JP2001119978A - Method and device for controlling brushless dc motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control a buried magnet motor with the maximum efficiency, without having to use rotary position sensors. SOLUTION: A rotary position θ and a rotary speed ω of the rotor of a brushless DC motor 12 are detected by a rotor rotation position detection port 13 and are supplied to a drive waveform generation part 14. Also, a torque T calculated by a torque calculation part 15 with load information as input is supplied to a current phase determination part 16 for performing the operation of an approximation expression for indicating a current phase β, to determine the current phase β, before supplying to the drive waveform generation part 14. Furthermore, a speed command value ω* being outputted from a speed control part 17 and an operation current I at an inverter 11 are also supplied to the drive waveform generation part 14. The drive waveform generation part 14 generates a PWM command, based on the input signals and supplies it to the inverter 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for controlling a brushless DC motor, and more particularly, to a method for operating a brushless DC motor with maximum efficiency without using a position sensor such as an encoder and the like. Related to the device.

[0002]

2. Description of the Related Art It has been known that, in controlling a brushless DC motor, it is essential to detect a rotational position of a rotor. As a method for detecting the rotational position of the rotor, a method using a rotary encoder, a method using a Hall element,
There is known a method of detecting a zero cross of an induced voltage while employing an energization waveform.

[0003] Of these methods, the method using a rotary encoder causes a significant increase in the cost of the entire apparatus. Therefore, there is a strong demand for cost reduction such as home electric appliances using a brushless DC motor as a power source. Cannot be applied. Further, it is extremely difficult or impossible to incorporate a method using a Hall element or the like into a device that generates a severe environment such as high temperature and high pressure such as a compressor.

[0006] Unlike the above, a method of employing a 120 ° conduction waveform and detecting a zero crossing of an induced voltage can be used even when it is difficult to apply a method using a rotary encoder or a method using a Hall element. Can be easily applied.

In controlling a brushless DC motor based on the rotational position detected as described above, the following control method has conventionally been adopted.

In controlling a brushless DC motor (hereinafter, abbreviated as a surface magnet motor) having a permanent magnet mounted on the surface of a rotor, reluctance torque is not generated, so that the d-axis current id is set to 0. The method has been adopted.

Further, the brushless DC motor (hereinafter, abbreviated as the embedded magnet motor or IPM,) formed by mounting a permanent magnet inside the rotor in controlling the Since the produce reluctance torque, i _d = A control method for increasing the current phase more than 0 is adopted.

[0008]

However, when controlling the embedded magnet motor by detecting the rotational position without using a sensor, 120 ° energization is generally employed and the zero cross of the induced voltage is detected. As a result, the desired current phase β cannot be obtained.

Further, as a conventional control method, a rotational position is detected by using a third harmonic, and the maximum efficiency of the embedded magnet motor is controlled while monitoring the supplied power.
There has been proposed a method for controlling the maximum efficiency of the interior magnet motor while monitoring the amplitude of the second harmonic.

However, when the former method is adopted,
In the environment where the load fluctuates, maximum efficiency control cannot be performed, and when the latter method is adopted, accurate phase control cannot be performed due to the inaccuracy of the third harmonic,
Consequently, maximum efficiency control cannot be achieved.

Further, in any of the above methods,
The detection of the rotational position is discrete and precise control cannot be performed, and the detected rotational position is likely to deviate from the actual rotational position depending on the operation state of the motor.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has a brushless D which can control the maximum efficiency of an embedded magnet motor without using a rotational position sensor.
It is an object of the present invention to provide a C motor control method and a device thereof.

[0013]

A brushless D according to claim 1
The C motor control method is based on detecting a rotational position of a rotor without using a rotational position sensor and controlling a brushless DC motor having a permanent magnet mounted inside the rotor. This is a method of controlling the phase to make the current phase the target current phase.

The brushless DC motor control method according to a second aspect of the present invention is a method in which a current phase capable of realizing the maximum efficiency obtained by measurement in advance for each operating state of the brushless DC motor is used as the target current phase.

According to a third aspect of the present invention, there is provided a brushless DC motor control method, wherein the target current phase is based on an equation which approximates a current phase capable of realizing maximum efficiency, which is obtained in advance for each operating state of the brushless DC motor by measurement. This is a method that employs the calculated value.

According to a fourth aspect of the present invention, a desired constant value is adopted as the target current phase regardless of the operating state of the brushless DC motor.

According to a fifth aspect of the present invention, there is provided a brushless DC motor control method, comprising:
The rotational position of the rotor is detected based on the average value of the terminal voltages of the stator windings, and the detected position signal is transferred to a brushless DC.
This is a method in which the current phase is corrected based on the operating condition of the motor, and the current phase is controlled based on the corrected position signal.

According to a sixth aspect of the present invention, there is provided a brushless DC motor control method, wherein a predetermined operation is performed using a voltage applied to a stator winding, a motor current, and a device constant of the brushless DC motor to calculate a rotational position of the rotor. This is a method of controlling the current phase based on the calculated rotational position.

According to a seventh aspect of the present invention, there is provided a method for controlling a brushless DC motor, comprising: calculating a rotational position of a rotor from an inductance obtained from a harmonic current generated by a voltage type inverter and saliency of the rotor; This is a method for controlling the current phase based on the current phase.

According to another aspect of the present invention, there is provided a brushless DC motor control device for controlling a brushless DC motor having a permanent magnet mounted inside the rotor by detecting the rotational position of the rotor without using a rotational position sensor. The present invention further includes current phase control means for controlling the current phase to achieve the maximum efficiency control and setting the current phase to the target current phase.

According to a ninth aspect of the present invention, the current phase control means employs, as the target current phase, a current phase capable of realizing the maximum efficiency obtained by measurement in advance for each operation state of the brushless DC motor. It is what adopts what is done.

According to a tenth aspect of the present invention, as the current phase control means, a target current phase, which can be obtained at the maximum efficiency and is obtained in advance for each operating state of the brushless DC motor, is stored as a map. It is something that adopts.

In the brushless DC motor control device according to the present invention, the current phase control means is based on a formula which approximates a current phase which can achieve the maximum efficiency, which is obtained in advance for each operation state of the brushless DC motor by measurement. In this case, the calculated value is adopted as the target current phase.

According to a twelfth aspect of the present invention, as the brushless DC motor control device, a current phase control means adopting a desired constant value as a target current phase irrespective of the operation state of the brushless DC motor is adopted.

A brushless DC motor control device according to a thirteenth aspect detects a rotational position of a rotor based on a voltage at a neutral point of a stator of the brushless DC motor and an average value of terminal voltages of a stator winding. A rotation position detection unit; and a correction unit that corrects the detected position signal based on an operation condition of the brushless DC motor. The current phase control unit controls a current phase based on the corrected position signal. It is something that adopts.

According to a fourteenth aspect of the present invention, there is provided a brushless DC motor control device which performs a predetermined operation using a voltage applied to a stator winding, a motor current, and a device constant of a brushless DC motor to calculate a rotational position of a rotor. The apparatus further includes a position calculating means, and employs a means for controlling a current phase based on the calculated rotational position as the current phase control means.

A brushless DC motor control device according to a fifteenth aspect further includes a rotational position calculating means for calculating a rotor rotational position from an inductance obtained from a harmonic current generated by the voltage type inverter and a saliency of the rotor. As the current phase control means, means for controlling a current phase based on the calculated rotational position is employed.

A brushless DC motor control method according to a sixteenth aspect of the present invention provides a method for controlling a motor voltage, a motor current and a brushless DC motor.
Estimates the rotational position of the rotor from the magnetic flux information using the motor constants, controls the inverter using this estimation result, and controls the inverter based on the magnetic flux in controlling the brushless DC motor with saliency. How to Here and in the following corresponding parts, “magnetic flux” is used as a concept representing “detected magnetic flux”. That is, it is not a stator linkage flux but a value obtained by further processing this (dimension is magnetic flux).

A brushless DC motor control method according to a seventeenth aspect is a method of controlling an inverter so as to avoid a region where the magnetic flux is substantially zero.

According to the brushless DC motor control method of the eighteenth aspect, it is detected that the magnetic flux is substantially zero, and the magnetic flux is substantially zero.
In this method, the phase advance control is performed in response to the detection that

According to the brushless DC motor control method of the nineteenth aspect, it is detected that the magnetic flux is substantially zero, and the magnetic flux is substantially zero.
In this method, the current drooping control is performed in response to the detection that

A brushless DC motor control method according to a twentieth aspect is characterized in that the motor voltage, the motor current, and the brushless DC
Estimating the rotational position of the rotor using the equipment constants of the motor,
In controlling the inverter using this estimation result and controlling the brushless DC motor, this is a method of controlling the current phase so that the current phase becomes a target current phase.

A brushless DC motor control method according to a twenty-first aspect is a method of estimating a rotational position of a rotor using a rotational coordinate motor model.

A brushless DC motor control method according to claim 22 is a method for controlling a motor voltage, a motor current, and a brushless DC motor.
Estimating the rotational position of the rotor using the equipment constants of the motor,
In controlling the inverter using this estimation result and controlling the brushless DC motor, this is a method of setting the gain of the loop transfer function relating to the rotation position estimation to a value that satisfies the stability condition in the target phase and torque range.

According to the brushless DC motor control method of the twenty-third aspect, the transfer function G is represented by the following equation 1, and the gain K _θ of the transfer function G is set so that all real roots of s of the denominator polynomial of G / (1 + G) become negative. And F (s).

A brushless DC motor control method according to a twenty-fourth aspect is a method of estimating a rotational position of a rotor using a fixed coordinate motor model.

A brushless DC motor control method according to a twenty-fifth aspect is a method for identifying motor equipment constants before starting operation.

In a brushless DC motor control method according to a twenty-sixth aspect, the target current phase is advanced to the maximum efficiency phase or the maximum torque phase of the motor.

A brushless DC motor control method according to claim 27 is a method of driving a compressor by a brushless DC motor.

According to a twenty-eighth aspect of the present invention, there is provided a brushless DC motor control device comprising: a motor voltage, a motor current, and a brushless DC motor;
It estimates the rotational position of the rotor from the magnetic flux information using the equipment constants of the motor, controls the inverter using this estimation result, and controls the brushless DC motor having saliency, based on the magnetic flux. And an inverter control means for controlling the power supply.

A brushless DC motor control device according to claim 29 employs, as the inverter control means, one that controls an inverter so as to avoid a region where the magnetic flux is substantially zero.

A brushless DC motor control device according to claim 30 is characterized in that the inverter control means detects that the magnetic flux is substantially zero, and responds to the detection that the magnetic flux is substantially zero to perform the phase advance control. In this case, a method is employed in which a region where the magnetic flux is substantially zero is avoided.

According to a thirty-first aspect of the present invention, the inverter control means detects that the magnetic flux is substantially zero, and performs the current droop control in response to the detection that the magnetic flux is substantially zero. In this case, a method is employed in which a region where the magnetic flux is substantially zero is avoided.

According to a thirty-second aspect of the present invention, there is provided a brushless DC motor control apparatus comprising:
Estimating the rotational position of the rotor using the equipment constants of the motor,
The inverter is controlled by using the estimation result to control the brushless DC motor, and includes inverter control means for controlling the current phase so as to attain the target current phase.

A brushless DC motor control device according to a thirty-third aspect employs, as the inverter control means, one that estimates the rotational position of a rotor using a rotary coordinate motor model.

A brushless DC motor control device according to a thirty-fourth aspect includes a motor voltage, a motor current, and a brushless DC motor.
Estimating the rotational position of the rotor using the equipment constants of the motor,
The inverter is controlled by using the estimation result, and the brushless DC motor is controlled. The rotation position is estimated using the transfer function, and the gain of the loop transfer function related to the rotation position estimation is set to the target phase and the torque range. And an inverter control means for setting a value satisfying the stability condition.

A brushless DC motor controller according to claim 35 employs a transfer function G represented by the following equation (1) as the inverter control means, and calculates a s of a denominator polynomial of G / (1 + G).
In this case, the gain _Kθ and F (s) of the transfer function G are set so that the real roots are all negative.

A brushless DC motor control device according to a thirty-sixth aspect employs, as the inverter control means, one that estimates a rotational position of a rotor using a fixed coordinate motor model.

A brushless DC motor control device according to a thirty-seventh aspect employs, as the inverter control means, one that identifies a motor device constant before starting operation.

A brushless DC motor control device according to claim 38 employs, as the inverter control means, one that advances a target current phase to a phase higher than a maximum efficiency phase or a maximum torque phase of the motor.

A brushless DC motor control apparatus according to claim 39 employs a brushless DC motor that drives a compressor.

[0052]

According to the brushless DC motor control method of the first aspect, a brushless DC motor having a permanent magnet mounted inside the rotor is controlled by detecting the rotational position of the rotor without using a rotational position sensor. In this case, the current phase is controlled to achieve the maximum efficiency control and the current phase is set to the target current phase, so that the rotational position of the rotor can be detected without using a position sensor, and the maximum efficiency control is performed. Can be achieved.

According to the brushless DC motor control method of the present invention, a current phase that can be obtained by measuring in advance for each operating state of the brushless DC motor and can achieve the maximum efficiency is used as the target current phase. Therefore, maximum efficiency control can be achieved regardless of the operation state.

According to the brushless DC motor control method of the present invention, the target current phase is obtained by measuring in advance for each operation state of the brushless DC motor, and approximating a current phase capable of realizing the maximum efficiency. Since a value calculated based on this is adopted, it is not necessary to measure the target current phase, the processing can be simplified, and the maximum efficiency control can be achieved.

According to the brushless DC motor control method of the present invention, a desired constant value is adopted as the target current phase irrespective of the operating state of the brushless DC motor, so that the processing is further simplified. And a certain degree of maximum efficiency control can be achieved.

According to the brushless DC motor control method of the fifth aspect, the rotational position of the rotor is determined based on the voltage at the neutral point of the stator of the brushless DC motor and the average value of the terminal voltage of the stator winding. Since the detected position signal is corrected based on the operating conditions of the brushless DC motor and the current phase is controlled based on the corrected position signal, the voltage at the neutral point of the stator of the brushless DC motor is controlled. When,
The present invention can be applied to the case where the rotational position of the rotor is detected based on the average value of the terminal voltage of the stator winding, and the maximum efficiency control can be achieved.

According to the brushless DC motor control method of the sixth aspect, the predetermined position is calculated using the applied voltage of the stator winding, the motor current, and the device constant of the brushless DC motor to calculate the rotational position of the rotor. Then, since the current phase is controlled based on the calculated rotational position, a predetermined calculation is performed using the applied voltage of the stator winding, the motor current, and the device constant of the brushless DC motor to perform the rotation of the rotor. This can be applied to the case where the position is calculated, and the maximum efficiency control can be achieved.

According to the brushless DC motor control method of the present invention, the rotation position of the rotor is calculated from the inductance obtained from the harmonic current generated by the voltage type inverter and the saliency of the rotor, and the calculated rotation is calculated. Since the current phase is controlled based on the position, it can be applied to the case where the rotational position of the rotor is calculated from the inductance obtained from the harmonic current generated by the voltage type inverter and the saliency of the rotor, Maximum efficiency control can be achieved.

According to the brushless DC motor control device of the present invention, a brushless DC motor having a permanent magnet mounted inside the rotor is controlled by detecting the rotational position of the rotor without using a rotational position sensor. In this case, the current phase can be set to the target current phase by controlling the current phase to achieve the maximum efficiency control by the current phase control means.

Therefore, the rotational position of the rotor can be detected without using a position sensor, and maximum efficiency control can be achieved.

In the brushless DC motor control device according to the ninth aspect, a brushless DC motor may be used as the current phase control means.
Since the current phase that can achieve the maximum efficiency obtained by measurement in advance for each operating state of the C motor is adopted as the target current phase, the maximum efficiency control can be achieved regardless of the operating state. it can.

According to the brushless DC motor control device of the tenth aspect, the current phase control means is obtained by measurement in advance for each operation state of the brushless DC motor.
Since the target current phase that can achieve the maximum efficiency is stored as a map, the target current phase can be easily extracted from the map, and the maximum efficiency control can be achieved regardless of the operation state.

In the brushless DC motor control device according to the eleventh aspect, the current phase control means is obtained by measurement in advance for each operating state of the brushless DC motor.
Since the one that is calculated based on the equation that approximates the current phase that can achieve the maximum efficiency is adopted as the target current phase, there is no need to measure the target current phase, and the processing can be simplified. And maximum efficiency control can be achieved.

According to the brushless DC motor control device of the twelfth aspect, the current phase control means adopts a device that adopts a desired constant value as the target current phase regardless of the operation state of the brushless DC motor. Therefore, the processing can be further simplified, and a certain maximum efficiency control can be achieved.

According to the brushless DC motor control device of the thirteenth aspect, the brushless DC motor is controlled by the rotational position detecting means.
Detecting the rotational position of the rotor based on the voltage at the neutral point of the stator of the C motor and the average value of the terminal voltages of the stator windings;
The position signal detected by the correction means is transferred to the brushless D
The current phase can be corrected based on the operating conditions of the C motor, and the current phase can be controlled by the current phase control means based on the corrected position signal.

Therefore, the present invention can be applied to the case where the rotational position of the rotor is detected based on the voltage at the neutral point of the stator of the brushless DC motor and the average value of the terminal voltages of the stator windings. Efficiency control can be achieved.

According to the brushless DC motor control device of the present invention, the rotation position calculating means performs predetermined calculation using the applied voltage of the stator winding, the motor current, and the device constant of the brushless DC motor to perform rotation. The rotational position of the child is calculated, and the current phase can be controlled by the current phase control means based on the calculated rotational position.

Therefore, the present invention can be applied to the case where a predetermined operation is performed using the applied voltage of the stator winding, the motor current, and the device constant of the brushless DC motor to calculate the rotational position of the rotor. Control can be achieved.

According to the brushless DC motor control device of the present invention, the rotational position calculating means calculates the rotational position of the rotor from the inductance obtained from the harmonic current generated by the voltage type inverter and the saliency of the rotor. ,
The current phase control means can control the current phase based on the calculated rotational position.

Therefore, the present invention can be applied to the case where the rotational position of the rotor is calculated from the inductance obtained from the harmonic current generated by the voltage type inverter and the saliency of the rotor, and the maximum efficiency control can be achieved. it can.

According to the brushless DC motor control method of the sixteenth aspect, the rotational position of the rotor is estimated from the magnetic flux information using the motor voltage, the motor current, and the device constant of the brushless DC motor, and the estimation result is used by using the estimation result. In controlling the inverter and controlling the brushless DC motor having saliency, the inverter is controlled based on the magnetic flux, so that the applicable range can be expanded without being affected by the structure of the motor. The brushless DC motor can be stably controlled by always accurately estimating the rotational position of the child.

According to the brushless DC motor control method of the seventeenth aspect, the inverter is controlled to avoid a region where the magnetic flux is substantially zero, so that step-out due to the inability to estimate the position can be avoided. The same operation as described above can be achieved.

According to the brushless DC motor control method of the eighteenth aspect, it is detected that the magnetic flux is substantially zero, and in response to the detection that the magnetic flux is substantially zero, the phase advance control is performed to reduce the magnetic flux. Because we want to avoid the area that is almost 0,
The same operation as the seventeenth aspect can be achieved.

According to the brushless DC motor control method of the nineteenth aspect, it is detected that the magnetic flux is substantially zero, and in response to the detection that the magnetic flux is substantially zero, the current drooping control is performed to reduce the magnetic flux. Since the region where the value becomes substantially zero is avoided, the same operation as that of the seventeenth aspect can be achieved.

According to the brushless DC motor control method of the twentieth aspect, the rotational position of the rotor is estimated using the motor voltage, the motor current, and the equipment constant of the brushless DC motor, and the inverter is controlled using the estimation result. In controlling the brushless DC motor, the current phase is controlled so that the current phase becomes a target current phase.
The range of application can be expanded without being affected by the structure of the motor, and the rotational position of the rotor can always be accurately estimated to stably control the brushless DC motor.

According to the brushless DC motor control method of the twenty-first aspect, the rotational position of the rotor is estimated using the rotary coordinate motor model. , Current, and angular velocity can be suitably applied to applications with small fluctuations.

According to the brushless DC motor control method of the present invention, the rotational position of the rotor is estimated using the motor voltage, the motor current, and the equipment constant of the brushless DC motor, and the inverter is controlled using the estimation result. In controlling the brushless DC motor, the gain of the loop transfer function for estimating the rotational position is set to a value that satisfies the stability conditions in the target phase and the torque range. Therefore, the rotational position of the rotor is always accurately estimated. Thus, the brushless DC motor can be controlled stably.

According to the brushless DC motor control method of the twenty-third aspect, the transfer function G is expressed by the following equation (1), and G / (1+
Since the gains _Kθ and F (s) of the transfer function G are set such that all real roots of s of the denominator polynomial of G) are negative, the same operation as in claim 22 can be achieved.

According to the brushless DC motor control method of the twenty-fourth aspect, the rotational position of the rotor is estimated using the fixed coordinate motor model. Thus, the rotational position of the rotor can be accurately estimated irrespective of changes in current and angular velocity.

According to the brushless DC motor control method of the twenty-fifth aspect, the motor device constants are identified before the start of operation. The rotation position can be estimated.

According to the brushless DC motor control method of the twenty-sixth aspect, the target current phase is advanced beyond the maximum efficiency phase or the maximum torque phase of the motor. In addition, the operating range of the brushless DC motor can be extended to a high speed side.

According to the brushless DC motor control method of claim 27, since the compressor is driven by the brushless DC motor, in addition to the function of any of claims 16 to 26, the load fluctuation is large and A compressor that needs to operate at high speed can be driven stably.

According to the brushless DC motor control device of the twenty-eighth aspect, the rotational position of the rotor is estimated from the magnetic flux information using the motor voltage, the motor current, and the equipment constant of the brushless DC motor, and the estimation result is used by using the estimation result. In controlling the inverter and controlling the brushless DC motor having saliency, the inverter can be controlled by the inverter control means based on the magnetic flux.

Therefore, the applicable range can be expanded without being influenced by the structure of the motor, and the rotational position of the rotor can always be accurately estimated to stably control the brushless DC motor.

In the brushless DC motor controller according to claim 29, since the inverter is controlled by the inverter control means so as to avoid the region where the magnetic flux becomes substantially zero, the step-out due to the inability to estimate the position can be avoided. In addition, the same operation as the twenty-eighth aspect can be achieved.

According to the brushless DC motor control device of the present invention, the inverter control means detects that the magnetic flux is almost zero, and responds to the detection that the magnetic flux is almost zero. Since the control is performed to avoid the region where the magnetic flux is substantially zero, the same operation as that of claim 29 can be achieved.

In the brushless DC motor controller according to claim 31, the inverter control means detects that the magnetic flux is substantially zero, and responds to the detection that the magnetic flux is substantially zero. Since the control is performed to avoid the region where the magnetic flux is substantially zero, the same operation as that of claim 29 can be achieved.

According to the brushless DC motor control apparatus of claim 32, the rotational position of the rotor is estimated using the motor voltage, the motor current, and the equipment constant of the brushless DC motor, and the inverter is controlled using the estimation result. In controlling the brushless DC motor, the current phase can be controlled by the inverter control means so that the current phase becomes a target current phase.

Therefore, the applicable range can be expanded without being influenced by the structure of the motor, and the rotational position of the rotor can always be accurately estimated to control the brushless DC motor stably.

According to the brushless DC motor control device of claim 33, since the inverter control means that estimates the rotational position of the rotor using a rotary coordinate motor model is adopted, Claim 32
In addition to the effects of any one of the above, the present invention can be suitably applied to an application in which fluctuations in current and angular velocity are small.

According to the brushless DC motor control apparatus of claim 34, the rotational position of the rotor is estimated using the motor voltage, the motor current, and the equipment constant of the brushless DC motor, and the inverter is controlled using the estimation result. In controlling the brushless DC motor, the inverter control means estimates the rotational position using the transfer function, and sets the gain of the loop transfer function related to the rotational position estimation to a value satisfying the stability condition in the target phase and torque range. Can be set.

Accordingly, the brushless DC motor can be stably controlled by always accurately estimating the rotational position of the rotor.

In the brushless DC motor controller according to claim 35, as the inverter control means, a transfer function G represented by the following equation (1) is adopted, and all real roots of s of the denominator polynomial of G / (1 + G) are negative. Since the one that sets the gains _Kθ and F (s) of the transfer function G is adopted so that the following function can be achieved.

According to the brushless DC motor control apparatus of claim 36, since the inverter control means for estimating the rotational position of the rotor using a fixed coordinate motor model is adopted, Claim 32
In addition to any of the above operations, the rotational position of the rotor can be accurately estimated irrespective of the change in the current or the angular velocity.

In the brushless DC motor control device according to claim 37, since a device for identifying a motor device constant before starting operation is adopted as the inverter control means, any one of claims 28 to 36 is used. In addition to the operation described above, the rotational position of the rotor can be accurately estimated.

In the brushless DC motor control device according to claim 38, since the inverter control means adopts one that advances the target current phase to the maximum efficiency phase or the maximum torque phase of the motor or more. In addition to the effect of any one of claims 37 to 37, the operating range of the brushless DC motor can be expanded to the high speed side.

According to the brushless DC motor control apparatus of claim 39, since a brushless DC motor that drives a compressor is employed, in addition to the operation of any of claims 28 to 38, load fluctuation , And a compressor that needs to operate at high speed can be driven stably.

Further description will be given.

"Sensorless control of IPM motor", Motor technology symposium B-5, Substituting Equation 7 of coordinate transformation into Equations 2, 3, 4, 5, and 6 described in March 1999 Then, when the voltage V _dq on the dq axes, the current _idq, and the true rotor angle θ are rewritten into a system using a motor inverse model and feedback, the result is as shown in FIG.

[0100]

(Equation 2)

[0101]

(Equation 3)

[0102]

(Equation 4)

[0103]

(Equation 5)

[0104]

(Equation 6)

[0105]

(Equation 7) In FIG. 8, θ is an electrical angle, ω is an electrical angular velocity,
v _γ and v _δ are γδ axis voltages, i _γ and i _δ are γδ currents,
ε _γ and ε _δ are γδ axis induced voltages, φ is armature interlinkage flux by permanent magnets, R is armature resistance, L _d and L _q are dq axis inductances, s is a differential operator, ＾ is an estimated value, Each is shown. Further, I in FIG. _{8, v γδ, i γ δ} ,
_εγδ , L _I , L _J , θ _e , T (θ _e ), α _I , and β _I are as shown in Expression 8.

[0106]

(Equation 8) Further, when the nonlinear elements in the feedback loop are linearized (cos θ _e → 1, sin θ _e → θ _e , ＾ ω → ω), the block configuration shown in FIG. 9 is obtained.

Consider the convergence when _idq is periodic using the block configuration of FIG. X from the linear approximation block diagram
_γ is given by _Equation 9.

[0108]

(Equation 9) Here, ｛｝ in Equation 9 is represented by a ₀ + a _1s sin θ ₁ + a _1c co
sθ ₁ , θ _e = e ₀ + e _1s sin θ ₁ + e _1c cos θ ₁ + e
Consider the case of _2s sin 2θ ₁ + e _2c cos 2θ ₁ . x _γ
Becomes the following equation (10).

[0109]

(Equation 10)θ_eCannot be detected, so x_γDC component and 1
When the next component is controlled to 0 (kθ → ∞ is required),
E so that the dotted line of₀, E_1s, E_1cIs adjusted
You. The purpose (e₀= E_1s= E_1c= 0)
In order to₀$ 0 and a_1s= A_1c= 0
No. And the former is ｛φ + (L_d-L_q) I _d｝ Ω flat
It is equivalent to the average value not being 0, and the latter is ｛φω +
(L_d-L_q) [Ω_s −s] i_dqPrimary component, secondary component of｝
This is equivalent to the minute being 0. This is because ω is constant
One L_d= L_qOr i_d, I_qIs equivalent to
You.

As a result, sufficient conditions for ＾ θ → θ are satisfied.
The condition is stable, and (1) θ_eIs small (cos θ_e→ 1,
sin θ_e→ θ_e), (2) Equipment constants other than φ (R,
L_d, L _q), (3) k_θ= ∞, (4) ＾ ω =
ω = constant, (5) L_d= L_qOr i_d, I_qIs constant,
(6) Δφ + (L_d-L_q) I_dThe average value of｝ ω is 0
Is to meet. At this time, in particular, (L_d-L_q)
i_d+ Φ ≠ 0 and stability are absolutely necessary for position detection.
The other conditions are conditions for error reduction.

FIG. 10 shows another block configuration for performing position detection using a motor reverse model and without using a sensor.

In FIG. 10, θ is an electrical angle, and ω is
Electric angular velocity, γδ coordinate is ＾ θ rotation coordinate, αβ coordinate is two phase
Cartesian stator coordinates, v_γ, V_δIs the γδ axis voltage, v_α, V_β
Is the αβ axis voltage, i_α, I_βIs αβ axis current, φ is armature chain
Intersection flux, R is armature resistance, L _d, L_qIs the dq axis inductor
, S is the differential operator, ＾ is the estimated value, ￣ is the sensor value,
Each is shown. Further, L in FIG._p, L_m,, v
_γδ, V_αβ, I_αβ, Φ_αβ, F (θ) is shown in Equation 11.
That's right.

[0113]

[Equation 11] Also, when this block configuration is adopted, ｛(L
^{_{d -L q) Φ αβ T i}} α β + φ} = (L d -L q) i d + φ ≠
It can be seen that 0 is a condition for position detection.

[0114] shows a graph of FIG. 11 to the current value I [psi for _a = (L _d -L _q) after the current phase and two-phase transformation with respect to the d-axis i _d + phi.

The current phase is from -50 ° to -130 °, I _a
Ψ = 0 is recognized in the region of> 7A, which indicates that position detection may not be possible in this region. Note that I
_a is (3/2) of the peak value of the phase current in the three-phase motor
^1/2 .

[0116]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a brushless DC motor control method according to an embodiment of the present invention;

FIG. 1 is a block diagram showing an embodiment of a brushless DC motor control device according to the present invention.

This brushless DC motor control device uses an output from an inverter (preferably a voltage-type inverter) 1 which receives DC power as input, and outputs a brushless DC motor 2 having a permanent magnet mounted inside a rotor. To supply. A rotor rotation position detection unit 3 that detects the rotation position θ of the rotor of the brushless DC motor 2 without using a position sensor and detects a rotation speed ω;
A speed control unit 4 that performs a speed control operation using a speed command given from outside and a detected rotation speed ω as an input and outputs a current phase command and a current amplitude command, and a rotation position θ, a current phase command, and a current amplitude command. It has a current control unit 5 that performs a current control operation as an input, outputs a PWM (pulse width modulation) command, and supplies the command to the inverter 1.

In the rotor rotational position detector 3, the position detector calculates the difference between the voltage at the neutral point of the stator winding of the brushless DC motor 12 and the average value of the terminal voltage of the stator winding. , Detecting a zero cross of the difference voltage, obtaining and outputting a predicted position of the rotor from the detected zero cross, and in a position correction unit, previously obtaining a relationship between the amplitude of the difference voltage and the phase error of the difference voltage, Is corrected so as to cancel out. Thus, the rotational position of the rotor is accurately detected.

However, instead of the position correction unit, the amplitude of the difference voltage, the amplitude of the integration signal of the difference voltage, the phase current of the brushless DC motor, the phase voltage of the brushless DC motor, the input current (DC current) of the inverter, and the inverter Input voltage (D
C voltage), the number of revolutions of the brushless DC motor, and at least one value selected from the inverter internal information {pulse width modulation (PWM) command, rotation speed, etc.} are input, and the correction amount is calculated. It is possible to employ a position correcting unit that corrects the tentative predicted position output from the position detecting unit based on the corrected position and outputs the corrected predicted position.

Further, instead of the position correction unit, a correction map for outputting a correction amount (correction angle) with the amplitude of the differential voltage and the amplitude of the phase current of the brushless DC motor as inputs, and a rotation map output from the position detection unit. It is also possible to employ an adder for adding the correction amount to the child's temporary predicted position to obtain and output the corrected predicted position.

Further, the first voltage of the rotor is inputted by using the differential voltage as an input.
A first position detector that outputs a temporary predicted position of
A motor model that outputs a modeled differential voltage using the WM command and the rotor position as inputs, and a second position detector that outputs a second temporary predicted position of the rotor using the modeled differential voltage as input. A difference calculating unit for calculating a difference between the first tentative predicted position and the second tentative predicted position, and obtaining and outputting a correction amount (correction angle) for setting the difference between the predicted positions to zero as an input. It is also possible to employ a configuration having a correction amount output unit for performing the correction and subtracting the correction amount from the first temporary predicted position to obtain and output a corrected predicted position (the rotor position). is there. In this case, a first amplitude detector that detects the amplitude of the difference voltage, a second amplitude detector that detects the amplitude of the modeled difference voltage, and a difference amplitude calculator that calculates the difference between the two amplitudes are further provided. In addition, instead of the correction amount output unit, a correction amount output unit that obtains and outputs a correction amount (correction angle) that takes the difference between the predicted positions and the difference between the two amplitudes as an input, and outputs the correction amount may be employed. It is.

Further, a first position detector for outputting a first tentative predicted position of the rotor with the differential voltage as an input, and a second position of the rotor with the phase voltage and the phase current of the brushless DC motor as inputs. A second position detector that outputs a temporary predicted position; a difference calculator that calculates a difference between the first temporary predicted position and the second temporary predicted position; and an error that stores the calculated difference as an input. It is also possible to adopt a configuration including a storage unit and an addition unit that adds the error stored in the error storage unit to the first temporary predicted position and outputs the result as a corrected predicted position ( See Japanese Patent Application No. 10-315035).

The rotor rotational position detector 3 estimates the speed electromotive force from the command voltage and the motor current, defines a γ-δ axis corresponding to the estimated speed electromotive force, and calculates the estimated speed electromotive force. Is controlled to match the speed electromotive force expressed as a q-axis direction vector of a predetermined magnitude, and the rotational position and speed of the rotor are estimated (specifically, the direction of the estimated speed electromotive force depends on the direction of the estimated speed electromotive force). Obtain the estimated rotational position and obtain the estimated speed by the magnitude of the estimated speed electromotive force. (“Sensorless salient-pole brushless DC motor control based on speed electromotive force estimation”, Takaharu Takeshita et al., T. IEEE Japan, Vol.
117-D, no. 1, '97).

Further, the rotor rotational position detector 3 extracts harmonic components contained in the motor terminal voltage and current (calculating the difference between the average output voltage vector of the inverter and each inverter output voltage vector). Extracts the harmonic components included in the motor terminal voltage, and calculates the difference between the first and last current vectors of the modulation cycle in a predetermined period with respect to the modulation period from the amount of change in the current vector due to the voltage vector not used in the modulation period. By extracting the harmonic component of the motor current vector, the rotational position of the rotor can be estimated (the inductance matrix is obtained by using the left-hand pseudo-inverse matrix for the equation for the harmonic component of one modulation period). , Estimating the rotational position of the rotor from this inductance matrix) (“Using a position estimation method based on saliency, Position sensorless IPM motor drive system ", Satoshi Ogasawara other, T.IEE Japan, V
ol. 118-D, no. 5, '98).

The speed control section 4 corrects the torque to be generated from the speed command and the rotational speed, and outputs a new current phase command and a new current amplitude command. In particular,
(1) A current amplitude command is calculated from the speed command and the rotation speed (by PI control or the like, generally, if the rotation speed is low, the current is increased in the direction of increasing the current command). The following equation is calculated from the current phase command to calculate the torque T, calculate and output the current phase for maximizing the efficiency of the brushless DC motor 2, and (3) the corrected current amplitude command and current phase command. Then, the torque T is calculated by the following equation, and the current phase for maximizing the efficiency of the brushless DC motor 2 is calculated and output, and the processes (4) and (3) are repeated as appropriate. _{T = P n {φ + (} L d -L q) (- Isinβ)} Ico
sβ Here, P _n is the number of pole pairs, I is the current amplitude, and β is the current phase.

Of course, when it is necessary to control the torque accurately and at high speed, it is also possible to directly calculate the current amplitude command and the current phase command by solving the inverse problem from the torque equation incorporating the current phase.

In the current control section 5, a current amplitude command, a current phase command, a rotation position (or a rotation speed) of the rotor,
Thus, the following operation can be performed to directly generate a PWM command.

The voltage equation of the IPM expressed in the rotating coordinate system (d, q axes) is expressed by the following equation (12).

[0130]

(Equation 12) Here, _Ra is the winding resistance, ω is the rotational speed, L _d is the d-axis inductance, L _q is the q-axis inductance, I _d and I _q are the d-axis and q-axis currents, V _d and V _q are the respective The d-axis, q-axis voltage, and φ represent the number of interlinkage magnetic fluxes.

Accordingly, it can be seen that the d-axis and q-axis voltages V _d and V _q can be calculated using the current command and the rotation speed.

At this time, voltage amplitude V and voltage phase δ
Is expressed as V = (V _d ² + V _q ² ) ^1/2 δ = tan ⁻¹ (−V _d / V _q ), and the phase voltage V _u (V _v , V _w also shifts by 120 ° in phase). of other similar) is represented as ^{_{V u = (2/3) 1/2 Vsin}} (θ + δ).

When the brushless DC motor control device having the above configuration is employed, the motor current is supplied to the brushless DC motor with a current phase that maximizes the efficiency according to the rotor position. Not only can the maximum efficiency control be performed, but also the maximum efficiency control can be performed stably.

As the current control unit 5, a unit that directly generates a PWM signal from a current phase command, a current amplitude command, and a rotor rotation position (rotational speed) is employed. A device that detects the rotational position of rotation based on the voltage at the neutral point of the wire and the average value of the terminal voltage of the stator winding is used, and the detected rotational position signal is used as the operating condition of the brushless DC motor. (Refer to Japanese Patent Application No. 10-315035) to obtain the rotational position of the rotor,
If the control is performed by calculating the rotation speed, a current sensor or the like becomes unnecessary, and the maximum efficiency control without a position sensor can be realized at low cost.

FIG. 2 is a block diagram showing another embodiment of the brushless DC motor control device of the present invention.

In this brushless DC motor control device, an output from an inverter (preferably a voltage-type inverter) 11 to which DC power is input is supplied to a brushless DC motor 12. And the rotational position θ of the rotor
And the rotation speed ω are detected by the rotor rotation position detection unit 13 and supplied to the drive waveform generation unit 14. Further, the torque T calculated by the torque calculation unit 15 with the load information as an input is supplied to the current phase determination unit 16 and the current phase β
The current phase β is determined by calculating an approximate expression representing Further, the speed control unit 1
7 and the speed command value ω * output from the inverter 7
1 is supplied to the drive waveform generator 14. The drive waveform generator 14 generates a PWM command (PWM pattern signal) based on these input signals, and supplies the PWM command to the inverter 11.

The operation of the brushless DC motor control device having the above configuration is as follows.

First, the torque calculator 15 calculates the torque T applied to the brushless DC motor 12 from the load information (for example, in the case of an air conditioner, the current temperature inside and outside the room and the set temperature value). Then, the calculated torque T is supplied to the current phase determination unit 16 to calculate an approximate expression representing the current phase β to determine the current phase β of the control target.

Further, the brushless DC motor 1 is adjusted by using a signal from the brushless DC motor 12 (for example, by correcting the third harmonic at the neutral point of the stator winding in accordance with the load condition).
The current rotational position θ of the second rotor is calculated.

Then, in addition to the determined current phase β and the current rotational position θ, the speed command value ω
*, And the operation current I in the inverter 12 is supplied to the drive waveform generator 14 to generate a PWM pattern signal for driving the brushless DC motor 12 and supply the same to the inverter 11. In the inverter 11, a power device such as an IGBT is controlled based on the PWM pattern signal to drive the brushless DC motor 12.

Here, the IP at a certain rotation speed (rotation speed)
The current phase at which the maximum efficiency is obtained for each torque of M is, for example, as shown in FIG. Further, the current phase characteristics that provide the maximum efficiency for each rotation speed are, for example, as shown in FIG.
3 and 4 that the maximum efficiency is obtained when the current phase is around 20 ° to 40 °. Therefore, this maximum efficiency phase β is calculated by a function of the torque T, for example, an approximate expression β = A · T + B
(A and B are constants). By incorporating this function in the current phase determination unit 16, the maximum efficiency phase β can be easily obtained and reflected in the generation of the drive waveform.

Therefore, if the brushless DC motor control device shown in FIG. 2 is employed, the maximum efficiency phase β can be easily calculated. By controlling the brushless DC motor with the maximum efficiency phase β as a control target, the brushless DC motor is controlled. Maximum efficiency control of the DC motor can be achieved.

FIG. 5 is a block diagram showing still another embodiment of the brushless DC motor control device of the present invention.

This brushless DC motor controller is shown in FIG.
The only difference from the brushless DC motor control device is that a maximum efficiency phase table 18 storing a current phase β corresponding to the torque T is employed instead of the current phase determination unit 16.

An example of the contents of the maximum efficiency phase table 18 is shown in Table 1.

[0146]

[Table 1] Of course, the contents of the maximum efficiency phase table 18 are set based on the previously determined maximum efficiency phase characteristics as shown in FIG. Here, the resolution of the maximum efficiency phase table 18 may be set in consideration of the capacity of the memory, and when the capacity of the memory is small, the resolution of the torque T may be reduced and interpolation may be performed between the points.

The operation of the brushless DC motor control device having the above configuration is as follows.

First, the torque calculating section 15 calculates the torque T applied to the brushless DC motor 12 from the load information (for example, in the case of an air conditioner, the current temperature inside and outside the room and the temperature set value). Then, the calculated torque T is supplied to the maximum efficiency phase table 18 to determine the control target current phase β.

Further, the signal from the brushless DC motor 12 is used (for example, the third harmonic at the neutral point of the stator winding is corrected according to the load condition).
The current rotational position θ of the second rotor is calculated.

Then, in addition to the determined current phase β and the current rotational position θ, the speed command value ω
*, And the operation current I in the inverter 12 is supplied to the drive waveform generator 14 to generate a PWM pattern signal for driving the brushless DC motor 12 and supply the same to the inverter 11. In the inverter 11, a power device such as an IGBT is controlled based on the PWM pattern signal to drive the brushless DC motor 12.

FIG. 6 is a block diagram showing still another embodiment of the brushless DC motor control device of the present invention.

This brushless DC motor controller is shown in FIG.
The only difference from the brushless DC motor control device is that a current phase setting unit 19 is provided instead of the torque calculation unit 15 and the current phase determination unit 16.

The current phase setting section 19 outputs a predetermined current phase β set irrespective of the operating state of the brushless DC motor 12. here,
If the current phase β is kept constant, there is a possibility that the maximum efficiency phase may not always be realized when fluctuations in torque, rotation speed, and the like occur. However, FIG.
As can be seen from FIG. 4, since the fluctuation of the maximum efficiency phase is not so large even if the fluctuation of the torque, the fluctuation of the rotation speed, etc. occur, the predetermined current phase β is referred to FIGS. With this setting, the brushless DC motor 12 can be operated with almost the same efficiency as in the case where the maximum efficiency phase is realized (see FIG. 7).

When each of the above embodiments is employed, it is possible to control the efficiency of the brushless DC motor at a low cost without adding a part such as a current sensor or a voltage sensor, for example, by means for detecting the motor efficiency. Can be. In particular, when the embodiments of FIGS. 5 and 6 are employed, it is not necessary to calculate the maximum efficiency phase in real time, and control can be realized by a low-cost microcomputer.

FIG. 12 is a block diagram showing still another embodiment of the brushless DC motor control device of the present invention.

The brushless DC motor control device includes a converter 22 having an AC power supply 21 as an input, a smoothing capacitor 23 for smoothing an output voltage of the converter 22, and an inverter 24 having a smoothed DC voltage as an input. A brushless DC motor 25 to which an AC voltage output from the inverter 24 is applied; a current detecting unit 26 for detecting a current supplied to the brushless DC motor 25;
Voltage detector 2 for detecting a voltage applied to C motor 25
7 and the magnetic flux 検 出 =
_{(L d -L q) i d} + φ, a position-speed detector 28 for detecting the rotor position and speed, detected and fast commands the as input the detected magnetic flux [psi is flux [psi ≒ 0 A # 0 detection unit 29 for outputting, a speed control unit 30 for performing a speed control operation with the detected speed and an externally applied speed command as inputs and outputting a current command, a current command, and an externally applied phase command , And a phase control unit 31 that outputs a phase by performing a phase control operation using a phase advance command as an input
The voltage control unit 32 outputs a voltage command by performing a current control operation using the phase, the detected current, and the rotor position output from the phase control unit 31 as inputs, and supplies the voltage command to the inverter 24.
And

The motor constants of the motor are preset in the position / speed detector 28, and the magnetic flux information is calculated by using the machine constants, the motor current (supply current) and the motor voltage (applied voltage). The rotor position is estimated from the calculated magnetic flux information and the rotor position is output, and the speed is detected from the motor current cycle and the like.

When the brushless DC motor control device having the above configuration is employed, the # 0 detector 29 detects the magnetic flux # 0
Since the phase control unit 31 performs the phase control calculation based on the phase command and the current command on condition that the rotor position is not detected, the rotor position is estimated using the motor current, the motor voltage, and the device constant. Then, the brushless DC motor 25 can be controlled based on the estimated rotor position.

Conversely, when the # 0 detecting section 29 detects that the magnetic flux is $ 0, it outputs a phase advance command, so that a phase control calculation is performed based on the phase command and the current command. The phase controller 31 outputs a phase advanced from the phase obtained by the above operation, and enables accurate estimation of the rotor position by avoiding the magnetic flux Ψ = 0, thereby stably operating the brushless DC motor 25. (Step-out can be prevented).

In the embodiment shown in FIG. 12, the position / velocity detecting section 28 calculates the magnetic flux 別 途. However, a separate Ψ calculating section for calculating the magnetic flux Ψ may be provided. An equivalent motor current value, motor current phase, or the like may be calculated and used (see FIG. 11). Further, voltage control may be performed directly without providing a current control system.
Further, the motor voltage may be calculated from the inverter command instead of detecting the motor voltage.

FIG. 13 is a block diagram showing still another embodiment of the brushless DC motor control device of the present invention.

This brushless DC motor controller is shown in FIG.
2 is different from the brushless DC motor controller of FIG. 2 in that the $ 0 detector 29 outputs a current drooping command and supplies the current drooping command to the current controller 32 instead of the # 0 detector 29 that outputs a phase advance command.
It is only the point that 9 'is adopted.

Therefore, in this embodiment,
When the ≒ 0 detector 29 detects that the magnetic flux is Ψ ≒ 0, the inverter output current is reduced based on the current droop command and the magnetic flux Ψ = 0 is avoided, so that the rotor position can be accurately estimated. As a result, the brushless DC motor 25 can be operated stably (step-out can be prevented).

FIG. 14 is a block diagram showing still another embodiment of the brushless DC motor control device of the present invention.

This brushless DC motor controller is shown in FIG.
2 is different from the brushless DC motor control device of FIG. 2 in that a current value and a current phase of Ψ> 0 are stored in advance in place of the Ψ ≒ 0 detection unit 29 that outputs a phase advance command.
Only in that the current command output from the speed control unit 30 and the phase command given from the outside are output as a read instruction signal and the current phase is supplied to the phase control unit 31.

Therefore, in this embodiment,
By reading a current phase such that> 0 from the Ψ> 0 table 29 '' and supplying it to the phase control unit 31,
By avoiding the magnetic flux Ψ = 0, it is possible to accurately estimate the rotor position, and thus, it is possible to operate the brushless DC motor 25 stably (step-out can be prevented).

Note that instead of providing the 位相> 0 table 29 ″, a phase limiter that satisfies Ψ> 0 may be provided.

FIG. 15 is a block diagram showing still another embodiment of the brushless DC motor control device of the present invention.

This brushless DC motor control device includes an inverter 41 that receives DC power as input,
A brushless DC motor 42 to which the AC voltage output from the DC motor is applied, a current detection unit 43 for detecting three-phase motor currents, and a two-phase current (α
A three-phase to two-phase conversion unit 44 for converting the current into a β-axis current), and an αβ-axis for converting the converted two-phase current (αβ-axis current) and the rotor angle (θ) into dq-axis currents →
a dq-axis conversion unit 45, a -sin processing unit 46 that performs a -sin process using an externally supplied phase command and current command as input, and outputs a d-axis current command, and receives an externally supplied phase command and current command. A cos processing unit 47 that performs a cos process and outputs a q-axis current command;
d-axis current output from the sin processing unit 46 and αβ-axis → d
a first difference calculator 48 for calculating a difference between the d-axis current output from the q-axis converter 45, and a q-axis current output from the cos processor 47 and an output from the αβ axis → dq axis converter 45. a second difference calculator 49 for calculating a difference from the q-axis current, a proportional processor 48a for multiplying a d-axis difference current output from the first difference calculator 48 by a proportional gain K _dp , An integral multiplier 48b for multiplying the d-axis difference current output from the difference calculator 48 by an integral gain K _di , and an integral multiplier 4
An integration processing unit 48c that performs integration processing (1 / s processing) on the output from 8b, an output from the proportional processing unit 48a and an output from the integration processing unit 48c are added and output as a d-axis voltage command. An adder 48d, a proportional processor 49a that multiplies the q-axis difference current output from the second difference calculator 49 by a proportional gain K _qp , and a q-axis difference current output from the second difference calculator 49 An integration multiplier 49b for multiplying the output by the integration gain _Kqi , an integration processor 49c for performing an integration process (1 / s process) on an output from the integration multiplier 49b,
An adder 4 that adds the output from the proportional processor 49a and the output from the integration processor 49c and outputs the result as a q-axis voltage command
9d, a dq-axis → αβ-axis converter 50 for converting the d-axis voltage, the q-axis voltage, and the rotor angle (θ) into an αβ-axis voltage, and converting the αβ-axis voltage into a three-phase voltage command -To-three-phase converter 51 for supplying to inverter 41
And

Although the portion for estimating the rotor angle (θ) is not shown, it is estimated from the motor current, the motor voltage and the equipment constant as described above.

When the brushless DC motor control device of this embodiment is employed, the brushless DC motor can be controlled by controlling the current phase so as to attain the target current phase. Therefore, by setting the target current phase so that the magnetic flux Ψ does not become zero, the brushless DC motor can always be stably controlled.

FIG. 16 is a block diagram showing still another embodiment of the brushless DC motor control device of the present invention.

This brushless DC motor control device includes an inverter 61 that inputs DC power,
Brushless DC motor 62 to which the AC voltage output from is applied, a current detection unit 63 for detecting three-phase motor currents, and a current vector length by performing r and θ conversion with the three-phase motor currents as inputs. And three phases that output the current phase →
an r / θ conversion unit 64, a first phase difference calculation unit 65 for calculating a difference between a current phase and a rotor angle (θ), and a current difference for calculating a difference between a current command given from outside and a current vector length. A calculating unit 66, a second phase difference calculating unit 67 for calculating a difference between a phase command given from the outside and a difference output from the first phase difference calculating unit 65, and an output from the current difference calculating unit 66. a proportional processing unit 66a for multiplying the proportional gain K _lp, and integrating the multiplication section 66b for multiplying the integration gain K _li to the output from the current difference calculating unit 66, the integration processing on the output from the integration multiplier unit 66b An integration processing unit 66c to be added, and an addition unit 66 that adds the output from the proportional processing unit 66a and the output from the integration processing unit 66c and outputs the result as a current vector length.
d, a proportional processing unit 67a that multiplies the output from the second phase difference calculation unit 67 by a proportional gain K _θp , and an integration that multiplies the output from the second phase difference calculation unit 67 by an integration gain K _θi. A multiplication unit 67b, an integration processing unit 67c that performs integration processing on the output from the integration multiplication unit 67b, and an addition unit 67d that adds and outputs the output from the proportional processing unit 67a and the output from the integration processing unit 67c. , An adder 68 that adds the output from the adder 67d and the rotor angle (θ) and outputs a voltage phase, a voltage vector length output from the adder 66d and a voltage phase output from the adder 68. Is input, and a three-phase conversion process is performed to convert it into a voltage command for three phases, which is supplied to the inverter 61.
9.

Although the portion for estimating the rotor angle (θ) is not shown, it is estimated from the motor current, the motor voltage and the equipment constant as described above.

Even when the brushless DC motor control device of this embodiment is employed, the brushless DC motor can be controlled by controlling the current phase so as to attain the target current phase. Therefore, by setting the target current phase so that the magnetic flux Ψ does not become zero, the brushless DC motor can always be stably controlled.

FIG. 17 is a block diagram showing an example of the configuration of the position / speed detector 28.

The position / velocity detecting unit 28 performs a γδ conversion with a three-phase voltage as an input and outputs a γδ voltage vector, and a three-phase → γδ conversion unit 28a.
3 phase that performs δ conversion and outputs γδ current vector → γδ
A conversion unit 28b, a motor inverse model unit 28c that outputs a voltage vector with a γδ current vector as an input, and a three-phase → γ with a voltage vector output from the motor inverse model unit 28c
A difference calculator 28d for calculating a difference between the voltage vector output from the δ converter 28a, a filter 28e having the difference output from the difference calculator 28d as an input, and a position / velocity having the output from the filter 28e as an input. And a position / velocity estimating unit 28f for estimating.

Therefore, in this case, the rotor position can be detected using the rotating coordinate motor model.
However, since there is a possibility that an angle error may be canceled with respect to fluctuations in current and angular velocity, it is not suitable for applications with large fluctuations, but can be suitably applied to applications with small fluctuations.

Further, the following equation is obtained by performing a Taylor linear approximation on the coordinate transformation unit shown in FIG. T = i + Jθ _e , where
3.

[0180]

(Equation 13) The above equation is substituted into the block diagram of FIG. 8 to obtain the block diagram of FIG. 9, from which the open-loop transfer function (circular loop transfer function) G (s) of the closed loop system is obtained.

[0181]

[Equation 14] Then, the stability can be ensured by setting the gains _Kθ and F (s) of the respective units so that the real roots of s of the denominator polynomial of G / (1 + G) are all negative.

Next, the procedure for setting the gain will be described. (1) Set the range of current phase, current amplitude, and speed that you want to operate stably.

The gains K _θ and F (s) and the initial gain value in the loop are set. (2) In all combinations of various quantities set in (1), it is checked using the rational function G whether all real roots of s of the denominator polynomial of G / (1 + G) are negative. (3) If a positive real root appears, change the gain and execute (2).

Conversely, if a positive real root does not appear, that value is adopted.

From the linear approximation block diagram of FIG. 9, (2)
As a result, a combination of gains in which all the real roots are negative is a stable gain.

More specifically, “Sensorless salient-pole brushless DC motor control based on speed electromotive force estimation”, Takeshita et al.
T. IEEE Japan, Vol. 117-D, no.
The transfer function G having the configuration of 1, 97 is given by the following equation (15).

[0187]

(Equation 15) Then, the same motor device constants as those in the above-mentioned literature are adopted, and the gain is set with, for example, a speed of 15 rps, a current amplitude of 0.84 A, and a current phase of 0 to 360 °. At this time, if K _θ = 1077 and K _e = 5202000 are set, the stability is determined to be stable in the conventional stability determination. However, when the above determination method is used, the current phase becomes approximately as shown in FIG. It turns out that it becomes unstable at 130 ° to 230 °.

Here, K _θ = 107.7 and K _e = 520
When 200 is set, it is understood that the current phase becomes stable in all current phases (see FIG. 18B), and it is understood that such a gain setting is necessary to satisfy this operation range.

The position / speed detecting unit 28
A fixed coordinate type position detector as shown in FIG. 10 may be employed.

In this case, there is no position estimation error due to a change in current or angular velocity, and suitable control of the brushless DC motor can be achieved even when the change in current or angular velocity is large.

Further, although the motor equipment constants employed in the above embodiment may be set in advance, identification processing is performed at the start of operation to set the motor equipment constants.
After that, it is preferable to control the brushless DC motor. The identification process is performed, for example, as follows. Step 1 A forced motive operation or an operation without using a position sensor is performed, and v _αβ and i _αβ are detected or estimated under the condition that the speed is almost constant and the voltage and the current are almost constant, and the calculation of _Formula 16 is performed.

[0192]

(Equation 16) Here, n is an integer of 1 or more. Step 2 Next, under the condition that the speed is substantially constant and the voltage and the current are substantially constant, v _αβ and i _αβ are detected or estimated under the condition that one or more of the speed, the voltage and the current are different from the above, and Is calculated.

[0193]

[Equation 17] Here, n is an integer of 1 or more.

Assuming that components other than the fundamental components of the voltage and the current can be neglected, Expression 18 is obtained.

[0195]

(Equation 18) Step 3 The voltage equation on the stator coordinates of the synchronous motor _{v αβ = Ri αβ + s {} L p i αβ + L m f (2θ) i
Substituting Equation 18 into _αβ ｝ + s ｛φΘ｝, and Equation 19, which is a mutually orthogonal variable,
The coefficients relating to each of Expression 20 are extracted, and Expression 21 is obtained.

[0196]

[Equation 19]

[0197]

(Equation 20)

[0198]

(Equation 21) Step 4 Each of θ _e in Step 1 and Step 2 is θ
_e1 and θ _{e2, and the} equations (16) and (17) are substituted into the equation (21) to obtain 8
Obtain eight simultaneous equations with two unknown constants. The initial values of the device constants are roughly set in advance, and 0 is set as the initial values of θ _e1 and θ _e2 , and the obtained equations are solved by Newton's method or the like to obtain the device constants (identify be able to).

Further, it is preferable that the target current phase in the above embodiment is advanced to the maximum efficiency phase or the maximum torque phase of the brushless DC motor.

FIG. 1 showing the maximum efficiency current phase-torque characteristics
9, FIG. 20 showing the motor terminal voltage with respect to the current phase-torque, and FIG. 21 showing the maximum torque current phase, it can be seen that the motor terminal voltage decreases as the current phase advances. Therefore, even when the inverter output voltage reaches the limit, a higher speed rotation can be performed by advancing the current phase. In other words, the operation range can be extended to the high speed side.

Next, consider a case where the compressor is driven by a brushless DC motor.

[0202] 1 Referring to Figure 22 showing the compression torque with respect to the rotation angle of the cylinder rotary compressor, large load fluctuation in the air conditioning compressor, and because it is _{fast, (L d -L q) i} d + φ It is not easy to satisfy> 0, but it is possible to control stably by high-speed current phase control.

Therefore, by adopting the brushless DC motor control device of the above embodiment, stable and precise control by the method using the motor model can be realized in the compressor, and energy saving and high efficiency can be achieved. The effect of can be achieved.

[0204]

According to the first aspect of the present invention, it is possible to detect the rotational position of the rotor without using a position sensor, and to achieve a specific effect that maximum efficiency control can be achieved.

The invention of claim 2 has a specific effect that the maximum efficiency control can be achieved regardless of the operation state.

According to the third aspect of the present invention, it is not necessary to measure the target current phase, the processing can be simplified, and the maximum efficiency control can be achieved.

The invention according to claim 4 has a specific effect that the processing can be further simplified and a certain maximum efficiency control can be achieved.

The invention according to claim 5 is applied to the case where the rotational position of the rotor is detected based on the voltage at the neutral point of the stator of the brushless DC motor and the average value of the terminal voltage of the stator winding. And achieves a unique effect that maximum efficiency control can be achieved.

[0209] The invention according to claim 6 is applied to the case where the rotation position of the rotor is calculated by performing a predetermined calculation using the applied voltage of the stator winding, the motor current, and the equipment constant of the brushless DC motor. And a unique effect that maximum efficiency control can be achieved.

[0210] The invention of claim 7 can be applied to the case where the rotational position of the rotor is calculated from the inductance obtained from the harmonic current generated by the voltage type inverter and the saliency of the rotor, and the maximum efficiency control is performed. Can be achieved.

[0211] The invention of claim 8 has a specific effect that the rotational position of the rotor can be detected without using a position sensor and maximum efficiency control can be achieved.

The ninth aspect of the invention has a specific effect that the maximum efficiency control can be achieved regardless of the operation state.

The tenth aspect of the invention has a specific effect that the target current phase can be easily obtained from the map, and the maximum efficiency control can be achieved regardless of the operation state.

According to the eleventh aspect of the present invention, it is not necessary to measure the target current phase, the processing can be simplified, and the maximum efficiency control can be achieved.

The twelfth aspect of the invention has a specific effect that the processing can be further simplified and a certain maximum efficiency control can be achieved.

The thirteenth aspect of the present invention is applied to the case where the rotational position of the rotor is detected based on the voltage at the neutral point of the stator of the brushless DC motor and the average value of the terminal voltage of the stator winding. And achieves a unique effect that maximum efficiency control can be achieved.

The invention according to claim 14 is applied to a case where a predetermined operation is performed using a voltage applied to a stator winding, a motor current, and a device constant of a brushless DC motor to calculate a rotational position of a rotor. And a unique effect that maximum efficiency control can be achieved.

The invention according to claim 15 can be applied to a case where the rotational position of the rotor is calculated from the inductance obtained from the harmonic current generated by the voltage type inverter and the saliency of the rotor, and the maximum efficiency control is performed. Can be achieved.

According to the sixteenth aspect, the applicable range can be expanded without being affected by the structure of the motor, and the rotational position of the rotor is always accurately estimated to stably control the brushless DC motor. It has a unique effect that it can be performed.

According to the seventeenth aspect of the present invention, the step-out due to the inability to estimate the position can be avoided, and the same effect as that of the sixteenth aspect can be obtained.

The eighteenth invention has the same effect as the seventeenth invention.

The nineteenth invention has the same effect as the seventeenth invention.

According to the twentieth aspect, the applicable range can be expanded without being affected by the structure of the motor, and the rotational position of the rotor is always accurately estimated to stably control the brushless DC motor. It has a unique effect that it can be performed.

[0224] The invention of claim 21 has a specific effect that it can be suitably applied to applications in which fluctuations in current and angular velocity are small, in addition to the effects of any of claims 16 to 20.

[0225] The invention of claim 22 has a unique effect that the brushless DC motor can be stably controlled by always accurately estimating the rotational position of the rotor.

The twenty-third aspect has the same effect as the twenty-second aspect.

According to the twenty-fourth aspect of the present invention, in addition to the effect of any one of the sixteenth to twentieth aspects, a unique effect that the rotational position of the rotor can be accurately estimated irrespective of a change in current or angular velocity. To play.

According to the twenty-fifth aspect of the invention, in addition to the effect of any one of the sixteenth to twenty-fourth aspects, a special effect is obtained in that the rotational position of the rotor can be accurately estimated.

[0229] The invention of claim 26 has the specific effect that the operating range of the brushless DC motor can be expanded to the high speed side in addition to the effect of any of claims 16 to 25.

According to the twenty-seventh aspect, in addition to the effects of any one of the sixteenth to the twenty-sixth aspects, the compressor having a large load variation and capable of operating at a high speed can be driven stably. It works.

According to the twenty-eighth aspect of the present invention, the applicable range can be expanded without being affected by the structure of the motor, and the rotational position of the rotor is always accurately estimated to stably control the brushless DC motor. It has a unique effect that it can be performed.

According to the twenty-ninth aspect of the present invention, step-out due to the inability to estimate the position can be avoided, and the same effect as that of the twenty-eighth aspect can be obtained.

The invention of claim 30 has the same effect as claim 29.

The invention of claim 31 has the same effect as claim 29.

According to the thirty-second aspect, the applicable range can be expanded without being affected by the structure of the motor, and the rotational position of the rotor is always accurately estimated to stably control the brushless DC motor. It has a unique effect that it can be performed.

[0236] The invention of claim 33 has a unique effect that it can be suitably applied to applications in which fluctuations in current and angular velocity are small, in addition to the effects of any of claims 28 to 32.

The invention of claim 34 has a unique effect that the brushless DC motor can be stably controlled by always accurately estimating the rotational position of the rotor.

The thirty-fifth aspect has the same effect as the thirty-fourth aspect.

[0239] The invention of claim 36 is characterized in that, in addition to the effect of any one of claims 28 to 32, the rotational position of the rotor can be accurately estimated irrespective of a change in current or angular velocity. To play.

The thirty-seventh aspect of the invention has a unique effect that the rotational position of the rotor can be accurately estimated in addition to the effects of the twenty-eighth to thirty-sixth aspects.

The invention of claim 38 has a specific effect that the operating range of the brushless DC motor can be extended to the high speed side in addition to the effect of any of claims 28 to 37.

The thirty-ninth aspect of the present invention has a feature that, in addition to the effects of any one of the twenty-eighth to thirty-eighth aspects, a compressor having a large load fluctuation and requiring high-speed operation can be driven stably. It works.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a brushless DC motor control device of the present invention.

FIG. 2 is a block diagram showing another embodiment of the brushless DC motor control device of the present invention.

FIG. 3 is a diagram illustrating an example of a current phase characteristic of an interior magnet motor.

FIG. 4 is a diagram showing a maximum efficiency current phase for each rotation speed of an embedded magnet motor.

FIG. 5 is a block diagram showing still another embodiment of the brushless DC motor control device of the present invention.

FIG. 6 is a block diagram showing still another embodiment of the brushless DC motor control device of the present invention.

FIG. 7 is a diagram showing a change in efficiency when a current phase is kept constant.

FIG. 8 is a block diagram illustrating a position detection unit based on a rotation coordinate model.

FIG. 9 is a block diagram obtained by linearly approximating FIG. 8;

FIG. 10 is a block diagram illustrating a motor control device including a position detection unit based on a fixed coordinate model.

11 is a graph of Ψ with respect to the current phase based on the d-axis current value _{I a} after 2 phase conversion _{= (L d -L q) i} d + φ.

FIG. 12 is a block diagram showing still another embodiment of the brushless DC motor control device of the present invention.

FIG. 13 is a block diagram showing still another embodiment of the brushless DC motor control device of the present invention.

FIG. 14 is a block diagram showing still another embodiment of the brushless DC motor control device of the present invention.

FIG. 15 is a block diagram showing still another embodiment of the brushless DC motor control device of the present invention.

FIG. 16 is a block diagram showing still another embodiment of the brushless DC motor control device of the present invention.

FIG. 17 is a block diagram illustrating a configuration of a position / speed detection unit.

FIG. 18 is a diagram showing a real part maximum value-current phase characteristic of a closed loop pole.

FIG. 19 is a diagram showing a maximum efficiency current phase-torque characteristic.

FIG. 20 is a diagram showing motor terminal voltage with respect to current phase-torque.

FIG. 21 is a diagram showing a maximum torque current phase.

FIG. 22 is a diagram showing a torque pattern of a one-cylinder rotary compressor.

[Description of Signs] 1, 11, 24, 41, 61 Inverter 2, 12, 25, 42, 62 Brushless DC motor 3, 13 Rotor rotation position detection unit 4 Speed control unit 14 Drive waveform generation unit 29, 29 ' ≒ 0 detection unit 29 '' Ψ> 0 table

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Manabu Manabu 1000 Oya, Okamoto-cho, Kusatsu-shi, Shiga 2 Inside Daikin Air Conditioning Technology Laboratory Co., Ltd. (72) Inventor Masanobu Kita 1000-Oya, Okamoto-cho, Kusatsu-shi, Shiga Of Daikin Air Conditioning Technology Laboratory Co., Ltd.

Claims (39)

[Claims] 1. A brushless DC motor control method for controlling a brushless DC motor (2) (12) having a permanent magnet mounted inside the rotor by detecting the rotational position of the rotor without using a rotational position sensor. Wherein a current phase is controlled to achieve a maximum efficiency control and the current phase is set to a target current phase.
Motor control method. 2. The target current phase is a current phase capable of realizing the maximum efficiency, which is obtained by measurement in advance for each operation state of the brushless DC motor (2) (12).
3. The brushless DC motor control method according to 1. 3. The target current phase is calculated based on an expression that approximates a current phase that can achieve the maximum efficiency, which is obtained by measurement in advance for each operating state of the brushless DC motor (2) (12). The method for controlling a brushless DC motor according to claim 1. 4. The brushless DC motor control method according to claim 1, wherein the target current phase is a desired constant value irrespective of an operation state of the brushless DC motor. 5. A rotation position of a rotor is detected based on a voltage at a neutral point of a stator of the brushless DC motors (2) and (12) and an average value of terminal voltages of stator windings. The brushless DC according to any one of claims 1 to 4, wherein the corrected position signal is corrected based on operating conditions of the brushless DC motors (2) and (12), and the current phase is controlled based on the corrected position signal. Motor control method. 6. A predetermined operation is performed using a voltage applied to a stator winding, a motor current, and device constants of the brushless DC motors (2) and (12) to calculate a rotational position of the rotor.
5. The brushless DC motor control method according to claim 1, wherein a current phase is controlled based on the calculated rotational position. 7. A rotation position of the rotor is calculated from an inductance obtained from a harmonic current generated by the voltage type inverters (1) and (11) and a saliency of the rotor, and a current is calculated based on the calculated rotation position. 5. The brushless DC motor control method according to claim 1, wherein the phase is controlled. 8. A brushless DC motor control device for controlling a brushless DC motor (2) (12) having a permanent magnet mounted inside the rotor by detecting the rotational position of the rotor without using a rotational position sensor. Current phase control means for controlling the current phase to achieve the maximum efficiency control and setting the current phase to the target current phase (4) (14)
A brushless DC motor control device comprising: 9. The current phase control means (4) (14).
Is the brushless DC motor (2) as the target current phase
The brushless DC motor control device according to claim 8, wherein a current phase capable of realizing the maximum efficiency, which is obtained by measurement in advance for each operation state of (12), is adopted. 10. The current phase control means (4) (14).
Wherein a target current phase capable of realizing the maximum efficiency, which is obtained by measurement in advance for each operating state of the brushless DC motor (2) (12), is stored as a map.
3. The brushless DC motor control device according to 1. 11. The current phase control means (4) (14).
Is the brushless DC motor (2) as the target current phase
9. The brushless DC motor control according to claim 8, wherein a value calculated based on an expression approximating a current phase capable of realizing the maximum efficiency, which is obtained by measurement in advance for each operation state of (12), is adopted. apparatus. 12. The brushless apparatus according to claim 8, wherein said current phase control means (14) adopts a desired constant value as the target current phase irrespective of the operation state of the brushless DC motor (12). DC motor control device. 13. A brushless DC motor (2) (12).
Rotational position detecting means (3) and (13) for detecting the rotational position of the rotor based on the voltage at the neutral point of the stator and the average value of the terminal voltages of the stator windings; (3) and (13) for correcting the current phase based on the operating conditions of the brushless DC motor, wherein the current phase control means (4) and (14) control the current phase based on the corrected position signal. Claims 8 to 12
The brushless DC motor control device according to any one of the above. 14. An applied voltage of a stator winding, a motor current,
And rotational position calculating means (3) and (13) for performing a predetermined operation using the device constants of the brushless DC motors (2) and (12) to calculate the rotational position of the rotor. 4) The brushless DC motor control device according to claim 8, wherein (14) controls the current phase based on the calculated rotational position. 15. A rotation position calculating means (3) (13) for calculating a rotor rotation position from an inductance obtained from a harmonic current generated by the voltage type inverters (1) and (11) and a saliency of the rotor. The apparatus according to claim 8, further comprising a current phase control unit configured to control the current phase based on the calculated rotational position.
3. The brushless DC motor control device according to any one of 2. 16. A rotational position of a rotor is estimated from magnetic flux information using a motor voltage, a motor current, and device constants of the brushless DC motors (25), (42), (62), and an inverter ( 24) (41) (61)
Brushless DC motor with saliency control (25)
(42) A method for controlling (62), wherein the inverters (24), (41), (6) are controlled based on the magnetic flux.
A brushless DC motor control method characterized by controlling 1). 17. The brushless DC motor control method according to claim 16, wherein the inverters (24), (41), and (61) are controlled to avoid a region where the magnetic flux is substantially zero. 18. The apparatus according to claim 17, wherein the magnetic flux is detected to be substantially zero, and a phase advance control is performed in response to the detection that the magnetic flux is substantially zero to avoid a region where the magnetic flux becomes substantially zero.
3. The brushless DC motor control method according to 1. 19. The method according to claim 17, wherein the magnetic flux is detected to be substantially zero, and current droop control is performed in response to the detection that the magnetic flux is substantially zero to avoid a region where the magnetic flux becomes substantially zero. The method for controlling a brushless DC motor according to the above description. 20. A rotational position of a rotor is estimated using a motor voltage, a motor current, and a device constant of a brushless DC motor (25) (42) (62), and an inverter (24) ( 41) A method for controlling a brushless DC motor (25), (42), (62) by controlling (61), wherein the current phase is controlled so as to become a target current phase. Motor control method. 21. The brushless DC motor control method according to claim 16, wherein the rotation position of the rotor is estimated using a rotation coordinate motor model. 22. The rotational position of the rotor is estimated using the motor voltage, the motor current, and the device constants of the brushless DC motors (25), (42), (62), and the inverter (24) ( 41) A method of controlling (61) and controlling a brushless DC motor (25) (42) (62), wherein a gain of a loop transfer function relating to rotation position estimation is satisfied in a target phase and a torque range to satisfy a stability condition. A brushless DC motor control method characterized by setting to a value. 23. A transfer function G is represented by Equation 1, and G / (1
23. The gains K _θ and F (s) of the transfer function G are set such that all real roots of s of the denominator polynomial of (+ G) become negative.
3. The brushless DC motor control method according to 1. (Equation 1) 24. The brushless DC motor control method according to claim 16, wherein the rotation position of the rotor is estimated using a fixed coordinate motor model. 25. The brushless DC motor control method according to claim 16, wherein a motor device constant is identified before starting operation. 26. The brushless DC motor control method according to claim 16, wherein the target current phase is advanced to be equal to or more than the maximum efficiency phase or the maximum torque phase of the motor. 27. A brushless DC motor (25) (4)
2) (62) for driving the compressor.
27. The brushless DC motor control method according to claim 26. 28. A rotational position of a rotor is estimated from magnetic flux information using a motor voltage, a motor current, and device constants of a brushless DC motor (25), (42), (62), and an inverter ( 24) (41) (61)
Brushless DC motor with saliency control (25)
(42) An apparatus for controlling (62), which controls inverters (24), (41), and (61) based on magnetic flux.
9 ″). A brushless DC motor control device, comprising: 29. Inverter control means (29) (2)
29. The brushless DC motor control device according to claim 28, wherein 9 ') and 29' control the inverters 24, 41, and 61 to avoid a region where the magnetic flux is substantially zero. 30. The inverter control means (29),
30. The method according to claim 29, further comprising: detecting that the magnetic flux is substantially zero; and performing phase advance control in response to detecting that the magnetic flux is substantially zero to avoid a region where the magnetic flux is substantially zero. Brushless DC motor controller. 31. The inverter control means (29 ')
And detecting the magnetic flux is substantially zero, and performing current droop control in response to detecting that the magnetic flux is substantially zero to avoid a region where the magnetic flux is substantially zero.
10. The brushless DC motor control device according to 9. 32. A rotational position of a rotor is estimated using a motor voltage, a motor current, and a device constant of a brushless DC motor (25) (42) (62), and an inverter (24) ( 41) A device for controlling (61) and controlling the brushless DC motors (25), (42) and (62), including an inverter control means for controlling a current phase so as to be a target current phase. Characteristic brushless D
C motor control device. 33. The brushless DC motor control device according to claim 28, wherein said inverter control means estimates a rotational position of the rotor using a rotational coordinate motor model. 34. A rotational position of a rotor is estimated using a motor voltage, a motor current, and a device constant of a brushless DC motor (25) (42) (62), and an inverter (24) ( 41) A device for controlling (61) and controlling a brushless DC motor (25), (42), (62), wherein a rotational position is estimated using a transfer function, and a gain of a loop transfer function relating to the rotational position estimation. A brushless DC motor control device including an inverter control means for setting a value satisfying a stability condition in a target phase and a torque range. 35. The inverter control means adopts a transfer function G expressed by the following equation (1), and a gain K _θ of the transfer function G such that all real roots of s of the denominator polynomial of G / (1 + G) become negative. 35. The brushless DC motor control device according to claim 34, wherein the brushless DC motor control device is configured to set the following. 36. The brushless DC motor control device according to claim 28, wherein said inverter control means estimates the rotational position of the rotor using a fixed coordinate motor model. 37. The brushless DC motor control device according to claim 28, wherein said inverter control means identifies a motor device constant before starting operation. 38. The brushless DC motor control device according to claim 28, wherein said inverter control means advances the target current phase to be higher than a maximum efficiency phase or a maximum torque phase of the motor. 39. The brushless DC motor control device according to claim 28, wherein the brushless DC motor drives a compressor.