CN107643449A - Detection circuit and detection method of the high pressure to the insulaion resistance of low pressure - Google Patents

Abstract

A kind of detection circuit of high pressure to the insulaion resistance of low pressure, including：With the first detection circuit, the in parallel with the second insulaion resistance second detection circuit and acquisition module that the first insulaion resistance is connected in parallel, the first detection circuit includes：First circuit resistor bridge group, the first sampling resistor, the second detection circuit include：Second circuit resistor bridge group, the second sampling resistor, the first sampling resistor access low-pressure end, the relative other end access low-pressure end being connected with second circuit resistor bridge group of the second sampling resistor with respect to the other end of the first circuit resistor bridge group；First circuit resistor bridge group or variable resistor group that second circuit resistor bridge group is resistance value changeable terminals or first, second resistance group are variable resistor group；Detection circuit and detection method of the above-mentioned high pressure to the insulaion resistance of low pressure, directly just detect that reality is total just over the ground, total negative actual resistance over the ground, detection is segmented independent of pattern, Standard resistance range has continuity, is more nearly with the situation of reality.

Description

Detection circuit and detection method of the high pressure to the insulaion resistance of low pressure

Technical field

The present invention relates to one kind to detect circuit, more particularly to a kind of to be used to detect high pressure to the insulaion resistance resistance of low pressure Detect circuit and detection method.

Background technology

The detection of existing insulaion resistance is sampled using the sampling module with isolation to insulaion resistance mostly, is isolated Cheng Zhong, the EMI that isolating device is brought have a great influence.Some are sampled using the AD sampling A/D chips of low precision to it, so meeting Cause accuracy of detection low；, again or using resistance bridge single-point sample mode, such detection mode, calculating process is complicated, single for some Load factor is excessive in piece machine calculating process, and the result stability of detection is poor, is easily disturbed by external signal；Or using hypothesis insulation The mode of failure carries out sample detecting, and the Standard resistance range that so can cause to detect again has limitation, discontinuously.

The content of the invention

Based on this, it is necessary to provide a kind of energy and improve to the high pressure of the detection accuracy of insulaion resistance to be measured to the exhausted of low pressure The detection circuit of edge resistance.

Simultaneously, there is provided a kind of to improve to the high pressure of the detection accuracy of insulaion resistance to be measured to the insulaion resistance of low pressure Detection method.

A kind of detection circuit of high pressure to the insulaion resistance of low pressure, including：Between high-voltage power cathode and low-pressure end The second insulaion resistance between the first detection circuit and high voltage power supply negative pole and low-pressure end that first insulaion resistance is connected in parallel is simultaneously The the second detection circuit and acquisition module of connection, the first detection circuit include：First circuit resistor bridge group and with described One circuit resistor bridge group is connected or disconnects and the first sampling resistor of its voltage is gathered by the acquisition module, second detection Circuit includes：Second circuit resistor bridge group and connect or disconnect and by the acquisition module with the second circuit resistor bridge group Gather the second sampling resistor of its voltage, the relative another termination being connected with the first circuit resistor bridge group of first sampling resistor Enter low-pressure end, the relative other end access low-pressure end being connected with the second circuit resistor bridge group of second sampling resistor；Institute State the first circuit resistor bridge group or second circuit resistor bridge group variable resistor group or first, second resistance group for resistance value changeable terminals For variable resistor group.

In a preferred embodiment, the first circuit resistor bridge group or second circuit resistor bridge group are to be switched by setting Closure or disconnection change the variable resistor group of access resistance value to change detection circuit for access resistance.

In a preferred embodiment, the first circuit resistor bridge group or second circuit resistor bridge group include：Fixed access Resistance and variable access or the regulation resistance being switched in or out as needed.

In a preferred embodiment, the low-pressure end is earth terminal, and the first circuit resistor bridge group includes：One or more Individual first fixes access resistance, one or more first regulation resistances and is connected in parallel on the first regulation resistance both ends and basis The the first test switch for needing to be closed or disconnecting；The second circuit resistor bridge group includes：One or more second is fixed Access resistance, one or more second regulation resistances and be connected in parallel on the second regulation resistance both ends and closed as needed The the second test switch for closing or disconnecting.

In a preferred embodiment, the first fixation access resistance is identical with the second fixation access resistance setting, First regulation resistance is identical with the second adjusting resistance values setting, first sampling resistor and the second sampling resistor resistance Set identical.

In a preferred embodiment, the acquisition module is provided with two-way and transmits the first sampling electricity respectively using differential signal Resistance, the difference analogue data acquisition channel of the second sampling resistor collection transmission data, the electric current of the detection circuit are equal to or small In 3mA, the first fixation access resistance is resistance R1, and first regulation resistance is resistance R2, and described second fixes access Resistance is resistance R3, and second regulation resistance is resistance R4, the R1=R2, R3=R4.

In a preferred embodiment, between the first circuit resistor bridge group and the first sampling resistor or it is described second electricity High and low voltage isolation switch is provided between road and bridge resistance group and the second sampling resistor.

A kind of high pressure to the detection method of the insulaion resistance of low pressure, including：

Obtain the electric current of the first detection circuit：Detection circuit is connected, gathers the voltage of the first sampling resistor, according to the first collection electricity The voltage and resistance of resistance solve the electric current of the first collection resistance, so as to obtain the first sampling resistor and the first circuit resistor bridge group string The electric current for the first detection circuit that connection connection is formed；

The electric current of first insulaion resistance represents：The first detection electricity is solved according to the resistance sizes of the first detection circuit and electric current Road voltage, so as to obtain and the first detection circuit in parallel is connected and is connected to be measured between high-voltage power cathode and low-pressure end The first insulaion resistance voltage, the electricity of the first insulaion resistance is represented according to the voltage of the first insulaion resistance and resistance formula Stream；

Obtain the electric current of the second detection circuit：The voltage of the second sampling resistor is gathered, according to the voltage and electricity of the second collection resistance Resistance solves the electric current of the second collection resistance, is connected in series to form so as to obtaining the second sampling resistor and second circuit resistor bridge group The electric current of second detection circuit；

The electric current of second insulaion resistance represents：The second detection electricity is solved according to the resistance sizes of the second detection circuit and electric current Road voltage, so as to obtain and the second detection circuit in parallel is connected and is connected to be measured between high voltage power supply negative pole and low-pressure end The second insulaion resistance voltage, the electricity of the second insulaion resistance is represented according to the voltage of the second insulaion resistance and resistance formula Stream；

List expression formula：Second detection circuit is equal to according to the electric current sum of the electric current of the first detection circuit and the first insulaion resistance Electric current and the electric current sum of the second insulaion resistance list the solution equation comprising the first insulaion resistance and the second insulaion resistance；

Change detection circuit resistance：Change the resistance or second circuit resistor bridge group resistance of the first circuit resistor bridge group,

Detection circuit according to resistance is changed performs following steps：

Obtain the current step of the first detection circuit, the electric current of the first insulaion resistance represents step, obtains the second detection circuit Current step, the electric current of the second insulaion resistance represent step, list expression formula step；

Simultaneous equations solve:The different detected values for detecting and being obtained before and after circuit resistance according to changing, and the electricity of the first detection circuit The electric current sum of stream and the first insulaion resistance is equal to the electric current of the second detection circuit and the electric current sum equation of the second insulaion resistance Two obtained solve equation expression formula comprising the first insulaion resistance and the different of the second insulaion resistance, and simultaneous obtains the first equation Group, solution the first insulaion resistance to be measured, the resistance of the second insulaion resistance.

In a preferred embodiment, in addition to：Change detection circuit resistance again：Change the resistance of the first circuit resistor bridge group Value or second circuit resistor bridge group resistance or first, second circuit resistor bridge group resistance of change,

According to the detection circuit for changing resistance again, following steps are performed：

Obtain the electric current of the first detection circuit, the electric current of the first insulaion resistance represents, acquisition second detects the electric current of circuit, second The electric current expression of insulaion resistance,

Then perform

List expression formula：The electric current for the first detection circuit tried to achieve according to changing again after detection circuit resistance is examined with changing again The electric current sum for the first insulaion resistance tried to achieve after slowdown monitoring circuit resistance is equal to second tried to achieve after change detection circuit resistance again Detect the electric current of circuit and change the electric current sum of the second insulaion resistance tried to achieve after detection circuit resistance again, list comprising the The solution equation of one insulaion resistance and the second insulaion resistance；

Simultaneous equations solve:The first insulaion resistance and the second insulaion resistance are included by what is formed after change detection circuit resistance again Solution equation with change detection circuit resistance after formed solve equation or with initial detecting circuit formed solution equation join Vertical acquisition second equation group, solution the first insulaion resistance to be measured, the resistance of the second insulaion resistance,

Error judgment：If the first solving equations obtain the resistance of the first insulaion resistance to be measured and the solution of second equation group is treated Survey the resistance of the first insulaion resistance difference or difference ratio in error range, the first solving equations obtain second insulation The resistance and second equation group of resistance solve the resistance difference for obtaining the second insulaion resistance or difference ratio in error range, then Judge that detection passes through,

If judging that detection passes through

Obtain insulaion resistance resistance：First solving equations are obtained into the first insulaion resistance to be measured and solve acquisition with second equation group First insulaion resistance to be measured takes average or weighted average to obtain the resistance of the first insulaion resistance, and the first solving equations are obtained into the The resistances of two insulaion resistances solves with second equation group to be obtained the resistance of the second insulaion resistance and takes average or weighted average obtains the The resistance of two insulaion resistances.

In a preferred embodiment, in addition to：Result optimizing：Repeat or change detection circuit resistance simultaneous equations Group, to repeatedly obtaining the resistance for the first insulaion resistance that insulaion resistance resistance step obtains, the resistance of the second insulaion resistance is distinguished Mean value computation or weighted average calculation optimization result of calculation are carried out, the first insulaion resistance resistance, the second insulation after being optimized Resistance；

In the error judgment step：If the first solving equations obtain the resistance and second equation group of the first insulaion resistance to be measured The difference or difference ratio for solving the resistance for obtaining the first insulaion resistance to be measured are not given up then in error range；If or first Solving equations obtain the second insulaion resistance resistance and second equation group solve the resistance difference that obtains the second insulaion resistance or Difference ratio is then given up not in error range；

If the solution value of the resistance of the first insulaion resistance and the solution value of the second insulaion resistance are given up,

Then perform the current step for obtaining the first detection circuit；

The first circuit resistor bridge group includes：One or more first fixes access resistance, the regulation electricity of one or more first Resistance and the first test switch for being connected in parallel on the first regulation resistance both ends and being closed or being disconnected as needed；Described Two circuit resistor bridge groups include：One or more second is fixed access resistance, one or more second regulation resistances and is connected in parallel on The second regulation resistance both ends and the second test switch for being closed or being disconnected as needed；

It is described to change detection circuit resistance step or change detection circuit resistance step again by changing the first regulation resistance Access or access number change the resistance of the first circuit resistor bridge group, or by changing the access or access of the second regulation resistance Number changes second circuit resistor bridge group resistance；The low-pressure end is earth terminal.

Detection circuit and detection method of the above-mentioned high pressure to the insulaion resistance of low pressure, directly just detect actual total face Ground, total negative actual resistance over the ground, it is segmented and detects independent of pattern, Standard resistance range has continuity, with actual situation more Adjunction is near；The computational methods and calculation formula of use make amount of calculation few, and calculating process need not open radical sign, and resource is taken to computing It is few.

Brief description of the drawings

Fig. 1 is the schematic diagram of detection circuit of the high pressure of one embodiment of the invention to the insulaion resistance of low pressure；

Fig. 2 is the schematic diagram of the acquisition module of one embodiment of the invention；

Fig. 3 is the flow chart of the high pressure to the detection method of the insulaion resistance of low pressure of one embodiment of the invention；

Fig. 4 is the flow chart of the high pressure to the detection method of the insulaion resistance of low pressure of one embodiment of the present invention；

Fig. 5 is flow chart of the high pressure to the detection method of the insulaion resistance of low pressure of another preferred embodiment of the present invention.

Embodiment

As shown in figure 1, detection circuit 100 of the high pressure of one embodiment of the invention to the insulaion resistance of low pressure, including：With connecing Enter the first detection circuit 20 and access high-tension electricity that the first testing resistance between high-voltage power cathode and low-pressure end is connected in parallel The second testing resistance between source negative pole and low-pressure end the second detection circuit 40 and acquisition module U1 in parallel.The present embodiment High voltage power supply is relatively high pressure power supply for low pressure terminal voltage.Preferably, the high voltage power supply of the present embodiment is mainly phase To non-security voltage source, alternating current is more than or equal to 36V power supplys, and direct current is more than or equal to 60V power supplys.High voltage power supply can be Power supply, battery bag, accumulation power supply, high voltage cable etc. can provide the equipment or system of power supply function.The low pressure of the present embodiment End is for high voltage power supply terminal voltage, less than high voltage power supply terminal voltage.The low-pressure end of the present embodiment is preferably low pressure ground terminal.

First testing resistance of the present embodiment is insulaion resistance Rp；Second testing resistance is insulaion resistance Rn.

First detection circuit includes：First circuit resistor bridge group and connected with the first circuit resistor bridge group or disconnect and by Acquisition module U1 gathers the first sampling resistor Rx of its voltage.

First circuit resistor bridge group can be a resistance, can be also made up of multiple resistance.First circuit resistor bridge group can be with As needed using multiple resistance composition in parallel or series.Preferably, the first circuit resistor bridge group can use as needed Change the connected mode between resistance or the different resistance of series connection or different resistance in parallel or the different resistance of connection or change connection The number of resistance adjusts the resistance of the first circuit resistor bridge group.

Second detection circuit includes：Second circuit resistor bridge group and connected with second circuit resistor bridge group or disconnect and by Acquisition module gathers the second sampling resistor Ry of its voltage.First circuit resistor bridge group or second circuit resistor bridge group are can variable resistance The variable resistor group of value.Any one can be selected as variable resistor in first circuit resistor bridge group, second circuit resistor bridge group Group, can also be both variable resistor group.

Second circuit resistor bridge group can be a resistance, can be also made up of multiple resistance.Second circuit resistor bridge group can be with As needed using multiple resistance composition in parallel or series.Preferably, second circuit resistor bridge group can use as needed Change the connected mode between resistance or the different resistance of series connection or different resistance in parallel or the different resistance of connection or change connection The number of resistance adjusts the resistance of second circuit resistor bridge group.

Preferably, at least one in the first circuit resistor bridge group, second circuit resistor bridge group is made up of multiple resistance, or At least one is by that can test resistance or know that the variable resistor of resistance value changeable terminals forms.

Further, the first circuit resistor bridge group of the present embodiment or second circuit resistor bridge group include：Fixed access resistance, And the variable regulation resistance for accessing or being switched in or out as needed.

Further, the first circuit resistor bridge group of the present embodiment or second circuit resistor bridge group are by setting switch closure Or disconnect and change the variable resistor group of access resistance value to change the resistance of detection circuit for access.

Further, the first circuit resistor bridge group of the present embodiment or second circuit resistor bridge group include：Fixed access resistance, And the variable regulation resistance for accessing or being switched in or out as needed.The fixed access resistance of the present embodiment can be one or more It is individual.Regulation resistance can also be arranged as required to one or more.

Further, the low-pressure end of the present embodiment is earth terminal.

According to the setting of the first circuit resistor bridge group, the first circuit resistor bridge group of the present embodiment includes：It is one or more First fixes access resistance, one or more first regulation resistances and is connected in parallel on the first regulation resistance both ends and enters as needed Row closure or the first test switch disconnected.

First test switch is worked by folding so as to control the first regulation resistance whether to access the first detection circuit, so as to Change the resistance of the first circuit resistor bridge group.

First regulation resistance can set multiple, one first test in parallel can be opened in each first regulation resistance Close, one first test switch in parallel in multiple first regulation resistances can also be selected.Multiple first regulation resistances can be in parallel, It can connect, can be combined with connection in series-parallel.One first test switch in parallel in multiple first regulation resistances is selected, first adjusts The number of economize on electricity resistance is selected as needed, does not influence test.

According to the setting of second circuit resistor bridge group, the second circuit resistor bridge group of the present embodiment includes：It is one or more Second fixes access resistance, one or more second regulation resistances and is connected in parallel on the second regulation resistance both ends and enters as needed Row closure or the second test switch disconnected.

Second test switch is worked by folding so as to control the second regulation resistance whether to access the second detection circuit, so as to Change the resistance of second circuit resistor bridge group.

Second regulation resistance can set multiple, one second test in parallel can be opened in each second regulation resistance Close, one second test switch in parallel in multiple second regulation resistances can also be selected.Multiple second regulation resistances can be in parallel, It can connect, can be combined with connection in series-parallel.One second test switch in parallel in multiple second regulation resistances is selected, second adjusts The number of economize on electricity resistance is selected as needed, does not influence test.

Further, detected for convenience, the first of preferable the present embodiment fixes access resistance connects with the second fixation Enter resistance and set identical, the first regulation resistance is identical with the second adjusting resistance values setting, the first sampling resistor Rx and the Two sampling resistor Ry resistances set identical, i.e. Rx=Ry.

Further, in order to facilitate design arrangement, while convenient measuring and calculating, reduction error, the detection circuit of the present embodiment use Symmetric design arranges that first fixes access resistance is connected in series with the first regulation resistance, and the first regulation resistance both ends are parallel with the One test switch S1, first fix access resistance the other end be connected with the first testing resistance, the first regulation resistance other end and First sampling resistor Rx connections；Second fixes access resistance is connected in series with the second regulation resistance, and the second regulation resistance both ends are simultaneously The second test switch S3 is associated with, second other end for fixing access resistance is connected with the second testing resistance, and the second regulation resistance is another One end is connected with the second sampling resistor Ry.Further, in order to further facilitate design arrangement, and convenient detect calculates, preferred The present embodiment in, first to fix access resistance be resistance R1, and the first regulation resistance is resistance R2, and second fixes and access resistance and is Resistance R3, the second regulation resistance are resistance R4.Resistance R1 is connected in series with resistance R2, resistance the R1 other end and insulaion resistance Rp High pressure one end is the connection of positive source one end, and the resistance R2 other ends are connected with the first sampling resistor Rx, and the first sampling resistor Rx is another One end accesses low pressure ground terminal and is linked into insulaion resistance Rp low-pressure end, and resistance R2 both ends are also parallel with the first test switch S1, Acquisition module U1 is also accessed at first sampling resistor Rx both ends；Resistance R3 is connected in series with resistance R4, the resistance R3 other end with absolutely Edge resistance Rn high-pressure sides are the connection of power cathode one end, and the resistance R4 other ends are connected with the second sampling resistor Ry, the second sampling electricity Resistance Ry other ends access low pressure ground terminal is simultaneously linked into insulaion resistance Rn low-pressure end, and resistance R4 both ends are also parallel with the second test and opened S3 is closed, acquisition module U1 is also accessed at the second sampling resistor Ry both ends.

Detected and calculated to further facilitate, the first of the present embodiment, which fixes access resistance and second, fixes access Resistance setting is identical, and the first regulation resistance is identical with the second adjusting resistance values setting；That is R1=R2, R3=R4.

As shown in Fig. 2 further, it is preferred that the acquisition module U1 of the present embodiment is provided with to be passed respectively using differential signal The difference analogue data acquisition channel of defeated first sampling resistor Rx, the second sampling resistor Ry collection transmission data.

Preferably, the acquisition module U1 of the present embodiment is 24 sampling with high precision chips, have wider multiplication factor and Low noise input analog voltage sampling characteristics, two-way fully differential analog voltage sampling channel and 4 tunnel pseudo-differential sampling channels, ensure The precision and stability of sampled data in analog voltage sampling process.Acquisition module U1 fully differential analog voltage sampling Passage is connected respectively on the first sampling resistor Rx, the second sampling resistor Ry.First sampling resistor Rx, the second sampling resistor Ry with Low-pass filter circuit is both provided with the differential signal line that acquisition module U1 fully differential analog voltage sampling channel connects respectively, Ensure the stability of signal transmission.

As shown in Fig. 2 when acquisition module U1 10 pin AINCOM are configured to pseudo-differential mode of operation, simulation input AIN1 is extremely AIN4 is on the basis of this is inputted.

Acquisition module U1 11 pin AIN1 are simulation input, with reference to AIN2 in use, being configurable to fully differential input pair Positive input；With reference to AINCOM in use, being configurable to pseudo-differential input.

Acquisition module U1 12 pin AIN2 are simulation input, with reference to AIN1 in use, being configurable to fully differential input pair Negative input；With reference to AINCOM in use, being configurable to pseudo-differential input.

Acquisition module U1 13 pin AIN3 are simulation input, with reference to AIN4 in use, being configurable to fully differential input pair Positive input；With reference to AINCOM in use, being configurable to pseudo-differential input.

Acquisition module U1 14 pin AIN4 are simulation input, with reference to AIN3 in use, being configurable to fully differential input pair Negative input；With reference to AINCOM in use, being configurable to pseudo-differential input.

Acquisition module U1 15 pin REFIN1（+）Inputted for positive benchmark.

Acquisition module U1 16 pin REFIN1（-）For negative benchmark input.

Acquisition module U1 17 pin BPDSW are electric bridge shut-off switch, are connected with AGND.

Acquisition module U1 18 pin AGND be ground foundation simulation on schedule.

Acquisition module U1 19 pin DGND are digitally datum mark.

Acquisition module U1 23 pinFor serial data output/data ready output.

Meanwhile analog voltage is transferred to and adopted by the first sampling resistor Rx, the second sampling resistor Ry using difference cabling At the two-pass DINSAR analogue data sampling channel for collecting module U1, it is suffered in circuit transmitting procedure to reduce analog sampled data External interference influence.

The first sampling resistor Rx, the second sampling resistor Ry of the present embodiment are high-precision sampling resistor, its accuracy guarantee In the range of 1%, ensure that its sampled voltage precision can be higher.

Further, between the first circuit resistor bridge group of the present embodiment and the first sampling resistor or second circuit resistor bridge High and low voltage isolation switch is provided between group and the second sampling resistor.The high and low voltage isolation switch of the present embodiment includes：First every Leave and close S2, the second disconnecting switch S4.

First disconnecting switch S2 is set between the first circuit resistor bridge group of the present embodiment and the first sampling resistor；Second electricity Second disconnecting switch S4 is set between road and bridge resistance group and the second sampling resistor.

Further, first regulation resistance of the present embodiment is to set first to isolate between resistance R2 and the first sampling resistor Rx Switch S2；Second regulation resistance of the present embodiment is that the second disconnecting switch S4 is set between resistance R4 and the second sampling resistor Ry.

Because human-body safety electric current is 10 mA, the electric current of the detection circuit of the present embodiment is equal to or less than 10mA.In order to protect Card safety, it is preferred that the electric current of the detection circuit of the present embodiment is equal to or less than 3mA.During design, Rp, Rn are accessed no, only In the case of circuit access loop only being detected in the case of having R1, R2, R3, R4 access loop（Including being turned on and off Any one or more situation in one test switch S1, the second test switch S3）, the max-flow overcurrent in whole circuit is small In or equal to 3mA.It is so as to acquisition module U1 full scale：Ux ≤ Rx×3mA; Uy ≤ Ry×3mA.Detect circuit In each resistance own power requirement：P≥ (3mA）×(3mA）×R;Immobilized according to limitation electric current, it is also contemplated that into The design, known according to U z=R × I：Uz is bigger, and its resistance requires bigger, while resistance own power requires also higher；Root According to Ohm's law, resistance circuit is matched according to supply voltage, ensures that the electric leakage that high pressure is pressed over the ground is maintained within 3mA.

The acquisition module U1 of the present invention is sampled using 24 sampling with high precision chips, and signal is carried out using differential signalling form Transmission, prevent the overwhelming majority common mode disturbances；Low-pass filter circuit is all done on every differential signal line, ensures signal transmission Stability.To prevent resistance failure, resistance rated power requirements of type selecting P >=(3mA）×(3mA）×R；Meanwhile ensure by list Only R1 and R3 is sealed in high-tension circuit together, during loop current I≤3mA, R >=Uz/I;Resistance R1, R2, R3, R4 are mainly The bridge circuit of test insulaion resistance is built, and is arranged to R1=R3, R2=R4, Rx=Ry symmetric circuit.When R1, R3 access circuit In, when can obtain a prescription formula according to the node voltage theorem of kirchhoff, then R2, R4 being accessed, according to kirchhoff Node voltage theorem can obtain another prescription formula；Simultaneous solution, it is possible to the magnitude of voltage sampled according to sampling A/D chip Calculate insulation resistance value Rp, Rn.

As shown in figure 3, one embodiment of the invention enters horizontal high voltage to the insulaion resistance of low pressure using above-mentioned detection circuit Detection method, including：

Step S101, obtain the electric current of the first detection circuit：Detection circuit is connected, gathers the voltage of the first sampling resistor, according to The voltage and resistance of first collection resistance solve the electric current of the first collection resistance, so as to obtain the first sampling resistor and the first circuit The electric current for the first detection circuit that resistor bridge group is connected in series to form；

Step S103, the electric current of the first insulaion resistance represent：According to solving the resistance sizes of the first detection circuit and electric current First detection circuit voltage, it is connected with the first detection circuit in parallel so as to obtain and is connected to high-voltage power cathode and low-pressure end Between the first insulaion resistance to be measured voltage, the first insulated electro is represented according to the voltage of the first insulaion resistance and resistance formula The electric current of resistance；

Step S105, obtain the electric current of the second detection circuit：The voltage of the second sampling resistor is gathered, according to the second collection resistance Voltage and resistance solve the electric current of the second collection resistance, are connected so as to obtain the second sampling resistor with second circuit resistor bridge group company The electric current for the second detection circuit to be formed is connect,

Step S107, the electric current of the second insulaion resistance represent：According to solving the resistance sizes of the second detection circuit and electric current Second detection circuit voltage, it is connected with the second detection circuit in parallel so as to obtain and is connected to high voltage power supply negative pole and low-pressure end Between the second insulaion resistance to be measured voltage, the second insulated electro is represented according to the voltage of the second insulaion resistance and resistance formula The electric current of resistance；

Step S109, lists expression formula：According to the electric current sum of electric current and the first insulaion resistance of the first detection circuit equal to the The electric current of two detection circuits and the electric current sum of the second insulaion resistance are listed comprising the first insulaion resistance and the second insulaion resistance Solve equation；

Step S111, change detection circuit resistance：Change resistance or the resistance of second circuit resistor bridge group of the first circuit resistor bridge group Value, or the first, first circuit resistor bridge group resistance；

Repeated the above steps and detected according to the detection circuit after change resistance：

Step S101, obtain the electric current of the first detection circuit；

Step S103, the electric current of the first insulaion resistance represent；

Step S105, obtain the electric current of the second detection circuit；

Step S107, the electric current of the second insulaion resistance represent；

Step S109, lists expression formula；

Step S113, simultaneous equations solve:The different detected values for detecting and being obtained before and after circuit resistance according to changing, and the first detection The electric current sum of the electric current of circuit and the first insulaion resistance is equal to the electric current of the second detection circuit and the electric current of the second insulaion resistance Two different solution equation expression formulas comprising the first insulaion resistance and the second insulaion resistance that sum equation obtains, simultaneous obtain First equation group, solution the first insulaion resistance to be measured, the resistance of the second insulaion resistance.

The electric current that the electric current of step S103 the first insulaion resistance represents to obtain the first detection circuit according to step S101 enters Row, which derives, to be represented, so as to which step S103 is oppositely arranged after step slol, only represents that step S103 is placed in after step S101 , do not indicate that it is to be bordered by ordinal relation.

The electric current that the electric current of the insulaion resistances of step S107 second obtains the second detection circuit according to step S105 is derived Represent, step S107 is oppositely arranged on after step S105, is not indicated that and is performed relation successively.

Step S101, obtain electric current and the step S105 of the first detection circuit, obtain the electric current of the second detection circuit regardless of Sequencing.

Step S109, list expression formula and be placed in after step S103, step S107, do not indicate that and perform relation successively. As long as step S109 lists expression formula step and is arranged on after step S103, step S107, step S113 simultaneous equations solve it Before, do not indicate that and perform relation successively.

As shown in figure 4, further, it is preferred that the high pressure of the present embodiment is also wrapped to the detection method of the insulaion resistance of low pressure Include：Step S115, change detection circuit resistance again：Change the resistance or second circuit resistor bridge group of the first circuit resistor bridge group Resistance,

According to the detection circuit after change resistance again, following steps are performed：

Step S101, obtain the electric current of the first detection circuit；

Step S103, the electric current of the first insulaion resistance represent；

Step S105, obtain the electric current of the second detection circuit；

Step S107, the electric current of the second insulaion resistance represent；

Step S109, lists expression formula：According to again change detection circuit resistance after try to achieve first detection circuit electric current with After changing the electric current sum for detecting the first insulaion resistance tried to achieve after circuit resistance again equal to detection circuit resistance is changed again Electric current sum of the electric current for the second detection circuit tried to achieve with changing the second insulaion resistance tried to achieve after detection circuit resistance again List the solution equation comprising the first insulaion resistance and the second insulaion resistance；

Step S117, simultaneous equations solve:To change again formed after detection circuit resistance comprising the first insulaion resistance and the The solution equations of two insulaion resistances with change formed after detection circuit resistance solve equation or formed with initial detecting circuit Solve equations simultaneousness and obtain second equation group, solution the first insulaion resistance to be measured, the resistance of the second insulaion resistance；

Step S119, error judgment：If the first solving equations obtain the resistance and second equation group of the first insulaion resistance to be measured In error range, the first solving equations obtain the difference or difference ratio of the resistance of solution acquisition the first insulaion resistance to be measured Obtain the resistance of the second insulaion resistance and second equation group solves the resistance difference for obtaining the second insulaion resistance or difference ratio by mistake In poor scope, then judge that detection passes through,

If judging that detection passes through

Step S121, obtain insulaion resistance resistance：First solving equations are obtained into the first insulaion resistance to be measured and second equation Group solves the resistance for obtaining that the first insulaion resistance to be measured takes average or weighted average obtains the first insulaion resistance, by the first equation group Solve the resistance for obtaining the second insulaion resistance and the resistance of second equation group solution the second insulaion resistance of acquisition takes average or weighting Averagely obtain the resistance of the second insulaion resistance.

Further, step S117, during simultaneous equations solve, first is included by what is formed after change detection circuit resistance again The solution equation of insulaion resistance and the second insulaion resistance detects the solution equation formed after circuit resistance with change or examined with initial The solution equations simultaneousness that slowdown monitoring circuit is formed obtains second equation group, solves the resistance of the first insulaion resistance, the second insulaion resistance to be measured Value.Wherein, change the detection circuit formed after detection circuit resistance again and detected with the change formed and its simultaneous equations solves The detection circuit or initial detecting circuit formed after circuit resistance is different.

Further, it is preferred that the high pressure of the present embodiment also includes to the detection method of the insulaion resistance of low pressure：Step S123, result optimizing：Repeat or change detection circuit resistance Simultaneous Equations, to repeatedly obtaining insulaion resistance resistance step Resistance, the resistance of the second insulaion resistance of the first insulaion resistance obtained carry out mean value computation or weighted average calculation optimization respectively Result of calculation, the first insulaion resistance resistance, the second insulaion resistance resistance after being optimized.

Further, step S119, in error judgment step：If the first solving equations obtain the first insulaion resistance to be measured The difference or difference ratio of resistance and the resistance of second equation group solution acquisition the first insulaion resistance to be measured be not in error range Then give up；Or if the first solving equations obtain the resistance of the second insulaion resistance and second equation group solves the second insulated electro of acquisition The resistance difference or difference ratio of resistance are then given up not in error range；

If the solution value of the resistance of the first insulaion resistance and the solution value of the second insulaion resistance are given up, detect again；Perform：

Step S101, obtain the electric current of the first detection circuit：The voltage of the first sampling resistor is gathered, according to the first collection resistance Voltage and resistance solve the electric current of the first collection resistance, are connected so as to obtain the first sampling resistor with the first circuit resistor bridge group company Connect the electric current for the first detection circuit to be formed；

Step S103, the electric current of the first insulaion resistance represent：According to solving the resistance sizes of the first detection circuit and electric current First detection circuit voltage, it is connected with the first detection circuit in parallel so as to obtain and is connected to high-voltage power cathode and low-pressure end Between the first insulaion resistance to be measured voltage, the first insulated electro is represented according to the voltage of the first insulaion resistance and resistance formula The electric current of resistance；

Step S105, obtain the electric current of the second detection circuit：The voltage of the second sampling resistor is gathered, according to the second collection resistance Voltage and resistance solve the electric current of the second collection resistance, are connected so as to obtain the second sampling resistor with second circuit resistor bridge group company The electric current for the second detection circuit to be formed is connect,

Step S107, the electric current of the second insulaion resistance represent：According to solving the resistance sizes of the second detection circuit and electric current Second detection circuit voltage, it is connected with the second detection circuit in parallel so as to obtain and is connected to high voltage power supply negative pole and low-pressure end Between the second insulaion resistance to be measured voltage, the second insulated electro is represented according to the voltage of the second insulaion resistance and resistance formula The electric current of resistance；

Step S109, lists expression formula：According to the electric current sum of electric current and the first insulaion resistance of the first detection circuit equal to the The electric current of two detection circuits and the electric current sum of the second insulaion resistance are listed comprising the first insulaion resistance and the second insulaion resistance Solve equation；

Step S111, change detection circuit resistance：Change resistance or the resistance of second circuit resistor bridge group of the first circuit resistor bridge group Value,

Repeated the above steps and detected according to the detection circuit after change resistance：

Step S101, obtain the electric current of the first detection circuit；

Step S103, the electric current of the first insulaion resistance represent；

Step S105, obtain the electric current of the second detection circuit；

Step S107, the electric current of the second insulaion resistance represent；

Step S109, lists expression formula；

Step S113, simultaneous equations solve:The different detected values for detecting and being obtained before and after circuit resistance according to changing, and the first detection The electric current sum of the electric current of circuit and the first insulaion resistance is equal to the electric current of the second detection circuit and the electric current of the second insulaion resistance Two different solution equation expression formulas comprising the first insulaion resistance and the second insulaion resistance that sum equation obtains, simultaneous obtain First equation group, solution the first insulaion resistance to be measured, the resistance of the second insulaion resistance.

The resistance for continuing to change detection circuit is detected；Perform：Step S115, change detection circuit resistance again：Change Become the resistance or second circuit resistor bridge group resistance of the first circuit resistor bridge group,

According to the detection circuit after change resistance again, following steps are performed：

Step S101, obtain the electric current of the first detection circuit；

Step S103, the electric current of the first insulaion resistance represent；

Step S105, obtain the electric current of the second detection circuit；

Step S107, the electric current of the second insulaion resistance represent；

Step S109, lists expression formula：According to again change detection circuit resistance after try to achieve first detection circuit electric current with After changing the electric current sum for detecting the first insulaion resistance tried to achieve after circuit resistance again equal to detection circuit resistance is changed again Electric current sum of the electric current for the second detection circuit tried to achieve with changing the second insulaion resistance tried to achieve after detection circuit resistance again List the solution equation comprising the first insulaion resistance and the second insulaion resistance；

Step S117, simultaneous equations solve:To change again formed after detection circuit resistance comprising the first insulaion resistance and the The solution equation or electric with changing preceding or initial detecting formed after the solution equation and change detection circuit resistance of two insulaion resistances The solution equations simultaneousness that road is formed obtains second equation group, solution the first insulaion resistance to be measured, the resistance of the second insulaion resistance.

Further, the first circuit resistor bridge group of the present embodiment includes：One or more first fix access resistance, one Or multiple first regulation resistances and it is connected in parallel on the first regulation resistance both ends and closed or disconnected as needed first Test switch.Second circuit resistor bridge group includes：One or more second fixes access resistance, the regulation electricity of one or more second Resistance and the second test switch for being connected in parallel on the second regulation resistance both ends and being closed or being disconnected as needed.

Step S111, change detection circuit resistance, or step S115, change again in detection circuit resistance step by changing Become the access of the first regulation resistance or access number changes the resistance of the first circuit resistor bridge group, or by changing the second regulation electricity The access of resistance or access number change second circuit resistor bridge group resistance.

In the present embodiment, the access that preferable selection changes the first regulation resistance is the access of the first regulation resistance or not accessed With the resistance of the first circuit resistor bridge group of change in first detection circuit；Change access i.e. the second regulation electricity of the second regulation resistance Resistance access or not in the second detection circuit to change the resistance of second circuit resistor bridge group.

Further, the low-pressure end of the present embodiment is earth terminal.

As shown in Figures 1 and 5, one embodiment of the present invention using above-mentioned detection circuit enters horizontal high voltage to the exhausted of low pressure The detection method of edge resistance, including it is as follows：

Step S301, the first disconnecting switch S2 of closure, the second disconnecting switch S4, connect detection circuit；

Step S303, acquisition module U1 gather voltage Ux1, the second sampling resistor of the first sampling resistor by differential signal transmission Voltage Uy1；

Step S305, the first sampling resistor electric current is calculated according to I1.1=Ux1/Rx, so as to obtain the electricity of the first detection circuit Stream,

Second sampling resistor electric current is calculated according to I4.1=Uy1/Ry, so as to obtain the electric current of the second detection circuit,

Step S307, the voltage of the first detection circuit is calculated according to Up.1=(R1+R2+Rx) × I1.1, so as to obtain with First testing resistance of the first detection circuit in parallel is the voltage at insulaion resistance Rp both ends,

The voltage of the second detection circuit is calculated according to Un.1=(R3+R4+Ry) × I4.1, so as to obtain and the second detection Second testing resistance of circuit in parallel is the voltage at insulaion resistance Rn both ends；

Step S309, according to formula I2.1=Up.1/Rp, i.e., it is insulaion resistance Rp two according to the first required testing resistance The voltage at end represents that the first testing resistance is insulaion resistance Rp electric current with its resistance formula to be asked,

According to I3.1=Un .1/ Rn, i.e., treated according to the voltage that the second required testing resistance is insulaion resistance Rn both ends with it Resistance formula is asked to represent the second testing resistance i.e. insulaion resistance Rn electric current；

Step S311, according to formula I1.1+I2. 1=I3.1+I4.1, list and insulated comprising the first insulaion resistance and second The solution equation of resistance；

Step S501, the first disconnecting switch S2 of closure, the second disconnecting switch S4, the first test switch S1, connect detection circuit；

Step S503, gather voltage Ux2, the voltage Uy2 of the second sampling resistor of the first sampling resistor；

Step S505, the first sampling resistor electric current is calculated according to I1.2=Ux2/Rx, so as to obtain the electricity of the first detection circuit Stream,

Second sampling resistor electric current is calculated according to I4.2=Uy2/Ry, so as to obtain the electric current of the second detection circuit；

Step S507, the voltage of the first detection circuit is calculated according to Up.2=(R1+Rx) × I1.2, so as to obtain and first First testing resistance of detection circuit in parallel is the voltage at insulaion resistance Rp both ends,

The voltage of the second detection circuit is calculated according to Un.2=(R3+R4+Ry) × I4.2, so as to obtain and the second detection Second testing resistance of circuit in parallel is the voltage at insulaion resistance Rn both ends；

Step S509, according to formula I2.2=Up.2/Rp, i.e., it is insulaion resistance Rp two according to the first required testing resistance The voltage at end represents that the first testing resistance is insulaion resistance Rp electric current with its resistance formula to be asked,

According to I3.2=Un .2/ Rn, i.e., treated according to the voltage that the second required testing resistance is insulaion resistance Rn both ends with it Resistance formula is asked to represent the second testing resistance i.e. insulaion resistance Rn electric current；

Step S511, according to formula I1.2+I2. 2=I3.2+I4.2, list and insulated comprising the first insulaion resistance and second The solution equation of resistance；

Step S701, the first disconnecting switch S2 of closure, the second disconnecting switch S4, the first test switch S1, the second test switch S3, Connect detection circuit；

Step S703, gather voltage Ux3, the voltage Uy3 of the second sampling resistor of the first sampling resistor；

Step S705, the first sampling resistor electric current is calculated according to I1.3=Ux3/Rx, so as to obtain the electricity of the first detection circuit Stream,

Second sampling resistor electric current is calculated according to I4.3=Uy3/Ry, so as to obtain the electric current of the second detection circuit；

Step S707, the voltage of the first detection circuit is calculated according to Up.3=(R1+Rx) × I1.3, so as to obtain and first First testing resistance of detection circuit in parallel is the voltage at insulaion resistance Rp both ends,

The voltage of the second detection circuit is calculated according to Un.2=(R3+Ry) × I4.3, so as to obtain and the second detection circuit Second testing resistance in parallel is the voltage at insulaion resistance Rn both ends；

Step S709, according to formula I2.3=Up.3/ Rp, i.e., it is insulaion resistance Rp both ends according to the first required testing resistance Voltage represent that first testing resistance is insulaion resistance Rp electric current with its resistance formula to be asked,

According to I3.3=Un.3/ Rn, i.e., treated according to the voltage that the second required testing resistance is insulaion resistance Rn both ends with it Resistance formula is asked to represent the second testing resistance i.e. insulaion resistance Rn electric current；

Step S711, according to formula I1.3+I2. 3=I3.3+I4.3, list and insulated comprising the first insulaion resistance and second The solution equation of resistance；

It can certainly select to close the first disconnecting switch S2, the second disconnecting switch S4, the second test switch S3, connect detection electricity Road；Then voltage Ux4, the voltage Uy4 of the second sampling resistor of the first sampling resistor are gathered；Calculated again, it is similar to the above, Do not repeating herein.

The solution side comprising the first insulaion resistance and the second insulaion resistance is listed in I1.x+I2. x=I3.x+I4.x Optional two solve equations simultaneousness equation group the first equation group of formation in journey, and solve the first insulaion resistance, the second insulaion resistance Resistance；

Any selection two solves second equation group of the equations simultaneousnesses in addition to first equation group i.e. with the first equation group not again With, and solve the first insulaion resistance, the resistance of the second insulaion resistance.

In the present embodiment, I1.1+I2. 1=I3.1+I4.1 and I1.2+I2.2=I3.2+I4.2 connection are selected Vertical first equation group illustrates.Select I1.3+ I2.3=I3.3+I4.3 and I1.1 1=I3.1 of+I2.+I4.1 Simultaneous second equation group illustrates.Simultaneous mode is only for purposes of illustration only, be not limited to above-mentioned simultaneous mode.

Step S901, simultaneous I1.1+I2. 1=I3.1+I4.1 and I1.2+I2.2=I3.2+I4.2 are formed First equation group, it is insulaion resistance Rp and the second testing resistance i.e. insulaion resistance Rn resistance to calculate the first testing resistance,

Rp=[（R1+R2+Rx）×(R3+R4+Ry) ×(Ux1×Uy2-Ux2×Uy1) ] /[(R3+R4+Ry) ×(Uy1× Uy2+Uy1×Ux2)-(R3+R4+Ry) ×(Uy1×Uy2+Uy2×Ux1)]；

Rn =[（R1+R2+Rx）×(R1+Rx) ×(Ux1×Uy3-Ux3×Uy1) ] /[(R1+Rx) ×(Uy1×Uy3+ Uy1×Ux3)-(R1+R2+Rx) ×(Uy1×Uy3+Uy3×Ux1)]；

Step S903, simultaneous I1.3+ I2.3=I3.3+I4.3 and I1.1 1=I3.1 of+I2.+I4.1 form second Equation group, it is insulaion resistance Rp and the second testing resistance i.e. insulaion resistance Rn resistance to calculate the first testing resistance,

Rp=[（R1+R2+Rx）×(R3+Ry) ×(Ux1×Uy3-Ux3×Uy1) ] /[(R3+Ry) ×(Uy1×Uy3+Uy1 × Ux3)-(R3+R4+Ry) × (Uy1 × Uy3+Uy3 × Ux1)],

Rn =[（R1+R2+Rx）×(R1+Rx) ×(Ux1×Uy3-Ux3×Uy1) ] /[(R1+Rx) ×(Uy1×Uy3+ Uy1×Ux3)-(R1+R2+Rx) ×(Uy1×Uy3+Uy3×Ux1)]；

Step S905, compare the resistance according to Rp, Rn of the first solving equations with Rp, Rn's according to the solution of second equation group Resistance, if in setting error range；Detect and pass through if error is in setting range,

Filtered out if more than setting error, re-start detection；

If detection passes through, perform：

Step S907, by Rp, Rn of the first solving equations resistance and Rp, Rn for being solved according to second equation group resistance point It is not weighted averagely, or mean value computation, try to achieve Rp, Rn resistance measured for the first time.

According to setting number, repeat the above steps, as operating and setting 10 is inferior.

Step S909, Rp, Rn resistance tried to achieve every time are each weighted respectively average or averaged, obtain last Rp, Rn resistances.

Preferably, step S905, solved according to Rp, Rn of the first solving equations resistance and according to second equation group The control errors of Rp, Rn resistance are within 5%, i.e., the difference of Rp, Rn that two equation groups are tried to achieve resistance is come relative to resistance Say control within 5%.

Present invention is mainly applied to the detection that relatively high pressure electricity is carried out to the insulaion resistance resistance of low tension, including such as high pressure Cable detects to the insulation impedance of low-voltage line, and total just total negative insulation impedance to system low-voltage of automobile power cell bag detects, The detections of all high pressures to the insulation impedance of low-pressure system such as the total just total negative insulaion resistance detection to low-pressure system of powering of energy storage.

For the high pressure of the present invention to the insulating resistor detecting circuit and detection method of low pressure, it is few to take resource to microcomputer computing, Calculating process need not open radical sign；Results contrast is made using calculating, ensures the accuracy of result of calculation；It is averaging using multiple Value, ensure that the further accurate stable of data.

The A/D chip for 24 precision that the acquisition module U1 of the present invention is used, the precision of collection are high；Relatively existing detection Scheme is all that merotype judges detection, the total face low pressure of its high pressure insulation resistance value it is minimum, high pressure always negative resistance of to low pressure insulating Value is minimum, always just, total negative resistance such as to low pressure when, the resultant error that it is detected is very big；And the high pressure of the present invention is to low pressure Insulating resistor detecting circuit and the Standard resistance range that detects of detection method there is continuity, be segmented and detect independent of pattern, Directly just detect that reality is total just over the ground, total negative actual resistance over the ground, be more nearly with the situation of reality.

Embodiment described above only expresses the several embodiments of the present invention, and its description is more specific and detailed, but simultaneously Therefore the limitation to the scope of the claims of the present invention can not be interpreted as.It should be pointed out that for one of ordinary skill in the art For, without departing from the inventive concept of the premise, various modifications and improvements can be made, these belong to the guarantor of the present invention Protect scope.Therefore, the protection domain of patent of the present invention should be determined by the appended claims.

Claims (10)

1. A kind of 1. detection circuit of high pressure to the insulaion resistance of low pressure, it is characterised in that including：With high-voltage power cathode and low pressure Second between the first detection circuit and high voltage power supply negative pole and low-pressure end that the first insulaion resistance between end is connected in parallel is exhausted The the second detection circuit and acquisition module of edge resistor coupled in parallel, the first detection circuit include：First circuit resistor bridge group and Connected with the first circuit resistor bridge group or disconnect and the first sampling resistor of its voltage is gathered by the acquisition module, it is described Second detection circuit includes：Second circuit resistor bridge group and connect or disconnect and by described with the second circuit resistor bridge group Acquisition module gathers the second sampling resistor of its voltage, what first sampling resistor was connected with the first circuit resistor bridge group relatively The other end accesses low-pressure end, and the relative other end being connected with the second circuit resistor bridge group of second sampling resistor accesses low Pressure side；The first circuit resistor bridge group or the variable resistor group or first, second that second circuit resistor bridge group is resistance value changeable terminals Resistance group is variable resistor group.
2. 2. detection circuit of the high pressure according to claim 1 to the insulaion resistance of low pressure, it is characterised in that：First electricity Road and bridge resistance group or second circuit resistor bridge group be by set switch closure or disconnect with change detection circuit for access resistance from And change the variable resistor group of access resistance value.
3. 3. detection circuit of the high pressure according to claim 1 to the insulaion resistance of low pressure, it is characterised in that：First electricity Road and bridge resistance group or second circuit resistor bridge group include：Fixed access resistance and variable access are switched in or out as needed Regulation resistance.
4. 4. high pressure according to claims 1 to 3 any one exists to the detection circuit of the insulaion resistance of low pressure, its feature In：The low-pressure end is earth terminal, and the first circuit resistor bridge group includes：One or more first fixes access resistance, one Individual or multiple first regulation resistances and be connected in parallel on the first regulation resistance both ends and closed or disconnected as needed One test switch；The second circuit resistor bridge group includes：One or more second fixes access resistance, one or more second Regulation resistance and the second test switch for being connected in parallel on the second regulation resistance both ends and being closed or being disconnected as needed.
5. 5. detection circuit of the high pressure according to claim 4 to the insulaion resistance of low pressure, it is characterised in that：Described first is solid Surely it is identical with the second fixation access resistance setting to access resistance, first regulation resistance is set with the second adjusting resistance values Put identical, first sampling resistor is identical with the second sampling resistor resistance setting.
6. 6. detection circuit of the high pressure according to claim 4 to the insulaion resistance of low pressure, it is characterised in that：The collection mould Block is provided with two-way and uses differential signal to transmit the first sampling resistor, the differential mode of the second sampling resistor collection transmission data respectively Intend data acquisition channel, the electric current of the detection circuit is equal to or less than 3mA, and the first fixation access resistance is resistance R1, First regulation resistance is resistance R2, and the second fixation access resistance is resistance R3, and second regulation resistance is resistance R4, the R1=R2, R3=R4.
7. 7. high pressure according to claims 1 to 3 any one exists to the detection circuit of the insulaion resistance of low pressure, its feature In：Between the first circuit resistor bridge group and the first sampling resistor or the second circuit resistor bridge group samples electricity with second High and low voltage isolation switch is provided between resistance.
8. 8. a kind of high pressure is to the detection method of the insulaion resistance of low pressure, it is characterised in that including：

   Obtain the electric current of the first detection circuit：Detection circuit is connected, gathers the voltage of the first sampling resistor, according to the first collection electricity The voltage and resistance of resistance solve the electric current of the first collection resistance, so as to obtain the first sampling resistor and the first circuit resistor bridge group string The electric current for the first detection circuit that connection connection is formed；

   The electric current of first insulaion resistance represents：The first detection electricity is solved according to the resistance sizes of the first detection circuit and electric current Road voltage, so as to obtain and the first detection circuit in parallel is connected and is connected to be measured between high-voltage power cathode and low-pressure end The first insulaion resistance voltage, the electricity of the first insulaion resistance is represented according to the voltage of the first insulaion resistance and resistance formula Stream；

   Obtain the electric current of the second detection circuit：The voltage of the second sampling resistor is gathered, according to the voltage and electricity of the second collection resistance Resistance solves the electric current of the second collection resistance, is connected in series to form so as to obtaining the second sampling resistor and second circuit resistor bridge group The electric current of second detection circuit；

   The electric current of second insulaion resistance represents：The second detection electricity is solved according to the resistance sizes of the second detection circuit and electric current Road voltage, so as to obtain and the second detection circuit in parallel is connected and is connected to be measured between high voltage power supply negative pole and low-pressure end The second insulaion resistance voltage, the electricity of the second insulaion resistance is represented according to the voltage of the second insulaion resistance and resistance formula Stream；

   List expression formula：Second detection circuit is equal to according to the electric current sum of the electric current of the first detection circuit and the first insulaion resistance Electric current and the electric current sum of the second insulaion resistance list the solution equation comprising the first insulaion resistance and the second insulaion resistance；

   Change detection circuit resistance：Change the resistance or second circuit resistor bridge group resistance of the first circuit resistor bridge group,

   Detection circuit according to resistance is changed performs following steps：

   Obtain the current step of the first detection circuit, the electric current of the first insulaion resistance represents step, obtains the second detection circuit Current step, the electric current of the second insulaion resistance represent step, list expression formula step；

   Then perform

   Simultaneous equations solve:The different detected values for detecting and being obtained before and after circuit resistance according to changing, and the electricity of the first detection circuit The electric current sum of stream and the first insulaion resistance is equal to the electric current of the second detection circuit and the electric current sum equation of the second insulaion resistance Two obtained solve equation expression formula comprising the first insulaion resistance and the different of the second insulaion resistance, and simultaneous obtains the first equation Group, solution the first insulaion resistance to be measured, the resistance of the second insulaion resistance.
9. 9. high pressure according to claim 8 is to the detection method of the insulaion resistance of low pressure, it is characterised in that also includes：Again It is secondary to change detection circuit resistance：Change resistance or second circuit resistor bridge group resistance or the change the of the first circuit resistor bridge group First, second circuit resistor bridge group resistance,

   According to the detection circuit for changing resistance again, following steps are performed：

   Obtain the current step of the first detection circuit, the electric current of the first insulaion resistance represents step, obtains the second detection circuit Current step, the electric current of the second insulaion resistance represent step,

   List expression formula：The electric current for the first detection circuit tried to achieve according to changing again after detection circuit resistance is examined with changing again The electric current sum for the first insulaion resistance tried to achieve after slowdown monitoring circuit resistance is equal to second tried to achieve after change detection circuit resistance again Detect the electric current of circuit and change the electric current sum of the second insulaion resistance tried to achieve after detection circuit resistance again, list comprising the The solution equation of one insulaion resistance and the second insulaion resistance；

   Simultaneous equations solve:The first insulaion resistance and the second insulaion resistance are included by what is formed after change detection circuit resistance again Solution equation with change detection circuit resistance after formed solve equation or with initial detecting circuit formed solution equation join It is vertical to obtain second equation group, solution the first insulaion resistance to be measured, the resistance of the second insulaion resistance；

   Error judgment：If the first solving equations obtain the resistance of the first insulaion resistance to be measured and the solution of second equation group is treated Survey the resistance of the first insulaion resistance difference or difference ratio in error range, the first solving equations obtain second insulation The resistance and second equation group of resistance solve the resistance difference for obtaining the second insulaion resistance or difference ratio in error range, then Judge that detection passes through,

   If judging that detection passes through

   Obtain insulaion resistance resistance：First solving equations are obtained into the first insulaion resistance to be measured and solve acquisition with second equation group First insulaion resistance to be measured takes average or weighted average to obtain the resistance of the first insulaion resistance, and the first solving equations are obtained into the The resistances of two insulaion resistances solves with second equation group to be obtained the resistance of the second insulaion resistance and takes average or weighted average obtains the The resistance of two insulaion resistances.
10. 10. high pressure according to claim 9 is to the detection method of the insulaion resistance of low pressure, it is characterised in that also includes：Knot Fruit optimizes：Repeat or change detection circuit resistance Simultaneous Equations, to repeatedly obtaining what insulaion resistance resistance step obtained The resistance of first insulaion resistance, the resistance of the second insulaion resistance carry out mean value computation respectively or weighted average calculation optimization calculates knot Fruit, the first insulaion resistance resistance, the second insulaion resistance resistance after being optimized；

    In the error judgment step：If the first solving equations obtain the resistance and second equation group of the first insulaion resistance to be measured The difference or difference ratio for solving the resistance for obtaining the first insulaion resistance to be measured are not given up then in error range；If or first Solving equations obtain the second insulaion resistance resistance and second equation group solve the resistance difference that obtains the second insulaion resistance or Difference ratio is then given up not in error range；

    If the solution value of the resistance of the first insulaion resistance and the solution value of the second insulaion resistance are given up, detect again；

    The first circuit resistor bridge group includes：One or more first fixes access resistance, the regulation electricity of one or more first Resistance and the first test switch for being connected in parallel on the first regulation resistance both ends and being closed or being disconnected as needed；Described Two circuit resistor bridge groups include：One or more second is fixed access resistance, one or more second regulation resistances and is connected in parallel on The second regulation resistance both ends and the second test switch for being closed or being disconnected as needed；

    It is described to change detection circuit resistance step or change detection circuit resistance step again by changing the first regulation resistance Access or access number change the resistance of the first circuit resistor bridge group, or by changing the access or access of the second regulation resistance Number changes second circuit resistor bridge group resistance；

    The low-pressure end is earth terminal.