JP3576827B2 - Rotor position estimation device for synchronous motor - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an apparatus and a method for estimating a rotor position of a synchronous motor, and more particularly, to a synchronous apparatus for estimating a rotor position of a synchronous motor using magnetic saturation without providing a rotor absolute rotation angle detector. The present invention relates to a rotor position estimation device and a rotor position estimation method for an electric motor.
[0002]
[Prior art]
Usually, in order to control the rotation of the synchronous motor, it is necessary to grasp the position of the rotor and to supply a current having a phase corresponding to the position to the winding. Normally, a synchronous motor is provided with a rotation angle detector for detecting the absolute position of the rotor, and the motor winding current is controlled based on rotor position information detected according to the rotation of the rotor. However, when a rotation angle detector is used, there are problems in the reliability of the sensor itself, problems in the alignment work and installation accuracy, cost reductions, and layout problems such as the axial protrusion of the motor.
[0003]
On the other hand, in recent years, sensorless motor control without a rotation angle detector has been proposed in consideration of the burden of securing the reliability of the sensor part and to reduce the cost associated with the work of mounting the sensor itself. I have. The 1983 (P4-280-281) "Performance evaluation of the permanent magnet synchronous motor simple magnetic pole position sensorless method" of the 1998 IEEJ National Conference [4], "Sensorless magnetic pole position as a motor without salient pole type motor" Has been disclosed. On the other hand, 882 (P4-279) “Method of estimating magnetic pole position at start of permanent magnet synchronous motor” in the 1998 IEEJ National Convention Papers [4], regardless of the type of motor, the rotor position and A method of estimating the rotor position by utilizing the magnetic flux saturation of the motor core between the response of the winding current and the current is disclosed.
[0004]
[Problems to be solved by the invention]
However, in the former prior art, the motor is limited to a salient pole type motor, and it is difficult to apply the motor to a cylindrical motor. In addition, the latter conventional rotor estimation method using magnetic flux saturation can be applied to a cylindrical motor, but there is room for improvement in estimation time and accuracy. There are still problems in applying it to real fields, such as staying with proposals.
[0005]
SUMMARY OF THE INVENTION An object of the present invention is to provide a synchronous motor rotor position estimating apparatus and a rotor position estimating method capable of accurately determining a rotor position of a synchronous motor using magnetic pole saturation without providing a rotation angle detector. Is to provide.
[0006]
Still another object of the present invention is to provide a synchronous motor rotor position estimating apparatus and a rotor position estimating method capable of obtaining a rotor position of a cylindrical synchronous motor in a short time by utilizing magnetic pole saturation. Is to provide.
[0007]
[Means for Solving the Problems]
The present invention employs the following means in order to solve the above problems.
[0008]
The rotation of the rotor of the synchronous motor is fixed, a plurality of command voltages having different phases are applied to the motor winding of the synchronous motor, and a response time of each response current detected with respect to the plurality of command voltages is determined. A synchronous motor rotor position estimating device for estimating the position of the rotor,
The phase to which the plurality of command voltages are applied is A main section exhibiting a phase set in a plurality of main sections obtained by dividing the electrical angle of the synchronous motor by 360 degrees at a fixed angle, and a maximum response time in a response current detected in the phases set in the plurality of main sections. Is a phase set for a plurality of subsections obtained by dividing The position estimation of the rotor is calculated based on a phase exhibiting a maximum response time in the response current detected at the set plurality of phases.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
First, a first embodiment of the present invention will be described with reference to FIGS.
[0017]
FIG. 1 is a block diagram showing an overall configuration of a synchronous motor control device including a rotor position estimating device according to the present embodiment.
[0018]
In the figure, the control unit of the PWM inverter converter connected to the synchronous motor has a single-phase or three-phase configuration according to the number of power supply phases. ing.
[0019]
In the figure, 1 is an AC power supply, 2 is an AC reactor, 3 is a PWM converter configured using a self-extinguishing element such as an IGBT (insulated gate bipolar transistor), 4 is a smoothing capacitor, 5 is a PWM inverter, and 6 is a PWM inverter. A synchronous motor, 7 is a load connected to the motor and acting as a driving device for generating an external torque, 8 is a brake for fixing the rotation of the rotor, 9 is an AC voltage detector for detecting the voltage of the AC power supply 1, 10, 11 is a current detector for detecting the input current Ic flowing on the AC side of the PWM converter 3 and the output current Ii flowing on the AC side of the PWM inverter 5, 12 is a DC voltage detector for detecting the voltage of the smoothing capacitor 4, and 13 is This is a pulse generator that detects the rotation of the synchronous motor 6.
[0020]
Hereinafter, 14 to 19 are control units for driving the PWM converter 3, and 20 to 24 are control units for driving the PWM inverter 5, which have the following functions. Reference numeral 14 denotes a DC command voltage generation unit which receives a power supply voltage Es (phase voltage effective value) and designates a voltage of a smoothing capacitor 4 connected to the DC side of the PWM converter 3. ^* appear. Numeral 15 indicates that the smoothing capacitor voltage is the DC command voltage Ed. ^* Is a voltage control unit that instructs the magnitude of the current flowing to the input side of the PWM converter so that the voltage is based on the DC command voltage Ed. ^* And the voltage Ed of the smoothing capacitor 4, and the command current Ic ^* Occurs. 16 is a phase calculation unit for generating a unit sine wave in phase with the power supply voltage, and 17 is a magnitude Ic. ^* And the converter input side command voltage ec such that the phase becomes the input current Ic in phase with the unit sine wave. ^* The current control unit 18 instructs the carrier signal etc ^* , And 19 is a command voltage ec ^* And carrier signal etc ^* And a PWM pulse generation unit of a converter unit that generates a PWM pulse Gpc for driving the PWM converter 3 from the above. Reference numeral 20 denotes a speed command generator for instructing the speed of the motor 6, and reference numeral 21 denotes a speed command ω ^* The speed control unit 22 instructs the output torque of the electric motor 6 so as to follow the torque command τ. ^* Is converted to a motor command current, and a current control unit for calculating a command voltage indicating a voltage to be output by the PWM inverter 5 from the command current and the negative feedback current; 23, a carrier generation unit; and 24, a PWM pulse generation of the inverter unit. The unit 25 outputs an estimated value phase θ of the rotor at the time of normal rotation, and a predetermined phase set at the time of measuring the rising response of the current at the time of estimating the rotor position. This is a position estimating unit that performs processing for estimating the rotor position by taking the θM and the time response waveform of the current IdM under the condition in association with each other.
[0021]
FIG. 2 is a block diagram showing a detailed configuration of the current control unit 22 shown in FIG.
[0022]
In the figure, 220 and 221 are switches for switching between a normal operation mode and a rotor position estimation mode, and 222 is a torque τ from the speed control unit 21. ^* Is the command current Id ^* , Iq ^* 223 is a sin / cos table, 224 is a three-phase to two-phase converter for converting the detected three-phase load current Ii into two-phase currents Id and Iq, and 225 is a command. Voltage Vd ^* , Vq ^* To the three-phase command voltage ei ^* The two-phase to three-phase converter 226 converts a pulse-like command voltage value Vd when the rotor position estimation mode is set. ^* 227 generates a command voltage value Vq when the rotor position estimation mode is set. ^* 228 is a measurement phase generator used in setting the rotor position estimation mode.
[0023]
During normal operation, the switches 220 and 221 are turned down by the switch change / command generation signal M, and the torque command τ ^* And the estimated rotor phase θ and the inverter output current Ii. Torque command τ ^* Is the command current Id by the torque control unit 222. ^* , Iq ^* Is decomposed into On the other hand, the sin / cos table 223 is referred to by the phase θ estimated by the position estimating unit 25, and the three-phase to two-phase converter detects the three-phase inverter current detected according to the data of the referenced sin / cos table 223. Ii is converted into two-phase currents Id and Iq. Command current Id ^* , Iq ^* Are subjected to negative feedback control with currents Id and Iq, and command voltage Vd ^* , Vq ^* Is created. Further, the command voltage Vd ^* , Vq ^* Is the three-phase command voltage ei in the two-phase to three-phase converter 225. ^* Is generated, and the carrier wave eti finally output from the carrier wave generation unit 23 ^* Is output as a PWM signal from the pulse generator 24 by comparing the magnitudes of the two.
[0024]
On the other hand, in the rotor position estimation mode, the switches 220 and 221 are tilted upward in the figure by the switch switching / command generation signal M, and the negative feedback control is released. Thereby, the command voltage Vd ^* , Vq ^* Are the command voltages for measuring the current rise time response from the command generators 226 and 227, respectively. As shown in the figure, the command generator 226 outputs a measurement step command voltage for generating a step-like voltage change, and the command generator 227 outputs a zero command voltage. In addition, the command voltage Vd ^* , Vq ^* Is converted by a two-phase to three-phase converter 225 according to predetermined phase generation information θM given from the phase generator 228 at the time of measurement, and a three-phase command voltage ei for response measurement ^* Is created. Three-phase command voltage ei ^* Is finally converted into a PWM signal and a predetermined current flows through the motor winding.
[0025]
Here, when the rotor is fixed by the brake and no induced voltage is generated in the winding, the total magnetic flux linked to the equivalent winding depends on the angle difference between the axis of the rotor and the current vector. Change. When the interlinking magnetic flux is large, the influence of the magnetic flux saturation becomes large, and the equivalent inductance becomes small, and when the opposite, the inductance becomes large. This difference in inductance is regarded as a change in response time of the response current, and the position of the rotor is determined from the difference.
[0026]
One of the aims of the present invention is to make the measurement of the change in the response current less susceptible to the current control system and the like, and to accurately measure the response time. Therefore, in FIG. 2, the switch 220 is provided to cut off the negative feedback control function.
[0027]
Note that the response current waveform is captured by outputting the Id component of the output of the three-phase to two-phase conversion 224 to the position estimating unit 25 as IdM, but as described in the command generators 226 and 227, the response measurement step is performed. When the step command voltage is generated from the state command voltage generator 226, the Iq component is sent to the phase estimating unit 25 as IqM.
[0028]
Next, a processing procedure of position estimation in the rotor position estimating unit 25 shown in FIG. 1 will be described with reference to a flowchart shown in FIG.
[0029]
In step 100, when the start command is issued by the signal M shown in FIG. 2 and the start of the rotor position estimation process is started, the switches 220 and 221 are turned upward as described above, and the response measurement step command is issued. A step-like command voltage is generated from the voltage generator 226, and a response current IdM converted by a three-phase to two-phase converter is sequentially detected from the motor current Ii detected in response thereto. In step 101, a processing device such as a microcomputer sets a plurality of phases obtained by dividing the electrical angle of the synchronous motor of 360 ° by a certain angle, and fetches a response current IdM in association with the set phase. In step 102, it is determined from the step duration information of the step-like command voltage 226 in FIG. 2 whether or not the acquisition of the response current under the same phase condition has been completed, and if not completed, the acquisition of the response current is continued. If completed, a response time is obtained from a series of response currents taken in step 103. In taking in the response current, the present invention does not operate the current negative feedback control, but operates in the state of the open loop control using the command voltage directly. By doing so, it takes longer to measure the rise of the current than in the case where the negative feedback control is added, but there is a characteristic that a characteristic that clearly indicates a characteristic difference due to a difference in inductance is obtained. Next, in step 104, it is determined whether the acquisition of the response currents in all the set phases and the calculation of the response time for each response current have been completed, and if not completed, the acquisition of the data is continued. If it has been completed, the maximum value is retrieved from the response times already measured in step 105, and a predetermined value (here, 180 °) is added to the phase that generates the maximum value in step 106, and the estimated position of the rotor is calculated. Ask for. Here, 180 ° is added because the phase at which the response time becomes maximum is shifted by 180 ° from the magnetic pole position of the rotor.
[0030]
Next, a method of measuring a rotor position using the rotor position estimating apparatus of the present embodiment will be described with reference to FIGS.
[0031]
FIG. 4 is a diagram for explaining a measurement method (division method) for measuring the rotor position in a short time with the minimum number of response waveform measurements.
[0032]
In the figure, the horizontal axis represents the set phase, the vertical axis represents the response time of the measured response current, and (a) to (g) show examples of the characteristics in which the response time to the set phase differs depending on the position of the rotor. The white circles shown and shown show the measurement points in the main section, and the black circles show the measurement points in the sub-section when divided into sub-sections.
[0033]
The important point of this measurement method (division method) lies in the method of setting the phase condition when measuring the response current. As shown in the figure, the magnetic flux generated by the rotor and the motor winding overlaps, and the effect of magnetic saturation What appears in the current is a portion that exhibits a mountain-shaped characteristic in an approximately 180 ° section.
[0034]
In this measurement method (division method), instead of calculating the response time of the response current by changing the phase in order from 0 ° to 360 °, the phase section is first divided into several main sections. , The response time at the median phase of the main section is measured. The main section that generates the maximum response time is selected from the response times, and then the selected main section is further divided into some sub-sections. Further, a response time at the central phase value of each of the divided sub-intervals is obtained. The position of the rotor is estimated by adding 180 ° to the maximum set phase from the response times measured in the selected main section and each sub-section, and using the added phase angle to determine the position of the rotor. presume.
[0035]
As described above, according to the present embodiment, the number of main and sub sections contributes to the total number of measurements. FIG. 4A shows an example in which the main section is divided into two sections. In this case, a mountain having a width of 180 ° cannot be recognized. Therefore, as shown in FIG. 4B and thereafter, the main section needs to be divided into at least three or more sections. By dividing the main section into three or more sections, a section where a mountain having a width of 180 ° exists can be grasped. . 4 (b), 4 (e) and 4 (f) show the case of subdivision, and FIGS. 4 (c), 4 (d) and 4 (g) show the case of subdivision. Is shown. It is understood that the phase near the top of a 180-degree wide mountain can be searched for even if the main section is divided into three sub-sections, that is, as long as the sub-section is divided into smaller sections than 120 degrees. That is, assuming an ideal state, the minimum number of measurements is three in the main section and two in the subsection, for a total of five times.
[0036]
Next, a processing procedure according to this measurement method (division method) will be described with reference to a flowchart shown in FIG.
[0037]
First, in step 201, response current is captured, and then, in step 202, it is determined whether response current capture in one set phase is completed. If not completed, the process returns to step 201 to continue the response current capturing process. If completed, the response time of the response current waveform taken in step 203 is calculated. Next, in step 204, it is determined whether or not data is being captured in the sub-interval. If data is still being measured in the main interval, it is determined in step 205 whether the data of the three main intervals has been measured. If it is not completed, the process returns to step 201 to continue taking the response current. If the capture has been completed, the main section having the maximum value is searched from the three response times for which the measurement has been completed in step 206. Next, in step 207, it is determined whether the capture of the current waveform of the response current corresponding to the two sub-sections divided in the searched main section has been completed. If not completed, the process returns to step 201 to take in the response current. If completed, in step 208, the maximum value is searched from the response times measured in the main section and the two sub-sections, and in step 209, 180 ° is set to the phase that generated the maximum response time. The addition is performed, and the obtained phase angle is estimated as the position of the rotor.
[0038]
As described above, according to this measurement method (division method), the position of the rotor can be confirmed with a small number of measurements. Here, in order to reduce the search time, an example is shown of the minimum number of times that the number of divisions of the main section is 3 and the number of divisions of the sub-section is 2 assuming an ideal state. In order to improve the reliability of, a good result can be obtained by further increasing three sections of the main section and two sections of the subsection.
[0039]
FIG. 6 is a diagram for explaining a measurement method (pattern matching method) for measuring a rotor position in a short time using pattern matching.
[0040]
In the figure, the horizontal axis represents the set phase, the vertical axis represents the response time of the measured response current, and (a) to (g) show examples of the characteristics in which the response time to the set phase differs depending on the position of the rotor. The white circles and the black circles shown in FIG.
[0041]
The important point of this measurement method is that the phase is changed in detail as an initial state such as when the system is started up, and the response time table of the corresponding response current waveform (the characteristic indicated by the solid line in the figure) is measured in advance. It is in. This measurement method is particularly suitable for searching for the rotor position in a short number of times with a small number of measurements when the rotor position becomes unknown due to a power failure or the like.
[0042]
In FIG. 6, as shown in FIGS. 6A and 6B, response currents measured in three set phases indicated by black circles (measured by dividing a 360 ° section for every 120 ° phase) 6A, the difference between the solid lines in FIG. 6A and FIG. 6B cannot be recognized. In other words, it can be understood that position estimation by pattern matching based on three measurement results for each 120 ° phase and a pre-measured phase / response time pattern causes a position estimation error of up to 60 °. On the other hand, as shown in FIGS. 6 (c) to 6 (g), response currents measured in four set phases indicated by white circles (measured by dividing a 360 ° section for every 90 ° phase) Measurement of the response time from the measured response current), it is possible to substantially confirm the existence section at the top (maximum value) of the characteristic. As described above, even with this measurement method (pattern matching method), the position estimation of the rotor corresponding to the maximum value of the response can be accurately performed with a small number of searches. In this measurement method (pattern matching method), it takes time and effort to measure the data for table construction in detail, but after the motor drive system starts operating, the power outage etc. When the position of the rotor is not known, it is excellent in that the position of the rotor can be quickly and accurately grasped.
[0043]
Next, a processing procedure according to this measurement method (pattern matching method) will be described with reference to a flowchart shown in FIG.
[0044]
Here, it is assumed that the number of measurements is four, and the phase / response time table in the initial state has already been constructed. First, in step 300, when a situation occurs in which the rotor position must be estimated due to a power failure or the like, the processing of the present measurement method is started. In step 301, a response current corresponding to the step command voltage is fetched. In step 302, it is determined whether or not the response current has been captured in the same set phase. If not completed, the process returns to step 301 to continue the response current capturing process. If it has been completed, a rise response time is calculated from the response current taken in step 303. Next, in step 304, it is determined whether or not the response current has been captured in each set phase corresponding to each measurement count. Here, four measurements are performed, which is the minimum number of times that the phase can be estimated in principle, assuming an ideal state. The 360 ° section is divided into four equal parts, and the response current of each set phase of 0 °, 90 °, 180 °, and 270 ° is measured. If the acquisition of the response current has not been completed, the process returns to step 301 to continue the acquisition. If the capture is completed, the maximum value (first value) and the second largest value (second value) are selected from the four response times measured in step 305 and the first value is given. Specify the phase (φ1). In step 306, it is determined whether the response time of the selected first value and the second value is longer than a predetermined value and substantially equal. Here, the reason why the condition larger than the predetermined value is provided is to eliminate the case where two values of the four data become substantially zero. When these conditions are satisfied, in step 307, a phase obtained by adding 180 ° to the intermediate phase value between the two phases giving the first value and the second value is obtained, and this is set as the estimated rotor position. . If step 306 is not satisfied, the process enters the process of estimating the rotor position by matching the first and second values with the phase / response time table. In step 308, a phase (φT1) giving a response time equal to the first value which is the maximum value of the response time is searched from the phase / response time table. Here, since there are two phases that give the first value, the search is performed from the smaller phase angle. Next, in step 309, a response time corresponding to the phase (φT1 + 90 °) is searched from the phase / response time table in the phase / response time table. At step 310, it is determined whether or not the retrieved response time is substantially equal to the previously acquired second value. If they are equal, in step 311, the difference between the phase (φM) that causes the maximum response time on the phase / response time table and the phase (φT1) on the table that provides the response time equal to the first value is the phase (φM ) And the phase (φ1) that gives the first value, the difference between φM−φT1 is added to φ1, and a phase angle obtained by adding 180 ° to the added value is obtained. The position of the rotor. On the other hand, if it is determined in step 310 that the search value is different from the second value, a response time corresponding to the phase (φT1−90 °) is searched in the phase / response time table in step 312. . Next, if the retrieved response time is substantially equal to the second value obtained in step 313, in step 314, the phase (φM) that causes the maximum response time on the phase / response time table and the first value are calculated. Since the difference between the phase (φT1) on the table giving the same response time corresponds to the difference between the phase (φM) and the phase (φ1) giving the first value, the difference between φM−φT1 is added to φ1. , A phase obtained by adding 180 ° to the added value is obtained, and this is set as the estimated rotor position. If the response time searched in step 313 is not equal to the previously obtained second value, it is determined that the pattern matching process has failed due to noise or a measurement error, and in step 315, the allowable value for the matching process is relaxed. The process of step 310 is performed again, and the process of obtaining a match is executed.
[0045]
Note that the maximum value of the number of response current measurements required to construct the initial phase / response time table or to measure the rotor current when the rotor phase must be re-estimated, such as during a power outage, is determined by the significant resolution From the viewpoint of the total required time for measurement, etc., it can be said that a phase angle of about 10 ° and a frequency of about 40 times are appropriate measurements in a real field.
[0046]
Next, a processing procedure of the rotor position estimating apparatus according to the second embodiment of the present invention will be described with reference to a flowchart shown in FIG.
[0047]
In the present embodiment, in a state where the rotor is fixed by the brake in the first embodiment, and no induced voltage is generated, the command voltages having different phases are sequentially applied to the motor winding to obtain the response time from the response current. The same command voltage is applied to the windings, while the load on the elevator car connected to the rotor side is used to raise and lower the car automatically to balance the car. The same command voltage is applied to the winding by rotating and displacing by the load torque, and the rotor position is estimated from the response time of the response current waveform.
[0048]
Here, the same command voltage is applied to the windings, and the non-uniformity of the conditions (mixing of errors) accompanying the command generation that can occur by applying a plurality of types of command voltages in response time measurement is eliminated. . The configuration of the rotor position estimating apparatus is substantially the same as that shown in FIGS.
[0049]
First, when the process is started in step 400, the brake is opened in step 401, the rotor is rotated by using the load torque, and then the rotor is fixed by controlling the brake. When the load torque is small and the rotor does not rotate, the rotor is rotated by a predetermined angle by a low-frequency synchronous start method using a command having a low frequency and a small absolute value. As a reference of the rotation angle, 90 ° or less is desirable from the relationship between measurement accuracy and measurement time. At this time, in step 402, the rotation angle from the previous stop position is measured. Here, as shown in FIG. 1, the rotation angle displacement is measured by counting the pulses generated by a pulse encoder coupled to the rotor. When the setting of the measurement conditions is completed, the response current corresponding to the step-like command voltage is captured in step 403, and it is determined in step 404 whether the capture of the response current under the same phase condition is completed. If not completed, capture of the response current is continued. Upon completion, a response current rise response time is calculated in step 405. Next, in step 406, it is determined whether the response time obtained in step 405 is smaller than a predetermined value 1. Here, the predetermined value 1 is a value which is larger than zero set for performing the determination but is relatively small. If it is determined that the response time is smaller, it is determined in step 407 whether the previously measured response time is smaller than a predetermined value 1. If it is smaller, it is determined that it is still apart from the rotation angle for measuring the rotor position, and the process returns to step 401 to rotate the rotor again and return to the operation for measuring the response current. When it is determined in step 407 that the response time measured last time is larger than the predetermined value 1, in step 408, the rotation angle of the rotor position measurement is excessive, and the rotation angle in the previous measurement was appropriate. Then, the phase angle obtained by adding 180 ° to the rotation angle is estimated as the position of the rotor, and the process ends. On the other hand, if the response time measured this time is longer than the predetermined value 1 in step 406, it is determined in step 409 whether the response time is longer than the predetermined value 2. Here, the predetermined value 2 is a value larger than the predetermined value 1 but slightly smaller than the maximum response time. If it is determined in step 409 that the rotation angle is large, in step 410, the phase angle obtained by adding 180 ° to the rotation angle measured this time is estimated as the position of the rotor, and the process ends. If the response time is smaller than the predetermined value 2 in step 409, it is determined in step 411 whether the previous response time is larger than the predetermined value 1. If it is determined that the rotation angle is smaller, it is determined that the rotation angle for estimating the rotor position is a little further ahead, and the process returns to step 401 to rotate the rotor again and retry the processing. If it is determined in step 411 that the rotation angle is large, in step 412, the phase angle obtained by adding 180 ° to the rotation angle between the rotation angle of the previous measurement and the rotation angle of the current measurement is estimated as the position of the rotor, and the processing is performed. To end.
[0050]
As described above, according to the present embodiment, since the same command voltage is used for measuring the response current for each rotor rotation, it is possible to eliminate external factors such as errors that can be mixed in with the creation of the command voltage, The position of the rotor can be accurately estimated by grasping the influence of the saturation as much as possible.
[0051]
【The invention's effect】
As described above, according to one aspect of the present invention, the difference in the response time of the response current caused by the saturation of the magnetic circuit caused by the difference in the phase difference between the rotor position and the command voltage can be measured with a small number of measurements. The position of the rotor can be measured in a short time.
[0052]
According to another aspect of the present invention, the difference in the response current caused by the saturation of the magnetic circuit caused by the difference in the phase difference between the rotor position and the command voltage is the same as the error that can be mixed in the process of creating the command. The voltage is eliminated by using the voltage, and the occurrence of the relative phase difference can be accurately measured by setting the rotation of the rotor by an external torque or a low frequency synchronous torque of the electric motor.
According to another aspect of the present invention, the difference in the saturation current of the magnetic circuit caused by the difference in the phase difference between the rotor position and the command current on the response current is eliminated by removing the influence on the response of the control device. The position of the child can be measured accurately.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an overall configuration of a synchronous motor control device including a rotor position estimating device according to a first embodiment of the present invention.
FIG. 2 is a block diagram showing a detailed configuration of a current control unit 22 shown in FIG.
FIG. 3 is a flowchart showing a position estimation processing procedure in a rotor position estimator 25 shown in FIG. 1;
FIG. 4 is a diagram for explaining a measurement method (division method) for measuring a rotor position with a minimum number of response waveform measurement times according to the present embodiment.
FIG. 5 is a flowchart illustrating a processing procedure according to a measurement method (division method) according to the present embodiment.
FIG. 6 is a diagram for explaining a measurement method (pattern matching method) for measuring a rotor position using pattern matching according to the present embodiment.
FIG. 7 is a flowchart illustrating a processing procedure according to a measurement method (pattern matching method) according to the present embodiment.
FIG. 8 is a flowchart showing a processing procedure of a measuring method (rotor position changing method) for measuring a rotor position in the synchronous motor rotor position estimating apparatus according to the second embodiment of the present invention.
[Explanation of symbols]
1 power supply
3 PWM converter
5 PWM inverter
6 Synchronous motor
7 Load
8 brake
9 AC voltage detector
10,11 Current detector
12 DC voltage detector
13 Pulse generator
14 DC command voltage generator
15 Voltage controller
16 Power supply phase calculator
17,22 Current control unit
18, 23 Carrier generator
19,24 PWM pulse generator
20 Speed command generator
21 Speed control unit
25 Rotor position estimator
226 Step measurement command voltage generator for response measurement
227 Zero command voltage generator for response measurement
228 Response measurement phase generator

Claims (4)

The rotation of the rotor of the synchronous motor is fixed, a plurality of command voltages having different phases are applied to the motor winding of the synchronous motor, and a response time of each response current detected with respect to the plurality of command voltages is determined. A synchronous motor rotor position estimating device for estimating the position of the rotor,
The phases to which the plurality of command voltages are applied are detected in a phase set in a plurality of main sections obtained by dividing the electrical angle of the synchronous motor by 360 degrees at a fixed angle, and in a phase set in the plurality of main sections. Phase set in a plurality of sub-sections obtained by dividing the main section exhibiting the maximum response time in the response current, and the rotor position estimation is performed based on the response current detected in the set plurality of phases. A rotor position estimating device for a synchronous motor, wherein the rotor position estimating device is calculated based on a phase exhibiting a maximum response time of the rotor. 2. The rotor position estimating device according to claim 1, wherein the number of the divided phases is at least 4 or more and 40 or less. 3. 3. The rotor position estimating device according to claim 1, wherein the main section is divided into three or more areas and the sub section is divided into two or more areas. 4. The rotor position estimating device according to any one of claims 1 to 3, wherein a negative feedback control function provided in a control device that controls the operation of the synchronous motor is stopped when the position of the rotor is estimated. A rotor position estimating device for a synchronous motor, comprising:

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