Thyristor converter and hybrid trigger control method for thyristor converter

Abstract

This application relates to a thyristor converter and a hybrid triggering control method for the thyristor converter. The hybrid triggering control method for the thyristor converter includes: in a first triggering mode, outputting a first trigger signal to the thyristors of each sub-bridge, such that the triggering angle of the common-cathode group thyristors in each sub-bridge is the same as the triggering angle of the common-anode group thyristors; the thyristors of the sub-bridge include common-cathode group thyristors and common-anode group thyristors; in a second triggering mode, outputting a second trigger signal to the common-cathode group thyristors of each sub-bridge, and outputting a third trigger signal to the common-anode group thyristors of each sub-bridge, such that the triggering angle of the common-cathode group thyristors in each sub-bridge is different from the triggering angle of the common-anode group thyristors; wherein, the maximum value of the DC output voltage jointly output by each sub-bridge in the first triggering mode is greater than the maximum value of the DC output voltage jointly output by each sub-bridge in the second triggering mode.

Description

Technical Field

[0001] This application relates to the field of converter technology, and in particular to a thyristor converter and a hybrid triggering control method for the thyristor converter. Background Technology

[0002] In controlled nuclear fusion devices (such as tokamaks) and other large-scale physics experimental facilities, steady-state magnet power supplies need to provide controllable excitation current to large magnets. The corresponding typical load curve includes three stages: an excitation stage with high voltage demand and rapid voltage changes, a demagnetization stage, and a flat-top stage that accounts for a very large portion of the time and only requires low voltage to maintain a large current. However, traditional thyristor phase-controlled rectifiers generate a large amount of reactive power under low-voltage constant-current conditions, thus requiring extremely large-capacity reactive power compensation equipment. This results in high power supply equipment costs and poor power quality. Summary of the Invention

[0003] Therefore, it is necessary to provide a thyristor converter and a hybrid triggering control method for the thyristor converter that can take into account the voltage requirements of the steady-state magnet under all operating conditions and significantly reduce reactive power.

[0004] In a first aspect, a hybrid triggering control method for a thyristor converter is provided, applied in a thyristor converter, wherein the thyristor converter includes at least two sub-full-bridges, each sub-full-bridge including connected common-cathode thyristors and common-anode thyristors; the method includes:

[0005] In the first trigger mode, a first trigger signal is output to the thyristors of each sub-full bridge so that the trigger angle of the common cathode group thyristors in each sub-full bridge is the same as the trigger angle of the common anode group thyristors; the thyristors of the sub-full bridge include common cathode group thyristors and common anode group thyristors;

[0006] In the second trigger mode, a second trigger signal is output to the common cathode group thyristors of each sub-full bridge, and a third trigger signal is output to the common anode group thyristors of each sub-full bridge, so that the trigger angle of the common cathode group thyristors in each sub-full bridge is different from that of the common anode group thyristors.

[0007] Among them, the maximum DC output voltage of each sub-bridge in the first trigger mode is greater than the maximum DC output voltage of each sub-bridge in the second trigger mode.

[0008] In one embodiment, the hybrid triggering control method for the thyristor converter further includes:

[0009] In the transition mode from the first trigger mode to the second trigger mode, a fourth trigger signal is output to the thyristors of each sub-full bridge so that the minimum trigger angle of each sub-full bridge thyristor is greater than the minimum trigger angle of each sub-full bridge in the first trigger mode.

[0010] After a preset time window, a fifth trigger signal is output to the common anode group thyristors of each sub-full bridge, so that the firing angle of the common anode group thyristors in each sub-full bridge is greater than the firing angle of the common cathode group thyristors.

[0011] In one embodiment, the hybrid triggering control method for the thyristor converter further includes:

[0012] In the switching mode, in each sub-full bridge, the difference between the firing angle of the common anode group thyristors and the firing angle of the common cathode group thyristors is greater than or equal to 75°.

[0013] In one embodiment, the preset time window is greater than or equal to 10ms.

[0014] In one embodiment, the hybrid triggering control method for the thyristor converter further includes:

[0015] In the second trigger mode, the sixth trigger signal is output to the common cathode group thyristor of the target sub-full bridge, and the seventh trigger signal is output to the common anode group thyristor of the target sub-full bridge, so as to adjust the trigger angle of the thyristors of the target sub-full bridge and maintain the maximum value of the DC output voltage of the two sub-full bridges.

[0016] The target sub-bridge is either one of the two sub-bridges.

[0017] Secondly, a thyristor converter is also provided, comprising:

[0018] At least two reactors are connected in parallel at their first ends to form a parallel node, which is used to connect the input end of the load.

[0019] At least two sub-full-bridges, each sub-full-bridge including connected common-cathode thyristors and common-anode thyristors. The common-anode thyristors of each sub-full-bridge are used to connect to the output terminals of the load respectively, and the common-cathode thyristors of each sub-full-bridge are connected one-to-one to the second terminal of each reactor. The number of sub-full-bridges is the same as the number of reactors.

[0020] The control module has multiple control terminals that are respectively connected to the controlled terminals of each sub-full bridge;

[0021] The control module is used to execute the steps of the hybrid trigger control method for the thyristor converter described above.

[0022] In one embodiment, where the thyristor converter includes two sub-full bridges, the thyristor converter further includes:

[0023] A rectifier transformer, the first winding of the secondary side of the rectifier transformer is connected to the AC side of one of the sub-full bridges, and the second winding of the secondary side of the rectifier transformer is connected to the AC side of the other sub-full bridge.

[0024] The line voltage phase of the second winding on the secondary side of the rectifier transformer is offset by a preset angle relative to the line voltage phase of the first winding on the secondary side of the rectifier transformer; the preset angle is configured to cancel out the characteristic subharmonics generated by the two sub-full bridges.

[0025] In one embodiment, the preset angle is 180°.

[0026] In one embodiment, the first winding of the secondary side of the rectifier transformer is connected to the AC side of one of the sub-full bridges in a delta connection, and the second winding of the secondary side of the rectifier transformer is connected to the AC side of the other sub-full bridge in a delta connection.

[0027] In one embodiment, the common cathode thyristor group includes three first thyristors, and the common anode thyristor group includes three second thyristors;

[0028] The cathodes of each first thyristor are connected in parallel and then connected to the second terminal of each reactor. The anodes of each first thyristor are used to connect to the three-phase AC signal.

[0029] The anodes of each second thyristor are connected in parallel to connect to the output terminals of the loads respectively, and the cathodes of each second thyristor are connected one-to-one to the anodes of each first thyristor.

[0030] The aforementioned thyristor converter and its hybrid triggering control method, based on the time-sharing use of the first and second triggering modes, can achieve rapid response based on the high DC voltage output capability of the first triggering mode during the excitation and demagnetization phases of the load, and achieve low reactive power operation based on the second triggering mode during the flattening phase of the load, thereby meeting the full-cycle operation requirements of the steady-state magnet. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 A flowchart illustrating a hybrid triggering control method for a thyristor converter according to one embodiment;

[0033] Figure 2This is a schematic diagram illustrating the switching of trigger modes based on the current change requirements of the load in a hybrid trigger control method for a thyristor converter, as described in one embodiment.

[0034] Figure 3 This is a schematic diagram of the trigger mode switching timing in a hybrid trigger control method for a thyristor converter according to an embodiment.

[0035] Figure 4 This is a schematic diagram of the operating conditions in a hybrid triggering control method for a thyristor converter according to an embodiment.

[0036] Figure 5 This is a simulation verification diagram of the circulating current control effect in a hybrid triggering control method for a thyristor converter according to an embodiment;

[0037] Figure 6 This is a structural block diagram of a thyristor converter according to one embodiment;

[0038] Figure 7 This is a block diagram of a sub-full bridge in a thyristor converter according to one embodiment;

[0039] Figure 8 One of the simulation verification waveforms of the switching mode of a thyristor converter according to an embodiment;

[0040] Figure 9 The second simulation verification waveform diagram of the switching mode of a thyristor converter according to an embodiment;

[0041] Figure 10 The grid-side current waveform of a thyristor converter in the second triggering mode is shown in one embodiment.

[0042] Figure 11 This is a harmonic analysis diagram of a thyristor converter in the second triggering mode, according to one embodiment. Detailed Implementation

[0043] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0045] It is understood that the terms "first," "second," etc., used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first thyristor may be referred to as a second thyristor, and similarly, a second thyristor may be referred to as a first thyristor. Both the first thyristor and the second thyristor are thyristors, but they are not the same thyristor.

[0046] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0047] It is understandable that "at least two" refers to two or more, and "more than" refers to two or more. "At least part of the element" refers to part or all of the element.

[0048] When used here, the singular forms of “a,” “an,” and “ / the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “including / contains” or “having” specify the presence of the stated feature, whole, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof.

[0049] In the low-voltage, high-current operation of a thyristor phase-controlled rectifier during the flat-top phase, the firing angle is pushed to nearly 90°, resulting in a large amount of fundamental reactive power in the converter system, requiring an additional, expensive reactive power compensation device. To address this issue, existing technologies have proposed a scheme based on cascaded thyristor converters with sequential control. This scheme can effectively reduce reactive power, but it requires multiple full-bridge modules to be physically cascaded, resulting in a complex topology and high cost, making it unsuitable for high-current steady-state magnet loads requiring low-voltage output.

[0050] In a specific embodiment, such as Figure 1 As shown, a hybrid triggering control method for a thyristor converter is provided, applied in a thyristor converter. The thyristor converter includes at least two sub-full-bridges, each sub-full-bridge including connected common-cathode thyristors and common-anode thyristors; the method includes:

[0051] S10, in the first trigger mode, output the first trigger signal to the thyristors of each sub-full bridge so that the trigger angle of the common cathode group thyristor in each sub-full bridge is the same as the trigger angle of the common anode group thyristor; the thyristors of the sub-full bridge include the common cathode group thyristors and the common anode group thyristors.

[0052] S20, in the second trigger mode, output a second trigger signal to the common cathode group thyristors of each sub-full bridge, and output a third trigger signal to the common anode group thyristors of each sub-full bridge, so that the trigger angle of the common cathode group thyristors in each sub-full bridge is different from that of the common anode group thyristors.

[0053] Among them, the maximum DC output voltage of each sub-bridge in the first trigger mode is greater than the maximum DC output voltage of each sub-bridge in the second trigger mode.

[0054] like Figure 2 As shown, in the first triggering mode, a first trigger signal is output to all thyristors. Since the trigger signals received by the common-cathode and common-anode thyristors are consistent, the first triggering mode is symmetrical triggering. At this time, the triggering angles of the common-cathode and common-anode thyristors within the same sub-bridge are the same. The maximum DC output voltage of the sub-bridge at this time is:

[0055] ,

[0056] in, The ideal maximum DC output voltage is the maximum value. This refers to the firing angle in the first firing mode. Adjusting the firing angle in the first firing mode, from 0° to nearly 90°, allows for continuous adjustment of the maximum DC output voltage from its maximum value down to near zero. This first firing mode outputs a higher DC voltage at a smaller firing angle, suitable for the high di / dt (current change rate) requirements of the load's excitation and demagnetization phases.

[0057] In the second triggering mode, phase-shifted trigger signals at the second trigger angle are distributed to all main circuit thyristors in the common-cathode group, and phase-shifted trigger pulses at the third trigger angle are distributed to all main circuit thyristors in the common-anode group. Since the trigger angles configured for the common-cathode and common-anode thyristors are different, the second triggering mode is asymmetrical triggering. At this time, the trigger angles of the common-cathode and common-anode thyristors within the same sub-bridge are different. The maximum DC output voltage of the thyristor converter at this time is:

[0058] ,

[0059] in, This refers to the common cathode group firing angle in the second firing mode. This is the common anode group trigger angle in the second trigger mode. By selecting a suitable ( , In a thyristor full-bridge configuration, the reactive power generated increases with the sine of the firing angle. Therefore, when a thyristor converter operates in asymmetrical firing mode, its reactive power increases with the sinusoidal value of the firing angle. ) and sin ( The voltage increases as the sum of the two groups increases. For example, taking the common cathode group firing angle as 15° and the common anode group firing angle as 128° in the second firing mode, and substituting them into the formula for the maximum DC output voltage in the second firing mode, the DC output voltage in this second firing mode corresponds to the DC output voltage corresponding to the firing angle of approximately 80° in the first firing mode, thus meeting the low voltage requirement during the flat-top phase. It should be noted that when the firing angle is determined, the specific value of the DC output voltage is also determined accordingly.

[0060] Specifically, cos15° + cos128° is approximately equal to 2*cos80°. Thus, the same DC output voltage of the converter is obtained. However, in asymmetrical triggering mode, the reactive power generated by the converter (sin15° + sin128°) is only 53% of the reactive power generated in symmetrical triggering mode (corresponding to 2*sin80°), which can greatly reduce the reactive power generated by the converter.

[0061] Therefore, this hybrid triggering control method for the thyristor converter, based on the time-sharing use of the first and second triggering modes, enables rapid response during the excitation and demagnetization phases of the load using the high DC voltage output capability of the first triggering mode, and achieves low reactive power operation during the flat-top phase of the load using the second triggering mode, thus meeting the full-cycle operation requirements of the steady-state magnet. Furthermore, this hybrid triggering control method can employ asymmetrical triggering under the second triggering mode during the flat-top phase, which accounts for the majority of the operating cycle, resulting in a significantly lower fundamental reactive power compared to traditional methods.

[0062] In one specific embodiment, the hybrid triggering control method for thyristor converters further includes:

[0063] In the transition mode from the first trigger mode to the second trigger mode, a fourth trigger signal is output to the thyristors of each sub-full bridge so that the minimum trigger angle of each sub-full bridge thyristor is greater than the minimum trigger angle of each sub-full bridge in the first trigger mode.

[0064] After a preset time window, a fifth trigger signal is output to the common anode group thyristors of each sub-full bridge, so that the firing angle of the common anode group thyristors in each sub-full bridge is greater than the firing angle of the common cathode group thyristors. Specifically, the difference between the minimum firing angle of the common anode group and the maximum firing angle of the common cathode group is greater than or equal to 75 degrees.

[0065] like Figure 3 and Figure 4 As shown, during the transition from the first trigger mode to the second trigger mode, the trigger angle changes significantly, and a sudden change in the trigger angle may cause commutation failure. For example, when switching the trigger angle from 75° to 15° / 115°, a direct jump may cause commutation failure. In the transition mode, the trigger angle of each sub-bridge is gradually adjusted from the trigger angle in the first trigger mode to the trigger angle corresponding to the fourth trigger signal in the transition mode. At this time, the AC converter enters an intermediate state, and all thyristors in the sub-bridges use the trigger angle corresponding to the fourth trigger signal in the transition mode. The trigger angle in the first trigger mode is greater than the trigger angle corresponding to the fourth trigger signal in the transition mode.

[0066] After a preset time window, the AC circuit can be guaranteed to enter steady-state operation. At this time, the firing angles of all common-cathode thyristors are kept constant, and the firing angles of all common-anode thyristors are changed from the firing angle corresponding to the fourth firing signal to the firing angle corresponding to the fifth firing signal in one go.

[0067] After the trigger angle change, the common anode trigger pulse corresponding to the fifth trigger signal will arrive only after a sufficiently large electrical angle, thus ensuring that all ongoing or impending commutation processes can be safely completed before this point, eliminating the possibility of commutation failure. Figure 3 In The common anode group firing angle before the conversion occurs. This is the firing angle of the common anode group after the conversion. Considering both before and after the conversion, = , = , and Δ = - .

[0068] In one specific embodiment, the hybrid triggering control method for thyristor converters further includes:

[0069] In the switching mode, in each sub-full bridge, the difference between the firing angle of the common anode group thyristors and the firing angle of the common cathode group thyristors is greater than or equal to 75°.

[0070] The maximum commutation overlap angle of a conventional thyristor converter is usually no more than 20°~30°. The 75° jump gap is more than twice this conventional value, providing sufficient safety margin for the completion of the commutation process, thereby ensuring the stable completion of commutation.

[0071] In one specific embodiment, the preset time window is greater than or equal to 10ms.

[0072] Waiting at least 10ms, or at least half a power frequency cycle, ensures that the thyristor converter enters a stable operating state upon receiving the fourth trigger signal. For example, the preset time window is 50ms. Preferably, the preset time window is 20ms.

[0073] In one specific embodiment, the hybrid triggering control method for thyristor converters further includes:

[0074] In the second trigger mode, the sixth trigger signal is output to the common cathode group thyristors of the target sub-full bridge, and the seventh trigger signal is output to the common anode group thyristors of the target sub-full bridge, so as to adjust the trigger angle of the thyristors of the target sub-full bridge and maintain the maximum value of the DC output voltage of the two sub-full bridges.

[0075] The target sub-bridge is either one of the two sub-bridges.

[0076] like Figure 5 As shown, the bridge 1 current represents the maximum DC output voltage of one sub-full bridge, and the bridge 2 current represents the maximum DC output voltage of the other sub-full bridge. In asymmetrical triggering mode, to avoid introducing extremely small or large trigger angles that could lead to excessively large commutation angles or commutation failure, the following method can be used: First, assume that the asymmetrical triggering mode has minimized... Set it to be close to the minimum trigger angle, Set it close to the maximum firing angle to minimize the reactive power generated by the thyristor converter.

[0077] In asymmetrical triggering mode, circulating current control can be introduced to ensure that the load current is evenly distributed between the two sub-full bridges. When the two sub-full bridges are connected in parallel, the firing angle combination corresponding to the maximum DC output voltage of the thyristor converter is ( ). , ), and the firing angles in this firing angle combination are commutation-safe firing angles. If one of the firing angle combinations of a sub-full bridge is ( , If a positive circulating voltage is introduced from one sub-bridge to the other, the load current of the first sub-bridge will increase, and the load current of the second sub-bridge will decrease. Therefore, the firing angle combination of the second sub-bridge can be selected as ( , ),in Greater than ,and Less than .because Greater than It is further away from the minimum firing angle, thus reducing the risk of commutation failure; and because Less than This distances the thyristor converter from the maximum firing angle, thus reducing the risk of commutation failure. Furthermore, by adjusting the appropriate firing angle combination, the following can be achieved regarding the maximum DC output voltage of the thyristor converter:

[0078] 0.5*[0.5*(cos +cos ) + 0.5 * (cos +cos )]=0.5*(cos +cos ),

[0079] In the above equation, the left side is the average value of the DC output voltage of the two sub-full bridges, which represents the actual maximum value of the DC output voltage of the thyristor converter; the right side is the expected value of the DC output voltage of the thyristor converter.

[0080] In a specific embodiment, such as Figure 6 As shown, a thyristor converter 10 is provided, including: at least two reactors 110, at least two sub-full bridges 120, and a control module ( Figure 6 (Not shown in the image).

[0081] The first terminals of each reactor 110 are connected in parallel to form a parallel node, which is used to connect to the input terminal of the load. The reactors are current-sharing reactors.

[0082] Each sub-bridge 120 includes a common cathode thyristor group 122 and a common anode thyristor group 124 connected together. The common anode thyristor group 124 of each sub-bridge 120 is used to connect to the output terminal of the load respectively. The common cathode thyristor group 122 of each sub-bridge 120 is connected to the second terminal of each reactor 110 in a one-to-one correspondence. The number of sub-bridges 120 is the same as the number of reactors 110.

[0083] The multiple control terminals of the control module are respectively connected to the controlled terminals of each sub-full bridge 120.

[0084] The control module is used for:

[0085] In the first trigger mode, a first trigger signal is output to the thyristors of each sub-full bridge 120 so that the trigger angle of the common cathode group thyristor 122 in each sub-full bridge 120 is the same as the trigger angle of the common anode group thyristor 124; the thyristors of the sub-full bridge 120 include the common cathode group thyristor 122 and the common anode group thyristor 124.

[0086] In the second trigger mode, a second trigger signal is output to the common cathode group thyristor 122 of each sub-full bridge 120, and a third trigger signal is output to the common anode group thyristor 124 of each sub-full bridge 120, so that the trigger angle of the common cathode group thyristor 122 and the trigger angle of the common anode group thyristor 124 in each sub-full bridge 120 are different.

[0087] Among them, the maximum DC output voltage of each sub-full bridge 120 in the first trigger mode is greater than the maximum DC output voltage of each sub-full bridge 120 in the second trigger mode.

[0088] Based on the time-sharing use of the first and second triggering modes, the high DC voltage output capability of the first triggering mode enables rapid response during the excitation and demagnetization phases of the load, while the second triggering mode enables low reactive power operation during the load plateau phase, thus meeting the full-cycle operation requirements of the steady-state magnet. Furthermore, this thyristor converter 10 can employ asymmetrical triggering under the second triggering mode during the plateau phase, which accounts for the majority of the operating cycle, resulting in a significant reduction in fundamental reactive power compared to traditional technical solutions.

[0089] In a specific embodiment, such as Figure 6 As shown, in the case where the thyristor converter 10 includes two sub-full bridges 120, the thyristor converter 10 also includes a rectifier transformer 130.

[0090] The first winding of the secondary side of the rectifier transformer 130 is connected to the AC side of one of the sub-full bridges 120, and the second winding of the secondary side of the rectifier transformer 130 is connected to the AC side of the other sub-full bridge 120.

[0091] The line voltage phase of the second winding on the secondary side of the rectifier transformer 130 is offset by a preset angle relative to the line voltage phase of the first winding on the secondary side of the rectifier transformer 130; the preset angle is configured to cancel out the characteristic subharmonics generated by the two sub-full bridges 120.

[0092] Since the secondary windings of the rectifier transformer 130, which are connected to the two sub-full bridges respectively, have opposite polarities, there is a 180° phase shift between the two sub-full bridges.

[0093] The DC sides of the two thyristor converters 10 are connected in parallel through corresponding reactors 110 to supply power to the load. This load can be a magnetic load, which can be equivalent to a resistor module and an inductor module connected in series. The reactor 110 can be a current-sharing reactor 110.

[0094] In the second triggering mode, due to the large difference between the triggering angles of the common cathode group and the common anode group, a shoot-through phenomenon will occur inside the sub-full bridge 120. That is, the load current will directly continue through the thyristor and no longer flow through the transformer winding, thereby significantly reducing the effective value of the transformer current and reactive power.

[0095] Therefore, the thyristor converter 10 does not require physical cascading of multiple sub-full bridges 120. By using the parallel structure of two sub-full bridges 120 and cooperating with the control module for symmetrical and asymmetrical triggering under different operating conditions, it can meet the voltage requirements of all operating conditions with low cost and high reliability.

[0096] In one specific embodiment, the preset angle is 180°.

[0097] With a preset angle of 180°, the primary and secondary sides of the rectifier transformer 130 have a phase shift of 0° / -180°, that is, the line voltage phase of the secondary side lags behind the line voltage phase of the primary side by 180°, thereby reliably canceling the characteristic subharmonics generated by the two sub-full bridges 120.

[0098] In one specific embodiment, the first winding of the secondary side of the rectifier transformer 130 is connected to the AC side of one of the sub-full bridges 120 in a delta connection, and the second winding of the secondary side of the rectifier transformer 130 is connected to the AC side of the other sub-full bridge 120 in a delta connection.

[0099] Thyristor rectification is a nonlinear load, generating third harmonic currents of the 3rd, 9th, and 15th orders. The three-phase third harmonics are in identical phase. In a delta-connected winding, the windings form a closed loop, and the third harmonic circulates within the delta coil, thus being dissipated by the winding copper losses. Furthermore, the delta connection prevents harmonics from entering the primary-side power grid, avoiding grid distortion and overheating.

[0100] In a specific embodiment, such as Figure 7 As shown, the common cathode group thyristor 122 includes three first thyristors 1222, and the common anode group thyristor 124 includes three second thyristors 1242.

[0101] The cathodes of each first thyristor 1222 are connected in parallel to the second terminal of each reactor 110, and the anodes of each first thyristor 1222 are used to connect to the three-phase AC signal.

[0102] The anodes of each second thyristor 1242 are connected in parallel to connect to the output terminals of the loads respectively, and the cathodes of each second thyristor 1242 are connected one-to-one to the anodes of each first thyristor 1222.

[0103] like Figure 8 and Figure 9 As shown, in =25° =135° and =15° Simulations were conducted under two conditions: 135° and 135°. It can be observed that all thyristors commutate smoothly without any commutation failures; each bridge arm current experiences a brief, predictable circulating current disturbance at the moment of switching, which decays naturally within one power frequency cycle. The simulation results verify the effectiveness and controllability of the thyristor converter 10. Specifically, the sub-full-bridge 1 current represents the maximum DC output voltage of one sub-full-bridge, and the sub-full-bridge 2 current represents the maximum DC output voltage of the other sub-full-bridge.

[0104] Furthermore, such as Figure 10 and Figure 11 As shown, in the asymmetric triggering mode ( =15°, Harmonic analysis of the primary grid-side current of the transformer was performed at an angle of 130°. The results showed that the second harmonic content was extremely low, verifying the cancellation effect of the 0° / -180° phase shift topology on even harmonics at the preset angle. Reactive power calculations showed that, compared with the traditional symmetrically triggered thyristor converter 10 under the same operating conditions, the reactive power output of this thyristor converter 10 was significantly reduced. Specifically, bridge 1 is one of the two sub-full-bridges 120, and bridge 2 is the other sub-full-bridge 120.

[0105] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0106] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0107] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A hybrid trigger control method of a thyristor converter, characterized by, The method is applied in a thyristor converter, wherein the thyristor converter includes at least two sub-full-bridges, each sub-full-bridge including connected common-cathode thyristors and common-anode thyristors; the method includes: In the first trigger mode, a first trigger signal is output to the thyristors of each sub-full bridge so that the trigger angle of the common cathode group thyristor in each sub-full bridge is the same as the trigger angle of the common anode group thyristor; the thyristors of the sub-full bridge include the common cathode group thyristors and the common anode group thyristors; In the second trigger mode, a second trigger signal is output to the common cathode group thyristors of each of the sub-full bridges, and a third trigger signal is output to the common anode group thyristors of each of the sub-full bridges, so that the trigger angle of the common cathode group thyristors in each of the sub-full bridges is different from that of the common anode group thyristors. Wherein, the maximum value of the DC output voltage jointly output by each of the sub-full bridges in the first trigger mode is greater than the maximum value of the DC output voltage jointly output by each of the sub-full bridges in the second trigger mode; In the transition mode from the first trigger mode to the second trigger mode, a fourth trigger signal is output to the thyristors of each of the sub-full bridges, so that the minimum trigger angle of each of the sub-full bridges is greater than the minimum trigger angle of each of the sub-full bridges in the first trigger mode. After a preset time window, a fifth trigger signal is output to the common anode group thyristors of each of the sub-full bridges, so that the trigger angle of the common anode group thyristors in each of the sub-full bridges is greater than the trigger angle of the common cathode group thyristors.

2. The hybrid trigger control method of the thyristor converter according to claim 1, characterized by, Also includes: In the switching mode, in each of the sub-full bridges, the difference between the firing angle of the common anode group thyristor and the firing angle of the common cathode group thyristor is greater than or equal to 75°.

3. The hybrid trigger control method of the thyristor converter according to claim 1, characterized by, The preset time window is greater than or equal to 10ms.

4. The hybrid trigger control method of the thyristor converter according to claim 1, characterized by, In the case where the thyristor converter includes two sub-full bridges, it also includes: In the second trigger mode, a sixth trigger signal is output to the common cathode group thyristors of the target sub-full bridge, and a seventh trigger signal is output to the common anode group thyristors of the target sub-full bridge, so as to adjust the trigger angle of the thyristors of the target sub-full bridge and maintain the maximum value of the DC output voltage output by the two sub-full bridges unchanged. The target sub-full bridge is either of the two sub-full bridges.

5. A thyristor converter, characterized in that, include: At least two reactors, the first ends of each reactor are connected in parallel to form a parallel node, the parallel node being used to connect to the input terminal of the load; At least two sub-full-bridges, each sub-full-bridge including a common cathode group thyristor and a common anode group thyristor connected together, the common anode group thyristors of each sub-full-bridge being used to connect to the output terminal of the load respectively, and the common cathode group thyristors of each sub-full-bridge being connected one-to-one to the second terminal of each reactor; the number of sub-full-bridges is the same as the number of reactors; A control module, wherein multiple control terminals of the control module are respectively connected to the controlled terminals of each of the sub-full bridges; The control module is used to perform the steps of the method according to any one of claims 1 to 4.

6. The thyristor converter according to claim 5, characterized in that, In the case where the thyristor converter includes two sub-full bridges, the thyristor converter further includes: A rectifier transformer, wherein the first winding of the secondary side of the rectifier transformer is connected to the AC side of one of the sub-full bridges, and the second winding of the secondary side of the rectifier transformer is connected to the AC side of the other sub-full bridge. The line voltage phase of the second winding on the secondary side of the rectifier transformer is offset by a preset angle relative to the line voltage phase of the first winding on the secondary side of the rectifier transformer; the preset angle is configured to cancel out the characteristic subharmonics generated by the two sub-full bridges.

7. The thyristor converter according to claim 6, characterized in that, The preset angle is 180°.

8. The thyristor converter according to claim 6, characterized in that, The first winding of the secondary side of the rectifier transformer is connected to the AC side of one of the sub-full bridges in a delta connection, and the second winding of the secondary side of the rectifier transformer is connected to the AC side of the other sub-full bridge in a delta connection.

9. The thyristor converter according to claim 5, characterized in that, The common cathode thyristor group includes three first thyristors, and the common anode thyristor group includes three second thyristors; The cathodes of each of the first thyristors are connected in parallel and then connected to the second terminal of each of the reactors. The anodes of each of the first thyristors are used to receive three-phase AC signals. The anodes of each of the second thyristors are connected in parallel to connect to the output terminals of the load, and the cathodes of each of the second thyristors are connected one-to-one to the anodes of each of the first thyristors.

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