Energy taking system suitable for IGCT (integrated gate commutated thyristor) and power electronic equipment

Abstract

The utility model provides an energy taking system suitable for an IGCT (integrated gate commutated thyristor) and power electronic equipment. The energy taking system comprises an IGCT device; the RC damping circuit is connected with the anode of the IGCT device; the CT circuit is connected with the cathode of the IGCT device; the bidirectional energy taking circuit comprises an energy taking structure and a bidirectional controllable switch; when the bidirectional controllable switch is turned off or turned on, the RC damping circuit or the CT circuit charges the energy taking structure or stops charging the energy taking structure. The problems that in the prior art, an IGCT device is insufficient in energy supply in the whole operation period, a traditional energy taking circuit is low in energy taking efficiency, and the energy requirements of IGCT high-frequency on-off and hard driving cannot be met are solved.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and more specifically, to a power harvesting system and power electronic equipment suitable for IGCT. Background Technology

[0002] IGCT devices are highly effective in DC transmission due to their controllable turn-on and turn-off capabilities, strong current-carrying capacity, and strong short-circuit current withstand capability. However, the enormous energy required for their operation, especially during turn-off, has long limited their application in power systems. Ensuring the reliable turn-on and turn-off of IGCT devices is a prerequisite for maintaining the stable operation of converter valves. Therefore, ensuring a continuous and stable energy supply for IGCT actuation is particularly important.

[0003] In the existing technology, the energy supply of IGCT devices is insufficient throughout the entire operating cycle, especially when the device is subjected to positive and negative voltages and in the on state. The energy harvesting efficiency of traditional energy harvesting circuits is low, which makes it impossible to meet the energy requirements of IGCT high-frequency switching and hard drive. Utility Model Content

[0004] The main objective of this application is to provide an energy harvesting system and power electronic equipment suitable for IGCT, which solves the problem that the energy supply of IGCT devices is insufficient throughout the entire operating cycle and the energy harvesting efficiency of traditional energy harvesting circuits is low, resulting in the inability to meet the energy requirements of IGCT high-frequency switching and hard drive.

[0005] To achieve the above objectives, according to one aspect of this application, a power harvesting system suitable for IGCT is provided, comprising: an IGCT device; an RC damping circuit electrically connected to the anode of the IGCT device; a CT circuit electrically connected to the cathode of the IGCT device, the CT circuit being a circuit capable of generating a voltage in the presence of current flowing through the IGCT device; and a bidirectional power harvesting circuit, including a power harvesting structure and a bidirectional controllable switch; the power harvesting structure being electrically connected to the output terminal of the RC damping circuit and the output terminal of the CT circuit, respectively, and the power harvesting structure being connected in parallel with the bidirectional controllable switch. When the controllable switch is off, the RC damping circuit or the CT circuit charges the energy harvesting structure; when the bidirectional controllable switch is on, the RC damping circuit or the CT circuit stops charging the energy harvesting structure. Alternatively, the energy harvesting structure is electrically connected to the output terminals of the RC damping circuit and the CT circuit respectively via the bidirectional controllable switch. When the bidirectional controllable switch is on, the RC damping circuit or the CT circuit charges the energy harvesting structure; when the bidirectional controllable switch is off, the RC damping circuit or the CT circuit stops charging the energy harvesting structure.

[0006] Optionally, the energy harvesting structure is directly electrically connected to the output terminal of the RC damping circuit and the output terminal of the CT circuit, respectively. The bidirectional energy harvesting circuit further includes: a first diode, the cathode of which is electrically connected to the output terminal of the RC damping circuit, the cathode of which is also electrically connected to the first terminal of the bidirectional controllable switch, and the anode of which is electrically connected to the first terminal of the energy harvesting structure; and a second diode, the anode of which is electrically connected to the anode of the first diode, the cathode of which is electrically connected to the cathode of the IGCT device, and the cathode of which is also electrically connected to the second terminal of the bidirectional controllable switch.

[0007] Optionally, the bidirectional power extraction circuit further includes: a third diode, the anode of which is electrically connected to the cathode of the first diode, and the cathode of which is electrically connected to the second terminal of the power extraction structure; and a fourth diode, the anode of which is electrically connected to the cathode of the second diode, and the cathode of which is electrically connected to the second terminal of the power extraction structure.

[0008] Optionally, the energy harvesting structure is electrically connected to the output terminal of the RC damping circuit and the output terminal of the CT circuit respectively via the bidirectional controllable switch. The bidirectional controllable switch includes: a first reverse-conducting device, the first end of which is electrically connected to the output terminal of the RC damping circuit, and the second end of which is electrically connected to the first end of the energy harvesting structure; and a second reverse-conducting device, the first end of which is electrically connected to the first end of the first reverse-conducting device, and the second end of which is electrically connected to the second end of the energy harvesting structure.

[0009] Optionally, the bidirectional power extraction circuit further includes: a fifth diode, the anode of which is electrically connected to the second terminal of the first reverse-conducting device, and the cathode of which is electrically connected to the cathode of the IGCT device; and a sixth diode, the anode of which is electrically connected to the cathode of the fifth diode, and the cathode of which is electrically connected to the second terminal of the second reverse-conducting device.

[0010] Optionally, the first reverse-conducting device includes a first fully controlled device and a seventh diode connected in anti-parallel, wherein the cathode of the seventh diode is the first terminal of the first reverse-conducting device, and the anode of the seventh diode is the second terminal of the first reverse-conducting device; the second reverse-conducting device includes a second fully controlled device and an eighth diode connected in anti-parallel, wherein the anode of the eighth diode is the first terminal of the second reverse-conducting device, and the cathode of the eighth diode is the second terminal of the second reverse-conducting device.

[0011] Optionally, the energy harvesting structure is directly electrically connected to the output terminal of the RC damping circuit and the output terminal of the CT circuit, respectively. The energy harvesting structure is connected in parallel with the bidirectional controllable switch, and the bidirectional controllable switch includes a MOSFET.

[0012] Optionally, the RC damping circuit includes a first resistor and a second capacitor connected in series, and the CT circuit includes a current transformer.

[0013] Optionally, the energy harvesting system further includes a second resistor connected in parallel with the IGCT device.

[0014] According to another aspect of this application, a power electronic device is provided, comprising: any of the described energy harvesting systems suitable for IGCT.

[0015] Applying the technical solution of this application, the energy harvesting system of this application includes an IGCT device, an RC damping circuit, a CT circuit, and a bidirectional energy harvesting circuit including an energy harvesting structure and a bidirectional controllable switch. The RC damping circuit is electrically connected to the anode of the IGCT device, and the CT circuit is electrically connected to the cathode of the IGCT device. The energy harvesting structure is electrically connected to the output terminals of the RC damping circuit and the CT circuit, respectively. The energy harvesting structure is connected in parallel with the bidirectional controllable switch. When the bidirectional controllable switch is turned off or on, the RC damping circuit or the CT circuit charges or stops charging the energy harvesting structure. Alternatively, the energy harvesting structure is electrically connected to the output terminals of the RC damping circuit and the CT circuit, respectively, through the bidirectional controllable switch. When the bidirectional controllable switch is turned on or off, the RC damping circuit or the CT circuit charges or stops charging the energy harvesting structure. Existing technologies suffer from insufficient energy supply to IGCT devices throughout their entire operating cycle, and traditional energy harvesting circuits exhibit low energy extraction efficiency, resulting in an inability to meet the energy requirements for high-frequency switching and hard driving of IGCTs. This application addresses this issue by combining an RC damping circuit, a CT circuit, and a bidirectional energy harvesting circuit to achieve energy extraction from the IGCT device under three different states: positive and negative voltages during turn-off, and current flow during turn-on. The RC damping circuit is connected to the anode of the IGCT device to buffer and absorb voltage spikes generated during switching, while also providing an energy source for the energy harvesting circuit. The CT circuit is connected to the cathode of the IGCT device and can extract energy from the current of the IGCT device, thereby charging the energy harvesting structure. The bidirectional power extraction circuit, with its power extraction structure and bidirectional controllable switch, enables the circuit to adapt to the energy requirements of the IGCT device under different voltage directions and on / off states. This allows for full-cycle online power extraction of the IGCT device, enabling it to withstand positive and negative voltages when off and to have current flowing through it when on. This improves power extraction efficiency and the width of the power extraction window. Furthermore, the bidirectional controllable switch can be turned on or off to charge or stop charging the power extraction structure, avoiding unnecessary energy consumption by the RC damping circuit and CT circuit. This ensures that the voltage of the power extraction structure is within a safe and effective operating range, thereby improving the reliability of the driving energy and ensuring sufficient energy supply for the IGCT during high-frequency turn-on and turn-off, avoiding problems such as commutation failure due to insufficient energy. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0017] Figure 1 A schematic diagram of the circuit structure of a bidirectional energy harvesting circuit in an energy harvesting system according to an embodiment of this application is shown.

[0018] Figure 2 A schematic diagram of the topology of an energy harvesting system provided in an embodiment of this application is shown;

[0019] Figure 3 This illustrates an IGCT device subjected to positive and negative voltages. Figure 1 A schematic diagram of the bidirectional energy harvesting circuit in the diagram;

[0020] Figure 4 A schematic diagram of the current path provided by the RC damping circuit and the CT circuit in the on-state of an IGCT device is shown.

[0021] Figure 5 A waveform diagram comparing the energy harvesting effect of a conventional RC energy harvesting circuit and the energy harvesting system of this application is shown.

[0022] Figure 6 A schematic diagram of another bidirectional energy harvesting circuit topology provided according to an embodiment of this application is shown;

[0023] Figure 7 An IGCT device is shown under a forward voltage. Figure 7 A schematic diagram of the current flow in the bidirectional energy extraction circuit.

[0024] Figure 8 An IGCT device is shown when subjected to a negative voltage. Figure 7 A schematic diagram of the current flow in the bidirectional energy extraction circuit.

[0025] The above figures include the following reference numerals:

[0026] 10. RC damping circuit; 11. Transformer. Detailed Implementation

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0029] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0030] As described in the background section, existing IGCT devices suffer from insufficient energy supply throughout their entire operating cycle, and traditional energy harvesting circuits have low energy harvesting efficiency, resulting in an inability to meet the energy requirements for high-frequency switching and hard driving of IGCTs. To address the above problems, embodiments of this application provide an energy harvesting system and power electronic equipment suitable for IGCTs.

[0031] It should be noted that the operation of an IGCT requires "hard-drive" of the gate circuit, that is, applying a high-rate-of-rise and high-amplitude current pulse to the gate of the IGCT. This process consumes a significant amount of energy to ensure reliable turn-off. Therefore, improving the efficiency and stability of the energy harvesting circuit of existing devices is a major challenge to achieve more reliable and efficient energy harvesting and management.

[0032] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0033] This application provides an energy harvesting system suitable for IGCT, such as... Figure 1 , Figure 2 and Figure 6 As shown, it includes:

[0034] IGCT devices;

[0035] The RC damping circuit 10 is electrically connected to the anode of the aforementioned IGCT device;

[0036] The CT circuit is electrically connected to the cathode of the IGCT device. The CT circuit is a circuit that can generate a voltage when current flows through the IGCT device.

[0037] A bidirectional power extraction circuit includes a power extraction structure Ce and a bidirectional controllable switch T. The power extraction structure Ce includes a first capacitor (not shown).

[0038] like Figure 1 and Figure 2As shown, the energy harvesting structure Ce is electrically connected to the output terminal of the RC damping circuit 10 and the output terminal of the CT circuit, respectively. The energy harvesting structure Ce is connected in parallel with the bidirectional controllable switch T. When the bidirectional controllable switch T is turned off, the RC damping circuit 10 or the CT circuit charges the energy harvesting structure Ce. When the bidirectional controllable switch T is turned on, the RC damping circuit 10 or the CT circuit stops charging the energy harvesting structure Ce.

[0039] Specifically, the bidirectional controllable switch is turned off when the IGCT device is subjected to a positive or negative voltage, so that the RC damping circuit can charge the energy harvesting structure; the bidirectional controllable switch is also turned off when there is current flowing through the IGCT device, so that the CT circuit can charge the energy harvesting structure.

[0040] Specifically, an IGCT device withstands a positive voltage (i.e., the voltage across the IGCT device is greater than 0) or a negative voltage (i.e., the voltage across the IGCT device is less than 0) when it is turned off; current flowing through an IGCT device refers to the situation where the IGCT device is in the on state (when the voltage across the IGCT device is 0).

[0041] like Figure 2 and Figure 6 As shown, the energy harvesting structure Ce is electrically connected to the output terminal of the RC damping circuit 10 and the output terminal of the CT circuit through the bidirectional controllable switch (not shown). When the bidirectional controllable switch is turned on, the RC damping circuit 10 or the CT circuit charges the energy harvesting structure Ce. When the bidirectional controllable switch is turned off, the RC damping circuit 10 or the CT circuit stops charging the energy harvesting structure Ce.

[0042] Through the above embodiments, the energy harvesting system of this application includes an IGCT device, an RC damping circuit, a CT circuit, and a bidirectional energy harvesting circuit including an energy harvesting structure and a bidirectional controllable switch. The RC damping circuit is electrically connected to the anode of the IGCT device, and the CT circuit is electrically connected to the cathode of the IGCT device. The energy harvesting structure is electrically connected to the output terminals of the RC damping circuit and the CT circuit, respectively. The energy harvesting structure is connected in parallel with the bidirectional controllable switch. When the bidirectional controllable switch is turned off or on, the RC damping circuit or the CT circuit charges or stops charging the energy harvesting structure. Alternatively, the energy harvesting structure is electrically connected to the output terminals of the RC damping circuit and the CT circuit, respectively, through the bidirectional controllable switch. When the bidirectional controllable switch is turned on or off, the RC damping circuit or the CT circuit charges or stops charging the energy harvesting structure. Existing technologies suffer from insufficient energy supply to IGCT devices throughout their entire operating cycle, and traditional energy harvesting circuits exhibit low energy extraction efficiency, resulting in an inability to meet the energy requirements for high-frequency switching and hard driving of IGCTs. This application addresses this issue by combining an RC damping circuit, a CT circuit, and a bidirectional energy harvesting circuit to achieve energy extraction from the IGCT device under three different states: positive and negative voltages during turn-off, and current flow during turn-on. The RC damping circuit is connected to the anode of the IGCT device to buffer and absorb voltage spikes generated during switching, while also providing an energy source for the energy harvesting circuit. The CT circuit is connected to the cathode of the IGCT device and can extract energy from the current of the IGCT device, thereby charging the energy harvesting structure. The bidirectional power extraction circuit, with its power extraction structure and bidirectional controllable switch, enables the circuit to adapt to the energy requirements of the IGCT device under different voltage directions and on / off states. This allows for full-cycle online power extraction of the IGCT device, enabling it to withstand positive and negative voltages when off and to have current flowing through it when on. This improves power extraction efficiency and the width of the power extraction window. Furthermore, the bidirectional controllable switch can be turned on or off to charge or stop charging the power extraction structure, avoiding unnecessary energy consumption by the RC damping circuit and CT circuit. This ensures that the voltage of the power extraction structure is within a safe and effective operating range, thereby improving the reliability of the driving energy and ensuring sufficient energy supply for the IGCT during high-frequency turn-on and turn-off, avoiding problems such as commutation failure due to insufficient energy.

[0043] Specifically, Figure 2The diagram shows the topology of the energy harvesting system. The bidirectional energy harvesting circuit mainly captures energy through two transmission units: the RC damping circuit 10 and the CT circuit. The IGCT device, as the core high-voltage switching device, harvests energy through the RC damping circuit 10 and the CT circuit, and then rectifies, filters, and stores the acquired electrical energy. The energy is then converted into a stable DC power supply by the DC-DC voltage regulator circuit to power other circuits. The second resistor R is a static voltage equalization resistor, Rs is the first resistor, and Cs is the second capacitor. The IGCT device harvests energy through the RC damping circuit 10 and the CT circuit together to supply power to other circuits. Figure 2 In the DC-DC voltage regulator circuit, there are transistor S, inductor Lm, diode D, capacitor C, resistor R1 and transformer 11. Transformer 11 includes inductor coil N1 and inductor coil N2.

[0044] In one exemplary embodiment, such as Figure 1 , Figure 3 and Figure 4 As shown, the energy harvesting structure Ce is directly electrically connected to the output terminal of the RC damping circuit (not shown) and the output terminal of the CT circuit, respectively. The energy harvesting structure Ce is connected in parallel with the bidirectional controllable switch T. The bidirectional energy harvesting circuit further includes: a first diode D1, the cathode of the first diode D1 is electrically connected to the output terminal of the RC damping circuit (not shown), the cathode of the first diode D1 is also electrically connected to the first terminal of the bidirectional controllable switch T, and the anode of the first diode D1 is electrically connected to the first terminal of the energy harvesting structure Ce; a second diode D2, the anode of the second diode D2 is electrically connected to the anode of the first diode D1, the cathode of the second diode D2 is electrically connected to the cathode of the IGCT device, and the cathode of the second diode D2 is also electrically connected to the second terminal of the bidirectional controllable switch T. In this embodiment, the configuration of the first diode and the second diode enables bidirectional energy capture. When the IGCT device is subjected to a positive voltage, the second diode conducts, and energy is output from the RC damping circuit or the CT circuit to charge the energy harvesting structure. When subjected to a negative voltage, the first diode conducts, and energy can also be output from the RC damping circuit or the CT circuit to charge the energy harvesting structure, further ensuring that the energy harvesting circuit can work effectively regardless of the voltage polarity of the IGCT.

[0045] Specifically, when the charging conditions are met, the bidirectional controllable switch is in the off state, allowing current to flow through the energy harvesting structure to charge it. When the conditions for stopping charging are met, the bidirectional controllable switch is in the on state, forming a bypass to prevent current from continuing to flow into the energy harvesting structure, thereby protecting the energy harvesting structure from overvoltage damage.

[0046] According to some other exemplary embodiments of this application, such as Figure 1 , Figure 3 and Figure 4As shown, the bidirectional energy harvesting circuit further includes: a third diode D3, the anode of which is electrically connected to the cathode of the first diode D1, and the cathode of which is electrically connected to the second terminal of the energy harvesting structure Ce; and a fourth diode D4, the anode of which is electrically connected to the cathode of the second diode D2, and the cathode of which is electrically connected to the second terminal of the energy harvesting structure Ce. In this embodiment, four diodes form an energy transfer path between the energy harvesting structure, the RC damping circuit, and the IGCT device. The second and third diodes constitute a positive charging path, allowing current to flow from the RC damping circuit to the energy harvesting structure when the IGCT device is subjected to a positive voltage; the first and fourth diodes constitute a negative charging path, allowing current to flow to the energy harvesting structure even when the IGCT device is subjected to a negative voltage. This design ensures that the energy harvesting structure can be charged through an appropriate path regardless of whether the IGCT device is subjected to a positive or negative voltage, improving the flexibility and efficiency of the energy harvesting circuit and meeting the energy requirements of the IGCT device under different operating conditions.

[0047] Specifically, bidirectional power extraction circuits include various topologies, one implementation being, for example... Figure 1 As shown, the bidirectional power extraction circuit consists of a bidirectional controllable switch T, a power extraction structure Ce, a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4.

[0048] Figure 3 When the IGCT device is subjected to positive and negative voltages Figure 1 A schematic diagram of the bidirectional energy harvesting circuit in the diagram. Figure 3 (a) is a schematic diagram of the current path through which the RC damping circuit provides energy to the IGCT device during the process of being subjected to a positive voltage. Figure 3 (b) is a schematic diagram of the current path through which the IGCT device is powered by the RC damping circuit when it is subjected to a negative voltage. Figure 4 This diagram illustrates the current path provided by the RC damping circuit and the CT circuit for the IGCT device in the on-state. Figure 4 (a) is a schematic diagram of the current path provided by the RC damping circuit for the IGCT device in the on-state. Figure 4 (b) is a schematic diagram of the current path provided by the CT circuit for the IGCT device in the on-state.

[0049] like Figure 3 As shown in (a), the voltage V across the IGCT device IGCT When the bidirectional controllable switch T is turned off (i.e., it is subjected to positive voltage), the current obtains electrical energy through the RC damping circuit and charges the energy harvesting structure Ce through the second diode D2 and the third diode D3.

[0050] like Figure 3 As shown in (b), the voltage V across the IGCT device IGCT When the voltage is less than 0 (i.e., it withstands negative voltage), the current charges the energy harvesting structure Ce through the first diode D1 and the fourth diode D4, ensuring that the energy harvesting structure Ce is in a charging state, thus enabling the IGCT device to harvest energy normally under the off-state negative voltage working mode. Figure 3 The dashed line represents the path through which the current flows.

[0051] like Figure 4 As shown in (a), the voltage V across the IGCT device IGCT When the current is 0, the energy harvesting structure Ce is charged through the RC damping circuit under on-state conditions. When the IGCT device transitions from the off state to the on state, due to the presence of the second capacitor Cs in the RC damping circuit, energy will still be released to the bidirectional energy harvesting circuit at the moment of conduction. At this time, the discharge current of the second capacitor Cs flows through the first resistor Rs, the IGCT device, the first diode D1, and the fourth diode D4, charging the energy harvesting structure Ce, thereby effectively utilizing part of the energy in the second capacitor Cs and improving the efficiency of the bidirectional energy harvesting circuit. Figure 4 As shown in (b), the voltage V across the IGCT device IGCT When =0, the CT circuit also charges the energy harvesting structure Ce through the first diode D1 and the fourth diode D4. Figure 4 The dashed line represents the path through which the current flows.

[0052] Figure 5 A waveform diagram showing the comparison of the energy harvesting effect between a conventional RC energy harvesting circuit and the energy harvesting system of this application is presented. Figure 5 (a) represents the operating status of the IGCT device, with the horizontal axis representing time and the vertical axis representing the voltage across the IGCT device; Figure 5 In (b), the horizontal axis represents time, and the vertical axis represents the voltage across Ce of the energy harvesting structure. The red waveform represents full-cycle energy harvesting (i.e., the energy harvesting system of this application), and the blue waveform represents the traditional RC energy harvesting circuit. It can be seen that full-cycle energy harvesting is superior to traditional RC energy harvesting in terms of both energy harvesting efficiency and time, and can realize normal energy harvesting of IGCT devices in three operating states: positive voltage, negative voltage, and on-state (i.e., current flows through).

[0053] According to some other exemplary embodiments of this application, such as Figures 6 to 8As shown, the energy harvesting structure is electrically connected to the output terminals of the RC damping circuit and the CT circuit respectively via the bidirectional controllable switch (not shown). The bidirectional controllable switch includes: a first reverse-conducting device T1, the first end of which is electrically connected to the output terminal of the RC damping circuit 10, and the second end of which is electrically connected to the first end of the energy harvesting structure Ce; and a second reverse-conducting device T2, the first end of which is electrically connected to the first end of the first reverse-conducting device T1, and the second end of which is electrically connected to the second end of the energy harvesting structure Ce. In this embodiment, the first and second reverse-conducting devices form an energy transfer path between the energy harvesting structure and the RC damping circuit. The circuit can automatically adjust the energy transfer direction according to the positive or negative change of the voltage across the IGCT, which means that the energy harvesting structure can be charged regardless of whether the IGCT is in a positive or negative voltage state, further improving the flexibility and efficiency of the energy harvesting circuit.

[0054] In other embodiments, the bidirectional power extraction circuit further includes: a fifth diode D5, the anode of which is electrically connected to the second terminal of the first reverse-conducting device T1, and the cathode of which is electrically connected to the cathode of the IGCT device; and a sixth diode D6, the anode of which is electrically connected to the cathode of the fifth diode D5, and the cathode of which is electrically connected to the second terminal of the second reverse-conducting device T2. In this embodiment, the fifth and sixth diodes constitute the energy transfer path between the power extraction structure and the IGCT device, ensuring that the power extraction structure can be charged when the IGCT device is subjected to either a positive or negative voltage, thus improving the flexibility and efficiency of the power extraction circuit.

[0055] In some other alternatives to this application, such as Figures 6 to 8As shown, the first reverse-conducting device T1 includes a first fully controlled device K1 connected in anti-parallel and a seventh diode D7. The cathode of the seventh diode D7 is the first terminal of the first reverse-conducting device T1, and the anode of the seventh diode D7 is the second terminal of the first reverse-conducting device T1. The second reverse-conducting device T2 includes a second fully controlled device K2 connected in anti-parallel and an eighth diode D8. The anode of the eighth diode D8 is the first terminal of the second reverse-conducting device T2, and the cathode of the eighth diode D8 is the second terminal of the second reverse-conducting device T2. In this embodiment, by using a first fully controlled device and a seventh diode connected in antiparallel to form a first reverse-conducting device, and a second fully controlled device and an eighth diode connected in antiparallel to form a second reverse-conducting device, intelligent charging control of the energy harvesting structure is achieved when the IGCT device is subjected to positive or negative voltage. The first and second fully controlled devices are used to control the direction of the current, and the seventh and eighth diodes are used to ensure that the current can only flow in one direction. This design ensures that the energy harvesting structure can charge when the IGCT device is subjected to positive or negative voltage, improving the flexibility and efficiency of the energy harvesting circuit.

[0056] Specifically, the first fully controlled device and the second fully controlled device can be IGBT devices or other fully controlled devices, and this application does not impose any specific restrictions on them.

[0057] Another bidirectional energy harvesting circuit diagram is shown below. Figure 6 As shown, the bidirectional power extraction circuit consists of a power extraction structure Ce, a fifth diode D5, a sixth diode D6, a first reverse-conducting device T1, and a second reverse-conducting device T2. The first reverse-conducting device T1 is composed of an anti-parallel first fully controlled device K1 and a seventh diode D7, and the second reverse-conducting device T2 is composed of an anti-parallel second fully controlled device K2 and an eighth diode D8.

[0058] Specifically, the fifth diode D5 and the sixth diode D6 utilize their single-phase conduction characteristics to allow current to flow in one direction when the energy harvesting branch is subjected to either a positive or negative voltage. The first and second reverse-conducting devices are fully controllable devices, which can effectively control whether the energy harvesting structure needs to be charged.

[0059] Figure 7 When the IGCT device is subjected to a forward voltage Figure 7 A schematic diagram of the current flow in the bidirectional power extraction circuit. The forward charging state is as follows: Figure 7 As shown in (a), the fifth diode D5 and the second reverse-conducting device T2 form a forward power extraction branch. When the power extraction structure Ce is charged, the second reverse-conducting device T2 is turned on (specifically, the eighth diode D8 in the second reverse-conducting device T2 is turned on), and current flows through the second reverse-conducting device T2 and the fifth diode D5. The forward current flow state is as follows: Figure 7As shown in (b), the fifth diode D5 and the first reverse-conducting device T1 form a forward current branch. When the energy extraction structure Ce is fully charged, the first reverse-conducting device T1 is turned on (specifically, the first fully controlled device K1 in the first reverse-conducting device T1 is turned on), and the current flows through the first reverse-conducting device T1 and the fifth diode D5. Figure 7 The red area indicates the path through which the current flows.

[0060] Figure 8 When the IGCT device is subjected to a negative voltage Figure 6 A schematic diagram of the current flow in the bidirectional power extraction circuit. The negative charging state is as follows: Figure 8 As shown in (a), the sixth diode D6 and the first reverse-conducting device T1 form a negative energy extraction branch. When the capacitor is charged, the first reverse-conducting device T1 is turned on (specifically, the seventh diode D7 in the first reverse-conducting device T1 is turned on), and current flows through the first reverse-conducting device T1 and the sixth diode D6. The negative current flow state is as follows. Figure 8 As shown in (b), the sixth diode D6 and the second reverse-conducting device T2 form a negative current branch. When the capacitor is fully charged, the second reverse-conducting device T2 is turned on (specifically, the second fully controlled device K2 in the second reverse-conducting device T1 is turned on), and the current flows through the second reverse-conducting device T2 and the sixth diode D6. Figure 8 The red area indicates the path through which the current flows.

[0061] In other embodiments, the energy harvesting system further includes a thermoelectric energy harvesting structure, a rectifier circuit, and a boost circuit. The thermoelectric energy harvesting structure includes a thermocouple with a hot junction and a cold junction. The hot junction is in physical contact with the IGCT device, and the cold junction is electrically connected to the input terminal of the rectifier circuit. The output terminal of the rectifier circuit is electrically connected to the input terminal of the boost circuit. The boost circuit has a first output terminal and a second output terminal. The first output terminal is electrically connected to a first terminal of the energy harvesting structure, and the second output terminal is electrically connected to a second terminal of the energy harvesting structure. In this embodiment, the thermocouple can convert the heat energy generated by the IGCT device during high-power operation into electrical energy to power the energy harvesting structure, improving energy harvesting efficiency. The rectifier circuit can convert the weak AC signal generated by the thermocouple into DC power, and the boost circuit can raise the voltage to a level suitable for the energy harvesting structure while ensuring the stability of the output voltage.

[0062] In another embodiment, the energy harvesting system further includes: a temperature compensation circuit, a signal amplifier, and an analog comparator. The temperature compensation circuit includes a temperature sensor and a variable capacitor. The temperature sensor is in physical contact with the first capacitor and is used to obtain the temperature of the first capacitor. The output terminal of the temperature sensor is connected to the input terminal of the signal amplifier. The input terminal of the analog comparator is connected to the output terminal of the signal amplifier. The variable capacitor is connected in parallel across the first capacitor. A signal amplifier can amplify the weak electrical signal from the temperature sensor so that it can be better recognized and processed by subsequent circuits (such as an analog comparator). The analog comparator can compare the amplified temperature signal with a preset reference voltage. The analog comparator compares the signal sent by the temperature sensor with a voltage value corresponding to a standard or target temperature. If the actual detected temperature is higher or lower than the target temperature, the comparator will output corresponding high and low level signals. The high and low level signals control the capacitance value of the variable capacitor. When the temperature rises and causes the capacitance value of the first capacitor to decrease, the analog comparator outputs a high level, which controls the capacitance value of the variable capacitor to increase, thereby compensating for the decrease in the capacitance value of the first capacitor. When the temperature falls and causes the capacitance value of the first capacitor to increase, the analog comparator outputs a low level, which controls the capacitance value of the variable capacitor to decrease, thereby reducing the increase in the capacitance value of the first capacitor and the overall capacitance value of the variable capacitor. The high level is a level greater than 0, and the low level is a level less than 0. In this embodiment, since the capacitance of the first capacitor decreases as the temperature rises, this directly affects the energy harvesting capability of the energy harvesting circuit at different temperatures. By connecting a variable capacitor in parallel, the overall energy harvesting efficiency of the energy harvesting system is ensured to remain in a relatively stable state, unaffected by temperature changes.

[0063] In one alternative embodiment, the energy harvesting structure is directly electrically connected to the output terminals of the RC damping circuit and the CT circuit, respectively. The energy harvesting structure is connected in parallel with the bidirectional controllable switch, which includes a MOSFET. In this embodiment, using a MOSFET as the bidirectional controllable switch provides precise control, ensuring that the energy harvesting structure is not overloaded or overvoltaged, protecting the energy harvesting circuit and subsequent drive circuits. The MOSFET can quickly respond to control signals, enabling effective management of the energy harvesting process.

[0064] In other embodiments, the RC damping circuit includes a first resistor and a second capacitor connected in series, and the CT circuit includes a current transformer. In this embodiment, by using a first resistor and a second capacitor connected in series to form an RC damping loop, and using a current transformer to form a CT circuit, a stable and reliable energy source is provided for the energy harvesting circuit. The combination of the first resistor and the second capacitor can effectively suppress voltage spikes generated by the IGCT device during switching, while providing energy for the bidirectional energy harvesting circuit. The current transformer can extract energy from the current of the IGCT device, providing an additional energy source for the bidirectional energy harvesting circuit.

[0065] Specifically, the first resistor and the second capacitor form a dynamic energy harvesting branch, which simultaneously suppresses the flow of large current and protects the energy harvesting branch.

[0066] In other embodiments, such as Figure 2 As shown, the energy harvesting system further includes a second resistor R, which is connected in parallel with the IGCT device. In this embodiment, the parallel second resistor can absorb overvoltage during the IGCT device turn-off process, preventing the voltage across the IGCT from exceeding its breakdown voltage, thus protecting the IGCT.

[0067] In summary, this application enables online energy harvesting throughout the entire operating cycle of the IGCT device, effectively improving energy harvesting efficiency, reducing the risk of insufficient drive energy supply preventing device shutdown, and enhancing the reliability of the converter valve and DC grid operation. It significantly extends the energy harvesting time of the original energy harvesting circuit, broadens the energy harvesting window, facilitates short-term energy capture, improves the reliability of the energy harvesting circuit, and reduces commutation failure caused by insufficient shutdown energy. Furthermore, by utilizing a dynamic voltage equalization circuit (i.e., an RC damping circuit) and the CT circuit, it achieves full-condition energy harvesting for the device, limiting the magnitude of the first capacitor voltage and reducing the impact on the downstream DC power supply. The design requirements of the DC converter, since the potential of the RC damping circuit is the same as that of the IGCT, reduce the insulation level of the power supply from several kilovolts to several hundred volts, thereby greatly reducing the cost and size of the power supply design; it provides sufficient energy for driving the IGCT device, making it possible to use it in the controllable commutation valve, while assisting the controllable commutation valve to cope with various complex operating conditions and meet the energy requirements in resisting commutation failure; it improves the charging efficiency of the drive energy harvesting, and can replenish energy in time when the controllable commutation valve with active shutdown function performs active shutdown, thereby improving the reliability of resisting commutation failure.

[0068] This application also provides a power electronic device, including: any of the above-described energy harvesting systems suitable for IGCT.

[0069] 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.

[0070] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0071] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0072] The energy harvesting system of this application includes an IGCT device, an RC damping circuit, a CT circuit, and a bidirectional energy harvesting circuit including an energy harvesting structure and a bidirectional controllable switch. The RC damping circuit is electrically connected to the anode of the IGCT device, and the CT circuit is electrically connected to the cathode of the IGCT device. The energy harvesting structure is electrically connected to the output terminals of the RC damping circuit and the CT circuit, respectively. The energy harvesting structure is connected in parallel with the bidirectional controllable switch. When the bidirectional controllable switch is turned off or on, the RC damping circuit or the CT circuit charges or stops charging the energy harvesting structure. Alternatively, the energy harvesting structure is electrically connected to the output terminals of the RC damping circuit and the CT circuit, respectively, through the bidirectional controllable switch. When the bidirectional controllable switch is turned on or off, the RC damping circuit or the CT circuit charges or stops charging the energy harvesting structure. Existing technologies suffer from insufficient energy supply to IGCT devices throughout their entire operating cycle, and traditional energy harvesting circuits exhibit low energy extraction efficiency, resulting in an inability to meet the energy requirements for high-frequency switching and hard driving of IGCTs. This application addresses this issue by combining an RC damping circuit, a CT circuit, and a bidirectional energy harvesting circuit to achieve energy extraction from the IGCT device under three different states: positive and negative voltages during turn-off, and current flow during turn-on. The RC damping circuit is connected to the anode of the IGCT device to buffer and absorb voltage spikes generated during switching, while also providing an energy source for the energy harvesting circuit. The CT circuit is connected to the cathode of the IGCT device and can extract energy from the current of the IGCT device, thereby charging the energy harvesting structure. The bidirectional power extraction circuit, with its power extraction structure and bidirectional controllable switch, enables the circuit to adapt to the energy requirements of the IGCT device under different voltage directions and on / off states. This allows for full-cycle online power extraction of the IGCT device, enabling it to withstand positive and negative voltages when off and to have current flowing through it when on. This improves power extraction efficiency and the width of the power extraction window. Furthermore, the bidirectional controllable switch can be turned on or off to charge or stop charging the power extraction structure, avoiding unnecessary energy consumption by the RC damping circuit and CT circuit. This ensures that the voltage of the power extraction structure is within a safe and effective operating range, thereby improving the reliability of the driving energy and ensuring sufficient energy supply for the IGCT during high-frequency turn-on and turn-off, avoiding problems such as commutation failure due to insufficient energy.

[0073] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An energy harvesting system suitable for IGCT, characterized in that, include: IGCT devices; An RC damping circuit is electrically connected to the anode of the IGCT device; A CT circuit, which is electrically connected to the cathode of the IGCT device, wherein the CT circuit is a circuit that can generate a voltage when current flows through the IGCT device. A bidirectional power harvesting circuit includes a power harvesting structure and a bidirectional controllable switch, wherein the power harvesting structure includes a first capacitor; The energy harvesting structure is electrically connected to the output terminal of the RC damping circuit and the output terminal of the CT circuit, respectively. The energy harvesting structure is connected in parallel with the bidirectional controllable switch. When the bidirectional controllable switch is turned off, the RC damping circuit or the CT circuit charges the energy harvesting structure. When the bidirectional controllable switch is turned on, the RC damping circuit or the CT circuit stops charging the energy harvesting structure. Alternatively, the energy harvesting structure is electrically connected to the output terminals of the RC damping circuit and the CT circuit respectively via the bidirectional controllable switch. When the bidirectional controllable switch is on, the RC damping circuit or the CT circuit charges the energy harvesting structure. When the bidirectional controllable switch is off, the RC damping circuit or the CT circuit stops charging the energy harvesting structure.

2. The energy harvesting system for IGCT according to claim 1, characterized in that, The energy harvesting structure is directly electrically connected to the output terminals of the RC damping circuit and the CT circuit, respectively. The energy harvesting structure is connected in parallel with the bidirectional controllable switch. The bidirectional energy harvesting circuit further includes: The first diode has its cathode electrically connected to the output terminal of the RC damping circuit, and its cathode is also electrically connected to the first terminal of the bidirectional controllable switch. The anode of the first diode is electrically connected to the first terminal of the energy harvesting structure. The second diode has its anode electrically connected to the anode of the first diode, its cathode electrically connected to the cathode of the IGCT device, and its cathode also electrically connected to the second terminal of the bidirectional controllable switch.

3. The energy harvesting system for IGCT according to claim 2, characterized in that, The bidirectional power extraction circuit also includes: The third diode has its anode electrically connected to the cathode of the first diode, and its cathode electrically connected to the second terminal of the energy harvesting structure. The fourth diode has its anode electrically connected to the cathode of the second diode, and its cathode electrically connected to the second terminal of the energy harvesting structure.

4. The energy harvesting system for IGCT according to claim 1, characterized in that, The energy harvesting structure is electrically connected to the output terminals of the RC damping circuit and the CT circuit respectively via the bidirectional controllable switch. The bidirectional controllable switch includes: The first reverse-conducting device has a first end electrically connected to the output end of the RC damping circuit, and a second end electrically connected to the first end of the energy harvesting structure. The second reverse-conducting device has a first end electrically connected to the first end of the first reverse-conducting device, and a second end electrically connected to the second end of the energy harvesting structure.

5. The energy harvesting system for IGCT according to claim 4, characterized in that, The bidirectional power extraction circuit also includes: The fifth diode, the anode of which is electrically connected to the second terminal of the first reverse-conducting device, and the cathode of which is electrically connected to the cathode of the IGCT device; The sixth diode has its anode electrically connected to the cathode of the fifth diode, and its cathode electrically connected to the second terminal of the second reverse-conducting device.

6. The energy harvesting system for IGCT according to claim 4, characterized in that, The first reverse-conducting device includes a first fully controlled device and a seventh diode connected in anti-parallel. The cathode of the seventh diode is the first terminal of the first reverse-conducting device, and the anode of the seventh diode is the second terminal of the first reverse-conducting device. The second reverse-conducting device includes a second fully controlled device connected in anti-parallel and an eighth diode, wherein the positive terminal of the eighth diode is the first terminal of the second reverse-conducting device, and the negative terminal of the eighth diode is the second terminal of the second reverse-conducting device.

7. The energy harvesting system for IGCT according to claim 1, characterized in that, The energy harvesting structure is directly electrically connected to the output terminal of the RC damping circuit and the output terminal of the CT circuit, respectively. The energy harvesting structure is connected in parallel with the bidirectional controllable switch, and the bidirectional controllable switch includes a MOS transistor.

8. The energy harvesting system for IGCT according to claim 1, characterized in that, The RC damping circuit includes a first resistor and a second capacitor connected in series, and the CT circuit includes a current transformer.

9. The energy harvesting system for IGCT according to claim 1, characterized in that, The energy harvesting system further includes a second resistor, which is connected in parallel with the IGCT device.

10. A power electronic device, characterized in that, include: The energy harvesting system for IGCT according to any one of claims 1 to 9.

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