阅读说明：本技术 晶闸管整流软启控制方法、装置及存储介质 (Thyristor rectification soft start control method and device and storage medium ) 是由 李龙文 刘诗敏 于 2020-07-27 设计创作，主要内容包括：本发明提供一种晶闸管整流软启控制方法、装置及存储介质,该晶闸管整流软启控制方法包括以下步骤：获取所述晶闸管整流模块的相电压；确定相电压的相位；在相电压的相位处于预设导通角度范围时,控制晶闸管整流模块中对应的晶闸管导通,并增加晶闸管的导通角度直至晶闸管整流模块的母线电压建立完成。本发明的技术方案,旨在解决采用软启电路建立晶闸管整流模块的母线电压,导致成本增加的技术问题。(The invention provides a soft start control method, a soft start control device and a storage medium for thyristor rectification, wherein the soft start control method for thyristor rectification comprises the following steps: obtaining phase voltage of the thyristor rectification module; determining a phase of the phase voltage; and when the phase of the phase voltage is in the preset conduction angle range, controlling the conduction of the corresponding thyristor in the thyristor rectification module, and increasing the conduction angle of the thyristor until the establishment of the bus voltage of the thyristor rectification module is completed. The technical scheme of the invention aims to solve the technical problem of cost increase caused by adopting a soft start circuit to establish the bus voltage of the thyristor rectification module.)

1. A soft start control method for thyristor rectification is applied to a thyristor rectification module and is characterized by comprising the following steps:

obtaining phase voltage of the thyristor rectification module;

determining a phase of the phase voltage;

when the phase of the phase voltage is in a preset conduction angle range, controlling the conduction of a corresponding thyristor in the thyristor rectification module, and increasing the conduction angle of the thyristor until the establishment of the bus voltage of the thyristor rectification module is completed; and when the increased conduction angle of the thyristor reaches a preset angle threshold value, the establishment of the bus voltage of the thyristor rectification module is finished.

2. The thyristor rectified soft start control method of claim 1, wherein said step of obtaining phase voltages of said thyristor rectified modules comprises:

collecting the line voltage of alternating current input to the thyristor rectification module;

and obtaining the phase voltage of the thyristor rectification module according to the line voltage.

3. The thyristor rectification soft start control method according to claim 2, wherein the step of controlling the conduction of the corresponding thyristor in the thyristor rectification module and increasing the conduction angle of the thyristor until the establishment of the bus voltage of the thyristor rectification module is completed when the phase of the phase voltage is in a preset conduction angle range comprises:

when the phase of the phase voltage is in a preset conduction angle range, acquiring the bus voltage of the thyristor rectifier module;

calculating a voltage difference between the line voltage and the bus voltage;

judging whether the voltage difference value is smaller than a preset voltage threshold value or not;

and when the voltage difference value is smaller than the preset voltage threshold value, controlling the conduction of a corresponding thyristor in the thyristor rectification module, and increasing the conduction angle of the thyristor until the establishment of the bus voltage of the thyristor rectification module is completed.

4. The thyristor rectification soft start control method as claimed in claim 3, wherein after the step of determining whether the voltage difference is smaller than a preset voltage threshold, the method further comprises:

and when the voltage difference value is larger than the preset voltage threshold value, controlling the corresponding thyristor in the thyristor rectification module to be switched off, and reducing the conduction angle of the thyristor when the switched-off thyristor is switched on next time.

5. The thyristor-rectified soft-start control method of claim 4, wherein a bus voltage of the thyristor-rectified module increases as the conduction angle of the thyristor increases.

6. The thyristor rectified soft start control method of claim 1 wherein said step of determining the phase of said phase voltages comprises:

counting a count value of the phase voltage between two adjacent zero-crossing points by a counting device;

determining a phase corresponding to a count value of the counting means;

the determined phase is used as the phase of the phase voltage.

7. The thyristor rectified soft start control method of claim 6, wherein said step of counting the count value of said phase voltage between two adjacent zero crossings by said counting means further comprises:

and performing band-pass filtering processing and low-pass filtering processing on the phase voltage.

8. The soft start control method for thyristor rectification according to claim 1, wherein the thyristor rectification module comprises a first phase line, a second phase line and a third phase line, and the step of controlling the conduction of the corresponding thyristor in the thyristor rectification module when the phase of the phase voltage is in a preset conduction angle range, and increasing the conduction angle of the thyristor until the establishment of the bus voltage of the thyristor rectification module is completed comprises:

when the phase of the phase voltage of the first phase line is in a preset conduction angle range, controlling the conduction of an upper bridge arm thyristor of the first phase line and a lower bridge arm thyristor of the third phase line, and increasing the conduction angle of the upper bridge arm thyristor of the first phase line and the conduction angle of the lower bridge arm thyristor of the third phase line until the establishment of the bus voltage of the thyristor rectifier module is completed;

when the phase of the phase voltage of the second phase line is in a preset conduction angle range, controlling the conduction of an upper bridge arm thyristor of the second phase line and a lower bridge arm thyristor of the first phase line, and increasing the conduction angle of the upper bridge arm thyristor of the second phase line and the conduction angle of the lower bridge arm thyristor of the first phase line until the establishment of the bus voltage of the thyristor rectifier module is completed;

and when the phase of the phase voltage of the third phase line is in a preset conduction angle range, controlling the conduction of an upper bridge arm thyristor of the third phase line and a lower bridge arm thyristor of the second phase line, and increasing the conduction angle of the upper bridge arm thyristor of the third phase line and the conduction angle of the lower bridge arm thyristor of the second phase line until the establishment of the bus voltage of the thyristor rectifier module is completed.

9. A thyristor rectification soft start control device, characterized in that the thyristor rectification soft start control device comprises a memory, a processor and a thyristor rectification soft start control program stored on the memory and operable on the processor, and when the thyristor rectification soft start control program is executed by the processor, the thyristor rectification soft start control program realizes each step of the thyristor rectification soft start control method according to any one of claims 1 to 8.

10. A storage medium having a thyristor rectification soft start control program stored thereon, wherein the thyristor rectification soft start control program, when executed by a processor, implements the steps of the thyristor rectification soft start control method according to any one of claims 1 to 8.

Technical Field

The invention relates to the technical field of circuits, in particular to a thyristor rectification soft start control method, a thyristor rectification soft start control device and a storage medium.

Background

At present, most thyristor rectifying devices such as rectifiers have soft start circuits, the soft start circuits often comprise soft start switches and soft start resistors, and the working principle of the soft start circuits is as follows: when the soft-start switch is closed, the grid voltage charges the bus through the soft-start resistor to slowly build the bus voltage.

However, establishing the bus voltage through the soft start circuit may result in increased costs due to the large number of components involved in the soft start circuit.

Disclosure of Invention

The invention provides a thyristor rectification soft start control method, a thyristor rectification soft start control device and a storage medium, and aims to solve the technical problem of cost increase caused by the fact that a soft start circuit is adopted to establish bus voltage of a thyristor rectification module.

In order to achieve the above object, the present invention provides a soft start control method for thyristor rectification, which comprises the following steps:

obtaining phase voltage of the thyristor rectification module;

determining a phase of the phase voltage;

when the phase of the phase voltage is in a preset conduction angle range, controlling the conduction of a corresponding thyristor in the thyristor rectification module, and increasing the conduction angle of the thyristor until the establishment of the bus voltage of the thyristor rectification module is completed; and when the increased conduction angle of the thyristor reaches a preset angle threshold value, the establishment of the bus voltage of the thyristor rectification module is finished.

Optionally, the step of obtaining the phase voltage of the thyristor rectifier module comprises:

collecting the line voltage of alternating current input to the thyristor rectification module;

and obtaining the phase voltage of the thyristor rectification module according to the line voltage.

Optionally, the step of controlling the conduction of the corresponding thyristor in the thyristor rectification module when the phase of the phase voltage is within the preset conduction angle range, and increasing the conduction angle of the thyristor until the establishment of the bus voltage of the thyristor rectification module is completed includes:

when the phase of the phase voltage is in a preset conduction angle range, acquiring the bus voltage of the thyristor rectifier module;

calculating a voltage difference between the line voltage and the bus voltage;

judging whether the voltage difference value is smaller than a preset voltage threshold value or not;

and when the voltage difference value is smaller than the preset voltage threshold, controlling the conduction of a corresponding thyristor in the thyristor rectification module, and increasing the conduction angle of the thyristor until the bus voltage of the thyristor rectification module is established.

Optionally, after the step of determining whether the voltage difference is smaller than a preset voltage threshold, the method further includes:

and when the voltage difference value is larger than the preset voltage threshold value, controlling the corresponding thyristor in the thyristor rectification module to be switched off, and reducing the conduction angle of the thyristor when the switched-off thyristor is switched on next time.

Optionally, the bus voltage of the thyristor rectification module increases as the conduction angle of the thyristor increases.

Optionally, the step of determining the phase of the phase voltages comprises:

counting a count value of the phase voltage between two adjacent zero-crossing points by a counting device;

determining a phase corresponding to a count value of the counting means;

the determined phase is used as the phase of the phase voltage.

Optionally, before the step of counting the count value of the phase voltage between two adjacent zero-crossing points by the counting device, the method further includes:

and performing band-pass filtering processing and low-pass filtering processing on the phase voltage.

Optionally, the thyristor rectification module includes a first phase line, a second phase line, and a third phase line, and the step of controlling the conduction of the corresponding thyristor in the thyristor rectification module and increasing the conduction angle of the thyristor until the bus voltage of the thyristor rectification module is established when the phase of the phase voltage is in the preset conduction angle range includes:

when the phase of the phase voltage of the first phase line is in a preset conduction angle range, controlling the conduction of an upper bridge arm thyristor of the first phase line and a lower bridge arm thyristor of the third phase line, and increasing the conduction angle of the upper bridge arm thyristor of the first phase line and the conduction angle of the lower bridge arm thyristor of the third phase line until the establishment of the bus voltage of the thyristor rectifier module is completed;

when the phase of the phase voltage of the second phase line is in a preset conduction angle range, controlling the conduction of an upper bridge arm thyristor of the second phase line and a lower bridge arm thyristor of the first phase line, and increasing the conduction angle of the upper bridge arm thyristor of the second phase line and the conduction angle of the lower bridge arm thyristor of the first phase line until the establishment of the bus voltage of the thyristor rectifier module is completed;

and when the phase of the phase voltage of the third phase line is in a preset conduction angle range, controlling the conduction of an upper bridge arm thyristor of the third phase line and a lower bridge arm thyristor of the second phase line, and increasing the conduction angle of the upper bridge arm thyristor of the third phase line and the conduction angle of the lower bridge arm thyristor of the second phase line until the establishment of the bus voltage of the thyristor rectifier module is completed.

In order to achieve the above object, the present invention further provides a thyristor rectification soft start control device, where the thyristor rectification soft start control device includes a memory, a processor, and a thyristor rectification soft start control program stored in the memory and operable on the processor, and when the thyristor rectification soft start control program is operated by the processor, the thyristor rectification soft start control device implements the steps of the thyristor rectification soft start control method described above.

In order to achieve the above object, the present invention further provides a storage medium, where the storage medium stores a thyristor rectification soft start control program, and the thyristor rectification soft start control program, when executed by a processor, implements the steps of the thyristor rectification soft start control method according to any one of the above aspects.

According to the technical scheme, the phase voltage of the thyristor rectifier module is obtained firstly, the phase position of the phase voltage is determined, the conduction of the thyristor is controlled through the phase position of the phase voltage, the conduction angle of the transistor is gradually increased until the establishment of the bus voltage is completed, and therefore the bus voltage of the thyristor rectifier module is not required to be established through the soft start circuit, and therefore cost can be saved.

Drawings

Fig. 1 is a schematic structural diagram of an electronic device in a hardware operating environment according to an embodiment of the present invention;

FIG. 2 is a schematic flow chart of an embodiment of a soft start control method for thyristor rectification according to the present invention;

FIG. 3 is a schematic circuit diagram of a thyristor rectifier module in an exemplary embodiment;

FIG. 4 is a detailed flowchart of step S2 in FIG. 2;

fig. 5 is a detailed flowchart of step S3 in fig. 2.

Detailed Description

It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The main solution of the embodiment of the invention is as follows: obtaining phase voltage of the thyristor rectification module; determining a phase of the phase voltage; and when the phase of the phase voltage is in a preset conduction angle range, controlling the conduction of a corresponding thyristor in the thyristor rectification module, and increasing the conduction angle of the thyristor until the establishment of the bus voltage of the thyristor rectification module is completed.

According to the technical scheme, the phase voltage of the thyristor rectifier module is obtained firstly, the phase position of the phase voltage is determined, the conduction of the thyristor is controlled through the phase position of the phase voltage, the conduction angle of the transistor is gradually increased until the establishment of the bus voltage is completed, and therefore the bus voltage of the thyristor rectifier module is not required to be established through the soft start circuit, and therefore cost can be saved.

As an embodiment, the thyristor rectification soft-start control device may be as shown in fig. 1.

The embodiment of the invention relates to a thyristor rectification soft start control device, which comprises: a processor 1001, such as a CPU, a communication bus 1002, and a memory 1003. Wherein a communication bus 1002 is used to enable connective communication between these components.

The memory 1003 may be a high-speed RAM memory or a non-volatile memory (e.g., a disk memory). As shown in fig. 1, the memory 1003, which is a kind of computer storage medium, may include therein a thyristor rectification soft-start control program; and the processor 1001 may be configured to call the thyristor rectification soft start control program stored in the memory 1003, and perform the following operations:

obtaining phase voltage of the thyristor rectification module;

determining a phase of the phase voltage;

when the phase of the phase voltage is in a preset conduction angle range, controlling the conduction of a corresponding thyristor in the thyristor rectification module, and increasing the conduction angle of the thyristor until the establishment of the bus voltage of the thyristor rectification module is completed; and when the increased conduction angle of the thyristor reaches a preset angle threshold value, the establishment of the bus voltage of the thyristor rectification module is finished.

Alternatively, the processor 1001 may be configured to call a thyristor rectification soft start control program stored in the memory 1003, and perform the following operations:

collecting the line voltage of alternating current input to the thyristor rectification module;

and obtaining the phase voltage of the thyristor rectification module according to the line voltage.

Alternatively, the processor 1001 may be configured to call a thyristor rectification soft start control program stored in the memory 1003, and perform the following operations: when the phase of the phase voltage is in a preset conduction angle range, acquiring the bus voltage of the thyristor rectifier module;

calculating a voltage difference between the line voltage and the bus voltage;

judging whether the voltage difference value is smaller than a preset voltage threshold value or not;

and when the voltage difference value is smaller than the preset voltage threshold, controlling the conduction of a corresponding thyristor in the thyristor rectification module, and increasing the conduction angle of the thyristor until the bus voltage of the thyristor rectification module is established.

Alternatively, the processor 1001 may be configured to call a thyristor rectification soft start control program stored in the memory 1003, and perform the following operations: and when the voltage difference value is larger than the preset voltage threshold value, controlling the corresponding thyristor in the thyristor rectification module to be switched off, and reducing the conduction angle of the thyristor when the switched-off thyristor is switched on next time.

Alternatively, the processor 1001 may be configured to call a thyristor rectification soft start control program stored in the memory 1003, and perform the following operations: counting a count value of the phase voltage between two adjacent zero-crossing points by a counting device;

determining a phase corresponding to a count value of the counting means;

the determined phase is used as the phase of the phase voltage.

Alternatively, the processor 1001 may be configured to call a thyristor rectification soft start control program stored in the memory 1003, and perform the following operations:

and performing band-pass filtering processing and low-pass filtering processing on the phase voltage.

Alternatively, the processor 1001 may be configured to call a thyristor rectification soft start control program stored in the memory 1003, and perform the following operations:

when the phase of the phase voltage of the first phase line is in a preset conduction angle range, controlling the conduction of an upper bridge arm thyristor of the first phase line and a lower bridge arm thyristor of the third phase line, and increasing the conduction angle of the upper bridge arm thyristor of the first phase line and the conduction angle of the lower bridge arm thyristor of the third phase line until the establishment of the bus voltage of the thyristor rectifier module is completed;

when the phase of the phase voltage of the second phase line is in a preset conduction angle range, controlling the conduction of an upper bridge arm thyristor of the second phase line and a lower bridge arm thyristor of the first phase line, and increasing the conduction angle of the upper bridge arm thyristor of the second phase line and the conduction angle of the lower bridge arm thyristor of the first phase line until the establishment of the bus voltage of the thyristor rectifier module is completed;

and when the phase of the phase voltage of the third phase line is in a preset conduction angle range, controlling the conduction of an upper bridge arm thyristor of the third phase line and a lower bridge arm thyristor of the second phase line, and increasing the conduction angle of the upper bridge arm thyristor of the third phase line and the conduction angle of the lower bridge arm thyristor of the second phase line until the establishment of the bus voltage of the thyristor rectifier module is completed.

Fig. 2 is a schematic flow chart of an embodiment of a thyristor rectification soft start control method of the invention.

Referring to fig. 2, the thyristor rectification soft start control method comprises the following steps:

step S1, obtaining phase voltage of the thyristor rectification module;

in this embodiment, the thyristor rectification module may be a three-phase full-bridge thyristor rectification module, a three-phase half-bridge thyristor rectification module, a two-phase full-bridge thyristor rectification module, or a two-phase half-bridge thyristor rectification module. For convenience of description, the thyristor rectification module is taken as a three-phase full-bridge thyristor rectification module as an example, the circuit structure of a specific embodiment of the three-phase full-bridge thyristor rectification module is shown in fig. 3, VT 1-VT 6 are thyristors of the three-phase full-bridge thyristor rectification module, U is a bus voltage, and A, B, C are a first phase line, a second phase line and a third phase line of the three-phase full-bridge thyristor rectification module.

In this embodiment, when the system is powered on, three-phase voltages Ua, Ub, and Uc of the three-phase full-bridge thyristor rectification module are obtained first, where the three-phase voltages Ua, Ub, and Uc of the three-phase full-bridge thyristor rectification module may be obtained by calculating line voltages Uab, Ubc, and Uca of alternating current input to the three-phase full-bridge thyristor rectification module.

Specifically, in an alternative embodiment, step S1 includes:

step S11, collecting the line voltage of the alternating current input to the thyristor rectification module;

and step S12, obtaining the phase voltage of the thyristor rectifier module according to the line voltage.

Firstly, sampling line voltages Uab, Ubc and Uca of alternating current input to a three-phase full-bridge thyristor rectification module, wherein the Uab is Ua-Ub; ubc ═ Ub-Uc; uca ═ Uc-Ua; and Uab + Ubc + Uca ═ 0, Ua + Ub + Uc ═ 0. Calculating three-phase voltages Ua, Ub and Uc according to the sampled line voltages Uab, Ubc and Uca, wherein Ua is (Uab-Uca)/3; ub ═ (Ubc-Uab)/3; uc ═ (Uca-Ubc)/3.

Step S2, determining a phase of the phase voltage;

after phase voltages Ua, Ub and Uc of the three-phase full-bridge thyristor rectifier module are obtained, the phase of the three-phase voltage is determined in a mode of determining the phase voltage. Specifically, the phase of the phase voltage Ua, the phase of the phase voltage Ub, and the phase of the phase voltage Uc may be determined by a software phase-locked loop method or a zero-crossing counting method.

Specifically, referring to fig. 4, in an alternative embodiment, step S2 includes:

step S20, performing band-pass filtering and low-pass filtering on the phase voltage;

after three-phase voltages Ua, Ub and Uc of the three-phase full-bridge thyristor rectification module are obtained, band-pass filtering processing is firstly carried out on each phase voltage Ua, Ub and Uc to filter out high-frequency components and direct-current components in the power grid voltage, and the three-phase voltages Ua _ bp, Ub _ bp and Uc _ bp which are subjected to band-pass filtering processing are obtained. Wherein the band-pass filter transfer function is: [ s ([ omega ]/Q) ]/[ s2+ s ([ omega/Q) + omega ]; wherein, ω is the band-pass angular frequency, ω is 2 × pi × f, f is the band-pass frequency, and f can take the value of 50 hz; q is a quality factor. After the three-phase voltages Ua, Ub and Uc are subjected to the band-pass filtering processing, since the band-pass filtering processing has a characteristic of allowing the wave of a specific frequency band to pass while shielding the waves of other frequency bands, the direct-current component and the high-frequency component in the grid voltage are basically attenuated to 0. And then, carrying out low-pass filtering processing on the three-phase voltages Ua _ bp, Ub _ bp and Uc _ bp after the band-pass filtering processing so as to filter high-frequency sawtooth waves and small jump waves in the power grid voltage, thus obtaining the three-phase voltages UaFilt, UbFilt and UcFilt after the low-pass filtering processing, and further improving the anti-interference performance of the power grid for wave generation.

Step S21, counting the count value of the phase voltage between two adjacent zero-crossing points through a counting device;

the counting value of each phase voltage UaFilt, UbFilt, UcFilt between two adjacent zero crossings is calculated by a counting device such as a counter. The phase voltage zero crossing is recorded as the phase voltage zero crossing if the phase voltage is less than 0 for the first time and greater than 0 for the next time, for example, the phase voltage UaFilt is less than 0 at the last time and is greater than 0 at the next time. And starting the counting device to count from 0 when the last phase voltage crosses zero, and controlling the counting device to stop counting when the phase voltage crosses zero once, so as to obtain a count value of the phase voltage between two adjacent zero crossings, namely the count value of the phase voltage in one period.

A step S22 of determining a phase corresponding to the count value of the counting means;

step S23, the determined phase is taken as the phase of the phase voltage.

After the count value of the phase voltage between two adjacent zero-crossing points is obtained, that is, the count value of the phase voltage within one cycle is obtained, the phase of the phase voltage is determined based on the obtained count value. Specifically, the phase corresponding to the count value of the counting device can be determined by a pre-established mapping table of the count value and the phase, and the determined phase is used as the phase of the phase voltage; the phase corresponding to the count value of the counting means can also be determined by the equivalence relation of the single count value and the phase. For example, if the sampling period is 15000s and the grid frequency is 50hz, the cycle count value is 15000/50 300, and the cycle count value 300 corresponds to the phase 360 °, then 1 count value corresponds to the phase 1.2 °. If the count value of the phase voltage between two adjacent zero-crossing points is m, the phase n of the phase voltage is 1.2 × m.

Step S3, when the phase of the phase voltage is in the preset conduction angle range, controlling the conduction of the corresponding thyristor in the thyristor rectification module, and increasing the conduction angle of the thyristor until the establishment of the bus voltage of the thyristor rectification module is completed; and when the increased conduction angle of the thyristor reaches a preset angle threshold value, the establishment of the bus voltage of the thyristor rectification module is finished.

When the phases of the three-phase voltage UaFilt, UbFilt or UcFilt are in the preset conduction angle range, controlling the corresponding thyristors of the thyristor rectification module to be conducted, and increasing the conduction angles of the thyristors when the thyristors are conducted each time until the bus voltage of the three-phase full-bridge thyristor rectification module is established. For example, if the phase of the phase voltage UaFilt of the first phase line a is in the preset conduction angle range, the upper arm thyristor VT1 of the first phase line a and the lower arm thyristor VT2 of the third phase line C are controlled to be conducted, and the conduction angle of the upper arm thyristor VT1 of the first phase line a and the lower arm thyristor VT2 of the third phase line C is increased each time the upper arm thyristor VT1 of the first phase line a and the lower arm thyristor VT2 of the third phase line C are conducted until the bus voltage is established. Namely, the conduction angles of the upper arm thyristor VT1 of the first phase line A and the lower arm thyristor VT2 of the third phase line C are increased at intervals until the bus voltage is established. The predetermined on-angle range is dynamic, and in this embodiment, the predetermined on-angle range is [ (210 ° - Δ θ × N), 210 ° ], where Δ θ is an increased on-angle of the thyristor during each on-state, and N is the number of on-states of the thyristor, and it can be seen that the predetermined on-angle range of the thyristor gradually decreases as the number of on-states of the thyristor increases. Further, since the bus voltage of the thyristor rectification module is increased along with the increase of the conduction angle of the thyristor, when the conduction angle increased by the thyristor reaches the preset angle threshold, it is determined that the establishment of the bus voltage of the three-phase thyristor rectification module is completed. Optionally, when the increased conduction angle Δ θ × N of the thyristor is 120 °, it may be determined that the bus voltage establishment of the three-phase thyristor rectification module is completed. Where Δ θ is determined by the sampling frequency, for example, the Δ θ may be 1 °, 1.2 °, or other angles. And when the bus voltage of the three-phase thyristor rectification module is established, the rectification is finished, and the system enters a normal wave sending process.

That is to say, when the phase of the phase voltage of the three-phase thyristor rectifier module is within the preset conduction angle range, then the corresponding thyristor of the three-phase thyristor rectifier module is controlled to be conducted, and the conduction angle of the thyristor is increased by Δ θ every time the thyristor is conducted, until the bus voltage of the three-phase thyristor rectifier module is established.

Optionally, in an embodiment, step S3 includes:

step S36, when the phase of the phase voltage of the first phase line is in a preset conduction angle range, controlling the conduction of the upper bridge arm thyristor of the first phase line and the lower bridge arm thyristor of the third phase line, and increasing the conduction angle of the upper bridge arm thyristor of the first phase line and the conduction angle of the lower bridge arm thyristor of the third phase line until the establishment of the bus voltage of the thyristor rectifier module is completed;

in this embodiment, the thyristor rectification module is a three-phase full-bridge thyristor rectification module, and the three-phase full-bridge thyristor rectification module includes a first phase line a, a second phase line B, and a third phase line C. When the phase of the phase voltage UaFilt of the first phase line a is in the preset conduction angle range [ (210 ° - Δ θ × N), 210 ° ], the upper arm thyristor VT1 of the first phase line a and the lower arm thyristor VT2 of the third phase line C are conducted, because the first phase line a is just slightly larger than the third phase line C and smaller than the second phase line B in the voltage angle interval, the upper arm thyristor VT1 of the first phase line a and the lower arm thyristor VT2 of the third phase line C are conducted at this time, and a small voltage is charged to the bus. Subsequently, with each conduction, the conduction angle of the upper arm thyristor VT1 of the first phase line a and the lower arm thyristor VT2 of the third phase line C gradually increases from Δ θ, that is, when the upper arm thyristor VT1 of the first phase line a and the lower arm thyristor VT2 of the third phase line C are each conducted, the conduction angle increases by Δ θ, when Δ θ N is 120 degrees, the bus voltage U of the three-phase full-bridge thyristor rectification module is established, the rectification is finished, and the system enters a normal wave-generating flow.

Step S37, when the phase of the phase voltage of the second phase line is in the preset conduction angle range, controlling the conduction of the upper bridge arm thyristor of the second phase line and the lower bridge arm thyristor of the first phase line, and increasing the conduction angle of the upper bridge arm thyristor of the second phase line and the conduction angle of the lower bridge arm thyristor of the first phase line until the establishment of the bus voltage of the thyristor rectifier module is completed;

or when the phase of the phase voltage UbFilt of the second phase line B is in the preset conduction angle range [ (210 ° - Δ θ × N), 210 ° ], the upper arm thyristor VT3 of the second phase line B and the lower arm thyristor VT4 of the first phase line a are conducted, and a small voltage is charged to the bus. Then, with each conduction, the conduction angle of the upper arm thyristor VT3 of the second phase line B and the lower arm thyristor VT4 of the first phase line a gradually increases from Δ θ, that is, when the upper arm thyristor VT3 of the second phase line B and the lower arm thyristor VT4 of the first phase line a are conducted each time, the conduction angle increases by Δ θ, when Δ θ N is 120 degrees, the bus voltage U of the three-phase full-bridge thyristor rectification module is established, the rectification is finished, and the system enters a normal wave-generating flow.

And step S38, when the phase of the phase voltage of the third phase line is in a preset conduction angle range, controlling the conduction of the upper bridge arm thyristor of the third phase line and the lower bridge arm thyristor of the second phase line, and increasing the conduction angle of the upper bridge arm thyristor of the third phase line and the conduction angle of the lower bridge arm thyristor of the second phase line until the bus voltage of the thyristor rectification module is established.

Or, when the phase of the phase voltage UcFilt of the third phase line C is in the preset conduction angle range [ (210 ° - Δ θ × N), 210 ° ], the upper arm thyristor VT5 of the third phase line C and the lower arm thyristor VT6 of the second phase line B are conducted, and the bus is charged with a small voltage. Then, with each conduction, the conduction angle of the upper arm thyristor VT5 of the third phase line C and the lower arm thyristor VT6 of the second phase line B gradually increases from Δ θ, that is, when the upper arm thyristor VT5 of the third phase line C and the lower arm thyristor VT6 of the second phase line B are each conducted, the conduction angle increases by Δ θ, when Δ θ × N is 120 degrees, the bus voltage U of the three-phase full-bridge thyristor rectification module is established, the rectification is finished, and the system enters a normal wave-sending flow.

According to the technical scheme, the phase voltage of the thyristor rectifier module is obtained firstly, the phase position of the phase voltage is determined, the conduction of the thyristor is controlled through the phase position of the phase voltage, the conduction angle of the transistor is gradually increased until the establishment of the bus voltage is completed, and therefore the bus voltage of the thyristor rectifier module is not required to be established through the soft start circuit, and therefore the system cost can be saved.

Referring to fig. 5, in one embodiment, step S3 includes:

step S31, when the phase of the phase voltage is in a preset conduction angle range, acquiring the bus voltage of the thyristor rectification module;

in practical application, during the system soft start, if the grid voltage suddenly changes, the soft start overcurrent can be caused to damage the thyristor. Therefore, in order to avoid damaging the thyristor, when the phase of the phase voltage of the thyristor rectifier module is in the preset conduction angle range, the corresponding thyristor is not controlled to be conducted, and the bus voltage U of the current thyristor rectifier module is sampled.

Step S32, calculating a voltage difference value between the line voltage and the bus voltage;

step S33, judging whether the voltage difference value is smaller than a preset voltage threshold value;

and then, calculating a voltage difference value between the line voltage and the bus voltage to judge whether the voltage difference value between the line voltage and the bus voltage exceeds a preset voltage threshold value or not and whether a protection mechanism needs to be started or not.

And step S34, when the voltage difference value is smaller than the preset voltage threshold value, controlling the corresponding thyristor in the thyristor rectification module to be conducted, and increasing the conduction angle of the thyristor until the bus voltage of the thyristor rectification module is established.

If the voltage difference value between the line voltage and the bus voltage is smaller than the preset voltage threshold, controlling the corresponding thyristor in the thyristor rectification module to be conducted, and increasing the conduction angle of the thyristor until the bus voltage is established when the corresponding thyristor is conducted every time. For example, before the upper arm thyristor VT1 of the first phase line a and the lower arm thyristor VT2 of the third phase line C are turned on, the voltage difference between the line voltage Uac and the bus voltage U at this time is determined, and when the voltage difference between the line voltage Uac and the bus voltage U is smaller than a preset voltage threshold, for example, smaller than 50V, the upper arm thyristor VT1 of the first phase line a and the lower arm thyristor VT2 of the third phase line C are controlled to be turned on. For another example, before the upper arm thyristor VT3 of the second phase line B and the lower arm thyristor VT4 of the first phase line a, the voltage difference between the line voltage Uba and the bus voltage U at this time is determined, and when the voltage difference between the line voltage Uba and the bus voltage U is smaller than the preset voltage threshold, the upper arm thyristor VT3 of the second phase line B and the lower arm thyristor VT4 of the first phase line a are controlled to be turned on; for another example, before the upper arm thyristor VT5 of the third phase line C and the lower arm thyristor VT6 of the second phase line B are turned on, the voltage difference between the line voltage Ucb and the bus voltage U at this time is determined, and when the voltage difference between the line voltage Ucb and the bus voltage U is smaller than the preset voltage threshold, the upper arm thyristor VT5 of the third phase line C and the lower arm thyristor VT6 of the second phase line B are controlled to be turned on.

And step S35, when the voltage difference value is greater than the preset voltage threshold value, controlling the corresponding thyristor in the thyristor rectification module to be turned off, and reducing the conduction angle of the thyristor when the turned-off thyristor is turned on next time.

If the voltage difference value between the line voltage and the bus voltage is greater than the preset voltage threshold value, the grid voltage is considered to be suddenly changed, then the thyristor which is supposed to be conducted in the thyristor rectification module at this time maintains the turn-off state, and the conduction angle of the thyristor is controlled to be reduced when the thyristor is conducted next time, so that the situation that the grid voltage is continuously far greater than the bus voltage, and the soft start is unsuccessful is avoided. For example, before the upper arm thyristor VT1 of the first phase line a and the lower arm thyristor VT2 of the third phase line C are turned on, the voltage difference between the line voltage Uac and the bus voltage U at this time is determined, when the voltage difference between the line voltage Uac and the bus voltage U is greater than the preset voltage threshold, the upper arm thyristor VT1 of the first phase line a and the lower arm thyristor VT2 of the third phase line C are controlled not to be turned on, and when the upper arm thyristor VT1 of the first phase line a and the lower arm thyristor VT2 of the third phase line C are turned on next time, the conduction angles of the upper arm thyristor VT1 of the first phase line a and the lower arm thyristor VT2 of the third phase line C are reduced. For another example, before the upper arm thyristor VT3 of the second phase line B and the lower arm thyristor VT4 of the first phase line a are turned on, the voltage difference between the line voltage Uba and the bus voltage U at this time is determined, when the voltage difference between the line voltage Uba and the bus voltage U is greater than the preset voltage threshold, the upper arm thyristor VT3 of the second phase line B and the lower arm thyristor VT4 of the first phase line a are controlled not to be turned on, and when the upper arm thyristor VT3 of the second phase line B and the lower arm thyristor VT4 of the first phase line a are turned on next time, the conduction angles of the upper arm thyristor VT3 of the second phase line B and the lower arm thyristor VT4 of the first phase line a are reduced; for another example, before the upper arm thyristor VT5 of the third phase line C and the lower arm thyristor VT6 of the second phase line B are turned on, the voltage difference between the line voltage Ucb and the bus voltage U at this time is determined, when the voltage difference between the line voltage Ucb and the bus voltage U is greater than the preset voltage threshold, the upper arm thyristor VT5 of the third phase line C and the lower arm thyristor VT6 of the second phase line B are controlled not to be turned on, and when the upper arm thyristor VT5 of the third phase line C and the lower arm thyristor VT6 of the second phase line B are turned on next time, the conduction angle between the upper arm thyristor VT5 of the third phase line C and the lower arm thyristor VT6 of the second phase line B is reduced. By the arrangement, the thyristor is subjected to wave sealing treatment when the voltage of the power grid jumps, so that the situation that the voltage of the power grid line is far larger than the voltage of a bus all the time to cause unsuccessful soft start can be avoided.

The invention also provides a thyristor rectification soft start control device which comprises a memory, a processor and a thyristor rectification soft start control program which is stored on the memory and can be operated on the processor, wherein when the thyristor rectification soft start control program is operated by the processor, each step of the thyristor rectification soft start control method is realized.

The invention also provides a storage medium, wherein the storage medium is stored with a thyristor rectification soft start control program, and the thyristor rectification soft start control program realizes each step of the thyristor rectification soft start control method when being executed by a processor.

The above description is only an alternative embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications and equivalents that can be made by the present invention through the use of the contents of the specification and the drawings or directly/indirectly applied to other related technical fields are included in the scope of the present invention.