000V (third zone), set the threshold to 125mA;

[0121] In the range of 1000V-486V (fourth zone), set the threshold to 60.7mA;

[0122] When less than or equal to 485V (fifth partition), set the threshold to 50mA. ;

[0123] 2. Real-time data collection

[0124] Collect the operating voltage and grounding current of each group of silicon rods in the reduction furnace.

[0125] 3. Based on the operating voltage and grounding current, the reduction furnace fault detection is carried out and the power supply is safely controlled.

[0126] (1) After the power supply is restored to series operation, the operating voltage is in the range of 2200-2000V (first range):

[0127] If the current running grounding current is 200mA (assumed value) and the running grounding current 3 minutes ago is ≥250mA; then the DCS screen pops up a wall-hitting alarm & continuously detects for 2 minutes that the grounding current is ≥250mA, then the phase will be tripped and the DCS will pop up a wall-hitting tripping prompt screen.

[0128] If the current running ground current is 270mA (assumed value) and the running ground current 3 minutes ago is ≥250mA, then the DCS screen pops up a wall alarm & the ground current is <250mA for 2 minutes of continuous detection and continues to run.

[0129] (2) After the power supply is restored to series operation, the operating voltage is in the range of 1999 to 1551 V (the second range):

[0130] If the current grounding current is 200mA (assumed value) and the grounding current 3 minutes ago is ≥193.6mA; the DCS screen pops up a wall-hitting alarm & continuously detects that the grounding current is ≥193.6mA for 2 minutes, the phase will be tripped and the DCS will pop up a wall-hitting tripping prompt screen;

[0131] If the current running grounding current is 200mA (assumed value) and the running grounding current 3 minutes ago is ≥193.6mA; the DCS screen pops up a wall alarm & the grounding current is <193.6mA for 2 minutes of continuous detection, then continue to run.

[0132] (3) After the power supply is restored to series operation, the operating voltage is in the range of 1550-1000V (the third range):

[0133] If the current grounding current is 128mA (assumed value) and the grounding current 3 minutes ago is ≥125mA, the DCS screen pops up a wall-hitting alarm and the grounding current ≥125mA is continuously detected for 2 minutes, the phase is tripped and the DCS pops up a wall-hitting tripping prompt screen;

[0134] If the current running grounding current is 128mA (assumed value) and the running grounding current 3 minutes ago is ≥193.6mA, a wall-hitting alarm will pop up on the DCS screen and the grounding current will be <125mA for 2 minutes of continuous detection, then the operation will continue.

[0135] (4) After the power supply is restored to run in series, the operating voltage is between 1000 and 486 V (the fourth interval):

[0136] If the current grounding current is 80mA (assumed value) and the grounding current 3 minutes ago is ≥60.7mA, the DCS screen pops up a wall-hitting alarm & continuously detects the grounding current ≥60.7mA for 2 minutes, then the phase is tripped and the DCS pops up a wall-hitting tripping prompt screen;

[0137] If the current running ground current is 80mA (assumed value) and the running ground current 3 minutes ago is ≥60.7mA, the DCS screen pops up a wall alarm & the ground current is <60.7mA for 2 minutes, then continue to run;

[0138] (5) After the power supply is restored to series operation, the operating voltage is below 485V (fifth interval):

[0139] The current grounding current is ≥50mA, and the DCS only alarms but does not trip. Since the operating voltage is ≤485V, it takes an average of 10 hours to shut down the furnace. After querying the curve, it is more likely to have silicon powder deposition and the fluctuation is large due to the low voltage in the last 10 hours. In order to avoid false alarms and loss of polysilicon production, when the operating voltage is ≤485V, only an alarm will be issued to prompt the restoration of the main control operator.

[0140] 4. Detection of faults caused by ignition or silicon powder deposition in the furnace

[0141] Ignition in the furnace: During the growth and operation of the silicon rods in the reduction furnace, ignition occurs between the silicon rods and the silicon powder, or between the silicon rods and the furnace barrel. The reaction phenomenon is a sudden increase in the grounding current, but the maintenance time is short, generally 1S to 10S. If the grounding current caused by the ignition in the furnace is ≥ the grounding trip value set by the reduction power supply (a fixed threshold) and maintained for 3S, the phase will be tripped and stopped. If the grounding current caused by the ignition in the furnace does not maintain 3S or the grounding current does not reach the grounding trip value set by the reduction power supply, the normal operation will continue.

[0142] Silicon powder deposition: During the growth process of the silicon rods in the reduction furnace, the silicon powder is not adsorbed on the silicon rods and falls around the silicon rods on the bottom plate of the furnace, resulting in silicon powder deposition. The silicon rods discharge to the surrounding silicon powder, and the grounding current increases slowly and fluctuates. Due to the general small grounding current caused by silicon powder deposition, the reduction power supply sets a grounding trip value. If the grounding trip value is exceeded, the single phase is stopped.

[0143] 5. After one week of continuous monitoring and confirmation that there are no false alarms, all reduction furnaces will undergo an adaptive DCS wall protection program upgrade and continuous observation.

[0144] The reduction furnace power supply control method provided in this embodiment can realize the wall-hitting protection of the reduction furnace during operation, and stop the operation of the phase when the wall-hitting fault is detected; realize the automatic adjustment of the wall-hitting protection trip value according to the operating voltage; realize the 100% wall-hitting alarm rate of the reduction furnace, and protect the safety of the assembly team. Furthermore, it can distinguish the ignition in the furnace, silicon powder deposition, and wall-hitting faults to avoid misjudgment.

[0145] Embodiment 2:

[0146] This embodiment provides a reduction furnace power control device 200. The furnace body of the reduction furnace includes N silicon rod groups, each silicon rod group includes a plurality of rod pairs, and N is a positive integer, such as Figure 4 As shown, the device comprises:

[0147] A collecting mechanism 201 is used to collect the operating voltage and grounding current of a first silicon rod group, where the first silicon rod group is any one of the N silicon rod groups;

[0148] The first determination module 202 is connected to the acquisition mechanism and is used to determine a fault judgment threshold of the first silicon rod group according to the operating voltage, where the fault judgment threshold is a power supply trip protection threshold corresponding to a preset voltage interval to which the operating voltage belongs;

[0149] An analysis module 203, connected to the determination module, is used to perform a fault analysis on the first silicon rod group according to the fault judgment threshold and the ground current to obtain a fault analysis result, and the fault analysis result is used to indicate whether a fault occurs in the first silicon rod group;

[0150] The control module 204 is connected to the analysis module, and is used to execute power supply control measures on the first silicon rod group when the fault analysis result indicates that the first silicon rod group has a fault.

[0151] Optionally, the device further comprises:

[0152] A partitioning module, used for partitioning the operating voltage range of the first silicon rod group to obtain P voltage partitions, where P is a positive integer;

[0153] The second determination module is connected to the division module and is used to determine the fault judgment threshold of the first silicon rod group in each voltage partition according to the lowest voltage in each voltage partition range, the grounding resistance of the first silicon rod group and the number of pairs of silicon rods in the first silicon rod group.

[0154] Optionally, the second determining module is specifically used to:

[0155] The fault judgment threshold of each voltage partition is calculated by the following formula (1):

[0156] Fault judgment threshold = minimum voltage / ground resistance / number of silicon rod pairs (1)

[0157] The minimum voltage is the minimum voltage within the voltage partition range, the grounding resistance is the resistance of the grounding resistance cabinet of the silicon rod group, and the number of silicon rod pairs is the number of pairs of rods in the first silicon rod group.

[0158] Optionally, the analysis module 203 includes:

[0159] A first acquisition unit is used to acquire a first continuous grounding current of the first silicon rod group from the first moment to the second moment when it is detected that the grounding current at the first moment is greater than or equal to a first threshold, wherein the time interval between the first moment and the second moment is a first preset unit time;

[0160] a second acquisition unit, connected to the first acquisition unit, and configured to acquire, when the first continuous grounding current is greater than or equal to a first threshold, a second continuous grounding current of the first silicon rod group from the second moment to a third moment, the first threshold being a fault judgment threshold corresponding to the operating voltage of the first silicon rod group at the first moment, and a time interval between the third moment and the second moment being a second preset unit time;

[0161] The first determining unit is connected to the second acquiring unit, and is used for determining that the fault analysis result is that the first silicon rod group has a wall-hitting fault when the second continuous grounding current is greater than or equal to the first threshold.

[0162] Optionally, the control module 204 includes:

[0163] A first control unit, configured to execute power tripping of the first silicon rod group when the fault analysis result indicates that the first silicon rod group has a fault and the operating voltage is greater than a preset voltage;

[0164] The second control unit is used to output fault warning information when the fault analysis result indicates that the first silicon rod group has a fault and the operating voltage is less than or equal to a preset voltage.

[0165] Optionally, the above device further includes:

[0166] an acquisition module, configured to acquire, when detecting that the grounding current of the first silicon rod group at the fourth moment is greater than or equal to a preset threshold, a third continuous grounding current of the first silicon rod group from the fourth moment to the fifth moment, wherein the time interval between the fourth moment and the fifth moment is a third preset unit time and a preset threshold;

[0167] The determination module is connected to the acquisition module and is used to determine that a short circuit fault occurs in the first silicon rod group when the third continuous grounding current is greater than or equal to a target threshold.

[0168] In this embodiment, the operating voltage and grounding current of each group of silicon rods can be collected in real time, and the fault judgment threshold can be dynamically determined according to the current operating voltage, thereby achieving accurate monitoring and adaptive protection of the reduction furnace power supply system.

[0169] Embodiment 3:

[0170] This embodiment provides a reduction furnace, which includes:

[0171] Reduction furnace body;

[0172] N silicon rod groups are arranged in the reduction furnace body, each silicon rod group includes a plurality of rod pairs, and N is a positive integer;

[0173] The reduction furnace power supply control device provided in any of the above embodiments is used to control the power supply of the N groups of silicon rods.

[0174] Specifically, the reduction furnace body is the main structure of the entire reduction furnace, which is used to accommodate silicon rods and provide the physical environment required for the reduction reaction. The N groups of silicon rods arranged in the reduction furnace body are used for the reduction reaction to obtain polysilicon; the power supply control device can monitor the current and voltage in real time, provide overload, short circuit and other protection functions, ensure the safe operation of the equipment, and have a fault self-checking function, which can detect and handle abnormal situations in time to avoid accidents. Through real-time monitoring and control, possible faults can be prevented and handled in time to reduce downtime.

[0175] The reduction furnace provided in this embodiment can be used for preparing polysilicon materials. Through the organic combination of the furnace body, the silicon rod group with adjustable number and the advanced power supply control device, an efficient, flexible and safe reduction reaction equipment is formed.

[0176] It should be clear that the present application is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present application is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present application.

[0177] The functional blocks shown in the above block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0178] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.

[0179] Aspects of the present disclosure are described above with reference to the flowchart and / or block diagram of the method, device (system) and computer program product according to the embodiment of the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the implementation of the function / action specified in one or more boxes of the flowchart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field programmable logic circuit. It can also be understood that each box in the block diagram and / or flowchart and the combination of boxes in the block diagram and / or flowchart can also be implemented by dedicated hardware that performs a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0180] The above are only specific implementation methods of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.

Claims

1. A reduction furnace power supply control method, characterized in that: The reduction furnace includes N silicon rod groups in its furnace body, each silicon rod group includes a plurality of rod pairs, and N is a positive integer. The method includes: collecting an operating voltage and a grounding current of a first silicon rod group, where the first silicon rod group is any group among the N silicon rod groups; Determine a fault judgment threshold of the first silicon rod group according to the operating voltage, wherein the fault judgment threshold is a power supply trip protection threshold corresponding to a preset voltage interval to which the operating voltage belongs; Performing a fault analysis on the first silicon rod group according to the fault judgment threshold and the grounding current to obtain a fault analysis result, wherein the fault analysis result is used to indicate whether a fault occurs in the first silicon rod group; When the fault analysis result indicates that a fault occurs in the first silicon rod group, power supply control measures are performed on the first silicon rod group.

2. The reduction furnace power supply control method according to claim 1, characterized in that: Before determining the fault judgment threshold of the first silicon rod group according to the operating voltage, the method further includes: Divide the operating voltage range of the first silicon rod group into partitions to obtain P voltage partitions, where P is a positive integer; A fault judgment threshold of the first silicon rod group in each voltage partition is determined according to the lowest voltage within each voltage partition, the grounding resistance of the first silicon rod group, and the number of pairs of silicon rods in the first silicon rod group.

3. The reduction furnace power supply control method according to claim 2, characterized in that: The determining, according to the lowest voltage within each voltage partition range, the grounding resistance of the first silicon rod group, and the number of pairs of silicon rods in the first silicon rod group, each fault judgment threshold of the first silicon rod group in each voltage partition specifically includes: The fault judgment threshold of each voltage partition is calculated by the following formula (1): Fault judgment threshold = minimum voltage / ground resistance / number of silicon rod pairs (1) The minimum voltage is the minimum voltage within the voltage partition range, the grounding resistance is the resistance of the grounding resistance cabinet of the silicon rod group, and the number of silicon rod pairs is the number of pairs of rods in the first silicon rod group.

4. The reduction furnace power supply control method according to claim 1, characterized in that: The performing fault analysis on the first silicon rod group according to the fault judgment threshold and the ground current to obtain a fault analysis result specifically includes: When it is detected that the grounding current at the first moment is greater than or equal to the first threshold, a first continuous grounding current of the first silicon rod group from the first moment to the second moment is obtained, and the time interval between the first moment and the second moment is a first preset unit time; When the first continuous grounding current is greater than or equal to a first threshold, obtaining a second continuous grounding current of the first silicon rod group from the second moment to a third moment, wherein the first threshold is a fault judgment threshold corresponding to the operating voltage of the first silicon rod group at the first moment, and the time interval between the third moment and the second moment is a second preset unit time; When the second continuous grounding current is greater than or equal to the first threshold, it is determined that the fault analysis result is that the first silicon rod group has a wall-hitting fault.

5. The reduction furnace power supply control method according to claim 1, characterized in that: When the fault analysis result indicates that the first silicon rod group has a fault, executing power control measures on the first silicon rod group specifically includes: When the fault analysis result indicates that the first silicon rod group has a fault and the operating voltage is greater than a preset voltage, powering off the first silicon rod group; When the fault analysis result indicates that the first silicon rod group has a fault and the operating voltage is less than or equal to a preset voltage, fault warning information is output.

6. The reduction furnace power supply control method according to claim 2, characterized in that: After collecting the operating voltage and grounding current of the first silicon rod group, where the first silicon rod group is any group of silicon rods in the N groups of silicon rods, the method further includes: When it is detected that the grounding current of the first silicon rod group at a fourth moment is greater than or equal to a preset threshold, a third continuous grounding current of the first silicon rod group from the fourth moment to a fifth moment is obtained, the time interval between the fourth moment and the fifth moment is a third preset unit time, and the preset threshold is determined according to historical detection data of the reduction furnace; When the third continuous grounding current is greater than or equal to a preset threshold, it is determined that a short circuit fault occurs in the first silicon rod group.

7. A reduction furnace power supply control device, characterized in that: The reduction furnace includes N silicon rod groups in the furnace body, each silicon rod group includes a plurality of rod pairs, N is a positive integer, and the device includes: A collecting mechanism, used for collecting the operating voltage and grounding current of a first silicon rod group, where the first silicon rod group is any one of the N silicon rod groups; A first determination module, connected to the acquisition mechanism, is used to determine a fault judgment threshold of the first silicon rod group according to the operating voltage, wherein the fault judgment threshold is a power supply trip protection threshold corresponding to a preset voltage interval to which the operating voltage belongs; an analysis module, connected to the determination module, and configured to perform a fault analysis on the first silicon rod group according to the fault judgment threshold and the ground current to obtain a fault analysis result, wherein the fault analysis result is used to indicate whether a fault occurs in the first silicon rod group; A control module is connected to the analysis module and is used to execute power supply control measures on the first silicon rod group when the fault analysis result indicates that the first silicon rod group has a fault.

8. The reduction furnace power supply control device according to claim 7, characterized in that: The device also includes: A partitioning module, used for partitioning the operating voltage range of the first silicon rod group to obtain P voltage partitions, where P is a positive integer; The second determination module is connected to the division module and is used to determine the fault judgment threshold of the first silicon rod group in each voltage partition according to the lowest voltage within each voltage partition range, the grounding resistance of the first silicon rod group and the number of pairs of silicon rods in the first silicon rod group.

9. The reduction furnace power supply control device according to claim 7, characterized in that: The analysis module comprises: A first acquisition unit is used to acquire a first continuous grounding current of the first silicon rod group from the first moment to a second moment when it is detected that the grounding current at the first moment is greater than or equal to a first threshold, wherein the time interval between the first moment and the second moment is a first preset unit time; a second acquisition unit, connected to the first acquisition unit, and configured to acquire, when the first continuous grounding current is greater than or equal to a first threshold, a second continuous grounding current of the first silicon rod group from the second moment to a third moment, wherein the first threshold is a fault judgment threshold corresponding to the operating voltage of the first silicon rod group at the first moment, and a time interval between the third moment and the second moment is a second preset unit time; The first determining unit is connected to the second acquiring unit, and is used for determining that the fault analysis result is that the first silicon rod group has a wall-hitting fault when the second continuous grounding current is greater than or equal to a first threshold.

10. The reduction furnace power supply control device according to claim 7, characterized in that: The device also includes: an acquisition module, configured to acquire, when detecting that the grounding current of the first silicon rod group at a fourth moment is greater than or equal to a preset threshold, a third continuous grounding current of the first silicon rod group from the fourth moment to a fifth moment, wherein the time interval between the fourth moment and the fifth moment is a third preset unit time, and the preset threshold is determined according to historical detection data of the reduction furnace; A determination module is connected to the acquisition module and is used to determine that a short circuit fault occurs in the first silicon rod group when the third continuous grounding current is greater than or equal to a target threshold.

11. A reduction furnace, characterized in that: The reduction furnace comprises: Reduction furnace body; N silicon rod groups are arranged in the reduction furnace body, each silicon rod group includes a plurality of rod pairs, and N is a positive integer; The reduction furnace power supply control device according to any one of claims 7 to 10 is used to control the power supply of the N groups of silicon rods.

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