Multi-power-supply power supply system and control equipment for polycrystalline silicon reduction furnace

Abstract

The utility model relates to the technical field of polycrystalline silicon reduction furnace power supply, and discloses a polycrystalline silicon reduction furnace multi-power-supply power supply system and control equipment, and the power supply system comprises a power frequency power supply module and a variable frequency power supply module which are respectively connected with a silicon rod group in a polycrystalline silicon reduction furnace through a switch module and supply power to the silicon rod group; the silicon rod group is composed of silicon rods which are sequentially connected in series, when the first end and the second end of the switch module are conducted, the power frequency power supply module supplies power to the silicon rod group, and when the third end and the fourth end of the switch module are conducted, the variable frequency power supply module supplies power to the silicon rod group. According to the utility model, the power frequency power supply module and the variable-frequency power supply module are arranged, and the switch module is used for selecting the power supply module for supplying power to the silicon rod group, so that the requirements on different currents and frequencies in the polycrystalline silicon growth process are met, and only the surfaces of polycrystalline silicon rods are heated, the temperature of silicon cores is reduced, and the core melting risk is reduced; meanwhile, production energy consumption is reduced, production efficiency is improved, a single variable-frequency power source is avoided, and element type selection is facilitated.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply for polysilicon reduction furnaces, and particularly relates to a multi-power supply system and a control device for polysilicon reduction furnaces. Background Art

[0002] In recent years, with the development of new energy technologies, the installed capacity of photovoltaic power generation has shown a sharp growth trend. Photovoltaic solar panels are made of polysilicon materials. Currently, most manufacturers use the improved Siemens reduction method to produce polysilicon. During the growth process of silicon rods, as the silicon rods are continuously deposited, the cross-sectional area of the silicon rods increases continuously, causing the resistance value of the silicon rods to gradually decrease. However, during the entire production process, it is necessary to maintain the temperature inside the reduction furnace at about 2040°C. Therefore, it is necessary to continuously adjust the voltage applied across the two ends according to the change in the resistance value of the silicon rods.

[0003] Existing power supplies for polysilicon reduction furnaces mostly use industrial frequency alternating current with a frequency of 50 Hz (Hertz). Due to the low frequency of the industrial frequency power supply, the skin effect is not obvious. During the growth process of silicon rods, the temperature inside the silicon rods is higher than that on the surface of the silicon rods. As the diameter of the silicon rods increases continuously, the temperature difference between the inside and outside of the silicon rods becomes larger and larger. When the temperature inside the silicon rods exceeds 1400°C, it is easy to cause the core of the silicon rod to melt, thus limiting the diameter of the silicon rods and affecting the production efficiency of the reduction furnace. There are also variable frequency power supplies using controllable switching elements such as IGBTs. Because the voltage required by polysilicon rods is too high in the initial stage of reduction, and the current is too large in the later stage of silicon rod growth, it is difficult to select the appropriate type of controllable switching elements such as IGBTs and the cost is too high, so it is not suitable for large-scale promotion. Summary of the Utility Model

[0004] In view of this, the utility model provides a multi-power supply system and a control device for polysilicon reduction furnaces to solve the problems in the prior art that the industrial frequency power supply of polysilicon reduction furnaces affects production efficiency and it is difficult to select the appropriate type of variable frequency power supply components.

[0005] In the first aspect, the utility model provides a multi-power supply system for polysilicon reduction furnaces. The power supply system includes: an industrial frequency power supply module, a variable frequency power supply module, and a switching module. The industrial frequency power supply module and the variable frequency power supply module are respectively connected to a silicon rod group inside the polysilicon reduction furnace through the switching module and supply power to the silicon rod group. The silicon rod group is composed of silicon rods connected in series in sequence. Among them,

[0006] The industrial frequency power supply module, its input end is connected to a first external power supply, its first output end is connected to the first end of the switching module, and its second output end is connected to the second end of the switching module, and is used to convert the first external power supply into industrial frequency power to supply power to the silicon rod group;

[0007] A variable-frequency power supply module, whose input end is connected to a second external power supply, whose first output end is connected to the third end of a switch module, and whose second output end is connected to the fourth end of the switch module, is used to convert the second external power supply into a power-frequency power supply to supply power to a silicon rod group;

[0008] A switch module, whose first output end is connected to the first power supply end of the silicon rod group and whose second output end is connected to the second power supply end of the silicon rod group, is used to conduct the first end and the second end or conduct the third end and the fourth end;

[0009] When the first end and the second end of the switch module are conducted, the power-frequency power supply module supplies power to the silicon rod group. When the third end and the fourth end of the switch module are conducted, the variable-frequency power supply module supplies power to the silicon rod group.

[0010] The multi-power-supply system for a polysilicon reduction furnace provided by the present utility model, by setting a power-frequency power supply module and a variable-frequency power supply module, and using the switch module to select the power supply module for the silicon rod group, meets the requirements for different currents and frequencies during the growth of polysilicon, realizes surface heating only on the polysilicon rod, reduces the temperature of the silicon core, reduces the risk of core melting, and at the same time reduces production energy consumption and improves production efficiency, avoids using a single variable-frequency power supply, and facilitates component selection.

[0011] In an optional implementation manner, the power-frequency power supply module includes: a transformer and multiple thyristor groups, where

[0012] The transformer, whose primary is connected to a first external power supply, and whose secondary includes multiple taps, each tap is connected to a thyristor group, is used to convert the first external power supply into a power-frequency power supply with different voltages and currents according to the diameter of the polysilicon rods in the silicon rod group, and output through different taps respectively;

[0013] The thyristor group, whose input end is connected to the secondary tap of the transformer and whose output end is connected to the switch module, is used to adjust the voltage and current of the power-frequency power supply to make the voltage and current of the power-frequency power supply stable.

[0014] The multi-power-supply system for a polysilicon reduction furnace provided by the present utility model, uses multiple taps on the secondary of the transformer connected to different thyristor groups to form a gear, and realizes gear shifting and output power adjustment by controlling the thyristor, ensuring the requirements for the power supply at different growth stages of polysilicon, and improving the production efficiency of polysilicon.

[0015] In an optional implementation manner, the thyristor group includes: a first thyristor and a second thyristor connected in antiparallel.

[0016] The multi-power-supply system for a polysilicon reduction furnace provided by the present utility model, by connecting two thyristors in antiparallel to provide the required power-frequency output voltage and current for silicon rod reduction, more precisely adjusts the voltage and current, and realizes power regulation heating control by controlling the thyristor.

[0017] In an alternative embodiment, the variable frequency power supply module includes: a power input unit and a variable frequency unit, wherein,

[0018] The power input unit, whose input end is connected to the second external power supply, and whose output end is connected to the input end of the variable frequency unit, is used to convert the second external power supply into a DC power supply and input it into the variable frequency unit;

[0019] The variable frequency unit, whose first output end is connected to the third end of the switch module, and whose second output end is connected to the fourth end of the switch module, is used to adjust the frequency and power of the DC power supply according to the diameter of the polysilicon rods in the silicon rod group.

[0020] For the multi-power supply system of the polysilicon reduction furnace provided by the present utility model, the variable frequency unit module uses the power input unit to ensure that the power input into the variable frequency unit is a DC power supply, and uses the variable frequency unit to control the frequency and power output by the variable frequency unit to adapt to the current diameter of the polysilicon rods according to the diameter of the polysilicon rods, so as to provide heating power for the polysilicon rod load and realize the continuous reduction growth of polysilicon.

[0021] In an alternative embodiment, the variable frequency unit is a three-level topology structure, including: a first resistor, a first capacitor, a second resistor, a second capacitor, a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a seventh transistor, an eighth transistor, a ninth transistor, a tenth transistor, an eleventh transistor, a twelfth transistor, a first inductor, and a second inductor, wherein,

[0022] The first resistor, whose first end is connected to the positive connection pole of the DC power supply, and whose second end is connected to the first end of the second resistor;

[0023] The first capacitor, which is connected in parallel with the first resistor to form a first filter circuit for filtering the DC power supply;

[0024] The second resistor, whose second end is connected to the negative pole of the DC power supply;

[0025] The second capacitor, which is connected in parallel with the second resistor to form a second filter circuit for filtering the DC power supply;

[0026] The first transistor, whose first end is connected to the positive pole of the DC power supply, and whose second end is connected to the first end of the second transistor;

[0027] The second transistor, whose second end is connected to the second end of the first resistor;

[0028] The third transistor, whose first end is connected to the second end of the second transistor, and whose second end is connected to the first end of the fourth transistor;

[0029] The fourth transistor, whose second end is connected to the negative pole of the DC power supply;

[0030] A fifth transistor, having its first end connected to the second end of the first transistor and its second end connected to the first end of the sixth transistor;

[0031] A sixth transistor, having its first end connected to the first end of the first inductor and its second end connected to the second end of the third transistor;

[0032] A first inductor, having its second end connected to the third end of the switching module;

[0033] A seventh transistor, having its first end connected to the positive pole of the DC power supply and its second end connected to the first end of the eighth transistor;

[0034] An eighth transistor, having its second end connected to the second end of the first resistor;

[0035] A ninth transistor, having its first end connected to the second end of the eighth transistor and its second end connected to the first end of the tenth transistor;

[0036] A tenth transistor, having its second end connected to the negative pole of the DC power supply;

[0037] An eleventh transistor, having its first end connected to the second end of the seventh transistor and its second end connected to the first end of the twelfth transistor;

[0038] A twelfth transistor, having its first end connected to the first end of the second inductor and its second end connected to the first end of the tenth transistor;

[0039] A second inductor, having its second end connected to the fourth end of the switching module.

[0040] For the multi - power - supply system of the polysilicon reduction furnace provided by the present utility model, the frequency - conversion unit adopts a three - level topology structure. By using more levels to control the output voltage, the harmonic distortion is reduced, the output current is more stable. The three - level topology structure adopts a lower switching frequency, the waveforms of the voltage and current of the components are more stable, the thermal loss and voltage stress of the components are reduced, the service life of each component is prolonged, the input voltage is divided into more levels, the output voltage is controlled more precisely, and the efficiency of the power - supply system is improved. The voltage withstand of controllable switching components such as IGBTs is reduced, which is convenient for component selection and reduces costs at the same time.

[0041] In an optional embodiment, when the second external power supply is an AC power supply, the electric - energy input unit includes a rectification circuit for converting the second external power supply into a DC power supply and inputting it into the frequency - conversion unit.

[0042] For the multi - power - supply system of the polysilicon reduction furnace provided by the present utility model, when the second external power supply is an AC power supply, a rectification circuit is added to the electric - energy input unit, so that the power supply input to the frequency - conversion unit is a DC power supply, improving the flexibility with respect to the second external power supply.

[0043] In an alternative embodiment, the switch module includes: an interlocked first switch group and second switch group, the first switch group includes a first switch and a second switch, and the second switch group includes a third switch and a fourth switch, wherein,

[0044] The first switch has its first end connected to the first output end of the industrial frequency power supply module and its second end connected to the first power supply end of the silicon rod group;

[0045] The second switch has its first end connected to the second output end of the industrial frequency power supply module and its second end connected to the second power supply end of the silicon rod group;

[0046] The third switch has its first end connected to the first output end of the variable frequency power supply module and its second end connected to the first power supply end of the silicon rod group;

[0047] The fourth switch has its first end connected to the second output end of the variable frequency power supply module and its second end connected to the second power supply end of the silicon rod group.

[0048] The multi-power supply system for a polysilicon reduction furnace provided by the present utility model uses two interlocked switch groups to control the industrial frequency power supply module or the variable frequency power supply module to supply power to the polysilicon reduction furnace, avoiding the simultaneous connection of the two power supply modules to the polysilicon reduction furnace, reducing the mutual influence between the two power supply modules, and ensuring the reliability of multi-power supply.

[0049] In an alternative embodiment, the first switch, the second switch, the third switch, and the fourth switch are vacuum contactors.

[0050] For the multi-power supply system for a polysilicon reduction furnace provided by the present utility model, each switch uses a vacuum contactor, which has high reliability and durability, improves the stability and reliability of power supply switching in the multi-power supply system for a polysilicon reduction furnace, and reduces the maintenance cost.

[0051] In a second aspect, the present utility model provides a control device, including the multi-power supply system for a polysilicon reduction furnace according to any one of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the specific embodiments of the present utility model or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0053] Figure 1 is a schematic structural diagram of a multi-power supply system for a polysilicon reduction furnace according to an embodiment of the present utility model;

[0054] Figure 2 It is a schematic structural diagram of the power frequency power supply module in the multi - power - supply system of the polysilicon reduction furnace according to an embodiment of the present utility model;

[0055] Figure 3 It is a schematic structural diagram of the variable - frequency power supply module in the multi - power - supply system of the polysilicon reduction furnace according to an embodiment of the present utility model;

[0056] Figure 4 It is a schematic structural diagram of a specific embodiment of the multi - power - supply system of the polysilicon reduction furnace according to an embodiment of the present utility model;

[0057] Figure 5 It is a schematic structural diagram of the control device of the multi - power - supply system of the polysilicon reduction furnace according to an embodiment of the present utility model. Detailed implementation manners

[0058] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without making creative efforts belong to the scope of protection of the present utility model.

[0059] The embodiments of the present utility model provide a multi - power - supply system and a control device for a polysilicon reduction furnace, which supply power to the silicon rod group in the reduction furnace through a power - frequency power supply module or a variable - frequency power supply module to achieve the effects of improving production efficiency, simplifying model selection, and reducing costs.

[0060] In this embodiment, a multi - power - supply system for a polysilicon reduction furnace is provided. As Figure 1 shown, the power - supply system includes: a power - frequency power supply module 1, a variable - frequency power supply module 2, and a switch module 3. The power - frequency power supply module 1 and the variable - frequency power supply module 2 are respectively connected to the silicon rod group in the polysilicon reduction furnace through the switch module 3 and supply power to the silicon rod group. The silicon rod group is composed of silicon rods connected in series in sequence.

[0061] As Figure 1 shown, for the power - frequency power supply module 1, its input end is connected to the first external power supply, its first output end is connected to the first end of the switch module 3, and its second output end is connected to the second end of the switch module 3, and it is used to convert the first external power supply into a power - frequency power supply to supply power to the silicon rod group.

[0062] Specifically, the power frequency power supply module 1 is a power frequency power supply composed of a thyristor group 12, which has a good heating penetration effect and is mainly applied in the later stage of silicon rod growth. According to the requirements of voltage and current for silicon rod growth in different stages, the power frequency power supply module 1 adjusts the output voltage and current, and the specific adjustment method can be common voltage and current adjustment methods, which will not be elaborated here.

[0063] As Figure 1 shown, the variable frequency power supply module 2 has its input end connected to the second external power supply, its first output end connected to the third end of the switch module 3, and its second output end connected to the fourth end of the switch module 3, and is used to convert the second external power supply into a power frequency power supply to supply power to the silicon rod group.

[0064] Specifically, the variable frequency power supply module 2 is a medium-high frequency variable frequency power supply module, which has a fast heating speed and is mainly applied in the early stage of silicon rod growth. In the early stage of silicon rod growth, the diameter of the silicon rod is small, the temperature difference between its inside and surface is small, the skin effect of the medium-high frequency power supply is obvious, and the silicon rod grows fast. It should be noted that the power frequency power supply module 1 and the variable frequency power supply module 2 do not supply power to the silicon rod group at the same time.

[0065] As Figure 1 shown, the switch module 3 has its first output end connected to the first power supply end of the silicon rod group and its second output end connected to the second power supply end of the silicon rod group, and is used to conduct the first end and the second end or conduct the third end and the fourth end.

[0066] When the first end and the second end of the switch module are conducted, the power frequency power supply module 1 supplies power to the silicon rod group. When the third end and the fourth end of the switch module are conducted, the variable frequency power supply module 2 supplies power to the silicon rod group.

[0067] Specifically, the switch module 3 includes four terminals, and each terminal is connected to the silicon rod group in the reduction furnace through a switch. By conducting or closing the switch corresponding to each terminal, the variable frequency power supply module 2 or the power frequency power supply module 1 is selected to supply power to the silicon rod group. For example, when the switches connected to the first end and the second end are closed and the switches connected to the third end and the fourth end are opened, the power frequency power supply module 1 is connected and conducted to supply power to the silicon rod group; when the switches connected to the first end and the second end are opened and the switches connected to the third end and the fourth end are closed, the variable frequency power supply module 2 is connected and conducted to supply power to the silicon rod group. This is only for example, but not limited thereto.

[0068] The multi-power supply system for polysilicon reduction furnaces provided in this embodiment satisfies the requirements for different currents and frequencies during the growth of polysilicon by setting a power frequency power supply module 1 and a variable frequency power supply module 2, and using a switch module 3 to select the power supply module for the silicon rod group. It realizes surface heating only on the polysilicon rods, reduces the temperature of the silicon core, reduces the risk of core melting, and at the same time reduces production energy consumption and improves production efficiency. It avoids using a single variable frequency power supply and facilitates component selection.

[0069] In some alternative embodiments, such as Figure 2 shown, the power frequency power supply module 1 includes: a transformer T1 and multiple thyristor groups 12.

[0070] As Figure 2 shown, for the transformer T1, its primary is connected to a first external power supply, and its secondary includes multiple taps. Each tap is connected to a thyristor group 12, and is used to convert the first external power supply into a power frequency power supply with different voltages and currents according to the diameter of the polysilicon rods in the silicon rod group, and output through different taps respectively.

[0071] Specifically, the secondary of the transformer T1 is composed of multiple taps of a single phase to form multiple gears. The primary of the transformer T1 inputs the first external power supply, and the first external power supply is alternating current. After being isolated and transformed by the transformer T1, it is connected to a thyristor group 12 through a tap of the secondary, and different voltage levels with different parameters can be selected according to actual needs, so as to adapt to more situations. The switching between different gears can be achieved through a vacuum contactor, which is only an example and not limited thereto.

[0072] As Figure 2 shown, for the thyristor group 12, its input end is connected to the secondary tap of the transformer T1, and its output end is connected to the switch module 3, and is used to adjust the voltage and current of the power frequency power supply to make the voltage and current of the power frequency power supply stable.

[0073] In some alternative embodiments, such as Figure 2 shown, the thyristor group 12 includes: a first thyristor Q1 and a second thyristor Q2 connected in antiparallel.

[0074] The multi-power supply system for polysilicon reduction furnaces provided in this embodiment provides the required power frequency output voltage and current for silicon rod reduction by connecting two thyristors in antiparallel, adjusts the voltage and current more precisely, and realizes power regulation heating control by controlling the thyristors.

[0075] Specifically, the thyristor group 12 is composed of a group of two thyristors connected in antiparallel, which can quickly connect or disconnect the circuit where it is located. By controlling the conduction of the thyristor groups in different gears, the heating power for the silicon rod group in the reduction furnace can be adjusted. At the same time, the alternating current output from the secondary tap of the transformer T1 is rectified to obtain direct current to supply power to the silicon rod group.

[0076] The multi - power - supply system for a polysilicon reduction furnace provided in this embodiment uses multiple taps on the secondary of transformer T1 to connect to different thyristor groups 12 to form a gear. By controlling the thyristors, gear shifting and output power adjustment are achieved, ensuring the power requirements of polysilicon at different growth stages and improving the production efficiency of polysilicon.

[0077] In some alternative embodiments, as Figure 3 shown, the variable - frequency power - supply module 2 includes: a power - input unit 21 and a variable - frequency unit 22, where

[0078] as Figure 3 shown, the power - input unit 21, whose input end is connected to the second external power supply and whose output end is connected to the input end of the variable - frequency unit 22, is used to convert the second external power supply into a DC power supply and input it into the variable - frequency unit 22.

[0079] Specifically, the second external power supply input by the power - input unit 21 can be a DC power supply or an AC power supply. When the second external power supply is a DC power supply, the power - input unit 21 can directly input the second external power supply into the variable - frequency unit 22, or input the second external power supply into the variable - frequency unit 22 after voltage stabilization and filtering through a voltage - stabilization and filtering circuit. This is only an example and not limited thereto; when the second external power supply is an AC power supply, the power - input unit 21 further includes: a rectification circuit for converting the second external power supply into a DC power supply and inputting it into the variable - frequency unit 22.

[0080] For the multi - power - supply system of the polysilicon reduction furnace provided in this embodiment, when the second external power supply is an AC power supply, a rectification circuit is added to the power - input unit 21 to make the power supply input to the variable - frequency unit 22 a DC power supply, improving the flexibility of the second external power supply.

[0081] as Figure 3 shown, the variable - frequency unit 22, whose first output end is connected to the third end of the switch module 3 and whose second output end is connected to the fourth end of the switch module 3, is used to adjust the frequency and power of the DC power supply according to the diameter of the polysilicon rods in the silicon - rod group.

[0082] Specifically, the function of the variable - frequency unit 22 is to adjust the frequency and power of the DC power supply according to the diameter of the polysilicon rods in the silicon - rod group, and its frequency range is medium - high frequency. The variable - frequency power - supply module 2 can be divided into three levels: an input level, an intermediate level, and an output level. The input level is the power - input unit 21, which provides DC power supply for the intermediate level. The intermediate level adopts a three - level topology structure, simplifying the component selection. The output level is the second switch group 32 in the switch module 3 as the output switch, which is used to control whether the silicon - rod group uses the variable - frequency power - supply module 2 for power supply. Figure 3 In which, R1, R2, ……, Rn represent silicon rods.

[0083] The multi-power supply system for a polysilicon reduction furnace provided in this embodiment uses the electric energy input unit 21 to ensure that the power supply input to the frequency conversion unit 22 is a DC power supply. The frequency conversion unit 22 controls the output frequency and power adapted to the current diameter of the polysilicon rod according to the diameter of the polysilicon rod, provides heating electric energy for the polysilicon rod load, and realizes the continuous reduction and growth of polysilicon.

[0084] In some alternative embodiments, as Figure 3 shown, the frequency conversion unit 22 has a three-level topology structure and includes: a first resistor R1, a first capacitor C1, a second resistor R2, a second capacitor C2, a first transistor Q21, a second transistor Q22, a third transistor Q23, a fourth transistor Q24, a fifth transistor Q25, a sixth transistor Q26, a seventh transistor Q27, an eighth transistor Q28, a ninth transistor Q29, a tenth transistor Q30, an eleventh transistor Q31, a twelfth transistor Q32, a first inductor L1, and a second inductor L2.

[0085] The first resistor R1, its first end is connected to the positive connection pole of the DC power supply, and its second end is connected to the first end of the second resistor R2.

[0086] The first capacitor C1 is connected in parallel with the first resistor R1 to form a first filter circuit for filtering the DC power supply.

[0087] The second resistor R2, its second end is connected to the negative pole of the DC power supply.

[0088] The second capacitor C2 is connected in parallel with the second resistor R2 to form a second filter circuit for filtering the DC power supply.

[0089] The first transistor Q21, its first end is connected to the positive pole of the DC power supply, and its second end is connected to the first end of the second transistor Q22.

[0090] The second transistor Q22, its second end is connected to the second end of the first resistor R1.

[0091] The third transistor Q23, its first end is connected to the second end of the second transistor Q22, and its second end is connected to the first end of the fourth transistor Q24.

[0092] The fourth transistor Q24, its second end is connected to the negative pole of the DC power supply.

[0093] The fifth transistor Q25, its first end is connected to the second end of the first transistor Q21, and its second end is connected to the first end of the sixth transistor Q26.

[0094] The sixth transistor Q26, its first end is connected to the first end of the first inductor L1, and its second end is connected to the second end of the third transistor Q23.

[0095] A first inductor L1, whose second terminal is connected to the third terminal of the switching module 3.

[0096] A seventh transistor Q27, whose first terminal is connected to the positive pole of the DC power supply, and whose second terminal is connected to the first terminal of an eighth transistor Q28.

[0097] An eighth transistor Q28, whose second terminal is connected to the second terminal of a first resistor R1.

[0098] A ninth transistor Q29, whose first terminal is connected to the second terminal of the eighth transistor Q28, and whose second terminal is connected to the first terminal of a tenth transistor Q30.

[0099] A tenth transistor Q30, whose second terminal is connected to the negative pole of the DC power supply.

[0100] An eleventh transistor Q31, whose first terminal is connected to the second terminal of the seventh transistor Q27, and whose second terminal is connected to the first terminal of a twelfth transistor Q32.

[0101] A twelfth transistor Q32, whose first terminal is connected to the first terminal of a second inductor L2, and whose second terminal is connected to the first terminal of the tenth transistor Q30.

[0102] A second inductor L2, whose second terminal is connected to the fourth terminal of the switching module 3.

[0103] Specifically, the frequency conversion unit 22, as a core component of the frequency conversion power supply module 2, controls the intermediate stage according to the diameter of the polysilicon rod to achieve corresponding frequency and power output. Its structure is a three-level topology structure, which is a relatively mature circuit structure and will not be elaborated here.

[0104] In the polysilicon reduction furnace multi-power supply system provided in this embodiment, the frequency conversion unit 22 adopts a three-level topology structure, uses more levels to control the output voltage, reduces harmonic distortion, and the output current is more stable. The three-level topology structure adopts a lower switching frequency, and the voltage and current waveforms of the components are more stable, reducing the thermal loss and voltage stress of the components, extending the life of each component, dividing the input voltage into more levels, controlling the output voltage more precisely, improving the efficiency of the power supply system, reducing the withstand voltage of controllable switching elements such as IGBTs, facilitating the selection of components, and reducing costs at the same time.

[0105] In some alternative embodiments, as Figure 4 shown, the switching module 3 includes: an interlocked first switch group S1 and a second switch group S2. The first switch group S1 includes a first switch K1 and a second switch K2, and the second switch group S2 includes a third switch K3 and a fourth switch K4.

[0106] The first switch K1, whose first end is connected to the first output end of the power frequency power supply module 1, and whose second end is connected to the first power supply end of the silicon rod group.

[0107] The second switch K2, whose first end is connected to the second output end of the power frequency power supply module 1, and whose second end is connected to the second power supply end of the silicon rod group.

[0108] The third switch K3, whose first end is connected to the first output end of the variable frequency power supply module 2, and whose second end is connected to the first power supply end of the silicon rod group.

[0109] The fourth switch K4, whose first end is connected to the second output end of the variable frequency power supply module 2, and whose second end is connected to the second power supply end of the silicon rod group.

[0110] In some alternative embodiments, the first switch K1, the second switch K2, the third switch K3, and the fourth switch K4 are vacuum contactors.

[0111] For the multi-power supply system of the polysilicon reduction furnace provided in this embodiment, each switch uses a vacuum contactor, which has high reliability and durability, improves the stability and reliability of power supply switching in the multi-power supply system of the polysilicon reduction furnace, and reduces the maintenance cost.

[0112] Specifically, the first switch K1 and the second switch K2 together form the first switch group S1, which are respectively connected to the two output ends of the power frequency power supply module 1. When the first switch K1 and the second switch K2 are closed simultaneously, the power frequency power supply module 1 supplies power to the silicon rod group; the third switch K3 and the fourth switch K4 together form the second switch group S2, which are respectively connected to the two output ends of the variable frequency power supply module 2. When the third switch K3 and the fourth switch K4 are closed simultaneously, the variable frequency power supply module 2 supplies power to the silicon rod group. And in order to prevent the switches in the two switch groups from being closed simultaneously, an interlock control unit is used to control the vacuum contactors of the power frequency power supply module 1 and the variable frequency power supply module 2.

[0113] For the multi-power supply system of the polysilicon reduction furnace provided in this embodiment, two interlocked switch groups are used to control the power frequency power supply module 1 or the variable frequency power supply module 2 to supply power to the polysilicon reduction furnace, preventing the two power supply modules from being connected to the polysilicon reduction furnace simultaneously, reducing the mutual influence between the two power supply modules, and ensuring the reliability of multi-power supply.

[0114] In this embodiment, a control device is provided, such as Figure 5 shown, including the multi-power supply system of the polysilicon reduction furnace according to any one of the previous embodiments.

[0115] Although embodiments of the present utility model have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present utility model, and such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A multi-power supply system for a polysilicon reduction furnace, characterized in that: The power supply system includes: an industrial frequency power supply module, a variable frequency power supply module, and a switch module. The industrial frequency power supply module and the variable frequency power supply module are respectively connected to the silicon rod group in the polysilicon reduction furnace through the switch module and supply power to the silicon rod group. The silicon rod group consists of silicon rods connected in series, wherein: an industrial frequency power supply module, whose input end is connected to a first external power source, whose first output end is connected to a first end of the switch module, and whose second output end is connected to a second end of the switch module, and is configured to convert the first external power source into an industrial frequency power source to power the silicon rod assembly; a variable frequency power supply module, whose input end is connected to the second external power supply, whose first output end is connected to the third end of the switch module, and whose second output end is connected to the fourth end of the switch module, for converting the second external power supply into an industrial frequency power supply to power the silicon rod assembly; a switch module, wherein a first output end thereof is connected to the first power supply end of the silicon rod group, and a second output end thereof is connected to the second power supply end of the silicon rod group, and is used to conduct the first end and the second end or conduct the third end and the fourth end; When the first and second ends of the switch module are conductive, the industrial frequency power supply module supplies power to the silicon rod group; when the third and fourth ends of the switch module are conductive, the variable frequency power supply module supplies power to the silicon rod group.

2. The power supply system according to claim 1, wherein The industrial frequency power supply module includes: a transformer, a plurality of thyristor groups, wherein: a transformer having a primary connected to the first external power source and a secondary including multiple taps, each tap being connected to a thyristor group, and configured to convert the first external power source into an industrial frequency power source having different voltages and currents according to the diameters of the polysilicon rods in the silicon rod group, and output the power source through different taps; The thyristor group has an input end connected to the secondary tap of the transformer and an output end connected to the switch module, and is used to adjust the voltage and current of the power frequency power supply to stabilize the voltage and current of the power frequency power supply.

3. The power supply system according to claim 2, characterized in that: The thyristor group includes a first thyristor and a second thyristor connected in anti-parallel.

4. The power supply system according to claim 1, wherein: The variable frequency power supply module includes: an electric energy input unit and a frequency conversion unit, wherein: an electric energy input unit, whose input end is connected to the second external power supply and whose output end is connected to the input end of the frequency conversion unit, for converting the second external power supply into a DC power supply and inputting it into the frequency conversion unit; A frequency conversion unit, whose first output end is connected to the third end of the switch module and whose second output end is connected to the fourth end of the switch module, is used to adjust the frequency and power of the DC power supply according to the diameter of the polysilicon rods in the silicon rod group.

5. The power supply system according to claim 4, characterized in that, The frequency conversion unit is a three-level topology structure, including: a first resistor, a first capacitor, a second resistor, a second capacitor, a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a seventh transistor, an eighth transistor, a ninth transistor, a tenth transistor, an eleventh transistor, a twelfth transistor, a first inductor, and a second inductor, wherein: a first resistor, having a first end connected to the positive terminal of the DC power supply and a second end connected to the first end of the second resistor; a first capacitor, connected in parallel with the first resistor to form a first filtering circuit for filtering the DC power supply; A second resistor, whose second terminal is connected to the negative pole of the DC power supply; A second capacitor, which is connected in parallel with the second resistor to form a second filter circuit for filtering the DC power supply; A first transistor, whose first terminal is connected to the positive pole of the DC power supply, and whose second terminal is connected to the first terminal of the second transistor; A second transistor, whose second terminal is connected to the second terminal of the first resistor; A third transistor, whose first terminal is connected to the second terminal of the second transistor, and whose second terminal is connected to the first terminal of the fourth transistor; A fourth transistor, whose second terminal is connected to the negative pole of the DC power supply; A fifth transistor, whose first terminal is connected to the second terminal of the first transistor, and whose second terminal is connected to the first terminal of the sixth transistor; A sixth transistor, whose first terminal is connected to the first terminal of the first inductor, and whose second terminal is connected to the second terminal of the third transistor; A first inductor, whose second terminal is connected to the third terminal of the switch module; A seventh transistor, whose first terminal is connected to the positive pole of the DC power supply, and whose second terminal is connected to the first terminal of the eighth transistor; An eighth transistor, whose second terminal is connected to the second terminal of the first resistor; A ninth transistor, whose first terminal is connected to the second terminal of the eighth transistor, and whose second terminal is connected to the first terminal of the tenth transistor; A tenth transistor, whose second terminal is connected to the negative pole of the DC power supply; An eleventh transistor, whose first terminal is connected to the second terminal of the seventh transistor, and whose second terminal is connected to the first terminal of the twelfth transistor; A twelfth transistor, whose first terminal is connected to the first terminal of the second inductor, and whose second terminal is connected to the first terminal of the tenth transistor; A second inductor, whose second terminal is connected to the fourth terminal of the switch module.

6. The power supply system according to claim 4, characterized in that: When the second external power supply is an AC power supply, the electric energy input unit includes: a rectifier circuit for converting the second external power supply into a DC power supply and inputting it into the frequency conversion unit.

7. The power supply system according to claim 1, wherein: The switch module includes: an interlocked first switch group and second switch group. The first switch group includes a first switch and a second switch, and the second switch group includes a third switch and a fourth switch, where The first switch, whose first terminal is connected to the first output terminal of the industrial frequency power supply module, and whose second terminal is connected to the first power supply terminal of the silicon rod group; The second switch, whose first terminal is connected to the second output terminal of the industrial frequency power supply module, and whose second terminal is connected to the second power supply terminal of the silicon rod group; The third switch, whose first terminal is connected to the first output terminal of the frequency conversion power supply module, and whose second terminal is connected to the first power supply terminal of the silicon rod group; The fourth switch, whose first terminal is connected to the second output terminal of the frequency conversion power supply module, and whose second terminal is connected to the second power supply terminal of the silicon rod group.

8. The power supply system according to claim 7, characterized in that The first switch, second switch, third switch, and fourth switch are vacuum contactors.

9. A control device, characterized in that, Including the polysilicon reduction furnace multi-power supply system according to any one of claims 1-8.

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