CN104549774A - Operating method of intelligent superfine aluminum power classification system - Google Patents

Abstract

The invention relates to a superfine aluminum powder classification system which comprises a plurality of levels of aluminum powder classification devices, wherein the powder outlet of a front-level aluminum powder classification device is connected with the powder inlet of a rear-level aluminum powder classification device; the powder inlet of a first-level aluminum powder classification device is connected with the power outlet of an aluminum powder preparation device; the powder outlet of a tail-level aluminum powder classification device is connected with the air inlet of a cyclone duster; all the aluminum powder classification devices are same in structure and comprise centrifugal classifiers, buffer tanks and material conveying tanks, wherein the buffer tanks are applicable to collecting coarse powder separated out from a current-level aluminum powder classification device, and the material conveying tanks are applicable to conveying the coarse powder in the buffer tanks to an aluminum powder packaging unit. By virtue of the plurality of aluminum powder classification devices, multiple classifications of aluminum powder are realized, and the technical problem of wide particle size range distribution existing in aluminum powder classification is solved.

Description

The method of work of intelligent superfine aluminium power hierarchy system

Technical field

The present invention relates to a kind of method of work of intelligent superfine aluminium power hierarchy system.

Background technology

In the prior art, hierarchy system is be unable to do without in the production process of aluminium powder, hierarchy system carries out classification according to need of production to the aluminium powder of different-diameter to aluminium powder raw material, traditional grader has aluminium powder graded particie and controls not strict, the aluminium powder of the easy different-diameter that adulterates in superfine aluminium power, grading effect often cannot meet need of production.

Summary of the invention

Technical problem to be solved by this invention is to provide a kind of method of work of intelligent superfine aluminium power hierarchy system, and this intelligent superfine aluminium power hierarchy system solves the particle size range that aluminium powder classification exists and to distribute wide technical problem.

In order to solve the problems of the technologies described above, the invention provides a kind of method of work of superfine aluminium power hierarchy system, this system comprises: some grades of aluminium powder grading plants, and the meal outlet of previous stage aluminium powder grading plant is connected with the powder inlet of rear stage aluminium powder grading plant; Wherein, the powder inlet of first order aluminium powder grading plant is connected with the meal outlet of aluminium powder fuel pulverizing plant; The meal outlet of final stage aluminium powder grading plant is connected with the air inlet of cyclone dust removal machine; The structure of described each aluminium powder grading plant is identical, and it comprises: centrifugal classifier, is applicable to the surge tank of the isolated meal of aluminium powder grading plant collected when prime, is suitable for the transmission batch can meal in this surge tank being delivered to aluminium powder packaging unit.

In order to better realize impeller speed governing, described centrifugal classifier comprises: be suitable for the three-phase alternating-current motor that drives impeller is rotated, this three-phase alternating-current motor is connected with a converter plant, and this converter plant is suitable for carrying out speed governing to described three-phase alternating-current motor.

Described converter plant comprises: three-phase inverter, this three-phase inverter is controlled by a DSP, the DC side of this three-phase inverter, AC are respectively equipped with direct current, alternating voltage current detection circuit, and described direct current, alternating voltage current detection circuit are connected with described DSP.

Described DSP is suitable for producing SVPWM modulation signal, and the method for work of superfine aluminium power hierarchy system comprises the method that DSP produces this SVPWM modulation signal, and it comprises: set up a three-phase static coordinate system according to its axis, from direction respectively is I, II, III, IV, V, VI sector counterclockwise.Required reference voltage vector relevant voltage vector action time T in each sector ₁, T ₂:

Wherein, N=3, N=1, N=5, N=4, N=6, N=2 corresponding I, II, III, IV, V, VI sector respectively; T _sbe a sampling period, V _a, V _bfor required reference voltage vector in three-phase static coordinate system projection on direction, V _dcfor DC bus-bar voltage.

T ₁, T ₂after assignment, also to judge it, work as T ₁+ T ₂>T _s, then T is got ₁=T ₁ts/ (T ₁+ T ₂), T ₂=T ₂ts/ (T ₁+ T ₂); Finally, adopt DSP inside to have hardware to realize, as required, the SVPWM of five sections or seven segmentations can be selected.

Further, the method for described DSP generation SVPWM modulation signal also comprises:

Judge required reference voltage vector in the step of respective sectors, this step comprises:

If sector discriminate: N=A+2B+4C;

Wherein, V _a+ 2V _b> 0 A=1, otherwise A=0;

V _a-V _b> 0, then B=1, otherwise B=0;

2V _a+ V _b< 0, then C=1, otherwise C=0;

V _a, V _bsubstitute into above-mentioned formula respectively, to obtain the value of corresponding A, B, C, substitute into described sector discriminate to obtain required reference voltage vector sector, place, that is, N=3, N=1, N=5, N=4, N=6, N=2 corresponding I, II, III, IV, V, VI sector respectively.

The present invention has positive effect relative to prior art:

(1) the present invention is by some aluminium powder grading plants, realizes the multiple fractionation of aluminium powder, solves particle size range that aluminium powder classification exists and to distribute wide technical problem; (2) modulator approach of SVPWM modulation signal of the present invention simplifies the calculating process of the modulator approach of traditional SVPWM modulation signal, has saved the computing time of DSP, has improve computational accuracy.

Accompanying drawing explanation

In order to clearly demonstrate innovative principle of the present invention and the technical advantage compared to existing product thereof, by applying the limiting examples of described principle, a possible embodiment is described by means of accompanying drawing below.In the drawings:

Fig. 1 is the structural representation of superfine aluminium power hierarchy system of the present invention;

The circuit structure block diagram of Fig. 2 DC voltage module of the present invention and converter plant;

The circuit structure block diagram of Fig. 3 converter plant of the present invention;

Fig. 4 voltage space-vector decomposition figure of the present invention.

Wherein, aluminium powder grading plant 1, aluminium powder fuel pulverizing plant 2, cyclone dust removal machine 3.

Detailed description of the invention

Below in conjunction with drawings and Examples, the present invention is described in detail:

Embodiment

As shown in Figure 1, a kind of superfine aluminium power hierarchy system, comprising: some grades of aluminium powder grading plants 1, and the meal outlet of previous stage aluminium powder grading plant is connected with the powder inlet of rear stage aluminium powder grading plant; Wherein, the powder inlet of first order aluminium powder grading plant is connected with the meal outlet of aluminium powder fuel pulverizing plant 2; The meal outlet of final stage aluminium powder grading plant is connected with the air inlet of cyclone dust removal machine 3; The structure of described each aluminium powder grading plant 1 is identical, and it comprises: centrifugal classifier, is applicable to the surge tank of the isolated meal of aluminium powder grading plant collected when prime, is suitable for the transmission batch can meal in this surge tank being delivered to aluminium powder packaging unit.

Described superfine aluminium power is diametric requirements at the particle of 0.5-12 μm.

By the raw material that the isolated aluminium powder of the described superfine aluminium power hierarchy system first order is separated as the second level, be separated so layer by layer, until isolated aluminium powder meets production requirement.

As shown in Figure 2, described centrifugal classifier comprises: be suitable for the three-phase alternating-current motor that drives impeller is rotated, this three-phase alternating-current motor is connected with a converter plant, this converter plant is suitable for carrying out speed governing to described three-phase alternating-current motor, described converter plant is connected with a direct current voltage module, this DC voltage module obtains voltage from external voltage, galvanic current pressure is obtained by rectification module, filtration module, Voltage stabilizing module, the physical circuit obtaining DC voltage all has associated description in the prior art, no longer describes in detail here.

See Fig. 3, described converter plant comprises: three-phase inverter, this three-phase inverter is controlled by a DSP, and the DC side of this three-phase inverter, AC are respectively equipped with direct current, alternating voltage current detection circuit, and described direct current, alternating voltage current detection circuit are connected with described DSP.

Described DSP is suitable for producing SVPWM modulation signal, and the method producing this SVPWM modulation signal comprises: see Fig. 4, set up a three-phase static coordinate system according to its axis, from direction respectively is I, II, III, IV, V, VI sector counterclockwise.Required reference voltage vector relevant voltage vector action time T in each sector ₁, T ₂:

Wherein, N=3, N=1, N=5, N=4, N=6, N=2 corresponding I, II, III, IV, V, VI sector respectively; T _sbe a sampling period, be the sampling period that described DSP gathers direct current, AC signal, V _a, V _bfor required reference voltage vector in three-phase static coordinate system projection on direction, V _dcfor DC bus-bar voltage.

T ₁, T ₂after assignment, also to judge it, work as T ₁+ T ₂>T _s, then T is got ₁=T ₁ts/ (T ₁+ T ₂), T ₂=T ₂ts/ (T ₁+ T ₂).

Finally, realized by dsp program.Wherein, as required, can select the SVPWM of five sections or seven segmentations, DSP can adopt the dsp chip of MC56F8346 or other models all can realize this modulation.

The method that described DSP produces SVPWM modulation signal also comprises:

Judge required reference voltage vector in the step of respective sectors, this step comprises:

If sector discriminate: N=A+2B+4C;

Wherein, V _a+ 2V _b> 0 A=1, otherwise A=0;

V _a-V _b> 0, then B=1, otherwise B=0;

2V _a+ V _b< 0, then C=1, otherwise C=0;

Judge according to above-mentioned formula the value determining corresponding A, B, C, substitute into described sector discriminate to obtain required reference voltage vector sector, place, that is, N=3, N=1, N=5, N=4, N=6, N=2 corresponding I, II, III, IV, V, VI sector respectively.

Wherein, three-phase inverter, two power tube synchronizations of its every phase brachium pontis only have a conducting, and have 8 kinds of on off states to exist like this, its fundamental space vector comprises the amplitude of six non-zero is (Vdc is DC bus-bar voltage).By controlling fundamental space vectorial combination and action time, SVPWM is according to reference voltage vector carry out rotating operation _.v ₁, V ₂, V ₃, V ₄, V ₅, V ₆represent vector respectively mould, namely have: V ₁=V ₂=V ₃=V ₄=V ₅=V ₆=(2/3) V _dc.

In the modulator approach of SVPWM modulation signal, three-phase system model needs to be transformed in two-phase rest frame:

$\left[\begin{array}{c}{V}_{\mathrm{alf}}\\ V_{\mathrm{bet}}\end{array}\right]=\frac{2}{3}\&times;\begin{array}{}\end{array}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\&times;\left[\begin{array}{c}{V}_a\\ V_b\\ V_c\end{array}\right]$ (formula 1)

In formula, V _a, V _b, V _cfor space voltage vector in three-phase static coordinate system projection on direction, V _alf, V _betfor reference voltage vector at two phase coordinate systems projection on direction, V _sfor mould, then have:

V _alf=V _s* cos θ (formula 2)

V _bet=V _s* sin θ (formula 3)

Reference voltage vector adjacent fundamental space Vector modulation can be crossed obtain:

${\stackrel{\&RightArrow;}{V}}_s=\frac{T_k}{T_s}{\stackrel{\&RightArrow;}{V}}_k+\frac{T_{k+1}}{T_s}{\stackrel{\&RightArrow;}{V}}_{k+1}$ (formula 4)

In above formula, T _k, T _k+1for fundamental space vector at a sampling period T _sin action time.K is vector place sector number, and azimuth θ can be obtained by antitrigonometric function computing in two-phase rest frame.

Judge reference voltage vector sector, place, analyzes V _alf, V _betrelation, following rule can be obtained, namely judge inequality:

If V _bet> 0, A=1, then A=1, otherwise A=0;

If then B=1, otherwise B=0;

If then C=1, otherwise C=0;

N=A+2B+4C is differentiated by sector.

Easily know N=3, N=1, N=5, N=4, N=6, N=2 be corresponding I, II, III, IV, V, VI sector respectively.

Work as reference voltage vector when the Ith sector, fundamental space vector action time can calculate by through type:

$V_{\mathrm{alf}}*T_s=V_1*T_1+\frac{1}{2}{V}_2*T_2$

$V_{\mathrm{bet}}*T_s=\frac{\sqrt{3}}{2}{V}_2*T_2$

Can obtaining of solution:

$\begin{array}{c}{T}_1=\frac{\frac{3}{2}*V_{\mathrm{alf}}-\frac{\sqrt{3}}{2}*V_{\mathrm{bet}}}{V_{\mathrm{dc}}}*T_s\\ T_2=\frac{\sqrt{3}*V_{\mathrm{bet}}}{V_{\mathrm{dc}}}*T_s\end{array}$ (formula 5)

Work as reference voltage vector when the IIth sector,

$\begin{array}{c}{T}_1=\frac{\frac{\sqrt{3}}{2}*V_{\mathrm{bet}}+\frac{3}{2}*V_{\mathrm{alf}}}{V_{\mathrm{dc}}}*T_s\\ T_2=\frac{\frac{\sqrt{3}}{2}*V_{\mathrm{bet}}-\frac{3}{2}*V_{\mathrm{alf}}}{V_{\mathrm{dc}}}*T_s\end{array}$ (formula 6)

In like manner can deriving the voltage vector action time in other sector, all there is computing as above when needing the vector of synthesis to be positioned at each different sector.By being not difficult to find that they are combinations of some basic times to solving of each sector basic vector actuation time.See Fig. 4, required reference voltage vector projection in three-phase static coordinate system is respectively V _a, V _b, V _c, then have

$V_a+V_b+V_c=\mathrm{Vs}*\cos +\mathrm{Vs}*\cos (\mathrm{\&theta;}-\frac{2}{3}\mathrm{\&pi;})+\mathrm{Vs}*\cos (\mathrm{\&theta;}+\frac{2}{3}\mathrm{\&pi;})=0$ Formula (7)

Obtained by formula (1) and formula (7)

$\left(\begin{array}{c}{V}_{\mathrm{alf}}\\ V_{\mathrm{bet}}\end{array}\right)=\left(\begin{array}{cc}1& 0\\ \frac{\sqrt{3}}{3}& \frac{2}{3}\sqrt{3}\end{array}\right)\&times;\left(\begin{array}{c}{V}_a\\ V_b\end{array}\right)$ Formula (8)

Obtain V _alfand V _betwith V _a, V _bcorresponding relation namely

V _al _f=1*V _a+0*V _b=V _a

$V_{\mathrm{bet}}=\frac{\sqrt{3}}{3}*V_a+\frac{2}{3}\sqrt{3}*V_b$ Formula (9)

Judge required reference voltage vector sector, place, analyzes V _alf, V _betrelation, by V _alf, V _betuse V respectively _a, V _b, judge reference voltage vector sector, place, substitutes into above-mentioned judgement inequality by formula (9), obtains following rule:

If V _a+ 2V _b> 0 A=1, otherwise A=0;

V _a-V _b> 0, then B=1, otherwise B=0;

2V _a+ V _b< 0, then C=1, otherwise C=0;

According to the value calculating A, B, C, bring N=A+2B+4C into, to determine required reference voltage vector sector, place, that is, N=3, N=1, N=5, N=4, N=6, N=2 corresponding I, II, III, IV, V, VI sector respectively.

When required reference voltage vector when the Ith sector, fundamental space vector action time can be passed through formula (5) and be calculated, and namely formula (9) is substituted into respectively,

$T_1=\frac{\frac{3}{2}*V_{\mathrm{alf}}-\frac{\sqrt{3}}{2}*V_{\mathrm{bet}}}{V_{\mathrm{dc}}}*T_s=\frac{V_a-V_b}{V_{\mathrm{dc}}}*T_s$

$T_2=\frac{\sqrt{3}*V_{\mathrm{bet}}}{V_{\mathrm{dc}}}*T_s=\frac{2V_b+V_a}{V_{\mathrm{dc}}}*T_s$

When required reference voltage vector when the IIth sector, formula (9) is substituted into formula (6) respectively,

$T_1=\frac{\frac{\sqrt{3}}{2}*V_{\mathrm{bet}}+\frac{3}{2}*V_{\mathrm{alf}}}{V_{\mathrm{dc}}}*T_s=\frac{2V_a+V_b}{V_{\mathrm{dc}}}*T_s$

$T_2=\frac{\frac{\sqrt{3}}{2}*V_{\mathrm{bet}}-\frac{3}{2}*V_{\mathrm{alf}}}{V_{\mathrm{dc}}}*T_s=\frac{V_b+V_a}{V_{\mathrm{dc}}}*T_s$

Wherein, T _sbe a sampling period, V _dcfor DC bus-bar voltage.

In like manner can derive the voltage vector action time in other sector, here not in repetition, conclusion action time is as shown in the table:

Wherein, N=3, N=1, N=5, N=4, N=6, N=2 corresponding I, II, III, IV, V, VI sector respectively; T _sbe a sampling period, V _a, V _bfor required reference voltage vector in three-phase static coordinate system projection on direction, V _dcfor DC bus-bar voltage.

As can be seen here, in the method for whole SVPWM modulation signal, without the need to using V _c, only need V _a, V _bcan modulation operation be met, optimize computing greatly, improve operation efficiency.

Obviously, above-described embodiment is only for example of the present invention is clearly described, and is not the restriction to embodiments of the present invention.For those of ordinary skill in the field, can also make other changes in different forms on the basis of the above description.Here exhaustive without the need to also giving all embodiments.And these belong to spirit institute's apparent change of extending out of the present invention or change and are still among protection scope of the present invention.

Claims (2)

1. a method of work for superfine aluminium power hierarchy system, is characterized in that: described superfine aluminium power hierarchy system comprises:

Some grades of aluminium powder grading plants, and the meal outlet of previous stage aluminium powder grading plant is connected with the powder inlet of rear stage aluminium powder grading plant; Wherein, the powder inlet of first order aluminium powder grading plant is connected with the meal outlet of aluminium powder fuel pulverizing plant; The meal outlet of final stage aluminium powder grading plant is connected with the air inlet of cyclone dust removal machine;

The structure of described each aluminium powder grading plant is identical, and it comprises: centrifugal classifier, is applicable to the surge tank of the isolated meal of aluminium powder grading plant collected when prime, is suitable for the transmission batch can meal in this surge tank being delivered to aluminium powder packaging unit;

Described centrifugal classifier comprises: be suitable for the three-phase alternating-current motor that drives impeller is rotated, this three-phase alternating-current motor is connected with a converter plant, and this converter plant is suitable for carrying out speed governing to described three-phase alternating-current motor;

Described converter plant comprises: three-phase inverter, this three-phase inverter is controlled by a DSP, the DC side of this three-phase inverter, AC are respectively equipped with direct current, alternating voltage current detection circuit, and described direct current, alternating voltage current detection circuit are connected with described DSP;

Described DSP is suitable for producing SVPWM modulation signal, and the method for work of described superfine aluminium power hierarchy system comprises the method that DSP produces this SVPWM modulation signal, and it comprises: set up a three-phase static coordinate system according to its axis, from direction respectively is I, II, III, IV, V, VI sector counterclockwise; Required reference voltage vector relevant voltage vector action time T in each sector ₁, T ₂:

Wherein, N=3, N=1, N=5, N=4, N=6, N=2 corresponding I, II, III, IV, V, VI sector respectively; T _sbe a sampling period, V _a, V _bfor required reference voltage vector in three-phase static coordinate system projection on direction, V _dcfor DC bus-bar voltage.

2. superfine aluminium power hierarchy system according to claim 1, is characterized in that, the method that described DSP produces SVPWM modulation signal also comprises:

Judge required reference voltage vector in the step of respective sectors, this step comprises:

If sector discriminate: N=A+2B+4C;

Wherein, V _a+ 2V _b> 0 A=1, otherwise A=0;

V _a-V _b> 0, then B=1, otherwise B=0;

2V _a+ V _b< 0, then C=1, otherwise C=0;

V _a, V _bsubstitute into above-mentioned formula respectively, to obtain the value of corresponding A, B, C, substitute into described sector discriminate to obtain required reference voltage vector sector, place, that is, N=3, N=1, N=5, N=4, N=6, N=2 corresponding I, II, III, IV, V, VI sector respectively.