JP7001043B2 - Inverter device - Google Patents

Description

The present invention relates to an inverter device.

As PWM control in an inverter device, a triangular wave comparison method that generates a pulse pattern (switching pulse) of a switching element by comparing a voltage command value and a triangular wave is generally used (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-79033

By the way, as shown in FIG. 9, the frequency of the pulse pattern of the switching element depends on the triangular wave (carrier) frequency. Further, the duty of the pulse pattern depends on the voltage command value in a sinusoidal shape. As a result, it is difficult to generate a pulse pattern that is turned on / off at an arbitrary timing or duty.

An object of the present invention is to provide an inverter device capable of generating a pulse pattern that can be turned on / off at an arbitrary timing or duty.

The inverter device that solves the above problems has a switching element that constitutes the upper and lower arms for each phase of u, v, and w between the positive and negative bus wires, and the DC voltage is converted to an AC voltage by the switching operation of the switching element. An inverter circuit that converts and supplies to the motor, a signal generator that generates a signal with a waveform corresponding to the u, v, w phase voltage command value based on the angle information and the d, q-axis voltage command value, and a modulation factor. Or, based on the first constant generator that generates the first constant that defines the switching timing for each control cycle based on the line voltage effective value or torque command value, and the modulation factor or line voltage effective value or torque command value. It corresponds to the voltage command value of the u, v, w phase generated in the signal generation unit and the second constant generation unit that generates the second constant that defines the switching timing different from the first constant in each control cycle. The pulse pattern of the switching element for the upper arm and the lower arm in the inverter circuit are compared with the signal of the waveform to be generated and the first constant generated in the first constant generation unit and the second constant generated in the second constant generation unit. The gist is that it is equipped with a comparator that outputs the pulse pattern of the switching element.

According to this, in the first constant generation unit, the first constant defining the switching timing is generated for each control cycle based on the modulation factor, the line voltage effective value, or the torque command value. In the second constant generation unit, a second constant that defines a switching timing different from the first constant is generated for each control cycle based on the modulation factor, the line voltage effective value, or the torque command value. Then, in the comparator, the signal of the waveform corresponding to the voltage command value of the u, v, w phase generated in the signal generation unit and the second constant generated in the first constant generation unit and the second constant generated in the second constant generation unit. The pulse pattern of the switching element for the upper arm and the pulse pattern of the switching element for the lower arm in the inverter circuit are output by being compared with the constant. Therefore, by adjusting each constant, it is possible to generate a pulse pattern that can be turned on / off at an arbitrary timing or duty.

Further, in the inverter device, the first constant generation unit generates the first constant for each control cycle based on the rotational speed information in addition to the modulation factor, the effective line voltage value, or the torque command value, and the second constant. The generation unit may generate the second constant for each control cycle based on the rotational speed information in addition to the modulation factor, the effective line voltage value, or the torque command value.

According to the present invention, it is possible to generate a pulse pattern that can be turned on / off at an arbitrary timing or duty.

The block diagram which shows the structure of the inverter device in an embodiment. The block diagram which shows the structure of the d, q / u, v, w conversion circuit in 1st Embodiment. (A) and (b) are diagrams showing the relationship between the modulation factor and the rotation speed and the constant. (A) is a diagram showing comparison processing by a comparator, (b) is a diagram showing a pulse pattern of an upper arm switching element, and (c) is a diagram showing a pulse pattern of a lower arm switching element. The block diagram which shows the structure of the d, q / u, v, w conversion circuit in 2nd Embodiment. (A) is a diagram showing comparison processing by a comparator in the second embodiment, (b) is a diagram showing a pulse pattern of an upper arm switching element, and (c) is a diagram showing a pulse pattern of a lower arm switching element. .. The block diagram which shows the structure of the d, q / u, v, w conversion circuit in 3rd Embodiment. (A) is a diagram showing comparison processing by another example comparator, (b) is a diagram showing a pulse pattern of an upper arm switching element, and (c) is a diagram showing a pulse pattern of a lower arm switching element. Waveform diagram to explain the problem.

(First Embodiment)
Hereinafter, an embodiment embodying the present invention will be described with reference to the drawings.
As shown in FIG. 1, the inverter device 10 includes an inverter circuit 20 and an inverter control device 30. The inverter control device 30 includes a drive circuit 31 and a control unit 32.

The inverter circuit 20 has six switching elements Q1 to Q6 and six diodes D1 to D6. IGBTs are used as switching elements Q1 to Q6. A switching element Q1 constituting the u-phase upper arm and a switching element Q2 constituting the u-phase lower arm are connected in series between the positive electrode bus Lp and the negative electrode bus Ln. A switching element Q3 constituting a v-phase upper arm and a switching element Q4 constituting a v-phase lower arm are connected in series between the positive electrode bus Lp and the negative electrode bus Ln. A switching element Q5 constituting the w-phase upper arm and a switching element Q6 constituting the w-phase lower arm are connected in series between the positive electrode bus Lp and the negative electrode bus Ln. Diodes D1 to D6 are connected in antiparallel to the switching elements Q1 to Q6. A battery B as a DC power source is connected to the positive electrode bus Lp and the negative electrode bus Ln via a smoothing capacitor C.

The switching element Q1 and the switching element Q2 are connected to the u-phase terminal of the motor 60. The switching element Q3 and the switching element Q4 are connected to the v-phase terminal of the motor 60. The switching element Q5 and the switching element Q6 are connected to the w-phase terminal of the motor 60. The inverter circuit 20 having the switching elements Q1 to Q6 constituting the upper and lower arms can convert the DC voltage, which is the voltage of the battery B, into an AC voltage and supply it to the motor 60 in accordance with the switching operation of the switching elements Q1 to Q6. You can do it. The motor 60 is a vehicle drive motor.

A drive circuit 31 is connected to the gate terminals of the switching elements Q1 to Q6. The drive circuit 31 switches the switching elements Q1 to Q6 of the inverter circuit 20 based on the pulse pattern which is a control signal.

A position detection unit 61 is provided on the motor 60, and the position detection unit 61 detects the electric angle θ as the rotation position of the motor 60. The u-phase current Iu of the motor 60 is detected by the current sensor 62. Further, the v-phase current Iv of the motor 60 is detected by the current sensor 63.

The control unit 32 is composed of a microcomputer, and the control unit 32 includes a subtraction unit 33, a torque control unit 34, a torque / current command value conversion unit 35, subtraction units 36 and 37, a current control unit 38, and d. It includes a q / u, v, w conversion circuit 39, a coordinate conversion unit 40, and a speed calculation unit 41.

The speed calculation unit 41 calculates the speed (rotational speed) ω from the electric angle θ detected by the position detection unit 61. The subtraction unit 33 calculates the difference Δω between the command speed (command rotation speed) ω * and the speed (rotation speed) ω calculated by the speed calculation unit 41. The torque control unit 34 calculates the torque command value T * from the difference Δω of the rotation speed ω.

The torque / current command value conversion unit 35 converts the torque command value T * into the d-axis current command value Id * and the q-axis current command value Iq *. For example, the torque / current command value conversion unit 35 uses a table in which the target torque stored in advance in the storage unit (not shown) is associated with the d-axis current command value Id * and the q-axis current command value Iq *. Torque / current command value conversion is performed.

The coordinate conversion unit 40 obtains the w-phase current Iw of the motor 60 from the u-phase current Iu and the v-phase current Iv by the current sensors 62 and 63, and based on the electric angle θ detected by the position detection unit 61, the u-phase current. Iu, v-phase current Iv and w-phase current Iw are converted into d-axis current Id and q-axis current Iq. The d-axis current Id is a current vector component for generating a field in the current flowing through the motor 60, and the q-axis current Iq is a current vector component for generating torque in the current flowing through the motor 60. ..

The subtraction unit 36 calculates the difference ΔId between the d-axis current command value Id * and the d-axis current Id. The subtraction unit 37 calculates the difference ΔIq between the q-axis current command value Iq * and the q-axis current Iq. The current control unit 38 calculates the d-axis voltage command value Vd * and the q-axis voltage command value Vq * based on the difference ΔId and the difference ΔIq.

The voltage sensor 42 detects the voltage (DC voltage) Vdc of the battery B. This detection result is sent to the d, q / u, v, w conversion circuit 39.
The d, q / u, v, w conversion circuit 39 inputs the electric angle θ, the rotation speed ω, the d-axis voltage command value Vd *, the q-axis voltage command value Vq *, and the DC voltage Vdc, which are angle information, respectively. The pulse patterns of the switching elements Q1 to Q6 for the upper and lower arms of the phase are output to the drive circuit 31. That is, from the d-axis voltage command value Vd * and the q-axis voltage command value Vq * based on the electric angle θ, the rotation speed ω, and the DC voltage Vdc detected by the position detection unit 61, each switching element Q1 to the inverter circuit 20 Outputs a pulse pattern for turning Q6 on and off. That is, in the d, q / u, v, w conversion circuit 39, the d-axis current and the q-axis current in the motor 60 are targeted based on the currents Iu, Iv, Iw of each phase of u, v, w flowing through the motor 60. The switching elements Q1 to Q6 provided in the current path of the motor 60 are controlled so as to have a value.

The d, q / u, v, w conversion circuit 39 has the configuration shown in FIG. In FIG. 2, the d, q / u, v, w conversion circuit 39 includes a triangular wave generation unit 50, a comparator 51, a modulation factor calculation unit 52, a first constant generation unit 53, and a second constant generation unit 54. , Equipped with. The triangular wave generation unit 50 generates a u, v, w phase triangular wave from the electric angle θ as the angle information and the d, q-axis voltage command values Vd *, Vq *. The frequency of the triangular wave changes according to the number of rotations (the rate of change over time of the electric angle θ), and is one cycle of the triangular wave for one cycle of the current. The amplitude of the triangular wave is 1. The triangular wave is input to the comparator 51.

The modulation factor calculation unit 52 converts the d, q-axis voltage command values Vd * and Vq * into the modulation factor M. Specifically, the modulation factor M is calculated by the following equation (1). Vdc is a DC voltage.

・・・（１）
第１定数生成部５３は、図３（ａ）に示すマップを用いて変調率Ｍ及び回転速度ωを参照して事前に算出したデータをもとに、第１定数Ｋ１を生成する。第１定数Ｋ１は、スイッチングタイミング（図４（ａ）でのｔ１）を規定する。図３（ａ）において、横軸に変調率Ｍ及び回転速度ωをとり、縦軸に第１定数Ｋ１をとっている。特性線Ｌ１００は、事前に算出されたデータであり、このデータはマップデータである。第１定数生成部５３での処理は、記憶部（図示略）に予め記憶される変調率Ｍ及び回転速度ωと第１定数Ｋ１とが対応付けられたテーブルを用いて行われる。この第１定数Ｋ１がパルス幅を決定する要素となる。図４（ａ）に示すように、第１定数Ｋ１はプラスの値とマイナスの値の両方がコンパレータ５１に入力される。

... (1)
The first constant generation unit 53 generates the first constant K1 based on the data calculated in advance with reference to the modulation factor M and the rotation speed ω using the map shown in FIG. 3A. The first constant K1 defines the switching timing (t1 in FIG. 4A). In FIG. 3A, the horizontal axis represents the modulation factor M and the rotation speed ω, and the vertical axis represents the first constant K1. The characteristic line L100 is data calculated in advance, and this data is map data. The processing in the first constant generation unit 53 is performed using a table in which the modulation factor M and the rotation speed ω stored in advance in the storage unit (not shown) and the first constant K1 are associated with each other. This first constant K1 is an element that determines the pulse width. As shown in FIG. 4A, both a positive value and a negative value of the first constant K1 are input to the comparator 51.

The second constant generation unit 54 generates the second constant K2 based on the data calculated in advance with reference to the modulation factor M and the rotation speed ω using the map shown in FIG. 3 (b). The second constant K2 defines a switching timing (t2 in FIG. 4A) different from that of the first constant K1. In FIG. 3B, the horizontal axis represents the modulation factor M and the rotation speed ω, and the vertical axis represents the second constant K2. The characteristic line L101 is data calculated in advance, and this data is map data. The processing in the second constant generation unit 54 is performed using a table in which the modulation factor M and the rotation speed ω stored in advance in the storage unit (not shown) and the second constant K2 are associated with each other. This second constant K2 is an element that determines the pulse width. As shown in FIG. 4A, both a positive value and a negative value of the second constant K2 are input to the comparator 51.

The characteristic line L100 in FIG. 3A and the characteristic line L101 in FIG. 3B are determined by simulation in order to reduce high frequencies, and are products incorporating a motor / inverter even if the motor 60 is used. The characteristic line L100'and the characteristic line L101'are different depending on the above.

As shown in FIG. 4A, the comparator 51 compares the input triangular wave with the values of ± K1 and ± K2. The comparator 51 includes a pulse pattern of the u-phase upper arm switching element Q1 as shown in FIG. 4 (b) and a u-phase lower arm switching element Q2 as shown in FIG. 4 (c). Calculate the pulse pattern of. In FIGS. 4A, 4B, and 4C, the pulse pattern is inverted even at zero cross.

Similarly, the comparator 51 compares the input triangular wave with the values of ± K1 and ± K2, and compares the pulse pattern of the switching element Q3 for the upper arm of the v phase and the pulse of the switching element Q4 for the lower arm of the v phase. Calculate the pattern. Further, the comparator 51 compares the input triangular wave with the values of ± K1 and ± K2, and has a pulse pattern of the switching element Q5 for the upper arm of the w phase and a pulse pattern of the switching element Q6 for the lower arm of the w phase. Is calculated. As described above, since the phase of the triangular wave is delayed by ± 2 / 3π with respect to the phase of the u-phase triangular wave for the v and w phases, each phase triangular wave is compared with ± K1 and ± K2.

Next, the operation of the inverter device 10 will be described.
In FIG. 2, as the pulse generation algorithm, the input is the electric angle θ, the rotation speed ω, d, the q-axis voltage command value Vd *, Vq *, and the DC voltage Vdc, and the output is the pulse pattern of the switching element for each phase upper and lower arm. Is.

In FIG. 2, a triangular wave of u, v, and w phases is generated from the electric angle θ and the d, q-axis voltage command values Vd *, Vq *.
On the other hand, in the modulation factor calculation unit 52, the d, q-axis voltage command values Vd * and Vq * are converted into the modulation factor M using the DC voltage Vdc.

The first constant K1 is generated in the first constant generation unit 53 based on the data calculated in advance from the modulation factor M and the rotation speed ω. Further, the second constant K2 is generated in the second constant generation unit 54 based on the data calculated in advance from the modulation factor M and the rotation speed ω.

The comparator 51 compares the input u-phase triangular wave with the values of ± K1 and ± K2. The pulse pattern of the switching element for the upper arm is calculated by comparing the values of the triangular wave and ± K1 and ± K2. The pulse pattern of the switching element for the lower arm is calculated by comparing the values of the triangular wave and ± K1 and ± K2.

Since the v and w phases have command values that are ± 2 / 3π deviated from the voltage command values of the u phase, the triangular wave is compared with ± K1 and ± K2.
In this way, free switching is possible by using a triangular wave synchronized with the electric angle and a plurality of constants K1 and K2. That is, the method of obtaining the pulse pattern by comparing the triangular wave synchronized with the electric angle with the constants K1 and K2 defining different switching timings can output the same as the triangular wave comparison method.

As described above, a pulse pattern (switching pulse) of arbitrary timing and duty can be output. For example, it is possible to obtain the optimum switching with low loss in advance and realize the pulse pattern.

According to the above embodiment, the following effects can be obtained.
(1) As the configuration of the inverter device 10, the switching elements Q1 to Q6 constituting the upper and lower arms for each phase of u, v, w between the positive and negative bus Lp and Ln are provided, and the switching operations of the switching elements Q1 to Q6 are performed. Along with this, an inverter circuit 20 that converts a DC voltage into an AC voltage and supplies it to the motor 60 is provided. A triangular wave generation unit 50 is provided as a signal generation unit, and the triangular wave generation unit 50 has a waveform (triangle wave) signal corresponding to the u, v, w phase voltage command values based on the angle information and the d, q-axis voltage command values. To generate. A first constant generation unit 53 is provided, and the first constant generation unit 53 generates a first constant K1 that defines switching timing for each control cycle based on the modulation factor M. A second constant generation unit 54 is provided, and the second constant generation unit 54 generates a second constant K2 that defines a switching timing different from that of the first constant K1 for each control cycle based on the modulation factor M. A comparator 51 is provided, and the comparator 51 includes a waveform signal corresponding to the u, v, w phase voltage command values generated by the triangular wave generation unit 50, and the first constant K1 and the second constant generated by the first constant generation unit 53. The pulse pattern of the upper arm switching element and the pulse pattern of the lower arm switching element in the inverter circuit 20 are output by comparing with the second constant K2 generated in the generation unit 54. Therefore, by adjusting the constants K1 and K2, it is possible to generate a pulse pattern (switching pulse) that can be turned on / off at an arbitrary timing or duty. For example, low-loss switching can be realized by seeking optimum switching with low loss.

(2) The first constant generation unit 53 further generates the first constant K1 in the modulation factor M based on the rotation speed information (ω) for each control cycle, and the second constant generation unit 54 further generates the first constant K1 in the modulation factor M. A second constant K2 is generated for each control cycle based on the rotation speed information (ω). Therefore, it is possible to generate a pulse pattern that can be turned on / off at an arbitrary timing or duty with higher accuracy.

(Second embodiment)
Next, the second embodiment will be described focusing on the differences from the first embodiment.
Instead of FIG. 2, in this embodiment, the configuration shown in FIG. 5 is used.

In FIG. 5, the d, q / u, v, w conversion circuit 39 includes a d, q / u, v, w conversion unit 70, a scaling unit 71, a comparator 72, and a line voltage effective value calculation unit 73. , A phase peak value conversion unit 74, a first constant generation unit 75, and a second constant generation unit 76.

The d, q / u, v, w conversion unit 70 sets the d, q-axis voltage command values Vd *, Vq * in the u, v, w phases based on the electric angle θ, which is the angle information (rotor position). Coordinates are converted to voltage command values Vu *, Vv *, Vw *.

The line voltage effective value calculation unit 73 converts the d, q-axis voltage command values Vd * and Vq * into the line voltage effective value Vline-rms of the motor. Specifically, it is calculated by Vline-rms = √ (Vd * ² + Vq * ² ).

The phase peak value conversion unit 74 calculates the peak value Vphase-peak of the u, v, w phases of the line voltage effective value Vline-rms. Specifically, it is calculated by Vphase-peak = Vline-rms × √2 / √3.

The scaling unit 71 sets the u, v, w phase voltage command values Vu *, Vv *, Vw * to the u, v, w phase peak value Vphase-peak of the line voltage effective value Vline-rms from -1 to -1. Scale to +1. The scaled u, v, w phase voltage command values Vu **, Vv **, Vw ** are input to the comparator 51.

In this way, the d, q / u, v, w conversion unit 70 and the scaling unit 71 as the signal generation unit make u, v, u, v, based on the electric angle θ and the q-axis voltage command values Vd *, Vq *. A signal having a waveform (sine wave) corresponding to the w-phase voltage command values Vu *, Vv *, and Vw * is generated.

The first constant generation unit 75 determines the switching timing (t11 in FIG. 6A) of the line voltage effective value Vline-rms converted by the line voltage effective value calculation unit 73 using the map. Convert to K1. This first constant K1 is an element that determines the pulse width of the pulse pattern. Both a positive value and a negative value of the first constant K1 are input to the comparator 72. That is, the first constant generation unit 75 generates the first constant K1 of ± 0 to 1.

The second constant generation unit 76 converts the line voltage effective value Vline-rms converted by the line voltage effective value calculation unit 73 using the map into a switching timing different from that of the first constant K1 (t12 in FIG. 6A). ) Is converted to the second constant K2. This second constant K2 is an element that determines the pulse width of the pulse pattern. As for the second constant K2, both a positive value and a negative value are input to the comparator 72. That is, the second constant generation unit 76 generates the second constant K2 of ± 0 to 1.

As shown in FIG. 6A, the comparator 72 corresponds to the u, v, w phase voltage command values Vu *, Vv *, Vw * generated by the d, q / u, v, w conversion unit 70. The waveform (sine wave) signal is compared with the first constant K1 and the second constant K2 generated by the first constant generation unit 75 and the second constant generation unit 76. Then, as shown in FIGS. 6 (b) and 6 (c), the comparator 72 has a pulse pattern of the upper arm switching elements Q1, Q3 and Q5 in the inverter circuit 20 and the lower arm switching elements Q2, Q4 and Q6. Outputs the pulse pattern of.

According to the above embodiment, the following effects can be obtained.
(3) As a configuration of the inverter device 10, a d, q / u, v, w conversion unit 70 as a signal generation unit and a scaling unit 71 are provided, and a signal generation unit (d, q / u, v, w conversion unit 70) is provided. , The scaling unit 71) corresponds to the u, v, w phase voltage command values Vu *, Vv *, Vw * based on the electric angle θ as the angle information and the d, q-axis voltage command values Vd *, Vq *. Generates a signal with a waveform (sine wave). A first constant generation unit 75 is provided, and the first constant generation unit 75 generates a first constant K1 that defines switching timing for each control cycle based on the line voltage effective value Vline-rms. A second constant generation unit 76 is provided, and the second constant generation unit 76 sets a second constant K2 that defines a switching timing different from that of the first constant K1 for each control cycle based on the line voltage effective value Vline-rms. Generate. A comparator 72 is provided, and the comparator 51 includes a signal having a waveform corresponding to the voltage command value of the u, v, w phase generated by the signal generation unit (d, q / u, v, w conversion unit 70, scaling unit 71). The pulse pattern of the switching element for the upper arm and the switching element for the lower arm in the inverter circuit 20 are compared with the first constant K1 generated by the first constant generation unit 75 and the second constant K2 generated by the second constant generation unit 76. Outputs the pulse pattern of. Therefore, by adjusting the constants K1 and K2, it is possible to generate a pulse pattern that can be turned on / off at an arbitrary timing or duty.

The first constant generation unit 75 further generates the first constant K1 for each control cycle based on the rotation speed information (ω) in the line voltage effective value Vline-rms, and the second constant generation unit 76 generates the line voltage. A second constant K2 may be generated for each control cycle based on the rotation speed information (ω) in the effective value Voltage-rms.

(Third embodiment)
Next, the third embodiment will be described focusing on the differences from the second embodiment.
Instead of FIG. 5, the present embodiment has the configuration shown in FIG. 7, and in FIG. 5, a sine wave is generated with the voltage command values Vu *, Vv *, Vw * of the u, v, w phases. In the embodiment, a sine wave is generated by the d and q-axis voltage command values Vd * and Vq *.

Also in FIG. 7, the input is the d, q-axis voltage command values Vd *, Vq * and the electric angle θ as the angle information (rotor position), and the output is the pulse of the switching elements Q1 to Q6 for the upper and lower arms of each phase. It is a pattern.

The d, q / u, v, w conversion circuit 39 of the present embodiment includes a sine wave generation unit 80, a comparator 81, a line voltage effective value calculation unit 82, a first constant generation unit 83, and a second constant. A generation unit 84 is provided. The sine wave generation unit 80 generates a u, v, w phase sine wave from the electric angle θ as the angle information and the d, q-axis voltage command values Vd *, Vq *. The phase of the sine wave, that is, the phase difference from the electric angle θ is calculated from the electric angle phase (θ) and the voltage phase δ (calculated from Vd * and Vq *). The amplitude of the sine wave is 1. The frequency of the sine wave changes according to the number of rotations (the rate of change over time of the electric angle θ). There is one sine wave cycle for one current cycle. The sine wave is input to the comparator 81.

The line voltage effective value calculation unit 82 converts the d, q-axis voltage command values Vd * and Vq * into the line voltage effective value Vline-rms of the motor. Specifically, it is calculated by Vline-rms = √ (Vd * ² + Vq * ² ).

The first constant generation unit 83 converts the line voltage effective value Vline-rms into the first constant K1 that defines the switching timing based on the data calculated in advance using the map. This first constant K1 is an element that determines the pulse width. Both a positive value and a negative value of the first constant K1 are input to the comparator 81.

The second constant generation unit 84 converts the line voltage effective value Vline-rms into a second constant K2 that defines a switching timing different from that of the first constant K1 based on the data calculated in advance using the map. .. This second constant K2 is an element that determines the pulse width. As for the second constant K2, both a positive value and a negative value are input to the comparator 81.

The comparator 81 compares the input sine wave with the values of ± K1 and ± K2. Then, the comparator 81 outputs the pulse pattern of the upper arm switching elements Q1, Q3 and Q5 in the inverter circuit 20 and the pulse pattern of the lower arm switching elements Q2, Q4 and Q6.

According to the above embodiment, the following effects can be obtained.
(4) The inverter device 10 includes a sine wave generation unit 80 as a signal generation unit, and the sine wave generation unit 80 has u, v, and w phases based on angle information and d, q-axis voltage command values. Generates a signal with a waveform (sine wave) corresponding to the voltage command value. A first constant generation unit 83 is provided, and the first constant generation unit 83 generates a first constant K1 that defines switching timing for each control cycle based on the line voltage effective value Vline-rms. A second constant generation unit 84 is provided, and the second constant generation unit 84 sets a second constant K2 that defines a switching timing different from that of the first constant K1 for each control cycle based on the line voltage effective value Vline-rms. Generate. A comparator 81 is provided, and the comparator 81 includes a signal having a waveform corresponding to the u, v, w phase voltage command value generated by the sine wave generation unit 80, and the first constant K1 and the second constant K1 generated by the first constant generation unit 83. The pulse pattern of the upper arm switching element and the pulse pattern of the lower arm switching element in the inverter circuit 20 are output by comparing with the second constant K2 generated by the constant generation unit 84. Therefore, by adjusting the constants K1 and K2, it is possible to generate a pulse pattern that can be turned on / off at an arbitrary timing or duty.

The embodiment is not limited to the above, and may be embodied as follows, for example.
○ In FIGS. 4 and 6, the first constant K1 and the second constant K2 are generated, and the waveform signals corresponding to the voltage command values of the u, v, and w phases in the comparators 51 and 72, and the first constant K1 and the second constant K1 and the second constant The pulse pattern of the switching element was output in comparison with K2. Instead, generate three or more constants, compare the waveform signal corresponding to the u, v, w phase voltage command value with the three or more constants in the comparator, and output the pulse pattern of the switching element. May be good. Specifically, for example, as shown in FIG. 8A, a signal having a waveform corresponding to a voltage command value of the u, v, w phase is generated in a comparator by generating four constants K1, K2, K3, and K4. Compare with. Then, as shown in FIGS. 8 (b) and 8 (c), a pulse pattern of the switching element for the upper arm and a pulse pattern of the switching element for the lower arm are obtained. As described above, when it is desired to increase the number of switchings, it can be realized by increasing the number of constants K.

○ As shown by the two-dot chain line in FIG. 1, the d, q / u, v, w conversion circuit 39 takes in the torque command value T *, and the first constant generator switches based on the torque command value T *. The first constant K1 that defines the timing is generated for each control cycle, and the second constant generator generates the second constant K2 that defines the switching timing different from the first constant K1 based on the torque command value T *. It may be generated for each control cycle. Further, the first constant generation unit generates the first constant K1 for each control cycle based on the rotation speed information (ω) in the torque command value T *, and the second constant generation unit generates the torque command value T *. Further, the second constant K2 may be generated for each control cycle based on the rotation speed information (ω).

○ A map was used to calculate the constants, but the results of real-time calculations may be used instead. That is, the constant K (switching angle information) may be stored in a map and referred to for each calculation cycle, or the switching angle that realizes low loss may be calculated and used for each calculation cycle. You may.

10 ... Inverter device, 20 ... Inverter circuit, 50 ... Triangular wave generation unit, 51 ... Comparator, 52 ... Modulation rate calculation unit, 53 ... First constant generation unit, 54 ... Second constant generation unit, 70 ... d, q / u , V, w conversion unit, 71 ... scaling unit, 72 ... converter, 73 ... line voltage effective value calculation unit, 74 ... phase peak value conversion unit, 75 ... first constant generation unit, 76 ... second constant generation unit, 80 ... Sine wave generation unit, 81 ... Comparator, 82 ... Line voltage effective value calculation unit, 83 ... First constant generation unit, 84 ... Second constant generation unit, K1 ... First constant, K2 ... Second constant, Ln ... Negative voltage bus, Lp ... Positive voltage bus, M ... Modulation rate, Q1 ... u phase upper arm switching element, Q2 ... u phase lower arm switching element, Q3 ... v phase upper arm switching element, Q4 ... v phase lower arm Switching element, Q5 ... w phase upper arm switching element, Q6 ... w phase lower arm switching element, Vd * ... d-axis voltage command value, Vq * ... q-axis voltage command value, θ ... electric angle.

Claims (2)

An inverter circuit that has a switching element that constitutes the upper and lower arms for each of the u, v, and w phases between the positive and negative bus, and converts the DC voltage into an AC voltage and supplies it to the motor along with the switching operation of the switching element. ,
A signal generator that generates a waveform signal corresponding to the u, v, w phase voltage command values based on the angle information and the d, q-axis voltage command values.
A first constant generator that generates a first constant that defines switching timing for each control cycle based on the modulation factor, line voltage effective value, or torque command value.
A second constant generator that generates a second constant that defines a switching timing different from the first constant for each control cycle based on the modulation factor, the line voltage effective value, or the torque command value.
The waveform signal corresponding to the u, v, w phase voltage command value generated in the signal generation unit, the first constant generated in the first constant generation unit, and the second constant generated in the second constant generation unit. And a comparator that outputs the pulse pattern of the switching element for the upper arm and the pulse pattern of the switching element for the lower arm in the inverter circuit.
An inverter device characterized by being equipped with. The first constant generation unit generates the first constant for each control cycle based on the rotation speed information in addition to the modulation factor, the line voltage effective value, or the torque command value.
The first aspect of claim 1, wherein the second constant generation unit generates the second constant for each control cycle based on the rotational speed information in addition to the modulation factor, the line voltage effective value, or the torque command value. Inverter device.

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