Energy taking module and energy taking system of power device

Abstract

The utility model provides an energy taking module and an energy taking system of a power device. The energy taking module of the power device comprises a first voltage-sharing circuit, a first end is used for being electrically connected with an input end of the power device, the first voltage-sharing circuit comprises a first branch, a second branch and a third branch, the first branch and the second branch are connected in parallel, a parallel circuit of the first branch and the second branch is connected with the third branch in series, the first branch comprises a switching device, and the switching device is electrically connected with the input end of the power device. One of the second branch circuit and the third branch circuit comprises an energy storage device, the other one of the second branch circuit and the third branch circuit comprises an impedance adjusting device, and the equivalent impedance of the first voltage-sharing circuit is reduced under the condition that the switching device is changed from the off state to the on state; the first end of the energy storage circuit is electrically connected with the second end of the first voltage-sharing circuit, the second end of the energy storage circuit is electrically connected with the output end of the power device and a driving circuit of the power device, and the energy storage circuit is used for storing the electric energy output by the first voltage-sharing circuit and outputting the electric energy to the driving circuit. According to the invention, the energy-taking power of the energy-taking module is improved.

Description

Technical Field

[0001] This application relates to the technical field of electronic power devices, and more particularly, to an energy extraction module and an energy extraction system for a power device. Background Art

[0002] A power device is a new type of power device used in large-capacity power electronic devices. For example, the power device can be an Integrated Gate-Commutated Thyristor (IGCT). The main function of the drive circuit of the power device is to receive the communication signal from the upper control system and convert it into voltage and current signals for turning on and off the power device. The drive circuit of the power device is powered by an energy extraction module. In actual application, high-voltage and large-capacity power semiconductor devices represented by IGCT consume hundreds of watts of power during repeated turn-off, which is more than 10 times that of normal operation. When the energy extraction power of the energy extraction module is insufficient, the device cannot be turned off and operate normally, resulting in serious system failures. Summary of the Utility Model

[0003] The main object of this application is to provide an energy extraction module and an energy extraction system for a power device, so as to solve the problem in the prior art that when the energy extraction power of the energy extraction module of the power device is insufficient, it cannot supply enough electric energy to the drive circuit of the power device, resulting in the drive circuit being unable to turn off the power device and maintain the normal operation of the power device, leading to serious system failures.

[0004] To achieve the above object, according to one aspect of this application, an energy extraction module for a power device is provided, including: a first voltage equalization circuit having a first end and a second end, the first end of the first voltage equalization circuit being used for electrically connecting to the input end of the power device, the first voltage equalization circuit including a first branch, a second branch, and a third branch, the first branch and the second branch being in parallel, the parallel circuit of the first branch and the second branch being in series with the third branch, the first branch including a switching device, one of the second branch and the third branch including an energy storage device, and the other of the second branch and the third branch including an impedance adjustment device, wherein in the case where the switching device changes from off to on, the equivalent impedance between the first end and the second end of the first voltage equalization circuit decreases; an energy storage circuit, the first end of the energy storage circuit being electrically connected to the second end of the first voltage equalization circuit, the second end of the energy storage circuit being used for electrically connecting to the output end of the power device and the drive circuit of the power device respectively, and the energy storage circuit being used for storing the electric energy output by the first voltage equalization circuit and outputting the electric energy to the drive circuit.

[0005] Optionally, the first branch further includes a first resistor, the first resistor is connected in series with the switching device, the second branch includes the impedance adjustment device, the impedance adjustment device includes a second resistor, the third branch includes the energy storage device, and the energy storage device includes a first capacitor.

[0006] Optionally, the first branch further includes a second capacitor, the second capacitor is connected in series with the switching device, the second branch includes the energy storage device, the energy storage device includes a third capacitor, and the third branch includes an impedance adjustment device, the impedance adjustment device includes a third resistor.

[0007] Optionally, the second branch includes the impedance adjustment device, the third branch includes the energy storage device, the energy storage device includes a fourth capacitor and a fourth resistor, and the fourth capacitor and the fourth resistor are connected in series.

[0008] Optionally, the impedance adjustment device includes a fifth capacitor or a fifth resistor.

[0009] Optionally, the energy extraction module of the power device further includes: a diode, an anode of the diode is electrically connected to a first end of the fourth resistor, a cathode of the diode is electrically connected to a second end of the fourth resistor, and a current direction is from the first end of the fourth resistor to the second end of the fourth resistor.

[0010] Optionally, the energy extraction module of the power device further includes: a second voltage equalization circuit, including a sixth resistor, one end of the sixth resistor is electrically connected to a first end of the first voltage equalization circuit, the other end of the sixth resistor is electrically connected to a second end of the first voltage equalization circuit, and an impedance of the sixth resistor is less than an equivalent impedance when the power device is in a blocking state.

[0011] Optionally, the energy storage circuit includes a sixth capacitor, one end of the sixth capacitor is a first end of the energy storage circuit, and the other end of the sixth capacitor is a second end of the energy storage circuit.

[0012] Optionally, the switching device has a control end, and the control end of the switching device is used to be electrically connected to the driving circuit.

[0013] According to another aspect of the present application, there is provided an energy extraction system, including: a plurality of power devices, the plurality of power devices are connected in series; driving circuits of the plurality of power devices, which are electrically connected to the power devices in one-to-one correspondence; energy extraction modules of any one of the plurality of power devices, and the energy extraction modules of the power devices are electrically connected to the power devices and the driving circuits in one-to-one correspondence respectively.

[0014] Applying the technical solution of the present application, in the first voltage equalizing circuit of the energy extraction module, a first branch including a switching device, a second branch including one of an energy storage device and an impedance adjusting device, and a third branch including the other of the energy storage device and the impedance adjusting device are provided, and the first branch is connected in parallel with the second branch and then connected in series with the third branch. One end of the first voltage equalizing circuit is electrically connected to the input end of the power device, and the other end of the first voltage equalizing circuit is electrically connected to the output end of the power device and its driving circuit respectively. When the energy extraction power of the driving circuit is insufficient, the switching state of the switching device can be changed to make the state of the switching device change from off to on, so as to reduce the equivalent impedance of the first voltage equalizing circuit, increase the current flowing through the first voltage equalizing circuit to the energy storage circuit, thereby improving the energy extraction power of the energy storage circuit, ensuring that the energy storage circuit can supply sufficient electric energy to the driving circuit to support the normal control of the power device by the driving circuit, and avoiding the problem that the driving circuit cannot turn off the power device and maintain the normal operation of the power device due to insufficient power supply, resulting in serious system failures. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings forming a part of this application are used to provide a further understanding of the application. The schematic embodiments and descriptions thereof of the application are used to explain the application and do not constitute an improper limitation to the application. In the drawings:

[0016] Figure 1 FIG. shows a schematic diagram of an energy extraction module of a power device according to an embodiment of the present application;

[0017] Figure 2 FIG. shows a specific structural schematic diagram of an energy extraction module of a power device according to an embodiment of the present application;

[0018] Figure 3 FIG. shows a specific structural schematic diagram of another energy extraction module of a power device according to an embodiment of the present application;

[0019] Figure 4 FIG. shows a specific structural schematic diagram of yet another energy extraction module of a power device according to an embodiment of the present application;

[0020] Figure 5 FIG. shows a specific structural schematic diagram of another energy extraction module of a power device according to an embodiment of the present application.

[0021] Among them, the above-mentioned accompanying drawings include the following reference numerals:

[0022] 10. Power device; 11. Energy extraction module; 12. First voltage equalization circuit; 13. First branch; 14. Second branch; 15. Third branch; 16. Switching device; 17. Energy storage circuit; 18. Drive circuit; 19. First resistor; 20. Second resistor; 21. First capacitor; 22. Second capacitor; 23. Third capacitor; 24. Third resistor; 25. Fourth capacitor; 26. Fourth resistor; 27. Fifth resistor; 28. Fifth capacitor; 29. Diode; 30. Sixth resistor. Detailed implementation manners

[0023] It should be noted that the following detailed description is exemplary and is intended to provide further illustration of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs.

[0024] It should be noted that the terms used herein are only for describing the specific implementation manners and are not intended to limit the exemplary implementation manners according to the present application. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0025] It should be understood that when an element (such as a layer, film, region, or substrate) is described as being "on" another element, the element can be directly on the other element, or there can also be an intermediate element. Moreover, in the specification and the claims, when an element is described as being "connected" to another element, the element can be "directly connected" to the other element, or "connected" to the other element through a third element.

[0026] As introduced in the background art, in the prior art, when the energy extraction power of the energy extraction module of the power device is insufficient, it cannot supply enough electrical energy to the drive circuit of the power device, resulting in the drive circuit being unable to turn off the power device and maintain the normal operation of the power device, leading to serious system failure problems. To solve the above problems, the present application proposes an energy extraction module and an energy extraction system for a power device.

[0027] An embodiment of the present application provides an energy extraction module for a power device, Figure 1 Exemplarily, a schematic structural diagram of an energy extraction module 11 of a power device 10 according to an embodiment of the present application is shown, as Figure 1 shown, the energy extraction module 11 of the power device 10 includes:

[0028] The first voltage equalizing circuit 12 has a first end and a second end. The first end of the first voltage equalizing circuit 12 is used to be electrically connected to the input end of the power device 10. The first voltage equalizing circuit 12 includes a first branch 13, a second branch 14 and a third branch 15. The first branch 13 and the second branch 14 are connected in parallel. The parallel circuit of the first branch 13 and the second branch 14 is connected in series with the third branch 15. The first branch 13 includes a switching device 16. One of the second branch 14 and the third branch 15 includes an energy storage device, and the other of the second branch and the third branch includes an impedance adjusting device. When the switching device 16 changes from off to on, the equivalent impedance between the first end and the second end of the first voltage equalizing circuit 12 decreases;

[0029] Specifically, the first branch 13 and the second branch 14 are connected in parallel and then connected in series with the third branch 15. The first end of the first branch 13 is electrically connected to the first end of the second branch 14. After the second end of the first branch 13 and the second end of the second branch 14 are electrically connected, they are electrically connected to the first end of the third branch 15. The first ends of the first branch 13 and the second branch 14 can be used as the first end of the first voltage equalizing circuit 12, and then the second end of the third branch 15 is used as the second end of the first voltage equalizing circuit 12; the second end of the third branch 15 can also be used as the first end of the first voltage equalizing circuit 12, and then the first ends of the first branch 13 and the second branch 14 are used as the second end of the first voltage equalizing circuit 12. When the switching device changes from off to on, the impedance of the parallel circuit of the first branch 13 and the second branch 14 becomes smaller, and the impedance after being connected in series with the third branch 15 becomes smaller, so that the equivalent impedance between the two ends of the first voltage equalizing circuit 12 decreases.

[0030] An energy storage circuit 17. The first end of the energy storage circuit 17 is electrically connected to the second end of the first voltage equalizing circuit 12. The second end of the energy storage circuit 17 is used to be electrically connected to the output end of the power device 10 and the drive circuit 18 of the power device 10 respectively. The energy storage circuit 17 is used to store the electric energy output by the first voltage equalizing circuit 12 and output the electric energy to the drive circuit 18.

[0031] Specifically, the drive circuit 18 is used to receive the electric energy provided by the energy storage circuit 17 and send an electric signal for turning on and off the power device 10 to the control end of the power device 10.

[0032] Through the above embodiments, in the first voltage equalizing circuit of the energy extraction module, a first branch including a switching device, a second branch including one of an energy storage device and an impedance adjustment device, and a third branch including the other of the energy storage device and the impedance adjustment device are provided, and the first branch is connected in parallel with the second branch and then connected in series with the third branch. One end of the first voltage equalizing circuit is electrically connected to the input end of the power device, and the other end of the first voltage equalizing circuit is electrically connected to the output end of the power device and its drive circuit respectively. When the energy extraction power of the drive circuit is insufficient, the switching state of the switching device can be changed to make the state of the switching device change from off to on, so as to reduce the equivalent impedance of the first voltage equalizing circuit and increase the current flowing through the first voltage equalizing circuit to the energy storage circuit, thereby improving the energy extraction power of the energy storage circuit, ensuring that the energy storage circuit can supply sufficient electric energy to the drive circuit to support the normal control of the power device by the drive circuit, and avoiding the problem that the drive circuit cannot turn off the power device and maintain the normal operation of the power device due to insufficient power supply, resulting in serious system failures.

[0033] In addition, one of the second branch and the third branch has a blocking adjustment device, and the other has an energy storage device. The series circuit formed by the two can slow down the voltage change rate at both ends of the power device during the turn-on and turn-off transients of the power device, and can prevent the power device from being damaged during the turn-on and turn-off transients.

[0034] In the actual application process, those skilled in the art can select any suitable switching element as the above-mentioned switching device of the present application, such as selecting semiconductor switching devices such as triodes, field effect transistors, thyristors, or selecting mechanical switches such as knife switches, push-button switches, or travel switches.

[0035] Exemplarily, as Figures 2 to 5 shown, the present application uses a three-terminal semiconductor switching device as the above-mentioned switching device 16 of the present application. In addition to the input end and the output end, the above-mentioned switching device 16 also has a control end, and the control end of the above-mentioned switching device 16 is used to be electrically connected to the above-mentioned drive circuit 18. That is, the turn-off and turn-on of the switching device can be controlled by the drive circuit.

[0036] In the specific application process, the drive circuit can judge whether the energy extraction power of the energy storage circuit is insufficient by the time when the voltage of the turn-off capacitor bank is lower than the set value, and control the switching device to turn off or turn on according to the judgment result.

[0037] In addition to the above method, an external electric energy detection device can also be used to detect the electric energy of the drive circuit, or an energy extraction power detection device can be used to detect the energy extraction power of the energy storage circuit. When the electric energy is insufficient or the energy extraction power is insufficient, the switching device is turned on through manual control or automatic control to increase the energy extraction power.

[0038] Such as Figure 1As shown, in the energy extraction module 11 of the above-mentioned power device 10 of the present application, when the above-mentioned switching device 16 changes from closed to off, the equivalent impedance between the first end and the second end of the above-mentioned first voltage equalization circuit 12 increases. Therefore, when the energy extraction power of the energy storage circuit 17 is large and the electric energy supplied to the drive circuit 18 is sufficient, the switching state of the above-mentioned switching device 16 can be changed from closed to off, so that the equivalent impedance between the two ends of the first voltage equalization circuit 12 increases and returns to the value before closing, and the energy extraction power of the energy storage circuit 17 is reduced to the value before closing.

[0039] According to some optional embodiments of the present application, as Figure 2 shown, the above-mentioned first branch 13 further includes a first resistor 19, the first resistor 19 is connected in series with the above-mentioned switching device 16, the second branch 14 includes the above-mentioned impedance adjustment device, the impedance adjustment device includes a second resistor 20, the third branch 15 includes the above-mentioned energy storage device, and the energy storage device includes a first capacitor 21.

[0040] In the above embodiment, a series branch of a first resistor and a switching device is connected in parallel across the second resistor. When the energy extraction power of the energy storage circuit is insufficient, by turning on the switching device, the first resistor and the second resistor are connected in parallel to reduce the equivalent impedance of the first voltage equalization circuit and increase the current at both ends of the first voltage equalization circuit, so that the energy extraction power increases, further improving the electric energy supplied by the energy storage circuit to the drive circuit, and further avoiding the problem that the drive circuit cannot turn off the power device and maintain the normal operation of the power device due to insufficient power supply.

[0041] In addition, when the energy extraction power of the energy storage circuit 17 is sufficient, the above-mentioned switching device 16 can be turned off, so that the equivalent impedance of the first voltage equalization circuit 12 is restored and the energy extraction power of the energy storage circuit 17 is reduced.

[0042] In an optional embodiment, as Figure 2 shown, the above-mentioned first branch 13 is composed of the above-mentioned switching device 16 and the above-mentioned first resistor 19, the second branch 14 is composed of the above-mentioned second resistor 20, and the third branch 15 is composed of the above-mentioned first capacitor 21. Of course, in addition to the above elements, the above-mentioned first branch 13, the above-mentioned second branch 14, and the above-mentioned third branch 15 of the present application may further include other elements.

[0043] In the present application, as Figure 2As shown, when the switching device 16 is turned off and the power device 10 is in the turn-off transient state, the voltage across its two ends rises and charges the first capacitor 21 through the second resistor 20. The first voltage-sharing circuit 12 provides an additional current path, reducing the equivalent input impedance across the power device 10 and the rising rate of the voltage across its two ends. When the switching device 16 is turned off and the power device 10 is in the turn-on transient state, the voltage across its two ends drops and discharges the first capacitor 21 through the second resistor 20. The first voltage-sharing circuit 12 provides an additional current source, reducing the equivalent output impedance across the power device 10 and the dropping rate of the voltage across its two ends. When the switching device 16 is closed and the power device 10 is in the turn-off transient state, the voltage across its two ends rises and charges the first capacitor 21 through the first resistor 19 and the second resistor 20 connected in parallel. The first voltage-sharing circuit 12 provides an additional current path, reducing the equivalent input impedance across the power device 10 and the rising rate of the voltage across its two ends. When the switching device 16 is closed and the power device 10 is in the turn-on transient state, the voltage across its two ends drops and discharges the first capacitor 21 through the first resistor 19 and the second resistor 20 connected in parallel. The first voltage-sharing circuit 12 provides an additional current source, reducing the equivalent output impedance across the power device 10 and the dropping rate of the voltage across its two ends. At the switching moment of the power device 10, current flows through the first voltage-sharing circuit 12 into the energy storage circuit 17. The energy storage circuit 17 stores this current and converts it into a fixed voltage to supply high-level energy to the drive circuit 18. The limit energy-taking power of the energy storage circuit 17 is positively correlated with the current flowing through the first voltage-sharing circuit 12.

[0044] In some embodiments, as Figure 2 shown, the energy-taking module 11 of the above-mentioned power device 10 further includes: a diode 29. The anode of the diode 29 is electrically connected to the first end of the second resistor 20, and the cathode of the diode 29 is electrically connected to the second end of the second resistor 20. The current direction is from the first end of the second resistor 20 to the second end of the second resistor 20. In this embodiment, by adding a diode to the first voltage-sharing circuit, the diode, the resistor and the capacitor in the first voltage-sharing circuit form an RCD circuit, which can play a role in protecting the power device and improving the stability and efficiency of the circuit.

[0045] Among them, Figure 2 exemplarily shows that the first end of the second resistor 20, as the first end of the first voltage-sharing circuit, is electrically connected to the input end of the power device 10, and the second end of the second resistor 20 is electrically connected to one end of the first capacitor 21.

[0046] In another alternative solution, as Figure 3As shown, the first branch 13 further includes a second capacitor 22. The second capacitor 22 is connected in series with the switching device 16. The second branch 14 includes the energy storage device. The energy storage device includes a third capacitor 23. The third branch 15 includes an impedance adjustment device. The impedance adjustment device includes a third resistor 24.

[0047] In the above embodiment, a series branch of a second capacitor and a switching device is connected in parallel across the third capacitor. When the energy extraction power of the energy storage circuit is insufficient, by turning on the switching device, the second capacitor and the third capacitor are connected in parallel to reduce the equivalent impedance of the first voltage equalization circuit and increase the current across the first voltage equalization circuit, so that the energy extraction power increases, further improving the electric energy supplied by the energy storage circuit to the drive circuit and further avoiding the problem that the drive circuit cannot turn off the power device and maintain the normal operation of the power device due to insufficient power supply.

[0048] In addition, when the energy extraction power of the energy storage circuit 17 is sufficient, the switching device 16 can be turned off to restore the equivalent impedance of the first voltage equalization circuit 12 and reduce the energy extraction power of the energy storage circuit 17.

[0049] In an alternative embodiment, as Figure 3 shown, the first branch 13 is composed of the switching device 16 and the second capacitor 22. The second branch 14 is composed of the third capacitor 23. The third branch 15 is composed of the third resistor 24. Of course, in addition to the above elements, the first branch 13, the second branch 14, and the third branch 15 of the present application may further include other elements.

[0050] In the present application, as Figure 3As shown, when the switching device 16 is turned off and the power device 10 is in the turn-off transient state, the voltage across the two ends rises and charges the third capacitor 23 through the third resistor 24. The first voltage equalization circuit 12 provides an additional current path, reducing the equivalent input impedance across the power device 10 and the rising rate of the voltage across the two ends. When the switching device 16 is turned off and the power device 10 is in the turn-on transient state, the voltage across the two ends drops and discharges the third capacitor 23 through the third resistor 24. The first voltage equalization circuit 12 provides an additional current source, reducing the equivalent output impedance across the power device 10 and the dropping rate of the voltage across the two ends. When the switching device 16 is closed and the power device 10 is in the turn-off transient state, the voltage across the two ends rises and charges the second capacitor 22 and the third capacitor 23 connected in parallel through the third resistor 24. The first voltage equalization circuit 12 provides an additional current path, reducing the equivalent input impedance across the power device 10 and the rising rate of the voltage across the two ends. When the switching device 16 is closed and the power device 10 is in the turn-on transient state, the voltage across the two ends drops and discharges the second capacitor 22 and the third capacitor 23 connected in parallel through the third resistor 24. The first voltage equalization circuit 12 provides an additional current source, reducing the equivalent output impedance across the power device 10 and the dropping rate of the voltage across the two ends. At the switching moment of the power device 10, current flows through the first voltage equalization circuit 12 into the energy storage circuit 17. The energy storage circuit 17 stores this current and converts it into a fixed voltage to supply high-level energy to the drive circuit 18. The limit energy-taking power of the energy storage circuit 17 is positively correlated with the current flowing through the first voltage equalization circuit 12.

[0051] In some embodiments, as Figure 3 shown, the energy-taking module 11 of the above-mentioned power device 10 further includes: a diode 29. The anode of the diode 29 is electrically connected to the first end of the third resistor 24, and the cathode of the diode 29 is electrically connected to the second end of the third resistor 24. The current direction is from the first end of the third resistor 24 to the second end of the third resistor 24. In this embodiment, by adding a diode in the first voltage equalization circuit, the diode, the resistor and the capacitor in the first voltage equalization circuit form an RCD circuit, which can play a role in protecting the power device and improving the stability and efficiency of the circuit.

[0052] Among them, Figure 3 in, the second end after the first branch 13 and the second branch 14 are connected in parallel is electrically connected to the first end of the third resistor 24, and the first end after the first branch 13 and the second branch 14 are connected in parallel is electrically connected to the input end of the power device 10, and is electrically connected to the input end of the power device 10; the second end of the second resistor 20 serves as the second end of the first voltage equalization circuit and is electrically connected to the energy storage circuit 17.

[0053] In some other alternative embodiments, as Figure 4 and Figure 5As shown, the second branch 14 described above includes the impedance adjustment device, the third branch 15 includes the energy storage device, the energy storage device includes a fourth capacitor 25 and a fourth resistor 26, and the fourth capacitor 25 and the fourth resistor 26 are connected in series. In this embodiment, a switching device is connected in parallel across the impedance adjustment device. When the power extraction of the energy storage circuit is insufficient, by turning on the switching device, the switching device shorts the impedance adjustment device to reduce the equivalent impedance of the first voltage equalization circuit and increase the current across the first voltage equalization circuit, thereby increasing the power extraction and further improving the electrical energy supplied by the energy storage circuit to the drive circuit, and further avoiding the problem that the drive circuit cannot turn off the power device and maintain the normal operation of the power device due to insufficient power supply.

[0054] Specifically, as Figure 4 and Figure 5 shown, the switching device 16 controls the switching of the impedance adjustment device. When the switching device 16 is off, the impedance adjustment device is connected in series with the fourth resistor 26, and the equivalent resistance of the first voltage equalization circuit is relatively large; when the power extraction of the energy storage circuit 17 is insufficient, by controlling the switching device 16 to close, the switching device 16 shorts the impedance regulator, so that the impedance adjustment device is not connected in series with the fourth resistor 26, thereby reducing the equivalent resistance of the first voltage equalization circuit; when the power extraction of the energy storage circuit 17 is sufficient, the switching device 16 is controlled to turn off to restore the equivalent impedance of the first voltage equalization circuit and reduce the power extraction of the energy storage circuit 17.

[0055] Optionally, the impedance adjustment device may include, as Figure 4 shown, a fifth resistor 27, or the impedance adjustment device may include, as Figure 5 shown, a fifth capacitor 28.

[0056] In an alternative embodiment, as Figure 4 shown, the first branch 13 is constituted by the switching device 16, the second branch 14 is constituted by the fifth resistor 27, and the third branch 15 is constituted by the fourth capacitor 25 and the fourth resistor 26. Of course, in addition to the above elements, the first branch 13, the second branch 14, and the third branch 15 of the present application may further include other elements.

[0057] In an alternative embodiment, as Figure 5 shown, the first branch 13 is constituted by the switching device 16, the second branch 14 is constituted by the fifth capacitor 28, and the third branch 15 is constituted by the fourth capacitor 25 and the fourth resistor 26. Of course, in addition to the above elements, the first branch 13, the second branch 14, and the third branch 15 of the present application may further include other elements.

[0058] In this application, as Figure 4 shown, when the switching device 16 is turned off and the power device 10 is in the turn-off transient state, the voltage across its two ends rises and charges the fourth capacitor 25 through the series-connected fourth resistor 26 and fifth resistor 27. The first voltage equalization circuit 12 provides an additional current path, reducing the equivalent input impedance across the two ends of the power device 10 and the rising rate of the voltage across its two ends. When the switching device 16 is turned off and the power device 10 is in the turn-on transient state, the voltage across its two ends drops and discharges the fourth capacitor 25 through the series-connected fourth resistor 26 and fifth resistor 27. The first voltage equalization circuit 12 provides an additional current source, reducing the equivalent output impedance across the two ends of the power device 10 and the dropping rate of the voltage across its two ends. When the switching device 16 is closed and the power device 10 is in the turn-off transient state, the voltage across its two ends rises and charges the fourth capacitor 25 through the fourth resistor 26. The first voltage equalization circuit 12 provides an additional current path, reducing the equivalent input impedance across the two ends of the power device 10 and the rising rate of the voltage across its two ends. When the switching device 16 is closed and the power device 10 is in the turn-on transient state, the voltage across its two ends drops and discharges the fourth capacitor 25 through the fourth resistor 26. The first voltage equalization circuit 12 provides an additional current source, reducing the equivalent output impedance across the two ends of the power device 10 and the dropping rate of the voltage across its two ends. At the switching instant of the power device 10, there is current passing through the first voltage equalization circuit 12 into the energy storage circuit 17. The energy storage circuit 17 stores this current and converts it into a fixed voltage to supply high-level energy to the drive circuit 18. The limit energy extraction power of the energy storage circuit 17 is positively correlated with the current flowing through the first voltage equalization circuit 12.

[0059] As Figure 5As shown, when the switching device 16 is turned off and the power device 10 is in the turn-off transient state, the voltage across both ends rises and charges the series-connected fourth capacitor 25 and fifth capacitor 28 through the fourth resistor 26. The first voltage equalizing circuit 12 provides an additional current path, reducing the equivalent input impedance across the power device 10 and the rising rate of the voltage across both ends. When the switching device 16 is turned off and the power device 10 is in the turn-on transient state, the voltage across both ends drops and discharges the series-connected fourth capacitor 25 and fifth capacitor 28 through the fourth resistor 26. The first voltage equalizing circuit 12 provides an additional current source, reducing the equivalent output impedance across the power device 10 and the dropping rate of the voltage across both ends. When the switching device 16 is closed and the power device 10 is in the turn-off transient state, the voltage across both ends rises and charges the fourth capacitor 25 through the fourth resistor 26. The first voltage equalizing circuit 12 provides an additional current path, reducing the equivalent input impedance across the power device 10 and the rising rate of the voltage across both ends. When the switching device 16 is closed and the power device 10 is in the turn-on transient state, the voltage across both ends drops and discharges the fourth capacitor 25 through the fourth resistor 26. The first voltage equalizing circuit 12 provides an additional current source, reducing the equivalent output impedance across the power device 10 and the dropping rate of the voltage across both ends. At the switching instant of the power device 10, current passes through the first voltage equalizing circuit 12 into the energy storage circuit 17. The energy storage circuit 17 stores this current and converts it into a fixed voltage to supply high-level energy to the drive circuit 18. The limit energy extraction power of the energy storage circuit 17 is positively correlated with the current flowing through the first voltage equalizing circuit 12.

[0060] In some embodiments, as Figure 4 and Figure 5 shown, the energy extraction module 11 of the above-mentioned power device 10 further includes: a diode 29. The anode of the diode 29 is electrically connected to the first end of the fourth resistor 26, and the cathode of the diode 29 is electrically connected to the second end of the fourth resistor 26. The current direction is from the first end of the fourth resistor 26 to the second end of the fourth resistor 26. In this embodiment, by adding a diode in the first voltage equalizing circuit, the diode, the resistor and the capacitor in the first voltage equalizing circuit form an RCD circuit, which can play a role in protecting the power device and improving the stability and efficiency of the circuit.

[0061] Wherein, Figure 4 and Figure 5 in, the first end of the fourth resistor 26 serves as the first end of the first voltage equalizing circuit and is electrically connected to the input end of the power device 10; the second end of the fourth resistor 26 is electrically connected to one end of the fourth capacitor 25.

[0062] According to still some other embodiments of the present application, as Figures 2 to 5As shown, the energy extraction module 11 of the above-mentioned power device 10 further includes: a second voltage equalization circuit, including a sixth resistor 30. One end of the sixth resistor 30 is electrically connected to the first end of the first voltage equalization circuit 12, and the other end of the sixth resistor 30 is electrically connected to the second end of the first voltage equalization circuit 12. The impedance of the sixth resistor 30 is less than the equivalent impedance of the power device 10 when it is in the blocking state. By providing a second voltage equalization circuit including the sixth resistor and setting the resistance value of the second voltage equalization circuit to be less than the equivalent impedance of the power device when it is blocked, the second voltage equalization circuit can balance the leakage current of the power device when the power device is blocked, thereby reducing the static voltage difference between the power device and other power devices.

[0063] In some embodiments, the above-mentioned energy storage circuit includes a sixth capacitor. One end of the sixth capacitor is the first end of the energy storage circuit, that is, one end of the sixth capacitor is electrically connected to the second end of the first voltage equalization circuit. The other end of the sixth capacitor is the second end of the energy storage circuit, that is, the other end of the sixth capacitor is electrically connected to the drive circuit and the output end of the power device respectively.

[0064] In an alternative embodiment, as Figures 2 to 5 shown, the above-mentioned second voltage equalization circuit is composed of the sixth resistor 30. The sixth resistor 30 can be a large resistor or composed of multiple resistors connected in series and parallel. Of course, in addition to the sixth resistor 30, the second voltage equalization circuit can also include other components.

[0065] Specifically, the above-mentioned power device includes at least one of the following: IGBT (Insulate-Gate Bipolar Transistor), IGCT, GTO (Gate Turn-Off Thyristor), SGTO (Super Gate Turn-Off Thyristor), ETO (Emitter Turn-Off Thyristor), and IETO (Integrated Emitter Turn-Off Thyristor).

[0066] An embodiment of the present application further provides an energy extraction system, as Figures 2 to 5 shown, the above-mentioned energy extraction system includes: a plurality of power devices 10 connected in series; drive circuits 18 of the plurality of power devices 10, electrically connected to the power devices 10 in one-to-one correspondence; energy extraction modules 11 of the plurality of any one of the above-mentioned power devices 10, and the energy extraction modules 11 of the power devices 10 are electrically connected to the power devices 10 and the drive circuits 18 in one-to-one correspondence respectively.

[0067] Through the above embodiments, multiple power devices are connected in series, and multiple drive circuits are used to achieve the drive control of the multiple power devices. Multiple energy extraction modules as described above are used to achieve high-level energy extraction of the power devices. When the energy extraction power of the drive circuit is insufficient, the switching state of the switching device in the energy extraction module can be changed to make the state of the switching device change from off to on, so as to reduce the equivalent impedance of the first voltage equalization circuit, increase the current flowing through the first voltage equalization circuit to the energy storage circuit, thereby improving the energy extraction power of the energy storage circuit, ensuring that the energy storage circuit can supply sufficient electric energy to the drive circuit to support the normal control of the power devices by the drive circuit, and avoiding the problem that the drive circuit cannot turn off the power device and maintain the normal operation of the power device due to insufficient power supply, resulting in serious system failures.

[0068] In the arm formed by directly connecting multiple power devices in series, series voltage equalization is the key to the normal operation of the power device direct series arm. The series voltage equalization is realized by the first voltage equalization circuit and the second voltage equalization circuit in each energy extraction module. The second voltage equalization circuit is a large-value resistor, and the resistance value of the second voltage equalization circuit is much smaller than the equivalent impedance when the power device is blocked, which can balance the leakage current of the power device during blocking, thereby reducing the static voltage difference between the series-connected power devices. The first voltage equalization circuit is used to slow down the change rate of the voltage across the power device during the on and off transients of the power device, thereby reducing the dynamic voltage difference between the series-connected power devices.

[0069] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0070] 1), In the energy extraction module of the power device of the present application, in the first voltage equalization circuit of the energy extraction module, a first branch including a switching device, a second branch including one of an energy storage device and an impedance adjustment device, and a third branch including the other of the energy storage device and the impedance adjustment device are provided, and the first branch is connected in parallel with the second branch and then connected in series with the third branch. One end of the first voltage equalization circuit is electrically connected to the input end of the power device, and the other end of the first voltage equalization circuit is electrically connected to the output end of the power device and its drive circuit respectively. When the energy extraction power of the drive circuit is insufficient, the switching state of the switching device can be changed to make the state of the switching device change from off to on, so as to reduce the equivalent impedance of the first voltage equalization circuit, increase the current flowing through the first voltage equalization circuit to the energy storage circuit, thereby improving the energy extraction power of the energy storage circuit, ensuring that the energy storage circuit can supply sufficient electric energy to the drive circuit to support the normal control of the power devices by the drive circuit, and avoiding the problem that the drive circuit cannot turn off the power device and maintain the normal operation of the power device due to insufficient power supply, resulting in serious system failures.

[0071] 2) In the energy extraction system of the present application, multiple power devices are connected in series, and multiple drive circuits are used to achieve the drive control of the multiple power devices. Multiple energy extraction modules as described above are used to achieve the high-level energy extraction of the power devices. When the energy extraction power of the drive circuit is insufficient, the switching state of the switching device in the energy extraction module can be changed to make the state of the switching device change from off to on, so as to reduce the equivalent impedance of the first voltage equalization circuit and increase the current flowing through the first voltage equalization circuit to the energy storage circuit, thereby improving the energy extraction power of the energy storage circuit and ensuring that the energy storage circuit can supply sufficient electric energy to the drive circuit to support the normal control of the power devices by the drive circuit, and avoiding the problem of serious system failures caused by the inability of the drive circuit to turn off the power devices and maintain the normal operation of the power devices due to insufficient power supply.

[0072] The foregoing is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An energy extraction module for a power device, characterized in that: include: a first voltage balancing circuit, having a first end and a second end, wherein the first end of the first voltage balancing circuit is used to be electrically connected to the input end of the power device, wherein the first voltage balancing circuit comprises a first branch, a second branch and a third branch, wherein the first branch and the second branch are connected in parallel, and the parallel circuit of the first branch and the second branch is connected in series with the third branch, wherein the first branch comprises a switch device, wherein one of the second branch and the third branch comprises an energy storage device, and the other of the second branch and the third branch comprises an impedance adjustment device, wherein when the switch device changes from being turned off to being turned on, the equivalent impedance between the first end and the second end of the first voltage balancing circuit decreases; An energy storage circuit, wherein the first end of the energy storage circuit is electrically connected to the second end of the first voltage equalizing circuit, the second end of the energy storage circuit is used to be electrically connected to the output end of the power device and the driving circuit of the power device respectively, and the energy storage circuit is used to store the electric energy output by the first voltage equalizing circuit and output the electric energy to the driving circuit.

2. The energy extraction module of the power device according to claim 1, characterized in that: The first branch also includes a first resistor, which is connected in series with the switch device. The second branch includes the impedance adjustment device, which includes a second resistor. The third branch includes the energy storage device, which includes a first capacitor.

3. The energy extraction module of the power device according to claim 1, characterized in that: The first branch also includes a second capacitor, which is connected in series with the switch device. The second branch includes the energy storage device, which includes a third capacitor. The third branch includes an impedance adjustment device, which includes a third resistor.

4. The energy extraction module of the power device according to claim 1, characterized in that: The second branch includes the impedance adjustment device, the third branch includes the energy storage device, the energy storage device includes a fourth capacitor and a fourth resistor, and the fourth capacitor and the fourth resistor are connected in series.

5. The energy extraction module of the power device according to claim 4, characterized in that: The impedance adjusting device includes a fifth capacitor or a fifth resistor.

6. The energy extraction module of the power device according to claim 4, characterized in that: The energy acquisition module of the power device also includes: A diode, wherein an anode of the diode is electrically connected to a first end of a fourth resistor, a cathode of the diode is electrically connected to a second end of the fourth resistor, and a current direction is from the first end of the fourth resistor to the second end of the fourth resistor.

7. The energy extraction module of a power device according to any one of claims 1 to 6, characterized in that: The energy acquisition module of the power device also includes: The second voltage balancing circuit includes a sixth resistor, one end of the sixth resistor is electrically connected to the first end of the first voltage balancing circuit, the other end of the sixth resistor is electrically connected to the second end of the first voltage balancing circuit, and the impedance of the sixth resistor is less than the equivalent impedance when the power device is in a blocking state.

8. The energy extraction module of a power device according to any one of claims 1 to 6, characterized in that: The energy storage circuit includes a sixth capacitor, one end of the sixth capacitor is the first end of the energy storage circuit, and the other end of the sixth capacitor is the second end of the energy storage circuit.

9. The energy extraction module of a power device according to any one of claims 1 to 6, characterized in that: The switch device has a control terminal, and the control terminal of the switch device is used to be electrically connected to the drive circuit.

10. An energy harvesting system, characterized in that: include: A plurality of power devices, wherein the plurality of power devices are connected in series; A plurality of driving circuits of the power devices, electrically connected to the power devices in a one-to-one correspondence; A plurality of energy extraction modules for power devices according to any one of claims 1 to 9, wherein the energy extraction modules for power devices are electrically connected to the power devices and the drive circuits in a one-to-one correspondence.

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