CN104779851B - Counter electromotive force of motor detection method - Google Patents

Abstract

The present invention relates to the counter electromotive force detection method of air-conditioning permanent magnet synchronous DC motor outer ventilation machine, for in the prior art without a kind of method of counter electromotive force of effective detection air-conditioning permanent magnet synchronous DC motor outer ventilation machine the problem of, there is provided a kind of counter electromotive force of motor detection method.This method includes following not step：DC offset voltage AD conversion value between detecting the phase back-emf of motor three over the ground, is expressed as V_u_offset、V_v_ offset and V_w_ offset, the AD conversion value of voltage, is expressed as V between detecting the phase back-emf of motor three over the ground_{u_GND1}、V_{v_GND1}And V_{w_GND1}；According to V_u_offset、V_v_offset、V_w_offset、V_{u_GND1}、V_{v_GND1}And V_{w_GND1}Three phase back-emfs are calculated to the phase voltage back-emf value U between motor coil central point_{u_GND}、U_{v_GND}And U_{w_GND}；According to U_{u_GND}、U_{v_GND}And U_{w_GND}Voltage U between calculating motor coil central point over the ground_{N_GND}, and according to U_{N_GND}、U_{u_GND}、U_{v_GND}And U_{w_GND}Calculate the phase voltage V of the phase back-emf of motor three_u、V_uAnd V_w.The present invention is applied to air-conditioning permagnetic synchronous motor.

Description

Counter electromotive force of motor detection method

Technical field

The present invention relates to the counter electromotive force inspection of air conditioner controlling technology, more particularly to air-conditioning permanent magnet synchronous DC motor outer ventilation machine Survey method.

Background technology

Permanent-magnet synchronous DC brushless motor, its counter electromotive force are sine wave shape, when using the brushless electricity of permanent magnet synchronous DC When machine is as outdoor fan of air-conditioner driving part, due to reasons such as sea winds, before activation, outdoor fan motor may just be located air-conditioning Rotated in positive direction or opposite direction, controller needs to detect position, rotating speed and its rotation direction of motor, but it is anti-to be intended to detection Electromotive force, testing goal is reached by counter electromotive force detection, the in good time working order according to motor is controlled accordingly, is reached To correct controlled motor operation the purpose of.

Number of patent application discloses a kind of control of outdoor fan of air-conditioner driving for the patent application of " 201410183282.3 " Method processed, control device and there is its air-conditioning, the importance and counter electromotive force detection method of counter electromotive force detection are carried out Explanation.But specific detection algorithm is not provided in the patent application, moreover, its specification page eight:Work as E_AB=Usin θ, E_BCDuring=Usin (θ -120 °), formula is obtainedIt is wrong, correct formula isFurthermore formula is also without explanation E_AB/E_BCDetection method.

The content of the invention

The present invention is in the prior art without a kind of anti-electricity of effective detection air-conditioning permanent magnet synchronous DC motor outer ventilation machine The problem of method of kinetic potential, there is provided a kind of counter electromotive force of motor detection method, this method comprise the following steps：

DC offset voltage AD conversion value between detecting the phase back-emf of motor three over the ground, is expressed as V_u_ offset、V_v_ offset and V_w_ offset, voltage AD conversion value between detecting the phase back-emf of motor three over the ground, is represented respectively For V_{u_GND1}、V_{v_GND1}And V_{w_GND1}；

According to V_u_offset、V_v_offset、V_w_offset、V_{u_GND1}、V_{v_GND1}And V_{w_GND1}Calculate three phase back-emfs To the phase voltage back-emf value U between motor coil central point_{u_GND}、U_{v_GND}And U_{w_GND}；

According to U_{u_GND}、U_{v_GND}And U_{w_GND}Voltage U between calculating motor coil central point over the ground_{N_GND}, and according to U_{N_GND}、U_{u_GND}、U_{v_GND}And U_{w_GND}Calculate the phase voltage V of the phase back-emf of motor three_u、V_uAnd V_w。

Specifically, the specific method bag of the DC offset voltage AD conversion value between detecting the phase back-emf of motor three over the ground Include the following two kinds method：First, under conditions of motor is motionless, DC offset voltage V is directly detected_u_offset、V_v_ offset and V_w_offset；2nd, voltage between directly detecting the phase back-emf of motor three over the ground, wherein being straight line portion per phase back-emf Voltage be DC offset voltage V_u_offset、V_v_ offset and V_w_offset。

Specifically, U_{u_GND}、U_{v_GND}And U_{w_GND}Pass through formula U respectively_{u_GND}=V_{u_GND1}-V_u_offset、U_{v_GND}=V_{v_GND1}- V_v_ offset and U_{w_GND}=V_{w_GND1}-V_w_ offset is calculated.

Specifically, motor coil central point over the ground between voltage U_{N_GND}Pass through formula It is calculated.

Specifically, V_u、V_uAnd V_wPass through formula V respectively_u=U_{u_GND}-U_{N_GND}、V_v=U_{v_GND}-U_{N_GND}And V_w=U_{w_GND}- U_{N_GND}It is calculated.

Can be according to V_u、V_uAnd V_wResult of calculation obtain motor current location angle, θ and rotational speed omega.

The invention has the advantages that by above-mentioned counter electromotive force detection method, it is opposite can correctly to detect motor three Electromotive force, motor rotor position the information θ, rotor rotational frequency f and rotor included in counter electromotive force of motor is calculated accordingly The information such as ω, f=2 π ω and rotor rotating, solution start preceding because factor such as sea wind from outside etc. causes sky several times at angle Adjust outdoor fan own rotation, the caused startup control problem to motor.Meanwhile counter electromotive force of motor detection is also caused to become Simply.

Embodiment

Technical scheme is further described with reference to embodiment, it is noted that embodiment is only It is to aid in reader and more fully understands technical scheme, is not intended to limit the invention the protection model of claim Enclose.

The present invention provides a kind of counter electromotive force of motor detection method, passes through electric resistance partial pressure, single-chip microprocessor MCU detection motor three-phase Counter electromotive force U, V/W over the ground between AD conversion value V_{u_GND1}/V_{v_GND1}/V_{W_GND1}, and to obtain motor three opposite by publicity conversion Electromotive force U/V/W phase voltage V_u、V_u、V_w.On this basis, can be by V_u、V_u、V_wObtain motor current location angle, θ and turn Fast ω, the contrary wind for controlled motor start.Change comprising the following steps that for method：First, the phase back-emf pair of motor three is detected DC offset voltage AD conversion value between ground, is expressed as V_u_offset、V_v_ offset and V_w_ offset, detect motor Three phase back-emfs over the ground between voltage AD conversion value, be expressed as V_{u_GND1}、V_{v_GND1}And V_{w_GND1}；According to V_u_ offset、V_v_offset、V_w_offset、V_{u_GND1}、V_{v_GND1}And V_{w_GND1}Three phase back-emfs are calculated to motor coil center Phase voltage back-emf value U between point_{u_GND}、U_{v_GND}And U_{w_GND}；Then, according to U_{u_GND}、U_{v_GND}And U_{w_GND}Calculate motor Hub of a spool point over the ground between voltage U_{N_GND}, and according to U_{N_GND}、U_{u_GND}、U_{v_GND}And U_{w_GND}It is conversely electronic to calculate motor three The phase voltage V of gesture_u、V_uAnd V_w。

Embodiment

MCU detect the phase back-emf U/V/W of motor three first over the ground between DC offset voltage V_u_offset、V_v_ offset、V_w_ offset, and according to U_{u_GND}=V_{u_GND1}-V_u_offset、U_{v_GND}=V_{v_GND1}-V_v_ offset and U_{w_GND}= V_{w_GND1}-V_w_ offset calculates three phase back-emfs to the phase voltage back-emf value U between motor coil central point_{u_GND}、 U_{v_GND}And U_{w_GND}。

U_{u_GND}=U_{u_N}+U_{N_GND} (1)

U_{v_GND}=U_{v_N}+U_{N_GND} (2)

U_{w_GND}=U_{w_N}+U_{N_GND} (3)

Wherein U_{N_GND}Be motor coil central point N over the ground between voltage, U_{u_N}、U_{v_N}、U_{w_N}Respectively U/V/W is to motor Phase voltage back-emf value between hub of a spool point N, is separately designated as V_u、V_v、V_w。

(1), (2) and (3) is added：

U_{u_GND}+U_{v_GND}+U_{w_GND}=(U_{u_N}+U_{v_N}+U_{w_N})+3U_{N_GND}

Due to U_{u_N}+U_{v_N}+U_{w_N}=V_u+V_v+V_w=0；

So

Similarly, obtained by (1), (2) and (3)：

U_{u_GND}=V_u+U_{N_GND}, U_{v_GND}=V_v+U_{N_GND}, U_{w_GND}=V_w+U_{N_GND},

So V_u=U_{u_GND}-U_{N_GND},V_v=U_{v_GND}-U_{N_GND},V_w=U_{w_GND}-U_{N_GND}。

Calculating V_u、V_uAnd V_wValue after, motor current location angle, θ and rotational speed omega can be further obtained, to right Motor is actuated for controlling.

Claims (5)

1. counter electromotive force of motor detection method, it is characterised in that comprise the following steps：

The AD conversion value of DC offset voltage between detecting the phase back-emf of motor three over the ground, is expressed as V_u_offset、 V_v_ offset and V_w_ offset, the AD conversion value of voltage, is expressed as between detecting the phase back-emf of motor three over the ground V_{u_GND1}、V_{v_GND1}And V_{w_GND1}；

According to V_u_offset、V_v_offset、V_w_offset、V_{u_GND1}、V_{v_GND1}And V_{w_GND1}Three phase back-emfs are calculated to electricity Phase voltage back-emf value U between machine hub of a spool point_{u_GND}、U_{v_GND}And U_{w_GND}；

According to U_{u_GND}、U_{v_GND}And U_{w_GND}Voltage U between calculating motor coil central point over the ground_{N_GND}, and according to U_{N_GND}、 U_{u_GND}、U_{v_GND}And U_{w_GND}Calculate the phase voltage V of the phase back-emf of motor three_u、V_vAnd V_w；

U_{u_GND}、U_{v_GND}And U_{w_GND}Pass through formula U respectively_{u_GND}=V_{u_GND1}-V_u_offset、U_{v_GND}=V_{v_GND1}-V_v_ offset and U_{w_GND}=V_{w_GND1}-V_w_ offset is calculated.

2. counter electromotive force of motor detection method as claimed in claim 1, it is characterised in that the detection phase back-emf pair of motor three The specific method of DC offset voltage AD conversion value between ground is as follows：Under conditions of motor is motionless, it is inclined directly to detect direct current Put voltage V_u_offset、V_v_ offset and V_w_offset。

3. counter electromotive force of motor detection method as claimed in claim 1, it is characterised in that the detection phase back-emf pair of motor three The specific method of DC offset voltage AD conversion value between ground is as follows：Electricity between directly detecting the phase back-emf of motor three over the ground Pressure, wherein every phase back-emf is DC offset voltage V for the voltage of straight line portion_u_offset、V_v_ offset and V_w_ offset。

4. counter electromotive force of motor detection method as claimed in claim 1, it is characterised in that motor coil central point over the ground between Voltage U_{N_GND}Pass through formulaIt is calculated.

5. counter electromotive force of motor detection method as claimed in claim 1, it is characterised in that V_u、V_vAnd V_wPass through formula V respectively_u =U_{u_GND}-U_{N_GND}、V_v=U_{v_GND}-U_{N_GND}And V_w=U_{w_GND}-U_{N_GND}It is calculated.