JP2002252995A - Controlling apparatus of brushless dc motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a calculating process and reduce the cost required for constituting an apparatus while improving accuracy and rapidness of initial response when a motor is controlled. SOLUTION: A constant detecting apparatus 15 of a motor controlling apparatus comprises a detecting part 26, a high frequency voltage applying part 27 and a calculating part 28. The calculating part 28 estimates a winding temperature Ts based on an ambient temperature Tat of the motor 11 and calculates a phase resistance R after a temperature correction. The high frequency voltage applying part 27 superimposes a high frequency voltage Vh on a voltage for driving the motor 11. The calculating part 28 calculates an inductance of a stator winding based on a change of each phase current and searches a value of a magnetic ole position θ re of a rotor from map data in a memory 29. The calculating part 28 stops a switching operation of an inverter 13 and detects an induced voltage waveform when a torque instructing value *T is zero. The calculating part 28 calculates a q-axis inductance Lq only when a q-axis target current *Iq is greater than a predetermined value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a brushless DC motor including a rotor having a permanent magnet and a stator for generating a rotating magnetic field for rotating the rotor.

[0002]

2. Description of the Related Art Conventionally, vehicles equipped with a brushless DC motor using a permanent magnet as a magnetic field have been known as a power source for running the vehicle, such as an electric vehicle or a hybrid vehicle. As a control device of such a brushless DC motor, for example, a rectangular coordinate which measures a phase current supplied to each phase of the brushless DC motor and rotates the measured value of the phase current in synchronization with the rotor, for example, a rotor The direction of the magnetic flux is defined as a d-axis (torque axis), and a direction orthogonal to the d-axis is converted into a d-axis current and a q-axis current on a dq coordinate with a q-axis (field axis). A control device that performs feedback control so that the deviation between the current command value and the measured value becomes zero is known.

That is, from the deviation between the current command value and the measured value on the dq coordinate, that is, the d-axis current deviation and the q-axis current deviation, the d-axis voltage command value and the q The shaft voltage command value is calculated, and then the phase voltages supplied to each phase of the brushless DC motor, for example, three phases of U phase, V phase, and W phase from these d axis voltage command value and q axis voltage command value. Are calculated.
Each of these voltage command values is input as a switching command to an inverter including a switching element such as an IGBT, for example, and AC power for driving the brushless DC motor is output from the inverter in accordance with the switching command.

In such a control device, for example, when calculating a d-axis current command value and a q-axis current command value based on a torque command corresponding to an accelerator operation amount of a vehicle driver, the d-axis inductance and the q-axis current value are calculated. A method of calculating the shaft inductance as a parameter is known. For example,
"T. IEE Japan, Vol. 113-D, No.11, 1993, pp1330"
The d-axis inductance Ld and the q-axis inductance Lq are calculated by the following equation (1) based on a circuit equation obtained from an equivalent circuit of a brushless DC motor in a steady state, as in the method of measuring an equivalent circuit constant disclosed in US Pat. You. Here, R is the resistance of each phase of the brushless DC motor, ω is the electrical angular velocity of the brushless DC motor, ψ is the field main magnetic flux of the brushless DC motor, i
d and iq are the respective d-axis and q-axis currents, vd and vq
Are the d-axis and q-axis voltages.

[0005]

(Equation 1)

[0006]

In the control device for a brushless DC motor according to an example of the prior art, the d-axis inductance Ld is calculated by dividing by the d-axis current id as shown in the above equation (1). And q
The axis inductance Lq is calculated by division by the q-axis current iq. Here, the d-axis current id and the q-axis current i
Since q is calculated from the detected value of the phase current supplied to each phase of the brushless DC motor, for example, when the values of the d-axis current id and the q-axis current iq are relatively small, the detection error of the phase current is calculated. Gives the d-axis inductances Ld and q
There is a possibility that the value of the shaft inductance Lq fluctuates greatly.
In particular, the q-axis current, which is the field axis current, is a brushless DC
When improving the operation efficiency of the motor, since the value is set to a relatively small value, there is a problem that a large error occurs in the calculation result of the q-axis inductance Lq.

Further, the d-axis inductance Ld and the q-axis inductance Lq are accurately calculated, and an accurate d-axis current command value and a q-axis current command value corresponding to a torque command are calculated using these inductances Ld and Lq. In order to calculate and improve the initial response accuracy of the control device and the response at the time of feedback control, for example, the winding resistance value is determined by the magnetic pole position of the rotor of the brushless DC motor or the temperature change during the rotation driving of the brushless DC motor. It is necessary to accurately detect various data such as the winding temperature of the stator winding, which fluctuates, and the induced voltage that fluctuates with the temperature change of the permanent magnet of the rotor. However, various detection errors may occur in each detection device that detects data such as the magnetic pole position of the rotor and the winding temperature of the stator winding, depending on the operation state of the brushless DC motor. For example, a position sensor that detects the magnetic pole position of the rotor has a phase lag characteristic. Therefore, as the rotation speed increases, a signal of the position sensor indicating a predetermined reference position deviates from a true reference position. May be shown. For this reason, correction processing for correcting these detection errors may be required, and the arithmetic processing becomes complicated, the scale of the control device increases, and the cost required for constructing the control device increases. Problems arise.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is intended to improve the initial response accuracy and responsiveness at the time of control, to simplify arithmetic processing, and to reduce the cost required for configuring an apparatus. It is an object of the present invention to provide a control device for a brushless DC motor that is possible.

[0009]

In order to achieve the above object, the present invention provides a brushless DC motor control apparatus according to the present invention, comprising: a rotor having a permanent magnet; And a stator having a plurality of stator windings for generating a rotating magnetic field for rotating the stator.
A control device for a brushless DC motor in which a C motor is rotationally driven by an energization switching means (for example, an inverter 13 in an embodiment described later) which includes a plurality of switching elements and sequentially commutates energization to the stator winding. A phase voltage detecting means (for example, a phase voltage detector 46 in an embodiment described later) for detecting a phase angle and an effective value of a phase voltage of the brushless DC motor, and detecting a phase angle and an effective value of a phase current Phase current detecting means (for example, a phase current detector 47 in an embodiment to be described later) and a position detecting means for detecting a phase angle of an induced voltage from a magnetic pole position of the rotor (for example, in an embodiment to be described later). The magnetic pole position calculation unit 55) and the rotation speed detecting means (for example, the rotation sensor 41 in the embodiment described later) for detecting the rotation speed, and the temperature of the brushless DC motor are detected. Temperature detecting means (for example, an atmosphere temperature sensor 43 or a cooling water temperature sensor in an embodiment described later) and a phase resistance value calculating means (for example, described later) for calculating a phase resistance value based on the detected temperature. (Step S12 in the embodiment described below) and an induced voltage constant deriving means for deriving an induced voltage constant (for example, Step S22 in an embodiment described later), and a voltage level comprising a phase difference between the induced voltage and the phase voltage. Phase difference calculating means for calculating a phase difference and a current phase difference consisting of a phase difference between the induced voltage and the phase current (for example, step S15 in an embodiment described later)
And step S16), an iron loss calculating means for calculating the iron loss of the brushless DC motor being rotationally driven (for example, steps S18 to S24 in an embodiment to be described later), and the phase based on the iron loss. Real-phase current calculation means for calculating the real-phase current by subtracting the iron loss component from the current (for example, step S26 in an embodiment described later)
And inductance calculating means for calculating a field axis inductance and a torque axis inductance based on the phase resistance value, the rotation speed, the induced voltage constant, the voltage phase difference, the current phase difference, and the real phase current (for example, Step S27 in an embodiment described later), torque command input means for inputting a torque command value (for example, torque command calculation unit 21 in an embodiment described later), the induced voltage constant and the field axis inductance. Current command value calculating means for calculating a field axis current command value and a torque axis current command value based on the torque axis inductance and the torque command value (for example, a target current calculation unit 2 in an embodiment described later)
2) and pulse width modulation signal output means for outputting a pulse width modulation signal to the energization switching means based on the field axis current command value and the torque axis current command value (for example, in an embodiment described later) And a feedback control unit 23).
The inductance calculating means calculates only the torque axis inductance when the field axis current command value or the torque axis current command value is equal to or less than a predetermined value, and calculates the field axis current command value or the torque axis current command value. When the value exceeds the predetermined value, the field axis inductance and the torque axis inductance are calculated.

According to the control device for a brushless DC motor having the above configuration, when calculating the torque axis inductance calculated by dividing the torque axis current and the field axis inductance calculated by dividing the field axis current, When the magnetic axis current command value or the torque axis current command value exceeds a predetermined value, the torque axis inductance and the field axis inductance are calculated, and when the field axis current command value or the torque axis current command value is equal to or less than the predetermined value. Then, only the torque axis inductance is calculated. Accordingly, even if the field axis current and the torque axis current calculated based on the detected values of the phase currents supplied to the respective phases of the brushless DC motor include an appropriate detection error, the torque axis inductance can be reduced. In addition, it is possible to suppress an increase in an error with respect to the calculation result of the field axis inductance. Therefore, the torque axis inductance and the field axis inductance can be calculated with high accuracy without excessively increasing the detection accuracy of the phase current detection means for detecting each phase current, and a control device for the brushless DC motor is constructed. The cost required for the operation can be reduced. In addition, if the desired calculation accuracy cannot be expected from the calculation results of the torque axis inductance and the field axis inductance, the calculation processing is not executed, so that the calculation load on the control device can be reduced.

According to a second aspect of the present invention, there is provided a brushless DC motor control apparatus including a rotor having a permanent magnet, and a plurality of phases of stator windings for generating a rotating magnetic field for rotating the rotor. Brushless DC with stator
A motor is formed by a plurality of switching elements, and a current switching means (for example,
A control device for a brushless DC motor that is driven to rotate by an inverter 13 according to an embodiment described below, and includes a phase voltage detection unit (for example, an embodiment described below) that detects a phase angle and an effective value of a phase voltage of the brushless DC motor. Phase voltage detector 46), phase current detection means for detecting the phase angle and the effective value of the phase current (for example, phase current detector 47 in an embodiment to be described later) and the magnetic pole position of the rotor. Position detecting means for detecting the phase angle of the induced voltage (for example,
A magnetic pole position calculating unit 55 in an embodiment described later) and a rotation speed detecting means (for example, a rotation sensor 41 in an embodiment described later) for detecting a rotation speed, and a phase resistance based on the temperature of the brushless DC motor. Phase resistance value calculating means for calculating the value (for example, step S1 in an embodiment described later)
2) and a phase difference calculating means for calculating a voltage phase difference consisting of a phase difference between the induced voltage and the phase voltage and a current phase difference consisting of a phase difference between the induced voltage and the phase current (for example, an embodiment described later) Steps S15 and S16 in the form)
Iron loss calculating means for calculating iron loss of the brushless DC motor during rotation (for example, steps S18 to S24 in an embodiment described later), and iron loss from the phase current based on the iron loss. A real-phase current calculating means for calculating a real-phase current by subtracting a component (for example, step S26 in an embodiment described later), and a power supply to the brushless DC motor is temporarily stopped by stopping a switching operation of the energization switching means. Power supply stop control means (for example, step S34 in an embodiment to be described later) for stopping the operation, and the phase voltage detection means detecting the voltage value of the induced voltage during the stop of the switching operation, and Field axis inductance and torque axis inductance based on the voltage value of the induced voltage, the voltage phase difference, the current phase difference, and the real phase current. Calculated for inductance calculation means (e.g., step S27 in the embodiment described below)
And a torque command input means for inputting a torque command value (for example, a torque command calculation unit 21 in an embodiment described later)
Current command value calculating means for calculating a field axis current command value and a torque axis current command value based on a voltage value of the induced voltage, the field axis inductance, the torque axis inductance, and the torque command value ( For example, a pulse width modulation that outputs a pulse width modulation signal to the energization switching means based on a target current calculation unit 22) in the embodiment described later and the field axis current command value and the torque axis current command value. And a signal output unit (for example, a feedback control unit 23 in an embodiment described later).

According to the control device for a brushless DC motor having the above-described configuration, when the energization of the brushless DC motor may be stopped according to the operating state of the brushless DC motor, for example, a request is made for the brushless DC motor. When the torque command value is zero, when the field axis current command value and the torque axis current command value are zero, when the phase voltage command values are zero, or when the field axis voltage command value and the torque axis voltage command When the value is zero or the like, the switching operation of the power supply switching means is stopped by the power supply stop control means, and the power supply to the brushless DC motor is temporarily stopped. Thereby, when the voltage waveform of the induced voltage is directly detected by the phase voltage detecting means, for example, a brushless DC
The induced voltage can be detected only at an appropriate timing at which the energization can be stopped, without the need to provide a cutoff circuit or the like for cutting off the power supply line to the motor, which is necessary when building a control device for a brushless DC motor. Costs can be reduced.

According to a third aspect of the present invention, there is provided a brushless DC motor control apparatus including a rotor having a permanent magnet and a plurality of phases of stator windings for generating a rotating magnetic field for rotating the rotor. Brushless DC with stator
A motor is formed by a plurality of switching elements, and a current switching means (for example,
A control device for a brushless DC motor that is driven to rotate by an inverter 13 according to an embodiment described below, and includes a phase voltage detection unit (for example, an embodiment described below) that detects a phase angle and an effective value of a phase voltage of the brushless DC motor. Phase voltage detector 46), phase current detection means for detecting the phase angle and the effective value of the phase current (for example, phase current detector 47 in an embodiment to be described later) and the magnetic pole position of the rotor. Position detecting means for detecting the phase angle of the induced voltage (for example,
A magnetic pole position calculating unit 55 in an embodiment described later) and a rotation speed detecting means (for example, a rotation sensor 41 in an embodiment described later) for detecting a rotation speed, and a phase resistance based on the temperature of the brushless DC motor. Phase resistance value calculating means for calculating the value (for example, step S1 in an embodiment described later)
2) and a phase difference calculating means for calculating a voltage phase difference consisting of a phase difference between the induced voltage and the phase voltage and a current phase difference consisting of a phase difference between the induced voltage and the phase current (for example, an embodiment described later) Steps S15 and S16 in the form)
Iron loss calculating means for calculating iron loss of the brushless DC motor during rotation (for example, steps S18 to S24 in an embodiment described later), and iron loss from the phase current based on the iron loss. A real-phase current calculation means (for example, step S26 in an embodiment described later) for calculating a real-phase current by subtracting a component, and a power supply to the brushless DC motor is temporarily stopped by stopping a switching operation of the energization switching means. Power supply stop control means (for example, step S34 in an embodiment to be described later) for stopping the power supply, and an input to the plural-phase stator windings connected between the power supply switching means and the brushless DC motor. A rectifier for performing full-wave rectification of current (for example, a three-phase bridge rectifier circuit 56a in an embodiment described later) and a rectifier for detecting a full-wave rectified voltage by the rectifier. A voltage detecting unit (for example, a rectified voltage detecting unit 56b in an embodiment described later) and the rectified voltage detecting unit detects a voltage value of the induced voltage while the switching operation is stopped, and detects the phase resistance value and the phase resistance value. Inductance calculating means for calculating a field axis inductance and a torque axis inductance based on the voltage value of the induced voltage, the voltage phase difference, the current phase difference, and the real phase current (for example, step S27 in an embodiment described later). Torque command input means (for example, a torque command calculation unit 21 in an embodiment described later) for inputting a torque command value, a voltage value of the induced voltage, the field axis inductance, the torque axis inductance, and the torque Based on the command value,
Current command value calculation means (for example, a target current calculation unit 22 in an embodiment described later) for calculating a field axis current command value and a torque axis current command value, and the field axis current command value and the torque axis current A pulse width modulation signal output unit (for example, a feedback control unit 23 in an embodiment described later) that outputs a pulse width modulation signal to the energization switching unit based on the command value.

According to the control device for a brushless DC motor having the above configuration, the switching operation of the power supply switching means is stopped by the power supply stop control means to temporarily supply power to the brushless DC motor in accordance with the operation state of the brushless DC motor. Stop. Then, the rectifier converts the phase voltage of the brushless DC motor into full-wave rectified voltage by full-wave rectification. Next, the rectified voltage detection means detects, for example, the voltage value of the induced voltage after smoothing the full-wave rectified voltage. Thereby, for example, a complicated calculation process of detecting the voltage waveform of the induced voltage by the phase voltage detection means, extracting a primary component from the voltage waveform and calculating the effective value can be omitted, and such a process can be omitted. Since the relatively high-speed sampling process required in the calculation of the effective value can be omitted, the calculation load on the control device can be reduced.

Further, the control device for a brushless DC motor according to the present invention includes an output torque detecting means (for example, a torque sensor 42 in an embodiment described later) for detecting an output torque. When the detection cycle of the current detection means is a first cycle T1, the detection cycle of the output torque detection means is a second cycle T2, and the temperature detection cycle is a third cycle T3, The detection control is performed by setting the second and third periods in a relationship of T1 ≦ T2 ≦ T3.

According to the control device for a brushless DC motor having the above-described configuration, for example, a control parameter that makes relatively slow or small fluctuations, a control parameter that requires an integration process to be included in a required calculation process, and the like. By setting the detection cycle to be long, the calculation load of the control device can be reduced.

Further, in the control device for a brushless DC motor according to the present invention, the inductance calculating means stores operation data during rotation driving of the brushless DC motor, and stops the rotation of the brushless DC motor. It is characterized in that calculation processing of the field axis inductance and the torque axis inductance is performed therein.

According to the control device for a brushless DC motor having the above-described configuration, the process of calculating the field axis inductance and the torque axis inductance having a relatively large calculation load is performed when the brushless DC motor is stopped, that is, feedback control for the brushless DC motor. By executing the above calculation process when the calculation load that makes unnecessary is light, it is possible to suppress an increase in the calculation load of the control device.

According to a sixth aspect of the present invention, there is provided a brushless DC motor control device comprising: a rotor having a permanent magnet; and a plurality of phases of stator windings for generating a rotating magnetic field for rotating the rotor. Brushless DC with stator
A motor is formed by a plurality of switching elements, and a current switching means (for example,
A control device for a brushless DC motor that is driven to rotate by an inverter 13 according to an embodiment described below, and includes a phase voltage detection unit (for example, an embodiment described below) that detects a phase angle and an effective value of a phase voltage of the brushless DC motor. Phase voltage detector 46), phase current detection means for detecting the phase angle and the effective value of the phase current (for example, phase current detector 47 in an embodiment to be described later) and the magnetic pole position of the rotor. Position detecting means for detecting the phase angle of the induced voltage (for example,
A magnetic pole position calculating unit 55 in an embodiment described later) and a rotation speed detecting unit (for example, a rotation sensor 41 in an embodiment described later) for detecting a rotation speed, and a temperature of the brushless DC motor are measured by the rotation speed. Or the brushless DC
A predetermined temperature stored in advance based on a motor cooling water temperature (for example, a cooling water temperature Tc in an embodiment described later) or a surrounding temperature of the brushless DC motor (for example, an ambient temperature Tat in an embodiment described later). Temperature estimating means calculated from data (for example, in an embodiment described later,
A phase resistance value calculating means (for example, step S12 in an embodiment to be described later) for calculating a phase resistance value based on the temperature estimated by the temperature estimating means, and an induced voltage constant. (For example, an induced voltage constant calculation unit 53 in an embodiment described later), a voltage phase difference including a phase difference between the induced voltage and a phase voltage, and an induced voltage and a phase current. Phase difference calculating means (for example, steps S15 and S16 in an embodiment described later) for calculating a current phase difference composed of the phase difference between the brushless D and the brushless D during rotation driving.
Iron loss calculating means for calculating iron loss of the C motor (for example,
Step S18 to step S2 in the embodiment described later
4) actual phase current calculating means (for example, step S26 in an embodiment described later) for calculating an actual phase current by subtracting an iron loss component from the phase current based on the iron loss; Inductance calculating means for calculating a field axis inductance and a torque axis inductance based on the rotation speed, the induced voltage constant, the voltage phase difference, the current phase difference, and the real phase current (for example, in an embodiment described later) Step S27), torque command input means for inputting a torque command value (for example, a torque command calculation unit 21 in an embodiment described later), the induced voltage constant, the field axis inductance, the torque axis inductance, Current command value calculation means for calculating a field axis current command value and a torque axis current command value based on the torque command value (for example, A target current calculation unit 22) in the form,
Pulse width modulation signal output means for outputting a pulse width modulation signal to the energization switching means based on the field axis current command value and the torque axis current command value (for example, a feedback control unit 23 in an embodiment described later) ).

According to the control device for a brushless DC motor having the above-described configuration, for example, in a brushless DC motor that is being driven in rotation, when the phase resistance value that increases as the winding temperature of the stator winding increases is appropriately calculated. In addition, a winding temperature detector for directly detecting the winding temperature of the stator winding can be omitted. That is, for example, the ambient temperature of the brushless DC motor detected by an ambient temperature sensor provided in a housing or the like of the brushless DC motor, or the cooling water temperature detected by a cooling water temperature sensor provided in a cooling system of the brushless DC motor, for example. For example, predetermined data indicating the relationship between the number of revolutions of a brushless DC motor having a predetermined correlation with iron loss and copper loss and the winding temperature is stored in a memory or the like in advance, and the detected atmosphere is stored. This data is retrieved according to the temperature, the cooling water temperature, and the number of rotations to obtain an estimated value of the winding temperature. Thereby, brushless D
The cost required for constructing the control device for the C motor can be reduced.

According to a seventh aspect of the present invention, there is provided a brushless DC motor control device comprising: a rotor having a permanent magnet; and a plurality of phases of stator windings for generating a rotating magnetic field for rotating the rotor. Brushless DC with stator
A motor is formed by a plurality of switching elements, and a current switching means (for example,
A control device for a brushless DC motor that is driven to rotate by an inverter 13 according to an embodiment described below, and includes a phase voltage detection unit (for example, an embodiment described below) that detects a phase angle and an effective value of a phase voltage of the brushless DC motor. Phase voltage detector 46), phase current detection means for detecting the phase angle and the effective value of the phase current (for example, phase current detector 47 in an embodiment to be described later) and the magnetic pole position of the rotor. Position detecting means for detecting the phase angle of the induced voltage (for example,
A magnetic pole position calculation unit 55 in an embodiment described later), a rotation speed detection unit (for example, a rotation sensor 41 in an embodiment described later) for detecting a rotation speed, and an output torque detection unit (for example, a rotation sensor 41 for an embodiment described later) Based on the detected temperature, a torque sensor 42 in an embodiment described later) and temperature detecting means for detecting the temperature of the brushless DC motor (for example, step S12 is also used in an embodiment described later). A phase resistance value calculating means for calculating a phase resistance value (for example, in an embodiment described later, step S12
And an induced voltage constant deriving means for deriving an induced voltage constant (for example, an induced voltage constant calculation unit 53 in an embodiment to be described later), and a voltage phase difference comprising a phase difference between the induced voltage and the phase voltage. A phase difference calculating means (for example, steps S15 and S16 in an embodiment described later) for calculating a current phase difference comprising a phase difference between the induced voltage and the phase current, and the brushless DC motor being rotationally driven. Iron loss calculating means for calculating iron loss (for example, steps S18 to S24 in the embodiment described later)
A real-phase current calculating means (for example, a real-phase current calculating means for calculating a real-phase current by subtracting an iron-loss component from the phase current based on the iron loss)
Step S26 in an embodiment to be described later), a field axis inductance and a torque axis based on the phase resistance value, the rotation speed, the induced voltage constant, the voltage phase difference, the current phase difference, and the real phase current. An inductance calculating means for calculating the inductance (for example, step S27 in an embodiment described later), a torque command inputting means for inputting a torque command value (for example, a torque command calculating unit 21 in an embodiment to be described later), Current command value calculating means (for example, a current command value calculating means for calculating a field axis current command value and a torque axis current command value based on the induced voltage constant, the field axis inductance, the torque axis inductance, and the torque command value)
A target current calculation unit 22) according to an embodiment described later, and a pulse width modulation signal output that outputs a pulse width modulation signal to the energization switching unit based on the field axis current command value and the torque axis current command value. Means (for example, a feedback control unit 23 in an embodiment to be described later), wherein the iron loss calculating means includes a motor output power and a motor input power of the brushless DC motor based on the output torque and the rotation speed. (For example, step S18 in an embodiment to be described later) and a copper loss calculation unit for calculating a copper loss based on the phase resistance value and the phase current (for example, an embodiment to be described later). Step S19), and a motor total loss calculating means (for example, a rear motor loss calculating unit) for calculating the motor total loss by subtracting the motor output power from the motor input power. Step S in the embodiments of
20), mechanical loss calculating means for calculating the mechanical loss of the brushless DC motor (for example, step S21 in the embodiment described later), and subtracting the copper loss and the mechanical loss from the total motor loss, Subtraction means for calculating iron loss (for example, step S in the embodiment described later)
24) and equivalent resistance value calculating means (for example, step S25 in an embodiment described later) for calculating an actually measured iron loss equivalent resistance value based on the effective value including all frequency components of the phase voltage and the iron loss. Wherein the temperature detecting means calculates the temperature of the brushless DC motor from predetermined estimated temperature data in which an estimated temperature for the total loss of the motor is stored in advance.

According to the control device for a brushless DC motor having the above-described configuration, for example, in a brushless DC motor that is being driven in rotation, when the phase resistance value that increases as the winding temperature of the stator winding increases is appropriately calculated. In addition, a winding temperature detector for detecting the winding temperature of the stator winding can be omitted. That is, for example, predetermined data indicating the relationship between the total motor loss that can be calculated based on the rotation speed detected by the rotation sensor and the output torque detected by the torque sensor and the winding temperature is stored in a memory or the like in advance. The data is retrieved according to the calculated total motor loss to obtain the value of the winding temperature. As a result, it is possible to reduce the cost required when constructing the control device for the brushless DC motor.

Further, in the control device for a brushless DC motor according to the present invention, the position detecting means may include:
A magnetic pole position of the rotor is calculated from an amount of change in inductance when a high-frequency voltage is applied to the brushless DC motor.

According to the control device for a brushless DC motor having the above configuration, the position of the magnetic pole of the rotor is detected by so-called position sensorless control, so that the position sensor provided in the brushless DC motor can be omitted. In order to correct a detection error caused by a phase delay characteristic of a position sensor, that is, a signal of a position sensor indicating a predetermined reference position indicating a value deviated from a true reference position as the rotation speed increases. Can be omitted. As a result, it is possible to reduce the cost required when constructing a control device for the brushless DC motor, and
The calculation load on the control device can be reduced.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a control device for a brushless DC motor according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a configuration diagram of a control device 10 for a brushless DC motor according to an embodiment of the present invention.
FIG. 3 is a configuration diagram showing a specific configuration of the feedback control unit 23 and the calculation unit 28 shown in FIG. 1, and FIG. 3 is a configuration diagram showing a specific configuration of the constant detection device 15 shown in FIG. The brushless DC motor control device 10 (hereinafter, referred to as “motor control device 10”) according to the present embodiment is a brushless DC motor mounted on, for example, an electric vehicle or a hybrid vehicle.
The motor 11 (hereinafter, referred to as “motor 11”) is driven and controlled. The motor 11 includes a rotor (not shown) having a permanent magnet used for a field, and a rotation for rotating the rotor. And a stator (not shown) for generating a magnetic field. As shown in FIG. 1, this motor control device 10 is, for example, an ECU (Electric Control Uniform).
t) 12, an inverter 13, a power supply 14, and a constant detection device 15.

The inverter 13 serving as the current switching means is, for example, a PWM inverter based on pulse width modulation, and is composed of a switching circuit in which a plurality of switching elements such as IGBTs are connected in a bridge.
Then, the inverter 13 converts DC power supplied from a power supply 14 composed of, for example, a battery or a fuel cell, into three-phase AC power, and supplies the three-phase AC power to the motor 11. That is, a motor 11 of a plurality of phases (for example, three phases of a U phase, a V phase, and a W phase)
Of the stator windings are sequentially commutated. The ECU 12 controls the power conversion operation of the inverter 13 and inputs the U-phase AC voltage command value * Vu, the V-phase AC voltage command value * Vv, and the W-phase AC voltage command value * Vw to the inverter 13 as switching commands. , U-phase current I according to each of these voltage command values * Vu, * Vv, * Vw
u and V-phase current Iv and W-phase current Iw
3 to each phase of the motor 11.

For this purpose, the ECU 12 includes a torque command calculator 21, a target current calculator 22, and a feedback controller 23. Torque command calculator 21
Is, for example, an accelerator operation amount Ac relating to a depression operation of an accelerator pedal by a driver and a detection unit 26 described later.
The required torque value is calculated based on the rotation speed N of the motor 11 detected by
Is generated and output to the target current calculator 22.

The target current calculator 22 calculates a torque command value * T
, A current command for designating each phase current Iu, Iv, Iw supplied from the inverter 13 to the motor 11 is calculated based on the d-axis target current * on the rotating rectangular coordinates. As Id and q-axis target current * Iq,
It is output to the feedback control unit 23. The dq coordinates forming the rotation orthogonal coordinates are, for example, the d-axis (torque axis) in the magnetic flux direction of the rotor and the q-axis (field axis) in the direction orthogonal to the d-axis. Omitted)
At the same time with the electrical angular velocity ωre. As a result, a d-axis target current * Id and a q-axis target current * Iq, which are DC signals, are given as a current command for an AC signal supplied from the inverter 13 to each phase of the motor 11.

Here, the target current calculator 22 includes a d-axis current calculator 24 and a q-axis current calculator 25. The d-axis current calculator 24 calculates a torque command value * T and an induced voltage constant K
Based on e, a d-axis target current * Id is calculated. The q-axis current calculator 25 calculates the q-axis target current based on the torque command value * T, the induced voltage constant Ke, the d-axis inductance Ld, and the q-axis inductance Lq, as shown in the following equation (3). * Calculate Iq.

[0030]

(Equation 2)

[0031]

[Equation 3]

The feedback control section 23 performs current feedback control on the dq coordinates. Based on the d-axis target current * Id and the q-axis target current * Iq, the respective voltage command values * Vu, * Vv, * Vw is calculated, a pulse width modulation signal is input to the inverter 13, and each phase current Iu,
Control is performed so that each deviation between the d-axis current Id and the q-axis current Iq obtained by converting Iv and Iw on the dq coordinate and the d-axis target current * Id and the q-axis target current * Iq becomes zero. . For this reason, the d-axis current Id and the q-axis current Iq output from the constant detecting device 15 and the d-axis inductance Ld and the q-axis inductance L
Signals such as q are input.

The constant detecting device 15 includes a detecting unit 26, a high-frequency voltage applying unit 27, and a calculating unit 28. The detecting unit 26 outputs a detection signal of the rotation speed N of the motor 11, The detection signal of the motor torque Tor and the motor 11
Detection signal of the ambient temperature Tat and the motor temperature Tmag
That is, the detection signal of the temperature of the rotor (not shown) of the motor 11 and the phase voltage supplied to each phase of the motor 11 (for example, the U-phase output point U and the neutral point of each phase output point of the inverter 13) N and the detection signal of the U-phase voltage Vun)
1, a detection signal of a phase current (for example, a U-phase current Iu and a W-phase current Iw) supplied to each phase and a detection signal of a power supply voltage Vdc output from the power supply 14 are output. The data is input to the calculation unit 28. Then, as described later, a predetermined calculation process is performed based on various detection signals output from the detection unit 26, and the d-axis currents Id and q
The shaft current Iq, the induced voltage constant Ke, the d-axis inductance Ld, and the q-axis inductance Lq are calculated.

Hereinafter, the feedback control section 23 will be described with reference to FIG. The d-axis current Id and the q-axis current Iq detected and output by the constant detection device 15 are:
The signals are input to subtracters 31 and 32, respectively. And
The subtractor 31 calculates a deviation ΔId between the d-axis target current * Id and the d-axis current Id, and the subtractor 32 calculates a deviation ΔIq between the q-axis target current * Iq and the q-axis current Iq. In this case, d
Since the axis target current * Id and the q-axis target current * Iq and the d-axis current Id and the q-axis current Iq are DC signals, for example, phase delay, amplitude error, etc. are detected as DC components.

The deviation Δ output from each of the subtracters 31 and 32
Id and the deviation ΔIq are calculated by the current control units 33 and 34, respectively.
Has been entered. The current control unit 33 controls and amplifies the deviation ΔId by, for example, PI (proportional integration) operation to calculate a d-axis voltage command value * Vd, and the current control unit 34 controls and amplifies the deviation ΔIq by, for example, PI operation. To calculate the q-axis voltage command value * Vq.

The d-axis voltage command value * Vd output from the current control unit 33 and the q-axis voltage command value * Vq output from the current control unit 34 are input to a dq.3-phase AC coordinate converter 38. The dq · three-phase AC coordinate converter 38 calculates the d-axis voltage command value * Vd and the q-axis voltage command value * Vq on the dq coordinates.
Are, for example, U-phase AC voltage command values * Vu and V-phase AC voltage command values * Vv and W on three-phase AC coordinates that are stationary coordinates.
It is converted into a phase AC voltage command value * Vw.

The U-phase AC voltage command value * Vu, V-phase AC voltage command value * Vv, and W-phase AC voltage command value * Vw output from the dq · 3-phase AC coordinate converter 38 It is supplied to the inverter 13 as a switching command (for example, a pulse width modulation signal) for turning on / off the element.

The constant detecting device 15 will now be described with reference to FIG.
This will be described with reference to FIG. As shown in FIG.
The detection unit 26 includes, for example, a rotation sensor 41 and a torque sensor 42 that perform a detection operation at predetermined timings described below.
, Ambient temperature sensor 43, and rotor temperature sensor 44
, A phase voltage detector 46 and, for example, two phase current detectors 4
7, 47 are provided.

The rotation sensor 41 detects the rotation speed N of a rotor (not shown) of the motor 11. Torque sensor 42
Detects the motor torque Tor output from the motor 11. The ambient temperature sensor 43 is provided in, for example, a housing (not shown) that fixedly accommodates the motor 11 and detects the ambient temperature Tat of the motor 11. The rotor temperature sensor 44 detects a motor temperature Tmag, that is, a temperature of a permanent magnet provided in a rotor (not shown) of the motor 11.

The phase voltage detector 46 detects a phase voltage supplied to each phase of the motor 11 (for example, a U-phase output point between the U-phase output point U and the neutral point N of each phase output point of the inverter 13). Voltage V
un), and the calculation unit 28 calculates the phase and the effective value of the primary component of the phase voltage and the effective value including all frequency components based on the detection signal. The phase current detectors 47, 47 detect the phase currents I supplied to each phase of the motor 11.
m (for example, U-phase current Iu), and the calculation unit 28 calculates the phase and the effective value of the primary component of the phase current and the effective value including all frequency components based on the detection signal. .

The high frequency voltage applying section 27 has a torque command value *
The frequencies of the phase voltages Vu, Vv, Vw supplied from the inverter 13 to the respective phases of the motor 11 can be discriminated therefrom so that the respective phase currents Iu, Iv, Iw calculated based on T can be obtained. A high frequency voltage Vh of a frequency that is high enough is superimposed and output. That is, the high-frequency voltage applying unit 27
Is a high-frequency voltage Vh for detection when calculating the magnetic pole position θre of the rotor by so-called position sensorless control.
Is the voltage for driving the motor 11 (that is, the phase voltages Vu, V
v, Vw), and the phase current detectors 47, 47 detect the inductance of the stator winding, which changes with the rotation of the rotor, in the calculation unit 28 as described later. Calculation is performed based on the behavior of each phase current (for example, U-phase current Iu and W-phase current Iw), and the magnetic pole position θre of the rotor is calculated from the inductance value.

As shown in FIG. 2, the calculating unit 28 of the constant detecting device 15 includes, for example, an AC / dq coordinate converter 51, a d-axis / q-axis current calculating unit (Id / Iq calculating unit) 52, and an induced voltage. A constant operation unit (Ke operation unit) 53, a d-axis / q-axis inductance estimation operation unit (Ld / Lq estimation operation unit) 54,
And a magnetic pole position calculation unit 55. The AC / dq coordinate converter 51 converts an appropriate one-phase current on the stationary coordinates, for example, the U-phase current Iu, into the rotational coordinates based on the rotational phase of the motor 11, that is, the d-axis current Id and the q-axis current Iq on the dq coordinates. Convert to

As will be described later, the d-axis / q-axis current calculation unit 52 performs a predetermined correction process on the d-axis current Id and the q-axis current Iq including the iron loss component calculated by the AC / dq coordinate converter 51. The d-axis current Id and the q-axis current Iq after the correction by removing the iron loss component by performing
Output to the feedback control unit 23 as q. As will be described later, the induced voltage constant calculator 53 includes, for example, a torque command value * T, target currents * Id, * Iq, voltage command values * Vu, * Vv, * Vw, and voltage command values * Vd, *
Under predetermined conditions for Vq and the like, the inverter 13
Is stopped, and the induced voltage waveform of the motor 11 is directly measured by the phase voltage detector 46.
Then, the induced voltage constant Ke is calculated by calculating the effective value E of the induced voltage and dividing the effective value E by the number of revolutions N, and outputs it to the target current calculator 22. As will be described later, the d-axis / q-axis inductance estimating calculation unit 54 calculates the d-axis inductance Ld and the q-axis inductance Lq in the actual operation state of the motor 11.
Is calculated and output to the ECU 12.

The magnetic pole position calculating section 55 detects the inductance of the stator winding, which changes with the rotation of the rotor of the motor 11, for each phase current (for example, U phase current) detected by the phase current detectors 47, 47. Iu and W-phase current Iw). For example, in the high-frequency voltage application unit 27, the driving voltages of the motor 11 (that is, the phase voltages Vu, Vv, V
A high frequency voltage Vh having a frequency high enough to be discriminated therefrom is superimposed on w). And this high frequency voltage V
Measurement data detected as a transient response of each phase current after application of h, for example, a time until the current value reaches a predetermined value, a current value after a predetermined time, a magnetic pole position of the rotor, or the like. Measurement data correlated with the inductance of the stator winding that changes according to θre is measured based on the detected value of the phase current by the phase current detector 47.

Here, the memory 29 stores in advance the value of the stator winding inductance corresponding to these measurement data or a predetermined calculation formula for calculating the stator winding inductance based on these measurement data. The magnetic pole position calculation unit 55 measures, for example, the time until the current value reaches a predetermined value, based on the detection of the phase current by the phase current detector 47, or the time after the lapse of the predetermined time. The value of the inductance of the stator winding corresponding to the measurement data such as the current value is searched and read. Further, the memory 29 previously stores data indicating the relationship between the inductance of the stator winding and the magnetic pole position θre of the rotor corresponding to the phase angle of the induced voltage. The value of the magnetic pole position θre of the rotor corresponding to the obtained value of the inductance of the stator winding is retrieved and read.

The motor control device 10 according to the present embodiment has the above configuration.
, In particular, the operation of the constant detection device 15 will be described with reference to the accompanying drawings. FIG. 4 is a flowchart showing a schematic operation of the constant detection device 15, FIG. 5 is a flowchart showing a specific calculation operation of the constant detection device 15, and FIG.
FIG. 7 is a graph showing an estimated winding temperature T that varies with the rotational speed N. FIG.
It is a graph which shows loss_mecha.

First, in step S01 shown in FIG. 4, each detection signal (measured value) is obtained from the detection unit 26.
Next, in step S02, as described later, the winding temperature Ts of the stator winding of the motor 11 is estimated based on the ambient temperature Tat of the motor 11 detected by the ambient temperature sensor 43. By correcting the winding resistance Ro that changes according to the temperature Ts, the copper loss Pl after the temperature correction is corrected.
oss_r is calculated. Next, in step S03, for example, the total loss Ploss_all of the motor 11
, Copper loss Ploss_r, and mechanical loss Ploss_m
The iron loss Ploss_iron is calculated based on the echa.

Next, in step S04, the measured iron loss equivalent resistance ri_real is calculated as described later. Next, in step S05, an effective phase current after iron loss separation (hereinafter, referred to as “actual phase current”) is calculated. Next, in step S06, based on the actual phase current after iron loss separation, the phase resistance value derived using the above measured values, the induced voltage, and the actual current phase difference, the d-axis inductance Ld And the q-axis inductance Lq. Next, in step S07, a voltage vector diagram is drawn based on the inductances Ld and Lq.

Hereinafter, a specific calculation operation in the calculation unit 28 of the constant detection device 15 will be described with reference to the accompanying drawings. First, in step S11 shown in FIG. 5, as an initial setting value, a predetermined normal temperature (for example, temperature #
At T = 20 ° C.), the winding resistance Ro and the wiring resistance r are read from data stored in the memory 29 in advance. next,
In step S12, as shown in the following equation (4), the ambient temperature sensor 4
3, the winding temperature Ts of the stator winding of the motor 11 estimated based on the ambient temperature Tat of the motor 11 detected in
The wiring resistance r is added to a value obtained by correcting the winding resistance Ro based on a predetermined temperature gradient coefficient C that differs according to the material of the winding, and the phase resistance value R after temperature correction is calculated. . Here, the estimated winding temperature T for the stator winding of the motor 11
6 changes in accordance with an increase in the ambient temperature Tat of the motor 11 detected by the ambient temperature sensor 43 as shown in FIG.
The arithmetic unit 28 searches for the estimated winding temperature T corresponding to the ambient temperature Tat detected during the rotation driving, and stores a data map of the estimated winding temperature T that changes according to
It is read as the winding temperature Ts.

[0050]

(Equation 4)

Next, in step S13, the phase voltage detected by the phase voltage detector 46 (for example, the U-phase voltage V
un), a primary component of the phase voltage is calculated by, for example, a fast Fourier transformer FFT (not shown), and an effective value voltage for the primary component, that is, a primary voltage of the phase voltage, is calculated. Next, in step S14, the magnetic pole position calculation unit 55 causes the phase current detector 47,
A magnetic pole position θre of the rotor corresponding to the phase angle of the induced voltage is calculated based on each phase current detected at 47 (for example, the U-phase current Iu and the W-phase current Iw).

Next, in step S15, the magnetic pole position θre of the rotor corresponding to the phase angle of the induced voltage calculated by the magnetic pole position calculation unit 55 and the phase voltage detected by the phase voltage detector 46 (for example, , U phase voltage Vun) based on a primary component of the phase voltage obtained by, for example, the fast Fourier transformer FFT, a voltage phase difference γ representing a phase difference between the phase of the induced voltage and the phase of the primary component of the phase voltage is calculated. calculate. The voltage phase difference γ is used for calculating a field axis inductance (q-axis inductance Lq) and a torque axis inductance (d-axis inductance Ld), which will be described later.

Next, in step S16, from the phase current Im (for example, U-phase current Iu) detected by the phase current detector 47, the primary component of the phase current obtained by, for example, the fast Fourier transformer FFT is calculated. Phase and magnetic pole position calculator 5
Based on the phase of the induced voltage calculated in step 5, the current phase difference α1 representing the phase difference between the primary component of the phase current and the induced voltage is calculated. The phase difference α1 still includes an iron loss component, and is used for calculating a field axis inductance (q-axis inductance Lq) and a torque axis inductance (d-axis inductance Ld), which will be described later.

Next, at step S17, the rotation speed N of the rotor (not shown) of the motor 11 is acquired by the rotation sensor 41. Next, in step S18, as shown in the following equation (5), based on the rotation speed N of the motor 11 detected by the rotation sensor 41 and the motor torque Tor detected by the torque sensor 42, Motor 11
Is calculated.

[0055]

(Equation 5)

Next, in step S19, as shown in the following equation (6), the phase resistance value R calculated in step S12 and all the frequency components of the phase current detected by the phase current detector 47 are included. Phase current Im which is an effective current value
(For example, U-phase current Iu), the copper loss Plo
ss_r is calculated.

[0057]

(Equation 6)

Next, in step S20, as shown in the following equation (7), the output power Pout of the motor 11 calculated in step S18 is detected by detecting the motor input power Pin supplied from the inverter 13 to the motor 11. By subtracting from the value, the total loss Ploss of the motor 11 is obtained.
_All is calculated.

[0059]

(Equation 7)

Next, in step S21, the mechanical loss Ploss_ that changes according to the rotation speed N of the motor 11 is determined.
“mecha” is searched from the data map stored in the memory 29 in advance. Here, mechanical loss Ploss_mec
As shown in FIG. 7, ha has a characteristic of changing in an increasing trend with an increase in the rotation speed N. The value of the mechanical loss Ploss_mecha for each rotation speed N is stored in the memory 29. , The value of the mechanical loss Ploss_mecha corresponding to the rotation speed N detected during the rotation driving is searched and read. Next, in step S22, the effective value E of the induced voltage is calculated from the induced voltage waveform of the motor 11 directly detected by the phase voltage detector 46 in the induced voltage detection processing described later, and is represented by the following equation (8). As described above, the induced voltage constant Ke is calculated by dividing by the rotation speed N.

[0061]

(Equation 8)

Next, in step S23, from the phase current Im (for example, U-phase current Iu) detected by the phase current detector 47, the primary component of the phase current obtained by, for example, the fast Fourier transformer FFT is calculated. An effective value current, that is, a phase current primary component effective value current Ie is calculated. Next, step S
At 24, as shown in the following equation (9), the total loss Ploss_of the motor 11 calculated in step S20 is obtained.
all, the copper loss Plos calculated in step S19
s_r and the mechanical loss Plo found in step S21
ss_mecha and iron loss Ploss_i
ron is calculated.

[0063]

(Equation 9)

Next, in step S25, as shown in the following equation (10), a phase voltage (for example, U-phase voltage Vun) detected by the phase voltage detector 46 is used to calculate the phase voltage by, for example, a fast Fourier transformer FFT. The actually measured iron loss equivalent resistance ri_real is calculated based on the obtained effective value Vall including all frequency components of the phase voltage and the iron loss Ploss_iron calculated in step S24. When deriving the following equation (10), for example, FIG.
As shown in (3), the method of separating the core loss current based on the parallel circuit parameters is applied to the three-phase winding, and a value three times the core loss equivalent resistance ri is calculated.

[0065]

(Equation 10)

Next, in step S26, as shown in the following equation (11), the phase component primary component effective value current Ie calculated in step S23, the primary component of the phase current calculated in step S16, and the magnetic pole The current phase difference α1 from the phase of the induced voltage calculated by the position calculation unit 55, the phase component primary component effective value voltage V calculated in step S13, the primary component of the phase voltage calculated in step S15, and the induced voltage And the torque axis current value Id and the torque axis current value Id after the iron loss separation are calculated based on the voltage phase difference γ of the iron loss and the measured iron loss equivalent resistance ri_real calculated in step S25.
An actual current phase difference α after iron loss separation is calculated from the calculated current values Id and Iq, and further, the calculated actual current phase difference α
, The primary component I of the phase current after the iron loss separation is calculated.

[0067]

(Equation 11)

Next, in step S27, as shown in the following equation (12), the number of pole pairs P of the motor 11, the angular velocity ω, the voltage phase difference γ, and the value after iron loss separation calculated in step S26. The actual current phase difference α, the primary component I of the phase current after iron loss separation, the phase resistance value R calculated in step S12, and the effective value E of the induced voltage calculated by the induced voltage detection process described later in step S26. , Step S13
The d-axis (torque axis) inductance Ld and the q-axis (field axis) inductance L at predetermined timings to be described later based on the phase voltage primary component effective value voltage V calculated in
q is calculated, and the series of processing ends.

[0069]

(Equation 12)

Hereinafter, a specific induced voltage detection process in the induced voltage constant calculator 53 in the above-described step S22 will be described with reference to FIGS. 8 and 9. FIG. 8 is a flowchart showing a specific induced voltage detection process in the induced voltage constant calculation unit 53, and FIG.
FIG. 7 is a graph showing a change in the ON / OFF flag for instructing according to the rotation speed N. First, step S3 shown in FIG.
In step 1, it is determined whether the torque command value * T is zero. If the result of this determination is "YES", then step S
Go to 32. On the other hand, if the result of this determination is “NO”, the series of processing ends. In step S32, it is determined whether an energization gate signal for controlling the switching operation of inverter 13 is ON. If this determination is "YES", the flow proceeds to step S33. On the other hand, if the result of this determination is "NO", the flow proceeds to step S37 described later.

In step S33, it is determined whether or not the rotation speed N of the motor 11 is lower than a predetermined first rotation speed N1. If this determination is "YES", the flow proceeds to step S34. On the other hand, if the result of this determination is "NO", the flow proceeds to step S38 described later. Step S
At 34, as the gate OFF process, the output of the energizing gate signal for controlling the switching operation of the inverter 13 is stopped, and the switching operation is stopped.

In step S35, the induced voltage waveform of the motor 11 is directly detected by the phase voltage detector 46. Then, in step S36, the effective value E of the induced voltage is calculated from the detected induced voltage waveform. Then, as shown in the above equation (8), the effective value of the induced voltage E
Is divided by the number of revolutions N to calculate the induced voltage constant Ke, and a series of processes is ended.

On the other hand, in step S37, it is determined whether or not the rotation speed N of the motor 11 is smaller than a predetermined second rotation speed N2 which is higher than the first rotation speed N1. If this determination is "YES", the flow proceeds to step S35. On the other hand, if the result of this determination is “NO”, the flow proceeds to step S38. In step S38, the gate O
In the N process, the energizing gate signal for controlling the switching operation of the inverter 13 is turned ON, the switching operation is started, and a series of processes is ended.

Here, as shown in FIG. 9, the first and second rotational speeds N1 and N2 are set such that the induced voltage of the motor 11 is rectified to a single phase by the inverter 13 regardless of the temperature of the motor 11, for example. Rectified voltage value does not exceed the power supply voltage Vdc of the power supply 14, and the first rotation speed N1 is set to the conduction gate in accordance with the hysteresis set for the threshold rotation speed. The signal is set to a gate-off start rotation number at which the signal is turned off, and the second rotation number N2 is set to a gate-off end rotation number at which the energization gate signal is switched from OFF to ON. The first and second rotational speeds N1 and N2 are set so as to be variable according to the primary-side power supply voltage of the inverter 13, that is, the power supply voltage Vdc of the power supply 14.
3, map data indicating the value of the first rotation speed N1 according to the primary power supply voltage of the inverter 13 and map data indicating the value of the second rotation speed N2 according to the primary power supply voltage of the inverter 13. The induced voltage constant calculation unit 53 searches and reads the first and second rotational speeds N1 and N2 corresponding to the primary power supply voltage of the inverter 13 from these map data.

That is, for example, even when the torque command value * T is set to zero, the phase voltage is detected only when the rectified voltage value of the induced voltage of the motor 11 at the inverter 13 does not exceed the power supply voltage Vdc. The induced voltage waveform of the motor 11 is directly detected by the detector 46. Thereby, the motor 1
In the state where the rectified voltage value of the induced voltage of 1 in the inverter 13 exceeds the power supply voltage Vdc, for example, the rotation speed N
In a so-called field-weakening control or the like, the q-axis (field axis) target current * Iq is increased in response to the back electromotive voltage of the motor 11 which increases in proportion to To stop detecting the induced voltage waveform by stopping the switching operation.

Hereinafter, a method of calculating the measured iron loss equivalent resistance ri_real in step S25 will be described with reference to FIG. FIG. 10 is a diagram illustrating a model of a method of separating an iron loss current based on parallel circuit parameters. As shown in FIG. 10 and the following equation (13), the d-axis phase current Ied and the q-axis phase current I of the phase current Ie including iron loss
eq is expressed as the sum of the d-axis phase current Id and the q-axis phase current Iq of the phase current I that does not include iron loss, and the d-axis phase current Id ′ and the q-axis phase current Iq ′ of the iron loss current I ′. You.

[0077]

(Equation 13)

Here, as shown in the following equation (14),
Iron loss Piron_loss is represented by iron loss equivalent resistance ri,
Voltage Voverall at both ends of iron loss equivalent resistance ri
And represented by

[0079]

[Equation 14]

As shown in the following equation (15), the d-axis phase current Id and the q-axis phase current Iq not including the iron loss phase current are calculated by using the above-mentioned equations (13) and (14) and the d-axis phase voltage Vd. And the q-axis phase voltage Vq, and the d-axis phase current Id and the q-axis phase current Iq in the above equation (11) are expressed by the following equation (15).
It is calculated by the calculation method of iron loss separation based on

[0081]

(Equation 15)

FIG. 11 shows a voltage vector diagram based on the parallel circuit parameters of FIG. In drawing the vector diagram, each phase current Id (I · cosα), Iq from which iron loss components derived by the above-described calculation method are removed
From (I · sin α), the point F (I
Cos α, I · sin α). Next, the effective value E of the induced voltage calculated by the induced voltage constant calculation unit 53, that is, A on the d axis indicating the product of the induced voltage constant Ke and the rotation speed N
Find the point (Ke · N, 0). Next, using the phase resistance value R in consideration of the variation of the copper loss, the voltage drop of the d-axis component due to the phase resistance value R is calculated at the point B (Ke · N + I · cosα · R, 0).

Next, from the phase voltage primary component effective value voltage V, the actual current phase difference α and the voltage phase difference γ, point E (V · cos (α +
β), V · sin (α + β)). Next, point D (Ke · N +) indicating the voltage drop of the field axis (q axis) from point B
I · cosα · R, V · sin (α + β)) are obtained.
Here, β = γ−α. Next, a point C (K) indicating a voltage drop of the field axis (q axis) inductance Lq from the point B.
e · N + I · cos α · R, V · sin (α + β) -I
· Sin α · R).

As described above, the points F, A, B, E,
A voltage vector diagram can be drawn by obtaining vector coordinates in the order of point D and point C. When a phase current including an iron loss component is used, the point F ′ (Ie · cos1α, Ie
Since a phase current shift including an error occurs as in sin1α), it is difficult to draw an accurate voltage vector diagram.

In this embodiment, the phase resistance value R taking into account the variation in copper loss, the induced voltage constant Ke calculated from the induced voltage waveform directly detected by the phase voltage detector 46, and the phase voltage detector 46 Using the current phase difference α1 calculated based on the directly detected induced voltage waveform and the measured iron loss equivalent resistance ri_real, which is an iron loss component, as shown in the above equation (11), the variation in copper loss is taken into account, and It is possible to obtain highly accurate phase currents Id and Iq from which iron loss components have been removed. Further, as shown in the above equation (11), the actual current phase difference α obtained by removing the iron loss component from the highly accurate phase currents Id and Iq.
Can be calculated, and as shown in the above equation (12), the d-axis (torque axis) inductance Ld and the q-axis (field axis)
Since the inductance Lq can also be calculated with high accuracy, a voltage vector diagram can be easily drawn with high accuracy.

Therefore, it is possible to display a voltage vector diagram from which iron loss components have been removed on the display unit 30 provided in the constant detection device 15. The display unit 30 includes a current phase difference α1 including iron loss, a voltage phase difference γ, a d-axis phase current (torque axis current value) Id not including iron loss phase current, and q not including iron loss phase current.
The detected values and calculated values used for calculating the constants such as the axis phase current (field axis current value) Iq, the d-axis phase voltage Vd, and the q-axis phase voltage Vq may be displayed.

Hereinafter, the calculation processing of the d-axis and q-axis inductances Ld and Lq in the above-described step S27, in particular, the timing of calculating the q-axis (field axis) inductance Lq will be described with reference to FIGS. explain. FIG. 12 shows the d-axis and q-axis inductances Ld,
FIG. 13 is a flowchart showing a process of calculating Lq, in particular, a process of calculating a q-axis (field axis) inductance Lq. FIG. 13 shows a flag of an Lq calculation permission flag instructing calculation of a q-axis (field axis) inductance Lq. Change the value to q
FIG. 6 is a graph showing the value of an axis (field axis) target current * Iq.

First, in step S41 shown in FIG. 12, it is determined whether or not the q-axis target current * Iq is larger than a predetermined q-axis target current constant * Iq1. If the result of this determination is “NO”, a series of processing ends. on the other hand,
If the result of this determination is "YES", then step S42 is reached.
Proceed to. In step S42, the above equation (12)
, The q-axis (field axis) inductance Lq is calculated, and the series of processes is terminated.

Here, a predetermined q-axis target current constant * Iq1
Is the q-axis phase current Iq (Iq = Iq) calculated by feedback control according to the q-axis target current constant * Iq1.
The q-axis inductance Lq calculated by the division of (sin α) is set to a value having a desired calculation accuracy. For example, the q-axis target current * Iq is increased according to the back electromotive voltage of the motor 11 which increases in proportion to the rotation speed N to weaken the magnetic flux of the field equivalently. calculate.

Hereinafter, the execution timing of the detection operation in the detection unit 26 and the execution timing of the arithmetic processing based on each detection value obtained by the detection unit 26 will be described with reference to FIG. FIG. 14 is a graph showing the execution timing of each detection operation in the detection unit 26 and the execution timing of an arithmetic process based on each detection value obtained in the detection unit 26.

In the feedback control of the motor 11, for example, for a control parameter that causes relatively slow or small fluctuation, a control parameter that includes an integration process in the calculation process, and the like, a longer detection and calculation cycle is required. Set. For example, the phase voltage detector 46 and the phase current detector 4
7, the detection is performed in a first sampling period T1 (for example, 50 to 100 μs) which is a relatively short period. Accordingly, as in steps S15, S16, and S23 described above, for example, a fast Fourier transformer FFT extracts a primary component of a phase voltage or a phase current, and an FFT operation for calculating an effective value thereof is also performed. It is executed in one sampling cycle T1. That is, the first
The sampling period T1 is set to a period at which a detection resolution higher than a predetermined resolution required for the phase angle of the phase voltage or the phase current can be obtained.

Further, for example, the torque sensor 42 and the detection of the power supply voltage Vdc are detected by a second sampling period T2 (for example, 10 ms) which is longer than the first sampling period T1. Accordingly, as in step S26 described above, for example, the field axis current value I
The two-axis current servo calculation for calculating q and the torque axis current value Id is also executed in the second sampling period T2. In this case, since the fluctuation of the motor torque Tor of the motor 11 does not exceed the period of the carrier in the PWM inverter by, for example, pulse width modulation, the motor torque Tor is detected at the frequency of the carrier.

Further, for example, an atmosphere temperature sensor 43,
For the rotor temperature sensor 44, a third sampling period T3 which is longer than the second sampling period T2
(For example, 100 ms). Accordingly, as in the above-described steps S19, S20, S21, and S24, the copper loss Ploss is obtained.
_R and total loss Ploss_all and mechanical loss Ploss
_Mecha or iron loss Ploss_iron, or the d-axis and q-axis as in step S27 described above.
Processing for calculating the shaft inductances Ld and Lq is also executed in the third sampling period T3. That is, since there is little sharp change in temperature, detection and calculation processing are performed at a relatively long cycle.

As described above, according to the brushless DC motor control device 10 of the present embodiment, when calculating the winding resistance value that fluctuates with the temperature change during the rotational driving of the brushless DC motor, Since the winding temperature Ts is obtained using the data map of the estimated winding temperature T that changes according to the ambient temperature Tat stored in the memory 29,
For example, a winding temperature detector for detecting the winding temperature of the stator winding can be omitted. Thus, by simplifying the configuration of the motor control device 10, it is possible to reduce the cost required for configuring the motor control device 10. Further, when detecting the magnetic pole position θre of the rotor corresponding to the phase angle of the induced voltage, based on the change of each phase current detected according to the high frequency voltage Vh superimposed on the driving voltage of the motor 11. The inductance of the stator winding is calculated, and data indicating the relationship between the inductance of the stator winding and the magnetic pole position θre of the rotor stored in the memory 29 in advance is searched, and the magnetic pole position θre corresponding to the calculated inductance is searched. , The magnetic pole position θr of the rotor
The position sensor for detecting e can be omitted. Accordingly, the correction processing for correcting the phase delay characteristic of the position sensor can be omitted, and the calculation load on the motor control device 10 can be reduced.

Further, when the voltage waveform of the induced voltage is directly detected by the phase voltage detecting means, the energization to the brushless DC motor may be stopped, and when the torque command value * T is zero, Since the switching operation of the inverter 13 is stopped and the induced voltage waveform of the motor 11 is directly detected by the phase voltage detector 46, the induced voltage can be reduced without providing a cutoff circuit for cutting off the power supply line to the motor 11, for example. The voltage can be detected, and the cost required for configuring the motor control device 10 can be reduced.

Further, the q-axis phase current Iq (Iq = I · si
nα) q-axis inductance L calculated by division
q is a q-axis target current * Iq is a predetermined q-axis target current constant *
Since the calculation is performed only when the current is larger than Iq1, even if the q-axis phase current Iq calculated based on the detection values of the respective phase currents Iu, Iv, Iw includes an appropriate detection error. , An increase in the error with respect to the calculation result of the q-axis inductance Lq can be suppressed. Therefore, the q-axis inductance Lq can be accurately calculated without excessively increasing the detection accuracy of the phase current detector 47, and the cost required for constructing the motor control device 10 can be reduced. . In addition, if a desired calculation accuracy cannot be expected in the calculation result of the q-axis inductance Lq, the calculation processing is not performed, so that the calculation load on the control device can be reduced. Furthermore, for control parameters that cause relatively slow or small fluctuations, such as temperature-related data, or control parameters that require integration to be included in the required calculation processing, the detection cycle is set relatively. By setting the length as long as possible, the calculation load of the control device can be further reduced.

In the above-described embodiment, in step S12, the estimated winding temperature T corresponding to the ambient temperature Tat detected during the rotation driving is read from the memory 29 in step S12.
And is read as the winding temperature Ts. For example, in a water-cooled motor or the like, an estimated winding temperature T corresponding to the cooling water temperature Tc detected during the rotation driving is searched for,
It may be read as the winding temperature Ts. In this case,
The ambient temperature sensor 43 is not required, and instead,
For example, a cooling system (not shown) for the motor 11 is provided with a cooling water temperature sensor (not shown). Here, the estimated winding temperature T of the stator winding of the motor 11 is, as shown in FIG. 15, the cooling water temperature Tc of the motor 11 detected by the cooling water temperature sensor.
The data of the estimated winding temperature T that changes according to the cooling water temperature Tc is stored in the memory 29, and the arithmetic unit 28 detects the data during rotation driving. The estimated winding temperature T corresponding to the obtained cooling water temperature Tc is retrieved and read as the winding temperature Ts.

Also, for example, the total loss Plos of the motor 11
The estimated winding temperature T corresponding to s_all may be retrieved and read as the winding temperature Ts. In this case, the above-described ambient temperature sensor 43 and cooling water temperature sensor are not required, and the rotation sensor 41
Based on the rotational speed N of the motor 11 detected by the torque sensor 42 and the motor torque Tor detected by the torque sensor 42.
The output power Pout of the motor 11 is calculated, and the output power Pout of the motor 11 is subtracted from the detected value of the motor input power Pin supplied from the inverter 13 to the motor 11, thereby obtaining the total loss Ploss_a of the motor 11.
11 is calculated. Here, the estimated winding temperature T for the stator winding of the motor 11 is, as shown in FIG.
The total loss Ploss_a of the memory 29 is changed to increase with the increase of the total loss Ploss_all of the
11, the data of the estimated winding temperature T that changes according to the stored winding data is stored. The calculation unit 28 searches the estimated winding temperature T corresponding to the total loss Ploss_all detected during the rotation driving, and Read as Ts. In this case, the ambient temperature sensor 43 and the cooling water temperature sensor can be omitted, and by simplifying the configuration of the motor control device 10, the cost required for configuring the motor control device 10 can be reduced. it can.

Further, for example, an estimated winding temperature T corresponding to the rotation speed N of the motor 11 detected by the rotation sensor 41 may be searched and read as the winding temperature Ts. In this case, for example, as shown in FIG. 17, the q-axis target current * I in accordance with the back electromotive voltage of the motor 11 which increases in proportion to the rotation speed N.
At the time of so-called field-weakening control in which q is increased to equivalently weaken the magnetic flux of the field, the iron loss changes to increase and the copper loss due to the field-weakening current changes to increase.
As a result, the estimated winding temperature T of the motor 11 with respect to the stator winding changes in a tendency to increase as the rotation speed N of the motor 11 increases as shown in FIG. The data of the estimated winding temperature T that changes according to N is stored. The arithmetic unit 28 searches for the estimated winding temperature T corresponding to the rotation speed N detected during the rotation driving, and Read as Ts.

In the above-described embodiment, the induced voltage constant calculation unit 53 performs step S of the induced voltage detection process.
At 31, it is determined whether the torque command value * T is zero, but the present invention is not limited to this. For example, it is determined whether both the d-axis target current * Id and the q-axis target current * Iq are zero. Alternatively, it may be determined whether all of the U-phase AC voltage command value * Vu, the V-phase AC voltage command value * Vv, and the W-phase AC voltage command value * Vw are zero, Alternatively, it may be determined whether the d-axis voltage command value * Vd and the q-axis voltage command value * Vq are both zero.

Further, in the above-described embodiment, the induced voltage constant calculation unit 53 stores the first and second rotational speeds N1 and N2 corresponding to the primary power supply voltage of the inverter 13 in the memory 29 in advance in the induced voltage detection processing. Is searched from each of the predetermined map data stored in the storage unit. For example, as shown in the following equation (16), predetermined constants A and B (A> B)
And the first and second rotation speeds N based on the primary power supply voltage of the inverter 13, that is, the power supply voltage Vdc of the power supply 14.
1, N2 may be calculated, or, for example, as shown in the following equation (17), predetermined constants A and C and the primary-side power supply voltage of the inverter 13, that is, the power supply voltage V
Based on dc, the first and second rotational speeds N1 and N2 with the constant C as the width of the hysteresis may be calculated.

[0102]

(Equation 16)

[0103]

[Equation 17]

Further, in the above-described embodiment, the rotation speed N of the motor 11 is calculated from the time interval of the zero cross point of the induced voltage detected by the phase voltage detector 46 when the switching operation of the inverter 13 is stopped. Alternatively, the rotation sensor 41 may be omitted. Also, the phase voltage detector 46
Is U if there is no neutral line from the motor 11
It is sufficient to detect the line voltage between the -V phase, the V-W phase, and the W-U phase, and the same operation and effect can be obtained by using these line voltages.

Further, in the above-described embodiment, the induced voltage constant calculation unit 53 performs step S in the induced voltage detection process.
In 35, when the switching operation of the inverter 13 is stopped, the induced voltage waveform of the motor 11 is measured directly by the phase voltage detector 46. However, as in the constant detection device 55 according to the modification of the present embodiment shown in FIG. , A three-phase rectification sensor 56 for smoothing each phase voltage supplied to the motor 11 is provided between the inverter 13 and the motor 11, and is detected by the three-phase rectification sensor 56 when the switching operation of the inverter 13 is stopped. The respective inductances Ld and Lq may be calculated based on the average voltage Va.

That is, the three-phase rectification sensor 56 includes, for example, a three-phase bridge rectification circuit 56 a formed by connecting six diodes in a bridge, and a three-phase bridge rectification circuit 56.
and a rectified voltage detection unit 56b for smoothing and detecting the full-wave rectified voltage obtained in a. The three-phase bridge rectifier circuit 56a performs full-wave rectification on each phase current input to the stator winding of the motor 11. Thereby, as shown in FIG. 20, for example, each phase voltage Vu, Vv, Vw is converted into a full-wave rectified voltage Vr in the three-phase bridge rectifier circuit 56a. Further, the full-wave rectified voltage Vr is smoothed by a CR filter in which a resistor and a capacitor are connected in a rectified voltage detector 56b, and detected as an average voltage Va.

In this case, for example, each phase voltage Vu, Vv,
Even if the sampling is performed once for Vw, the average voltage V
Since a can be calculated, the sampling period for reading the average voltage Va can be set relatively long. As a result, as in the case where the induced voltage waveform of the motor 11 is directly measured by the phase voltage detector 46, for example, a primary component is extracted from the instantaneously read value of the induced voltage detected by relatively high-speed sampling, and the effective value is extracted. Or the complicated processing of converting to an average value can be omitted, and the calculation load of the motor control device 10 can be reduced.

Note that, in the above-described embodiment, d
Although the timing for calculating the q-axis (field axis) inductance Lq in the axis / q-axis inductance estimation calculation unit 54 is determined based on the q-axis target current * Iq, for example, as shown in FIG. The determination may be made based on the current Iq (= I · sin α). Here, FIG. 21 is a flowchart showing a process of calculating the q-axis inductance Lq in the d-axis / q-axis inductance estimation calculating unit 54, and FIG. 22 is a flowchart of an Lq calculation permission flag instructing the calculation of the q-axis inductance Lq. The change in the value is represented by the q-axis phase current I.
FIG. 9 is a graph showing the values of q (= I · sin α) according to the values.

In this case, first, in step S51 shown in FIG. 21, it is determined whether or not the q-axis phase current Iq is larger than a predetermined q-axis phase current constant Iq1. If the result of this determination is “NO”, a series of processing ends. On the other hand, if the result of this determination is “YES”, then step S
Go to 52. In step S52, the above equation (1)
According to 2), the q-axis inductance Lq is calculated, and a series of processing is ended.

In the present embodiment described above, the d-axis and q-axis inductances Ld,
Although the process of calculating Lq is performed in the third sampling period T3, for example, the detection timing of various detection signals (each sensor value) in the detection unit 26 shown in FIG.
As shown in the graph showing the calculation timings of the inductances Ld and Lq, various data required for the calculations of the inductances Ld and Lq are detected when the motor 11 is driven and updated in real time. The calculation of the inductances Ld and Lq based on the above may be executed when the operation of the motor 11 is stopped. In this case, the respective inductances Ld and Lq are calculated only when the operation is stopped without any processing load required for the feedback control of the motor 11, and are used as control parameters until the next operation stop. Then, when the operation of the motor 11 is stopped again, the respective inductances Ld and Lq are calculated and updated. Thereby, the calculation load of the motor control device 10 can be reduced.

In the present embodiment described above, in step S22, the effective value E of the induced voltage is obtained from the induced voltage waveform of the motor 11 directly detected by the phase voltage detector 46 when the switching operation of the inverter 13 is stopped. Then, as shown in the above equation (8), the induced voltage constant Ke is calculated by dividing by the rotation speed N.
The effective value E of the induced voltage may be calculated based on the induced voltage constant Ke after temperature correction obtained from the memory 29 by a map search. That is, as shown in FIG. 24, the induced voltage constant Ke changes in a decreasing trend with an increase in the rotor temperature Tmag during motor driving detected by the rotor temperature sensor 44. A data map of the induced voltage constant Ke that changes according to the child temperature Tmag is stored. In step S22, the calculation unit 28 searches for the induced voltage constant Ke corresponding to the rotor temperature Tmag detected during the rotation driving. Then, the effective value E of the induced voltage after the temperature correction is calculated by multiplying by the rotation speed N.

[0112]

As described above, according to the brushless DC motor control apparatus of the present invention, the detection accuracy of the phase current detecting means for detecting each phase current is not excessively increased. In addition, the torque axis inductance and the field axis inductance can be accurately calculated, and the cost required for constructing a control device for the brushless DC motor can be reduced. In addition, if the desired calculation accuracy cannot be expected from the calculation results of the torque axis inductance and the field axis inductance, the calculation processing is not executed, so that the calculation load on the control device can be reduced.

According to the control device for a brushless DC motor of the present invention, when the voltage waveform of the induced voltage is directly detected by the phase voltage detecting means, for example, power is supplied to the brushless DC motor. The induced voltage can be detected only at an appropriate timing at which energization of the brushless DC motor can be stopped without providing an interrupting circuit or the like for interrupting the line, which is necessary when constructing a control device for the brushless DC motor. Costs can be reduced. According to the control device for a brushless DC motor of the present invention, the rectifier and the rectified voltage detector convert the phase voltage of the brushless DC motor into a full-wave rectified voltage, and after smoothing the phase voltage, induce the voltage. Since the voltage value is detected as a voltage value, for example, a complicated calculation process of detecting a voltage waveform of an induced voltage by a phase voltage detection unit, extracting a primary component from the voltage waveform, and calculating an effective value can be omitted. In addition, the calculation load on the control device can be reduced.

Further, according to the brushless DC motor control apparatus of the present invention, for example, control parameters for performing relatively slow or small fluctuations, and integration processing for necessary arithmetic processing are performed. By setting a longer detection cycle for the included control parameters and the like, the calculation load of the control device can be reduced. Further, according to the brushless DC motor control device of the present invention, the calculation processing of the field axis inductance and the torque axis inductance having a relatively large calculation load is performed when the brushless DC motor is stopped, that is, when the brushless DC motor is stopped. By performing the calculation processing of the feedback control for the DC motor when the calculation load that makes unnecessary is light, the increase in the calculation load of the control device can be suppressed.

Further, according to the brushless DC motor control device of the present invention, for example, in a brushless DC motor being driven in rotation, a phase which increases with an increase in the winding temperature of the stator windings. When properly calculating the resistance value, it is possible to omit a winding temperature detector or the like for detecting the winding temperature of the stator winding, thereby reducing costs required for constructing a brushless DC motor control device. be able to.

According to the control device for a brushless DC motor of the present invention, for example, in a brushless DC motor being driven in rotation, a phase which increases with an increase in the winding temperature of the stator windings. When properly calculating the resistance value, it is possible to omit a winding temperature detector or the like for detecting the winding temperature of the stator winding, thereby reducing costs required for constructing a brushless DC motor control device. be able to.
Further, according to the brushless DC motor control apparatus of the present invention, for example, the position sensor for detecting the magnetic pole position of the rotor and the correction processing for correcting the phase delay characteristic of the position sensor are omitted. The cost required for constructing a control device for the brushless DC motor can be reduced, and the calculation load of the control device can be reduced.

[Brief description of the drawings]

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

FIG. 2 is a configuration diagram illustrating a specific configuration of a feedback control unit and a calculation unit illustrated in FIG. 1;

FIG. 3 is a configuration diagram showing a specific configuration of a constant detection device shown in FIG. 1;

FIG. 4 is a flowchart showing the operation of the control device for the brushless DC motor shown in FIG. 1, particularly the schematic operation of the constant detection device.

FIG. 5 is a flowchart showing a specific calculation operation of the constant detection device shown in FIG.

FIG. 6 is a graph showing an estimated winding temperature T that changes according to the ambient temperature Tat of the motor.

FIG. 7 shows a mechanical loss P that changes with a change in the rotation speed N.
It is a graph which shows loss_mecha.

FIG. 8 is a flowchart illustrating a specific induced voltage detection process in an induced voltage constant calculation unit.

FIG. 9: ON / OF of the switching operation of the inverter
FIG. 9 is a graph showing a change in ON / OFF flag indicating F according to the rotation speed N.

FIG. 10 is a diagram showing a model of a method for separating an iron loss current based on parallel circuit parameters.

11 is a diagram showing a voltage vector diagram based on the parallel circuit parameters of FIG.

FIG. 12 is a flowchart illustrating a process of calculating d-axis and q-axis inductances Ld and Lq in a d-axis / q-axis inductance estimation calculation unit, particularly a process of calculating a q-axis (field axis) inductance Lq.

FIG. 13 shows a change in a flag value of an Lq calculation permission flag for instructing calculation of a q-axis inductance Lq, which is determined by a q-axis target current *.
FIG. 9 is a graph showing the value of Iq.

FIG. 14 is a graph showing the execution timing of each detection operation in the detection unit and the execution timing of an arithmetic process based on each detection value obtained in the detection unit.

FIG. 15 is a graph showing an estimated winding temperature T that changes according to a cooling water temperature Tc.

FIG. 16 is a graph showing an estimated winding temperature T that changes according to the total loss Ploss_all of the motor.

FIG. 17 is a graph showing iron loss and copper loss due to a field weakening current that change according to the rotation speed N.

FIG. 18: Estimated winding temperature T that changes according to rotation speed N
FIG.

FIG. 19 is a brushless DC according to a modification of the embodiment.
FIG. 3 is a configuration diagram of a constant detection device of the motor control device.

20 is a graph showing phase voltages Vu, Vv, Vw, a full-wave rectified voltage Vr, and a detected average voltage Va input to the three-phase rectification sensor shown in FIG.

FIG. 21 is a flowchart illustrating a process of calculating a q-axis inductance Lq in a d-axis / q-axis inductance estimation calculation unit.

FIG. 22 shows a change in the flag value of an Lq calculation permission flag for instructing the calculation of the q-axis inductance Lq,
FIG. 4 is a graph showing the value of (= I · sin α) according to the present invention.

FIG. 23 shows detection timings of various detection signals (each sensor value) in the detection unit and inductances Ld and Lq.
FIG. 5 is a graph showing the operation timing of the calculation.

FIG. 24 is a graph showing an induced voltage constant Ke that changes with a change in the rotor temperature Tmag.

[Explanation of symbols]

 Reference Signs List 10 brushless DC motor control device 13 inverter 15, 55 constant detection device 21 torque command calculation unit 22 target current calculation unit 23 feedback control unit 28 calculation unit 29 memory 30 display unit 41 rotation sensor 42 torque sensor 43 atmosphere temperature sensor 44 rotor Temperature sensor 45 Winding temperature sensor 46 Phase voltage detector 47 Phase current detector 53 Induced voltage constant calculation unit 55 Magnetic pole position calculation unit 56a Three-phase bridge rectifier circuit 56b Rectified voltage detector

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) LL40 LL41 LL45 MM12

Claims (8)

[Claims] 1. A brushless DC motor including a rotor having a permanent magnet and a stator having a plurality of stator windings for generating a rotating magnetic field for rotating the rotor, comprising a plurality of switching elements. What is claimed is: 1. A control device for a brushless DC motor, wherein said brushless DC motor is rotationally driven by an energization switching unit that sequentially commutates energization to said stator winding, said phase voltage detection unit detecting a phase angle and an effective value of a phase voltage of said brushless DC motor. Phase current detecting means for detecting a phase angle and an effective value of a phase current, position detecting means for detecting a phase angle of an induced voltage from a magnetic pole position of the rotor, and rotational speed detecting means for detecting a rotational speed; and the brushless DC. Temperature detection means for detecting the temperature of the motor, phase resistance value calculation means for calculating a phase resistance value based on the detected temperature, and an induced voltage constant are derived. Electromotive voltage constant deriving means; phase difference calculating means for calculating a voltage phase difference consisting of the phase difference between the induced voltage and the phase voltage; and a current phase difference consisting of a phase difference between the induced voltage and the phase current. An iron loss calculating means for calculating an iron loss of the brushless DC motor therein; an actual phase current calculating means for calculating an actual phase current by subtracting an iron loss component from the phase current based on the iron loss; Inductance calculating means for calculating a field axis inductance and a torque axis inductance based on the rotation speed, the induced voltage constant, the voltage phase difference, the current phase difference, and the real phase current; and a torque for inputting a torque command value. Command input means, based on the induced voltage constant, the field axis inductance, the torque axis inductance, and the torque command value, a field axis current command value and a Current command value calculation means for calculating a torque axis current command value; and a pulse width modulation signal output for outputting a pulse width modulation signal to the energization switching means based on the field axis current command value and the torque axis current command value. The inductance calculation means calculates only the torque axis inductance when the field axis current command value or the torque axis current command value is equal to or less than a predetermined value, and the field axis current command value or the A controller for a brushless DC motor, wherein the field axis inductance and the torque axis inductance are calculated when a torque axis current command value exceeds the predetermined value. 2. A brushless DC motor comprising: a rotor having a permanent magnet; and a stator having a plurality of phases of stator windings for generating a rotating magnetic field for rotating the rotor, comprising a plurality of switching elements. What is claimed is: 1. A control device for a brushless DC motor, wherein said brushless DC motor is rotatably driven by current switching means for sequentially commutating the current to said stator winding, said phase voltage detecting means detecting a phase angle and an effective value of a phase voltage of said brushless DC motor. Phase current detecting means for detecting a phase angle and an effective value of a phase current, position detecting means for detecting a phase angle of an induced voltage from a magnetic pole position of the rotor, and rotational speed detecting means for detecting a rotational speed; and the brushless DC. Phase resistance value calculating means for calculating a phase resistance value based on a motor temperature; a voltage phase difference comprising a phase difference between the induced voltage and the phase voltage; Phase difference calculating means for calculating a current phase difference consisting of a difference between the phases of currents; iron loss calculating means for calculating an iron loss of the brushless DC motor being rotationally driven; and iron from the phase current based on the iron loss. A real-phase current calculating unit that calculates a real-phase current by subtracting a loss component; an energization stop control unit that stops a switching operation of the energization switching unit to temporarily stop power supply to the brushless DC motor; While the operation is stopped, the voltage value of the induced voltage is detected by the phase voltage detecting means, based on the phase resistance value, the voltage value of the induced voltage, the voltage phase difference, the current phase difference, and the real phase current. Inductance calculating means for calculating a field axis inductance and a torque axis inductance; torque command input means for inputting a torque command value; and a voltage value of the induced voltage. Current command value calculating means for calculating a field axis current command value and a torque axis current command value based on the field axis inductance, the torque axis inductance and the torque command value; and A control device for a brushless DC motor, comprising: a pulse width modulation signal output unit that outputs a pulse width modulation signal to the energization switching unit based on the torque axis current command value. 3. A brushless DC motor comprising a rotor having a permanent magnet and a stator having a plurality of stator windings for generating a rotating magnetic field for rotating the rotor, comprising a plurality of switching elements. What is claimed is: 1. A control device for a brushless DC motor, wherein said brushless DC motor is rotatably driven by current switching means for sequentially commutating the current to said stator winding, said phase voltage detecting means detecting a phase angle and an effective value of a phase voltage of said brushless DC motor. Phase current detecting means for detecting a phase angle and an effective value of a phase current, position detecting means for detecting a phase angle of an induced voltage from a magnetic pole position of the rotor, and rotational speed detecting means for detecting a rotational speed; and the brushless DC. Phase resistance value calculating means for calculating a phase resistance value based on a motor temperature; a voltage phase difference comprising a phase difference between the induced voltage and the phase voltage; Phase difference calculating means for calculating a current phase difference consisting of a difference between the phases of currents; iron loss calculating means for calculating an iron loss of the brushless DC motor being rotationally driven; and iron from the phase current based on the iron loss. A real-phase current calculating unit that calculates a real-phase current by subtracting a loss component; an energization stop control unit that stops a switching operation of the energization switching unit to temporarily stop power supply to the brushless DC motor; A rectifier connected between the switching means and the brushless DC motor for full-wave rectification of the input current to the plurality of stator windings; a rectified voltage detector for detecting a full-wave rectified voltage by the rectifier And detecting the voltage value of the induced voltage by the rectified voltage detecting means while the switching operation is stopped, and detecting the phase resistance value, the voltage value of the induced voltage, the voltage phase difference, and the current. Inductance calculating means for calculating a field axis inductance and a torque axis inductance based on a phase difference and the real phase current; torque command input means for inputting a torque command value; and a voltage value of the induced voltage and the field axis inductance. Current command value calculation means for calculating a field axis current command value and a torque axis current command value based on the torque axis inductance and the torque command value; and the field axis current command value and the torque axis current command value. And a pulse width modulation signal output means for outputting a pulse width modulation signal to said energization switching means based on said control signal. 4. An output torque detecting means for detecting an output torque, wherein a detection cycle of the phase current detecting means is a first cycle T1,
When the detection cycle of the output torque detecting means is a second cycle T2 and the temperature detection cycle is a third cycle T3,
The first, second and third periods are defined as T1 ≦ T2 ≦
3. The brushless DC according to claim 1, wherein detection control is performed by setting the relationship to T3.
Motor control device. 5. The inductance calculation means stores calculation data during rotation driving of the brushless DC motor, and performs a calculation process of the field axis inductance and the torque axis inductance while rotation of the brushless DC motor is stopped. 3. The control device for a brushless DC motor according to claim 1, wherein: 6. A brushless DC motor comprising a rotor having a permanent magnet and a stator having a plurality of stator windings for generating a rotating magnetic field for rotating the rotor, comprising a plurality of switching elements. What is claimed is: 1. A control device for a brushless DC motor, wherein said brushless DC motor is rotatably driven by current switching means for sequentially commutating the current to said stator winding, said phase voltage detecting means detecting a phase angle and an effective value of a phase voltage of said brushless DC motor. Phase current detecting means for detecting a phase angle and an effective value of a phase current, position detecting means for detecting a phase angle of an induced voltage from a magnetic pole position of the rotor, and rotational speed detecting means for detecting a rotational speed; and the brushless DC. The temperature of the motor is stored in advance based on the rotation speed, the cooling water temperature of the brushless DC motor, or the ambient temperature of the brushless DC motor. Temperature estimating means for calculating from the predetermined data, based on the temperature estimated by the temperature estimating means, a phase resistance value calculating means for calculating a phase resistance value, and an induced voltage constant deriving means for deriving an induced voltage constant, A phase difference calculating means for calculating a voltage phase difference consisting of a phase difference between the induced voltage and the phase voltage, and a current phase difference consisting of a phase difference between the induced voltage and the phase current; and Iron loss calculation means for calculating iron loss; real phase current calculation means for calculating an actual phase current by subtracting an iron loss component from the phase current based on the iron loss; the phase resistance value, the rotation speed, and the induction Inductance calculating means for calculating a field axis inductance and a torque axis inductance based on a voltage constant, the voltage phase difference, the current phase difference, and the real phase current; A torque command inputting means, a current command for calculating a field axis current command value and a torque axis current command value based on the induced voltage constant, the field axis inductance, the torque axis inductance and the torque command value. Value calculation means, and pulse width modulation signal output means for outputting a pulse width modulation signal to the energization switching means based on the field axis current command value and the torque axis current command value. Control device for brushless DC motor. 7. A brushless DC motor including a rotor having a permanent magnet and a stator having a plurality of stator windings for generating a rotating magnetic field for rotating the rotor, comprising a plurality of switching elements. What is claimed is: 1. A control device for a brushless DC motor, wherein said brushless DC motor is rotatably driven by current switching means for sequentially commutating the current to said stator winding, said phase voltage detecting means detecting a phase angle and an effective value of a phase voltage of said brushless DC motor. Phase current detecting means for detecting the phase angle and the effective value of the phase current, position detecting means for detecting the phase angle of the induced voltage from the magnetic pole position of the rotor, rotational speed detecting means for detecting the rotational speed, and detecting the output torque. Output torque detecting means, temperature detecting means for detecting the temperature of the brushless DC motor, and calculating a phase resistance value based on the detected temperature. Resistance value calculating means and induced voltage constant deriving means for deriving an induced voltage constant, a voltage phase difference consisting of a phase difference between the induced voltage and the phase voltage, and a current phase difference consisting of a phase difference between the induced voltage and the phase current. , An iron loss calculating means for calculating an iron loss of the brushless DC motor during rotational driving, and an actual phase current calculated by subtracting an iron loss component from the phase current based on the iron loss. Real phase current calculating means, and an inductance for calculating a field axis inductance and a torque axis inductance based on the phase resistance value, the rotation speed, the induced voltage constant, the voltage phase difference, the current phase difference, and the real phase current. Calculating means; torque command input means for inputting a torque command value; the induced voltage constant, the field axis inductance, the torque axis inductance, and the torque Current command value calculating means for calculating a field axis current command value and a torque axis current command value based on the current command value, and the energizing based on the field axis current command value and the torque axis current command value. Pulse width modulation signal output means for outputting a pulse width modulation signal to the switching means, wherein the iron loss calculation means is configured to output a motor output power and a motor input power of the brushless DC motor based on the output torque and the rotation speed. , A copper loss calculation means for calculating a copper loss based on the phase resistance value and the phase current, and a motor total loss calculated by subtracting the motor output power from the motor input power. Motor total loss calculating means; mechanical loss calculating means for calculating mechanical loss of the brushless DC motor; copper loss and mechanical loss from the motor total loss Subtraction means for calculating the iron loss by subtraction, and equivalent resistance value calculation means for calculating an actual iron loss equivalent resistance value based on the effective value including all frequency components of the phase voltage and the iron loss, The control device for a brushless DC motor, wherein the temperature detecting means calculates the temperature of the brushless DC motor from predetermined temperature data in which an estimated temperature for the total loss of the motor is stored in advance. 8. The brushless D.
The magnetic pole position of the rotor is calculated from an amount of change in inductance when a high frequency voltage is applied to the C motor, according to any one of claims 1 to 2, or 6 or 7. Control device for brushless DC motor.