KR102091589B1 - Apparatus for reducing common mode voltage of system for controlling multi phase motor using interleaved - Google Patents

Abstract

The present invention relates to a device for reducing a common mode voltage in a multi-phase motor control system using an interphase control method comprising: a motor control module including a current control unit which outputs a reference voltage for each phase based on the rotation angle of a motor, a PWM generating unit which generates a PWM signal for driving the motor based on the reference voltage, and an inverter unit in which a plurality of inverters are provided to correspond to each of a plurality of sectors of the motor and which drives the motor according to a switching operation of the inverter based on the PWM signal; a voltage measuring unit measuring the reference voltage; a voltage modulation index calculation unit which calculates a voltage modulation index based on a DC voltage applied to the motor and the measured reference voltage; and a parameter calculating unit which calculates an optimal parameter corresponding to the lowest point of a common mode voltage generation amount of the inverter unit by using a preset linear function for the voltage modulation index consisting of the sum of a plurality of trigonometric functions having a plurality of parameters. Accordingly, an interleaved method applied to an existing three-phase two-level inverter is extensively applied to a six-phase excitation method so that each phase current is independently controlled at a predetermined switching cycle, thereby reducing torque pulsation during phase transition and interphase imbalance, minimizing the common mode voltage, and reducing the amount of leakage current.

Description

A common mode voltage reduction device for a multi-phase motor control system using a phase-to-phase control method {APPARATUS FOR REDUCING COMMON MODE VOLTAGE OF SYSTEM FOR CONTROLLING MULTI PHASE MOTOR USING INTERLEAVED}

The present invention relates to a common mode voltage reduction device of a multi-phase motor control system using a phase-to-phase phase control method that can minimize a common mode voltage by applying an interphase interleaved method to a 6-phase excitation method.

Multi-phase motors are used in systems that require high power in a limited space, such as underwater electric propulsion, because torque ripple is less and output power density is higher than conventional three-phase motors.

In particular, through the recent development of high-performance DSPs and semiconductors for power, the use of polyphase motors is being considered as it is possible to arbitrarily adjust the size and frequency of the output voltage regardless of the magnitude of the DC link voltage.

In general, a method of controlling a polyphase motor includes a hysteresis control method and a vector control method. Among these, the hysteresis control method has a disadvantage in that it is difficult to predict the heat generation of the system due to the variable switching frequency, and the vector control method has a difficult disadvantage in that the coordinate conversion process is difficult and the low-order harmonic components that help torque in addition to the basic wave must be controlled. have.

In the case of an electric motor driving an underwater propellant, a lot of operation is performed in a region having a high operating frequency, and operation in a high-speed region causes a current delay phenomenon due to an increase in reactance of a phase winding and a torque pulsation due to a lack of current sampling.

As one of the methods for solving the torque pulsation, a method of increasing the current control period and switching frequency can be used, but an increase in switching frequency causes an increase in common mode noise.

For this reason, studies of various methods for reducing the common mode voltage have been conducted. Among the most basic methods, there are a method of designing a passive filter at the output and input terminals, a method of using an active filter that senses and cancels the common mode voltage or current, and a method of changing or combining the PWM switching pattern.

However, these conventional studies are applicable to two-level or three-level inverters, and the underwater propulsion system using a polyphase motor has many limitations in adding hardware, such as a passive filter or an active filter, because there are many spatial limitations.

KR 10-1610469 B1 KR 10-0920586 B1

An object of the present invention is to solve the above problem, a common mode voltage reduction device of a multi-phase motor control system using a phase-to-phase phase control method capable of minimizing a common mode voltage by applying an interphase interleaved method to a six-phase excitation method. It aims to provide.

A common mode voltage reduction device of a multi-phase motor control system using a phase-to-phase phase control method according to an aspect of the present invention for achieving the above object is a current controller for outputting a reference voltage for each phase based on the rotation angle of the motor, PWM generator for generating a PWM signal for driving the motor based on a reference voltage, and a plurality of inverters are provided to correspond to each of a plurality of sectors of the motor, according to the switching operation of the inverter based on the PWM signal A motor control module including an inverter unit driving the motor; A voltage measuring unit measuring the reference voltage; A voltage modulation index calculation unit for calculating a voltage modulation index based on the DC voltage applied to the motor and the measured reference voltage; And a parameter calculator configured to calculate an optimal parameter corresponding to the lowest point of the common mode voltage generation amount of the inverter unit by using a preset linear function for the voltage modulation index consisting of a sum of a plurality of trigonometric functions having a plurality of parameters. It is characterized by.

According to the present invention, by extending and applying the interleaved method between phases applied to the existing three-phase two-level inverter to the six-phase excitation method, each phase current is independently controlled in a constant switching cycle to control the phase imbalance and phase transition. In addition to reducing torque pulsation, there is an advantage of minimizing common mode voltage and reducing the magnitude of leakage current.

1 is a view showing a typical 7-phase BLDC motor control system as an equivalent circuit model,
2 is a block diagram showing the configuration of a common mode voltage reduction device of a multi-phase motor control system using a phase-to-phase control method according to an embodiment of the present invention,
3 is a conceptual diagram of the motor control module shown in FIG. 2,
4 is a view for explaining the operation of the carrier signal generation unit shown in FIG. 2,
5 and 6 are views for explaining the operation of the switching signal generator shown in FIG. 2,
FIG. 7 is a view for explaining a process of calculating an optimal parameter by the parameter calculator shown in FIG. 2.
8 is a graph for comparing a common mode voltage according to an embodiment of the present invention with a common mode voltage according to the prior art.
9 is a graph showing a common mode voltage according to a switching operation when MI is 0, 0.3, 0.6, 0, 9, respectively, when k = 0 ° in the prior art.
10 is a view for explaining an embodiment of the present invention, when MI = 0, k is a graph showing the common mode voltage according to the switching operation when each of 60 ° 90 ° 120 °.
11 is a graph showing a common mode voltage according to a switching operation when MI = 0.4 and k is 0 ° 90 ° 120 °, respectively, in an embodiment of the present invention.
12 is a graph showing a common mode voltage according to a switching operation when MI is 0.8 and k is 0 ° 90 ° and 120 °, respectively, in an embodiment of the present invention.

The problems to be solved for the present invention as described above, the means for solving the problems, and specific matters including the effects of the invention are included in the following examples and drawings. Advantages and features of the present invention, and a method of achieving the advantages and features will be apparent with reference to embodiments described below in detail together with the accompanying drawings. The same reference numerals refer to the same components throughout the specification.

1 is a view showing a typical 7-phase BLDC motor control system as an equivalent circuit model, and FIG. 2 shows a configuration of a common mode voltage reduction device of a multi-phase motor control system using a phase-to-phase phase control method according to an embodiment of the present invention 3 is a conceptual diagram of the motor control module shown in FIG. 2, FIG. 4 is a view for explaining the operation of the carrier signal generator shown in FIG. 2, and FIGS. 5 and 6 are shown in FIG. FIG. 7 is a view for explaining the operation of the switching signal generation unit, and FIG. 7 is a view for explaining a process of calculating an optimal parameter by the parameter calculation unit shown in FIG. 2.

Hereinafter, a common mode voltage reduction device of a multi-phase motor control system using a phase-to-phase phase control method according to an embodiment of the present invention will be described with reference to the aforementioned drawings.

First, the multi-phase motor control system according to an embodiment of the present invention, as shown in Figure 1, from the seven Hall sensors arranged in correspondence with 14 sectors that divide the position of the rotor of the motor by a certain angle unit When a Hall sensor signal is output, control for a 7-phase BLDC motor that controls the switching operation of ₁₄ switches (S ₁ to S ₁₄ ) corresponding to each sector to operate in a 6-phase excitation method by applying a voltage for each sector based on this. It can be a system.

At this time, when a voltage is applied by selecting a section (6 * π / 7) having a flat back electromotive force for each phase, positive three phases (a, e, f), negative three phases (b, c, d) and The non-conductive phase (g) exists, and the equation for the torque (T _e ) of the 7-phase BLDC motor 10 generated by this is as shown in Equation 1 below.

Here, ω _m represents the angular speed of the rotor of the motor 10, e _a , e _b , e _c , e _d , e _e , e _f , e _g are a phase, b phase, c phase, d phase, e-phase, f-phase, and g-phase counter electromotive force, i _a , i _b , i _c , i _d , i _e , i _f , i _g are respectively a phase, b phase, c phase, d phase, e phase, f The phase and g phase currents are represented, e _s represents the maximum value of back EMF, and i _s represents the maximum value of phase current.

At this time, the non-conductive phase (g) was assumed to be open, and the sum of the 7-phase current and back electromotive force was assumed to be '0', and the neutral point (s) of the motor 10 and the DC terminal in the 6-phase excitation method The common mode voltage (V _cm ) corresponding to the potential difference between the neutral points (n) can be expressed as Equation 2 below corresponding to the sum of the pole voltages of each phase.

Table 1 below summarizes the conduction current according to the six-phase excitation method.

Here, pst 1 indicates when the position of the rotor is in the range from '0' to 'π / 7', and pst 2 is the position of the rotor from 'π / 7' to '2π / 7' Time, pst 3 indicates when the position of the rotor ranges from '2π / 7' to '3π / 7', pst 4 indicates the position of the rotor from '3π / 7' to '4π / 7' When the range is from, pst 5 indicates when the position of the rotor ranges from '4π / 7' to '5π / 7', pst 6 indicates the position of the rotor from '5π / 7' to ' When it is in the range from 6π / 7 ', pst 7 indicates when the position of the rotor is in the range from' 6π / 7 'to' π ', pst 8 is when the position of the rotor is from' π 'to' 8π / 7 ', pst 9 indicates when the rotor position ranges from' 8π / 7 'to' 9π / 7 ', pst 10 indicates the rotor position is' 9π / 7 'to '10 π / 7', pst 11 indicates the position of the rotor from '10 π / 7 'to '11 π / 7' When it is in the range of the paper, pst 12 indicates when the position of the rotor is in the range from '11 π / 7 'to '12 π / 7', and pst 13 is when the position of the rotor is from '12 π / 7 'to '13 π / 7 'and pst 0 indicates when the rotor position is in the range of '13 π / 7' to '2π'.

In addition, '-' and '+' indicate the polarity of the conducting current, and '0' indicates that the value of the back electromotive force becomes 0.

Location i _a i _b i _c i _d i _e i _f i _g pst 0 - - - 0 + + + pst 1 0 - - - + + + pst 2 + - - - 0 + + pst 3 + 0 - - - + + pst 4 + + - - - 0 + pst 5 + + 0 - - - + pst 6 + + + - - - 0 pst 7 + + + 0 - - - pst 8 0 + + + - - - pst 9 - + + + 0 - - pst 10 - 0 + + + - - pst 11 - - + + + 0 - pst 12 - - 0 + + + - pst 13 - - - + + + 0

Next, referring to Figure 2, the common mode voltage reduction device of the multi-phase motor control system using a phase-to-phase control method according to an embodiment of the present invention, the motor control module 100, the current controller voltage measuring unit 200, Includes a voltage modulation index calculation unit 300, a reference value setting unit 400, a parameter calculation unit 500, an interleaved angle calculation unit 600, a carrier signal generation unit 800, and a switching signal generation unit 700 do.

The motor control module 100 is for controlling the speed of the motor 10 by a PWM (Pulse Width Modulation) method, as shown in FIG. 3, based on each phase based on the rotation angle ω of the motor 10 voltage (V ^* _{_ref)} to a current controller 120 which outputs, to the PWM generator 130 based on a reference voltage (V ^* _{_ref)} generates a PWM signal for driving the motor 10, a plurality of inverters Is provided to correspond to each of a plurality of sectors of the motor 10, may include an inverter unit 140 for driving the motor 10 according to the switching operation of the inverter based on the PWM signal.

For example, referring to FIG. 3, the speed controller 110 estimates the angular velocity ω of the motor 10 based on the Hall signal output from the hall sensor of the motor 10 and the preset reference angular velocity ( When generating and outputting the current command (I ^* ) based on the result of comparing ω ^* ), the current controller 120 generates each phase based on the position of the rotor for each sector and the current command (I ^* ). Voltage commands for (a, b, c, d, e, f, g) (V _a ^* _{_ref} , V _b ^* _{_ref} , V _c ^* _{_ref} , V _d ^* _{_ref} , V _e ^* _{_ref} , V _f ^* _{_ref} , The reference voltage corresponding to V _g ^* _{_ref} ) is generated and output.

The current controller voltage measuring unit 200 measures the reference voltage (V ^* _{_ref} ) output from the current controller 120 of the motor control module 100.

The voltage modulation index calculation unit 300 is based on a DC voltage (V _dc ) applied to the motor 10 and a reference voltage (V ^* _{_ref} ) measured by the voltage controller 200 of the current controller (MI). ).

At this time, the formula for the voltage modulation index (MI) is summarized as shown in Equation 3 below.

Here, V ^* _ref represents a reference voltage value measured by the current controller voltage measurement unit 200, and V _dc represents a DC voltage value applied to the motor 10.

The interleaved angle calculator 600 is for calculating an interleaved angle k corresponding to a phase difference between switching signals for each phase based on the PWM signal generated by the PWM generator 130 of the motor control module 100.

Here, the interleaved angle calculation unit 600 compares the voltage modulation index (MI) calculated by the voltage modulation index calculation unit 300 with a preset reference value, according to the phase difference between the switching signals for each phase based on the PWM signal. The interleaved angle k may be calculated by using the conditional expression for determining the corresponding interleaved angle k as one of the first and second predetermined values and the linear function Y.

At this time, the conditional expression for the interleaved angle k determined based on the range condition to which the value of the voltage modulation index MI belongs may be expressed by Equation 4 and Equation 5 below.

Here, the reference value is set to '0.6', and the first value and the second value are set to '120˚' and '60 ˚ ', respectively.

The parameter calculating unit 500 is a preset linearity for the voltage modulation index (MI) consisting of the sum of a plurality of trigonometric functions having a plurality of parameters (a ₁ , b ₁ , c ₁ , a ₂ , b ₂ , c ₂ ) The optimum parameter corresponding to the lowest point of the common mode voltage generation amount of the inverter unit 140 is calculated using the function Y.

At this time, the equation for the linear function (Y) is summarized as in Equation 6 below.

Here, MI represents a voltage modulation index, Y represents a linear function, a ₁ represents a first sine gain constant, b ₁ represents a first voltage modulation gain constant, c ₁ represents a first constant, and a ₂ represents the second sine gain constant, b ₂ represents the second voltage modulation gain constant, and c ₂ represents the second constant.

In this case, the parameter calculating unit 500 is a result of simultaneous calculation by applying the above-described Equations 4 to 6 to a MATLAB (Matrix Laboratory) simulation, as shown in FIG. 7, an interleaved angle and After deriving a 3D graph corresponding to the common mode voltage generation amount for the voltage modulation index (MI), the lowest point of the common mode voltage generation amount can be detected by curve fitting the graph.

The carrier signal generation unit 800 is a first carrier (carrier) based on the variation width (-V _ref ~ + V _ref ) of the reference voltage (V ^* _{_ref} ), and the first carrier (carrier) in both directions the interleaved angle ( A second carrier (+ k carrier) phase shifted by k) and a third carrier (-k carrier) phase shifted by the interleaved angle k in the negative direction of the phase of the first carrier are generated. .

At this time, the motor control module 100 according to the present invention is the first two voltage commands (+ V ^* _ref , -V ^* _ref ) based on the reference voltage (V ^* _{_ref} ) measured by the voltage measuring unit 200. The time when the upper switch on the positive conduction is turned on and the time when the lower switch on the negative conduction is turned on based on the result of comparison with the carrier, the second carrier (+ k carrier), and the third carrier (-k carrier). It can operate in a double uni-polar way to determine each.

In addition, in the present invention, as a method for minimizing the torque pulsation due to the phase shift of the carrier when the position of the rotor changes, the type of carrier that is compared according to the position of the rotor in the conduction section of each phase current is' second. It can be changed in the order of 'carrier (+ k carrier)-> first carrier (carrier)-> third carrier (-k carrier)'.

In general, in the case of the six-phase excitation method, since the polarity of the conducting phase and the non-conduction phase are changed according to the position of the rotor as shown in Table 1 above, in order to achieve phase equilibrium, the carriers to be compared must also be changed according to the position Is considered.

For example, as shown in FIG. 4, when the rotor position passes the 'pst = 2' section, the conducting phases are positive polarity "a", "f", "g" phase and negative polarity "b" It consists of "," c "," d "phases. At this time, the "a" phase is compared to the second carrier (+ k carrier) that is advanced by k, the "f" phase is compared to the third carrier (-k carrier) that is ground by k, and the "g" phase is the first carrier that is the primary carrier ( carrier), the switch states (S _a , S _f , Sg, S _b , S _c , S _d ) shown in FIG. 5 are finally determined.

Switching signal generation unit 700 is a first carrier (carrier), the second carrier (+ k carrier) and the third carrier (-k carrier) generated by the carrier signal generation unit 800, respectively, the reference voltage (V ^* _{_ref} ) generates a switching signal that controls the on-off operation of the switch of the inverter corresponding to each phase based on the result of comparison with the maximum and minimum values of the fluctuation range.

Here, the switching signal generator 700 uses the voltage modulation index (MI) and the interleaved angle (k) calculated by the voltage modulation index calculation unit 300 and the interleaved angle calculation unit 600, respectively. After calculating the switch-on period of the inverter corresponding to each phase according to Equation 7 to Equation 12, a switching signal to prevent overlapping of the start and end points of the switch-on period for each phase based on the calculated switch-on period You can create

In this regard, the process of deriving the above-described Equations 7 to 12 with reference to FIG. 5 will be briefly described.

Equation 13 below is a redefinition of the switch state defined based on the phase in FIG. 5 as the reference of the carrier and the upper bottom in order to calculate the amount of common mode voltage generation without considering the rotor position.

At this time, when the upper switch is turned on, it is indicated by 'T' (T: upper arm switch), when the lower switch is turned on, it is indicated by 'B' (B: lower arm switch), and when compared with the primary carrier, the first carrier Represented as '1' (1: compared 0 ° carrier), compared to the second carrier advanced by + k (+ k carrier), represented by '2' (2: compared + k ° carrier), grounded by -k When compared with the third carrier (-k carrier), it is represented as '3' (3: compared -k ° carrier).

In addition, in relation to the on / off timing of the switch, when the simplified diagram of FIG. 5 is schematically illustrated for the two-phase switching state, as shown in FIG. 6, the voltage command is compared with each carrier to switch The on (on) angle was defined as θ _re and the off (off) angle was defined as θ _fe .

For example, as shown in FIG. 6 (a), when the interleaved angle k is 30 ° and the voltage modulation index MI is 0, the upper switch S _T1 compared with the first carrier is' π / It turns on at 2 'and turns off at' -π / 2 '. Also, S _T3 is shifted by 'π / 6' because '-π / 6' is also compared with a carrier, so that it turns on at '4π / 6' and turns off at '-π / 3'.

In addition, as shown in FIG. 6 (b), when the voltage modulation index MI increases, θ _re of S _T1 moves to 0 ° based on 'π / 2', so 'π / 2 (1-MI ) 'Is established, and θ _re of S _T3 compared to a carrier shifted by' π / 6 'results in' π / 6 + π / 2 (1-MI) '.

Based on the above, the switch on / off angles of all phases may be expressed as Equation 14 below, including the voltage modulation index (MI) and the interleaved angle (k).

At this time, assuming that the voltage modulation index (MI) is constant, since the switch state has a periodicity, if the Fourier coefficient is obtained using Equation 15 to Equation 17 below, it can be expressed by Equation 18 below. Can.

Here, from S _T1 to S _T3 , since the upper switch is on, the size of f (x) is indicated as '1', and from S _B1 to S _B3 , the size of the lower switch is indicated as '-1', and the effective integration The interval is from θ _re to θ _fe as in Equation 14 above.

Thereafter, when all the calculations in Equation 18 are performed, the state of each switch in a section from '-π' to 'π' can be expressed by Equation 19 below.

Here, x is a value between -π and π, and n represents the precision of the operation. The larger it is, the closer the square wave is to the switch signal.

At this time, using the switching functions of Equation 1 and Equation 19 defining the common mode voltage, the common mode voltage V _{cm that} changes according to the voltage modulation index MI and the interleaved angle k is expressed by Equation 20 below. Can be obtained as

In addition, the root mean square (RMS) value of the common mode voltage generated in one cycle of the switch is defined by Equation 21 below.

In this case, if the RMS average value of the common mode voltage of Equation 21 is obtained and normalized while changing the voltage modulation index MI from 0 to 1 in 0.1 steps, the interleaved angle k is 60 °, as shown in FIG. 8. The amount of common mode voltage generated when applied at 90 ° or 120 ° can be obtained. Through this, when the voltage modulation index (MI) is '0.5' or less based on '0.5', if the interleaved angle (k) is set to 120 °, the common mode voltage generation amount is small, and if it is '0.5' or more As the common mode voltage generation amount when the interleaved angle (k) is set to 120 ° is small, EMI noise can be minimized by differently applying the interleaved angle (k) according to the magnitude of the voltage modulation index (MI). It becomes possible. In addition, according to FIG. 8, it can be seen that the amount of common mode voltage generation according to the embodiment of the present invention is smaller than the amount of common mode voltage generation according to the prior art.

In this regard, in the conventional double unipolar method, the maximum value of the common mode voltage is generated as' ± Vdc / 2, and as the voltage modulation index MI increases, the generation amount of the common mode voltage (Vcm) is shown in FIG. 9. As can be seen, it is confirmed that the width is the same level.

In addition, if the interleaved angle (k) is applied to 60 °, 90 °, and 120 ° in a state where the voltage modulation index (MI) is fixed to '0', ST1 and SB1 are primary carriers, which are the basic carriers. 10, since ST2 and SB2 are compared to a second carrier (+ k carrier), which is a + k-degree carrier, and ST3 and SB3 are compared to a third carrier (-k carrier), which is -k. Through comparison of (a) and FIG. 10 (b), it can be seen that as the interleaved angle (k) increases, the width at which the common mode voltage (Vcm) is maximized decreases. As shown in FIG. 10 (b), the interleaved angle When (k) is 90 °, it can be seen that the maximum magnitude of the common mode voltage (Vcm) decreases from ± Vdc / 2 to ± Vdc / 6, and as shown in FIG. 10 (c), the interleaved angle (k) In the case of 120 °, the average generated amount of the common mode voltage (Vcm) is the same, but it can be confirmed that the leakage current is generated more due to the large number of variations.

In addition, when the interleaved angle k is applied to 0 °, 90 °, and 120 ° in a state where the voltage modulation index MI is fixed to '0.4', the interleaved angle k shown in FIG. 11 (a) is It can be seen that the average generation amount of the common mode voltage is smaller in the case where the interleaved angles k shown in FIGS. 11 (b) and 11 (c) are 90 ° and 120 ° than the 0 ° case.

In addition, when the interleaved angle k is applied to 0 °, 90 °, and 120 ° in a state where the voltage modulation index MI is fixed to '0.8', the interleaved angle k shown in FIG. 12 (b) is In the case of 90 °, it can be seen that the average generated amount of the common mode voltage is smaller than the case where the interleaved angles k shown in FIGS. 12 (a) and 12 (c) are 0 ° and 120 °.

Accordingly, according to the present invention described above, by extending and applying the interleaved method applied to the existing three-phase two-level inverter to the six-phase excitation method, each phase current is independently controlled at a constant switching cycle to unbalance the phases. And not only reducing the torque pulsation during the phase change section, but also minimizing the common mode voltage and reducing the magnitude of the leakage current.

As described above, the present invention has been described in detail through preferred embodiments, but the present invention is not limited thereto and may be variously implemented within the scope of the claims.

In particular, the foregoing has described the features and technical strengths of the present invention somewhat broadly to better understand the claims of the invention, which will be described later, so that the concept and specific embodiments of the present invention described above perform similar purposes to the present invention. It should be appreciated by those skilled in the art that it can be used immediately as the basis for designing or modifying other shapes for.

In addition, the above-described embodiments are only one embodiment according to the present invention, and can be implemented in various modified and changed forms within the scope of the technical spirit of the present invention by those skilled in the art. You will understand. Therefore, the disclosed embodiments are to be considered in terms of explanation, not limitation, and various modifications and changes are also indicated in the claims of the present invention described above as belonging to the scope of the technical spirit of the present invention, and equivalent ranges thereof. All differences within should be construed as being included in the present invention.

10: motor
100: motor control module
110: speed controller
120: current controller
130: PWM generator
140: inverter unit
200: current controller voltage measurement unit
300: voltage modulation index calculation unit
400: reference value setting unit
500: parameter calculation unit
600: interleaved angle calculation unit
700: switching signal generator
800: carrier signal generation unit

Claims (5)

The current controller outputs a reference voltage for each phase based on the rotation angle of the motor, a PWM generator for generating a PWM signal for driving the motor based on the reference voltage, and a plurality of inverters, each of a plurality of sectors of the motor A motor control module including an inverter unit configured to drive the motor according to the switching operation of the inverter based on the PWM signal;
A current controller voltage measuring unit measuring the reference voltage;
A voltage modulation index calculation unit for calculating a voltage modulation index based on the DC voltage applied to the motor and the measured reference voltage;
It includes a parameter calculating unit for calculating an optimal parameter corresponding to the lowest point of the common mode voltage generation amount of the inverter unit by using a preset linear function for the voltage modulation index consisting of a sum of a plurality of trigonometric functions having a plurality of parameters. Device for reducing the common mode voltage of a multi-phase motor control system using a phase-to-phase phase control method. According to claim 1,
According to the result of comparing the voltage modulation index calculated by the voltage modulation index calculation unit with a preset reference value, the interleaved angle corresponding to the phase difference between the switching signals for each phase based on the PWM signal is one of the preset first value and second value. And an interleaved angle calculation unit for calculating the interleaved angle using the conditional expression to determine and the linear function. According to claim 2,
A first carrier based on the variation of the reference voltage, a second carrier phase-shifted the first carrier by the interleaved angle in both directions, and a third phase shifted the phase of the first carrier by the interleaved angle in the negative direction A carrier mode generator for generating a carrier; a common mode voltage reduction device of a multi-phase motor control system using a phase-to-phase phase control method further comprising a. According to claim 3,
The on-off operation of the switch of the inverter corresponding to each phase is controlled based on a result of comparing the first carrier, the second carrier, and the third carrier with the maximum and minimum values of the fluctuation range of the reference voltage, respectively. Switching signal generator for generating a switching signal; Common mode voltage reduction device of a multi-phase motor control system using a phase-to-phase phase control method further comprising a. According to claim 4,
The switching signal generation unit,
After calculating the switch-on section of the inverter corresponding to each phase according to the following equations I to VI using the calculated voltage modulation index and the interleaved angle, each phase is calculated based on the calculated switch-on section. A common mode voltage reduction device for a multiphase motor control system using a phase-to-phase phase control method, characterized in that a switching signal is generated so that the start and end points of the switch-on section do not overlap each other.
(Equation I)

(Equation II)

(Equation III)

(Equation IV)

(Equation V)

(Equation VI)

MI is a voltage modulation index, k is an interleaved angle, S _a [On] is a switch-on period of the first inverter corresponding to a phase, and S _b [On] is a switch-on of a second inverter corresponding to phase b Section, S _c [On] is the switch-on section of the third inverter corresponding to c phase, S _d [On] is the switch-on section of the fourth inverter corresponding to d phase, S _e [On] is e It is a switch-on section of the fifth inverter corresponding to the phase, and S _f [On] is a switch-on section of the sixth inverter corresponding to the f phase.

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