A surge protection device, electromagnetic heating equipment and surge protection method thereof

Abstract

The present invention discloses a surge protection device, an electromagnetic heating device and a surge protection method thereof, the device comprising: a first protection module, which, in a first case, performs primary absorption of surge energy; a rectifier module, which, in a first case, performs rectification processing on the AC power supply after primary absorption of surge energy at the power input end; or, in a second case, performs rectification processing on the AC power supply at the power input end; a second protection module, which, in a first case, performs secondary absorption on the residual surge energy after rectification processing on the AC power supply; or, in a second case, absorbs the surge energy after rectification processing on the AC power supply. The scheme of the present invention can solve the problem of low protection reliability when realizing surge protection of electromagnetic heating equipment through a primary varistor, and achieve the effect of improving protection reliability.

Description

Technical Field

[0001] The present invention belongs to the technical field of surge protection, and specifically relates to a surge protection device, an electromagnetic heating device and a surge protection method thereof, and more particularly to an IH (induction heat, electromagnetic heating) product surge protection circuit, an electromagnetic heating device and a surge protection method thereof. Background Art

[0002] The surge protection circuits of existing IH products are mostly primary varistor protection, which absorbs surge energy through varistor. If the varistor is too large, it will not be able to protect the subsequent circuits well; if the varistor is too small, it will affect the life of the varistor itself; after the varistor fails, the impedance is uncontrollable, and there are hidden dangers such as explosion, heating, and fire.

[0003] The above contents are only used to assist in understanding the technical solution of the present invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0004] The purpose of the present invention is to provide a surge protection device, an electromagnetic heating device and a surge protection method thereof to address the above-mentioned defects, so as to solve the problem of low protection reliability when realizing surge protection of electromagnetic heating equipment through a primary varistor, thereby achieving the effect of improving protection reliability.

[0005] The present invention provides a surge protection device, comprising: a first protection module, a rectifier module and a second protection module; wherein the first protection module is used to perform primary absorption of surge energy in a first case where the surge energy at the power input end of an electromagnetic heating device to be surge protected does not exceed the surge absorption range of the first protection module; the rectifier module is used to rectify the AC power supply after the surge energy at the power input end is absorbed in the first case; or to rectify the AC power supply at the power input end in a second case where the surge energy at the power input end of the electromagnetic heating device to be surge protected exceeds the surge absorption range of the first protection module; the second protection module is used to perform secondary absorption of the residual surge energy of the AC power supply after the rectification in the first case; or to absorb the surge energy of the AC power supply after the rectification in the second case.

[0006] Optionally, the second protection module includes: a first protection device and a second protection device, the first protection device and the second protection device are arranged in series; one of the first protection device and the second protection device includes: at least one second voltage-sensitive protection device; the other protection device of the first protection device and the second protection device includes: an open circuit failure device.

[0007] Optionally, the first protection module includes: at least one first pressure-sensitive protection device.

[0008] Optionally, the protection voltage of the first voltage-sensitive protection device is greater than or equal to the protection voltage of the second voltage-sensitive protection device.

[0009] Optionally, the impedance of the open circuit failure device is greater than the impedance of the second voltage-sensitive protection device.

[0010] Optionally, at least one of the first voltage-sensitive protection device and the second voltage-sensitive protection device includes: a varistor; and / or, the open-circuit failure device includes: an open-circuit failure type gas discharge tube.

[0011] Optionally, it further includes: a fuse module; the fuse module is used to perform primary protection on the power input end of the electromagnetic heating device to be surge protected.

[0012] Matching the above device, the present invention further provides an electromagnetic heating device, including: the surge protection device described above.

[0013] Optionally, the electromagnetic heating device includes: an electric rice cooker, an induction cooker or an electric hot pot.

[0014] Matching the above-mentioned electromagnetic heating equipment, the present invention provides a surge protection method for electromagnetic heating equipment on another aspect, comprising: through a first protection module, in the first case that the surge energy at the power input end of the electromagnetic heating equipment to be surge protected does not exceed the surge absorption range of the first protection module, the surge energy is absorbed in the primary stage; through a rectifier module, in the first case, the AC power supply after the surge energy at the power input end is absorbed in the primary stage; or in the second case that the surge energy at the power input end of the electromagnetic heating equipment to be surge protected exceeds the surge absorption range of the first protection module, the AC power supply at the power input end is rectified; through a second protection module, in the first case, the residual surge energy after the rectification of the AC power supply is absorbed in the secondary stage; or in the second case, the surge energy after the rectification of the AC power supply is absorbed.

[0015] Optionally, the method further includes: performing primary protection on the power input terminal of the electromagnetic heating device to be surge protected by a fuse module.

[0016] The solution of the present invention can improve the surge resistance of IH products and provide better protection for subsequent circuits by adding a first protection device and a second protection device to the rear side of the rectifier module to form a secondary protection module.

[0017] Furthermore, the solution of the present invention can increase the life of the varistor in the secondary protection module by making the first protection device a group or multiple groups of varistor protection devices, and the second protection device a device that has an open circuit characteristic after the device fails.

[0018] Furthermore, the solution of the present invention, by setting a primary protection module before the rectifier module and a secondary protection module after the rectifier module, can avoid the problem of explosion, heat and fire after the failure of the varistor in the secondary protection module, thereby improving the reliability and safety of surge protection.

[0019] Among them, the varistor of the second protection module and the open circuit failure device are connected in series, which can improve the reliability of the varistor in the second protection module and avoid the hidden dangers of explosion, heating, fire, etc. after the varistor fails in the second protection module. Due to the addition of the second protection module, the varistor voltage selection of the varistor in the first protection module can be appropriately increased to extend the service life of the varistor in the first protection module; for example: the varistor voltage of the varistor in the first protection module can be appropriately increased to extend the service life of the varistor in the first protection module.

[0020] Therefore, the solution of the present invention forms a secondary protection module by adding a first protection device and a second protection device on the rear side of the rectifier module, and the first protection device is connected in series with the second protection device; the problem of low protection reliability when implementing surge protection of electromagnetic heating equipment through a primary varistor is solved, thereby achieving the effect of improving protection reliability.

[0021] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention.

[0022] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of an embodiment of a surge protection device of the present invention;

[0024] Figure 2 A schematic diagram of a surge protection structure of an embodiment of an electromagnetic heating device of the present invention;

[0025] Figure 3 A schematic diagram of a surge protection structure of another embodiment of the electromagnetic heating device of the present invention;

[0026] Figure 4 FIG. 4 is a flow chart of a surge protection method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0028] According to an embodiment of the present invention, a surge protection device is provided. Figure 1 The schematic diagram of the structure of an embodiment of the device of the present invention is shown. The surge protection device may include: a first protection module, a rectification module and a second protection module.

[0029] Specifically, the first protection module is arranged between the power input end of the electromagnetic heating device to be surge protected and the rectifier module, and can be used to perform primary absorption of surge energy in the first case where the surge energy of the power input end of the electromagnetic heating device to be surge protected does not exceed the surge absorption range of the first protection module.

[0030] Optionally, the first protection module may include: at least one first pressure-sensitive protection device.

[0031] For example, the surge protection circuit may include a first protection module applied before the rectifier module, and the first protection module includes at least one voltage-sensitive protection device.

[0032] For example: The surge protection circuit of an IH product includes a first protection module placed in front of the rectifier module, and the first protection module includes no less than one varistor protection device.

[0033] Thus, primary protection is achieved through at least one first varistor protection device, the structure is simple, and the primary absorption of surge energy is more reliable.

[0034] Specifically, the rectifier module can be used to rectify the AC power supply at the power input end after the surge energy at the first level is absorbed in the first case; or to rectify the AC power supply at the power input end in the second case when the surge energy at the power input end of the electromagnetic heating equipment to be surge protected exceeds the surge absorption range of the first protection module.

[0035] Specifically, the second protection module is arranged on the rear side of the rectifier module, and can be used to perform secondary absorption of residual surge energy after rectification of the AC power supply in the first case; or to absorb surge energy after rectification of the AC power supply in the second case.

[0036] For example, a surge protection circuit for an IH product can improve the surge resistance of the IH product and provide better protection for the subsequent circuits; it can also improve the life of the varistor; and it can also prevent the varistor from bursting, heating, and catching fire after failure. For example, a surge protection circuit placed after a rectifier module can include a first protection device and a second protection device, and the first protection device and the second protection device are connected in series.

[0037] Therefore, by respectively arranging the protection modules on the front and rear sides of the rectifier module, secondary protection is implemented on both sides of the rectifier module, thereby improving the reliability of the protection.

[0038] Optionally, the second protection module may include: a first protection device and a second protection device, wherein the first protection device and the second protection device are arranged in series. The series positions of the first protection device and the second protection device can be interchanged, such as the first protection device is on the front side of the second protection device, or the first protection device is on the rear side of the second protection device.

[0039] Specifically, one of the first protection device and the second protection device may include: at least one second pressure-sensitive protection device. The other of the first protection device and the second protection device may include: an open circuit failure device. For example: the first protection device may include: at least one second pressure-sensitive protection device. The second protection device may include: a failure open circuit device.

[0040] For example: the first protection device is one or more groups of varistor protection devices; the second protection device is a device that makes the device become an open circuit characteristic after failure. The positions of the first protection device and the second protection device are interchangeable. Here, the open circuit failure device or the failed open circuit device can define the time for cutting off the circuit corresponding to different currents. Under this current time, the varistor can withstand; the open circuit failure device has an open circuit characteristic after failure; the open circuit failure device will clamp the voltage within a lower range after being impacted by a surge; the open circuit failure device has a very small leakage current under normal power frequency voltage.

[0041] For example: Figure 3 As shown, this circuit includes a second protection module placed after the rectifier module, including a first protection device and a second protection device. The first protection device includes at least one set of voltage-sensitive protection devices; the second protection device is a set of open-circuit failure type devices, and the connection method is as follows Figure 3 shown.

[0042] Specifically, it can also be arranged as follows: the first protection module can include: at least one first voltage-sensitive protection device; and / or the second protection module can include: a first protection device and a second protection device, and the first protection device and the second protection device are arranged in series.

[0043] The series positions of the first protection device and the second protection device can be interchanged, such as the first protection device is on the front side of the second protection device, or the first protection device is on the rear side of the second protection device. One of the first protection device and the second protection device may include: at least one second voltage-sensitive protection device. The other of the first protection device and the second protection device may include: an open circuit failure device. For example: the first protection device may include: at least one second voltage-sensitive protection device. The second protection device may include: a failure open circuit device.

[0044] Therefore, by setting two protection devices in the secondary protection, further surge protection and safe disconnection protection are respectively performed, which greatly improves the safety of the protection.

[0045] More optionally, the protection voltage of the first voltage-sensitive protection device is greater than or equal to the protection voltage of the second voltage-sensitive protection device.

[0046] For example, the protection voltage of the varistor protection device of the first protection module is greater than or equal to the protection voltage of the varistor protection device of the second protection module.

[0047] For example: while improving the selection of the varistor of the first protection module, a second protection module is added (a varistor and an open circuit failure device are connected in series), wherein the varistor voltage of the varistor of the second protection module is ≤ the varistor voltage of the varistor of the first protection module.

[0048] Therefore, by making the protection voltage of the first voltage-sensitive protection device in the primary protection greater than or equal to the protection voltage of the second voltage-sensitive protection device in the secondary protection, it is beneficial to improve the reliability and safety of the two-stage protection.

[0049] More optionally, the impedance of the open circuit failure device is greater than the impedance of the second voltage-sensitive protection device.

[0050] For example: the second protection module absorbs the relatively small amount of surge energy remaining in the first protection module, which has certain benefits for the life of the varistor selected in the second protection module; at the same time, in order to avoid the risk of explosion, heating, and fire after the varistor selected in the second protection module fails, an open circuit failure device is added in series with the varistor selected in the second protection module. Since the impedance of the open circuit failure device is larger than that of the varistor, the open circuit failure device will work first when it is impacted by a surge. If the varistor fails, the open circuit failure device will open in a shorter time due to excessive current, which can avoid the risk of varistor heating and fire.

[0051] Therefore, by setting the impedance of the open-circuit failure device in the secondary protection to be greater than the impedance of the second voltage-sensitive protection device, step-by-step protection can be further implemented in the secondary protection, making the stability and safety of the secondary protection better.

[0052] More optionally, the configuration of specific components of the first protection module and the second protection module may include at least one of the following configuration scenarios.

[0053] The first setting scenario: at least one of the first pressure-sensitive protection device and the second pressure-sensitive protection device may include: a varistor.

[0054] The second setting scenario: open circuit failure device, which may include: open circuit failure type gas discharge tube.

[0055] For example, the open circuit failure device may be an open circuit failure type gas discharge tube.

[0056] Therefore, by making the voltage-sensitive protection device a varistor and the open-circuit failure device a gas discharge tube, the structure is simple and the surge protection effect can be guaranteed, which is reliable and safe.

[0057] In an optional embodiment, it may also include: a fuse module. The fuse module is arranged between the power input terminal and the first protection module, and can be used to perform primary protection on the power input terminal of the electromagnetic heating device to be subjected to surge protection. For example: the fuse module is arranged between the power input terminal of the electromagnetic heating device to be subjected to surge protection and the first protection module, and can be used to perform primary protection on the power input terminal of the electromagnetic heating device to be subjected to surge protection.

[0058] Therefore, by arranging the insurance module between the power input terminal and the first protection module, the safety of surge protection can be better guaranteed.

[0059] A large number of tests have shown that the technical solution of the present invention can be used to improve the surge resistance of IH products by adding a first protection device and a second protection device on the rear side of the rectifier module to form a secondary protection module, thereby providing better protection for the subsequent circuits.

[0060] According to an embodiment of the present invention, an electromagnetic heating device corresponding to the surge protection device is also provided. The electromagnetic heating device may include: the surge protection device described above.

[0061] Optionally, the electromagnetic heating device may include: an electric rice cooker, an induction cooker or an electric hot pot.

[0062] In an optional embodiment, the solution of the present invention provides an IH product surge protection circuit, which can improve the surge resistance of the IH product and provide better protection for the subsequent circuit; it can increase the life of the varistor; and it can also avoid the problem of explosion, heating and fire of the varistor after failure.

[0063] In an optional example, in the solution of the present invention, a surge protection circuit placed after a rectifier module may include: a first protection device and a second protection device, wherein the first protection device and the second protection device are connected in series.

[0064] The first protection device is one or more sets of voltage-sensitive protection devices; the second protection device is a device that makes the device become an open circuit after failure. The positions of the first protection device and the second protection device are interchangeable.

[0065] Here, the open circuit failure device or the failed open circuit device can define the time for cutting off the circuit corresponding to different currents, under which the varistor can withstand; the open circuit failure device exhibits an open circuit characteristic after failure; the open circuit failure device will clamp the voltage within a lower range after being impacted by a surge; the open circuit failure device has a very small leakage current under normal power frequency voltage. Preferably, the open circuit failure device can be an open circuit failure type gas discharge tube.

[0066] Optionally, the surge protection circuit may include a first protection module applied before the rectifier module, and the first protection module includes at least one voltage-sensitive protection device.

[0067] Wherein, the protection voltage of the varistor protection device of the first protection module is greater than or equal to the protection voltage of the varistor protection device of the second protection module.

[0068] In an alternative embodiment, see Figure 3 and Figure 3 The examples shown are used to illustrate the specific implementation process of the solution of the present invention.

[0069] In an optional specific example, the IH product surge protection circuit provided by the solution of the present invention includes a first protection module placed in front of the rectifier module, and the first protection module includes no less than one voltage-sensitive protection device.

[0070] like Figure 2 As shown, this circuit includes a second protection module placed after the rectifier module, including a first protection device and a second protection device. The first protection device includes at least one set of voltage-sensitive protection devices; the second protection device is a set of open-circuit failure type devices, and the connection method is as follows Figure 3 shown.

[0071] Figure 3 is one way to achieve this. Figure 3In the figure, L and N are the power input terminals; RV1 corresponds to Figure 2 The first protection module may include a varistor; DB1 corresponds to Figure 2 The rectifier module may include a rectifier bridge or multiple diodes; TVS1 and RV2 correspond to Figure 2 The second protection module includes an open circuit failure device TVS1 and a varistor RV2. TVS1 and RV2 are in series relationship and their positions can be interchanged.

[0072] Among them, TVS1 protects the secondary varistor. The primary varistor protects itself by increasing its own resistance. The larger the resistance of the varistor, the weaker its absorption capacity. The resistance of the primary varistor is greater than or equal to the resistance of the secondary varistor. If the resistance of the primary varistor is too large and the surge is too large for the primary varistor to absorb the surge in time, the surge will directly reach the secondary level and be completely absorbed by the secondary protection.

[0073] When subjected to surge impact, traditional circuits mainly rely on varistors to discharge surge energy. When the varistor is working normally, there is a certain leakage current, and the failure mode is generally short circuit. After failure, there is a risk of explosion, heating, and fire. Compared with the solution of the present invention, if the first protection module uses a varistor with a smaller varistor voltage, although its limiting voltage is small, the surge voltage can be suppressed within a smaller range, which plays a better protective role for the subsequent stage, but the varistor will frequently enter the nonlinear region or saturation region under a small interference, resulting in varistor aging, failure, and even abnormal conditions such as heating and explosion, which has a great impact on the life of the varistor itself. If the first protection module uses a varistor with a larger varistor voltage, although it can extend the life of the varistor to absorb a larger surge impact, its limiting voltage is higher, and the surge residual pressure will also be relatively increased, which cannot play a good protective role for the subsequent stage devices (such as rectifier devices, power devices, etc.).

[0074] From the above analysis, it can be seen that increasing the size of the varistor of the first protection module can extend its life and absorb surge energy; the second protection module added after the rectifier module can also absorb surge energy and protect the subsequent devices (such as rectifier devices, power devices, etc.). Therefore, in the scheme of the present invention, while improving the size of the varistor of the first protection module, the present invention adds a second protection module (a varistor and an open circuit failure device are connected in series), wherein the varistor voltage of the varistor of the second protection module is ≤ the varistor voltage of the varistor of the first protection module.

[0075] In this way, the second protection module absorbs the relatively small amount of surge energy remaining in the first protection module, which has certain benefits for the life of the varistor selected in the second protection module; at the same time, in order to avoid the risk of explosion, heating, and fire after the varistor selected in the second protection module fails, an open circuit failure device is added in series with the varistor selected in the second protection module. Since the impedance of the open circuit failure device is larger than that of the varistor, the open circuit failure device will work first when it is impacted by a surge. If the varistor fails, the open circuit failure device will open in a short time due to excessive current, which can avoid the risk of varistor heating and fire.

[0076] It can be seen that the solution of the present invention provides an IH product surge protection circuit, which can effectively absorb surge voltage and extend the life of the device by setting two protection modules, and avoid the risks of heating, fire, etc.; it can effectively avoid the problem of heating and fire after the failure of the varistor, and can also be detected quickly after the failure of the varistor.

[0077] Among them, the surge protection circuit is a secondary surge protection, with a rectifier module between the two protection modules, and the rectifier circuit converts AC power into DC power; moreover, the second protection module uses a separate varistor + discharge tube, with a total of four pins, to prevent the first protection module from not completely suppressing the surge and causing damage to the circuit components. The problem of incomplete surge protection by the first protection module is solved, and the second level is used for secondary protection, in which the discharge tube is used to protect the varistor of the secondary protection module from being damaged. In addition, the surge protection circuit is used in rice cookers or induction cookers, not in blenders.

[0078] In summary, the scheme of the present invention can improve the selection of the varistor of the first protection module, can absorb a larger surge impact, and can also extend its life; adding a varistor and an open-circuit failure device in series at the later stage can provide better protection for the later stage devices and avoid the risk of heating and fire of the varistor; it has a good effect on improving the surge resistance of IH products.

[0079] In an alternative specific example, the second protection module can directly use a single varistor without an open-circuit failure device, but there will be a risk of heat and fire after the varistor fails. Alternatively, a varistor with a smaller varistor voltage and an open-circuit failure device can be selected in series in the first protection module, which still has a good effect on surge absorption and can also avoid the risk of heat and fire due to varistor failure. However, the failure of the varistor or the open-circuit failure device is not easy to detect, and will cause greater damage when it is subjected to a larger surge again.

[0080] Since the processing and functions implemented by the electromagnetic heating device of this embodiment are basically corresponding to the aforementioned Figure 1The embodiments, principles and examples of the device shown are as follows. Therefore, for matters not fully described in the description of this embodiment, reference can be made to the relevant descriptions in the aforementioned embodiments, and no further elaboration will be given here.

[0081] A large number of tests have verified that by adopting the technical solution of the present invention, in the secondary protection module, the first protection device is made into one or more groups of voltage-sensitive protection devices, and the second protection device is a device that has an open-circuit characteristic after the device fails, thereby increasing the life of the varistor in the secondary protection module.

[0082] According to an embodiment of the present invention, a surge protection method for an electromagnetic heating device corresponding to the electromagnetic heating device is also provided, such as Figure 4 The schematic diagram of the flow chart of an embodiment of the method of the present invention is shown. The surge protection method of the electromagnetic heating device may include: step S110 to step S130.

[0083] In step S110, a first protection module, such as a first protection module arranged between a power input terminal of the electromagnetic heating device to be surge protected and a rectifier module, performs primary absorption on surge energy at the power input terminal of the electromagnetic heating device to be surge protected.

[0084] At step S120, through the rectifier module, in the first case, the AC power supply after the surge energy at the power input end is absorbed by the first level is rectified; or in the second case when the surge energy at the power input end of the electromagnetic heating equipment to be surge protected exceeds the surge absorption range of the first protection module, the AC power supply at the power input end is rectified.

[0085] In step S130, the residual surge energy after rectification of the AC power is secondarily absorbed by the second protection module, which is arranged at the rear side of the rectification module.

[0086] For example, a surge protection circuit for an IH product can improve the surge resistance of the IH product and provide better protection for the subsequent circuits; it can also improve the life of the varistor; and it can also prevent the varistor from bursting, heating, and catching fire after failure. For example, a surge protection circuit placed after a rectifier module can include a first protection device and a second protection device, and the first protection device and the second protection device are connected in series.

[0087] Therefore, by respectively arranging the protection modules on the front and rear sides of the rectifier module, secondary protection is implemented on both sides of the rectifier module, thereby improving the reliability of the protection.

[0088] In an optional embodiment, the present invention may further include: performing primary protection on the power input end of the electromagnetic heating device to be subjected to surge protection by means of a fuse module, such as a fuse module disposed between the power input end and the first protection module. For example, the fuse module is disposed between the power input end of the electromagnetic heating device to be subjected to surge protection and the first protection module, and is used to perform primary protection on the power input end of the electromagnetic heating device to be subjected to surge protection.

[0089] Therefore, by arranging the insurance module between the power input terminal and the first protection module, the safety of surge protection can be better guaranteed.

[0090] Since the processing and functions implemented by the method of this embodiment are basically corresponding to the aforementioned Figures 1 to 3 The embodiments, principles and examples of the electromagnetic heating device shown in the figure, so for the details not exhaustive in the description of this embodiment, please refer to the relevant descriptions in the aforementioned embodiments, and no further description will be given here.

[0091] After a large number of tests and verifications, the technical solution of this embodiment is adopted. By setting a primary protection module before the rectifier module and a secondary protection module after the rectifier module, the problem of explosion, heat and fire after failure of the varistor in the secondary protection module can be avoided, thereby improving the reliability and safety of surge protection.

[0092] In summary, it is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0093] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A surge protection device, characterized in that: include: A first protection module, a rectifier module and a second protection module; wherein, The first protection module is used to absorb the surge energy in the first stage under the first condition that the surge energy of the power input end of the electromagnetic heating device to be surge protected does not exceed the surge absorption range of the first protection module; The rectifier module is used to rectify the AC power supply after the surge energy at the power input end is absorbed by the first level in the first case; or rectify the AC power supply at the power input end in the second case when the surge energy at the power input end of the electromagnetic heating device to be surge protected exceeds the surge absorption range of the first protection module; The second protection module is used to perform secondary absorption of residual surge energy after rectification of the AC power supply in the first case; or to absorb surge energy after rectification of the AC power supply in the second case; A second protection module formed by a first protection device and a second protection device is added to the rear side of the rectifier module, and the first protection device and the second protection device are connected in series; in the second protection module, the first protection device is one or more groups of voltage-sensitive protection devices, and the second protection device includes an open-circuit failure device.

2. The device according to claim 1, characterized in that The first protection device includes: at least one second voltage-sensitive protection device.

3. The device according to claim 2, characterized in that The first protection module includes: at least one first pressure-sensitive protection device.

4. The device according to claim 3, characterized in that The protection voltage of the first voltage-sensitive protection device is greater than or equal to the protection voltage of the second voltage-sensitive protection device.

5. The device according to claim 3, characterized in that The impedance of the open circuit failure device is greater than the impedance of the second voltage sensitive protection device.

6. The device according to claim 3, characterized in that At least one of the first pressure-sensitive protection device and the second pressure-sensitive protection device comprises: a varistor; and / or, Open circuit failure devices include: open circuit failure type gas discharge tubes.

7. The device according to claim 1 or 2, characterized in that: Also includes: Insurance module; The insurance module is used to perform primary protection on the power input end of the electromagnetic heating device to be surge protected.

8. The device according to claim 3, characterized in that Also includes: Insurance module; The insurance module is used to perform primary protection on the power input end of the electromagnetic heating device to be surge protected.

9. An electromagnetic heating device, characterized in that: include: A surge protection device as claimed in any one of claims 1 to 8.

10. The electromagnetic heating device according to claim 9, characterized in that: The electromagnetic heating equipment includes: an electric rice cooker, an induction cooker or an electric hot pot.

11. A surge protection method for electromagnetic heating equipment according to claim 9 or 10, characterized in that: include: By means of the first protection module, in a first case where the surge energy at the power input end of the electromagnetic heating device to be surge protected does not exceed the surge absorption range of the first protection module, the surge energy is firstly absorbed; By means of the rectifier module, in the first case, the AC power supply after the surge energy at the power input end is absorbed by the first level is rectified; or in the second case when the surge energy at the power input end of the electromagnetic heating device to be surge protected exceeds the surge absorption range of the first protection module, the AC power supply at the power input end is rectified; Through the second protection module, in the first case, the residual surge energy after the rectification of the AC power supply is secondarily absorbed; or in the second case, the surge energy after the rectification of the AC power supply is absorbed.

12. The method according to claim 11, characterized in that Also includes: The fuse module provides primary protection for the power input terminal of the electromagnetic heating device to be surge protected.

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