CN203324419U - Direct-current power insulation detection device - Google Patents

Direct-current power insulation detection device Download PDF

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Publication number
CN203324419U
CN203324419U CN2013202956097U CN201320295609U CN203324419U CN 203324419 U CN203324419 U CN 203324419U CN 2013202956097 U CN2013202956097 U CN 2013202956097U CN 201320295609 U CN201320295609 U CN 201320295609U CN 203324419 U CN203324419 U CN 203324419U
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China
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current
sense resistor
detection
current sense
pair
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CN2013202956097U
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Chinese (zh)
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许昭德
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深圳奥特迅电力设备股份有限公司
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Abstract

The utility model discloses a direct-current power insulation detection device. The detection device comprises a voltage detection module, a pair of balance bridge resistors and a pair of detection bridge resistors. The detection device further comprises a current detection module and a calculation module; the current detection module is used for detecting the sum of currents of the pair of balance bridge resistors during single-pole grounding insulation resistance detection and detecting the sum of the currents of the pair of detection bridge resistors and current of each in the pair of detection bridge resistors during dual-pole grounding insulation resistance detection; and the calculation module is used for acquiring leakage current and calculating single-pole grounding insulation resistance according to grounding voltages of direct-current positive and negative buses and the acquired leakage current during single-pole grounding insulation resistance detection, and acquiring leakage current and calculating dual-pole grounding insulation resistance according to the grounding voltages of the direct-current positive and negative buses and the acquired leakage current during dual-pole grounding insulation resistance detection. According to the technical scheme of the utility model, the direct-current power insulation detection device is low in cost and high in precision.

Description

A kind of direct supply insulation detection device

Technical field

The utility model relates to the measurement field tests, especially relates to a kind of direct supply insulation detection device.

Background technology

In order to ensure the safe operation of electric system, the control of generating plant, transformer station and protection loop all adopt DC power supply.The DC bus insulativity descends or DC bus ground connection is the DC power system most common failure, generally, when DC bus generation one pole ground connection, can not affect the normal operation of system, but must find out in time earth point, fixes a breakdown.Otherwise, when the ground connection of the two poles of the earth, will cause major accident.Therefore need to grasp in time the DC power system bus insulating property.The principle of work of popular direct supply insulation detection device is on the market at present: detect DC bus insulating resistance value over the ground, send warning after insulation resistance is lower than setting value.

Fig. 1 is the circuit diagram of direct supply insulation detection device at present commonly used, and wherein, a pair of balance bridge resistance R b1, Rb2 are fixedly connected on respectively between positive and negative bus and ground, and are the fixed resistance of standard.A pair of detection resistor bridge RL1, RL2 pass through respectively K switch 1, K2 switching to DC bus, and are the fixed resistance of standard.Positive and negative bus voltage U p, Un over the ground is measurand, and, DC bus-bar voltage U=Up-Un, Rx, Ry are Equivalent DC bus insulation against ground resistance to be measured.If in Fig. 1, geodetic point voltage is zero potential, can obtain following formula:

IRb1+IRb2+IRL1+IRL2+IRx+IRy=0

This formula can be rewritten into:

Un/Rb1+Up/Rb2+Un/RL1+Up/RL2+Un/Rx+Up/Ry=0

When measuring, by the closed of change-over switch K1, K2 or turn-off, then, according to the standard electric resistance of the voltage measuring value of the positive and negative bus of direct current and resistance R b1, Rb2, RL1, RL2, can calculate Rx to be measured, the resistance value of Ry.

Yet, in this measuring method, about IRb1, IRb2, IRL1, IRL2, it is respectively to calculate acquisition according to the resistance value of measured bus voltage value and resistance R b1, Rb2, RL1, RL2.And the fixed resistance of resistance R b1, Rb2, RL1, RL2 employing standard, the fixed resistance of these standards has error in process of production, directly affects the calculated value of the insulation against ground resistance of DC bus.If resistance R b1, Rb2, RL1, RL2 adopt the high precision measuring resistance, cost is too high, and temperature still can't solve the impact of measuring resistance.

The utility model content

The technical problems to be solved in the utility model is,, error large defect high for the above-mentioned cost of prior art, provide the direct supply that a kind of cost is low, precision is high insulation detection device.

The utility model solves the technical scheme that its technical matters adopts: construct a kind of direct supply insulation detection device, insulation against ground resistance for detection of DC bus, described direct supply insulation detection device comprises: for detection of direct current just, the voltage detection module of negative busbar difference voltage over the ground, a pair of balance bridge resistance and a pair of detection resistor bridge, and, described a pair of balance bridge resistance just is being fixedly connected on respectively direct current, between negative busbar and ground, described a pair of detection resistor bridge just is being connected to direct current by corresponding switch respectively, between negative busbar and ground, described direct supply insulation detection device also comprises:

For the electric current that detects described a pair of balance bridge resistance when detecting one pole insulation against ground resistance value and, and detect bipolar while detect during the ground insulation resistance value electric current of described a pair of balance bridge resistance and respectively with described a pair of detection resistor bridge in each the current detection module of electric current sum;

Be connected in described voltage detection module and described current detection module, and for when detecting one pole insulation against ground resistance value, the electric current of the described a pair of balance bridge resistance detected according to described current detection module and obtain the positive and negative bus of direct current leakage current over the ground, and the positive and negative bus of the direct current detected according to described voltage detection module voltage over the ground and the leakage current obtained respectively, calculate one pole insulation against ground resistance value; Detecting bipolar while during the ground insulation resistance value, the electric current of the described a pair of balance bridge resistance detected according to described current detection module and respectively with described a pair of detection resistor bridge in each electric current sum obtain the positive and negative bus of direct current leakage current over the ground, and the positive and negative bus of the direct current detected according to described voltage detection module voltage over the ground and the leakage current obtained respectively, calculate the computing module of bipolar while ground insulation resistance value.

In direct supply insulation detection device described in the utility model, described current detection module comprises:

For when detecting one pole insulation against ground resistance value, the electric current of the described a pair of balance bridge resistance of sampling; And detecting bipolar while during the ground insulation resistance value, at least one current sense resistor of the electric current of the described a pair of balance bridge resistance of sampling and the electric current of described a pair of detection resistor bridge.

In direct supply insulation detection device described in the utility model, described at least one current sense resistor is the first current sense resistor, and, the first end ground connection of described the first current sense resistor, the second end of described the first current sense resistor connects the positive and negative bus of direct current by described a pair of balance bridge resistance respectively, and the second end of described the first current sense resistor also connects the positive and negative bus of direct current by described a pair of detection resistor bridge and each self-corresponding switch respectively.

In direct supply insulation detection device described in the utility model, described at least one current sense resistor comprises the second current sense resistor and the 3rd current sense resistor, the first end of the first end of described the second current sense resistor and described the 3rd current sense resistor is ground connection respectively, the second end of described the second current sense resistor connects the positive and negative bus of direct current by described a pair of balance bridge resistance respectively, and the second end of described the 3rd current sense resistor connects the positive and negative bus of direct current by described a pair of detection resistor bridge and each self-corresponding switch respectively.

In direct supply insulation detection device described in the utility model, described at least one current sense resistor comprises the 4th current sense resistor and the 5th current sense resistor, the first end of the first end of described the 4th current sense resistor and described the 5th current sense resistor is ground connection respectively, the second end of described the 4th current sense resistor connects the direct current negative busbar by one of them in described a pair of balance bridge resistance, the second end of described the 4th current sense resistor also connects direct current positive bus by one of them and corresponding switch thereof in described a pair of detection resistor bridge, the second end of described the 5th current sense resistor is crossed another in described a pair of balance bridge resistance and is connect direct current positive bus, the second end of described the 5th current sense resistor also connects the direct current negative busbar by another and corresponding switch thereof in described a pair of detection resistor bridge.

In direct supply insulation detection device described in the utility model, described at least one current sense resistor comprises the 6th current sense resistor, the 7th current sense resistor and the 8th current sense resistor, the first end of described the 6th current sense resistor, the first end of the first end of the 7th current sense resistor and the 8th current sense resistor is ground connection respectively, the second end of described the 6th current sense resistor is just connecing direct current by described a pair of balance bridge resistance respectively, negative busbar, the second end of described the 7th current sense resistor, the second end of described the 8th current sense resistor is just connecing direct current by one in described a pair of detection resistor bridge and each self-corresponding switch respectively, negative busbar.

In direct supply insulation detection device described in the utility model, described at least one current sense resistor comprises the 9th current sense resistor, the tenth current sense resistor, the 11 current sense resistor and the 12 current sense resistor, the first end of described the 9th current sense resistor, the first end of the tenth current sense resistor, the first end of the first end of the 11 current sense resistor and the 12 current sense resistor is ground connection respectively, the second end of described the 9th current sense resistor, the second end of described the tenth current sense resistor is just connecing direct current by one in described a pair of balance bridge resistance respectively, negative busbar, the second end of described the 11 current sense resistor, the second end of described the 12 current sense resistor is just connecing direct current by one in described a pair of detection resistor bridge and each self-corresponding switch respectively, negative busbar.

In direct supply insulation detection device described in the utility model, described current detection module is Hall current sensor or shunt.

Implement the technical solution of the utility model, electric current by detecting balance bridge resistance and (when detecting one pole insulation against ground resistance value) or detect the electric current of balance bridge resistance and respectively with a pair of detection resistor bridge in each electric current sum (in the bipolar while of detection during the ground insulation resistance value), just can obtain the leakage current of direct supply, and then, according to DC bus-bar voltage and the leakage current obtained, just can calculate the insulation against ground resistance of DC bus.Compared to existing technology, balance bridge resistance and detect the fixed resistance that resistor bridge does not need to adopt standard, therefore, measuring accuracy is higher, measurement range is larger, cost is low and precision is not subject to the impact of temperature.

The accompanying drawing explanation

Below in conjunction with drawings and Examples, the utility model is described in further detail, in accompanying drawing:

Fig. 1 is the circuit diagram of direct supply insulation detection device at present commonly used;

Fig. 2 is the logical diagram of the utility model direct supply insulation detection device embodiment mono-;

Fig. 3 is the circuit diagram of electric current embodiment bis-in the utility model direct supply insulation detection device;

Fig. 4 A, Fig. 4 B are respectively the equivalent circuit diagram of Fig. 3 when detecting one pole insulation against ground resistance value;

To be respectively Fig. 3 detecting bipolar while equivalent circuit diagram during the ground insulation resistance value for Fig. 4 C, Fig. 4 D;

Fig. 5 is the circuit diagram of the utility model direct supply insulation detection device embodiment tri-;

Fig. 6 is the circuit diagram of the utility model direct supply insulation detection device embodiment tetra-;

Fig. 7 A is the process flow diagram while detecting one pole insulation against ground resistance value in the utility model direct supply insulation detecting method embodiment mono-;

Fig. 7 B is bipolar while process flow diagram during the ground insulation resistance value in the utility model direct supply insulation detecting method embodiment mono-.

Embodiment

In the logical diagram of the utility model direct supply insulation detection device embodiment mono-shown in Fig. 2, this direct supply insulation detection device can be used for detecting the insulation against ground resistance of DC bus, comprises one pole insulation against ground resistance value, bipolar while ground insulation resistance value.This direct-current power supply detection device comprises a pair of balance bridge resistance (not shown), a pair of detection resistor bridge (not shown), voltage detection module 10, current detection module 20 and computing module 30.Wherein, a pair of balance bridge resistance is fixedly connected on respectively between the positive and negative bus of direct current and ground.A pair of detection resistor bridge is connected between the positive and negative bus of direct current and ground by corresponding switch respectively.Voltage detection module 10 is for detection of the positive and negative bus difference of direct current voltage over the ground.Current detection module 20 for the electric current that detects a pair of balance bridge resistance when detecting one pole insulation against ground resistance value and, and detect bipolar while detect during the ground insulation resistance value electric current of a pair of balance bridge resistance and respectively with a pair of detection resistor bridge in each electric current sum.Computing module 30 is for when detecting one pole insulation against ground resistance value, the electric current of a pair of balance bridge resistance detected according to current detection module and obtain the positive and negative bus of direct current leakage current over the ground, and the positive and negative bus of the direct current detected according to voltage detection module voltage over the ground and the leakage current obtained respectively, calculate one pole insulation against ground resistance value; Detecting bipolar while during the ground insulation resistance value, the electric current of a pair of balance bridge resistance detected according to current detection module and respectively with a pair of detection resistor bridge in each electric current sum obtain the positive and negative bus of direct current leakage current over the ground, and the positive and negative bus of the direct current detected according to voltage detection module voltage over the ground and the leakage current obtained respectively, calculate bipolar while ground insulation resistance value.About computing module 30, it should be noted that, computing module 30 can or be realized together with totalizer by multiplier, divider, and its logical organization with computing module of the prior art is identical.

Implement the technical solution of the utility model, electric current by detecting a pair of balance bridge resistance and (when detecting one pole insulation against ground resistance value) or detect the electric current of a pair of balance bridge resistance and respectively with a pair of detection resistor bridge in each electric current sum (in the bipolar while of detection during the ground insulation resistance value), just can obtain the leakage current of direct supply, and then, according to DC bus-bar voltage and the leakage current obtained, just can calculate the insulation against ground resistance of DC bus.Compared to existing technology, balance bridge resistance and detect the fixed resistance that resistor bridge does not need to adopt standard, therefore, measuring accuracy is higher, measurement range is larger, cost is low and precision is not subject to the impact of temperature.

In a preferred embodiment of the utility model direct supply insulation detection device, current detection module comprises at least one current sense resistor, the first computing unit and the second computing unit, and,

At least one current sense resistor, for when detecting one pole insulation against ground resistance value, the electric current of the described a pair of balance bridge resistance of sampling; And detecting bipolar while during the ground insulation resistance value, the electric current of the described a pair of balance bridge resistance of sampling and the electric current of described a pair of detection resistor bridge;

The first computing unit, for according to the ohmically sampled voltage of corresponding current detecting, reaching the electric current that the Current calculation model built in advance calculates corresponding current sense resistor, and constructed Current calculation model is:

I=K*U+B

Wherein, the electric current that I is corresponding current sense resistor, U is the ohmically sampled voltage of corresponding current detecting, K, B are respectively calibration parameter, and calibration parameter K, B are that according to two specific current value and corresponding current sense resistor, the sampled voltage under each specific current value obtains in advance.About obtaining of calibration parameter K, B, it should be noted that: before this direct supply insulation detection device dispatches from the factory, need to be calibrated the calibration parameter in the Current calculation model of this direct supply insulation detection device, at first, determine the current source that can export the first specific current value Iref1, for example, and it is upper that this current source is loaded into to the current sense resistor (RI in Fig. 3) of electric current to be measured, the sampling voltage U 1 on this current sense resistor now then.Then, then determine that another can export the current source of the second specific current value Iref2, and it is upper that this current source is loaded into to the current sense resistor (for example RI in Fig. 3) of electric current to be measured, then the sampling voltage U 2 on this current sense resistor now.Finally, for example, according to the sampled voltage of current sense resistor (RI in Fig. 3) under each specific current value of two specific current value and electric current to be measured, by separating the linear equation in two unknowns group, can obtain the corresponding calibration parameter K of this current sensing means, B.

The second computing unit, for when detecting one pole insulation against ground resistance value, according to calculated electric current obtain described a pair of balance bridge resistance electric current and, and detecting bipolar while during the ground insulation resistance value, according to calculated electric current obtain the electric current of described a pair of balance bridge resistance and respectively with described a pair of detection resistor bridge in each electric current sum.

Certainly, in other embodiments, current detection module also can be Hall current sensor or shunt, can directly from Hall current sensor or shunt, read the current value of balance bridge resistance and the current value of detection resistor bridge.

Fig. 3 is the circuit diagram of the utility model direct supply insulation detection device embodiment bis-, in this embodiment, the quantity of current sense resistor is one,, current sense resistor RI, and the end of a pair of balance bridge resistance R b2, Rb1 is fixedly connected with respectively the positive and negative bus of direct current (KM+, KM-), the other end of this balance bridge resistance R b1, Rb2 is respectively by current sense resistor RI ground connection.The end of a pair of detection resistor bridge RL2, RL1 is fixedly connected with respectively the positive and negative bus of direct current, this detection resistor bridge RL1, RL2 connect respectively the end of current sense resistor RI by corresponding K switch 1, K2, the other end ground connection of current sense resistor RI, K switch 1, K2 can be relay switch.Resistance R y, Rx are respectively the insulation against ground resistance of the equivalent positive and negative bus of direct current.The voltage detection module (not shown) can detect the positive and negative bus difference of direct current voltage (Up, Un) over the ground.

When measuring, at first explanation, measuring method has balance bridge mensuration and uneven bridge mensuration.In the balance bridge measuring method, K switch 1, K2 all turn-off, and can measure like this one pole insulation against ground resistance value.In uneven bridge measuring method, under the state turn-offed in K switch 1 closure, K switch 2 respectively and in K switch 1, turn-off, under the state of K switch 2 closures to the electric current of the voltage-to-ground of direct current positive and negative busbar, a pair of balance bridge resistance with measured with one of them electric current that detects resistor bridge, can measure so bipolar while ground insulation resistance value.Because the balance bridge measuring method has advantages of that detection speed is fast, but while thering is bipolar ground connection simultaneously, the shortcoming that measuring error is large, can not detect balance ground connection; Uneven bridge measuring method has advantages of that any earthing mode all can accurately detect, but, simultaneously due in measuring process, needs positive and negative bus throw over the ground respectively resistance (detection resistor bridge), thus Bus Voltage be change and detection speed slow.So in actual applications, the mode of generally all using two kinds of measuring methods to combine detects the insulation against ground resistance of DC bus.Below illustrate two kinds of measuring methods:

When carrying out the balance bridge measurement, introduce and detect resistor bridge RL1, RL2, can only measure one pole insulation against ground resistance value.If carry out negative busbar one pole insulation against ground resistance measurement, as shown in Figure 4 A, can draw: I+IRx=0, wherein, I is the electric current on current sense resistor RI, the insulation against ground resistance that Rx is equivalent direct current negative busbar, electric current on the insulation against ground resistance R x that IRx is equivalent direct current negative busbar, and then can push away to obtain Rx=-Un/I, and at this, it should be noted that, "-" represents direction of current.In the Rx=-Un/I formula, due to the Un voltage-to-ground that is K switch 1, K2 direct current negative busbar while all turn-offing, can directly measure by voltage detection module, and the electric current I on current sense resistor RI can directly measure by current detection module, therefore, can calculate negative busbar one pole insulation against ground resistance value.

When carrying out the balance bridge measurement, similarly, if will carry out positive bus-bar one pole insulation against ground resistance measurement, as shown in Figure 4 B, can draw: I+IRy=0, wherein, I is the electric current on current sense resistor RI, the insulation against ground resistance that Ry is equivalent direct current positive bus, electric current on the insulation against ground resistance R y that IRy is equivalent direct current positive bus, and then can push away to obtain Ry=-Up/I, and at this, it should be noted that, "-" represents direction of current.In the Ry=-Up/I formula, due to the Up voltage-to-ground that is K switch 1, K2 direct current positive bus while all turn-offing, can directly measure by voltage detection module, and the electric current I on current sense resistor RI can directly measure by current detection module, therefore, can calculate positive bus-bar one pole insulation against ground resistance value.

When carrying out uneven bridge measurement, because detection resistor bridge RL1 or RL2 are introduced respectively in twice measurement, can measure the two poles of the earth situation of ground connection simultaneously.When K switch 1 closure, K switch 2 are turn-offed, the equivalent electrical circuit of Fig. 3 as shown in Figure 4 C, can draw: I1+IRx1+IRy1=0, and then can derive:

I1+Un1/Rx+Up1/Ry=0; Formula 1

Wherein, I1 is when K switch 1 closure, K switch 2 are turn-offed, the electric current on current sense resistor RI; Un1 is when K switch 1 closure, K switch 2 are turn-offed, the voltage-to-ground of direct current negative busbar; Up1 is when K switch 1 closure, K switch 2 are turn-offed, the voltage-to-ground of direct current positive bus; The insulation against ground resistance that Rx is equivalent direct current negative busbar; The insulation against ground resistance that Ry is equivalent direct current positive bus.

When K switch 1 shutoff, K switch 2 closure, the equivalent electrical circuit of Fig. 3 as shown in Figure 4 D, can draw: I2+IRx2+IRy2=0,, and then can derive:

I2+Un2/Rx+Up2/Ry=0 formula 2

Wherein, I2 is when K switch 1 shutoff, K switch 2 closure, the electric current on current sense resistor RI; Un2 is when K switch 1 shutoff, K switch 2 closure, the voltage-to-ground of direct current negative busbar; Up2 is when K switch 1 shutoff, K switch 2 closure, the voltage-to-ground of direct current positive bus; The insulation against ground resistance that Rx is equivalent direct current negative busbar; The insulation against ground resistance that Ry is equivalent direct current positive bus.

Because electric current I 1, I2, Up1, U n1, Up2, U n2 all can directly measure, so, formula 1, formula 2 are separated to the value that the linear equation in two unknowns group can calculate Rx, R y, that is,

Rx=(Un1*Up2-Un2*Up1)/(I2*Up1-I1*Up2)

Ry=(Up1*Un2-Up2*Un1)/(I2*Un1-I1*Un2)。

Fig. 5 is the circuit diagram of the utility model direct supply insulation detection device embodiment tri-, this embodiment compares the embodiment bis-shown in Fig. 3, difference is only the quantity of current sense resistor, the quantity of the current sense resistor of this embodiment is two, be current sense resistor RI1, RI2, and, the first end of the first end of current sense resistor RI1 and current sense resistor RI2 is ground connection respectively, the second end of current sense resistor RI1 is respectively by a pair of balance bridge resistance R b2, Rb1 is just connecing direct current, negative busbar, the second end of current sense resistor RI2 is respectively by a pair of detection resistor bridge RL2, RL1 and each self-corresponding K switch 2, K1 is just connecing direct current, negative busbar.When measuring, with the embodiment bis-difference places shown in Fig. 3, be: in the balance bridge measuring method, because K switch 1, K2 all turn-off, so, only need to detect the electric current on current sense resistor RI1, the electric current of a pair of balance bridge resistance and.In uneven bridge measuring method, K switch 1, K2 guarantee an only switch closure in twice measurement, and, need to when each the measurement, detect electric current on current sense resistor RI1 and the electric current sum of current sense resistor RI2, that is, the electric current of a pair of balance bridge resistance and respectively with a pair of detection resistor bridge in each electric current sum.

Fig. 6 is the circuit diagram of the utility model direct supply insulation detection device embodiment tetra-, this embodiment compares the embodiment bis-shown in Fig. 3, difference is only the quantity of current sense resistor, the quantity of the current sense resistor of this embodiment is two, be current sense resistor RI3, RI4, and, the first end of the first end of current sense resistor RI3 and current sense resistor RI4 is ground connection respectively, the second end of current sense resistor RI3 connects the direct current negative busbar by balance bridge resistance R b1, the second end of current sense resistor RI3 is also by K switch 2, detect resistor bridge RL2 and connect direct current positive bus, the second end overbalance resistor bridge Rb2 of current sense resistor RI4 connects direct current positive bus, the second end of current sense resistor RI4 is also by K switch 1, detect resistor bridge RL1 and connect the direct current negative busbar.When measuring, with the embodiment bis-difference places shown in Fig. 3, be: in the balance bridge measuring method, K switch 1, K2 all turn-off, and detect respectively the electric current on current sense resistor RI3, current sense resistor RI4, both sums be a pair of balance bridge resistance electric current and.In uneven bridge measuring method, K switch 1, K2 guarantee an only switch closure in twice measurement, and, need to when each the measurement, detect the electric current and the electric current of current sense resistor RI4 on current sense resistor RI3, the electric current that both sums are a pair of balance bridge resistance and with the electric current sum of one of them detection resistor bridge.

In other embodiment of the utility model direct supply insulation detection device, the quantity of current sense resistor also can be three, for example, in an example, three current sense resistors are respectively the 6th current sense resistors, the 7th current sense resistor and the 8th current sense resistor, the first end of the 6th current sense resistor, the first end of the first end of the 7th current sense resistor and the 8th current sense resistor is ground connection respectively, the second end of the 6th current sense resistor is just connecing direct current by a pair of balance bridge resistance respectively, negative busbar, the second end of the 7th current sense resistor, the second end of described the 8th current sense resistor is just connecing direct current by one in a pair of detection resistor bridge and each self-corresponding switch respectively, negative busbar.Certainly, in other example, the annexation of three current sense resistors can be done corresponding adjustment, for example, the first end of three current sense resistors is ground connection respectively, the second end of the second end of the 6th current sense resistor, the 7th current sense resistor connects the positive and negative bus of direct current by one in a pair of balance bridge resistance respectively, and the second end of the 8th current sense resistor is crossed respectively described a pair of detection resistor bridge and each self-corresponding switch and connect the positive and negative bus of direct current.

In other embodiment of the utility model direct supply insulation detection device, the quantity of current sense resistor also can be four, for example, these four current sense resistors for example are respectively the 9th current sense resistor, the tenth current sense resistor, the 11 current sense resistor and the 12 current sense resistor, the first end of the 9th current sense resistor, the first end of the tenth current sense resistor, the first end of the first end of the 11 current sense resistor and the 12 current sense resistor is ground connection respectively, the second end of the 9th current sense resistor, the second end of the tenth current sense resistor is just connecing direct current by one in a pair of balance bridge resistance respectively, negative busbar, the second end of the 11 current sense resistor, the second end of the 12 current sense resistor is just connecing direct current by one in a pair of detection resistor bridge and each self-corresponding switch respectively, negative busbar.

Finally also it should be noted that, any current sense resistor in above-described embodiment all can or mix the resistance string joined by a plurality of series, parallel and replace.

In the utility model direct supply insulation detecting method embodiment mono-, in conjunction with Fig. 7 A, Fig. 7 B, when detecting one pole insulation against ground resistance value, carry out:

A1. detect the positive and negative bus difference of direct current voltage over the ground;

B1. detect a pair of balance bridge resistance electric current and, wherein, described a pair of balance bridge resistance is fixedly connected on respectively between the positive and negative bus of direct current and ground;

C1. according to the electric current of detected described a pair of balance bridge resistance with obtain the positive and negative bus of direct current leakage current over the ground, and, according to the positive and negative bus of detected direct current voltage over the ground and the leakage current obtained respectively, calculate one pole insulation against ground resistance value;

Detecting bipolar while during the ground insulation resistance value, carrying out:

A2. detect the positive and negative bus difference of direct current voltage over the ground;

B2. detect the electric current of described a pair of balance bridge resistance and respectively with a pair of detection resistor bridge in each electric current sum, wherein, described a pair of detection resistor bridge is connected between the positive and negative bus of direct current and ground by corresponding switch respectively;

C2. according to the electric current of detected described a pair of balance bridge resistance and respectively with described a pair of detection resistor bridge in each electric current sum obtain the positive and negative bus of direct current leakage current over the ground, and, according to the positive and negative bus of detected direct current voltage over the ground and the leakage current obtained respectively, calculate bipolar while ground insulation resistance value.

Preferably, step B1 specifically comprises:

B11. the electric current of the described a pair of balance bridge resistance of at least one current sense resistor sampling, and obtain the sampled voltage on each current sense resistor;

B12. reach according to the sampled voltage on each current sense resistor the electric current that the Current calculation model built in advance calculates each current sense resistor respectively;

B13. according to the electric current of the described a pair of balance bridge resistance of the Current calculation of described at least one current sense resistor;

Described step B2 comprises:

B21. the electric current of the described a pair of balance bridge resistance of at least one current sense resistor sampling and the electric current of described a pair of detection resistor bridge, and obtain the sampled voltage on each current sense resistor;

B22. reach according to the sampled voltage on each current sense resistor the electric current that the Current calculation model built in advance calculates each current sense resistor respectively;

B13. according to the electric current of the described a pair of balance bridge resistance of the Current calculation of described at least one current sense resistor respectively with a pair of detection resistor bridge in each electric current sum; Wherein,

The Current calculation model built in advance is:

I=K*U+B

Wherein, the current value that I is electric current to be detected, U is the ohmically sampled voltage of corresponding current detecting, K, B are respectively calibration parameter, and calibration parameter K, B are that according to two specific current value and corresponding current sense resistor, the sampled voltage under each specific current value obtains in advance.

The foregoing is only preferred embodiment of the present utility model, be not limited to the utility model, for a person skilled in the art, the utility model can have various changes, combination and variation.All within spirit of the present utility model and principle, any modification of doing, be equal to replacement, improvement etc., within all should being included in claim scope of the present utility model.

Claims (8)

1. a direct supply insulation detection device, insulation against ground resistance for detection of DC bus, described direct supply insulation detection device comprises: for detection of voltage detection module, a pair of balance bridge resistance and a pair of detection resistor bridge of the positive and negative bus difference of direct current voltage over the ground, and, described a pair of balance bridge resistance is fixedly connected on respectively between the positive and negative bus of direct current and ground, described a pair of detection resistor bridge is connected between the positive and negative bus of direct current and ground by corresponding switch respectively, it is characterized in that, described direct supply insulation detection device also comprises:
For the electric current that detects described a pair of balance bridge resistance when detecting one pole insulation against ground resistance value and, and detect bipolar while detect during the ground insulation resistance value electric current of described a pair of balance bridge resistance and respectively with described a pair of detection resistor bridge in each the current detection module of electric current sum;
Be connected in described voltage detection module and described current detection module, and for when detecting one pole insulation against ground resistance value, the electric current of the described a pair of balance bridge resistance detected according to described current detection module and obtain the positive and negative bus of direct current leakage current over the ground, and the positive and negative bus of the direct current detected according to described voltage detection module voltage over the ground and the leakage current obtained respectively, calculate one pole insulation against ground resistance value; Detecting bipolar while during the ground insulation resistance value, the electric current of the described a pair of balance bridge resistance detected according to described current detection module and respectively with described a pair of detection resistor bridge in each electric current sum obtain the positive and negative bus of direct current leakage current over the ground, and the positive and negative bus of the direct current detected according to described voltage detection module voltage over the ground and the leakage current obtained respectively, calculate the computing module of bipolar while ground insulation resistance value.
2. direct supply insulation detection device according to claim 1, is characterized in that, described current detection module comprises:
For when detecting one pole insulation against ground resistance value, the electric current of the described a pair of balance bridge resistance of sampling; And detecting bipolar while during the ground insulation resistance value, at least one current sense resistor of the electric current of the described a pair of balance bridge resistance of sampling and the electric current of described a pair of detection resistor bridge.
3. direct supply insulation detection device according to claim 2, it is characterized in that, described at least one current sense resistor is the first current sense resistor, and, the first end ground connection of described the first current sense resistor, the second end of described the first current sense resistor connects the positive and negative bus of direct current by described a pair of balance bridge resistance respectively, and the second end of described the first current sense resistor also connects the positive and negative bus of direct current by described a pair of detection resistor bridge and each self-corresponding switch respectively.
4. direct supply insulation detection device according to claim 2, it is characterized in that, described at least one current sense resistor comprises the second current sense resistor and the 3rd current sense resistor, the first end of the first end of described the second current sense resistor and described the 3rd current sense resistor is ground connection respectively, the second end of described the second current sense resistor connects the positive and negative bus of direct current by described a pair of balance bridge resistance respectively, and the second end of described the 3rd current sense resistor connects the positive and negative bus of direct current by described a pair of detection resistor bridge and each self-corresponding switch respectively.
5. direct supply insulation detection device according to claim 2, it is characterized in that, described at least one current sense resistor comprises the 4th current sense resistor and the 5th current sense resistor, the first end of the first end of described the 4th current sense resistor and described the 5th current sense resistor is ground connection respectively, the second end of described the 4th current sense resistor connects the direct current negative busbar by one of them in described a pair of balance bridge resistance, the second end of described the 4th current sense resistor also connects direct current positive bus by one of them and corresponding switch thereof in described a pair of detection resistor bridge, the second end of described the 5th current sense resistor is crossed another in described a pair of balance bridge resistance and is connect direct current positive bus, the second end of described the 5th current sense resistor also connects the direct current negative busbar by another and corresponding switch thereof in described a pair of detection resistor bridge.
6. direct supply insulation detection device according to claim 2, it is characterized in that, described at least one current sense resistor comprises the 6th current sense resistor, the 7th current sense resistor and the 8th current sense resistor, the first end of described the 6th current sense resistor, the first end of the first end of the 7th current sense resistor and the 8th current sense resistor is ground connection respectively, the second end of described the 6th current sense resistor is just connecing direct current by described a pair of balance bridge resistance respectively, negative busbar, the second end of described the 7th current sense resistor, the second end of described the 8th current sense resistor is just connecing direct current by one in described a pair of detection resistor bridge and each self-corresponding switch respectively, negative busbar.
7. direct supply insulation detection device according to claim 2, it is characterized in that, described at least one current sense resistor comprises the 9th current sense resistor, the tenth current sense resistor, the 11 current sense resistor and the 12 current sense resistor, the first end of described the 9th current sense resistor, the first end of the tenth current sense resistor, the first end of the first end of the 11 current sense resistor and the 12 current sense resistor is ground connection respectively, the second end of described the 9th current sense resistor, the second end of described the tenth current sense resistor is just connecing direct current by one in described a pair of balance bridge resistance respectively, negative busbar, the second end of described the 11 current sense resistor, the second end of described the 12 current sense resistor is just connecing direct current by one in described a pair of detection resistor bridge and each self-corresponding switch respectively, negative busbar.
8. direct supply insulation detection device according to claim 1, is characterized in that, described current detection module is Hall current sensor or shunt.
CN2013202956097U 2013-05-27 2013-05-27 Direct-current power insulation detection device CN203324419U (en)

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CN106093576B (en) * 2016-06-02 2019-01-15 谢林 A kind of electrolytic cell group insulation against ground resistor detection method and device
CN108152589A (en) * 2017-12-13 2018-06-12 四川长虹电器股份有限公司 DC power supply insulating resistor detecting circuit and method
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