CN104113239A - Detection method of direct-current motor system and direct-current motor system - Google Patents

Abstract

The invention discloses a detection method of a direct-current motor system. The direct-current motor system comprises N direct-current motors in parallel connection, an IPM module respectively connected to the N direct-current motors, and a master control module, wherein the master control module outputs six paths of PWM signals to the IPM module to control the N direct-current motors. The detection method comprises the following steps that: the IPM module is controlled to apply a first direct current Id1 to straight shafts of the N direct-current motors; after preset time, first straight shaft voltages Vd1 of the N direct-current motors are obtained; according to the first direct current Id1 and the first straight shaft voltages Vd1, equivalent resistances of the N direct-current motors are calculated; when the equivalent resistances of the N direct-current motors are larger than or equal to a preset resistance, the number of the direct-current motors in a normal electrification mode in the direct-current motor system is determined to be less than N. Therefore, a neglected loading phenomenon of direct-current motors or a loosening or shedding phenomenon of connecting wire terminals of the direct-current motors during the using process can be detected, thereby realizing reliable control of the system and avoiding potential safety hazard. In addition, the invention also discloses a direct-current motor system.

Description

The detection method of direct current motor system and direct current motor system

Technical field

The present invention relates to technical field of motors, particularly a kind of detection method of direct current motor system and a kind of direct current motor system.

Background technology

It is more energy-conservation, efficient that direct current machine is compared alternating current machine, and along with advocating that national energy-saving reduces discharging, more and more air-conditioning producer utilizes direct current machine development and Design air conditioner.Existing direct current motor system mostly adopts 1 IPM module of 1 master control module controls (Intelligent Power Module, Intelligent Power Module), then by 1 direct current machine of IPM module drive.But the shortcoming that prior art exists is that direct current machine cost than alternating current machine cost summary height a bit, correspondingly, compare AC motor system and want complicated, more expensive by direct current motor system.Particularly all dependence on import of IPM module major part, domestic little manufacturer production, thus cause the cost of IPM module high.For example, for two through-flow cabinet indoor units and two outdoor type of wind wheel of 2 direct current machines of needs, just need 2 IPM to drive 2 direct current machines, thereby make the cost of two through-flow cabinet indoor units and two outdoor types of wind wheel higher.Thus, the sky high cost of direct current motor system becomes the universal most important obstacle of obstruction direct current machine.

In correlation technique, propose a kind of direct current motor system, as shown in Figure 1, can adopt 1 main control module 30 ' to control 1 IPM module 20 ' and drive 1 direct current machine 1 '; As shown in Figure 2, also adopt 1 main control module 30 ' to control 2 direct current machines of 2 IPM module drive, IPM module 20 ' drives direct current machine 1 ' and IPM module 21 ' to drive direct current machine 2 '; As shown in Figure 3, also can adopt 1 main control module 30 ' to control 3 motors of 3 IPM module drive, IPM module 20 ' drives direct current machine 1 ', IPM module 21 ' to drive direct current machine 2 ' and IPM module 22 ' to drive direct current machine 3 '.And, because the main control module in correlation technique is up to the control interface of 3 IPM modules, just need to increase main control module if need to control more direct current machines.

To sum up, there are improved needs in the direct current motor system of correlation technique.

Summary of the invention

The present invention is intended to solve at least to a certain extent above-mentioned technological deficiency.

For this reason, one object of the present invention is to propose a kind of detection method of direct current motor system, and this detection method can detect multiple direct current machines in the direct current motor system that adopts 1 IPM module to control multiple direct current machines, avoids potential safety hazard.

Another object of the present invention is to propose a kind of direct current motor system.

For achieving the above object, the detection method of a kind of direct current motor system that one aspect of the present invention embodiment proposes, described direct current motor system comprises N direct current machine in parallel, is connected respectively to IPM module and the extremely main control module of described IPM module so that a described N direct current machine is controlled of output six road pwm signals of a described N direct current machine, N is more than or equal to 2 integer, and described detection method comprises the following steps: control described IPM module and apply the first direct current I to the d-axis of a described N direct current machine _d1; After Preset Time, obtain the first direct-axis voltage V of a described N direct current machine _d1; According to described the first direct current I _d1with described the first direct-axis voltage V _d1calculate the equivalent resistance of a described N direct current machine; In the time that the equivalent resistance of a described N direct current machine is more than or equal to preset resistance, judge that the quantity of the direct current machine of normal power-up in described direct current motor system is less than N.

The detection method of the direct current motor system proposing according to the present invention, first controls IPM module and applies the first direct current I to the d-axis of N direct current machine _d1, and after Preset Time, obtain the first direct-axis voltage V of N direct current machine _d1, afterwards, according to the first direct current I _d1with the first direct-axis voltage V _d1the equivalent resistance that calculates N direct current machine, in the time that the equivalent resistance of N direct current machine is more than or equal to preset resistance, judges that the quantity of the direct current machine of normal power-up in direct current motor system is less than N.Thus, in the direct current motor system that adopts 1 IPM module to control N direct current machine, whether whether this detection method can detect in neglected loading direct current machine or use procedure has the connecting line terminal of direct current machine to get loose, thereby guarantee the normal operation of direct current motor system, ensure systematic function, realize the reliable control of direct current motor system, avoid potential safety hazard.

Particularly, in one embodiment of the present of invention, can calculate according to following formula the equivalent resistance of a described N direct current machine:

V _d1-e-I _d1*R _real＝0

Wherein, R _realfor the equivalent resistance of a described N direct current machine, e is the equivalent pressure drop of IGBT in described IPM module.

Further, in another embodiment of the present invention, the detection method of described direct current motor system also comprises: control described IPM module and apply the second direct current I to the d-axis of a described N direct current machine _d2; After described Preset Time, obtain the second direct-axis voltage V of a described N direct current machine _d2, with according to described the first direct current I _d1with described the first direct-axis voltage V _d1and described the second direct current I _d2with described the second direct-axis voltage V _d2calculate the equivalent resistance of a described N direct current machine.

Particularly, in another embodiment of the present invention, can calculate according to following formula the equivalent resistance of a described N direct current machine:

$\left\{\begin{array}{c}{V}_{d1}-e-I_{d1}*R_{\mathrm{real}}=0\\ V_{d2}-e-I_{d2}*R_{\mathrm{real}}=0\end{array}\right.$

Wherein, R _realfor the equivalent resistance of a described N direct current machine, e is the equivalent pressure drop of IGBT in described IPM module.

In a preferred embodiment of the invention, described preset resistance can be greater than the resistance R of N direct current machine _nand be less than the resistance R of N-1 direct current machine _n-1, wherein, can obtain according to following formula the resistance R of a described N direct current machine _nresistance R with a described N-1 direct current machine _n-1:

$\left\{\begin{array}{c}{R}_N=R_{\mathrm{rated}}/N\\ R_{N-1}=R_{\mathrm{rated}}/(N-1)\end{array}\right.$

Wherein, R _ratedfor the rated resistance of the single direct current machine in a described N direct current machine.

In embodiments of the present invention, the model of a described N direct current machine can be identical.

For achieving the above object, the present invention's a kind of direct current motor system that embodiment proposes on the other hand comprises: N direct current machine, and a described N direct current machine is connected in parallel, and wherein, N is more than or equal to 2 integer; Be connected respectively to the IPM module of a described N direct current machine; Export six road pwm signals to the main control module of described IPM module so that a described N direct current machine is controlled, described main control module applies the first direct current I for controlling described IPM module to the d-axis of a described N direct current machine _d1, and after Preset Time, obtain the first direct-axis voltage V of a described N direct current machine _d1, and according to described the first direct current I _d1with described the first direct-axis voltage V _d1calculate the equivalent resistance of a described N direct current machine, in the time that the equivalent resistance of a described N direct current machine is more than or equal to preset resistance, in direct current motor system, the quantity of the direct current machine of normal power-up is less than N described in described master control module judges.

The direct current motor system proposing according to the present invention, main control module export six road pwm signals to IPM module so that N direct current machine controlled, and main control module is also controlled IPM module and is applied the first direct current I to the d-axis of N direct current machine _d1, and after Preset Time, obtain the first direct-axis voltage V of N direct current machine _d1, afterwards, main control module is according to the first direct current I _d1with the first direct-axis voltage V _d1the equivalent resistance that calculates N direct current machine, in the time that the equivalent resistance of N direct current machine is more than or equal to preset resistance, in master control module judges direct current motor system, the quantity of the direct current machine of normal power-up is less than N.Thus, this direct current motor system adopts 1 IPM module to control N direct current machine, can effectively save system cost, and whether can detect in neglected loading direct current machine or use procedure whether have the connecting line terminal of direct current machine to get loose, thereby guarantee the normal operation of direct current motor system, ensure systematic function, realize the reliable control of direct current motor system, avoid potential safety hazard.

Particularly, in one embodiment of the invention, described main control module can calculate according to following formula the equivalent resistance of a described N direct current machine:

V _d1-e-I _d1*R _real＝0

Wherein, R _realfor the equivalent resistance of a described N direct current machine, e is the equivalent pressure drop of IGBT in described IPM module.

In another embodiment of the present invention, described main control module also applies the second direct current I for controlling described IPM module to the d-axis of a described N direct current machine _d2, and after described Preset Time, obtain the second direct-axis voltage V of a described N direct current machine _d2, with according to described the first direct current I _d1with described the first direct-axis voltage V _d1and described the second direct current I _d2with described the second direct-axis voltage V _d2calculate the equivalent resistance of a described N direct current machine.

Particularly, in another embodiment of the present invention, described main control module can calculate according to following formula the equivalent resistance of a described N direct current machine:

$\left\{\begin{array}{c}{V}_{d1}-e-I_{d1}*R_{\mathrm{real}}=0\\ V_{d2}-e-I_{d2}*R_{\mathrm{real}}=0\end{array}\right.$

Wherein, R _realfor the equivalent resistance of a described N direct current machine, e is the equivalent pressure drop of IGBT in described IPM module.

In a preferred embodiment of the invention, described preset resistance can be greater than the resistance R of N direct current machine _nand be less than the resistance R of N-1 direct current machine _n-1, wherein, described main control module can obtain according to following formula the resistance R of a described N direct current machine _nresistance R with a described N-1 direct current machine _n-1:

$\left\{\begin{array}{c}{R}_N=R_{\mathrm{rated}}/N\\ R_{N-1}=R_{\mathrm{rated}}/(N-1)\end{array}\right.$

Wherein, R _ratedfor the rated resistance of the single direct current machine in a described N direct current machine.

In embodiments of the present invention, the model of a described N direct current machine is identical.

The aspect that the present invention is additional and advantage in the following description part provide, and part will become obviously from the following description, or recognize by practice of the present invention.

Brief description of the drawings

The present invention above-mentioned and/or additional aspect and advantage will become from the following description of the accompanying drawings of embodiments obviously and easily and understand, wherein:

Fig. 1 is the direct current motor system structural representation that drives 1 direct current machine in correlation technique;

Fig. 2 is the direct current motor system structural representation that drives 2 direct current machines in correlation technique;

Fig. 3 is the direct current motor system structural representation that drives 3 direct current machines in correlation technique;

Fig. 4 is according to the flow chart of the detection method of the direct current motor system of the embodiment of the present invention;

Fig. 5 is the flow chart of the detection method of the direct current motor system of a specific embodiment according to the present invention;

Fig. 6 is the flow chart of the detection method of the direct current motor system of another specific embodiment according to the present invention;

Fig. 7 is the flow chart of the detection method of the direct current motor system of another specific embodiment according to the present invention;

Fig. 8 is direct-axis current and direct-axis voltage waveform schematic diagram in another specific embodiment according to the present invention;

Fig. 9 is the flow chart of the detection method of the direct current motor system of another specific embodiment according to the present invention;

Figure 10 is direct-axis current and direct-axis voltage waveform schematic diagram in another specific embodiment according to the present invention;

Figure 11 is according to the structural representation of the direct current motor system of the embodiment of the present invention;

Figure 12 is the structural representation of the direct current motor system of a specific embodiment according to the present invention; And

Figure 13 is the structural representation of the direct current motor system of another specific embodiment according to the present invention.

Reference numeral:

N direct current machine 10, IPM module 20 and main control module 30.

Embodiment

Describe embodiments of the invention below in detail, the example of described embodiment is shown in the drawings, and wherein same or similar label represents same or similar element or has the element of identical or similar functions from start to finish.Be exemplary below by the embodiment being described with reference to the drawings, only for explaining the present invention, and can not be interpreted as limitation of the present invention.

Disclosing below provides many different embodiment or example to be used for realizing different structure of the present invention.Of the present invention open in order to simplify, hereinafter the parts to specific examples and setting are described.Certainly, they are only example, and object does not lie in restriction the present invention.In addition, the present invention can be in different examples repeat reference numerals and/or letter.This repetition is in order to simplify and object clearly, itself do not indicate the relation between discussed various embodiment and/or setting.In addition, the various specific technique the invention provides and the example of material, but those of ordinary skill in the art can recognize the property of can be applicable to of other techniques and/or the use of other materials.In addition, First Characteristic described below Second Characteristic it " on " structure can comprise that the first and second Characteristics creations are the direct embodiment of contact, also can comprise the embodiment of other Characteristics creation between the first and second features, such the first and second features may not be direct contacts.

In description of the invention, it should be noted that, unless otherwise prescribed and limit, term " installation ", " being connected ", " connection " should be interpreted broadly, for example, can be mechanical connection or electrical connection, also can be the connection of two element internals, can be to be directly connected, and also can indirectly be connected by intermediary, for the ordinary skill in the art, can understand as the case may be the concrete meaning of above-mentioned term.

With reference to description and accompanying drawing below, these and other aspects of embodiments of the invention will be known.In these descriptions and accompanying drawing, specifically disclose some specific implementations in embodiments of the invention, represent some modes of the principle of implementing embodiments of the invention, but should be appreciated that the scope of embodiments of the invention is not limited.On the contrary, embodiments of the invention comprise all changes, amendment and the equivalent within the scope of spirit and the intension that falls into additional claims.

Detection method and the direct current motor system of the direct current motor system proposing according to the embodiment of the present invention are described with reference to the accompanying drawings.

Fig. 4 is the flow chart of the detection method of direct current motor system according to an embodiment of the invention.Direct current motor system comprises N direct current machine in parallel, is connected respectively to IPM module (the Intelligent Power Module of N direct current machine, Intelligent Power Module) and output six road PWM (Pulse Width Modulation, pulse width modulation) signal is to the main control module of IPM module so that N direct current machine controlled, and N is more than or equal to 2 integer.Specifically, IPM module is used for receiving main control module output Liu road pwm signal, and simultaneously to N direct current machine output U, V, W three-phase driving signal, N direct current machine module is according to U, the V of the output of IPM module, the running of W three-phase driving signal, i.e. speech, the U of N direct current machine is all connected with the U phase output terminal of IPM module mutually, and the V of N direct current machine is all connected with the V phase output terminal of IPM module mutually, and the W of N direct current machine is all connected with the W phase output terminal of IPM module mutually.It should be noted that, can regard N direct current machine as an integrated motor model, the UVW three-phase current of N direct current machine is the UVW three-phase current of integrated motor model,

In one embodiment of the invention, the model of N direct current machine is identical.It should be noted that, here identical refers to the identical of broad sense, approximate identical.That is to say, the direct current motor system of the embodiment of the present invention is adapted to the occasion that need to simultaneously adopt the model of two or more direct current machines and multiple direct current machines identical, load is approaching, for example, the direct current motor system of the embodiment of the present invention is adapted to the two through-flow bi-motor indoor sets of air-conditioning, two wind wheel off-premises stations etc.

In addition, it should be noted that, compared with adopting 1 direct current machine of 1 IPM module drive in correlation technique, there is following technical barrier in N direct current machine of 1 IPM module drive of employing of the embodiment of the present invention: if 1 direct current machine of 1 IPM module drive, in the time that the socket of direct current machine in direct current machine neglected loading or user's use procedure gets loose, cannot detect U, the V of this direct current machine, the phase current of W three-phase, thereby can quote scarce electrical fault, and reminding user; And if N direct current machine of 1 IPM module drive, detect U, the V of N direct current machine, the phase current of W three-phase, in the time that the connecting line terminal of direct current machine in wherein 1 direct current machine neglected loading or user's use procedure gets loose, because U, V, the W three-phase of other direct current machine are still communicated with, still can detect the phase current of U, V, W three-phase.Thus, correlation technique cannot detect scarce electrical fault, in the time occurring to lack electrical fault, if continue operation direct current motor system, can affect the performance of system, and may have potential safety hazard.Based on this, the embodiment of the present invention proposes a kind of detection method of direct current motor system.

In an embodiment of the present invention, as shown in Figure 4, the detection method of this direct current motor system comprises the following steps:

S1: control IPM module and apply the first direct current I to the d-axis of N direct current machine _d1.

Specifically, can export the first direct current I to a N in parallel direct current machine by IPM module _d1, and keeping the angle θ of N direct current machine to immobilize, in N direct current machine, the electric angle speed omega of each direct current machine is 0.

Preferably, the first direct current I _d1current value can be less than the demagnetization current of single direct current machine in N direct current machine.For example, the demagnetization current of single direct current machine can be 1.5 amperes, the first direct current I _d1current value can be 0.6 ampere.

Wherein, it should be noted that, in an embodiment of the present invention, can regard N direct current machine as an integrated motor model, the d-axis of N direct current machine is the d-axis of this integrated motor model, applies the first direct current I to the d-axis of N direct current machine _d1be to the d-axis of integrated motor model and apply the first direct current I _d1.

S2: after preset time T, obtain the first direct-axis voltage V of N direct current machine _d1.

That is to say, applying the first direct current I to the d-axis of N direct current machine _d1time reach after preset time T, obtain the first direct-axis voltage V of N direct current machine _d1.

Wherein, due to the first direct current I _d1, the first direct-axis voltage V _d1after stable, direct current machine can be regarded pure resistive load as, ensures the first direct current I so preset time T should be _d1, the first direct-axis voltage V _d1reach and stablize the required retention time.Preferably, preset time T can be between 0.5 second-3 seconds value, for example, preset time T can be 1 second.

In addition, it should be noted that the first direct-axis voltage V of N direct current machine _d1be the direct-axis voltage of integrated motor model.

S3: according to the first direct current I _d1with the first direct-axis voltage V _d1calculate the equivalent resistance R of N direct current machine _real.

Particularly, in one embodiment of the invention, can calculate according to following formula the equivalent resistance R of N direct current machine _real:

V _d1-e-I _d1*R _real＝0

Wherein, R _realfor the equivalent resistance of N direct current machine, e is the equivalent pressure drop of IGBT in IPM module, for being constant with a IPM module e.

Specifically, master control module controls IPM module applies default straight the first direct current I to the d-axis of N parallel connection direct motor _d1, meanwhile, it is the first direct current I of 0 that master control module controls IPM module applies current value to the quadrature axis of N parallel connection direct motor _q1, the first direct current I applying _d1after stable, detect the first direct-axis voltage V of N direct current machine _d1, thus, can be according to the first direct current I _d1the first direct-axis voltage V with N direct current machine _d1calculate the equivalent resistance R of N direct current machine _real.

Particularly, can calculate according to the direct-axis voltage equation of N direct current machine the equivalent resistance of N direct current machine:

E _d1＝V _d1-e-I _d1*R _real+ω*I _q1*L _q (1)

Wherein, E _d1for the first d-axis induced electromotive force of N direct current machine, V _d1for the first direct-axis voltage of N direct current machine, e is the equivalent pressure drop of IGBT in IPM module, I _d1for the first direct current applying to the d-axis of N direct current machine, R _realfor the equivalent resistance of N direct current machine, ω is the electric angle speed of each direct current machine in N direct current machine, I _q1for the first direct current applying to the quadrature axis of N direct current machine, L _qfor the quadrature axis inductance of each direct current machine in N direct current machine.It should be noted that the first d-axis induced electromotive force E of N direct current machine _d1be the d-axis induced electromotive force of integrated motor model.

Thus, the first direct current I applying to the d-axis of N direct current machine _d1after stable, the first d-axis induced electromotive force E of N direct current machine _d1be 0, and applying the first direct current I to the d-axis of N direct current machine _d1time, master control module controls N direct current machine maintains static, and in N direct current machine, the rotational speed omega of each direct current machine all remains 0, meanwhile, the first direct current I applying to the quadrature axis of N direct current machine _q1also be 0, above formula (1) can be reduced to:

V _d1-e-I _d1*R _real＝0。

Like this, artificial measure IPM module in after the equivalent pressure drop e of IGBT, can be according to the first direct current I _d1with the first direct-axis voltage V _d1calculate the equivalent resistance R of N direct current machine _real.

S4: as the equivalent resistance R of N direct current machine _realbe more than or equal to preset resistance R _x, i.e. R _real>=R _xtime, judge that the quantity of the direct current machine of normal power-up in direct current motor system is less than N, judge that the socket of direct current machine in neglected loading direct current machine or user's use procedure gets loose, there is to lack electrical fault in direct current motor system.

Like this, judging that direct current motor system occurs to lack after electrical fault, can point out to user.

In a preferred embodiment of the invention, preset resistance R _xcan be greater than the resistance R of N direct current machine _nand be less than the resistance R of N-1 direct current machine _n-1, wherein, can obtain according to following formula the resistance R of N direct current machine _nresistance R with N-1 direct current machine _n-1:

$\left\{\begin{array}{c}{R}_N=R_{\mathrm{rated}}/N\\ R_{N-1}=R_{\mathrm{rated}}/(N-1)\end{array}\right.$

Wherein, R _ratedfor the rated resistance of the single direct current machine in N direct current machine.

It should be noted that preset resistance R _xtheoretical value should be more than or equal to the resistance R of N-1 direct current machine _n-1, still, in practical application, consider accuracy of detection and interference problem, preset resistance R _xcan be set to the resistance R between N direct current machine _nresistance R with N-1 direct current machine _n-1between value.Preferably, preset resistance R _x=R _n+ (R _n-1-R _n) × 0.9.

Further, in another embodiment of the present invention, the detection method of this direct current motor system also comprises: control IPM module and apply the second direct current I to the d-axis of N direct current machine _d2; After Preset Time, obtain the second direct-axis voltage V of N direct current machine _d2, with according to the first direct current I _d1with the first direct-axis voltage V _d1and the second direct current I _d2with the second direct-axis voltage V _d2calculate the equivalent resistance of N direct current machine.

Specifically, can export the second direct current I to a N in parallel direct current machine by IPM module _d2, and keeping the angle θ of N direct current machine to immobilize, in N direct current machine, the electric angle speed omega of each direct current machine is 0.Applying the second direct current I to the d-axis of N direct current machine _d2time reach after preset time T, obtain the second direct-axis voltage V of N direct current machine _d2.

Preferably, the second direct current I _d2current value can be less than the demagnetization current of single direct current machine in N direct current machine, for example, the demagnetization current of single direct current machine can be 1.5 amperes, the second direct current I _d2current value can be 0.6 ampere.Preset time T can be between 0.5 second-3 seconds value, for example, preset time T can be 1 second.

Wherein, it should be noted that, apply the second direct current I to the d-axis of N direct current machine _d2be to the d-axis of integrated motor model and apply the second direct current I _d2.The second direct-axis voltage V of N direct current machine _d2be the direct-axis voltage of integrated motor model.

Particularly, can calculate according to following formula the equivalent resistance of N direct current machine:

$\left\{\begin{array}{c}{V}_{d1}-e-I_{d1}*R_{\mathrm{real}}=0\\ V_{d2}-e-I_{d2}*R_{\mathrm{real}}=0\end{array}\right.$

Wherein, R _realfor the equivalent resistance of N direct current machine, e is the equivalent pressure drop of IGBT in IPM module, for being constant with a IPM module e.

That is to say, applying the first direct current I to the d-axis of N direct current machine _d1and obtain the first direct-axis voltage V of N direct current machine _d1after, main control module is controlled IPM module again and is applied default straight the second direct current I to the d-axis of N parallel connection direct motor _d2, meanwhile, it is the second direct current I of 0 that master control module controls IPM module applies current value to the quadrature axis of N parallel connection direct motor _q2, the second direct current I applying _d2after stable, detect the second direct-axis voltage V of N direct current machine _d2, thus, can be according to the first direct current I _d1with the first direct-axis voltage V _d1and the second direct current I _d2with the second direct-axis voltage V _d2calculate the equivalent resistance R of N direct current machine _real.

Particularly, can calculate according to the direct-axis voltage equation of N direct current machine the equivalent resistance of N direct current machine:

$\left\{\begin{array}{c}{E}_{d1}=V_{d1}-e-I_{d1}*R_{\mathrm{real}}+\mathrm{\ω}*I_{q1}*L_q\\ E_{d2}=V_{d2}-e-I_{d2}*R_{\mathrm{real}}+\mathrm{\ω}*I_{q2}*L_q\end{array}\right.---\left(2\right)$

Wherein, E _d1for the first d-axis induced electromotive force of N direct current machine, V _d1for the first direct-axis voltage of N direct current machine, E _d2for the second d-axis induced electromotive force of N direct current machine, V _d2for the second direct-axis voltage of N direct current machine, e is the equivalent pressure drop of IGBT in IPM module, I _d1for the first direct current applying to the d-axis of N direct current machine, I _d2for the second direct current applying to the d-axis of N direct current machine, R _realfor the equivalent resistance of N direct current machine, ω is the electric angle speed of each direct current machine in N direct current machine, I _q1for the first direct current applying to the quadrature axis of N direct current machine, I _q2for the second direct current applying to the quadrature axis of N direct current machine, L _qfor the quadrature axis inductance of each direct current machine in N direct current machine.It should be noted that the first d-axis induced electromotive force E of N direct current machine _d1with the second d-axis induced electromotive force E _d2be the d-axis induced electromotive force of integrated motor model.

Thus, the first direct current I applying to the d-axis of N direct current machine _d1after stable, the first d-axis induced electromotive force E of N direct current machine _d1be 0, and applying the first direct current I to the d-axis of N direct current machine _d1time, master control module controls N direct current machine maintains static, and in N direct current machine, the rotational speed omega of each direct current machine all remains 0, meanwhile, the first direct current I applying to the quadrature axis of N direct current machine _q1also be 0.Afterwards, the second direct current I applying to the d-axis of N direct current machine _d2after stable, the second d-axis induced electromotive force E of N direct current machine _d2be 0, and applying the second direct current I to the d-axis of N direct current machine _d2time, master control module controls N direct current machine maintains static, and in N direct current machine, the rotational speed omega of each direct current machine all remains 0, meanwhile, the second direct current I applying to the quadrature axis of N direct current machine _q2also be 0, above formula (2) can be reduced to:

$\left\{\begin{array}{c}{V}_{d1}-e-I_{d1}*R_{\mathrm{real}}=0\\ V_{d2}-e-I_{d2}*R_{\mathrm{real}}=0\end{array}\right.---\left(3\right)$

Like this, after two equations in (3) formula subtract each other, can cancellation IPM module in the equivalent pressure drop e of IGBT, can calculate the equivalent resistance R of N direct current machine _real.

Generally speaking, in a specific embodiment of the present invention, as shown in Figure 5, the detection method of this direct current motor system comprises the following steps:

S101: control IPM module and apply the first direct current I to the d-axis of N direct current machine _d1.

S102: apply the first direct current I to the d-axis of N direct current machine _d1time reach after preset time T, obtain the first direct-axis voltage V of N direct current machine _d1.

S103: according to direct-axis voltage equation E _d1=V _d1-e-I _d1* R _real+ ω * I _q1* L _qcalculate the equivalent resistance of N direct current machine.

S104: the resistance R of obtaining N direct current machine _nresistance R with N-1 direct current machine _n-1.

S105: the equivalent resistance R that judges N direct current machine _realwhether be more than or equal to preset resistance R _x.If so, perform step S106; If not, perform step S107.

Wherein, preset resistance R _xcan be greater than the resistance R of N direct current machine _nand be less than the resistance R of N-1 direct current machine _n-1, preferably, preset resistance R _x=R _n+ (R _n-1-R _n) × 0.9.

S106: judge that electrical fault occurs to lack direct current motor system.

S107: judge that electrical fault does not occur to lack direct current motor system.

In another specific embodiment of the present invention, as shown in Figure 6, the detection method of this direct current motor system comprises the following steps:

S201: control IPM module and apply the first direct current I to the d-axis of N direct current machine _d1.

S202: apply the first direct current I to the d-axis of N direct current machine _d1time reach after preset time T, obtain the first direct-axis voltage V of N direct current machine _d1.

S203: control IPM module and apply the second direct current I to the d-axis of N direct current machine _d2.

S204: apply the second direct current I to the d-axis of N direct current machine _d2time reach after preset time T, obtain the second direct-axis voltage V of N direct current machine _d2.

S205: according to direct-axis voltage equation E _d1=V _d1-e-I _d1* R _real+ ω * I _q1* L _qand E _d2=V _d2-e-I _d2* R _real+ ω * I _q2* L _qcalculate the equivalent resistance of N direct current machine.

S206: the resistance R of obtaining N direct current machine _nresistance R with N-1 direct current machine _n-1.

S207: the equivalent resistance R that judges N direct current machine _realwhether be more than or equal to preset resistance R _x.If so, perform step S208; If not, perform step S209.

Wherein, preset resistance R _xcan be greater than the resistance R of N direct current machine _nand be less than the resistance R of N-1 direct current machine _n-1, preferably, preset resistance R _x=R _n+ (R _n-1-R _n) × 0.9.

S208: judge that electrical fault occurs to lack direct current motor system.

S209: judge that electrical fault does not occur to lack direct current motor system.

Below as an example of N=2 example and N=3 be example, describe the detection method of the direct current motor system of the embodiment of the present invention in detail.

In another specific embodiment of the present invention, work as N=2, the quantity of direct current machine is 2 o'clock, as shown in Figure 7, the detection method of the direct current motor system of the embodiment of the present invention comprises the following steps:

S301: control IPM module and apply the first direct current I to the d-axis of 2 direct current machines _d1.

S302: apply the first direct current I to the d-axis of 2 direct current machines _d1time reach after preset time T, obtain the first direct-axis voltage V of 2 direct current machines _d1.

Wherein, be illustrated in figure 8 the waveform schematic diagram of direct-axis current and the direct-axis voltage of 2 direct current machines in the present embodiment.In the short of electricity machine fault detect stage, direct-axis current is increased to the first direct current I gradually _d1after remain unchanged, direct-axis voltage is increased to the first direct-axis voltage V gradually _d1after remain unchanged, and, lack when electrical fault occurring, direct-axis voltage is as shown in curve 1; In the time not occurring to lack electrical fault, direct-axis voltage is as shown in curve 2.By as shown in Figure 8, the direct-axis voltage that occurs to obtain while lacking electrical fault is greater than the direct-axis voltage that electrical fault obtains does not occur to lack.

S303: according to direct-axis voltage equation E _d1=V _d1-e-I _d1* R _real+ ω * I _q1* L _qcalculate the equivalent resistance of 2 direct current machines.

S304: the resistance R of obtaining 2 direct current machines ₂resistance R with 1 direct current machine ₁.

Wherein, R ₂=R _rated/ 2, R ₁=R _rated.

S305: the equivalent resistance R that judges 2 direct current machines _realwhether be more than or equal to preset resistance R _x.If so, perform step S106; If not, perform step S107.

Wherein, preset resistance R _xcan be greater than the resistance R of 2 direct current machines ₂and be less than the resistance R of 1 direct current machine ₁, preferably, preset resistance R _x=R ₂+ (R ₁-R ₂) × 0.9.

S306: judge that electrical fault occurs to lack direct current motor system.

S307: judge that electrical fault does not occur to lack direct current motor system.

In another specific embodiment of the present invention, work as N=3, the quantity of direct current machine is 3 o'clock, as shown in Figure 9, the detection method of the direct current motor system of the embodiment of the present invention comprises the following steps:

S401: control IPM module and apply the first direct current I to the d-axis of 3 direct current machines _d1.

S402: apply the first direct current I to the d-axis of 3 direct current machines _d1time reach after preset time T, obtain the first direct-axis voltage V of 3 direct current machines _d1.

S403: control IPM module and apply the second direct current I to the d-axis of 3 direct current machines _d2.

S404: apply the second direct current I to the d-axis of 3 direct current machines _d2time reach after preset time T, obtain the second direct-axis voltage V of 3 direct current machines _d2.

Wherein, be as shown in figure 10 the waveform schematic diagram of direct-axis current and the direct-axis voltage of 3 direct current machines in the present embodiment.In the short of electricity machine fault detect stage, direct-axis current is increased to the first direct current I gradually _d1after remain unchanged, direct-axis voltage is increased to the first direct-axis voltage V gradually _d1after remain unchanged, afterwards, direct-axis current is increased to the second direct current I gradually _d2after remain unchanged, direct-axis voltage is increased to the second direct-axis voltage V gradually _d2after remain unchanged, and, lack when electrical fault occurring, direct-axis voltage is as shown in curve 3; In the time not occurring to lack electrical fault, direct-axis voltage is as shown in curve 4.By as shown in Figure 10, the direct-axis voltage that occurs to obtain while lacking electrical fault is greater than the direct-axis voltage that electrical fault obtains does not occur to lack.

S405: according to direct-axis voltage equation E _d1=V _d1-e-I _d1* R _real+ ω * I _q1* L _qand E _d2=V _d2-e-I _d2* R _real+ ω * I _q2* L _qcalculate the equivalent resistance of 3 direct current machines.

S406: the resistance R of obtaining 3 direct current machines ₃resistance R with 2 direct current machines ₂.

Wherein, R ₃=R _rated/ 3, R ₂=R _rated/ 2.

S407: the equivalent resistance R that judges 3 direct current machines _realwhether be more than or equal to preset resistance R _x.If so, perform step S408; If not, perform step S409.

Wherein, preset resistance R _xcan be greater than the resistance R of 3 direct current machines ₃and be less than the resistance R of 2 direct current machines ₂, preferably, preset resistance R _x=R ₃+ (R ₂-R ₃) × 0.9.

S408: judge that electrical fault occurs to lack direct current motor system.

S409: judge that electrical fault does not occur to lack direct current motor system.

To sum up, the detection method of the direct current motor system proposing according to the present invention, first controls IPM module and applies the first direct current I to the d-axis of N direct current machine _d1, and after Preset Time, obtain the first direct-axis voltage V of N direct current machine _d1, afterwards, according to the first direct current I _d1with the first direct-axis voltage V _d1the equivalent resistance that calculates N direct current machine, in the time that the equivalent resistance of N direct current machine is more than or equal to preset resistance, judges that the quantity of the direct current machine of normal power-up in direct current motor system is less than N.Thus, in the direct current motor system that adopts 1 IPM module to control N direct current machine, whether whether this detection method can detect in neglected loading direct current machine or use procedure has the connecting line terminal of direct current machine to get loose, thereby guarantee the normal operation of direct current motor system, ensure systematic function, realize the reliable control of direct current motor system, avoid potential safety hazard.

Figure 11 is according to the structural representation of the direct current motor system of the embodiment of the present invention.As shown in figure 11, direct current motor system comprises N direct current machine 10, IPM module 20 and main control module 30.

The direct current motor system of the embodiment of the present invention can adopt a main control module 30 to control an IPM module 20 driving N direct current machine 10.Main control module 30 is for sending six road pwm control signals to IPM module 20, and obtain U, V, the W three-phase current of N direct current machine, to estimate rotating speed and the position of N DC motor rotor according to the U, the V that obtain, W three-phase current, realize the real-time control to N direct current machine, wherein, can gather N direct current machine U, V, W three-phase current by the current sensor of IPM module 20 outsides or current sampling resistor.IPM module 20 is exported Liu road pwm control signal for receiving main control module 30, and exports U, V, W three-phase driving signal to N direct current machine 10 simultaneously, and N direct current machine 10 turns round for U, V, the W three-phase driving signal exported according to IPM module 20.Wherein, the U of N direct current machine 10 is all connected with the U phase output terminal of IPM module 20 mutually, and the V of N direct current machine 10 is all connected with the V phase output terminal of IPM module 20 mutually, and the W of N direct current machine 10 is all connected with the W phase output terminal of IPM module 20 mutually.It should be noted that, can regard N direct current machine as an integrated motor model, the UVW three-phase current of N direct current machine is the UVW three-phase current of integrated motor model.

Thus, compared with adopting 1 direct current machine of 1 IPM module drive in correlation technique, there is following technical barrier in N direct current machine of 1 IPM module drive of employing of the embodiment of the present invention: if 1 direct current machine of 1 IPM module drive, in the time that the socket of direct current machine in direct current machine neglected loading or user's use procedure gets loose, cannot detect U, the V of this direct current machine, the phase current of W three-phase, thereby can quote scarce electrical fault, and reminding user; And if N direct current machine of 1 IPM module drive, detect U, the V of N direct current machine, the phase current of W three-phase, in the time that the socket of direct current machine in wherein 1 direct current machine neglected loading or user's use procedure gets loose, because U, V, the W three-phase of other direct current machine are still communicated with, still can detect the phase current of U, V, W three-phase.Thus, correlation technique cannot detect scarce electrical fault, in the time occurring to lack electrical fault, if continue operation direct current motor system, can affect the performance of system, and may have potential safety hazard.Based on this, the embodiment of the present invention proposes a kind of direct current motor system.

In embodiments of the present invention, as shown in figure 11, N direct current machine 10 is connected in parallel, and N can be the integer that is more than or equal to 2, for example, N direct current machine 10 can be direct current machine 1, direct current machine 2 ..., direct current machine N; IPM module 20 is connected respectively to N direct current machine 10; Main control module 30 for export six road pwm signals to IPM module 20 so that N direct current machine 10 controlled, main control module 30 applies the first direct current I for controlling IPM module 20 to the d-axis of N direct current machine 10 _d1, and after Preset Time, obtain the first direct-axis voltage V of N direct current machine 10 _d1, and according to the first direct current I _d1with the first direct-axis voltage V _d1the equivalent resistance that calculates N direct current machine, in the time that the equivalent resistance of N direct current machine is more than or equal to preset resistance, main control module 30 judges that the quantity of the direct current machine of normal power-up in direct current motor system is less than N.

Specifically, main control module 30 can be exported the first direct current I to a N in parallel direct current machine 10 by IPM module 20 _d1, and keeping the angle θ of N direct current machine 10 to immobilize, the electric angle speed omega that makes each direct current machine in N direct current machine 10 is 0.Applying the first direct current I to the d-axis of N direct current machine _d1time reach after preset time T, main control module 30 obtains the first direct-axis voltage V of N direct current machine _d1.Afterwards, main control module 30 is according to the first direct current I _d1with the first direct-axis voltage V _d1calculate the equivalent resistance R of N direct current machine _real, and work as the equivalent resistance R of N direct current machine _realbe more than or equal to preset resistance R _x, i.e. R _real>=R _xtime, main control module 30 judges that the quantity of the direct current machine of normal power-up in direct current motor system is less than N, and main control module 30 judges that the socket of direct current machine in neglected loading direct current machine or user's use procedure gets loose, and there is to lack electrical fault in direct current motor system.Like this, judge that at main control module 30 direct current motor system occurs to lack after electrical fault, main control module 30 also can be controlled alarm set and point out to user.

Preferably, the first direct current I _d1current value can be less than the demagnetization current of single direct current machine in N direct current machine.For example, the demagnetization current of single direct current machine can be 1.5 amperes, the first direct current I _d1current value can be 0.6 ampere.

And, due to the first direct current I _d1, the first direct-axis voltage V _d1after stable, direct current machine can be regarded pure resistive load as, ensures the first direct current I so preset time T should be _d1, the first direct-axis voltage V _d1reach while stablizing required maintenance.Preferably, preset time T can be between 0.5 second-3 seconds value, for example, preset time T can be 1 second.

In addition, it should be noted that, in an embodiment of the present invention, can regard N direct current machine as an integrated motor model, the d-axis of N direct current machine is the d-axis of this integrated motor model, applies the first direct current I to the d-axis of N direct current machine _d1be to the d-axis of integrated motor model and apply the first direct current I _d1, the first direct-axis voltage V of N direct current machine _d1be the direct-axis voltage of integrated motor model.

In a preferred embodiment of the invention, preset resistance R _xcan be greater than the resistance R of N direct current machine _nand be less than the resistance R of N-1 direct current machine _n-1, wherein, main control module 30 can obtain according to following formula the resistance R of N direct current machine _nresistance R with N-1 direct current machine _n-1:

$\left\{\begin{array}{c}{R}_N=R_{\mathrm{rated}}/N\\ R_{N-1}=R_{\mathrm{rated}}/(N-1)\end{array}\right.$

Wherein, R _ratedfor the rated resistance of the single direct current machine in N direct current machine.

It should be noted that preset resistance R _xtheoretical value should be more than or equal to the resistance R of N-1 direct current machine _n-1, still, in practical application, consider accuracy of detection and interference problem, preset resistance R _xcan be set to the resistance R between N direct current machine _nresistance R with N-1 direct current machine _n-1between value.Preferably, preset resistance R _x=R _n+ (R _n-1-R _n) × 0.9.

Particularly, in one embodiment of the invention, main control module 30 can calculate according to following formula the equivalent resistance R of N direct current machine _real:

V _d1-e-I _d1*R _real＝0

Wherein, R _realfor the equivalent resistance of N direct current machine, e is the equivalent pressure drop of IGBT in IPM module, for being constant with a IPM module e.

Specifically, main control module 30 is controlled IPM module 20 and is applied default straight the first direct current I to the d-axis of N direct current machine 10 _d1, meanwhile, main control module 30 is controlled IPM module 20, and to apply current value to the quadrature axis of N direct current machine 10 be the first direct current I of 0 _q1, the first direct current I applying _d1after stable, main control module 30 obtains the first direct-axis voltage V of N direct current machine _d1, thus, main control module 30 can be according to the first direct current I _d1the first direct-axis voltage V with N direct current machine _d1calculate the equivalent resistance R of N direct current machine _real.

Particularly, main control module 30 can calculate according to the direct-axis voltage equation of N direct current machine the equivalent resistance of N direct current machine:

E _d1＝V _d1-e-I _d1*R _real+ω*I _q1*L _q (1)

Wherein, E _d1for the first d-axis induced electromotive force of N direct current machine, V _d1for the first direct-axis voltage of N direct current machine, e is the equivalent pressure drop of IGBT in IPM module, I _d1for the first direct current applying to the d-axis of N direct current machine, R _realfor the equivalent resistance of N direct current machine, ω is the electric angle speed of each direct current machine in N direct current machine, I _q1for the first direct current applying to the quadrature axis of N direct current machine, L _qfor the quadrature axis inductance of each direct current machine in N direct current machine.It should be noted that the first d-axis induced electromotive force E of N direct current machine _d1be the d-axis induced electromotive force of integrated motor model.

Thus, control at main control module 30 the first direct current I that IPM module 20 applies to the d-axis of N direct current machine _d1after stable, the first d-axis induced electromotive force E of N direct current machine _d1be 0, and applying the first direct current I to the d-axis of N direct current machine _d1time, main control module 30 is controlled N direct current machine 10 and is maintained static, and in N direct current machine 10, the rotational speed omega of each direct current machine all remains 0, and meanwhile, main control module 30 is controlled the first direct current I that IPM module 20 applies to the quadrature axis of N direct current machine _q1also be 0, above formula (1) can be reduced to:

V _d1-e-I _d1*R _real＝0。

Like this, in artificial mensuration IPM module, after the equivalent pressure drop e of IGBT, main control module 30 can be according to the first direct current I _d1with the first direct-axis voltage V _d1calculate the equivalent resistance R of N direct current machine _real.

Further, in another embodiment of the present invention, main control module 30 also applies the second direct current I for controlling IPM module 20 to the d-axis of N direct current machine _d2and after Preset Time, obtain the second direct-axis voltage V of N direct current machine _d2, with according to the first direct current I _d1with the first direct-axis voltage V _d1and the second direct current I _d2with the second direct-axis voltage V _d2calculate the equivalent resistance of N direct current machine.

Specifically, first, main control module 30 can be exported the first direct current I to a N in parallel direct current machine 10 by IPM module 20 _d1, and keeping the angle θ of N direct current machine 10 to immobilize, the electric angle speed omega that makes each direct current machine in N direct current machine 10 is 0, is applying the first direct current I to the d-axis of N direct current machine _d1time reach after preset time T, main control module 30 obtains the first direct-axis voltage V of N direct current machine _d1.Afterwards, main control module 30 can be exported the second direct current I to a N in parallel direct current machine 10 by IPM module 20 _d2, and keeping the angle θ of N direct current machine 10 to immobilize, in N direct current machine 10, the electric angle speed omega of each direct current machine is 0, is applying the second direct current I to the d-axis of N direct current machine _d2time reach after preset time T, main control module 30 obtains the second direct-axis voltage V of N direct current machine _d2.Afterwards, main control module 30 is according to the first direct current I _d1with the first direct-axis voltage V _d1and the second direct current I _d2with the second direct-axis voltage V _d2calculate the equivalent resistance R of N direct current machine _real, and work as the equivalent resistance R of N direct current machine _realbe more than or equal to preset resistance R _x, i.e. R _real>=R _xtime, main control module 30 judges that the quantity of the direct current machine of normal power-up in direct current motor system is less than N, and main control module 30 judges that the socket of direct current machine in neglected loading direct current machine or user's use procedure gets loose, and there is to lack electrical fault in direct current motor system.Like this, judge that at main control module 30 direct current motor system occurs to lack after electrical fault, main control module 30 also can be controlled alarm set and point out to user.

Preferably, the second direct current I _d2current value can be less than the demagnetization current of single direct current machine in N direct current machine, for example, the demagnetization current of single direct current machine can be 1.5 amperes, the second direct current I _d2current value can be 0.6 ampere.Preset time T can be between 0.5 second-3 seconds value, for example, preset time T can be 1 second.

Wherein, it should be noted that, apply the second direct current I to the d-axis of N direct current machine _d2be to the d-axis of integrated motor model and apply the second direct current I _d2.The second direct-axis voltage V of N direct current machine _d2be the direct-axis voltage of integrated motor model.

Particularly, main control module 30 can calculate according to following formula the equivalent resistance of N direct current machine:

$\left\{\begin{array}{c}{V}_{d1}-e-I_{d1}*R_{\mathrm{real}}=0\\ V_{d2}-e-I_{d2}*R_{\mathrm{real}}=0\end{array}\right.$

Wherein, R _realfor the equivalent resistance of N direct current machine, e is the equivalent pressure drop of IGBT in IPM module, for being constant with a IPM module e.

That is to say, applying the first direct current I to the d-axis of N direct current machine _d1and obtain the first direct-axis voltage V of N direct current machine _d1after, main control module 30 is controlled IPM module 20 again and is applied default straight the second direct current I to the d-axis of N parallel connection direct motor _d2, meanwhile, main control module 30 is controlled IPM module 20, and to apply current value to the quadrature axis of N parallel connection direct motor be the second direct current I of 0 _q2, the second direct current I applying _d2after stable, main control module 30 obtains the second direct-axis voltage V of N direct current machine _d2, thus, main control module 30 can be according to the first direct current I _d1with the first direct-axis voltage V _d1and the second direct current I _d2with the second direct-axis voltage V _d2calculate the equivalent resistance R of N direct current machine _real.

Particularly, main control module 30 can calculate according to the direct-axis voltage equation of N direct current machine the equivalent resistance of N direct current machine:

$\left\{\begin{array}{c}{E}_{d1}=V_{d1}-e-I_{d1}*R_{\mathrm{real}}+\mathrm{\ω}*I_{q1}*L_q\\ E_{d2}=V_{d2}-e-I_{d2}*R_{\mathrm{real}}+\mathrm{\ω}*I_{q2}*L_q\end{array}\right.---\left(2\right)$

Wherein, E _d1for the first d-axis induced electromotive force of N direct current machine, V _d1for the first direct-axis voltage of N direct current machine, E _d2for the second d-axis induced electromotive force of N direct current machine, V _d2for the second direct-axis voltage of N direct current machine, e is the equivalent pressure drop of IGBT in IPM module, I _d1for the first direct current applying to the d-axis of N direct current machine, I _d2for the second direct current applying to the d-axis of N direct current machine, R _realfor the equivalent resistance of N direct current machine, ω is the electric angle speed of each direct current machine in N direct current machine, I _q1for the first direct current applying to the quadrature axis of N direct current machine, I _q2for the second direct current applying to the quadrature axis of N direct current machine, L _qfor the quadrature axis inductance of each direct current machine in N direct current machine.It should be noted that the first d-axis induced electromotive force E of N direct current machine _d1with the second d-axis induced electromotive force E _d2be the d-axis induced electromotive force of integrated motor model.

Thus, the first direct current I applying to the d-axis of N direct current machine _d1after stable, the first d-axis induced electromotive force E of N direct current machine _d1be 0, and applying the first direct current I to the d-axis of N direct current machine _d1time, main control module 30 is controlled N direct current machine 10 and is maintained static, and in N direct current machine 10, the rotational speed omega of each direct current machine all remains 0, meanwhile, the first direct current I applying to the quadrature axis of N direct current machine _q1also be 0.Afterwards, the second direct current I applying to the d-axis of N direct current machine _d2after stable, the second d-axis induced electromotive force E of N direct current machine _d2be 0, and applying the second direct current I to the d-axis of N direct current machine _d2time, main control module 30 is controlled N direct current machine 10 and is maintained static, and in N direct current machine, the rotational speed omega of each direct current machine all remains 0, meanwhile, the second direct current I applying to the quadrature axis of N direct current machine _q2also be 0, above formula (2) can be reduced to:

$\left\{\begin{array}{c}{V}_{d1}-e-I_{d1}*R_{\mathrm{real}}=0\\ V_{d2}-e-I_{d2}*R_{\mathrm{real}}=0\end{array}\right.---\left(3\right)$

Like this, after two equations in (3) formula subtract each other, can cancellation IPM module in the equivalent pressure drop e of IGBT, main control module 30 can calculate the equivalent resistance R of N direct current machine _real.

Below as an example of N=2 example and N=3 be example, describe the direct current motor system of the embodiment of the present invention in detail.

In a specific embodiment of the present invention, work as N=2, the quantity of direct current machine is 2 o'clock, as shown in figure 12, direct current motor system comprises: 2 direct current machines 10, IPM module 20, main control module 30.Wherein, 2 direct current machines 10 can be direct current machine 1 and direct current machine 2, main control module 30 is for sending six road pwm control signals to IPM module 20, and gather the electric current of 2 parallel connection direct motors, IPM module 20 is exported Liu road pwm control signal for receiving main control module 30, and export three-phase driving signal to 2 direct current machines 10,2 direct current machines 10 turn round for the three-phase driving signal of exporting according to IPM module 20.

Specifically, main control module 30 can be exported the first direct current I to 2 direct current machines 10 of parallel connection by IPM module 20 _d1, and keeping the angle θ of N direct current machine 10 to immobilize, the electric angle speed omega that makes each direct current machine in 2 direct current machines 10 is 0.Applying the first direct current I to the d-axis of 2 direct current machines _d1time reach after preset time T, main control module 30 obtains the first direct-axis voltage V of 2 direct current machines _d1.Afterwards, main control module 30 is according to the first direct current I _d1with the first direct-axis voltage V _d1calculate the equivalent resistance R of 2 direct current machines _real, and work as the equivalent resistance R of 2 direct current machines _realbe more than or equal to preset resistance R _x, i.e. R _real>=R _xtime, main control module 30 judges that the quantity of the direct current machine of normal power-up in direct current motor system is less than 2, and main control module 30 judges that the socket of direct current machine in neglected loading direct current machine or user's use procedure gets loose, and there is to lack electrical fault in direct current motor system, wherein, R _x=R ₂+ (R ₁-R ₂) × 0.9.

In another specific embodiment of the present invention, work as N=3, the quantity of direct current machine is 3 o'clock, as shown in figure 13, direct current motor system comprises: 3 direct current machines 10, IPM module 20, main control module 30.Wherein, 3 direct current machines 10 can be direct current machine 1, direct current machine 2 and direct current machine 3, main control module 30 is for sending six road pwm control signals to IPM module 20, and gather the electric current of 3 parallel connection direct motors, IPM module 20 is exported Liu road pwm control signal for receiving main control module 30, and export three-phase driving signal to 3 direct current machines 10,3 direct current machines 10 turn round for the three-phase driving signal of exporting according to IPM module 20.

Specifically, main control module 30 can be exported the first direct current I to 3 direct current machines 10 of parallel connection by IPM module 20 _d1, and keeping the angle θ of 3 direct current machines 10 to immobilize, the electric angle speed omega that makes each direct current machine in 3 direct current machines 10 is 0, is applying the first direct current I to the d-axis of 3 direct current machines _d1time reach after preset time T, main control module 30 obtains the first direct-axis voltage V of 3 direct current machines _d1.Afterwards, main control module 30 can be exported the second direct current I to 3 direct current machines 10 of parallel connection by IPM module 20 _d2, and keeping the angle θ of 3 direct current machines 10 to immobilize, in 3 direct current machines 10, the electric angle speed omega of each direct current machine is 0, is applying the second direct current I to the d-axis of 3 direct current machines _d2time reach after preset time T, main control module 30 obtains the second direct-axis voltage V of 3 direct current machines _d2.Afterwards, main control module 30 is according to the first direct current I _d1with the first direct-axis voltage V _d1and the second direct current I _d2with the second direct-axis voltage V _d2calculate the equivalent resistance R of 3 direct current machines _real, and work as the equivalent resistance R of 3 direct current machines _realbe more than or equal to preset resistance R _x, i.e. R _real>=R _xtime, main control module 30 judges that the quantity of the direct current machine of normal power-up in direct current motor system is less than 3, and main control module 30 judges that the socket of direct current machine in neglected loading direct current machine or user's use procedure gets loose, and there is to lack electrical fault in direct current motor system, wherein, R _x=R ₃+ (R ₂-R ₃) × 0.9.

In addition, in embodiments of the present invention, the model of N direct current machine 10 is identical.It should be noted that, here identical refers to the identical of broad sense, approximate identical.That is to say, the direct current motor system of the embodiment of the present invention is adapted to the occasion that need to simultaneously adopt the model of two or more direct current machines and multiple direct current machines identical, load is approaching, for example, the direct current motor system of the embodiment of the present invention is adapted to the two through-flow bi-motor indoor sets of air-conditioning, two wind wheel off-premises stations etc.In a concrete example of the present invention, main control module 30 can be MCU (Micro Control Unit, micro-control unit).

To sum up, the direct current motor system proposing according to the present invention, main control module export six road pwm signals to IPM module so that N direct current machine controlled, and main control module is also controlled IPM module and is applied the first direct current I to the d-axis of N direct current machine _d1, and after Preset Time, obtain the first direct-axis voltage V of N direct current machine _d1, afterwards, main control module is according to the first direct current I _d1with the first direct-axis voltage V _d1the equivalent resistance that calculates N direct current machine, in the time that the equivalent resistance of N direct current machine is more than or equal to preset resistance, in master control module judges direct current motor system, the quantity of the direct current machine of normal power-up is less than N.Thus, this direct current motor system adopts 1 IPM module to control N direct current machine, can effectively save system cost, and whether can detect in neglected loading direct current machine or use procedure whether have the connecting line terminal of direct current machine to get loose, thereby guarantee the normal operation of direct current motor system, ensure systematic function, realize the reliable control of direct current motor system, avoid potential safety hazard.

Any process of otherwise describing in flow chart or at this or method are described and can be understood to, represent to comprise that one or more is for realizing module, fragment or the part of code of executable instruction of step of specific logical function or process, and the scope of the preferred embodiment of the present invention comprises other realization, wherein can be not according to order shown or that discuss, comprise according to related function by the mode of basic while or by contrary order, carry out function, this should be understood by embodiments of the invention person of ordinary skill in the field.

The logic and/or the step that in flow chart, represent or otherwise describe at this, for example, can be considered to the sequencing list of the executable instruction for realizing logic function, may be embodied in any computer-readable medium, use for instruction execution system, device or equipment (as computer based system, comprise that the system of processor or other can and carry out the system of instruction from instruction execution system, device or equipment instruction fetch), or use in conjunction with these instruction execution systems, device or equipment.With regard to this specification, " computer-readable medium " can be anyly can comprise, device that storage, communication, propagation or transmission procedure use for instruction execution system, device or equipment or in conjunction with these instruction execution systems, device or equipment.The example more specifically (non-exhaustive list) of computer-readable medium comprises following: the electrical connection section (electronic installation) with one or more wirings, portable computer diskette box (magnetic device), random access memory (RAM), read-only memory (ROM), the erasable read-only memory (EPROM or flash memory) of editing, fiber device, and portable optic disk read-only memory (CDROM).In addition, computer-readable medium can be even paper or other the suitable medium that can print described program thereon, because can be for example by paper or other media be carried out to optical scanner, then edit, decipher or process in electronics mode and obtain described program with other suitable methods if desired, be then stored in computer storage.

Should be appreciated that each several part of the present invention can realize with hardware, software, firmware or their combination.In the above-described embodiment, multiple steps or method can realize with being stored in software or the firmware carried out in memory and by suitable instruction execution system.For example, if realized with hardware, the same in another embodiment, can realize by any one in following technology well known in the art or their combination: there is the discrete logic for data-signal being realized to the logic gates of logic function, there is the application-specific integrated circuit (ASIC) of suitable combinational logic gate circuit, programmable gate array (PGA), field programmable gate array (FPGA) etc.

Those skilled in the art are appreciated that realizing all or part of step that above-described embodiment method carries is can carry out the hardware that instruction is relevant by program to complete, described program can be stored in a kind of computer-readable recording medium, this program, in the time carrying out, comprises step of embodiment of the method one or a combination set of.

In addition, the each functional unit in each embodiment of the present invention can be integrated in a processing module, can be also that the independent physics of unit exists, and also can be integrated in a module two or more unit.Above-mentioned integrated module both can adopt the form of hardware to realize, and also can adopt the form of software function module to realize.If described integrated module realizes and during as production marketing independently or use, also can be stored in a computer read/write memory medium using the form of software function module.

The above-mentioned storage medium of mentioning can be read-only memory, disk or CD etc.

In the description of this specification, the description of reference term " embodiment ", " some embodiment ", " example ", " concrete example " or " some examples " etc. means to be contained at least one embodiment of the present invention or example in conjunction with specific features, structure, material or the feature of this embodiment or example description.In this manual, the schematic statement of above-mentioned term is not necessarily referred to identical embodiment or example.And specific features, structure, material or the feature of description can be with suitable mode combination in any one or more embodiment or example.

Although illustrated and described embodiments of the invention, for the ordinary skill in the art, be appreciated that without departing from the principles and spirit of the present invention and can carry out multiple variation, amendment, replacement and modification to these embodiment, scope of the present invention is by claims and be equal to and limit.

Claims (12)

1. the detection method of a direct current motor system, it is characterized in that, described direct current motor system comprises N direct current machine in parallel, is connected respectively to IPM module and the extremely main control module of described IPM module so that a described N direct current machine is controlled of output six road pwm signals of a described N direct current machine, N is more than or equal to 2 integer, and described detection method comprises the following steps:

Control described IPM module and apply the first direct current I to the d-axis of a described N direct current machine _d1;

After Preset Time, obtain the first direct-axis voltage V of a described N direct current machine _d1;

According to described the first direct current I _d1with described the first direct-axis voltage V _d1calculate the equivalent resistance of a described N direct current machine;

In the time that the equivalent resistance of a described N direct current machine is more than or equal to preset resistance, judge that the quantity of the direct current machine of normal power-up in described direct current motor system is less than N.

2. the detection method of direct current motor system according to claim 1, is characterized in that, calculates the equivalent resistance of a described N direct current machine according to following formula:

V _d1-e-I _d1*R _real＝0

Wherein, R _realfor the equivalent resistance of a described N direct current machine, e is the equivalent pressure drop of IGBT in described IPM module.

3. the detection method of direct current motor system according to claim 1, is characterized in that, also comprises:

Control described IPM module and apply the second direct current I to the d-axis of a described N direct current machine _d2;

After described Preset Time, obtain the second direct-axis voltage V of a described N direct current machine _d2, with according to described the first direct current I _d1with described the first direct-axis voltage V _d1and described the second direct current I _d2with described the second direct-axis voltage V _d2calculate the equivalent resistance of a described N direct current machine.

4. the detection method of direct current motor system according to claim 3, is characterized in that, calculates the equivalent resistance of a described N direct current machine according to following formula:

$\left\{\begin{array}{c}{V}_{d1}-e-I_{d1}*R_{\mathrm{real}}=0\\ V_{d2}-e-I_{d2}*R_{\mathrm{real}}=0\end{array}\right.$

Wherein, R _realfor the equivalent resistance of a described N direct current machine, e is the equivalent pressure drop of IGBT in described IPM module.

5. the detection method of direct current motor system according to claim 3, is characterized in that, described preset resistance is greater than the resistance R of N direct current machine _nand be less than the resistance R of N-1 direct current machine _n-1, wherein, obtain the resistance R of a described N direct current machine according to following formula _nresistance R with a described N-1 direct current machine _n-1:

$\left\{\begin{array}{c}{R}_N=R_{\mathrm{rated}}/N\\ R_{N-1}=R_{\mathrm{rated}}/(N-1)\end{array}\right.$

Wherein, R _ratedfor the rated resistance of the single direct current machine in a described N direct current machine.

6. the detection method of direct current motor system according to claim 1, is characterized in that, the model of a described N direct current machine is identical.

7. a direct current motor system, is characterized in that, comprising:

N direct current machine, a described N direct current machine is connected in parallel, and wherein, N is more than or equal to 2 integer;

Be connected respectively to the IPM module of a described N direct current machine;

Export six road pwm signals to the main control module of described IPM module so that a described N direct current machine is controlled, described main control module applies the first direct current I for controlling described IPM module to the d-axis of a described N direct current machine _d1, and after Preset Time, obtain the first direct-axis voltage V of a described N direct current machine _d1, and according to described the first direct current I _d1with described the first direct-axis voltage V _d1calculate the equivalent resistance of a described N direct current machine, in the time that the equivalent resistance of a described N direct current machine is more than or equal to preset resistance, in direct current motor system, the quantity of the direct current machine of normal power-up is less than N described in described master control module judges.

8. direct current motor system according to claim 7, is characterized in that, described main control module calculates the equivalent resistance of a described N direct current machine according to following formula:

V _d1-e-I _d1*R _real＝0

Wherein, R _realfor the equivalent resistance of a described N direct current machine, e is the equivalent pressure drop of IGBT in described IPM module.

9. direct current motor system according to claim 7, is characterized in that, described main control module also applies the second direct current I for controlling described IPM module to the d-axis of a described N direct current machine _d2, and after described Preset Time, obtain the second direct-axis voltage V of a described N direct current machine _d2, with according to described the first direct current I _d1with described the first direct-axis voltage V _d1and described the second direct current I _d2with described the second direct-axis voltage V _d2calculate the equivalent resistance of a described N direct current machine.

10. direct current motor system according to claim 9, is characterized in that, described main control module calculates the equivalent resistance of a described N direct current machine according to following formula:

$\left\{\begin{array}{c}{V}_{d1}-e-I_{d1}*R_{\mathrm{real}}=0\\ V_{d2}-e-I_{d2}*R_{\mathrm{real}}=0\end{array}\right.$

Wherein, R _realfor the equivalent resistance of a described N direct current machine, e is the equivalent pressure drop of IGBT in described IPM module.

11. direct current motor systems according to claim 9, is characterized in that, described preset resistance is greater than the resistance R of N direct current machine _nand be less than the resistance R of N-1 direct current machine _n-1, wherein, described main control module obtains the resistance R of a described N direct current machine according to following formula _nresistance R with a described N-1 direct current machine _n-1:

$\left\{\begin{array}{c}{R}_N=R_{\mathrm{rated}}/N\\ R_{N-1}=R_{\mathrm{rated}}/(N-1)\end{array}\right.$

Wherein, R _ratedfor the rated resistance of the single direct current machine in a described N direct current machine.

12. direct current motor systems according to claim 7, is characterized in that, the model of a described N direct current machine is identical.