WO2024057913A1 - Dispositif de conversion de puissance - Google Patents

Dispositif de conversion de puissance Download PDF

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Publication number
WO2024057913A1
WO2024057913A1 PCT/JP2023/031172 JP2023031172W WO2024057913A1 WO 2024057913 A1 WO2024057913 A1 WO 2024057913A1 JP 2023031172 W JP2023031172 W JP 2023031172W WO 2024057913 A1 WO2024057913 A1 WO 2024057913A1
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voltage
modulation
phase
voltage vector
region
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PCT/JP2023/031172
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English (en)
Japanese (ja)
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雄志 荒木
辰樹 柏原
孝次 小林
潔 大石
勇希 横倉
勇斗 小林
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サンデン株式会社
国立大学法人長岡技術科学大学
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Publication of WO2024057913A1 publication Critical patent/WO2024057913A1/fr

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode

Definitions

  • the present invention relates to a power conversion device that converts DC voltage to AC voltage.
  • PWM pulse width modulation
  • the former method includes pulse width modulation that outputs only odd voltage vectors or only even voltage vectors. According to this method, it is possible to completely suppress fluctuations in common mode voltage within a carrier period. There is also pulse width modulation that switches between outputting only odd-numbered voltage vectors and outputting only even-numbered voltage vectors depending on the electrical angle phase. Also by this method, fluctuations in the common mode voltage can be largely suppressed (see, for example, Patent Document 1).
  • the latter method includes pulse width modulation in which the timing of the rise and fall of the phase voltage of a specific phase is matched with the fall and rise of the phase voltage of other phases in a PWM pattern (for example, see Patent Document 2). Furthermore, fluctuations in the common mode voltage can also be suppressed by pulse width modulation of two-phase modulation in which switching of one phase is fixed and switching of the other two phases is fixed (see, for example, Patent Document 3).
  • Patent No. 5397448 WO2019/180763 Patent No. 5298003
  • Patent Document 1 is the most effective method for suppressing common mode voltage fluctuations, it has limitations on the voltage vectors used, so it is limited to the linear output region (where the voltage vector can rotate once with a constant radius).
  • the disadvantage is that the maximum value of amplitude) is limited, and the modulation rate that can be output is limited. Therefore, it is difficult to apply this method when driving a compressor motor, or when the rotational speed and modulation rate are high, it is necessary to switch the modulation method as in Patent Document 3.
  • the modulation method is switched, there is a problem in that the common mode voltage fluctuates at the time of switching, and the effect of suppressing common mode voltage fluctuation is degraded in a modulation method having a wider linear output region.
  • Patent Document 2 Patent Document 3
  • Patent Document 3 Patent Document 3
  • Patent Document 3 two-phase modulation and three-phase modulation are switched depending on the operating region, and it is possible to switch between the former method and the latter method described above in the same way, but switching of the pulse width modulation method A shock problem arises.
  • the present invention has been made in order to solve such conventional technical problems, and provides a power conversion device that enables high modulation rate operation in pulse width modulation, which has a high noise suppression effect but has a limited modulation rate.
  • the purpose is to provide.
  • the present invention provides a power conversion device that converts a DC voltage into an AC voltage, and includes an inverter circuit that applies phase voltages generated at connection points of switching elements of each phase to a load, and that controls switching of the switching elements of the inverter circuit.
  • a control device the control device includes a modulator whose modulation region is a part of a basic voltage space that is a voltage vector region that can be output in the inverter circuit; a phase voltage command correction unit that calculates a corrected voltage vector in which the command voltage vector is corrected to be within the modulation possible area when the command voltage vector is within the modulation possible area and outside the modulation possible area;
  • This is a power conversion device characterized by outputting power using a power converter.
  • the modulation unit includes a first modulation processing unit having a first modulation area that is the modulation area, and an area that is the modulation area and is different from the first modulation area. a second modulation processing section having a second modulation possible region, wherein the phase voltage command modification section has a second modulation processing section having a second modulation possible region; It may also be a feature to modify the vector.
  • the phase voltage command modification section includes a modulation region selection section that selects either the first modulation possible region or the second modulation possible region as a modification destination of the command voltage vector.
  • the modulation area selection unit may switch between the first modulation possible area and the second modulation possible area based on the phase of the command voltage vector.
  • the first modulation processing section executes pulse width modulation that outputs only odd voltage vectors
  • the second modulation processing section executes pulse width modulation that outputs only even voltage vectors. It may also be characterized by executing.
  • the phase voltage command modification section includes a modulation region selection section that selects either the first modulation possible region or the second modulation possible region as a modification destination of the command voltage vector. and the modulation area selection unit does not switch the first modulation area and the second modulation area immediately after switching the first modulation area and the second modulation area. may be a feature.
  • the modulation region selection section when defining a phase that is a boundary for switching between the first modulation possible region and the second modulation possible region in the modulation region selection section as a switching boundary phase, the modulation region selection section , when the voltage vector passes through the switching boundary phase in the reverse rotation direction, switching between the first modulation possible region and the second modulation possible region may not be performed.
  • the modulation region selection unit estimates continuous switching of the first modulation possible region and the second modulation possible region by predicting the future command voltage vector; As a result of the estimation, if it is estimated that switching will be performed continuously, switching of the first modulation possible region and the second modulation possible region is not performed when the command voltage vector arrives in the future. Good too.
  • a command calculation unit that generates the command voltage vector is provided, and the command calculation unit is configured to combine the corrected voltage vector calculated by the phase voltage command correction unit and the command voltage vector before correction.
  • the present invention may be characterized in that the error in the command voltage vector is compensated for in the calculation of the command voltage vector from the next time onwards.
  • the phase voltage command correction unit may set the corrected voltage vector on a boundary line that defines the modifiable region.
  • the phase voltage command correction unit sets the relationship between the voltage vector and the corrected voltage vector so that the lengths thereof are the same and the phases thereof are different from each other. You can also use it as
  • the phase voltage command correction unit sets the relationship between the voltage vector and the corrected voltage vector so that they have the same phase and different lengths. You can also use it as
  • the modulator can perform modulation control after correcting a voltage vector that is outside the operable region to within the operable region, so a modulation method that always suppresses the excitation of common mode noise is used. This makes it possible to achieve an excellent effect of comprehensively suppressing common mode noise.
  • the next voltage vector to be output is calculated by taking into account the error between the corrected voltage vector and the voltage vector before correction. However, even when the inverter circuit is within the output range and outside the modulation unit's operable range, it is possible to output a voltage vector equivalent to the immediately previous command voltage vector.
  • FIG. 1 is an electrical circuit diagram of a power conversion device according to an embodiment of the present invention.
  • FIG. 3 is a diagram showing three-phase AC voltage command values.
  • FIG. 3 is a diagram showing a basic voltage space for explaining a linear output region.
  • FIG. 3 is a diagram showing the relationship between voltage vectors and phase voltages. It is a figure showing a voltage vector (basic voltage vector). It is a flowchart explaining the operation of the control device of the power converter.
  • FIG. 3 is a diagram showing a voltage space for explaining an output region of an odd voltage RSPWM.
  • FIG. 3 is a diagram showing a correlation between an output region and a function value.
  • FIG. 3 is a diagram illustrating a linear output region of an odd voltage RSPWM.
  • FIG. 6 is a diagram showing an example of an output vector of odd voltage RSPWM. It is a figure which shows the PWM pattern of odd voltage RSPWM.
  • FIG. 7 is a diagram showing a modulation waveform of an odd voltage RSPWM at a low modulation rate.
  • FIG. 3 is a diagram showing a voltage space for explaining an output region of an even voltage RSPWM.
  • FIG. 3 is a diagram showing a correlation between an output region and a function value.
  • FIG. 3 is a diagram illustrating a linear output region of an even voltage RSPWM. It is a figure which shows the output vector and output time of even number voltage RSPWM.
  • FIG. 6 is a diagram showing an example of an output vector of odd voltage RSPWM. It is a figure which shows the PWM pattern of odd voltage RSPWM.
  • FIG. 7 is a diagram showing a modulation waveform of an odd voltage RSPWM at a low modulation rate.
  • FIG. 3 is a diagram showing a voltage space for explaining an
  • FIG. 7 is a diagram showing an example of an output vector of even voltage RSPWM.
  • FIG. 7 is a diagram showing an example of an output vector of even voltage RSPWM. It is a figure which shows the PWM pattern of even number voltage RSPWM.
  • FIG. 7 is a diagram showing a modulation waveform of an even voltage RSPWM at a low modulation rate.
  • FIG. 13 is a diagram showing the operating region of the full voltage RSPWM.
  • FIG. 7 is a diagram showing in voltage space the application range of odd voltage RSPWM and even voltage RSPWM in the total voltage RSPWM of the phase determination formula.
  • FIG. 7 is a diagram showing each phase range to which an odd voltage RSPWM and an even voltage RSPWM are applied in the total voltage RSPWM of a phase determination formula.
  • FIG. 6 is a diagram showing a modulation waveform at a low modulation rate of full voltage RSPWM.
  • FIG. 3 is a diagram representing a voltage vector correction method in voltage space.
  • FIG. 3 is a diagram representing a voltage vector correction method in voltage space.
  • FIG. 3 is a diagram representing a voltage vector correction method in voltage space.
  • FIG. 3 is a diagram representing a voltage vector correction method in voltage space.
  • FIG. 7 is a diagram showing the correspondence between each phase range of the voltage vector, the operable region to which the voltage vector is corrected, and the line segment of the boundary selected in the correction destination in full voltage RSPWM.
  • FIG. 2 is a block diagram showing the functional configuration of a phase voltage command modification section in the control device.
  • FIG. 6 is a diagram showing a voltage vector correction destination in a voltage space for an inoperable region in full voltage RSPWM.
  • FIG. 3 is a diagram representing a voltage vector correction method in voltage space.
  • FIG. 3 is a diagram representing a voltage vector correction method in voltage space. It is a block diagram showing a modification of the functional configuration of a phase voltage command modification section in the control device. It is a flowchart explaining the modification of the operation of a common mode voltage command modification part.
  • FIG. 3 is a diagram representing a voltage vector correction method in voltage space.
  • FIG. 3 is a diagram representing a voltage vector correction method in voltage space.
  • FIG. 3 is a diagram representing a voltage vector correction method in voltage space.
  • FIG. 3 is a diagram representing a voltage vector correction method in voltage space.
  • FIG. 3 is a diagram showing a modulation waveform at a high modulation rate of the present power conversion device.
  • (A) is a conceptual diagram that averages the movement locus of three-phase voltage command values generated by the present power converter
  • (B) is a conceptual diagram that shows a part of the same movement locus in an enlarged manner.
  • FIG. 3 is a diagram showing a modulation waveform at a high modulation rate of the present power conversion device.
  • FIG. 7 is a diagram representing a modification of a voltage vector correction method in a voltage space.
  • a power conversion device 1 drives a motor 8 (load) of a so-called inverter-integrated electric compressor that constitutes a refrigerant circuit of a vehicle air conditioner installed in a vehicle such as an electric vehicle. It is something.
  • the power converter 1 of the embodiment includes a three-phase inverter circuit 27 and a control device 21.
  • the inverter circuit 27 is a circuit that converts the DC voltage Vdc of a DC power source (vehicle battery: for example, 350V) 29 into a three-phase AC voltage and applies it to the motor 8 .
  • the motor 8 of the embodiment is an IPMSM (Interior Permanent Magnet Synchronous Motor).
  • the inverter circuit 27 includes a U-phase half-bridge circuit 19U, a V-phase half-bridge circuit 19V, and a W-phase half-bridge circuit 19W.
  • Each phase half-bridge circuit 19U to 19W is connected to an upper arm switching element 18A to 18C, respectively. and lower arm switching elements 18D to 18F. Further, a free wheel diode 31 is connected in antiparallel to each of the switching elements 18A to 18F.
  • each of the upper and lower arm switching elements 18A to 18F is composed of an insulated gate bipolar transistor (IGBT) in which a MOS structure is incorporated in the gate portion.
  • IGBT insulated gate bipolar transistor
  • the collectors of the upper arm switching elements 18A to 18C of the inverter circuit 27 are connected to the DC power supply 29 and the upper arm power supply line (positive bus) 10 of the smoothing capacitor 32.
  • the emitters of the lower arm switching elements 18D to 18F of the inverter circuit 27 are connected to the lower arm power supply line (negative bus) 15 of the DC power supply 29 and the smoothing capacitor 32.
  • the emitter of the upper arm switching element 18A of the U-phase half bridge circuit 19U and the collector of the lower arm switching element 18D are connected in series, and the emitter of the upper arm switching element 18B and the lower arm switching element of the V-phase half bridge circuit 19V are connected in series.
  • 18E are connected in series, and the emitter of the upper arm switching element 18C and the collector of the lower arm switching element 18F of the W-phase half bridge circuit 19W are connected in series.
  • connection point (U phase voltage Vu) between the upper arm switching element 18A and the lower arm switching element 18D of the U phase half bridge circuit 19U is connected to the U phase armature coil of the motor 8, and the V phase half bridge circuit 19U is connected to the U phase armature coil of the motor 8.
  • the connection point (V-phase voltage Vv) between the upper arm switching element 18B and the lower arm switching element 18E is connected to the V-phase armature coil of the motor 8
  • the connection point between the upper arm switching element 18C and the lower arm switching element 18B of the W-phase half bridge circuit 19W is connected to the V-phase armature coil of the motor 8.
  • a connection point (W-phase voltage Vw) of the arm switching element 18F is connected to the W-phase armature coil of the motor 8.
  • the control device 21 is composed of a microcomputer having a processor, and in the embodiment, inputs a rotation speed command value from the ECU of the vehicle, obtains a motor current (phase current) from the motor 8, and based on these, , controls the ON/OFF state (switching) of each switching element 18A to 18F of the inverter circuit 27. Specifically, the gate voltage applied to the gate of each switching element 18A to 18F is controlled.
  • the control device 21 of the embodiment includes a dq-axis current command calculation section 28, a phase voltage command value calculation section 33, a phase voltage command modification section 40, a modulation section 50, a PWM signal generation section 36, and a gate driver 37.
  • Each current sensor 26A to 26C is connected to a phase voltage command calculation section 33.
  • the current sensor 26A measures the U-phase current iu
  • the current sensor 26B measures the V-phase current iv
  • the current sensor 26C measures the W-phase current iw.
  • the V-phase current iv may be measured by the current sensor 26B, and the W-phase current iw may be calculated from these.
  • the current value of the lower arm power supply line 15 is detected with a shunt resistor, and the current value and the motor 8
  • the phase voltage command calculation unit 33 there is no particular limitation on the method of detecting and estimating each phase current, as there is a method for the phase voltage command calculation unit 33 to estimate it from the operating state of the phase voltage command calculation unit 33.
  • the dq-axis current command calculation unit 28 outputs a d-axis current command value and a q-axis current command value as target values for controlling the motor 8.
  • phase voltage command calculation unit 33 calculates the electrical angle of the motor 8, the d-axis current command value Id ref , the q-axis current command value Iq ref , and the d-axis current obtained by converting the three-phase current detected by the current sensor 26B into the dq-axis.
  • Phase voltage command for three-phase modulation to generate U-phase voltage Vu, V-phase voltage Vv, and W-phase voltage Vw to be applied to the armature coil of each phase of motor 8 by vector control based on Id and q-axis current Iq.
  • the values Vu ref (hereinafter referred to as U-phase voltage command value Vu ref ), Vv ref (hereinafter referred to as V-phase voltage command value Vv ref ), and Vw ref (hereinafter referred to as W-phase voltage command value Vw ref ) are calculated and output.
  • the phase voltage command calculation unit 33 includes a dq-axis current controller 34 and a coordinate conversion unit 35. Note that although a case is exemplified here in which the phase voltage command calculation unit 33 outputs a three-phase AC phase voltage command value (command voltage vector), the present invention is not limited to this. Other forms of output may be used as long as the command calculation unit can calculate some command voltage vector.
  • the dq-axis current controller 34 outputs a d-axis current Id and a q-axis current Iq obtained by converting the three-phase current flowing through the motor 8 into dq-axes, and a d-axis current command value Id ref output from the dq-axis current command calculation unit 28. and q-axis current command value Iq ref are compared, and the current is feedback-controlled (for example, PI control) so that the two match.
  • this dq-axis current controller 34 has a d-axis correction amount converted into a dq-axis voltage by a correction amount (Vm'-Vm) of a corrected voltage vector Vm' outputted from a phase voltage command correction unit 40, which will be described later. It is fed back in the form of Vd err and q-axis correction amount Vq err , and these values are also reflected in the above-mentioned PI control. As a result, the dq-axis current controller 34 outputs the d-axis voltage command value Vd ref and the q-axis voltage command value Vq ref . As a specific example, the dq-axis current controller 34 may perform PI control using the following formula (I).
  • the coordinate conversion unit 35 converts the ⁇ -axis voltage command value V ⁇ ref and the ⁇ -axis voltage command value V ⁇ ref and the ⁇ -axis voltage command value using the following formula (II) from the d-axis voltage command value Vd ref and the q-axis voltage command value Vq ref obtained from the dq-axis current controller 34.
  • the voltage command value V ⁇ ref is calculated, and the voltage command values Vu ref , Vv ref , Vw ref ( phases voltage command value).
  • FIG. 2 shows the waveforms of the voltage command values Vu ref , Vv ref , and Vw ref for each phase calculated using formula (IV), and FIG. 3 shows the linear output region kH.
  • the linear output region is the maximum value of the amplitude at which the voltage vector can make one complete rotation (draw a circle) in the diagram representing the voltage space in FIG. 3. Since the voltage space of a three-phase inverter is hexagonal as shown in FIG. 3, the linear output region is theoretically the inscribed circle of the hexagon. In this application, the linear output region kH in general three-phase modulation is expressed as 1, and the linear output regions of other modulation methods are normalized and discussed.
  • the coordinate conversion unit 35 of the embodiment further calculates voltage command values Vu ref2 , Vv ref2 , and Vw ref2 for two-phase modulation of each phase using the following formula (V) and formula (VI).
  • Vmod in each formula (V) and (VI) calculates the voltage command values Vu ref2 , Vv ref2 , Vw ref2 for two-phase modulation from the voltage command values Vu ref , Vv ref , Vw ref for three-phase modulation.
  • it is the value obtained by adding the minimum value (min) of the three-phase voltage command values Vu ref , Vv ref , and Vw ref to Vdc/2
  • it is the correction value for The value is obtained by subtracting the maximum value (max) of the phase voltage command values Vu ref , Vv ref , and Vw ref from Vdc/2.
  • the amplitude is determined to be the maximum using formula (VI).
  • the upper arm switching element of the phase of Two-phase modulation is used in which the lower arm switching element of the phase with the maximum amplitude is fixed ON. If the sign of the phase with the maximum amplitude is positive, use formula (VI) to perform two-phase modulation in which the upper arm switching element of the phase with the maximum amplitude is fixed ON, and if the sign of the phase with the maximum amplitude is negative. In this case, two-phase modulation may be performed in which the lower arm switching element of the phase in which the amplitude is maximum is fixed to ON using equation (V).
  • the phase voltage command correction unit 40 corrects the voltage vector Vm composed of the ⁇ -axis voltage command value V ⁇ ref and the ⁇ -axis voltage command value V ⁇ ref , which are temporarily converted by the coordinate conversion unit 35, to obtain a modified ⁇ -axis voltage.
  • a corrected voltage vector Vm' composed of the command value V ⁇ ' ref and the corrected ⁇ -axis voltage command value V ⁇ ' ref is generated, and this is passed to the coordinate conversion unit 35 .
  • the phase voltage command correction unit 40 uses equation (III) to calculate a corrected phase voltage command value Vu' for three-phase modulation from the corrected ⁇ -axis voltage command value V ⁇ ' ref and the corrected ⁇ -axis voltage command value V ⁇ ' ref .
  • the modulation section 50 includes an odd voltage modulation processing section 52 and an even voltage modulation processing section 54.
  • the odd voltage modulation processing unit 52 uses the above-mentioned modified voltage vector Vm' to perform odd side pulse width modulation in which only the odd voltage vectors V1, V3, and V5 of the basic voltage vectors are output during one control period. do.
  • the even voltage modulation processing unit 54 executes even-number side pulse width modulation in which only the even voltage vectors V2, V4, and V6 of the basic voltage vectors are output during one control period.
  • the ON times tu, tv, and tw of the upper arm switching elements of each phase are directly generated from the modified ⁇ -axis voltage command value V ⁇ ' ref and the modified ⁇ -axis voltage command value V ⁇ ' ref , and the voltage Output vectors (V1, V3, V5) and their output times.
  • the ON times tuv, tvw, and twu of the two-phase upper arm switching elements are directly generated from the corrected ⁇ -axis voltage command value V ⁇ ' ref and the corrected ⁇ -axis voltage command value V ⁇ ' ref , and the voltage vector (V2, V4, V6) and their output times are output.
  • this odd-numbered pulse width modulation is hereinafter referred to as odd-numbered voltage RSPWM (Remote State PWM), and the even-numbered side pulse width modulation is hereinafter referred to as even-numbered voltage RSPWM (Remote State PWM).
  • RSPWM Remote State PWM
  • even-numbered voltage RSPWM Remote State PWM
  • pulse width modulation is based on the concept of instantaneous space vector modulation in which space vector modulation is performed without waiting for the next sampling point.
  • the modulation unit 50 switches between the odd voltage RSPWM and the even voltage RSPWM by determining whether the maximum phase is positive or negative.
  • this pulse width modulation is hereinafter referred to as the total voltage RSPWM of the maximum phase determination formula.
  • the PWM signal generation section 36 inputs the voltage vector and output time output by the modulation section 50, and compares the magnitude with the carrier signal, thereby generating signals between the U-phase inverter 19U, V-phase inverter 19V, and W-phase inverter of the inverter circuit 27.
  • a PWM signal serving as a 19W drive command signal is generated and output.
  • the gate driver 37 Based on the PWM signal output from the PWM signal generation section 36, the gate driver 37 outputs the gate voltages of the switching elements 18A and 18D of the U-phase inverter 19U, the gate voltages of the switching elements 18B and 18E of the V-phase inverter 19V, and W. Gate voltages of switching elements 18C and 18F of phase inverter 19W are generated.
  • each of the switching elements 18A to 18F of the inverter circuit 27 is driven ON/OFF based on the gate voltage output from the gate driver 37. That is, when the gate voltage is in an ON state (predetermined voltage value), the switching element is turned on, and when the gate voltage is in an OFF state (zero), the switching element is turned off.
  • the gate driver 37 is a circuit for applying a gate voltage to the IGBTs based on a PWM signal, and is composed of a photocoupler, a logic IC, a transistor, etc. Ru.
  • the voltage at the connection point between the upper arm switching element 18B and the lower arm switching element 18E of the V-phase half-bridge circuit 19V is applied (output) to the V-phase armature coil of the motor 8 as a V-phase voltage Vv (phase voltage)
  • Vv phase voltage
  • Vw W-phase voltage
  • FIG. 6 is a flowchart illustrating the overall flow of pulse width modulation performed by the modulation section 50.
  • step S1 a modified ⁇ -axis voltage command value V ⁇ ' ref and a modified ⁇ -axis voltage command value V ⁇ ' ref modified by the phase voltage command modification unit 40, the details of which will be described later, and a modified phase voltage command value Vu of three-phase modulation.
  • the modulator 50 receives ' ref , Vv'ref , and Vw'ref .
  • step S2 it is determined whether the sign of the phase with the maximum amplitude is positive or negative among the modified phase voltage command values Vu' ref , Vv' ref , and Vw' ref of the three-phase modulation described above. do. Then, if the sign of the phase with the maximum amplitude among the corrected phase voltage command values Vu' ref , Vv' ref , Vw' ref of the three-phase modulation is positive, the process proceeds to step S3, and odd voltage RSPWM is performed.
  • step S3 of the odd voltage RSPWM the modulation unit 50 calculates each phase from the corrected ⁇ -axis voltage command value V ⁇ ' ref and the corrected ⁇ -axis voltage command value V ⁇ ' ref using the following formula (VII) and formula (VIII).
  • the ON times tu, tv, and tw of the upper arm switching elements 18A, 18B, and 18C are calculated.
  • V1, V3, and V5 in formula (VII) are odd voltage vectors
  • Ts is one control period. This control period Ts may be one carrier period. However, this one control period Ts is a period sufficiently shorter than one period of electrical angle.
  • Su, Sv, and Sw are functions corresponding to output regions (sectors) A to C of the voltage space shown in FIG. 7, and the correspondence between each output region and the functions Su, Sv, and Sw is shown in FIG.
  • These functions Su, Sv, and Sw select voltage vectors in space vector modulation. Note that since the calculation result of formula (VIII) is the same as that of formula (V), either one may be used in step S3.
  • step S4 the zero voltage output time t0 , which is the time to output the zero voltage vector V0, is calculated using formula (IX). Note that here, since the modified ⁇ -axis voltage command value V ⁇ ' ref and the modified ⁇ -axis voltage command value V ⁇ ' ref that have been modified in advance through the modulation range determination unit 42, which will be described later, are adopted, this zero voltage output Time t0 always takes a value greater than or equal to zero.
  • step S5 based on the calculated zero voltage output time t0 , the ON time of the upper arm switching element of each phase is corrected using the following formula (X). This is done by adding t 0 /3 to all of the ON times tu, tv, and tw. This eliminates the zero voltage output time and eliminates fluctuations in the common mode voltage Vc of the motor 8.
  • step S6 the modulation unit 50 determines the odd voltage vectors (V1, V3, V5) and their output times based on each output region (Sector). These values are finally output to the PWM signal generation section 36 in step S14.
  • FIG. 10 shows the relationship among the output region (sector), voltage vector, and output time of the odd voltage RSPWM.
  • a circle Q1 in FIG. 9 indicates a linear output region when odd voltage RSPWM (odd RSPWM) is used alone.
  • the entire range of the triangular region Z1 (hereinafter referred to as the odd-number side operable region) connecting the vertices of the odd-numbered voltage vectors (V1, V3, V5) is used for output.
  • the odd-numbered operable region Z1 has three line segments Z1a, Z1b, and Z1c that define the region.
  • FIG. 11 shows the output times of odd voltage vectors V1, V3, and V5 calculated based on the corrected voltage vector Vm' in the output region A, for example.
  • FIG. 12 shows output patterns of odd voltage vectors V1, V3, and V5 in output region A.
  • the corrected voltage vector Vm' falls within the range of the circle Q1 in FIG. 9, it means that the control state in which the modulation rate is low continues. For example, assuming a case where modulation is performed with "only" the odd voltage RSPWM at a low modulation rate, the modulation waveform of each UVW phase will be as shown in Figure 13, and there will be no fluctuation in the common mode voltage Vc (at a low modulation rate). (Modulation waveform of odd voltage RSPWM only).
  • the corrected voltage vector Vm' does not fall within the range of the circle Q1, it means that the modulation rate is in a high control state. Details of the modulation waveform in this case will be described later.
  • step S2 if in step S2 the sign of the phase with the maximum amplitude among the corrected phase voltage command values Vu' ref , Vv' ref , Vw' ref of the three-phase modulation is negative, the process proceeds to step S8 and the even number voltage RSPWM is set.
  • the modulation unit 50 uses the following formula (XI) and formula (XII) to determine the two-phase upper arm switching from the modified ⁇ -axis voltage command value V ⁇ ′ ref and the modified ⁇ -axis voltage command value V ⁇ ′ ref .
  • the ON times tuv, tvw, and twu of the elements are calculated.
  • tuv is the ON time of the upper arm switching elements 18A and 18B of the U phase and V phase
  • tvw is the ON time of the upper arm switching elements 18B and 18C of the V phase and W phase
  • twu is the upper arm of the W phase and U phase. This is the ON time of the switching elements 18C and 18A.
  • V2, V4, and V6 in formula (XI) are even voltage vectors
  • Suv, Svw, and Swu are functions corresponding to output regions (Sectors) A to C of the voltage space shown in FIG. 14, and each output region and function The correspondence between Suv, Svw, and Swu is shown in FIG. 15. These functions Suv, Svw, and Swu select voltage vectors in space vector modulation.
  • the modulation unit 50 calculates the OFF times tu (upper bar), tv (upper bar), and tw (upper bar) of the upper arm switching elements 18A, 18B, and 18C of each phase using the following formula (XIII). do. Note that since the calculation result of formula (XIII) is the same as formula (XII), either one may be used in step S8.
  • step S9 the zero voltage output time t7 , which is the time to output the zero voltage vector V7, is calculated using formula (XIV). Note that here, since the modified ⁇ -axis voltage command value V ⁇ ' ref and the modified ⁇ -axis voltage command value V ⁇ ' ref that have been modified in advance through the modulation range determination unit 42, which will be described later, are adopted, this zero voltage output The time t7 always takes a value greater than or equal to zero.
  • step S10 based on the calculated zero voltage output time t7 , the OFF time of the upper arm switching element of each phase is corrected using the following formulas (XV) and (XVI). This is performed by adding t 7 /3, which is the OFF time, to all of the OFF times tu (upper bar), tv (upper bar), and tw (upper bar). This eliminates the zero voltage output time and eliminates fluctuations in the common mode voltage Vc of the motor 8.
  • step S11 the modulation unit 50 determines the even voltage vectors (V2, V4, V6) and their output times based on each output region (sector). Then, those values are finally output to the PWM signal generation section 36 in step S14.
  • FIG. 17 shows the relationship among the output region (sector), voltage vector, and output time of the even voltage RSPWM.
  • Circle Q2 in FIG. 16 indicates the linear output region when this even voltage RSPWM (even RSPWM) is used alone.
  • the entire range of the triangular region Z2 (hereinafter referred to as even-number side operable region) connecting the vertices of the even-numbered voltage vectors (V2, V4, V6) is used for output.
  • the even-numbered operable region Z2 has three line segments Z2a, Z2b, and Z2c that define the region.
  • FIG. 18 shows the output times of even voltage vectors V2, V4, and V6 based on the modified voltage vector Vm' in the output region A, for example, and FIG. The output times of the even voltage vectors V2, V4, and V6 based on the graph are shown.
  • FIG. 20 shows the output pattern of each voltage vector V4, V2, and V6 in the output region C.
  • the corrected voltage vector Vm' falls within the range of the circle Q2, it means that the control state with a low modulation rate continues. For example, assuming that in a low modulation rate state, modulation is performed with "only" the even voltage RSPWM, the modulation waveform of each phase of UVW will be as shown in Figure 21, and there will be no fluctuation in the common mode voltage Vc (low modulation rate (Modulation waveform of only even voltage RSPWM).
  • the corrected voltage vector Vm' does not fall within the range of the circle Q2, it means that the modulation rate is in a high control state. Details of the modulation waveform in this case will be described later.
  • Total voltage RSPWM of maximum phase determination formula Note that in this embodiment, since modulation control is performed while switching between the odd voltage RSPWM and the even voltage RSPWM, the result is RSPWM that uses all voltage vectors. This is called the total voltage RSPWM.
  • the total voltage RSPWM among the corrected phase voltage command values Vu' ref , Vv' ref , Vw' ref , the odd number is determined depending on whether the sign of the phase with the maximum amplitude is positive or negative. Since the voltage RSPWM and the even voltage RSPWM are switched, the total voltage RSPWM is the maximum phase determination formula.
  • FIG. 22 shows the operable region Z3 of the total voltage RSPWM of the maximum phase determination formula.
  • the full-voltage RSPWM operable region (hereinafter referred to as full-voltage operable region) Z3 is a region in which the odd-number side operable region Z1 and the even-number side operable region Z2 overlap.
  • there are a total of six areas X (hereinafter referred to as inoperable areas) that surround the full voltage operable area Z3 and are outside the range of the full voltage operable area Z3.
  • the inoperable region X is an isosceles triangle.
  • circle Q3 in FIG. 22 indicates the linear output region when the total voltage RSPWM of the maximum phase determination formula is used alone.
  • Circle Q3 which is the linear output region due to the total voltage RSPWM, is enlarged compared to circles Q1 and Q2, which are the linear output regions when odd voltage RSPWM or even voltage RSPWM is performed alone.
  • output is performed using the entire range of the full voltage operable region Z3 beyond this linear output region (circle Q3).
  • the corrected voltage vector Vm' falls within the range of the circle Q3, it means that the control state with a low modulation rate continues. On the other hand, if the corrected voltage vector Vm' does not fall within the range of the circle Q3, it means that the modulation rate is in a high control state.
  • Total voltage RSPWM of phase judgment formula In the total voltage RSPWM of the maximum phase determination formula described above, the modulation unit 50 selects the corrected phase voltage command values Vu' ref , Vv' ref , Vw' ref of the three-phase modulation, in which the sign of the phase with the maximum amplitude is positive. The positive and negative cases are determined, and the odd voltage RSPWM and the even voltage RSPWM are switched accordingly.
  • the present invention is not limited thereto.
  • the odd voltage RSPWM and the even voltage RSPWM may be switched depending on the phase ⁇ m' of the corrected voltage vector with respect to the ⁇ axis of the corrected voltage vector Vm'. In this application, this pulse width modulation is hereinafter referred to as phase-determined total voltage RSPWM.
  • FIG. 23 shows a phase region odd to which an odd voltage RSPWM is applied and a phase region even to which an even voltage RSPWM is applied in the operation region of the total voltage RSPWM of the phase determination formula.
  • FIG. 24 shows the correspondence between each phase range and the odd voltage RSPWM and even voltage RSPWM applied thereto.
  • one period of electrical angle is divided into six regions (330° ⁇ m' ⁇ 30°, 30° ⁇ m' ⁇ 90°, 90° ⁇ m' ⁇ 150°, 150° ⁇ m ' ⁇ 210°, 210° ⁇ m' ⁇ 270°, 270° ⁇ m' ⁇ 330°), and the odd voltage RSPWM and the even voltage RSPWM are alternately switched.
  • the operable region output region Z3 of the total voltage RSPWM of the phase determination formula is the same as the total voltage RSPWM of the maximum phase determination formula in FIG.
  • the full voltage RSPWM operable region (hereinafter referred to as full voltage operable region) Z3 is a region in which the odd-number side operable region Z1 and the even-number side operable region Z2 overlap.
  • the corrected voltage vector Vm' falls within the range of the circle Q3, it means that the control state with a low modulation rate continues.
  • the modulation waveform of each phase of UVW by the total voltage RSPWM is as shown in FIG.
  • the common mode voltage Vc fluctuates when switching between the odd voltage RSPWM and the even voltage RSPWM (modulation waveform due to the total voltage RSPWM at a low modulation rate).
  • the corrected voltage vector Vm' does not fall within the range of the circle Q3, it means that the modulation rate is in a high control state. Details of the modulation waveform in this case will be described later.
  • phase voltage command correction unit 40 adjusts the voltage vector Vm composed of the ⁇ -axis voltage command value V ⁇ ref and the ⁇ -axis voltage command value V ⁇ ref (before modification) to the full voltage operable region Z3. Determine whether it is within the range. Note that when the voltage vector Vm falls within the full voltage operable region Z3, there is no need to correct the voltage vector Vm, so the voltage vector Vm is set to be equal to the corrected voltage vector Vm'. On the other hand, as shown in FIG.
  • the inoperable area X means an area within the hexagonal basic voltage space B surrounded by the V1 to V6 basic voltage vectors in vector control and outside the full voltage operable area Z3.
  • this approximation range is, for example, a range in which the vector length N' of the corrected voltage vector Vm' is 0.3N ⁇ N' ⁇ 1.7N with respect to the vector length N of the voltage vector Vm, or 0.5N ⁇ Examples include a range where N' ⁇ 1.5N and a range where 0.7N ⁇ N' ⁇ 1.3N.
  • the approximation range is, for example, a range in which the voltage phase ⁇ m' of the corrected voltage vector Vm' satisfies ⁇ m-120° ⁇ m' ⁇ m+120° with respect to the voltage phase ⁇ m of the voltage vector Vm, or ⁇ m-90° ⁇ m
  • Examples include a range where ' ⁇ m+90°, a range where ⁇ m-60° ⁇ m' ⁇ m+60°, and a range where ⁇ m-45° ⁇ m' ⁇ m+45°.
  • Method A Correction to the boundary between the inoperable region and the voltage operable region
  • arbitrary coordinates on the boundary lines Y1 and Y2 between the inoperable region X to which the voltage vector Vm belongs and the full voltage operable region Z3 are set as the corrected voltage vector Vm'.
  • the correction is made on the boundary lines Y1 and Y2 of the full voltage operable region Z3
  • the present invention is not limited to this, and the correction is made on the boundary line between the inoperable region X and the odd-number side operable region Z1.
  • the correction may be made within the odd operable region Z1, or may be made on the boundary line between the inoperable region X and the even operable region Z2, or within the even operable region Z2.
  • Method B Voltage phase correction
  • the phase ⁇ m of the voltage vector Vm is modified without changing the length of the voltage vector Vm, and the location where it intersects with the boundary lines Y1 and Y2 of the inoperable region X and the full voltage operable region Z3 is shown. is the modified voltage vector Vm'.
  • the phase ⁇ m selects the one with the smaller absolute value of the amount of correction of the voltage phase ⁇ m. It is preferable to do so.
  • the present invention is not limited to this, and the correction is made on the boundary line between the inoperable region X and the odd-number side operable region Z1.
  • the correction may be made within the odd operable region Z1, or may be made on the boundary line between the inoperable region X and the even operable region Z2, or within the even operable region Z2.
  • Method C Voltage vector length correction
  • the correction is made on the boundary lines Y1 and Y2 of the full voltage operable region Z3
  • the present invention is not limited to this, and the correction is made on the boundary line between the inoperable region X and the odd-number side operable region Z1.
  • the correction may be made within the odd operable region Z1, or may be made on the boundary line between the inoperable region X and the even operable region Z2, or within the even operable region Z2.
  • Method D Correct the coordinates of the voltage vector by moving it parallel to the outermost line of the inoperable area X
  • Method D Correct the coordinates of the voltage vector by moving it parallel to the outermost line of the inoperable area X
  • the present invention is not limited to this, and the correction is made on the boundary line between the inoperable region X and the odd-number side operable region Z1.
  • the correction may be made within the odd operable region Z1, or may be made on the boundary line between the inoperable region X and the even operable region Z2, or within the even operable region Z2.
  • the corrected voltage vector Vm' may be calculated by appropriately combining the above (Method A) to (Method D).
  • the modification to the even-numbered operable region Z2 may be selected, and if the sign of the phase with the maximum amplitude is positive, the modification to the odd-numbered side operable region Z1 may be selected.
  • FIG. 31 shows a line segment of the boundary selected when correcting the voltage vector Vm on the neighboring boundary line of the even-number side operable region Z2 or the odd-number side operable region Z1 based on the phase ⁇ m. ).
  • FIG. 33 is a flowchart illustrating the flow of operation of the phase voltage command modification section 40.
  • the phase voltage command modification section 40 includes a modulation range determining section 42, a modulation region selection section 44, a modification command calculation section 46, a modification command selection section 48, and a feedback processing section 49.
  • the modulation range determining unit 42 determines whether the coordinates of the voltage vector Vm are within the full voltage operable region Z3 (step S41). If the voltage vector Vm falls within the full voltage operable region Z3, there is no need to correct the voltage vector Vm, so the process proceeds to step S42, where the correction command calculation unit 46 changes the voltage vector Vm itself to a corrected voltage. Set to vector Vm'. Next, the process proceeds to step S80, and this modified voltage vector Vm' is output to the modulation section 50.
  • step S41 if the coordinates of the voltage vector Vm are located outside the full voltage operable region Z3, that is, in the inoperable region X, the voltage vector Vm needs to be corrected, so the process proceeds to step S44. , the modulation area selection unit 44 is activated.
  • step S44 the modulation region selection unit 44 refers to the phase ⁇ m of the voltage vector Vm with respect to the ⁇ axis, and according to the relationship shown in FIG. Select one of the modifications to.
  • the inoperable region It will have X2. If the voltage vector Vm belongs to the odd modification region X1, the modulation region selection unit 44 modifies the voltage vector so that it falls within the odd operable region Z1.
  • the modulation region selection unit 44 modifies the voltage vector so that it falls within the even number side operable region Z2.
  • the correction destination of the voltage vector Vm of the odd correction area X1 is an isolated triangular area that is adjacent to the odd correction area It is preferable to correct the area Zlt.
  • the correction destination of the voltage vector Vm of the even correction region It is preferable to correct the area Z2t.
  • step S44 when the voltage vector Vm is in the state shown in FIG. 35, that is, the phase ⁇ m is within the range of 330° ⁇ m ⁇ 30°, the odd-number side operable region Z1 is selected based on the correlation table shown in FIG. Ru. After that, the process proceeds to step S50, and the modification command calculation unit 46 modifies the voltage vector Vm to be within the odd-number side operable region Z1.
  • the modification command calculation unit 46 defines a perfect circle P having a radius equal to the coordinates of the voltage vector Vm as a function of the ⁇ and ⁇ axes, as shown in FIG. As a result, the perfect circle P is expressed by the following formula (XX).
  • step S50 the modification command calculation unit 46 calculates first and second voltage vectors (hereinafter referred to as first and second modification candidate voltage vectors) VAm', VBm' is calculated.
  • step S52 the modification command selection unit 48 selects one voltage vector from the first and second modification candidate voltage vectors VAm' and VBm', and sets this as the modified voltage vector Vm'.
  • the modification command selection unit 48 selects a first phase modification amount ⁇ Amod of the first modification candidate voltage vector VAm' based on the voltage vector Vm, and a second modification candidate voltage vector based on the voltage vector Vm.
  • the second phase modification amount ⁇ Bmod of VBm' is calculated using the following formula (XXII).
  • the modification command selection unit 48 compares the first phase modification amount ⁇ Amod and the second phase modification amount ⁇ Bmod, and selects the smaller modification candidate voltage vector VAm', VBm' (here, the first modification candidate voltage vector VAm'). , the modified voltage vector Vm' is determined. Thereafter, the process proceeds to step S80, and this modified voltage vector Vm' is output to the modulation section 50. Furthermore, the process proceeds to step S82, and the feedback processing unit 49 converts the modification amount (Vm'-Vm) of the modified voltage vector Vm' into a dq-axis voltage, thereby obtaining the d-axis modification amount Vd err and the q-axis modification amount Vq err. is generated and fed back to the dq-axis current controller 34.
  • step S44 when the voltage vector Vm is in the state shown in FIG. 36, that is, the phase ⁇ m is within the range of 30° ⁇ m ⁇ 90°, the even-number side operable region Z2 is determined based on the correlation table of FIG. selected. After that, the process proceeds to step S60, and the modification command calculation unit 46 modifies the voltage vector Vm to be within the even number side operable region Z2.
  • the modification command calculation unit 46 defines a perfect circle P whose radius is the coordinates of the voltage vector Vm using the above formula (XX), as shown in FIG. Furthermore, since the phase ⁇ m of this voltage vector Vm belongs to 30° ⁇ m ⁇ 60°, a function representing the line segment Z2a is selected from formula (XVIII) based on the correlation table of FIG. , and the two intersection points (VA ⁇ ', VA ⁇ ') and (VB ⁇ ', VB ⁇ ') of the function representing the perfect circle P of formula (XX) are calculated. Note that the reason why line segment Z2a is selected is that when this voltage vector Vm is rotated in both forward and reverse directions, it intersects line segment Z2a first.
  • step S60 the modification command calculation unit 46 calculates the first and second voltage vectors (hereinafter referred to as first and second modification candidate voltage vectors) VAm′, which are candidates for modification to the even-number side operable region Z2.
  • VBm' is calculated.
  • step S62 the modification command selection unit 48 selects one voltage vector from the first and second modification candidate voltage vectors VAm' and VBm', and sets this as the modified voltage vector Vm'.
  • the modification command selection unit 48 selects a first phase modification amount ⁇ Amod of the first modification candidate voltage vector VAm' based on the voltage vector Vm, and a second modification candidate voltage vector based on the voltage vector Vm.
  • the second phase modification amount ⁇ Bmod of VBm' is calculated using the above formula (XXII).
  • the modification command selection unit 48 compares the first phase modification amount ⁇ Amod and the second phase modification amount ⁇ Bmod, and selects the smaller modification candidate voltage vector VAm', VBm' (here, the second modification candidate voltage vector VBm'). , the modified voltage vector Vm' is determined. Thereafter, the process proceeds to step S80, and this modified voltage vector Vm' is output to the modulation section 50. Furthermore, the process proceeds to step S82, and the feedback processing unit 49 converts the modification amount (Vm'-Vm) of the modified voltage vector Vm' into a dq-axis voltage, thereby obtaining the d-axis modification amount Vd err and the q-axis modification amount Vq err. is generated and fed back to the dq-axis current controller 34.
  • FIG. 38 is a flowchart illustrating the flow of operation of the phase voltage command modification section 40.
  • the phase voltage command modification section 40 includes a modulation range determining section 42, a modulation region selection section 44, a modification command calculation section 46, and a feedback processing section 49.
  • the modulation range determination unit 42 determines whether the coordinates of the voltage vector Vm are within the full voltage operable range Z3 (step S71). If the voltage vector Vm is within the full voltage operable range Z3, there is no need to modify the voltage vector Vm, so the process proceeds to step S72, where the correction command calculation unit 46 sets the voltage vector Vm itself to the modified voltage vector Vm'. Next, the process proceeds to step S100, where the modified voltage vector Vm' is output to the modulation unit 50.
  • step S71 if the coordinates of the voltage vector Vm are located outside the full voltage operable area Z3, that is, in the inoperable area X, the voltage vector Vm needs to be corrected, so the process proceeds to step S74. , the modulation area selection section 44 is activated.
  • step S74 the modulation area selection unit 44 refers to the phase ⁇ m of the voltage vector Vm with respect to the ⁇ axis, and according to the correlation table of FIG. Select one of the modifications to Z1. For example, when the voltage vector Vm is in the state shown in FIG. 39, that is, when the phase ⁇ m is within the range of 330° ⁇ m ⁇ 30°, the odd-number side operable region Z1 is selected based on the correlation table shown in FIG. After that, the process proceeds to step S80, and the modification command calculation unit 46 modifies the voltage vector Vm to be within the odd-number side operable region Z1.
  • the modification command calculation unit 46 defines a radial line segment E having the same phase as the voltage vector Vm as a function of the ⁇ and ⁇ axes, as shown in FIG. As a result, the radial line segment E becomes the following formula (XXIII).
  • step S80 the modification command calculation unit 46 calculates the modified voltage vector Vm' that is the result of modification to the odd-number side operable region Z1. Thereafter, the process proceeds to step S100, and this modified voltage vector Vm' is output to the modulation section 50. Furthermore, the process proceeds to step S102, and the feedback processing unit 49 converts the correction amount (Vm'-Vm) of the correction voltage vector Vm' into a dq-axis voltage, thereby obtaining the d-axis correction amount Vd err and the q-axis correction amount Vq err. is generated and fed back to the dq-axis current controller 34.
  • step S74 when the voltage vector Vm is in the state shown in FIG. 40, that is, the phase ⁇ m is within the range of 30° ⁇ m ⁇ 90°, the even-number side operable region Z2 is determined based on the correlation table of FIG. selected. After that, the process proceeds to step S90, and the modification command calculation unit 46 modifies the voltage vector Vm to be within the even number side operable region Z2.
  • the modification command calculation unit 46 defines a radial line segment E having the same phase as the voltage vector Vm as a function of the ⁇ and ⁇ axes, as shown in FIG. As a result, the radial line segment E becomes the above formula (XXIII).
  • step S90 the modification command calculation unit 46 calculates the modified voltage vector Vm' that is the result of modification to the even-number side operable region Z2. Thereafter, the process proceeds to step S100, and this modified voltage vector Vm' is output to the modulation section 50. Furthermore, the process proceeds to step S102, and the feedback processing unit 49 converts the correction amount (Vm'-Vm) of the correction voltage vector Vm' into a dq-axis voltage, thereby obtaining the d-axis correction amount Vd err and the q-axis correction amount Vq err. is generated and fed back to the dq-axis current controller 34.
  • the modulation range determining unit 42 determines whether the coordinates of the voltage vector Vm are within the full voltage operable region Z3 (step S71). If the voltage vector Vm falls within the full voltage operable region Z3, there is no need to modify the voltage vector Vm, so the process proceeds to step S72, where the modification command calculation unit 46 changes the voltage vector Vm itself to a modified voltage. Set to vector Vm'. Next, the process proceeds to step S100, and this modified voltage vector Vm' is output to the modulation section 50.
  • step S71 if the coordinates of the voltage vector Vm are located outside the full voltage operable area Z3, that is, in the inoperable area X, it is necessary to correct the voltage vector Vm, so the process proceeds to step S74. , the modulation area selection section 44 is activated.
  • step S74 the modulation area selection unit 44 refers to the phase ⁇ m of the voltage vector Vm with respect to the ⁇ axis, and according to the correlation table of FIG. Select one of the modifications to Z1.
  • step S74 when the voltage vector Vm is in the state shown in FIG. 41, that is, the phase ⁇ m is within the range of 330° ⁇ m ⁇ 30°, the odd-number side operable region Z1 is selected based on the correlation table shown in FIG. Ru. After that, the process proceeds to step S80, and the modification command calculation unit 46 modifies the voltage vector Vm to be within the odd-number side operable region Z1.
  • the modification command calculation unit 46 calculates the ON time of the upper arm switching elements 18A, 18B, and 18C of each phase by applying formula (VIII) to the voltage vector Vm, as shown in FIG. Calculate command values tu, tv, and tw. Note that adjustments using formulas (VIX) and (X) are not performed here. As a result, one of tu, tv, and tw is always zero. Note that in the case of the voltage vector Vm in FIG. 41, tw is always zero.
  • the remaining two non-zero command values among the ON times tu, tv, and tw calculated by applying formula (VIII) to the voltage vector Vm are Define t1 and t2.
  • the coordinates (t1', t2') that fall within the odd-numbered operable region Z1 of the corrected voltage vector Vm' are determined by maintaining the larger command value of t1 and t2 as is, and by changing the remaining smaller command value. , the following formula (XXVI) is obtained.
  • step S80 the modification command calculation unit 46 calculates the modified voltage vector Vm' that is the result of modification to the odd-number side operable region Z1. Thereafter, the process proceeds to step S100, and this modified voltage vector Vm' is output to the modulation section 50. Furthermore, the process proceeds to step S102, and the feedback processing unit 49 converts the correction amount (Vm'-Vm) of the correction voltage vector Vm' into a dq-axis voltage, thereby obtaining the d-axis correction amount Vd err and the q-axis correction amount Vq err. is generated and fed back to the dq-axis current controller 34.
  • step S74 when the voltage vector Vm is in the state shown in FIG. 42, that is, the phase ⁇ m is within the range of 30° ⁇ m ⁇ 90°, the even-number side operable region Z2 is determined based on the correlation table of FIG. selected. After that, the process proceeds to step S90, and the modification command calculation unit 46 modifies the voltage vector Vm to be within the even number side operable region Z2.
  • the modification command calculation unit 46 calculates the OFF time of the upper arm switching elements 18A, 18B, and 18C of each phase by applying formula (XIII) to the voltage vector Vm, as shown in FIG.
  • Command values tu (upper bar), tv (upper bar), and tw (upper bar) are calculated. Note that adjustment using formula (XIV) is not performed here. As a result, one of tu (upper bar), tv (upper bar), and tw (upper bar) is always zero. Note that in the case of the voltage vector Vm in FIG. 42, tu (upper bar) is always zero.
  • step S90 the modification command calculation unit 46 calculates the modified voltage vector Vm' that is the result of modification to the even-number side operable region Z2. Thereafter, the process proceeds to step S100, and this modified voltage vector Vm' is output to the modulation section 50. Furthermore, the process proceeds to step S102, and the feedback processing unit 49 converts the correction amount (Vm'-Vm) of the correction voltage vector Vm' into a dq-axis voltage, thereby obtaining the d-axis correction amount Vd err and the q-axis correction amount Vq err. is generated and fed back to the dq-axis current controller 34.
  • the phase voltage command correction unit 40 converts the voltage vector Vm belonging to the inoperable region X to the corrected voltage vector Vm' in the full voltage operable region Z3. Since the modulation section 50 then performs modulation control, it is possible to always perform modulation using the same modulation method. As a result, when controlling at a high modulation rate, even if the voltage vector Vm partially deviates from the full voltage operable region Z3, it is all corrected to within the full voltage operable region Z3, so common mode noise is always eliminated. Since it is driven using a modulation method that does not excite, common mode noise is significantly suppressed overall.
  • the voltage vector Vm when converting the voltage vector Vm into the corrected voltage vector Vm' within the full-voltage operable region Z3 in the phase voltage command modification unit 40, the voltage vector Vm is close to the inoperable region X to which the voltage vector Vm belongs.
  • the range is selected.
  • control since control is performed by feeding back the amount of correction of the corrected voltage vector Vm', it is possible to suppress the amount of correction of the corrected voltage vector Vm'. , Vv, and Vw can be stabilized.
  • FIG. 43 shows the waveform B (reference) of the three-phase voltage commands Vu, Vv, and Vw output from the modulation unit 50 by the power conversion device 1 of this embodiment and the common mode voltage waveform Vc. It can be seen that fluctuations in the common mode voltage waveform Vc are suppressed to a greater extent than in the conventional power converter 1.
  • the modulation region selection unit 44 refers to the phase ⁇ m of the voltage vector Vm with respect to the ⁇ axis, and according to the correlation table of FIG. In the method of selecting one of the modifications to the region Z1, as long as the rotational speed of the phase ⁇ m is always positive, the modulation region selection unit 44 selects the even-number side operable region Z2 and the phase ⁇ m at every phase interval of 60°. The odd number side operable region Z1 is alternately switched.
  • the amount of correction of the corrected voltage vector Vm' is fed back to the dq-axis current controller 34 to perform current control, as shown in equation (I). ing. Since the corrected voltage vector Vm' moves forward or backward in phase ⁇ m or increases or decreases in vector length with respect to the original voltage vector Vm, information regarding these correction amounts is fed back to the dq-axis current controller 34.
  • the current is controlled using the d-axis voltage command value Vd ref and the q-axis voltage command value Vq ref that are output, the influence thereof is reflected.
  • FIG. 44(A) shows the influence on the phase voltage command value due to the modification of the voltage vector Vm.
  • Line D in FIG. 44(A) indicates the ⁇ -axis voltage command value V ⁇ ref and the ⁇ -axis obtained by coordinate-converting the d-axis voltage command value Vd ref and the q-axis voltage command value Vq ref to the ⁇ -axis using formula (II).
  • the concept is to virtually smooth out the movement trajectory by applying filters in the rotational direction and the radial direction.
  • the voltage vector Vm has the switching boundary phase (30°, 90°, 150° , 210°, 270°, 330°).
  • FIG. 44(B) is a conceptual diagram showing a part of the movement locus in this area D1 enlarged without smoothing. Since the actual voltage vector Vm vibrates finely, the movement locus of the voltage vector Vm reciprocates in the circumferential direction before and after the switching boundary phase of 270°. If the movement locus of the voltage vector Vm is defined by the control timing time series k1 to k7 for each control cycle Ts, and if the correlation table of FIG.
  • the modulation area selection unit 44 modifies the correlation table of FIG. 31. Specifically, the voltage vector Vm rotates in the opposite direction, passes through the switching boundary phase (270° in FIG. 44(B)) in the reverse rotation direction, and enters the operable region of the reverse rotation destination (in FIG. 44(B)). When the odd-number side operable area Z1) is about to be selected, it is forcibly replaced with the operable area before reverse rotation (even-number side operable area Z2 in FIG. 44(B)).
  • the modulation area selection unit 44 selects the d-axis voltage command value Vd output from the dq-axis current controller 34 from the current control timing k to the next (future) control timing k+1. ref and the q-axis voltage command value Vq ref are estimated using the following formula (XXVIII).
  • the voltage vector Vm is reversely rotated at the next control timing k+1, and the switching boundary phase is also reversely rotated. It is possible to determine whether or not to pass in the direction. Only when the vehicle passes in the reverse rotation direction, the operable region before reverse rotation may be selected.
  • FIG. 45 shows the waveform B (reference) of the three-phase voltage commands Vu, Vv, and Vw output from the modulation section 50 and the common mode voltage waveform Vc when correction control is applied in the modulation region selection section 44. It can be seen that fluctuations in the common mode voltage waveform Vc are suppressed compared to the fluctuations in FIG. 43.
  • odd voltage RSPWM, even voltage RSPWM, or full voltage RSPWM has been exemplified as a modulation method using a part of the basic vector area B, but the present invention is not limited to this. , other modulation schemes can be adopted.
  • the modulation unit 50 has two modulation methods: the odd voltage modulation processing unit 52 that performs odd voltage RSPWM, and the even voltage modulation processing unit 54 that performs even voltage RSPWM.
  • Modulation section 50 may have a single modulation method.
  • the modulation section 50 may include a first modulation processing section that executes another first modulation method and a second modulation processing section that executes another second modulation method, and these may be switched as appropriate. Furthermore, in the present invention, the modulation section 50 can employ three or more types of modulation methods and switch between them as appropriate.
  • (Method A) in the phase voltage command modification unit 40 the case where the voltage vector Vm is modified to be on the boundary between the inoperable region and the voltage operable region is illustrated, but the present invention is limited to this. It is also possible to modify it inside this boundary. Further, (Method A), (Method B), (Method C), and (Method D) which are voltage vector correction methods are examples, and other correction methods can be adopted. For example, as an example of combining (Method A), (Method B), and (Method C), as shown in FIG. It is also preferable to correct the corrected voltage vector Vm' at the intersection of G and the boundary line Y1.
  • the driving of the motor (load) of an electric compressor has been explained as an example, but the present invention is not limited thereto, and is also effective when driving a motor other than the motor of the electric compressor. Furthermore, the present invention is applicable to various power conversion devices that convert DC voltage into AC voltage using an inverter and apply the voltage to a load.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Inverter Devices (AREA)

Abstract

La présente invention est destinée à supprimer le bruit en mode commun sans changer le procédé de modulation en émettant un vecteur de tension identique par utilisation uniquement d'une région capable de moduler un vecteur de tension à l'extérieur de la région capable de modulation dans un procédé de modulation afin de supprimer l'excitation d'un bruit en mode commun pour lequel la région capable de modulation est limitée. L'invention concerne un dispositif de conversion de puissance 1 équipé d'un circuit onduleur 27 et d'un dispositif de commande 21 servant à commander la commutation d'un élément de commutation. Le dispositif de commande 21 est équipé : d'une unité de modulation 50 qui définit une région partielle dans un espace de tension de base, qui est une région de vecteur de tension capable de délivrer en sortie dans un circuit onduleur, en tant que région capable de modulation ; et d'une unité de correction de commande de tension de phase 40 servant à calculer un vecteur de tension corrigé obtenu par correction du vecteur de tension dans la région capable de modulation lorsque le vecteur de tension se trouve dans l'espace de tension de base et hors de la région capable de modulation. Par conséquent, l'unité de modulation 50 délivre en sortie en utilisant le vecteur de tension corrigé.
PCT/JP2023/031172 2022-09-13 2023-08-29 Dispositif de conversion de puissance WO2024057913A1 (fr)

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JP2022145274A JP2024040733A (ja) 2022-09-13 2022-09-13 電力変換装置
JP2022-145274 2022-09-13

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012070619A (ja) * 2010-09-16 2012-04-05 Abb Technology Ag 回転電気機械のためのフラックスオフセット補償
US20170361732A1 (en) * 2016-06-20 2017-12-21 Faraday&Future Inc. Voltage generation with high modulation indices in inverter drives
JP2018506253A (ja) * 2015-01-06 2018-03-01 ユニヴェルシテ・クレルモン・オーヴェルニュ 電流変換方法及びデバイス並びにそのようなデバイスを備える車両
JP2019140896A (ja) * 2018-02-06 2019-08-22 エルエス産電株式会社Lsis Co., Ltd. インバータ制御装置

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012070619A (ja) * 2010-09-16 2012-04-05 Abb Technology Ag 回転電気機械のためのフラックスオフセット補償
JP2018506253A (ja) * 2015-01-06 2018-03-01 ユニヴェルシテ・クレルモン・オーヴェルニュ 電流変換方法及びデバイス並びにそのようなデバイスを備える車両
US20170361732A1 (en) * 2016-06-20 2017-12-21 Faraday&Future Inc. Voltage generation with high modulation indices in inverter drives
JP2019140896A (ja) * 2018-02-06 2019-08-22 エルエス産電株式会社Lsis Co., Ltd. インバータ制御装置

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