CN114527329A - Fill electric pile ground resistance detection circuitry - Google Patents

Fill electric pile ground resistance detection circuitry Download PDF

Info

Publication number
CN114527329A
CN114527329A CN202011320115.0A CN202011320115A CN114527329A CN 114527329 A CN114527329 A CN 114527329A CN 202011320115 A CN202011320115 A CN 202011320115A CN 114527329 A CN114527329 A CN 114527329A
Authority
CN
China
Prior art keywords
voltage
charging pile
line
dividing resistor
acquisition module
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
Application number
CN202011320115.0A
Other languages
Chinese (zh)
Inventor
冯君浩
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hanyu Group JSCL
Original Assignee
Hanyu Group JSCL
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hanyu Group JSCL filed Critical Hanyu Group JSCL
Priority to CN202011320115.0A priority Critical patent/CN114527329A/en
Publication of CN114527329A publication Critical patent/CN114527329A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
    • G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
    • G01R27/20—Measuring earth resistance; Measuring contact resistance, e.g. of earth connections, e.g. plates
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02T90/10—Technologies relating to charging of electric vehicles
    • Y02T90/12—Electric charging stations

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)

Abstract

The utility model provides a fill electric pile ground resistance detection circuitry, it inserts alternating current network to fill electric pile, it includes to fill electric pile ground resistance detection circuitry: the first voltage acquisition module is connected in series between a phase line of the alternating-current power grid and a phase line inlet end of the charging pile and used for acquiring the voltage of the phase line inlet end of the charging pile; the second voltage acquisition module is connected in series between a zero line of the alternating current power grid and a zero line incoming line end of the charging pile and used for acquiring the voltage of the zero line incoming line end of the charging pile; and the judging module is connected with the first voltage acquiring module and the second voltage acquiring module respectively and used for calculating the grounding resistance of the charging pile according to the voltage of the incoming line end of the phase line and the voltage of the incoming line end of the zero line and judging whether the grounding condition is abnormal or not. The invention improves the internal circuit of the charging pile, provides a simple and feasible grounding resistance measuring method with wide application value, and solves the technical problem that the conventional grounding resistance measuring method is inconvenient to implement.

Description

Fill electric pile ground resistance detection circuitry
Technical Field
The invention relates to the technical field of alternating current charging piles of electric vehicles, in particular to a charging pile ground resistance detection circuit, wherein IPC (International patent Classification) belongs to G01R 31/02.
Background
Whether the grounding is good or not is usually characterized by a grounding resistance, and a grounding resistance meter is usually adopted for measuring the grounding resistance. When the grounding resistance is measured, three points are usually selected on a grounding surface, the three points are generally required to be separated by 20m, and then the grounding resistance is measured by operating according to an operation method of a grounding resistance meter. In ac pile applications, the current measurement method is to select two suitable grounding points around the building and insert the probes of the grounding resistance meter into a depth of at least 40cm, and then measure the grounding resistance. However, in practical application, engineers find that in most cases, the measurement mode is limited by a plurality of objective factors, so that the measurement method is difficult to implement or even impossible to implement.
For terms and common knowledge, refer to the mechanical engineering handbook and the electromechanical engineering handbook, published in 1983 or 1997 of mechanical industry Press.
Disclosure of Invention
In order to solve the technical problem that the existing ground resistance measuring method is inconvenient to implement, the invention improves the internal circuit of the charging pile, provides a charging pile ground resistance detecting circuit which is simple, feasible and has wide application value, and the charging pile is connected to an alternating current power grid, and is characterized in that the charging pile ground resistance detecting circuit comprises:
the first voltage acquisition module is connected between a phase line of the alternating-current power grid and a phase line inlet end of the charging pile in series and used for acquiring a voltage signal of the phase line inlet end of the charging pile;
the second voltage acquisition module is connected in series between a zero line of the alternating current power grid and a zero line incoming line end of the charging pile and used for acquiring a voltage signal of the zero line incoming line end of the charging pile;
and the judging module is connected with the first voltage acquiring module and the second voltage acquiring module respectively and used for calculating the grounding resistance of the charging pile according to the voltage of the incoming line end of the phase line and the voltage of the incoming line end of the zero line and judging whether the grounding condition is abnormal or not.
Specifically, the first voltage obtaining module includes a first voltage dividing resistor, a second voltage dividing resistor, and a first voltage follower, where the first voltage dividing resistor is connected in series between a phase line of the ac power grid and a non-inverting input terminal of the first voltage follower; one end of the second voltage-dividing resistor is connected to the non-inverting input end of the first voltage follower, and the other end of the second voltage-dividing resistor is connected to a reference ground; the reverse phase input end of the first voltage follower is directly connected with the output end of the first voltage follower, and the output end of the first voltage follower is connected to the phase line inlet end of the charging pile; the first voltage acquisition module acquires a voltage signal of a phase line incoming line of the charging pile so as to acquire a voltage of a second voltage dividing resistor.
Specifically, the second voltage obtaining module includes a third voltage dividing resistor, a fourth voltage dividing resistor, and a second voltage follower, where the third voltage dividing resistor is connected in series between a zero line of the ac power grid and a non-inverting input end of the second voltage follower; one end of the fourth voltage-dividing resistor is connected to the non-inverting input end of the second voltage follower, and the other end of the fourth voltage-dividing resistor is connected to the reference ground; the reverse phase input end of the second voltage follower is directly connected with the output end of the second voltage follower, and the output end of the second voltage follower is connected to the zero line inlet end of the charging pile; the second voltage obtaining module obtains a voltage of a fourth voltage-dividing resistor by obtaining a voltage signal of a zero line incoming line of the charging pile.
Specifically, the first voltage acquisition module and the second voltage acquisition module are arranged in a mirror image mode.
Specifically, when the judging module calculates the grounding resistance of the charging pile according to the voltage of the inlet wire end of the phase wire and the voltage of the inlet wire end of the zero wire,
according to the formula
Figure BDA0002792624020000021
Calculating the grounding resistance RPE，
Wherein, U1For the voltage value of the voltage signal at the end of the phase line incoming line, U2For the voltage value of the voltage signal at the inlet wire end of the zero line, R1Is the first divider resistor, R2Is the second divider resistor.
Specifically, when the determining module determines whether the grounding condition is abnormal,
if the grounding resistance RPEIf the grounding condition is less than or equal to a first preset threshold value, judging that the grounding condition is not abnormal;
if the grounding resistance RPEIf the grounding condition is larger than or equal to a second preset threshold value, judging that the grounding condition is abnormal;
preferably, the second preset threshold is at least 100 times the first preset threshold.
The invention has the following beneficial effects:
(1) the charging pile ground resistance detection circuit is arranged inside the charging pile, does not need complex site construction treatment, and can be widely suitable for the practical application scene of the power grid in China.
(2) The charging pile ground resistance detection circuit can continuously calculate and obtain the ground resistance in the normal operation process of the charging pile through the charging pile phase line inlet end voltage and the zero line inlet end voltage obtained through detection and preset circuit element parameters, so that the charging pile ground resistance measurement method is simple and feasible.
Drawings
FIG. 1 is a circuit schematic of the present invention;
FIG. 2 is a simplified circuit schematic of the circuit of the present invention in an ideal situation;
FIG. 3 is a simplified circuit schematic of the circuit of the present invention in actual practice;
fig. 4 is an equivalent circuit schematic diagram of the circuit of the present invention in an actual situation.
Detailed Description
In order to make the technical solutions of the present invention better understood by those skilled in the art, 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.
As shown in fig. 1, charging pile is connected to an ac power grid, and the charging pile ground resistance detection circuit provided in this embodiment includes a first voltage acquisition module, a second voltage acquisition module, and a determination module. The first voltage acquisition module is connected in series between a phase line L of the alternating current power grid and a phase line inlet end D1 of the charging pile and used for acquiring a voltage signal of the phase line inlet end of the charging pile; the second voltage acquisition module is connected in series between a zero line N of the alternating current power grid and a zero line incoming line end D2 of the charging pile and is used for acquiring a voltage signal of the zero line incoming line end of the charging pile; the judging module is respectively connected with the first voltage obtaining module and the second voltage obtaining module and used for judging the voltage value U of the voltage signal at the inlet wire end of the phase wire according to the voltage value U of the voltage signal at the inlet wire end of the phase wire1Voltage value U of voltage signal at inlet wire end of neutral wire2Calculate fill ground resistance R of electric pilePEAnd judging whether the grounding condition is abnormal.
Specifically, the first voltage acquisition module comprises a first voltage dividing resistor R1A second voltage dividing resistor R2And a first voltage follower A1, the first divided voltageResistance R1The first voltage follower A1 is connected between the phase line L of the alternating current power grid and the non-inverting input end of the first voltage follower A1 in series; the second voltage-dividing resistor R2One end of the first voltage follower A1 is connected to the non-inverting input end of the first voltage follower A1, and the other end of the first voltage follower A1 is connected to the reference ground GND; the inverting input end of the first voltage follower A1 is directly connected with the output end thereof, and the output end is connected to the phase line inlet end D1 of the charging pile. The second voltage acquisition module comprises a third voltage dividing resistor R3A fourth voltage dividing resistor R4And a second voltage follower A2, the third voltage dividing resistor R3The zero line N is connected between the zero line N of the alternating current power grid and the non-inverting input end of the second voltage follower A2 in series; the fourth voltage dividing resistor R4One end of the first voltage follower is connected to the non-inverting input end of the second voltage follower A2, and the other end of the first voltage follower is connected to the reference ground GND; and the inverting input end of the second voltage follower A2 is directly connected with the output end thereof, and the output end is connected to the zero line incoming line end D2 of the charging pile.
The first voltage acquisition module and the second voltage acquisition module are arranged in a mirror image mode, so that the first divider resistor R1And a third voltage dividing resistor R3The resistance value of (2) is 9.6M omega, and the second divider resistor R2And a fourth voltage dividing resistor R4The same resistance value of (1) is 18K omega, and the first voltage follower and the second voltage follower are the operational amplifier of model TL082 IDT.
Since the input end voltage and the output end voltage of the voltage follower are equal, the voltage U at the inlet wire end of the phase wire obtained by the first voltage obtaining module1Is equal to the second voltage-dividing resistor R2Voltage U onR2(ii) a Similarly, the zero line incoming line terminal voltage U obtained by the second voltage obtaining module2Equal to the fourth voltage dividing resistor R4Voltage U onR4。
The judgment module acquires the signal voltage value U of the detected phase line inlet end1Zero line inlet end signal voltage value U2And a preset first divider resistance R1A second voltage dividing resistor R2A third voltage dividing resistor R3And a fourth voltage dividing resistor R4After resistance value of (1), according to the following algorithmFill inside resistance to protection ground PE of electric pile, ground resistance R promptlyPEAnd (4) calculating the numerical value of (1).
The voltage of a phase line L of an alternating current power grid relative to a protection ground PE is set to be ULThe voltage of the zero line N of the alternating current network relative to the protection ground PE is UN. As shown in fig. 2, in an ideal situation, the potentials of the neutral line N, the protective ground PE and the reference ground GND of the ac power network are equal and zero, so that U is equal to ULAnd UNAnd the signal voltage value U of the inlet end of the phase line1Signal voltage value U of inlet wire end of neutral wire2The following relationships exist:
U1＝UR2＝UL·R2/(R1+R2)…………①
U2＝UR4＝UN·R4/(R3+R4)＝UN·R2/(R1+R2)…………②
therefore, the voltage difference Δ U between the phase line L and the neutral line N is:
ΔU＝UL-UN＝(U1-U2)·(R1+R2)/R2
and because of UN＝UPE＝UGND0, so Δ U equals UL。
However, in practical situations, as shown in fig. 3, the potential of the ground reference GND is usually not zero, which is equivalent to a ground resistor R connected in series between the ground reference GND and the protection ground PEPE。
Let the equivalent resistance of reference ground GND to protection ground PE be RLThen there is
Figure BDA0002792624020000031
At this time, the above formula is changed to
Figure BDA0002792624020000032
Is changed into
Figure BDA0002792624020000033
Since the potentials of the neutral line N and the protection ground PE are equal, an equivalent circuit is shown in fig. 4, and the voltage difference Δ U' between the phase line L and the neutral line N is:
Figure BDA0002792624020000034
vertical combination of formula (III), (IV) and (IV)
Figure BDA0002792624020000035
The judgment module calculates to obtain the grounding resistance RPEAfter that, according to the ground resistance RPEThe preset value range judges whether the grounding condition is abnormal or not,
if the grounding resistance RPEAnd if the grounding condition is less than or equal to a first preset threshold, judging that the grounding condition is not abnormal, wherein the first preset threshold is selected to be 1K omega.
If the grounding resistance RPEAnd if the grounding condition is larger than or equal to a second preset threshold, judging that the grounding condition is abnormal, wherein the second preset threshold is selected to be 100K omega.
If the first preset threshold value and the second preset threshold value are too close to each other, the grounding resistance R is causedPEThe calculation result fluctuates under the influence of electromagnetic interference or other practical factors, the judgment of the grounding state of the charging pile by the judgment module can drift between abnormal and non-abnormal states, so that the second preset threshold is at least 100 times of the first preset threshold, the difference between the two value ranges is obvious enough, and the possibility of misjudgment by the judgment module is reduced.
The charging pile utilizes the internal circuit to detect the grounding resistance, and quickly and accurately judges whether the grounding condition of the charging pile is abnormal or not, so that the measurement of the grounding resistance of the charging pile becomes simple and feasible, and the complicated field construction treatment is not needed, so that the charging pile can be more widely suitable for the practical application scene of the power grid in China.
Although embodiments of the present invention have been shown and described, it is understood that the above embodiments are exemplary and not to be construed as limiting the present invention, and that changes, modifications, substitutions and alterations can be made in the above embodiments by one of ordinary skill in the art within the scope of the present invention.

Claims (3)

1. The utility model provides a fill electric pile ground resistance detection circuitry, it inserts alternating current network to fill electric pile, its characterized in that, it includes to fill electric pile ground resistance detection circuitry:
the first voltage acquisition module is connected between a phase line of the alternating-current power grid and a phase line inlet end of the charging pile in series and used for acquiring a voltage signal of the phase line inlet end of the charging pile;
the second voltage acquisition module is connected in series between a zero line of the alternating current power grid and a zero line incoming line end of the charging pile and used for acquiring a voltage signal of the zero line incoming line end of the charging pile;
the judging module is connected with the first voltage acquiring module and the second voltage acquiring module respectively and used for calculating the grounding resistance of the charging pile according to the voltage of the inlet wire end of the phase wire and the voltage of the inlet wire end of the zero wire and judging whether the grounding condition is abnormal or not;
the first voltage acquisition module and the second voltage acquisition module are arranged in a mirror image mode:
the first voltage acquisition module comprises a first voltage-dividing resistor, a second voltage-dividing resistor and a first voltage follower, wherein the first voltage-dividing resistor is connected in series between a phase line of the alternating-current power grid and a non-inverting input end of the first voltage follower; one end of the second voltage-dividing resistor is connected to the non-inverting input end of the first voltage follower, and the other end of the second voltage-dividing resistor is connected to a reference ground; the reverse phase input end of the first voltage follower is directly connected with the output end of the first voltage follower, and the output end of the first voltage follower is connected to the phase line inlet end of the charging pile; the first voltage acquisition module acquires a voltage signal of a phase line incoming line of the charging pile to acquire a voltage of a second divider resistor;
the second voltage acquisition module comprises a third voltage dividing resistor, a fourth voltage dividing resistor and a second voltage follower, wherein the third voltage dividing resistor is connected in series between a zero line of the alternating current power grid and a non-inverting input end of the second voltage follower; one end of the fourth voltage-dividing resistor is connected to the non-inverting input end of the second voltage follower, and the other end of the fourth voltage-dividing resistor is connected to the reference ground; the reverse phase input end of the second voltage follower is directly connected with the output end of the second voltage follower, and the output end of the second voltage follower is connected to the zero line inlet end of the charging pile; the second voltage acquisition module acquires a voltage of a fourth voltage-dividing resistor by acquiring a voltage signal of a zero line incoming line of the charging pile;
when the judging module calculates the grounding resistance of the charging pile according to the voltage of the inlet wire end of the phase wire and the voltage of the inlet wire end of the zero wire,
according to the formula
Figure FDA0002792624010000011
Calculating the grounding resistance RPE，
Wherein, U1For the voltage value of the voltage signal at the end of the phase line incoming line, U2For the voltage value of the voltage signal at the inlet wire end of the zero line, R1Is the first divider resistor, R2Is the second divider resistor.
2. The charging pile ground resistance detection circuit according to claim 1, wherein the determination module determines that the ground condition is not abnormal if the ground resistance is less than or equal to a first preset threshold when determining whether the ground condition is abnormal; and if the grounding resistance is larger than or equal to a second preset threshold value, judging that the grounding condition is abnormal.
3. The charging pile ground resistance detection circuit of claim 2, wherein the second predetermined threshold is at least 100 times the first predetermined threshold.
CN202011320115.0A 2020-11-23 2020-11-23 Fill electric pile ground resistance detection circuitry Pending CN114527329A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011320115.0A CN114527329A (en) 2020-11-23 2020-11-23 Fill electric pile ground resistance detection circuitry

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011320115.0A CN114527329A (en) 2020-11-23 2020-11-23 Fill electric pile ground resistance detection circuitry

Publications (1)

Publication Number Publication Date
CN114527329A true CN114527329A (en) 2022-05-24

Family

ID=81619764

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011320115.0A Pending CN114527329A (en) 2020-11-23 2020-11-23 Fill electric pile ground resistance detection circuitry

Country Status (1)

Country Link
CN (1) CN114527329A (en)

Similar Documents

Publication Publication Date Title
CN116879662A (en) Transformer fault detection method based on data analysis
CN107907832B (en) Metering instrument battery residual capacity calculation method
CN107632281B (en) Measurement and control method of automatic wiring detection instrument of three-phase three-wire metering device
CN104991110A (en) Voltage abnormity detection method and device for single phase alternating current power supply
CN103033667B (en) Current measurement device and method
CN105842540A (en) Method for detecting DC bus insulation resistance
CN110275082B (en) Grounding diagnosis method, system and device for main circuit of converter
CN109828173A (en) A kind of load-detecting system and its load detection method
CN103969614A (en) Calibration method for digital multimeter
CN103454479B (en) Signal generating apparatus, determinator, earth detector and signal creating method
CN105606908B (en) The detection method and detection device of three-phase circuit open-phase fault
CN204730958U (en) NTC temperature sensor thermal time constant proving installation
CN111707867B (en) Alternating current measuring method and device, electronic equipment and storage medium
CN109933883A (en) A kind of current in resistance property Growth Rate Calculation method based on multiple linear regression
CN117783658A (en) Current digital measurement method for power equipment
CN214473622U (en) Fill electric pile ground resistance detection circuitry
CN114527329A (en) Fill electric pile ground resistance detection circuitry
CN101210943A (en) Method for measuring grounding insulation resistance of electric power DC system
CN109341814A (en) A kind of all the period of time water level collection system and method
CN108957174A (en) A kind of voltage dip detection device and method
CN106645930A (en) Three-phase four-wire electric energy metering device having null line missing detection function
CN211955708U (en) Capacitor implosion detection circuit
CN110658414B (en) Power electronic parametric fault detection method based on model
CN107870298B (en) Circuit parameter detection circuit and method of voltage dividing circuit and electric energy meter
CN106546837A (en) Constant pressure water supply is without flow sleep detection method

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