CN109856509B - Effectively-grounded three-phase insulation type electric fire online prevention and control device and method - Google Patents
Effectively-grounded three-phase insulation type electric fire online prevention and control device and method Download PDFInfo
- Publication number
- CN109856509B CN109856509B CN201811512081.8A CN201811512081A CN109856509B CN 109856509 B CN109856509 B CN 109856509B CN 201811512081 A CN201811512081 A CN 201811512081A CN 109856509 B CN109856509 B CN 109856509B
- Authority
- CN
- China
- Prior art keywords
- phase
- distribution system
- power supply
- supply loop
- effectively grounded
- 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.)
- Active
Links
Images
Abstract
The invention discloses an effectively grounded three-phase insulation type electric fire on-line prevention and control device and a method, wherein the prevention and control device comprises a DSP unit, a singlechip module, a photoelectric coupler module, an alarm unit, a control output unit, an Ethernet communication unit, a reset circuit module, a residual current signal detection module, a conditioning circuit module, a voltage signal detection module and a conditioning circuit module; the prevention and control method adopts the prevention and control device to decompose and restore the lumped residual current of the power supply circuit of the effectively grounded three-phase alternating current power distribution system to each phase, extracts the resistive residual current component of each phase which really represents the insulation characteristic, and further calculates the relative grounding insulation resistance of each phase, thereby realizing the online monitoring of the insulation performance and the potential electrical fire hazard of the power supply circuit of the effectively grounded three-phase alternating current power distribution system, effectively preventing the occurrence of grounding short circuit faults and electrical fire accidents, and overcoming the defects of false alarm, missing alarm and incapability of online detection in the conventional method.
Description
Technical Field
The invention belongs to the field of electric fire prevention and control, and relates to an effectively-grounded three-phase insulation type electric fire online prevention and control device and method.
Background
In an effectively grounded three-phase alternating current power distribution system power supply loop, the insulation performance of a cable and a load insulation layer is reduced, and the insulation resistance value to ground 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.
At present, common insulation type electric fire prevention and control methods for an effectively grounded three-phase alternating-current power distribution system include a loop residual current method and a megger method. The loop residual current method is to monitor the effective value IR of the lumped residual current of the power supply loop of the effectively grounded three-phase AC distribution system on lineZThe amplitude value of the current circuit is used for judging whether insulation performance degradation and potential electric fire hazard exist in the current circuit, and the method often causes false alarm and false alarm phenomena because the lumped residual current of the circuit is the vector sum of the relative earth residual currents which comprise the relative earth grounding insulation resistances (R)a,Rb,Rc) The resulting resistive residual current component (effective value IRr)a、IRrb、IRrc) And each phase to ground capacitive insulation resistance (C)a,Cb,Cc) The capacitive residual current component (effective value IRc)a、IRcb、IRcc) I.e. by
But wherein only the respective relative earth-resistance insulation resistances (R)a,Rb,Rc) The resulting resistive residual current component (effective value IRr)a、IRrb、IRrc) The insulation performance of each phase is really characterized, and the capacitive insulation resistance (C) of each phasea,Cb,Cc) The capacitive residual current component (effective value IRc)a、IRcb、IRcc) The insulation properties of the phases cannot be characterized. Due to the relative capacitive insulation resistance (C)a,Cb,Cc) The capacitive residual current component (effective value IRc)a、IRcb、IRcc) Will change at any time along with the change of factors such as the laying length of the cable, the degree of unbalance of the arrangement of the phase lines relative to the ground, the load quantity, the environmental temperature and humidity, the service life and the like, and the vector sum (effective value is IR) of the resistive residual current components under the conditions of small resistive residual current components and large capacitive residual currentZ) The lower alarm threshold may be exceeded to cause a false alarm, and similarly, the resistive residual current component is largerTheir vector sum (effective value is IR) in case of very small capacitive residual currentZ) There is still a possibility that the lower alarm threshold is not exceeded, resulting in a missed alarm. The megger method is to utilize megger instrument to perform off-line measurement of insulation resistance after the power supply circuit of the measured effectively grounded three-phase AC distribution system is cut off, and when any one of the measured relative grounding insulation resistance values of the power supply circuit of the effectively grounded three-phase AC distribution system is smaller than the lower alarm threshold R of the insulation resistance0When the method is set according to actual conditions of a construction site or related national standards, the power supply loop of the effectively grounded three-phase alternating-current power distribution system is considered to have grounding short-circuit faults and potential electrical fire risks, and the method has the defect that the insulation performance of the current loop can not be monitored on line and the potential electrical fire risks can not be monitored.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides an effectively grounded three-phase insulation type electric fire online prevention and control device and method, which can monitor the insulation performance and the potential electric fire danger of a power supply loop of an effectively grounded three-phase alternating current power distribution system on line, avoid the false alarm and the false missing alarm of the insulation performance reduction and the potential electric fire danger and effectively prevent the occurrence of a ground short circuit fault and an electric fire accident.
In order to achieve the purpose, the effectively grounded three-phase insulation type electric fire on-line prevention and control device comprises a DSP unit, a single chip microcomputer module, a photoelectric coupler module, an alarm unit, a control output unit, a reset circuit module, a residual current signal conditioning circuit module, a voltage signal detection module for collecting phase voltage signals of a power supply loop of an effectively grounded three-phase alternating current power distribution system and a lumped current signal detection module for collecting residual current signals of the power supply loop of the effectively grounded three-phase alternating current power distribution system;
the residual current signal detection module is connected with the input end of the DSP unit through the residual current signal conditioning circuit module, the voltage signal detection module is connected with the input end of the DSP unit through the voltage signal conditioning circuit module, the output end of the DSP unit and the reset circuit module are connected with the single chip microcomputer module, and the output end of the single chip microcomputer module is connected with the alarm unit and the control output unit through the photoelectric coupler module.
The residual current signal conditioning circuit module consists 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 conditioning circuit module consists of an I/V conversion circuit, an RC filter circuit, an amplifying circuit and an amplitude limiting circuit which are connected in sequence.
The system also comprises an Ethernet communication unit used for connecting external equipment, and the Ethernet communication unit is connected with the singlechip module.
The residual current signal detection module is a residual current transformer arranged in a power supply loop of the effectively grounded three-phase alternating current power distribution system, wherein cables of an A phase, a B phase, a C phase and an N phase in the power supply loop of the effectively grounded three-phase alternating current power distribution system penetrate through the residual current transformer;
the voltage signal detection module is a voltage transformer.
The invention relates to an effectively grounded three-phase insulation type electric fire on-line prevention and control method, which comprises the following steps:
the voltage signal detection module collects phase voltage signals of a power supply loop of the effectively grounded three-phase alternating current power distribution system, and the collected phase voltage signals of the power supply loop of the effectively grounded three-phase alternating current power distribution system are input into the DSP unit after being conditioned by the voltage signal conditioning circuit module; meanwhile, the residual current signal detection module collects lumped residual current signals of a power supply loop of the effectively grounded three-phase alternating current power distribution system, the collected lumped residual current signals of the power supply loop of the effectively grounded three-phase alternating current power distribution system are conditioned by the residual current signal conditioning circuit module and then are input into the DSP unit, and the DSP unit calculates effective values UA, UB and UC of voltages of all phases of the power supply loop of the effectively grounded three-phase alternating current power distribution system according to the voltage signals of all phases of the power supply loop of the effectively grounded three-phase alternating current power distribution system conditioned by the voltage signal conditioning circuit module; and simultaneously, the calculation is carried out according to the lumped residual current signal of the effectively grounded three-phase alternating current power distribution system power supply loop conditioned by the residual current signal conditioning circuit moduleEffective value IR of lumped residual current of power supply loop of effectively grounded three-phase alternating-current power distribution systemZAnd calculating the phase angle difference between the A-phase voltage signal in the power supply loop of the effectively grounded three-phase alternating current power distribution system and the lumped residual current signal in the power supply loop of the effectively grounded three-phase alternating current power distribution system
Then, the effective values UA, UB and UC of the voltages of all phases of the power supply loop of the effectively grounded three-phase alternating current power distribution system and the effective value IR of the lumped residual current of the power supply loop of the effectively grounded three-phase alternating current power distribution system obtained by calculation are comparedZAnd the phase angle difference between the A-phase voltage signal in the power supply loop of the effectively grounded three-phase alternating-current power distribution system and the lumped residual current signal in the power supply loop of the effectively grounded three-phase alternating-current power distribution system
Sending the data to the singlechip module;
the single chip microcomputer module is used for collecting residual current effective values IR according to effective grounding three-phase alternating current power distribution system power supply circuit phase voltage effective values UA, UB and UC and effective grounding three-phase alternating current power distribution system power supply circuit lumped residual current effective values IRZAnd the phase angle difference between the A-phase voltage signal in the power supply loop of the effectively grounded three-phase alternating-current power distribution system and the lumped residual current signal in the power supply loop of the effectively grounded three-phase alternating-current power distribution system
Effective value IR of lumped residual current of power supply circuit of effectively grounded three-phase alternating-current power distribution systemZDecomposing the residual current into each phase of the power supply loop of the effectively grounded three-phase alternating current power distribution system, and extracting the effective value IRr of the resistive residual current component of each phase of the power supply loop of the effectively grounded three-phase alternating current power distribution systema、IRrb、IRrcThen, calculating the relative grounding insulation resistance R of the power supply loop of the effectively grounded three-phase AC distribution systema、RbAnd RcFinally, the relative grounding insulation resistors R of the power supply loop of the effectively grounded three-phase alternating current distribution systema、RbAnd RcAnd insulation resistanceLower alarm threshold R0By comparison, when R isa≥R0、Rb≥R0And Rc≥R0When the system is in operation, the effective grounding three-phase alternating current distribution system is determined to have good insulation performance of a power supply loop and no grounding short circuit fault or potential electrical fire hazard danger, and when R is in operationa<R0Or Rb<R0Or Rc<R0And then, after delaying t time, sending an alarm instruction and a breaking control instruction to an alarm unit and a control output unit respectively, carrying out sound-light alarm by the alarm unit according to the alarm instruction, and breaking the power supply loop of the effectively grounded three-phase alternating current power distribution system by the control output unit according to the breaking control instruction.
When R isa<R0When the current is in the zero-phase voltage range, the insulation performance of the phase A of the power supply loop of the effectively grounded three-phase alternating current power distribution system is determined to be damaged; when R isb<R0When the effective grounding three-phase alternating current power distribution system is in a state of being damaged, the insulation performance of the phase B of the power supply loop of the effective grounding three-phase alternating current power distribution system is determined to be damaged; when R isc<R0And when the voltage is higher than the set voltage, the insulation performance of the C phase of the power supply loop of the effectively grounded three-phase alternating current power distribution system is determined to be damaged.
When in use
Then effectively grounding the effective value IRr of the resistive residual current of the C phase of the power supply loop of the three-phase alternating current power distribution systemcNeglecting to be 0, and effectively grounding the effective value IR of the lumped residual current of the power supply circuit of the three-phase alternating current distribution systemZDecomposing the residual current into A phase and B phase of the power supply loop of the effectively grounded three-phase alternating current power distribution system to obtain effective value IRr of the resistive residual current component of the A phase and the B phase of the power supply loop of the effectively grounded three-phase alternating current power distribution systema、IRrb(ii) a When in use
In time, the resistive residual current of the A phase of the power supply loop of the effectively grounded three-phase alternating current distribution system is effectively usedValue IRraNeglecting to be 0, and effectively grounding the effective value IR of the lumped residual current of the power supply circuit of the three-phase alternating current distribution systemZDecomposing the residual current into B phase and C phase of the power supply loop of the effectively grounded three-phase alternating current power distribution system to obtain effective values IRr of the resistive residual current components of the B phase and the C phase of the power supply loop of the effectively grounded three-phase alternating current power distribution systemb、IRrc(ii) a When in use
Then effectively grounding the effective value IRr of the resistive residual current of the B phase of the power supply loop of the three-phase alternating current power distribution systembNeglecting to be 0, and effectively grounding the effective value IR of the lumped residual current of the power supply circuit of the three-phase alternating current distribution systemZDecomposing the residual current into the A phase and the C phase of the power supply loop of the effectively grounded three-phase alternating current power distribution system to obtain the effective value IRr of the resistive residual current component of the A phase and the C phase of the power supply loop of the effectively grounded three-phase alternating current power distribution systema、IRrcFurther, the following table is used to calculate the relative grounding insulation resistance R of each power supply circuit of the effectively grounded three-phase AC power distribution systema、RbAnd Rc。
Calculating the phase angle difference between the A-phase voltage signal in the power supply loop of the effectively grounded three-phase alternating current power distribution system and the lumped residual current signal in the power supply loop of the effectively grounded three-phase alternating current power distribution system by using an FFT (fast Fourier transform) method or a phase-locked amplification method
The invention has the following beneficial effects:
the invention relates to an effectively grounded three-phase insulation type electric fire on-line prevention and control device and a method thereof, wherein during specific operation, the effectively grounded three-phase alternating current distribution system power supply loop is lumped with a residual current effective value IRZDecomposing and restoring to each phase of power supply loop of effectively grounded three-phase alternating current power distribution system, and extracting effectively grounded three-phase alternating currentEffective value IRr of resistive residual current component for really representing insulation characteristic of each phase in each phase of power supply loop of power distribution systema、IRrb、IRrcThen, calculating the relative grounding insulation resistance R of the power supply loop of the effectively grounded three-phase AC distribution systema、RbAnd RcAnd then the relative earth insulation resistances R according to the effective earth of the power supply circuit of the three-phase AC distribution systema、RbAnd RcThe insulation performance of the power supply loop of the effectively grounded three-phase alternating-current power distribution system is judged, whether grounding short-circuit faults and potential electrical fire hazards exist or not is judged, and the false reporting and missing reporting of the grounding short-circuit faults and the potential electrical fire hazards caused by the fact that the insulation performance of a cable and a load insulation layer of the power supply loop of the effectively grounded three-phase alternating-current power distribution system is reduced and the grounding short-circuit faults and the potential electrical fire hazards are reduced are effectively avoided. In addition, in the operation process, the invention can monitor the relative grounding insulation resistance values of the power supply loop of the effectively grounded three-phase alternating-current power distribution system on line in real time without power failure, thereby ensuring the safety of the power system and saving manpower and material resources.
Drawings
Fig. 1 is a schematic 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:
referring to fig. 1, the effectively grounded three-phase insulation type online prevention and control device for electrical fire of the present invention includes a DSP unit 8, a single chip microcomputer module 6, a photocoupler module 7, an alarm unit 10, a control output unit 11, a reset circuit module 5, a residual current signal conditioning circuit module 2, a voltage signal conditioning circuit module 4, a voltage signal detection module 3 for collecting phase voltage signals of an effectively grounded three-phase ac power distribution system power supply loop, and a residual current signal detection module 1 for collecting lumped residual current signals of the effectively grounded three-phase ac power distribution system power supply loop; the residual current signal detection module 1 is connected with the input end of the DSP unit 8 through the residual current signal conditioning circuit module 2, the voltage signal detection module 3 is connected with the input end of the DSP unit 8 through the voltage signal conditioning circuit module 4, the output end of the DSP unit 8 and the reset circuit module 5 are connected with the single chip microcomputer module 6, the output end of the single chip microcomputer module 6 is connected with the alarm unit 10 and the control output unit 11 through the photoelectric coupler module 7, and the reset circuit module 5 is connected with the reset port of the single chip microcomputer module 6.
The residual current signal conditioning circuit module 2 consists of an I/V conversion circuit, an RC filter circuit, an amplifying circuit and an amplitude limiting circuit which are connected in sequence; 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 connected in sequence.
The invention also comprises an Ethernet communication unit 9 used for connecting external equipment, the Ethernet communication unit 9 is connected with the singlechip module 6, and the real-time earth-resisting insulation resistance value, alarm information, fault information and the like of each phase of the power supply loop of the effectively grounded three-phase alternating current power distribution system are transmitted to the external equipment through the Ethernet communication unit 9.
The residual current signal detection module 1 is a residual current transformer which is arranged in a power supply loop of an effectively grounded three-phase alternating current power distribution system, wherein cables of an A phase, a B phase, a C phase and an N phase in the power supply loop of the effectively grounded three-phase alternating current power distribution system penetrate through the residual current transformer; the voltage signal detection module 3 is a voltage transformer.
In actual operation, the DSP unit 8 can adopt an ADE9078 type DSP processor with high speed and high precision; the single chip module 6 can adopt a high-speed digital signal processor, such as Dspic30F6014A, ADuc 832; the reset circuit module 5 can adopt a mechanical button; the photocoupler module 7 may employ a general power photocoupler such as TLP 127; the alarm unit 10 is composed of a buzzer and an indicator light; the control output unit 11 may employ a general control relay or a solid state relay SSR, for example, JQX-14 or S310 ZK; the ethernet communication unit 9 may optionally be an ethernet specific module, e.g. HV 2002D-TX.
The invention relates to an effectively grounded three-phase insulation type electric fire on-line prevention and control method, which comprises the following steps:
the voltage signal detection module 3 collects phase voltage signals of the power supply loop of the effectively grounded three-phase alternating-current power distribution system, and the collected phase voltage signals of the power supply loop of the effectively grounded three-phase alternating-current power distribution system are conditioned by the voltage signal conditioning circuit module 4 and then are input into the DSP unit 8; meanwhile, the residual current signal detection module 1 collects lumped residual current signals of a power supply loop of the effectively grounded three-phase alternating-current power distribution system, the collected lumped residual current signals of the power supply loop of the effectively grounded three-phase alternating-current power distribution system are conditioned by the residual current signal conditioning circuit module 2 and then are input into the DSP unit 8, and the DSP unit 8 calculates voltage effective values UA, UB and UC of each phase of the power supply loop of the effectively grounded three-phase alternating-current power distribution system according to the voltage signals of each phase of the power supply loop of the effectively grounded three-phase alternating-current power distribution system conditioned by the voltage signal conditioning circuit module 4; meanwhile, the effective value IR of the lumped residual current of the power supply loop of the effectively grounded three-phase alternating current power distribution system is calculated according to the lumped residual current signal of the power supply loop of the effectively grounded three-phase alternating current power distribution system after being conditioned by the residual current signal conditioning circuit module 2ZAnd calculating the phase angle difference between the A-phase voltage signal in the power supply loop of the effectively grounded three-phase alternating current power distribution system and the lumped residual current signal in the power supply loop of the effectively grounded three-phase alternating current power distribution system
Then, the effective values UA, UB and UC of the voltages of all phases of the power supply loop of the effectively grounded three-phase alternating current power distribution system and the effective value IR of the lumped residual current of the power supply loop of the effectively grounded three-phase alternating current power distribution system obtained by calculation are comparedZAnd the phase angle difference between the A-phase voltage signal in the power supply loop of the effectively grounded three-phase alternating-current power distribution system and the lumped residual current signal in the power supply loop of the effectively grounded three-phase alternating-current power distribution system
SendingTo the singlechip module 6;
the singlechip module 6 is used for collecting the residual current effective value IR according to the effective voltage effective values UA, UB and UC of each phase of the power supply circuit of the effectively grounded three-phase alternating current power distribution system and the effective residual current effective value IR of the power supply circuit of the effectively grounded three-phase alternating current power distribution systemZAnd the phase angle difference between the A-phase voltage signal in the power supply loop of the effectively grounded three-phase alternating-current power distribution system and the lumped residual current signal in the power supply loop of the effectively grounded three-phase alternating-current power distribution system
Effective value IR of lumped residual current of power supply circuit of effectively grounded three-phase alternating-current power distribution systemZDecomposing and restoring the residual current into each phase of the power supply loop of the effectively grounded three-phase alternating current power distribution system, and extracting effective values IRr of the resistive residual current components of each phase of the power supply loop of the effectively grounded three-phase alternating current power distribution systema、IRrb、IRrcThen, calculating the relative grounding insulation resistance R of the power supply loop of the effectively grounded three-phase AC distribution systema、RbAnd RcFinally, the relative grounding insulation resistors R of the power supply loop of the effectively grounded three-phase alternating current distribution systema、RbAnd RcAnd insulation resistance lower limit alarm threshold R0By comparison, when R isa≥R0、Rb≥R0And Rc≥R0When the system is in operation, the effective grounding three-phase alternating current distribution system is determined to have good insulation performance of a power supply loop and no grounding short circuit fault or potential electrical fire hazard danger, and when R is in operationa<R0Or Rb<R0Or Rc<R0And then, after delaying t time, sending an alarm instruction and a breaking control instruction to an alarm unit 10 and a control output unit 11 respectively, wherein the alarm unit 10 performs sound-light alarm according to the alarm instruction, and the control output unit 11 breaks the power supply loop of the effectively grounded three-phase alternating current power distribution system according to the breaking control instruction.
Wherein when R isa<R0When the current is in the zero-phase voltage range, the insulation performance of the phase A of the power supply loop of the effectively grounded three-phase alternating current power distribution system is determined to be damaged; when R isb<R0When the effective grounding three-phase alternating current power distribution system is in a state of being damaged, the insulation performance of the phase B of the power supply loop of the effective grounding three-phase alternating current power distribution system is determined to be damaged; when R isc<R0And when the voltage is higher than the set voltage, the insulation performance of the C phase of the power supply loop of the effectively grounded three-phase alternating current power distribution system is determined to be damaged.
It should be noted that the lumped residual current of the power supply loop of the effectively grounded three-phase ac distribution system is the vector sum of the three-phase residual currents, the a-phase voltage signal is used as the phase reference, and the lagging phase of the lumped residual current of the loop is used as the lagging phase
Lumped residual current effective value IR of loopZDecomposing and reducing the residual current to each phase line to obtain effective value IRr of each phase resistive residual current componenta、IRrb、IRrcIn particular, when
Then effectively grounding the effective value IRr of the resistive residual current of the C phase of the power supply loop of the three-phase alternating current power distribution systemcNeglecting to be 0, and effectively grounding the effective value IR of the lumped residual current of the power supply circuit of the three-phase alternating current distribution systemZDecomposing the residual current into A phase and B phase of the power supply loop of the effectively grounded three-phase alternating current power distribution system to obtain effective value IRr of the resistive residual current component of the A phase and the B phase of the power supply loop of the effectively grounded three-phase alternating current power distribution systema、IRrb(ii) a When in use
Then effectively grounding the effective value IRr of the resistive residual current of the A phase of the power supply loop of the three-phase alternating current distribution systemaNeglecting to be 0, and effectively grounding the effective value IR of the lumped residual current of the power supply circuit of the three-phase alternating current distribution systemZDecomposing the residual current into B phase and C phase of the power supply loop of the effectively grounded three-phase alternating current power distribution system to obtain effective values IRr of the resistive residual current components of the B phase and the C phase of the power supply loop of the effectively grounded three-phase alternating current power distribution systemb、IRrc(ii) a When in use
Then effectively grounding the effective value IRr of the resistive residual current of the B phase of the power supply loop of the three-phase alternating current power distribution systembNeglecting to be 0, and effectively grounding the effective value IR of the lumped residual current of the power supply circuit of the three-phase alternating current distribution systemZDecomposing the residual current into the A phase and the C phase of the power supply loop of the effectively grounded three-phase alternating current power distribution system to obtain the effective value IRr of the resistive residual current component of the A phase and the C phase of the power supply loop of the effectively grounded three-phase alternating current power distribution systema、IRrcFurther, the effective grounding insulation resistances R of the power supply circuit of the three-phase AC distribution system are obtained by calculation according to the table 1a、RbAnd Rc。
TABLE 1
The invention respectively calculates and obtains the effective value UA of the phase A voltage, the effective value UB of the phase B voltage, the effective value UC of the phase C voltage and the effective value IR of the lumped residual current of the power supply loop of the effectively grounded three-phase AC power distribution system by utilizing an instantaneous reactive power theory formula or an effective value definition formulaZCalculating the phase angle difference between the A-phase voltage signal and the lumped residual current signal of the power supply loop of the effectively grounded three-phase alternating current power distribution system by using an FFT (fast Fourier transform) method or a phase-locked amplification method
Lower limit alarm threshold R of insulation resistance in the invention0Can be preset in the singlechip module 6, and the lower limit alarm threshold R of the insulation resistance is set according to the actual working condition or the relevant national standard (for example, GB50303-2002 construction quality acceptance criterion for building electrical engineering)0The value of (a).
The delay time t can be preset in the single chip microcomputer module 6, the adjusting range is 0-30 s, and the delay time t can be set to any value in the adjusting range according to the using requirement.
The basic principles, main features and advantages of the present invention have been described through the above description and embodiments, and particularly, the essence of the apparatus and method of the present invention is shown in which effective values UA, UB and UC of voltages of phases of a power supply loop of an effectively grounded three-phase ac power distribution system are calculated through real-time acquisition, processing and calculation, and effective values IR of residual current of loops are lumpedZPhase angle difference between A-phase voltage signal and loop lumped residual current signal
Effective value IR of lumped residual current in on-line decomposition loopZExtracting effective values IRr of resistive residual current components of all phases which really represent insulation characteristics from all phasesa、IRrb、IRrcFurther, the earth-grounded insulation resistance R of each phase of the power supply loop of the effectively grounded three-phase AC distribution system is calculateda、Rb、RcR is to bea、Rb、RcRespectively connected with the lower limit alarm threshold R of the insulation resistance0Comparing, when any one of the three phases is smaller than R0When (i.e. when R isa<R0Or Rb<R0Or Rc<R0In the time), the insulation performance of the power supply loop of the effectively grounded three-phase alternating-current power distribution system is determined to be damaged, the ground short circuit fault and the potential electrical fire hazard exist, and the insulation performance damage phase is that the insulation resistance to ground is smaller than R0Phase line (i.e. when R isa<R0The insulation properties of the A phase are judged to be deteriorated, Rb<R0The insulation properties of the B phase are judged to be deteriorated, Rc<R0The insulation performance of the C phase is determined to be damaged), and an alarm instruction and a breaking control instruction are sent after the delay time t, so that effective and accurate online prevention and control of the grounding short circuit fault and the potential electrical fire caused by the reduction of the insulation performance of the cable and the load insulation layer and the reduction of the grounding insulation resistance value of the power supply loop of the effectively grounded three-phase alternating current power distribution system are realized. The practical application of the present invention is not limited to the above-mentioned embodiments, and the present invention may be changed and modified in various ways without departing from the scope of the present inventionAre intended to fall within the scope of the invention as defined by the claims appended hereto and their equivalents.
Claims (7)
1. An effectively grounded three-phase insulation type electric fire on-line prevention and control method is characterized in that based on an effectively grounded three-phase insulation type electric fire on-line prevention and control device, the effectively grounded three-phase insulation type electric fire on-line prevention and control device comprises a DSP unit (8), a singlechip module (6), a photoelectric coupler module (7), an alarm unit (10), a residual current signal conditioning circuit module (2), a voltage signal conditioning circuit module (4), a control output unit (11), a reset circuit module (5), a voltage signal detection module (3) for collecting phase voltage signals of an effectively grounded three-phase alternating current power distribution system power supply loop and a residual current signal detection module (1) for collecting lumped residual current signals of an effectively grounded three-phase alternating current power distribution system power supply loop;
the residual current signal detection module (1) is connected with the input end of the DSP unit (8) through the residual current signal conditioning circuit module (2), the voltage signal detection module (3) is connected with the input end of the DSP unit (8) through the voltage signal conditioning circuit module (4), the output end of the DSP unit (8) and the reset circuit module (5) are connected with the single chip microcomputer module (6), and the output end of the single chip microcomputer module (6) is connected with the alarm unit (10) and the control output unit (11) through the photoelectric coupler module (7);
the method comprises the following steps:
the voltage signal detection module (3) collects phase voltage signals of a power supply loop of the effectively grounded three-phase alternating current power distribution system, and the collected phase voltage signals of the power supply loop of the effectively grounded three-phase alternating current power distribution system are conditioned by the voltage signal conditioning circuit module (4) and then input into the DSP unit (8); meanwhile, the residual current signal detection module (1) collects lumped residual current signals of the power supply circuit of the effectively grounded three-phase alternating-current power distribution system, the collected lumped residual current signals of the power supply circuit of the effectively grounded three-phase alternating-current power distribution system are conditioned by the residual current signal conditioning circuit module (2) and then are input into the DSP unit (8), and the DSP unit (8) adjusts the circuit module according to the voltage signalCalculating effective values UA, UB and UC of voltages of each phase of the power supply loop of the effectively grounded three-phase alternating current power distribution system by using the voltage signals of each phase of the power supply loop of the effectively grounded three-phase alternating current power distribution system after being conditioned by the block (4); meanwhile, the effective value IR of the lumped residual current of the power supply loop of the effectively grounded three-phase alternating current power distribution system is calculated according to the lumped residual current signal of the power supply loop of the effectively grounded three-phase alternating current power distribution system conditioned by the residual current signal conditioning circuit module (2)ZAnd calculating the phase angle difference between the A-phase voltage signal in the power supply loop of the effectively grounded three-phase alternating current power distribution system and the lumped residual current signal in the power supply loop of the effectively grounded three-phase alternating current power distribution system
Then, the effective values UA, UB and UC of the voltages of all phases of the power supply loop of the effectively grounded three-phase alternating current power distribution system and the effective value IR of the lumped residual current of the power supply loop of the effectively grounded three-phase alternating current power distribution system obtained by calculation are comparedZAnd the phase angle difference between the A-phase voltage signal in the power supply loop of the effectively grounded three-phase alternating-current power distribution system and the lumped residual current signal in the power supply loop of the effectively grounded three-phase alternating-current power distribution system
Sending the data to the singlechip module (6);
the singlechip module (6) effectively grounds the effective values UA, UB and UC of the voltages of the phases of the power supply circuit of the three-phase alternating current power distribution system and the effective value IR of the lumped residual current of the power supply circuit of the three-phase alternating current power distribution system according to the effective values UA, UB and UC of the voltages of the phases of the power supply circuit of the three-phase alternating current power distribution systemZAnd the phase angle difference between the A-phase voltage signal in the power supply loop of the effectively grounded three-phase alternating-current power distribution system and the lumped residual current signal in the power supply loop of the effectively grounded three-phase alternating-current power distribution system
Effective value IR of lumped residual current of power supply circuit of effectively grounded three-phase alternating-current power distribution systemZDecomposing the phase of the power supply loop of the effectively grounded three-phase alternating current power distribution system, and extracting the resistance of each phase of the power supply loop of the effectively grounded three-phase alternating current power distribution systemEffective value IRr of a sexual residual current componenta、IRrb、IRrcThen, calculating the relative grounding insulation resistance R of the power supply loop of the effectively grounded three-phase AC distribution systema、RbAnd RcFinally, the relative grounding insulation resistors R of the power supply loop of the effectively grounded three-phase alternating current distribution systema、RbAnd RcAnd insulation resistance lower limit alarm threshold R0By comparison, when R isa≥R0、Rb≥R0And Rc≥R0When the system is in operation, the effective grounding three-phase alternating current distribution system is determined to have good insulation performance of a power supply loop and no grounding short circuit fault or potential electrical fire hazard danger, and when R is in operationa<R0Or Rb<R0Or Rc<R0When the alarm unit (10) carries out acousto-optic alarm according to the alarm instruction, the control output unit (11) cuts off the power supply loop of the effectively grounded three-phase alternating-current power distribution system according to the cutting-off control instruction;
when in use
Then effectively grounding the effective value IRr of the resistive residual current of the C phase of the power supply loop of the three-phase alternating current power distribution systemcNeglecting to be 0, and effectively grounding the effective value IR of the lumped residual current of the power supply circuit of the three-phase alternating current distribution systemZDecomposing the residual current into A phase and B phase of the power supply loop of the effectively grounded three-phase alternating current power distribution system to obtain effective value IRr of the resistive residual current component of the A phase and the B phase of the power supply loop of the effectively grounded three-phase alternating current power distribution systema、IRrb(ii) a When in use
Then effectively grounding the effective value IRr of the resistive residual current of the A phase of the power supply loop of the three-phase alternating current distribution systemaNeglecting to be 0, and effectively grounding the effective value IR of the lumped residual current of the power supply circuit of the three-phase alternating current distribution systemZDecomposing the residual current into B phase and C phase of the power supply loop of the effectively grounded three-phase alternating current power distribution system to obtain effective values IRr of the resistive residual current components of the B phase and the C phase of the power supply loop of the effectively grounded three-phase alternating current power distribution systemb、IRrc(ii) a When in use
Then effectively grounding the effective value IRr of the resistive residual current of the B phase of the power supply loop of the three-phase alternating current power distribution systembNeglecting to be 0, and effectively grounding the effective value IR of the lumped residual current of the power supply circuit of the three-phase alternating current distribution systemZDecomposing the residual current into the A phase and the C phase of the power supply loop of the effectively grounded three-phase alternating current power distribution system to obtain the effective value IRr of the resistive residual current component of the A phase and the C phase of the power supply loop of the effectively grounded three-phase alternating current power distribution systema、IRrcFurther, the relative grounding insulation resistance R of the power supply loop of the three-phase AC distribution system can be effectively groundeda、RbAnd Rc；
Relative grounding insulation resistance R of power supply loop of effectively grounded three-phase alternating current power distribution systema、RbAnd RcComprises the following steps:
when in use
When in use
When in use
2. The effectively grounded three-phase insulation type electric fire on-line prevention and control method as claimed in claim 1, wherein 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.
3. The effectively grounded three-phase insulation type electric fire on-line prevention and control method as claimed in claim 1, wherein 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.
4. The effectively grounded three-phase insulation type electric fire on-line prevention and control method as claimed in claim 1, further comprising an ethernet communication unit (9) for connecting external equipment, wherein the ethernet communication unit (9) is connected with the single chip module (6).
5. The method for on-line prevention and control of effectively grounded three-phase insulation type electrical fire according to claim 1, wherein the residual current signal detection module (1) is a residual current transformer installed in the effectively grounded three-phase AC distribution system power supply loop, wherein the A-phase, B-phase, C-phase and N-phase cables in the effectively grounded three-phase AC distribution system power supply loop pass through the residual current transformer;
the voltage signal detection module (3) is a voltage transformer.
6. The method of claim 1, wherein R is the time when R is reacheda<R0When the current is in the zero-phase voltage range, the insulation performance of the phase A of the power supply loop of the effectively grounded three-phase alternating current power distribution system is determined to be damaged; when R isb<R0When the effective grounding three-phase alternating current power distribution system is in a state of being damaged, the insulation performance of the phase B of the power supply loop of the effective grounding three-phase alternating current power distribution system is determined to be damaged; when R isc<R0And when the voltage is higher than the set voltage, the insulation performance of the C phase of the power supply loop of the effectively grounded three-phase alternating current power distribution system is determined to be damaged.
7. The on-line protection and control method for effectively grounded three-phase insulation type electric fire as claimed in claim 1, wherein the calculation of the effectively grounded three-phase is performed by FFT or phase-locked amplificationPhase angle difference between A-phase voltage signal in AC distribution system supply loop and lumped residual current signal of effectively grounded three-phase AC distribution system supply loop
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811512081.8A CN109856509B (en) | 2018-12-11 | 2018-12-11 | Effectively-grounded three-phase insulation type electric fire online prevention and control device and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811512081.8A CN109856509B (en) | 2018-12-11 | 2018-12-11 | Effectively-grounded three-phase insulation type electric fire online prevention and control device and method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109856509A CN109856509A (en) | 2019-06-07 |
| CN109856509B true CN109856509B (en) | 2021-08-17 |
Family
ID=66890958
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811512081.8A Active CN109856509B (en) | 2018-12-11 | 2018-12-11 | Effectively-grounded three-phase insulation type electric fire online prevention and control device and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109856509B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110208627B (en) * | 2019-06-20 | 2021-06-25 | 应急管理部四川消防研究所 | Method for testing fire prevention and control capability of over-current ignition source prevention and control device |
| KR20210024921A (en) | 2019-08-26 | 2021-03-08 | 삼성전자주식회사 | Cooking apparatus and controlling method thereof |
| CN111337752B (en) * | 2020-03-12 | 2022-05-10 | 鲁东大学 | Power cable insulation resistance to ground on-line detection system and application thereof |
| CN111768599B (en) * | 2020-07-08 | 2021-08-10 | 安徽先兆科技有限公司 | AC380V loop electric safety control method and system |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE202004008334U1 (en) * | 2004-05-25 | 2004-09-02 | Geb, Nikolaus | Wall outlet socket fitting strip for portable electrical operating devices has an in-built differential current meter for measuring earth conductor current and contact-voltage current |
| CN202025406U (en) * | 2011-05-19 | 2011-11-02 | 淮阴师范学院 | Residual current type electric fire monitoring detector |
| CN102354427A (en) * | 2011-09-27 | 2012-02-15 | 赵怀军 | method and device for flexibly identifying residual current-type electrical fire on line |
| CN103489277A (en) * | 2013-09-26 | 2014-01-01 | 胡亨华 | Fire early-warning system used for monitoring resistance parameters of electrical circuit online |
| CN107179492A (en) * | 2017-07-03 | 2017-09-19 | 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 |
-
2018
- 2018-12-11 CN CN201811512081.8A patent/CN109856509B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE202004008334U1 (en) * | 2004-05-25 | 2004-09-02 | Geb, Nikolaus | Wall outlet socket fitting strip for portable electrical operating devices has an in-built differential current meter for measuring earth conductor current and contact-voltage current |
| CN202025406U (en) * | 2011-05-19 | 2011-11-02 | 淮阴师范学院 | Residual current type electric fire monitoring detector |
| CN102354427A (en) * | 2011-09-27 | 2012-02-15 | 赵怀军 | method and device for flexibly identifying residual current-type electrical fire on line |
| CN103489277A (en) * | 2013-09-26 | 2014-01-01 | 胡亨华 | Fire early-warning system used for monitoring resistance parameters of electrical circuit online |
| CN107179492A (en) * | 2017-07-03 | 2017-09-19 | 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 |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109856509A (en) | 2019-06-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109856509B (en) | Effectively-grounded three-phase insulation type electric fire online prevention and control device and method | |
| US10931094B2 (en) | Method for detecting an open-phase condition of a transformer | |
| US5659453A (en) | Arc burst pattern analysis fault detection system | |
| CN105891680A (en) | 10kV distribution line multiphase disconnection fault determination method based on three-phase voltage and current | |
| CN105866615A (en) | 10kV power distribution line disconnection fault judging method based on three-phase voltage current | |
| US11143715B2 (en) | Broken conductor detection in a multiple-phase electric power delivery system | |
| WO2008077942A1 (en) | System and method to determine the impedance of a disconnected electrical facility | |
| CN108132425A (en) | Power grid distribution line failure on-line monitoring method and system | |
| CN111474494B (en) | High-resistance grounding fault detection method and device of small-resistance grounding system | |
| CN104577999B (en) | Bus bar protecting method and system based on transient zero-sequence current feature | |
| CN101718813B (en) | Method for monitoring voltage acquisition circuit of electric power secondary system | |
| RU2356151C1 (en) | METHOD FOR AUTOMATIC CONTROL OF 0,4 kV OVERHEAD LINE NEUTRAL WIRE | |
| Li et al. | A review of techniques to detect downed conductors in overhead distribution systems | |
| CN201181321Y (en) | Earthing detection circuit of locomotive control circuit | |
| CN110320432A (en) | Single-phase wire break fault detection and guard method and system | |
| CN104090211B (en) | A kind of online test method of distribution line high resistance earthing fault | |
| Han et al. | Fault location on a mixed overhead and underground transmission feeder using a multiple-zone quadrilateral impedance relay and a double-ended travelling wave fault locator | |
| CN113075577A (en) | Residual current monitoring system and method for low-voltage alternating-current power supply system | |
| CN104062555A (en) | Identification method for distributing line high-resistance ground fault feature harmonic waves | |
| Dhakulkar et al. | Inspection of Voltage Sags and Voltage Swells Incident in Power Quality Problems—A Review | |
| CN109038517B (en) | Single-phase insulation type electric fire on-line prevention and control device and method | |
| CN108051693A (en) | A kind of method of the raising earth fault judgment accuracy based on TAS devices | |
| CN114498552A (en) | Residual current-based low-voltage power distribution network leakage protection method | |
| CN108666985B (en) | Accurate diagnosis and protection method for power frequency overvoltage of power transmission line | |
| CN116047355B (en) | Grounding transformer operation condition on-line detection method based on high-voltage side current signal |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |