Method and system for detecting wall collision of silicon rod of polycrystalline silicon reduction furnace

Abstract

The invention discloses a polycrystalline silicon reduction furnace silicon rod wall collision detection method and system, and relates to the technical field of polycrystalline silicon reduction power supplies, and the method comprises the following steps: S1, collecting a series voltage, a parallel voltage, a grounding voltage and a grounding current of a power regulation circuit during high-start pressing, parallel operation and series operation of the power regulation circuit; s2, according to the collected series voltage, parallel voltage, grounding voltage and grounding current, whether the reduction furnace is grounded or not is judged, and an alarm is given; and S3, judging the wall collision condition of the silicon rod according to the grounding alarm information of the reduction furnace. According to the invention, the conditions of abnormal growth of the silicon rod and damage to the furnace cylinder due to the fact that the voltage of the silicon rod is too low and the grounding alarm value cannot be triggered in the later period can be ensured; and judgment is carried out through a detected grounding voltage, a grounding current and a six-phase silicon rod load voltage program algorithm, which silicon rod collides with the wall can be accurately positioned to give an alarm, and the situation that the furnace wall is ablated by large current is prevented.

Description

Technical Field

[0001] The present invention relates to the technical field of polysilicon reduction power supply, and more specifically to a method and system for detecting silicon rods hitting a wall in a polysilicon reduction furnace. Background Art

[0002] Polysilicon is the raw material of the solar energy industry chain and the foundation of electronic information. The polysilicon reduction furnace is a very important core equipment for polysilicon production. In the process of producing polysilicon through the reduction furnace, due to process control and furnace loading defects, it is inevitable that the chassis silicon powder is too heavy, the graphite seat grows amorphous silicon, the silicon rod hits the wall, etc., which will cause grounding problems. This has a great restriction on the safety of polysilicon. Therefore, it is particularly important to provide a reliable and stable grounding detection method.

[0003] The commonly used grounding detection system at present directly determines whether there is a grounding condition in the furnace by detecting the current of the N line connected to the grounding resistance of each phase of the secondary side of the reduction transformer. This method ensures the stable operation of the reduction furnace, reduces the probability of shutdown due to faults, and is more in line with the actual operation of polysilicon production. However, in this detection method, the grounding detection voltage is Ux. According to the characteristics of polysilicon growth, this voltage gradually decreases with the continuous growth of the silicon rod. The voltage will be smaller in the later stage. The detected grounding current is small or zero, and the set grounding alarm value may not be triggered, which will not achieve the purpose of protection. In addition, in the actual operation of the current detection technology, when the silicon rod hits the wall, the existing detection means cannot directly determine that the silicon rod hits the wall. The contact point is prone to high temperature, ablation of the furnace wall, or even burning through the furnace wall, causing explosions and other major production accidents.

[0004] In the prior art, the patent with publication number CN216351147U discloses a reduction power supply power regulation circuit based on grounding monitoring of the whole cycle of polysilicon growth, including a power regulation control unit, a power regulation loop unit and a grounding monitoring unit; the grounding monitoring unit includes a JD switch, a current transformer JDCT and six identical resistors connected in series; the input end of the first resistor is connected to the power regulation loop unit, and is connected to the power regulation control unit through the JD switch; a voltage relay is connected in parallel to the last resistor, and the output end of the last resistor is grounded through the current transformer JDCT. This technical solution fills the blind spot of the reduction furnace grounding monitoring in the time period, realizes the real-time grounding monitoring of the reduction furnace during the whole process of the reduction power supply, and ensures the safe operation of the reduction furnace equipment and the reduction power supply to the maximum extent, providing an important guarantee for the smooth growth of polysilicon.

[0005] However, the reduction power supply power regulation circuit disclosed in the above patent does not disclose how to use the reduction power supply power regulation circuit to realize silicon rod wall collision detection. Therefore, a polysilicon reduction furnace silicon rod wall collision detection method and system are urgently needed to detect the silicon rod wall collision of the polysilicon reduction furnace. Summary of the invention

[0006] In order to overcome the defects in the above-mentioned prior art, the present invention discloses a method and system for detecting silicon rods hitting the wall in a polysilicon reduction furnace. The purpose of the present invention is to solve the problem that in the prior art, as the silicon rods continue to grow, the voltage gradually decreases and there is a detection blind area. When the voltage drops to the lower limit of the action voltage, when grounding occurs, the system cannot perform grounding alarms and cannot accurately alarm when abnormalities such as silicon rods hitting the wall occur. The present invention can accurately detect grounding throughout the entire cycle during the polysilicon production process in the reduction furnace and accurately determine whether the grounding fault is caused by silicon rods hitting the wall.

[0007] In order to achieve the above objectives, the technical solution adopted by the present invention is:

[0008] A method for detecting a silicon rod hitting a wall in a polysilicon reduction furnace comprises the following steps:

[0009] 1. Data Collection

[0010] S1. When the power regulating circuit is high-starting, operating in parallel or in series, the series voltage, parallel voltage, ground voltage and ground current of the power regulating circuit are collected;

[0011] During the production process of the polysilicon reduction furnace of the present invention, when the reduction furnace reduction power supply power regulation circuit is in high start-up voltage, parallel operation and series operation, the power regulation circuit series voltage detection unit PT1, the power regulation circuit parallel voltage detection unit PT2, the ground detection voltage transformer JDPT and the ground detection current transformer JDCT are respectively used to collect the series voltage, parallel voltage, ground voltage and ground current of the power regulation circuit in real time.

[0012] 2. Grounding judgment

[0013] S2. According to the collected series voltage, parallel voltage, ground voltage and ground current, determine whether the reduction furnace is grounded and alarm;

[0014] Preferably, in step S2, determining whether the reduction furnace is grounded and giving an alarm includes:

[0015] When the series voltage or parallel voltage is ≥1500V, the grounding voltage is ≥300V, and the grounding current is ≥600mA, it is judged that the reduction furnace is grounded and an alarm is issued;

[0016] When 760V≤series voltage or parallel voltage<1500V, grounding voltage≥152V, grounding current≥304mA, it is judged that the reduction furnace is grounded and an alarm is issued;

[0017] When 360V≤series voltage or parallel voltage<760V, grounding voltage≧72V, and grounding current≧144mA, it is judged that the reduction furnace is grounded and an alarm is issued.

[0018] 3. Wall judgment

[0019] S3. According to the reduction furnace grounding alarm information, determine whether the silicon rod hits the wall.

[0020] Preferably, in step S3, judging whether the silicon rod hits the wall includes: for each phase with a total number of N pairs, and a total of 2N silicon cores are loaded:

[0021] When the high-start voltage is applied or the parallel operation is in parallel, the average series voltage of the nth silicon core before the parallel point X is U1 after the ground alarm is triggered, and the average series voltage within t seconds after the alarm is U2. If the series voltage U2 of any of the other five phases is greater than U1, the nth silicon core will hit the wall;

[0022] When the high-start voltage is applied or the parallel operation is in parallel, the average series voltage of the nth silicon core after the parallel point Y triggers the ground alarm. The average series voltage of t seconds before the alarm is U3, and the average series voltage of t seconds after the alarm is U4. If the series voltage U4 of any of the other five phases is greater than U3, the nth silicon core will hit the wall; X+Y=N;

[0023] When the nth silicon core is connected in series and the ground alarm is triggered, the average series voltage t seconds before the alarm is U5, and the average series voltage within t seconds after the alarm is U6. And if the series voltage U6 of any of the other five phases is greater than U5, it means that the nth silicon core has hit a wall.

[0024] (1) 8 pairs of rods

[0025] Preferably, in step S3, judging whether the silicon rod hits the wall includes: for 8 pairs of rods, a total of 16 silicon cores are loaded:

[0026] When the high-start voltage is applied or the parallel operation is in parallel, the four pairs of n-th silicon cores before the parallel point trigger the grounding alarm. The average series voltage in the 5S before the alarm is U1, and the average series voltage in the 5S after the alarm is U2. If the series voltage U2 of any of the other five phases is greater than U1, the nth silicon core will hit the wall;

[0027] When the high-start voltage is applied or the parallel operation is in parallel, the four pairs of n-th silicon cores after the parallel point trigger the grounding alarm. The average series voltage in the 5S before the alarm is U3, and the average series voltage in the 5S after the alarm is U4. If the series voltage U4 of any of the other five phases is greater than U3, the nth silicon core will hit the wall;

[0028] When the nth silicon core is connected in series and the ground alarm is triggered, the average series voltage in the 5S before the alarm is U5, and the average series voltage in the 5S after the alarm is U6. And if the series voltage U6 of any of the other five phases is greater than U5, it means that the nth silicon core has hit a wall.

[0029] In the present invention, the series voltage refers to the series voltage collected by the series voltage detection unit PT1 of the power regulation circuit. There are 6 phases of silicon rods in the reduction furnace. When one phase hits the wall, it causes the heat in the furnace to decrease. In order to stabilize the current, the voltage will rise.

[0030] (2) 4 pairs of rods

[0031] Preferably, in step S3, judging whether the silicon rod hits the wall includes: for 4 pairs of rods, a total of 8 silicon cores are loaded:

[0032] When the two pairs of n-th silicon cores before the parallel point are in high-start voltage or parallel operation, the average series voltage of the 5S before the alarm is U1, and the average series voltage of the 5S after the alarm is U2. If the series voltage U2 of any of the other five phases is greater than U1, the nth silicon core will hit the wall;

[0033] When the two pairs of n-th silicon cores after the parallel point are in high-start voltage or parallel operation, the average series voltage of the 5S before the alarm is U3 and the average series voltage of the 5S after the alarm is U4. If the series voltage U4 of any of the other five phases is greater than U3, the nth silicon core will hit the wall;

[0034] When the nth silicon core is connected in series and the ground alarm is triggered, the average series voltage in the 5S before the alarm is U5, and the average series voltage in the 5S after the alarm is U6. And if the series voltage U6 of any of the other five phases is greater than U5, it means that the nth silicon core has hit a wall.

[0035] (3) 6 pairs of rods

[0036] Preferably, in step S3, determining whether the silicon rods hit the wall includes: for 6 pairs of rods, a total of 12 silicon cores are loaded:

[0037] When the high-start voltage is applied or the parallel operation is in parallel, the four pairs of n-th silicon cores before the parallel point trigger the grounding alarm. The average series voltage in the 5S before the alarm is U1, and the average series voltage in the 5S after the alarm is U2. If the series voltage U2 of any of the other five phases is greater than U1, the nth silicon core will hit the wall;

[0038] When the two pairs of n-th silicon cores after the parallel point are in high-start voltage or parallel operation, the average series voltage of the 5S before the alarm is U3 and the average series voltage of the 5S after the alarm is U4. If the series voltage U4 of any of the other five phases is greater than U3, the nth silicon core will hit the wall;

[0039] When the nth silicon core is connected in series and the ground alarm is triggered, the average series voltage in the 5S before the alarm is U5, and the average series voltage in the 5S after the alarm is U6. And if the series voltage U6 of any of the other five phases is greater than U5, it means that the nth silicon core has hit a wall.

[0040] Based on the above-mentioned polysilicon reduction furnace silicon rod wall collision detection method, the present invention also provides a polysilicon reduction furnace silicon rod wall collision detection system, comprising:

[0041] Power regulation circuit;

[0042] A plurality of grounding resistors are arranged in series and connected to the power regulation circuit;

[0043] A ground detection current transformer, connected in series with the ground resistor, for real-time acquisition of ground current;

[0044] A ground detection voltage transformer, connected in parallel with the ground resistor, for real-time acquisition of ground voltage;

[0045] A power regulation circuit series voltage detection unit, connected in series with the power regulation circuit and used for real-time acquisition of the power regulation circuit series voltage;

[0046] A power regulation circuit parallel voltage detection unit, connected in parallel with the power regulation circuit and used for real-time acquisition of the power regulation circuit parallel voltage;

[0047] A collection controller is connected to the ground detection current transformer, the ground detection voltage transformer, the power regulation circuit series voltage detection unit and the power regulation circuit parallel voltage detection unit respectively, and is used to receive the collected ground current, ground voltage, series voltage and parallel voltage;

[0048] The PLC is connected to the acquisition controller, and determines whether the reduction furnace is grounded and alarms according to the collected grounding current, grounding voltage, series voltage, and parallel voltage, and determines whether the silicon rod hits the wall.

[0049] Preferably, the first grounding resistor is connected to the N rows of the power regulation circuit and is connected in series with the grounding detection current transformer, and the grounding detection voltage transformer is connected in parallel on both sides of the last grounding resistor.

[0050] Beneficial effects of the present invention:

[0051] According to the growth characteristics of silicon rods, as the diameter of the silicon rods increases, the voltage of the loaded silicon rods decreases. In order to effectively and accurately detect the grounding condition in the whole cycle of the silicon rods, the technical solution collects the grounding current and the grounding voltage according to the actual voltage of the silicon rods; three grounding alarm areas and three different grounding current alarm values ​​are set. This solution can ensure that when the silicon rod voltage is too low in the later stage of operation and the grounding alarm value cannot be triggered, the silicon rod growth is abnormal and the furnace barrel is damaged; by judging in the program algorithm of the detected grounding voltage, grounding current, and 6-phase silicon rod load voltage, it can accurately locate which silicon rod hits the wall and alarms, thereby preventing the situation of large current ablating the furnace wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 The circuit diagram of the polysilicon reduction furnace silicon rod wall collision detection system of the present invention;

[0053] Figure 2 for Figure 1 A magnified image of the upper left part;

[0054] Figure 3 for Figure 1 A magnified image of the upper right part;

[0055] Figure 4 for Figure 1 Enlarged view of the lower part. DETAILED DESCRIPTION

[0056] The concept, specific structure and technical effects of the present invention will be clearly and completely described below in combination with the embodiments and drawings to fully understand the purpose, characteristics and effects of the present invention.

[0057] Example 1

[0058] like Figure 1-Figure 4As shown, the grounding system includes a power regulation control unit, a silicon core load, a switching vacuum contactor, a series vacuum circuit breaker, a series voltage detection unit, a parallel high-start voltage detection unit, and a grounding detection unit. During the production process of polysilicon, the power regulation system is divided into three stages: high-start voltage suppression, parallel operation, and series operation. Specifically, in the high-start process, the suppression current I is set, K21, K11, K1 closes the step-up transformer T2 to boost the silicon core R1 to break down. After the silicon core breaks down, the primary current rises to the conversion condition, and the suppression voltage drops below the conversion voltage. It can be switched to the maintenance heating stage, K1 opens, K2 closes, and when the silicon core current rises to the suppression current conversion condition, it enters the reduction and freewheeling stage, K2 opens, K11 opens , K3, K4 are closed; similarly, the system breaks down R2, R3-R4. When R3-R4 breaks down and K2 is closed to maintain the current rising to the set current I, the system enters the parallel operation stage. At this time, K2, K3, K4, K13, and K22 are in the closed state. When the operating current is greater than the set series current and the series voltage U1 + parallel voltage U2 is less than the series set voltage, K2, K3, K4, K13, and K22 are all opened, the vacuum circuit breaker QF1 is closed, and the system enters the series mode operation.

[0059] Based on the above grounding system, this embodiment provides a method for detecting silicon rods hitting the wall in a polysilicon reduction furnace, comprising the following steps:

[0060] S1. When the power regulating circuit is high-starting, operating in parallel or in series, the series voltage, parallel voltage, ground voltage and ground current of the power regulating circuit are collected;

[0061] S2. According to the collected series voltage, parallel voltage, ground voltage and ground current, determine whether the reduction furnace is grounded and alarm;

[0062] S3. According to the reduction furnace grounding alarm information, determine whether the silicon rod hits the wall.

[0063] Example 2

[0064] This embodiment further describes step S1 and step S2 based on embodiment 1. Figure 1-Figure 4As shown in the figure, during high start, parallel and series operation, the controller collects the system series voltage, high start parallel voltage, grounding voltage and grounding current in real time through PT1, PT2, JDPT and JDCT; and transmits the data to PLC through communication; the PLC program determines whether the system is grounded and at which position the system is grounded according to different voltages and currents, and the grounding type is silicon rod hitting the wall or other soft grounding; the grounding detection module includes 5 2000W 200Ω resistors in series, and the grounding voltage transformer is connected in parallel to both sides of the 5th resistor to detect the grounding voltage; since the restoration transformer is divided into 5 gears, the voltage of gear 1 is 2650V, the voltage of gear 2 is 1500V, the voltage of gear 3 is 1040V, the voltage of gear 4 is 760V, and the voltage of gear 5 is 360V; in the later stage of operation, the silicon rod voltage is only 400V. In order to accurately detect the grounding in the later stage of operation, 3 different grounding currents are set according to the 5 gear voltages:

[0065] When the series voltage or parallel voltage is ≥1500V, the grounding voltage is ≥300V, and the grounding current is ≥600mA, it is judged that the reduction furnace is grounded and an alarm is issued;

[0066] When 760V≤series voltage or parallel voltage<1500V, grounding voltage≥152V, grounding current≥304mA, it is judged that the reduction furnace is grounded and an alarm is issued;

[0067] When 360V≤series voltage or parallel voltage<760V, grounding voltage≧72V, and grounding current≧144mA, it is judged that the reduction furnace is grounded and an alarm is issued.

[0068] This solution setting can improve the detection and handling of ground faults. All the above alarm value parameters can be modified on the HMI according to the actual operating conditions.

[0069] Example 3

[0070] Based on Example 2, this embodiment further elaborates on step S3. In step S3, judging whether the silicon rod hits the wall includes: for each phase with a total number of pairs N, and a total of 2N silicon cores are loaded:

[0071] When the high-start voltage is applied or the parallel operation is in parallel, the average series voltage of the nth silicon core before the parallel point X is U1 after the ground alarm is triggered, and the average series voltage within t seconds after the alarm is U2. If the series voltage U2 of any of the other five phases is greater than U1, the nth silicon core will hit the wall;

[0072] When the high-start voltage is applied or the parallel operation is in parallel, the average series voltage of the nth silicon core after the parallel point Y triggers the ground alarm. The average series voltage of t seconds before the alarm is U3, and the average series voltage of t seconds after the alarm is U4. If the series voltage U4 of any of the other five phases is greater than U3, the nth silicon core will hit the wall; X+Y=N;

[0073] When the nth silicon core is connected in series and the ground alarm is triggered, the average series voltage t seconds before the alarm is U5, and the average series voltage within t seconds after the alarm is U6. And if the series voltage U6 of any of the other five phases is greater than U5, it means that the nth silicon core has hit a wall.

[0074] (1) 8 pairs of rods

[0075] In order to accurately judge whether the silicon rod hits the wall, take 8 pairs of rods as an example, with a total of 16 silicon cores:

[0076] When the high-start voltage is applied or the parallel operation is in parallel, the four pairs of n-th silicon cores before the parallel point trigger the grounding alarm. The average series voltage in the 5S before the alarm is U1, and the average series voltage in the 5S after the alarm is U2. If the series voltage U2 of any of the other five phases is greater than U1, the nth silicon core will hit the wall;

[0077] When the high-start voltage is applied or the parallel operation is in parallel, the four pairs of n-th silicon cores after the parallel point trigger the grounding alarm. The average series voltage in the 5S before the alarm is U3, and the average series voltage in the 5S after the alarm is U4. If the series voltage U4 of any of the other five phases is greater than U3, the nth silicon core will hit the wall;

[0078] When the nth silicon core is connected in series and the ground alarm is triggered, the average series voltage in the 5S before the alarm is U5, and the average series voltage in the 5S after the alarm is U6. And if the series voltage U6 of any of the other five phases is greater than U5, it means that the nth silicon core has hit a wall.

[0079] Similarly, set the alarm logic for 4 pairs of rods and 6 pairs of rods.

[0080] (2) 4 pairs of rods

[0081] Take 4 pairs of rods as an example, with a total of 8 silicon cores loaded:

[0082] When the two pairs of n-th silicon cores before the parallel point are in high-start voltage or parallel operation, the average series voltage of the 5S before the alarm is U1, and the average series voltage of the 5S after the alarm is U2. If the series voltage U2 of any of the other five phases is greater than U1, the nth silicon core will hit the wall;

[0083] When the two pairs of n-th silicon cores after the parallel point are in high-start voltage or parallel operation, the average series voltage of the 5S before the alarm is U3 and the average series voltage of the 5S after the alarm is U4. If the series voltage U4 of any of the other five phases is greater than U3, the nth silicon core will hit the wall;

[0084] When the nth silicon core is connected in series and the ground alarm is triggered, the average series voltage in the 5S before the alarm is U5, and the average series voltage in the 5S after the alarm is U6. And if the series voltage U6 of any of the other five phases is greater than U5, it means that the nth silicon core has hit a wall.

[0085] (3) 6 pairs of rods

[0086] Take 6 pairs of rods as an example, with a total of 12 silicon cores:

[0087] When the high-start voltage is applied or the parallel operation is in parallel, the four pairs of n-th silicon cores before the parallel point trigger the grounding alarm. The average series voltage in the 5S before the alarm is U1, and the average series voltage in the 5S after the alarm is U2. If the series voltage U2 of any of the other five phases is greater than U1, the nth silicon core will hit the wall;

[0088] When the two pairs of n-th silicon cores after the parallel point are in high-start voltage or parallel operation, the average series voltage of the 5S before the alarm is U3 and the average series voltage of the 5S after the alarm is U4. If the series voltage U4 of any of the other five phases is greater than U3, the nth silicon core will hit the wall;

[0089] When the nth silicon core is connected in series and the ground alarm is triggered, the average series voltage in the 5S before the alarm is U5, and the average series voltage in the 5S after the alarm is U6. And if the series voltage U6 of any of the other five phases is greater than U5, it means that the nth silicon core has hit a wall.

[0090] When grounding occurs during high start or parallel connection, taking 4 pairs of rods as an example, if the first 4 pairs are grounded, the current detection direction is ① passing through K3, passing through the grounding point, and then passing through the grounding resistor to detect the grounding voltage and grounding current. If it is the last 4 pairs, the current detection direction is ② passing through K2, K13, and then passing through the grounding point, and passing through the grounding resistor to detect the current and voltage.

[0091] Example 4

[0092] A polysilicon reduction furnace silicon rod wall detection system, such as Figure 1-Figure 4 As shown, including:

[0093] Power regulation circuit;

[0094] A plurality of grounding resistors are arranged in series and connected to the power regulation circuit;

[0095] A ground detection current transformer, connected in series with the ground resistor, for real-time acquisition of ground current;

[0096] A ground detection voltage transformer, connected in parallel with the ground resistor, for real-time acquisition of ground voltage;

[0097] A power regulation circuit series voltage detection unit, connected in series with the power regulation circuit and used for real-time acquisition of the power regulation circuit series voltage;

[0098] A power regulation circuit parallel voltage detection unit, connected in parallel with the power regulation circuit and used for real-time acquisition of the power regulation circuit parallel voltage;

[0099] A collection controller is connected to the ground detection current transformer, the ground detection voltage transformer, the power regulation circuit series voltage detection unit and the power regulation circuit parallel voltage detection unit respectively, and is used to receive the collected ground current, ground voltage, series voltage and parallel voltage;

[0100] The PLC is connected to the acquisition controller, and determines whether the reduction furnace is grounded and alarms according to the collected grounding current, grounding voltage, series voltage, and parallel voltage, and determines whether the silicon rod hits the wall.

[0101] The first grounding resistor is connected to the N rows of the power regulation circuit and is connected in series with the grounding detection current transformer, and the two sides of the last grounding resistor are connected in parallel with the grounding detection voltage transformer.

[0102] In this embodiment, the polysilicon reduction furnace silicon rod wall detection system includes a grounding detection current transformer JDCT, a grounding voltage transformer JDPT, a power regulation system series voltage detection PT1, a parallel voltage detection PT2, a collection controller TP and 5 series-connected grounding resistors. The input end of the first grounding resistor is connected to the N-row of the power regulation system and is connected in series with the grounding current transformer JDCT, and a grounding voltage transformer JDPT is connected in parallel on both sides of the last resistor.

[0103] The five series-connected grounding resistors of the grounding unit are 200Ω2000W, and the values ​​collected by the grounding voltage transformer JDPT are collected and converted by the collection controller.

[0104] The silicon rod hitting the wall judgment logic in the PLC program uses a program algorithm to determine whether the silicon rod hits the wall based on the changes in the series voltage, parallel voltage, ground voltage, and ground current collected by the 6-phase power cabinet.

[0105] The above is a specific description of the implementation mode of the present invention, but the present invention is not limited to the described embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention, and these equivalents or substitutions are all included in the scope defined by the claims of the present invention.

Claims

1. A method for detecting silicon rods hitting the wall in a polysilicon reduction furnace, characterized in that: The following steps are involved: S1. When the power regulating circuit is high-starting, operating in parallel or in series, the series voltage, parallel voltage, ground voltage and ground current of the power regulating circuit are collected; S2. According to the collected series voltage, parallel voltage, ground voltage and ground current, determine whether the reduction furnace is grounded and alarm; S3. According to the reduction furnace grounding alarm information, determine whether the silicon rod hits the wall.

2. The method for detecting silicon rod hitting the wall in a polysilicon reduction furnace according to claim 1, characterized in that: In step S2, determining whether the reduction furnace is grounded and issuing an alarm includes: When the series voltage or parallel voltage is ≥1500V, the grounding voltage is ≥300V, and the grounding current is ≥600mA, it is judged that the reduction furnace is grounded and an alarm is issued; When 760V≤series voltage or parallel voltage<1500V, grounding voltage≥152V, grounding current≥304mA, it is judged that the reduction furnace is grounded and an alarm is issued; When 360V≤series voltage or parallel voltage<760V, grounding voltage≧72V, and grounding current≧144mA, it is judged that the reduction furnace is grounded and an alarm is issued.

3. The method for detecting silicon rod hitting the wall in a polysilicon reduction furnace according to claim 1, characterized in that: In step S3, judging the situation of silicon rod hitting the wall includes: for each phase with a total number of N pairs, and a total of 2N silicon cores are loaded: When the high-start voltage is applied or the parallel operation is in parallel, the average series voltage of the nth silicon core before the parallel point X is U1 after the ground alarm is triggered, and the average series voltage within t seconds after the alarm is U2. And if the series voltage U2 of any other 5 phases is greater than U1, the nth silicon core will hit the wall.

4. The method for detecting silicon rod hitting the wall in a polysilicon reduction furnace according to claim 3, characterized in that: When the high-start voltage is applied or the parallel operation is in parallel, the average series voltage of the nth silicon core after the parallel point Y triggers the ground alarm. The average series voltage of t seconds before the alarm is U3, and the average series voltage of t seconds after the alarm is U4. And when the series voltage U4 of any of the other five phases is greater than U3, the nth silicon core will hit the wall; X+Y=N.

5. The method for detecting silicon rod hitting the wall in a polysilicon reduction furnace according to claim 4, characterized in that: When the nth silicon core is connected in series and the ground alarm is triggered, the average series voltage t seconds before the alarm is U5, and the average series voltage within t seconds after the alarm is U6. And if the series voltage U6 of any of the other five phases is greater than U5, it means that the nth silicon core has hit a wall.

6. The method for detecting silicon rod hitting the wall in a polysilicon reduction furnace according to claim 5, characterized in that: In step S3, judging whether the silicon rod hits the wall includes: for 8 pairs of rods, a total of 16 silicon cores are loaded: When the high-start voltage is applied or the parallel operation is in parallel, the four pairs of n-th silicon cores before the parallel point trigger the grounding alarm. The average series voltage in the 5S before the alarm is U1, and the average series voltage in the 5S after the alarm is U2. If the series voltage U2 of any of the other five phases is greater than U1, the nth silicon core will hit the wall; When the high-start voltage is applied or the parallel operation is in parallel, the four pairs of n-th silicon cores after the parallel point trigger the grounding alarm. The average series voltage in the 5S before the alarm is U3, and the average series voltage in the 5S after the alarm is U4. If the series voltage U4 of any of the other five phases is greater than U3, the nth silicon core will hit the wall; When the nth silicon core is connected in series and the ground alarm is triggered, the average series voltage in the 5S before the alarm is U5, and the average series voltage in the 5S after the alarm is U6. And if the series voltage U6 of any of the other five phases is greater than U5, it means that the nth silicon core has hit a wall.

7. The method for detecting silicon rod hitting the wall in a polysilicon reduction furnace according to claim 5, characterized in that: In step S3, judging whether the silicon rod hits the wall includes: for 4 pairs of rods, a total of 8 silicon cores are loaded: When the two pairs of n-th silicon cores before the parallel point are in high-start voltage or parallel operation, the average series voltage of the 5S before the alarm is U1, and the average series voltage of the 5S after the alarm is U2. If the series voltage U2 of any of the other five phases is greater than U1, the nth silicon core will hit the wall; When the two pairs of n-th silicon cores after the parallel point are in high-start voltage or parallel operation, the average series voltage of the 5S before the alarm is U3 and the average series voltage of the 5S after the alarm is U4. If the series voltage U4 of any of the other five phases is greater than U3, the nth silicon core will hit the wall; When the nth silicon core is connected in series and the ground alarm is triggered, the average series voltage in the 5S before the alarm is U5, and the average series voltage in the 5S after the alarm is U6. And if the series voltage U6 of any of the other five phases is greater than U5, it means that the nth silicon core has hit a wall.

8. The method for detecting silicon rod hitting the wall in a polysilicon reduction furnace according to claim 5, characterized in that: In step S3, judging whether the silicon rod hits the wall includes: for 6 pairs of rods, a total of 12 silicon cores are loaded: When the high-start voltage is applied or the parallel operation is in parallel, the four pairs of n-th silicon cores before the parallel point trigger the grounding alarm. The average series voltage in the 5S before the alarm is U1, and the average series voltage in the 5S after the alarm is U2. If the series voltage U2 of any of the other five phases is greater than U1, the nth silicon core will hit the wall; When the two pairs of n-th silicon cores after the parallel point are in high-start voltage or parallel operation, the average series voltage of the 5S before the alarm is U3 and the average series voltage of the 5S after the alarm is U4. If the series voltage U4 of any of the other five phases is greater than U3, the nth silicon core will hit the wall; When the nth silicon core is connected in series and the ground alarm is triggered, the average series voltage in the 5S before the alarm is U5, and the average series voltage in the 5S after the alarm is U6. And if the series voltage U6 of any of the other five phases is greater than U5, it means that the nth silicon core has hit a wall.

9. A polycrystalline silicon reduction furnace silicon rod wall collision detection system based on the polycrystalline silicon reduction furnace silicon rod wall collision detection method according to any one of claims 1 to 8, characterized in that: include: Power regulation circuit; A plurality of grounding resistors are arranged in series and connected to the power regulation circuit; A ground detection current transformer, connected in series with the ground resistor, for real-time acquisition of ground current; A ground detection voltage transformer, connected in parallel with the ground resistor, for real-time acquisition of ground voltage; A power regulation circuit series voltage detection unit, connected in series with the power regulation circuit and used for real-time acquisition of the power regulation circuit series voltage; A power regulation circuit parallel voltage detection unit, connected in parallel with the power regulation circuit and used for real-time acquisition of the power regulation circuit parallel voltage; A collection controller is connected to the ground detection current transformer, the ground detection voltage transformer, the power regulation circuit series voltage detection unit and the power regulation circuit parallel voltage detection unit respectively, and is used to receive the collected ground current, ground voltage, series voltage and parallel voltage; The PLC is connected to the acquisition controller, and determines whether the reduction furnace is grounded and alarms according to the collected grounding current, grounding voltage, series voltage, and parallel voltage, and determines whether the silicon rod hits the wall.

10. The polysilicon reduction furnace silicon rod wall collision detection system according to claim 9, characterized in that: The first grounding resistor is connected to the N rows of the power regulation circuit and is connected in series with the grounding detection current transformer, and the two sides of the last grounding resistor are connected in parallel with the grounding detection voltage transformer.

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