JP4349890B2 - Motor control device and equipment using the same - Google Patents

Description

  The present invention relates to a motor control device and an apparatus using the same.

  The drive circuit of the inverter circuit element is made into an IC, and a bootstrap circuit using a capacitor as a temporary power source is used as the drive circuit.

  FIG. 17 is a drive circuit diagram using a bootstrap circuit. In the bootstrap circuit, as shown in FIG. 17, when the switching element of the lower arm is turned on, the capacitor that acts as a power source for the switching element of the upper arm is charged. Thereby, the power supply for the switching element of the upper arm is obtained.

  Therefore, in the initial state such as at the time of start-up, the capacitor serving as the power supply for the switching element of the upper arm is not charged unless the lower arm is switched in the state where the capacitor has no charge, so the switching element of the upper arm does not operate. .

  In order to solve this problem, conventionally, a method of regulating the maximum output voltage of each phase in an open loop so that the lower arm is forcibly switched, or a voltage as disclosed in Japanese Patent Laid-Open No. 5-292755 is disclosed. A method of generating a zero vector PWM control pattern has been proposed.

JP-A-5-292755

  The conventional method has a problem that a switching loss occurs each time the switching element is turned on / off, resulting in a reduction in efficiency.

  An object of the present invention is to reliably perform the charging operation of the bootstrap circuit at the time of starting the motor so that the switching element operates reliably.

  Another object of the present invention is to realize a highly efficient motor drive by reducing switching loss during normal operation.

  It is another object of the present invention to realize high-efficiency motor driving without switching shocks at the time of motor startup and normal operation.

  Another object of the present invention is to obtain good motor current information from a direct current when the motor is started.

  Furthermore, this invention makes it the subject to make the motor control apparatus which performs said inverter control into a power module, and to integrate in an air conditioner, a refrigerator, a washing machine, and a cleaner.

  One object of the present invention is to reliably perform the charging operation of the bootstrap circuit at the time of starting the motor so that the switching element operates reliably.

One feature of the present invention is the motor control device, a three-phase applied voltage, with the same waveform generation method in a time when the two-phase modulation operation 3-phase modulation operation, and maximum phase at every electrical angle predetermined value period The minimum phase is an almost constant value alternately.

  The other features of the present invention are as described in the claims.

  According to one aspect of the present invention, when the motor is started, the bootstrap circuit can be reliably charged. Further, according to another feature of the present invention, during normal operation, switching loss can be reduced and high-efficiency motor driving can be realized.

  Hereinafter, the best mode of the present invention will be described by way of examples.

  As an example of the present invention, an embodiment of a motor control device using a permanent magnet synchronous motor will be described with reference to FIGS.

FIG. 1 is a block diagram showing an embodiment of a synchronous motor control device according to the present invention. This synchronous motor control device converts the voltage of the DC power source 1 into a pulse width modulated AC voltage and supplies it to the U-phase, V-phase, and W-phase three-phase stator windings of the synchronous motor 3. An inverter circuit 2 that rotates the synchronous motor 3, a control circuit (one-chip microcomputer or a hybrid IC using the same) 4 that performs control processing of the synchronous motor 3 in response to a speed command signal, A driver 5 for driving the inverter circuit 2 in accordance with the signal and a sensor 6 capable of detecting a motor current input from the DC power source 1 to the inverter circuit 2 are provided. As shown in the figure, the inverter circuit 2 is an inverter in which three pairs of two switching element pairs connected in series are respectively connected between the positive terminal and the negative terminal of the DC power source, and the upper arm on the positive terminal side. The side is represented as U ⁺ , V ⁺ , W ⁺ , and the lower arm side of the negative terminal side is represented as U ⁻ , V ⁻ , W ⁻ .

The control circuit 4 includes an A / D converter 7 having an A / D conversion unit for converting the output signal 6a of the motor current sensor 6 from an analog value to a digital value based on the carrier cycle information 19a, Motor current information unit 8 that outputs D conversion value 7a as motor current information 8a, 3φ / dq coordinate conversion unit 9 that receives motor current information 8a and converts it into d-axis q-axis current 9a, and 3φ / dq coordinate conversion Motor applied voltage that outputs d-axis q-axis voltage command information 10a calculated from the d-axis q-axis current 9a, motor constant 18a, speed command, d-axis current command, and q-axis current command converted from the three-phase current by the unit 9 The generation unit 10, the dq / magnitude V1 conversion unit 11 that converts the d-axis q-axis voltage command information 10a into the voltage magnitude V1 and outputs the motor applied voltage magnitude V1 information 11a, and the motor applied voltage magnitude V1 From the information 11a, the modulation rate KHV1 information 12a for the DC power supply 1 is converted into the voltage magnitude V1 / modulation rate KHV1 converter 12 and the d-axis of the d-axis q-axis voltage command for the DC power supply 1 from the modulation rate KHV1 information 12a for the DC power supply 1 Modulation rate KHV1 / modulation rate Vd / Vq converter 13 for outputting voltage modulation rate KHVd and q-axis voltage modulation rate KHVq information 13a, and before line-to-line modulation from d-axis voltage modulation rate KHVd and q-axis voltage modulation rate KHVq information 13a From the dq / 3φ voltage inverse conversion unit 14 that outputs the motor applied voltage information 14a for each of the three phases, from the three-phase motor applied voltage information 14a before the line-to-line modulation, from the modulation factor KHV1 and the reference modulation factor information 20a Inter-line modulation unit 15 that outputs 3-phase motor applied voltage information 15a after line modulation, 3-phase motor applied voltage information 15a after line modulation, and carrier cycle PWM signal generation timer information section 16 for outputting PWM signal generation timer information 16a for generating a PWM signal from information 19a, and a PWM signal 17a necessary for driving inverter circuit 2 from PWM signal generation timer information 16a A PWM signal generation unit 17 that outputs the carrier cycle information 19a, and a reference modulation rate generation unit 20 that determines the reference modulation rate information 20a.

  Each main part and operation will be described below.

<Creation of PWM signal (Principle explanation)>
FIG. 2 is an example of a diagram schematically showing the relationship between each phase applied voltage, the carrier signal (carrier wave signal), and the PWM signal when the phase voltage is a sine wave. Generally, when a sine wave current is passed through a synchronous motor, the output voltage of the inverter is a sine wave. For this purpose, generally, as shown in the figure, a carrier signal indicated by a triangular wave and signal waves Vu, Vv,
At a point where Vw intersects, a signal for turning on / off switching, a so-called PWM signal, is generated by the PWM signal generation unit, and the six switching elements constituting the inverter circuit are switched in accordance with this signal to apply a voltage to the motor. Apply. Here, when the level of the PWM signal is Hi in the figure, the upper arm of the inverter circuit is on, and when the level is Low, the lower arm is on. That is, when a general sine wave voltage is applied, the phase voltage is a sine wave, and when applied to the operation in FIG. 1, the line modulation signal output from the line modulation unit 15 is a sine wave. In the PWM signal generation timer information unit 16, the time data representing the voltage of each phase and the time data representing the carrier period are 4 so as to realize the phase voltages Vu, Vv, Vw of the carrier cycle information 19 a and the motor applied voltage information 15 a. The type of PWM signal generation timer information 16a is determined.

  Then, the PWM signal generation unit 17 operates an up / down type timer according to the PWM signal generation timer information 16a to generate a signal that is turned on / off when the time data representing the voltage of each phase matches the timer value. Thus, the PWM signal 17a is realized.

<Outline of two-phase line modulation>
However, in the above method, as can be seen from FIG. 2, the three phases (six elements) are always switched every PWM cycle. Further, switching loss occurs in each element with switching.

  In this embodiment, in order to avoid this and reduce the switching loss, the two-phase line-to-line modulation is performed. Two-phase line-to-line modulation is a line that modulates between the remaining two-phase lines so that a specific one-phase voltage is constant and the line voltage applied to the motor is kept constant before and after line-to-line modulation. Intermodulation method.

  FIG. 3 is an example of a diagram schematically showing the relationship between the three-phase motor applied voltage information 15a after line modulation, the carrier signal, and the PWM signal. For comparison, a sine wave voltage (hereinafter referred to as a fundamental wave) before line modulation and a carrier signal are also shown. As described above, when the level of the PWM signal is Hi, the upper arm of the inverter circuit 2 is turned on, and when the level is Low, the lower arm is turned on.

  In two-phase line modulation, the voltage at the electrical angle 60 degree period of the phase that becomes the minimum voltage or maximum voltage in the fundamental wave at an arbitrary time is fixed to the inverter minimum output voltage or maximum output voltage, and crosses the carrier signal. And create a period of no switching. Here, in order to keep the line voltage applied to the motor constant before and after the line modulation, in the non-switching phase, the inverter minimum output voltage or maximum output voltage in the electrical angle 60 degree period in which switching is not performed, and the fundamental wave Add the difference to other phases. As a result, as shown in FIG. 3, the applied voltage of each phase after two-phase line modulation appears to be greatly distorted from a sine wave, but the line voltage of the motor is not related to before and after the line modulation. A sine wave is maintained.

<Description of necessity of processing at startup>
On the other hand, when the operation is performed from the motor stopped state, a so-called low-frequency synchronous activation method is used in which the synchronous operation by the open loop is performed after the rotor positioning process in order to define the position of the rotor and then the operation is switched to the position sensorless operation. In the positioning described above, when only the upper arm is turned on in the maximum phase application voltage, the lower arm is not turned on, so that the bootstrap circuit is not charged. In this case, since there is no power supply for operating the upper arm, the inverter does not operate normally.

  Even if only the upper arm is turned on as described above, the bootstrap circuit may not be fully charged or discharged at an extremely low speed during startup, and the inverter may not operate normally. .

  Therefore, in this embodiment, the reference modulation factor generation unit 20 in FIG. 1 is provided, and the larger one is selected from the reference modulation factor information 20a and the modulation factor KHV1 in the motor applied voltage V1, and the phase voltage after line modulation is selected. That is, the function for determining the motor applied voltage information 15 a is provided in the line modulation unit 15. At startup and at extremely low speed, the chopping operation of the inverter element is performed to prevent charging failure of the bootstrap circuit, and at the time of normal operation, high efficiency operation by two-phase line modulation with reduced switching loss is realized.

  FIG. 4 is an example of operation waveforms until two-phase line modulation including positioning and synchronous operation is performed. As shown in the figure, the voltage in the 60-degree period, which is the smallest phase application voltage or the largest phase application voltage among the three phases of the fundamental wave, is equal to or less than the maximum output voltage of the inverter circuit. The voltage level at this time is determined based on the 60-degree period modulation rate. Then, the difference between the 60-degree period voltage and the fundamental wave is added to the other phases in the same manner as during the two-phase line-to-line modulation to determine the three-phase applied voltage and output it as motor applied voltage information 15a.

  FIG. 5 exemplifies the flow of the modulation rate selection process in the interline modulation unit 15 and the process of determining the 60-degree period modulation rate of the phase that becomes a constant voltage for the 60-degree period. Also, as shown in the figure, after determining the 60-degree period modulation factor, this value is used as the reference modulation factor information 20a, which is the reference modulation factor for the next processing. In this embodiment, the initial value of the reference modulation factor information 20a is set to zero. The modulation rate increase amount is a predetermined constant, but may be considered as a variable depending on the rotation speed.

  FIG. 6 exemplifies changes in the modulation rate in each of the positioning, synchronous operation, and sensorless operation. As shown in FIG. 6, by setting the initial value of the reference modulation factor information 20a to zero, the modulation factor KHV1 is selected according to the motor applied voltage V1 during positioning and synchronous operation. At this time, since the modulation rate is smaller than the maximum value of the modulation rate, the upper and lower arms reliably perform the switching operation, so that it is possible to prevent charging failure of the bootstrap circuit.

<Startup and switching shockless at extremely low speed and normal operation>
On the other hand, when the startup is completed and the operation shifts to the normal operation, it is desirable to operate with high efficiency from the viewpoint of effective use of energy based on the global environment.

  For this reason, during normal operation, the process shifts to two-phase line modulation that reduces switching loss. Specifically, as shown in FIG. 6, in the sensorless operation, the 60-degree period modulation rate increases with time and reaches the maximum voltage value. When the maximum value is reached, the operation shifts to a state in which the one-phase chopping operation is not performed in the 60-degree period (modulation between two-phase lines).

  With these processes, when starting up including positioning and synchronous operation, the upper / lower arm switching operation is reliably performed, the modulation rate is gradually increased by 60 degrees after sensorless switching, and the modulation rate is gradually increased to the maximum value of the modulation rate. The rate is increased to shift to two-phase line modulation. Without changing the waveform generation method after line modulation, it only changes until the voltage increases gradually to the maximum voltage during the 60-degree period. In the normal operation after that, it operates with two-phase line modulation to reduce switching loss.

<Explanation of operation results>
7 and 8 show operation waveforms in this embodiment.

  Fig. 7 shows the operation waveforms during positioning and synchronous operation. In the figure, the internal calculation value of the applied voltage for one phase and the terminal voltage (voltage between the negative terminal side of the inverter and the motor terminal) are input. The output value of the low-pass filter (consisting of a resistor and a capacitor) is shown as an example. FIG. 8A is an operation waveform during normal operation, illustrating the terminal voltage (voltage between the negative terminal side of the inverter and the motor terminal) and the phase current of the motor. FIG. 8B is an operation waveform during normal operation, and a low-pass filter when an internal calculation value of the applied voltage for one phase and a terminal voltage (voltage between the negative terminal side of the inverter and the motor terminal) are input. Examples of output values (composed of resistors and capacitors) are shown. In FIG. 7, since the applied voltage has not reached the maximum value at the time of activation, it can be confirmed that the upper and lower arms are operating so as to switch. In FIG. 8 (a), the period during which the terminal voltage is maximum or minimum (zero) is a period during which no switching is performed. Therefore, during normal operation, the switching operation is stopped every period of 60 degrees electrical angle. It can be confirmed that the motor is driven. From these operation waveforms, it can be confirmed that the motor control is performed well.

  FIG. 7 and FIG. 8B show that the internal quantity is the same shape as the low-pass filter output of the PWM signal at the normal time during startup. This is because the PWM signal is determined by an internal quantity (phase applied voltage) and a carrier wave (carrier signal). Therefore, if the PWM signal is cut by a carrier wave component filter, the original phase applied voltage appears roughly as shown in FIGS. 7 and 8B of the specification. Thus, it can be seen that the waveform of the applied voltage, which is a feature of the present invention, appears in the PWM signal at the start and the PWM signal at the normal operation.

  In the embodiments shown so far, the motor current sensor 6 is used to detect the motor current information. However, if the algorithm of the present invention is used, the configuration of the motor current information extracted from the DC current flowing through the DC shunt resistor or the inverter circuit The same effect can be obtained in a configuration in which a shunt resistor is provided in the lower arm and motor current information is extracted from current information flowing therethrough. In the above embodiments, a permanent magnet motor is used as the motor. However, the same applies to other synchronous motors and induction motors such as a reluctance motor known as a synchronous reluctance motor having no permanent magnet. The effect is obtained.

  FIG. 9 is a block diagram showing an embodiment of the present invention in a configuration for extracting a motor current from a direct current flowing through a direct current shunt resistor.

This synchronous motor control device converts the voltage of the DC power source 1 into a pulse width modulated AC voltage and supplies it to the U-phase, V-phase, and W-phase three-phase stator windings of the synchronous motor 3. An inverter circuit 2 that rotates the synchronous motor 3, a control circuit (one-chip microcomputer or a hybrid IC using the same) 4 that performs control processing of the synchronous motor 3 in response to a speed command signal, A driver 5 for driving the inverter circuit 2 in accordance with the signal and a resistor 96 capable of detecting a DC current IDC input from the DC power source 1 to the inverter circuit 2 are provided. As shown in the figure, the inverter circuit 2 is an inverter in which three pairs of two switching element pairs connected in series are respectively connected between the positive terminal and the negative terminal of the DC power source, and the upper arm on the positive terminal side. The side is represented as U ⁺ , V ⁺ , W ⁺ , and the lower arm side of the negative terminal side is represented as U ⁻ , V ⁻ , W ⁻ .

The control circuit 4 constitutes a DC current detection circuit together with the resistor 96 to amplify a DC current detection voltage 96a that is a voltage of the resistor 96, and an output voltage 97a of the amplifier 97 is converted to A / A An A / D conversion unit 98 including an A / D conversion unit that samples and converts an analog value into a digital value in accordance with an A / D activation time 911a output from the D activation time determination unit 911, and an A / D conversion value 98a is divided into zero current information 99a and motor current information 99b based on the energization mode information 923a, and the selector 99 outputs A / D activation output from the energization mode information 923a and the A / D activation interval setting unit 912. An A / D activation time determining unit that determines the A / D activation time 911a from the interval Tw and the A / D sampling time 922a set by the A / D converter sampling time setting unit 922. 911, a motor current reproduction unit 913 that reproduces the motor current and outputs a motor current reproduction value 913a based on the conduction mode information 923a, the zero current information 99a, the motor current information 99b, and the three-phase motor current estimation value 916a, The 3φ / dq coordinate converter 914 that inputs the motor current reproduction value 913a and converts it to the d-axis q-axis current value 914a, the filter 915 that inputs the d-axis q-axis current 914a and outputs the average value 915a, and the average The dq / 3φ inverse conversion unit 916 that inputs the d-axis current and the q-axis current 915a and outputs the three-phase motor current estimated value 916a, the d-axis q-axis current 914a, the motor constant 926a, the speed command, the d-axis current command, And a motor applied voltage generator 917 that generates d-axis q-axis voltage command information 917a to be applied to the motor from the q-axis current command, and d-axis q-axis voltage command information 917a The dq / magnitude V1 conversion unit 918 that converts the magnitude V1 of the pressure and outputs the magnitude V1 information 918a of the motor applied voltage, and the modulation rate KHV1 information for the DC power source 1 from the magnitude V1 information 918a of the motor applied voltage 919a output magnitude V1 / modulation factor KHV1 converter 919, and modulation factor KHV1 information 919a for DC power supply 1 d-axis voltage modulation factor KHVd and q-axis voltage modulation factor KHVq for DC power supply 1 of the d-axis q-axis voltage command Modulation rate KHV1 / modulation rate Vd, Vq conversion unit 920 that outputs information 920a, and motor application for each of three phases before carrier period information and interline modulation from d-axis voltage modulation rate KHVd and q-axis voltage modulation rate KHVq information 920a Dq / 3φ voltage coordinate inverse transform unit 921 that outputs four pieces of information 921a combined with voltage, and three-phase motor applied voltage information before line modulation The line modulation unit 922 that outputs the modulation rate KHV1 for the DC power source 1 from 21a and the three-phase motor applied voltage information 922a after the line modulation from the reference modulation rate information 925a, and the three-phase motor after the carrier period information and the line modulation. PWM signal generation timer for outputting timer information 923b for generating a PWM signal from four pieces of information 922a combined with applied voltage information, and energization mode information 923a necessary for determining A / D conversion start time 911a and motor current reproduction An information unit 923, a PWM signal generation unit 924 that outputs a PWM signal 924a necessary for driving the inverter circuit 2 from timer information 923b for generating a PWM signal, and a reference modulation rate for determining reference modulation rate information 925a A generation unit 925.

  FIG. 10 is an enlarged schematic view illustrating the relationship between the phase applied voltage, the PWM signal, and the direct current according to the present invention. For comparison, similar signals are illustrated in FIG. 11 when the present invention is not applied.

In the present invention, with the above-described configuration, the motor current 913a is reproduced from the DC current information 96a flowing through the DC shunt resistor. At this time, by performing the processing of the present invention as in Example 1, the time interval between b and c in the figure can be increased as shown in FIG. 10 compared with FIG. 11 (Twbcn> Twbc). Before the A / D conversion at b is completed, the A / D conversion at c can be prevented from starting, and the motor current information can be reliably obtained from the direct current.

  On the other hand, as in the first embodiment, the upper / lower arm switching operation is surely performed at the start including positioning and synchronous operation, the modulation rate is gradually increased after the sensorless switching, and the operation is performed by the two-phase line modulation during the normal operation. Reducing switching loss. At this time, as described above, as in the case of the modulation between the two-phase lines, the voltage for the 60-degree period, which is the smallest phase application voltage or the largest phase application voltage among the three phases, is the minimum or maximum peak of the phase. It is equal to the voltage, and the difference between the voltage and the sinusoidal voltage before the interline modulation is added to the other phases to determine the three-phase applied voltage. After that, by gradually increasing the modulation rate to the limit of the modulation rate and shifting to the two-phase line modulation, there is no shock when switching, etc. Realize the transition.

  FIG. 12 is an example of a schematic diagram of a module 100 in which the inverter circuit 2 and the control circuit 4 of the synchronous motor control device to which the present invention is applied are incorporated in one package. When the control circuit of the synchronous motor control device of the present invention is used, a small and good motor control module capable of high-efficiency operation can be realized.

  FIG. 13 is an example of a schematic diagram of an air conditioner 110 provided with a synchronous motor control device 110a including a control circuit 4 to which the present invention is applied as a drive source of a compressor. When the synchronous motor control device of the present invention is used as a drive source for a compressor, a high-efficiency air conditioner capable of high-efficiency operation can be realized.

  Similarly, FIG. 14 is an example of a schematic diagram of a refrigerator 120 provided with a synchronous motor control device 120a including the control circuit 4 to which the present invention is applied as a drive source of a compressor for the refrigerator. When the motor control device of the present invention is used as a drive source for a compressor for a refrigerator, a highly efficient refrigerator that can be operated with high efficiency can be realized.

  FIG. 15 is a schematic diagram of a washing machine 130 provided with a motor control device to which the present invention is applied as a drive source of the washing machine. When the motor control device of the present invention is used as a driving source of a washing machine, an example of a good washing machine capable of high efficiency operation can be realized.

  FIG. 16 is an example of a schematic view of a cleaner 140 provided with a motor control device 140a to which the present invention is applied as a drive source of the cleaner. When a control device for a synchronous motor to which the present invention is applied is used as a driving source for a cleaner, a high-efficiency vacuum cleaner capable of high-efficiency operation can be realized.

  Further, when the motor control device to which the present invention is applied is used as a drive source, it is possible to realize a high-efficiency operation and good equipment.

  As described above, according to the present invention, since the switching element operates reliably, the charging operation of the bootstrap circuit at the time of starting the motor can be performed reliably.

  Further, according to the present invention, during normal operation, switching loss can be reduced and high-efficiency motor driving can be realized.

  In addition, according to the present invention, it is possible to realize high-efficiency motor driving without switching shocks when the motor is started and during normal operation.

  Also, according to the present invention, motor current information can be favorably obtained from a direct current even when the motor is started.

  By using this motor control device as a power source, a highly efficient and high quality air conditioner, refrigerator, washing machine, vacuum cleaner, and other devices can be realized.

1 is a block diagram illustrating an embodiment of a motor control device according to the present invention. An explanatory schematic diagram illustrating the relationship among a phase applied voltage, a carrier signal, and a PWM signal. FIG. 3 is an explanatory schematic view illustrating the relationship between a phase applied voltage, a carrier signal, and a PWM signal during two-phase line modulation according to the present embodiment. The flowchart which illustrates the algorithm of the modulation factor determination of a present Example. Explanatory drawing which illustrates the change of the modulation factor at the time of starting of a present Example. Explanatory schematic diagram illustrating the relationship between the phase applied voltage, the carrier signal, and the PWM signal excluding the two-phase line-to-line modulation of the present embodiment. The figure which illustrates the internal quantity of the phase terminal voltage and phase applied voltage at the time of starting in an Example. The figure which illustrates the phase terminal voltage and motor current waveform at the time of the normal driving | operation in an Example. 1 is a block diagram illustrating an embodiment of a motor control device according to the present invention. The schematic diagram which illustrates the phase application voltage, PWM signal, and direct current in an Example. The schematic diagram which illustrates the phase application voltage, PWM signal, and direct current when not applying this invention. The schematic diagram which illustrates the module of the synchronous motor control apparatus which becomes this invention. The schematic diagram of an example of the air conditioner which uses the synchronous motor control apparatus which becomes this invention as a drive source. The schematic diagram of an example of the refrigerator which uses the synchronous motor control apparatus which becomes this invention as a drive source. The schematic diagram of an example of the washing machine which uses the synchronous motor control apparatus which becomes this invention as a drive source. The schematic diagram of an example of the cleaner which uses the synchronous motor control apparatus which becomes this invention as a drive source. FIG. 6 is an explanatory schematic diagram illustrating the operation of a bootstrap circuit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... DC power supply, 2 ... Inverter circuit, 3 ... Synchronous motor, 4 ... Control circuit, 5 ... Driver, 6 ... Motor current sensor, 6a ... Output signal of motor current sensor, 7 ... A / D converter, 7a ... A / D conversion value, 8 ... motor current information section, 8a ... motor current information, 9 ... 3φ / dq coordinate conversion section, 9a ... d-axis q-axis current, 10 ... motor applied voltage generation section, 10a ... d-axis q-axis voltage Command information, 11 ... dq voltage / magnitude V1 converter, 11a ... Motor applied voltage magnitude V1 information, 12 ... Voltage magnitude V1 / modulation factor KHV1 converter, 14 ... dq / 3φ inverse converter, 14a ... 3-phase Motor applied voltage information, 15 ... line modulation section, 15a ... motor applied voltage information, 16 ... PWM signal generation timer information section, 16a ... PWM signal generation timer information, 17 ... PWM signal generation section, 17a ... PWM signal, 18 ... Motor constant Part 18a motor constant information 19 carrier period information generator 19a carrier period information 20 reference modulation rate generator 20a reference modulation rate information

Claims (12)

Motor control having a drive circuit that drives a switching element of a three-phase PWM inverter that converts direct current to alternating current, and a control unit that outputs a three-phase PWM signal obtained by comparing the three-phase applied voltage and a carrier wave to the drive circuit In the device
Wherein the three-phase applied voltage, with the same waveform generation method in a time three-phase modulation operation and two-phase modulation operation, every electrical angle predetermined value period maximum phase and the minimum phase are substantially constant alternating A motor control device. In claim 1,
The motor control device according to claim 1, wherein the electrical angle predetermined value period is substantially every electrical angle 60 degree period. In claim 1,
The motor control device according to claim 1, wherein when the motor is started, the substantially constant value is smaller than an amplitude of a carrier wave. In claim 1,
When the motor is started, the upper and lower arms of the switching element are always switched during the electrical angle predetermined value period. In claim 1,
During normal operation, the motor control device is characterized in that the substantially constant value is less than or equal to the amplitude of a carrier wave. In claim 1,
During normal operation, the motor control device is characterized in that the switching element does not switch in any phase during the electrical angle predetermined value period. In claim 1,
A motor control device that determines an applied voltage of each phase based on an applied voltage of a phase having a substantially constant value.   A power module comprising the motor control device according to claim 1.   An air conditioner comprising a compressor and / or a blower controlled by the motor control device according to claim 1.   A refrigerator having a compressor and / or a blower controlled by the motor control device according to any one of claims 1 to 7.   A washing machine comprising the motor control device according to any one of claims 1 to 7.   A vacuum cleaner comprising the motor control device according to claim 1.

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