CN203217057U - Star connection three-phase motor and single-phase motor system and operation state test device - Google Patents
Star connection three-phase motor and single-phase motor system and operation state test device Download PDFInfo
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- CN203217057U CN203217057U CN201320207071XU CN201320207071U CN203217057U CN 203217057 U CN203217057 U CN 203217057U CN 201320207071X U CN201320207071X U CN 201320207071XU CN 201320207071 U CN201320207071 U CN 201320207071U CN 203217057 U CN203217057 U CN 203217057U
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Abstract
Provided are a star connection three-phase motor system, a single-phase motor system and an operation state test device. The motor operation state test device includes a resistor network which is capable of being connected to the three-phase windings of a motor stator and the resistor network is provided with a pair of test points; a measurement unit for measurement of physical quantities which reflect the resistance between the pair of test points; and a winding state determination unit for determining the operation state of the windings according to measured values of the physical quantities, wherein the resistor network and the pair of test points are arranged such that the resistance, which is caused by one of the on-off state combination of each phase of the winding in the three-phase windings, between the pair of the test points is different from the resistance, which is caused by another combination, between the pair of the test points.
Description
Technical field
Disclosure relate generally to motor open-phase protection field relates in particular to a kind of three phase electric machine system, monophase machine system of Y-connection and motor operating state pick-up unit.
Background technology
Motor damages mainly because motor moves under phase failure state and causes.The motor phase failure mainly comprises: motor winding itself disconnects the phase failure that the connection line disconnection causes between the phase failure, three-phase alternating-current supply and the motor terminal that causes, and the phase failure or the anti-phase that take place in each phase line of AC power.Carry out the motor running protection, then need accurately and detecting above-mentioned several situations in time.
In a kind of known arrangement, consider that motor operation under the failure condition of winding own can cause the abnormal heating of winding, detect the damage of winding by the overheating that detects winding.Particularly, detect temperature rise by the temperature sensor of when motor is installed, installing at the winding place.Perhaps, consider temperature to the influence of resistance, determine the stator winding temperature rise indirectly by the resistance value of estimating motor stator winding, whether damage thereby detect winding.
In another kind of known arrangement, utilize photoelectrical coupler, when the three-phase contactor closure of AC power, each phase line voltage is coupled, detect the phase failure and the anti-phase fault of three-phase supply by the pulsion phase difference algorithm.
The utility model content
Yet, in above-mentioned first kind of known arrangement, the temperature rise of winding also may since problem such as overload cause, thereby change to determine that according to winding temperature the winding phase failure may be inaccurate.In addition, detect the method for the phase failure by the estimation winding resistance and need set up complicated mathematical model and algorithm, increased the detection cost.Moreover only the phase failure detects this scheme to winding, and the motor open-phase running that does not have consideration to cause owing to power fail, thereby can't detect motor operating state all sidedly.
In addition, in above-mentioned second kind of known arrangement, owing to used photoelectrical coupler, then when being applied to the motor of Y-connection, can can't detecting the circuit that takes place between three-phase contactor and the motor stator because of the back electromotive force that motor stator produces and disconnect.In addition, this scheme only detects power supply status, and can not detect the phase failure of motor winding, thereby also can't detect motor operating state all sidedly.
In view of the problem that exists, a purpose of the present utility model provides that a kind of circuit structure is simple, algorithm simple, can detect the pick-up unit of the motor operation troubles that takes place owing to the phase failure of motor winding exactly, use its electric system.
In addition, another purpose of the present utility model provides that a kind of circuit structure is simple, algorithm is simple, can detect the motor operation troubles that a variety of causes causes exactly, and accuracy is not subjected to the pick-up unit that the reverse electrodynamic type of stator influences, the electric system that uses it.
In addition, another purpose of the present utility model provides that a kind of circuit structure is simple, algorithm is simple, can detect exactly because the motor operation troubles that power fail causes, and accuracy is not subjected to the pick-up unit that the reverse electrodynamic type of stator influences, the electric system that uses it.
According to an aspect of the present disclosure, a kind of pick-up unit is provided, for detection of motor operating state, comprising: resistor network, can be connected to three phase windings of motor stator, and it is right to be provided with check point; Measuring unit, be used for to measure can reflect check point between the physical quantity of resistance value; And the winding state determining unit, for the running status of determining winding according to the value of measured physical quantity; Wherein, resistor network and check point check point that one of on off operating mode combination of being arranged to each phase winding in three phase windings is caused between resistance value be different from check point that another combination causes between resistance value.
In according to embodiment of the present disclosure, resistor network can comprise first resistor, second resistor, the 3rd resistor and the 4th resistor, and according to the 3rd, the order of first, second and the 4th resistor is connected in series.The tie point of the two ends of resistors in series group and first and second resistors is configured to be connected with three phase windings of motor stator respectively.And the tie point of the tie point of the 3rd and first resistor and the second and the 4th resistor can be right as check point.
In according to embodiment of the present disclosure, measuring unit can comprise: partial pressure unit; Direct supply is connected to first check point of check point centering via partial pressure unit; And voltage measurement unit, be used for measuring the magnitude of voltage at the first check point place as physical quantity.Wherein, second check point of check point centering can be grounded.
In according to embodiment of the present disclosure, pick-up unit can also comprise: control module is used under the situation that motor disconnects from AC power the start detection Device Testing.
In according to embodiment of the present disclosure, control module can be further configured into after the pick-up unit initialization, AC power connect before the start detection Device Testing.
In according to embodiment of the present disclosure, control module can be further configured to be in periodically start detection Device Testing between turnoff time at motor.
In according to embodiment of the present disclosure, the winding state determining unit can be further configured to determine the running status of winding according to the mean value of the physical quantity of the predetermined quantity of measuring.
In according to embodiment of the present disclosure, pick-up unit can also comprise the AC power detecting unit.The AC power detecting unit can comprise: line voltage computing unit is used for calculating the line voltage between each phase line; And the power supply status determining unit, for the duty of determining AC power according to the line voltage that calculates.
In according to embodiment of the present disclosure, line voltage computing unit can comprise first and second differential operational amplifiers.The forward of this first and second differential operational amplifier and reverse input end are connected to one of them phase line of three-phase supply jointly.The remaining input end of this first and second differential operational amplifier is connected to two other phase line via resistor respectively.And the output terminal of this first and second differential operational amplifier is connected to the power supply status determining unit.
In according to embodiment of the present disclosure, the remaining input end of this of this first and second differential operational amplifier is respectively via being connected to two other phase line according to the resistor in the resistor network of the present disclosure.
In according to embodiment of the present disclosure, the power supply status determining unit can be further configured to by calculating the effective value of supply voltage according to line voltage, and compares to determine the duty of power supply with nominal value.
According to an aspect of the present disclosure, a kind of pick-up unit also is provided, for detection of the AC power state, comprising: line voltage computing unit is used for calculating the line voltage between each phase line; And the power supply status determining unit, for the duty of determining power supply according to the line voltage that calculates.
In according to embodiment of the present disclosure, line voltage computing unit can comprise first and second differential operational amplifiers; The forward of first and second differential operational amplifiers and reverse input end are connected to one of them phase line of three-phase supply jointly, and the remaining input end of first and second differential operational amplifiers is connected to two other phase line via resistor respectively; And the output terminal of first and second differential operational amplifiers is connected to the power supply status determining unit.
In according to embodiment of the present disclosure, the power supply status determining unit can be further configured to by calculating the effective value of supply voltage according to line voltage, and compares to determine the duty of power supply with nominal value.
According to an aspect of the present disclosure, a kind of three phase electric machine system of Y-connection also is provided, comprise according to above-described pick-up unit.
According to an aspect of the present disclosure, a kind of monophase machine system also is provided, comprising: main winding; Auxiliary winding; Auxiliary resistor, the one end is connected to the common port of main winding and auxiliary winding, and the resistance of auxiliary resistor is determined according to the resistance of main winding and auxiliary winding; And resistor network, its different port is connected respectively to the non-common port of main winding and auxiliary winding and the other end of auxiliary resistor, and resistor network to be provided with check point right; Measuring unit, be used for to measure can reflect check point between the physical quantity of resistance value; And the winding state determining unit, for the running status of determining winding according to the value of measured physical quantity; Wherein, resistor network and check point check point that one of on off operating mode combination of being arranged in main winding and the auxiliary winding each is caused between resistance value be different from check point that another combination causes between resistance value.
Utilization is according to motor operating state pick-up unit of the present disclosure, power detector and their electric system of use and method, and the running status of detection motor provides possibility in order to utilize simple circuit configuration, simple algorithm to come accurately comprehensively.
Description of drawings
With reference to below in conjunction with the explanation of accompanying drawing to the utility model embodiment, can understand above and other purpose of the present utility model, characteristics and advantage more easily.In the accompanying drawings, technical characterictic or parts identical or correspondence will adopt identical or corresponding Reference numeral to represent.Needn't go out size and the relative position of unit in the accompanying drawings according to scale.
Fig. 1 is the block diagram that illustrates according to the structure of the motor operating state pick-up unit of disclosure embodiment.
Fig. 2 is the circuit diagram that illustrates when using according to the structure of the motor operating state pick-up unit of disclosure embodiment and in the detection of star three phase electric machine.
(a) of Fig. 3 is the pc equivalent circuit figure of the three phase windings closed-loop path that resistor network and winding constitute when normally moving.
(b) of Fig. 3 and (c) are star connected to the equivalent circuit diagram that obtains after circuit conversion that triangle is connected and the connection in series-parallel conversion to the circuit shown in Fig. 3 (a).
(a) of Fig. 4 is the pc equivalent circuit figure of the circuit that resistor network and winding constituted when U mutually the phase failure took place in three phase windings.
(b) of Fig. 4 carries out the equivalent circuit diagram that obtains after the connection in series-parallel conversion to the circuit shown in Fig. 4 (a).
(a) of Fig. 5 is the pc equivalent circuit figure of the circuit that resistor network and winding constituted when V mutually the phase failure took place in three phase windings.
(b) of Fig. 5 carries out the equivalent circuit diagram that obtains after the connection in series-parallel conversion to the circuit shown in Fig. 5 (a).
(a) of Fig. 6 is the pc equivalent circuit figure of the circuit that resistor network and winding constituted when W mutually the phase failure took place in three phase windings.
(b) of Fig. 6 carries out the equivalent circuit diagram that obtains after the connection in series-parallel conversion to the circuit shown in Fig. 6 (a).
(a) of Fig. 7 is the pc equivalent circuit figure of the circuit that resistor network and winding constitute when mutually mutually the phase failure taking place with V of the U in three phase windings.
The circuit diagram that (b) of Fig. 7 obtains after the circuit diagram shown in Fig. 7 (a) is put in order.
(a) of Fig. 8 is the circuit diagram that schematically shows the structure of monophase machine.
(b) of Fig. 8 simplifies to be illustrated in the synoptic diagram that uses on the monophase machine according to the method for attachment of the pick-up unit of the utility model embodiment.
Fig. 9 is the process flow diagram that illustrates according to the workflow of the motor operating state pick-up unit of disclosure embodiment.
Figure 10 is the circuit diagram that illustrates according to the structure of the motor operating state pick-up unit of disclosure embodiment.
Figure 11 is the circuit diagram that illustrates according to the structure of the line voltage computing unit of disclosure embodiment.
Figure 12 is the process flow diagram that illustrates according to the process that three-phase supply is detected of disclosure embodiment.
Figure 13 illustrates the process flow diagram that detects the process of dress according to the motor operating state of disclosure embodiment.
Figure 14 illustrates according to the motor winding of disclosure embodiment and the sequential chart of power supply detection processing execution sequential.
Embodiment
Embodiment of the present utility model is described with reference to the accompanying drawings.Should be noted that for purpose clearly, omitted in accompanying drawing and the explanation and the utility model expression and description irrelevant, parts well known by persons skilled in the art and processing.
Can be divided into generally to the motor stator winding status detection and to the power supply state of three-phase supply the detection of motor operating state and to detect.Wherein, to the motor stator winding status detection based on such design: if construct a resistor network, make each phase winding of itself and motor stator form closed-loop path, then can also select corresponding resistance value for the resistor in the resistor network by specific structure is set for this resistor network, make it possible in this resistor network, exist at least a pair of check point, when one of at least open phase fault taking place in each phase winding of stator, at this resistance value between check point is changed.Thereby, can perhaps measure the state that other physical quantity that can reflect this resistance value is determined winding by measuring this resistance value.
Fig. 1 is the block diagram that illustrates according to the structure of the motor operating state pick-up unit 100 of disclosure embodiment.Motor operating state pick-up unit 100 comprises: resistor network 101, measuring unit 102 and winding state determining unit 103.
Resistor network 101 can be connected to three phase windings (U phase, V phase and W are mutually) of motor stator, and is provided with check point to a and b.When resistor network 101 had been connected to three phase windings of motor, resistor network 101 constituted new resistor network with the resistance of three phase windings.When suitably arrange resistor network and check point to the time, the check point that one of the on off operating mode of three phase windings combination causes between resistance value be different from check point that another combination causes between resistance value.As for the resistance of the structure how resistor network is set particularly and each resistor and suitably select the right position of check point, the check point that is caused with one of on off operating mode combination of reaching three phase windings between resistance value be different from check point that another combination causes between the effect of resistance value, those skilled in the art can design by calculating or the experiment of limited number of time.
Directly the resistance value between check point a and the b is measured, for example, can be according to different metering systems, such as the resistance measurement (R=P/I under the resistance measurement under the DC condition (R=U/I) or the interchange condition
2) wait to realize.Correspondingly, measuring unit 102 can be realized in different ways, as long as can measure check point to the resistance of a resistance.
Winding state determining unit 103 determines that according to the value of the physical quantity that obtains stator winding is normal operation or open-phase running.If open-phase running, status determining unit 103 can also learn it specifically is which (a bit) phase winding phase failure according to the size of the magnitude of physical quantity that obtains.Can be by disconnecting different windings respectively in simulated experiment or in calculating, obtain in advance that check point can react the magnitude of physical quantity of this resistance value to the resistance value between a and the b or other under the different phase failure situations, for status determining unit 103 as the benchmark of determining state.
Example when describing the circuit structure of motor operating state pick-up unit 200 and being applied to the detection of three-phase Y-connection motor below in conjunction with Fig. 2.Pick-up unit 200 is exemplary implementations of pick-up unit 100, but the realization of pick-up unit 100 is not limited to this mode.
As shown in Figure 2, three-phase supply (its triple-phase line is L1, L2 and L3) is the motor power supply of Y-connection.Here, the winding resistance of three-phase stator winding (U, V and W) is equal substantially, and unification is represented with Rs.N represents the neutral line of three-phase supply.
In the embodiment of Fig. 2, resistor network comprises resistor R1, R2, R3 and R4, and is connected with stator winding.As shown in Figure 2, resistor R1, R2, R3 and R4 and winding resistance Rs have constituted the closed-loop path.Particularly, resistor R3, R1, R2 and R4 are connected in series in order, and an end of the resistors in series group that obtains is connected with winding U, and the other end is connected with winding W, and winding V is connected the tie point place of resistor R1 and R2.It is right to be configured to check point at the some a between resistor R1 and the R3 and the some b between resistor R2 and R4.Thereby measuring unit can be measured the resistance value between check point a and the b.
Be appreciated that in resistor network shown in Figure 2, make that the resistance between the check point a and b can be got different resistances when the out of phase winding generation phase failure, can make the value of resistor R1, R2, R3 and R4 asymmetric with respect to three phase windings.Similarly, in the implementation of other resistor network, make that the resistance between the check point a and b can be got different resistances when the out of phase winding generation phase failure, can make check point asymmetric with respect to three phase windings to the structure (comprising topological sum institute power taking resistance) of the resistor network between a and the b.In this example, can get R1=10M Ω, R2=9M Ω, R3=1M Ω and R4=10M Ω.
Utilize Fig. 3 to Fig. 7 below, in conjunction with the resistor network example in detail shown in Fig. 2 when the connection status of winding changes, the variation of the resistance value Rab between check point a and the b.Resistor network shown in Figure 2 is exemplary.Those skilled in the art can obtain constructing the enlightenment that meets other resistor network that resistance change requires between check point by with reference to below in conjunction with the analysis of Fig. 3 to Fig. 7 to the example resistor network.
(a) of Fig. 3 is the pc equivalent circuit figure of the three phase windings closed-loop path that resistor network and winding constitute when normally moving (namely not having open phase fault).In situation shown in (a) of Fig. 3, there are not the phase failure in three phase winding U, V, W, thereby three phase windings are connected with the two ends of resistors in series group and the tie point of R1 and R2 respectively.(b) of Fig. 3 and (c) are star connected to the equivalent circuit diagram that obtains after circuit conversion that triangle is connected and the connection in series-parallel conversion to the circuit shown in Fig. 3 (a).From Fig. 3 (c) as can be known, under the normal situation about connecting of three phase windings, the value of Rab as the formula (1):
Rab=Ra’+Rb’+(R1’+R2’)//(R3’+3Rs+R4’) （1）
Wherein, Ra ', Rb ', R1 ', R2 ', R3 ' and R4 ' are through the resulting equivalent resistance of above-mentioned conversion.Because this conversion is known for a person skilled in the art, thereby omits its detailed description at this.
(a) of Fig. 4 is the pc equivalent circuit figure of the circuit that resistor network and winding constituted when U mutually the phase failure took place in three phase windings.(b) of Fig. 4 carries out the equivalent circuit diagram that obtains after the connection in series-parallel conversion to the circuit shown in Fig. 4 (a).As Fig. 4 (b) as can be known, in the U phase winding generation phase failure, under the situation of the normal operation of other two phase winding, the value of Rab as the formula (2):
Rab=R1+R2//(2Rs+R4) （2）
(a) of Fig. 5 is the pc equivalent circuit figure of the circuit that resistor network and winding constituted when V mutually the phase failure took place in three phase windings.(b) of Fig. 5 carries out the equivalent circuit diagram that obtains after the connection in series-parallel conversion to the circuit shown in Fig. 5 (a).From Fig. 5 (b) as can be known, in the V phase winding generation phase failure, under the situation of the normal operation of other two phase winding, the value of Rab as the formula (3):
Rab=(R1+R2)//(R3+2Rs+R4) （3）
(a) of Fig. 6 is the pc equivalent circuit figure of the circuit that resistor network and winding constituted when W mutually the phase failure took place in three phase windings.(b) of Fig. 6 carries out the equivalent circuit diagram that obtains after the connection in series-parallel conversion to the circuit shown in Fig. 6 (a).From Fig. 6 (b) as can be known, in the W phase winding generation phase failure, under the situation of the normal operation of other two phase winding, the value of Rab as the formula (4):
Rab=R1//(R3+2Rs)+R2 （4）
(a) of Fig. 7 is the pc equivalent circuit figure of the circuit that resistor network and winding constitute when mutually mutually the phase failure taking place with V of the U in three phase windings.The circuit diagram that (b) of Fig. 7 obtains after the circuit diagram shown in Fig. 7 (a) is put in order.Through observing as can be known to (a) of Fig. 7 with (b), except U mutually and V the situation of the phase failure takes place mutually, in fact, in the two-phase generation phase failure arbitrarily and under the situation that third phase normally moves, the value of Rab all as the formula (5):
Rab=R1+R2 （5）
Can clearly be seen that according to top formula (1)～(5) corresponding to the different conditions of winding, Rab has different resistance values, thereby can reflect that maybe other physical quantity of the value of Rab determines the running status of each phase winding of motor by measure R ab.
According to formula (1)～(4) as can be known, the resistance value Rs of winding can influence resistance value Rab between check point under the normal and single-phase phase failure situation of winding.Therefore, in certain embodiments, the resistance of R1, R2, R3 and R4 is got height as far as possible, for example, be taken as have megaohm (M Ω) level high resistance measurement.One of benefit of doing like this is: because winding resistance Rs only has the resistance in several Europe or tens Europe usually, so the variation that winding resistance Rs takes place along with the lifting of winding temperature can not produce obviously influence to the accuracy that measurement and even the motor operating state of Rab are determined.Even, in certain embodiments, calculate different winding state check points between resistance value the time, can ignore winding resistance Rs.
In certain embodiments, can measure the magnitude of voltage of resistance between the reflection check point.For example, can be when AC power stops motor being powered, by providing direct current via resistor network to three phase windings, the voltage of measuring the check point place then come the indirect detection check point between resistance change.For example, can provide direct current from first check point of check point centering to detecting network via divider resistance, and with the second check point ground connection.In this case, the magnitude of voltage at the first check point place will reflect check point between resistance change, and then reflect the normal or phase failure state of three phase windings that connect.
Particularly, measuring unit 102 may be implemented as and comprises: partial pressure unit; Direct supply is connected to first check point of check point centering via partial pressure unit; And voltage measurement unit, under the situation of the second check point ground connection of check point centering, detect the magnitude of voltage at the first check point place, with as the parameter of determining winding state.
Return with reference to figure 2.The example of the Switching Power Supply 201(of DC voltage Vdd as " direct supply " is provided) via voltage grading resistor R
Div(as the example of " partial pressure unit ") is connected to the check point a(of the check point centering on the resistor network as the example of " first check point ").Though with the example of Switching Power Supply 201 as direct supply, it will be appreciated by those skilled in the art that here: can use various other direct supply well known in the art as required.Direct supply Vdd for example can be 12V, 18V or 24V etc.
Another check point b(on resistor network is as the example of " second check point ") when being grounded, check point to resistance R ab and voltage grading resistor R
DivVdd is carried out dividing potential drop, because voltage grading resistor R
DivResistance is fixed, so the magnitude of voltage on the resistance R ab is namely proportional at magnitude of voltage and the resistance R ab at check point a place.Thereby, can measure the magnitude of voltage at check point a place, as the parameter of determining winding state.Voltage grading resistor R
DivResistance can pre-determine according to the possible resistance of Rab, generally get with resistor network in the same level of resistor other resistance, for example mega-ohms resistance.
In the example of Fig. 2, partial pressure unit is embodied as voltage grading resistor R
DivBut the implementation of partial pressure unit is not limited thereto.For example, also can be other connection in series-parallel resistor network etc.
Here, the measuring unit 102 that comprises a partial pressure unit example of measuring unit just.In different embodiment, measuring unit 102 can also comprise other element, can use the configuration that is different from the dividing potential drop design.
In the example of Fig. 2, be used for determining that according to the value of the physical quantity of measuring the winding state determining unit of running status of winding is by the MCU(microprocessor) 202 realize.Those skilled in the art can understand, and the example of winding state determining unit is not limited thereto, and for example can also be special circuit structures of building etc.Here, mention along band that Switching Power Supply 201 can also be used for the power supply to MCU202, such as 5V or 3.3V except direct supply Vdd is provided.
As shown in Figure 2, after direct supply was connected, the voltage at check point a place was input to MCU202 by the ADC input end via MCU202.In MCU202, can at first carry out analog to digital conversion to the magnitude of voltage that obtains, magnitude of voltage is converted to the parameter of representing with some bits, so that MCU202 handles.Then, the magnitude of voltage after the analog to digital conversion and a plurality of specific voltage values that prestore are compared, to determine the running status of winding.Particularly, the magnitude of voltage after analog to digital conversion equals specific threshold, or with to a certain degree near under the situation of specific threshold, winding state is defined as the state corresponding with this specific voltage value.
In certain embodiments, can carry out the sampling of predetermined quantity to the voltage at check point a place, and will compare through mean value and the specific voltage value of the voltage after the analog to digital conversion, to determine the state of winding.The benefit of doing like this is that the erroneous judgement that can avoid causing because of incident is broken.
In one embodiment, motor operating state pick-up unit 200 can also comprise control module, is used for control motor operating state pick-up unit 200 and starts or the detection of end processing.Particularly, when control module disconnects from AC power at motor, the detection of start detection device 200.For example, control module detects demand based on winding, disconnects in response to AC power, connects the direct supply in the measuring unit, and starts the winding state determining unit.
In the example as Fig. 2, at power supply Vdd and voltage grading resistor R
DivBetween also be connected with starting switch K.Starting switch K in response to from MCU202(as the example of " control module ") the power supply of connecting direct supply Vdd of detection enabling signal, thereby the check point that begins to obtain reflected resistance Rab is the magnitude of voltage at check point a place to the magnitude of voltage between a and the b here.The MCU202 basis is determined disconnection or the closure of three-phase contactor from the signal of the three-phase contactor of three-phase supply.Disconnecting at three-phase contactor is AC power not under the situation to the motor power supply, and to measuring unit, particularly, the starting switch K in the measuring unit sends and detects enabling signal MCU202 via its I/O pin I/O.
In one embodiment, MCU202 can control, with after the pick-up unit initialization, and before AC power is connected, the start detection Device Testing.Simultaneously, or selectively, for example, MCU202 can control, to be in periodically start detection Device Testing between turnoff time at motor.This can be applied in the compressor of air conditioner application especially.Particularly, be in the periodically down periods at compressor of air conditioner owing to environment temperature reaches requirement, carry out winding state and detect.
In one embodiment, as open-phase protection, when detecting winding generation open phase fault, MCU202 can control to disconnect the three-phase contactor (as pointing to shown in the arrow of three-phase contactor from MCU202 among Fig. 2) of AC power.
Another advantage that adopts the resistance of higher resistance value from example shown in Figure 2 as can be seen in resistor network is to carry out good isolation/decoupling to ac high-voltage and dc low-voltage in ground.
The example that uses in the three phase electric machine of Y-connection according to the pick-up unit of the utility model embodiment has been shown among Fig. 2.Below, illustrate that with reference to figure 8 pick-up unit according to the utility model embodiment also can be used for monophase machine.
(a) of Fig. 8 is the circuit diagram that schematically shows the structure of monophase machine.Monophase machine comprises two windings, i.e. main winding R
MainWith auxiliary winding R
AuxilliaryShown in Fig. 8 (a), be connected and be the main winding of monophase machine between R, the C end, be connected and be the auxiliary winding of monophase machine between S, the C.Find after deliberation, if by increasing auxiliary resistor Rt, the one end is connected with C point as main winding and auxiliary winding common point, then can construct the structure of the three phase electric machine that is similar to Y-connection.As shown in Fig. 8 (b).
(b) of Fig. 8 simplifies to be illustrated in the synoptic diagram that uses on the monophase machine according to the method for attachment of the pick-up unit of the utility model embodiment.The non-common port of main winding, auxiliary winding links to each other respectively with according to two tie points in the resistor network of the pick-up unit of the utility model embodiment, and the end of auxiliary resistor Rt is connected with the common port of main winding and auxiliary winding, and the other end links to each other with tie point of residue of resistor network.The resistance value of resistor Rt can be determined based on the resistance of auxiliary winding and main winding by experiment or the calculating of limited number of time.In the embodiment of Fig. 8 (b), pick-up unit has adopted the resistor network structure shown in Fig. 2, but those skilled in the art will appreciate that: can use the pick-up unit according to any embodiment that illustrates in the disclosure to detect single-phase resistor, need only according to above-mentioned explanation structure auxiliary resistor, and get final product with suitable connection of the resistor network of detecting device.
The workflow of motor operating state pick-up unit is described below in conjunction with Fig. 9.
Fig. 9 is the process flow diagram that illustrates according to the workflow of the motor operating state pick-up unit of disclosure embodiment.Be example with the pick-up unit 200 shown in Fig. 2, in step S901, MCU202 determines whether motor cuts off the power supply, and determines namely whether three-phase contactor disconnects.MCU202 can determine according to make this from the signal of three-phase contactor.(be "Yes" among the step S901) when being defined as motor and not being provided alternating current, then enter into step S903, MCU202 sends via I/O pin (I/O pin) and detects enabling signal with the start detection Device Testing.And when being defined as providing alternating current for motor, (be "No" among the step S901), and under the situation of needs startup to the detection of motor winding, then proceeding to step S902, MCU202 sends the order of turn-offing three-phase contactor.Then, after turn-offing, three-phase contactor enters into step S903, the start detection device.
For example, as in the embodiment shown in Figure 2, starting switch K is closed in response to the request (detection enabling signal) of MCU202 start detection, to connect Switching Power Supply 201, to voltage grading resistor R
DivAnd the closed-loop path formed of resistor network and winding (because check point b ground connection, therefore in fact be exactly to the resistance R ab between divider resistance and the check point) here provides direct current.At starting switch K period of contact, keep the dc voltage value of output reflection Rab resistance at check point a place.This magnitude of voltage is provided to analog to digital conversion (ADC) pin of MCU202.
In step S904, MCU202 samples to the magnitude of voltage at check point a place according to predetermined interval, and utilizes its ADC module that comprises that the magnitude of voltage that samples is converted to digital signal, so that MCU202 handles.
When sampling enough predetermined N samplings, in step S905, the N of a MCU202 sampled value is averaged.In actual applications, N can get integer more than or equal to 1 as required.
In step S906, MCU202 compares obtained mean value and specific threshold value, when this mean value equals specific threshold, or with under the to a certain degree close situation of specific threshold, be defined as the motor current state for the corresponding running status of this specific threshold (being "Yes" among the step S906), then in step S907, obtain different states and determine the result.And if obtained mean value is not equal to or near (being "No" among the step S906) under the situation of any one specific threshold, flow process is got back to step S904, MCU202 restarts to sample.
In step S907, illustrated different definite results with and definite foundation.Wherein, " Th
Nor", " Th
U", " Th
V", " TH
W" and " Th
UVW" be illustrated respectively in that the motor winding is in normal operating condition, U phase phase failure state, V phase phase failure state, W phase phase failure state and at least under the situation of two-phase phase failure state; the standard value that the measured physical quantity (being that its sampled value is averaging the mean value that obtains here after analog to digital conversion) of measuring unit should reach; can by as referring to figs. 3 to circuit conversion and the calculating of Fig. 7 explanation, and the conversion between the respective physical amount (as resistance to voltage) is asked for." Δ " expression is apart from the distance of specific threshold (near degree), for example Δ=± 1V or ± 1M Ω.For the threshold value at different situations, the size of Δ can be identical also can be different.After definite winding running status, testing process finishes.
The apparatus and method that winding running status to motor detects above have been discussed.In other embodiments, can also in the motor operating state pick-up unit, increase the three-phase supply detecting unit in order to prevent owing to the problem of the three-phase supply phase failure or anti-phase generation.The three-phase supply detecting unit can comprise: line voltage computing unit is used for calculating the line voltage between each phase line; And the power supply status determining unit, for the duty of determining power supply according to the line voltage that calculates.For example, the power supply status determining unit can utilize the line voltage of acquisition to calculate the effective value (RMS) of supply voltage.Then, can the effective value (nominal value) by with known operate as normal the time compare to determine the duty of power supply.
Figure 10 is the circuit diagram that illustrates according to the circuit structure of the motor operating state pick-up unit 1000 of disclosure embodiment.Here only parts different with Fig. 2 among Figure 10 is described, omit the description of same section.Compare with motor operating state pick-up unit 200 shown in Figure 2, motor operating state pick-up unit 1000 further is provided with the three-phase supply detecting unit.In the embodiment shown in fig. 10, realized line voltage computing unit and the power supply status determining unit of three-phase supply detecting unit respectively by line voltage computing unit 1003 and MCU1002.
In the example of Figure 10, the line voltage that line voltage computing unit 1003 calculates between each phase line.Three input ends of line voltage computing unit 1003 are connected three tie point places of the resistors in series group of being made up of resistor R1 to R4, based on the line voltage V that calculates from the interchange input of these three somes acquisitions between the first phase line L1 and the second phase line L2 and third phase line L3 and the second phase line L2
L1L2And V
L3L2Then, line voltage computing unit 1003 is with line voltage V
L1L2And V
L3L2Be input to MCU1002.Here, MCU1002 is as the example of power supply status determining unit, and it can calculate RMS according to the line voltage that calculates, and then by comparing with predetermined threshold, further determines under-voltage/overvoltage, the phase failure, anti-phase or the imbalance of three-phase supply.
Line voltage computing unit 1003 can adopt various structure known in the art, mode to construct, as long as can calculate the line voltage between each phase line.And the connection of line voltage computing unit 1003 in the motor operating state pick-up unit is not limited to the example among Figure 10.In fact, it is in order to take full advantage of existing device that line voltage computing unit 1003 is connected to existing resistor network R1 to R4 place, thereby the device count that reduces to use also can arrange special-purpose devices such as resistor for line voltage computing unit separately.In addition, as a kind of example of motor operating state pick-up unit, can under the situation that does not have the layout that the winding phase failure is detected, in circuit, arrange separately to be used for carrying out the three-phase supply detecting unit that power supply detects.
Below in conjunction with the schematic construction of Figure 11 description according to the line voltage computing unit 1100 of the utility model embodiment.As shown in figure 11, line voltage computing unit 1100 comprises two sign-changing amplifiers.Wherein, by the position that illustrates among the figure, the positive input of the sign-changing amplifier of top is connected with the reverse input end of below sign-changing amplifier, and is connected to the second phase line L2 of three-phase supply jointly.In addition, the positive input of the reverse input end of top sign-changing amplifier and below sign-changing amplifier is connected to two other phase line L1 and L3 via resistor R3 and R4 respectively.
According to the circuit structure shown in Figure 11, can obtain following equation set (6):
V
L1-V
L2=K1×V
L1L2；
V
L3-V
L2=K2 * V
L3L2And
V
L1+V
L2+V
L3=0 （6）
Wherein, K1 and K2 are circuit gains.
Therefore, can obtain the line voltage V of triple-phase line
L1, V
L2, V
L3Value be:
V
L1=2/3×K1×V
L1L2-1/3×K2×V
L3L2；
V
L2=-1/3 * K1 * V
L1L2-2/3 * K2 * V
L3L2And
V
L3=-1/3×K1×V
L1L2+2/3×K2×V
L3L2。
Based on the line voltage that obtains, can determine whether three-phase supply exists the phase failure or anti-phase.
Illustration among Figure 11 and described the structure of line voltage computing unit without limitation.It will be appreciated by those skilled in the art that: also can use forward amplifier and/or other circuit component to build line voltage computing unit, as long as line voltage or phase voltage are transformed to the low-voltage that MCU can identify and detect.Build line voltage computing unit at the use differential operational amplifier, and when this line voltage computing unit comprises first and second differential operational amplifiers, make the forward of first and second differential operational amplifiers be connected with reverse input end, and be connected to one of them phase line of three-phase supply jointly.And, make the remaining input end of first and second differential operational amplifiers be connected to two other phase line via resistor respectively.
Figure 12 illustrates the process flow diagram according to the process that three-phase supply is detected of the utility model embodiment.In step S1201, to the line voltage (V between the phase line
L1L2And V
L3L2) measure or calculate.Can adopt the whole bag of tricks known in the art to obtain power line voltage.Next, in step S1202, utilize the line voltage that obtains to calculate the effective value (RMS) of three-phase electricity.Next, in step S1203, utilize the RMS value of asking for, by comparing with nominal effective value or predetermined threshold value, judge whether power supply status is normal.
If be defined as power supply status and be normal (being "Yes" among the step S1203), power supply detects to carry out next time then to return step S1201, perhaps enters other processing according to system requirements.
If be defined as power supply status undesired (among the step S1203 for "No"), then in step S1204 by comparing to identify the power fail kind with nominal value or specific threshold.For example, in step S1205, the power fail kind may be defined as under-voltage/overvoltage, the phase failure, anti-phase and imbalance etc.Then, power supply detects the processing end.
Figure 13 is the process flow diagram that the testing process of the pick-up unit of motor operating state shown in Figure 10 is shown.
At first, in step S1301, start the three-phase supply status detection.Whether in step S1302, it is normal to detect three-phase supply.Three-phase supply operation is undesired when detecting, and (is "No" among the step S1302) when for example having the phase failure or anti-phase, handles and enters into step S1303, and the power fail that enters customization is in advance handled routine.When detecting three-phase supply normal power supply (being "Yes" among the step S1302), in step S1304, disconnect the three-phase contactor of AC power, stop motor being powered.And, in step S1305, start winding and detect.
In S1306, resistance value or other physical quantity of check point are sampled.Handle back (such as analog to digital conversion and/or ask for the mean value of specific quantity physical quantity) according to pre-defined rule, compare with predetermined threshold value.
In S1307, determine according to comparative result whether winding state is normal.If winding state undesired (being "No" among the step S1307) then proceeds to step S1308, enter winding failure and handle routine.
If winding state normal (being "Yes" among the step S1307) then determines whether starter motor in step S1309.If be defined as not starter motor (being "No" among the step S1309), for example, the timing of no show starter motor still then in one embodiment, can turn back to step S1301, proceeds the detection of three-phase supply.
If be defined as starter motor (being "Yes" among the step S1309), then starter motor in step S1310 brings into operation motor.Motor operating state detects and finishes.
In the embodiment shown in fig. 13, for example initiatively disconnecting three-phase contactor in step S1304 detects to carry out winding.In specific implementation, also can the on off operating mode of three-phase supply be monitored, during for example energy supply periodic disconnection, start winding and detect processing.
Figure 14 illustrates the sequential relationship of winding detection and power supply detection and machine operation is carried out in utilization according to the motor operating state pick-up unit of the utility model embodiment sequential chart.Work schedule shown in Figure 14 is particularly useful for the detection of compressor of air conditioner running status.
As shown in figure 14, after the pick-up unit power-up initializing, the timing period before the electrical power, pick-up unit can carry out the first time to the motor winding and detect.After definite winding non-fault, with electrical power, beginning is operation normally.During electrical power, can the state of three-phase supply be detected.Subsequently, for such as compressor of air conditioner, because environment temperature reaches preset value, the compressor outage enters periodically and shuts down.Between the periodicity down period, compressor can carry out self check, can use pick-up unit that winding state is detected.Similarly, in refrigeration or the heat supply cycle (energising cycle) of normal operation period, compressor can carry out self check, uses pick-up unit that three-phase supply is detected.
As can be seen, the power state detection part in the motor status pick-up unit detects under the situation of ac power supply from top embodiment, and the winding state test section is detected under the situation that exchanges disconnection, DC power supply.This shows, in order to ensure the isolation/decoupling of high-voltage alternating and low-voltage direct, between power state detection part and winding state test section, interlocking mechanism can be set.In the above-described embodiments, interlocking mechanism is to realize by the control to three-phase contactor and starting switch K.
With reference to specific embodiment the utility model has been described in the instructions in front.Yet those of ordinary skill in the art understands, and can carry out various modifications and change under the prerequisite that does not depart from the scope of the present utility model that limits as claims.
Claims (22)
1. a pick-up unit for detection of motor operating state, is characterized in that, comprising:
Resistor network can be connected to three phase windings of motor stator, and it is right to be provided with check point;
Measuring unit, be used for to measure can reflect described check point between the physical quantity of resistance value; And
The winding state determining unit is for the running status of determining described winding according to the value of measured physical quantity;
Wherein, described resistor network and described check point described check point that one of on off operating mode combination of being arranged to each phase winding in described three phase windings is caused between resistance value be different from described check point that another described combination causes between resistance value.
2. pick-up unit according to claim 1, wherein, described resistor network comprises first resistor, second resistor, the 3rd resistor and the 4th resistor, and according to the 3rd, the order of first, second and the 4th resistor is connected in series;
Wherein, the tie point of the two ends of resistors in series group and first and second resistors is configured to be connected with described three phase windings respectively; And
Wherein, the described the 3rd and the tie point of first resistor and described second and the tie point of the 4th resistor can be right as described check point.
3. pick-up unit according to claim 1, wherein, described measuring unit comprises:
Partial pressure unit;
Direct supply is connected to first check point of described check point centering via described partial pressure unit; And
Voltage measurement unit is used for measuring the voltage at the described first check point place as described physical quantity;
Wherein, second check point of described check point centering is grounded.
4. pick-up unit according to claim 3 also comprises: control module is used for starting the detection of described pick-up unit under the situation that described motor disconnects from AC power.
5. pick-up unit according to claim 4, wherein, described control module be further configured into after described pick-up unit initialization, the time of described AC power before connecting, start the detection of described pick-up unit.
6. pick-up unit according to claim 4, wherein, described control module is further configured to being at described motor periodically between turnoff time, starts the detection of described pick-up unit.
7. pick-up unit according to claim 1, wherein, described winding state determining unit is further configured to determine the running status of winding according to the mean value of the described physical quantity of the predetermined quantity of measuring.
8. pick-up unit according to claim 1 also comprises the AC power detecting unit, and wherein, described AC power detecting unit comprises:
Line voltage computing unit is used for calculating the line voltage between each phase line; And
The power supply status determining unit is for the duty of determining AC power according to described line voltage.
9. pick-up unit according to claim 8, wherein, described line voltage computing unit comprises first and second differential operational amplifiers; The forward of described first and second differential operational amplifiers and reverse input end are connected to a phase line in the three-phase supply jointly, and the remaining input end of described first and second differential operational amplifiers is connected to two other phase line via resistor respectively; And the output terminal of described first and second differential operational amplifiers is connected to described power supply status determining unit.
10. pick-up unit according to claim 9, wherein, the described remaining input end of described first and second differential operational amplifiers is connected to described two other phase line via the resistor in the described resistor network respectively.
11. pick-up unit according to claim 8, wherein, described power supply status determining unit is further configured to by calculating the effective value of supply voltage according to described line voltage, and compares to determine the duty of power supply with nominal value.
12. the three phase electric machine system of a Y-connection is characterized in that, comprising: according to any described pick-up unit in the claim 1 to 11.
13. a monophase machine system is characterized in that, comprising:
Main winding;
Auxiliary winding;
Auxiliary resistor, the one end is connected to the common port of described main winding and described auxiliary winding, and the resistance of described auxiliary resistor is determined according to the resistance of described main winding and auxiliary winding; And
Resistor network, its different port are connected respectively to the non-common port of described main winding and described auxiliary winding and the other end of described auxiliary resistor, and described resistor network to be provided with check point right;
Measuring unit, be used for to measure can reflect described check point between the physical quantity of resistance value; And
The winding state determining unit is for the running status of determining described winding according to the value of measured physical quantity;
Wherein, described resistor network and described check point described check point that one of on off operating mode combination of being arranged in described main winding and the described auxiliary winding each is caused between resistance value be different from described check point that another described combination causes between resistance value.
14. monophase machine according to claim 13 system, wherein, described resistor network comprises first resistor, second resistor, the 3rd resistor and the 4th resistor, and according to the 3rd, the order of first, second and the 4th resistor is connected in series;
Wherein, the tie point of the two ends of resistors in series group and first and second resistors is configured to be connected with the non-common port of described main winding and described auxiliary winding and the other end of described auxiliary resistor respectively; And
Wherein, the described the 3rd and the tie point of first resistor and described second and the tie point of the 4th resistor can be right as described check point.
15. monophase machine according to claim 13 system, wherein, described measuring unit comprises:
Partial pressure unit;
Direct supply is connected to first check point of described check point centering via described partial pressure unit; And
Voltage measurement unit is used for measuring the voltage at the described first check point place as described physical quantity;
Wherein, second check point of described check point centering is grounded.
16. monophase machine according to claim 15 system also comprises: control module is used for connecting described direct supply under the situation that described motor disconnects from AC power.
17. monophase machine according to claim 16 system, wherein, described control module is further configured to being at described motor periodically between turnoff time, connects described direct supply.
18. monophase machine according to claim 13 system, wherein, described winding state determining unit is further configured to determine the running status of winding according to the mean value of the described physical quantity of the predetermined quantity of measuring.
19. monophase machine according to claim 13 system also comprises the AC power detecting unit, wherein, described AC power detecting unit comprises:
Line voltage computing unit is used for calculating the line voltage between each phase line; And
The power supply status determining unit is for the duty of determining AC power according to described line voltage.
20. monophase machine according to claim 19 system, wherein, described line voltage computing unit comprises first and second differential operational amplifiers; The forward of described first and second differential operational amplifiers and reverse input end are connected to a phase line in the three-phase supply jointly, and the remaining input end of described first and second differential operational amplifiers is connected to two other phase line via resistor respectively; And the output terminal of described first and second differential operational amplifiers is connected to described power supply status determining unit.
21. monophase machine according to claim 20 system, wherein, the described remaining input end of described first and second differential operational amplifiers is connected to described two other phase line via the resistor in the described resistor network respectively.
22. monophase machine according to claim 19 system, wherein, described power supply status determining unit is further configured to by calculating the effective value of supply voltage according to described line voltage, and compares to determine the duty of power supply with nominal value.
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| CN201320207071XU CN203217057U (en) | 2013-04-22 | 2013-04-22 | Star connection three-phase motor and single-phase motor system and operation state test device |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104111419B (en) * | 2013-04-22 | 2017-08-08 | 艾默生环境优化技术有限公司 | Three phase electric machine system, monophase machine system, running state detecting device and method |
| CN107247242A (en) * | 2017-07-31 | 2017-10-13 | Tcl空调器(中山)有限公司 | Frequency converter failure detection method and device |
-
2013
- 2013-04-22 CN CN201320207071XU patent/CN203217057U/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104111419B (en) * | 2013-04-22 | 2017-08-08 | 艾默生环境优化技术有限公司 | Three phase electric machine system, monophase machine system, running state detecting device and method |
| CN107247242A (en) * | 2017-07-31 | 2017-10-13 | Tcl空调器(中山)有限公司 | Frequency converter failure detection method and device |
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