KR100317828B1 - A servo controller and control method using the same for driving Permanent Magnet Type Servo Motor - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a servo controller for driving a permanent magnet type servomotor and a driving control method of the motor. In the type synchronous motor 30, the command speed ( ) Is compared with the rotational speed (ω _r ) of the motor 30 and the current command value ( , A current command value determining unit 50 determining (); Phase current of the measured static three-phase coordinate system ) In the synchronous two-phase coordinate system Coordinate transformation unit 70 for transforming the image and coordinates; The determined current command value and the measured current ( ) And outputs the command voltage, but compensates for the interference component included in the command voltage. Current controller compensation unit 80 for outputting; Compared with the compensated command voltage and the maximum output voltage (V _{s, max} ) the final command voltage ( A voltage command compensator 90 for determining C); And a final command voltage signal of the stationary three-phase coordinate system for generating the intermittent control signal to the pulse width modulation circuit 10 by inverting the phase / coordinate of the final command voltage ( It is configured to include a coordinate inverse conversion unit 100 to provide, to improve the reliability of the servo controller, there is an effect of reducing the size, low cost.

Description

Servo controller for permanent magnet type servo motor driving and servo motor driving control method using the servo controller {A servo controller and control method using the same for driving Permanent Magnet Type Servo Motor}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a servo controller for driving a Permanent Magnet Type Servo Motor and a drive control method of a servo motor using the servo controller, and in particular, a surface-mounted permanent magnet synchronous motor (SPMSM). The present invention relates to a servo controller for driving a surface-mounted permanent magnet synchronous motor and a control method thereof.

Servo is defined as' a control system configured to control the position, orientation, posture, etc. of an object as a control amount and follow an arbitrary change in a target value. A servomotor is a motor designed to quickly and accurately follow a command value of a frequently changing position or speed. Such servomotors must have a large acceleration and deceleration, and in order to do so, the torque and the moment of inertia must be small.

In the early days, due to the deterioration of control technology, DC motors, which are easy to control and easy to implement, were used as variable speed servo motors. This DC motor is easy to control due to the generation of torque, which is proportional to the input voltage, that is, the armature current.However, by using a brush to supply current to the armature, Maintenance was required, and there were limitations in the working environment and difficulties in high speed operation. The development of power semiconductor devices such as vector control theory developed in the early 1970s and perfect control algorithms in the early 1980s, and insulated gate bipolar transistors (IGBTs) developed for medium power applications in the 80s, Due to the development of a high performance digital microprocessor such as a digital signal processor (DSP), an AC servo motor system that solves the shortcomings of the DC motor has been developed and developed. The AC servo motor is maintenance free and has the advantage of being able to rotate at high speed. It is mainly classified into induction motor and permanent magnet synchronous motor. The induction motor has the advantage of being cheaper, structurally simple, robust and easy to manufacture than other electric motors, but has a disadvantage in that efficiency, rapid response and output density are lower than those of the permanent magnet motor.

The permanent magnet type (servo) motor is classified into a permanent magnet synchronous motor (PMSM) and a brushless DC motor (BLDC) according to a counter electromotive force and a current waveform. Since the pulsating torque at low speed is severe, it is mainly used for low precision applications and speed control, and the PMSM is mainly used for servo systems requiring high accuracy and high resolution. The PMSM is classified into a surface-mounted PMSM (SPMSM) and an interior-mounted PMSM (IPMSM) according to a magnet mounting method of the rotor.

Permanent magnet servo motors, which are subdivided as described above, have a structure opposite to that of a DC motor, and the rotor becomes a permanent magnet so that magnetic flux is generated regardless of an external power source, thereby minimizing power consumption and improving overall system efficiency. In addition, the permanent magnet servo motor has a high torque and miniaturization due to the development of high pressure insulator and ferrite magnets with improved performance and development of high performance rare earth magnets, resulting in high torque and miniaturization. Because of the heat dissipation through the case has excellent cooling characteristics compared to other motors.

On the other hand, in recent production lines, the demand for automation is steadily increasing to increase productivity and quality, and thus, factory automation equipment and machine tools require high speed and high precision speed and position control. Such high speed and high precision speed and position control requires the servo motor and a servo controller for driving and controlling the motor. However, since the conventional servo controller is expensive, there is a disadvantage in that the price of products and equipment using the same increases.

The present invention was created to solve the above problems of the conventional servo controller, the object of which is to drive and control the permanent magnet servomotor having the above advantages more effectively, and by a simple software of a complex algorithm By simplifying the implementation and control circuit, it is to provide a servo controller for driving a permanent magnet type servomotor with improved reliability and low cost, and a servo motor driving control method using the servo controller.

1 is an equivalent model of a permanent magnet synchronous motor assuming the number of poles of the motor for the present invention to two poles,

2 is an equivalent circuit diagram of FIG. 1;

3 is a two-phase rectangular coordinate system according to FIG.

4 is a view showing the limit trajectories for the voltage and current of the surface-mounted permanent magnet synchronous motor,

5 is a compensation block diagram of a current controller compensation unit according to the present invention;

6 is a flowchart illustrating voltage command compensation according to the present invention;

7 is a configuration diagram of a servo controller for a permanent magnet synchronous motor according to the present invention;

8 is a flowchart illustrating a driving control method of a permanent magnet synchronous motor according to the present invention.

※ Explanation of code for main part of drawing

10: pulse width modulation circuit 20: inverter

30: permanent magnet synchronous motor 40: speed detection unit

41: encoder 50: current command value determination unit

60: analog / digital conversion unit 70: coordinate conversion unit

80: current controller compensation unit 90: voltage command compensation unit

100: coordinate inverse transform unit

In order to achieve the above object, a servo controller for driving a permanent magnet servomotor according to the present invention includes an inverter for intermittently outputting and outputting power input according to a control signal of a pulse width modulation circuit (PWM circuit), and A permanent magnet synchronous motor driven by an output signal, comprising: current command value determining means for comparing a command speed with a rotational speed of the motor detected by the speed detecting means to determine a current command value; Coordinate conversion means for phase-converting and coordinate-converting the current of each phase measured by an analog / digital (A / D) converter; Current controller compensation means for outputting a command voltage by comparing the determined current command value with the phase-converted and coordinate-converted measured current, and compensating for interference components included in the command voltage to output a compensated command voltage; Voltage command compensation means for comparing the compensated command voltage with a predetermined maximum output voltage to determine a final command voltage; And inverse transform means for inversely transforming the phase and coordinates of the final command voltage and providing the pulse width modulation circuit as a signal for generating the control signal.

In order to achieve the above object, a permanent magnet servomotor drive control method according to the present invention includes: a command current determining step of determining a command current of each axis of a two-phase synchronous coordinate system corresponding to a difference between a command speed and a measurement speed; A coordinate conversion step of measuring a current of each phase of the motor and converting the current into a current of each axis of the two-phase synchronous coordinate system; Comparing the command current and the measured current converted by coordinates, and obtaining a command voltage corresponding to the difference, compensating an interference component included in the command voltage to generate a compensated command voltage and generating a compensated command voltage. step; A final command voltage determining step of determining a final command voltage of each axis by readjusting the output of the command voltage when the compensated command voltage exceeds a preset maximum output voltage; A coordinate reverse conversion step of converting a final command voltage of each axis of the two-phase synchronous coordinate system into a final command voltage of each phase of the three-phase stop coordinate system; And a drive control signal output step of generating an inverter drive control signal corresponding to the final command voltage and outputting the inverter drive control signal as a switch interruption signal of the inverter for driving the motor.

Hereinafter, with reference to the accompanying drawings will be described in detail a servo controller for driving a permanent magnet servo motor and a servo motor drive control method using the servo controller according to a preferred embodiment of the present invention.

1 is an equivalent model of a permanent magnet synchronous motor assuming the number of poles of the motor for the present invention as two poles, in which the windings of the stator are denoted by a, b and c to show the direction of the linkage flux. For this purpose, the concept of d-axis and q-axis was introduced and denoted by the letters d and q, respectively. Here, the direction of the direct axis refers to the direction in which the magnetic flux is directly bridged and corresponds to the direction indicated by the north pole (N pole) of the magnet when the field is supplied to the permanent magnet. On the other hand, the horizontal axis indicates a direction electrically 90 ° away from the linear axis.

Considering the magnetomotive source of the permanent magnet as a constant current source can simplify the modeling of the permanent magnet synchronous motor. Under this concept, a circuit equivalently representing the permanent magnet synchronous motor of FIG. 1 is shown in FIG.

In the permanent magnet AC motor, since the rotor is composed of permanent magnets of constant magnetic flux, no separate analysis is required, and only a voltage equation for the stator is derived. An entire circuit that links each phase of the stator from the equivalent circuit of FIG. Magnetic flux , And In this case, the voltage equation in the three-phase stationary coordinate system for each phase is given by the following equation (1).

Where V^s= [ ]^TAnd λ^s= [ ]^TIs,,AndIs composed of magnetic inductance, mutual inductance in linkage with other phases, and mutual inductance by magnetic flux of the rotor.

In order to make the dynamic analysis easier, the method of converting three-phase voltage equation into two-phase voltage equation is used. Representative methods include a stationary frame having a stator axis as a reference coordinate and a method of analyzing a synchronous coordinate system having a rotor rotating at a synchronous speed as a reference coordinate.

3 is a two-phase Cartesian coordinate system according to FIG. 2, and if the real axis is the d ^s imaginary axis as the q ^s axis, the stator three phase can be considered as the stator two phase equivalently stopped. It is a fixed two-phase coordinate system independent of the position of. If the magnetic flux direction of the rotor is referred to as the d ^r axis and the direction perpendicular to this axis is referred to as the q ^r axis, this coordinate system becomes a synchronous coordinate system that rotates at a synchronous speed. The relationship between the fixed stop coordinate system and the synchronous coordinate system is as follows.

First, the voltage equation of the fixed stationary coordinate system is decomposed into real and imaginary values on a plane and represented as a value on the d ^s -q ^s axis defined in FIG. 3 by the following equation (2).

Where L _ds = L _qs = (3/2) L _o . ψ _f = λ _f I _F (magnetic flux constant by permanent magnets that link to stator windings).

As shown in Equation (2), it is difficult to analyze the transient characteristics of the permanent magnet synchronous motor using the two-phase stationary coordinate system method. Therefore, in the synchronous coordinate system based on the rotor, the coordinate axis (d ^r -q ^r axis) is rotating at the synchronous speed, so the voltage and current vectors of the stator rotating at the synchronous speed are similar to the DC values when viewed from the rotor axis. It is a constant value. As can be seen in the two-phase stationary coordinate system, all terms related to the position of the rotor become constant values, so the equation can be further simplified as shown in Equation (3) below.

Where ω _r is the synchronous angular velocity, , D, q-axis terminal voltage, , D is the d, q-axis stator current, L _ds , L _qs is the d, q-axis inductance, Rs is the stator resistance, and ψ _f is the linkage flux by the permanent magnet.

On the other hand, the torque equation of the synchronous motor can be obtained from the output of the motor. If the instantaneous input by the three-phase input is P _in , the value is given by the following equation (4).

Substituting Equation (3) into Equation (4) and arranging it is as in Equation (5) below.

On the right side of Equation (5), the first term represents the copper loss, the second term represents the magnetic energy conversion rate, and the third term represents the mechanical output. Therefore, the mechanical output P _out is given by the following equation (6).

In addition, since P _out = ω _m T _e and ω _r = (P / 2) ω _m , the torque equation is as follows.

The mechanical motion equation of the motor is given by the following equation (8).

Where T _L is the load torque, J is the moment of inertia, and B is the friction coefficient.

Subsequently, the equations for designing the current and voltage controller of the permanent magnet synchronous motor will be defined based on the voltage and current equations defined above.

First, the formula for the voltage and current limit of the permanent magnet synchronous motor is defined as follows.

The maximum voltage V _{s, max} is determined by the DC link voltage and PWM method. The maximum voltage available when applying the space vector PWM method is The maximum current I _{s, max} is determined by the current rating of the inverter and the thermal rating of the motor. If this is expressed by a formula, it is as following Formula (9) and Formula (10).

Next, the voltage equation at steady state is defined as follows.

As the speed increases above the rated speed, the voltage drop component due to the resistance component can be ignored in the voltage equation (in a two-phase synchronous coordinate system such as Equation (3) above), and the steady state voltage equation is It can be expressed briefly as (11) and (12).

In the above formulas (11) and (12), L _ds = L _qs = L _s when the type of permanent magnet synchronous motor is SMPSM. Therefore, the steady-state voltage limiting equation can be changed into the following equations (13) and (14).

It can be seen from Equation (14) that the voltage limiting equation has a circular locus as shown in FIG. , The center point It can be seen that. Since the radius is a function of the velocity, it can be seen that as the velocity increases, the radius decreases, which in turn decreases the voltage margin.

Next, using equations (7) and (10), equations for maximum torque control per unit current (maximum torque control equation in the constant torque range) are obtained as follows.

That is, when Formula (10) is substituted into Formula (7), Formula (15) is obtained.

The following formula (17) can be obtained from the above formula (15) through the same process as the following formula (16).

Next, the equation for control in the constant power area is obtained as follows.

Since the voltage is limited in the constant output region, the voltage equation in the steady state is as shown in the following equation (18), which is the same as the above equations (11) and (12).

In the formula (18), by applying a voltage limiting formula such as the following formula (19) (this formula is the same as the formula (9)) can be obtained as follows.

That is, the following formula (20) is derived from the above formula (19),

Substituting Equation (20) into Equation (18) and going through the same process as Equation (21) below, Equation (22) can be obtained.

=

In the above formula (22), the following formula (23) is derived (for current control in the constant output region) from the condition that the inside of?

Next, the compensation of the current controller and the compensation for the voltage command value will be described based on the equations derived for the voltage and current controller design of the permanent magnet synchronous motor as described above.

First, the current controller compensation will be described.

In the formula (3), the voltage component of the d-axis Voltage component of and q axis There are different ingredients Wow Each contains. That is, d-axis voltage In the term, there is an influence by the q-axis current and the q-axis voltage Since there is an effect of dcnr current in the term, the current component of the d-axis and q-axis is the voltage component of the d-axis and the q-axis. Wow Can not be controlled independently of each other.

In PMSM, these mutual coupling components appear very large due to their relatively large inductance components, and the higher the speed, the greater the effect of these components. Therefore, since the component affects the current and torque dynamic characteristics during operation in the field weakening region of the high speed region, the component must compensate for the interference component. The voltage components to be compensated for the d-axis and q-axis current controller outputs are equal to V _do and V _qo , respectively, and are given by Equations (24) and (25).

That is, as shown in FIG. 5, the current controller compensation relationship is measured in the d-axis current. And q-axis current Multiplied by the inductance and speed of each axis to compensate for the output voltage. Wow In the following formula (26).

Where G _cd and G _cq are PI controllers.

Next, the voltage command value in the field weakening area with reference to FIG. Wow Adjust the output voltage setpoint Wow It will be described how to determine. That is, in the field weakening area, the output voltage V _o is kept equal to V _{s, max} and the terminal voltage V _a is kept almost equal to the voltage limit V _{s, max} , but the voltage command value Wow In the transient state, the output voltage available from the inverter exceeds the bar. In this case, the d and q-axis current controllers become saturated and have mutual influences, thereby deteriorating the transient characteristics and the actual current following the command current value. You can't. Therefore, to solve this problem, the voltage command value compensation method as shown in FIG. 6 is performed.

First, the voltage command value (or command voltage) of each axis is expressed by the equation (25). Wow Is determined, Wow Command voltage by ) And the maximum output voltage (V _smax ) determined according to the DC link voltage and the PWM method (S1), and if the command voltage is smaller than the maximum output voltage, the voltage command value Wow Output voltage command value (or called final command voltage) without compensation Wow (S2), when large, the voltage command value of each axis Wow Adjust as follows.

Voltage command value of the d-axis Synthesis of values and the V _qo hit by the q-axis voltage compensation according to the d-axis current ( ) And the maximum output voltage V _smax (S3), and Is smaller than V _smax , the d-axis voltage is equal to the d-axis voltage command value. Output voltage command value of d axis without compensation Q-axis output voltage setpoint Is Adjust to output to (S4), the Is greater than V _smax , the output voltage command value on the q-axis Adjust the output such that the q-axis voltage compensation hit V _qo, and the output d-axis voltage command value Is The output is adjusted to be (S5).

7 is a configuration diagram of a servo controller for driving a permanent magnet servomotor according to the present invention, wherein an inverter 20 intermittently outputs the input power according to an interruption control signal of a pulse width modulation circuit (PWM circuit) 10. And a command speed (commanded by voltage or pulse) in the permanent magnet synchronous motor (PMSM) 30 driven by the output signal of the inverter 20. ) And the rotational speed ω _r of the motor 30 detected by the speed detector 40 through the encoder 41 to compare the current command value ( , A current command value determining unit 50 determining (); Two phase currents of the static three-phase coordinate system measured by the analog-to-digital (A / D) converter 60 ) In the synchronous two-phase coordinate system Coordinate transformation unit 70 for the phase transformation and coordinate transformation to the; Current command value determined by the current command value determination unit 50 ( , ) And the measured current (phase-converted and coordinate-converted by the coordinate transformation unit 70) ) And outputs a command voltage, and compensates for the interference component (that is, the voltage component according to the speed and current of the other phase included in the voltage component of each phase) and compensates as shown in Equation (26). Command voltage ( A current controller compensator 80 for outputting; The compensated command voltage ( ) And the maximum command voltage (V _{s, max} ) determined according to the method of the pulse width modulation circuit 10 with the DC link voltage of the power supply based on Equation (9). A voltage command compensator 90 for determining C); And the final command voltage of the synchronous two-phase coordinate system ( Final command voltage signal of the stationary three-phase coordinate system for generating the intermittent control signal to the pulse width modulation circuit It is configured to include a coordinate inverse transform unit 100 to provide.

In the current controller compensation unit 80, the compensation of the interference component is as described above with reference to FIG. 5 and the equations (24), 25 and 26, and in the voltage command compensation unit 90, The final command voltage ( ) Is the same as described above with reference to FIG.

FIG. 8 is a flowchart illustrating a method of controlling a permanent magnet servo motor driving according to the present invention. Since the method is applied to the servo controller of the present invention as shown in FIG. 7, the operation of the servo controller of the present invention as shown in FIG. 7 is described. In parallel with this, the flowchart of FIG. 8 will be described.

First, the speed as voltage or pulse ( Command) (S10), four encoders 41 mounted on the motor shaft of the PMSM 30 are removed, and the rotational speed of the PMSM 30 After measuring (S11), the command speed ( ) And the rotational speed detected by the speed detector 40 through the encoder 41 ) Is inputted to the PI controller of the current command value determining unit 50, the PI controller outputs a command current (q-axis) corresponding to the input signal. ) Is generated and determined (S12), and the command current ( ) Is input to the limiter LIMITER of the current command value determining unit 50 and the output is limited, and the command current of the d-axis ( ) Is 0 (zero) (S13).

In addition, the rotation speed ( At the same time as the measurement time, u-phase and v-phase currents of the three-phase output current of the inverter ( ) Is measured through the A / D converter 60 and the measured u-phase and v-phase currents ( Is the d-axis and q-axis currents of the synchronous two-phase coordinate system through the coordinate transformation unit 70. Are converted to (S14).

Then, through the current controller compensation unit 80, the measured current of the d-axis and q-axis ( ) And command current ( ) And calculate a reference voltage corresponding to the difference, and compensate for the interference component (that is, the voltage component according to the speed and current of the other phase included in the voltage component of each phase). Compensated reference voltage ) Is output (S15). The method of compensating for the interference component in detail at step S15 is as described above with reference to FIG. 5 and the equations (24), (25) and (26).

Subsequently, the compensated command voltage, ) And the maximum command voltage (V _{s, max} ) determined according to the method of the pulse width modulation circuit 10 with the DC link voltage of the power supply based on Equation (9). Determine (S16), the final command voltage ( The detailed description of the step S16 for generating) will be omitted since it has already been described above with reference to FIG. 6.

Finally, the last command voltage (d, q-axis) of the two-phase synchronous coordinate system through the coordinate inverse transform unit 100 ) Is the u, v and w phase final command voltage ( (S17) and the final command voltage (V) via the pulse width modulation circuit unit 10 as a medium. ) And calculates and outputs a pulse width control signal corresponding to the calculated pulse number, that is, an inverter drive control signal for controlling the switch of the inverter 20 (S19).

As described in detail above, according to the servo controller for driving a permanent magnet type servomotor according to the present invention and a servomotor drive control method using the servocontroller, the servo controller can be implemented by simple software of a complex algorithm and by simplifying a control circuit. It has the effect of improving reliability and making it smaller and cheaper.

Claims (12)

In the inverter for interrupting and outputting the power input according to the control signal of the pulse width modulation circuit (PWM circuit), and the permanent magnet type synchronous motor driven by the output signal of the inverter, Current command value determining means for comparing the command speed and the rotational speed of the motor detected by the speed detecting means to determine the current command value, and determining the current command value to be equal to or less than the maximum output current at the constant output ; Coordinate conversion means for inputting two phase currents of each phase current measured through an analog / digital (A / D) converter and performing phase conversion and coordinate conversion from a stationary three-phase coordinate system to a synchronous two-phase coordinate system ; Current controller compensation means for outputting a command voltage by comparing the determined current command value with the phase-converted and coordinate-converted measured current, and compensating for interference components included in the command voltage to output a compensated command voltage; The final command voltage is determined by comparing the compensated command voltage with a predetermined maximum output voltage, wherein a first synthesis value of the compensated command voltage of each axis is compared with the maximum output voltage, and the first synthesis value is the maximum output voltage. If it is less than the voltage, the command voltage of each axis is output as the final command voltage without adjustment. If the first synthesis value is larger than the maximum output voltage, the maximum output voltage is the value of the other axis by the command voltage of one axis and the current of that axis. If it is determined that the maximum output voltage is greater than the second synthesized value by comparing with the voltage compensation value greater than the second synthesized value, the command voltage of the one axis is output as the final command voltage of the same axis without adjustment, and Final command voltage Where V _smax is the maximum output voltage and V _q is the command voltage of the other axis, and is output. When it is determined that the maximum output voltage is smaller than the second synthesized value, the final command voltage of one axis is (V _smax is the maximum output voltage, V _qo is a voltage command compensation means for adjusting and outputting to be the voltage compensation value of the other axis) ; And And inversely converting means for converting the phases and coordinates of the final command voltage from a synchronous two-phase coordinate system to a stationary three-phase coordinate system as a signal for generating the control signal to the pulse width modulation circuit. Servo controller for driving magnet type servomotor. The method of claim 1, And said command speed is commanded by a voltage or pulse. delete The method of claim 1, The interference component is a permanent magnet servo motor drive servo controller, characterized in that the voltage component according to the speed and current of the other phase included in the voltage component of each phase. The method of claim 1, The maximum output voltage is a permanent magnet servo motor drive servo controller, characterized in that determined according to the pulse width modulation method of the power supply voltage and the pulse width modulation circuit. delete A command current determining step of determining a command current of each axis of the two-phase synchronous coordinate system corresponding to the difference between the command speed and the measurement speed; A coordinate conversion step of measuring a current of each phase of the motor and converting the current into a current of each axis of the two-phase synchronous coordinate system; Comparing the command current and the measured current converted by coordinates, and obtaining a command voltage corresponding to the difference, compensating an interference component included in the command voltage to generate a compensated command voltage and generating a compensated command voltage. step; A final command voltage determining step of determining the final command voltage of each axis by readjusting the output of the command voltage when the compensated command voltage exceeds a preset maximum output voltage; A coordinate reverse conversion step of converting a final command voltage of each axis of the two-phase synchronous coordinate system into a final command voltage of each phase of the three-phase stop coordinate system; And And a drive control signal output step of generating an inverter drive control signal corresponding to the final command voltage and outputting the inverter drive control signal to the switch interrupt signal of the inverter for driving the motor. The method of claim 7, wherein The command speed is a permanent magnet servo motor drive control method characterized in that the command by the voltage or pulse. The method of claim 7, wherein The measuring speed is a permanent magnet servo motor drive control method characterized in that the incremental encoder is mounted on the motor shaft and measured by multiplying it. The method of claim 7, wherein The interference component is a permanent magnet servo motor drive control method, characterized in that the voltage component according to the speed and current of the other axis included in the voltage component of each axis of the two-phase synchronous coordinate system. The method of claim 7, wherein The maximum output voltage is a permanent magnet servo motor drive control method, characterized in that determined by the DC link voltage and the pulse width modulation scheme of the inverter. The method of claim 7, wherein The final command voltage determination step, Comparing the first synthesized value of the command voltage of each axis with the maximum output voltage; If the first synthesis value is less than the maximum output voltage, outputting the command voltage of each axis as the final command voltage without adjustment; If the first synthesis value is greater than the maximum output voltage, comparing and determining whether the maximum output voltage is greater than a second synthesis value between the command voltage of one axis and the voltage compensation value of the other axis by the current of the axis; If it is determined that the maximum output voltage is larger than the second synthesis value, the command voltage of the one axis is output as the final command voltage of the same axis without adjustment, and the final command voltage of the other axis is (Wherein V _smax is the maximum output voltage, V _q is the command voltage of the other axis) and is outputted; And If it is determined that the maximum output voltage is less than the second synthesis value, the final command voltage of one axis is (Where, V _qo is the voltage compensation value of the other axis), and adjusting to output the permanent magnet servo drive control method characterized in that it comprises a.