TWI475238B - Method for estimating power of motor and apparatus using the same - Google Patents

Description

Motor power estimation method and device thereof

This invention relates to an estimating device and, more particularly, to a motor power estimating device.

The motor is an integral part of the various automated production machines. In general, the energy consumed by the motor during operation accounts for a considerable proportion of its cost of use. Therefore, if the energy efficiency of the motor can be accurately controlled, the management efficiency of the motor can be effectively improved.

The current energy management engineers in charge of the factory often face the operation of the whole plant (including power consumption, efficiency and mechanical characteristics, etc.) when they are faced with different types of motors. Therefore, most of the current practices are based on the experience of the engineer to view the motor situation; or, in the annual repair and sudden failure, the engineer performs inspection and maintenance operations. The above method not only affects the operating efficiency of the motor, but also may affect the production schedule in a serious case, which in turn leads to an increase in maintenance costs. Therefore, if a complete online efficiency estimation diagnostic analysis tool is available, the energy management engineer can grasp the operation status of the whole plant motor, and then perform preventive maintenance on the problematic motor in real time.

In view of this, the present invention provides a motor power estimation method and apparatus thereof, which can output power to a motor without stopping or disassembling the motor. Make an estimate.

The present invention provides a motor power estimating apparatus including a measuring unit, a rotational speed estimating unit, a converting unit, an adaptive estimating unit, a voltage calculating unit, a magnetic flux calculating unit, and a power estimating unit. The measuring unit measures the three-phase power applied to the motor. The speed estimation unit estimates the magnetic field speed of the motor and the rotor speed based on the three-phase current in the three-phase power source. The conversion unit converts the three-phase power supply into a two-phase power supply. The adaptive estimation unit adaptively produces an estimated stator resistance. The voltage calculation unit calculates the two-phase induced voltage based on the two-phase power supply and the estimated stator resistance. The flux calculation unit calculates the two-phase magnetic flux of the motor based on the two-phase induced voltage adaptability. The power estimation unit estimates the output power of the motor based on the two-phase flux, the rotor speed, and a plurality of parameters of the motor. Wherein, the adaptive estimation unit generates an estimated stator resistance based on the two-phase power source, the two-phase magnetic flux, and the magnetic field rotational speed.

In another aspect, the present invention provides a motor power estimation method suitable for a motor power estimating device, the method comprising the following steps. First, the three-phase power applied to the motor is measured, and the magnetic field speed of the motor and the rotor speed are estimated based on the three-phase currents in the three-phase power. Next, the three-phase power source is converted to a two-phase power source, and the estimated stator resistance is adaptively generated. Then, based on the two-phase power supply and the estimated stator resistance, the two-phase induced voltage is calculated, and then the two-phase magnetic flux of the motor is adaptively calculated according to the two-phase induced voltage. Next, the output power of the motor is estimated based on the two-phase flux, the rotor speed, and various parameters of the motor. Among them, the estimation of the stator resistance is based on the two-phase power supply, the two-phase magnetic flux, and the magnetic field rotational speed.

Based on the above, the method and device proposed by the present invention can measure three-phase electricity After the source, the estimated stator resistance is adaptively generated based on its corresponding two-phase voltage and the magnetic field speed. Moreover, since the two-phase magnetic flux of the motor is adaptively estimated, it can lead to higher estimation accuracy, thereby making the estimation result of the motor output efficiency more accurate.

The above described features and advantages of the present invention will be more apparent from the following description.

1 is a schematic diagram of estimating motor power using a motor power estimating device, according to an embodiment of the invention. In the present embodiment, when the motor IM is operated by the three-phase power supplied from the power supply AC, the motor power estimating device 100 can estimate the motor IM after measuring the three-phase power on the primary side of the motor IM. The output power and other parameters. The power supply AC is, for example, an AC power source that can supply a three-phase power source. The motor IM is, for example, an induction motor including a stator and a rotor. The stator may generate a rotating magnetic field according to an applied voltage, and the rotor may rotate according to the rotating magnetic field. It should be understood by those of ordinary skill in the art that the three-phase power applied to the motor IM can include a three-phase voltage V 3 _ψ and a three-phase current I ₃ 。 . The three-phase voltage V 3 _ψ includes phase voltages V1, V2, and V3, and the phase voltage V1 and the phases of the phase voltages V2 and V3 are individually different by 120 degrees and -120 degrees. The three-phase current I 3 _包括 includes phase currents I1, I2, and I3, and the phase current I1 and the phases of the phase currents I2 and I3 are individually different by 120 degrees and -120 degrees.

The motor power estimating device 100 includes a measuring unit 110, a rotational speed estimating unit 120, a converting unit 130, an adaptive estimating unit 140, a voltage calculating unit 150, a magnetic flux calculating unit 160, and a power estimating unit 170. The measuring unit 110 can be used to measure the three-phase voltage V 3 _ψ and the three-phase current I ₃ 。 . The rotational speed estimating unit 120 is coupled to the measuring unit 110, and can respectively estimate the magnetic field rotational speed WS of the motor IM (ie, the rotational magnetic field rotational speed generated by the stator) and the rotor rotational speed WR according to the three-phase current I ₃ 。. In an embodiment, the speed estimation unit 120 may introduce a digital phase locked loop (DPLL) theory to estimate the magnetic field speed WS and the rotor speed WR after performing signal processing using a wavelet package theory. However, the embodiments of the present invention are not limited thereto.

The converting unit 130 is coupled to the measuring unit 110 for converting the three-phase power source (ie, the three-phase voltage V 3 _ψ and the three-phase current I 3 _ψ ) into a two-phase power source (including the two-phase voltage V 2 _ψ and the two-phase current I 2 _ψ ). In an embodiment, the conversion unit 130 may perform a Clark transform on the three-phase voltage V 3 _ψ and the three-phase current I ₃ , to convert the three-phase voltage V 3 _ψ and the three-phase current I 3 _为 to α and The form represented by the component on the β axis. In other words, three-phase voltage _V 3ψ (i.e., phase voltages V1, V2 and the V3) can be converted into two-phase voltages _V 2ψ through operations such as the following formula (1). The two-phase voltage V 2 _ψ includes phase voltages VA and VB, which are components of the three-phase voltage V 3 _ψ on the α and β axes, respectively.

Where v _α and v _β are the values of the phase voltages VA and VB, respectively, v _a , v _b and v _c are the values of the phase voltages V1 , V2 and V3 , respectively, and T _Clarke is the Clark conversion matrix.

On the other hand, three-phase current _I 3ψ (i.e., the phase currents I1, I2 and I3) also through the calculation formula (2) is converted to two-phase currents _I 2ψ. The two-phase current I 2 _ψ includes phase currents IA and IB, which are components of the three-phase current I 3 _ψ on the α and β axes, respectively.

Where i _α and i _β are the values of the phase currents IA and IB, respectively, and i _a , i _b and i _c are the values of the phase currents I1, I2 and I3, respectively.

In another aspect, the conversion unit 130 can convert the stationary coordinate system to which the three-phase power source (ie, the three-phase voltage V 3 _ψ and the three-phase current I 3 _ψ ) belongs to a two-phase orthogonal stationary coordinate system (for example, to the α and β axes). The upper component represents the three-phase power supply).

The adaptability estimating unit 140 is coupled to the converting unit 130 and the rotational speed estimating unit 120 for adaptively generating the estimated stator resistance ER. In the present embodiment, the adaptability estimating unit 140 may calculate an adjustment value for adjusting the previous estimated stator resistance value to the current estimated stator resistance ER according to the adaptive theory. For example, the adaptability estimating unit 140 can The adjustment value is calculated by, for example, the following equations (3), (4), and (5).

Where ω _s is the value of the magnetic field speed WS, R _s is the true value of the estimated stator resistance ER, R _s is the estimated value of the stator resistance, and V _s is the absolute value of the input voltage calculated from the two-phase voltage, V _s is based on Two-phase current, two-phase magnetic flux, magnetic field rotation speed, and estimated stator resistance value, the estimated value of the absolute value of the input voltage calculated, Δ R _s is the adjustment value, and k _p and k _I are respectively voltage error ratios The voltage error is integrated with the gain constant, s is the integral operator, and λ _α and λ _β are the components of the stator's magnetic flux on the α and β axes, respectively (ie, the flux components FA and FB).

In an embodiment, since the magnetic flux components FA and FB may not be known at the initial estimation of the stator resistance by the adaptive estimation unit 140, the initial values of the magnetic flux components FA and FB may be designed by the designer according to the design requirements. It is decided, but the embodiments of the invention are not limited thereto.

The voltage calculation unit 150 is coupled to the conversion unit 130 and the adaptive estimation unit 140 for calculating the two-phase induced voltage according to the two-phase power sources (ie, the phase voltages VA and VB and the phase currents IA and IB) and the estimated stator resistance ER. The two-phase induced voltage includes induced voltages EA and EB. The induced voltage EA is the component of the induced voltage on the rotor on the α-axis, and the induced voltage EB is the component of the induced voltage on the rotor on the β-axis. detailed In other words, after obtaining the phase voltages VA and VB and the phase currents IA and IB, the voltage calculation unit 150 can obtain the induced voltages EA and EB by the following equations (6) and (7), respectively.

e _α = v _a R _s i _a (6)

e _β = v _β - R _s i _β (7) where e _α is the value of the induced voltage EA and e _β is the value of the induced voltage EB.

The magnetic flux calculation unit 160 is coupled to the voltage calculation unit 150 and the adaptive estimation unit 140 for adaptively calculating the two-phase magnetic flux of the stator according to the two-phase induced voltage. The two-phase magnetic flux includes magnetic flux components FA and FB.

In an embodiment, the magnetic flux calculation unit 160 may calculate the values of the magnetic flux components FA and FB, respectively, according to the following equations (8) and (9).

ʃ{ Lp [ e _α,i ]-( λ _{α,i -1} -| λ _{s,i -1} |cos θ _s ). K _p }. Dt = λ _α,i (8)

ʃ{ Lp [ e _β,i ]-( λ _{β,i -1} -| λ _{s,i -1} |sin θ _s ). K _p }. Dt = λ _β,i (9)

Where e _α,i and e _β,i are the induced voltages EA and EB at time _i , respectively, λ _α,i and λ _β,i are the magnetic flux components FA and FB at time _i , respectively, λ _{α, i -1} and λ _{β, i -1} are the magnetic flux components FA and FB at time point (i-1), respectively, K _p is a gain constant, and Lp [ ̇ ] is a low-pass filter function. and, , θ _s =tan ^-1 (- Lp [ e _α,i ]/ Lp [ e _β,i ]).

After obtaining λ _α,i and λ _β,i , the magnetic flux calculation unit 160 can perform polar coordinate conversion to obtain the magnetic flux size value ( λ _s,i ) and the magnetic flux phase at the ith time point ( =tan ^-1 ( λ _β,i / λ _α,i )). At this time, if the values of the estimated magnetic flux components FA and FB (i.e., λ _{α, i} and λ _{β, i} ) are correct, θ _s will be equal to θ _s . Therefore, the values multiplied by the gain constant ( K _p ) in equations (8) and (9) will be equal to zero. From another point of view, the value multiplied by the gain constant ( K _p ) in the equations (8) and (9) can be regarded as estimating the magnetic flux components FA and FB (ie, λ _{α, i} and λ _{β, i} The voltage error compensation signal at the time. That is, when the estimation results of the magnetic flux components FA and FB at the time point i-1 are inaccurate, the equivalent value is multiplied by the gain constant at the next time point, thereby increasing the magnetic flux component FA at the time point i. And the estimated accuracy of FB.

In addition, the flux calculation unit 160 may further transmit the flux components FA and FB to the adaptive estimation unit 140 to allow the adaptive estimation unit 140 to generate another estimated stator resistance ER at the next point in time.

The power estimation unit 170 is coupled to the rotation speed estimating unit 120 and the magnetic flux calculation unit 160 for estimating the output of the motor IM according to the two-phase magnetic flux (ie, the magnetic flux components FA and FB), the rotor rotational speed WR, and the plurality of parameters of the motor IM. power. The plurality of parameters include, for example, a pole of the motor IM, an iron loss, and the like, but are not limited thereto.

In detail, the power estimating unit 170 may first calculate the electromagnetic torque of the motor IM by the following equation (10).

Where T _e is the electromagnetic torque and pl is the number of poles of the motor IM. Next, the power estimating unit 170 can calculate the electromagnetic power of the motor IM by the following equation (11).

P _G = T _e . ω _r (11) where PG is the electromagnetic power of the motor IM and ω _r is the rotor speed of the motor IM. Thereafter, the power estimating unit 170 can calculate the output power of the motor IM by the following equation (12).

P _out = P _G - P _iron ( V _αβ , ω _s ) (12) where P _iron is the iron loss of the motor IM, which is V _αβ (which is the motor two-phase power supply voltage) and ω _s (which is the magnetic field speed) function. In general, in the case where the voltage and the rotational speed are known, the iron loss ( P _iron ) corresponding to the current voltage and the rotational speed can be known by means of a look-up table.

In other embodiments, the voltage calculation unit 150 can calculate the input power supplied by the power supply AC to the motor IM according to the two-phase power source (ie, the phase voltages VA, VB and the phase currents IA, IB). And, the voltage calculation unit 150 can transmit the input power to the power estimation unit 170, and the power estimation unit 170 can calculate the output efficiency of the motor IM according to the following formula (13).

η = P _out /P _in (13) where P _in is the input power supplied by the power supply AC to the motor IM, which can be calculated according to the three-phase power source (ie, the three-phase voltage V 3 _ψ and the three-phase current I 3 _ψ ) .

In this way, when the user wants to measure various operating parameters (such as output efficiency) of the motor IM, the user only needs to connect the motor power estimating device 100 to the power supply line of the motor IM without first having to the motor IM. Perform actions such as stopping or disassembling. Therefore, the user can control the operation of the motor IM more immediately and conveniently. Moreover, since the estimated stator resistance ER is generated according to the adaptive theory, a more accurate estimation result can be achieved. In addition, due to the two-phase flux (ie, flux components FA and FB) In the calculation process, the concept of error compensation is introduced, so the estimation accuracy of the two-phase flux can also be improved.

In other embodiments, all of the units in motor power estimation device 100 may be implemented in software, hardware, or a combination thereof.

2 is a schematic diagram of a magnetic flux calculation unit according to the embodiment of FIG. 1. In the present embodiment, the arithmetic operations performed by the magnetic flux calculation unit 160 in the equations (8) and (9) can be performed through the respective operation blocks in FIG.

First, after receiving the e _α,i transmitted from the voltage calculation unit 150, the magnetic flux calculation unit 160 may low-pass filter e _α,i via the block 210_1 to generate Lp [ e _α,i ]. In block 210_1, ω _c is the cutoff frequency used for low pass filtering, and s is the complex variable in the Laplace transform. Having ordinary knowledge in the art should be understood, the e _{α, i} s in the field and _{ω c / (s + ω c} ) i.e. equivalent to multiplication of e _{α, i} low-pass filtering operation. Similarly, the magnetic flux calculation unit 160 can also perform the same operation on e _{β, i} via the block 210_2 to generate Lp [ e _{β, i} ].

Next, the flux calculation unit 160 may calculate θ _s via the block 220 and further calculate the values of cos θ _s and sin θ _s . And, the magnetic flux calculation unit 160 can calculate Lp [ e _α,i ]-( λ _{α,i -1} -| λ _{s,i -1} |cos θ _s ) via the blocks 225_1 and 225_2, respectively. K _p and Lp [ e _β,i ]-( λ _{β,i -1} -| λ _{s,i -1} |sin θ _s ). The value of K _p . Where ( λ _{α,i -1} -| λ _{s,i -1} |cos θ _s ). K _p and ( λ _{β,i -1} -| λ _{s,i -1} |sin θ _s ). K _p can be obtained by multiplying K _p by the previous time point in blocks 230_1 and 230_2 ( λ _{α,i -1} -| λ _{s,i -1} |cos θ _s ) and ( λ _{β,i - 1} -| λ _{s,i -1} |sin θ _s ).

Thereafter, the magnetic flux calculation unit 160 may calculate ʃ{ Lp [ e _α,i ]-( λ _{α,i -1} -| λ _{s,i -1} |cos θ _s ) via the blocks 240_1 and 240_2, respectively. K _p }. Dt and ʃ{ Lp [ e _β,i ]-( λ _{β,i -1} -| λ _{s,i -1} |sin θ _s ). K _p }. Dt , which in turn produces λ _α,i and λ _β,i . Next, the flux calculation unit 160 may perform polar coordinate conversion of λ _α,i and λ _β,i via the block 250 to generate λ _{s,i −1} and θ _s . After obtaining λ _{s,i -1} , the magnetic flux calculation unit 160 may multiply it by -cos θ _s and -sin θ _s , respectively, and further λ _α,i in the blocks 235_1 and 235_2 with the previous time point. And λ _β,i are added to generate ( λ _{α,i -1} -| λ _{s,i -1} |cos θ _s ) and ( λ _{β,i -1} -| λ _{s,i -1} |sin θ _s ). After generating ( λ _{α,i -1} -| λ _{s,i -1} |cos θ _s ) and ( λ _{β,i -1} -| λ _{s,i -1} |sin θ _s ), the magnetic flux calculation unit 160 the same can be respectively multiplied with K _p blocks 230_1 and 230_2 in order to generate a new subsequent _{λ α, I} and λ _{β, i} of recursive operations.

3 is a flow chart of a motor power estimation method according to an embodiment of the invention. In the present embodiment, the method can be performed by the motor power estimating apparatus 100 of FIG. 1, and the steps of the motor power estimating method provided by the present invention are explained below with elements in the motor power estimating apparatus 100. In step S310, the measuring unit 110 measures the three-phase power source (i.e., the three-phase voltage V 3 _ψ and the three-phase current I 3 _施加 ) applied to the motor IM. In step S320, the rotational speed estimating unit 120 estimates the magnetic field rotational speed WS of the motor IM and the rotor rotational speed WR based on the three-phase current I 3 _中 in the three-phase power source. In step S330, the conversion unit 130 converts the three-phase power source into a two-phase power source (ie, the two-phase voltage V 2 _ψ and the two-phase current I 2 _ψ ). In step S340, the adaptive estimation unit 140 adaptively generates the estimated stator resistance ER. In step S350, the voltage calculation unit 150 calculates the two-phase induced voltage (ie, the induced voltages EA and EB) based on the two-phase power source and the estimated stator resistance ER. In step S360, the magnetic flux calculation unit 160 calculates the two-phase magnetic flux (i.e., the magnetic flux components FA and FB) of the motor IM in accordance with the two-phase induced voltage adaptability. In step S370, the power estimating unit 170 estimates the output power of the motor IM based on the two-phase magnetic flux, the rotor rotational speed WR, and a plurality of parameters of the motor IM.

4 is a schematic diagram of a motor power estimating device according to another embodiment of the present invention. In this embodiment, the motor power estimating device 100 may further include a storage unit 180 for storing other basic data associated with the motor IM and measurement data. For example, the basic information is, for example, information on the motor production company, information on the location of the motor, or the motor number. The measurement data is, for example, a motor name plate, a rated speed, a rated voltage, and a rated power.

In addition, the measuring unit 110 may include a power measuring unit 110_1, an image monitoring unit 110_2, a temperature sensing unit 110_3, and a vibration sensing unit 110_4. The power measuring unit 110_1 can be used to measure a three-phase power source. The image monitoring unit 110_2 can be used to image the motor IM to facilitate the user to view the operation of the motor IM. The temperature sensing unit 110_3 can be used to sense the temperature of the motor IM during operation. The vibration sensing unit 110_4 can be used to sense the vibration condition of the motor IM during operation, so that the user can determine whether the vibration of the motor IM will affect its performance.

Moreover, the items stored in the storage unit 180 can be accessed by the monitoring system 410 to facilitate the user's control of the state of the motor IM. Monitoring system 410 is, for example, a system that can simultaneously monitor multiple motor states, and monitoring system 410 can store data for all of the motors it monitors. For example, the monitoring system 410 can store the whole plant motor data, the motor data to be tested, the measurement data, and the efficiency analysis data. The whole plant motor information includes, for example, information on the production company of the motor to be tested, information on the location of the plant, or number. The motor data to be tested includes, for example, a nameplate, a rated speed, a rated voltage, and a rated power of the motor to be tested. The measurement data includes, for example, a three-phase power supply, and a transport The data obtained by the measurement unit 110, such as temperature, vibration recording, and image recording, can be measured. The efficiency analysis data includes, for example, electromagnetic torque, magnetic field rotational speed, rotor rotational speed, output power, and output efficiency, which can be estimated by the motor power estimating device 100. It should be understood by those of ordinary skill in the art that the above-described various materials are merely illustrative and are not intended to limit the embodiments of the invention.

In summary, the motor power estimating device and the method thereof provided by the embodiments of the present invention can measure various parameters of the motor only when the user only needs to connect the motor power estimating device 100 to the power supply line of the motor. In other words, when the user wants to measure the parameters of the motor, the user does not need to stop or disassemble the motor to perform the measurement. Therefore, the user can control the operation of the motor more instantaneously and conveniently. Moreover, since the estimated stator resistance is generated based on the adaptive theory, a more accurate estimation result can be achieved. In addition, since the concept of error compensation is introduced in the calculation of the two-phase magnetic flux, the estimation accuracy of the two-phase magnetic flux can also be improved.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

100‧‧‧Motor power estimation device

110‧‧‧Measurement unit

120‧‧‧Speed Estimation Unit

130‧‧‧Transfer unit

140‧‧‧Adaptive Estimation Unit

150‧‧‧Voltage calculation unit

160‧‧‧Magnetic calculation unit

170‧‧‧Power Estimation Unit

210_1, 210_2, 220, 225_1, 225_2, 230_1, 230_2, 235_1, 235_2, 240_1, 240_2, 250‧‧‧ blocks

AC‧‧‧Power supply

EA, EB‧‧‧ induced voltage

ER‧‧‧ Estimated stator resistance

FA, FB‧‧‧ flux component

IM‧‧‧ motor

V1~V3, VA, VB‧‧‧ phase voltage

V _{3ψ ‧‧‧Three-} phase voltage

V _2ψ ‧‧‧ two-phase voltage

I1~I3, IA, IB‧‧‧ phase current

I _{3ψ ‧‧‧Three-} phase current

I _2ψ ‧‧‧ two-phase current

WS‧‧‧Magnetic speed

WR‧‧‧Rotor speed

S310~S370‧‧‧Steps

1 is a schematic diagram of estimating motor power using a motor power estimating device, according to an embodiment of the invention.

2 is a schematic diagram of a magnetic flux calculation unit according to the embodiment of FIG. Figure.

3 is a flow chart of a motor power estimation method according to an embodiment of the invention.

4 is a schematic diagram of a motor power estimating device according to another embodiment of the present invention.

S310~S370‧‧‧Steps

Claims (4)

A motor power estimating device comprises: a measuring unit for measuring a three-phase power source applied to a motor; and a speed estimating unit for utilizing wavelet packet theory and digital phase locking according to a three-phase current in the three-phase power source The loop theory estimates a magnetic field speed of the motor and a rotor speed; a conversion unit converts the three-phase power source into a two-phase power source, wherein the three-phase power source includes a three-phase voltage and a three-phase current, and the two-phase power source Include a two-phase voltage and a two-phase current, and the conversion unit converts the three-phase voltage into the two-phase voltage through a Clark conversion, and converts the three-phase current into the two-phase current; an adaptive estimation unit, Adaptively generating an estimated stator resistance, wherein the adaptive estimating unit determines an adjustment value for adjusting a previous stator resistance value to the estimated stator resistance according to an adaptive theory, and adding the previous stator resistance value The adjustment value is used to obtain the estimated stator resistance; a voltage calculation unit calculates a two-phase induced voltage according to the two-phase power source and the estimated stator resistance, In the voltage calculating unit based _{e α = v α - R s} i α and _{e β = v β - R s} i β obtained by the two-phase induced voltage, _wherein, e α _e β and that two phase voltages, R _s For estimating the stator resistance, v _α and v _{β are} the two-phase voltages, i _α and i _{β are} the two-phase currents; and a magnetic flux calculation unit calculates a two-phase magnetic of the motor according to the two-phase induced voltage adaptability. Passing, wherein the flux calculation unit is based on ʃ{ Lp [ e _{α, i} ]-(λ _{α, i -1} -|λ _{s , i -1} |cos θ _s ). K _p }. Dt = λ _{α, i} and ʃ { Lp [ e _{β, i} ] - (λ _{β, i -1} - | λ _{s , i -1} | sin θ _s ). K _p }. Dt = λ _{β, i} calculates the two-phase flux, where e _{α, i} and e _{β, i} are the two-phase induced voltages at time i, λ _{α, i} and λ _{β, i} are at time points The two-phase magnetic flux at _i , λ _{α, i -1} and λ _{β, i -1} is the two-phase magnetic flux at time point (i-1), K _p is a gain constant, Lp [●] Is a low pass filter function, , θ _s =tan ^-1 (- Lp [ e _{α, i} ]/ Lp [ e _{β, i} ]); and a power estimation unit, based on the two-phase flux, the rotor speed, and a plurality of parameter estimates of the motor An output power of the motor, wherein the parameters include a pole number of the motor and an iron loss, and the power estimating unit calculates an electromagnetic of the motor according to the pole number, the two-phase flux, and the two-phase current Torque, and the power estimating unit calculates an electromagnetic power of the motor according to the electromagnetic torque and the rotor rotational speed, and calculates the output power of the motor according to the electromagnetic power and the iron loss; wherein the adaptive estimating unit The estimated stator resistance is generated based on the two-phase power source, the two-phase flux, and the magnetic field rotational speed. The motor power estimating device according to claim 1, wherein the voltage calculating unit calculates an input power input to the motor according to the three-phase power source, and the power estimating unit calculates the power according to the input power and the output power. An output efficiency of the motor. A motor power estimating method is suitable for a motor power estimating device, the method comprising the steps of: measuring a three-phase power applied to a motor; and using a wavelet packet theory according to a three-phase current in the three-phase power source The digital phase-locked loop theory estimates a magnetic field speed of the motor and a rotor speed; and converts the three-phase power source into a two-phase power source, wherein the three-phase power source includes a three-phase voltage and a three-phase current, and the two-phase power source includes a two-phase voltage and a two-phase current, and converting the three-phase power supply to the two-phase power supply comprises converting the three-phase voltage into the two-phase voltage through a Clark conversion, and converting the three-phase current into the two Phase current; adaptively generating an estimated stator resistance, comprising determining an adjustment value for adjusting a previous stator resistance value to the estimated stator resistance according to an adaptive theory, and adding the previous stator resistance value Adjusting the value to obtain the estimated stator resistance; calculating a two-phase induced voltage according to the two-phase power source and the estimated stator resistance, including according to e _α = v _α - R _s i _α and e _β = v _β - R _s i _β obtain the two-phase induced voltage, wherein e _α and e _{β are} the two-phase voltage, R _{s is} the estimated stator resistance, and v _α and v _{β are} the two The phase voltages, i _α and i _{β are} the two-phase currents; the two-phase magnetic flux of the motor is calculated according to the two-phase induced voltage adaptability, including according to ʃ{ Lp [ e _{α, i} ]-(λ _{α, i -1} -|λ _{s , i -1} |cos θ _s ). K _p }. Dt = λ _{α, i} and ʃ { Lp [ e _{β, i} ] - (λ _{β, i -1} - | λ _{s , i -1} | sin θ _s ). K _p }. Dt = λ _{β, i} calculates the two-phase magnetic flux, where e _{α, i} and e _{β, i} are the two-phase induced voltages at time i, λ _{α, i} and λ _{β, i} are at time points The two-phase magnetic flux at _i , λ _{α, i -1} and λ _{β, i -1} is the two-phase magnetic flux at time point (i-1), K _p is a gain constant, Lp [●] Is a low pass filter function, , θ _s =tan ^-1 (- Lp [ e _{α, i} ]/ Lp [ e _{β, i} ]); and estimating an output of the motor based on the two-phase flux, the rotor speed, and a plurality of parameters of the motor Power, wherein the parameters include a number of poles of the motor and an iron loss, and estimating the output power of the motor according to the two-phase flux, the rotor speed, and the plurality of parameters of the motor, including the number of poles Calculating an electromagnetic torque of the motor by the two-phase magnetic flux and the two-phase current, and calculating an electromagnetic power of the motor according to the electromagnetic torque and the rotor rotational speed, and calculating according to the electromagnetic power and the iron loss The output power of the motor, wherein the estimated stator resistance is generated based on the two-phase power source, the two-phase flux, and the magnetic field speed. The method of claim 3, wherein after the step of estimating the output power of the motor, the method further comprises: calculating an input power input to the motor according to the three-phase power; and according to the input power and the output The power calculates an output efficiency of the motor.