JP3622666B2 - Synchronous motor control method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a synchronous motor control method and apparatus for controlling a synchronous motor by supplying an output voltage of an inverter to the synchronous motor.
[0002]
[Prior art]
Conventionally, a synchronous motor control device for controlling a synchronous motor by supplying an output voltage of an inverter to the synchronous motor has been proposed.
[0003]
And as such a synchronous motor control device,
(1) In addition to overmodulation, the inverter is controlled using voltage control and voltage phase control together, and the synchronous motor is controlled by supplying the inverter output voltage.
(2) Without controlling overmodulation, controlling the inverter using current control and current phase control together, and controlling the synchronous motor by supplying the inverter output voltage,
(3) Controlling an inverter by switching between voltage control and current control and controlling a synchronous motor by supplying an inverter output waveform
Has been proposed. Also,
(4) In the synchronous motor control device of (2), the maximum value of the current phase controlled by the current phase control is limited to an appropriate value.
Has also been proposed. For example, in the brushless DC motor control device disclosed in Japanese Patent Application Laid-Open No. 8-322279, the maximum phase is set according to the required torque.
[0004]
[Problems to be solved by the invention]
When the synchronous motor control device of (1) is adopted, the inverter output voltage can be used to the maximum, but a current trip occurs during an overload, so the inverter output current must be used to the maximum. There is an inconvenience that cannot be done.
[0005]
When the synchronous motor control device (2) is employed, the occurrence of a current trip can be prevented in advance, but there is a disadvantage that the inverter output voltage cannot be utilized to the maximum extent. In other words, there is a disadvantage that the efficiency cannot be sufficiently increased.
[0006]
When the synchronous motor control device of (3) is adopted, there are inconveniences when the synchronous motor control device of (1) is adopted according to switching, and inconveniences when the synchronous motor control device of (2) is adopted. In addition to being generated, a configuration for performing voltage control and a configuration for performing current control are necessary, and there is a disadvantage that the configuration becomes complicated.
[0007]
When the synchronous motor control device of (4) is adopted, the maximum value of the current phase is only limited by an appropriate value, so that the capacity of the synchronous motor and inverter can be utilized to the maximum. There is inconvenience that we cannot do it. Further explanation will be given.
[0008]
Since the synchronous motor cannot be brought into a state where maximum torque can be generated, it is necessary to enlarge the synchronous motor more than necessary. In addition, when high-speed rotation is performed, it is necessary to use a motor with a low induced voltage, so the drive current increases, and when the compressor is driven by a synchronous motor, the compressor rating (medium speed range) Efficiency will decrease. Furthermore, since the current phase is not properly limited, if the current phase exceeds the true limit value, the synchronous motor will stall, causing inconveniences such as trips or a significant decrease in efficiency and inability to achieve the operating range. End up.
[0009]
Further explanation will be given.
[0010]
Conventionally, when controlling a synchronous motor, the maximum torque condition under voltage constraint has not been shown at all, and in a servo application, speed droop control is not allowed, and there is a margin in voltage and current. Since the margin design that provides the basic torque was fundamental, it was impossible to control the synchronous motor under the maximum torque condition. Since the margin design is common sense in applications other than servos, it has been impossible to control the synchronous motor under the maximum torque condition. In other words, it has been impossible to use the maximum capacity of the synchronous motor such as maximum acceleration and maximum torque. For this reason, when the margin is exceeded, the synchronous motor stalls, resulting in a trip, a reduction in efficiency, and a lack of the operating range.
[0011]
When the inverter output voltage is sufficiently higher than the motor induced voltage, torque control is performed with the motor current. When the motor voltage cannot be increased due to the motor induced voltage at high speed rotation, the current is It is known to further rotate at a higher speed by advancing the phase to weaken the magnetic flux and increase the motor current. However, no method has been proposed to extract the maximum capacity of the motor using them, and no method has been proposed to prevent the divergence of the control system when a command exceeding the capacity is instantaneously given. . Therefore, it is impossible to use up the full capacity of the motor inverter while maintaining good controllability (high response speed, high efficiency).
[0012]
Furthermore, since the current control system is considered to diverge when the inverter output voltage reaches the limit value, current control cannot be performed when the inverter output voltage is used near the limit value. Inconvenience such as divergence of the control system occurs.
[0013]
OBJECT OF THE INVENTION
The present invention has been made in view of the above-described problems, can make the most of the ability of the synchronous motor, can make the most of the ability of the inverter while ensuring high controllability, Moreover, it is an object of the present invention to provide a synchronous motor control method and apparatus capable of performing tripless and current control while making maximum use of an inverter output voltage.
[0014]
[Means for Solving the Problems]
In the synchronous motor control method according to claim 1, in controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the upper limit value of the current phase is set to a phase that maximizes the motor torque at each instantaneous inverter output voltage. Or it is the method of setting to the vicinity.
[0015]
In the synchronous motor control method according to claim 2, in controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the upper limit value of the current phase is set to the motor torque at the inverter maximum output voltage for each rotation speed. This is a method of setting the phase to be maximized or the vicinity thereof.
[0016]
The synchronous motor control method according to claim 3 is a method of changing the upper limit value of the current phase in response to at least the rotational speed.
[0017]
In the synchronous motor control method according to claim 4, when the synchronous motor is controlled by supplying the output voltage of the inverter to the synchronous motor, the upper limit value of the current phase is set to the maximum motor torque at the maximum output voltage of the inverter at the highest speed rotation. This is a method of setting at or near the phase.
[0018]
In the synchronous motor control method according to the fifth aspect, when the synchronous motor is controlled by supplying the output voltage of the inverter to the synchronous motor, the limit value of the current phase is limited to the inverter output current for each required torque. This is a method of setting the maximum phase, the minimum phase, or the vicinity thereof.
[0019]
In the synchronous motor control method according to claim 6, when the synchronous motor is controlled by supplying the output voltage of the inverter to the synchronous motor, the upper limit value of the current phase is set to the motor torque at each instantaneous inverter output voltage. The maximum value set in the vicinity or the upper limit value set in the vicinity thereof, the maximum value set in the vicinity of the motor torque at the inverter maximum output voltage or the upper limit value set in the vicinity thereof at each rotation speed, the inverter maximum at the maximum speed rotation The smallest of the phase that maximizes the motor torque at the output voltage or the upper limit value that is set in the vicinity thereof, the maximum phase that limits the inverter output current for each required torque, or the upper limit value that is set in the vicinity thereof This is a method of selecting an upper limit value.
[0020]
In the synchronous motor control method according to claim 7, the lower limit value of the current phase is set at or near the current phase that maximizes the efficiency or the torque, and is synchronized with the smallest current phase that can output the required torque. This is a method of driving a motor.
[0021]
The synchronous motor control method of claim 8 is a method of driving an air conditioner compressor by the synchronous motor.
[0022]
The synchronous motor control method according to claim 9 is a method in which a permanent magnet motor is employed as the synchronous motor, and the upper limit value of the current phase is set to approximately 60 to 80 degrees.
[0023]
In the synchronous motor control method according to claim 10, in controlling the permanent magnet motor by supplying the output voltage of the inverter to the permanent magnet motor, the output voltage of the inverter has reached a limit value as the number of rotations increases. In this method, the current phase is advanced in response, and the speed drooping control is performed in response to reaching a predetermined current phase limit value or current limit value.
[0024]
In the synchronous motor control method according to claim 11, when the permanent magnet motor is controlled by supplying the output voltage of the inverter to the permanent magnet motor, the output voltage of the inverter reaches a limit value as the number of rotations increases. In response, the current phase is advanced, and in response to reaching a predetermined current phase limit value or current limit value, the internal state of the speed control means is held in a state immediately before reaching the limit value.
[0025]
The synchronous motor control method according to claim 12 outputs a desired voltage waveform from the inverter when the inverter output voltage has a margin with respect to the output voltage limit value, and responds to the inverter output voltage approaching the output voltage limit value. In this way, the output voltage waveform from the inverter is brought closer to the output voltage waveform having a high voltage utilization rate.
[0026]
A synchronous motor control method according to a thirteenth aspect employs a sine wave as the desired voltage waveform.
[0027]
A synchronous motor control method according to a fourteenth aspect is a method of adopting a rectangular wave as the output voltage waveform having a high voltage utilization rate.
[0028]
The synchronous motor control method according to claim 15 is a method of driving the compressor by a permanent magnet motor.
[0029]
A synchronous motor control method according to a sixteenth aspect is a method of controlling the motor current when the inverter output voltage amplitude is limited in controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor.
[0030]
In the synchronous motor control method according to claim 17, the motor current is controlled by increasing the motor terminal voltage command value in response to a small motor current and increasing the motor terminal voltage command value in response to a large motor current. It is a method performed by decreasing.
[0031]
A synchronous motor control method according to claim 18 is a method of controlling an inverter to compensate for a decrease in torque caused by the voltage limitation.
[0032]
A synchronous motor control method according to a nineteenth aspect is a method in which the decrease in the torque is compensated by compensating for the decrease in the amplitude of the fundamental wave component of the phase voltage command due to voltage limitation.
[0033]
21. The synchronous motor control method according to claim 20, wherein the current phase is controlled so that the degree of overmodulation becomes a predetermined value in response to the degree of overmodulation increasing the voltage utilization rate exceeding a predetermined value. It is.
[0034]
A synchronous motor control method according to a twenty-first aspect is a method in which a permanent magnet motor in which a permanent magnet is embedded in a rotor is adopted as the synchronous motor.
[0035]
A synchronous motor control method according to a twenty-second aspect is a method of driving a compressor by the synchronous motor.
[0036]
The synchronous motor control device according to claim 23 controls the synchronous motor by supplying the output voltage of the inverter to the synchronous motor. The upper limit value of the current phase is set to maximize the motor torque at each instantaneous inverter output voltage. Inverter control means for setting at or near the phase is included.
[0037]
The synchronous motor control device according to claim 24 controls the synchronous motor by supplying the output voltage of the inverter to the synchronous motor. The upper limit value of the current phase is set to the motor torque at the inverter maximum output voltage for each rotation speed. Inverter control means for setting the phase to the maximum or the vicinity thereof is included.
[0038]
The synchronous motor control apparatus according to claim 25 employs, as the inverter control means, one that changes the upper limit value of the current phase in response to at least the rotational speed.
[0039]
The synchronous motor control device according to claim 26 controls the synchronous motor by supplying the output voltage of the inverter to the synchronous motor. The upper limit value of the current phase is set to the motor torque at the maximum output voltage of the inverter at the highest speed rotation. Inverter control means set at or near the maximum phase is included.
[0040]
The synchronous motor control device according to claim 27 controls the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, and the inverter output current is limited for each required torque with the current phase limit value. Inverter control means for setting the maximum phase and the minimum phase, or the vicinity thereof are included.
[0041]
The synchronous motor control device according to claim 28 controls the synchronous motor by supplying the output voltage of the inverter to the synchronous motor. The upper limit value of the current phase is set to the motor at each instantaneous inverter output voltage. Phase at which torque is maximized or an upper limit value set in the vicinity thereof, and the phase at which motor torque is maximized at the inverter maximum output voltage or an upper limit value set in the vicinity thereof at each rotation speed, inverter at maximum speed Of the maximum output voltage, the maximum value set in or near the phase that maximizes the motor torque, the maximum phase that will limit the inverter output current for each required torque, or the maximum value set in the vicinity thereof Inverter control means for selecting a small upper limit value is included.
[0042]
In the synchronous motor control device according to claim 29, as the inverter control means, the lower limit value of the current phase is set to the current phase that maximizes the efficiency or the torque, or the vicinity thereof, and the current phase that can output the required torque is selected. The one that controls the inverter to drive the synchronous motor with the smallest current phase is adopted.
[0043]
A synchronous motor control device according to a thirty-third aspect employs a motor that drives a compressor for an air conditioner as the synchronous motor.
[0044]
A synchronous motor control device according to a thirty-first aspect employs a permanent magnet motor as the synchronous motor, and employs an inverter control means that sets an upper limit value of a current phase to approximately 60 degrees to 80 degrees.
[0045]
The synchronous motor control device according to claim 32 controls the permanent magnet motor by supplying the output voltage of the inverter to the permanent magnet motor, and the output voltage of the inverter has reached a limit value as the rotational speed increases. Inverter control means for advancing the current phase in response to the above and performing speed droop control in response to reaching a predetermined current phase limit value or current limit value.
[0046]
The synchronous motor control device according to claim 33 controls the permanent magnet motor by supplying the output voltage of the inverter to the permanent magnet motor, and the output voltage of the inverter has reached a limit value as the rotational speed increases. And an inverter control means for holding the internal state of the speed control means in a state immediately before reaching the limit value in response to reaching the predetermined current phase limit value or the current limit value.
[0047]
The synchronous motor control device according to claim 34 outputs, as the inverter control means, a desired voltage waveform from the inverter when the inverter output voltage has a margin with respect to the output voltage limit value, and the inverter output voltage is the output voltage limit value. The output voltage waveform from the inverter is approximated to the output voltage waveform having a high voltage utilization rate in response to approaching.
[0048]
A synchronous motor control device according to a thirty-fifth aspect employs a sine wave having the desired voltage waveform as the inverter control means.
[0049]
A synchronous motor control device according to a thirty-sixth aspect employs, as the inverter control means, a rectangular wave having an output voltage waveform having a high voltage utilization rate.
[0050]
A synchronous motor control apparatus according to a thirty-seventh aspect employs a motor that drives a compressor as the permanent magnet motor.
[0051]
The synchronous motor control device according to claim 38 controls the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, and when the inverter output voltage amplitude is limited, the inverter is controlled to control the motor current. Inverter control means for controlling is included.
[0052]
The synchronous motor control device according to claim 39, as the inverter control means, controls the motor current by increasing a motor terminal voltage command value in response to a small motor current and in response to a large motor current. What is performed by decreasing the motor terminal voltage command value is adopted.
[0053]
In a synchronous motor control device according to a forty-fourth aspect, as the inverter control means, one that controls an inverter to compensate for a decrease in torque caused by the voltage limitation is adopted.
[0054]
The synchronous motor control device according to claim 41 employs, as the inverter control means, one that compensates for the decrease in torque by compensating for the decrease in the amplitude of the fundamental component of the phase voltage command due to voltage limitation. is there.
[0055]
The synchronous motor control apparatus according to claim 42, as the inverter control means, controls the current phase so that the degree of overmodulation becomes a predetermined value in response to the degree of overmodulation exceeding a predetermined value. The thing is adopted.
[0056]
A synchronous motor control device according to a forty-third aspect employs a permanent magnet motor in which a permanent magnet is embedded in a rotor as the synchronous motor.
[0057]
A synchronous motor control device according to a 44th aspect employs a device that drives a compressor as the synchronous motor.
[0058]
[Action]
According to the synchronous motor control method of claim 1, in controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the upper limit value of the current phase is set to the maximum motor torque at each instantaneous inverter output voltage. When the voltage phase or current phase is operated to increase the maximum rotation speed, or the voltage phase or current phase is controlled to control the speed, it is set near the maximum torque that can be generated by the synchronous motor. Can be operated. As a result, the occurrence of trips can be prevented, and the voltage and current can be utilized to the maximum. As a result, the synchronous motor can be miniaturized and the maximum efficiency can be realized by optimal tuning.
[0059]
According to the synchronous motor control method of claim 2, in controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the upper limit value of the current phase is set to the motor at the inverter maximum output voltage for each rotation speed. Since the torque is set at the maximum phase or in the vicinity thereof, the synchronous motor can be controlled using the upper limit value of the current phase set for each speed, and the upper limit of the current phase during field-weakening control at high speed. Can be kept below the value. As a result, the occurrence of trips can be prevented, and the voltage and current can be utilized to the maximum. As a result, the synchronous motor can be miniaturized and the maximum efficiency can be realized by optimum tuning.
[0060]
According to the synchronous motor control method of the third aspect, since the upper limit value of the current phase is changed at least in response to the rotational speed, the same operation as that of the first or second aspect can be achieved.
[0061]
According to the synchronous motor control method of claim 4, in controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the upper limit value of the current phase is set to the motor torque at the maximum output voltage of the inverter at the highest speed rotation. Is set at or near the phase that maximizes the frequency, which simplifies the process and prevents trips from occurring, and maximizes the use of voltage and current. And maximum efficiency through optimization and tuning.
[0062]
According to the synchronous motor control method of claim 5, when controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the limit value of the current phase is limited to the inverter output current for each required torque. Therefore, the torque phase can be prevented from decreasing and the current phase can be controlled to the maximum. As a result, the occurrence of trips can be prevented, and the voltage and current can be utilized to the maximum. As a result, the synchronous motor can be miniaturized and the maximum efficiency can be realized by optimum tuning.
[0063]
According to the synchronous motor control method of claim 6, in controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the upper limit value of the current phase is determined for each instantaneous inverter output voltage. Phase at which motor torque is maximized or an upper limit value set in the vicinity thereof, for each rotation speed, phase at which motor torque is maximized at the inverter maximum output voltage, or upper limit value set in the vicinity thereof, at maximum speed Of the maximum inverter output voltage, the phase that maximizes the motor torque or the upper limit value set in the vicinity thereof, the maximum phase that the inverter output current is limited for each required torque, or the upper limit value set in the vicinity thereof, Since the smallest upper limit value is selected, the current phase is limited by the selected upper limit value. With a trip of occurrence can be prevented, voltage, current can be fully utilized, and therefore, it is possible to reduce the size of the synchronous motor, and the maximum efficiency by optimally tuning realized.
[0064]
According to the synchronous motor control method of claim 7, the lower limit value of the current phase is set at or near the current phase that maximizes the efficiency or torque, and the smallest current phase among the current phases that can output the required torque. Since the synchronous motor is driven in this way, the current phase can be controlled to a phase between the lower limit value and the upper limit value, and the same operation as any one of claims 1 to 6 can be achieved. .
[0065]
According to the synchronous motor control method of claim 8, since the compressor for an air conditioner is driven by the synchronous motor, the synchronous motor that generates a large amount of heat during field weakening control can be cooled by the refrigerant. The effect similar to any one of claims 1 to 7 can be achieved without particularly considering heat dissipation.
[0066]
According to the synchronous motor control method of claim 9, since a permanent magnet motor is adopted as the synchronous motor and the upper limit value of the current phase is set to about 60 degrees to 80 degrees, the maximum capacity of the permanent magnet motor is extracted. In addition, good operating characteristics can be realized, and the same effect as in the eighth aspect can be achieved.
[0067]
In the synchronous motor control method according to claim 10, in controlling the permanent magnet motor by supplying the output voltage of the inverter to the permanent magnet motor, the output voltage of the inverter has reached a limit value as the number of rotations increases. In response to this, the current phase is advanced, and the speed drooping control is performed in response to reaching the predetermined current phase limit value or current limit value, so the permanent magnet motor is driven below the current limit and phase limit. Thus, the divergence of the control system can be prevented. The occurrence of trips can be prevented and the voltage and current can be utilized to the maximum. As a result, the synchronous motor can be miniaturized and the maximum efficiency can be realized by optimal tuning.
[0068]
According to the synchronous motor control method of claim 11, in controlling the permanent magnet motor by supplying the output voltage of the inverter to the permanent magnet motor, the output voltage of the inverter has reached a limit value as the number of rotations increases. In response to this, the current phase is advanced, and in response to reaching the predetermined current phase limit value or current limit value, the internal state of the speed control means is held in the state immediately before reaching the limit value. System divergence can be prevented. The occurrence of trips can be prevented and the voltage and current can be utilized to the maximum. As a result, the synchronous motor can be miniaturized and the maximum efficiency can be realized by optimal tuning.
[0069]
According to the synchronous motor control method of claim 12, when the inverter output voltage has a margin with respect to the output voltage limit value, a desired voltage waveform is output from the inverter, and the inverter output voltage approaches the output voltage limit value. In response to this, the output voltage waveform from the inverter is brought close to the output voltage waveform with a high voltage utilization rate, so if the voltage waveform is adjusted appropriately, noise reduction can be achieved in the low speed range and the high speed operation range can be expanded. In addition, it is possible to achieve the same effects as those of the tenth or eleventh aspect.
[0070]
According to the synchronous motor control method of claim 13, since a sine wave is adopted as the desired voltage waveform, noise and vibration due to harmonics can be easily suppressed, and the same effect as in claim 12 can be obtained. Can be achieved.
[0071]
According to the synchronous motor control method of claim 14, since a rectangular wave is adopted as the output voltage waveform having a high voltage utilization rate, a sufficiently high speed operation range can be achieved. An effect similar to that of the thirteenth aspect can be achieved.
[0072]
According to the synchronous motor control method of the fifteenth aspect, since the compressor is driven by a permanent magnet motor, noise and vibration can be reduced and the compressor can be driven to a high speed. The same effect as any one of Item 14 can be achieved.
[0073]
According to the synchronous motor control method of the sixteenth aspect, the motor current is controlled when the inverter output voltage amplitude is limited in controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor. Therefore, the motor current can be controlled even when the current increases due to disturbance or the like when the voltage is limited. The occurrence of trips can be prevented and the voltage and current can be utilized to the maximum. As a result, the synchronous motor can be miniaturized and the maximum efficiency can be realized by optimal tuning.
[0074]
According to the synchronous motor control method of claim 17, the motor current control is performed by increasing the motor terminal voltage command value in response to a small motor current and in response to a large motor current. Since the operation is performed by decreasing the value, the same effect as that of the sixteenth aspect can be achieved.
[0075]
According to the synchronous motor control method of claim 18, since the inverter is controlled so as to compensate for the decrease in torque caused by the voltage limitation, the torque before the current limitation can be maintained, and Alternatively, an effect similar to that of the seventeenth aspect can be achieved.
[0076]
According to the synchronous motor control method of claim 19, the torque reduction is compensated by compensating for the amplitude reduction of the fundamental wave component of the phase voltage command due to voltage limitation. The action can be achieved.
[0077]
21. The synchronous motor control method according to claim 20, wherein the current phase is controlled so that the degree of overmodulation becomes a predetermined value in response to the degree of overmodulation increasing the voltage utilization rate exceeding a predetermined value. Therefore, it is possible to prevent the degree of overmodulation from becoming too large, and to achieve the same effect as any one of claims 16 to 19.
[0078]
According to the synchronous motor control method of claim 21, since the permanent magnet motor in which a permanent magnet is embedded in the rotor is adopted as the synchronous motor, it is possible to effectively use the field weakening action. In addition, the same effect as any one of claims 9 to 20 can be achieved.
[0079]
According to the synchronous motor control method of claim 22, since the compressor is driven by the synchronous motor, overcurrent that causes damage to the synchronous motor and the inverter is prevented even when a sudden load increase occurs. In addition, the same action as any one of claims 16 to 21 can be achieved.
[0080]
In the synchronous motor control device according to claim 23, in controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the inverter control means sets the upper limit value of the current phase in each instantaneous inverter output voltage. It can be set at or near the phase that maximizes the motor torque.
[0081]
Therefore, when the current phase is advanced to increase the maximum rotation speed, or the voltage phase or the current phase is controlled for speed control, control with the maximum torque that can be generated by the synchronous motor can be performed. As a result, the occurrence of trips can be prevented, and the voltage and current can be utilized to the maximum. As a result, the synchronous motor can be miniaturized and the maximum efficiency can be realized by optimal tuning.
[0082]
In the synchronous motor control device according to claim 24, when the synchronous motor is controlled by supplying the output voltage of the inverter to the synchronous motor, the inverter control means sets the upper limit value of the current phase for each rotation speed. It can be set at or near the phase that maximizes the motor torque at the maximum output voltage.
[0083]
Therefore, the synchronous motor can be controlled using the upper limit value of the current phase set for each speed, and the current phase during field-weakening control at high speed can be kept below the upper limit value. As a result, the occurrence of trips can be prevented, and the voltage and current can be utilized to the maximum. As a result, the synchronous motor can be miniaturized and the maximum efficiency can be realized by optimum tuning.
[0084]
In the synchronous motor control device according to claim 25, the inverter control means employs a device that changes the upper limit value of the current phase in response to at least the rotational speed. Similar effects can be achieved.
[0085]
In the synchronous motor control device according to claim 26, when the synchronous motor is controlled by supplying the output voltage of the inverter to the synchronous motor, the upper limit value of the current phase is set by the inverter control means to the maximum value of the inverter at the maximum speed rotation. The output voltage can be set at or near the phase at which the motor torque is maximized.
[0086]
Therefore, the current phase can be limited only to the transient change at the maximum voltage and maximum current phase. As a result, the configuration can be simplified and trips can be prevented, voltage and current can be used to the maximum, and synchronous motors can be miniaturized and maximum efficiency can be achieved through optimal tuning. Can do.
[0087]
In the synchronous motor control device according to claim 27, in controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the inverter control means sets the limit value of the current phase to the inverter output current for each required torque. Can be set at or near the maximum and minimum phases that will be limited.
[0088]
Therefore, torque reduction can be prevented and the current phase can be controlled to the maximum. As a result, the occurrence of trips can be prevented, and the voltage and current can be utilized to the maximum. As a result, the synchronous motor can be miniaturized and the maximum efficiency can be realized by optimum tuning.
[0089]
In the synchronous motor control device according to claim 28, in controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the inverter control means sets the upper limit value of the current phase for each moment. In the inverter output voltage, the phase that maximizes the motor torque or an upper limit value set in the vicinity thereof, for each rotation speed, the phase that maximizes the motor torque in the inverter maximum output voltage or the upper limit value set in the vicinity thereof, At the maximum inverter output voltage at the highest speed, the phase that maximizes the motor torque or an upper limit value set in the vicinity thereof, the maximum phase at which the inverter output current is limited for each required torque, or the vicinity thereof is set Among the upper limit values, the smallest upper limit value can be selected.
[0090]
Therefore, by limiting the current phase according to the selected upper limit value, it is possible to prevent the occurrence of trips and to maximize the use of voltage and current. As a result, the synchronous motor can be reduced in size and optimally tuned. Can achieve maximum efficiency.
[0091]
30. The synchronous motor control device according to claim 29, wherein the inverter control means sets the lower limit value of the current phase to a current phase that maximizes efficiency or torque, or the vicinity thereof, and outputs a desired torque. 24. Since the inverter is controlled to drive the synchronous motor with the smallest current phase, the current phase can be controlled to a phase between the lower limit value and the upper limit value. An effect similar to that of any of the twenty-eighth aspects can be achieved.
[0092]
If it is a synchronous motor control apparatus of Claim 30, since the thing which drives the compressor for air conditioners is employ | adopted as said synchronous motor, a synchronous motor can be cooled with a refrigerant | coolant, and heat radiation of a synchronous motor is carried out. The action similar to that of any of claims 23 to 29 can be achieved without particular consideration.
[0093]
If it is a synchronous motor control apparatus of Claim 31, a permanent magnet motor is employ | adopted as said synchronous motor, and what sets the upper limit of an electric current phase to about 60 to 80 degree | times is employ | adopted as said inverter control means. Therefore, the maximum capacity of the permanent magnet motor can be extracted to achieve a flat torque characteristic, and the same effect as that of the thirty-third aspect can be achieved.
[0094]
In the synchronous motor control device according to the thirty-second aspect, in controlling the permanent magnet motor by supplying the output voltage of the inverter to the permanent magnet motor, the output voltage of the inverter is increased by the inverter control means as the rotational speed increases. The current phase is advanced in response to reaching the limit value, and the speed drooping control can be performed in response to reaching a predetermined current phase limit value or current limit value.
[0095]
Therefore, the permanent magnet motor can be driven below the current limit and phase limit to prevent the control system from diverging. The occurrence of trips can be prevented and the voltage and current can be utilized to the maximum. As a result, the synchronous motor can be miniaturized and the maximum efficiency can be realized by optimal tuning.
[0096]
In the synchronous motor control device according to claim 33, when the permanent magnet motor is controlled by supplying the output voltage of the inverter to the permanent magnet motor, the inverter control means causes the output voltage of the inverter to increase as the rotational speed increases. In response to reaching the limit value, the current phase is advanced, and in response to reaching the predetermined current phase limit value or current limit value, the internal state of the speed control means is held in the state immediately before reaching the limit value. Can do.
[0097]
Accordingly, the divergence of the speed control system can be prevented. The occurrence of trips can be prevented and the voltage and current can be utilized to the maximum. As a result, the synchronous motor can be miniaturized and the maximum efficiency can be realized by optimal tuning.
[0098]
In the synchronous motor control device according to claim 34, as the inverter control means, when the inverter output voltage has a margin with respect to the output voltage limit value, a desired voltage waveform is output from the inverter, and the inverter output voltage is the output voltage. In response to approaching the limit value, the output voltage waveform from the inverter is closer to the output voltage waveform with a high voltage utilization rate. The expansion of the range can be achieved, and the same effect as that of claim 32 or claim 33 can be achieved.
[0099]
If it is a synchronous motor control apparatus of Claim 35, since what uses a sine wave as said desired voltage waveform as said inverter control means is employ | adopted, the noise and vibration by a harmonic can be suppressed easily. In addition, the same effect as that of the 34th aspect can be achieved.
[0100]
According to the synchronous motor control device of claim 36, since the inverter control means adopts a rectangular wave as the output voltage waveform having a high voltage utilization rate, sufficient expansion of the high-speed operation range is achieved. In addition, the same effect as in the thirty-fourth or thirty-fifth aspect can be achieved.
[0101]
If it is a synchronous motor control device of Claim 37, since it uses what drives a compressor as said permanent magnet motor, while being able to reduce noise and vibration, it can drive to high speed, The same effect as in any one of claims 32 to 36 can be achieved.
[0102]
In the synchronous motor control device according to claim 38, when controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, when the inverter output voltage amplitude is limited by the inverter control means, the motor current The inverter can be controlled to control
[0103]
Therefore, the motor current can be controlled even when the current increases due to disturbance or the like when the voltage is limited. The occurrence of trips can be prevented and the voltage and current can be utilized to the maximum. As a result, the synchronous motor can be miniaturized and the maximum efficiency can be realized by optimal tuning.
[0104]
In the synchronous motor control device according to claim 39, as the inverter control means, the control of the motor current is performed by increasing the motor terminal voltage command value in response to a small motor current and responding to a large motor current. Thus, since the operation performed by decreasing the motor terminal voltage command value is adopted, the same operation as that of the 38th aspect can be achieved.
[0105]
In the synchronous motor control device according to claim 40, since the inverter control means employs a device that controls the inverter to compensate for a decrease in torque caused by the voltage limitation, the torque before the current limitation is maintained. In addition, the same action as that of claim 38 or claim 39 can be achieved.
[0106]
In the synchronous motor control device according to claim 41, the inverter control means that compensates for the decrease in torque by compensating for the decrease in the amplitude of the fundamental component of the phase voltage command due to voltage limitation is adopted. Therefore, the same effect as in the 40th aspect can be achieved.
[0107]
In the synchronous motor control device according to claim 42, as the inverter control means, in response to the degree of overmodulation exceeding a predetermined value, the current phase is adjusted so that the degree of overmodulation becomes a predetermined value. Since what is to be controlled is adopted, it is possible to prevent the degree of overmodulation from becoming too large, and to achieve the same effect as any one of claims 38 to 41.
[0108]
According to the synchronous motor control device of claim 43, since the permanent magnet motor in which a permanent magnet is embedded in the rotor is adopted as the synchronous motor, it is possible to effectively use the field weakening action. In addition, the same effect as any one of claims 31 to 42 can be achieved.
[0109]
The synchronous motor control device according to claim 44 employs a device that drives a compressor as the synchronous motor, so that even if a sudden load increase occurs, the synchronous motor and the inverter may be damaged. In addition to preventing current, the same action as in any one of claims 38 to 43 can be achieved.
[0110]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a synchronous motor control method and apparatus according to the present invention will be described below in detail with reference to the accompanying drawings.
[0111]
FIG. 1 is a block diagram showing an embodiment of a synchronous motor control device of the present invention.
[0112]
This synchronous motor control device includes a converter 1a that outputs AC power with an AC power supply 1 as an input, an inverter 2 that outputs AC power with DC power as an input and supplies the AC power to the synchronous motor 3, and current detection that detects motor current. Part 3a, voltage detection part 3b for detecting the motor voltage, the rotational position of the rotor of the synchronous motor 3 (hereinafter referred to as the rotor position) and the rotational speed of the rotor (hereinafter simply referred to as the motor position) A position / velocity detection unit 4 that outputs a speed), a speed control unit 5 that performs a speed control by inputting a speed from the position / velocity detection unit 4 and a speed command given from outside, and outputs a current command; A phase control unit 6 that performs phase control by inputting a current command from the speed control unit 5 and a phase command given from the outside and outputs a current amplitude command; Current amplitude command, motor current, and rotor position (θ) are input to control the current and output a voltage command to supply the inverter 2 with the speed and current from the position / speed detector 4. The voltage command from the control unit 7 is input, and the corresponding maximum current phase is output from the preset maximum current phase (the preset maximum current phase corresponding to the motor output voltage and the rotation speed). A maximum phase table 8 and a phase limit unit 9 that limits the phase command based on the maximum current phase to be supplied to the phase control unit 6 are provided.
[0113]
Examples of the synchronous motor 3 include a permanent magnet motor {hereinafter referred to as an embedded permanent magnet motor (IPM)} in which a permanent magnet is disposed inside a rotor. Can be used.
[0114]
The maximum phase table 8 may hold the maximum current phase in the form of a function.
[0115]
The position / speed detector 4 may detect the rotor position and speed based on the induced voltage in the non-energized section. However, the position detection mechanism is provided in the synchronous motor 3 and the position detection result is obtained. The rotor position and speed may be output. Of course, a calculation based on the motor model may be performed to output the rotor position and speed.
[0116]
Further, since the configuration of each of the components is conventionally known, detailed description thereof is omitted.
[0117]
First, the current phase-torque characteristics of the IPM will be described.
[0118]
FIG. 2 is a diagram showing the current phase-torque characteristics of the IPM when the motor current is fixed.
[0119]
Since IPM generates reluctance torque in addition to magnet torque, maximum torque is generated in a phase that is ahead of the current phase of 0 degrees. At this time, as the current phase is advanced, the voltage applied to the IPM decreases because the field is weakened to weaken the field of the permanent magnet.
[0120]
As can be seen from FIGS. 3A and 3B showing the current phase-torque characteristics when the voltage is fixed, when the applied voltage of the IPM is constant, the motor current increases by advancing the current phase. The torque generation amount with respect to the motor current decreases. The IPM used for the evaluation in FIG. 3 generates a maximum torque when the current phase is 70 to 80 degrees.
[0121]
The operation of the synchronous motor control apparatus having the above configuration is as follows.
[0122]
While the synchronous motor 3 is operated by applying the output voltage of the inverter 2, the motor current is detected by the current detector 3a, the motor voltage is detected by the voltage detector 3b, and the motor current and the motor voltage are positioned. The rotor position and speed are detected by supplying to the speed detector 4.
[0123]
Based on the detected speed and a speed command given from the outside, the speed control unit 5 performs speed control to generate a current command.
[0124]
Also, a phase command given from the outside is supplied to the phase limiter 9 to limit the phase command so as not to exceed the maximum current phase output from the maximum phase table 8 based on the voltage command and speed. Of course, when the phase command is smaller than the maximum current phase, the phase command is output as it is.
[0125]
The phase control unit 6 performs phase control based on the current command from the speed control unit 5 and the phase command from the phase limit unit 9 to output a current amplitude command (and current phase).
[0126]
Based on the current amplitude command, the motor current, and the rotor position, current control is performed by the current control unit 7, and a voltage command is output so as to match the magnitude and phase of the motor current with the command value and supplied to the inverter 2.
[0127]
Therefore, the process of advancing the current phase is performed in order to increase the maximum rotation speed, and the process of controlling the current phase, not the voltage value, is performed for the speed control, and the control with the maximum torque that can be generated by the synchronous motor 3 is performed. It can be performed.
[0128]
In the synchronous motor control device having the above-described configuration, the current control unit 7 is omitted, the voltage control unit 5 directly generates voltage amplitude, the phase control unit 6 performs voltage phase control, and an inverter that matches the rotor position. Can be configured to generate a voltage command to.
[0129]
FIG. 4 is a block diagram showing another embodiment of the synchronous motor control device of the present invention.
[0130]
This synchronous motor control device is different from the synchronous motor control device of FIG. 1 only in that a maximum phase table 8 that retains the maximum current phase for each speed is employed.
[0131]
Therefore, in this case, the corresponding maximum current phase can be output from the maximum phase table 8 based on the velocity from the position / velocity detector 4 and supplied to the phase limiter 9.
[0132]
As a result, similar to the synchronous motor control device of FIG. 1, the process of advancing the current phase to increase the maximum rotation speed and the process of controlling the current phase instead of the voltage value when performing the speed control, In addition, control with the maximum torque that can be generated by the synchronous motor 3 can be performed.
[0133]
In this embodiment, the maximum phase table 8 can be replaced with a constant.
[0134]
Usually, in a synchronous motor control device having a current control loop, when torque is required, a process of increasing the motor current value is performed, and the current phase is not moved greatly. For this reason, it is often the case that current phase limitation is required only during field-weakening control at high speed. Therefore, by adopting the synchronous motor control device of this embodiment, the current phase can be limited only when it is really necessary.
[0135]
FIG. 5 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.
[0136]
This synchronous motor control device is different from the synchronous motor control device of FIG. 1 only in that a maximum phase holding unit 8 ′ is employed instead of the maximum phase table 8.
[0137]
The maximum phase holding unit 8 ′ is preset with a maximum current phase that maximizes the motor torque at the maximum output voltage of the inverter at the maximum rotation.
[0138]
Therefore, in this case, the phase command is limited by the phase limit unit 9 based on the maximum current phase from the maximum phase holding unit 8 ′, and the same operation as that of the synchronous motor control device of FIG. 1 can be achieved. .
[0139]
As a result, the configuration of the maximum phase holding unit 8 ′ can be simplified as compared with the maximum phase table 8.
[0140]
Normally, when the voltage is sufficient, the torque is controlled by the current amplitude. When the rotation speed becomes high and the voltage becomes insufficient, the current phase is advanced and field weakening control is performed. Therefore, the maximum voltage and the maximum phase are obtained at the maximum load. Therefore, there are many applications where there is no problem if the phase is limited with respect to the maximum voltage and the transient change at the maximum phase. By applying the synchronous motor control device of this embodiment to these applications, the maximum voltage, the maximum It is possible to limit the phase only to a transient change during the phase.
[0141]
FIG. 6 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.
[0142]
The synchronous motor control device is different from the synchronous motor control device of FIG. 1 in that the maximum current phase and the minimum current phase immediately before the inverter output current becomes the limit value are stored in advance as the maximum phase table 8 for each required torque. The point which employ | adopted the thing and the point which further includes the torque estimation part 10 which estimates output torque from a current amplitude and a current phase, and supplies it to the maximum phase table 8 are only.
[0143]
Therefore, in this case, the torque estimation unit 10 estimates the output torque from the current amplitude and current phase and supplies the estimated output torque to the maximum phase table 8, and the output current at that torque is limited from the maximum phase table 8. Read the current phase. And the phase limit part 9 restrict | limits a phase instruction | command with the electric current phase, and it can prevent the problem that an output torque falls because an electric current restriction | limiting acts by the overshooting of an electric current phase.
[0144]
As a result, the phase can be controlled to the maximum while preventing a decrease in torque.
[0145]
FIG. 7 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.
[0146]
This synchronous motor control device is different from the synchronous motor control device of FIG. 1 in that instead of providing the maximum phase table 8, the current control unit 7 functions to limit the output current when the output current exceeds the limit, The only thing that has been adopted is the one having a function of outputting a flag indicating that the current is limited.
[0147]
Therefore, in this case, by supplying a flag from the current control unit 7 indicating that the output current has reached the limit value to the phase limit unit 9, it is prohibited that the current phase protrudes further. It is possible to prevent the disadvantage that the output torque is reduced due to the current limit acting more than excessively.
[0148]
As a result, the phase can be controlled to the maximum while preventing a decrease in torque.
[0149]
FIG. 8 is a diagram showing torque-current phase characteristics when the voltage and current are limited.
[0150]
This characteristic was obtained for an IPM having a maximum voltage of 200 V, a maximum current of 20 A, and a maximum rotation speed of 120 rps.
[0151]
In the synchronous motor control device of FIG. 4 (Claim 2), the line passing through (1) at 120 rps and (2) at 70 rps becomes the maximum current phase, and in the synchronous motor control device (Claim 1) of FIG. The current phase of the synchronous motor control device of FIG. 4 is obtained for each voltage. In the synchronous motor control device of FIG. 5 (Claim 4), the vertical line passing (1) is the maximum current phase, and FIG. Alternatively, in the synchronous motor control device of FIG. 7 (Claim 5), the current phase is limited within the line outside the current limit 20 Arms.
[0152]
Further, it is preferable to obtain these maximum current phases and select a smaller maximum current phase among them to limit the phase command, and it is possible to prevent the phase command from becoming larger than necessary.
[0153]
FIG. 9 is a diagram for explaining the operation phase of the IPM.
[0154]
When there is a margin in the inverter output voltage during low-speed rotation, the current phase is changed in the order of (1) → (2) → (3) as the torque increases.
[0155]
If the inverter output voltage does not flow sufficiently at the operating point (1) → (2) → (3) during high-speed rotation, the field is weakened by advancing the phase and the current value is increased. To generate more torque. For example, in the case of 70 rps, the operating point of (2) → (3) cannot be taken, so by controlling the current phase in the order of (1) → (2) → (4), the maximum IPM has Torque can be extracted.
[0156]
In a further high-speed region, a region where the torque decreases conversely by advancing the current phase occurs in a region below the current limit value (see the right side of (6) of 120 rps). In this region, if the phase is advanced to generate torque, the torque decreases conversely, so that the maximum capability of the IPM cannot be exhibited.
[0157]
Therefore, the maximum current phase indicated by (5) → (6) may be provided for each rotation speed so as not to enter this region, and the maximum torque of the IPM can be extracted.
[0158]
In the above, the lower limit value of the current phase is set to the maximum torque line, but it can be set to the maximum efficiency line. However, since the maximum efficiency is around 40 degrees, the lower limit value of the current phase can be set to a straight line (constant), and the configuration can be simplified.
[0159]
FIG. 10 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.
[0160]
The synchronous motor control device is different from the synchronous motor control device of FIG. 6 in that it further includes a minimum phase table 11 that receives the output torque from the torque estimation unit 10 and a maximum phase table 8 from the torque estimation unit 10. A point that uses the output torque and the detected speed as an input and outputs a maximum current phase, instead of the phase limit unit 9, a maximum current phase from the maximum phase table 8, a minimum current phase from the minimum phase table 11, And a point that employs a phase calculation unit 9 ′ that calculates a current phase by inputting a voltage command from the current control unit 7 and outputs the current phase, and a point that outputs a current amplitude command as the speed control unit 5, And only the point which adopted what outputs a current command as phase control part 6 is adopted.
[0161]
Since the minimum phase table 11 holds a torque-minimum current phase curve to output the minimum current phase, when the torque is given, the corresponding minimum current phase is output. Specifically, the torque-minimum current phase curve represented by (1) → (2) → (3) in FIG. 9 is held. However, a fixed value can be substituted.
[0162]
The maximum phase table 8 holds the maximum current phase due to current limitation and the maximum current phase for each rotation speed under voltage constraint, and outputs the smaller maximum current phase as appropriate when torque is applied. Specifically, each rotation under the maximum current phase due to current limitation represented by (3) → (4) → (5) in FIG. 9 and the voltage constraint represented by (5) → (6). The maximum current phase for each number is retained.
[0163]
The phase calculation unit 9 ′ performs phase-lag control of the phase command when the voltage command does not reach the maximum voltage, and performs phase-advance control of the phase command when the voltage command reaches the maximum voltage. If the minimum current phase from the minimum phase table 11 is reached as a result of the slow phase control, the slow phase control is stopped and the minimum current phase from the minimum phase table 11 is used as the phase command. Conversely, when the phase advance control results in the maximum current phase from the maximum phase table 8, the phase advance control is stopped and the maximum current phase from the maximum phase table 8 is used as the phase command.
[0164]
Therefore, in this case, the output torque is estimated by the torque estimation unit 10 based on the current command and supplied to the maximum phase table 8 and the minimum phase table 11, so that the maximum current phase and the minimum phase from the maximum phase table 8 are obtained. The minimum current phase from the table 11 is supplied to the phase calculator 9 ′.
[0165]
The phase calculation unit 9 ′ outputs a phase command by performing a phase advance control or a phase delay control corresponding to whether or not the voltage command reaches the maximum voltage between the maximum current phase and the minimum current phase. To do.
[0166]
Based on the output phase command, the same operation as that of the synchronous motor control device of FIG. 6 can be achieved.
[0167]
As a result, the synchronous motor can be controlled by setting the current phase to a value between the maximum current phase and the minimum current phase.
[0168]
FIG. 11 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.
[0169]
This synchronous motor control device is different from the synchronous motor control device of FIG. 10 in that only the speed detected as the maximum phase table 8 is input and the maximum current phase is output, and the phase calculation unit 9 ′ The current phase is calculated by inputting the maximum current phase from the maximum phase table 8, the minimum current phase from the minimum phase table 11, the current command from the phase control unit 6, and the voltage command from the current control unit 7 as a phase command. It is only the point which adopts what is output.
[0170]
The maximum phase table 8 holds only the maximum current phase for each rotation speed under voltage constraint.
[0171]
The phase calculation unit 9 ′ performs the phase delay control when the current phase is limited by the maximum current phase, and achieves the same operation as the phase calculation unit 9 ′ of FIG.
[0172]
Therefore, also in this case, the synchronous motor can be controlled by setting the current phase to a value between the maximum current phase and the minimum current phase.
[0173]
It is preferable that the compressor for an air conditioner is driven by a synchronous motor controlled by any one of the synchronous motor control devices.
[0174]
In this case, the synchronous motor is cooled by the refrigerant, and extremely high cooling efficiency can be achieved. Therefore, the limit of the capacity of the synchronous motor can be drawn without particularly considering the heat radiation of the synchronous motor.
[0175]
Moreover, when driving the compressor for air conditioners by IPM, it is preferable to set the upper limit of the current phase to approximately 60 to 80 degrees.
[0176]
FIG. 12 is a diagram showing an operation area of the air conditioner compressor.
[0177]
The compressor for an air conditioner does not require operation at extremely low speed and operation at high speed and high load, and constant torque is required at other rotational speeds. For this reason, the maximum current limit is not applied during low-speed operation. Also, the maximum torque current phase is not applied during medium speed rotation.
[0178]
Therefore, by setting the upper limit of the current phase to the maximum torque current phase in the vicinity of the maximum rotational speed, the maximum capacity of the IPM can be extracted and the air conditioner compressor can be operated.
[0179]
FIG. 13 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.
[0180]
The synchronous motor control device is different from the synchronous motor control device of FIG. 11 in that the phase calculation unit 9 ′ further has a function of outputting a command to drop the speed on condition that the current limit and the phase limit are reached. It is only the point which further includes the subtraction part 5a which subtracted the speed drooping command from the point employ | adopted and the speed command given from the outside, and supplies to the speed control part 5.
[0181]
In this case, on the condition that the current limit and the phase limit are reached, a speed drooping command can be output from the phase calculation unit 9 ′, and the subtraction unit 5a can decrease the speed command.
[0182]
Based on the reduced speed command, the same operation as that of the synchronous motor control device of FIG. 11 can be achieved.
[0183]
As a result, the synchronous motor can be driven below the current limit and the phase limit, and the divergence of the control system can be prevented.
[0184]
Further explanation will be given.
[0185]
When speed droop control is not performed at all, there is a possibility that the synchronous motor can be driven without any inconvenience as long as the current limit and phase limit are reached for a moment and the current and phase are limited. However, if the current and phase are constantly limited, the phase error and current error accumulate in the internal state of the controller such as the PI controller, causing inconveniences such as divergence of the PI controller. In addition, the speed control system controller also diverges because the required torque required by the speed control system cannot be generated.
[0186]
However, if the synchronous motor control device of FIG. 13 is employed, it is possible to prevent the current and phase from being limited by performing the speed droop control, and to prevent the controller from diverging.
[0187]
FIG. 14 is a block diagram showing a main part of still another embodiment of the synchronous motor control device of the present invention.
[0188]
This synchronous motor control device performs PI control calculation using the difference between the speed command given from outside and the detected speed as input, and performs phase control using the current amplitude command as input. , A phase control unit 6 that outputs a current command, a current limiter unit 23 that performs current limitation using the current command as an input, and performs a PI control calculation using the difference between the current command from the current limiter unit 23 and the motor current as an input, A current control unit 7 that outputs a voltage command; a non-interference unit 25 that outputs a d-axis voltage command and a q-axis voltage command by performing non-interference processing using the voltage command as an input; and a d-axis voltage command and a q-axis voltage command Dq → three-phase conversion unit 26 that converts a three-phase voltage command based on the rotor position as an input, a dead time compensation unit 27 that performs a dead time compensation by receiving a three-phase voltage command, The duty limit unit 28 that outputs the three-phase voltage command by limiting the duty by receiving the three-phase voltage command after compensation of the dtime, and the three-phase voltage command from the duty limit unit 28 is used as a control signal to generate a three-phase AC voltage. The inverter 2 to be applied to the synchronous motor 3, the voltage detection unit 3 b that detects the voltage based on the rotor position with the input of the three-phase voltage command from the duty limit unit 28, and the motor current based on the rotor position It includes a current detection unit 3a and a position / speed detection unit 4 that receives the detected voltage and motor current as input and estimates the rotor position and speed based on a preset motor model.
[0189]
When the output voltage of the inverter 2 reaches the limit, the duty limit unit 28 multiplies the constant K2 by the constant K2 unit 34 and outputs a voltage over value to be supplied to the phase control unit 6 as a phase advance command.
[0190]
The current limiter 23 determines whether or not the current command is over the current limit, and reduces the current value to the current limit while maintaining the phase of the current command in response to the supply of the current command over the current limit. In addition, an I term limit command is output to fix the internal state integral term (hereinafter referred to as I term) of the speed control unit 5 to a value before the current command reaches the upper limit.
[0191]
The phase control unit 6 performs phase advance control of the current phase in response to the phase advance command being supplied, stops the phase advance when the current phase reaches the upper limit, and sets the internal state I term of the speed control unit 5 to An I term restriction command is output to fix the current phase to a value before reaching the upper limit.
[0192]
FIG. 15 is a block diagram showing in detail the configuration of the phase control unit.
[0193]
A phase control unit 22a that performs phase advance control based on the phase advance command and performs phase control in response to the fact that the phase advance command is not supplied and outputs the phase command, and the phase command is set to the phase lower limit value. A phase lower limit unit 22b that detects that the phase command has been reached and supplies a phase control stop command to the phase control unit 22a, and detects that the phase command has reached the phase upper limit value and issues a phase advance control stop command to the phase control unit 22a. And a phase upper limit unit 22c for outputting an I term restriction command, a cos unit 22d for obtaining a cos component of the phase command, a sin unit 22e for obtaining a sin component of the phase command, a cos component and a current amplitude command. A first multiplication unit 22f that multiplies and outputs a q-axis current command, and a second multiplication unit 22g that multiplies the sin component and the current amplitude command to output a d-axis current command.
[0194]
The operation of the synchronous motor control apparatus having the above configuration is as follows.
[0195]
Until the output voltage of the inverter 2 reaches the limit as the rotational speed of the synchronous motor 3 increases, the inverter 2 is controlled by performing speed control, phase control, current control, etc., and the rotational speed of the synchronous motor 3 is increased. Let
[0196]
When the output voltage of the inverter 2 reaches the limit as the rotational speed of the synchronous motor 3 increases, a phase advance command is supplied from the duty limit unit 28 to the phase control unit 6. Phase control is performed to advance the current phase.
[0197]
When the current phase reaches the upper limit, a phase advance control stop command is output from the phase upper limit unit 22c to stop the phase advance control, and an I term limit command is output to output the internal state in the speed control unit 5 The I term (integral term) is fixed to a value just before the current phase reaches the upper limit.
[0198]
When the current command exceeds the current limit, the current limiter unit 23 reduces the current value to the current limit while maintaining the current phase, and outputs an I term limit command to output the current command in the speed control unit 5. Of the internal states, the I term is fixed to a value just before the current value reaches the current limit.
[0199]
As a result, divergence of the speed control unit can be prevented and stable control of the synchronous motor can be realized.
[0200]
FIG. 16 is a block diagram showing a main part of still another embodiment of the synchronous motor control device of the present invention.
[0201]
The synchronous motor control device is different from the synchronous motor control device of FIG. 13 in that a position / speed detection unit 4 that uses a motor model to detect the rotor position and speed is employed, instead of the phase control unit 6. A waveform generator 12 that generates a waveform pattern in which an arbitrary harmonic component is superimposed according to the rotor position, and a multiplier 12a that multiplies the current command by the waveform pattern and outputs a current command to be supplied to the current controller 7. And a point that further includes a voltage limiter 13 that clips the voltage command from the current control unit 7 with the inverter output limit voltage.
[0202]
In this synchronous motor control device, since the waveform generator 12 outputs a waveform pattern in which an arbitrary harmonic component is superimposed according to the rotor position, it is superimposed on the current command and supplied to the current controller 7. Outputs voltage command.
[0203]
If this voltage command is less than or equal to the inverter output limit voltage, it can be supplied to the inverter 3 as it is, but if it is greater than the inverter output limit voltage, it is clipped at the inverter output limit voltage by the voltage limiter 13 and supplied to the inverter 3.
[0204]
If the voltage command is clipped, the output voltage approaches a rectangular wave, the fundamental wave component can be increased even at the same output limit voltage, and high-speed rotation can be achieved. In such a high speed range, the mechanical noise becomes larger than the motor noise, and the noise reduction of the motor becomes less meaningful.
[0205]
In this embodiment, in order to approximate the voltage waveform to a rectangular wave, it is possible to have a characteristic that gradually approaches the output limit voltage. Moreover, even if it is a waveform other than a rectangular wave, the same effect | action can be achieved by employ | adopting a waveform with a high voltage utilization factor.
[0206]
Furthermore, since arbitrary harmonic components can be superimposed to obtain a free waveform, it is possible to achieve noise reduction in a low speed region (current waveform optimization method in a brushless DC motor), Chikiri et al., 1995. (Refer to the annual conference of the Industrial Application Division of the Institute of Electrical Engineers of Japan). Here, if this waveform is set to a sine wave, the harmonic component becomes only the fundamental wave, so that noise and vibration due to harmonics can be easily suppressed.
[0207]
FIG. 17A is a diagram showing a state in which the voltage command is set to the inverter output limit voltage or lower, and the fundamental wave component is also lower than the inverter output limit voltage.
[0208]
On the other hand, (B) in FIG. 17 is a diagram showing a state in which the voltage command is set to be larger than the inverter output limit voltage. By clipping the voltage command by the voltage limiter 13, an output voltage waveform close to a rectangular wave is obtained. To do. As a result, the fundamental wave component can be increased as compared with the case of FIG.
[0209]
17A and 17B both show a single-phase case for simplification of description, but can also be similarly expressed in the case of three phases.
[0210]
18 shows the actual measurement result of the operation range {see (A)} by the synchronous motor control device of FIG. 16, the simulation result of the operation range by the synchronous motor control device of FIG. 16 (see (B)), and the synchronization without using the voltage limiter. It is a figure which shows the simulation result {refer (C)} of the driving range by a motor control apparatus.
[0211]
As can be seen from FIG. 18, by providing a voltage limiter, the operating range can be expanded to the high speed side.
[0212]
The compressor can be driven by a synchronous motor controlled by the synchronous motor control device shown in FIGS.
[0213]
In general, a compressor has a problem of noise and vibration and needs to be driven to a high speed. However, by adopting the synchronous motor control device shown in FIGS. 13 to 16, noise and vibration can be reduced and high speed can be achieved. Can be driven up to.
[0214]
FIG. 19 is a block diagram showing a main part of still another embodiment of the synchronous motor control device of the present invention.
[0215]
This synchronous motor control device performs PI control calculation using the difference between the speed command given from outside and the detected speed as input, and performs phase control using the current amplitude command as input. The phase control unit 6 that outputs a current command (d-axis current command and q-axis current command) and outputs a phase over value (over value based on the limit phase), and the difference between the current command and the motor current A current control unit 7 that performs a PI control calculation as an input and outputs a voltage command (d-axis voltage command and q-axis voltage command); an overvoltage detector 35 that detects an overvoltage condition using the voltage command as input; and d The dq → three-phase converter 26 that converts the shaft voltage command and the q-axis voltage command as inputs and converts them into a three-phase voltage command based on the rotor position; From the duty limit unit 28 that outputs a phase voltage command, the inverter 2 that generates a three-phase AC voltage by using the three-phase voltage command from the duty limit unit 28 as a control signal, and applies it to the synchronous motor 3, and the duty limit unit 28 The voltage detector 3b detects the voltage based on the rotor position with the three-phase voltage command as input, the current detector 3a detects the motor current based on the rotor position, and the rotor with the detected voltage and motor current as input. And a position detector 33 ′ for estimating the position and speed.
[0216]
In order to prevent the current control unit 7 from diverging with respect to a transient large current, the duty limit unit 28 responds to the duty limitation in response to the internal state I term of the current control unit 7. Can be configured to output an I-term limit command to fix the voltage command to a value before the voltage command reaches the upper limit.
[0217]
The phase control unit 6 also outputs a phase over value (over value with reference to the limit phase), and supplies the value obtained by multiplying the constant K3 by the constant K3 unit 36 to the subtracting unit 37, so that it is given from the outside. Decrease the speed command. Therefore, when the current phase exceeds the limit phase by the phase advance control, the phase over value can be multiplied by the constant K3 and subtracted from the speed command to prevent the control system from diverging.
[0218]
In the synchronous motor control device configured as described above, a current amplitude command is generated by the speed control 21 based on the speed difference, and a phase control is performed by the phase control unit 6 to generate a current command.
[0219]
Then, based on the difference between the current command from the phase control unit 6 and the detected motor current, the current control unit 7 generates a voltage command to control the motor output voltage.
[0220]
When the rotational speed increases and the motor induced voltage rises and reaches the inverter output limit voltage, the inverter 2 cannot output the voltage command output from the current control unit 7 completely. Exceeds 100%, the output voltage is clamped.
[0221]
However, if only the peak of the output voltage is clamped and the duty does not exceed 100%, voltage control is possible. For this reason, the current control unit 7 does not diverge immediately, and can perform current control on average even when the output voltage becomes a rectangular wave shape.
[0222]
As a result, the amplitude of the inverter output voltage is increased, and the motor current can be controlled even when voltage clamping occurs.
[0223]
A conventional synchronous motor control device is shown in FIG. 20 for comparison with the synchronous motor control device of FIG.
[0224]
The synchronous motor control device in FIG. 20 detects a motor current, a converter 1a that outputs DC power with an AC power supply 1 as an input, an inverter 2 that outputs AC power with DC power as an input, and supplies the AC power to the synchronous motor 3. A current detection unit 3a, a voltage detection unit 3b for detecting the motor voltage, a position / speed detection unit 4 for detecting the rotor position and speed by inputting the motor current and the motor voltage, a speed command given from the outside, The speed control unit 5 that performs speed control by inputting the rotor position and speed from the speed detection unit 4 and outputs a current command or voltage command, and performs current control by inputting the current command and motor current from the speed control unit 5 A current control unit 7 that outputs a voltage command, a selection unit 15 that selects a voltage command from the speed control unit 5 or a voltage command from the current control unit 7, and a selection The voltage command selected by 15 is input and clipped at the inverter output limit voltage, and the voltage limiter 13 that outputs the voltage saturation signal and the voltage saturation signal are input to perform switching determination, and the switching signal is sent to the speed control unit 5 and The switching determination part 14 supplied to the selection part 15 is included.
[0225]
In this synchronous motor control device, the current control loop is used and the inverter output voltage is used to the full to control the voltage clamp to occur. At the time of voltage clamp, the current control minor loop is stopped and the voltage control is performed. .
[0226]
Therefore, the motor current cannot be controlled when voltage clamping occurs. As a result, when the current increases due to disturbance or the like at the time of voltage clamping, current control cannot be performed, and there arises a disadvantage that the synchronous motor and the inverter are destroyed.
[0227]
As can be seen by comparing with the synchronous motor control device of FIG. 20, by adopting the synchronous motor control device of FIG. 19, current control is performed even when the current increases due to disturbance or the like during voltage clamping. And the destruction of the synchronous motor and the inverter can be prevented.
[0228]
FIG. 21 is a block diagram showing a main part of still another embodiment of the synchronous motor control device of the present invention.
[0229]
This synchronous motor control device performs PI control calculation using the difference between the speed command given from outside and the detected speed as input, and performs phase control using the current amplitude command as input. The current control is output as a phase control unit 6; the current command is input to detect a current excess state; the current excess value is output; and the current command from the current excess detector 38 is input. The current limiter 23 for limiting the current when the current limiter 23 is input, the difference between the current command from the current limiter unit 23 and the motor current is input to perform the PI control calculation, and the voltage control unit 7 outputs the voltage command. A non-interference unit 25 that performs non-interference processing as an input and outputs a d-axis voltage command and a q-axis voltage command, and detects an overvoltage state using the d-axis voltage command and the q-axis voltage command as inputs. An overvoltage detector 35 that outputs a voltage overvalue, an overmodulation gain correction unit 39 that performs correction based on an overmodulation gain using the d-axis voltage command and the q-axis voltage command from the overvoltage detector 35 as inputs, A dq → three-phase conversion unit 26 that converts the d-axis voltage command and the q-axis voltage command from the modulation gain correction unit 39 into inputs and converts them into a three-phase voltage command based on the rotor position; A dead time compensation unit 27 that performs time compensation, a duty limit unit 28 that outputs a three-phase voltage command by performing a duty limit by inputting a three-phase voltage command after the dead time compensation, and a three-phase voltage from the duty limit unit 28 Using the command as a control signal, the inverter 2 that generates a three-phase AC voltage and applies it to the synchronous motor 3, and the three-phase voltage command from the duty limit unit 28 A voltage detector 3b that detects a voltage based on the rotor position as an input, a current detector 3a that detects a motor current based on the rotor position, and a motor model that is set in advance using the detected voltage and motor current as inputs. And a position / speed detector 4 for estimating the rotor position and speed based on the above.
[0230]
The overvoltage detector 35 detects the degree of overmodulation (for example, phase voltage command before clamping / phase voltage after clamping), and the constant K2 unit 34 multiplies the constant K2 to control the phase as a phase advance command. The voltage over value is output to be supplied to the unit 6.
[0231]
The current limiter 23 determines whether or not the current command is over the current limit, and reduces the current value to the current limit while maintaining the phase of the current command in response to the supply of the current command over the current limit. In addition, an I term limit command is output to fix the internal state I term of the speed control unit 5 to a value before the current command reaches the upper limit.
[0232]
The duty limit unit 28 fixes the internal state I term of the current control unit 7 to a value before the voltage reaches the upper limit in response to the duty being limited (for example, the duty has reached 100%). Therefore, an I term restriction command is output.
[0233]
The phase control unit 6 performs phase advance control of the current phase in response to the supply of the phase advance command, stops phase advance when the current phase reaches the upper limit, and is multiplied by the constant K3 by the constant K3 unit 36. Then, a phase over value is output to be supplied to the subtraction unit 37 as a deceleration command. Specifically, for example, the phase control unit 6 is configured by the configuration shown in FIG.
[0234]
In response to detecting an overcurrent state, the overcurrent detector 38 multiplies the constant K1 by the constant K1 unit 40 and outputs an overcurrent value to be supplied to the subtraction unit 37 as a deceleration command.
[0235]
When the synchronous motor control device having this configuration is adopted, the inverter 2 is controlled by performing speed control by the speed control unit 5, phase control by the phase control unit 6, and current control by the current control unit 7, and the synchronous motor 3. When the voltage command exceeding the inverter output limit voltage is supplied to the duty limit unit 28 while driving the voltage command, the voltage command is clamped, so that the output voltage command is lowered. However, in this synchronous motor control device, the overmodulation gain correction unit 39 amplifies the voltage amplitude so as to compensate for the decrease in the voltage command due to the clamp, so that it is possible to compensate for the decrease in the voltage command. It is possible to compensate for a decrease in torque due to a decrease in voltage command.
[0236]
For example, when the output waveform before clamping is a sine wave, the voltage correction coefficient in the overmodulation gain correction unit 39 is set as shown in FIG. For example, the voltage correction coefficient may be given as a table, but an expression representing the voltage correction coefficient may be given.
[0237]
Therefore, a corrected voltage command can be obtained by selecting a voltage correction coefficient according to the command voltage and multiplying the command voltage.
[0238]
The voltage correction coefficient shown in FIG. 22 corresponds to the case of a single phase, and is obtained by plotting the ratio between the fundamental wave of the command voltage and the fundamental wave after clamping. Of course, it can be easily calculated in the same manner for the case of three phases.
[0239]
FIG. 23 is a block diagram showing a main part of still another embodiment of the synchronous motor control device of the present invention.
[0240]
The synchronous motor control device is different from the synchronous motor control device of FIG. 21 in that the non-interference unit 25, the overmodulation gain correction unit 39, and the dead time compensation unit 27 are omitted, and the observer unit 33 is replaced with a motor. The only difference is that a position detector 33 ′ that detects the rotor position and speed using the current and motor voltage as inputs is employed.
[0241]
When the synchronous motor control device having this configuration is adopted, the inverter 2 is controlled by performing speed control by the speed control unit 5, phase control by the phase control unit 6, and current control by the current control unit 7, and the synchronous motor 3. During the driving, the degree of overmodulation is detected by the voltage excess detector 35 and fed back to the phase controller 6 through the constant K2 unit 34.
[0242]
Then, the phase controller 6 delays the current phase when the degree of overmodulation is lower than a predetermined value, and finally commands a desired current phase such as a current phase corresponding to maximum efficiency, maximum torque, etc. Conversely, when the degree of overmodulation is greater than or equal to a predetermined value, the current phase is advanced, the motor induced voltage is lowered by field weakening control, and the degree of overmodulation is lowered, thereby making the degree of overmodulation a desired value. it can.
[0243]
Moreover, it is preferable to employ IPM as a synchronous motor controlled by the synchronous motor control device of FIG. 19, FIG. 21, or FIG. In this case, the inductance of the IPM is large and field weakening control can be performed effectively.
[0244]
Furthermore, it is preferable to drive the compressor by a synchronous motor controlled by the synchronous motor control device of FIG. 19, FIG. 21, or FIG.
[0245]
Conventionally, in a compressor, there is a demand for using the inverter output voltage to the limit in order to place importance on efficiency. For this reason, the synchronous motor was conventionally driven by voltage control.
[0246]
In general, in a compressor for an air conditioner or a refrigerator, a sudden load increase occurs due to suction of liquid refrigerant. At this time, if current control is not performed, there is a high risk that an excessive current will damage the synchronous motor and the inverter. In order to eliminate such inconvenience, conventionally, protection by hardware is performed, but in this case, the compressor is completely stopped at the time of overcurrent, and it takes time to restart. Because the temperature can not be adjusted, comfort and so on will be impaired.
[0247]
However, if the synchronous motor control device of FIG. 23 is adopted, current control can be performed even in the above-described case. As a result, the inverter voltage is utilized to the limit while preventing damage to the synchronous motor and the inverter. Since the synchronous motor can be driven, it is possible to prevent a decrease in comfort due to the stop of the compressor.
[0248]
【The invention's effect】
According to the first aspect of the present invention, when the current phase is advanced to increase the maximum rotation speed, or the voltage phase or the current phase is operated to control the speed, the control is performed near the maximum torque that can be generated by the synchronous motor. In addition, it is possible to prevent the occurrence of trips and to maximize the use of voltage and current, and to achieve maximum efficiency by miniaturizing the synchronous motor and optimal tuning. There is an effect.
[0249]
The invention of claim 2 can control the synchronous motor using the upper limit value of the current phase set for each speed, and can maintain the current phase at the time of field weakening control at high speed below the upper limit value. In addition, the occurrence of trips can be prevented, and the voltage and current can be utilized to the maximum. As a result, the synchronous motor can be miniaturized and the maximum efficiency can be achieved by optimal tuning. Play.
[0250]
The invention of claim 3 has the same effect as that of claim 1 or claim 2.
[0251]
The invention of claim 4 can simplify the process and prevent the occurrence of trips, and can maximize the use of voltage and current. As a result, the synchronous motor can be miniaturized and the maximum efficiency can be achieved by optimal tuning. There is a specific effect that can be realized.
[0252]
The invention of claim 5 can prevent a torque drop and can control the current phase to the maximum, and can prevent the occurrence of a trip, and can make maximum use of voltage and current. As a result, the synchronous motor can be miniaturized and the maximum efficiency can be achieved by the optimum tuning.
[0253]
According to the invention of claim 6, by limiting the current phase by the selected upper limit value, it is possible to prevent the occurrence of trip and to make maximum use of the voltage and current. And a special effect that the maximum efficiency can be achieved by the optimum tuning.
[0254]
The invention of claim 7 can control the current phase to a phase between the lower limit value and the upper limit value, and has the same effect as any one of claims 1 to 6.
[0255]
The invention of claim 8 can cool the synchronous motor that generates a large amount of heat during field-weakening control by the refrigerant, and has the same effect as any one of claims 1 to 7 without particularly considering the heat dissipation of the synchronous motor. Play.
[0256]
According to the ninth aspect of the present invention, the maximum capacity of the permanent magnet motor can be extracted to achieve good controllability, and the same effect as the eighth aspect can be achieved.
[0257]
According to the invention of claim 10, the permanent magnet motor can be driven below the current limit and the phase limit to prevent the control system from diverging, and the occurrence of trip can be prevented and the voltage and current can be maximized. Therefore, the synchronous motor can be miniaturized and the maximum efficiency can be achieved by the optimum tuning.
[0258]
The invention of claim 11 can prevent the divergence of the speed control system, can prevent the occurrence of trip, and can make maximum use of the voltage and current. And a special effect that the maximum efficiency can be achieved by the optimum tuning.
[0259]
The invention of claim 12 can achieve noise reduction in a low speed range by adjusting a voltage waveform as appropriate, and can achieve an expansion of a high-speed operation range, and is similar to claim 10 or claim 11. The effect of.
[0260]
The invention of claim 13 has the same effect as that of claim 12 in addition to being able to easily suppress noise and vibration due to harmonics.
[0261]
The invention of claim 14 can achieve a sufficient expansion of the high-speed operation range, and has the same effect as that of claim 12 or claim 13.
[0262]
The invention of claim 15 can reduce noise and vibration and can be driven to a high speed, and has the same effect as any of claims 10 to 14.
[0263]
The invention of claim 16 can control the motor current even when the current increases due to a disturbance or the like when the voltage is limited, and can prevent the occurrence of a trip, and make maximum use of the voltage and current. As a result, the synchronous motor can be miniaturized and the maximum efficiency can be achieved by the optimum tuning.
[0264]
The invention of claim 17 has the same effect as that of claim 16.
[0265]
The invention of claim 18 can maintain the torque before the current limit, and has the same effect as that of claim 16 or claim 17.
[0266]
The invention of claim 19 has the same effect as that of claim 18.
[0267]
The invention of claim 20 can prevent the degree of overmodulation from becoming too large, and has the same effect as any of claims 16 to 19.
[0268]
The invention of claim 21 can effectively use the field-weakening action, and has the same effect as any one of claims 9 to 20.
[0269]
The invention of claim 22 can prevent an overcurrent that causes damage to the synchronous motor and the inverter even when a sudden load increase occurs, and has the same effect as any of claims 16 to 21. Play.
[0270]
The invention according to claim 23 controls the vicinity of the maximum torque that can be generated by the synchronous motor when the current phase is advanced to increase the maximum rotation speed or the voltage phase or the current phase is manipulated to control the speed. In addition, it is possible to prevent trips from occurring and to maximize the use of voltage and current, and to achieve maximum efficiency by miniaturization of synchronous motors and optimal tuning. There is an effect.
[0271]
The invention of claim 24 can control the synchronous motor using the upper limit value of the current phase set for each speed, and can maintain the current phase at the time of field-weakening control at high speed below the upper limit value. In addition, the occurrence of trips can be prevented, and the voltage and current can be utilized to the maximum. As a result, the synchronous motor can be miniaturized and the maximum efficiency can be achieved by optimal tuning. Play.
[0272]
The invention of claim 25 has the same effect as that of claim 23 or claim 24.
[0273]
According to the invention of claim 26, the configuration can be simplified to prevent the occurrence of a trip, and the voltage and current can be utilized to the maximum. As a result, the synchronous motor can be miniaturized and the maximum efficiency can be achieved by the optimum tuning. There is a specific effect that can be realized.
[0274]
According to the invention of claim 27, it is possible to prevent torque reduction and to control the current phase as much as possible, to prevent the occurrence of a trip in advance and to make maximum use of voltage and current. As a result, the synchronous motor can be miniaturized and the maximum efficiency can be achieved by the optimum tuning.
[0275]
According to the invention of claim 28, by limiting the current phase by the selected upper limit value, it is possible to prevent the occurrence of trip and to make maximum use of voltage and current, and in turn, the size of the synchronous motor can be reduced. And a special effect that the maximum efficiency can be achieved by the optimum tuning.
[0276]
The invention of claim 29 can control the current phase to a phase between the lower limit value and the upper limit value, and has the same effect as any of claims 23 to 28.
[0277]
The invention of claim 30 can cool the synchronous motor with the refrigerant, and has the same effect as any of claims 23 to 29 without particularly considering the heat radiation of the synchronous motor.
[0278]
The invention of claim 31 can bring out the maximum performance of the permanent magnet motor to realize good operation characteristics, and has the same effect as that of claim 30.
[0279]
According to the invention of claim 32, the permanent magnet motor can be driven below the current limit and the phase limit to prevent the control system from diverging, and the occurrence of trip can be prevented and the voltage and current can be maximized. Therefore, the synchronous motor can be miniaturized and the maximum efficiency can be achieved by the optimum tuning.
[0280]
The invention of claim 33 can prevent divergence of the speed control system, can prevent the occurrence of trip, and can make maximum use of the voltage and current, and further downsize the synchronous motor. In addition, there is a characteristic that the maximum efficiency can be realized by the optimum tuning.
[0281]
The invention of claim 34 can achieve noise reduction in a low speed range by adjusting the voltage waveform as appropriate, and can achieve an expansion of the high speed operation range, and is similar to claim 32 or claim 33. The effect of.
[0282]
The invention of claim 35 has the same effect as that of claim 34 in addition to being able to easily suppress noise and vibration due to harmonics.
[0283]
The invention of claim 36 can achieve a sufficient expansion of the high-speed operation range, and has the same effect as that of claim 34 or claim 35.
[0284]
The invention of claim 37 can reduce noise and vibration and can be driven to a high speed, and has the same effects as any of claims 32 to 36.
[0285]
According to the invention of claim 38, the motor current can be controlled even when the current increases due to disturbance or the like when the voltage is limited, and the occurrence of trip can be prevented and the voltage and current are utilized to the maximum. As a result, the synchronous motor can be miniaturized and the maximum efficiency can be achieved by the optimum tuning.
[0286]
The invention of claim 39 has the same effect as that of claim 38.
[0287]
The invention of claim 40 has the same effect as that of claim 38 or claim 39 in addition to being able to keep the torque before the current is limited.
[0288]
The invention of claim 41 has the same effect as that of claim 40.
[0289]
The invention of claim 42 can prevent the degree of overmodulation from becoming too large, and has the same effect as any of claims 38 to 41.
[0290]
The invention of claim 43 can effectively use the field-weakening action and has the same effect as any of claims 31 to 42.
[0291]
The invention of claim 44 can prevent an overcurrent that causes damage to the synchronous motor and the inverter even when a sudden load increase occurs, and has the same effect as any of claims 38 to 43. Play.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of a synchronous motor control device of the present invention.
FIG. 2 is a diagram showing a current phase-torque characteristic of an IPM when a motor current is fixed.
FIG. 3 is a diagram showing current phase-torque characteristics when the voltage is fixed.
FIG. 4 is a block diagram showing another embodiment of the synchronous motor control device of the present invention.
FIG. 5 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.
FIG. 6 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.
FIG. 7 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.
FIG. 8 is a diagram showing torque-current phase characteristics when voltage and current are limited.
FIG. 9 is a diagram illustrating an operation phase of IPM.
FIG. 10 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.
FIG. 11 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.
FIG. 12 is a diagram showing an operation area of an air conditioner compressor.
FIG. 13 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.
FIG. 14 is a block diagram showing a main part of still another embodiment of the synchronous motor control device of the present invention.
FIG. 15 is a block diagram showing in detail the configuration of a phase control unit.
FIG. 16 is a block diagram showing a main part of still another embodiment of the synchronous motor control device of the present invention.
FIG. 17 is a diagram illustrating a state in which the voltage command is set to be equal to or lower than the inverter output limit voltage, and a diagram illustrating a state in which the voltage command is set to be greater than the inverter output limit voltage.
18 shows the actual measurement result of the operation range by the synchronous motor control device of FIG. 16, the simulation result of the operation range by the synchronous motor control device of FIG. 16, and the simulation result of the operation range by the synchronous motor control device without using the voltage limiter. FIG.
FIG. 19 is a block diagram showing a main part of still another embodiment of the synchronous motor control device of the present invention.
FIG. 20 is a block diagram showing a conventional synchronous motor control device.
FIG. 21 is a block diagram showing a main part of still another embodiment of the synchronous motor control device of the present invention.
FIG. 22 is a diagram illustrating an example of voltage correction coefficient-command voltage characteristics;
FIG. 23 is a block diagram showing a main part of still another embodiment of the synchronous motor control device of the present invention.
[Explanation of symbols]
2 Inverter 3 Synchronous motor
5 Speed control unit 5a Subtraction unit
6 Phase controller 7 Current controller
8 Maximum phase table 8 'Maximum phase holding section
9 Phase limit part 9 'Phase calculation part
11 Minimum phase table 12 Waveform generator
12a Multiplier 13 Voltage limiter
35 Overvoltage detector 39 Overmodulation gain correction unit

Claims (44)

In the synchronous motor control method for controlling the synchronous motor (3) by supplying the output voltage of the inverter (2) to the synchronous motor (3),
A synchronous motor control method, wherein an upper limit value of a current phase is set at or near a phase that maximizes motor torque at each instantaneous inverter output voltage. In the synchronous motor control method for controlling the synchronous motor (3) by supplying the output voltage of the inverter (2) to the synchronous motor (3),
A synchronous motor control method, wherein an upper limit value of a current phase is set at or near a phase at which a motor torque is maximized at an inverter maximum output voltage for each rotation speed. The synchronous motor control method according to claim 1 or 2, wherein the upper limit value of the current phase is changed in response to at least the rotational speed. In the synchronous motor control method for controlling the synchronous motor (3) by supplying the output voltage of the inverter (2) to the synchronous motor (3),
A synchronous motor control method characterized in that the upper limit value of the current phase is set at or near the phase at which the motor torque is maximum at the maximum output voltage of the inverter at the highest speed rotation. In the synchronous motor control method for controlling the synchronous motor (3) by supplying the output voltage of the inverter (2) to the synchronous motor (3),
A synchronous motor control method, characterized in that a current phase limit value is set at a maximum phase and a minimum phase at which an inverter output current is limited for each required torque, or in the vicinity thereof. In the synchronous motor control method for controlling the synchronous motor (3) by supplying the output voltage of the inverter (2) to the synchronous motor (3),
Set the upper limit value of the current phase for each moment, the phase at which the motor torque is maximized at the inverter output voltage at each moment, or the upper limit value set in the vicinity thereof, and the motor torque at the inverter maximum output voltage for each rotation speed. The maximum phase set in the vicinity or the upper limit value set in the vicinity, the phase that maximizes the motor torque at the maximum inverter output voltage at the highest speed or the upper limit set in the vicinity thereof, and the inverter output current is limited for each required torque A synchronous motor control method, wherein the smallest upper limit value is selected from among the maximum phases to be set or the upper limit values set in the vicinity thereof . The lower limit value of the current phase is set at or near the current phase that maximizes the efficiency or torque, and the synchronous motor is driven with the smallest current phase that can output the required torque. The synchronous motor control method according to any one of claims 6 to 7. The synchronous motor control method according to any one of claims 1 to 7, wherein a compressor for an air conditioner is driven by the synchronous motor (3). The synchronous motor control method according to claim 8, wherein the synchronous motor (3) is a permanent magnet motor, and an upper limit value of a current phase is set to approximately 60 to 80 degrees. In the synchronous motor control method for controlling the permanent magnet motor by supplying the output voltage of the inverter (2) to the permanent magnet motor,
As the number of revolutions increases, the current phase is advanced in response to the output voltage of the inverter (2) reaching a limit value, and the speed droops in response to reaching a predetermined current phase limit value or current limit value. A synchronous motor control method characterized by performing control. In the synchronous motor control method for controlling the permanent magnet motor by supplying the output voltage of the inverter (2) to the permanent magnet motor,
As the number of revolutions increases, the current phase is advanced in response to the output voltage of the inverter (2) reaching a limit value, and the speed is controlled in response to reaching a predetermined current phase limit value or current limit value. A synchronous motor control method, characterized in that the internal state of the means is maintained in a state immediately before reaching the limit value. When the inverter output voltage has a margin with respect to the output voltage limit value, a desired voltage waveform is output from the inverter (2), and in response to the inverter output voltage approaching the output voltage limit value, the inverter (2) The synchronous motor control method according to claim 10 or 11, wherein the output voltage waveform is made closer to an output voltage waveform having a high voltage utilization rate. The synchronous motor control method according to claim 12, wherein a sine wave is adopted as the desired voltage waveform. The synchronous motor control method according to claim 12 or 13, wherein a rectangular wave is adopted as the output voltage waveform having a high voltage utilization rate. The synchronous motor control method according to any one of claims 10 to 14, wherein the compressor is driven by a permanent magnet motor. In the synchronous motor control method for controlling the synchronous motor (3) by supplying the output voltage of the inverter (2) to the synchronous motor (3),
A synchronous motor control method, wherein a motor current is controlled when an inverter output voltage amplitude is limited. 17. The synchronous motor according to claim 16, wherein the motor current control increases the motor terminal voltage command value in response to a small motor current and decreases the motor terminal voltage command value in response to a large motor current. Control method. The synchronous motor control method according to claim 16 or 17, wherein the inverter (2) is controlled to compensate for a decrease in torque caused by the voltage limitation. 19. The synchronous motor control method according to claim 18, wherein the torque reduction is compensated by compensating for a decrease in amplitude of a fundamental wave component of a phase voltage command due to voltage limitation. 20. The current phase is controlled such that the degree of overmodulation becomes a predetermined value in response to the degree of overmodulation increasing the voltage utilization rate exceeding a predetermined value. The synchronous motor control method as described. The synchronous motor control method according to any one of claims 9 to 20, wherein the synchronous motor (3) is a permanent magnet motor in which a permanent magnet is embedded in a rotor. The synchronous motor control method according to any one of claims 16 to 21, wherein a compressor is driven by the synchronous motor (3). In the synchronous motor control device for controlling the synchronous motor (3) by supplying the output voltage of the inverter (2) to the synchronous motor (3),
Inverter control means (6) (7) (8) (8 ') (9) (9') for setting the upper limit value of the current phase at or near the phase at which the motor torque is maximized at each instantaneous inverter output voltage A synchronous motor control device comprising (11). In the synchronous motor control device for controlling the synchronous motor (3) by supplying the output voltage of the inverter (2) to the synchronous motor (3),
Inverter control means (6) (7) (8) (8 ') (9) for setting the upper limit value of the current phase at or near the phase at which the motor torque is maximized at the inverter maximum output voltage for each rotational speed (9 ′) A synchronous motor control device including (11). The synchronous motor control device according to claim 23 or 24, wherein the inverter control means (8) changes the upper limit value of the current phase in response to at least the rotational speed. In the synchronous motor control device for controlling the synchronous motor (3) by supplying the output voltage of the inverter (2) to the synchronous motor (3),
Inverter control means (6) (7) (8) (8 ') (9) (9) (9) (9) (9) (9) (9) (9) 9 ') A synchronous motor control device including (11). In the synchronous motor control device for controlling the synchronous motor (3) by supplying the output voltage of the inverter (2) to the synchronous motor (3),
Inverter control means (6) (7) (8) (9) for setting the limit value of the current phase at the maximum phase and the minimum phase at which the inverter output current is limited for each required torque, or in the vicinity thereof (9 ′) A synchronous motor control device including (11). In the synchronous motor control device for controlling the synchronous motor (3) by supplying the output voltage of the inverter (2) to the synchronous motor (3),
Set the upper limit value of the current phase for each moment, the phase that maximizes the motor torque at the inverter output voltage at each moment, or the upper limit value set in the vicinity thereof, and the motor torque at the inverter maximum output voltage for each rotation speed. The maximum phase set in the vicinity or the upper limit value set in the vicinity, the phase that maximizes the motor torque at the maximum inverter output voltage at the highest speed or the upper limit set in the vicinity thereof, and the inverter output current is limited for each required torque A synchronous motor control device comprising inverter control means for selecting the smallest upper limit value among the maximum phase to be set or the upper limit value set in the vicinity thereof . The inverter control means (6), (7), (8), (9 ′), and (11) set the lower limit value of the current phase to the current phase that maximizes the efficiency or torque, or the vicinity thereof, and set the required torque. The synchronous motor control device according to any one of claims 23 to 28, wherein the inverter (2) is controlled so as to drive the synchronous motor with the smallest current phase that can be output. The synchronous motor control device according to any one of claims 23 to 29, wherein the synchronous motor (3) drives a compressor for an air conditioner. The synchronous motor (3) is a permanent magnet motor, and the inverter control means (6) (7) (8) (9) sets the upper limit value of the current phase to approximately 60 degrees to 80 degrees. Item 31. The synchronous motor control device according to Item 30. In the synchronous motor control device that controls the permanent magnet motor by supplying the output voltage of the inverter (2) to the permanent magnet motor,
As the rotation speed increases, the current phase is advanced in response to the output voltage of the inverter (2) reaching the limit value, and the speed droops in response to reaching the predetermined current phase limit value or current limit value. The synchronous motor control apparatus characterized by including the inverter control means (5) (5a) (6) (7) (8) (9 ') (10) (11) (13) which performs control. In the synchronous motor control device that controls the permanent magnet motor by supplying the output voltage of the inverter (2) to the permanent magnet motor,
As the number of revolutions increases, the current phase is advanced in response to the output voltage of the inverter (2) reaching a limit value, and the speed is controlled in response to reaching a predetermined current phase limit value or current limit value. A synchronous motor control device comprising inverter control means (5) (6) (7) (8) (9) (13) for maintaining the internal state of the means (5) in a state immediately before reaching the limit value. The inverter control means (5) (7) (12) (12a) (13) outputs a desired voltage waveform from the inverter (2) when the inverter output voltage has a margin with respect to the output voltage limit value, 34. The synchronization according to claim 32 or 33, wherein the output voltage waveform from the inverter (2) is brought close to an output voltage waveform having a high voltage utilization factor in response to the inverter output voltage approaching the output voltage limit value. Motor control device. The synchronous motor control device according to claim 34, wherein the inverter control means (5) (7) (12) (12a) (13) employs a sine wave as the desired voltage waveform. 36. The synchronization according to claim 34 or claim 35, wherein the inverter control means (5) (7) (12) (12a) (13) employs a rectangular wave as the output voltage waveform having a high voltage utilization rate. Motor control device. 37. The synchronous motor control device according to claim 32, wherein the permanent magnet motor drives a compressor. In the synchronous motor control device for controlling the synchronous motor (3) by supplying the output voltage of the inverter (2) to the synchronous motor (3),
Synchronous motor control comprising inverter control means (6) (7) (35) (39) for controlling the inverter (2) to control the motor current when the inverter output voltage amplitude is limited apparatus. The inverter control means (6) (7) (35) (39) controls the motor current to increase the motor terminal voltage command value in response to a small motor current and to respond to a large motor current. The synchronous motor control device according to claim 38, wherein the synchronous motor control device is performed by decreasing the motor terminal voltage command value. 40. The synchronous motor according to claim 38 or 39, wherein the inverter control means (6) (35) (39) controls the inverter (2) to compensate for a decrease in torque caused by the voltage limitation. Control device. 41. The inverter control means (6) (35) (39) performs compensation for the decrease in the torque by compensating for the decrease in the amplitude of the fundamental component of the phase voltage command due to voltage limitation. The synchronous motor control device described. The inverter control means (6) (35) controls the current phase so that the degree of overmodulation becomes a predetermined value in response to the degree of overmodulation exceeding a predetermined value. Item 42. The synchronous motor control device according to any one of Items 38 to 41. The synchronous motor control device according to any one of claims 31 to 42, wherein the synchronous motor (3) is a permanent magnet motor in which a permanent magnet is embedded in a rotor. The synchronous motor control device according to any one of claims 38 to 43, wherein the synchronous motor (3) drives a compressor.

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