JP4639585B2 - Motor control device, motor control method, and vehicle including motor control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of a conventional motor controller that it requires a large capacity of capacitor so as to smooth and stabilize voltage between the output of a boosting circuit and the input of an inverter. <P>SOLUTION: This motor controller 100 is equipped with a DC voltage converting means 110 which converts inputted DC voltage by switching, a motor application voltage generating means 120 which receives the output voltage from the DC voltage converting means 110 and generates voltage to be applied to the motor by switching, and a cooperation control means 130 which controls the cooperation so as to synchronize the timing of an output current and the timing of an input current by cooperatively controlling the switching frequency of the DC voltage converting means 110 and the switching timing of the motor application voltage generating means 120. According to this constitution, it becomes possible to let a pulse-form current outputted from the DC voltage converting means and a pulse-form current needed to be supplied to the motor application voltage generating means flow in the desired timing, and it becomes possible to lessen the capacity of a capacitor 140 needed to be provided between both means by synchronizing the timing this way. <P>COPYRIGHT: (C)2005,JPO&amp;NCIPI

Description

  The present invention relates to an efficient motor control device, a motor control method, and a vehicle including the motor control device. More specifically, the present invention relates to a motor control device that can control a motor even if a smaller capacitor is used. It is about.

As a conventional example of an electric motor drive device using an inverter, switching is performed between a region where PWM control is performed while the DC voltage of the inverter is kept constant, and a region where PDC control of the inverter is performed by changing the DC input voltage of the inverter using a booster circuit. Thus, there has been disclosed a technique aimed at efficient driving over a wide range by controlling the electric motor (see Patent Document 1).
Japanese Patent Laid-Open No. 2001-314095 (FIG. 1, paragraphs 0008-0010)

Since the booster circuit and the inverter of the driving device described above both generate the desired output voltage by switching the input voltage, this voltage is set between the output of the booster circuit and the inverter input. A capacitor for smoothing and stabilization is required. The capacitor has a problem that it becomes a large size for the following reason.
• A large capacity is required to sufficiently suppress voltage ripple and surge.
・ Capacitors with high heat dissipation are required because of the large current flowing in and out of the capacitors.

Therefore, in order to solve the above-described problems, the present invention can reduce the size of the capacitor provided between the DC voltage conversion means (including the booster circuit) and the inverter by cooperatively controlling the switching. The purpose is to provide technology.
That is, the motor control device according to the present invention is
DC voltage conversion means for converting a DC voltage by switching and outputting the voltage;
Motor applied voltage generating means for inputting an output voltage from the DC voltage converting means and generating a voltage to be applied to the motor by switching;
Cooperative control means for cooperatively controlling (synchronizing) the timing of the time when the output current output from the DC voltage conversion means flows and the timing of the time when the input current input to the motor applied voltage generating means flows. ,
It is characterized by comprising.
According to the present invention, the timing of the time the output current flows to be output in accordance with a voltage from the DC voltage converting means, of the timing of the motor applied voltage time flowing the input current to be inputted to the generating means, The timing of the time when the output current flows is synchronized with the timing of the time when the input current flows so that the shorter period during which the current flows is included in the range of the longer period during which the current flows. It is possible to minimize the ripple current and loss by matching the time when both currents flow as much as possible, and to significantly reduce the capacitance of the capacitor that needs to be provided between both means. Become.

Coordinated control of switching between DC voltage converting means and motor applied voltage generating means
DC voltage conversion means for converting the magnitude of the input DC voltage by switching, that is, the voltage, and outputting it;
Motor applied voltage generating means for inputting an output voltage from the DC voltage converting means and generating a voltage to be applied to the motor by switching;
A motor connected to the output of the motor applied voltage generating means;
By controlling the switching frequency of the DC voltage conversion means and the switching timing of the motor applied voltage generation means in a coordinated manner, the timing of the time when the output current flows and the timing of the time when the input current flows are synchronized. Cooperative control means for controlling to take,
It is characterized by comprising.
According to the present invention, it is possible to change the pulsed current output from the DC voltage converting means and the timing of supplying the pulsed current that needs to be supplied to the motor applied voltage generating means in a coordinated manner. In other words, the pulsed current output from the DC voltage converting means and the pulsed current that needs to be supplied to the motor applied voltage generating means can be intentionally operated so as to flow (synchronize) at a desired timing. Thus, by synchronizing the timing in this way, the size (capacitance) of the capacitor that needs to be provided between the two means can be reduced. As a result, current loss and capacitor cost can be reduced.

Control of switching frequency ratio between DC voltage converting means and motor applied voltage generating means The motor control device according to the reference technique of the present invention is:
The motor is an AC motor;
The motor applied voltage generating means is a PWM (pulse width modulation type) inverter,
The cooperative control means controls the switching frequency of the DC voltage converting means to be a positive integer multiple (preferably even multiple, more preferably double) less than 18 with respect to the switching frequency of the PWM inverter. ,
It is characterized by that.
According to this reference technique, it is possible to further reduce the ripple current of the capacitor provided between the output of the DC voltage converting means and the input of the PWM inverter.
The number of pulses per unit time of the pulsed current output from the DC voltage converting means is twice the number of pulses per unit time of the pulsed current input to the PWM inverter. Therefore, when the cooperative control means is used to control, for example, 1 to 4 times, the ratio of the pulsed current per unit time can be 1: 2 to 2: 1. By controlling the ratio of the number of pulses per unit time to be within such a range in the vicinity of 1, the current output from the DC voltage conversion means and the charge amount per pulse of the current input to the PWM inverter Therefore, the difference between the two currents is reduced, and the ripple current of the capacitor provided between the output of the DC voltage conversion means and the input of the PWM inverter can be reduced, thereby reducing the capacity of the capacitor. Is done.

Control of frequency and phase in the case of a triangular wave comparison PWM inverter .
The motor is an AC motor;
The motor applied voltage generation means is a triangular wave comparison PWM inverter,
The cooperative control means includes
Means for controlling a first carrier for determining a switching frequency and a switching timing of the DC voltage converting means and a second carrier for determining a switching frequency and a switching timing of the triangular wave comparison PWM inverter; The frequency of one carrier is twice the frequency of the second carrier, and the first carrier valley (at least one of the lowest amplitude points) and the second carrier valley or peak (the amplitude Control to synchronize with the lowest point or at least one of the vertices,
It is characterized by that.
According to this configuration, the ripple current of the capacitor provided between the output of the DC voltage converting means and the input of the PWM inverter can be reduced by controlling the relationship between the first and second carriers as described below. That is, the size of the capacitor can be reduced.
-The frequency of the first carrier is set to be twice the frequency of the second carrier.
-The first carrier valley and the second carrier valley or mountain are synchronized.
By satisfying the above relationship, the timing of the pulsed current output from the DC voltage converting means and the pulsed current to be supplied to the triangular wave comparison PWM inverter overlap, and the current flowing in and out of the capacitor can be reduced. Become.

Control of frequency and phase in case of AC motor + space PWM inverter Furthermore, the motor control device according to the present invention is
The motor is an AC motor;
The motor applied voltage generating means is a spatial PWM inverter,
The cooperative control means includes
Means for controlling a carrier for determining the switching frequency and switching timing of the DC voltage converting means, and a voltage vector generating means for determining the switching frequency and switching timing of the spatial PWM inverter, wherein the frequency of the carrier is It is twice the reciprocal of the voltage vector pattern generation period of the voltage vector generation means, and the valley of the carrier (the lowest point of the amplitude) and the midpoint of the zero voltage vector output period output by the voltage vector generation means Control to synchronize,
It is characterized by that.
According to the present invention, by controlling the relationship between the carrier of the DC voltage converting means and the voltage vector output from the voltage vector generating means as follows, the output between the DC voltage converting means and the input of the PWM inverter is controlled. The ripple current of the capacitor provided can be reduced. That is, the size of the capacitor can be reduced.
The carrier frequency of the DC voltage conversion means is set to twice the reciprocal of the voltage vector pattern generation cycle of the voltage vector generation means.
Control is performed so that the timing of the valley of the carrier and the center of the zero voltage vector output period output by the voltage vector generating means are synchronized.

Control of frequency and phase in the case of a direct current motor .
The motor is a DC motor;
The motor applied voltage generation means is a DC motor drive circuit,
The cooperative control means includes
Means for controlling a first carrier for determining the switching frequency and switching timing of the DC voltage converting means and a second carrier for determining the switching frequency and switching timing of the motor applied voltage generating means; The frequency of the carrier is equal to the frequency of the second carrier, and the valley of the first carrier (the lowest point of amplitude) and the peak of the second carrier (the peak of amplitude) are controlled to be synchronized.
It is characterized by that.
According to the present invention, the ripple current of the capacitor can be reduced by controlling the relationship between the first carrier in the DC voltage converting means and the second carrier in the motor applied voltage generating means as follows. That is, the size of the capacitor can be reduced.
Make the frequency of the first carrier equal to the frequency of the second carrier.
Control is performed so that the valley of the first carrier and the peak of the second carrier are synchronized.

Further, the frequency control variable, and the motor control device according to the present invention includes:
A means (control circuit) for changing the switching frequency of the DC voltage converting means and the switching frequency of the motor applied voltage generating means in conjunction with each other;
It is characterized by that.
According to the present invention, the switching frequency of the DC voltage converting means and the switching frequency of the motor applied voltage generating means can be changed in conjunction with each other. As a method of driving the motor, there is a method of changing the frequency of switching performed to generate a pulse voltage applied to the motor according to the motor state. For example, in an AC motor, a method of changing the switching frequency according to the motor rotation speed may be used. Even in such a drive system, the present invention is configured to change the switching frequency of the motor applied voltage generating means in conjunction with the change of the switching frequency of the motor applied voltage generating means. The timing of the pulsed current output from the converting means and the pulsed current to be supplied to the motor applied voltage generating means overlaps, and the current flowing in and out of the capacitor can be reduced. That is, the size of the capacitor can be reduced.

As described above, the solution of the present invention has been described as an apparatus. However, the present invention can be realized as a method, a program, and a storage medium that records the program substantially corresponding to these. It should be understood that these are included in the scope.
For example, the motor control method according to the present invention includes:
DC voltage conversion step for converting the input DC voltage by switching and outputting the voltage; and
A motor applied voltage generating step for inputting an output voltage from the DC voltage converting step and generating a voltage to be applied to the motor by switching using a switching frequency;
A cooperative control step for cooperatively controlling the switching frequency used in the DC voltage conversion step and the switching timing of the motor applied voltage generation step;
Including
Of the timing of the time when the output current output according to the voltage from the DC voltage conversion step flows and the timing of the time when the input current input to the motor applied voltage generation step flows, the time when the current flows is short Control so that the timing of the time when the output current flows and the timing of the time when the input current flows are synchronized so that the longer period is included in the range of the longer period during which the current flows It is characterized by that.

Furthermore, the present invention can also be realized in the form of a vehicle.
For example, a vehicle comprising a motor control device according to the present invention is
The motor control device is
DC voltage conversion means for converting a DC voltage by switching and outputting the voltage;
Motor applied voltage generating means for inputting an output voltage from the DC voltage converting means and generating a voltage to be applied to the motor by switching;
A motor connected to the output of the motor applied voltage generating means;
A cooperative control means for controlling the switching frequency of the DC voltage converting means and the switching timing of the motor applied voltage generating means in a coordinated manner;
Of the timing of the time when the output current output according to the voltage from the DC voltage converting means flows and the timing of the time when the input current input to the motor applied voltage generating means flows, the time when the current flows is short By matching the intermediate point of the interval of the output current and the intermediate point of the interval of the input current so that the one period is included in the range of the longer period in which the current flows , Control so that the timing of the time when the output current flows and the timing of the time when the input current flows are synchronized,
It is characterized by that.

First, a basic configuration of the high power unit of the motor control device will be described.
FIG. 1 is a block diagram showing a configuration of a high voltage unit of the motor control device. As shown in the figure, the DC voltage converting means 15, the battery 16, the motor applied voltage converting means, the capacitor 19, and the motor 10 constitute a high voltage section. When the motor is driven by a motor control device having such a strong electric part without applying the present invention, the capacitor 19 needs a large capacity as described above.
FIG. 2 is a circuit diagram showing the configuration of the high voltage section of the AC motor control device. Even when the motor is driven by such a motor control device having a strong electric section, the capacitor 19 needs to have a large capacity.

FIG. 3 is a block diagram showing basic components of the motor control apparatus according to the present invention. As shown in the figure, the motor control device 100 according to the present invention includes a DC voltage conversion means 110, a motor applied voltage generation means 120, a cooperative control means 130, and a capacitor 140. The DC voltage converting means 110 is coupled to the power source 150, and the motor applied voltage generating means 120 is coupled to the motor 160.
The DC voltage conversion means 110 converts the DC voltage supplied from the power supply 150 by switching and outputs the voltage, and the motor applied voltage generation means 120 inputs the output voltage from the DC voltage conversion means 110 and performs switching. A voltage to be applied to the motor 160 is generated. The cooperative control unit 130 controls the timing of the output current output from the DC voltage conversion unit 110 and the timing of the input current input to the motor applied voltage generation unit 120 in a coordinated manner.

Several embodiments of the low-loss and efficient motor control apparatus in which the present invention is applied to the above-described high-power section, which requires a low-capacitance capacitor, are shown.
First Embodiment FIG. 8 is a block diagram showing the configuration of a first embodiment of the motor control apparatus according to the present invention. This embodiment is an example applied to an AC motor control device using a step-up DCDC converter and a triangular wave comparison PWM inverter.
As shown in the figure, the motor 10 is an AC motor, and the battery 16, the DCDC converter 15, the capacitor 19, and the PWM inverter 8 constitute a high power unit of the present control device. The voltage of the battery 16 is converted by the DCDC converter 15, and the converted voltage is supplied to the triangular wave comparison PWM inverter 8. The DCDC converter is a switching type voltage converter, and this switching is executed based on an on / off signal output from DCDC converter control means described below.

  The PWM inverter 8 converts the DC output voltage of the DCDC converter 15 into an AC voltage by PWM and applies it to the motor 10. This PWM is executed based on a PWM signal output from a motor control unit described below. The capacitor 19 is for stabilizing the DC voltage supplied from the DCDC converter 15 to the PWM inverter 8. Reference numeral 1 denotes a torque control / DC voltage command value generating means for generating a DCDC converter voltage command Vdc * and a motor dq-axis current command value id *, iq *. A voltage command value Vdc * and motor dq-axis current command values id * and iq * are given to a DCDC converter control unit and a motor control unit described below, respectively. The d-axis current command value id *, the q-axis current command value iq *, and the DC voltage command value Vdc * are calculated based on the motor torque command value Te * given from the outside and the rotational speed ωe of the motor.

  The DCDC converter control unit includes a DC link voltage detection unit 17, a PWM pulse generation unit 14, and a carrier generation unit 18. The carrier generation means 18 generates both carriers so that the carrier of the DCDC converter 15 and the carrier of the PWM inverter 8 satisfy a predetermined relationship. The carrier for the DCDC converter 15 is output from the carrier generation means 18 to the PWM pulse generation means 14. The PWM pulse generator 14 outputs the DC link voltage Vdc, which is the output voltage of the DCDC converter and the input voltage of the PWM inverter, from the torque control / DC voltage command value generator using the signal of the DC link voltage detector 17. Feedback control is performed so as to match the DC voltage command value Vdc *. The PWM pulse output from the PWM pulse generation means 14 is output to the DCDC converter 15, and the power element of the DCDC converter performs switching. The motor 10 is provided with a position sensor 11.

The motor control unit includes a current detection unit 9, a 3-phase / dq conversion unit 5, a current control unit 2, a non-interference control unit 6, an adder 3, a dq / 3-phase conversion unit 4, a standardized voltage command generation unit 12, and a PWM. The pulse generator 13, the phase / velocity calculator 7, the carrier generator 18, and the DC voltage detector 17 are configured. The carrier generation unit 18 generates both carriers so as to satisfy a predetermined relationship between the carrier of the DCDC converter and the carrier of the PWM inverter. In this control unit, the carrier of the PWM inverter is used, and the PWM pulse generation unit 13 is used. Then, mu *, mv *, mw * three-phase PWM pulses, which are standardized command values for the three-phase voltage of the motor, are generated.
The main items of the present invention are the carrier generation means 18, the motor PWM pulse generation means 13, the DCDC converter PWM pulse generation means 14, and the PWM inverter 8, DCDC converter 15, capacitor 19 and battery 16 constituting the high voltage section. Since it is a related part, it demonstrates below centering on these.

Next, the basic operation of the DCDC converter will be described.
FIG. 4 is a circuit diagram showing a configuration of the DCDC converter. As shown in the figure, when the power elements Tr_h and Tr_l are alternately turned on and off, the battery current Ib is output as the output current Io or circulated as Icir. The output current Io is supplied to the capacitor C and a load (not shown).
FIG. 5 is a timing chart showing the operation of the DCDC converter shown in FIG. As shown in the figure, on / off of the power element is determined by comparing a carrier that is a triangular wave with a duty command that is a ratio of time for turning on Tr_l for one carrier period. The output current Io is a pulsed current waveform supplied to the output side only when Tr_h is in the on state. Therefore, it is generally necessary to stabilize the output voltage by providing a capacitor C having a sufficiently large capacitance value.

Next, the basic operation of the triangular wave comparison PWM inverter will be described.
FIG. 6 shows the configuration of the PWM inverter.
A desired voltage is applied to the motor by alternately turning on and off the upper power element and the lower power element in each of the three phases.
FIG. 7 shows the operation of the PWM inverter shown in FIG. 6 as a timing chart. As shown in the figure, ON / OFF of the power element of each phase is determined by comparing a triangular wave carrier with voltage command values (mu *, mv *, mw *). Moreover, as shown in the figure, the input current Idc of the inverter flows in a pulse shape twice in one carrier cycle. Since a pulsed current is input, it is generally necessary to stabilize the voltage by sufficiently increasing the capacitance of the capacitor C.

The basic operation of the DCDC converter and the PWM inverter has been described so far. Hereinafter, the operation unique to the present embodiment that makes it possible to reduce the capacitor will be described.
In the carrier generation means 18 of FIG. 8, the carrier of the DCDC converter 15 and the carrier of the PWM inverter 8 are generated, and these are generated so as to have the following relationship. That is, as shown in FIG.
-The DCDC converter carrier frequency is doubled that of the inverter carrier frequency.-The DCDC converter valley and the PWM inverter carrier valley or peak match.
Is generated as follows.

The output current Io of the DCDC converter is a pulsed current that flows once per carrier period. The output timing is output for the same time before and after the peak of the carrier. Before and after time t1 in FIG. 9, the time widths Td1 and Td2 in which the output current Io of the DCDC converter is output are equal. At time t2, times Td3 and Td4 are equal.
Since the PWM inverter performs triangular wave comparison PWM, the input current Idc becomes a pulsed current that flows twice in one cycle of the carrier. The output period is the same time before and after the intermediate point between the valley and the peak of the carrier. Before and after the time t1 in FIG. 9, the times Ti1 and Ti2 in which the input current Io flows are equal. At time t2, times Ti3 and Ti4 are equal.

  In the present embodiment, the carrier of the DCDC converter and the carrier of the PWM inverter are generated so as to have the above relationship, so the period in which the output current of the DCDC converter flows (eg, t1-Td1 to t1 + Td2) and the inverter The periods during which the input current flows (eg, t1-Ti1 to t1 + Ti2) overlap. The time width in which the former flows and the time width in which the latter flows generally do not coincide with each other, but in this embodiment, the period in which the current having the shorter flowing time flows falls within the range of the period in which the longer current flows. The capacitor C is for suppressing voltage fluctuations caused by the difference between the current Io output from the DCDC converter and the Idc input from the inverter. Therefore, the capacitor can be reduced by reducing this difference. . Therefore, by generating both carriers as in this embodiment, the difference between the two currents can be minimized, and the capacitor can be made smaller.

In FIG. 10, when the frequency ratio of the DCDC converter carrier and the inverter carrier is 2: 1, the deviation between the DCDC converter carrier valley and the inverter carrier valley, the effective value of the ripple current of the capacitor, and the internal loss The relationship was shown. Note that “deviation” is expressed by the phase of the carrier of the inverter as shown in FIG.
From this figure, it can be seen that the shift (phase) is minimized in the vicinity of 0 deg. In this example, the ripple current hardly changes in the range of 0 to 45 deg. This is because the pulse width of the output current of the DCDC converter is different from the pulse width of the input current of the inverter. This is due to the fact that the ripple current hardly changes in the range of the wider pulse. Depending on the operating state, the pulse widths may be substantially the same. In this case, the ripple current is minimized only at 0 deg. Therefore, it is desirable that the phase difference between the valleys of both carriers be as close to 0 as possible. , 0 is most preferable. In the state of 0 deg with respect to the case where the phase shift is 180 deg, the effective value of the ripple current is about 0.7 times and the internal loss is less than half. That is, if the motor control device to which the present invention is applied is used, the loss can be considerably reduced.

  FIG. 11 shows the effective row value and internal loss of the ripple current of the capacitor with respect to the frequency ratio of the carrier of the DCDC converter and the carrier of the inverter. The phase shift is 0 deg, that is, the valleys of both carriers are matched. From this figure, it is understood that when the carrier frequency of the DCDC converter / the carrier frequency of the inverter is set to 2, the ripple current of the capacitor is minimized and the loss is also minimized. Therefore, it is desirable to set the carrier frequency of the DCDC converter / the carrier frequency of the inverter to 2, but it can be seen that there is an effect even in the vicinity thereof.

As explained above, the carrier of the DCDC converter and the carrier of the inverter are
・ The carrier frequency of the DCDC converter is doubled that of the inverter.
・ Make the DCDC converter valley and PWM inverter carrier valley or peak coincide.
In this way, the ripple current of the capacitor can be minimized by operating the motor control device. Thereby, the loss of the capacitor can be greatly reduced, the capacitor can be miniaturized, and the cost can be reduced. Further, since the loss of the capacitor is reduced, the efficiency of the entire apparatus can be improved. Further, when such a motor control device is used in a vehicle, it is possible to improve fuel consumption. In the conventional example, the frequency ratio and phase of the carrier are not controlled so that the DCDC converter and the PWM inverter are synchronized at the pulse level as in the present example, so that this example can reduce the ripple current compared to the conventional example. With regard to the conventional carrier frequency, for example, when the carrier frequency of the DCDC converter is set sufficiently higher than the carrier frequency of the inverter, or when the same power element is used in the DCDC converter and the inverter, both carriers are set to the same frequency. It seems that the frequency was set to a certain level.

The effect of this embodiment is that the DCDC converter carrier frequency is doubled that of the PWM inverter carrier frequency and only the phase difference effect is seen. If the phase difference is 0 deg, then it is 180 deg. The ripple current of the capacitor can be reduced to about 70%, and the internal loss can be reduced to about half. Combined with the effect of setting the carrier frequency to 2: 1, the capacitor can be reduced by 50% or more compared to the conventional one.
By the way, the same effect can be obtained even with an inverter using synchronous PWM, which is a control method for changing the carrier of the inverter so that the carrier frequency of the inverter is an integral multiple of the electrical rotation speed ωe of the motor. Although the motor rotation speed ωe is input to the carrier generation means in FIG. 8, the carrier of the inverter is changed so as to have a predetermined integer ratio with respect to this frequency, and the carrier of the DCDC converter is changed to this carrier as described above. It is only necessary to control so as to maintain a proper relationship.

Second Embodiment FIG. 13 is a block diagram showing the configuration of a motor control apparatus according to the second embodiment.
First, the configuration will be described. In the first embodiment, the motor control unit uses a triangular wave comparison PWM, but in this embodiment, a space PWM is used.
In FIG. 13, the same reference numerals as those in the first embodiment (FIG. 8) basically perform the same operations. The different components are the output voltage vector calculation means 20 and the carrier generation means 18A. Although the motor control unit of the present embodiment uses space PWM, the output voltage vector calculation means 20 is configured such that the DC link voltage Vdc input to the PWM inverter 8, the dq axis voltage commands vdo * and vqo * of the motor, and the motor. An output voltage vector and its output time are calculated from the rotational phase θe to generate a PWM pulse command, which is given to the PWM inverter 8. The carrier generation unit 18A generates only the carrier of the DCDC converter and outputs it to the PWM pulse generation unit 14. The operation of other means is the same as in the first embodiment.

FIG. 14 is a diagram illustrating operations of the DCDC converter and the spatial PWM inverter shown in FIG. 13 as a timing chart.
As shown in the figure, DCDC converter and PWM inverter are
・ The voltage vector pattern generation cycle is twice the carrier cycle of the DCDC converter,
-The intermediate timing of the voltage vector pattern generation period is matched with the carrier valley of the DCDC converter.
To be controlled.
By doing so, as in the case of the first embodiment, the overlap between the section in which the output current of the DCDC converter flows and the section in which the input current of the PWM inverter flows is maximized. Therefore, the ripple current flowing through the capacitor is minimized, the internal loss is minimized, and the capacitor can be miniaturized.

  In the present embodiment and the first embodiment, an example in which the means for supplying a DC voltage to the PWM inverter is only a DCDC converter has been shown. FIG. 18 shows an example of the configuration of the high voltage section of the motor drive device using the fuel cell, but the same effect can be obtained even when a power source other than the DCDC converter is connected in parallel to the inverter. can get.

Third Embodiment The present embodiment is an example in which the present invention is applied to a DC motor control device using a step-up DCDC converter and an H bridge as shown in FIG.
FIG. 15 shows the configuration of a motor control apparatus according to the third embodiment. As shown in the figure, reference numeral 1B denotes torque control / DC voltage command value generating means for generating a voltage command Vdc * for the DCDC converter 15 and a command value im * for the current of the DC motor 10B. A voltage command value Vdc * and a motor current command value m * are given to the DCDC converter control unit and the motor control unit described below, respectively.
The DCDC converter control unit includes a DC link voltage detection means 17, a PWM pulse generation means 14, and a carrier generation means 18B. Except for the carrier generation means 18B, the second embodiment is the same as the first embodiment.

The motor control unit includes a current control unit 2B, a standardized voltage command generation unit 12B, a PWM pulse generation unit 13B, a carrier generation unit 18B ′, and a DC voltage detection unit 17.
The current control means 2B calculates a voltage command value vm * from the motor current command im * and the motor current detection value im. The standardized voltage command generation means 12B stops the voltage command value m * obtained by standardizing the voltage command value vm * based on the detected value of the DC link voltage Vdc. The PWM pulse generator 13B generates an H-bridge PWM pulse from m * and the H-bridge carrier.
The carrier generation means 18B generates both carriers so as to satisfy a predetermined relationship between the carrier of the DCDC converter and the carrier of the H bridge. In this control unit, the carrier for the H bridge is used, and the PWM pulse generation means. In 13B, an H-bridge PWM pulse is generated from m *, which is a standardized command value of the motor applied voltage.

The carrier generation means 18B in FIG. 15 generates a DCDC converter carrier and an H-bridge carrier, which are generated in the following relationship. That is, as shown in FIG.
・ The carrier frequency of the DCDC converter and the carrier frequency of the inverter are the same.
・ Make DCDC converter valley and PWM inverter carrier peak coincide,
Is generated as follows.
As described in the first embodiment, the output current Io of the DCDC converter is a pulsed current that flows once per carrier cycle. The output timing is output for the same time before and after the peak of the carrier. Before and after time t1 in FIG. 17, the time widths Td1 and Td2 during which the output current Io of the DCDC converter is output are equal.
The H bridge performs PWM by comparing the triangular wave as a carrier with the standardized voltage command m *. The input current Idc is a pulsed current that flows once per carrier cycle. The output period is the same time before and after the carrier valley. Before and after the time t1 in FIG. 17, the times Th11 and Th2 in which the input current Idc flows are equal.

In this embodiment, the DCDC converter carrier and the H-bridge carrier are generated so as to have the above-described relationship, so the period during which the output current of the DC-DC converter flows (eg, t1-Td1 to t1 + Td2) and the H-bridge The periods during which the input current flows (eg, t1-Th1 to t1 + Th2) overlap. The time width in which the former flows and the time width in which the latter flows generally do not coincide with each other, but in this embodiment, the period in which the current having the shorter time width flows is within the range of the period in which the current having the longer time width flows. . The capacitor C is for suppressing voltage fluctuation caused by the current difference between the current Io output from the DCDC converter and the Idc input from the inverter. As described above, the difference between the two can be reduced. Therefore, the capacitor can be made small. As described above, in the case of a DC motor, the current ripple can be reduced as in the case of an AC motor. Accordingly, the loss can be reduced and the capacitor can be made smaller.

  In the present specification, the principles and advantages of the present invention have been described in various embodiments. However, those skilled in the art can make various modifications and changes to the present invention based on the present disclosure. Note that it is included in the range. For example, although the triangular wave comparison PWM inverter and the spatial PWM inverter are cited as the inverter, these are merely examples, and the present invention can be widely applied to known inverters such as a sawtooth wave comparison PWM inverter. Moreover, although the vehicle was mentioned as an object for incorporating the motor control device, this is merely an example, and the motor control device or method according to the present invention is a product having a motor such as a washing machine, an air conditioner, a refrigerator, or a refrigerator. It can be widely applied to.

It is a block diagram which shows the structure of the high electric power part of a motor control apparatus. It is a circuit diagram which shows the structure of the high electric power part of an AC motor control apparatus. It is a block diagram which shows the basic component of the motor control apparatus by this invention. It is a circuit diagram which shows the structure of a DCDC converter. 5 is a timing chart showing an operation of the DCDC converter shown in FIG. 4. It is a circuit diagram which shows the structure of an inverter. It is a timing chart which shows operation | movement of an inverter. 1 is a block diagram illustrating a configuration of a motor control device according to a first embodiment. FIG. It is a timing chart explaining operation | movement of the DC link part of 1st Example. It is a figure which shows the relationship between the phase difference of the carrier of a DCDC converter, and the carrier of an inverter, and the ripple current and internal loss of a capacitor | condenser. It is a figure which shows the relationship between the ratio of the carrier frequency of a DCDC converter, and the carrier frequency of an inverter, and the ripple current and internal loss of a capacitor | condenser. It is a figure which shows the phase difference of the carrier of a DCDC converter, and the carrier of an inverter. It is a block diagram which shows the structure of the motor control apparatus which is 2nd Example. It is a timing chart explaining operation | movement of the DC link part of 2nd Example shown in FIG. It is a block diagram which shows the structure of the motor control apparatus which is 3rd Example. It is a circuit diagram which shows the structure of the strong electric part of a direct-current motor control apparatus. It is a timing chart explaining operation | movement of the DC link part of 3rd Example. It is a block diagram which shows the example applied to the system using a fuel cell.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Torque control and DC voltage command value generation means 2 Current control means 3 Adder 4 dq / 3 phase conversion means 5 3 phase / dq conversion means 6 Non-interference control means 7 Phase / speed calculation means 8 PWM inverter 9 Current detection means 10 Motor 11 Position sensor 12 Normalized voltage command generation means 13 PWM pulse generation means 14 PWM pulse generation means 15 DCDC converter 16 Battery 17 DC link voltage detection means 18 Carrier generation means 19 Capacitor 100 Motor controller 110 Motor 115 DC voltage conversion means 116 Power source 119 Capacitor 120 Cooperative control means

Claims (8)

DC voltage conversion means for converting a DC voltage by switching and outputting the voltage;
Motor applied voltage generating means for inputting an output voltage from the DC voltage converting means and generating a voltage to be applied to the motor by switching;
Of the timing of the time when the output current output according to the voltage from the DC voltage converting means flows and the timing of the time when the input current input to the motor applied voltage generating means flows, the time when the current flows is short Control so that the timing of the time when the output current flows and the timing of the time when the input current flows are synchronized so that the longer period is included in the range of the longer period during which the current flows Cooperative control means;
The equipped,
The coordinated control means matches the intermediate point of the output current flow interval with the intermediate point of the input current flow interval, so that the timing of the time the output current flows and the time the input current flows A motor control device that controls to synchronize with timing . The motor control device according to claim 1,
The cooperative control means includes
By controlling the switching frequency of the DC voltage conversion means and the switching timing of the motor applied voltage generation means in a coordinated manner, the timing of the time when the output current flows and the timing of the time when the input current flows are synchronized. Control to take,
The motor control apparatus characterized by the above-mentioned. The motor control device according to claim 2,
The motor applied voltage generation means is a triangular wave comparison PWM inverter,
The cooperative control means includes
Means for controlling a first carrier for determining a switching frequency and a switching timing of the DC voltage converting means and a second carrier for determining a switching frequency and a switching timing of the triangular wave comparison PWM inverter; Control so that the frequency of one carrier is twice the frequency of the second carrier and the valley of the first carrier and the valley or peak of the second carrier are synchronized.
The motor control apparatus characterized by the above-mentioned. In the motor control device according to claim 2 or 3,
The motor applied voltage generating means is a spatial PWM inverter,
The cooperative control means includes
Means for controlling a carrier for determining the switching frequency and switching timing of the DC voltage converting means, and a voltage vector generating means for determining the switching frequency and switching timing of the spatial PWM inverter, wherein the frequency of the carrier is Control is performed so that the reciprocal of the voltage vector pattern generation cycle of the voltage vector generation means is twice and the valley of the carrier is synchronized with the midpoint of the zero voltage vector output period output by the voltage vector generation means .
The motor control apparatus characterized by the above-mentioned. The motor control device according to claim 2,
The motor applied voltage generation means is a DC motor drive circuit,
The cooperative control means includes
Means for controlling a first carrier for determining the switching frequency and switching timing of the DC voltage converting means and a second carrier for determining the switching frequency and switching timing of the motor applied voltage generating means; The frequency of the carrier is equal to the frequency of the second carrier, and the valley of the first carrier and the peak of the second carrier are controlled to be synchronized,
The motor control apparatus characterized by the above-mentioned. In the motor control device according to any one of claims 2 to 4,
A means for interlockingly changing the switching frequency of the DC voltage converting means and the switching frequency of the motor applied voltage generating means;
The motor control apparatus characterized by the above-mentioned. DC voltage conversion step for converting DC voltage by switching and outputting the voltage; and
A motor applied voltage generating step for inputting an output voltage from the DC voltage converting step and generating a voltage to be applied to the motor by switching using a switching frequency;
A cooperative control step for cooperatively controlling the switching frequency used in the DC voltage conversion step and the switching timing of the motor applied voltage generation step;
Including
In the cooperative control step, among the timing of the time when the output current output according to the voltage from the DC voltage conversion step flows and the timing of the time when the input current input to the motor applied voltage generation step flows, The timing of the time when the output current flows and the timing of the time when the input current flows so that the shorter period during which the current flows is included in the range of the longer period during which the current flows And control to take
The synchronization is performed by matching an intermediate point of the output current flowing interval with an intermediate point of the input current flowing interval. A vehicle comprising a motor control device,
The motor control device
DC voltage conversion means for converting a DC voltage by switching and outputting the voltage;
Motor applied voltage generating means for inputting an output voltage from the DC voltage converting means and generating a voltage to be applied to the motor by switching;
A cooperative control means for controlling the switching frequency of the DC voltage converting means and the switching timing of the motor applied voltage generating means in a coordinated manner;
The cooperative control means includes a timing of a time when an output current output according to a voltage from the DC voltage conversion means flows, and a timing of a time when an input current input to the motor applied voltage generation means flows, In order that the shorter period during which the current flows is included in the range of the longer period during which the current flows,
Synchronizing the timing of the time when the output current flows and the timing of the time when the input current flows by matching the midpoint of the interval where the output current flows and the midpoint of the interval where the input current flows A vehicle characterized by controlling as described above .

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