CN117879415B

CN117879415B - Excitation control device and method and electronic equipment

Info

Publication number: CN117879415B
Application number: CN202410052569.6A
Authority: CN
Inventors: 阳清风; 谢连忠; 李�根; 杨立强
Original assignee: Beijing Kedian Yiheng Electric Power Technology Co ltd
Current assignee: Beijing Kedian Yiheng Electric Power Technology Co ltd
Priority date: 2024-01-13
Filing date: 2024-01-13
Publication date: 2024-07-23
Anticipated expiration: 2044-01-13
Also published as: CN117879415A

Abstract

The application provides an excitation control device, an excitation control method and electronic equipment, and relates to the technical field of power systems, wherein the device comprises: the device comprises a three-phase transformer, a phase shifting unit, a voltage comparing unit and a pulse trigger, wherein the phase shifting unit carries out phase shifting treatment on a three-phase input voltage signal to obtain a target phase shifting signal, and the frequency of the three-phase input voltage signal is in a wide frequency range including 50 Hz; the voltage comparison unit is used for carrying out zero crossing point comparison on the target phase-shifting signal to obtain a synchronous square wave signal; and generating a target pulse trigger signal according to the synchronous square wave signal to trigger and control the thyristor in the three-phase full-control rectifier, wherein the target pulse trigger signal is obtained by taking the turning moment of the synchronous square wave signal as a starting point and delaying a preset angle, and the preset angle is equal to the sum of a theoretical trigger angle and a target compensation angle. By implementing the technical scheme provided by the application, the technical problem of poor applicability of the excitation control circuit in the related technology is solved.

Description

Excitation control device and method and electronic equipment

Technical Field

The application relates to the technical field of power systems, in particular to an excitation control device, an excitation control method and electronic equipment.

Background

In general, the large-sized hydraulic generator generates electricity after the generator reaches the rated rotation speed, and the frequency of the grid-connected generator set in China is 50Hz. The generator is generally a self-shunt excitation generator, an excitation power supply for providing magnetic field current for a rotor winding is taken from a generator end, namely, after the voltage of the generator end is reduced by an excitation transformer, the three-phase thyristor rectifier bridge provides excitation current for the rotor winding, the generator rotor is an inductive load, serious voltage distortion can be generated during three-phase rectification, and the thyristor rectification triggering is realized by taking a line voltage zero crossing point as a triggering angle starting point, so that voltage interference generated by the thyristor commutation is required to be filtered, and three-phase alternating voltage (also called synchronous voltage) is subjected to low-pass filtering.

The control of the excitation voltage of the generator is controlled by adopting a formula U _d＝1.35U_L cos alpha, U _d is the excitation voltage, U _L is the voltage of a three-phase excitation power line, U _L is 2 times the rated excitation voltage of the generator, the limiting requirement of an excitation system on the trigger angle alpha is 20-150 degrees, in the related art, a two-stage second-order low-pass filter is generally adopted in a trigger circuit, the two-stage second-order low-pass filter is shifted 180 degrees at 50Hz and is exactly overlapped with the original waveform in the opposite direction, and the zero crossing point is exactly used as the starting point of the trigger angle. But the circuit can only trigger correctly at 50Hz, when the frequency is not 50Hz, the zero crossing point is subjected to phase shift, so that the trigger angle is changed, and when the synchronous square wave signals at the generator frequencies of 30Hz, 50Hz and 85Hz are related to the input voltage signals, the relation between the synchronous square wave signals and the input voltage signals is shown in figures 1, 2 and 3. Therefore, the excitation control circuit in the related art is only suitable for 50Hz, but is not suitable for input voltage signals with other frequencies, i.e. the excitation control circuit in the related art has poor applicability, and is not suitable for input voltage signals with a wide frequency range.

Aiming at the technical problem of poor applicability of an excitation control circuit in the related art, no effective solution is proposed at present.

Disclosure of Invention

The application provides an excitation control device, an excitation control method and electronic equipment, which at least solve the technical problem of poor applicability of an excitation control circuit in the related technology.

In a first aspect, the present application provides an excitation control device including: the three-phase transformer is connected with the input end of the three-phase transformer, the output end of the three-phase transformer is electrically connected with the input end of the phase shifting unit, the phase shifting unit is used for carrying out phase shifting treatment on the three-phase input voltage signals to obtain target phase shifting signals, the frequency of the three-phase input voltage signals is larger than or equal to a first frequency threshold value and smaller than or equal to a second frequency threshold value, the first frequency threshold value is smaller than 50Hz, the second frequency threshold value is larger than 50Hz, and the phase difference between the target phase shifting signals and the three-phase input voltage signals is in the range of 100-140 degrees; the output end of the phase shifting unit is electrically connected with the input end of the voltage comparison unit, and the voltage comparison unit is used for carrying out zero crossing point comparison on the target phase shifting signal to obtain a synchronous square wave signal; the input end of the pulse trigger is electrically connected with the output end of the voltage comparison unit, the pulse trigger is used for generating a target pulse trigger signal according to the synchronous square wave signal and carrying out pulse trigger control on the thyristor in the three-phase fully-controlled rectifier based on the target pulse trigger signal, wherein the target pulse trigger signal is obtained by taking the turning moment of the synchronous square wave signal as a starting point and delaying a preset angle, the preset angle is equal to the sum of a theoretical trigger angle and a target compensation angle, the target compensation angle is determined based on a pre-established compensation phase table, the compensation phase table comprises the corresponding relation between the frequency of an input voltage signal and the compensation angle, and the theoretical trigger angle is the trigger angle determined by the excitation system according to the voltage of the generator end.

By adopting the technical scheme, the excitation control device comprises a three-phase transformer, a phase shifting unit, a voltage comparison unit and a pulse trigger, wherein the phase shifting unit carries out phase shifting treatment on a three-phase input voltage signal to obtain a target phase shifting signal, the phase difference between the target phase shifting signal and the three-phase input voltage signal is within the range of 100-140 degrees, the frequency of the three-phase input voltage signal is between a first frequency threshold value and a second frequency threshold value, namely the frequency of the input voltage signal can be in a wider frequency range including 50 Hz; and then, carrying out zero crossing point comparison on the target phase-shifting signal through a voltage comparison unit to obtain a synchronous square wave signal, generating a target pulse trigger signal by a pulse trigger according to the synchronous square wave signal, wherein the target pulse trigger signal is obtained by taking the turning moment of the synchronous square wave signal as a starting point and delaying a preset angle, the preset angle is equal to the sum of a theoretical trigger angle and a target compensation angle, namely, the preset angle is an actual trigger angle, so that the error of the actual trigger angle is controlled within a small range, and then, carrying out pulse trigger control on a thyristor in the three-phase full-control rectifier based on the target pulse trigger signal. The problem that the generator cannot normally operate when the frequency of the input voltage signal is smaller than 50Hz or larger than 50Hz, such as 30Hz or 85Hz, in the related art is avoided, the technical problem that the applicability of the excitation control circuit is poor in the related art is solved, and the effect of expanding the application range of the excitation system is achieved.

Optionally, the primary side and the secondary side of the three-phase transformer are all in star connection, the phase shifting unit comprises a first phase shifter, a second phase shifter and a third phase shifter, wherein the input end of the first phase shifter is electrically connected with the first phase output end of the three-phase transformer, the first phase shifter is used for performing phase shifting treatment on an input voltage signal UAB to obtain a first phase shifting signal, the input end of the second phase shifter is electrically connected with the second phase output end of the three-phase transformer, the second phase shifter is used for performing phase shifting treatment on an input voltage signal UBC to obtain a second phase shifting signal, the input end of the third phase shifter is electrically connected with the third phase output end of the three-phase transformer, the third phase shifter is used for performing phase shifting treatment on an input voltage signal UCA to obtain a third phase shifting signal, and the target phase shifting signal comprises the first phase shifting signal, the second phase shifting signal and the third phase shifting signal; the voltage comparison unit comprises a first comparator, a second comparator and a third comparator, wherein the inverting input end of the first comparator is electrically connected with the output end of the first phase shifter, the inverting input end of the second comparator is electrically connected with the output end of the second phase shifter, the inverting input end of the third comparator is electrically connected with the output end of the third phase shifter, the first comparator is used for carrying out zero-crossing comparison on the first phase-shifting signal to obtain a first square wave signal, the second comparator is used for carrying out zero-crossing comparison on the second phase-shifting signal to obtain a second square wave signal, the third comparator is used for carrying out zero-crossing comparison on the third phase-shifting signal to obtain a third square wave signal, and the synchronous square wave signal comprises the first square wave signal, the second square wave signal and the third square wave signal.

By adopting the technical scheme, the primary side and the secondary side of the three-phase transformer are in a star connection mode, wherein three output ends of the secondary side respectively correspond to one phase shifter, namely three phase shifters are arranged, each phase shifter respectively carries out phase shifting treatment on one input voltage signal, for example, a first phase shifter carries out phase shifting treatment on an input voltage signal UAB to obtain a first phase shifting signal, a second phase shifter carries out phase shifting treatment on an input voltage signal UBC to obtain a second phase shifting signal, and a third phase shifter carries out phase shifting treatment on an input voltage signal UCA to obtain a third phase shifting signal; the output end of each phase shifter is respectively connected with a corresponding comparator, namely a voltage comparator, and the first phase-shifting signal, the second phase-shifting signal and the third phase-shifting signal are respectively subjected to zero crossing comparison, namely zero voltage comparison, so that corresponding first square wave signals, second square wave signals and third square wave signals are obtained, the aim of obtaining synchronous square wave signals is fulfilled, and corresponding pulse triggering signals can be obtained accordingly, so that the thyristor in the three-phase fully-controlled rectifier is subjected to pulse triggering control.

Optionally, the pulse trigger is electrically connected with the output end of the first comparator, the output end of the second comparator and the output end of the third comparator, wherein the pulse trigger generates a first pulse trigger signal according to the first square wave signal, the pulse trigger generates a second pulse trigger signal according to the second square wave signal, the pulse trigger generates a third pulse trigger signal according to the third square wave signal, the target pulse trigger signal comprises a first pulse trigger signal, a second pulse trigger signal and a third pulse trigger signal, the first pulse trigger signal is obtained by taking the turning moment of the first square wave signal as a starting point and delaying a preset angle, the second pulse trigger signal is obtained by taking the turning moment of the second square wave signal as a starting point and delaying the preset angle, and the third pulse trigger signal is obtained by taking the turning moment of the third square wave signal as a starting point and delaying the preset angle.

By adopting the technical scheme, the pulse trigger is respectively and electrically connected with the first comparator, the second comparator and the third comparator, generates a first pulse trigger signal according to the first square wave signal, generates a second pulse trigger signal according to the second square wave signal and generates a third pulse trigger signal according to the third square wave signal, and then three paths of pulse trigger signals are obtained, wherein each path of pulse trigger signal is obtained by taking the turning moment of the corresponding square wave signal as a starting point and delaying the turning moment of the corresponding square wave signal by a preset angle, the turning moment of the square wave signal is the starting moment of the trigger angle, and then the pulse trigger is controlled after the preset angle is delayed, so that the actual trigger angle error is controlled within a small range.

Optionally, the first phase shifter, the second phase shifter and the third phase shifter are each composed of a first-stage second-order low-pass filter, a phase difference between the first phase-shifted signal and the input voltage signal UAB is in a range of 100 ° to 140 °, a phase difference between the second phase-shifted signal and the input voltage signal UBC is in a range of 100 ° to 140 °, and a phase difference between the third phase-shifted signal and the input voltage signal UCA is in a range of 100 ° to 140 °.

By adopting the technical scheme, the first phase shifter, the second phase shifter and the third phase shifter are all composed of the first-stage second-order low-pass filter, the phase difference is enabled to be in the range of 100-140 degrees through the phase shifter, phase shifting signals obtained after phase shifting, such as the first phase shifting signal, the second phase shifting signal and the third phase shifting signal, coincide with or are close to other input line voltage signals, and then the target compensation angle is used for compensation, so that the final trigger angle error is controlled within the range of +/-1 degree. Compared with the scheme that a two-stage second-order low-pass filter is generally adopted in the related art to shift the phase of 50Hz by 180 degrees, the technical scheme can achieve the aim of reliably exciting the generator in a wide frequency range and can also achieve the aim of saving the design cost of a circuit.

Optionally, the first phase shifter includes a first resistor, a second resistor, a third resistor, a first capacitor, a second capacitor and a first operational amplifier, where a first end of the first resistor is electrically connected to a first phase output end of a secondary side of the three-phase transformer, a second end of the first resistor is connected to a first end of the second resistor, a second end of the second resistor is connected to an inverting input end of the first operational amplifier, common ends of a non-inverting input end of the first operational amplifier and the secondary side of the three-phase transformer are both connected to a ground end, the third resistor is connected between the second end of the first resistor and an output end of the first operational amplifier, the first capacitor is connected between the inverting input end of the first operational amplifier and the output end of the first operational amplifier, and the second capacitor is connected between the second end of the first resistor and the ground end; the second phase shifter comprises a fourth resistor, a fifth resistor, a sixth resistor, a third capacitor, a fourth capacitor and a second operational amplifier, wherein the first end of the fourth resistor is electrically connected with the second phase output end of the secondary side of the three-phase transformer, the second end of the fourth resistor is connected with the first end of the fifth resistor, the second end of the fifth resistor is connected with the inverting input end of the second operational amplifier, the common end of the non-inverting input end of the second operational amplifier and the secondary side of the three-phase transformer is connected with the grounding end, the sixth resistor is connected between the second end of the fourth resistor and the output end of the second operational amplifier, the third capacitor is connected between the inverting input end of the second operational amplifier and the output end of the second operational amplifier, and the fourth capacitor is connected between the second end of the fourth resistor and the grounding end; the third phase shifter comprises a seventh resistor, an eighth resistor, a ninth resistor, a fifth capacitor, a sixth capacitor and a third operational amplifier, wherein the first end of the seventh resistor is electrically connected with the third phase output end of the secondary side of the three-phase transformer, the second end of the seventh resistor is connected with the first end of the eighth resistor, the second end of the eighth resistor is connected with the inverting input end of the third operational amplifier, the non-inverting input end of the third operational amplifier and the common end of the secondary side of the three-phase transformer are both connected with the ground end, the ninth resistor is connected between the second end of the seventh resistor and the output end of the third operational amplifier, the fifth capacitor is connected between the inverting input end of the third operational amplifier and the output end of the third operational amplifier, and the sixth capacitor is connected between the second end of the seventh resistor and the ground end.

By adopting the technical scheme, the three-way phase shifter adopts the same circuit design scheme, so that the output signal is more stable, and the aim of effectively reducing noise interference is fulfilled.

In a second aspect of the present application, there is also provided an excitation control method applied to any one of the excitation control devices described above, including: carrying out phase shifting treatment on three-phase input voltage signals of a three-phase transformer to obtain target phase shifting signals, wherein the frequency of the three-phase input voltage signals is larger than or equal to a first frequency threshold value and smaller than or equal to a second frequency threshold value, the first frequency threshold value is smaller than 50Hz, the second frequency threshold value is larger than 50Hz, and the phase difference between the target phase shifting signals and the three-phase input voltage signals is within the range of 100-140 degrees; zero crossing point comparison is carried out on the target phase-shifting signal, and a synchronous square wave signal is obtained; generating a target pulse trigger signal according to the synchronous square wave signal, wherein the target pulse trigger signal is obtained by taking the turning moment of the synchronous square wave signal as a starting point and delaying a preset angle, the preset angle is equal to the sum of a theoretical trigger angle and a target compensation angle, the target compensation angle is determined based on a pre-established compensation phase table, the compensation phase table comprises a corresponding relation between the frequency of an input voltage signal and the compensation angle, and the theoretical trigger angle is a trigger angle determined by an excitation system according to the voltage of a generator terminal; and performing pulse triggering control on the thyristor in the three-phase full-control rectifier based on the target pulse triggering signal.

By adopting the technical scheme, the three-phase input voltage signal is subjected to phase shifting treatment to obtain the target phase shifting signal, wherein the phase difference between the target phase shifting signal and the three-phase input voltage signal is in the range of 100-140 degrees, and the frequency of the three-phase input voltage signal is between a first frequency threshold value and a second frequency threshold value, namely the frequency of the input voltage signal can be in a wider frequency range including 50 Hz; and then carrying out zero crossing point comparison on the target phase-shifting signal to obtain a synchronous square wave signal, and then generating a target pulse trigger signal according to the synchronous square wave signal, wherein the target pulse trigger signal is obtained by taking the turning moment of the synchronous square wave signal as a starting point and delaying a preset angle, the preset angle is equal to the sum of a theoretical trigger angle and a target compensation angle, namely the preset angle is an actual trigger angle, so that the error of the actual trigger angle is controlled within a small range, and then carrying out pulse trigger control on a thyristor in the three-phase fully-controlled rectifier based on the target pulse trigger signal. The problem that the generator cannot normally operate when the frequency of the input voltage signal is smaller than 50Hz or larger than 50Hz, such as 30Hz or 85Hz, in the related art is avoided, the technical problem that the applicability of the excitation control circuit is poor in the related art is solved, and the effect of expanding the application range of the excitation system is achieved.

Optionally, generating the target pulse trigger signal according to the synchronous square wave signal includes: determining a target compensation angle corresponding to the frequency of the three-phase input voltage signal; determining the sum of the target compensation angle and the theoretical trigger angle as a preset angle; and delaying a preset angle by taking the zero crossing point of the synchronous square wave signal as a starting point to obtain a target pulse trigger signal.

By adopting the technical scheme, the target compensation angle corresponding to the frequency of the three-phase input voltage signal is determined, namely, the different frequencies have corresponding compensation angles, the sum of the target compensation angle and the theoretical trigger angle is determined to be a preset angle, namely, the sum of the target compensation angle and the theoretical trigger angle is taken as an actual trigger angle, then, the zero crossing point of the synchronous square wave signal is taken as a starting point to delay the preset angle to obtain a target pulse trigger signal, or the turning moment of the synchronous square wave signal is taken as the starting point to delay the preset angle to obtain the target pulse trigger signal. The aim of obtaining a target pulse trigger signal for controlling the pulse trigger of the controllable silicon of the three-phase full-control rectifier according to the synchronous square wave signal is achieved.

Optionally, determining a target compensation angle corresponding to a frequency of the three-phase input voltage signal includes one of: in the case where the frequency of the three-phase input voltage signal is less than 50Hz, the target compensation angle is determined according to the following formula: θ= (50.16-f) ×0.575, where θ is a target compensation angle, and f is a frequency of the three-phase input voltage signal; in the case where the frequency of the three-phase input voltage signal is greater than 50Hz, the target compensation angle is determined according to the following formula: θ= (50.16-f) ×0.525, where θ is the target compensation angle and f is the frequency of the three-phase input voltage signal.

By adopting the technical scheme, the target compensation angle is calculated by adopting a corresponding calculation formula according to the frequencies of different input voltage signals, namely the phase difference is compensated, and when the frequency of the three-phase input voltage signals is equal to 50Hz, the target compensation angle is not calculated, namely the compensation is not needed. According to the difference of the frequency of the input voltage signal, the purpose of the corresponding target compensation angle can be determined.

Optionally, before determining the target compensation angle corresponding to the frequency of the three-phase input voltage signal, the method further comprises: and establishing a compensation phase table, wherein the compensation phase table comprises the corresponding relation between the frequencies of different input voltage signals and the compensation angles.

By adopting the technical scheme, the compensation phase table can be established in advance, so that the compensation angle corresponding to the frequency of the input voltage signal can be rapidly determined, and the corresponding pulse trigger signal can be accurately obtained.

In a third aspect of the application there is also provided an electronic device comprising a memory and a processor, the memory having stored thereon a computer program, the processor performing the method steps of any of the above when the program is executed.

In a fourth aspect of the application, there is also provided a computer readable storage medium storing instructions that, when executed, perform the method steps of any of the above.

In summary, one or more technical solutions provided in the embodiments of the present application at least have the following technical effects or advantages:

1. the problem that the generator cannot normally operate when the frequency of the input voltage signal is smaller than 50Hz or larger than 50Hz in the related art is avoided, the technical problem that the applicability of an excitation control circuit is poor in the related art is solved, and the effect of expanding the application range of an excitation system is achieved.

2. Compared with the scheme that a two-stage second-order low-pass filter is generally adopted in the related art to shift the phase of 50Hz by 180 degrees, the technical scheme can achieve the aim of reliably exciting the generator in a wide frequency range and can also achieve the aim of saving the design cost of a circuit.

Drawings

FIG. 1 is a diagram of a synchronous square wave signal and input voltage waveform at 50Hz in the related art;

FIG. 2 is a diagram of a waveform of a synchronous square wave signal and an input voltage at 30Hz in the related art;

FIG. 3 is a diagram of a synchronous square wave signal and input voltage waveform at 85Hz in the related art;

Fig. 4 is a block diagram of an excitation control device according to an embodiment of the present application;

fig. 5 is a block diagram II of an excitation control device according to an embodiment of the present application;

Fig. 6 is a schematic flow chart of an excitation control method according to an embodiment of the present application;

FIG. 7 is a schematic diagram of a low-pass filter circuit with low phase shift according to an embodiment of the present application;

FIG. 8 is a schematic diagram of a simulation of an input voltage UAB and an output voltage UTAB at 50Hz provided by an embodiment of the present application;

FIG. 9 is a schematic diagram of a simulation of an input voltage UAB and a synchronous square wave signal at 50Hz provided by an embodiment of the present application;

FIG. 10 is a schematic diagram of simulation of an input voltage UAB and a synchronous square wave signal at 30Hz provided by an embodiment of the present application;

FIG. 11 is a schematic diagram of a simulation of an input voltage UAB and a synchronous square wave signal at 85Hz provided by an embodiment of the present application;

FIG. 12 is a schematic diagram of a three-phase fully controlled rectifier circuit;

FIG. 13 is a schematic diagram of the actual trigger effect at 30Hz provided by an embodiment of the present application;

FIG. 14 is a schematic diagram of the actual trigger effect at 50Hz provided by an embodiment of the present application;

FIG. 15 is a schematic diagram of an actual trigger effect at 85Hz provided by an embodiment of the present application;

fig. 16 is a schematic structural view of an electronic device according to the disclosure of an embodiment of the present application.

Reference numerals illustrate: 1600-electronic device, 1601-processor, 1602-communication bus, 1603-user interface, 1604-network interface, 1605-memory.

Detailed Description

In order that those skilled in the art will better understand the technical solutions in the present specification, the technical solutions in the embodiments of the present specification will be clearly and completely described below with reference to the drawings in the embodiments of the present specification, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments.

In describing embodiments of the present application, words such as "for example" or "for example" are used to mean serving as examples, illustrations, or descriptions. Any embodiment or design described herein as "such as" or "for example" in embodiments of the application should not be construed as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "or" for example "is intended to present related concepts in a concrete fashion.

In the description of embodiments of the application, the term "plurality" means two or more. For example, a plurality of systems means two or more systems, and a plurality of screen terminals means two or more screen terminals. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating an indicated technical feature. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless expressly specified otherwise.

As can be seen from fig. 2 and 3, in the related art, when the frequency of the input voltage signal is 30Hz, the synchronous square wave signal advances the input voltage by 74 ° and when the input voltage signal is triggered by 20 °, the thyristor is under the reverse voltage, the thyristor is not conductive, and when the input voltage signal is triggered by 150 °, the actual trigger angle is 76 °, and the trigger angle is smaller than the trigger angle (generally 83 °) for establishing the rated voltage, which may cause serious overvoltage of the generator; when the frequency of the input voltage signal is 85Hz, the synchronous square wave signal lags the input voltage by 75 degrees, even if the minimum trigger angle is 20 degrees, the actual trigger angle is 95 degrees, and the generator voltage cannot be established in an inversion state.

In the related art, the generator is generally configured with low-frequency and high-frequency protection, and the generator excitation is stopped when the frequency is lower than or higher than 50Hz, so that the generator safety is ensured. However, in order to maintain the power supply of the system in the isolated network system, the excitation is required to reliably operate within the range of 30 Hz-85 Hz of the generator frequency, and the filter circuit is not applicable any more. As can be seen, the excitation control circuit in the related art has poor applicability and cannot be applied to input voltage signals in a wide frequency range. The embodiment of the application aims to provide a scheme which can safely and stably operate at the generator frequency of 30-85 Hz.

The application provides an excitation control device, referring to fig. 4, fig. 4 is a block diagram of an excitation control device according to an embodiment of the application, where the excitation control device includes: a three-phase transformer, a phase shifting unit, a voltage comparing unit and a pulse trigger, wherein,

The input end of the three-phase transformer is connected with a three-phase input voltage signal, the output end of the three-phase transformer is electrically connected with the input end of the phase shifting unit, the phase shifting unit is used for carrying out phase shifting treatment on the three-phase input voltage signal to obtain a target phase shifting signal, wherein the frequency of the three-phase input voltage signal is larger than or equal to a first frequency threshold value and smaller than or equal to a second frequency threshold value, the first frequency threshold value is smaller than 50Hz, the second frequency threshold value is larger than 50Hz, and the phase difference between the target phase shifting signal and the three-phase input voltage signal is within the range of 100-140 degrees;

The output end of the phase shifting unit is electrically connected with the input end of the voltage comparison unit, and the voltage comparison unit is used for carrying out zero crossing point comparison on the target phase shifting signal to obtain a synchronous square wave signal;

The input end of the pulse trigger is electrically connected with the output end of the voltage comparison unit, the pulse trigger is used for generating a target pulse trigger signal according to the synchronous square wave signal and carrying out pulse trigger control on the thyristor in the three-phase fully-controlled rectifier based on the target pulse trigger signal, wherein the target pulse trigger signal is obtained by taking the turning moment of the synchronous square wave signal as a starting point and delaying a preset angle, the preset angle is equal to the sum of a theoretical trigger angle and a target compensation angle, the target compensation angle is determined based on a pre-established compensation phase table, the compensation phase table comprises the corresponding relation between the frequency of an input voltage signal and the compensation angle, and the theoretical trigger angle is the trigger angle determined by the excitation system according to the voltage of the generator end.

In the above embodiment, the excitation control device includes a three-phase transformer, a phase shifting unit, a voltage comparing unit and a pulse trigger, where the phase shifting unit performs a phase shifting process on a three-phase input voltage signal to obtain a target phase shifting signal, a phase difference between the target phase shifting signal and the three-phase input voltage signal is in a range of 100 ° to 140 °, and a frequency of the three-phase input voltage signal is between a first frequency threshold and a second frequency threshold, that is, the frequency of the input voltage signal may be in a wider frequency range including 50Hz, for example, the first frequency threshold is 30Hz (or 35Hz, or 40Hz, or other frequencies), and the second frequency threshold is 85Hz (or 80Hz, or 70Hz, or other frequencies); the voltage comparison unit is a zero voltage comparator, and the pulse trigger generates a target pulse trigger signal according to the synchronous square wave signal, wherein the target pulse trigger signal is obtained by taking the turning moment of the synchronous square wave signal as a starting point and delaying a preset angle, the preset angle is equal to the sum of a theoretical trigger angle and a target compensation angle, namely the preset angle is an actual trigger angle, the theoretical trigger angle is determined by an excitation system according to the generator terminal voltage, or the trigger angle calculated according to a calculation formula is the target trigger angle obtained by carrying out phase difference compensation on the target phase-shifting signal obtained after the phase shifting treatment, so that the actual trigger angle error is controlled within a small range, and then pulse trigger control is carried out on a thyristor in the three-phase fully-controlled rectifier based on the target pulse trigger signal, for example, the theoretical trigger angle is equal to 20 DEG is taken as an illustration, when the frequency of an input voltage signal is 30Hz, the corresponding target compensation angle is 11.59 DEG, and the preset angle is 20 DEG+ 11.59 DEG 31.59 DEG; when the frequency of the input voltage signal is 85Hz, the corresponding target compensation angle is-18.29 degrees, the preset angle is 20-18.29 degrees=1.71 degrees, and different frequencies have corresponding compensation angles. The problem that the generator cannot normally operate when the frequency of the input voltage signal is smaller than 50Hz or larger than 50Hz, such as 30Hz or 85Hz or other frequencies in the related art is avoided, the technical problem that the applicability of the excitation control circuit in the related art is poor is solved, and the effect of expanding the application range of the excitation system is achieved.

In an alternative embodiment, both the primary side and the secondary side of the three-phase transformer adopt a star connection mode, the phase shifting unit comprises a first phase shifter, a second phase shifter and a third phase shifter, wherein the input end of the first phase shifter is electrically connected with the first phase output end of the three-phase transformer, the first phase shifter is used for carrying out phase shifting treatment on an input voltage signal UAB to obtain a first phase shifting signal, the input end of the second phase shifter is electrically connected with the second phase output end of the three-phase transformer, the second phase shifter is used for carrying out phase shifting treatment on the input voltage signal UBC to obtain a second phase shifting signal, the input end of the third phase shifter is electrically connected with the third phase output end of the three-phase transformer, the third phase shifter is used for carrying out phase shifting treatment on the input voltage signal UCA to obtain a third phase shifting signal, and the target phase shifting signal comprises the first phase shifting signal, the second phase shifting signal and the third phase shifting signal; the voltage comparison unit comprises a first comparator, a second comparator and a third comparator, wherein the inverting input end of the first comparator is electrically connected with the output end of the first phase shifter, the inverting input end of the second comparator is electrically connected with the output end of the second phase shifter, the inverting input end of the third comparator is electrically connected with the output end of the third phase shifter, the first comparator is used for carrying out zero-crossing comparison on the first phase-shifting signal to obtain a first square wave signal, the second comparator is used for carrying out zero-crossing comparison on the second phase-shifting signal to obtain a second square wave signal, the third comparator is used for carrying out zero-crossing comparison on the third phase-shifting signal to obtain a third square wave signal, and the synchronous square wave signal comprises the first square wave signal, the second square wave signal and the third square wave signal.

In the above embodiment, the primary side and the secondary side of the three-phase transformer are all in a star connection manner, the common end of the secondary side is connected to the ground end, where the three output ends of the secondary side respectively correspond to one phase shifter, that is, three phase shifters are provided, each phase shifter respectively performs phase shifting processing on one of the input voltage signals, for example, the first phase shifter performs phase shifting processing on the input voltage signal UAB to obtain a first phase-shifted signal, the second phase shifter performs phase shifting processing on the input voltage signal UBC to obtain a second phase-shifted signal, and the third phase shifter performs phase shifting processing on the input voltage signal UCA to obtain a third phase-shifted signal, so that the first phase-shifted signal coincides with or has a phase close to other input line voltages (for example, UCA), and similarly, the second phase-shifted signal coincides with or has a phase close to other input line voltages (for example, UAB); the output end of each phase shifter is respectively connected with a corresponding comparator, namely a voltage comparator, and the first phase-shifting signal, the second phase-shifting signal and the third phase-shifting signal are respectively subjected to zero crossing comparison, namely are compared with zero voltage, so that corresponding first square wave signals, second square wave signals and third square wave signals are obtained, the purpose of obtaining synchronous square wave signals is achieved as shown in fig. 5, and corresponding pulse triggering signals can be obtained accordingly, so that the thyristor in the three-phase fully-controlled rectifier is subjected to pulse triggering control.

In an alternative embodiment, the pulse trigger is electrically connected to the output end of the first comparator, the output end of the second comparator, and the output end of the third comparator, where the pulse trigger generates a first pulse trigger signal according to the first square wave signal, the pulse trigger generates a second pulse trigger signal according to the second square wave signal, the pulse trigger generates a third pulse trigger signal according to the third square wave signal, the target pulse trigger signal includes the first pulse trigger signal, the second pulse trigger signal, and the third pulse trigger signal, the first pulse trigger signal is obtained after the turning moment of the first square wave signal is set as a starting point and the preset angle is delayed, the second pulse trigger signal is obtained after the turning moment of the second square wave signal is set as a starting point and the preset angle is delayed, and the third pulse trigger signal is obtained after the turning moment of the third square wave signal is set as a starting point and the preset angle is delayed.

In the above embodiment, the pulse trigger is electrically connected to the first comparator, the second comparator and the third comparator, and generates the first pulse trigger signal according to the first square wave signal, generates the second pulse trigger signal according to the second square wave signal and generates the third pulse trigger signal according to the third square wave signal, so as to obtain three paths of pulse trigger signals, where each path of pulse trigger signal is obtained by taking the turning moment of the corresponding square wave signal as a starting point and delaying the turning moment by a preset angle, the turning moment can be from 0 to 1, or the turning moment of the square wave signal is from 1 to 0, the turning moment of the square wave signal is the starting moment of the trigger angle, and then the pulse trigger is controlled after delaying the preset angle, so that the actual trigger angle error is controlled in a small range.

In an alternative embodiment, the first phase shifter, the second phase shifter and the third phase shifter are each composed of a first-order second-order low-pass filter, the phase difference between the first phase-shifted signal and the input voltage signal UAB is in the range of 100 ° to 140 °, the phase difference between the second phase-shifted signal and the input voltage signal UBC is in the range of 100 ° to 140 °, and the phase difference between the third phase-shifted signal and the input voltage signal UCA is in the range of 100 ° to 140 °.

In the above embodiment, the first phase shifter, the second phase shifter and the third phase shifter are each composed of a first-stage second-order low-pass filter, the phase difference between the phase-shifted signal obtained by each phase shifter and the corresponding input voltage signal is located in the range of 100 ° to 140 ° through the phase shifter, so that the phase-shifted signals obtained after phase shifting, such as the first phase-shifted signal, the second phase-shifted signal and the third phase-shifted signal, coincide with or approach to other input line voltage signals, for example, the first phase-shifted signal coincides with or approaches to other input line voltages (such as UCAs) by within 20 °), the second phase-shifted signal coincides with or approaches to other input line voltages (such as UAB), and the third phase-shifted signal coincides with or approaches to other input line voltages (such as UBC), and is compensated by the target compensation angle, so that the final trigger angle error is controlled within ±1°. Compared with the scheme that a two-stage second-order low-pass filter is generally adopted in the related art to shift the phase of 50Hz by 180 degrees, the technical scheme can achieve the aim of reliably exciting the generator in a wide frequency range and can also achieve the aim of saving the design cost of a circuit.

In an alternative embodiment, the first phase shifter includes a first resistor, a second resistor, a third resistor, a first capacitor, a second capacitor and a first operational amplifier, where a first end of the first resistor is electrically connected to a first phase output end of a secondary side of the three-phase transformer, a second end of the first resistor is connected to a first end of the second resistor, a second end of the second resistor is connected to an inverting input end of the first operational amplifier, common ends of an in-phase input end of the first operational amplifier and the secondary side of the three-phase transformer are both connected to a ground end, the third resistor is connected between the second end of the first resistor and an output end of the first operational amplifier, the first capacitor is connected between the inverting input end of the first operational amplifier and an output end of the first operational amplifier, and the second capacitor is connected between the second end of the first resistor and a ground end; the second phase shifter comprises a fourth resistor, a fifth resistor, a sixth resistor, a third capacitor, a fourth capacitor and a second operational amplifier, wherein the first end of the fourth resistor is electrically connected with the second phase output end of the secondary side of the three-phase transformer, the second end of the fourth resistor is connected with the first end of the fifth resistor, the second end of the fifth resistor is connected with the inverting input end of the second operational amplifier, the common end of the non-inverting input end of the second operational amplifier and the secondary side of the three-phase transformer is connected with the grounding end, the sixth resistor is connected between the second end of the fourth resistor and the output end of the second operational amplifier, the third capacitor is connected between the inverting input end of the second operational amplifier and the output end of the second operational amplifier, and the fourth capacitor is connected between the second end of the fourth resistor and the grounding end; the third phase shifter comprises a seventh resistor, an eighth resistor, a ninth resistor, a fifth capacitor, a sixth capacitor and a third operational amplifier, wherein the first end of the seventh resistor is electrically connected with the third phase output end of the secondary side of the three-phase transformer, the second end of the seventh resistor is connected with the first end of the eighth resistor, the second end of the eighth resistor is connected with the inverting input end of the third operational amplifier, the non-inverting input end of the third operational amplifier and the common end of the secondary side of the three-phase transformer are both connected with the ground end, the ninth resistor is connected between the second end of the seventh resistor and the output end of the third operational amplifier, the fifth capacitor is connected between the inverting input end of the third operational amplifier and the output end of the third operational amplifier, and the sixth capacitor is connected between the second end of the seventh resistor and the ground end.

In the above embodiment, the three-way phase shifter adopts the same circuit design scheme, and referring to fig. 7, the output signal can be more stable, so as to achieve the purpose of effectively reducing noise interference.

The application also provides an excitation control method, which is applied to the excitation control device of any one of the embodiments, and fig. 6 is a schematic flow chart of the excitation control method provided by the embodiment of the application, and the method comprises the following steps:

Step S601, performing phase shifting processing on a three-phase input voltage signal of a three-phase transformer to obtain a target phase shifting signal, wherein the frequency of the three-phase input voltage signal is greater than or equal to a first frequency threshold and less than or equal to a second frequency threshold, the first frequency threshold is less than 50Hz, the second frequency threshold is greater than 50Hz, and the phase difference between the target phase shifting signal and the three-phase input voltage signal is in the range of 100-140 degrees;

step S602, performing zero crossing point comparison on a target phase-shift signal to obtain a synchronous square wave signal;

Step S603, generating a target pulse trigger signal according to the synchronous square wave signal, wherein the target pulse trigger signal is obtained by taking the turning moment of the synchronous square wave signal as a starting point and delaying a preset angle, the preset angle is equal to the sum of a theoretical trigger angle and a target compensation angle, the target compensation angle is determined based on a pre-established compensation phase table, the compensation phase table comprises a corresponding relation between the frequency of an input voltage signal and the compensation angle, and the theoretical trigger angle is a trigger angle determined by an excitation system according to the generator terminal voltage;

step S604, pulse triggering control is performed on the thyristors in the three-phase fully controlled rectifier based on the target pulse triggering signal.

Through the steps, the three-phase input voltage signal is subjected to phase shifting processing to obtain a target phase-shifted signal, wherein the phase difference between the target phase-shifted signal and the three-phase input voltage signal is in the range of 100 DEG to 140 DEG, and the frequency of the three-phase input voltage signal is between a first frequency threshold and a second frequency threshold, namely the frequency of the input voltage signal can be in a wider frequency range including 50Hz, for example, the first frequency threshold is 30Hz (or 35Hz, or 40Hz, or other frequencies), and the second frequency threshold is 85Hz (or 80Hz, or 70Hz, or other frequencies); then, performing zero crossing point comparison on a target phase-shifting signal to obtain a synchronous square wave signal, and generating a target pulse trigger signal according to the synchronous square wave signal, wherein the target pulse trigger signal is obtained by taking the turning moment of the synchronous square wave signal as a starting point and delaying a preset angle, the preset angle is equal to the sum of a theoretical trigger angle and a target compensation angle, namely the preset angle is an actual trigger angle, the theoretical trigger angle is determined by an excitation system according to the voltage of a generator end, or is a trigger angle calculated according to a calculation formula, the target compensation angle is a target phase-shifting signal obtained after phase-shifting processing, phase difference compensation is performed on the target phase-shifting signal, so that the actual trigger angle error is controlled within a small range, and then, performing pulse trigger control on a thyristor in a three-phase fully-controlled rectifier based on the target pulse trigger signal, for example, the theoretical trigger angle is equal to 20 DEG is illustrated, and when the frequency of an input voltage signal is 30Hz, the corresponding target compensation angle is 11.59 DEG, and the preset angle is 20 DEG+ 11.59 DEG 31.59 DEG; when the frequency of the input voltage signal is 85Hz, the corresponding target compensation angle is-18.29 degrees, the preset angle is 20-18.29 degrees=1.71 degrees, and different frequencies have corresponding compensation angles. The problem that the generator cannot normally operate when the frequency of the input voltage signal is smaller than 50Hz or larger than 50Hz, such as 30Hz or 85Hz or other frequencies in the related art is avoided, the technical problem that the applicability of the excitation control circuit in the related art is poor is solved, and the effect of expanding the application range of the excitation system is achieved.

In an alternative embodiment, generating the target pulse trigger signal from the synchronous square wave signal includes: determining a target compensation angle corresponding to the frequency of the three-phase input voltage signal; determining the sum of the target compensation angle and the theoretical trigger angle as a preset angle; and delaying a preset angle by taking the zero crossing point of the synchronous square wave signal as a starting point to obtain a target pulse trigger signal.

In the above embodiment, the target compensation angle corresponding to the frequency of the three-phase input voltage signal is determined first, that is, the different frequencies have corresponding compensation angles, for example, when the frequency of the input voltage signal is 30Hz, the corresponding target compensation angle is 11.59 °, when the frequency of the input voltage signal is 40Hz, the corresponding target compensation angle is 5.84 °, when the frequency of the input voltage signal is 60Hz, the corresponding target compensation angles are-5.17 °, each frequency has corresponding compensation angles, the sum of the target compensation angle and the theoretical trigger angle is determined as a preset angle, that is, the sum of the target compensation angle and the theoretical trigger angle is taken as an actual trigger angle, and then the target pulse trigger signal is obtained by delaying the preset angle with the zero crossing point of the synchronous square wave signal as a starting point, or delaying the preset angle with the turning time of the synchronous square wave signal as a starting point. The aim of obtaining a target pulse trigger signal for controlling the pulse trigger of the controllable silicon of the three-phase full-control rectifier according to the synchronous square wave signal is achieved.

In an alternative embodiment, determining a target compensation angle corresponding to a frequency of the three-phase input voltage signal includes one of: in the case where the frequency of the three-phase input voltage signal is less than 50Hz, the target compensation angle is determined according to the following formula: θ= (50.16-f) ×0.575, where θ is a target compensation angle, and f is a frequency of the three-phase input voltage signal; in the case where the frequency of the three-phase input voltage signal is greater than 50Hz, the target compensation angle is determined according to the following formula: θ= (50.16-f) ×0.525, where θ is the target compensation angle and f is the frequency of the three-phase input voltage signal.

In the above embodiment, the calculation of the target compensation angle, that is, the compensation of the phase difference, is performed by adopting the corresponding calculation formula for the frequencies of the different input voltage signals, and when the frequency of the three-phase input voltage signal is equal to 50Hz, the target compensation angle may not be calculated, that is, the compensation is not required. According to the difference of the frequency of the input voltage signal, the purpose of the corresponding target compensation angle can be determined.

In an alternative embodiment, the method further comprises, prior to determining the target compensation angle corresponding to the frequency of the three-phase input voltage signal: and establishing a compensation phase table, wherein the compensation phase table comprises the corresponding relation between the frequencies of different input voltage signals and the compensation angles.

In the above embodiment, the compensation phase table may be pre-established, where the compensation phase table includes relationships between different frequencies of the input voltage signal and corresponding compensation angles, so that the compensation angle corresponding to the frequency of the input voltage signal may be rapidly determined, and thus the corresponding pulse trigger signal may be accurately obtained.

It should be noted that the above-described embodiments are only some embodiments, but not all embodiments of the present application. The present application will be specifically described with reference to the following examples.

The embodiment of the application provides a filter circuit with a phase difference lower than +/-20 degrees in a range of 30-85 Hz, and the filter phase difference is compensated in a program, so that the actual trigger angle error is within a range of +/-1 degree.

Fig. 7 is a schematic diagram of a low-pass filter circuit with low phase shift, as shown in fig. 7, in which primary sides and secondary sides of synchronous voltage transformers T1, T2 and T3 are connected into a star shape, so that an output voltage signal of a transformer T2 lags an input line voltage UBC by 30 °, and then a first-stage second-order low-pass filter is used to advance phase shift by 150 ° at 50Hz so as to coincide with a line voltage UAB. The input UAB and the output signal UTAB are subjected to 50Hz alternating current phase shift simulation, the waveforms of the simulation are shown in fig. 8, the input (blue) and the output (red) are just different by 0 degrees, and the phases of the other two paths of UBC and UTBC, UCA and UTCA are also different by 0 degrees, so that the principle of three-phase power symmetry is skillfully utilized, the three-phase mutual difference is 120 degrees, the synchronous signals are input in a staggered way by 120 degrees, zero crossing comparison is carried out to form square wave signals, the overturning moment of the square wave FAB is just the zero crossing of the input UAB, and therefore the FAB is used as the triggering angle phase shift triggering timing of the UAB.

As shown in fig. 7, the three output ends of the three-phase transformer are respectively corresponding to a first-stage second-order low-pass filter, for example, the secondary output end of the T1 transformer is connected to a first-stage second-order low-pass filter (corresponding to the first phase shifter), the first-stage second-order low-pass filter is composed of a first resistor R1, a second resistor R2, a third resistor R3, a first capacitor C1, a second capacitor C2 and a first operational amplifier U1A, the output end of the first operational amplifier U1A is connected to the inverting input end of the first comparator U3A through a nineteenth resistor R19, the non-inverting input end of the first comparator U3A provides zero voltage as a comparison, and other peripheral circuits of the first comparator are composed of a tenth resistor R10, an eleventh resistor R11 and a twelfth resistor R12, which are not described here.

Similarly, the secondary output end of the T2 transformer is connected to a second first-stage second-order low-pass filter (corresponding to the second phase shifter), which is composed of a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a third capacitor C3, a fourth capacitor C4 and a second operational amplifier U1B, the output end of the second operational amplifier U1B is connected to the inverting input end of the second comparator U3B through a twentieth resistor R20, the non-inverting input end of the second comparator U3B provides zero voltage as a comparison, and other peripheral circuits of the second comparator are composed of a thirteenth resistor R13, a fourteenth resistor R14 and a fifteenth resistor R15, referring to fig. 7. The secondary output end of the T3 transformer is connected to a third first-stage second-order low-pass filter (corresponding to the third phase shifter), which is composed of a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a fifth capacitor C5, a sixth capacitor C6 and a third operational amplifier U1C, the output end of the third operational amplifier U1C is connected to the inverting input end of the third comparator U3C through a twenty-first resistor R21, the non-inverting input end of the third comparator U3C provides zero voltage as a comparison, and other peripheral circuits of the third comparator are composed of a sixteenth resistor R16, a seventeenth resistor R17 and an eighteenth resistor R18, which are not described here.

The alternating current transmission characteristic analysis is carried out on the circuits UAB and UTAB, and the phase relation between the input voltage UAB and the synchronous square wave signal at 50Hz is shown in figure 9; the phase relation between the input voltages UAB of 30Hz and 85Hz and the synchronous square wave signals is shown as fig. 10 and 11 respectively, wherein the synchronous square wave signals lead UAB by 11.66 degrees at 30Hz and lag UAB by 18.08 degrees at 85 Hz.

It can be seen from fig. 10 and 11 that the farther the phase shift angle is from 180 ° under different frequencies, the maximum deviation of the trigger angle can reach 18.08 °, and in order to further improve the accuracy of the trigger angle, the deviation angle needs to be compensated, and the specific compensation method compensates according to the phase frequency characteristic formula of the second-order low-pass filter.

Alternatively, the calculation can be performed by using a correlation formula; in practical applications, a simple compensation phase table may also be built in advance, for example, the actual processing in the program is as follows: another simple compensation phase table is built up by the transmission characteristics of the circuit, as shown in table 1 below, specifically the algorithm is such that the frequency point shifted by 150 ° is 50.16Hz, then the phase compensation is performed by θ= (50.16-f) x 0.575 for frequency phase compensation angles lower than 50.16Hz, and the phase compensation is performed by θ= (50.16-f) x 0.525 for frequency phase compensation angles greater than 50.16Hz, ensuring that the angle error is lower than 1 °.

TABLE 1

After the synchronous square wave signal (such as the foregoing FAB) is obtained, the FAB may be used as a trigger angle of the UAB for phase-shifting triggering timing, for example, a preset angle is delayed by taking the turning moment of the FAB as a starting point, for a thyristor on a corresponding bridge arm in the three-phase fully-controlled rectifier, where the preset angle is the sum of the theoretical trigger angle and the compensation angle. For example, assuming that the theoretical firing angle is 30 °, when the frequency of the input voltage signal is 30Hz, the corresponding compensation angle is 11.59 °, then the preset angle is 30 ° +11.59 ° =41.59°, and the preset angle may be understood as the actual firing angle.

FIG. 12 is a schematic diagram of a three-phase fully controlled rectifier circuit with a positive sequence conduction sequence 1,2,3,4,5,6,1; negative sequence on sequence 2,1,6,5,4,3,2. In the figure, AB ∈ and AB ∈ correspond to the downward overturn and upward overturn of the FAB.

Fig. 13, fig. 14, fig. 15 are schematic diagrams of actual triggering effects of 30Hz, 50Hz, and 85Hz, in which Ud represents output voltage of the three-phase fully-controlled rectifier, and simulation diagrams of the actual triggering effects with triggering angles of 20 ° and 90 ° are provided in each diagram, so that the embodiment of the application is applicable to the generator frequency in a wide frequency range of 30-85 Hz, and can reliably operate.

In the embodiment of the application, a filter circuit is provided, the phase difference is lower than +/-20 degrees in the range of 30-85 Hz, and meanwhile, the filter phase difference is compensated in a program, so that the actual trigger angle error is within the range of +/-1 degree, and the aim of reliably operating the excitation in the range of 30-85 Hz of the generator frequency is fulfilled. Compared with the related art, the embodiment of the application is suitable for generator excitation in a wide frequency range.

From the description of the above embodiments, it will be clear to a person skilled in the art that the method according to the above embodiments may be implemented by means of software plus the necessary general hardware platform, but of course also by means of hardware, but in many cases the former is a preferred embodiment. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art in the form of a software product stored in a storage medium (e.g. ROM/RAM, magnetic disk, optical disk) comprising instructions for causing a terminal device (which may be a mobile phone, a computer, a server, or a network device, etc.) to perform the method according to the embodiments of the present application.

The application also provides a computer readable storage medium having instructions stored therein which, when executed, perform the method steps of any of the above.

In one exemplary embodiment, the computer readable storage medium may include, but is not limited to: a usb disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory RAM), a removable hard disk, a magnetic disk, or an optical disk, or other various media capable of storing a computer program.

The application also discloses electronic equipment. As shown in fig. 16, fig. 16 is a schematic structural diagram of an electronic device according to the disclosure in an embodiment of the present application. The electronic device 1600 may include: at least one processor 1601, at least one network interface 1604, a user interface 1603, a memory 1605, at least one communication bus 1602.

Wherein a communication bus 1602 is used to enable connected communication between these components.

The user interface 1603 may include a Display screen (Display), a Keyboard (Keyboard), and the optional user interface 1603 may also include standard wired interfaces, wireless interfaces, among others.

The network interface 1604 may optionally comprise a standard wired interface, a wireless interface (e.g., WI-FI interface), among others.

Wherein the processor 1601 may include one or more processing cores. The processor 1601 utilizes various interfaces and lines to connect various portions of the overall electronic device (e.g., a server) and performs various functions of the server and processes data by executing or executing instructions, programs, code sets, or instruction sets stored in the memory 1605, and invoking data stored in the memory 1605. Alternatively, the processor 1601 may be implemented in at least one hardware form of digital signal Processing (DIGITAL SIGNAL Processing, DSP), field-Programmable gate array (Field-Programmable GATE ARRAY, FPGA), programmable logic array (Programmable Logic Array, PLA). The processor 1601 may integrate one or a combination of several of a central processing unit (Central Processing Unit, CPU), an image processing unit (Graphics Processing Unit, GPU), and a modem, etc. The CPU mainly processes an operating system, a user interface, an application program and the like; the GPU is used for rendering and drawing the content required to be displayed by the display screen; the modem is used to handle wireless communications. It will be appreciated that the modem may not be integrated into the processor 1601 and may be implemented by a single chip.

The Memory 1605 may include a random access Memory (Random Access Memory, RAM) or a Read-Only Memory (Read-Only Memory). Optionally, the memory 1605 includes a non-transitory computer readable medium (non-transitory computer-readable storage medium). Memory 1605 may be used to store instructions, programs, code, sets of codes, or sets of instructions. The memory 1605 may include a stored program area that may store instructions for implementing an operating system, instructions for at least one function (e.g., a touch function, a sound playing function, an image playing function, etc.), instructions for implementing the various method embodiments described above, etc., and a stored data area; the storage data area may store data or the like involved in the above respective method embodiments. Memory 1605 may also optionally be at least one storage device located remotely from the aforementioned processor 1601. Referring to fig. 16, an operating system, a network communication module, a user interface module, and an application program of an excitation control method may be included in a memory 1605 as a computer storage medium.

In the electronic device 1600 shown in fig. 16, the user interface 1603 is mainly used as an interface for providing input for a user, and obtains data input by the user; and processor 1601 may be configured to invoke an application of an excitation control method stored in memory 1605, which when executed by one or more processors 1601, causes electronic device 1600 to perform the method as described in one or more of the embodiments above. It should be noted that, for simplicity of description, the foregoing method embodiments are all described as a series of acts, but it should be understood by those skilled in the art that the present application is not limited by the order of acts described, as some steps may be performed in other orders or concurrently in accordance with the present application. Further, those skilled in the art will also appreciate that the embodiments described in the specification are all of the preferred embodiments, and that the acts and modules referred to are not necessarily required for the present application.

In the foregoing embodiments, the descriptions of the embodiments are emphasized, and for parts of one embodiment that are not described in detail, reference may be made to related descriptions of other embodiments.

In the several embodiments provided by the present application, it should be understood that the disclosed apparatus may be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative, such as a division of units, merely a division of logic functions, and there may be additional divisions in actual implementation, such as multiple units or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be through some service interface, device or unit indirect coupling or communication connection, electrical or otherwise.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed over a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.

The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable memory. Based on this understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in whole or in part in the form of a software product stored in a memory, comprising several instructions for causing a computer device (which may be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method of the various embodiments of the present application. And the aforementioned memory includes: various media capable of storing program codes, such as a U disk, a mobile hard disk, a magnetic disk or an optical disk.

The foregoing is merely exemplary embodiments of the present disclosure and is not intended to limit the scope of the present disclosure. That is, equivalent changes and modifications are contemplated by the teachings of this disclosure, which fall within the scope of the present disclosure. Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure.

This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains.

Claims

1. An excitation control device, comprising: a three-phase transformer, a phase shifting unit, a voltage comparing unit and a pulse trigger, wherein,

The input end of the three-phase transformer is connected with a three-phase input voltage signal, the output end of the three-phase transformer is electrically connected with the input end of the phase shifting unit, the phase shifting unit is used for carrying out phase shifting treatment on the three-phase input voltage signal to obtain a target phase shifting signal, wherein the frequency of the three-phase input voltage signal is larger than or equal to a first frequency threshold and smaller than or equal to a second frequency threshold, the first frequency threshold is smaller than 50Hz, the second frequency threshold is larger than 50Hz, and the phase difference between the target phase shifting signal and the three-phase input voltage signal is in the range of 100-140 degrees;

the output end of the phase shifting unit is electrically connected with the input end of the voltage comparing unit, and the voltage comparing unit is used for carrying out zero crossing point comparison on the target phase shifting signal to obtain a synchronous square wave signal;

The input end of the pulse trigger is electrically connected with the output end of the voltage comparison unit, the pulse trigger is used for generating a target pulse trigger signal according to the synchronous square wave signal, and pulse trigger control is carried out on the thyristor in the three-phase full-control rectifier based on the target pulse trigger signal, wherein the target pulse trigger signal is obtained by taking the turning moment of the synchronous square wave signal as a starting point and delaying a preset angle, the preset angle is equal to the sum of a theoretical trigger angle and a target compensation angle, the target compensation angle is determined based on a pre-established compensation phase table, the compensation phase table comprises a corresponding relation between the frequency of an input voltage signal and the compensation angle, and the theoretical trigger angle is the trigger angle determined by an excitation system according to the generator terminal voltage.

2. The excitation control apparatus according to claim 1, wherein,

The primary side and the secondary side of the three-phase transformer are in a star connection mode, the phase shifting unit comprises a first phase shifter, a second phase shifter and a third phase shifter, wherein the input end of the first phase shifter is electrically connected with the first phase output end of the three-phase transformer, the first phase shifter is used for carrying out phase shifting treatment on an input voltage signal UAB to obtain a first phase shifting signal, the input end of the second phase shifter is electrically connected with the second phase output end of the three-phase transformer, the second phase shifter is used for carrying out phase shifting treatment on the input voltage signal UBC to obtain a second phase shifting signal, the input end of the third phase shifter is electrically connected with the third phase output end of the three-phase transformer, the third phase shifter is used for carrying out phase shifting treatment on an input voltage signal UCA to obtain a third phase shifting signal, and the target phase shifting signal comprises the first phase shifting signal, the second phase shifting signal and the third phase shifting signal;

The voltage comparison unit comprises a first comparator, a second comparator and a third comparator, wherein the inverting input end of the first comparator is electrically connected with the output end of the first phase shifter, the inverting input end of the second comparator is electrically connected with the output end of the second phase shifter, the inverting input end of the third comparator is electrically connected with the output end of the third phase shifter, the first comparator is used for performing zero crossing comparison on the first phase-shifting signal to obtain a first square wave signal, the second comparator is used for performing zero crossing comparison on the second phase-shifting signal to obtain a second square wave signal, the third comparator is used for performing zero crossing comparison on the third phase-shifting signal to obtain a third square wave signal, and the synchronous square wave signal comprises the first square wave signal, the second square wave signal and the third square wave signal.

3. The excitation control device according to claim 2, wherein the pulse trigger is electrically connected to the output of the first comparator, the output of the second comparator, and the output of the third comparator, wherein the pulse trigger generates a first pulse trigger signal based on the first square wave signal, the pulse trigger generates a second pulse trigger signal based on the second square wave signal, the pulse trigger generates a third pulse trigger signal based on the third square wave signal, the target pulse trigger signal includes the first pulse trigger signal, the second pulse trigger signal, and the third pulse trigger signal, the first pulse trigger signal is obtained after the turning-over time of the first square wave signal is set as a start point and the preset angle is delayed, the second pulse trigger signal is obtained after the turning-over time of the second square wave signal is set as a start point and the preset angle is delayed, and the third pulse trigger signal is obtained after the turning-over time of the third square wave signal is set as a start point and the preset angle is delayed.

4. The excitation control device according to claim 2, wherein the first phase shifter, the second phase shifter, and the third phase shifter are each composed of a first-order second-order low-pass filter, a phase difference between the first phase-shifted signal and the input voltage signal UAB is in a range of 100 ° to 140 °, a phase difference between the second phase-shifted signal and the input voltage signal UBC is in a range of 100 ° to 140 °, and a phase difference between the third phase-shifted signal and the input voltage signal UCA is in a range of 100 ° to 140 °.

5. The excitation control apparatus according to claim 4, wherein,

The first phase shifter comprises a first resistor, a second resistor, a third resistor, a first capacitor, a second capacitor and a first operational amplifier, wherein the first end of the first resistor is electrically connected with a first phase output end of a secondary side of the three-phase transformer, the second end of the first resistor is connected with the first end of the second resistor, the second end of the second resistor is connected with an inverting input end of the first operational amplifier, the non-inverting input end of the first operational amplifier is connected with a common end of the secondary side of the three-phase transformer, the third resistor is connected between the second end of the first resistor and an output end of the first operational amplifier, the first capacitor is connected between the inverting input end of the first operational amplifier and the output end of the first operational amplifier, and the second capacitor is connected between the second end of the first resistor and the ground end;

the second phase shifter comprises a fourth resistor, a fifth resistor, a sixth resistor, a third capacitor, a fourth capacitor and a second operational amplifier, wherein the first end of the fourth resistor is electrically connected with the second phase output end of the secondary side of the three-phase transformer, the second end of the fourth resistor is connected with the first end of the fifth resistor, the second end of the fifth resistor is connected with the inverting input end of the second operational amplifier, the common end of the non-inverting input end of the second operational amplifier and the secondary side of the three-phase transformer is connected with the ground end, the sixth resistor is connected between the second end of the fourth resistor and the output end of the second operational amplifier, the third capacitor is connected between the inverting input end of the second operational amplifier and the output end of the second operational amplifier, and the fourth capacitor is connected between the second end of the fourth resistor and the ground end;

the third phase shifter comprises a seventh resistor, an eighth resistor, a ninth resistor, a fifth capacitor, a sixth capacitor and a third operational amplifier, wherein the first end of the seventh resistor is electrically connected with the third phase output end of the secondary side of the three-phase transformer, the second end of the seventh resistor is connected with the first end of the eighth resistor, the second end of the eighth resistor is connected with the inverting input end of the third operational amplifier, the common end of the non-inverting input end of the third operational amplifier and the secondary side of the three-phase transformer is connected with the grounding end, the ninth resistor is connected between the second end of the seventh resistor and the output end of the third operational amplifier, the fifth capacitor is connected between the inverting input end of the third operational amplifier and the output end of the third operational amplifier, and the sixth capacitor is connected between the second end of the seventh resistor and the grounding end.

6. An excitation control method, characterized by being applied to the excitation control device according to any one of claims 1 to 5, comprising:

Performing phase shifting treatment on a three-phase input voltage signal of the three-phase transformer to obtain a target phase shifting signal, wherein the frequency of the three-phase input voltage signal is larger than or equal to a first frequency threshold value and smaller than or equal to a second frequency threshold value, the first frequency threshold value is smaller than 50Hz, the second frequency threshold value is larger than 50Hz, and the phase difference between the target phase shifting signal and the three-phase input voltage signal is in a range of 100-140 degrees;

zero crossing point comparison is carried out on the target phase-shift signal, so that a synchronous square wave signal is obtained;

Generating a target pulse trigger signal according to the synchronous square wave signal, wherein the target pulse trigger signal is obtained by taking the turning moment of the synchronous square wave signal as a starting point and delaying a preset angle, the preset angle is equal to the sum of a theoretical trigger angle and a target compensation angle, the target compensation angle is determined based on a pre-established compensation phase table, the compensation phase table comprises a corresponding relation between the frequency of an input voltage signal and the compensation angle, and the theoretical trigger angle is a trigger angle determined by an excitation system according to the generator terminal voltage;

And performing pulse triggering control on the thyristor in the three-phase full-control rectifier based on the target pulse triggering signal.

7. The method of claim 6, wherein generating a target pulse trigger signal from the synchronous square wave signal comprises:

determining a target compensation angle corresponding to a frequency of the three-phase input voltage signal;

determining the sum of the target compensation angle and the theoretical trigger angle as a preset angle;

and delaying the preset angle by taking the zero crossing point of the synchronous square wave signal as a starting point to obtain the target pulse trigger signal.

8. The method of claim 7, wherein determining a target compensation angle corresponding to a frequency of the three-phase input voltage signal comprises one of:

In the case where the frequency of the three-phase input voltage signal is less than 50Hz, the target compensation angle is determined according to the following equation: θ= (50.16-f) ×0.575, where θ is the target compensation angle and f is the frequency of the three-phase input voltage signal;

In the case where the frequency of the three-phase input voltage signal is greater than 50Hz, the target compensation angle is determined according to the following equation:

θ= (50.16-f) ×0.525, where θ is the target compensation angle and f is the frequency of the three-phase input voltage signal.

9. The method of claim 7, wherein prior to determining a target compensation angle corresponding to a frequency of the three-phase input voltage signal, the method further comprises:

And establishing a compensation phase table, wherein the compensation phase table comprises corresponding relations between frequencies of different input voltage signals and compensation angles.

10. An electronic device comprising a memory and a processor, the memory having stored thereon a computer program, characterized in that the processor, when executing the program, implements the method according to any of claims 6 to 9.