High-precision large-current phase-control current sharing system

Abstract

The invention discloses a high-precision large-current phase-control current-sharing system, a thyristor adaptive control module comprises a main control module and a controller, the main control module collects power supply voltage data, and the closing time of a thyristor is calculated according to an angle given by an operation instruction; and then the controller readjusts the closing time point of each branch according to the angle self-adaptive correction value of each branch, and thyristor trigger signals are generated in sequence, so that self-adaptive control of the thyristors is realized. According to the high-precision large-current phase-control current-sharing system disclosed by the invention, each thyristor selects a proper switching-on angle to switch on current according to the condition of the branch where the thyristor is located, so that the adverse effect caused by non-uniform current is reduced, the working state of the thyristors is optimized, all the thyristors are enabled to always work in the most proper parameter range, and the service life of the thyristors is prolonged. And various abnormal states can be rapidly responded, and rapid protection and alarm can be realized.

Description

Technical Field

[0001] The invention belongs to the technical field of thyristor operation control, and in particular relates to a high-precision large-current phase-controlled current-sharing system. Background Art

[0002] There are many thyristors involved in the short-circuit test device of low-voltage protection appliances. Although the thyristors have been carefully selected to reduce the performance differences between individuals, and the length of the copper bars of each current bridge arm is as consistent as possible, and the bolt installation torque is unified, it is still inevitable that there are differences between branches, resulting in inconsistent transient and steady-state conditions of current in each branch. Uneven transient current affects the operation of the devices in each branch, and uneven steady-state circuits affect the heating of each branch, both of which are not conducive to the stable operation of the system.

[0003] Therefore, further improvements are made to the above problems. Summary of the invention

[0004] The main purpose of the present invention is to provide a high-precision large-current phase-controlled current sharing system, which is linked by a thyristor adaptive control module and a multi-source heterogeneous information fusion module. Each thyristor selects an appropriate closing angle to connect the current according to the branch situation, thereby reducing the adverse effects of uneven current and optimizing the working state of the thyristor, so that all thyristors always work within the most appropriate parameter range, and can respond quickly to various abnormal conditions, thereby achieving rapid protection and alarm.

[0005] To achieve the above objectives, the present invention provides a high-precision large current phase-controlled current sharing system, including a thyristor adaptive control module and a multi-source heterogeneous information fusion module, wherein:

[0006] The thyristor adaptive control module includes a main control module and a controller. The main control module collects power supply voltage data and calculates the thyristor closing time according to the angle given by the operation instruction; then the controller readjusts (fine-tunes) the closing time point of each branch with reference to the angle adaptive correction value of each branch, and generates thyristor trigger signals in sequence, thereby realizing adaptive control of the thyristor;

[0007] The multi-source heterogeneous information fusion module monitors the working status of each thyristor in real time, and optimizes the working status of the thyristor, so that all thyristors always work within the most appropriate parameter range, and quickly responds to abnormal conditions including temperature, current and voltage to achieve rapid protection and alarm.

[0008] As a further preferred technical solution of the above technical solution, the adaptive control of the thyristor adaptive control module is specifically implemented as follows:

[0009] The expression of current i with respect to inductance L and resistance R in the loop is as follows:

[0010]

[0011] Among them, U is the voltage of the test power supply, ω is the angular velocity of the test power supply voltage, R is the equivalent resistance of the loop, and L is the equivalent inductance of the loop;

[0012] The different timings of thyristor conduction are equivalent to different initial phases of voltage when conducting. By controlling the turn-on timing of the thyristor, that is, controlling the thyristor to close at different voltage phase angles, the current of each circuit can be controlled. The current control adopts an intelligent learning mode. By recording the actual closing current waveform of each thyristor and performing intelligent analysis, the conduction angles of each circuit are fine-tuned according to the difference in current of each circuit (for example, the thyristor circuit with a larger current is turned on later, and the thyristor circuit with a smaller current is turned on first). After multiple closings and current analysis, the most suitable closing parameters are obtained and memorized to obtain an optimized current sharing effect and overall current waveform.

[0013] As a further preferred technical solution of the above technical solution, in the multi-source heterogeneous information fusion module, for the collection and protection of temperature:

[0014] The temperature sensor is placed close to the center of the thyristor electrode to truly monitor the temperature of the thyristor.

[0015] As a further preferred technical solution of the above technical solution, for temperature collection and protection (this system has a large number of thyristors, with a total of 72 in phases A and C. Based on the concept of redundant design, each thyristor AK electrode is equipped with a temperature sensor, so the number of temperature sensors is as high as 144. If all are transmitted to the control board in real time for collection and processing, the collection capability, data throughput capability, and data processing capability of the processing center module are very high, and the rapidity of protection cannot be guaranteed. Therefore, the DCS concept is adopted) an edge terminal is arranged at each thyristor anti-parallel group (consisting of two thyristors in anti-parallel), and the edge terminal includes an overheating protection circuit, a working status indication circuit, a conditioning circuit, an MCU and a communication peripheral (the overheating protection circuit can be built with analog circuits such as comparators, without the need for algorithm calculation, and protection is performed immediately when the preset threshold is exceeded). The MCU uses an intelligent algorithm to analyze the working status of the thyristor, performs predictive protection, and uploads the temperature data to the control center through the communication peripheral.

[0016] As a further preferred technical solution of the above technical solution, in the multi-source heterogeneous information fusion module, for current collection and protection, including peak current protection, I 2 t protection and current effective value protection:

[0017] A Rogowski coil current transformer is installed on each group of thyristor anti-parallel groups, and the output of each Rogowski coil current transformer is connected to its own edge terminal. The MCU uses an intelligent algorithm to analyze the working status of the thyristor, performs predictive protection, and uploads the current data to the control center through communication peripherals.

[0018] As a further preferred technical solution of the above technical solution, in the multi-source heterogeneous information fusion module, for voltage collection and protection:

[0019] The voltage sampling line of each group of thyristor anti-parallel groups is connected to the corresponding edge terminal nearby. The MCU of the edge terminal performs intelligent protection. The MCU uses intelligent algorithms to analyze the working status of the thyristor, performs predictive protection, and uploads the voltage data to the control center through communication peripherals.

[0020] The beneficial effects of the present invention are:

[0021] Combining the adaptive parallel control method with the edge computing method, not only can the closing angle of each thyristor be controlled individually to obtain the required current characteristics and improve the system's current sharing coefficient, but each line can also be protected from overvoltage, overcurrent, overheating, etc., effectively increasing the reliability of the system.

[0022] As a further preferred technical solution of the above technical solution, the comprehensive protection of the multi-source heterogeneous information fusion module is specifically implemented as follows:

[0023] Parameter definition:

[0024] T: thyristor case temperature;

[0025] T max : Maximum allowable shell temperature of thyristor;

[0026] I P : Thyristor current peak value;

[0027] Maximum allowable current peak value of thyristor;

[0028] I 2 t pred : The predicted value of the current-time product collected by the thyristor at the next moment;

[0029] I 2 t ref : The value corresponding to the current-time product curve in the thyristor product manual;

[0030] V P : Peak voltage across the thyristor;

[0031] The maximum allowable voltage across the thyristor;

[0032] Protection conditions:

[0033] Over temperature protection: If T>T max , the protection is triggered;

[0034] Overcurrent protection: If The protection is triggered;

[0035] Over voltage protection: If The protection is triggered;

[0036] Protection logic:

[0037] Use a logical expression to express the protection condition.

[0038] Among them, | | represents the logical OR operation;

[0039] In the above protection, the sampling time interval is fixed Δt. First, the I 2 The t curve is fitted, and the formula is as follows:

[0040] y=At 2 +Bt+C, t∈[0,+∞);

[0041] Among them, A, B, C are coefficients, t is time, y is I 2 The value of t;

[0042] By using the table lookup method or formula calculation method to store it in the software, when the system starts to collect current, the corresponding time point is entered to query the maximum current-time product value I specified in the manual. 2 t ref ;

[0043] Then, the collected current data is fitted according to the above formula and brought into the next time point to predict I 2 The value of t is I 2 t pred ;

[0044] Finally, compare I 2 t pred with I 2 t ref Size, when I 2 t pred >I 2 t ref The protection is triggered. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is the current waveform diagram of different phase conduction.

[0046] Figure 2It is the current difference diagram when different phases are turned on.

[0047] Figure 3 It is the main loop equivalent circuit diagram of the present invention. DETAILED DESCRIPTION

[0048] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0049] In the preferred embodiments of the present invention, those skilled in the art should note that the thyristor and the like involved in the present invention may be regarded as prior art.

[0050] Preferred embodiments.

[0051] like Figure 1-3 As shown, the present invention discloses a high-precision large current phase-controlled current sharing system, including a thyristor adaptive control module and a multi-source heterogeneous information fusion module, wherein:

[0052] The thyristor adaptive control module includes a main control module and a controller. The main control module collects power supply voltage data and calculates the thyristor closing time according to the angle given by the operating instruction; then the controller refers to the angle adaptive correction value of each branch, readjusts (fine-tunes) the closing time point of each branch, and generates thyristor trigger signals in sequence, thereby realizing the adaptive control of the thyristor; during the test, the edge terminal collects the current of each branch; after the test, it receives the reference current value sent by the main control module, calculates, stores and uploads the closing angle that needs to be adjusted under the current total current setting value, and provides an adaptive correction value for the next current characteristic test. After multiple tests with multiple currents, each edge terminal can iteratively learn the angle correction parameters that meet its own branch under various current conditions, and this set of parameters will be continuously optimized as the number of uses increases.

[0053] The multi-source heterogeneous information fusion module monitors the working status of each thyristor in real time, and optimizes the working status of the thyristor, so that all thyristors always work within the most appropriate parameter range, and quickly responds to abnormal conditions including temperature, current and voltage to achieve rapid protection and alarm.

[0054] Specifically, the adaptive control of the thyristor adaptive control module is specifically implemented as follows:

[0055] The short circuit test equivalent circuit diagram of the present invention is as follows: Figure 3As shown, U is the voltage of the test power supply, R is the equivalent resistance of the entire test circuit, L is the equivalent inductance of the entire test circuit, SCR is a thyristor anti-parallel group composed of two thyristors connected in anti-parallel (thyristors are unidirectional, but the circuit is used for AC testing), and i is the current flowing through the circuit. Consider the thyristor as an ideal device, and assume that the initial phase of the voltage when closing the switch is The expression of current i with respect to inductance L and resistance R in the loop is as follows:

[0056]

[0057] Among them, U is the voltage of the test power supply, ω is the angular velocity of the test power supply voltage, R is the equivalent resistance of the loop, and L is the equivalent inductance of the loop;

[0058] The different timings of thyristor conduction are equivalent to different initial phases of voltage when conducting.

[0059] Observe the trend of current waveform change under different initial phases. Assume R = 0.002Ω, U = 50V, L = 5uH, f = 50Hz, R is the total impedance of the loop, L is the total inductance of the loop, and U is the voltage amplitude added to the loop. Assuming that the load impedance is much larger than the impedance of the thyristor loop, the conduction of different groups of thyristor loops basically does not affect the overall impedance. Take In several cases, we get Figure 1 The waveform of As increases, the amplitude of the first wave of current gradually decreases. The current values ​​are respectively Subtract the current value from Figure 2 As can be seen from the figure, with The difference increases, the current difference becomes larger, but the difference between the several cases gradually becomes smaller with time.

[0060] Analytically Figure 1-2 It can be seen that by controlling the conduction timing of the thyristor, that is, controlling the thyristor to close at different voltage phase angles, the current control of each circuit is achieved. The current control adopts an intelligent learning mode. By recording the actual closing current waveform of each thyristor, after intelligent analysis, according to the difference in current of each circuit, the respective conduction angles are fine-tuned (for example, the thyristor circuit with a larger current is turned on later, and the thyristor circuit with a smaller current is turned on first). After multiple closings and current analysis, the most suitable closing parameters are obtained and memorized, and an optimized current sharing effect and overall current waveform are obtained.

[0061] More specifically, in the multi-source heterogeneous information fusion module, for temperature collection and protection:

[0062] The temperature sensor is placed close to the center of the thyristor electrode to truly monitor the temperature of the thyristor.

[0063] Furthermore, for temperature collection and protection (this system has a large number of thyristors, with a total of 72 in phases A and C. Based on the concept of redundant design, each thyristor AK electrode is equipped with a temperature sensor, so the number of temperature sensors is as high as 144. If all of them are transmitted to the control board in real time for collection and processing, the collection capability, data throughput capability, and data processing capability of the processing center module are very high, and the rapidity of protection cannot be guaranteed. Therefore, the DCS concept is adopted), an edge terminal is arranged at each thyristor anti-parallel group (consisting of two thyristors in anti-parallel), which includes an overheating protection circuit, a working status indication circuit, a conditioning circuit, an MCU and communication peripherals (the overheating protection circuit can be built with analog circuits such as comparators, without the need for algorithm calculation, and protection is performed immediately when the preset threshold is exceeded). The MCU uses an intelligent algorithm to analyze the working status of the thyristor, performs predictive protection, and uploads the temperature data to the control center through communication peripherals.

[0064] Furthermore, in the multi-source heterogeneous information fusion module, current collection and protection, including peak current protection, I 2 t protection and current effective value protection:

[0065] A Rogowski coil current transformer is installed on each group of thyristor anti-parallel groups, and the output of each Rogowski coil current transformer is connected to its own edge terminal. The MCU uses an intelligent algorithm to analyze the working status of the thyristor, performs predictive protection, and uploads the current data to the control center through communication peripherals.

[0066] Preferably, in the multi-source heterogeneous information fusion module, for voltage collection and protection:

[0067] The voltage sampling line of each group of thyristor anti-parallel groups is connected to the corresponding edge terminal nearby. The MCU of the edge terminal performs intelligent protection. The MCU uses intelligent algorithms to analyze the working status of the thyristor, performs predictive protection, and uploads the voltage data to the control center through communication peripherals.

[0068] Preferably, the comprehensive protection of the multi-source heterogeneous information fusion module is specifically implemented as follows:

[0069] Parameter definition:

[0070] T: thyristor case temperature;

[0071] T max : Maximum allowable shell temperature of thyristor;

[0072] I P : Thyristor current peak value;

[0073] Maximum allowable current peak value of thyristor;

[0074] I 2 t pred : The predicted value of the current-time product collected by the thyristor at the next moment;

[0075] I 2 t ref : The value corresponding to the current-time product curve in the thyristor product manual;

[0076] V P : Peak voltage across the thyristor;

[0077] The maximum allowable voltage across the thyristor;

[0078] Protection conditions:

[0079] Over temperature protection: If T>T max , the protection is triggered;

[0080] Overcurrent protection: If The protection is triggered;

[0081] Over voltage protection: If The protection is triggered;

[0082] Protection logic:

[0083] Use a logical expression to express the protection condition.

[0084] Among them, | | represents the logical OR operation;

[0085] In the above protection, the sampling time interval is fixed Δt. First, the I 2 The t curve is fitted, and the formula is as follows:

[0086] y=At 2 +Bt+C, t∈[0,+∞);

[0087] Among them, A, B, C are coefficients, t is time, y is I 2 The value of t;

[0088] By using the table lookup method or formula calculation method to store it in the software, when the system starts to collect current, the corresponding time point is entered to query the maximum current-time product value I specified in the manual. 2 t ref .

[0089] Then, the collected current data is fitted according to the above formula and brought into the next time point to predict I2 The value of t is I 2 t pred ;

[0090] Finally, compare I 2 t pred with I 2 t ref Size, when I 2 t pred >I 2 t ref The protection is triggered.

[0091] For the present invention:

[0092] Combining neural network and adaptive control theory, the main control module collects and analyzes the current of each branch node, adaptively adjusts the closing parameters of each thyristor in the next test, intelligently adjusts the current of each branch, optimizes the dynamic current sharing capability of the system, and continuously approaches the ideal current sharing effect through iterative learning.

[0093] System parameter optimization and protection system based on multi-source heterogeneous information fusion. Adopting the concept of distributed control system, the protection strategy combines analog circuit fast protection with digital intelligent protection, taking into account the timeliness and intelligence of protection. By comprehensively analyzing the temperature, current, voltage, phase and other data resources collected by each edge node, the comprehensiveness and accuracy of data analysis are improved, thereby achieving more accurate and effective information understanding and intelligent decision-making.

[0094] It is worth mentioning that the technical features such as thyristors involved in the patent application of this invention should be regarded as prior art. The specific structure, working principle and possible control method and spatial layout method of these technical features can be selected by conventional methods in the field, and should not be regarded as the inventive point of the patent of this invention. The patent of this invention will not be further elaborated.

[0095] For those skilled in the art, it is still possible to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-precision large current phase-controlled current sharing system, characterized in that: It includes a thyristor adaptive control module and a multi-source heterogeneous information fusion module, where: The thyristor adaptive control module includes a main control module and a controller. The main control module collects power supply voltage data and calculates the thyristor closing time according to the angle given by the operation instruction; then the controller readjusts the closing time point of each branch with reference to the angle adaptive correction value of each branch, and generates thyristor trigger signals in sequence, thereby realizing adaptive control of the thyristor; The multi-source heterogeneous information fusion module monitors the working status of each thyristor in real time, and optimizes the working status of the thyristor, so that all thyristors always work within the most appropriate parameter range, and quickly responds to abnormal conditions including temperature, current and voltage to achieve rapid protection and alarm.

2. A high-precision large current phase-controlled current sharing system according to claim 1, characterized in that: The adaptive control of the thyristor adaptive control module is specifically implemented as follows: The expression of current i with respect to inductance L and resistance R in the loop is as follows: Among them, U is the voltage of the test power supply, ω is the angular velocity of the test power supply voltage, R is the equivalent resistance of the loop, and L is the equivalent inductance of the loop; The different timings of thyristor conduction are equivalent to different initial phases of voltage when conducting. By controlling the conduction timing of the thyristor, that is, controlling the thyristor to close at different voltage phase angles, the current regulation of each circuit is achieved. The current regulation adopts an intelligent learning mode. By recording the actual closing current waveform of each thyristor and performing intelligent analysis, the respective conduction angles are fine-tuned according to the difference in current of each circuit. After multiple closings and current analysis, the most suitable closing parameters are obtained and memorized to obtain an optimized current sharing effect and overall current waveform.

3. A high-precision large current phase-controlled current sharing system according to claim 2, characterized in that: In the multi-source heterogeneous information fusion module, for temperature collection and protection: The temperature sensor is placed close to the center of the thyristor electrode to truly monitor the temperature of the thyristor.

4. A high-precision large current phase-controlled current sharing system according to claim 3, characterized in that: For temperature collection and protection, an edge terminal is arranged at each thyristor anti-parallel group. The edge terminal includes an overheat protection circuit, a working status indication circuit, a conditioning circuit, an MCU and communication peripherals. The MCU uses an intelligent algorithm to analyze the working status of the thyristor, performs predictive protection, and uploads the temperature data to the control center through the communication peripherals.

5. A high-precision large current phase-controlled current sharing system according to claim 4, characterized in that: In the multi-source heterogeneous information fusion module, current collection and protection, including peak current protection, I 2 t protection and current effective value protection: A Rogowski coil current transformer is installed on each group of thyristor anti-parallel groups, and the output of each Rogowski coil current transformer is connected to its own edge terminal. The MCU uses an intelligent algorithm to analyze the working status of the thyristor, performs predictive protection, and uploads the current data to the control center through communication peripherals.

6. A high-precision large current phase-controlled current sharing system according to claim 5, characterized in that: In the multi-source heterogeneous information fusion module, for voltage collection and protection: The voltage sampling line of each group of thyristor anti-parallel groups is connected to the corresponding edge terminal nearby. The MCU of the edge terminal performs intelligent protection. The MCU uses intelligent algorithms to analyze the working status of the thyristor, performs predictive protection, and uploads the voltage data to the control center through communication peripherals.

7. A high-precision large current phase-controlled current sharing system according to claim 6, characterized in that: The comprehensive protection of the multi-source heterogeneous information fusion module is specifically implemented as follows: Parameter definition: T: thyristor case temperature; T max : Maximum allowable shell temperature of thyristor; I P : Thyristor current peak value; Maximum allowable current peak value of thyristor; I 2 t pred : The predicted value of the current-time product collected by the thyristor at the next moment; I 2 t ref : The value corresponding to the current-time product curve in the thyristor product manual; V P : Peak voltage across the thyristor; The maximum allowable voltage across the thyristor; Protection conditions: Over temperature protection: If T>T max , the protection is triggered; Overcurrent protection: If The protection is triggered; Over voltage protection: If The protection is triggered; Protection logic: Use a logical expression to express the protection condition. Among them, || represents the logical OR operation; In the above protection, the sampling time interval is fixed Δt. First, the I 2 The t curve is fitted, and the formula is as follows: y=At 2 +Bt+C,t∈[0,+∞); Among them, A, B, C are coefficients, t is time, y is I 2 The value of t; By using the table lookup method or formula calculation method to store it in the software, when the system starts to collect current, the corresponding time point is entered to query the maximum current-time product value I specified in the manual. 2 t ref ; Then, the collected current data is fitted according to the above formula and brought into the next time point to predict I 2 The value of t is I 2 t pred ; Finally, compare I 2 t pred with I 2 t ref Size, when I 2 t pred >I 2 t ref The protection is triggered.

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