JP2005318702A - Motor controller and apparatus employing it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor controller operating with high efficiency in which high efficiency points of both two-phase line modulation and three-phase line modulation can be taken in any rotational region. <P>SOLUTION: In the motor controller comprising the drive circuit of a switching element in a three-phase PWM inverter for inverting DC power into AC power, and a control section outputting a three-phase PWM signal being obtained through comparison of a three-phase applying voltage and a carrier to the drive circuit, a decision is made whether the switching element is switched or not at some phase during a period of 60° electric angle of the three-phase applying voltage based on the r.p.m. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

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

  In a motor drive device, in order to pass a sine wave current to a synchronous motor, a triangular wave carrier signal is generally compared with a sine wave that is an applied voltage of each phase to generate a PWM signal. Interline modulation is used. Also, in order to reduce the loss in the inverter circuit, the specific one-phase voltage among the three-phase voltages applied to the motor is made constant, and the line voltage applied to the motor is kept constant before and after the line modulation. In addition, two-phase line-to-line modulation, which is a line-to-line modulation method that modulates between the remaining two-phase lines, is also used.

  On the other hand, the energy loss in the inverter and the energy loss in the motor are different between the two-phase line modulation and the three-phase line modulation. In addition, the amount of energy loss that combines the energy loss in the inverter and the energy loss in the motor also varies depending on the size of the inverter circuit, the motor, and the amount of current. In order to control, it is necessary to grasp whether the two-phase line modulation or the three-phase line modulation is efficient under the motor driving conditions, and use either the two-phase line modulation or the three-phase line modulation. Was. However, one of two-phase line-to-line modulation and three-phase line-to-line modulation is not always efficient, and the effective control differs depending on conditions. Both of the two efficient points could not be used.

  In the conventional method, since the two-phase line modulation and the three-phase line modulation are used independently, the optimum high-efficiency control cannot be performed depending on the conditions.

  An object of the present invention is to switch between two-phase line modulation and three-phase line modulation depending on the number of rotations, and to perform optimum high-efficiency control in any rotation region.

  The motor control device of the present invention has a function of switching between two-phase line modulation and three-phase line modulation depending on the rotation speed.

  According to the characteristics of the present invention, the two-phase line modulation and the three-phase line modulation are switched depending on the rotation speed, and optimum high-efficiency control can be performed in any rotation region.

(Example 1)
Hereinafter, an embodiment of a motor control device using a permanent magnet synchronous motor will be described as an example of the present invention.

  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 voltage 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 conversion unit 7 including an A / D conversion unit that converts an 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 current 9a converted from three-phase current by unit 9 and motor constant 18a, speed command, d-axis current command, and d-axis q-axis voltage command information 10a calculated from q-axis current command A generator 10; a dq / magnitude V1 converter 11 that converts the d-axis q-axis voltage command information 10a into a voltage magnitude V1 and outputs a motor applied voltage magnitude V1 information 11a; and a motor applied voltage magnitude. From the V1 information 11a, the modulation rate KHV for the power supply voltage 1 1 information 12a is converted into voltage magnitude V1 / modulation rate KHV1 converter 12 and modulation rate KHV1 information 12a for power supply voltage 1 d-axis voltage modulation rate KHVd and q-axis voltage modulation rate of d-axis q-axis voltage command for power supply voltage 1 Modulation rate KHV1 / modulation rate Vd, Vq conversion unit 13 that outputs KHVq information 13a, and d-axis voltage modulation rate KHVd and q-axis voltage modulation rate KHVq information 13a to three-phase motor applied voltage information 14a before line modulation Output dq / 3φ voltage inverse conversion unit 14, modulation rate KHV1, 60 degree period modulation rate information 20a and two-phase three-phase line-to-line modulation determination for power supply voltage 1 from three-phase motor applied voltage information 14a before line modulation The line modulator 15 for outputting the three-phase motor applied voltage information 15a after the line modulation from the information 21a, and the PWM signal is generated from the three-phase motor applied voltage information 15a after the line modulation and the carrier cycle information 19a. The PWM signal generation timer information unit 16 that outputs the PWM signal generation timer information 16a and the PWM signal generation type PWM signal generation unit 17 that outputs PWM signal 17a necessary for driving inverter 2 from information 16a, carrier cycle information generation unit 19 that outputs carrier cycle information 19a, and 60-degree period modulation rate information 20a are determined. A 60-degree period modulation factor generation unit 20 and a two-phase three-phase determination unit 21 that determines two-phase line modulation and three-phase line modulation from a speed command and outputs two-phase three-phase determination information 21a are provided.

Each main part and operation will be described below.
<Create PWM signal (Principle explanation)>
FIG. 2 is an example of a diagram schematically illustrating 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, as shown in the figure, switching is generally turned on / off at the point where the carrier signal indicated by a triangular wave and the signal waves Vu, Vv, and Vw indicated by sine waves that are applied to each phase intersect. A so-called PWM signal is generated by a PWM signal generator, and the six switching elements constituting the inverter circuit are switched in accordance with this signal to apply a voltage to the motor. Here, when the level of the PWM signal is Hi in the figure, the upper arm of the inverter circuit is turned on, and when the level is Low, the lower arm is turned 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 15a 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 realized so as to realize the phase voltages Vu, Vv, Vw of the carrier cycle information 19a and the motor applied voltage information 15a. Four types of timer information 16a are determined.

Then, the PWM signal generation unit 17 operates the up / down type timer according to the timer information 16a to create a signal that is turned on / off when the time data representing the voltage of each phase matches the timer value, The PWM signal 17a is realized.
<Outline of two-phase line modulation>
However, in the above method, as can be seen from FIG. 2, three phases (six elements) are always switched every PWM period. Further, switching loss occurs in each element with switching.

  In the present embodiment, in order to avoid this and reduce the switching loss, the two-phase line modulation is performed in the set rotation speed region. 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 sinusoidal 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 the two-phase line-to-line modulation, the voltage that crosses the carrier signal by fixing the voltage at the electrical angle 60 degree period of the phase that is the minimum voltage or maximum voltage in the fundamental wave at any time to the inverter minimum output voltage or maximum output voltage. 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 non-switching electrical angle 60 degree period, 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.
<Necessary processing at startup>
On the other hand, when the operation is performed from the motor stop state, a so-called low-frequency synchronous activation method is used in which synchronous operation by an 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 that 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 the present embodiment, the reference modulation factor generation unit 20 in FIG. 1 is provided, and the larger one of the reference modulation factor 20a and the modulation factor KHV1 in the motor applied voltage V1 is selected, and the phase voltage after line modulation, That is, the function for determining the interline modulation information 15a is provided in the interline modulation unit 15. At start-up and at extremely low speeds, the chopping operation of the inverter element is performed to prevent charging failure of the bootstrap circuit, and at the time of normal operation and in the set rotation speed range, the switching loss is reduced due to the high-frequency modulation between the two phases. Realize efficient operation.

  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 applied voltage or the largest phase applied voltage among the three phases of the fundamental wave, is less than or equal to 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 in the two-phase line-to-line modulation, the three-phase applied voltage is determined, and is output as the line modulation information 15a.

  FIG. 5 exemplifies the flow of the modulation rate selection process in the inter-line 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. Further, as shown in the figure, after determining the 60-degree period modulation factor, this value is set as the reference modulation factor 20a, which is used as the reference modulation factor for the next processing. In this embodiment, the initial value of the reference modulation factor 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 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 the normal operation and in the set rotation speed range, the process shifts to the two-phase line modulation that reduces the 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 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 and lower arm switching operations are performed reliably, 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, the voltage only gradually changes until the voltage increases gradually until it reaches the maximum voltage, so there is no shock when switching, etc. Smooth transitions are realized, and during the subsequent normal operation and in the set rotation region, operation is performed with two-phase line modulation to reduce switching loss.
<Outline of 2-phase line modulation and 3-phase line modulation switching>
FIG. 7 is an example showing the efficiency with respect to the rotational speed of the two-phase line modulation and the three-phase line modulation. Two-phase line-to-line modulation can reduce switching loss, but the overall efficiency of the total energy loss in the inverter and the motor in the motor can be reduced between the three-phase lines rather than the two-phase line-to-line modulation depending on the rotation region. Modulation may be more efficient. Therefore, by experiment, it is determined in which rotation region the control between the two-phase line modulation and the three-phase line modulation is efficient, and the control is switched to the efficient control depending on the rotation region. Thereby, it is possible to realize optimal high-efficiency control in any rotation region.

  FIG. 8 illustrates the flow of the switching process between the two-phase line modulation and the three-phase line modulation.

In the two-phase / three-phase determination unit 21, the three-phase switching flag is enabled when the motor rotation speed is larger than the switching rotation speed setting value, and the three-phase switching flag is disabled when the motor rotation speed is smaller than the switching rotation speed setting value. . When the three-phase switching flag is valid in the line-to-line modulator 15, three-phase line modulation is performed. When the three-phase switching flag is invalid, two-phase line modulation is performed.
<Explanation of operation results>
9 and 10 show operation waveforms in this embodiment.

  FIG. 9 is an operation waveform at the time of positioning and synchronous operation. In the figure, an internal calculation value of applied voltage for one phase and a 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. 10 is an operation waveform during normal operation, and illustrates the terminal voltage (voltage between the negative terminal side of the inverter and the motor terminal) and the motor phase current. Further, in FIG. 10, the period in which the terminal voltage is maximum or minimum (zero) is a period in which switching is not performed. Therefore, during normal operation, the switching operation is stopped for each period of 60 electrical degrees and the motor is driven. You can confirm that From these operation waveforms, it can be confirmed that the motor control is performed well.

  In the embodiments shown so far, the motor current sensor 6 is used to detect the motor current information. However, the motor current information is extracted from the DC current flowing through the DC shunt resistor, and a shunt resistor is provided on the lower arm of the inverter circuit. The same effect can be obtained in the configuration in which the motor current information is extracted from the current information flowing there. 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.

(Example 2)
FIG. 11 is a block diagram showing an embodiment of the present invention in a configuration for extracting a motor current from a direct current flowing in 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 voltage 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 which 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 according to 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 on the basis of energization mode information 923a, and the selector 99 outputs the A / D activation output from the energization mode information 923a and the A / D activation interval setting unit 912. A / D activation time determination unit 911 for determining A / D activation time 911a from interval Tw and A / D sampling time 922a set by A / D converter sampling time setting device 922, energization mode information 923a and zero Current information 99a, motor current information 99b and three-phase motor current estimation Based on the constant value 916a, the motor current reproduction unit 913 that reproduces the motor current and outputs the motor current reproduction value 913a, and the 3φ / dq coordinate that inputs the motor current reproduction value 913a and converts it into the d-axis q-axis current value 914a The conversion unit 914, the filter 915 that inputs the d-axis q-axis current 914a and outputs the average value 915a, the averaged d-axis current and the q-axis current 915a are input, and the three-phase motor current estimated value 916a is output. A motor that generates d-axis q-axis voltage command information 917a to be applied to the motor from the dq / 3φ inverse conversion unit 916 and the d-axis q-axis current 914a, the motor constant 926a, the speed command, the d-axis current command, and the q-axis current command Applied voltage generator 917, dq / magnitude V1 converter 918 for converting d-axis q-axis voltage command information 917a into voltage magnitude V1 and outputting motor applied voltage magnitude V1 information 918a, motor applied voltage The modulation rate KHV1 information 919a for the power supply voltage 1 is output from the magnitude V1 information 918a. The magnitude V1 / modulation rate KHV1 converter 919 and the modulation rate KHV1 information 919a for the power supply voltage 1 to the d-axis voltage modulation rate KHVd and the q-axis voltage modulation rate KHVq information 920a for the power supply voltage 1 of the d-axis q-axis voltage command Modulation rate KHV1 / modulation rate VdVq conversion unit 920, d-axis voltage modulation rate KHVd, and q-axis voltage modulation rate KHVq information 920a are combined with carrier period information and motor applied voltage for each of the three phases before line modulation. Dq / 3φ voltage coordinate inverse transform unit 921 that outputs four pieces of information 921a, three-phase motor applied voltage information 921a before line modulation, modulation rate KHV1, reference modulation rate information 925a, and two-phase three-phase determination for power supply voltage 1 The PWM signal from the line modulation unit 928 that outputs the three-phase motor applied voltage information 928a after the line modulation from the information 927a, and the four information 928a that combines the carrier period information and the three-phase motor applied voltage information after the line modulation. Information 923b and A / D conversion PWM signal generation timer information unit 923 that outputs energization mode information 923a necessary for determination of dynamic time 911a and motor current reproduction, and a PWM signal necessary for driving inverter 2 from timer information 923b for generating a PWM signal PWM signal generation unit 924 that outputs 924a, reference modulation rate generation unit 925 that determines reference modulation rate information 925a, and two-phase three-phase determination unit that determines two-phase line modulation and three-phase line modulation from a speed command 927.

  FIG. 12 is an enlarged schematic view illustrating the relationship among the phase application voltage, the PWM signal, and the direct current. For comparison, a similar signal is illustrated in FIG. 13 when the reference modulation rate is not used.

  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, as in the first embodiment, by processing the reference modulation rate, as shown in FIG. 12, the time interval between b and c in the figure can be widened (Twbcn> Twbc) as compared with FIG. , B can be prevented from starting A / D conversion before the end of A / D conversion at b, and 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, and 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, among the three phases, the voltage of the 60-degree period that is the smallest phase application voltage or the largest phase application voltage 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.

Example 3
FIG. 14 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. 15 is an example of a schematic diagram of an air conditioner 110 provided with a synchronous motor control device 110a including the control circuit 4 to which the present invention is applied as a drive source of the 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. 16 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. 17 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. 18 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.

  According to the present invention, high-efficiency motor driving can be realized in any rotation region by switching between two-phase line modulation or three-phase line modulation depending on the number of rotations.

  And 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. FIG. 3 is an explanatory schematic view illustrating the relationship among a phase applied voltage, a carrier signal, and a PWM signal. FIG. 3 is an explanatory schematic diagram 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. Explanatory schematic diagram illustrating the relationship between the carrier signal and the PWM signal until the two-phase line modulation including the positioning and synchronous operation of 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. The figure which shows the efficiency with respect to the rotation speed of 2 phase line modulation | alteration and 3 phase line modulation | alteration of a present Example. Explanatory drawing which illustrates the algorithm of the switching process of 2 phase line modulation | alteration and 3 phase line modulation | alteration of a present Example. 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 in an Example, a PWM signal, and a direct current. The schematic diagram which illustrates the phase application voltage, PWM signal, and direct current when not applying a reference modulation factor. The schematic diagram which illustrates the module of the motive 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 ... d-axis q-axis voltage / voltage magnitude V1 converter, 11a ... motor applied voltage magnitude V1 information, 12 ... voltage magnitude V1 / modulation factor KHV1 converter, 12a ... modulation factor KHV1 information, 13 ... Modulation rate KHV1 / modulation rate VdVq conversion unit, 13a ... modulation rate VdVq information, 14 ... dq / 3φ inverse conversion unit, 14a ... 3-phase motor applied voltage information, 15 ... line modulation unit, 15a ... 3 after line modulation Phase 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 cycle information generation part, 19a ... carrier cycle information, 20 ... reference modulation rate generation part, 20a ... reference modulation rate information, 21 ... two phase 3 Phase determination unit, 21a ... 2-phase 3-phase determination information.

Claims (6)

Motor control having a drive circuit that drives a switching element of a three-phase PWM inverter that converts direct current into 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
A motor control device characterized by switching whether or not the switching element performs switching in any phase during a period in which a three-phase applied voltage is at an electrical angle of 60 degrees.   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 claim 1.   A washing machine comprising the motor control device according to claim 1. A vacuum cleaner comprising the motor control device according to claim 1.

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