A zero-crossing detection device and method for high-voltage solid-state soft-start equipment

Abstract

The present invention relates to the technical field of soft start, and discloses a zero-crossing detection device and method for high-voltage solid-state soft start equipment, comprising a voltage conversion processing module, a filtering processing module, a phase correction processing module, a zero-crossing detection module and a software processing module, wherein one end of the voltage conversion processing module is connected to a power system, the other end of the voltage conversion processing module is connected to one end of the filtering processing module, the other end of the filtering processing module is connected to one end of the phase correction processing module, the other end of the phase correction processing module is connected to one end of the zero-crossing detection module, and the other end of the zero-crossing detection module is connected to the software processing module. The present invention has the characteristics of strong anti-interference ability and high detection accuracy.

Description

Technical Field

[0001] The present invention relates to the field of soft starting technology, and in particular to a zero-crossing detection device and method for high-voltage solid-state soft starting equipment. Background Art

[0002] The high voltage solid-state soft start device involves the trigger control technology of the thyristor. The control of the thyristor trigger angle is based on the judgment of the zero crossing point, and the zero crossing point is used as the starting time point of the trigger angle.

[0003] Traditional solution 1 uses a zero-crossing circuit to detect the zero-crossing point. Due to the high sensitivity of the comparator, when there is harmonic or noise interference, the voltage fluctuation will cause multiple zero-crossing points to be detected in one cycle, which will seriously affect the forward and reverse rotation judgment of the motor and the triggering of the thyristor.

[0004] Traditional solution 2 uses an optocoupler circuit to detect zero-crossing points. Because the optocoupler switches between the luminous and non-luminous states, current changes are required. When the AC voltage signal amplitude is large, the optocoupler current is large, the device is easily damaged, and the stability is poor. When the AC voltage signal amplitude is small, the optocoupler current is small, and there is a large error in zero-crossing point detection. When there is harmonic or noise interference, the optocoupler detection method can also detect multiple zero-crossing points in one cycle.

[0005] In view of the above problems, the present invention provides a zero-crossing detection device and method with filtering anti-interference measures, which can ensure the reliability and accuracy of zero-crossing detection when there is harmonic or noise interference, and the cost increase can be ignored. Summary of the invention

[0006] The purpose of the present invention is to provide a zero-crossing detection device and method for a high-voltage solid-state soft-start device, which has the characteristics of strong anti-interference ability and high detection accuracy.

[0007] The above technical objectives of the present invention are achieved through the following technical solutions: a zero-crossing detection device for a high-voltage solid-state soft-start device, comprising a voltage conversion processing module, a filtering processing module, a phase correction processing module, a zero-crossing detection module and a software processing module, wherein one end of the voltage conversion processing module is connected to a power system, the other end of the voltage conversion processing module is connected to one end of the filtering processing module, the other end of the filtering processing module is connected to one end of the phase correction processing module, the other end of the phase correction processing module is connected to one end of the zero-crossing detection module, and the other end of the zero-crossing detection module is connected to the software processing module;

[0008] The voltage conversion processing module is used to convert the voltage of the power system to obtain a low-voltage AC signal;

[0009] The filtering processing module is used to perform active low-pass filtering on the low-voltage AC signal from the voltage conversion processing module to obtain a filtered voltage signal;

[0010] The phase correction processing module is used to perform phase correction on the voltage signal after being filtered by the filtering processing module;

[0011] The zero-crossing detection module is used to detect the voltage signal that has been phase-corrected by the phase correction processing module to obtain a zero-crossing level signal;

[0012] The software processing module is used to process the zero-crossing level signal from the zero-crossing detection module to obtain a stable zero-crossing point signal.

[0013] The present invention is further configured as follows: the voltage conversion processing module includes a first-level voltage conversion unit and a second-level voltage conversion unit;

[0014] The first-level voltage conversion unit includes two single-phase voltage transformers, the two single-phase voltage transformers adopt a VV connection mode, the primary voltage side of the first-level voltage conversion unit is connected to the power system, and the secondary voltage side of the first-level voltage conversion unit is connected to the primary voltage side of the second-level voltage conversion unit;

[0015] The second-level voltage conversion unit includes three voltage converters, and the three voltage converters adopt a YY connection method. The primary voltage side of the second-level voltage conversion unit is connected to the secondary voltage side of the first-level voltage conversion unit, and the secondary voltage side of the second-level voltage conversion unit is connected to the filtering processing module.

[0016] The present invention is further configured as follows: the filtering processing module is a second-order active low-pass filtering circuit, and the second-order active low-pass filtering circuit includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1, a capacitor C2 and an operational amplifier U1, wherein one end of the resistor R1 is connected to the voltage conversion processing module, the other end of the resistor R1 is respectively connected to one end of the resistor R2 and one end of the capacitor C2, the other end of the resistor R2 is respectively connected to the positive input end of the operational amplifier U1 and one end of the capacitor C1, the other end of the capacitor C1 is connected to one end of the resistor R3, the other end of the resistor R3 is respectively connected to the negative input end of the operational amplifier U1 and one end of the resistor R4, the other end of the resistor R4 is connected to the output end of the operational amplifier U1, the positive power supply end of the operational amplifier U1 is connected to a +12V power supply, the negative power supply end of the operational amplifier U1 is connected to a -12V power supply, and the output end of the operational amplifier U1 is connected to the phase correction processing module.

[0017] The present invention is further configured as follows: the phase correction processing module includes a capacitor C3, a resistor R5, a resistor R6, a resistor R7 and an operational amplifier U2, wherein one end of the capacitor C3 is connected to the output end of the operational amplifier U1, the other end of the capacitor C3 is respectively connected to the positive input end of the operational amplifier U2 and one end of the resistor R5, the other end of the resistor R5 is connected to one end of the resistor R7, the other end of the resistor R7 is respectively connected to the negative input end of the operational amplifier U2 and one end of the resistor R6, the other end of the resistor R6 is connected to the output end of the operational amplifier U2, the positive power supply end of the operational amplifier U2 is connected to a +12V power supply, the negative power supply end of the operational amplifier U2 is connected to a -12V power supply, and the output end of the operational amplifier U2 is connected to the zero-crossing detection module.

[0018] The present invention is further configured as follows: the zero-crossing detection module is a hysteresis comparator zero-crossing detection circuit, and the zero-crossing detection module includes a resistor R8, a capacitor C4, a resistor R9, a resistor R10 and a comparator U3, wherein one end of the resistor R8 is connected to the output end of the operational amplifier U2, the other end of the resistor R8 is respectively connected to one end of the resistor R10, one end of the capacitor C4 and the positive input end of the comparator U3, the other end of the resistor R10 is connected to the output end of the comparator U3, the other end of the capacitor C4 is connected to one end of the resistor R9, the other end of the resistor R9 is connected to the negative input end of the comparator U3, the positive power supply end of the comparator U3 is connected to a +12V power supply, the negative power supply end of the comparator U3 is connected to a -12V power supply, and the output end of the comparator U3 is connected to the software processing module.

[0019] The present invention is further configured as follows: one end of the capacitor C1 away from the resistor R2, one end of the resistor R5 away from the capacitor C3, one end of the resistor R7 away from the resistor R6, and one end of the capacitor C4 away from the resistor R8 are all connected to the 0V signal line.

[0020] The present invention is further configured as follows: the software processing module detects the rising edge zero-crossing signal, and performs locking and unlocking processing on the rising edge zero-crossing signal of each phase within one cycle.

[0021] On the other hand, the present invention also provides a method for detecting zero crossing of a high voltage solid-state soft start device, comprising the following steps:

[0022] S1, the voltage conversion processing module converts the voltage of the power system to obtain a low voltage sampling voltage;

[0023] S2, the filtering processing module performs a second-order active low-pass filter processing on the sampled voltage to filter out harmonics and noise in the sampled voltage signal;

[0024] S3, the sampled voltage will generate a phase lag offset after filtering, and the phase correction processing module performs phase correction on the sampled voltage;

[0025] S4, the sampled voltage corrected by the phase correction processing module enters the zero-crossing detection module to obtain a zero-crossing level signal;

[0026] S5, the zero-crossing level signal enters the software processing module through the MCU pin, and the software processing module detects the rising edge zero-crossing signal, locks and unlocks the zero-crossing signal, and obtains a stable and reliable zero-crossing signal.

[0027] The beneficial effects of the present invention are:

[0028] In the present invention, the voltage conversion processing module converts the voltage of the power system to obtain a low-voltage sampling voltage; the filtering processing module performs a second-order active low-pass filter processing on the sampling voltage to filter out harmonics and noise in the sampling voltage signal; the sampling voltage will produce a phase lag offset after filtering, and the phase correction processing module performs phase correction on the sampling voltage; the sampling voltage corrected by the phase correction processing module enters the zero-crossing detection module to obtain a zero-crossing level signal; the zero-crossing level signal enters the software processing module through the MCU pin, and the software processing module detects the rising edge zero-crossing signal, and performs locking and unlocking processing on the zero-crossing signal to obtain a stable and reliable zero-crossing signal. In the present invention, under the harmonic or noise interference environment, the high-voltage solid-state soft start device can detect an accurate zero-crossing signal, ensure the reliability and accuracy of the thyristor triggering, and compared with the traditional method, it has the characteristics of strong anti-interference ability and high detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 The invention discloses a flow chart of a zero-crossing detection device for a high-voltage solid-state soft-start device.

[0031] Figure 2 The invention discloses a structural schematic diagram of a zero-crossing detection device for a high-voltage solid-state soft-start device.

[0032] Figure 3The invention discloses a circuit structure diagram of a filter processing module, a phase correction processing module and a zero-crossing detection module in a zero-crossing detection device for a high-voltage solid-state soft-start device.

[0033] Figure 4 The invention discloses a flow chart of a zero-crossing detection method for a high-voltage solid-state soft-start device.

[0034] In the figure, 1. voltage conversion processing module; 2. filtering processing module; 3. phase correction processing module; 4. zero-crossing detection module; 5. software processing module. DETAILED DESCRIPTION

[0035] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Examples, such as Figure 1 As shown, a high-voltage solid-state soft starter zero-crossing detection device comprises a voltage conversion processing module 1, a filtering processing module 2, a phase correction processing module 3, a zero-crossing detection module 4 and a software processing module 5, wherein one end of the voltage conversion processing module 1 is connected to the power system, the other end of the voltage conversion processing module 1 is connected to one end of the filtering processing module 2, the other end of the filtering processing module 2 is connected to one end of the phase correction processing module 3, the other end of the phase correction processing module 3 is connected to one end of the zero-crossing detection module 4, and the other end of the zero-crossing detection module 4 is connected to the software processing module 5; the voltage conversion processing module 1 is used to The voltage of the power system is transformed and processed to obtain a low-voltage AC signal; the filtering processing module 2 is used to perform active low-pass filtering on the low-voltage AC signal from the voltage conversion processing module 1 to obtain a filtered voltage signal; the phase correction processing module 3 is used to perform phase correction on the voltage signal after filtering by the filtering processing module 2; the zero-crossing detection module 4 is used to detect the voltage signal that has been phase-corrected by the phase correction processing module 3 to obtain a zero-crossing level signal; the software processing module 5 is used to process the zero-crossing level signal from the zero-crossing detection module 4 to obtain a stable zero-crossing point signal.

[0037] like Figure 2As shown, the voltage conversion processing module 1 includes a first-level voltage conversion unit and a second-level voltage conversion unit; the first-level voltage conversion unit includes two single-phase voltage transformers, the two single-phase voltage transformers adopt a VV wiring method, the primary voltage side of the first-level voltage conversion unit is connected to the power system, and the secondary voltage side of the first-level voltage conversion unit is connected to the primary voltage side of the second-level voltage conversion unit; the second-level voltage conversion unit includes three voltage converters, the three voltage converters adopt a YY wiring method, the primary voltage side of the second-level voltage conversion unit is connected to the secondary voltage side of the first-level voltage conversion unit, and the secondary voltage side of the second-level voltage conversion unit is connected to the filtering processing module 2.

[0038] Specifically, the voltage conversion processing module 1 is used to collect the voltage of the power system. The first-level voltage conversion unit changes the system voltage into a standard PT secondary voltage of 100V, and the second-level voltage conversion unit converts the standard PT secondary voltage into a low-voltage sampling voltage, wherein the main circuit voltage of the power system can be 10KV, 6KV or 3KV, and the sampling voltage value of the 100V standard PT secondary voltage converted by the second-level voltage conversion unit is lower than 5V.

[0039] It should be understood that in zero-crossing detection, the voltage magnitude has no effect on the detection result, so when there is an error in the input and output voltages of the voltage conversion processing module 1, it does not affect the final result.

[0040] like Figure 3 As shown, the filtering processing module 2 is a second-order active low-pass filtering circuit, which includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1, a capacitor C2 and an operational amplifier U1, wherein one end of the resistor R1 is connected to the voltage conversion processing module 1, the other end of the resistor R1 is respectively connected to one end of the resistor R2 and one end of the capacitor C2, the other end of the resistor R2 is respectively connected to the positive input end of the operational amplifier U1 and one end of the capacitor C1, the other end of the capacitor C1 is connected to one end of the resistor R3, the other end of the resistor R3 is respectively connected to the negative input end of the operational amplifier U1 and one end of the resistor R4, the other end of the resistor R4 is connected to the output end of the operational amplifier U1, the positive power supply end of the operational amplifier U1 is connected to the +12V power supply, the negative power supply end of the operational amplifier U1 is connected to the -12V power supply, and the output end of the operational amplifier U1 is connected to the phase correction processing module 3.

[0041] Specifically, the sampled voltage first enters the filtering processing module 2, which is a second-order active low-pass filtering circuit composed of two RC filtering circuits and a common-mode proportional operational amplifier. Its cut-off frequency is 106 Hz and the voltage amplification factor is 2 times. It can filter out voltage harmonic signals of more than three times, and filter out harmonics and noise in the voltage signal. The filtered voltage signal has a phase lag of 0-90 degrees.

[0042] Further, such as Figure 3 As shown, the phase correction processing module 3 includes a capacitor C3, a resistor R5, a resistor R6, a resistor R7 and an operational amplifier U2, wherein one end of the capacitor C3 is connected to the output end of the operational amplifier U1, the other end of the capacitor C3 is respectively connected to the positive input end of the operational amplifier U2 and one end of the resistor R5, the other end of the resistor R5 is connected to one end of the resistor R7, the other end of the resistor R7 is respectively connected to the negative input end of the operational amplifier U2 and one end of the resistor R6, the other end of the resistor R6 is connected to the output end of the operational amplifier U2, the positive power supply end of the operational amplifier U2 is connected to the +12V power supply, the negative power supply end of the operational amplifier U2 is connected to the -12V power supply, and the output end of the operational amplifier U2 is connected to the zero-crossing detection module 4.

[0043] Specifically, the voltage signal after filtering by the filtering processing module 2 enters the phase correction processing module 3, which is composed of a resistor, a capacitor and an operational amplifier. It can perform a 0-90 degree lead correction on the voltage signal phase. The voltage amplification factor of the phase correction processing module 3 is about 0.5 times, combined with the 2 times amplification factor in the filtering processing module 2, and the final voltage amplification factor is about 1 times. A small change in the voltage amplification factor does not affect the final zero-crossing point detection.

[0044] Further, such as Figure 3 As shown, the zero-crossing detection module 4 is a hysteresis comparator zero-crossing detection circuit, and the zero-crossing detection module 4 includes a resistor R8, a capacitor C4, a resistor R9, a resistor R10 and a comparator U3, wherein one end of the resistor R8 is connected to the output end of the operational amplifier U2, the other end of the resistor R8 is respectively connected to one end of the resistor R10, one end of the capacitor C4 and the positive input end of the comparator U3, the other end of the resistor R10 is connected to the output end of the comparator U3, the other end of the capacitor C4 is connected to one end of the resistor R9, the other end of the resistor R9 is connected to the negative input end of the comparator U3, the positive power supply end of the comparator U3 is connected to the +12V power supply, the negative power supply end of the comparator U3 is connected to the -12V power supply, and the output end of the comparator U3 is connected to the software processing module 5.

[0045] Specifically, the voltage signal corrected by the phase correction processing module 3 enters the zero-crossing detection module 4, and the zero-crossing signal is detected. The zero-crossing detection module 4 is a hysteresis comparator circuit composed of a resistor, a capacitor and a comparator. The hysteresis comparator has strong anti-interference ability. The voltage has a slight change near the threshold. As long as the voltage fluctuation amplitude is within the hysteresis voltage range, the comparator will not flip and will not cause zero-crossing false detection.

[0046] Further, such as Figure 3As shown, one end of the capacitor C1 away from the resistor R2, one end of the resistor R5 away from the capacitor C3, one end of the resistor R7 away from the resistor R6, and one end of the capacitor C4 away from the resistor R8 are all connected to the 0V signal line.

[0047] Further, such as Figure 2 As shown, the software processing module 5 detects the rising edge zero-crossing point signal, and performs locking and unlocking processing on the rising edge zero-crossing point signal of each phase within one cycle.

[0048] Specifically, the zero-crossing signal enters the software processing module 5 through the MCU pin, and the software processing module 5 judges and processes it. The software only detects the rising edge zero-crossing signal, and does not detect the falling edge zero-crossing signal. The software locks and unlocks the rising edge zero-crossing signal detection of each phase in one cycle. Wherein, the software processing method is as follows: the three-phase AC voltage signal is symmetrically distributed, and the three-phase voltages are spaced 120° (1 / 3 cycle) from each other. In one cycle, the rising edge zero-crossing point of the A-phase voltage is taken as the starting point. When the A-phase detects the rising edge zero-crossing point, the A-phase zero-crossing detection function is locked. When the B-phase rising edge zero-crossing point is detected after a period of time, the A-phase zero-crossing detection is unlocked, and the B-phase rising edge zero-crossing detection function is locked at the same time. When the C-phase rising edge zero-crossing point is detected after a period of time, the B-phase rising edge zero-crossing detection is unlocked, and the C-phase rising edge zero-crossing detection function is locked at the same time, and then the detection is carried out in a cyclic manner according to the ABC sequence. In one power frequency cycle, only one rising edge zero-crossing point can be detected in a certain phase.

[0049] Similarly, when the three-phase voltage sequence is ACB, the software processing method is the same. After being processed by the software processing module 5, not only can the forward and reverse rotation directions of the motor be accurately determined, but also a time reference for triggering the trigger angle is provided.

[0050] On the other hand, Figure 4 As shown, the present invention also provides a zero-crossing detection method for a high-voltage solid-state soft-start device, comprising the following steps:

[0051] S1, the voltage conversion processing module 1 converts the voltage of the power system to obtain a low voltage sampling voltage;

[0052] S2, the filtering processing module 2 performs a second-order active low-pass filter processing on the sampled voltage to filter out harmonics and noise in the sampled voltage signal;

[0053] S3, the sampling voltage will produce a phase lag offset after filtering, and the phase correction processing module 3 performs phase correction on the sampling voltage;

[0054] S4, the sampled voltage corrected by the phase correction processing module 3 enters the zero-crossing detection module 4 to obtain a zero-crossing level signal;

[0055] S5, the zero-crossing level signal enters the software processing module 5 through the MCU pin, and the software processing module 5 detects the rising edge zero-crossing signal, performs locking and unlocking processing on the zero-crossing signal to obtain a stable and reliable zero-crossing signal.

Claims

1. A zero-crossing detection device for a high-voltage solid-state soft-start device, characterized in that: The invention comprises a voltage conversion processing module (1), a filtering processing module (2), a phase correction processing module (3), a zero-crossing detection module (4) and a software processing module (5), wherein one end of the voltage conversion processing module (1) is connected to the power system, the other end of the voltage conversion processing module (1) is connected to one end of the filtering processing module (2), the other end of the filtering processing module (2) is connected to one end of the phase correction processing module (3), the other end of the phase correction processing module (3) is connected to one end of the zero-crossing detection module (4), and the other end of the zero-crossing detection module (4) is connected to the software processing module (5); The voltage conversion processing module (1) is used to convert the voltage of the power system to obtain a low-voltage AC signal; The filtering processing module (2) is used to perform active low-pass filtering on the low-voltage AC signal from the voltage conversion processing module (1) to obtain a filtered voltage signal; The phase correction processing module (3) is used to perform phase correction on the voltage signal after being filtered by the filtering processing module (2); The zero-crossing detection module (4) is used to detect the voltage signal that has been phase-corrected by the phase correction processing module (3) to obtain a zero-crossing level signal; The software processing module (5) is used to process the zero-crossing level signal from the zero-crossing detection module (4) to obtain a stable zero-crossing point signal; The phase correction processing module (3) comprises a capacitor C3, a resistor R5, a resistor R6, a resistor R7 and an operational amplifier U2, wherein one end of the capacitor C3 is connected to the output end of the operational amplifier U1, the other end of the capacitor C3 is respectively connected to the positive input end of the operational amplifier U2 and one end of the resistor R5, the other end of the resistor R5 is connected to one end of the resistor R7, the other end of the resistor R7 is respectively connected to the negative input end of the operational amplifier U2 and one end of the resistor R6, the other end of the resistor R6 is connected to the output end of the operational amplifier U2, the positive power supply end of the operational amplifier U2 is connected to a +12V power supply, the negative power supply end of the operational amplifier U2 is connected to a -12V power supply, and the output end of the operational amplifier U2 is connected to the zero-crossing detection module (4).

2. A zero-crossing detection device for a high-voltage solid-state soft-start device according to claim 1, characterized in that: The voltage conversion processing module (1) comprises a first-level voltage conversion unit and a second-level voltage conversion unit; The first-level voltage conversion unit includes two single-phase voltage transformers, the two single-phase voltage transformers adopt a VV connection mode, the primary voltage side of the first-level voltage conversion unit is connected to the power system, and the secondary voltage side of the first-level voltage conversion unit is connected to the primary voltage side of the second-level voltage conversion unit; The second-level voltage conversion unit includes three voltage converters, and the three voltage converters adopt a YY connection method. The primary voltage side of the second-level voltage conversion unit is connected to the secondary voltage side of the first-level voltage conversion unit, and the secondary voltage side of the second-level voltage conversion unit is connected to the filtering processing module (2).

3. A zero-crossing detection device for a high-voltage solid-state soft-start device according to claim 2, characterized in that: The filtering processing module (2) is a second-order active low-pass filtering circuit, which comprises a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1, a capacitor C2 and an operational amplifier U1, wherein one end of the resistor R1 is connected to the voltage conversion processing module (1), the other end of the resistor R1 is respectively connected to one end of the resistor R2 and one end of the capacitor C2, the other end of the resistor R2 is respectively connected to the positive input end of the operational amplifier U1 and one end of the capacitor C1, the other end of the capacitor C1 is connected to one end of the resistor R3, the other end of the resistor R3 is respectively connected to the negative input end of the operational amplifier U1 and one end of the resistor R4, the other end of the resistor R4 is connected to the output end of the operational amplifier U1, the positive power supply end of the operational amplifier U1 is connected to a +12V power supply, the negative power supply end of the operational amplifier U1 is connected to a -12V power supply, and the output end of the operational amplifier U1 is connected to the phase correction processing module (3).

4. A zero-crossing detection device for a high-voltage solid-state soft-start device according to claim 3, characterized in that: The zero-crossing detection module (4) is a hysteresis comparator zero-crossing detection circuit, and the zero-crossing detection module (4) comprises a resistor R8, a capacitor C4, a resistor R9, a resistor R10 and a comparator U3, wherein one end of the resistor R8 is connected to the output end of the operational amplifier U2, the other end of the resistor R8 is respectively connected to one end of the resistor R10, one end of the capacitor C4 and the positive input end of the comparator U3, the other end of the resistor R10 is connected to the output end of the comparator U3, the other end of the capacitor C4 is connected to one end of the resistor R9, the other end of the resistor R9 is connected to the negative input end of the comparator U3, the positive power supply end of the comparator U3 is connected to a +12V power supply, the negative power supply end of the comparator U3 is connected to a -12V power supply, and the output end of the comparator U3 is connected to the software processing module (5).

5. A zero-crossing detection device for a high-voltage solid-state soft-start device according to claim 4, characterized in that: One end of the capacitor C1 away from the resistor R2 , one end of the resistor R5 away from the capacitor C3 , one end of the resistor R7 away from the resistor R6 , and one end of the capacitor C4 away from the resistor R8 are all connected to the 0V signal line.

6. A zero-crossing detection device for a high-voltage solid-state soft-start device according to claim 1, characterized in that: The software processing module (5) detects the rising edge zero-crossing point signal, and performs locking and unlocking processing on the rising edge zero-crossing point signal of each phase within one cycle.

7. A method for detecting zero crossing of a high-voltage solid-state soft-start device using the zero crossing detection device of a high-voltage solid-state soft-start device according to any one of claims 1 to 6, characterized in that: The following steps are included: S1, the voltage conversion processing module (1) converts the voltage of the power system to obtain a low voltage sampling voltage; S2, the filtering processing module (2) performs a second-order active low-pass filter process on the sampled voltage to filter out harmonics and noise in the sampled voltage signal; S3, the sampled voltage will generate a phase lag offset after filtering, and the phase correction processing module (3) performs phase correction on the sampled voltage; S4, the sampled voltage corrected by the phase correction processing module (3) enters the zero-crossing detection module (4) to obtain a zero-crossing level signal; S5, the zero-crossing level signal enters the software processing module (5) through the MCU pin, and the software processing module (5) detects the rising edge zero-crossing signal, performs locking and unlocking processing on the zero-crossing signal, and obtains a stable and reliable zero-crossing signal.

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