TWI680631B - Surge protective apparatus of power conversion circuit - Google Patents

Abstract

A lightning protection device for a power conversion circuit includes an AC-to-DC conversion circuit and a two-voltage clamping unit. The AC-to-DC conversion circuit receives AC power and converts the AC power to DC power. The DC power is connected between the positive output terminal and the negative output terminal of the AC-DC conversion circuit. The first terminal of each voltage clamping unit is respectively coupled to the first AC terminal and the second AC terminal of the AC power source, and the second terminal of each voltage clamping unit is commonly coupled to the positive output terminal or the negative output terminal; thereby, it is effective Ground to achieve suppression of lightning energy.

Description

Lightning protection device for power conversion circuit

The invention relates to a protection device for a power conversion circuit, and more particularly to a lightning protection device for a power conversion circuit.

The current lightning protection circuit is to connect lightning protection components, varistors, or other safety-recognized and controlled protection components at the AC input end to achieve lightning energy suppression to avoid damage to the main circuit components. However, because the protection element is connected across the AC input terminal, it must be recognized and controlled by safety regulations, for example, it must be limited by 1.25 times the rated power. Therefore, once the protection device operates at a higher voltage, the energy it can clamp is lower, so that the energy that cannot be clamped enters the main circuit, which may still cause damage to the main circuit components. Another current technology is to set a bypass diode at the AC input terminal to bypass the lightning strike energy to the output capacitor via the diode, but it may cause excessive damage to the output capacitor voltage. If the above-mentioned problems are to be solved, when a protection element with a higher clamping energy is used, the cost and the space occupied by the protection element will increase.

It is an object of the present invention to provide a lightning protection device for a power conversion circuit, which solves the problems that a lightning protection component is restricted by safety regulations and control and cannot effectively suppress the lightning energy.

In order to achieve the purpose of disclosure, the lightning protection device for a power conversion circuit provided by the present invention includes an AC-to-DC conversion circuit and a two-voltage clamping unit. The AC-to-DC conversion circuit receives AC power and converts the AC power to DC power. The DC power is connected between the positive output terminal and the negative output terminal of the AC-DC conversion circuit. A first terminal of each voltage clamping unit is respectively coupled to a first AC terminal and a second AC terminal of an AC power source, and a second terminal of each voltage clamping unit is commonly coupled to a positive output terminal or a negative output terminal.

With the proposed lightning protection device of the power conversion circuit, the suppression of lightning energy can be effectively achieved, and the cost and the space occupied by the protection element can be reduced, thereby achieving a miniaturized design requirement.

Another object of the present invention is to provide a lightning protection device for a power conversion circuit, which solves the problems that the lightning protection component is restricted by safety regulations and control and cannot effectively suppress the lightning energy.

In order to achieve the purpose of disclosure, the lightning protection device for a power conversion circuit provided by the present invention includes an AC-to-DC conversion circuit and a two-voltage clamping unit. The AC-to-DC conversion circuit receives AC power and converts the AC power to DC power. The DC power is connected between the positive output terminal and the negative output terminal of the AC-DC conversion circuit. The first terminal of each voltage clamping unit is commonly coupled to the live or neutral terminal of the AC power supply, and the second terminal of each voltage clamping unit is respectively coupled to the positive output terminal and the negative output terminal.

With the proposed lightning protection device of the power conversion circuit, the suppression of lightning energy can be effectively achieved, and the cost and the space occupied by the protection element can be reduced, thereby achieving a miniaturized design requirement.

In order to further understand the technology, means and effects adopted by the present invention to achieve the intended purpose, please refer to the following detailed description of the present invention and the accompanying drawings. It is believed that the object, features and The characteristics can be obtained through a deep and specific understanding, but the drawings are provided for reference and description only, and are not intended to limit the present invention.

10‧‧‧AC to DC Conversion Circuit

20‧‧‧Voltage clamping unit

21‧‧‧First Voltage Clamping Unit

22‧‧‧Second Voltage Clamping Unit

23‧‧‧Third Voltage Clamping Unit

Vac‧‧‧AC Power

Vdc‧‧‧DC Power Supply

Pac1‧‧‧The first communication terminal

Pac2‧‧‧Second communication terminal

Pdc1‧‧‧ positive output

Pdc2‧‧‧ negative output

Co‧‧‧ output capacitor

VAR‧‧‧Varistor

GDT‧‧‧Gas discharge tube

PSW‧‧‧Power Switch

TVS‧‧‧Transient Voltage Suppressor

P1‧‧‧First energy release path

P2‧‧‧second energy release path

FIG. 1 is a circuit block diagram of a first embodiment of a lightning protection device for a power conversion circuit according to the present invention.

FIG. 2 is a circuit block diagram of a second embodiment of a lightning protection device of a power conversion circuit according to the present invention.

FIG. 3 is a circuit block diagram of a third embodiment of a lightning protection device of a power conversion circuit according to the present invention.

4 is a circuit block diagram of a fourth embodiment of a lightning protection device of a power conversion circuit according to the present invention.

5A is a circuit diagram of a first embodiment of a voltage clamping unit according to the present invention.

5B is a circuit diagram of a second embodiment of a voltage clamping unit according to the present invention.

5C is a circuit diagram of a third embodiment of a voltage clamping unit according to the present invention.

FIG. 6A is a detailed circuit diagram of the AC-to-DC conversion circuit in FIG. 1 as the first embodiment.

FIG. 6B is a detailed circuit diagram of the AC-to-DC conversion circuit in FIG. 2 as the first embodiment.

FIG. 6C is a detailed circuit diagram of the AC-to-DC conversion circuit in FIG. 3 as the first embodiment.

FIG. 6D is a detailed circuit diagram of the AC-to-DC conversion circuit in FIG. 4 as the first embodiment.

FIG. 7A is a detailed circuit diagram of the AC-to-DC conversion circuit in FIG. 1 as a second embodiment.

FIG. 7B is a detailed circuit diagram of the second embodiment of the AC-to-DC conversion circuit in FIG. 2.

FIG. 7C is a detailed circuit diagram of the AC-to-DC conversion circuit in FIG. 3 as a second embodiment.

FIG. 7D is a detailed circuit diagram of the AC-to-DC conversion circuit in FIG. 4 as a second embodiment.

FIG. 8A is a detailed circuit diagram of a third embodiment of the AC-to-DC conversion circuit in FIG. 1.

8B is a detailed circuit diagram of the third embodiment of the AC-to-DC conversion circuit in FIG. 2.

FIG. 8C is a detailed circuit diagram of the third embodiment of the AC-to-DC conversion circuit in FIG. 3.

8D is a detailed circuit diagram of the third embodiment of the AC-to-DC conversion circuit in FIG. 4.

FIG. 9A is a detailed circuit diagram of a fourth embodiment of the AC-to-DC conversion circuit in FIG. 1.

FIG. 9B is a detailed circuit diagram of the fourth embodiment of the AC-to-DC conversion circuit in FIG. 2.

FIG. 9C is a detailed circuit diagram of the fourth embodiment of the AC-to-DC conversion circuit in FIG. 3.

FIG. 9D is a detailed circuit diagram of the fourth embodiment of the AC-to-DC conversion circuit in FIG. 4.

FIG. 10 is a circuit block diagram of a fifth embodiment of a lightning protection device of a power conversion circuit according to the present invention.

11 is a circuit block diagram of a sixth embodiment of a lightning protection device of a power conversion circuit according to the present invention.

FIG. 12 is a circuit block diagram of a seventh embodiment of a lightning protection device of a power conversion circuit according to the present invention.

13 is a circuit block diagram of an eighth embodiment of a lightning protection device of a power conversion circuit according to the present invention.

The technical content and detailed description of the present invention are described below with reference to the drawings.

Please refer to FIG. 1, which is a circuit block diagram of a first embodiment of a lightning protection device of a power conversion circuit according to the present invention. The lightning protection device of the power conversion circuit includes an AC-to-DC conversion circuit 10 and two voltage clamping units 20, which include a first voltage clamping unit 21 and a second voltage clamping unit 22. The AC-to-DC conversion circuit 10 receives an AC power source Vac, and the AC-to-DC conversion circuit 10 converts the AC power source Vac to a DC power source Vdc. In one embodiment, the AC-to-DC conversion circuit 10 may be a power factor correction (PFC) circuit, and may be a power factor correction circuit of a different topology, which will be described later.

The output of the DC power source Vdc converted by the AC-to-DC conversion circuit 10 is connected between the positive output terminal Pdc1 and the negative output terminal Pdc2 of the AC-to-DC conversion circuit 10. Specifically, the lightning protection device of the power conversion circuit further includes an output capacitor Co, which is coupled between the positive output terminal Pdc1 and the negative output terminal Pdc2 to provide a DC power source Vdc.

A first terminal of each voltage clamping unit 20 is respectively coupled to a first AC terminal Pac1 and a second AC terminal Pac2 of an AC power source Vac, and a second terminal of each voltage clamping unit 20 is coupled to a positive output terminal Pdc1 or a negative output.端 Pdc2. In this embodiment, the first AC terminal Pac1 may be a live line terminal of the AC power source Vac, and the second AC terminal Pac2 may be a neutral line terminal of the AC power source Vac. Therefore, in the first embodiment shown in FIG. 1, the first terminal of the first voltage clamping unit 21 is coupled to the live terminal Pac1 of the AC power source Vac, and the first terminal of the second voltage clamping unit 22 is coupled to the AC power source. The neutral terminal Pac2 of Vac, and the second terminal of the first voltage clamping unit 21 and the second terminal of the second voltage clamping unit 22 are commonly coupled to the positive output terminal Pdc1.

Please refer to FIG. 2, which is a circuit block diagram of a second embodiment of a lightning protection device of a power conversion circuit according to the present invention. The biggest difference between the second embodiment shown in FIG. 2 and the first embodiment shown in FIG. 1 is that the first voltage clamping unit 21 and the second voltage clamping unit 22 of the former (that is, the second embodiment) The two terminals are commonly coupled to the negative output terminal Pdc2.

Please refer to FIG. 3, which is a circuit block diagram of a third embodiment of a lightning protection device for a power conversion circuit according to the present invention. The biggest difference between the third embodiment shown in FIG. 3 and the first embodiment shown in FIG. 1 is that the first voltage clamping unit 21 and the second voltage clamping unit 22 of the former (that is, the third embodiment) One terminal is commonly coupled to the neutral terminal Pac2 of the AC power source Vac, and the second terminal of the first voltage clamping unit 21 is coupled to the positive output terminal Pdc1, and the second terminal of the second voltage clamping unit 22 is coupled to the negative output terminal. Pdc2.

Please refer to FIG. 4, which is a circuit block diagram of a fourth embodiment of a lightning protection device of a power conversion circuit according to the present invention. The biggest difference between the fourth embodiment shown in FIG. 4 and the third embodiment shown in FIG. 3 is that the first voltage clamping unit 21 and the second voltage clamping unit of the former (that is, the fourth embodiment) The first terminal of 22 is commonly coupled to the live terminal Pac1 of the AC power source Vac, and the second terminal of the first voltage clamping unit 21 is coupled to the positive output terminal Pdc1, and the second terminal of the second voltage clamping unit 22 is coupled to the negative output.端 Pdc2.

Please refer to FIG. 5A to FIG. 5C, which are circuit diagrams of the first embodiment, the second embodiment, and the third embodiment of the voltage clamping unit of the present invention, respectively. As shown in the first embodiment shown in FIG. 5A, each voltage clamping unit 20 includes a varistor VAR and a gas discharge tube GDT. The gas discharge tube GDT is connected in series with a varistor VAR to form a series structure. One end of the series structure is coupled to an AC power source Vac and the other end is coupled to a DC power source Vdc. The voltage clamping unit 20 is formed in a series structure to achieve lightning energy absorption and suppression when a lightning voltage occurs, and protects the AC-to-DC conversion circuit 10 from damage.

As shown in the second embodiment shown in FIG. 5B, each voltage clamping unit 20 includes a transient voltage suppressor (TVS). One end of the transient voltage suppressor TVS is coupled to the AC power source Vac and the other end is coupled to the DC power source Vdc. Thus, the voltage clamping unit 20 formed by the transient voltage suppressor TVS is used to achieve the lightning strike energy when the lightning voltage occurs. Absorption and suppression, protecting the AC-to-DC conversion circuit 10 from damage.

As shown in the third embodiment shown in FIG. 5C, each voltage clamping unit 20 includes a varistor VAR and a power switch PSW. The power switch PSW is connected in series with the varistor VAR to form a series structure. One end of the series structure is coupled to the AC power source Vac and the other end is coupled to the DC power source Vdc. Thus, the power switch PSW is connected in series with the varistor VAR. The structure of the voltage clamping unit 20 achieves lightning energy absorption and suppression when a lightning voltage occurs, and protects the AC-to-DC conversion circuit 10 from damage. It is worth mentioning that in the third embodiment, it is usually necessary to cooperate with a control unit that generates a control signal to turn on or off the power switch PSW to achieve a state equivalent to the open circuit and the short circuit of the gas discharge tube GDT shown in FIG. 5A. Specifically, when detecting that the voltage on the AC power supply Vac or the output capacitor Co increases to reach a preset operating voltage, the control unit turns on the power switch PSW, so that the varistor VAR starts to suck. Lightning energy released from the DC power source Vdc terminal to the AC power source Vac is received to achieve lightning protection for the AC to DC conversion circuit 10.

Please refer to FIG. 6A, which is a detailed circuit diagram of the first embodiment of the AC-to-DC conversion circuit in FIG. 1. The AC-to-DC conversion circuit 10 of the first embodiment is a rectifier circuit with a boost. Circuit, common in general PFC applications. In the subsequent different embodiments, the voltage clamping unit 20 formed in series by the gas discharge tube GDT series varistor VAR shown in FIG. 5A is used as an example for description. Similarly, FIGS. 6B to 6D correspond to the detailed circuit diagrams of the first embodiment of the AC-to-DC conversion circuit in FIGS. 2 to 4, respectively.

Please refer to FIG. 7A, which is a detailed circuit diagram of the second embodiment of the AC-to-DC conversion circuit in FIG. 1. The AC-to-DC conversion circuit 10 of the second embodiment is a bridgeless PFC. . In the subsequent different embodiments, the voltage clamping unit 20 formed in series by the gas discharge tube GDT series varistor VAR shown in FIG. 5A is used as an example for description. Similarly, FIGS. 7B to 7D correspond to the detailed circuit diagrams of the second embodiment of the AC-to-DC conversion circuit in FIGS. 2 to 4, respectively.

Please refer to FIG. 8A, which is a detailed circuit diagram of the third embodiment of the AC-to-DC conversion circuit in FIG. 1, and the AC-to-DC conversion circuit 10 of the third embodiment is a Totem pole PFC. In the subsequent different embodiments, the voltage clamping unit 20 formed in series by the gas discharge tube GDT series varistor VAR shown in FIG. 5A is used as an example for description. Similarly, FIGS. 8B to 8D correspond to the detailed circuit diagrams of the third embodiment of the AC-to-DC conversion circuit in FIGS. 2 to 4, respectively.

Please refer to FIG. 9A, which is a detailed circuit diagram of the fourth embodiment of the AC-to-DC conversion circuit in FIG. 1. The AC-to-DC conversion circuit 10 of the fourth embodiment is a boost PFC. In different subsequent embodiments, the varistor VAR is connected in series with the gas discharge tube GDT shown in FIG. 5A The voltage clamping unit 20 formed in a series structure will be described as an example. Similarly, FIGS. 9B to 9D correspond to the detailed circuit diagrams of the fourth embodiment of the AC-to-DC conversion circuits in FIGS. 2 to 4, respectively.

In the following, the operation of providing AC to DC conversion circuit 10 with lightning strike protection will be described using 6A to 6D. Please refer to FIG. 6A again. When the AC power supply Vac is normally supplied, the so-called “normal power supply” herein means that there is no abnormal high voltage on the AC power supply terminal, such as a lightning strike voltage. The AC-to-DC conversion circuit 10 is used to convert AC. The power supply Vac is used to output the DC power supply Vdc to provide the DC converter of the subsequent stage or directly provide the load.

However, when the AC power supply Vac is abnormally high voltage, such as a lightning strike voltage, in this case, if the two voltage clamping unit 20 is not provided, once the lightning stroke energy generated by the AC power supply Vac is transmitted to the AC-to-DC conversion circuit 10 , Will cause damage to the AC to DC conversion circuit 10. Therefore, the present invention uses the selection and configuration of the first voltage clamping unit 21 and the second voltage clamping unit 22, which can not only meet the design requirements for miniaturization, but also achieve the lightning energy when the lightning voltage occurs. Absorption and suppression protect the AC-to-DC conversion circuit 10 from damage, as described below.

As shown in FIG. 6A, the first voltage clamping unit 21 is coupled between the hot line terminal Pac1 of the AC power source Vac and the positive output terminal Pdc1 of the DC power source Vdc, and the second voltage clamping unit 22 is coupled to the AC power source Vac. Between the neutral terminal Pac2 and the positive output terminal Pdc1 of the DC power supply Vdc to provide complete protection when the lightning strike voltage is generated during the positive half cycle of AC or the negative half cycle of AC. For the convenience of explanation, a quantized voltage value is used for explanation, which is only used for illustration, and is not intended to limit the technical spirit of the present invention. For example, the operating voltage on the output capacitor Co coupled between the positive output terminal Pdc1 and the negative output terminal Pdc2 may be 400 volts. Accordingly, the operating voltage of the gas discharge tube GDT may be designed to be greater than 500 of the operating voltage volt.

Under the normal power supply of the AC power source Vac, the voltage output by the AC-to-DC conversion circuit 10 between the positive output terminal Pdc1 and the negative output terminal Pdc2, that is, the operating voltage on the output capacitor Co is smaller than the operating voltage of the gas discharge tube GDT, Not enough to turn on the gas discharge tube GDT, so the gas discharge The electric tube GDT is in an open circuit state. At this time, the energy path generated by the AC power source Vac is transmitted to the DC converter at the subsequent stage via the AC-to-DC conversion circuit 10.

Conversely, when the AC power source Vac is an abnormal lightning strike high voltage, the lightning strike high voltage charges the output capacitor Co, so that the voltage on the output capacitor Co rises sharply, that is, the voltage at the positive output terminal Pdc1 rises sharply. Once the voltage on the output capacitor Co increases to the operating voltage of the gas discharge tube GDT, that is, when it reaches 500 volts, the gas discharge tube GDT of the second voltage clamping unit 22 is in a state of being turned on and shorted, and the second voltage is clamped. The varistor VAR of the unit 22 starts to absorb the lightning strike energy released from the DC power source Vdc terminal to the AC power source Vac neutral terminal Pac2, as shown in the first energy release path P1 of FIG. 6A, or the first current release path Showed. It is worth mentioning that when the lightning strikes a high voltage momentarily, the gas discharge tube GDT of the first voltage clamping unit 21 will also be turned on, so that the lightning strike energy can also charge the output capacitor Co through the first voltage clamping unit 21, The voltage clamping unit 21 first absorbs part of the lightning strike energy, and further, the lightning strike energy can be transmitted back to the AC power source Vac terminal through the second voltage clamping unit 22 as a release path to prevent the damage of the general PFC element by the lightning strike energy.

When the AC power supply Vac is a negative impulse abnormal lightning high voltage, once the voltage on the output capacitor Co increases to reach the operating voltage of the gas discharge tube GDT, the gas discharge tube GDT of the first voltage clamping unit 21 at this time It is in a state of being short-circuited, and at the same time, the varistor VAR of the first voltage clamping unit 21 starts to absorb the lightning strike energy released from the DC power source Vdc terminal to the AC power source Vac live terminal Pac1, as shown in the second energy of FIG. 6A The release path P2, or the second current release path is illustrated. Similarly, when the lightning strikes a high voltage momentarily, the gas discharge tube GDT of the second voltage clamping unit 22 will also be turned on, so that the lightning strike energy can also charge the output capacitor Co through the second voltage clamping unit 22, and the second voltage The clamping unit 22 first absorbs a portion of the lightning strike energy, and further, the lightning strike energy can be transmitted back to the AC power source Vac terminal through the first voltage clamping unit 21 as a release path to prevent the damage of the general PFC element by the lightning strike energy.

In summary, through the design of the first voltage clamping unit 21 and the second voltage clamping unit 22, it is possible to achieve suppression of lightning strike energy generated by positive and negative pulse lightning strike high voltages. And when the gas discharge tube GDT is turned on and shorted due to abnormal high lightning voltage, the varistor VAR can clamp the voltage of the DC power supply Vdc terminal to not exceed its maximum clamping yoltage, so that the lightning strike energy is in the form of current The first voltage clamping unit 21 or the second voltage clamping unit 22 is bypassed to return to the AC power source Vac terminal, thereby protecting the AC to DC conversion circuit 10.

Because the biggest difference between 6B ~ 6D and 6A is that the first voltage clamping unit 21 and the second voltage clamping unit 22 are coupled to the hot line terminal Pac1 and the neutral line terminal Pac2 of the AC power supply Vac and the positive output of the DC power supply Vdc. The positions of the terminal Pdc1 and the negative output terminal Pdc2 are different. However, the first voltage clamping unit 21 and the second voltage clamping unit 22 can also achieve the suppression of the lightning strike energy generated by the positive and negative pulse lightning strike high voltage. The energy (current) release path can be referred to the corresponding diagram, and its action and operation can be coordinated with reference to the corresponding description of FIG. 6A, so it will not be described in detail here.

Furthermore, the differences between FIGS. 7A-7D, 8A-8D, and 9A-9D compared to FIGS. 6A-6D are that the AC-to-DC conversion circuit 10 is basically a bridgeless PFC, a totem pole PFC, and a bidirectional Switching boost PFC, in which the first voltage clamping unit 21 and the second voltage clamping unit 22 are selected in the same configuration as in FIGS. 6A to 6D, so the first voltage clamping unit 21 and the second voltage The clamping unit 22 can also achieve the suppression of the lightning strike energy generated by the high voltage of positive and negative pulse lightning strikes, and its energy (current) release path can be shown in the corresponding diagram, and its actions and operations can be coordinated. The corresponding description of 6A will not be repeated here.

Please refer to FIG. 10, which is a circuit block diagram of a fifth embodiment of a lightning protection device for a power conversion circuit according to the present invention. The fifth embodiment is a lightning protection device of a power conversion circuit applied to a three-phase AC power source Va, Vb, Vc, and the three-phase AC power source Va, Vb, Vc is a star connection, that is, a wye connection To provide lightning protection for the AC-to-DC conversion circuit 10. In this embodiment, the voltage clamping unit 20 includes a first voltage clamping unit 21, a second voltage clamping unit 22, and a third power source. 压 夹 unit23. The first terminal of each voltage clamping unit 20 is correspondingly coupled to the live wire terminal of any of the corresponding AC power sources Va, Vb, Vc, and the second terminal of each voltage clamping unit 20 is commonly coupled to the positive output of the DC power source Vdc.端 Pdc1. That is, the first terminal of the first voltage clamp unit 21 is coupled to the a-phase live wire terminal of the AC power source, the first terminal of the second voltage clamp unit 22 is coupled to the b-phase live wire terminal of the AC power source, and the third voltage clamp. The first terminal of the unit 23 is coupled to the c-phase live wire terminal of the AC power source, and the second terminals of the first voltage clamping unit 21, the second voltage clamping unit 22, and the third voltage clamping unit 23 are commonly coupled to the DC power source. The positive output terminal Pdc1 of Vdc provides the suppression of the lightning strike energy generated by the high voltage of the lightning strike, and achieves the protection of the AC to DC conversion circuit 10. Similarly, the AC-to-DC conversion circuit 10 may be a general PFC, a substantially bridgeless PFC, a totem pole PFC, a bidirectional switch boost PFC, or other AC-to-DC converters.

Please refer to FIG. 11, which is a circuit block diagram of a sixth embodiment of a lightning protection device of a power conversion circuit according to the present invention. The biggest difference between the sixth embodiment shown in FIG. 11 and the fifth embodiment shown in FIG. 10 is that the first voltage clamping unit 21, the second voltage clamping unit 22, and the first voltage clamping unit 22 of the former (that is, the sixth embodiment). The second terminal of the three-voltage clamping unit 23 is commonly coupled to the negative output terminal Pdc2 to provide absorption suppression of lightning strike energy generated by a high-voltage lightning strike, thereby achieving protection of the AC to DC conversion circuit 10.

Please refer to FIG. 12, which is a circuit block diagram of a seventh embodiment of a lightning protection device for a power conversion circuit according to the present invention. The biggest difference between the seventh embodiment shown in FIG. 12 and the fifth embodiment shown in FIG. 10 is that the former (ie, the seventh embodiment) is a lightning protection device for a power conversion circuit applied to a three-phase AC power supply Va, Vb. Vc, and the three-phase AC power sources Va, Vb, Vc are in a delta connection, that is, a delta connection, to provide lightning protection for the AC-to-DC conversion circuit 10.

Please refer to FIG. 13, which is a circuit block diagram of an eighth embodiment of a lightning protection device of a power conversion circuit according to the present invention. The biggest difference between the eighth embodiment shown in FIG. 13 and the seventh embodiment shown in FIG. 12 lies in the first voltage clamping unit 21 and the second voltage clamping unit of the former (that is, the eighth embodiment). 22 and the second terminal of the third voltage clamping unit 23 are commonly coupled to the negative output terminal Pdc2, so as to provide the suppression of the lightning strike energy generated by the high voltage of the lightning strike, so as to achieve the protection of the AC to DC conversion circuit 10.

In summary, the present invention has the following characteristics and advantages:

1. By using the design of the first voltage clamping unit 21 and the second voltage clamping unit 22, it is possible to avoid the lightning protection component across the AC input terminal from being subject to safety recognition and control restrictions.

2. Through the selection and configuration of the first voltage clamping unit 21 and the second voltage clamping unit 22, not only the cost can be reduced, but also the space occupied by the protection components can be reduced, thereby achieving a miniaturized design requirement.

3. The lightning protection device of the power conversion circuit can be flexibly applied to the single-phase AC power supply and the three-phase AC power supply to achieve lightning protection of the AC to DC conversion circuit 10.

4. Through the operation of the first voltage clamping unit 21 and the second voltage clamping unit 22 on the DC conversion circuit 10 according to the AC of different topologies, it is possible to absorb the lightning energy generated by the positive and negative pulse lightning high voltage strikes. Suppress and protect the AC-to-DC conversion circuit 10 from damage.

The above are only detailed descriptions and drawings of the preferred embodiments of the present invention, but the features of the present invention are not limited thereto, and are not intended to limit the present invention. The scope of the present invention shall be in the scope of the following patent applications. For the purposes of this disclosure, all embodiments that are within the spirit of the scope of the present invention and similar changes should be included in the scope of the present invention. Any person skilled in the art can easily consider the changes or modifications in the field of the present invention. Both can be covered by the patent scope of this case.

Claims (18)

A lightning protection device for a power conversion circuit includes an AC-to-DC conversion circuit that receives an AC power source and converts the AC power source to a DC power source, wherein the DC power source is connected across a positive output terminal of the AC-to-DC conversion circuit. And a negative output terminal; and at least two voltage clamping units, a first terminal of each of the voltage clamping units is respectively coupled to a first AC terminal and a second AC terminal of the AC power source, and each of the voltages A second terminal of the clamping unit is commonly coupled to the positive output terminal, or the second terminal is commonly coupled to the negative output terminal. The lightning protection device of the power conversion circuit according to item 1 of the scope of the patent application, wherein each of the voltage clamping units includes: a varistor; and a gas discharge tube connected in series with the varistor to form a series Structure; wherein one end of the series structure is coupled to the AC power source and the other end is coupled to the DC power source. According to the lightning protection device of the power conversion circuit described in item 1 of the scope of the patent application, each of the voltage clamping units includes: a transient voltage suppressor, one end of the transient voltage suppressor is coupled to the AC power source, and the other end Is coupled to the DC power source. The lightning protection device of the power conversion circuit according to item 1 of the scope of the patent application, wherein each of the voltage clamping units includes: a varistor; and a power switch in series with the varistor to form a series structure ; One end of the series structure is coupled to the AC power source, and the other end is coupled to the DC power source. The lightning protection device of the power conversion circuit according to item 4 of the patent application scope further includes: a control unit that provides a control signal to turn on or off the power switch. The lightning protection device for a power conversion circuit according to item 1 of the scope of the patent application, wherein the AC-to-DC conversion circuit is a power factor correction circuit. The lightning protection device of the power conversion circuit according to item 2 of the scope of the patent application, wherein an operating voltage of the gas discharge tube is greater than an operating voltage between the positive output terminal and the negative output terminal. The lightning protection device for a power conversion circuit according to item 1 of the scope of patent application, wherein when the AC power source is a three-phase AC power source, the number of the at least two voltage clamping units is three, and each of the voltage clamping units Correspondingly coupled between any output phase of the AC power source and the positive output terminal or the negative output terminal. The lightning protection device of the power conversion circuit according to item 8 of the scope of the patent application, wherein the three-phase AC power supply is a star connection or a delta connection. A lightning protection device for a power conversion circuit includes an AC-to-DC conversion circuit that receives an AC power source and converts the AC power source to a DC power source, wherein the DC power source is connected across a positive output terminal of the AC-to-DC conversion circuit. And a negative output terminal; and two voltage clamping units, a first terminal of each voltage clamping unit is commonly coupled to a live wire terminal of the AC power source, or the first terminal is commonly coupled to a neutral wire terminal And a second terminal of each voltage clamping unit is respectively coupled to the positive output terminal and the negative output terminal. The lightning protection device of the power conversion circuit according to item 10 of the scope of the patent application, wherein each of the voltage clamping units includes: a varistor; and a gas discharge tube connected in series with the varistor to form a series Structure; wherein one end of the series structure is coupled to the AC power source and the other end is coupled to the DC power source. The lightning protection device of the power conversion circuit according to item 10 of the scope of the patent application, wherein each of the voltage clamping units includes: a transient voltage suppressor, one end of the transient voltage suppressor is coupled to the AC power source, and the other end Is coupled to the DC power source. The lightning protection device of the power conversion circuit according to item 10 of the scope of the patent application, wherein each of the voltage clamping units includes: a varistor; and a power switch in series with the varistor to form a series structure ; One end of the series structure is coupled to the AC power source, and the other end is coupled to the DC power source. The lightning protection device of the power conversion circuit according to item 13 of the scope of patent application, further comprising: a control unit that provides a control signal to turn on or off the power switch. The lightning protection device of the power conversion circuit according to item 10 of the patent application scope, wherein the AC-to-DC conversion circuit is a power factor correction circuit. The lightning protection device of the power conversion circuit according to item 11 of the scope of the patent application, wherein an operating voltage of the gas discharge tube is greater than an operating voltage between the positive output terminal and the negative output terminal. The lightning protection device of the power conversion circuit according to item 10 of the scope of the patent application, wherein when the AC power source is a three-phase AC power source, the number of the at least two voltage clamping units is three, and each of the voltage clamping units Correspondingly coupled between any output phase of the AC power source and the positive output terminal or the negative output terminal. The lightning protection device of the power conversion circuit according to item 17 of the scope of the patent application, wherein the three-phase AC power supply is a star connection or a delta connection.