Synchronous voltage zero-crossing detection device for power supply of polycrystalline silicon reduction furnace

Abstract

The application relates to a polysilicon reduction furnace power synchronous voltage zero-crossing detection device and a polysilicon reduction furnace control equipment, which comprises a phaseless delay differential circuit and a zero-crossing detection circuit. A synchronous voltage generation element of a polysilicon reduction furnace power is connected with the phaseless delay differential circuit, and the phaseless delay differential circuit is connected with the zero-crossing detection circuit. The phaseless delay differential circuit obtains the synchronous voltage generated by the synchronous voltage generation element, and transmits the synchronous voltage after pretreatment to the zero-crossing detection circuit. The zero-crossing detection circuit is used for outputting a voltage signal according to the pretreated synchronous voltage, and the voltage signal is used for representing the zero point of the synchronous voltage. The phase delay of the pretreatment process of the phaseless delay differential circuit on the synchronous voltage is maintained within an allowable range. The application can improve the accuracy of the synchronous voltage zero-crossing detection of the polysilicon reduction furnace power.

Description

Technical Field

[0001] This application relates to the field of circuit testing technology, and in particular to a synchronous voltage zero-crossing detection device for a polysilicon reduction furnace power supply and a polysilicon reduction furnace control device. Background Technology

[0002] Polysilicon reduction furnace power supplies typically employ multi-stage stacked control, featuring multiple thyristor rectifier branches with synchronized phase, collectively supplying power to the polysilicon (equivalent to a resistive load). The power supply includes a synchronization voltage generator; the thyristors in each thyristor rectifier branch are triggered based on the synchronization voltage of this generator. In actual polysilicon production, a stable, reliable, and accurate power supply ensures continuous and stable voltage and current during polysilicon reduction growth, guaranteeing smooth production and contributing to the production of consistently high-quality polysilicon products. Therefore, voltage monitoring of the polysilicon reduction furnace power supply is necessary to monitor the polysilicon production status.

[0003] In traditional technologies, zero-crossing detection of the synchronization voltage is typically performed to observe the operating status of the synchronization voltage generating element, thereby monitoring the production status of polysilicon. Common detection methods include current transformer detection and optocoupler detection, which use current transformers or a combination of current transformers and optocoupler relays to detect the zero-crossing of the synchronization voltage.

[0004] However, current transformers are easily affected by external environmental factors, resulting in aging or damage. Furthermore, the switching on and off of optocoupler relays has a long delay time for circuit detection. Neither of these detection methods can maintain accurate zero-crossing detection of the synchronous voltage of the polysilicon reduction furnace power supply. Summary of the Invention

[0005] Therefore, it is necessary to provide a synchronous voltage zero-crossing detection device and a polysilicon reduction furnace control device that can maintain accurate synchronous voltage zero-crossing detection of the power supply of the polysilicon reduction furnace, in response to the above-mentioned technical problems.

[0006] In a first aspect, this application provides a synchronous voltage zero-crossing detection device for a polysilicon reduction furnace power supply, including a phase-delay-free differential circuit and a zero-crossing detection circuit. The synchronous voltage generating element of the polysilicon reduction furnace power supply is connected to the phase-delay-free differential circuit, and the phase-delay-free differential circuit is connected to the zero-crossing detection circuit.

[0007] The phase-delay-free differential circuit acquires the synchronization voltage generated by the synchronization voltage generating element, preprocesses the synchronization voltage, and transmits it to the zero-crossing detection circuit. The zero-crossing detection circuit outputs a voltage signal based on the preprocessed synchronization voltage. The voltage signal is used to characterize the zero point of the synchronization voltage. The phase delay of the preprocessing process of the synchronization voltage by the phase-delay-free differential circuit is maintained within an allowable range.

[0008] In one embodiment, the phase-delay-free differential circuit includes a first operational amplifier, a first resistor, a second resistor, a third resistor, and a fourth resistor;

[0009] The synchronization voltage is connected to the non-inverting input of the first operational amplifier through the second resistor. The first end of the first resistor is connected to the common terminal of the second resistor and the non-inverting input of the first operational amplifier, and the second end of the first resistor is grounded. The first end of the third resistor is connected to the inverting input of the first operational amplifier and the fourth resistor, and the second end of the third resistor is grounded. The first end of the fourth resistor is connected to the output of the first operational amplifier, and the second end of the fourth resistor is connected to the inverting input of the first operational amplifier.

[0010] In one embodiment, the first resistor is an adjustable resistor.

[0011] In one embodiment, the zero-crossing detection circuit includes a zero-crossing comparison unit and a voltage output unit, and the phase-delay-free differential circuit is connected to the voltage output unit through the zero-crossing comparison unit;

[0012] The zero-crossing comparison unit is used to compare the preprocessed synchronization voltage with the reference voltage and output the voltage comparison result to the voltage output unit. The voltage output unit is used to output the voltage signal according to the voltage comparison result.

[0013] In one embodiment, the zero-crossing comparator includes a comparator chip and a fifth resistor. The first input terminal of the comparator chip is connected to the phase-delay-free differential circuit, the second input terminal of the comparator chip is grounded through the fifth resistor, and the output terminal of the comparator chip is connected to the voltage output unit.

[0014] In one embodiment, the comparator chip includes a second operational amplifier and a first switching transistor. The non-inverting input of the second operational amplifier is connected to the phase-delay-free differential circuit, the inverting input of the second operational amplifier is grounded through the fifth resistor, the output of the second operational amplifier is connected to the control terminal of the first switching transistor, and both the input and output of the first switching transistor are connected to the voltage output unit.

[0015] In one embodiment, the voltage output unit includes a sixth resistor, a seventh resistor, and a second switch. The first end of the sixth resistor is connected to the input terminal of the second switch and the input voltage. The second end of the sixth resistor is connected to the control terminal of the second switch and the input terminal of the first switch. The first end of the seventh resistor is connected to the output terminal of the first switch and grounded. The second end of the seventh resistor is connected to the output terminal of the second switch, and is used to output the voltage signal.

[0016] In one embodiment, the zero-crossing detection circuit is an analog-to-digital converter chip.

[0017] In one embodiment, the synchronous voltage zero-crossing detection device for the polysilicon reduction furnace power supply further includes a processor connected to the zero-crossing detection circuit.

[0018] Secondly, this application also provides a polysilicon reduction furnace control device, including a polysilicon reduction furnace power supply and a synchronous voltage zero-crossing detection device for the polysilicon reduction furnace power supply as described above.

[0019] The aforementioned synchronous voltage zero-crossing detection device and control equipment for the polysilicon reduction furnace power supply include a phase-delay-free differential circuit and a zero-crossing detection circuit. The synchronous voltage generating element of the polysilicon reduction furnace power supply is connected to the phase-delay-free differential circuit, which in turn is connected to the zero-crossing detection circuit. The phase-delay-free differential circuit acquires the synchronous voltage generated by the synchronous voltage generating element, preprocesses the synchronous voltage, and then transmits it to the zero-crossing detection circuit. The zero-crossing detection circuit outputs a voltage signal based on the preprocessed synchronous voltage. This voltage signal characterizes the zero point of the synchronous voltage. The phase delay during the preprocessing of the synchronous voltage by the phase-delay-free differential circuit is maintained within an allowable range. By preprocessing the synchronous voltage using the phase-delay-free differential circuit and maintaining the phase delay within an allowable range, the phase deviation of the preprocessed synchronous voltage during zero-crossing detection in the zero-crossing detection circuit can be reduced, resulting in a smaller voltage signal delay and improved accuracy of the synchronous voltage zero-crossing detection in the polysilicon reduction furnace power supply. Attached Figure Description

[0020] Figure 1 This is an application environment diagram of the synchronous voltage zero-crossing detection device for the power supply of a polysilicon reduction furnace in one embodiment;

[0021] Figure 2 This is a schematic diagram of the synchronous voltage zero-crossing detection device for the power supply of a polysilicon reduction furnace in one embodiment;

[0022] Figure 3 This is a circuit structure diagram of a phase-delay-free differential circuit in one embodiment;

[0023] Figure 4 This is a schematic diagram of the zero-crossing detection circuit in one embodiment;

[0024] Figure 5 This is a schematic diagram of the zero-crossing comparison unit in one embodiment;

[0025] Figure 6 This is a circuit diagram of a zero-crossing detection circuit in one embodiment;

[0026] Figure 7 This is a schematic diagram of the synchronous voltage zero-crossing detection device for the power supply of the polysilicon reduction furnace in another embodiment;

[0027] Figure 8 This is a schematic diagram of the synchronous voltage zero-crossing detection device for the power supply of the polysilicon reduction furnace in another embodiment;

[0028] Figure 9 This is a comparison diagram showing the waveforms of the synchronization voltage and voltage signal after analysis in one embodiment. Detailed Implementation

[0029] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0031] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0032] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0033] It is understandable that "at least one" refers to one or more, and "multiple" refers to two or more. "At least a part of an element" refers to part or all of an element.

[0034] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising,” “including,” or “having,” etc., specify the presence of the stated feature, whole, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0036] The synchronous voltage zero-crossing detection device for the polysilicon reduction furnace power supply provided in this application embodiment can be applied to, for example... Figure 1 In the application environment shown, the AC power supply in the polysilicon reduction furnace power supply 104 supplies power to each thyristor rectifier branch (corresponding to) through a multi-tap transformer and synchronous voltage generation element. Figure 1 The voltage and current in the thyristor rectifiers 1, 2 to 5 are adjusted, and then each thyristor rectifier branch supplies power to the load 106. In this application, the load 106 is a resistor of polysilicon. By continuously supplying power to the polysilicon, the polysilicon is reduced and grown, thereby realizing the production of polysilicon. The polysilicon reduction furnace power supply often employs multi-stage stacked control. The synchronization voltage generating element of the polysilicon reduction furnace power supply 104 generates a synchronization voltage. The zero-crossing point of this synchronization voltage serves as the trigger reference point for the thyristors in each thyristor rectifier branch, ensuring that the voltage phases in each thyristor rectifier branch are the same. To accurately measure the zero-crossing point of the synchronization voltage, the synchronization voltage generating element of the polysilicon reduction furnace power supply 104 is connected to the synchronization voltage zero-crossing detection device 102 of the polysilicon reduction furnace power supply. The synchronization voltage zero-crossing detection device 102 detects the operating status of the polysilicon reduction furnace power supply by detecting the zero-crossing of the synchronization voltage, thereby monitoring the production status of the polysilicon.

[0037] In one embodiment, such as Figure 2As shown, a zero-crossing detection device for the synchronization voltage of a polysilicon reduction furnace power supply is provided, including a phase-delay-free differential circuit 202 and a zero-crossing detection circuit 204. The synchronization voltage generating element of the polysilicon reduction furnace power supply 104 is connected to the phase-delay-free differential circuit 202, and the phase-delay-free differential circuit 202 is connected to the zero-crossing detection circuit 204. The phase-delay-free differential circuit 202 acquires the synchronization voltage generated by the synchronization voltage generating element, preprocesses the synchronization voltage, and then transmits it to the zero-crossing detection circuit 204. The zero-crossing detection circuit 204 outputs a voltage signal based on the preprocessed synchronization voltage. The voltage signal is used to characterize the zero point of the synchronization voltage, and the phase delay of the synchronization voltage preprocessing process by the phase-delay-free differential circuit 202 is maintained within an allowable range.

[0038] The voltage generated by the polysilicon reduction furnace power supply 104 is relatively high, meaning the synchronization voltage is also high, typically ranging from several hundred to over a thousand volts. Commonly used detection circuits usually cannot withstand such high voltages. Therefore, the synchronization voltage needs to be pre-processed before detection to facilitate detection by the zero-crossing detection circuit 204 and reduce damage or impact on the zero-crossing detection circuit 204 caused by excessive voltage, thus reducing the probability of distortion in the voltage signal obtained by the zero-crossing detection circuit 204. This pre-processing mainly includes high-voltage elimination measures such as amplitude limiting.

[0039] Specifically, the phase-delay-free differential circuit 202 is used to preprocess the synchronization voltage. Unlike the phase delay caused by the circuit structure characteristics of current transformers or optocoupler relays, the phase delay of the synchronization voltage preprocessing process by the phase-delay-free differential circuit 202 is maintained within an allowable range. The phase-delay-free differential circuit 202 outputs the preprocessed synchronization voltage to the zero-crossing detection circuit 204. The zero-crossing detection circuit 204 performs zero-crossing detection on the preprocessed synchronization voltage to obtain a voltage signal. The voltage signal is used to characterize the zero point of the synchronization voltage, and the voltage signal includes, but is not limited to, the phase (or time) corresponding to the synchronization voltage crossing the zero point.

[0040] Optionally, the preprocessing of the synchronization voltage by the phase-delay-free differential circuit 202 may include, but is not limited to, limiting, and may also include filtering. The voltage signal is used to characterize the zero point of the synchronization voltage. Since the trigger reference point of the thyristors in each thyristor rectifier branch is the zero point of the synchronization voltage from negative to positive, the corresponding voltage signal may only include the zero point of the synchronization voltage from negative to positive. The allowable range of phase delay in the synchronization voltage preprocessing is 0-0.1 ms. For example, the phase delay in the synchronization voltage preprocessing by the phase-delay-free differential circuit 202 may be 0 ms.

[0041] The aforementioned zero-crossing detection device for the synchronous voltage of the polysilicon reduction furnace power supply includes a phase-delay-free differential circuit 202 and a zero-crossing detection circuit 204. The synchronous voltage generating element of the polysilicon reduction furnace power supply is connected to the phase-delay-free differential circuit 202, and the phase-delay-free differential circuit 202 is connected to the zero-crossing detection circuit 204. The phase-delay-free differential circuit 202 acquires the synchronous voltage generated by the synchronous voltage generating element, preprocesses the synchronous voltage, and then transmits it to the zero-crossing detection circuit 204. The zero-crossing detection circuit 204 outputs a voltage signal based on the preprocessed synchronous voltage. This voltage signal characterizes the zero point of the synchronous voltage. The phase delay of the phase delay during the preprocessing process of the synchronous voltage by the phase-delay-free differential circuit 202 is maintained within an allowable range. By preprocessing the synchronous voltage using the phase-delay-free differential circuit 202 and maintaining the phase delay of this preprocessing process within an allowable range, the phase deviation of the preprocessed synchronous voltage during zero-crossing detection in the zero-crossing detection circuit 204 can be reduced, resulting in a smaller delay in the obtained voltage signal and improving the accuracy of the zero-crossing detection of the synchronous voltage of the polysilicon reduction furnace power supply.

[0042] In one embodiment, such as Figure 3 As shown, the phase-delay-free differential circuit 202 includes a first operational amplifier 302, a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4. The synchronization voltage is connected to the non-inverting input of the first operational amplifier 302 via the second resistor R2. The first terminal of the first resistor R1 is connected to the common terminal of the second resistor R2 and the non-inverting input of the first operational amplifier 302, and the second terminal of the first resistor R1 is grounded. The first terminal of the third resistor R3 is connected to the inverting input of the first operational amplifier 302 and the fourth resistor R4, and the second terminal of the third resistor R3 is grounded. The first terminal of the fourth resistor R4 is connected to the output of the first operational amplifier 302, and the second terminal of the fourth resistor R4 is connected to the inverting input of the first operational amplifier 302.

[0043] Specifically, the phase-delay-free differential circuit 202 can reduce the voltage component of the peak voltage of the synchronization voltage, leaving only the voltage component near the zero-crossing point of the synchronization voltage, i.e., limiting. The positive power supply terminal of the first operational amplifier 302 is connected to the power supply VCC, and the negative power supply terminal is connected to a negative voltage opposite in magnitude to VCC. The synchronization voltage is input to the non-inverting input terminal of the first operational amplifier 302 through the second resistor R2. The first end of the third resistor R3 is connected to the inverting input terminal of the first operational amplifier 302 and the fourth resistor R4, and the second end of the third resistor R3 is grounded. The first end of the fourth resistor R4 is connected to the output terminal of the first operational amplifier 302, and the second end of the fourth resistor R4 is connected to the inverting input terminal of the first operational amplifier 302. The first resistor R1 is grounded and connected to the non-inverting input terminal of the first operational amplifier 302. By changing the resistance value of the first resistor R1, the degree of limiting during preprocessing can be changed. Correspondingly, the larger the resistance value of the first resistor R1, the greater the degree of limiting during preprocessing, i.e., the smaller the amplitude of the synchronization voltage after preprocessing.

[0044] Optionally, the power supply VCC can be a +12V power supply. The resistance values ​​of the first resistor R1, second resistor R2, third resistor R3, and fourth resistor R4 are not limited, and their values ​​can be the same. For example, the resistance values ​​of the first resistor R1, second resistor R2, third resistor R3, and fourth resistor R4 can be 380KΩ. Optionally, the resistance value of the first resistor R1 can also be different from the resistance values ​​of the second resistor R2, third resistor R3, and fourth resistor R4; for example, the resistance value of the first resistor R1 is 20KΩ. The model of the first operational amplifier 302 is not limited; for example, the first operational amplifier 302 is an OP4117 model amplifier.

[0045] In this embodiment, the synchronization voltage is preprocessed by a phase-delay-free differential circuit 202. The phase-delay-free differential circuit 202 includes only resistors and operational amplifiers, avoiding the use of circuit components with inherent delay characteristics such as inductors and capacitors. This allows the phase delay of the preprocessing process to be maintained within an allowable range when the phase-delay-free differential circuit 202 preprocesses the synchronization voltage.

[0046] In one embodiment, the first resistor R1 is an adjustable resistor. As described above, the degree of limiting during preprocessing can be changed by altering the value of the first resistor R1. To facilitate handling different synchronization voltages or different testing requirements, the first resistor R1 is set as an adjustable resistor, allowing operators to easily adjust its value as needed.

[0047] Optionally, the adjustable resistor can be a sliding rheostat or an adjustable resistor whose resistance is changed by other media. For example, the adjustable resistor can be a photoresistor or a thermistor.

[0048] In one embodiment, such as Figure 4 As shown, the zero-crossing detection circuit 204 includes a zero-crossing comparison unit 402 and a voltage output unit 404. The phase-delay-free differential circuit 202 is connected to the voltage output unit 404 through the zero-crossing comparison unit 402. The zero-crossing comparison unit 402 is used to compare the pre-processed synchronization voltage with the reference voltage and output the voltage comparison result to the voltage output unit 404. The voltage output unit 404 is used to output a voltage signal according to the voltage comparison result.

[0049] Specifically, the zero-crossing comparison unit 402 is connected to the phase-delay-free differential circuit 202 and receives the pre-processed synchronization voltage from the phase-delay-free differential circuit 202. The zero-crossing comparison unit 402 compares the pre-processed synchronization voltage with a reference voltage. Since the zero-crossing comparison unit 402 is mainly used to detect the zero-crossing point of the pre-processed synchronization voltage, the reference voltage can be zero. The zero-crossing comparison unit 402 compares the magnitudes of the pre-processed synchronization voltage and the reference voltage and obtains a voltage comparison result. The zero-crossing comparison unit 402 outputs the voltage comparison result to the voltage output unit 404, which outputs a voltage signal based on the voltage comparison result.

[0050] In one embodiment, such as Figure 5 As shown, the zero-crossing comparator 402 includes a comparator chip 502 and a fifth resistor R5. The first input terminal of the comparator chip 502 is connected to the phase-delay-free differential circuit 202, the second input terminal of the comparator chip 502 is grounded through the fifth resistor R5, and the output terminal of the comparator chip 502 is connected to the voltage output unit 404.

[0051] Specifically, the comparison chip 502 receives the pre-processed synchronization voltage and compares it with the reference voltage input by the grounded fifth resistor R5 to obtain the voltage comparison result, and then transmits the voltage comparison result to the voltage output unit 404.

[0052] For example, the comparator chip 502 can be an LM311D operational amplifier. The LM311D operational amplifier is a highly flexible voltage comparator with a relatively short propagation delay compared to other operational amplifiers and a faster response time under saturation conditions. It features low delay and fast response, which can meet the requirement of reducing phase delay in this application.

[0053] Based on the zero-crossing comparator unit 402, which includes comparator chip 502 and fifth resistor R5, as follows: Figure 6As shown, the comparator chip 502 includes a second operational amplifier 602 and a first switching transistor Q1. The non-inverting input of the second operational amplifier 602 is connected to the phase-delay-free differential circuit 202, and the inverting input of the second operational amplifier 602 is grounded through the fifth resistor R5. The output of the second operational amplifier 602 is connected to the control terminal of the first switching transistor Q1. Both the input and output of the first switching transistor Q1 are connected to the voltage output unit 404.

[0054] Specifically, the positive power supply terminal of the second operational amplifier 602 is connected to the power supply VCC, and the negative power supply terminal is connected to a negative voltage of the same magnitude but opposite polarity to the power supply VCC. The non-inverting input terminal of the second operational amplifier 602 is connected to the pre-processed synchronization voltage, and the inverting input terminal of the second operational amplifier 602 is connected to the fifth resistor R5 and grounded. The reference voltage can be 0V. The pre-processed reference voltage is compared with 0V as the reference voltage, and the comparison result is output to the control terminal of the first switching transistor Q1. This comparison result can control the on / off state of the first switching transistor Q1, and the first switching transistor Q1 then outputs the voltage comparison result.

[0055] Optionally, the power supply VCC of the second operational amplifier 602 and the first operational amplifier 302 can be the same power supply, which is 12V. The first switching transistor Q1 can be an NPN transistor. The fifth resistor R5 has a resistance of 10KΩ.

[0056] In one embodiment, such as Figure 6 As shown, the voltage output unit 404 includes a sixth resistor R6, a seventh resistor R7, and a second switch Q2. The first end of the sixth resistor R6 is connected to the input terminal of the second switch Q2 and the input voltage. The second end of the sixth resistor R6 is connected to the control terminal of the second switch Q2 and the input terminal of the first switch Q1. The first end of the seventh resistor R7 is connected to the output terminal of the first switch Q1 and grounded. The second end of the seventh resistor R7 is connected to the output terminal of the second switch Q2 and is used to output a voltage signal.

[0057] Specifically, the switching on / off state of the first switch Q1 controls the switching on / off state of the second switch Q2. When the pre-processed synchronization voltage is greater than the reference voltage, the second operational amplifier 602 outputs a positive voltage, the control terminal of the first switch Q1 is positively energized, and the first switch Q1 is turned on. When the first switch Q1 is turned on, the power supply VEE is grounded through the sixth resistor R6, the control terminal of the second switch Q2 is de-energized, and the second switch Q2 is turned off. When the pre-processed synchronization voltage is less than the reference voltage, the second operational amplifier 602 outputs a negative voltage, the control terminal of the first switch Q1 is negatively energized, and the first switch Q1 is turned off. When the first switch Q1 is turned off, the power supply VEE is transmitted to the control terminal of the second switch Q2 through the sixth resistor R6, the control terminal of the second switch Q2 is energized, and the second switch Q2 is turned on. When the pre-processed synchronization voltage equals the reference voltage, the output of the second operational amplifier 602 remains in its original state; that is, when the pre-processed synchronization voltage changes from positive to negative, the output of the second operational amplifier 602 corresponding to this zero point is a positive voltage. When the preprocessed synchronization voltage changes from negative to positive, the output of the second operational amplifier 602 corresponding to this zero point is negative.

[0058] When the first switch Q1 is turned on and the second switch Q2 is turned off, the power supply VEE is output through the first switch Q1 and the seventh resistor R7 (although...). Figure 6 The output of the first switching transistor Q1 is grounded, but in actual circuit applications, a weak current will flow through the seventh resistor R7 (output). When the first switching transistor Q1 is turned off and the second switching transistor Q2 is turned on, the power supply VEE is output through the second switching transistor Q2. The output of the power supply VEE is the voltage signal.

[0059] For example, the power supply VEE is a 7V power supply, the resistance of the sixth resistor R6 is 2KΩ, and the resistance of the seventh resistor R7 is 50KΩ. The second switching transistor Q2 is an NPN transistor.

[0060] The pre-processed synchronous voltage controls the conduction and cutoff of the first switch Q1, which in turn controls the conduction and cutoff of the second switch Q2, and finally controls the output circuit of the power supply VEE. The different outputs of the power supply VEE form voltage signals to realize the synchronous voltage zero-crossing detection of the polysilicon reduction furnace power supply.

[0061] The structure of the zero-crossing detection circuit 204 is not unique; in one embodiment, such as... Figure 7As shown, the zero-crossing detection circuit 204 is an analog-to-digital converter (ADC) chip 702. The ADC chip 702 can be a high-speed ADC chip. The ADC chip 702 receives the pre-processed synchronization voltage and performs analog-to-digital conversion on it. For example, the ADC chip 702 can be an AD7606 chip. The AD7606 chip supports simultaneous data acquisition from 8 channels, with a sampling depth of up to 16 bits, a sampling rate of up to 40 kHz, and a resolution of 25 microseconds, which can meet the processing requirements of the pre-processed synchronization voltage.

[0062] In one embodiment, such as Figure 8 As shown, the synchronous voltage zero-crossing detection device for the polysilicon reduction furnace power supply also includes a processor 802 connected to the zero-crossing detection circuit 204. Specifically, the processor 802 acquires and analyzes voltage signals, which can be analyzed in conjunction with software or processed independently to obtain the synchronous voltage zero-crossing detection result of the polysilicon reduction furnace power supply.

[0063] Optionally, the processor 802 can be an FPGA (Field Programmable Gate Array). An FPGA is a programmable integrated circuit pre-designed and implemented on a silicon die. It can be configured into a specified circuit structure according to the needs of the operator, freeing them from relying on ASIC chips designed and manufactured by chip manufacturers. It is widely used in prototyping, communications, automotive electronics, industrial control, aerospace, data centers, and other fields, and can acquire and / or analyze voltage signals to achieve zero-crossing detection of the synchronous voltage of the polysilicon reduction furnace power supply.

[0064] To better understand the above scheme, combined with Figure 1 The application scenarios shown below will be explained in detail with reference to a specific embodiment.

[0065] In one embodiment, the synchronous voltage zero-crossing detection device 102 of the polysilicon reduction furnace power supply includes a phase-delay-free differential circuit, a zero-crossing detection circuit, and an FPGA connected in sequence. The circuit structure of the phase-delay-free differential circuit is as follows: Figure 3 As shown, the zero-crossing detection circuit includes a zero-crossing comparison unit and a voltage output unit. The specific circuit structure is as follows: Figure 6 As shown.

[0066] The synchronous voltage generating element of the polysilicon reduction furnace power supply is connected to a phase-delay-free differential circuit, transmitting the synchronous voltage to the phase-delay-free differential circuit. The phase-delay-free differential circuit acquires the synchronous voltage generated by the synchronous voltage generating element, preprocesses it, and then transmits it to the zero-crossing comparison unit. The zero-crossing comparison unit compares the preprocessed synchronous voltage with a reference voltage (set to zero) and obtains the voltage comparison result. The zero-crossing comparison unit outputs the voltage comparison result to the voltage output unit, which outputs a voltage signal to the FPGA based on the comparison result. The FPGA acquires the voltage signal and transmits it to a connected host computer or terminal. The host computer or terminal analyzes the acquired voltage signal to achieve zero-crossing detection of the synchronous voltage of the polysilicon reduction furnace power supply. The synchronous voltage and the waveform obtained after analyzing the voltage signal are combined into a single array as shown in the figure. Figure 9 In the display page shown, waveform 1 is the synchronization voltage, and rectangular wave 2 is the voltage signal acquired by the FPGA. It can be seen that the delay phase error of the synchronization voltage zero-crossing detection device of the polysilicon reduction furnace power supply of this application is very small, approaching zero.

[0067] In one embodiment, such as Figure 1 As shown, a polysilicon reduction furnace control device is provided, including a polysilicon reduction furnace power supply 104 and a synchronous voltage zero-crossing detection device 102 for the polysilicon reduction furnace power supply as described above. The AC power supply in the polysilicon reduction furnace power supply 104, through a multi-tap transformer and a synchronous voltage generation element, rectifies each thyristor rectifier branch (corresponding to...) Figure 1 The voltage and current in the thyristor rectifiers 1, 2 to 5 are adjusted, and then each thyristor rectifier branch supplies power to the load 106 (i.e., polysilicon). The synchronous voltage zero-crossing detection device 102 of the polysilicon reduction furnace power supply detects the working status of the polysilicon reduction furnace power supply by detecting the zero-crossing of the synchronous voltage, thereby monitoring the production status of polysilicon.

[0068] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0069] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0070] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A synchronous voltage zero-crossing detection device for a polycrystalline silicon reduction furnace power supply, characterized in that, It includes a phase-delay differential circuit and a zero-crossing detection circuit. The synchronous voltage generating element of the polysilicon reduction furnace power supply is connected to the phase-delay differential circuit, and the phase-delay differential circuit is connected to the zero-crossing detection circuit. The phase-delay-free differential circuit acquires the synchronization voltage generated by the synchronization voltage generating element, preprocesses the synchronization voltage, and transmits it to the zero-crossing detection circuit. The zero-crossing detection circuit outputs a voltage signal based on the preprocessed synchronization voltage. The voltage signal is used to characterize the zero point of the synchronization voltage. The phase delay of the preprocessing process of the synchronization voltage by the phase-delay-free differential circuit is maintained within an allowable range.

2. The synchronous voltage zero-crossing detection device for the power supply of the polycrystalline silicon reduction furnace according to claim 1, characterized in that, The phase-delay-free differential circuit includes a first operational amplifier, a first resistor, a second resistor, a third resistor, and a fourth resistor; The synchronization voltage is connected to the non-inverting input of the first operational amplifier through the second resistor. The first end of the first resistor is connected to the common terminal of the second resistor and the non-inverting input of the first operational amplifier, and the second end of the first resistor is grounded. The first end of the third resistor is connected to the inverting input of the first operational amplifier and the fourth resistor, and the second end of the third resistor is grounded. The first end of the fourth resistor is connected to the output of the first operational amplifier, and the second end of the fourth resistor is connected to the inverting input of the first operational amplifier.

3. The synchronous voltage zero-crossing detection device for the power supply of the polycrystalline silicon reduction furnace according to claim 2, characterized in that, The first resistor is an adjustable resistor.

4. The synchronous voltage zero-crossing detection device for the power supply of the polycrystalline silicon reduction furnace according to claim 1, characterized in that, The zero-crossing detection circuit includes a zero-crossing comparison unit and a voltage output unit, and the phase-delay-free differential circuit is connected to the voltage output unit through the zero-crossing comparison unit. The zero-crossing comparison unit is used to compare the preprocessed synchronization voltage with the reference voltage and output the voltage comparison result to the voltage output unit. The voltage output unit is used to output the voltage signal according to the voltage comparison result.

5. The synchronous voltage zero-crossing detection device for the power supply of the polycrystalline silicon reduction furnace according to claim 4, characterized in that, The zero-crossing comparator unit includes a comparator chip and a fifth resistor. The first input terminal of the comparator chip is connected to the phase-delay-free differential circuit, the second input terminal of the comparator chip is grounded through the fifth resistor, and the output terminal of the comparator chip is connected to the voltage output unit.

6. The synchronous voltage zero-crossing detection device for the power supply of the polycrystalline silicon reduction furnace according to claim 5, characterized in that, The comparator chip includes a second operational amplifier and a first switching transistor. The non-inverting input of the second operational amplifier is connected to the phase-delay-free differential circuit, the inverting input of the second operational amplifier is grounded through the fifth resistor, and the output of the second operational amplifier is connected to the control terminal of the first switching transistor. Both the input and output of the first switching transistor are connected to the voltage output unit.

7. The synchronous voltage zero-crossing detection device for the power supply of the polycrystalline silicon reduction furnace according to claim 6, characterized in that, The voltage output unit includes a sixth resistor, a seventh resistor, and a second switch. The first end of the sixth resistor is connected to the input terminal of the second switch and the input voltage. The second end of the sixth resistor is connected to the control terminal of the second switch and the input terminal of the first switch. The first end of the seventh resistor is connected to the output terminal of the first switch and grounded. The second end of the seventh resistor is connected to the output terminal of the second switch, and is used to output the voltage signal.

8. The synchronous voltage zero-crossing detection device for the power supply of the polycrystalline silicon reduction furnace according to claim 1, characterized in that, The zero-crossing detection circuit is an analog-to-digital converter chip.

9. The synchronous voltage zero-crossing detection device for the power supply of the polycrystalline silicon reduction furnace according to claim 1, characterized in that, It also includes a processor connected to the zero-crossing detection circuit.

10. A control device for a polycrystalline silicon reduction furnace, characterized in that, It includes a power supply for a polysilicon reduction furnace and a synchronous voltage zero-crossing detection device for the power supply as described in any one of claims 1-9.

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