A self-starting high-voltage filter

Abstract

The present invention discloses a self-starting high-voltage filter, which includes a filtering module, a detection module, and a current suppression module. The input end of the current suppression module is connected to the positive pole of the power supply. The output end of the current suppression module is connected to the positive input end of the filtering module. The positive input end of the detection module is connected to the positive pole of the power supply. The negative input end of the detection module is connected to the negative pole of the power supply. The output end of the detection module is connected to the control end of the current suppression module. The current suppression module includes a semiconductor switching device and a current-limiting resistor, and the current-limiting resistor is connected in parallel with the semiconductor switching device. The present invention effectively suppresses the impact current, has a simple circuit structure, relatively low cost, does not require external accessories, and has very good functionality, real-time performance, and versatility.

Description

Technical Field

[0001] The present invention relates to the technical field of filters, and specifically to a self-starting high-voltage filter. Background Art

[0002] High-voltage power supplies use high-power devices such as motors and inverters, which generate large current and voltage noises during operation. To suppress these noises, high-voltage filters are required.

[0003] Currently, it is essential to use large-capacity filter capacitors in high-voltage filters. However, these filter capacitors are virtually short-circuited at the moment of high-voltage power-on, resulting in excessive inrush current, which can burn out switching devices, wiring harnesses, and even the battery itself. In addition, existing high-voltage filters have a complex circuit structure, high costs, and require external accessories during use, which greatly increases the cost of the entire system. Moreover, the functionality, real-time performance, and versatility of existing high-voltage filters are relatively poor. Summary of the Invention

[0004] The purpose of the present invention is to provide a self-starting high-voltage filter, which effectively suppresses the inrush current, has a simple circuit structure, relatively low costs, does not require external accessories, and has excellent functionality, real-time performance, and versatility.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A self-starting high-voltage filter includes a filtering module, a detection module, and a current suppression module. The input end of the current suppression module is connected to the positive pole of the power supply. The output end of the current suppression module is connected to the positive input end of the filtering module. The positive input end of the detection module is connected to the positive pole of the power supply. The negative input end of the detection module is connected to the negative pole of the power supply. The output end of the detection module is connected to the control end of the current suppression module; the current suppression module includes a semiconductor switching device and a current-limiting resistor, and the current-limiting resistor is connected in parallel with the semiconductor switching device.

[0006] Preferably, the current suppression module further includes a relay. The input end of the semiconductor switching device is connected to one end of the normally open contact of the relay, and the control end of the semiconductor switching device is connected to the other end of the normally open contact of the relay. The normally closed contact of the relay is connected to the output end of the detection module.

[0007] Preferably, the current suppression module further includes a suppression capacitor. One end of the suppression capacitor is connected to the control end of the semiconductor switching device, and the other end of the suppression capacitor is connected to the output end of the semiconductor switching device.

[0008] Preferably, the detection module includes a first diode, a second diode, a delay circuit, a first inductor, a first resistor, and a first capacitor. The input end of the first diode is connected to the positive pole of the power supply. The output end of the first diode is connected to one end of the first resistor. The other end of the first resistor is connected to one end of the first capacitor and one end of the delay circuit. The other end of the delay circuit is connected to one end of the first inductor. The other end of the first inductor is connected to one end of the second diode. The other end of the second diode is connected to the feedback end of the delay circuit.

[0009] Preferably, the first resistor and the first capacitor form a waiting time parameter change circuit.

[0010] Preferably, the detection module further includes a third diode and a second capacitor. One end of the third diode is connected to the other end of the delay circuit. One end of the second capacitor is connected to the other end of the first inductor. The other end of the third diode and the other end of the second capacitor are connected to the negative pole of the power supply.

[0011] Preferably, the second capacitor is a polarized capacitor.

[0012] Preferably, the filtering module includes a first filtering capacitor, a second filtering capacitor, and a filter. The positive input end of the filter is connected to the output end of the current suppression module. The negative input end of the filter is connected to the negative pole of the power supply. One end of the first filtering capacitor is connected to the positive input end of the filter, and the other end is connected to the negative input end of the filter. The second filtering capacitor is connected in parallel with the first filtering capacitor.

[0013] Preferably, the filtering module includes a third filtering capacitor and a fourth filtering capacitor. One end of the third filtering capacitor is connected to the positive output end of the filter, and the other end is connected to the negative output end of the filter. The fourth filtering capacitor is connected in parallel with the third filtering capacitor.

[0014] Preferably, the second filtering capacitor and the third filtering capacitor are polarized filtering capacitors.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] 1. On the basis of ensuring the performance of the traditional high-voltage filter, the present invention can greatly reduce the inrush current at the moment of high-voltage power-on, protecting high-voltage devices from high-voltage damage.

[0017] 2. In terms of the usage method, the present invention is compatible with the traditional filter and can be directly connected in series to the high-voltage line without additional accessories, which can greatly reduce the system cost and save energy.

[0018] 3. The detection module of the present invention issues a control signal to the semiconductor switching device by controlling the on / off of the relay. The advantage of this design is to avoid continuous power supply to the control end of the semiconductor switching device, reduce the failure rate, and is also beneficial to extend the service life of the semiconductor switching device.

[0019] 4. The current suppression module of the present invention also designs a suppression capacitor, which can further extend the service life of the semiconductor switching device and reduce the failure rate.

[0020] 5. The detection module of the present invention can automatically identify the moment of high-voltage power-on, automatically switch the working mode, and the entire design is implemented by pure hardware, without software intervention and without logical delay.

[0021] 6. The first resistor and the first capacitor of the present invention form a waiting time parameter change circuit, and the parameters of the first resistor and the first capacitor can be set to change the waiting time.

[0022] 7. The circuit structure of the present invention is simple, with low cost and small volume. The high-voltage detection module and the inrush current suppression module are directly powered by high voltage without external accessories, and its functionality, real-time performance, and versatility are very good, which is convenient for mass production and use.

[0023] Additional aspects and advantages of the present invention will be given in part in the following description, will become apparent in part from the following description, or will be understood through the practice of the present invention. Brief Description of the Drawings

[0024] Figure 1 is the circuit schematic diagram of the present invention;

[0025] Figure 2 is the circuit schematic diagram of the detection module of the present invention.

[0026] In the figure: 1. Current suppression module; 2. Filter module; 3. Detection module; Detailed Embodiments

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

[0028] In the present invention, unless otherwise clearly specified or limited, terms such as "installation", "connection", "linkage", "fixation" and the like shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection or an integral connection; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention may be understood according to specific circumstances.

[0029] Please refer to Figure 1-2 , the present invention provides a technical solution: a self-starting high-voltage filter, including a filtering module 2, a detection module 3, and a current suppression module 1. The input end of the current suppression module 1 is connected to the positive pole of the power supply, the output end of the current suppression module 1 is connected to the positive input end of the filtering module 2, the positive input end of the detection module 3 is connected to the positive pole of the power supply, the negative input end of the detection module 3 is connected to the negative pole of the power supply, and the output end of the detection module 3 is connected to the control end of the current suppression module 1; the current suppression module 1 includes a semiconductor switching device SCR and a current-limiting resistor R, and the current-limiting resistor R is connected in parallel with the semiconductor switching device SCR.

[0030] The working principle is as follows: The detection module 3 detects whether the state between the positive and negative poles of the power supply is a high-voltage state. When it detects a high-voltage power-on moment, it sends a control signal to the current suppression module 1 to start the current suppression module 1; the control signal causes the semiconductor switching device SCR in the current suppression module 1 to disconnect at the high-voltage power-on moment, and the current flows through the current-limiting resistor R to suppress the inrush current; after the high-voltage power-on is completed, it waits for the instruction of the detection module. When the detection module 3 detects that it is not in a high-voltage state, it controls the semiconductor switching device SCR to conduct, and the current-limiting resistor R is short-circuited to realize the normal function of the high-voltage filter.

[0031] On the basis of ensuring the performance of the traditional high-voltage filter, the present invention can greatly reduce the inrush current at the moment of high-voltage power-on and protect high-voltage devices from high-voltage damage. In addition, in terms of the usage method, the present invention is compatible with traditional filters and can be directly connected in series to the high-voltage line without additional accessories.

[0032] In another embodiment of the present invention, the current suppression resistor is a positive temperature coefficient resistor (PTC). When there is a short circuit in the high-voltage line, the resistance temperature rises and the resistance value increases, which can effectively protect the high-voltage line. The semiconductor switching device SCR selects different power components according to different loads.

[0033] In another embodiment of the present invention, in order to improve the control effect, the current suppression module 1 further includes a relay T. The input end of the semiconductor switching device SCR is connected to one end of the normally open contact of the relay T, the control end of the semiconductor switching device SCR is connected to the other end of the normally open contact of the relay T, and the normally closed contact of the relay T is connected to the output end of the detection module 3.

[0034] The detection module 3 issues a control signal to the semiconductor switching device by controlling the on / off of the relay. The advantage of this design is to avoid continuous power supply to the control terminal of the semiconductor switching device, reduce the failure rate, and also help extend the service life of the semiconductor switching device.

[0035] In another embodiment of the present invention, the current suppression module 1 further includes a suppression capacitor CR. One end of the suppression capacitor CR is connected to the control terminal of the semiconductor switching device, and the other end of the suppression capacitor CR is connected to the output terminal of the semiconductor switching device.

[0036] The purpose of designing the suppression capacitor CR is to further extend the service life of the semiconductor switching device and reduce the failure rate.

[0037] In another embodiment of the present invention, the detection module 3 includes a first diode D1, a second diode D2, a delay circuit, a first inductor L1, a first resistor Rp1, and a first capacitor Cp1. The input end of the first diode D1 is connected to the positive pole of the power supply, the output end of the first diode D1 is connected to one end of the first resistor Rp1, the other end of the first resistor Rp1 is connected to one end of the first capacitor Cp1 and one end of the delay circuit, the other end of the delay circuit is connected to one end of the first inductor L1, the other end of the first inductor L1 is connected to one end of the second diode D2, and the other end of the second diode D2 is connected to the feedback end of the delay circuit.

[0038] The detection module 3 further includes a third diode D3 and a second capacitor Cp2. One end of the third diode D3 is connected to the other end of the delay circuit, one end of the second capacitor Cp2 is connected to the other end of the first inductor L1, and the other end of the third diode D3 and the other end of the second capacitor Cp2 are connected to the negative pole of the power supply. Among them, the second capacitor is a polarized capacitor.

[0039] The working principle of the detection module 3: The positive pole of the power supply outputs after passing through the first diode D1, the first resistor Rp1, the delay circuit, and the first inductor L1. When the power supply voltage is higher than the preset value, the current returns to the delay circuit through the second diode D2 for delay until the power supply voltage is lower than the preset value, and then the output control signal is sent.

[0040] Among them, the first resistor Rp1 and the first capacitor Cp1 form a waiting time parameter change circuit, and the parameters of the first resistor Rp1 and the first capacitor Cp1 can be set to change the waiting time.

[0041] In another embodiment of the present invention, the filtering module 2 includes a first filtering capacitor, a second filtering capacitor, and a filter. The positive input terminal of the filter is connected to the output terminal of the current suppression module 1, the negative input terminal of the filter is connected to the negative power supply, one end of the first filtering capacitor is connected to the positive input terminal of the filter, and the other end thereof is connected to the negative input terminal of the filter. The second filtering capacitor is connected in parallel with the first filtering capacitor.

[0042] The filtering module 2 further includes a third filtering capacitor and a fourth filtering capacitor. One end of the third filtering capacitor is connected to the positive output terminal of the filter, and the other end thereof is connected to the negative output terminal of the filter. The fourth filtering capacitor is connected in parallel with the third filtering capacitor. The second filtering capacitor and the third filtering capacitor are polarized filtering capacitors.

[0043] Compared with the traditional high-voltage filter, the inrush current of the self-starting high-voltage filter of the present invention is effectively suppressed. Under the conditions of a high-voltage power supply of 600 VDC and a filtering capacitor of 100 uF, the measured inrush current is reduced by about 95% from 251 A to 12.4 A.

[0044] It also has the following advantages:

[0045] 1. Good functionality: The detection module and the current suppression module are built into the self-starting high-voltage filter. When the high voltage is powered on instantaneously, the current suppression module starts and the high-voltage line is closed. After the high voltage is powered on, the current suppression module is turned off and the high-voltage line is conducted.

[0046] 2. Good real-time performance: It is implemented by pure hardware, without software intervention and without logical delay.

[0047] 3. Good versatility: The high-voltage detection module and the current suppression module are directly powered by high voltage without external accessories.

[0048] In the description of the present invention, it should be understood that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0049] In the description of this specification, the description of reference terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0050] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A self-starting high-voltage filter, characterized by: The device comprises a filtering module, a detection module, and a current suppression module. The input end of the current suppression module is connected to the positive electrode of the power supply, the output end of the current suppression module is connected to the positive input end of the filtering module, the positive input end of the detection module is connected to the positive electrode of the power supply, the negative input end of the detection module is connected to the negative electrode of the power supply, and the output end of the detection module is connected to the control end of the current suppression module. The current suppression module comprises a semiconductor switch device and a current limiting resistor, and the current limiting resistor is connected in parallel with the semiconductor switch device. The current suppression module further includes a relay, the input terminal of the semiconductor switch device is connected to one end of the normally open contact of the relay, the control terminal of the semiconductor switch device is connected to the other end of the normally open contact of the relay, and the normally closed contact of the relay is connected to the output terminal of the detection module; The current suppression module further includes a suppression capacitor, one end of the suppression capacitor is connected to the control end of the semiconductor switch device, and the other end of the suppression capacitor is connected to the output end of the semiconductor switch device; The detection module includes a first diode, a second diode, a delay circuit, a first inductor, a first resistor, and a first capacitor, wherein an input end of the first diode is connected to a positive electrode of a power supply, an output end of the first diode is connected to one end of the first resistor, the other end of the first resistor is connected to one end of the first capacitor and one end of the delay circuit, the other end of the delay circuit is connected to one end of the first inductor, the other end of the first inductor is connected to one end of the second diode, and the other end of the second diode is connected to a feedback end of the delay circuit; The detection module also includes a third diode and a second capacitor, one end of the third diode is connected to the other end of the delay circuit, one end of the second capacitor is connected to the other end of the first inductor, and the other end of the third diode and the other end of the second capacitor are connected to the negative pole of the power supply.

2. The self-starting high-voltage filter according to claim 1, characterized in that: The first resistor and the first capacitor form a waiting time parameter changing circuit.

3. The self-starting high-voltage filter according to claim 2, characterized in that: The second capacitor is a polarized capacitor.

4. The self-starting high-voltage filter according to claim 1, characterized in that: The filtering module includes a first filter capacitor, a second filter capacitor, and a filter. The positive input terminal of the filter is connected to the output terminal of the current suppression module, the negative input terminal of the filter is connected to the negative pole of the power supply, one end of the first filter capacitor is connected to the positive input terminal of the filter, and the other end is connected to the negative input terminal of the filter. The second filter capacitor is connected in parallel with the first filter capacitor.

5. The self-starting high-voltage filter according to claim 4, characterized in that: The filtering module includes a third filter capacitor and a fourth filter capacitor. One end of the third filter capacitor is connected to the positive output end of the filter, and the other end is connected to the negative output end of the filter. The fourth filter capacitor is connected in parallel with the third filter capacitor.

6. The self-starting high-voltage filter according to claim 5, characterized in that: The second filter capacitor and the third filter capacitor are polarized filter capacitors.

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