CN104180858A - Method for measuring airflow of fan motor - Google Patents

Abstract

The invention discloses a method for measuring airflow of a fan motor. The method is characterized by comprising steps as follows: A), M constant airflow control functions Qi=F(n) corresponding to M airflow points CFMi are established in a microprocessor of a motor controller, wherein Q can be input power, direct current bus current or torque, and n is the rotating speed of the motor; B), the motor is started, the real-time rotating speed n0 and the parameter Q0 of the motor are detected after the motor is in a stable state, the Q0 is put into a plurality of constant airflow control functions Qi=F(n) corresponding to a plurality of airflow points CFMi, a plurality of rotating speeds ni are obtained, the real-time rotating speed n0 and a plurality of corresponding rotating speeds ni are compared, and the real-time detection airflow CFM0 is ensured to be located between CFMi and CFM(i-1); and C), the real-time detection CFM0 is calculated with an interpolation method. According to the method, blocking of an air filter net can be accurately judged, a signal can be output for giving an alarm, the mathematic model is simple, the control is reliable, and the accuracy is high.

Description

A kind of blower motor is measured the method for air quantity

Technical field:

The present invention relates to a kind of blower motor and measure the method for air quantity.

Background technology:

In recent years, along with appliance field competition, product technology is required to improve constantly, as required, the intelligent degree of product energy-conserving and environment-protective, controllability is high, the construction cycle is short, noise is little etc.As core component---motor, become undoubtedly the critical component solving the problems of the technologies described above, the motor of traditional domestic air conditioning the inside generally adopts load motor PSC, load motor, efficiency is low, and relatively power consumption, noise is also large, and controllability degree of intelligence is low.Along with the development of motor technology, direct current generator replaces alternating current generator gradually, direct current generator is with electric machine controller, utilize electric machine controller to realize the object of the electronic commutation of electric current, so also someone is called for short ECM motor (electronically commutated motor) or is DC brushless motor (BLDC MOTOR) in industry, it has energy-conserving and environment-protective, reliability and controllability are all higher, noise is little, easily realize the features such as intelligent, can solve the deficiency of load motor, therefore, the load motor of existing air-conditioning the inside is got and is replaced by DC brushless motor or ECM motor gradually.

Other national air-conditioning of China or Asia, its DC MOTOR CONTROL plate connects with air-conditioning mainboard, be provided with the connection signal on 5 tunnels, be respectively: GND port, VDC port, VCC port, VSP port, FG port, this interface becomes the interface of standard substantially, air-conditioning mainboard is by output VSP voltage port to DC MOTOR CONTROL plate input rotating speed of target, and motor, by FG port feedback motor actual speed, is realized the speed closed loop control of direct current generator.Make a slip of the tongue filter screen or air channel when blocked when the outlet and inlet of air-conditioning, and the air outlet air quantity of air-conditioning can decline, and affects air conditioner refrigerating or heating effect.This is that air-conditioning system is less desirable, for this reason, realizes permanent wind amount or air quantity monitoring/warning function is necessary on traditional B LDC motor.

Existing solution: the size that installs blast gauge additional and judge air quantity in air outlet or air channel having, some installation air volume meters are calculated air quantity, but all need like this to increase hardware especially, and installation wiring trouble, increases extra cost.

Summary of the invention:

The object of this invention is to provide blower motor and measure the method for air quantity, can accurately be judged as airstrainer and stop up also output signal warning, and mathematical model is simple, control is reliable, and precision is high.

The object of the invention is to be achieved by following technical proposals.

Blower motor is measured a method for air quantity, it is characterized in that: it comprises following steps:

A) set up M air quantity point CFM in the microprocessor the inside of electric machine controller _im corresponding permanent wind amount control function Q _i=F (n), wherein Q can be power input or DC bus current or moment, n is the rotating speed of motor; I is integer, starts to M by 1;

B) starter motor, enters after stable state, detects real-time rotate speed n0 and the parameter Q0 of motor, by several air quantity points CFM above-mentioned parameter Q0 substitution _icorresponding several permanent wind amount control functions Q _i=F (n) obtains several rotation speed n _i, relatively real-time rotate speed n0 and several air quantity points CFM _icorresponding several rotation speed n _i, determine and detect in real time air quantity CFM0 in those two air quantity point CFM _iand CFM _i-1between;

C) utilize two air quantity point CFM that determine _iand CFM _i-1and rotation speed n _iand n _i-1go out real-time detection air quantity CFM0 by interpolation calculation.

Detect air quantity CFM0=CFM _i+ (CFM _i-1-CFM _i) × (n _i-no) ÷ (n _i-n _i-1).

Function Q described above _i=F (n) obtains like this: first gather raw data, in the equipment of air channel, for M target air quantity, be adjusted to high static pressure from low static pressure always, this static pressure wants to contain the actual static pressure scope of application, in the process of regulating static, allow motor in constant speed control, and be target air quantity by regulating motor speed n and parameter Q to keep air quantity, and motor steady-state speed n now of record and corresponding parameter Q, like this, for M target air quantity, one group of rotation speed n and parameter Q are all produced, then produce the corresponding function Q of each target air quantity in M target air quantity by the method for curve _i=F (n).

Several air quantity points CFM described above _icomprise maximum discharge quantity of fan and minimum discharge quantity of fan.

Q described above _i=F (n) is a second order function, and each target air quantity is put corresponding function Q=C ₁+ C ₂× n+C ₃× n ².

Blower motor described above adopts BLDC motor or ECM motor, comprise motor monomer and electric machine controller, described motor monomer comprises rotating shaft, p-m rotor assembly, stator module and case component, p-m rotor assembly and stator module form magnetic lotus root and close, stator module comprises stator core and is wound on coil winding on stator core, described electric machine controller includes microprocessor, inverter circuit and operational parameter detection circuit, the output terminal of inverter circuit is connected with coil winding, the signal of detection is input to microprocessor by operational parameter detection circuit, the output terminal control inverter circuit of microprocessor, microprocessor the inside input target setting air quantity, when real-time detection air quantity CFM0 is lower than target setting air quantity, output signal is reported to the police.

Blower motor described above is operated in permanent wind amount control model, first whether microprocessor measured real power and arrived in rated power, reach rated power if measure real power, and when detecting air quantity and setting the deviation of air quantity and reach certain value, report to the police; When detecting that air quantity and setting air quantity have deviation in allowed band, select not report to the police.

Blower motor described above is operated in constant moment of force control model, in the time detecting air quantity and set the deviation of air quantity and reach certain value, is judged as airstrainer and stops up and report to the police.

Blower motor described above is operated in constant speed control pattern, in the time detecting air quantity and set the deviation of air quantity and reach certain value, is judged as airstrainer and stops up and report to the police.

The present invention compared with prior art, has following effect:

1) utilization of the present invention is set up M air quantity point CFM in the microprocessor the inside of electric machine controller _im corresponding permanent wind amount control function Q _i=F (n), real-time rotate speed n0 and the parameter Q0 of detection motor, by several air quantity points CFM above-mentioned parameter Q0 substitution _icorresponding several permanent wind amount control functions Q _i=F (n) obtains several rotation speed n _i, relatively real-time rotate speed n0 and several air quantity points CFM _icorresponding several rotation speed n _i, determine and detect in real time air quantity CFM0 in those two air quantity point CFM _iand CFM _i-1between, and utilize interpolation calculation to go out real-time detection air quantity CFM0, and mathematical model is simple, controls reliably, and degree of accuracy is high.

2) utilize blower motor as detecting the element of air quantity, in the time detecting air quantity Q1 and the deviation of setting air quantity Q0 and reach certain value, be judged as that airstrainer stops up and output signal is reported to the police, without increasing any hardware, simple installation, cost is low;

3) blower motor is operated in the control model of permanent wind amount, and first microprocessor is measured real power and whether arrived rated power, reaches rated power if measure real power, judgement detects air quantity Q1 and the deviation of setting air quantity Q0 again, scheme is simple, and microprocessor operand is little, and feasibility is high.

Function Qi=F (n) described above obtains like this: first gather raw data, in the equipment of air channel, for M target air quantity, be adjusted to high static pressure from low static pressure always, this static pressure wants to contain the actual static pressure scope of application, in the process of regulating static, allow motor in constant speed control, and be target air quantity by regulating motor speed n and parameter Q to keep air quantity, and motor steady-state speed n now of record and corresponding parameter Q, like this, for M target air quantity, one group of rotation speed n and parameter Q are all produced, then produce the corresponding function Qi=F of each target air quantity (n) in M target air quantity by the method for curve, above-mentioned M air quantity point refers to have at least 5, can effectively ensure the precision of measuring.

Brief description of the drawings:

Fig. 1 is the structural representation of traditional air-conditioning draught fan system;

Fig. 2 is the scheme of installation of blower motor of the present invention;

Fig. 3 is the stereographic map of blower motor of the present invention;

Fig. 4 is the stereographic map of the electric machine controller of blower motor of the present invention;

Fig. 5 is the cut-open view of blower motor of the present invention;

Fig. 6 is a kind of implementing circuit block scheme of the electric machine controller of blower motor of the present invention;

Fig. 7 is the circuit diagram that Fig. 6 is corresponding;

Fig. 8 is the control flow chart of the permanent wind amount control method of blower motor of the present invention;

Fig. 9 is that blower motor of the present invention records to obtain gang's permanent wind amount matched curve by experiment;

Figure 10 is the experimental data matched curve figure of the blower motor direct Power Control permanent wind amount of 1/3HP of the present invention;

Figure 11 is that blower motor of the present invention utilizes method of interpolation to solve any input air quantity experimental data matched curve figure;

Figure 12 is the steering logic figure of the permanent wind amount control method of blower motor of the present invention;

Figure 13 is a kind of control procedure schematic diagram of the permanent wind amount control method of blower motor of the present invention;

Figure 14 is the another kind of control procedure schematic diagram of the permanent wind amount control method of blower motor of the present invention;

Figure 15 is the test result figure through experimental verification of the permanent wind amount control method of blower motor of the present invention;

Figure 16 is the air quantity measuring and calculating schematic diagram of blower motor of the present invention.

Embodiment:

Below by specific embodiment, also the present invention is described in further detail by reference to the accompanying drawings.

Embodiment mono-:

First introduce the circuit structure of blower motor and the measurement control principle of air quantity that the present invention adopts below:

The present invention is as shown in Figure 1, inner at a typical ventilating duct for air-conditioner (abbreviation air channel), a blower system (as gas furnace or air processing machine) has been installed, in figure, replace with " motor+wind wheel ", in pipeline, also have airstrainer, when electric motor starting, start air blast, because the quantity of air outlet and air intake vent is relevant with room number, also ununified standard of the design of pipeline, airstrainer also may have different pressure drops simultaneously.Causing carrying traditional load motor---the blower system of PSC motor is in different pipelines, and actual air quantity can be different.Invention adopt blower motor be BLDC motor or ECM motor.

As shown in Figure 2,1) control of product is an Air-condition system control device, and peripheral circuit and the agreement configuration information of all product operation devices of Air-condition system control device control and the interface by a customization send to electric machine controller.2) electric machine controller comprises a microprocessor---single-chip microcomputer or DSP electron plate do Electric Machine Control, and it has a power unit to provide electric power to controller each several part circuit, and power supply is that a DC bus-bar voltage and electric current are set.Therefore, the control of motor will be carried out power delivery.The electric machine controller of low cost and batch production adopts parallel resistance circuit as electric current and voltage sensor hardware conventionally, control motor as the feedback of system and drive actuating motor control, for example vector controlled, Direct Torque Control, and the sensor of other types or without sensor control.As everyone knows, the variation of any electronic package runtime, these variations are to affect accuracy of detection and persistent reason.3) on blower motor rotor, there are magnet body and structure, in stator side or groove, have polyphase windings.In the time of temperature variation, permanent magnet and winding resistance can change, and this may cause the variation that Electric Machine Control is different.Motor manufacture process conventionally produces also variation to a certain degree, motor aging, and new motor and old motor, the accuracy of the factor controlling of contribution and persistence, in time of life etc., can be due to temperature variation from the magnetic flux of the motor of magnet, demagnetization etc.In addition, the possible risk that motor shaft lost efficacy, the security of system, and will detect or monitoring in real time.4) fan blower: fan blower is arranged on motor shaft, the air-flow that rotation produces is with certain speed.The position of installing may affect operation, increases friction, low discharge, or even wrong sense of rotation.5) airstrainer: airstrainer should regularly replace and maintenance service.But this may be the tracking having lost in a very long time.This will increase frictional influence stream pressure.6) pipe control: piping system may change due to dust and pipeline breaking, the reason that Region control and ON/OFF wind port system pressure change.Produce a lot of unstable factors if do permanent wind amount control meeting according to actual conditions above.

As Fig. 3, Fig. 4, shown in Fig. 5, blower motor is conventionally by electric machine controller 2 and motor monomer 1, described motor monomer 1 comprises stator module 12, rotor assembly 13 and case component 11, stator module 13 is arranged on case component 11, motor monomer 1 is provided with the Hall element 14 of detection rotor position, rotor assembly 13 is sleeved on inner side or the outside composition of stator module 12, electric machine controller 2 comprises control enclosure 22 and is arranged on the control circuit board 21 of control enclosure 22 the insides, control circuit board 21 generally comprises power circuit, microprocessor, bus current testing circuit, inverter circuit and rotor position measurement circuit 14 (being Hall element), power circuit is each several part circuit supply, rotor position measurement electric circuit inspection rotor-position signal is also input to microprocessor, the bus circuit of detection is input to microprocessor by bus current testing circuit, DC bus-bar voltage is input to microprocessor by busbar voltage testing circuit, microprocessor control inverter circuit, the power on/off of each phase coil winding of inverter circuit control stator module 12.

As shown in Figure 6, Figure 7, suppose that blower motor is 3 phase brushless direct current permanent magnetic synchronous motors, 3 Hall elements of rotor position measurement circuit 14 general employings, 3 Hall elements detect respectively the rotor-position in one 360 degree electrical angle cycle, often turn over the energising that 120 degree electrical angles change each phase coil winding of a stator module 12, form 3 phase 6 step control models.Exchange input (AC INPUT) process by diode D7, D8, D9, after the full-wave rectifying circuit of D10 composition, at one end of capacitor C 1 output DC bus-bar voltage Vbus, DC bus-bar voltage Vbus is relevant with input ac voltage, after the voltage of interchange input (AC INPUT) is determined, the line voltage U P of 3 phase windings is PWM copped wave output voltages, UP=Vbus*w, w is the dutycycle that microprocessor is input to the pwm signal of inverter circuit, change line voltage U P and can change DC bus current Ibus, inverter circuit is by electronic switching tube Q1, Q2, Q3, Q4, Q5, Q6 composition, electronic switching tube Q1, Q2, Q3, Q4, Q5, the 6 road pwm signal (P1 that the control end of Q6 is exported by microprocessor respectively, P2, P3, P4, P5, P6) control, inverter circuit also contact resistance R1 for detection of bus current Ibus, bus current testing circuit will be sent to microprocessor after the detection bus current Ibus conversion of resistance R 1.Power input to machine control is controlled by electronic switching tube Q7,1 road pwm signal of microprocessor output--and be P0, control the ON time of electronic switching tube Q7, to control power input to machine.

As shown in Figure 8, the permanent wind amount control method of the blower motor direct Power Control in air-conditioning system, described blower motor drives wind wheel and has stator module, p-m rotor assembly and electric machine controller, described electric machine controller comprises microprocessor, inverter circuit, rotor position measurement circuit, bus current testing circuit, busbar voltage testing circuit and power input to machine control circuit (not shown in FIG.), rotor position measurement electric circuit inspection rotor-position signal is also input to microprocessor, microprocessor calculates the real-time rotate speed n of motor according to rotor-position signal, bus current is input to microprocessor by bus current testing circuit, DC bus-bar voltage is input to microprocessor by busbar voltage testing circuit, microprocessor control inverter circuit, the power on/off of each phase coil winding of inverter circuit control stator module, microprocessor control power input to machine control circuit, it is characterized in that: it comprises the steps:

Steps A) actuating motor controller, receive or default target airflow value IN-CFM;

Step B) obtain corresponding function P=f (n) according to target airflow value IN-CFM, wherein n is rotating speed, P is power input to a machine;

Step C) enter direct Power Control permanent wind amount control model: controlling motor or motor speed is 1 o'clock starter motor, makes it arrive a stable working point (p along the control track of function P=f (n) _t, n _t); p _t, n _tto be positioned at a pair of power input and rotating speed on the track that meets permanent wind amount control function P=f (n);

Step D) keep direct Power Control permanent wind amount control model: calculate the real-time power input Pi of motor according to motor operating parameter; Calculate Δ P=|Pt-Pi|;

Step e) if power increment value Δ P is less than setting value P _set, keep work on hand point;

Step F) if power increment value Δ P is more than or equal to setting value P _set; Whether power/rotating speed steering logic reaches the running time of computing velocity ring; If the running time of speed ring does not reach, keep work on hand point;

Step G) if the running time of speed ring reaches, admission velocity control loop is pressed Δ n=|ni-nt| governing speed, ni is real-time rotate speed, realizes the new working point (Pi, ni) on track, even Pt=Pi, nt=ni, gets back to step C.

Function P=f (n) described above described above obtains like this: first gather raw data, for several target air quantity, be adjusted to high static pressure from low static pressure always, this static pressure wants to contain the actual static pressure scope of application, in the process of regulating static, allow motor in constant speed control, and be target air quantity by regulating the real-time power input Pi of motor speed n and motor to keep air quantity, and motor steady-state speed n now of record and the corresponding real-time power input Pi of motor, like this, for several target air quantity, one group of rotation speed n and the real-time power input Pi of motor are all produced, then produce the corresponding function P=f of each target air quantity (n) in several target air quantity by the method for curve.

If outside input target airflow value IN-CFM described above is not equal to one of them of several target air quantity of said determination, can pass through method of interpolation, the function P=f (n) that the Fitting Calculation is corresponding with any outside input target airflow value IN-CFM.Realize the permanent wind amount control of omnidistance arbitrary target air quantity.

Functional relation P=f (n) described above is polynomial function a: P=C ₁+ C ₂× n+...+C _m× n ^m-1, wherein C ₁, C ₂..., C _mbe coefficient, n is motor speed value, the corresponding one group of C of each target air quantity ₁, C ₂..., C _mcoefficient also stores, and microprocessor obtains one group of corresponding C according to the target airflow value IN-CFM of input by look-up table or method of interpolation ₁, C ₂..., C _mcoefficient, thus functional relation P=f (n) obtained.

Stating described functional relation P=f (n) is second order function a: P=C ₁+ C ₂× n+C ₃× n ².

Control method (Direct P Control for Constant Airflow Control Apparatus Method) exploitation and the Mathematical Models of direct Power Control permanent wind amount of the present invention are such: in general, a ventilating system, the air-flow air that the driving that blower fan is driven by blower motor produces at a stable state.A constant air quantity control realizes by the speed under a static pressure condition, power control, sees following relational expression: CFM=F (P, speed, pressure), wherein CFM is air quantity, and P is power, speed, is speed, and pressure is static pressure.When the variation of static pressure, maintain this permanent wind amount with the control of power and speed.Along with static pressure increases, power and speed change thereupon.Cluster permanent wind amount CFM curve can test out, as shown in Figure 9.Based on these permanent wind amounts CFM curve, model is controlled in exploitation, when air quantity requirement is determined in the control of product, provides a constant wind quantity CFM by power ratio control and speed at specific static pressure.In Fig. 9, family curve represent retentive control power and speed permanent wind amount physical characteristics, within the scope of the rated power of all motors, the air-conditioning producer of the air flow system of the design to any type, test result based on power and rate curve, can reach a conclusion, a typical quadratic function can perform well in developing modeling as the typical function of one, P=C ₁+ C ₂× n+C ₃× n ², by three point to be located of the person of choosing on curve (A, B and C), the data on its corresponding coordinate are (p1, n1), (p2, n2), and (p3, n3) obtains coefficient C1, C2, C3, sees following formula:

$F(A,B,C)={\mathrm{\Σ}}_i^m{(\mathrm{Yi}-(C1+C2*n+C3*n^2))}^2,$ Pass through $\∂F/\∂A=0,$ $\∂F/\∂B=0,$ and $\∂$ $F/\∂C=0,$ By solving equation, m=3.

The process of curve is to select polynomial expression to describe curve, and polynomial coefficient can be obtained by least square method.Can use in theory P=C ₁+ C ₂× n+C ₃× n ²+ ...+Cm × n ^m-1, in fact select binomial just can meet general needs.Functional relation P=f (n) is second order function a: P=C ₁+ C ₂× n+C ₃× n ², wherein C ₁, C ₂and C ₃be coefficient, n is motor speed value, the corresponding one group of C of any one target air quantity in several target air quantity of test ₁, C ₂and C ₃coefficient also stores, and microprocessor obtains one group of corresponding C according to the target airflow value IN-CFM of input by look-up table ₁, C ₂and C ₃coefficient, thus functional relation P=f (n) obtained, the corresponding one group of C of each target air quantity in certain load ₁, C ₂and C ₃shown in coefficient table 1 specific as follows:

Table 1

CFM	C 1	C 2	C 3
				150	0.338	—0.151	0.0458

300	0.4423	—0.2113	0.0765
				450	。。。	。。。	。。。
600	。。。	。。。	。。。
				750	。。。	。。。	。。。
900	。。。	。。。	。。。

Figure 10 is that the blower motor of 1/3HP is at the experimental data matched curve figure of the direct Power Control permanent wind amount of the air-conditioning system of small pipeline, for a given target air-flow, system selects some typical air quantity CFM to set up a database for setting up the use of mathematical model as test point.These typical points comprise minimum and maximum quantity of wind value, and more additional intermediate points are according to product specification, and typically air quantity CFM has 5 as test point, are respectively 150/300/450/600 and 750CFM.

Table 2 shows an example of test data result.The scope of the rotating speed of motor is from 200 to 1400rpm; The static pressure of system is from 0.1 to 1H ₂o.Keep default permanent wind amount CCFM output, obtain the power input to machine per unit value of a corresponding Figure 10, form a database.

Table 2

Utilize least square method, the quadratic function of the corresponding power of each predetermined CFM air quantity and rotating speed, obtains in the computing method of a standard: the power of these equation definition and the speed of the working point of any system at a specific static pressure.Set air quantity IN-CFM when input and preset, electric system has defined a function for correspondence with it, and the track of its working point is followed function definition.Equation (3) to (7) can be expressed as a standard equation, and C1, C2, C3 are constants.

$\mathrm{Power}\left(150\right)=0.3388{\left(\frac{n}{1000}\right)}^2-0.1551\left(\frac{n}{1000}\right)+0.0458---\left(3\right)$

$\mathrm{Power}\left(300\right)=0.4423{\left(\frac{n}{1000}\right)}^2-0.2113\left(\frac{n}{1000}\right)+0.0765---\left(4\right)$

$\mathrm{Power}\left(450\right)=0.3987{\left(\frac{n}{1000}\right)}^2-0.0308\left(\frac{n}{1000}\right)+0.0294---\left(5\right)$

$\mathrm{Power}\left(600\right)=0.2580{\left(\frac{n}{1000}\right)}^2+0.3983\left(\frac{n}{1000}\right)-0.1379---\left(6\right)$

$\mathrm{Power}\left(750\right)=0.1385{\left(\frac{n}{1000}\right)}^2+0.8150\left(\frac{n}{1000}\right)-0.3139---\left(7\right)$

Obtain P=C ₁+ C ₂× n+C ₃× n ², equation (3) to (7) modeling curve provides 5 of several permanent wind amount CFM demands to select the track of working point, and Power is power, and n is rotating speed.

As shown in figure 11, if request permanent wind amount IN-CFM require be not modeling curve one of them, obtain the permanent wind amount IN-CFM of new this request of secular equation matching with a kind of interpolation method, for example, when the permanent wind amount IN-CFM=525cfm of request requires to be received, adjacent two curve C FM1-600cfm and CFM2-450cfm modeling can be identified.So latter two corresponding equation can be for calculating the new equation of IN-CFM=525cfm curve.Need-based IN-CFM=525cfm, three selected speed omega 1, ω 2, ω 3, determine at these velographs and calculate performance number, utilize equation that these two model curves are corresponding for two power points in selected speed, linear weighted function interpolation can be used for calculating P value. first list matrix data as follows.

$\left[\begin{array}{c}{P}_i\\ P_1\left(600\right)\\ P_2\left(450\right)\end{array}\right]=\left[\begin{array}{ccc}{\mathrm{\ω}}_1& {\mathrm{\ω}}_2& {\mathrm{\ω}}_3\\ P_{11}& P_{12}& P_{13}\\ P_{21}& P_{22}& P_{23}\end{array}\right]$

For a pair of power points (p _1i, p _2i) a corresponding selected speed omega, selected speed omega 1, ω 2, the corresponding 3 couples of power points (p of ω 3 _1i, p _2i), linear weighted function interpolation can be used for calculating Pi value and be

p ⁱ＝p _2i+w.(p _1i-p _2i)。

Weighted value W calculates like this:

Note this CFM2≤IN-CFM≤CFM1, wait 0≤W≤1.Matrix equation is below computable,

$\left[\begin{array}{ccc}{\mathrm{\ω}}_1^2& {\mathrm{\ω}}_1& 1\\ {\mathrm{\ω}}_2^2& {\mathrm{\ω}}_2& 1\\ {\mathrm{\ω}}_3^2& {\mathrm{\ω}}_3& 1\end{array}\right]\left[\begin{array}{c}{C}_1\\ C_2\\ C_3\end{array}\right]=\left[\begin{array}{c}{P}_1\\ P_2\\ P_3\end{array}\right]$

The function P=C of corresponding IN-CFM=525cfm like this ₁+ C ₂× n+C ₃× n ²can be obtained.Solve this matrix equation, can calculate C1, C2, C3 coefficient.Therefore, any demand input air quantity IN-CFM can obtain power equation.Due to this process be electric machine controller the inside microprocessor---single-chip microcomputer initialization completes, so the calculating of power does not need to consume more real-time cpu resource.

Can find out, this direct Power Control DPC (Direct Power Control) realizes power control with rotating speed control.The function of power/rotating speed steering logic is that coordinating power/rotating speed loop time constant is to ensure the stability of system.Control can be by controlling the accurate control of motor, and torque control ratio.No matter be in scalar or vector controlled, speed control is more effective compared with torque control., improve control accuracy.

It is to carry out speed control by unique power and fans load velocity characteristic that DPC controls.Motor is from zero rotating speed to high rotating speed, and power is also like this from zero to increase.The rotating speed of motor by rising until reach a pair of working point A (power, speed), it is static pressure force, as shown in figure 13, when static pressure increases suddenly, under speed control mode, motor provides more power (or larger moment of torsion) maintenance speed, because higher static pressure needs very large power requirement.Power can rise to suddenly higher, and " B " that reached a new working point when electric system, with identical speed, this algorithm will know that whether this is in constant CFM geometric locus working point, thereby determine a pair of power/speed point " C ".But C point is not a stable working point, due to high-power requirement, then remove " D " point, repeatedly, wait " G " that converge to a new stable operating point, finish.

In force, when we can reduce power swing and change suddenly, by using restricted power increment control.It is presented in Figure 14, and increment power can be designated as Δ P.Exceed this power increment Δ P as long as power changes, speed control will be carried out speed control.In this mode, work in all working points under positive and negative bandwidth of corresponding permanent wind amount CFM geometric locus.The distinguished and admirable control system that static pressure changes in transient process is stable.

As shown in figure 15, above-mentioned motor direct Power Control permanent wind amount control method and algorithm are tested on our blower motor controller, and all system performances have met requirement as shown in figure 15.

Figure 12 is the logic diagram of this algorithm in blower motor scalar control application, and power input is by DC bus-bar voltage, and Current calculation obtains. power and rotating speed will be limited in peak power P _max, and rotation speed n _maxwithin.

Calculate the real-time power input value of motor Pi by the DC bus current/voltage of feedback, mate with power/speed data according to the air quantity IN-CFM of outside input so, obtain the calculated value Pt of power input to machine, relatively calculated value Pt and the real-time output power Pi of motor of power input to machine, obtain difference power Δ P, difference power Δ P is limited, and avoids difference power Δ P excessive, and regulating power fluctuation is larger.Difference power Δ P, by the output of power/speed control logic, carries out speed ring control, and PWM frequency converter carries out rotating speed control. and adopt scalar control, gather real-time bus current I _buscalculate the real-time power input P=I of motor with real-time busbar voltage _bus× V _bus.

The principle of the air measuring of blower motor is as follows:

Theoretical analysis based on above: Figure 10 is that the blower motor of 1/3HP is at the experimental data matched curve figure of the direct Power Control permanent wind amount of the air-conditioning system of small pipeline, air quantity CFM has 5 as test point, be respectively 150,300,450,600 and 750CFM, obtain equation (3) to (7), table 2 shows an example of test data result.The scope of the rotating speed of motor is from 200 to 1400rpm; The static pressure of system is from 0.1 to 1H ₂o, keeps default permanent wind amount CCFM output, obtains the power input to machine per unit value of a corresponding Figure 10.And the air quantity data of any one no longer above-mentioned 5 working point of description input, the function P=C of for example IN-CFM=525cfm ₁+ C ₂× n+C ₃× n ²can be obtained.Solving matrix equation, can calculate C1, C2, C3 coefficient.Therefore, any demand input air quantity IN-CFM can obtain power equation.Be that the target air quantity of any one input can obtain permanent wind amount control function P=C that should target air quantity ₁+ C ₂× n+C ₃× n ².

Backward reasoning according to above principle: that is petty, when machine operation is under stable situation, measure current realtime power Po and the rotation speed n o of motor, as shown in figure 16, by this M ((Po, no), we can extrapolate this point (Po, no) the curve C FM0 in that permanent wind amount control is upper, also just knows the airflow value that this M (Po, no) is corresponding.Its derivation is as follows:

It is between those two known air quantity curves.We P0 substitution equation (3) to (7), obtain 5 kinds of rotation speed n (150) that air quantity is corresponding, n (300), n (450), n (600), n (750), judge that by rotating ratio rotation speed n o is between those two known permanent wind discharge curves, suppose this M (Po, no) between permanent wind discharge curve CFM1 and CFM2, equal in Po situation in power input, the rotating speed that permanent wind discharge curve CFM1 and CFM2 are corresponding is respectively n1, n2, this M (Po, no) permanent wind value CFM0=CFM2+ (CFM1-CFM2) × (n2-no) ÷ (n2-n1), wherein CFM1, CFM2 is air quantity 150, n (300), 450, 600, in 750 one.From above derivation, the realtime power Po of known motor and rotation speed n o, with regard to the known airflow value CFM0 that obtains air-conditioning system output, in the time detecting air quantity and reach certain value lower than the deviation of setting air quantity, be judged as that airstrainer stops up and output signal is reported to the police.

Embodiment bis-:

Blower motor is measured a method for air quantity, it is characterized in that: it comprises following steps:

A) set up M air quantity point CFM in the microprocessor the inside of electric machine controller _im corresponding permanent wind amount control function Q _i=F (n), wherein Q is DC bus current parameter, n is the rotating speed of motor; I is integer, starts to M by 1;

B) starter motor, enters after stable state, detects real-time rotate speed n0 and the parameter Q0 of motor, by several air quantity points CFM above-mentioned parameter Q0 substitution _icorresponding several permanent wind amount control functions Q _i=F (n) obtains several rotation speed n _i, relatively real-time rotate speed n0 and several air quantity points CFM _icorresponding several rotation speed n _i, determine and detect in real time air quantity CFM0 in those two air quantity point CFM _iand CFM _i-1between;

C) utilize two air quantity point CFM that determine _iand CFM _i-1and rotation speed n _iand n _i-1go out real-time detection air quantity CFM0 by interpolation calculation.

Detect air quantity CFM0=CFM _i+ (CFM _i-1-CFM _i) × (n _i-no) ÷ (n _i-n _i-1).。

Function Qi=F (n) described above obtains like this: first gather raw data, in the equipment of air channel, for M target air quantity, be adjusted to high static pressure from low static pressure always, this static pressure wants to contain the actual static pressure scope of application, in the process of regulating static, allow motor in constant speed control, and be target air quantity by regulating motor speed n and DC bus current Q to keep air quantity, and motor steady-state speed n now of record and corresponding DC bus current Q, like this, for M target air quantity, one group of rotation speed n and DC bus current Q are all produced, then produce the corresponding function Qi=F of each target air quantity (n) in M target air quantity by the method for curve.

Blower motor is operated in constant speed control pattern, in the time detecting air quantity and set the deviation of air quantity and reach certain value, is judged as airstrainer and stops up and report to the police, and M air quantity point refers to have at least 5, to ensure to calculate real-time detection air quantity CFM0 precision.

Embodiment tri-:

Blower motor is measured a method for air quantity, it is characterized in that: it comprises following steps:

A) set up M air quantity point CFM in the microprocessor the inside of electric machine controller _im corresponding permanent wind amount control function Q _i=F (n), wherein Q is motor output torque, n is the rotating speed of motor; I is integer, starts to M by 1;

B) starter motor, enters after stable state, detects real-time rotate speed n0 and the parameter Q0 of motor, by several air quantity points CFM above-mentioned parameter Q0 substitution _icorresponding several permanent wind amount control functions Q _i=F (n) obtains several rotation speed n _i, relatively real-time rotate speed n0 and several air quantity points CFM _icorresponding several rotation speed n _i, determine and detect in real time air quantity CFM0 in those two air quantity point CFM _iand CFM _i-1between;

C) utilize two air quantity point CFM that determine _iand CFM _i-1and rotation speed n _iand n _i-1go out real-time detection air quantity CFM0 by interpolation calculation.

Detect air quantity CFM0=CFM _i+ (CFM _i-1-CFM _i) × (n _i-no) ÷ (n _i-n _i-1).。

Function Qi=F (n) described above obtains like this: first gather raw data, in the equipment of air channel, for M target air quantity, be adjusted to high static pressure from low static pressure always, this static pressure wants to contain the actual static pressure scope of application, in the process of regulating static, allow motor in constant speed control, and be target air quantity by regulating motor speed n and motor output torque Q to keep air quantity, and motor steady-state speed n now of record and corresponding motor output torque Q, like this, for M target air quantity, one group of rotation speed n and motor output torque Q are all produced, then produce the corresponding function Qi=F of each target air quantity (n) in M target air quantity by the method for curve.Motor output torque Q is directly proportional to the working current of motor, therefore can calculate motor output torque Q by the working current that detects motor.

Blower motor is operated in constant moment of force control model, in the time detecting air quantity and set the deviation of air quantity and reach certain value, is judged as airstrainer and stops up and report to the police, and M air quantity point refers to have at least 5, to ensure to calculate real-time detection air quantity CFM0 precision.

Claims (10)

1. blower motor is measured a method for air quantity, it is characterized in that: it comprises following steps:

A) set up M air quantity point CFM in the microprocessor the inside of electric machine controller _im corresponding permanent wind amount control function Q _i=F (n), wherein Q can be power input or DC bus current or moment, n is the rotating speed of motor; I is integer, starts to M by 1;

B) starter motor, enters after stable state, detects real-time rotate speed n0 and the parameter Q0 of motor, by several air quantity points CFM above-mentioned parameter Q0 substitution _icorresponding several permanent wind amount control functions Q _i=F (n) obtains several rotation speed n _i, relatively real-time rotate speed n0 and several air quantity points CFM _icorresponding several rotation speed n _i, determine and detect in real time air quantity CFM0 in those two air quantity point CFM _iand CFM _i-1between;

C) utilize two air quantity point CFM that determine _iand CFM _i-1and rotation speed n _iand n _i-1go out real-time detection air quantity CFM0 by interpolation calculation.

2. a kind of blower motor according to claim 1 is measured the method for air quantity, it is characterized in that: detect air quantity CFM0=CFM _i+ (CFM _i-1-CFM _i) × (n _i-no) ÷ (n _i-n _i-1).

3. a kind of blower motor according to claim 1 and 2 is measured the method for air quantity, it is characterized in that: function Qi=F (n) described above obtains like this: first gather raw data, in the equipment of air channel, for M target air quantity, be adjusted to high static pressure from low static pressure always, this static pressure wants to contain the actual static pressure scope of application, in the process of regulating static, allow motor in constant speed control, and be target air quantity by regulating motor speed n and parameter Q to keep air quantity, and motor steady-state speed n now of record and corresponding parameter Q, like this, for M target air quantity, one group of rotation speed n and parameter Q are all produced, then produce the corresponding function Qi=F of each target air quantity (n) in M target air quantity by the method for curve.

4. a kind of blower motor according to claim 1 and 2 is measured the method for air quantity, it is characterized in that: several air quantity points CFM _icomprise maximum discharge quantity of fan and minimum discharge quantity of fan.

5. a kind of blower motor according to claim 1 and 2 is measured the method for air quantity, it is characterized in that: Q _i=F (n) is a second order function, and each target air quantity is put corresponding function Q=C ₁+ C ₂× n+C ₃× n ².

6. a kind of blower motor according to claim 1 and 2 is measured the method for air quantity, it is characterized in that: described blower motor adopts BLDC motor or ECM motor, comprise motor monomer and electric machine controller, described motor monomer comprises rotating shaft, p-m rotor assembly, stator module and case component, p-m rotor assembly and stator module form magnetic lotus root and close, stator module comprises stator core and is wound on coil winding on stator core, described electric machine controller includes microprocessor, inverter circuit and operational parameter detection circuit, the output terminal of inverter circuit is connected with coil winding, the signal of detection is input to microprocessor by operational parameter detection circuit, the output terminal control inverter circuit of microprocessor, microprocessor the inside input target setting air quantity, when real-time detection air quantity CFM0 is lower than target setting air quantity, output signal is reported to the police.

7. a kind of blower motor according to claim 6 is measured the method for air quantity, it is characterized in that: blower motor is operated in permanent wind amount control model, when detecting air quantity and the deviation of setting air quantity and reaching certain value, reports to the police; When detecting that air quantity and setting air quantity have deviation in allowed band, select not report to the police.

8. a kind of blower motor according to claim 6 is measured the method for air quantity, it is characterized in that: blower motor is operated in constant moment of force control model, in the time detecting air quantity and the deviation of setting air quantity and reach certain value, is judged as airstrainer and stops up and report to the police.

9. a kind of blower motor according to claim 6 is measured the method for air quantity, it is characterized in that: blower motor is operated in constant speed control pattern, in the time detecting air quantity and the deviation of setting air quantity and reach certain value, is judged as airstrainer and stops up and report to the police.

10. a kind of blower motor according to claim 1 and 2 is measured the method for air quantity, it is characterized in that: M air quantity point refers to have at least 5.