Thyristor enhanced switching circuit and control method thereof
By adopting a thyristor-enhanced switching circuit in the power system, combining the IGBT branch and the thyristor-assisted overload branch, the overload bottleneck problem of voltage source converters is solved, and the overload capacity improvement and equipment robustness enhancement under limited cost and volume constraints are achieved.
Patent Information
- Application Number
- CN202510564589.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-30
- Publication Date
- 2025-08-12
AI Technical Summary
In existing power systems, the instantaneous overload capacity of voltage source converters is insufficient, resulting in increased equipment volume, low component utilization and poor economicality, making it difficult to meet the overload requirements of new power systems under limited costs and volume constraints.
The thyristor-enhanced switching circuit is adopted, combined with the IGBT branch and the thyristor-assisted overload branch, and the current is transferred when the current is overloaded through a specific control method, and the high current flow capacity of the thyristor is used to enhance the overload capacity and reduce costs.
Under the constraints of limited costs and volume, the overload capacity and robustness of the power system are improved, the internal components of the equipment are effectively utilized, and the equipment volume and cost are reduced.
Smart Images
Figure CN120474537A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of power electronics technology, and in particular to a thyristor enhancement type switching circuit and a control method thereof. Background Art
[0002] With the continuous advancement of the construction of new power systems, the scale of grid connection of new energy units has gradually increased, multi-circuit ultra-high voltage AC and DC projects have been put into operation one after another, and conventional thermal power units have been gradually withdrawn. The operating characteristics of the power grid have undergone profound changes. The connection of a high proportion of renewable energy to the power grid through power electronic converter valves has become an important trend in the development of the power system.
[0003] In traditional synchronous generators, the rotor is driven by a prime mover, and the rotor's speed makes changes in voltage and frequency more conducive to maintaining power system stability. When all power generation units are composed of power electronic converters, in order to ensure voltage support and active inertia support for renewable energy integration, thereby improving grid robustness, the converters need to have a current overload capacity similar to that of traditional dynamic generators, capable of withstanding overload currents in the event of system failures or fluctuations.
[0004] In related technologies, voltage source converters (VSCs) generally use insulated gate bipolar transistor (IGBT) modules as their core power devices. Limited by the thermal capacitance of semiconductor devices, their transient overload capacity is typically less than twice the rated current. To meet the current overload requirements of converters under grid control, related technologies generally employ a redundant parallel connection of components. However, this approach presents numerous issues, including an exponential increase in equipment size, low internal component utilization under non-overload conditions, and poor overall technical and economic efficiency.
[0005] In view of this, how to break through the transient overload bottleneck of voltage source converters under limited cost and volume constraints has become a key technical problem restricting the safe and stable operation of new power systems, and a feasible and effective solution is urgently needed. Summary of the Invention
[0006] In view of this, the embodiments of the present disclosure provide a thyristor-enhanced switching circuit and a control method thereof, which can replace the original IGBT module with a thyristor-enhanced switch while adopting a classic modular multi-level converter architecture, and adopt a specific control method during the current overload period, so that the voltage source converter can break through the transient overload bottleneck under limited cost and volume constraints, control the equipment volume, reduce costs, improve the utilization rate of the internal components of the equipment, and improve the overload capacity of the equipment and the robustness of the power system under grid control.
[0007] In a first aspect, an embodiment of the present disclosure provides a thyristor-enhanced switching circuit, comprising an IGBT branch consisting of an insulated gate bipolar transistor (1) and a thyristor auxiliary overload branch, wherein the thyristor auxiliary overload branch comprises a thyristor (2) and a passive auxiliary commutation module, and the passive auxiliary commutation module comprises a transient voltage suppression diode (3) and a capacitor (4) connected in parallel;
[0008] The collector of the insulated gate bipolar transistor (1) is connected to the anode of the thyristor (2); the emitter of the insulated gate bipolar transistor (1) is connected to the negative electrode of the capacitor (4) and one end of the transient voltage suppression diode (3); the cathode of the thyristor (2) is connected to the other end of the transient voltage suppression diode (3) and the positive electrode of the capacitor (4); and the transient voltage suppression diode (3) is connected in parallel to both ends of the capacitor (4).
[0009] In some embodiments, the transient voltage suppression diode (3) is used to control the magnitude of the clamping voltage, and the capacitor (4) is used to suppress the clamping voltage, so that the passive auxiliary commutation module obtained by connecting the transient voltage suppression diode (3) and the capacitor (4) in parallel is equivalent to a voltage source, thereby increasing the equivalent on-state voltage drop of the thyristor auxiliary overload branch;
[0010] The calculation formula of the equivalent on-state voltage drop is as follows:
[0011] U eq =U SCR +U C ;
[0012] Among them, U eq Indicates the equivalent on-state voltage drop; U SCR represents the on-state voltage drop of the thyristor (2); U C represents the voltage of the capacitor (4).
[0013] In some embodiments, the equivalent on-state voltage drop is greater than the on-state voltage drop of the insulated gate bipolar transistor (1), so that the current of the thyristor auxiliary overload branch is transferred to the IGBT branch for shutdown. The equivalent on-state voltage drop and the on-state voltage drop of the insulated gate bipolar transistor (1) are expressed by the following formula:
[0014] U eq >U IGBT ;
[0015] Among them, U eq Represents the equivalent on-state voltage drop; U IGBT represents the on-state voltage drop of the insulated gate bipolar transistor (1).
[0016] In some embodiments, when the forward current of the thyristor auxiliary overload branch is less than or equal to zero, the thyristor (2) is reliably turned off. Based on the volt-ampere characteristic curve of the thyristor (2), U SCR If the value is zero, the current of the thyristor auxiliary overload branch is transferred to the IGBT branch for shutdown, and the following conditions must be met:
[0017] U C >U IGBT ;
[0018] Among them, U C represents the voltage of the capacitor (4), U C The value is determined by the maximum clamping voltage of the transient voltage suppression diode (3); U IGBT represents the on-state voltage drop of the insulated gate bipolar transistor (1).
[0019] In a second aspect, an embodiment of the present disclosure further provides a thyristor-enhanced switching circuit, comprising an IGBT branch consisting of an insulated gate bipolar transistor (1) and a thyristor auxiliary overload branch, wherein the thyristor auxiliary overload branch comprises a thyristor (2) and a passive auxiliary commutation module, and the passive auxiliary commutation module comprises a varistor (5) and a capacitor (4);
[0020] The collector of the insulated gate bipolar transistor (1) is connected to the anode of the thyristor (2); the emitter of the insulated gate bipolar transistor (1) is connected to the negative electrode of the capacitor (4) and one end of the varistor (5); the cathode of the thyristor (2) is connected to the other end of the varistor (5) and the positive electrode of the capacitor (4); and the varistor (5) is connected in parallel to both ends of the capacitor (4).
[0021] In a third aspect, an embodiment of the present disclosure further provides a thyristor-enhanced switching circuit, comprising an IGBT branch consisting of an insulated gate bipolar transistor (1) and a thyristor auxiliary overload branch, wherein the thyristor auxiliary overload branch comprises a thyristor (2) and a passive auxiliary commutation module, and the passive auxiliary commutation module comprises a breakdown gap (6) and a capacitor (4);
[0022] The collector of the insulated gate bipolar transistor (1) is connected to the anode of the thyristor (2); the emitter of the insulated gate bipolar transistor (1) is connected to the negative electrode of the capacitor (4) and one end of the breakdown gap (6); the cathode of the thyristor (2) is connected to the other end of the breakdown gap (6) and the positive electrode of the capacitor (4); and the breakdown gap (6) is connected in parallel to both ends of the capacitor (4).
[0023] In a fourth aspect, an embodiment of the present disclosure further provides a thyristor-enhanced switching circuit, comprising an IGBT branch consisting of an insulated gate bipolar transistor (1) and a thyristor auxiliary overload branch, wherein the thyristor auxiliary overload branch comprises a thyristor (2) and a passive auxiliary commutation module, and the passive auxiliary commutation module comprises a constant resistor (7) and a capacitor (4);
[0024] The collector of the insulated gate bipolar transistor (1) is connected to the anode of the thyristor (2); the emitter of the insulated gate bipolar transistor (1) is connected to the negative electrode of the capacitor (4) and one end of the constant resistor (7); the cathode of the thyristor (2) is connected to the other end of the constant resistor (7) and the positive electrode of the capacitor (4); and the constant resistor (7) is connected in parallel to both ends of the capacitor (4).
[0025] In a fifth aspect, an embodiment of the present disclosure further provides a method for controlling a thyristor enhancement mode switch circuit, the method comprising the following steps:
[0026] When the converter current overload is not detected, the current flows through the IGBT branch;
[0027] When a current overload of the converter is detected, the thyristor auxiliary overload branch is controlled to be turned on, and after the thyristor auxiliary overload branch is fully turned on, the IGBT branch is controlled to be soft-turned off, so as to transfer the current from the IGBT branch to the thyristor auxiliary overload branch;
[0028] When the current is completely transferred from the IGBT branch to the thyristor auxiliary overload branch and flows through the transient voltage suppression diode (3) and the capacitor (4) connected in series with the thyristor (2), under the impact of transient current, the transient voltage suppression diode (3) clamps the voltage across the terminals to the voltage of the capacitor (4), and the capacitor C is quickly charged to the voltage of the capacitor (4); the thyristor (2) carries the overload current of the converter;
[0029] When the thyristor enhanced switching circuit needs to be turned off, the IGBT branch is controlled to be soft-turned on. Since the equivalent on-state voltage drop of the thyristor auxiliary overload branch is greater than the on-state voltage drop of the IGBT branch, the current will be transferred from the thyristor auxiliary overload branch to the IGBT branch.
[0030] When the current is completely transferred from the thyristor auxiliary overload branch to the IGBT branch, the conducting state of the IGBT branch is maintained within a preset time period.
[0031] In some embodiments, when the current is completely transferred from the thyristor auxiliary overload branch to the IGBT branch, after maintaining the IGBT branch in a conductive state for a preset time period, the method further includes:
[0032] The conduction time of the IGBT branch is greater than or equal to the reverse recovery time of the thyristor (2);
[0033] When the thyristor (2) is turned off, the IGBT branch is controlled to be turned off, thereby realizing the turn-off of the thyristor enhancement type switching circuit.
[0034] In some embodiments, when the thyristor enhanced switching circuit needs to be turned off, the IGBT branch is controlled to be soft-turned on. Since the equivalent on-state voltage drop of the thyristor auxiliary overload branch is greater than the on-state voltage drop of the IGBT branch, the current is transferred from the thyristor auxiliary overload branch to the IGBT branch, further comprising:
[0035] The transient voltage suppression diode (3) stabilizes the voltage of the capacitor (4) in the passive auxiliary commutation module near the reverse cut-off voltage of the transient voltage suppression diode (3), and the voltage of the passive auxiliary commutation module is greater than the on-state voltage drop of the IGBT branch, so that the current is smoothly commutated from the thyristor auxiliary overload branch to the IGBT branch;
[0036] The passive auxiliary commutation module includes the transient voltage suppression diode (3) and the capacitor (4) connected in parallel.
[0037] In a sixth aspect, the embodiments of the present disclosure further provide a computer device, which adopts the following technical solution:
[0038] The computer device comprises:
[0039] at least one processor; and,
[0040] a memory communicatively connected to the at least one processor; wherein,
[0041] The memory stores instructions that can be executed by the at least one processor. The instructions are executed by the at least one processor to enable the at least one processor to perform any of the above-mentioned control methods for thyristor enhancement type switching circuits.
[0042] In a seventh aspect, an embodiment of the present disclosure further provides a computer-readable storage medium, which stores computer instructions, and the computer instructions are used to enable a computer to execute any of the above-mentioned control methods for thyristor enhancement switching circuits.
[0043] In an eighth aspect, an embodiment of the present disclosure further provides a computer program product, comprising a computer program / instruction, which implements the steps of any of the above methods when executed by a processor.
[0044] The embodiments of the present disclosure provide a thyristor-enhanced switching circuit and a control method thereof. While adopting a classic modular multi-level converter architecture, thyristor-enhanced switches can replace the original IGBT modules. A specific control method is employed during current overload periods, enabling voltage source converters to break through the transient overload bottleneck within limited cost and volume constraints. The thyristor-enhanced switching circuit is applied to large-capacity converters, thereby improving the instantaneous multiple overload capacity of large-capacity converters at low cost and with high technical and economic efficiency. The high-current shutdown capability of insulated gate bipolar transistor devices and the high-current sharing capability of thyristor devices are effectively utilized, resulting in the hybrid switch's transient current overload performance significantly exceeding that of a single insulated gate bipolar transistor. This effectively controls equipment size, reduces costs, improves the utilization rate of internal components of the equipment, and enhances the equipment's overload capacity and the robustness of the power system under grid control.
[0045] The above description is only an overview of the technical solution of the present disclosure. In order to more clearly understand the technical means of the present disclosure, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present disclosure more obvious and easy to understand, the following specifically cites preferred embodiments and describes them in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0046] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.
[0047] Figure 1 A schematic diagram of a thyristor enhancement type switch circuit structure is provided for an embodiment of the present disclosure;
[0048] Figure 2 Equivalent diagram of the thyristor auxiliary overload branch and the IGBT branch provided in the embodiment of the present disclosure;
[0049] Figure 3 A schematic structural diagram of a passive auxiliary commutation module provided in an embodiment of the present disclosure;
[0050] Figure 4 A schematic structural diagram of another passive auxiliary commutation module provided in an embodiment of the present disclosure;
[0051] Figure 5 A schematic structural diagram of another passive auxiliary commutation module provided in an embodiment of the present disclosure;
[0052] Figure 6 A schematic flow chart of a control method for a thyristor enhancement type switching circuit provided by an embodiment of the present disclosure;
[0053] Figure 7 A schematic diagram of the principle of a control method for a thyristor enhancement type switching circuit provided by an embodiment of the present disclosure;
[0054] Figure 8 A schematic structural diagram of a large-capacity, high-transient-current-overload-capacity converter using a thyristor-enhanced switching circuit provided in an embodiment of the present disclosure;
[0055] Figure 9 A schematic diagram of the structure of a computer device provided in an embodiment of the present disclosure. DETAILED DESCRIPTION
[0056] The embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.
[0057] It should be clear that the following embodiments of the present disclosure are described through specific concrete examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. The present disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present disclosure. It should be noted that the following embodiments and features in the embodiments can be combined with each other in the absence of conflict. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present disclosure.
[0058] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on this disclosure, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.
[0059] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present disclosure. The illustrations only show components related to the present disclosure and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.
[0060] Additionally, in the following description, specific details are provided to provide a thorough understanding of the examples. However, one skilled in the art will appreciate that the aspects described can be practiced without these specific details.
[0061] like Figure 1 As shown, Figure 1 A schematic structural diagram of a thyristor enhancement type switching circuit is provided for an embodiment of the present disclosure. The embodiment of the present disclosure provides a thyristor enhancement type switching circuit, comprising an IGBT branch composed of an insulated gate bipolar transistor (1) and a thyristor auxiliary overload branch, wherein the thyristor auxiliary overload branch comprises a thyristor (2) and a passive auxiliary commutation module, and the passive auxiliary commutation module comprises a transient voltage suppression diode (3) and a capacitor (4) connected in parallel;
[0062] The collector of the insulated gate bipolar transistor (1) is connected to the anode of the thyristor (2); the emitter of the insulated gate bipolar transistor (1) is connected to the negative electrode of the capacitor (4) and one end of the transient voltage suppression diode (3); the cathode of the thyristor (2) is connected to the other end of the transient voltage suppression diode (3) and the positive electrode of the capacitor (4); and the transient voltage suppression diode (3) is connected in parallel to both ends of the capacitor (4).
[0063] The thyristor-enhanced switching circuit provided in the embodiments of the present disclosure can replace the original IGBT module with a thyristor-enhanced switch while adopting a classic modular multi-level converter architecture. By adopting a specific control method during current overload, the voltage source converter can break through the transient overload bottleneck under limited cost and volume constraints. This can effectively control the equipment volume, reduce costs, improve the utilization rate of the internal components of the equipment, and enhance the overload capacity of the equipment and the robustness of the power system under grid control.
[0064] like Figure 2 As shown, Figure 2 An equivalent diagram of a thyristor auxiliary overload branch and an IGBT branch provided in an embodiment of the present disclosure, wherein the transient voltage suppression diode (3) is used to control the magnitude of the clamping voltage, and the capacitor (4) is used to maintain the clamping voltage, so that the passive auxiliary commutation module obtained by connecting the transient voltage suppression diode (3) and the capacitor (4) in parallel is equivalent to a voltage source, thereby increasing the equivalent on-state voltage drop of the thyristor auxiliary overload branch;
[0065] The calculation formula of the equivalent on-state voltage drop is as follows:
[0066] U eq =U SCR +U C ;
[0067] Among them, U eqIndicates the equivalent on-state voltage drop; U SCR represents the on-state voltage drop of the thyristor (2); U C represents the voltage of the capacitor (4).
[0068] In some embodiments, the equivalent on-state voltage drop is greater than the on-state voltage drop of the insulated gate bipolar transistor (1), so that the current of the thyristor auxiliary overload branch is transferred to the IGBT branch for shutdown. The equivalent on-state voltage drop and the on-state voltage drop of the insulated gate bipolar transistor (1) are expressed by the following formula:
[0069] U eq >U IGBT ;
[0070] Among them, U eq Represents the equivalent on-state voltage drop; U IGBT represents the on-state voltage drop of the insulated gate bipolar transistor (1).
[0071] In some embodiments, when the forward current of the thyristor auxiliary overload branch is less than or equal to zero, the thyristor (2) is reliably turned off. Based on the volt-ampere characteristic curve of the thyristor (2), U SCR If the value is zero, the current of the thyristor auxiliary overload branch is transferred to the IGBT branch for shutdown, and the following conditions must be met:
[0072] U C >U IGBT ;
[0073] Among them, U C represents the voltage of the capacitor (4), U C The value is determined by the maximum clamping voltage of the transient voltage suppression diode (3); U IGBT represents the on-state voltage drop of the insulated gate bipolar transistor (1).
[0074] like Figure 3 As shown, Figure 3 A schematic structural diagram of a passive auxiliary commutation module provided in an embodiment of the present disclosure. The embodiment of the present disclosure further provides a thyristor-enhanced switching circuit, wherein a transient voltage suppression diode (3) in the passive auxiliary commutation module can be replaced by a varistor (5), and the thyristor-enhanced switching circuit comprises an IGBT branch composed of an insulated gate bipolar transistor (1) and a thyristor-assisted overload branch, wherein the thyristor-assisted overload branch comprises a thyristor (2) and a passive auxiliary commutation module, and the passive auxiliary commutation module comprises a varistor (5) and a capacitor (4);
[0075] The collector of the insulated gate bipolar transistor (1) is connected to the anode of the thyristor (2); the emitter of the insulated gate bipolar transistor (1) is connected to the negative electrode of the capacitor (4) and one end of the varistor (5); the cathode of the thyristor (2) is connected to the other end of the varistor (5) and the positive electrode of the capacitor (4); and the varistor (5) is connected in parallel to both ends of the capacitor (4).
[0076] like Figure 4 As shown, Figure 4 A schematic structural diagram of another passive auxiliary commutation module provided in an embodiment of the present disclosure. The embodiment of the present disclosure further provides a thyristor-enhanced switching circuit, wherein the transient voltage suppression diode (3) in the passive auxiliary commutation module can be replaced with a breakdown gap (6), and the thyristor-enhanced switching circuit includes an IGBT branch composed of an insulated gate bipolar transistor (1) and a thyristor-assisted overload branch, wherein the thyristor-assisted overload branch includes a thyristor (2) and a passive auxiliary commutation module, and the passive auxiliary commutation module includes a breakdown gap (6) and a capacitor (4);
[0077] The collector of the insulated gate bipolar transistor (1) is connected to the anode of the thyristor (2); the emitter of the insulated gate bipolar transistor (1) is connected to the negative electrode of the capacitor (4) and one end of the breakdown gap (6); the cathode of the thyristor (2) is connected to the other end of the breakdown gap (6) and the positive electrode of the capacitor (4); and the breakdown gap (6) is connected in parallel to both ends of the capacitor (4).
[0078] like Figure 5 As shown, Figure 5 A schematic structural diagram of another passive auxiliary commutation module provided in an embodiment of the present disclosure. The embodiment of the present disclosure further provides a thyristor-enhanced switching circuit, wherein a transient voltage suppression diode (3) in the passive auxiliary commutation module can be replaced by a constant resistor (7), and the thyristor-enhanced switching circuit comprises an IGBT branch composed of an insulated gate bipolar transistor (1) and a thyristor-assisted overload branch, wherein the thyristor-assisted overload branch comprises a thyristor (2) and a passive auxiliary commutation module, and the passive auxiliary commutation module comprises a constant resistor (7) and a capacitor (4);
[0079] The collector of the insulated gate bipolar transistor (1) is connected to the anode of the thyristor (2); the emitter of the insulated gate bipolar transistor (1) is connected to the negative electrode of the capacitor (4) and one end of the constant resistor (7); the cathode of the thyristor (2) is connected to the other end of the constant resistor (7) and the positive electrode of the capacitor (4); and the constant resistor (7) is connected in parallel to both ends of the capacitor (4).
[0080] like Figure 6 As shown, Figure 6 This is a flow chart of a control method for a thyristor enhancement type switching circuit provided by an embodiment of the present disclosure. The present disclosure also provides a control method for a thyristor enhancement type switching circuit, the method comprising the following steps:
[0081] S101 : When no current overload of the converter is detected, the current flows through the IGBT branch.
[0082] S102 . When a current overload of the converter is detected, control the thyristor auxiliary overload branch to be turned on, and control the IGBT branch to be soft-turned off after the thyristor auxiliary overload branch is fully turned on, so as to transfer current from the IGBT branch to the thyristor auxiliary overload branch.
[0083] S103. When the current is completely transferred from the IGBT branch to the thyristor auxiliary overload branch and flows through the transient voltage suppression diode (3) and the capacitor (4) connected in series with the thyristor (2), under the impact of the transient current, the transient voltage suppression diode (3) clamps the voltage across the terminals to the voltage of the capacitor (4), and the capacitor C is quickly charged to the voltage of the capacitor (4); the thyristor (2) carries the overload current of the converter.
[0084] S104. When the thyristor enhanced switching circuit needs to be turned off, the IGBT branch is controlled to be soft-turned on. Since the equivalent on-state voltage drop of the thyristor auxiliary overload branch is greater than the on-state voltage drop of the IGBT branch, the current will be transferred from the thyristor auxiliary overload branch to the IGBT branch.
[0085] S105 : When the current is completely transferred from the thyristor auxiliary overload branch to the IGBT branch, maintaining the on state of the IGBT branch within a preset time period.
[0086] In some embodiments, when the current is completely transferred from the thyristor auxiliary overload branch to the IGBT branch, after maintaining the IGBT branch in a conductive state for a preset time period, the method further includes:
[0087] The conduction time of the IGBT branch is greater than or equal to the reverse recovery time of the thyristor (2);
[0088] When the thyristor (2) is turned off, the IGBT branch is controlled to be turned off, thereby realizing the turn-off of the thyristor enhancement type switching circuit.
[0089] In some embodiments, when the thyristor enhanced switching circuit needs to be turned off, the IGBT branch is controlled to be soft-turned on. Since the equivalent on-state voltage drop of the thyristor auxiliary overload branch is greater than the on-state voltage drop of the IGBT branch, the current is transferred from the thyristor auxiliary overload branch to the IGBT branch, further comprising:
[0090] The transient voltage suppression diode (3) stabilizes the voltage of the capacitor (4) in the passive auxiliary commutation module near the reverse cut-off voltage of the transient voltage suppression diode (3), and the voltage of the passive auxiliary commutation module is greater than the on-state voltage drop of the IGBT branch, so that the current is smoothly commutated from the thyristor auxiliary overload branch to the IGBT branch;
[0091] The passive auxiliary commutation module includes the transient voltage suppression diode (3) and the capacitor (4) connected in parallel.
[0092] like Figure 7 As shown, Figure 7 A schematic diagram of the principle of a control method for a thyristor enhanced switching circuit provided by an embodiment of the present disclosure is provided. In the time period t0-t1, no current overload of the converter is detected, the power system operates normally, and the current flows through the IGBT branch. In the time period t1-t2, the current overload of the converter is detected at time t1, the thyristor (2) is controlled to be turned on, and the thyristor auxiliary overload branch is turned on. After the thyristor (2) is fully turned on, that is, after the thyristor auxiliary overload branch is fully turned on, the IGBT branch is controlled to be soft-turned off, and the current is transferred from the IGBT branch to the thyristor auxiliary overload branch. Due to the influence of stray inductance, the current will not be immediately transferred from the IGBT branch to the thyristor (2), and the shutdown process of the IGBT branch is soft shutdown, and the shutdown has little effect on the temperature rise of the IGBT branch.
[0093] During the t2-t3 time period, after time t2, the current is completely transferred from the IGBT branch to the thyristor auxiliary overload branch and flows through the transient voltage suppression diode (3) and capacitor (4) connected in series with the thyristor (2). Under the impact of the transient current, the transient voltage suppression diode (3) clamps the voltage at both ends to the voltage of the capacitor (4), and the capacitor C is quickly charged to the voltage of the capacitor (4). In this stage, the thyristor (2) carries the overload current of the converter, and the thyristor (2) exerts its large current flow capacity.
[0094] During the time period t3-t4, the thyristor enhanced switching circuit needs to be turned off, and the IGBT branch is controlled to be soft-opened at time t3. Since the equivalent on-state voltage drop of the thyristor auxiliary overload branch is greater than the on-state voltage drop of the IGBT branch, the current will be transferred from the thyristor auxiliary overload branch to the IGBT branch. The opening of the IGBT branch is a soft opening. During this stage, the presence of the transient voltage suppression diode (3) will stabilize the voltage of the capacitor (4) in the passive auxiliary commutation module near the reverse cut-off voltage of the transient voltage suppression diode (3). The voltage of the passive auxiliary commutation module is greater than the on-state voltage drop of the IGBT branch, so that the current is smoothly commutated from the thyristor auxiliary overload branch to the IGBT branch.
[0095] During the time period t4-t5, at time t4, the current is completely transferred from the thyristor auxiliary overload branch to the IGBT branch. During the time period t4-t5, the IGBT branch needs to maintain the on state, and the on time of the IGBT branch should be greater than or equal to the reverse recovery time of the thyristor (2). After the thyristor (2) is turned off, the IGBT branch is controlled to be turned off at time t5 to achieve the turn-off of the entire thyristor enhanced switching circuit, and the IGBT branch exerts its high current turn-off capability.
[0096] like Figure 8 As shown, Figure 8 The schematic diagram of the structure of a large-capacity, high-transient-current-overload-capacity converter using a thyristor-enhanced switching circuit provided in an embodiment of the present disclosure has the same basic architecture as the classic MMC, and the control of the proposed converter under non-overload conditions is also consistent with the control of the classic converter. Figure 8 The enhancement module in the MMC is a thyristor enhancement type switching circuit. The high current carrying capacity of the insulated gate bipolar transistor (IGBT) is relatively weak. Without increasing the IGBT redundancy configuration in the MMC, forcibly using the IGBT to carry the overload current when the current is overloaded may cause damage to the IGBT.
[0097] In order to improve the overall technical economy and reliability of the equipment, the embodiment of the present disclosure proposes a large-capacity, high-transient current overload capacity converter using a thyristor-enhanced switching circuit. The thyristor-enhanced switching circuit is used in the MMC. IGBTs are used to carry current during normal flow, and thyristors are mainly used to carry current during overload flow, and IGBTs are responsible for shutting off the current. When the MMC is not overloaded, IGBTs are used to carry current. At this time, the IGBT conduction loss still accounts for the majority of the total loss. When the current is overloaded, the thyristor auxiliary overload branch is put into use to carry the overload current, which can greatly reduce the conduction loss of the IGBT, so that the contribution of the conduction loss to the heat generation of the IGBT during the overload period is reduced.
[0098] The computer device according to an embodiment of the present disclosure includes a memory and a processor. The memory is used to store non-transitory computer-readable instructions. Specifically, the memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory (cache). The non-volatile memory may include, for example, read-only memory (ROM), a hard disk, a flash memory, etc.
[0099] The processor may be a central processing unit (CPU) or other form of processing unit with data processing capabilities and / or instruction execution capabilities, and may control other components in the computer device to perform desired functions. In one embodiment of the present disclosure, the processor is configured to execute the computer-readable instructions stored in the memory, causing the computer device to execute all or part of the steps of the control method for the thyristor enhancement switching circuit described in each embodiment of the present disclosure.
[0100] Those skilled in the art should understand that in order to solve the technical problem of how to obtain a good user experience, this embodiment may also include well-known structures such as a communication bus and an interface, and these well-known structures should also be included in the scope of protection of this disclosure.
[0101] like Figure 9 The present invention provides a schematic diagram of the structure of a computer device according to an embodiment of the present invention. Figure 9 The computer device shown is only an example and should not limit the functions and scope of use of the embodiments of the present disclosure.
[0102] like Figure 9 As shown, the computer device may include a processor (e.g., a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) or a program loaded from a storage device into a random access memory (RAM). Various programs and data required for the operation of the computer device are also stored in the RAM. The processor, ROM, and RAM are connected to each other via a bus. An input / output (I / O) interface is also connected to the bus.
[0103] Typically, the following devices can be connected to the I / O interface: input devices such as sensors or visual information acquisition devices; output devices such as display screens; storage devices such as tapes and hard disks; and communication devices. The communication device can allow the computer device to communicate with other devices (such as edge computing devices) wirelessly or by wire to exchange data. Figure 9A computer device having various devices is shown, but it should be understood that it is not required to implement or possess all of the devices shown. More or fewer devices may be implemented or possessed instead.
[0104] In particular, according to an embodiment of the present disclosure, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present disclosure includes a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network via a communication device, or installed from a storage device, or installed from a ROM. When the computer program is executed by a processor, all or part of the steps of the control method of the thyristor enhancement type switching circuit of the embodiment of the present disclosure are performed.
[0105] For detailed description of this embodiment, please refer to the corresponding description in the aforementioned embodiments, which will not be repeated here.
[0106] According to an embodiment of the present disclosure, a computer-readable storage medium stores non-transitory computer-readable instructions. When the non-transitory computer-readable instructions are executed by a processor, all or part of the steps of the control method of the thyristor enhancement mode switch circuit described in each embodiment of the present disclosure are executed.
[0107] The above-mentioned computer-readable storage media include, but are not limited to, optical storage media (e.g., CD-ROMs and DVDs), magneto-optical storage media (e.g., MOs), magnetic storage media (e.g., magnetic tapes or mobile hard disks), media with built-in rewritable non-volatile memory (e.g., memory cards), and media with built-in ROM (e.g., ROM cartridges).
[0108] For detailed description of this embodiment, please refer to the corresponding description in the aforementioned embodiments, which will not be repeated here.
[0109] The basic principles of the present disclosure have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, and effects mentioned in this disclosure are merely illustrative and not restrictive, and should not be construed as necessarily possessed by each embodiment of the present disclosure. Furthermore, the specific details disclosed above are provided for illustrative purposes and to facilitate understanding, rather than as limitations. These details do not limit the present disclosure to necessarily being implemented using these specific details.
[0110] In the present disclosure, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. The block diagrams of the devices, devices, equipment, and systems involved in the present disclosure are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these devices, devices, equipment, and systems can be connected, arranged, or configured in any manner. Words such as "including," "comprising," "having," and the like are open-ended words, meaning "including but not limited to," and can be used interchangeably therewith. The words "or" and "and" used herein refer to the words "and / or" and can be used interchangeably therewith, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to," and can be used interchangeably therewith.
[0111] Additionally, as used herein, "or" used in a list of items beginning with "at least one" indicates a separate list, so that, for example, a list of "at least one of A, B, or C" means A or B or C, or AB or AC or BC, or ABC (i.e., A and B and C). Furthermore, the word "exemplary" does not mean that the example described is preferred or better than other examples.
[0112] It should also be noted that in the system and method of the present disclosure, each component or each step can be decomposed and / or recombined. Such decomposition and / or recombination should be regarded as equivalent solutions of the present disclosure.
[0113] Various changes, substitutions, and modifications may be made to the technology described herein without departing from the teachings defined by the appended claims. Moreover, the scope of the claims of this disclosure is not limited to the specific aspects of the processes, machines, manufactures, compositions of things, means, methods, and actions described above. Currently existing or later developed processes, machines, manufactures, compositions of things, means, methods, or actions that perform substantially the same function or achieve substantially the same results as the corresponding aspects described herein may be utilized. Accordingly, the appended claims include within their scope such processes, machines, manufactures, compositions of things, means, methods, or actions.
[0114] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.
[0115] The above description has been provided for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present disclosure to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.
Claims
1. A thyristor enhancement switching circuit, characterized in that: The invention comprises an IGBT branch composed of an insulated gate bipolar transistor (1) and a thyristor auxiliary overload branch, wherein the thyristor auxiliary overload branch comprises a thyristor (2) and a passive auxiliary commutation module, and the passive auxiliary commutation module comprises a transient voltage suppression diode (3) and a capacitor (4) connected in parallel; The collector of the insulated gate bipolar transistor (1) is connected to the anode of the thyristor (2); the emitter of the insulated gate bipolar transistor (1) is connected to the negative electrode of the capacitor (4) and one end of the transient voltage suppression diode (3); the cathode of the thyristor (2) is connected to the other end of the transient voltage suppression diode (3) and the positive electrode of the capacitor (4); and the transient voltage suppression diode (3) is connected in parallel to both ends of the capacitor (4).
2. The thyristor enhancement type switching circuit according to claim 1, characterized in that: The transient voltage suppression diode (3) is used to control the magnitude of the clamping voltage, and the capacitor (4) is used to maintain the clamping voltage, so that the passive auxiliary commutation module obtained by connecting the transient voltage suppression diode (3) and the capacitor (4) in parallel is equivalent to a voltage source, thereby increasing the equivalent on-state voltage drop of the thyristor auxiliary overload branch; The calculation formula of the equivalent on-state voltage drop is as follows: IN eq =U SCR +U C ; Among them, U eq Indicates the equivalent on-state voltage drop; U SCR represents the on-state voltage drop of the thyristor (2); U C represents the voltage of the capacitor (4).
3. The thyristor enhancement type switching circuit according to claim 2, characterized in that: The equivalent on-state voltage drop is greater than the on-state voltage drop of the insulated gate bipolar transistor (1), so that the current of the thyristor auxiliary overload branch is transferred to the IGBT branch for shutdown. The equivalent on-state voltage drop and the on-state voltage drop of the insulated gate bipolar transistor (1) are expressed by the following formula: IN eq >In IGBT ; Among them, U eq Represents the equivalent on-state voltage drop; U IGBT represents the on-state voltage drop of the insulated gate bipolar transistor (1).
4. The thyristor enhancement type switching circuit according to claim 3, characterized in that: When the forward current of the thyristor auxiliary overload branch is less than or equal to zero, the thyristor (2) is reliably turned off. Based on the volt-ampere characteristic curve of the thyristor (2), U SCR If the value is zero, the current of the thyristor auxiliary overload branch is transferred to the IGBT branch for shutdown, and the following conditions must be met: IN C >In IGBT ; Among them, U C represents the voltage of the capacitor (4), U C The value is determined by the maximum clamping voltage of the transient voltage suppression diode (3); U IGBT represents the on-state voltage drop of the insulated gate bipolar transistor (1).
5. A thyristor enhancement switching circuit, characterized in that: The invention comprises an IGBT branch composed of an insulated gate bipolar transistor (1) and a thyristor auxiliary overload branch, wherein the thyristor auxiliary overload branch comprises a thyristor (2) and a passive auxiliary commutation module, and the passive auxiliary commutation module comprises a varistor (5) and a capacitor (4); The collector of the insulated gate bipolar transistor (1) is connected to the anode of the thyristor (2); the emitter of the insulated gate bipolar transistor (1) is connected to the negative electrode of the capacitor (4) and one end of the varistor (5); the cathode of the thyristor (2) is connected to the other end of the varistor (5) and the positive electrode of the capacitor (4); and the varistor (5) is connected in parallel to both ends of the capacitor (4).
6. A thyristor enhancement switching circuit, characterized in that: The invention comprises an IGBT branch composed of an insulated gate bipolar transistor (1) and a thyristor auxiliary overload branch, wherein the thyristor auxiliary overload branch comprises a thyristor (2) and a passive auxiliary commutation module, and the passive auxiliary commutation module comprises a breakdown gap (6) and a capacitor (4); The collector of the insulated gate bipolar transistor (1) is connected to the anode of the thyristor (2); the emitter of the insulated gate bipolar transistor (1) is connected to the negative electrode of the capacitor (4) and one end of the breakdown gap (6); the cathode of the thyristor (2) is connected to the other end of the breakdown gap (6) and the positive electrode of the capacitor (4); and the breakdown gap (6) is connected in parallel to both ends of the capacitor (4).
7. A thyristor enhancement switching circuit, characterized in that: The invention comprises an IGBT branch composed of an insulated gate bipolar transistor (1) and a thyristor auxiliary overload branch, wherein the thyristor auxiliary overload branch comprises a thyristor (2) and a passive auxiliary commutation module, and the passive auxiliary commutation module comprises a constant resistor (7) and a capacitor (4); The collector of the insulated gate bipolar transistor (1) is connected to the anode of the thyristor (2); the emitter of the insulated gate bipolar transistor (1) is connected to the negative electrode of the capacitor (4) and one end of the constant resistor (7); the cathode of the thyristor (2) is connected to the other end of the constant resistor (7) and the positive electrode of the capacitor (4); and the constant resistor (7) is connected in parallel to both ends of the capacitor (4).
8. A control method for a thyristor enhancement switching circuit, characterized in that: The method comprises the following steps: When the converter current overload is not detected, the current flows through the IGBT branch; When a current overload of the converter is detected, the thyristor auxiliary overload branch is controlled to be turned on, and after the thyristor auxiliary overload branch is fully turned on, the IGBT branch is controlled to be soft-turned off, so as to transfer the current from the IGBT branch to the thyristor auxiliary overload branch; When the current is completely transferred from the IGBT branch to the thyristor auxiliary overload branch and flows through the transient voltage suppression diode (3) and the capacitor (4) connected in series with the thyristor (2), under the impact of transient current, the transient voltage suppression diode (3) clamps the voltage across the terminals to the voltage of the capacitor (4), and the capacitor C is quickly charged to the voltage of the capacitor (4); the thyristor (2) carries the overload current of the converter; When the thyristor enhanced switching circuit needs to be turned off, the IGBT branch is controlled to be soft-turned on. Since the equivalent on-state voltage drop of the thyristor auxiliary overload branch is greater than the on-state voltage drop of the IGBT branch, the current will be transferred from the thyristor auxiliary overload branch to the IGBT branch. When the current is completely transferred from the thyristor auxiliary overload branch to the IGBT branch, the conducting state of the IGBT branch is maintained within a preset time period.
9. The control method of the thyristor enhancement mode switch circuit according to claim 8, characterized in that: When the current is completely transferred from the thyristor auxiliary overload branch to the IGBT branch, after the IGBT branch is maintained in the on state for a preset time period, the method further includes: The conduction time of the IGBT branch is greater than or equal to the reverse recovery time of the thyristor (2); When the thyristor (2) is turned off, the IGBT branch is controlled to be turned off, thereby realizing the turn-off of the thyristor enhancement type switching circuit.
10. The control method of the thyristor enhancement mode switch circuit according to claim 8, characterized in that: When the thyristor enhanced switching circuit needs to be turned off, the IGBT branch is controlled to be soft-turned on. Since the equivalent on-state voltage drop of the thyristor auxiliary overload branch is greater than the on-state voltage drop of the IGBT branch, the current will be transferred from the thyristor auxiliary overload branch to the IGBT branch, and further comprising: The transient voltage suppression diode (3) stabilizes the voltage of the capacitor (4) in the passive auxiliary commutation module near the reverse cut-off voltage of the transient voltage suppression diode (3), and the voltage of the passive auxiliary commutation module is greater than the on-state voltage drop of the IGBT branch, so that the current is smoothly commutated from the thyristor auxiliary overload branch to the IGBT branch; The passive auxiliary commutation module includes the transient voltage suppression diode (3) and the capacitor (4) connected in parallel.