JP4852867B2 - Motor drive system and motor drive method - Google Patents

Description

  The present invention relates to a motor driving system and a motor driving method for converting electric power from a DC power source into AC power and driving a motor with AC power.

  In a general motor drive system, a motor drive device opens and closes an internal semiconductor switching element (inverter) in response to a control signal from a control device, and converts power from a DC power source into three-phase AC power. The motor to be controlled is driven with AC power.

  In such a motor drive system, electromagnetic noise (hereinafter referred to as EMI (Electro-Magnetic Interface) noise) is generated during power conversion and conversion from electric power in the motor to physical power. It has been known. Specific examples include switching noise due to opening and closing of a semiconductor switch inside the motor driving device, a DC cable for transmitting DC power between the DC power source and the motor driving device, and a three-phase AC between the motor driving device and the motor. There are radiation noise generated by transmitting a three-phase cable for transmitting power, noise generated due to a change in the magnetic field for rotating the motor inside the motor, noise generated in signal processing in the control device, and the like.

  These EMI noises may cause malfunctions to electronic devices and the like, and may cause communication failures to various communication devices such as radio receivers. Therefore, various countermeasure methods for suppressing them have been considered and implemented.

  As a main countermeasure method, first, there is a method of shielding the entire motor drive system so that EMI noise generated from the motor drive system does not leak outside. In addition, a filter is formed in the cable that connects between the DC power supply and the motor drive device, the motor drive device and the motor, and transmits power, and the filter acts as a high frequency noise from the motor drive device to the DC cable and the three-phase cable. Is transmitted, and radiation noise generated with conduction noise is further suppressed. Examples of the filter in this case include a ferrite core, a choke coil, and a filter circuit.

  However, the countermeasure method for suppressing such EMI noise has the following problems. First, in the shield system, it may be difficult to realize a complete shield. For example, since heat is generated in a semiconductor switch or the like by operating a motor drive system, it is necessary to cool the generated device. For this purpose, for example, a countermeasure such as providing air holes for air cooling in and out can be considered. However, by providing holes, EMI noise leaks from the holes, and there is a problem that it is not possible to reliably suppress the failure of EMI noise to other systems.

  On the other hand, in the filter system, the necessary signal is transmitted and only the unnecessary noise is cut off so that the frequency characteristics are designed. It is impossible with today's technology to achieve a realistic filter. In addition, various countermeasures for suppressing EMI noise have been considered, but all have problems such as an increase in cost and an increase in volume and weight.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a motor drive system and a motor drive method that can reliably suppress the failure of EMI noise to other systems.

In order to achieve this object, in the motor drive system and motor drive method of the present invention, avoidance frequency setting means for setting a frequency value of EMI noise that is not desired to be generated among EMI noises generated from the motor drive system, and avoidance Carrier frequency determining means for determining a carrier frequency so as not to generate a peak group of a noise spectrum of EMI noise with the frequency value set by the frequency setting means.

In the motor drive system and the motor drive method according to the present invention, the carrier frequency determining means does not generate a peak group of the noise spectrum of the EMI noise with the frequency value output from the avoidance frequency setting means. Since the generation of EMI noise having a frequency that is not desired to be generated among the EMI noises to be generated can be suppressed, it is possible to reliably suppress a failure of the EMI noise to other systems.

First Embodiment FIG. 1 is a diagram showing a basic configuration of a first embodiment. Reference numeral 13 is a motor to be controlled, 11 is a DC power source for supplying power to the motor 13, 14 is a control device for outputting a command rotational speed signal (control signal) to the motor drive device 12, and 12 is DC power from the DC power source 11. Is converted into three-phase alternating current power and supplied to the motor 13, and the motor 13 is driven at the command speed by the switching action of the semiconductor element in response to a command speed signal from the control device 14.

The control device 14 includes a noise peak group avoidance frequency setting means 15 (avoidance frequency setting means) for determining a frequency value of EMI noise that is not desired to be generated among EMI noises generated from the motor drive system, and a noise peak group avoidance frequency setting. Carrier frequency determining means 17 for determining a carrier frequency so as not to generate a peak group of the noise spectrum of the EMI noise with the frequency value set by the means 15 is provided.

  Further, the control device 14 records a correlation between the motor rotation number detecting means 19 for detecting the rotation number of the motor 13 and the peak group of the rotation frequency of the motor 13, the carrier frequency, and the noise spectrum of the EMI noise as a map. Information recording means 16. Reference numeral 18 denotes command value generation means for outputting a rotation speed command signal to the motor drive device 12.

  Here, the noise peak group avoidance frequency setting means 15 is a frequency value that becomes an obstacle to electronic devices such as communication devices used around the motor drive system among EMI noises generated by the operation of the motor drive system. And the frequency value that becomes an obstacle is output to the carrier frequency determining means 17. For example, if another system used simultaneously around the motor drive system malfunctions in response to 500 kHz EMI noise, the peak group of the noise spectrum of the EMI noise generated from the motor drive system is 500 kHz. Is output to the carrier frequency determining means 17 so that the frequency value to be avoided is 500 kHz.

  The carrier frequency determining means 17 determines the frequency value of the carrier frequency for switching the semiconductor element corresponding to the command rotational speed of the motor 13. In this case, the carrier frequency of the frequency value set by the noise peak group avoidance frequency setting means 15 is not generated. That is, the carrier frequency is determined so that the peak group of the noise spectrum of the EMI noise determined by the rotation speed of the motor 13 does not occur in the frequency band set by the noise peak group avoidance frequency setting means 15.

  The command value generation means 18 receives a rotation speed command signal for driving the motor 13 from the carrier frequency determination means 17 and outputs it as a control signal to the motor drive device 12.

In the above configuration, DC power from the DC power source 11 is converted into three-phase AC power by the motor driving device 12 and transmitted to the motor 13. In this case, the motor drive device 12 receives a control signal from the control device 14 and converts the DC power into three-phase AC power by opening and closing an internal semiconductor switch. In the control device 14, the carrier frequency determination unit 17 determines the carrier frequency based on the frequency value output from the noise peak group avoidance frequency setting unit 15 so as not to generate a peak group of the noise spectrum of EMI noise .

  FIG. 2 is a diagram illustrating an example of a noise spectrum of EMI noise generated from the motor drive system when the motor drive system is operated. The carrier frequency determination method performed by the carrier frequency determination means 17 will be described with reference to FIG. 2 (a) and 2 (b) show the noise spectrum of EMI noise when the motor speed is N1 (rpm) and the carrier frequencies are fc1 and fc2, respectively. FIGS. 2 (c) and 2 (d) show the motor speed. It is a noise spectrum of EMI noise when the carrier frequency is N2 (rpm) and fc1 and fc2, respectively. In each figure, the horizontal axis represents the noise frequency and the vertical axis represents the noise level.

  From these spectrum distributions, the noise spectrum of EMI noise generated when the motor drive system operates has a spectrum of harmonic frequencies of carrier frequencies, which are fine spectra at each noise frequency, and these spectra form a group. It can be seen that it is formed in the irregular shape shown by the envelope. Then, the correlation of the number of rotations of the motor 13, the carrier frequency, and the peak group of the noise spectrum of the EMI noise illustrated in FIG. 2 is recorded in the noise correlation information recording means 16.

  When the convex regions indicated by the envelopes in each diagram of FIG. 2 are called peak groups, these peak groups depend on the motor rotation speeds N1 and N2 and the carrier frequencies fc1 and fc2, respectively. Furthermore, it can be seen that the center frequency of the peak group is proportional to the carrier frequencies fc1 and fc2, and inversely proportional to the motor rotational speeds N1 and N2. Therefore, if this relationship is used, the carrier frequency can be set so that no peak group is formed in the specific frequency band set by the noise peak group avoidance frequency setting means 15 at the desired motor speed. .

  Next, how the carrier frequency determining means 17 determines the carrier frequency will be described. When the carrier frequency is fc (Hz) and the motor rotation speed is N (rpm), the center frequency fp, n of the peak group is expressed as follows.

fp, n = n ・ A ・ fc / N where n is an integer and A is a proportional constant. Other electronic devices that are affected by EMI noise of the frequency fb (Hz) generated from the motor drive system are nearby. Assuming that the EMI noise generated from the motor drive system does not form a peak group at the frequency fb, the influence of the EMI noise on other electronic devices can be suppressed. For this purpose, the frequency fb may be between adjacent peak groups fp, n and fp, n + 1. Therefore, the following equation holds.

fp, n <fb <fp, n + 1
∴n ・ A ・ fc / N <fb <(n + 1) ・ A ・ fc / N
Here, the motor rotation speed N is a value determined by a request for the rotation speed of the motor 13 to be realized. Further, since the carrier frequency fc is a switching frequency in the motor driving device 12, the variable range is determined by its loss, heat generation, suppression of noise during operation, and the like. Accordingly, in the frequency spectrum of EMI noise, the value of the integer n is determined so that the frequency fb is located in an appropriate concave region avoiding the peak group, and the carrier frequency fc is determined within the variable range. Can be realized.

Next, the operation of the motor drive system of the present invention, that is, the motor drive method of the present embodiment will be described. The control device 14 outputs a command rotational speed signal to the motor drive device 12, and the motor drive device 12 drives the motor 13 to be controlled at the command rotational speed by the switching action of the semiconductor element in accordance with the command rotational speed signal. To do. In this case, the noise peak group avoidance frequency setting means 15 sets the frequency value of the EMI noise that is not desired to be generated among the EMI noises generated from the motor drive system. The frequency | count of the switching of the semiconductor element corresponding to the number is calculated, and the frequency value of the carrier frequency which performs switching is determined. At this time, the peak group of the noise spectrum of the EMI noise is not generated with the frequency value set by the noise peak group avoidance frequency setting means 15.

With the configuration described above, the carrier frequency determination unit 17 can prevent the generation of the peak group of the noise spectrum of the EMI noise at the frequency value that is output from the avoidance frequency setting unit and is not desired to be generated. Therefore, it is possible to reliably suppress the occurrence of a failure in other electronic devices and systems installed nearby that are affected by the EMI noise in this band.

  Note that a general EMI noise countermeasure method is often a so-called post-measurement that is performed according to the evaluation result of EMI noise generated by operating an actual machine after designing the device. When post-measures are required, a cycle of redesigning the equipment and subsequent re-evaluation is performed, but these measures may be taken many times. The problem of an increase in Since the present invention is not such a post-measure, it is possible to suppress an increase in cost, an increase in volume and weight, an increase in development period, and the like due to the post-measure.

  Further, the control device 14 records the correlation of the rotation number of the motor 13, the carrier frequency, and the peak group of the noise spectrum as the noise correlation information recording means 16, and the carrier frequency so that the peak group of the noise spectrum deviates in a specific frequency band. Therefore, it is possible to easily and reliably determine the carrier frequency for causing the peak group of the noise spectrum of the EMI noise to deviate from a specific band. With the operation of the motor drive system, The failure of the generated EMI noise to other systems can be reliably suppressed.

Second Embodiment FIG. 3 is a diagram illustrating a basic configuration of a second embodiment. The motor drive system of the present embodiment has a receiving device 23 that selects and receives a broadcast wave, and the control device 24 has a receiving channel frequency detecting means 25 that detects the receiving channel frequency of the receiving device 23, The frequency value of the EMI noise that is not desired to be generated is the frequency value of the reception channel frequency, and the avoidance frequency setting means is the reception channel frequency detection means 25.

  The receiving device 23 is arranged in the vicinity of the motor drive system, and is capable of selecting and receiving / listening to a favorite broadcast wave by switching a receiving channel frequency such as a radio receiver or a television receiver. . That is, in this embodiment, the noise peak group avoidance frequency setting means 15 in the first embodiment is replaced with a reception channel frequency detection means 25 that detects information on the reception channel frequency of the reception device 23.

In addition, the control device 24 includes a motor rotation number detection unit 29 that detects the rotation number of the motor 13, a noise correlation information recording unit 26 that records a correlation between the rotation number of the motor 13, the carrier frequency, and the reception channel frequency, and a reception channel. Carrier frequency determining means 27 for determining the carrier frequency so as not to generate a peak group of the noise spectrum of the EMI noise with the frequency value detected by the frequency detecting means 25, and a command value for outputting the rotational speed command signal to the motor drive device 12. Generating means 28.

  That is, in the noise correlation information recording means 16 in the first embodiment, “correlation of the rotation speed of the motor 13, the carrier frequency and the frequency of the noise peak group” is stored. In the noise correlation information recording means 26 in FIG. 6, “correlation of the rotational speed of the motor 13, the carrier frequency and the reception channel frequency” is stored. In the present embodiment, a carrier frequency determined in advance may be stored so that the noise peak group and the reception channel frequency do not overlap from the reception channel and the motor rotation speed at that time. Other configurations and operations are the same as those of the first embodiment.

  Next, a method for determining a carrier frequency in the present embodiment will be described with reference to FIG. First, the noise spectrum of the EMI noise generated when the motor rotation speed is N1 (rpm) will be described with reference to FIGS. 4 (a) and 4 (b). 4A and 4B show actual measurement examples when the carrier frequencies are fc1 (Hz) and fc2 (Hz), respectively. For example, when the reception channel frequency is CH1 shown in the figure, the reception channel frequency of CH1 exists in the frequency band of the peak group of the noise spectrum at the carrier frequency fc1 (FIG. 4A). There is a possibility that it becomes an obstacle to the reception of CH1.

  On the other hand, when the carrier frequency is fc2, the reception channel frequency of CH1 is located between adjacent peak groups of the EMI noise spectrum (FIG. 4B). Therefore, compared with the case where the carrier frequency is fc1, the influence of EMI noise can be suppressed. However, receiving the reception channel frequency CH2 is the reverse of the case of the reception channel frequency CH1 described above. That is, when the carrier frequency is fc2, the reception channel frequency of CH2 exists in the frequency band of the peak group, but when the carrier frequency is fc1, the peak group can be avoided.

  Next, FIGS. 4C and 4D show EMI noise spectra when the motor rotation speed is not N1 but N2. In this case, it can be seen that the appropriate carrier frequency is different from that in FIGS. 4A and 4B even if the reception channel frequencies CH1 and CH2 are the same because the motor rotation speed has changed from N1 to N2. . That is, when the carrier frequency is fc1, the reception channel frequency of CH1 is out of the frequency band of the peak group, but the reception channel frequency of CH2 exists (FIG. 4C). On the other hand, if the carrier frequency is fc2, the CH1 reception channel frequency is present in the peak band frequency band, but the CH2 reception channel frequency deviates (FIG. 4 (d)). Thus, in order to realize the desired number of rotations of the motor 13 and suppress the influence of the noise peak group on the reception channel frequency at that time, the carrier frequency is changed, so that the EMI noise from the motor drive system is reduced. It becomes possible to suppress the influence.

  As described above, the present embodiment has been described using examples. However, the present invention is not limited to the above-described embodiment. For example, although the motor drive device 12 has been described by taking an inverter that converts direct current to three-phase alternating current as an example, the present invention is not limited to this, and the same effect can be obtained with other power converter configurations.

  In the present embodiment, the carrier frequency is determined so that the reception frequency received by reception device 23 is out of the band of the peak group of the noise spectrum of EMI noise, and EMI generated when the motor drive system operates. It becomes possible to suppress a reception failure that noise gives to a receiving device such as a radio.

  In addition, in the case of the desired motor 13 rotation speed, it is owned as a map of the correlation between the motor 13 rotation speed, the reception channel frequency and the carrier frequency so that the reception channel frequency deviates from the peak group in the noise spectrum of EMI noise Therefore, even when the reception frequency changes variously, it is possible to easily suppress the reception failure to the reception device 23 such as a radio caused by the motor drive system.

Third Embodiment FIG. 5 is a diagram showing a basic configuration of a third embodiment. The control device 34 includes a noise peak group avoidance frequency setting unit 35 that sets a frequency value that becomes an obstacle to electronic devices among EMI noises, and outputs the set frequency value to the carrier frequency determination unit 37. The setting means is a noise peak group avoidance frequency setting means 35. That is, the noise peak group avoidance frequency setting means 35 sets a frequency value so that the peak group of the EMI noise noise spectrum generated by the operation of the motor drive system does not become an obstacle to other systems, and determines the carrier frequency. It outputs to the means 37.

Further, the control device 34 uses the noise peak group frequency band detecting means 32 for detecting the frequency band of the peak group of the noise spectrum of the EMI noise and the noise value of the EMI noise with the frequency value set by the noise peak group avoidance frequency setting means 35. Carrier frequency determining means 37 for determining a carrier frequency so as not to generate a spectrum peak group, and command value generating means 38 for outputting a rotation speed command signal to the motor drive device 12 are provided.

  FIG. 6 is a diagram illustrating a configuration example of the noise peak group frequency band detection unit 32. Reference numeral 81 is an antenna, 82 is a noise spectrum detection means, 83 is a memory (storage means), 84 is a spectrum envelope calculation means, and 85 is a noise peak group frequency band calculation means.

  That is, the noise peak group frequency band detection means 32 stores the noise spectrum detection means 82 for detecting the noise spectrum frequency and noise level of the EMI noise, and the frequency and noise level values detected by the noise spectrum detection means 82. The memory 83, the noise spectrum envelope calculation means 84 for calculating the envelope of the peak value of the noise spectrum of the EMI noise from the frequency and noise level values stored in the memory 83, and the noise peak group frequency band are calculated from the envelope. Noise peak group frequency band calculating means 85.

  With this configuration, the antenna 81 receives EMI noise generated from the motor drive system, and the noise spectrum detection means 82 detects the noise spectrum of the received EMI noise (referred to as a noise signal). The detected information (frequency value and noise level value at that frequency) is stored in the memory 83. The spectrum envelope calculation means 84 calculates an envelope created by the noise spectrum of EMI noise from the information stored in the memory 83. The noise peak group frequency band calculating means 85 calculates a frequency band that is a noise peak group in the obtained envelope.

  FIG. 7 is a diagram illustrating a configuration example of the noise spectrum detection unit. The configuration of the noise spectrum detecting means 82 in the present embodiment uses a method called a superheterodyne method used in radio receivers, spectrum analyzers and the like. A case where the noise level at the noise frequency fob is observed will be described. First, the local transmission circuit 93 generates a local transmission signal having a frequency fosc that is the sum of the observation frequency fob and the intermediate frequency fIF. Next, the noise signal and the local transmission signal output from the local transmission circuit 93 are input to the mixing circuit 92 that converts the noise frequency fob to the intermediate frequency fIF. The output of the mixing circuit 92 is input to a filter 94 that removes components other than the fIF frequency component. Therefore, the filter 94 outputs only the component of the fIF frequency. The level of the output noise frequency fob is the noise level A at the observation frequency fob. By changing the observation frequency fob in the entire frequency band to be observed, that is, by changing the frequency of the corresponding local transmission signal, a noise spectrum in a desired band can be detected.

  FIG. 8 is a flowchart showing a procedure for determining a carrier frequency for preventing the frequency band of the noise peak group from including a specific frequency fch. First, the motor drive system is operated in S10, and in S11, the carrier frequency fc is set to the carrier frequency fc1, which is the minimum value of the variable range of the carrier frequency fc. Next, in S12, the frequency of the EMI noise is observed. The observation frequency fob is set to the lowest frequency value fob1 in the observed frequency band. In this state, the noise level A at the observation frequency is detected by the noise spectrum detection means 82 in S13. Next, the obtained values of the carrier frequency fc, the observed frequency fob, and the noise level A are stored in the memory 83 in S14. Next, in S15, it is determined whether or not the observed frequency fob exceeds the maximum frequency value fob2 in the observed frequency band. If not, the process proceeds to S17 in order to continuously measure the value of the noise level A. In S17, Δfob, which is a resolution necessary for observing the noise spectrum, is added to the observation frequency fob, and the new observation frequency fob is changed to proceed to S13. In S13, the noise level A of the new observation frequency fob is detected. .

  By repeating the procedure described above until the observation frequency fob reaches the frequency fob2 that is the maximum value of the observed frequency band, noise spectrum data at the carrier frequency fc1 is obtained.

  Next, in S16, it is determined whether or not the value of the carrier frequency fc exceeds the maximum value fc2 of the variable range. If not, the noise level A is detected at each observation frequency fob. Is changed in S18 and returned to S12. That is, in S18, the value is changed to a value obtained by adding the resolution Δfc for determining the carrier frequency to the value of the carrier frequency fc, the process proceeds to S12, and noise spectrum data is acquired again.

  By repeating the procedure described above up to the maximum value fc2 of the variable range of the carrier frequency fc, data of the carrier frequency fc, the observation frequency fob, and the noise level A in the entire variable range of the carrier frequency is acquired. After all the data has been acquired, the process proceeds to S19, the data acquired in S19 is read, and the noise spectrum envelope calculation means 84 calculates the noise spectrum envelope at each carrier frequency fc in S20. Next, in S21, the noise peak group frequency band which is the frequency band of the noise peak group is calculated in the envelope obtained by the noise peak group frequency band calculating means 85. Next, the process proceeds to S22, where the carrier frequency determining means 37 is a carrier frequency at which the peak group is not formed with the frequency value of the EMI noise that is not desired to be generated at the frequency where it is desired to avoid the formation of the band of the peak group of the noise spectrum. The value is selected as the carrier frequency fc, and the process ends in S23.

  As described above, according to the present embodiment, it is possible to select a carrier frequency value at which no peak group is formed with a frequency value of EMI noise that is not desired to be generated, and EMI noise enters the frequency band. It is possible to reliably suppress the occurrence of failures in other systems that are affected by this.

  Furthermore, the noise peak group frequency band detecting means 32 for detecting the frequency band of the peak group of the noise spectrum of the EMI noise is used to specify the frequency band according to the EMI noise actually generated from the motor drive system. It is possible to appropriately determine the carrier frequency for making the peak group of the noise spectrum of the EMI noise deviate from the band of the EMI noise, and the EMI noise generated by the operation of the motor drive system to other electronic devices and systems. A failure can be reliably suppressed.

  The noise peak group frequency band detection means 32 includes a noise spectrum detection means 82 for detecting the frequency and level of the noise spectrum of EMI noise, and the frequency and level of the noise spectrum of the EMI noise detected by the noise spectrum detection means 82. A storage device 83 for storing data, a noise spectrum envelope calculation means 85 for calculating an envelope of the peak value of the EMI noise spectrum from the frequency and level data of the noise spectrum of the EMI noise stored in the storage device 83, This is a configuration of a motor drive system having noise peak group frequency band calculating means 85 for calculating a noise peak group frequency band from the obtained envelope. With such a configuration, it becomes possible to detect a noise peak group from the noise spectrum of the EMI noise, so that the EMI noise from a specific band in accordance with the EMI noise actually generated from the motor drive system. It is possible to appropriately determine the carrier frequency fc for removing the noise peak group of the noise spectrum of the noise spectrum, and to reliably suppress the failure of the EMI noise generated due to the operation of the motor drive system to other systems. be able to.

Fourth Embodiment FIG. 9 is a diagram showing a basic configuration of the fourth embodiment. The control device 44 includes a motor rotation speed detection means 49 for detecting the rotation speed of the motor 13, a noise peak group frequency band detection means 42 for detecting a frequency band of a peak group of a noise spectrum of EMI noise, and an electronic device among the EMI noises. The frequency value set by the noise peak group avoidance frequency setting means 45 and the noise peak group avoidance frequency setting means 45 that sets a frequency value that becomes an obstacle to the class and outputs the set frequency value to the carrier frequency determination means 47, and the EMI Carrier frequency determining means 47 for determining a carrier frequency so as not to generate a noise spectrum peak group of noise, and command value generating means 48 for outputting a rotation speed command signal to the motor drive device 12 are provided. In this configuration, the noise peak group frequency band detecting means 42 is operated when there is a change.

  In the present embodiment, a motor rotation number detecting means 49 is added to the control device 44 with respect to the third embodiment. The motor rotation speed detection means 49 detects the rotation speed of the motor 13, and issues a command to the noise peak group frequency band detection means 42 to detect the noise peak group frequency band when the rotation speed of the motor 13 changes. Output. That is, in the present embodiment, the noise peak group frequency band is detected by the noise peak group frequency band detecting means 42 only when the rotational speed of the motor 13 changes. When the number of rotations of the motor 13 does not change, the noise peak group does not change. Therefore, the noise peak group frequency band is not detected by the noise peak group frequency band detecting means 42.

  By adopting such a configuration, it is possible to suppress unnecessary noise peak group frequency band detection operation and carrier frequency change in the noise peak group frequency band detection means 42. As a result, it is possible to use a low-priced processing apparatus such as a CPU, for example, and it is possible to reduce costs. Moreover, it becomes possible to suppress the energy consumption accompanying a process.

Fifth Embodiment FIG. 10 is a diagram showing a basic configuration of the fifth embodiment. The control device 54 includes a reception channel frequency detection unit 51 that detects a reception channel frequency of the reception device 53, and a carrier frequency determination unit that determines a carrier frequency so as not to generate a carrier frequency having a frequency value detected by the reception channel frequency detection unit 51. 57, a command value generating means 58 for outputting a rotational speed command signal to the motor drive device 12, and a noise peak group frequency band detecting means 52 for detecting the frequency band of the peak group of the noise spectrum of the EMI noise.

  In the present embodiment, the avoidance frequency setting means is a reception channel frequency detection means 51. That is, it is assumed that the frequency at which it is desired to avoid the formation of a noise spectrum peak group is the reception channel frequency of the reception device 53 arranged together with the motor drive system. The details and operation of the configuration are the same as described above, but it is assumed that there are a plurality of channels that can be received by the receiving device 53, and therefore it is desired to avoid the formation of noise peak groups according to the reception channel frequency. The carrier frequency changes. Therefore, it is necessary to change the carrier frequency according to the reception channel frequency. Note that the method for determining the carrier frequency fc from the relationship between the reception channel frequency and the peak group of the noise spectrum is the same as in the second embodiment, and will be omitted.

  With this configuration, the carrier frequency determination unit 57 can determine the carrier frequency so that the reception channel frequency does not enter the frequency band of the peak group of the noise spectrum of the EMI noise. It is possible to reliably suppress the reception failure that the EMI noise generated by the operation of the radio device gives to the receiving device such as a radio.

Sixth Embodiment FIG. 11 is a diagram illustrating a basic configuration of a sixth embodiment. The control device 64 detects the reception channel frequency of the reception device 63, the reception channel frequency detection means 61, and the carrier frequency so as not to generate a peak group of the noise spectrum of the EMI noise with the frequency value detected by the reception channel frequency detection means 61. A carrier frequency determining means 67 for determining the frequency, a command value generating means 68 for outputting a rotational speed command signal to the motor drive device 12, a noise peak group frequency band detecting means 62 for detecting the frequency band of the peak group of the noise spectrum of EMI noise, The motor has a motor speed detector 69 that detects a change in the speed of the motor 13 and operates the noise peak group frequency band detector 62 when the reception channel frequency is changed.

  In the present embodiment, the motor rotation speed detection means 69 is provided, and it is possible to notify the noise peak group frequency band detection means 62 that the rotation speed of the motor 13 has changed. Further, the reception channel frequency detection means 61 notifies that the reception channel has changed. By adopting such a configuration, the noise peak group frequency band detecting means 62 is operated only when the rotational speed of the motor 13 and the reception frequency are changed, and the procedure for detecting the noise peak group frequency is executed. It is.

  With such a configuration, it is possible to suppress unnecessary noise peak group frequency band detecting operation and carrier frequency changing operation in the noise peak group frequency band detecting means 62. As a result, it is possible to use a low-priced processing apparatus such as a CPU, for example, and it is possible to further suppress energy consumption associated with the processing.

  Further, in the configuration of the present invention, it is possible to reliably prevent the EMI noise generated from the motor drive system from giving a fault to other systems. Furthermore, since the present invention is not a post-measure as described above, it is possible to suppress an increase in cost, an increase in volume and weight, an increase in development period, and the like due to the post-measure.

  Further, the control device 64 is configured to operate the noise peak group frequency band detecting means 62 when the reception channel frequency is changed, so that the reception channel frequency changes even if the noise peak group frequency does not change. Thus, since there is a possibility that the reception channel frequency enters the frequency band of the peak group, it is possible to operate the noise peak group frequency detection means only when the reception channel frequency changes. Therefore, by not operating the noise peak group frequency band detection means 62 when not necessary, the processing load can be reduced, and the cost and power consumption can be reduced.

It is a figure which shows the basic composition of 1st Embodiment. It is a figure which shows an example of the noise spectrum of the EMI noise which generate | occur | produces from a motor drive system. It is a figure which shows the basic composition of 2nd Embodiment. It is a figure which shows the relationship between the EMI noise spectrum generate | occur | produced from a motor drive system, and a receiving channel. It is a figure which shows the basic composition of 3rd Embodiment. It is a figure which shows the structural example of a noise peak group frequency band detection means. It is a figure which shows the structural example of a noise spectrum detection means. It is a flowchart which shows the procedure of carrier frequency determination for making the frequency band of a noise peak group not include a specific frequency. It is a figure which shows the basic composition of 4th Embodiment. It is a figure which shows the basic composition of 5th Embodiment. It is a figure which shows the basic composition of 6th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... DC power supply 12 ... Motor drive device 13 ... Motor 14 ... Control device 15 ... Noise peak group avoidance frequency setting means 16 ... Noise correlation information recording means 17 ... Carrier frequency determination means 18 ... Command value generation means 19 ... Motor rotation number detection Means 23 ... Receiver 25 ... Reception channel frequency detection means 32 ... Noise peak group frequency band detection means

Claims (9)

In a motor drive system having a motor, a motor drive device that drives the motor, and a control device that outputs a control signal to the motor drive device,
The control device
Motor rotation number detecting means for detecting the rotation number of the motor;
Avoidance frequency setting means for setting a frequency value of the EMI noise that is not desired to be generated among the EMI noise generated from the motor drive system;
The carrier frequency is set to the rotational speed of the motor detected by the motor rotational speed detecting means so that the peak group of the noise spectrum of the EMI noise generated from the motor driving system is not generated at the frequency value set by the avoidance frequency setting means. A motor drive system comprising carrier frequency determining means for determining based on the carrier frequency. The control device has noise correlation information recording means for recording a correlation with the number of rotations of the motor, the carrier frequency, and a peak group of a noise spectrum of the EMI noise,
The carrier frequency determining means is set by the avoidance frequency setting means and the correlation between the rotation speed of the motor recorded in the noise correlation information recording means, the carrier frequency and the peak group of the noise spectrum of the EMI noise, and Based on the frequency value and the motor rotation speed detected by the motor rotation speed detection means, the peak value of the noise spectrum of the EMI noise generated from the motor drive system is set to the frequency value set by the avoidance frequency setting means. The motor drive system according to claim 1, wherein the carrier frequency is determined so as not to be generated. 2. The motor drive system according to claim 1, wherein the avoidance frequency setting means is reception channel frequency detection means for detecting a reception channel frequency of a reception device that selects and receives a broadcast wave. The control device
Noise correlation information recording means for recording a correlation between a reception channel frequency and a carrier frequency determined in advance so that the EMI noise peak group does not overlap according to the reception channel frequency and the motor rotation number. Have
The carrier frequency determining means includes the number of rotations of the motor and the reception channel frequency recorded in the noise correlation information recording means, the correlation between the reception channel frequency and the carrier frequency at which the EMI noise peak group does not overlap, and the reception channel. 4. The motor drive according to claim 3, wherein the carrier frequency is determined based on a reception channel frequency value detected by the frequency detection means and a motor rotation speed detected by the motor rotation speed detection means. system. In a motor drive system having a motor, a motor drive device that drives the motor, and a control device that outputs a control signal to the motor drive device,
The control device
Avoidance frequency setting means for setting a frequency value of the EMI noise that is not desired to be generated among the EMI noise generated from the motor drive system;
Noise peak group frequency band detecting means for detecting the frequency band of the peak group of the noise spectrum of the EMI noise;
The peak of the noise spectrum detected by the noise peak group frequency band detecting means so as not to generate the peak group of the noise spectrum of the EMI noise generated from the motor drive system at the frequency value set by the avoidance frequency setting means. Carrier frequency determining means for determining a carrier frequency based on the frequency band of the group ;
Motor rotational speed detection means for detecting the rotational speed of the motor,
A motor drive system , wherein the noise peak group frequency band detecting means is operated when the rotational speed of the motor changes .   The avoidance frequency setting means is a noise peak group avoidance frequency setting means for setting a frequency value that is an obstacle to electronic equipment among the EMI noise and outputting the frequency value to the carrier frequency determination means. The motor drive system according to claim 5.   6. The motor drive system according to claim 5, wherein the avoidance frequency setting means is reception channel frequency detection means for detecting a reception channel frequency of a reception device that selects and receives a broadcast wave. 8. The motor drive system according to claim 7 , wherein the control device operates the noise peak group frequency band detecting means when the reception channel frequency is changed. The noise peak group frequency band detecting means detects noise spectrum frequency and noise level of the noise spectrum of the EMI noise, and stores the frequency and noise level values detected by the noise spectrum detecting means. Noise spectrum envelope calculation means for calculating an envelope of a peak value of the noise spectrum of the EMI noise from the frequency and noise level values stored in the storage means, and a noise peak group frequency band from the envelope the motor drive system according to any one of claims 5-8, characterized in that it comprises a noise peaks frequency band calculating means for calculating.

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