CN104297568A - Insulation resistance detection device and method for double-winding motor - Google Patents

Abstract

The invention provides a device and a method for detecting insulation resistance of a double-winding motor, wherein the device comprises the following components: the control unit is used for controlling the converter to apply the same-direction direct-current bus voltage and the reverse direct-current bus voltage; the voltage and current detection unit is used for detecting the voltage and the current of the output end of the first winding and the output end of the second winding relative to the grounding point under the state of applying the direct current bus voltage in the same direction and the direct current bus voltage in the opposite direction; and an insulation resistance calculation unit for calculating insulation resistance according to the detected voltage and current. Direct current bus voltage in different directions is applied to the winding by controlling the double-winding motor converter, the voltage value and the current value of a measuring loop under the direct current bus voltage in different directions are measured, then the insulation resistance value is calculated, manual detection of the insulation resistance of the motor by a maintainer through carrying an insulation resistance tester is avoided, and intelligent and normalized detection of the insulation resistance of the motor is realized.

Description

The insulation resistance detection device of double-winding motor and method

Technical field

The present invention relates to technical field of wind power generation, particularly relate to a kind of insulation resistance detection device and method of double-winding motor.

Background technology

In wind power generating set, the cost of generator accounts for the very large proportion of whole wind power generating set cost, along with the quantity of wind power generating set is on the increase, the continuous increase of generator operation time, people more and more pay close attention to the security of operation of generator, and people also often use the insulation resistance of generator as the evaluation index evaluating generator insulating level.Because aerogenerator is generally placed in the cabin of the blower fan of distance ground more than 60m, usually need maintainer to carry Insulation Resistance Tester by detecting the insulation resistance of motor in pylon to cabin, therefore the insulation resistance of manual type to motor detects very inconvenient.

Summary of the invention

The embodiment of the present invention provides a kind of insulation resistance detection device and method of double-winding motor, avoids the insulation resistance of manual testing's double-winding motor, the intellectuality that the insulation resistance realizing double-winding motor detects and normalization.

For achieving the above object, The embodiment provides a kind of insulation resistance detection device of double-winding motor, winding in any phase in described double-winding motor in one group of three-phase windings is as the first winding, using the winding of the corresponding phase in another group three-phase windings as the second winding, described device comprises:

Control module, applies DC bus-bar voltage in the same way and reverse DC bus-bar voltage for controlling current transformer to described first winding and described second winding;

Measure voltage & current unit, for detecting under the state applying DC bus-bar voltage in the same way and reverse DC bus-bar voltage, the output terminal of described first winding and the output terminal of described second winding connect the voltage and current in place;

Insulation resistance calculates unit, for the voltage and current arrived according to described measure voltage & current unit inspection, calculates described insulation resistance.

Embodiments of the invention additionally provide a kind of insulation resistance detection method of double-winding motor, winding in any phase in described double-winding motor in one group of three-phase windings is as the first winding, using the winding of the corresponding phase in another group three-phase windings as the second winding, described method comprises:

Detecting step: control current transformer and apply the identical DC bus-bar voltage in the direction DC bus-bar voltage contrary with direction to described first winding and described second winding, the voltage and current in place and the output terminal of the output terminal and described second winding that detect described first winding connects;

Insulation resistance calculates step: according to the voltage and current detected in described detecting step, calculate described insulation resistance.

The insulation resistance detection device of the double-winding motor that the embodiment of the present invention provides and method, by controlling the DC bus-bar voltage of double-winding motor current transformer to winding applying different directions, and measure magnitude of voltage and the current value of the measuring circuit under the DC bus-bar voltage of different directions, then calculate insulating resistance value and complete detection, avoid maintainer, by carrying Insulation Resistance Tester, manual detection is carried out to the insulation resistance of motor, achieve the intellectuality to the insulation resistance of motor and normalization detection.

Accompanying drawing explanation

Fig. 1 is the exemplary system architecture figure of double-winding motor.

Fig. 2 is the illustrative diagram of the equivalent insulation resistance model of double-winding motor.

One of insulation resistance detection device structural drawing of the double-winding motor that Fig. 3 provides for the embodiment of the present invention.

The insulation resistance detection device structural drawing two of the double-winding motor that Fig. 4 provides for the embodiment of the present invention.

The circuit structure simulation drawing of the equivalent insulation resistance detection system of the double-winding motor that Fig. 5 provides for the embodiment of the present invention two.

Fig. 6 is one of schematic flow sheet of the detection method of the insulation resistance of the double-winding motor of the embodiment of the present invention.

Fig. 7 is the schematic flow sheet two of the detection method of the insulation resistance of the double-winding motor of the embodiment of the present invention.

Drawing reference numeral illustrates:

1-permanent-magnetic wind driven generator double-winding motor; 2-first pusher side switch; 3-second pusher side switch; 4-pusher side wave filter; 5-current transformer; 501-first rectifying part; 502-second rectifying part; 503-first three phase full bridge; 504-second three phase full bridge; 6-net side filter; 7-nets side switch; 8-transformer; 100-control module; 200-measure voltage & current unit; 300-insulation resistance calculates unit; 110-switch control unit; 120-current transformer control module; The single-phase pusher side switch of 201-first; The single-phase pusher side switch of 301-second; 51-first single-phase rectifier part; 52-second single-phase rectifier part; Brachium pontis on 5011-first; 5012-first time brachium pontis; Brachium pontis on 5021-second; 5022-second time brachium pontis; 210-first current detection circuit; 211-first resistance; 212-first voltage operational amplifier; 213-first current calculation unit; 220-first voltage detecting circuit; 221-second resistance; 222-the 3rd resistance; 223-second voltage operational amplifier; 224-first voltage computation unit; 230-second voltage detecting circuit; 231-the 6th resistance; 232-the 5th resistance; 233-the 4th voltage operational amplifier; 234-second voltage computation unit; 240-second current detection circuit; 241-the 4th resistance; 242-tertiary voltage operational amplifier; 243-second current calculation unit; 250-detected value acquiring unit; 260-winding voltage computing unit; The equivalent insulation resistance of 310-first calculates unit; The equivalent insulation resistance of 320-second calculates unit; Unit calculated by the equivalent insulating-resistance meter of 330-the 3rd.

Embodiment

Below in conjunction with accompanying drawing, the insulation resistance detection device of the double-winding motor that the embodiment of the present invention provides and method are described in detail.

The insulation resistance detection device of double-winding motor of the present invention and the know-why of method are by controlling the DC bus-bar voltage of double-winding motor current transformer to winding applying different directions, and measure magnitude of voltage and the current value of the measuring circuit under the DC bus-bar voltage of different directions, carry out calculating again and can draw insulating resistance value, complete detection.

The illustrative diagram of Fig. 1 to be the exemplary system architecture figure of double-winding motor, Fig. 2 be equivalent insulation resistance model of double-winding motor.As shown in Figure 1, permanent-magnetic wind driven generator group double-winding motor (hereinafter referred to as motor) 1 generally adopts two three-phase windings form, the pusher side of the full power convertor (hereinafter referred to as current transformer) 5 mated with it adopts two three-phase full-bridge rectifiers (the first rectifying part 501, second rectifying part 502), its inside is by IGBT (Insulated Gate Bipolar Transistor, three phase isolated grid bipolar transistor) form, two pusher side switches are connected with the second transmission line respectively by the first transmission line, in an embodiment of the present invention, these two pusher side switches are called the first pusher side switch 2 and the second pusher side switch 3, wherein, each pusher side switch can be regarded as and is made up of three that are arranged on three-line single-phase pusher side switches, in the application of reality, pusher side switch is three-phase ganged.The other end of pusher side switch connects two windings of motor 1 respectively, and between the first pusher side switch 2, second pusher side switch 3 and current transformer 5, junctor side filter 4, its type of attachment as shown in Figure 1.After net side switch 7 adhesive, DC bus-bar voltage after net side three phase full bridge (the first three phase full bridge 503, the second three phase full bridge 504) rectification of current transformer 5 maintains 690 × 1.414=975.66V, connection network side filter 6 between net side switch 7 and current transformer 5, by net side filter 6 through cable transmission to transformer 8.In pusher side full-bridge, in any phase, brachium pontis is open-minded, and positive direct-current busbar voltage will be applied to motor winding, and lower brachium pontis opens negative DC bus-bar voltage will be applied to motor winding.When measuring insulation resistance, because three-phase windings is symmetrical, the winding therefore when measuring insulation resistance in optional any phase.

R in Fig. 2 ₁be first equivalent insulating resistance value, the R of the first winding to the casing PE (motor case PE is generally connected with system earth point) of motor ₂be that the second winding is to second of the casing of motor the equivalent insulating resistance value, R ₁₂it is the 3rd equivalent insulating resistance value between the first winding and the second winding.Wherein, the first winding is the winding in any phase in double-winding motor in one group of three-phase windings, and the second winding is the winding of the corresponding phase in another group three-phase windings.As shown in Figure 2, following equation can be drawn:

$\left\{\begin{array}{c}{I}_{R1}=V_1/R_1\\ I_{R2}=V_2/R_2\end{array}\right.---\left(1\right)$

$\left\{\begin{array}{c}{I}_1=I_{R1}+I_{R12}=\frac{V_1}{R_1}+\frac{V_1-V_2}{R_{12}}\\ I_2=I_{R2}+I_{R12}=-\frac{V_2}{R_2}+\frac{V_1-V_2}{R_{12}}\end{array}\right.---\left(2\right)$

Can draw according to formula (1) and formula (2):

$I_1-I_2=\frac{V_1}{R_1}+\frac{V_2}{R_2}---\left(3\right)$

Analyze theoretically, insulating resistance value R be measured ₁, R ₂and R ₁₂, I can be measured according to formula (1) _r1, I _r2, V ₁and V ₂, but in real process, the current value I of the equivalent insulation resistance flowing through single winding cannot be measured _r1and I _r2, therefore obtain formula (3) by derivation, I in publicity (3) ₁, I ₂, V ₁and V ₂all record by relevant apparatus and method, known according to formula (3), R be obtained ₁and R ₂need the V that two groups different ₁and V ₂value and at V ₁and V ₂under I ₁, I ₂value.On the basis of above-mentioned analysis, inventor contemplate and use the DC bus-bar voltage of wind power generating set as driving source, thus produce V ₁and V ₂and go to obtain the method for insulating resistance value by measurement and calculation on this basis and design the device realizing the method, this device can complete the real-time detection to insulation resistance by inner control module, avoid maintainer, by carrying Insulation Resistance Tester, manual detection is carried out to the insulation resistance of motor, achieve the intellectuality to the insulation resistance of motor and normalization detection.

Above the know-why of the embodiment of the present invention is introduced, will the concrete structure of the insulation resistance detection device of double-winding motor of the present invention be introduced by several embodiment in detail and the concrete steps of detection method are described in detail below.

Embodiment one

When measuring insulation resistance, because three-phase windings is symmetrical, therefore the winding when measuring insulation resistance in optional any phase, using the winding in any phase in one group of three-phase windings in double-winding motor as the first winding, using the winding of the corresponding phase in another group three-phase windings as the second winding.

The insulation resistance detection device structural drawing of the double-winding motor that Fig. 3 provides for the embodiment of the present invention; As shown in Figure 3, the insulation resistance detection device of embodiment of the present invention double-winding motor comprises:

Control module 100, applies DC bus-bar voltage in the same way and reverse DC bus-bar voltage for controlling current transformer to the first winding and the second winding.

Wherein, apply DC bus-bar voltage in the same way and refer to that to be applied to the first winding the same with the polarity of voltage on the second winding, such as positive direct-current busbar voltage is applied to respectively on the first winding and on the second winding by brachium pontis in the second single-phase rectifier part of brachium pontis and the second rectifying part 502 in the first single-phase rectifier part of the first rectifying part 501 in closed Fig. 1, or under the first single-phase rectifier part of closed first rectifying part 501 brachium pontis and the second rectifying part 502 the second single-phase rectifier part under brachium pontis be negative DC bus-bar voltage is applied to respectively on the first winding and on the second winding, apply reverse DC bus-bar voltage and refer to that the polarity of voltage be applied on the first winding and the second winding is contrary, such as by brachium pontis under the second single-phase rectifier part of brachium pontis and the second rectifying part 502 in the first single-phase rectifier part of the first rectifying part 501 in closed Fig. 1, positive direct-current busbar voltage is applied on the first winding, negative DC bus-bar voltage is applied on the second winding, or under the first single-phase rectifier part of closed first rectifying part 501 brachium pontis and the second rectifying part 502 the second single-phase rectifier part on brachium pontis, negative DC bus-bar voltage is applied on the first winding, positive direct-current busbar voltage is applied on the second winding.

Measure voltage & current unit 200, for detecting under the state applying DC bus-bar voltage in the same way and reverse DC bus-bar voltage, the output terminal of the first winding and the output terminal of the second winding connect the voltage and current in place.

Insulation resistance calculates unit 300, for the voltage and current arrived according to measure voltage & current unit inspection, calculates insulation resistance.

The pick-up unit of the insulation resistance of the double-winding motor of embodiments of the invention is by controlling the DC bus-bar voltage of current transformer to winding applying different directions, namely use DC bus-bar voltage as the driving source of insulation measurement, thus obtain corresponding electric current and voltage value and calculate insulating resistance value, realize the intellectuality to electrical machine insulation resistance and normalization detection.

Embodiment two

The insulation resistance detection device structural drawing two of the double-winding motor that Fig. 4 provides for the embodiment of the present invention; Fig. 5 is the circuit structure illustraton of model of the equivalent insulation resistance detection system of the double-winding motor of the embodiment of the present invention two, wherein, Fig. 5 has carried out more detailed description with the testing circuit of any phase winding to the measure voltage & current unit in the pick-up unit of the present embodiment, and corresponding part represents with identical label.In Figure 5, R _g1, R _g2be respectively current transformer positive direct-current bus and negative DC bus equivalent resistance over the ground, R ₀for electric generator casing PE is to the equivalent resistance of system earth point (earth point mentioned below is electric generator casing PE).In an embodiment of the present invention, R _g1, R _g2, R ₀too much influence is not had to the calculating of electrical machine insulation resistance, therefore, negligible.As shown in Figure 4 and Figure 5, the insulation resistance detection device of the double-winding motor of the present embodiment comprises control module 100, measure voltage & current unit 200 and insulation resistance and calculates unit 300, illustrates respectively below to each unit:

Control module 100, applies DC bus-bar voltage in the same way and reverse DC bus-bar voltage for controlling current transformer to the first winding and the second winding; Further, control module 100 can comprise:

Switch control unit 110, for controlling the first single-phase pusher side switch and the second single-phase pusher side switch; As shown in Figure 5, switch control unit 110 is the opening and closing (arrow shown in figure is for controlling to point to) of control first single-phase pusher side switch 201 and the second single-phase pusher side switch 301.

Current transformer control module 120, as shown in Figure 5, for under the state of the first single-phase pusher side switch 201 and the second single-phase pusher side switch 301 unlatching, control the first single-phase rectifier part 51 and the second single-phase rectifier part 52, to the first transmission line and the second transmission line applying DC bus-bar voltage in the same way, and apply reverse DC bus-bar voltage (arrow shown in figure is for controlling to point to) to the first transmission line and the second transmission line.

Wherein, first single-phase rectifier part 51 has brachium pontis 5011 and first time brachium pontis 5012 on first, second single-phase rectifier part 52 has brachium pontis 5021 and second time brachium pontis 5022 on second, further, current transformer control module can comprise the first current transformer sub-control unit, for brachium pontis 5021 on brachium pontis on closed first 5011 and second or closed first time brachium pontis 5012 and second time brachium pontis 5022, to apply DC bus-bar voltage in the same way; Second current transformer sub-control unit, for brachium pontis 5021 on brachium pontis 5011 on closed first and second time brachium pontis 5022 or closed first time brachium pontis 5012 and second, to apply reverse DC bus-bar voltage.

Measure voltage & current unit 200, for detecting under the state applying DC bus-bar voltage in the same way and reverse DC bus-bar voltage, the output terminal of the first winding and the output terminal of the second winding connect the voltage and current in place.Further, measure voltage & current unit 200 can comprise:

First current detection circuit 210, is connected in parallel on the two ends of the first single-phase pusher side switch 201, as shown in Figure 5, for detecting the electric current flowing through this first current detection circuit; According to Fig. 5, first current detection circuit 210 can comprise the first resistance 211, be arranged on first voltage operational amplifier 212, first current calculation unit 213, first current calculation unit 213 at these the first resistance two ends for the voltage of the first resistance 211 that exports according to the first voltage operational amplifier 212 and the resistance value R of the first resistance 211 _s1calculate the first same direction current I ₁₁with the first inverse current I ₁₂.

First voltage detecting circuit 220, is connected between the first current transformer end and earth point, as shown in Figure 5, for detecting the voltage between the first current transformer end to earth point.According to Fig. 5, first voltage detecting circuit 220 comprises the 3rd resistance 222 that the second resistance 221 of being connected in series and resistance be less than the second resistance and the second voltage operational amplifier 223, first voltage computation unit 224, first voltage computation unit 224 being connected to the 3rd resistance two ends for the voltage of the 3rd resistance 222 that exports according to the second voltage operational amplifier 223 and the resistance R of the second resistance 221 _s2with the resistance R of the 3rd resistance 222 _s3calculating first voltage V in the same way _c11with the first reverse voltage V _c12.

Second current detection circuit 240, is connected in parallel on the two ends of the second single-phase pusher side switch 301, as shown in Figure 5, for detecting the electric current flowing through this second current detection circuit.According to Fig. 5, second current detection circuit 240 comprises the 4th resistance 241, be arranged on the resistance value R of four resistance 241 of tertiary voltage operational amplifier 242, second current calculation unit 243, second current calculation unit 243 at the 4th resistance two ends for exporting according to tertiary voltage operational amplifier 242 _s4calculate the second same direction current I ₂₁with the second inverse current I ₂₂.

Second voltage detecting circuit 230, is connected between the second current transformer end and earth point, as shown in Figure 5, for detecting the voltage between the second current transformer end to earth point.Second voltage detecting circuit 230 comprises the 6th resistance 231 that the 5th resistance 232 that is connected in series and resistance be less than the 5th resistance and the 4th voltage operational amplifier 233, second voltage computation unit 234, second voltage computation unit 234 being connected to the 6th resistance two ends for the voltage of the 6th resistance 231 that exports according to the 4th voltage operational amplifier 233 and the resistance R of the 5th resistance 232 _s5with the resistance R of the 6th resistance 231 _s6calculating second voltage V in the same way _c21with the second reverse voltage V _c22.

Detected value acquiring unit 250, for obtaining under the state applying DC bus-bar voltage in the same way, the first same direction current I that the first current detection circuit 210, first voltage detecting circuit 220, second current detection circuit 240 and the second voltage detecting circuit 230 record ₁₁, the first voltage V in the same way _c11, the second same direction current I ₂₁, the second voltage V in the same way _c21, and calculate the first winding voltage V in the same way between the first motor side to earth point ₁₁and second the second winding voltage V in the same way between motor side to earth point ₂₁, and obtain the first inverse current I recorded under the state applying reverse DC bus-bar voltage ₁₂, the first reverse voltage V _c12, the second inverse current I ₂₂, the second reverse voltage V _c22, and calculate the first winding reverse voltage V between the first motor side to earth point ₁₂and second the second winding reverse voltage V between motor side to earth point ₂₂.

Winding voltage computing unit 260, resistance value for the voltage and current that gets according to detected value acquiring unit 250 and each first current detection circuit 210 and the second current detection circuit 220 calculates, under the state applying DC bus-bar voltage in the same way, the voltage V in the same way of the first winding between the first motor side to earth point ₁₁and second the second winding voltage V in the same way between motor side to earth point ₂₁, and under the state applying reverse DC bus-bar voltage, the first winding reverse voltage V between the first motor side to earth point ₁₂and second the second winding reverse voltage V between motor side to earth point ₂₂.Further, winding voltage computing unit 260 can comprise:

First winding voltage computing unit, for calculating the first winding voltage V in the same way by following formula ₁₁with the first winding reverse voltage V ₁₂,

$\left\{\begin{array}{c}{V}_{11}=V_{C11}-I_{11}{R}_{s1}\\ V_{12}=V_{C12}+I_{12}{R}_{s1}\end{array}\right.---\left(4\right);$

Second winding voltage computing unit, for calculating the second winding voltage V in the same way by following formula ₂₁, and the second winding reverse voltage V ₂₂,

$\left\{\begin{array}{c}{V}_{21}=V_{C21}-I_{21}{R}_{s4}\\ V_{22}=V_{C22}+I_{22}{R}_{s4}\end{array}\right.---\left(5\right).$

Insulation resistance calculates unit 300: for the voltage and current detected according to measure voltage & current unit 200, calculates insulation resistance.Further, as shown in Figure 4, insulation resistance calculating unit 300 can comprise:

First equivalent insulation resistance calculates unit 310, for calculating R by following formula ₁,

$R_1=\frac{V_{11}-\frac{V_{21}{V}_{12}}{V_{22}}}{(I_{11}-I_{12})-\frac{V_{2\_1}}{V_{2\_2}}(I_{21}-I_{22})}---\left(6\right);$

Second equivalent insulation resistance calculates unit 320, for calculating R by following formula ₂,

$R_2=\frac{V_{12}-\frac{V_{11}{V}_{22}}{V_{21}}}{(I_{11}-I_{21})-\frac{V_{11}}{V_{21}}(I_{21}-I_{22})}---\left(7\right);$

3rd equivalent insulating-resistance meter calculates unit 330, for calculating R by following formula ₁₂,

$R_{12}=\frac{V_{21}-V_{22}}{I_{21}-\frac{V_{21}}{R_1}}---\left(8\right).$

The insulation resistance detection device of the double-winding motor that the embodiment of the present invention provides, by controlling the DC bus-bar voltage of double-winding motor current transformer to winding applying different directions, and measure magnitude of voltage and the current value of the measuring circuit under the DC bus-bar voltage of different directions, show that insulating resistance value completes detection by special algorithm, avoid maintainer, by carrying Insulation Resistance Tester, manual detection is carried out to the insulation resistance of motor, achieve the intellectuality to the insulation resistance of motor and normalization detection.

Embodiment three

Fig. 6 is one of schematic flow sheet of the detection method of the insulation resistance of the double-winding motor of the embodiment of the present invention, wherein, winding in any phase in double-winding motor in one group of three-phase windings is as the first winding, using the winding of the corresponding phase in another group three-phase windings as the second winding, as shown in Figure 6, the step of the detection method of the insulation resistance of double-winding motor is:

Detecting step 400: control current transformer and apply the identical DC bus-bar voltage in the direction DC bus-bar voltage contrary with direction to the first winding and the second winding, the voltage and current in place and the output terminal of the output terminal and the second winding that detect the first winding connects;

Insulation resistance calculates step 500: according to the voltage and current detected in detecting step 400, calculates insulation resistance.

The detection method of the insulation resistance of the double-winding motor of embodiments of the invention is by controlling the DC bus-bar voltage of current transformer to winding applying different directions, namely use DC bus-bar voltage as the driving source of insulation measurement, thus obtain corresponding electric current and voltage value and calculate insulating resistance value, realize the intellectuality to electrical machine insulation resistance and normalization detection.

Embodiment four

Fig. 7 is the schematic flow sheet two of the detection method of the insulation resistance of the double-winding motor of the embodiment of the present invention, wherein, winding in any phase in double-winding motor in one group of three-phase windings is as the first winding, using the winding of the corresponding phase in another group three-phase windings as the second winding, the output terminal of the first winding and the second winding is connected respectively by the first single-phase rectifier part of the first transmission line and the second transmission line and the pusher side rectifying part of current transformer and the second single-phase rectifier part, first transmission line and the second transmission line are respectively arranged with the first single-phase pusher side switch and the second single-phase pusher side switch.As shown in Figure 7, the concrete steps of the detection method of the insulation resistance of double-winding motor are:

Switch control rule step 410: open the first single-phase pusher side switch and the second single-phase pusher side switch;

First voltage applies step 420: control the first single-phase rectifier part and the second single-phase rectifier part, to the first transmission line and the second transmission line applying DC bus-bar voltage in the same way;

First measure voltage & current step 430: the first voltage V in the same way detecting the output terminal of the first winding and earth point ₁₁with the first same direction current I of correspondence ₁₁with second of the output terminal of the second winding and earth point the voltage V in the same way ₂₁with the second same direction current I of correspondence ₂₁;

Second voltage applies step 440: control the first single-phase rectifier part and the second single-phase rectifier part, apply reverse DC bus-bar voltage to the first transmission line and the second transmission line;

Second measure voltage & current step 450: detect the output terminal of the first winding and the first reverse voltage V of earth point ₁₂with the first inverse current I of correspondence ₁₂with the output terminal of the second winding and the second reverse voltage V of earth point ₂₂with the second inverse current I of correspondence ₂₂.In step 450, the first winding voltage V in the same way can be calculated by through type (4) ₁₁with the first winding reverse voltage V ₁₂, through type (5) calculates the second winding voltage V in the same way ₂₁with the second winding reverse voltage V ₂₂;

Insulation resistance calculates step 500: according to the voltage and current detected in the first measure voltage & current step 430 and the second measure voltage & current step 450, calculates insulation resistance.In step 500, through type (6), formula (7) and formula (8) R can be calculated ₁, R ₂and R ₁₂.

It will be understood by those skilled in the art that, above-mentioned steps 420 ~ step is uninevitable to be performed according to above-mentioned steps, also first step 440 ~ step 450 can be performed, perform step 420 ~ step 430 again, that is, the execution sequence of the embodiment of the present invention to above-mentioned steps 420 ~ step 450 does not have strict restriction.

The insulation resistance detection device of the double-winding motor that the embodiment of the present invention provides and method, by controlling the DC bus-bar voltage of double-winding motor current transformer to winding applying different directions, and measure magnitude of voltage and the current value of the measuring circuit under the DC bus-bar voltage of different directions, show that insulating resistance value completes detection by special algorithm, avoid maintainer, by carrying Insulation Resistance Tester, manual detection is carried out to the insulation resistance of motor, achieve the intellectuality to the insulation resistance of motor and normalization detection.

The above; be only the specific embodiment of the present invention, but protection scope of the present invention is not limited thereto, is anyly familiar with those skilled in the art in the technical scope that the present invention discloses; change can be expected easily or replace, all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection domain of described claim.

Claims (12)

1. the insulation resistance detection device of a double-winding motor, winding in any phase in described double-winding motor in one group of three-phase windings is as the first winding, using the winding of the corresponding phase in another group three-phase windings as the second winding, it is characterized in that, described device comprises:

Control module, applies DC bus-bar voltage in the same way and reverse DC bus-bar voltage for controlling current transformer to described first winding and described second winding;

Measure voltage & current unit, for detecting under the state applying DC bus-bar voltage in the same way and reverse DC bus-bar voltage, the output terminal of described first winding and the output terminal of described second winding connect the voltage and current in place;

Insulation resistance calculates unit, for the voltage and current arrived according to described measure voltage & current unit inspection, calculates described insulation resistance.

2. device according to claim 1, it is characterized in that, the output terminal of described first winding and described second winding is connected respectively by the first single-phase rectifier part of the first transmission line and the second transmission line and the pusher side rectifying part of current transformer and the second single-phase rectifier part, described first transmission line and described second transmission line are respectively arranged with the first single-phase pusher side switch and the second single-phase pusher side switch, and described control module comprises:

Switch control unit, for controlling described first single-phase pusher side switch and described second single-phase pusher side switch;

Current transformer control module, for under the state of described first single-phase pusher side switch and described second single-phase pusher side switch open, control described first single-phase rectifier part and described second single-phase rectifier part, to described first transmission line and described second transmission line applying DC bus-bar voltage in the same way, and apply reverse DC bus-bar voltage to described first transmission line and described second transmission line.

3. device according to claim 2, it is characterized in that, described first single-phase pusher side switch has the first motor side of connection first winding output terminal and is connected the first current transformer end of current transformer side, and described second single-phase pusher side switch has the second motor side of connection second winding output terminal and is connected the second current transformer end of current transformer side;

Described measure voltage & current unit comprises:

First current detection circuit, is connected in parallel on the two ends of described first single-phase pusher side switch, for detecting the electric current flowing through this first current detection circuit;

First voltage detecting circuit, is connected between described first current transformer end and earth point, for detecting the voltage between described first current transformer end to earth point;

Second current detection circuit, is connected in parallel on the two ends of described second single-phase pusher side switch, for detecting the electric current flowing through this second current detection circuit;

Second voltage detecting circuit, is connected between described second current transformer end and earth point, for detecting the voltage between described second current transformer end to earth point;

Detected value acquiring unit, for obtaining under the state applying DC bus-bar voltage in the same way, the first same direction current I that described first current detection circuit, described first voltage detecting circuit, described second current detection circuit and described second voltage detecting circuit record ₁₁, the first voltage V in the same way _c11, the second same direction current I ₂₁, the second voltage V in the same way _c21, and calculate the first winding voltage V in the same way between described first motor side to earth point ₁₁and the second winding voltage V in the same way between described second motor side to earth point ₂₁, and obtain the first inverse current I recorded under the state applying reverse DC bus-bar voltage ₁₂, the first reverse voltage V _c12, the second inverse current I ₂₂, the second reverse voltage V _c22, and calculate the first winding reverse voltage V between described first motor side to earth point ₁₂and the second winding reverse voltage V between described second motor side to earth point ₂₂;

Winding voltage computing unit, resistance value for the voltage and current that gets according to described detected value acquiring unit and each first current detection circuit and the second current detection circuit calculates, under the state applying DC bus-bar voltage in the same way, the voltage V in the same way of the first winding between described first motor side to earth point ₁₁and the second winding voltage V in the same way between described second motor side to earth point ₂₁, and under the state applying reverse DC bus-bar voltage, the first winding reverse voltage V between described first motor side to earth point ₁₂and the second winding reverse voltage V between described second motor side to earth point ₂₂.

4. device according to claim 3, is characterized in that,

Described first current detection circuit comprises: the first resistance, the first voltage operational amplifier being arranged on these the first resistance two ends, the first current calculation unit, described first current calculation unit be used for according to described first voltage operational amplifier export the voltage of described first resistance and the resistance value R of described first resistance _s1calculate described first same direction current I ₁₁with described first inverse current I ₁₂;

Described first voltage detecting circuit comprises: the second resistance be connected in series and resistance are less than the 3rd resistance of described second resistance and are connected to the second voltage operational amplifier, first voltage computation unit at described 3rd resistance two ends, described first voltage computation unit be used for according to described second voltage operational amplifier export the voltage of described 3rd resistance and the resistance R of described second resistance _s2with the resistance R of the 3rd resistance _s3calculating first voltage V in the same way _c11with the first reverse voltage V _c12;

Described second current detection circuit comprises: the 4th resistance, the tertiary voltage operational amplifier being arranged on the 4th resistance two ends, the second current calculation unit, and described second current calculation unit is used for the resistance value R of described 4th resistance exported according to described tertiary voltage operational amplifier _s4calculate described second same direction current I ₂₁with the second inverse current I ₂₂;

Described second voltage detecting circuit comprises: the 5th resistance be connected in series and resistance are less than the 6th resistance of described 5th resistance and are connected to the 4th voltage operational amplifier, second voltage computation unit at described 6th resistance two ends, described second voltage computation unit be used for according to described 4th voltage operational amplifier export the voltage of described 6th resistance and the resistance R of described 5th resistance _s5with the resistance R of the 6th resistance _s6calculating second voltage V in the same way _c21with the second reverse voltage V _c22.

5. device according to claim 4, is characterized in that, described winding voltage computing unit comprises:

First winding voltage computing unit, for calculating the first winding voltage V in the same way by following formula ₁₁with the first winding reverse voltage V ₁₂:

$\left\{\begin{array}{c}{V}_{11}=V_{C11}-I_{11}{R}_{s1}\\ V_{12}=V_{C12}+I_{12}{R}_{s1}\end{array}\right.;$

Second winding voltage computing unit, for calculating the second winding voltage V in the same way by following formula ₂₁, and the second winding reverse voltage V ₂₂:

$\left\{\begin{array}{c}{V}_{21}=V_{C21}-I_{21}{R}_{s4}\\ V_{22}=V_{C22}+I_{22}{R}_{s4}\end{array}\right..$

6., according to the arbitrary described device of claim 3 to 5, it is characterized in that, described insulation resistance comprises described first winding to first of the casing of described motor the equivalent insulating resistance value R ₁, described second winding is to second of the casing of described motor the equivalent insulating resistance value R ₂, the 3rd equivalent insulating resistance value R between described first winding and described second winding ₁₂, described insulation resistance calculates unit and comprises:

First equivalent insulation resistance calculates unit, for calculating R by following formula ₁:

$R_1=\frac{V_{11}-\frac{V_{21}{V}_{12}}{V_{22}}}{(I_{11}-I_{12})-\frac{V_{2\_1}}{V_{2\_2}}(I_{21}-I_{22})};$

Second equivalent insulation resistance calculates unit, for calculating R by following formula ₂:

$R_2=\frac{V_{12}-\frac{V_{11}{V}_{22}}{V_{21}}}{(I_{11}-I_{21})-\frac{V_{11}}{V_{21}}(I_{21}-I_{22})};$

3rd equivalent insulating-resistance meter calculates unit, for calculating R by following formula ₁₂:

$R_{12}=\frac{V_{21}-V_{22}}{I_{21}-\frac{V_{21}}{R_1}}.$

7. according to the arbitrary described device of claim 2 to 5, it is characterized in that, described first single-phase rectifier part has brachium pontis and first time brachium pontis on first, and described second single-phase rectifier part has brachium pontis and second time brachium pontis on second, and described current transformer control module comprises:

First current transformer sub-control unit, for brachium pontis on brachium pontis and described second on closed described first, or closed described first time brachium pontis and described second time brachium pontis, to apply DC bus-bar voltage in the same way;

Second current transformer sub-control unit, for closing brachium pontis and described second time brachium pontis on described first, or brachium pontis on closed described first time brachium pontis and described second, to apply reverse DC bus-bar voltage.

8. the insulation resistance detection method of a double-winding motor, winding in any phase in described double-winding motor in one group of three-phase windings is as the first winding, using the winding of the corresponding phase in another group three-phase windings as the second winding, it is characterized in that, described method comprises:

Detecting step: control current transformer and apply the identical DC bus-bar voltage in the direction DC bus-bar voltage contrary with direction to described first winding and described second winding, the voltage and current in place and the output terminal of the output terminal and described second winding that detect described first winding connects;

Insulation resistance calculates step: according to the voltage and current detected in described detecting step, calculate described insulation resistance.

9. method according to claim 8, it is characterized in that, the output terminal of described first winding and described second winding is connected respectively by the first single-phase rectifier part of the first transmission line and the second transmission line and the pusher side rectifying part of current transformer and the second single-phase rectifier part, described first transmission line and described second transmission line are respectively arranged with the first single-phase pusher side switch and the second single-phase pusher side switch, and described detecting step comprises:

Switch control rule step: open described first single-phase pusher side switch and described second single-phase pusher side switch;

First voltage applies step: control described first single-phase rectifier part and described second single-phase rectifier part, to described first transmission line and described second transmission line applying DC bus-bar voltage in the same way;

First measure voltage & current step: the first voltage V in the same way detecting the output terminal of described first winding and earth point ₁₁with the first same direction current I of correspondence ₁₁with second of the output terminal of described second winding and earth point the voltage V in the same way ₂₁with the second same direction current I of correspondence ₂₁;

Second voltage applies step: control described first single-phase rectifier part and described second single-phase rectifier part, apply reverse DC bus-bar voltage to described first transmission line and described second transmission line;

Second measure voltage & current step: detect the output terminal of described first winding and the first reverse voltage V of earth point ₁₂with the first inverse current I of correspondence ₁₂with the output terminal of described second winding and the second reverse voltage V of earth point ₂₂with the second inverse current I of correspondence ₂₂.

10. method according to claim 9, is characterized in that, between described first transmission line and the second transmission line, be provided with device as claimed in claim 3, calculates the first winding voltage V in the same way by following formula ₁₁with the first winding reverse voltage V ₁₂:

$\left\{\begin{array}{c}{V}_{11}=V_{C11}-I_{11}{R}_{s1}\\ V_{12}=V_{C12}-I_{12}{R}_{s1}\end{array}\right.;$

The second winding voltage V is in the same way calculated by following formula ₂₁with the second winding reverse voltage V ₂₂:

$\left\{\begin{array}{c}{V}_{21}=V_{C21}-I_{21}{R}_{s4}\\ V_{22}=V_{C22}+I_{22}{R}_{s4}\end{array}\right..$

11. methods according to claim 9 or 10, it is characterized in that, described insulation resistance comprises described first winding to first of the casing of described motor the equivalent insulating resistance value R ₁, described second winding is to second of the casing of described motor the equivalent insulating resistance value R ₂, the 3rd equivalent insulating resistance value R between described first winding and described second winding ₁₂, described insulation resistance calculates step and comprises and calculate R by following formula ₁, R ₂and R ₁₂:

$R_1=\frac{V_{11}-\frac{V_{21}{V}_{12}}{V_{22}}}{(I_{11}-I_{12})-\frac{V_{2\_1}}{V_{2\_2}}(I_{21}-I_{22})};$

$R_2=\frac{V_{12}-\frac{V_{11}{V}_{22}}{V_{21}}}{(I_{11}-I_{21})-\frac{V_{11}}{V_{21}}(I_{21}-I_{22})};$

$R_{12}=\frac{V_{21}-V_{22}}{I_{21}-\frac{V_{21}}{R_1}}.$

12. methods according to claim 11, is characterized in that, described first single-phase rectifier part has brachium pontis and first time brachium pontis on first, and described second single-phase rectifier part has brachium pontis and second time brachium pontis on second,

Described first voltage applies step and comprises: brachium pontis on brachium pontis and described second on closed described first, or closes described first time brachium pontis and described second time brachium pontis, to apply DC bus-bar voltage in the same way;

Described second voltage applies step and comprises: brachium pontis and described second time brachium pontis on closed described first, or brachium pontis on closed described first time brachium pontis and described second, to apply reverse DC bus-bar voltage.