CN112787689A - Power line carrier same-frequency noise blocker and power system - Google Patents
Power line carrier same-frequency noise blocker and power system Download PDFInfo
- Publication number
- CN112787689A CN112787689A CN202110112684.4A CN202110112684A CN112787689A CN 112787689 A CN112787689 A CN 112787689A CN 202110112684 A CN202110112684 A CN 202110112684A CN 112787689 A CN112787689 A CN 112787689A
- Authority
- CN
- China
- Prior art keywords
- power line
- power
- line
- line carrier
- filtering
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000001914 filtration Methods 0.000 claims abstract description 70
- 239000003990 capacitor Substances 0.000 claims description 18
- 239000000758 substrate Substances 0.000 claims description 6
- 238000010276 construction Methods 0.000 abstract description 5
- 230000009286 beneficial effect Effects 0.000 abstract description 4
- 230000000903 blocking effect Effects 0.000 abstract description 2
- 230000005540 biological transmission Effects 0.000 description 16
- 238000004891 communication Methods 0.000 description 16
- 238000010586 diagram Methods 0.000 description 13
- 230000001419 dependent effect Effects 0.000 description 6
- 230000007935 neutral effect Effects 0.000 description 6
- 238000012423 maintenance Methods 0.000 description 4
- 238000000034 method Methods 0.000 description 3
- 238000013461 design Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000000644 propagated effect Effects 0.000 description 2
- 230000001052 transient effect Effects 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B3/00—Line transmission systems
- H04B3/54—Systems for transmission via power distribution lines
- H04B3/544—Setting up communications; Call and signalling arrangements
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B3/00—Line transmission systems
- H04B3/02—Details
- H04B3/04—Control of transmission; Equalising
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Power Engineering (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
The invention discloses a power line carrier same-frequency noise blocker and a power system. The power line carrier same-frequency noise blocker comprises three filtering units; each single phase line in the three-phase power line is connected with one filtering unit, and each filtering unit comprises a pressure-sensitive element which is connected between the single phase line and the zero line in series. The invention can be installed at the end of an interference source accessed to a power grid, wherein each single phase line in a three-phase power line of the power grid is connected with one filter unit, so that harmonic noise transmitted in each single phase line is filtered by the filter unit, thereby fundamentally blocking and eliminating the propagation of the harmonic noise of the power grid, reducing the investment cost of power grid construction, reducing the line loss and being beneficial to the good operation of the power grid. In addition, the filtering unit comprises a pressure-sensitive element, and the pressure-sensitive element is connected between the single-phase line and the zero line in series, so that the circuit can be prevented from being broken down by surge impact, pulse disturbance and the like of a power grid, and the circuit is protected.
Description
Technical Field
The embodiment of the invention relates to the technical field of line communication, in particular to a power line carrier same-frequency noise blocker and a power system.
Background
In recent years, smart grid construction uses power line carrier communication as a carrier for data transmission. The power line carrier communication has the advantages of wide coverage range, no need of laying a circuit again and the like, so that the power line carrier communication is widely applied to the technical field of automatic meter reading in low-voltage transformer areas, and the labor input of power grid workers to meter reading records of electric meters is greatly reduced.
However, in practical applications, the problem of harmonic noise interference generated by mobile base stations, water pump rooms, heating boilers, variable frequency motors and some household appliances is often encountered, which can seriously affect the transmission quality of power line carrier signals, and finally results in unsatisfactory meter reading effect. Fig. 1 is a schematic diagram of interference of power grid harmonic noise on a power carrier signal, as shown in fig. 1, an abscissa represents transmission time of the power grid harmonic noise and the power carrier signal, and an ordinate represents transmission amplitude of the power grid harmonic noise and the power carrier signal. Because the power grid harmonic noise is still stronger than the transmission amplitude of the power line carrier signal, when the power grid simultaneously transmits the harmonic noise and the power line carrier signal, a receiving end of signal transmission cannot receive correct effective information, and further, the power grid communication fails. In the actual operation and maintenance process, when the meter reading is unstable or fails due to power grid interference, the operation and maintenance personnel of the power grid line generally adopt a method of adding a concentrator and a repeater to solve the problem. However, the problem of harmonic noise interference is not fundamentally solved by adding the concentrator and the repeater, and only the transmission path of the power line carrier signal is enlarged by adding the concentrator and the repeater to bypass a signal interference source, so that the power line carrier signal is prevented from being influenced by power grid harmonic noise. The method not only increases the investment cost of power grid construction and increases the line loss, but also causes other electric equipment to age due to harmonic noise in the power grid, and is not beneficial to good operation of the power grid.
Disclosure of Invention
The invention provides a power line carrier same-frequency noise blocker and a power system, which are used for blocking an interference signal at an interference source, are beneficial to improving the transmission quality of the carrier signal, improving the quality of a power grid and reducing the input cost.
In a first aspect, an embodiment of the present invention provides a blocker for power line carrier same-frequency noise, including three filtering units; each single phase line in the three-phase power line is connected with one filtering unit, and each filtering unit comprises a pressure-sensitive element which is connected between the single phase line and the zero line in series.
Furthermore, the filtering unit comprises at least one filtering subunit, and the at least one filtering subunit is connected between the single-phase line and the zero line in series.
Further, the filtering subunit comprises at least one pressure-sensitive element and at least one capacitor; the capacitor is connected in parallel with the pressure sensitive element.
Further, the pressure sensitive element comprises a pressure sensitive resistor.
Further, the model number of the piezoresistor comprises 821KD 20.
Further, the piezoresistors are the same in different filtering subunits.
Furthermore, the capacitance values of the capacitors in different filter subunits are the same.
Furthermore, the power line carrier same-frequency noise blocker also comprises a printed circuit board substrate; the filtering unit is arranged on the printed circuit board substrate.
In a second aspect, an embodiment of the present invention further provides an electric power system, including an electric power device, a three-phase power line, and a blocker for implementing the same-frequency noise of the power line carrier according to any one of the first aspect; the power utilization equipment is connected with the power line carrier same-frequency noise blocker through a three-phase power line.
Further, the power system further comprises a transformer; the transformer is connected with the power line carrier same-frequency noise blocker through a three-phase power line.
Compared with power grid line operation and maintenance personnel, the scheme of adding the concentrator and the repeater is adopted to avoid the influence of power line carrier signals on power grid harmonic noise. The power line carrier same-frequency noise blocker provided by the embodiment of the invention can be arranged at the end of an interference source accessing to a power network. Each single phase line in a three-phase power line of the power grid is connected with one filtering unit, so that harmonic noise transmitted in each single phase line is filtered by the filtering unit, the propagation of the harmonic noise of the power grid can be fundamentally blocked and eliminated, the investment cost of power grid construction is reduced, the line loss is reduced, and the power grid can well run. In addition, the filtering unit comprises a pressure-sensitive element, and the pressure-sensitive element is connected between the single-phase line and the zero line in series, so that the circuit can be prevented from being broken down by surge impact, pulse disturbance and the like of a power grid, and the circuit is protected.
Drawings
FIG. 1 is a schematic diagram illustrating interference of power grid harmonic noise on a power carrier signal;
fig. 2 is a schematic structural diagram of a power line carrier co-frequency noise blocker according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of a power line carrier communication system according to an embodiment of the present invention;
fig. 4 is a schematic structural diagram of another power line carrier co-frequency noise blocker according to an embodiment of the present invention;
fig. 5 is a schematic structural diagram of another power line carrier co-frequency noise blocker according to an embodiment of the present invention;
fig. 6 is a schematic structural diagram of a printed circuit board of a power line carrier co-frequency noise blocker according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The embodiment of the invention provides a structural schematic diagram of a power line carrier same-frequency noise blocker, and fig. 2 is the structural schematic diagram of the power line carrier same-frequency noise blocker provided by the embodiment of the invention. As shown in fig. 2, the power line carrier on-channel noise blocker includes: three filtering units 110; each single phase line in the three-phase power line is connected to one filtering unit 110, and the filtering unit 110 includes a voltage-sensitive element, and the voltage-sensitive element is connected in series between the single phase line and the neutral line.
The frequency of an interference signal affecting transmission of a power line carrier signal in the power grid is generally 100-500 KHZ at present, and the filtering unit 110 is set to be a low-pass filter, so that the low-frequency interference signal can be allowed to pass through, and propagation of the interference signal in a three-phase power line of the power grid is blocked. Fig. 3 is a schematic structural diagram of a power line carrier communication system according to an embodiment of the present invention, and as shown in fig. 3, the power line carrier communication system includes: the system comprises a power line communication host, a power line communication slave, an interference source and a power line carrier same-frequency noise blocker. Specifically, the propagation path of the interference signal generated by the interference source is the direction of the signal indication (i), and if the system does not include the power line carrier co-frequency noise blocker, the interference signal generated by the interference source interferes with the power line carrier signal transmitted to the power line communication host and the power line carrier signal transmitted to the power line communication slave in the direction of the signal indication (ii), and the amplitude of the interference signal generated by the interference source is stronger than that of the power line carrier signal, so that the power line communication host and the power line communication slave cannot receive the effective power line carrier signal. However, the power line carrier same-frequency noise blocker is connected to the power grid terminal of the interference source, so that the interference signal can be blocked from the transmission source of the interference source, the transmission quality of the carrier signal is improved, the power grid quality is improved, and the investment cost is reduced. Three-phase power lines are typically three-phase four-wire systems (e.g., UA, UB, UC, and UN) and consist of three live wires (e.g., UA, UB, and UC) and one neutral wire (e.g., UN). Wherein, because the three-phase power line has three different single phase lines, every filtering unit 110 is connected with every single phase line in the three-phase power line, that is to say, need three filtering unit 110 to the single phase line UA, single phase line UB and the single phase line UC of power line are connected respectively to the first end of three filtering unit 110. Meanwhile, the second ends of the three filtering units 110 are connected with the zero line UN to form a filtering path, so that harmonic noise of a power grid transmitted in the three-phase power transmission line is filtered. Compared with power grid line operation and maintenance personnel, the scheme of adding the concentrator and the repeater is adopted to avoid the influence of power line carrier signals on power grid harmonic noise. The power line carrier same-frequency noise blocker can be installed at the end of an interference source accessing the power grid. Each single phase line in a three-phase power line of the power grid is connected with one filtering unit 110, so that harmonic noise transmitted in each single phase line is filtered by the filtering unit 110, the propagation of the harmonic noise of the power grid can be fundamentally blocked and eliminated, the investment cost of power grid construction is reduced, the line loss is reduced, and the power grid can well run. Meanwhile, the filtering unit 110 includes a voltage-sensitive element, and voltage clamping can be performed when the circuit is subjected to overvoltage by connecting the voltage-sensitive element in series between the single-phase line and the neutral line. The voltage-sensitive element is a voltage-limiting type protection device, and by utilizing the nonlinear characteristic of the voltage-sensitive resistor, when overvoltage appears between two poles of the voltage-sensitive resistor, the voltage-sensitive resistor can clamp the voltage to a relatively fixed voltage value, so that the circuit is prevented from being broken down by surge impact, pulse disturbance and the like of a power grid, and the circuit is protected.
Fig. 4 is a schematic structural diagram of another power line carrier on-channel noise blocker according to an embodiment of the present invention, and as shown in fig. 4, the filtering unit 110 includes at least one filtering subunit 111, and the at least one filtering subunit 111 is connected in series between the single-phase line and the neutral line UN.
The filtering unit 110 includes at least one filtering subunit 111, and the at least one filtering subunit 111 is connected in series between the single-phase line and the neutral line UN. At the moment, each phase line of the three-phase power line can form at least one filtering path, and the harmonic noise of the power grid transmitted in the three-phase power line is further filtered. Each phase line of the three-phase power line can be connected with the zero line in series with a plurality of filtering subunits 111, so that the overall filtering effect of each filtering unit 110 can be further enhanced. The power grid harmonic noise in the single phase line can flow into the zero line through the filtering subunit 111, so that the transmission of the power grid harmonic noise in the power line can be better blocked and eliminated, and the power line carrier signal can be favorably transmitted in the power grid.
It should be noted that fig. 4 exemplarily shows one filtering subunit, and in other embodiments, a designer may select the number of filtering subunits according to actual design requirements, which is not limited by the embodiments of the present disclosure.
Fig. 5 is a schematic structural diagram of another power line carrier on-channel noise blocker according to an embodiment of the present invention, and as shown in fig. 5, the filtering subunit 111 includes at least one pressure-sensitive element R1 and at least one capacitor C1; the capacitor C1 is connected in parallel with the pressure sensitive element R1.
Specifically, the filtering subunit 111 includes at least one pressure-sensitive element R1 and at least one capacitor C1, and the capacitor C1 is connected in parallel with the pressure-sensitive element R1, so as to form a simple RC low-pass filter, allow low-frequency signals to pass, and block signals with frequencies higher than a cut-off frequency from passing, thereby filtering low-frequency noise signals. Wherein the cut-off frequency fc＝1/2πRC。
It should be noted that fig. 5 exemplarily shows one pressure-sensitive element and one capacitor, and in other embodiments, a designer may select the number of pressure-sensitive elements and capacitors according to actual design requirements, which is not limited by the embodiments of the present disclosure.
Optionally, the pressure sensitive element comprises a piezo-resistor.
The sensitive resistor is a voltage-limiting type protection device. By utilizing the nonlinear characteristic of the piezoresistor, when overvoltage appears between two poles of the piezoresistor, the piezoresistor can clamp the voltage to a relatively fixed voltage value, thereby realizing the protection of a post-stage circuit. In addition, the piezoresistor has strong bearing capacity to surge impact and pulse disturbance of a power grid, has high-current processing and energy absorption capacity and quick response capacity, and can well protect a circuit.
Optionally, the model number of the piezoresistor comprises 821KD 20.
Among them, the 821KD20 voltage dependent resistor is surge suppressing type, and is used for suppressing transient overvoltage such as lightning overvoltage and operation overvoltage, the transient overvoltage is random and non-periodic, and the peak value of current and voltage may be very large. The biggest characteristic of the voltage dependent resistor is that when the voltage applied to it is lower than its threshold value "UX", the current flowing through it is very small, corresponding to a dead valve, and when the voltage exceeds UX, the current flowing through it increases sharply, corresponding to the valve being open. With this function, abnormal overvoltage which often occurs in the circuit can be suppressed, thereby protecting the circuit from overvoltage.
Optionally, the piezoresistors are the same in different filtering subunits. And in different filter subunits, the capacitance values of the capacitors are the same.
The interference signal generated by the interference source is simultaneously propagated in each single phase line of the three-phase power line, and the frequency of the interference signal propagated by each single phase line in the three-phase power line is the same, so that the filtering characteristics of the filtering subunit connected with each single phase line in the three-phase power line need to be kept consistent. The filter characteristics of the filter subunit are determined by the resistance of the voltage dependent resistor and the capacity of the capacitor, and the cut-off frequency of the filter with different characteristics is determined by the equivalent resistance and the equivalent capacitance of the filter unit. However, the filtering characteristics of the filtering subunit connected to each single phase line in the three-phase power line need to be kept consistent, so the filtering ranges of different filtering subunits need to be the same, so that the filtering characteristics of different filtering subunits are kept consistent, and further, the piezoresistors and capacitors of different filtering units are the same, so that the filtering subunit connected to each single phase line in the three-phase power line simultaneously filters the interference signal generated by the interference source.
Fig. 6 is a schematic diagram of a printed circuit board structure of a power line carrier co-frequency noise blocker according to an embodiment of the present invention, and as shown in fig. 6, the power line carrier co-frequency noise blocker further includes a printed circuit board substrate 120; the filter unit is disposed on the printed circuit board substrate 120.
The printed circuit board 120 is provided with three filtering units, which are respectively connected to UA phase lines, UB phase lines, and UC phase lines of the three-phase power lines. For example, the voltage dependent resistor R1 and the capacitor C1 form a filtering unit, which is respectively connected in series between the UA phase line and the neutral line UN of the three-phase power line; the voltage dependent resistor R2 and the capacitor C2 form a filtering unit which is respectively connected in series between a UB phase line and a zero line UN of the three-phase power line; the voltage dependent resistor R3 and the capacitor C3 form a filtering unit which is respectively connected in series between a UC phase line and a zero line UN of a three-phase power line; the power grid harmonic noise in each single phase line can flow into the zero line UN through the filtering unit, so that the transmission of the power grid harmonic noise in a power line is blocked and eliminated better, and the power line carrier signal is favorably transmitted in a power grid.
The embodiment of the invention also provides a power system which comprises electric equipment, a three-phase power line and the power line carrier same-frequency noise blocker in any one of the embodiments; the power utilization equipment is connected with the power line carrier same-frequency noise blocker through a three-phase power line. The power system comprises the power line carrier same-frequency noise blocker provided by any embodiment of the invention, so that the power line carrier same-frequency noise blocker provided by the embodiment of the invention has the beneficial effects, and the details are not repeated herein.
Optionally, the power system further comprises a transformer; the transformer is connected with the power line carrier same-frequency noise blocker through a three-phase power line.
The power line communication host or the power line communication slave can be a transformer, and the transformer is connected with the power line carrier same-frequency noise blocker through a three-phase power line. The electric equipment is generally connected to a branch circuit of the transformer, in order to block the transmission of noise signals generated by the electric equipment, the electric equipment is connected with the power line carrier co-frequency noise blocker, and the power line carrier co-frequency noise blocker is connected with a branch circuit of the transformer through a three-phase power line, so that the transmission of interference noise generated by the electric equipment on the three-phase power line can be blocked, and the good transmission of the power line carrier signals on a power grid is facilitated.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. A power line carrier same-frequency noise blocker, comprising: three filtering units;
each single phase line in the three-phase power line is connected with one of the filtering units, each filtering unit comprises a pressure-sensitive element, and the pressure-sensitive elements are connected in series between the single phase line and the zero line.
2. The power line carrier on-channel noise blocker according to claim 1, wherein the filtering unit comprises at least one filtering subunit, and at least one filtering subunit is connected in series between the single-phase line and the zero line.
3. The power line carrier on-channel noise blocker according to claim 2, wherein the filtering subunit comprises at least one voltage-sensitive element and at least one capacitor; the capacitor is connected in parallel with the pressure-sensitive element.
4. The power line carrier on-channel noise blocker according to claim 3, wherein the voltage-sensitive element comprises a voltage-sensitive resistor.
5. The power line carrier on-channel noise blocker according to claim 4, wherein the model of the piezoresistor comprises 821KD 20.
6. The power line carrier on-frequency noise blocker according to claim 3, wherein the piezoresistors are the same in different filtering subunits.
7. The power line carrier on-frequency noise blocker according to claim 3, wherein the capacitance values of the capacitors are the same in different filtering subunits.
8. The power line carrier on-channel noise blocker according to claim 1, further comprising a printed circuit board substrate;
the filtering unit is arranged on the printed circuit board substrate.
9. An electric power system, characterized in that, comprises electric equipment, a three-phase power line and a power line carrier same-frequency noise blocker of any one of claims 1-8;
and the electric equipment is connected with the power line carrier same-frequency noise blocker through the three-phase power line.
10. The power system of claim 9, further comprising a transformer; the transformer is connected with the power line carrier same-frequency noise blocker through the three-phase power line.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110112684.4A CN112787689A (en) | 2021-01-27 | 2021-01-27 | Power line carrier same-frequency noise blocker and power system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110112684.4A CN112787689A (en) | 2021-01-27 | 2021-01-27 | Power line carrier same-frequency noise blocker and power system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112787689A true CN112787689A (en) | 2021-05-11 |
Family
ID=75758448
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110112684.4A Pending CN112787689A (en) | 2021-01-27 | 2021-01-27 | Power line carrier same-frequency noise blocker and power system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112787689A (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201138510Y (en) * | 2008-01-03 | 2008-10-22 | 南京宇能仪表有限公司 | Wave damper for communication with low voltage electric power line carrier |
| CN101777771A (en) * | 2010-02-10 | 2010-07-14 | 湖北盛佳电器设备有限公司 | Working state monitoring device, capacitor and reactive power factor compensation device |
| CN101788597A (en) * | 2010-03-29 | 2010-07-28 | 福建师范大学 | Three-phase three-wire system phase voltage measuring method |
| CN202424718U (en) * | 2012-02-27 | 2012-09-05 | 山东凌宝电气有限公司 | Low voltage power line carrier isolator |
| JP2013013278A (en) * | 2011-06-30 | 2013-01-17 | Tabuchi Electric Co Ltd | Noise filter |
| CN106846782A (en) * | 2017-03-03 | 2017-06-13 | 武汉武新电气科技股份有限公司 | A kind of reactive-load compensation equipment that solves causes power carrier to be checked meter the equipment of problem |
| CN207442843U (en) * | 2017-12-01 | 2018-06-01 | 国家电网公司 | A kind of power line carrier noise suppressed filter |
-
2021
- 2021-01-27 CN CN202110112684.4A patent/CN112787689A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201138510Y (en) * | 2008-01-03 | 2008-10-22 | 南京宇能仪表有限公司 | Wave damper for communication with low voltage electric power line carrier |
| CN101777771A (en) * | 2010-02-10 | 2010-07-14 | 湖北盛佳电器设备有限公司 | Working state monitoring device, capacitor and reactive power factor compensation device |
| CN101788597A (en) * | 2010-03-29 | 2010-07-28 | 福建师范大学 | Three-phase three-wire system phase voltage measuring method |
| JP2013013278A (en) * | 2011-06-30 | 2013-01-17 | Tabuchi Electric Co Ltd | Noise filter |
| CN202424718U (en) * | 2012-02-27 | 2012-09-05 | 山东凌宝电气有限公司 | Low voltage power line carrier isolator |
| CN106846782A (en) * | 2017-03-03 | 2017-06-13 | 武汉武新电气科技股份有限公司 | A kind of reactive-load compensation equipment that solves causes power carrier to be checked meter the equipment of problem |
| CN207442843U (en) * | 2017-12-01 | 2018-06-01 | 国家电网公司 | A kind of power line carrier noise suppressed filter |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102255293B (en) | Single-ended electrical quantity full-line quick-action protection method for recognizing faults inside and outside high-voltage direct-current transmission line region | |
| CN103166679A (en) | Block filter for power line communication | |
| CN105527549A (en) | Partial discharge data collection circuit and detection system | |
| CN102522733B (en) | HVDC power-transmission whole-line speed protection method by using direct-current filter current | |
| EP3435509A1 (en) | System using a subcircuit shared between capacitors for providing reactive power | |
| CN101546909A (en) | Protective circuit, communication equipment and method for protecting device in communication equipment | |
| CN213212572U (en) | Lightning protection type anti-interference isolator of electric power meter reading system | |
| CN202750087U (en) | Drive circuit for power line carrier communication system lines | |
| CN112787689A (en) | Power line carrier same-frequency noise blocker and power system | |
| CN208608721U (en) | A kind of power distribution network zero line-breaking protector | |
| JPH10188187A (en) | Method and device for automatic meter-reading | |
| CN218767262U (en) | Lightning arrester monitoring device for monitoring leakage current | |
| CN112039473A (en) | Conformal anti-electromagnetic interference device for power end of substation equipment | |
| CN108808640B (en) | Power distribution network zero line breakage protector and control method thereof | |
| WO2020015496A1 (en) | Single-ended electrical quantity-based fast full-circuit protection method using choke to construct circuit boundary | |
| CN211630153U (en) | Filter device applied to low-voltage meter reading integrated carrier wave | |
| CN202693002U (en) | Two-wire system transmitter and anti-jamming circuit thereof | |
| CN203967743U (en) | Ground connection isolating transformer is exempted from a kind of lightning protection | |
| CN204859178U (en) | System for restrain power consumption information collection system interfering signal | |
| CN205811534U (en) | A kind of Ethernet Surge Protector | |
| CN205231739U (en) | A filtering system for electric wire netting | |
| CN106849998A (en) | Common mode disturbances restraining device | |
| CN219287146U (en) | Dynamometer resonance suppression device and dynamometer system based on C-type filter | |
| CN205724871U (en) | Three phase mains signal shares surge protector | |
| CN111313391A (en) | Ethernet port lightning protection surge protection circuit of industrial Internet of things gateway |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210511 |