CN201663544U - Filter module with electromagnetic interference resistance and transient suppression functions - Google Patents

Filter module with electromagnetic interference resistance and transient suppression functions Download PDF

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Publication number
CN201663544U
CN201663544U CN2009202783388U CN200920278338U CN201663544U CN 201663544 U CN201663544 U CN 201663544U CN 2009202783388 U CN2009202783388 U CN 2009202783388U CN 200920278338 U CN200920278338 U CN 200920278338U CN 201663544 U CN201663544 U CN 201663544U
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China
Prior art keywords
capacitor
inductor
discharge tube
gas discharge
voltage
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Expired - Fee Related
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CN2009202783388U
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Chinese (zh)
Inventor
丁永平
杨宝山
郭艳辉
王添文
党丽
米海涛
赵昕萌
苏醒
李子森
马丹
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CHINA NORTH INDUSTRY NEW TECHNOLOGY PROMOTION INSTITUTE
BEIJING ZHONGBEI INNOVATION TECHNOLOGY Co Ltd
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CHINA NORTH INDUSTRY NEW TECHNOLOGY PROMOTION INSTITUTE
BEIJING ZHONGBEI INNOVATION TECHNOLOGY Co Ltd
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Abstract

The utility model discloses a filter module with electromagnetic interference resistance and transient suppression functions, which comprises a gas discharge tube, a first inductor, a transient suppression diode, a second inductor, a first capacitor and a second capacitor. One end of the gas discharge tube is connected with the first end of the first inductor, the second end of the first inductor is connected with the first end of the transient suppression diode, the first end of the first capacitor and the first end of the second inductor, the second end of the second inductor is connected with the first end of the second capacitor, further the second end of the gas discharge tube, the second end of the transient suppression diode, the second end of the first capacitor and the second end of the second capacitor are connected one another and are all grounded, and the first end of the gas discharge tube and the first end of the second capacitor are connected to a load. The filter module has the functions of peak transient pulse suppression, surge suppression and EMI suppression, reduces volume of realizing the same effect, reduces purchase cost for users, and increases product competitiveness.

Description

Filtering module with anti-electromagnetic interference and transient suppression functions
Technical Field
The present invention relates to a filter module, and more particularly, to a filter module having anti-electromagnetic interference and electromagnetic immunity functions.
Background
Electronic systems and network lines are often interfered by external instantaneous overvoltage, and these interference sources mainly include: operating overvoltage due to on-off inductive load or on-off high-power load, line fault and the like; lightning surge due to natural phenomena such as lightning. Such an overvoltage (or overcurrent) is called a surge voltage (or a surge current), and is a kind of transient disturbance. Surge voltages can seriously jeopardize the safe operation of an electronic system. Eliminating surge noise interference and preventing surge damage are always the core problems related to safe and reliable operation of electronic equipment. In order to avoid damaging the electronic equipment by the surge voltage, a shunt defense measure is generally adopted, namely the surge voltage is in short circuit with the ground within a very short time, so that the surge voltage flows into the ground, the purpose of weakening and eliminating the overvoltage and the overcurrent is achieved, and the effect of protecting the safe operation of the electronic equipment is achieved.
At present, electromagnetic interference filters are the most important means for suppressing conducted interference and have been widely used in various military equipment and civil equipment. Surge suppression devices adopted by the traditional electromagnetic interference filter are generally a gas discharge tube, a transient voltage suppressor, a silicon diode and the like. The devices have different working principles but have similar volt-ampere characteristics, namely, when the voltage at two ends is lower than a specified voltage, the passing current is very small, and when the voltage at two ends is higher than the specified voltage, the passing current increases exponentially. The current-voltage characteristic makes it possible to satisfy the requirements of surge suppression effusion and amplitude limiting at the same time, and thus becomes the dominant device for surge suppression.
The use of one of the above devices alone, while all have some suppression of spike voltages, each has drawbacks. For example, the residual voltage of the gas discharge tube is high, the reaction time is slow (less than or equal to 100ns), the precision of the action voltage is low, and the follow current (follow current) exists; the transient voltage suppressor has poor current endurance capability and small current capacity, and is generally only hundreds of amperes. Therefore, depending on the specific application, one or a combination of several of the above devices is generally used to construct the corresponding protection circuit.
However, the conventional electromagnetic interference filter using the above-described device has a poor effect of suppressing transient oscillation lasting for several milliseconds or more, surge voltage, and peak voltage for nanosecond rising edge, and cannot simultaneously satisfy the requirement of suppressing the above-described interference. Moreover, the existing filtering device is large in size and occupies a large space. If transient oscillations, surge voltages, and spike voltages for nanosecond rising edges lasting more than a few milliseconds need to be suppressed simultaneously, different suppression devices need to be purchased, resulting in increased cost.
Therefore, a filtering module with improved combination function is needed, which has good suppression effect on transient oscillation lasting for more than several milliseconds, surge voltage, peak voltage of nanosecond rising edge and the like, and effectively improves the capability of weaponry and civil equipment to cope with complex electromagnetic effect environment. And the filtering module is expected to have small volume and low cost so as to increase the product competitiveness and further rapidly change the lagging state of the current military equipment (system) in China.
Disclosure of Invention
Therefore, an object of the present invention is to provide a filter module capable of overcoming the above disadvantages.
According to the utility model discloses a filtering module with combined function of an embodiment includes:
the transient suppression circuit comprises a gas discharge tube, a first inductor La, a transient suppression diode V2, a second inductor Lb, a first capacitor C1 and a second capacitor C2; wherein,
a first end of the gas discharge tube V1 is connected to a first end of the first inductor La; the second end of the first inductor La is connected to the first end of the transient suppression diode V2, the first end of the first capacitor C1, and the first end of the second inductor Lb; a second end of the second inductor Lb is connected to a first end of the second capacitor C2; the second end of the gas discharge tube V1, the second end of the transient suppression diode V2, the second end of the first capacitor C1 and the second end of the second capacitor C2 are connected and grounded; the first terminal of the gas discharge tube V1 and a first terminal of the second capacitor C2 are connected to a load.
Therefore, the utility model discloses an it suppresses three big functional organic integrations in same anti-electromagnetic interference (EMI)/electromagnetism immunity (EMS) combination function power filter device with peak transient pulse suppression, surge suppression and EMI, reduced the volume that realizes same effect, reduced user's purchasing cost, improve the competitiveness of product. At present, similar products do not exist in China, the successful research and development of the products can fill the blank of the products in China, effectively improve the capability of weapon equipment to deal with the complex electromagnetic effect environment, and realize good economic benefit.
Drawings
For the purpose of illustrating the invention, exemplary embodiments thereof will be described hereinafter with reference to the accompanying drawings, in which:
FIG. 1A shows a schematic diagram of the voltage change of the switch at the moment of opening;
FIG. 1B shows a schematic diagram of the electrical fast transient burst generation principle;
FIG. 2A shows a waveform schematic of a single transient pulse signal;
FIG. 2B shows a schematic diagram of the repetition frequency of an electrical fast transient pulse burst;
fig. 3 shows a circuit schematic of a filter module according to an embodiment of the invention;
fig. 4 illustrates an insertion loss curve of an EMI/EMS combined function dc power filter module according to a novel embodiment of the present invention;
fig. 5 is a schematic diagram illustrating the dimensions of the housing of the dc power filter module with EMI/EMS combination according to an embodiment of the present invention.
Detailed Description
The utility model discloses a filtering module includes gas discharge tube, transient state suppression diode and one-level filter circuit, and wherein, gas discharge tube and transient state suppression diode combination form peak, surge suppression circuit, and further can realize the suppression to suppressing peak, surge interference and conducted interference simultaneously with one-level filter circuit's combination to realize high insertion loss, little volume passive electromagnetic interference filtering module.
As is known, electronic systems and network lines are often disturbed by external transient signals, such as fast transient bursts, surge signals, etc.
Electrical fast transient pulse burst
The fast transient pulse packet will cause the phenomena of dislocation, system reset, memory error and dead halt of the digital system. At the IC input, the fast transient pulse group charges the parasitic capacitance, and through accumulation, eventually reaches and exceeds the immunity level of the IC chip. Such a situation may arise: several pulses (or short bursts) will not cause failure of the digital system, while long bursts will cause failure of the device. Each logic element of the microprocessor and the peripheral device has corresponding level and noise tolerance, and the system can be maintained to be normal as long as external noise does not exceed the tolerance value of the elements; if the noise intruding into the system exceeds a certain tolerance, the microprocessor system may be in error, which becomes a significant cause of malfunction and failure of the device.
Electrical fast transient bursts are a series of short rise time, high repetition rate and low energy transient interference bursts generated during switching inductive load transients, such as relay contact bounce events, opening of motors, timers, etc. Fig. 1A and 1B illustrate a physical process of generating an electrical fast transient pulse burst by taking a discharge process between contacts of a mechanical switch as an example. Fig. 1A shows a schematic diagram of the voltage variation of the switch at the moment of opening and fig. 1B shows a schematic diagram of the principle of the generation of an electrical fast transient pulse burst.
As shown in fig. 1A, when the switch contact is opened, since the current in the inductive load (e.g. inductor) cannot change suddenly, a high back electromotive force is generated on the inductive load to maintain the original current, and according to lenz's law, this electromotive force E is:
E=dФ/dt=-L(di-dt)
where Φ is the magnetic flux in the inductor, L is the inductor, i is the current flowing in the inductor, and t is time. When the switch is open, the current in the inductor is maintained, only the air between the contacts is broken down, and the arc is used to conduct. The arc means that when the electric field intensity applied to the gas is strong, free electrons or ions in the gas can obtain enough energy to impact other atoms or molecules, so that glow discharge is generated, and more free electrons and ions are generated to form a conductive gas. This glow discharge generates strong electromagnetic radiation.
Referring to FIG. 1B, assume that the contact is from t0Begin to separate gradually as the voltage (V) between the contacts1) When the voltage exceeds the insulation voltage, spark discharge occurs between the contacts, so that the voltage between the contacts is instantaneously reduced, t1It reaches zero. At this time, the voltage between the contacts begins to rise again due to the energy stored in the inductor, and the distance between the switch contacts continues to increase, so that the voltage at which spark discharge occurs between the contacts also increases accordingly, and when the voltage (V) between the contacts is equal to the voltage (V) between the contacts2) When the insulation voltage is exceeded again, a second spark discharge occurs. Similarly, the voltage across the contacts drops instantaneously after the second spark discharge occurs, t2Reaches zero, then slowly rises, and then can generate a third time (V)3) Fourth time (V)4) .. spark discharge. When the distance between the contacts is large to a certain degree, glow discharge can occur between the contacts, at the moment, the energy in the inductor is completely consumed, and the discharge process is finished. For an ac 220V grid, the voltage amplitude of such an electrical fast transient burst can reach as much as several thousand volts. In an electrical fast transient pulse burst, the rising edge of a single pulse is in the order of nanoseconds and the pulse duration is in the order of tens of nanoseconds to several milliseconds. Reference may be made to fig. 2A and 2B, where fig. 2A shows a waveform schematic of a single transient pulse signal and fig. 2B shows a repetition frequency schematic of an electrical fast transient pulse burst.
Electrical fast transient bursts may couple to the internal circuitry of the device through power and signal ports of the electrical and electronic devices, affecting the proper operation of the device, and causing damage to the device and systems connected thereto. The electrical fast transient pulse train is very disruptive to instrumentation, especially for high power and sensitive instrumentation.
Surge signal
A surge signal is a transient signal of current, voltage or power that propagates along a line and is characterized by a rapid rise followed by a slow fall. The surge is caused by switching and lightning transients, which are related to the following factors: main power system switching disturbances, such as switching of capacitor banks; slight switching activity or load changes in the power distribution system near the instrument; resonant circuits associated with the switching devices, such as thyristors; various system faults, such as short circuits to equipment group grounding systems, arc faults, etc. The principle of surge voltage generated by lightning is as follows: directly lighting an external circuit by lightning, and generating voltage by the injected large current flowing through a grounding resistor or external circuit impedance; indirect lightning can induce voltage and current on inner and outer conductors of a building; the lightning incoming currents of nearby direct lightning to ground discharges are coupled to a common ground path of the device group grounding system. When the lightning arrester is activated, the voltage and current may change rapidly and may be coupled to internal circuitry. These voltages or currents injected or coupled directly into the device not only damage the device, but also neighboring devices and even the entire system may be affected.
Although the working principle of the gas discharge tube is different from that of the transient suppression diode, the gas discharge tube and the transient suppression diode have similar volt-ampere characteristics, namely, when the voltage at two ends is lower than a specified voltage, the passing current is very small, and when the voltage at two ends is higher than the specified voltage, the passing current is exponentially increased. The current-voltage characteristic makes it possible to satisfy the requirements of surge suppression effusion and amplitude limiting at the same time, so that a gas discharge tube and a transient suppression diode are often adopted to suppress interference signals such as surge signals, electric fast transient pulse groups and the like.
Gas discharge tube
The gas discharge tube can be used for surge protection in the aspects of data lines, cable televisions, alternating current power supplies, telephone systems and the like, the voltage range of general devices is 75-10000V, and the impact resistant peak current 20000A can bear discharge of thousands of joules.
The main parameters of a gas discharge tube include:
1) the reaction time refers to the time from the time when the applied voltage exceeds the breakdown voltage to the time when the breakdown phenomenon occurs, and the reaction time of the gas discharge tube is generally in a mu s number pole.
2) The power capacity refers to the maximum energy that can be borne and dissipated by the gas discharge tube, and is defined as the current that can be borne and dissipated under a fixed current waveform of 8 × 20 μ s.
3) The capacitance refers to the capacitance between the two electrodes of the gas discharge tube measured at a specific frequency of 1 MHz. The gas discharge tube has a very small capacitance, typically less than or equal to 1 pF.
4) When the applied voltage rises at a rate of 500V/s, the breakdown voltage is the voltage at which the discharge tube ignites. Gas discharge tubes have a number of different dc breakdown voltages, the values of which depend on factors such as the type of gas and the distance between the electrodes.
5) The temperature range is generally between-55 ℃ and +125 ℃.
The gas discharge tube has the advantages of large flow capacity, high insulation resistance and small leakage current; its disadvantages are high residual voltage, slow reaction time (less than or equal to 100ns), low precision of operating voltage and follow current.
Transient suppression diode (TVS)
Also known as zener diodes, are devices that are used specifically to suppress overvoltages. The core part of the PN junction is a PN junction with a larger cross section, and the PN junction has stronger pulse absorption capacity when working in an avalanche state.
The transient suppression diode has the advantages of low residual voltage, high action precision, fast reaction time (less than 1ns) and no follow current (follow current); its disadvantages are poor current-resistance, small current capacity, generally only several hundred amperes.
The inventor of the utility model thinks that, the key point of realizing high insertion loss, little volume passive EMI wave filter is, correctly select the magnetic core material and constitute the progression of circuit under the prerequisite of finite volume and rated power. Therefore, according to the present invention, the filter module is used as a dc power filter, which includes a gas discharge tube, a transient suppression diode and a primary filter circuit, wherein the gas discharge tube and the transient suppression diode are combined to form a peak and a surge suppression circuit, and further the combination with the primary filter circuit can simultaneously realize the suppression of the peak, the surge interference and the conducted interference.
Fig. 3 shows a schematic circuit diagram of a filter module according to an embodiment of the present invention. As shown in the figure, the left half part of the circuit adopts a peak and surge suppression circuit combining a gas discharge tube and a transient suppression diode. Because the transient suppression diode has the characteristics of fast response but small flow, large flow of the gas discharge tube but slow response and high residual voltage, the transient suppression diode and the gas discharge tube are combined for use, so that the defects of the transient suppression diode and the gas discharge tube can be mutually eliminated, and the peak and surge suppression circuit can meet the design requirements. The right half of the circuit adopts a pi-shaped filter circuit, so that common mode interference can be effectively inhibited, and the requirement of GJB151A is met. Moreover, the filtering module combines the functions of anti-electromagnetic interference and electromagnetic sensitivity (EMS), has the characteristics of surge and peak suppression, and can enable military equipment or civil equipment using the filtering module to meet the requirements of GJB 151A-97: CE102, CE107, CS106, and GJB1389A, etc.
In fig. 3, V1 denotes a gas discharge tube, La denotes a first inductance (e.g., differential mode inductance), Lb denotes a second inductance (e.g., differential mode inductance), V2 denotes a transient suppression diode, C1 denotes a first capacitance (e.g., patch capacitance), and C2 denotes a second capacitance (e.g., patch capacitance).
Specifically, a first end of the gas discharge tube V1 is connected to a first end of the first inductor La; the second end of the first inductor La is connected to the first end of the transient suppression diode V2, the first end of the first capacitor C1, and the first end of the second inductor Lb; a second end of the second inductor Lb is connected to a first end of the second capacitor C2; the second end of the gas discharge tube V1, the second end of the transient suppression diode V2, the second end of the first capacitor C1 and the second end of the second capacitor C2 are connected and are all connected to ground; the first terminal of the gas discharge tube V1 and a first terminal of the second capacitor C2 are connected to a load.
The working temperature range of the filtering module is-55 ℃ to +105 ℃/-85 ℃ to +125 ℃, the rated voltage is 28/VDC, the rated current is 3A, and the attenuation is realized at 500KHz, 40dB, 1MHz and 50 dB.
Fig. 4 shows an insertion loss curve of the EMI/EMS combined function dc power filter module according to an embodiment of the present invention. Because two phase lines of the filter module circuit are respectively positive and ground, the insertion loss only has common-mode insertion loss and no differential-mode insertion loss.
According to the utility model discloses a surge suppression characteristic of filtering module is as follows: maximum line current: 3A, maximum line voltage: 28VDC, leakage current (at rated voltage): < 0.1mA, nominal discharge current (8/20 μ s, 10 times): 10KA, maximum discharge current (8/20 μ s, 1 time): 20KA, working temperature: -25 ℃ to +85 ℃, protector failure: and (4) short-circuiting.
In addition, in order to help those skilled in the art to implement the filter module, fig. 5 shows a schematic diagram of the size of a housing of a dc power filter module having an EMI/EMS combination function.
Although exemplary embodiments have been disclosed herein in terms of specific terms and specific component names and dimensions, such terms and specific component names and dimensions have been used for purposes of illustration and description only and are not intended to be limiting. It will, therefore, be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (1)

1. A filtering module having anti-electromagnetic interference and transient suppression functionality, comprising:
the transient suppression circuit comprises a gas discharge tube (V1), a first inductor (La), a transient suppression diode (V2), a second inductor (Lb), a first capacitor (C1) and a second capacitor (C2); wherein,
a first end of the gas discharge tube (V1) is connected with a first end of the first inductor (La); a second terminal of the first inductor (La) is connected to a first terminal of the transient suppression diode (V2), a first terminal of the first capacitor (C1), and a first terminal of the second inductor (Lb); a second terminal of the second inductance (Lb) is connected to a first terminal of the second capacitance (C2); a second terminal of the gas discharge tube (V1), a second terminal of the transient suppression diode (V2), a second terminal of the first capacitor (C1) and a second terminal of the second capacitor (C2) are connected and are all grounded; the first end of the gas discharge tube (V1) and a first end of the second capacitor (C2) are connected to a load.
CN2009202783388U 2009-12-25 2009-12-25 Filter module with electromagnetic interference resistance and transient suppression functions Expired - Fee Related CN201663544U (en)

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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102751926A (en) * 2012-07-31 2012-10-24 江苏浩峰汽车附件有限公司 Controller of brushless DC (direct current) motor for vehicle
CN104022497A (en) * 2014-05-27 2014-09-03 华为技术有限公司 Protective circuit and electronic equipment
CN104124675A (en) * 2013-04-26 2014-10-29 倍加福有限责任公司 Excess voltage protection apparatus and diagnostic method for multi-stage excess voltage protection apparatuses
CN105591576A (en) * 2014-10-23 2016-05-18 力山工业股份有限公司 Motor control circuit capable of suppressing interference signals
CN109444599A (en) * 2018-12-06 2019-03-08 郑州云海信息技术有限公司 A kind of system and method for eliminating electrical fast transient (eft) interference
CN111432519A (en) * 2020-04-20 2020-07-17 宁波市富来电子科技有限公司 Vehicle light subassembly integrated control system
CN111511059A (en) * 2020-04-21 2020-08-07 宁波市富来电子科技有限公司 Vehicle lamp control system for combined headlamp function

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102751926A (en) * 2012-07-31 2012-10-24 江苏浩峰汽车附件有限公司 Controller of brushless DC (direct current) motor for vehicle
CN102751926B (en) * 2012-07-31 2014-11-05 江苏浩峰汽车附件有限公司 Controller of brushless DC (direct current) motor for vehicle
CN104124675A (en) * 2013-04-26 2014-10-29 倍加福有限责任公司 Excess voltage protection apparatus and diagnostic method for multi-stage excess voltage protection apparatuses
CN104124675B (en) * 2013-04-26 2018-03-02 倍加福有限责任公司 Overvoltage protection and the diagnostic method for multistage overvoltage protection
CN104022497A (en) * 2014-05-27 2014-09-03 华为技术有限公司 Protective circuit and electronic equipment
CN105591576A (en) * 2014-10-23 2016-05-18 力山工业股份有限公司 Motor control circuit capable of suppressing interference signals
CN109444599A (en) * 2018-12-06 2019-03-08 郑州云海信息技术有限公司 A kind of system and method for eliminating electrical fast transient (eft) interference
CN111432519A (en) * 2020-04-20 2020-07-17 宁波市富来电子科技有限公司 Vehicle light subassembly integrated control system
CN111511059A (en) * 2020-04-21 2020-08-07 宁波市富来电子科技有限公司 Vehicle lamp control system for combined headlamp function
CN111511059B (en) * 2020-04-21 2022-07-01 宁波市富来电子科技有限公司 Vehicle lamp control system for combined headlamp function

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