CN109038517B - Single-phase insulation type electric fire on-line prevention and control device and method - Google Patents
Single-phase insulation type electric fire on-line prevention and control device and method Download PDFInfo
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- CN109038517B CN109038517B CN201810892435.XA CN201810892435A CN109038517B CN 109038517 B CN109038517 B CN 109038517B CN 201810892435 A CN201810892435 A CN 201810892435A CN 109038517 B CN109038517 B CN 109038517B
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
- H02H7/261—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured involving signal transmission between at least two stations
- H02H7/262—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured involving signal transmission between at least two stations involving transmissions of switching or blocking orders
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
- H02J13/00006—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment
- H02J13/00019—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment using optical means
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- H02J13/0062—
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Abstract
The invention discloses a single-phase insulation type electric fire on-line prevention and control device and a method, which comprises a control output unit, a singlechip module, a DSP unit, a residual current signal detection and conditioning unit for detecting and conditioning lumped residual current signals in a protected single-phase alternating current circuit in real time and a voltage signal detection and conditioning unit for detecting and conditioning phase voltage signals in the protected single-phase alternating current circuit in real time, wherein, the output end of the residual current signal detecting and conditioning unit and the output end of the voltage signal detecting and conditioning unit are both connected with the input end of the DSP unit, the output end of the DSP unit is connected with the input end of the singlechip module, the output end of the singlechip module is connected with the control output unit, the device and the method can monitor the insulation performance of the single-phase alternating current loop on line, identify potential electrical fire hazards on line and effectively prevent the occurrence of ground short circuit faults and electrical fire accidents.
Description
Technical Field
The invention belongs to the field of electric fire prevention and control, and relates to a single-phase insulation type electric fire online prevention and control device and method.
Background
In an effectively grounded single-phase alternating current power distribution system, the insulation performance of a cable and a load insulation layer in a power supply loop is reduced, and the amplitude of ground insulation resistance is reduced, so that a ground short circuit fault and even an electrical fire hazard are caused, and the life and property safety of people is threatened.
The known single-phase insulation type electric fire prevention and control methods comprise a loop residual current method and a megohmmeter method. The loop residual current method is to monitor the effective value I of the lumped residual current of the single-phase alternating current loop on line
ZThe magnitude of the residual current is used for judging whether the insulation performance of the current loop is good or not, but the effective value I of the lumped residual current
ZNot only contains the effective value I of the resistive residual current component formed by the insulation resistance of the current loop to the ground
RAnd further comprises an effective value I of the capacitive residual current component formed by the current loop capacitance to ground
CIn which only the effective value of the resistive residual current component I
RThe ground insulation performance of the current loop is characterized,the method can not extract the effective value I of the lumped residual current of the single-phase circuit separately
ZEffective value of resistive residual current component I
RBut not to the insulation resistance R of the current loop
1Accurate measurement is carried out, and the defects of false alarm and false negative alarm of grounding short circuit fault and potential electrical fire hazard are existed. The megohmmeter method is to use a megohmmeter instrument to perform off-line measurement of the insulation resistance after the single-phase circuit to be measured is powered off, and when the insulation resistance R of the current circuit is measured
1Less than the lower limit alarm threshold R of the insulation resistance
0When the method is set according to the actual conditions of a construction site or related national standards, the existence of a grounding short circuit fault and potential electrical fire danger is considered, and the method has the defect that the insulation performance of the current loop and the potential electrical fire danger caused by the current loop cannot be monitored on line.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a single-phase insulation type on-line electric fire prevention and control device and a single-phase insulation type on-line electric fire prevention and control method, which can monitor the insulation performance of a single-phase alternating current loop on line, identify potential electric fire risks on line and effectively prevent the occurrence of ground short circuit faults and electric fire accidents.
In order to achieve the above purpose, the single-phase insulation type on-line prevention and control device for electrical fire comprises a control output unit, a single chip microcomputer module, a DSP unit, a residual current signal detection and conditioning unit for detecting and conditioning lumped residual current signals in a protected single-phase alternating current circuit in real time and a voltage signal detection and conditioning unit for detecting and conditioning phase voltage signals in the protected single-phase alternating current circuit in real time, wherein the output end of the residual current signal detection and conditioning unit and the output end of the voltage signal detection and conditioning unit are both connected with the input end of the DSP unit, the output end of the DSP unit is connected with the input end of the single chip microcomputer module, and the output end of the single chip microcomputer module is connected with the control output unit.
The residual current signal detecting and conditioning unit comprises a residual current signal detecting module for detecting the lumped residual current signals in the protected single-phase alternating current circuit in real time and a residual current signal conditioning circuit module for conditioning the lumped residual current signals in the protected single-phase alternating current circuit.
The residual current signal detection module is a residual current transformer, and the residual current signal conditioning circuit module is composed of an I/V conversion circuit, an RC filter circuit, an amplifying circuit and an amplitude limiting circuit which are sequentially connected.
The voltage signal detection and conditioning unit comprises a voltage signal detection module for detecting the phase voltage signal in the protected single-phase alternating-current circuit in real time and a voltage signal conditioning circuit module for conditioning the phase voltage signal in the protected single-phase alternating-current circuit.
The voltage signal detection module is a voltage transformer, and the voltage signal conditioning circuit module is composed of an I/V conversion circuit, an RC filter circuit, an amplifying circuit and an amplitude limiting circuit which are sequentially connected.
The intelligent alarm device also comprises an Ethernet communication unit, a reset circuit module and an alarm unit which are connected with the single chip microcomputer module, wherein the single chip microcomputer module is connected with an upper computer through the Ethernet communication unit.
The singlechip module is connected with the alarm unit and the control output unit through the photoelectric coupler module.
The single-phase insulation type electric fire on-line prevention and control method comprises the following steps:
1) the residual current signal detection and conditioning unit detects and conditions the lumped residual current signal in the protected single-phase alternating current circuit in real time; the voltage signal detection and conditioning unit detects and conditions phase voltage signals in the protected single-phase alternating current loop in real time; the DSP unit calculates the effective value I of the lumped residual current signal in the protected single-phase alternating current circuit
ZAnd calculating the phase angle difference between the effective value U of the phase voltage signal in the protected single-phase alternating current circuit
2) The single chip microcomputer module is used for collecting effective value I of residual current signals in the protected single-phase alternating current circuit
ZEffective value of phase voltage signal in protected single-phase AC circuitAnd phase angle difference between the two
On-line separation and extraction of effective value I of lumped residual current signal in protected single-phase alternating current circuit
ZEffective value of internal resistive residual current component I
RAnd then calculating the insulation resistance R of the protected single-phase alternating current circuit
1When insulation resistance R of the single-phase AC circuit to be protected
1Less than a preset alarm threshold R
0And if so, outputting an alarm instruction to an alarm unit after delaying the time t, and simultaneously outputting a control instruction to a control output unit, wherein the alarm unit sends an audible and visual alarm instruction according to the alarm instruction, the control output unit generates a control signal for breaking the protected single-phase alternating-current circuit according to the control instruction, and breaks the protected single-phase alternating-current circuit according to the control signal for breaking the protected single-phase alternating-current circuit.
Insulation resistance R of protected single-phase alternating current circuit
1Comprises the following steps:
the invention has the following beneficial effects:
the single-phase insulation type electric fire on-line prevention and control device and the method detect the lumped residual current signal and the phase voltage signal in the protected single-phase alternating current circuit in real time and separate and extract the effective value I of the lumped residual current signal in the protected single-phase alternating current circuit during specific operation
ZEffective value of internal resistive residual current component I
RTo accurately calculate the insulation resistance R of the protected single-phase AC circuit
1Avoiding the missing report and the false report of the grounding short circuit fault and the potential electric fire hazard caused by the insulation property damage of the single-phase intersecting return circuit, and when the insulation resistance value R of the protected single-phase alternating current loop
1Less than a preset alarm threshold R
0And if so, sending a control instruction to the control output unit after delaying for t time, and generating a control signal for breaking the protected single-phase alternating-current loop by the control output unit according to the control instruction, thereby effectivelyThe occurrence of ground short circuit fault and electric fire accident can be prevented. In addition, the invention can ensure the safety of the power system without power failure in the operation process, thereby saving manpower and material resources.
Drawings
FIG. 1 is a schematic structural diagram of the present invention.
Wherein, 1 is residual current signal detection module, 2 is residual current signal conditioning circuit module, 3 is voltage signal detection module, 4 is voltage signal conditioning circuit module, 5 is reset circuit module, 6 is singlechip module, 7 is photoelectric coupler module, 8 is DSP unit, 9 is ethernet communication unit, 10 is alarm unit, 11 is control output unit.
Detailed Description
The invention is described in further detail below with reference to the accompanying drawings:
as shown in fig. 1, the single-phase insulation type online prevention and control device for electrical fire in the invention comprises a control output unit 11, a single chip microcomputer module 6, a DSP unit 8, a residual current signal detecting and conditioning unit for detecting and conditioning lumped residual current signals in a protected single-phase ac circuit in real time, and a voltage signal detecting and conditioning unit for detecting and conditioning phase voltage signals in the protected single-phase ac circuit in real time, wherein an output end of the residual current signal detecting and conditioning unit and an output end of the voltage signal detecting and conditioning unit are both connected with an input end of the DSP unit 8, an output end of the DSP unit 8 is connected with an input end of the single chip microcomputer module 6, and an output end of the single chip microcomputer module 6 is connected with the control output unit 11.
The residual current signal detecting and conditioning unit comprises a residual current signal detecting module 1 for detecting lumped residual current signals in the protected single-phase alternating-current circuit in real time and a residual current signal conditioning circuit module 2 for conditioning the lumped residual current signals in the protected single-phase alternating-current circuit, wherein the residual current signal detecting module 1 is a residual current transformer, and the residual current signal conditioning circuit module 2 is composed of an I/V (input/output) conversion circuit, an RC (resistor-capacitor) filter circuit, an amplifying circuit and an amplitude limiting circuit which are sequentially connected.
The voltage signal detection and conditioning unit comprises a voltage signal detection module 3 for detecting phase voltage signals in the protected single-phase alternating-current circuit in real time and a voltage signal conditioning circuit module 4 for conditioning the phase voltage signals in the protected single-phase alternating-current circuit, wherein the voltage signal detection module 3 is a voltage transformer, and the voltage signal conditioning circuit module 4 is composed of an I/V conversion circuit, an RC filter circuit, an amplifying circuit and an amplitude limiting circuit which are sequentially connected.
The invention also comprises an Ethernet communication unit 9, a reset circuit module 5 and an alarm unit 10 which are connected with the singlechip module 6, wherein the singlechip module 6 is connected with an upper computer through the Ethernet communication unit 9, and the singlechip module 6 is connected with the alarm unit 10 and a control output unit 11 through a photoelectric coupler module 7.
The single chip microcomputer module 6 uploads the real-time insulation resistance value and the fault information of the protected single-phase alternating current circuit to an upper computer through an Ethernet communication unit 9; the alarm unit 10 employs a buzzer or an indicator light.
The single-phase insulation type electric fire on-line prevention and control method comprises the following steps:
1) the residual current signal detection and conditioning unit detects and conditions the lumped residual current signal in the protected single-phase alternating current circuit in real time; the voltage signal detection and conditioning unit detects and conditions phase voltage signals in the protected single-phase alternating current loop in real time; the DSP unit 8 calculates the effective value I of the lumped residual current signal in the protected single-phase alternating current loop
ZAnd calculating the phase angle difference between the effective value U of the phase voltage signal in the protected single-phase alternating current circuit
2) The singlechip module 6 collects the effective value I of residual current signals in the single-phase alternating current circuit to be protected
ZEffective value U of phase voltage signal in protected single-phase alternating current circuit and phase angle difference between the effective value U and the phase voltage signal
On-line separation and extraction of effective value I of lumped residual current signal in protected single-phase alternating current circuit
ZEffective value of internal resistive residual current component I
RAnd then calculating the insulation resistance R of the protected single-phase alternating current circuit
1When insulation resistance R of the single-phase AC circuit to be protected
1Less than a preset alarm threshold R
0If so, outputting an alarm instruction to the alarm unit 10 after delaying t time, and simultaneously outputting a control instruction to the control output unit 11, wherein the delay time t is 0-30 s; the alarm unit 10 sends out an audible and visual alarm instruction according to the alarm instruction, the control output unit 11 generates a control signal for breaking the protected single-phase alternating current circuit according to the control instruction, and the protected single-phase alternating current circuit is broken according to the control signal for breaking the protected single-phase alternating current circuit.
Wherein, the insulation resistance R of the protected single-phase AC circuit
1Comprises the following steps:
wherein when R is
1≥R
0When R is equal to R, the insulation performance of the single-phase AC circuit to be protected is considered to be good
1<R
0When the single-phase alternating current circuit is in a fault state, the insulation performance of the protected single-phase alternating current circuit is determined to be damaged, and the protected single-phase alternating current circuit has grounding short circuit faults and potential electrical fire risks;
the effective value I of the lumped residual current signal in the protected single-phase alternating current circuit is separated and extracted on line in the step 2)
ZEffective value of internal resistive residual current component I
RThe specific operation is as follows: the phase of the resistive residual current component in the lumped residual current is consistent with the phase of the loop phase voltage, and the effective value I of the resistive residual current component
RIs equal to the component of the lumped residual current in the phase voltage direction, and the effective value I of the resistive residual current component
RHas a size of I
Z*cos
In addition, after the grounding short circuit fault and the potential electrical fire hazard are eliminated, the reset circuit module 5 controls the singlechip module 6 to reset.
The fundamental principles, main features and advantages of the invention have been described in the above specification and examples, particularly illustrating the essence of the invention-by real-time acquisition, processing, calculation of the phase voltage effective value U, the lumped residual current effective value I
ZAnd the phase angle difference between the phase voltage signal and the total residual current signal
Separating and extracting effective value I of resistive residual current component
RCalculating the insulation resistance R of the protected single-phase AC circuit
1And is compared with a preset alarm threshold value R
0By comparison, when R is
1<R
0And when the single-phase alternating current circuit is damaged, the insulation performance of the protected single-phase alternating current circuit is determined to be damaged, and the grounding short-circuit fault and the potential electric fire hazard danger exist, so that the effective and accurate online prevention and control of the grounding short-circuit fault and the electric fire hazard accident caused by the damage of the insulation performance of the line and the load of the single-phase alternating current circuit are realized.
The practical application of the present invention is not limited to the above-mentioned embodiments, and the present invention may be further modified and improved (for example, extended to a three-phase ac circuit) without departing from the spirit and scope of the present invention.
Claims (7)
1. A single-phase insulation type electric fire on-line prevention and control method is characterized in that based on a single-phase insulation type electric fire on-line prevention and control device, the single-phase insulation type electric fire on-line prevention and control device comprises a control output unit (11), a singlechip module (6), a DSP unit (8), a residual current signal detection and conditioning unit for detecting and conditioning lumped residual current signals in a protected single-phase alternating current circuit in real time and a voltage signal detection and conditioning unit for detecting and conditioning phase voltage signals in the protected single-phase alternating current circuit in real time, the output end of the residual current signal detection and conditioning unit and the output end of the voltage signal detection and conditioning unit are both connected with the input end of the DSP unit (8), the output end of the DSP unit (8) is connected with the input end of the single chip microcomputer module (6), and the output end of the single chip microcomputer module (6) is connected with the control output unit (11);
the method comprises the following steps:
1) the residual current signal detection and conditioning unit detects and conditions the lumped residual current signal in the protected single-phase alternating current circuit in real time; the voltage signal detection and conditioning unit detects and conditions phase voltage signals in the protected single-phase alternating current loop in real time; the DSP unit (8) calculates the effective value I of the lumped residual current signal in the protected single-phase alternating current loop
ZAnd calculating the phase angle difference between the effective value U of the phase voltage signal in the protected single-phase alternating current circuit
2) The singlechip module (6) collects the effective value I of residual current signals in the single-phase alternating current circuit according to the protection
ZEffective value U of phase voltage signal in protected single-phase alternating current circuit and phase angle difference between the effective value U and the phase voltage signal
On-line separation and extraction of effective value I of lumped residual current signal in protected single-phase alternating current circuit
ZEffective value of internal resistive residual current component I
RAnd then calculating the insulation resistance R of the protected single-phase alternating current circuit
1When insulation resistance R of the single-phase AC circuit to be protected
1Less than a preset alarm threshold R
0When the protection circuit is in use, an alarm instruction is output to an alarm unit (10) after t time delay, a control instruction is output to a control output unit (11) at the same time, the alarm unit (10) sends an audible and visual alarm instruction according to the alarm instruction, the control output unit (11) generates a control signal for breaking a protected single-phase alternating current circuit according to the control instruction, and the protected single-phase alternating current circuit is broken according to the control signal for breaking the protected single-phase alternating current circuit;
protected single phaseInsulation resistance R of alternating current loop
1Comprises the following steps:
2. the single-phase insulation type electric fire on-line prevention and control method according to claim 1, wherein the residual current signal detection and conditioning unit comprises a residual current signal detection module (1) for detecting the lumped residual current signal in the protected single-phase alternating current loop in real time and a residual current signal conditioning circuit module (2) for conditioning the lumped residual current signal in the protected single-phase alternating current loop.
3. The single-phase insulation type electric fire on-line prevention and control method according to claim 2, characterized in that the residual current signal detection module (1) is a residual current transformer, and the residual current signal conditioning circuit module (2) is composed of an I/V conversion circuit, an RC filter circuit, an amplifying circuit and a limiting circuit which are connected in sequence.
4. The single-phase insulation type electric fire on-line prevention and control method according to claim 1, characterized in that the voltage signal detection and conditioning unit comprises a voltage signal detection module (3) for detecting the phase voltage signal in the protected single-phase alternating current loop in real time and a voltage signal conditioning circuit module (4) for conditioning the phase voltage signal in the protected single-phase alternating current loop.
5. The single-phase insulation type electric fire on-line prevention and control method according to claim 4, characterized in that the voltage signal detection module (3) is a voltage transformer, and the voltage signal conditioning circuit module (4) is composed of an I/V conversion circuit, an RC filter circuit, an amplifying circuit and a limiting circuit which are connected in sequence.
6. The single-phase insulation type electric fire on-line prevention and control method according to claim 1, further comprising an Ethernet communication unit (9), a reset circuit module (5) and an alarm unit (10) which are connected with the single chip microcomputer module (6), wherein the single chip microcomputer module (6) is connected with an upper computer through the Ethernet communication unit (9).
7. The single-phase insulation type electric fire on-line prevention and control method as claimed in claim 6, wherein the single chip microcomputer module (6) is connected with the alarm unit (10) and the control output unit (11) through a photoelectric coupler module (7).
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| Application Number | Priority Date | Filing Date | Title |
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| CN201810892435.XA CN109038517B (en) | 2018-08-07 | 2018-08-07 | Single-phase insulation type electric fire on-line prevention and control device and method |
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|---|---|---|---|
| CN201810892435.XA CN109038517B (en) | 2018-08-07 | 2018-08-07 | Single-phase insulation type electric fire on-line prevention and control device and method |
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| CN109038517B true CN109038517B (en) | 2020-02-11 |
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| CN111781536B (en) * | 2020-08-04 | 2023-03-28 | 蚌埠依爱消防电子有限责任公司 | Method for monitoring ground insulation resistance and leakage capacitance of single-phase alternating current system |
| CN112821352B (en) * | 2021-01-04 | 2024-10-01 | 西安华瑞网电科技股份有限公司 | On-line detection method and protection device for personal electric shock of street lamp lighting system |
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| JP3201623B2 (en) * | 1991-07-22 | 2001-08-27 | 松下電工株式会社 | Line monitor terminal for remote monitoring and control system |
| CN102354427B (en) * | 2011-09-27 | 2013-05-01 | 赵怀军 | method and device for flexibly identifying residual current-type electrical fire on line |
| CN206920548U (en) * | 2017-07-03 | 2018-01-23 | 北京航天常兴科技发展股份有限公司 | The resistive electric leakage electrical fire monitoring detection device of on-line insulation monitoring formula |
| CN107528290A (en) * | 2017-09-29 | 2017-12-29 | 西安华瑞网电设备有限公司 | A kind of inverse time lag current-limiting type electrical fire prevention and control device and method |
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Denomination of invention: A single phase insulation type electric fire online prevention and control device and method Effective date of registration: 20201221 Granted publication date: 20200211 Pledgee: Pudong Development Bank of Shanghai Limited by Share Ltd. Xi'an branch Pledgor: XIAN HI-RATE POWER TECHNOLOGY Co.,Ltd. Registration number: Y2020610000240 |
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