Servo amplifier and open phase detection method

Abstract

To surely avoid a malfunction of a servo amplifier even when fluctuations of an input power source exist.SOLUTION: A master open-phase waveform analysis unit 113 analyzes whether or not power from an input power source 200 is deviated from a first allowable value based on a sampled value, and a master open-phase waveform determination unit 114 samples power and determines a master open-phase waveform when analysis results of the master open-phase waveform analysis unit 113 is normal. A polling open-phase waveform analysis unit 115 compares a polling open-phase waveform obtained from a value sampled after determination of the master open-phase waveform with the master open-phase waveform, and a main control unit 110 notifies an error each of when the master open-phase waveform determination unit 114 is determined to be abnormal and when a polling open-phase waveform determination unit 116 is abnormal.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a servo amplifier and a method for determining an open phase that are suitable for avoiding malfunctions of the servo amplifier due to fluctuations in the input power supply. [Background technology]

[0002] When installing a servo motor in a robot, machine tool, or other device, the gain of the servo amplifier must be adjusted according to the load inertia. Such servo amplifier gain adjustment is performed by manually or automatically setting parameters.

[0003] However, if the power supplied from the input power supply to the servo amplifier fluctuates, not only will it be necessary to readjust the gain, but the servo amplifier may also malfunction.

[0004] One known method for dealing with such power fluctuations is a servo amplifier control gain setting method as shown in Patent Document 1. This control gain setting method supplies a step-like reactive current component to a current loop of a servo motor driven by a servo amplifier, obtains a step response from the current loop, measures the voltage input to the servo amplifier due to the step response, and sets the control gain by using a control parameter set in advance that corresponds to the measured power supply voltage. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 08-205569 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the control gain setting method of Patent Document 1 requires supplying a step-like reactive current component to the current loop while the servo amplifier is operating and measuring the voltage input to the servo amplifier due to the step response, which makes it impossible to confirm before starting the servo amplifier operation whether the power to the servo amplifier is in a state where it will not cause malfunction of the servo amplifier.

[0007] Furthermore, for example, when power is supplied to a servo amplifier via a transformer, if there is a variation in the transformation accuracy of the transformer, the power supplied to the servo amplifier may fluctuate.

[0008] In this case, it is thought that the control gain can be appropriately set by using a control parameter that is preset corresponding to the measured power supply voltage, as in the control gain setting method of Patent Document 1. However, unless a control parameter that corresponds to variations in the transformation accuracy of the transformer is preset, the control gain cannot be appropriately set, and the control parameter must be reset.

[0009] Furthermore, if the user forgets to reset the control parameters or makes a mistake in the settings, the servo amplifier may malfunction.

[0010] The present invention has been made in view of the above circumstances, and has as its object to provide a servo amplifier and a method for determining an open phase that can solve the above problems. [Means for solving the problem]

[0011] The servo amplifier of the present invention includes a first analysis unit that analyzes whether or not the power from the input power supply deviates from a first allowable value based on a value sampled under certain conditions, and outputs an error if the power deviates; a loss-of-phase waveform determination unit that samples the power under the certain conditions, and if the analysis result by the first analysis unit is normal, determines a first loss-of-phase waveform including a first characteristic obtained from the sampled value; and a loss-of-phase waveform determination unit that compares the first characteristic with a second characteristic of a second loss-of-phase waveform obtained from values ​​sampled under the certain conditions after the first loss-of-phase waveform has been determined, and determines whether or not the second characteristic is a second analysis unit that analyzes whether the first characteristic deviates from a second allowable value and outputs an error if the first characteristic deviates; a loss-of-phase waveform determination unit that samples the power under certain conditions after determining the first loss-of-phase waveform and determines that the power is normal if the analysis result by the second analysis unit does not deviate from the second allowable value; and a main control unit that notifies an error when the loss-of-phase waveform determination unit determines that the power is abnormal based on the error output from the first analysis unit and when the loss-of-phase waveform determination unit determines that the power is abnormal based on the error output from the second analysis unit. the certain conditions include a certain threshold value and a certain sampling period, the first characteristic includes a first frequency and a first duty, the second characteristic includes a second frequency and a second duty, the first allowable value includes a third frequency and a third duty that are set manually or automatically, the second allowable value includes a fourth frequency and a fourth duty that are set manually or automatically, the open phase waveform determining unit binarizes the power using the certain threshold value and the certain sampling period, the first analysis unit determines the power based on a time difference between a timing at which the sampled value switches from LOW to HIGH and a timing at which the sampled value switches from HIGH to LOW, The first frequency and the first duty cycle are determined, and it is analyzed whether or not any or all of the first frequency and the first duty cycle deviate from any or all of the third frequency and the third duty cycle. The open-phase waveform determination unit binarizes the power using the constant threshold value and the constant sampling period. The second analysis unit determines the second frequency and the second duty cycle based on the time difference between the timing when the sampled value switches from LOW to HIGH and the timing when the sampled value switches from HIGH to LOW, and it is analyzed whether or not any or all of the second frequency and the second duty cycle deviate from any or all of the fourth frequency and the fourth duty cycle. Characterized by 。 The third frequency and the third duty have values ​​within a certain range, and the fourth frequency and the fourth duty have values ​​within a certain range. The missing phase determination method of the present invention comprises: A method for determining a phase loss waveform to check and avoid malfunctions of a servo amplifier and to set parameters,a step of analyzing by a first analysis unit whether or not the power from the input power supply deviates from a first allowable value based on a value sampled under certain conditions, and outputting an error if the power deviates; a step of sampling the power under the certain conditions by a loss-of-phase waveform determination unit, and determining a first loss-of-phase waveform including a first characteristic obtained from the sampled value if the analysis result by the first analysis unit is normal; and a step of comparing by a second analysis unit the first characteristic with a second characteristic of a second loss-of-phase waveform obtained from a value sampled under the certain conditions after the first loss-of-phase waveform has been determined, and determining the second characteristic. a step of analyzing whether the first characteristic deviates from a second allowable value with respect to the first characteristic and outputting an error if there is a deviation; a step of sampling the power under certain conditions by an open-phase waveform determination unit after determining the first open-phase waveform and determining that the power is normal if the analysis result by the second analysis unit does not deviate from the second allowable value by using the open-phase waveform determination unit; and a step of notifying an error by a main control unit when the open-phase waveform determination unit determines that there is an abnormality based on the error output from the first analysis unit and when the open-phase waveform determination unit determines that there is an abnormality based on the error output from the second analysis unit. the certain conditions include a certain threshold value and a certain sampling period, the first characteristic includes a first frequency and a first duty, the second characteristic includes a second frequency and a second duty, the first allowable value includes a third frequency and a third duty that are set manually or automatically, and the second allowable value includes a fourth frequency and a fourth duty that are set manually or automatically; and the method includes a step of binarizing the power by the open-phase waveform determining unit using the certain threshold value and the certain sampling period, and a step of binarizing the power by the first analyzing unit based on a time between a timing when the sampled value switches from LOW to HIGH and a timing when the sampled value switches from HIGH to LOW. the step of determining the number of phases and a first duty cycle and analyzing whether or not any or all of the first frequency and first duty cycle deviate from any or all of the third frequency and third duty cycle by the open-phase waveform determining unit; the step of binarizing the power using the constant threshold value and the constant sampling period by the open-phase waveform determining unit; and the step of determining the second frequency and second duty cycle by the second analyzing unit based on the time between the timing when the sampled value switches from LOW to HIGH and the timing when the sampled value switches from HIGH to LOW, and analyzing whether or not any or all of the second frequency and second duty cycle deviate from any or all of the fourth frequency and fourth duty cycle. Characterized by 。 The third frequency and the third duty have values ​​within a certain range, and the fourth frequency and the fourth duty have values ​​within a certain range. In the servo amplifier and open-phase detection method of the present invention, a open-phase waveform determination unit that samples power under certain conditions determines a first open-phase waveform from the analysis results of the first analysis unit based on a first tolerance. Furthermore, a phase waveform determination unit that samples the open-phase power under certain conditions determines the first open-phase waveform, and then, based on a second tolerance, determines whether the second open-phase waveform is normal or abnormal from the second analysis unit that compares a first characteristic of the first open-phase waveform with a second characteristic of the second open-phase waveform. The main control unit then issues an error notification when the open-phase waveform determination unit determines an abnormality based on the error output from the first analysis unit, and when the open-phase waveform determination unit determines an abnormality based on the error output from the second analysis unit. [Effects of the Invention]

[0012] According to the servo amplifier and phase loss detection method of the present invention, it is possible to first determine the first phase loss waveform, which serves as an indicator of the operational stability of the servo amplifier, so that it is possible to confirm whether the servo amplifier is in a state where it will not malfunction before starting operation of the servo amplifier. Furthermore, the first phase loss waveform is determined based on a first tolerance value that is set manually or automatically, and the normality or abnormality of the second phase loss waveform that is compared with the first phase loss waveform is determined based on a second tolerance value, which makes it easy to set the parameters of the servo amplifier. Furthermore, since the normality or abnormality of the first phase loss waveform is determined, and the normality or abnormality of the second phase loss waveform is determined, it is possible to prevent forgetting to set parameters, and furthermore, it is possible to reliably avoid malfunctions of the servo amplifier due to fluctuations in the input power supply. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram illustrating an embodiment of a servo amplifier of the present invention; [Figure 2] This is to explain an example of waveform analysis of a single-phase input voltage by the servo amplifier of Figure 1, where Figure 2(a) is a diagram showing the input voltage before rectification, Figure 2(b) is a diagram showing full-wave rectification of the input voltage, and Figure 2(c) is a diagram showing a sampled waveform for the input voltage of Figure 2(b). [Figure 3] This is to explain an example of waveform analysis of a three-phase input voltage by the servo amplifier of Figure 1, where Figure 3(a) is a diagram showing full-wave rectification of the input voltage, Figure 3(b) is a diagram showing a sampled waveform of the L1 phase, Figure 3(c) is a diagram showing a sampled waveform of the L2 phase, Figure 3(d) is a diagram showing a sampled waveform of the L3 phase, and Figure 3(e) is a diagram showing a sampled waveform obtained by combining the L1 to L3 phases. [Figure 4]This explains an example of a specific phenomenon of fluctuation in power from the input power supply in Figure 1, where Figure 4(a) is a diagram showing a normal waveform, Figure 4(b) is a diagram showing an example of a waveform with a shifted frequency, and Figure 4(c) is a diagram showing an example of a waveform with a shifted amplitude. [Figure 5] 10 is a flowchart for explaining an example of a master missing phase waveform determination process performed by the servo amplifier of FIG. [Figure 6] 10 is a flowchart for explaining an example of a master phase loss waveform analysis process performed by the servo amplifier of FIG. [Figure 7] 10 is a flowchart for explaining an example of a polling open-phase waveform determination process performed by the servo amplifier of FIG. [Figure 8] 10 is a flowchart for explaining an example of a polling missing phase waveform analysis process performed by the servo amplifier of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] An embodiment of the servo amplifier of the present invention will be described below with reference to FIGS. 1 to 8. In the following description, the master phase loss waveform is a waveform determined by a master phase loss waveform determination unit 114 (described later) before the servo amplifier 100 (described later) starts operating, and serves as an indicator of the stability of the servo amplifier 100. By determining this master phase loss waveform, it is possible to confirm whether the input power supply 200 is in a state that will not cause a malfunction of the servo amplifier 100 before the servo amplifier 100 starts operating. The polling phase loss waveform is a waveform that is used for comparison with the master phase loss waveform by a polling phase loss waveform determination unit 116 (described later) after the servo amplifier 100 starts operating, after the master phase loss waveform has been determined by the master phase loss waveform determination unit 114.

[0015] In addition, in the following description, (First open-phase waveform) Master open-phase waveform (Second phase loss waveform) Polling phase loss waveform (First characteristic) Includes the frequency (first frequency) and pulse width (first duty) of the master open-phase waveform (common to single-phase and three-phase). (Second characteristic) Includes the frequency (second frequency) and pulse width (second duty) of the polling open-phase waveform (common to single-phase and three-phase). (First tolerance) Includes a frequency (third frequency) and a duty (third duty) that are set manually or automatically before the servo amplifier 100 starts operating (common to single-phase and three-phase). (Second tolerance) Includes a frequency (fourth frequency) and a duty (fourth duty) that are set manually or automatically after the servo amplifier 100 starts operating (common to single-phase and three-phase). It is as follows.

[0016] 1, servo amplifier 100 has a main control unit 110. To main control unit 110, a single-phase / three-phase setting unit 112, a master phase loss waveform analysis unit 113, a master phase loss waveform determination unit 114, a polling phase loss waveform analysis unit 115, a polling phase loss waveform determination unit 116, and a monitor control unit 117 are connected via a signal line 111 such as a data bus. Servo amplifier 100 also has terminals L1, L2, and L3 connected to an input power source 200 (e.g., 200 V), and terminals U, V, and W connected to motor 300. Input power source 200 may be a commercial power source, or may be a transformer interposed between the commercial power source and servo amplifier 100 to transform power from the commercial power source.

[0017] The main control unit 110 controls the cooperative operation of each unit. In addition, the main control unit 110 instructs the monitor control unit 117 to notify an error when the master phase loss waveform determination unit 114 determines that an abnormality has occurred based on the error output from the master phase loss waveform analysis unit 113, and when the polling phase loss waveform determination unit 116 determines that an abnormality has occurred based on the error output from the polling phase loss waveform analysis unit 115.

[0018] The single-phase / three-phase setting unit 112 detects the input voltage obtained via any or all of terminals L1, L2, and L3, and sets whether the input voltage is single-phase or three-phase. Note that the single-phase / three-phase setting unit 112 may detect the input current instead of the input voltage and set whether it is single-phase or three-phase.

[0019] Before the servo amplifier 100 starts operating, the master phase loss waveform analysis unit 113 analyzes whether the AC voltage, which is the power from the input power supply 200, deviates from a first allowable value based on values ​​sampled under certain conditions by the master phase loss waveform determination unit 114 (described later). If there is a deviation, the master phase loss waveform analysis unit 113 outputs an error. In the analysis by the master phase loss waveform analysis unit 113, the frequency (first frequency) and pulse width (first duty) of the master phase loss waveform are determined based on the time difference between the timing at which the value sampled by the master phase loss waveform determination unit 114 (described later) switches from LOW to HIGH and the timing at which it switches from HIGH to LOW. The master phase loss waveform analysis unit 113 then analyzes whether any or all of the determined first frequency and first duty deviate from any or all of the frequency (third frequency) and duty (third duty) that are manually or automatically set before the servo amplifier 100 starts operating.

[0020] In addition, if a transformer (not shown) is interposed between the input power source 200 and the transformer, the master phase loss waveform determination unit 114 similarly analyzes the AC voltage from the transformer based on values ​​sampled under certain conditions to determine whether the value deviates from the first allowable value, and outputs an error if the value deviates.

[0021] Here, the "certain conditions" include a certain threshold value (for example, 100 V) and a certain sampling period (for example, 400 usec). The certain threshold value and the certain sampling period can be changed as appropriate. Furthermore, the first allowable value includes a frequency (third frequency) and a duty (third duty) that are set manually or automatically before the servo amplifier 100 starts operating. Note that here, the sampled value is based on AC voltage, but it may be based on AC current instead of AC voltage. Furthermore, the certain threshold value (for example, 100 V) is not limited to 100 V and may be set arbitrarily. Furthermore, the sampling period (for example, 400 usec) is not limited to 400 usec and may be based on AC current.

[0022] The first tolerance value also includes a frequency (third frequency) and a duty (third duty) that are set manually or automatically before the servo amplifier 100 starts operating. Here, the frequency (third frequency) is the allowable deviation amount expressed as a percentage from the frequency (first frequency) of the master open-phase waveform. The duty (third duty) is the allowable deviation amount expressed as a percentage from the pulse width (first duty) of the master open-phase waveform. In other words, the first tolerance value means the deviation amount (for example, 10%) that the master open-phase waveform determination unit 114, described later, allows for a certain sampled pulse waveform.

[0023] The first tolerance may be a value having a certain range (for example, 10 to 20%), or may be a value without a certain range. If the tolerance does not have a certain range, it may be any of the maximum value (for example, 20%), minimum value (for example, 10%), and average value (for example, 15%) of the tolerance values ​​of the frequency and duty.

[0024] Furthermore, in the analysis by the master open-phase waveform analyzer 113, fluctuations in power from the input power source 200 may be due to natural disasters such as lightning strikes and typhoons. On the other hand, fluctuations in power from a transformer (not shown) may be due to variations in the transformer's transformation accuracy. Specific examples of these power fluctuations include a frequency deviation as shown in Fig. 4(b) and an amplitude deviation as shown in Fig. 4(c) relative to the normal waveform shown in Fig. 4(a).

[0025] Before the servo amplifier 100 starts operating, the master loss-phase waveform determination unit 114 full-wave rectifies the AC voltage from the input power supply 200, as shown in FIG. 2(b) for single phase and FIG. 3(a) for three phase, samples and digitizes the voltage under the above-mentioned fixed conditions, and outputs a pulse waveform as shown in FIG. 2(c) or FIG. 3(e). The voltage of the pulse waveform is, for example, 5V. Also, a to e shown in FIG. 2(c) indicate change points corresponding to the rising and falling edges of the pulse obtained by sampling by the master loss-phase waveform determination unit 114, and details of these will be described later.

[0026] Furthermore, if the analysis result by master phase loss waveform analysis unit 113 is normal, master phase loss waveform determination unit 114 determines a master phase loss waveform including a first characteristic obtained from the sampled values. The first characteristic includes a frequency (first frequency) and a pulse width (first duty) of the master phase loss waveform obtained from the sampled values ​​by master phase loss waveform determination unit 114.

[0027] Here, when the AC voltage is single-phase as shown in Fig. 2(a), for example, the master loss-phase waveform determination unit 114 full-wave rectifies the AC voltage as shown in Fig. 2(b). Furthermore, the master loss-phase waveform determination unit 114 obtains a pulse waveform as shown in Fig. 2(c) by sampling under certain conditions including the above-mentioned certain threshold (e.g., 100V) and certain sampling period (e.g., 400usec).

[0028] Furthermore, when the AC voltage is three-phase, the master phase loss waveform determination unit 114 full-wave rectifies the AC voltage as shown in FIG. 3(a). Furthermore, the master phase loss waveform determination unit 114 obtains the pulse waveform shown in FIG. 3(e) by sampling under the above-mentioned constant conditions. This pulse waveform includes the L1-phase pulse waveform shown in FIG. 3(b), the L2-phase pulse waveform shown in FIG. 3(c), and the L3-phase pulse waveform shown in FIG. 3(d). Although the master phase loss waveform determination unit 114 full-wave rectifies the AC voltage, it may also full-wave rectify the AC current. Furthermore, although the master phase loss waveform determination unit 114 full-wave rectifies the AC voltage, it may also half-wave rectify the AC voltage.

[0029] After the master phase loss waveform (first phase loss waveform) is determined (after the servo amplifier 100 starts operating), the polling phase loss waveform analysis unit 115 compares a first characteristic including the frequency (first frequency) and pulse width (first duty) of the master phase loss waveform with a second characteristic including the frequency (second frequency) and pulse width (second duty) of the polling phase loss waveform obtained from values ​​sampled by the polling phase loss waveform determination unit 116 described below, based on certain conditions including the above-mentioned certain sampling period (for example, 400 usec).

[0030] In the analysis by the polling open phase waveform analysis unit 115, the frequency (second frequency) and pulse width (second duty) of the polling open phase waveform are determined based on the time difference between the timing at which the value sampled by the polling open phase waveform determination unit 116 (described later) switches from LOW to HIGH and the timing at which it switches from HIGH to LOW.The polling open phase waveform analysis unit 115 then analyzes whether or not any or all of the determined second frequency and second duty deviate from any or all of the frequency (fourth frequency) and duty (fourth duty) that are set manually or automatically after the servo amplifier 100 starts operating.

[0031] Furthermore, the polling phase loss waveform analyzer 115 analyzes whether the deviation of the second characteristic from the first characteristic is within a second tolerance, and outputs an error if it is not within the second tolerance. The error is output when the comparison result of the frequency (second frequency) of the polling phase loss waveform with the frequency (first frequency) of the master phase loss waveform is not within the second tolerance, or when the comparison result of the pulse width (second duty) of the polling phase loss waveform with the pulse width (first duty) of the master phase loss waveform is not within the second tolerance, or both.

[0032] The second allowable value includes a frequency (third frequency) and a duty (third duty) that are set manually or automatically after the servo amplifier 100 starts operating. The frequency (third frequency) here is, as above, the allowable deviation amount expressed as a percentage from the frequency (first frequency) of the master open phase waveform. Also, the duty (third duty) is the allowable deviation amount expressed as a percentage from the pulse width (first duty) of the master open phase waveform.

[0033] The frequency (third frequency) and duty (third duty) may be values ​​having a certain range, or may be values ​​without a certain range, as described above. In the case of values ​​without a certain range, the maximum value, minimum value, or average value of the frequency and duty may be used.

[0034] After the master phase loss waveform is determined, the polling phase loss waveform determination unit 116 samples and digitizes the AC voltage under the above-mentioned fixed conditions while the servo amplifier 100 is starting up, and determines that the waveform is normal if the analysis result by the polling phase loss waveform analysis unit 115 does not deviate from the second allowable value.

[0035] The monitor control unit 117 is connected to a monitor 120. When the monitor control unit 117 receives an error notification instruction from the main control unit 110, it notifies the monitor 120 of the error. The notification content may be, for example, a message indicating that a voltage fluctuation may cause a malfunction of the servo amplifier 100. In any case, the notification content only needs to notify the user that a malfunction of the servo amplifier 100 may occur. Furthermore, when notifying the user of an error, a warning sound from a buzzer may be used.

[0036] Next, the master open-phase waveform determination process will be described with reference to Fig. 5. In the following description, for convenience of explanation, the determination based on the binarized value is based on negative logic.

[0037] (Step S101) When the servo amplifier 100 is powered on, the master phase loss waveform determination unit 114, in response to instructions from the main control unit 110, initializes N (a value indicating a change in a single phase due to sampling) and M (a value indicating a change in three phases due to sampling) set in a memory not shown.

[0038] (Step S102) The master missing phase waveform determination unit 114 full-wave rectifies each phase voltage and sets the binarized value in a memory (not shown). In this case, when the AC voltage is single-phase as shown in FIG. 2(a), the master phase loss waveform determination unit 114 full-wave rectifies the AC voltage from the input power supply 200 as shown in FIG. 2(b), samples it at a fixed sampling period (for example, 400 usec) based on the above-mentioned fixed threshold value (for example, 100 V), and sets the binarized value in a memory (not shown). In addition, in the case of three phases, the master phase loss waveform determination unit 114 full-wave rectifies the AC voltage from the input power supply 200 as shown in FIG. 3(a), samples it at a fixed sampling period (for example, 400 usec) based on the above-mentioned fixed threshold value (for example, 100 V), and sets the binarized value in a memory (not shown).

[0039] (Step S103) The master missing phase waveform determining unit 114 determines whether there is a change in voltage level between the previous time and the current time. In this case, if the sampled value is 0 and the next sampled value is 1, for example, master missing phase waveform determination unit 114 determines that there is a change in the voltage level (step S103: Yes), and proceeds to step S104. On the other hand, if the sampled value is 0 and the next sampled value is also 0, master missing phase waveform determination unit 114 determines that there is no change in the voltage level (step S103: No) and proceeds to step S110. If the sampled value is 1 and the next sampled value is also 1, master missing phase waveform determination unit 114 similarly determines that there is no change in the voltage level.

[0040] (Step S104) The master missing phase waveform determination unit 114 records 1 at N (N=1), which indicates a change in a single phase, in the arrangement of a ring buffer (not shown).

[0041] (Step S105) The master missing phase waveform determining unit 114 determines whether N≧5. In this case, if N is less than 5, the master missing phase waveform determination unit 114 determines that N≧5 is not satisfied (step S105: No), and proceeds to step S102. On the other hand, if N is 5 or more, the master open phase waveform determination unit 114 determines that N≧5 (step S105: Yes), and proceeds to step S106. 2(c), N=5 corresponds to, for example, five points a to e (change points) indicating the rising and falling edges of a pulse obtained by sampling by master phase loss waveform determination unit 114. Note that master phase loss waveform determination unit 114 determines whether N is 5 or greater, but may also determine this when N is a value greater than 5.

[0042] (Step S106) The master phase loss waveform analysis unit 113 analyzes the master phase loss waveform. The analysis of the master phase loss waveform by the master phase loss waveform analyzer 113 will be described in detail later with reference to FIG.

[0043] (Step S107) The master loss-phase waveform determination unit 114 determines whether the analysis result of the master loss-phase waveform is normal. In this case, if the master phase loss waveform determination unit 114 analyzes that the frequency and duty obtained from values ​​sampled under certain conditions by the master phase loss waveform analysis unit 113 described later are both within the allowable values, it determines that the analysis result of the master phase loss waveform is normal (step S107: Yes) and proceeds to step S108. In response to this, the master phase loss waveform determination unit 114 analyzes that either one or both of the frequency and duty obtained from values ​​sampled under certain conditions by the master phase loss waveform analysis unit 113 described later are not within the allowable values, and if an error is output, it determines that the analysis result of the master phase loss waveform is not normal (step S107: No) and proceeds to step S109.

[0044] (Step S108) The master loss-phase waveform determination unit 114 determines a master loss-phase waveform for a single phase. In this case, the master phase loss waveform determination unit 114 determines a waveform having a frequency and duty obtained from values ​​sampled under certain conditions as a single-phase master phase loss waveform, and stores the frequency (first frequency) and pulse width (first duty) of the master phase loss waveform determined by the master phase loss waveform analysis unit 113 described later as a first characteristic in a memory not shown.

[0045] (Step S109) In step S107, if the master phase loss waveform determination unit 114 determines that the analysis result of the master phase loss waveform is not normal based on the error output by the master phase loss waveform analysis unit 113 described later when it analyzes that either or both of the frequency and duty are not within the allowable values, the main control unit 110 notifies the monitor 120 of the error via the monitor control unit 117.

[0046] (Step S110) The master missing phase waveform determining unit 114 determines whether the voltage level is LOW. In this case, as shown in FIG. 3(e), if the sampled values ​​are all 1, the master missing phase waveform determination unit 114 determines that the voltage level is LOW using negative logic (step S110: Yes), and proceeds to step S111. In contrast, if the sampled value is 0 in step S103 and the next sampled value is also 0, the master missing phase waveform determination unit 114 determines that the voltage level is HIGH using negative logic (step S110: No) and proceeds to step S112.

[0047] (Step S111) The master open-phase waveform determining unit 114 counts LOW.

[0048] (Step S112) The master open-phase waveform determination unit 114 counts HIGHs.

[0049] (Step S113) The master open-phase waveform determination unit 114 determines whether M, which is the total number of the LOW count value and the HIGH count value, is greater than a specified number (for example, 200). Note that the specified number is not limited to 200 and can be changed arbitrarily. In this case, if the master open-phase waveform determination unit 114 determines that M, which is the total number of LOW count values ​​and HIGH count values, is greater than the specified number of times (step S113: Yes), the process proceeds to step S114. On the other hand, if the master open-phase waveform determination unit 114 determines that the total number M of the LOW count value and the HIGH count value is not greater than the specified number of times (step S113: No), the process proceeds to step S102.

[0050] (Step S114) The master missing phase waveform determining unit 114 determines whether the LOW count value is greater than the HIGH count value. In this case, if the master open-phase waveform determination unit 114 determines that the LOW count value is greater than the HIGH count value (step S114: Yes), the process proceeds to step S115. On the other hand, if the master open-phase waveform determination unit 114 determines that the LOW count value is not greater than the HIGH count value (step S114: No), the process proceeds to step S116. If the LOW count value is not greater than the HIGH count value, this means that a phase loss has occurred.

[0051] (Step S115) The master loss-phase waveform determining unit 114 determines the master loss-phase waveforms for the three phases. In this case, the master phase loss waveform determination unit 114 determines a waveform having a frequency and duty obtained from values ​​sampled under certain conditions as the three-phase master phase loss waveform, and stores the frequency (first frequency) and pulse width (first duty) of the master phase loss waveform determined by the master phase loss waveform analysis unit 113 described later as the first characteristic in a memory not shown.

[0052] (Step S116) If the master open-phase waveform determining unit 114 determines in step S114 that the LOW count value is not greater than the HIGH count value, the main control unit 110 causes the monitor control unit 117 to notify the monitor 120 of an error.

[0053] Next, the master open phase waveform analysis process will be described with reference to Fig. 6. It is assumed that the first allowable values ​​described below, ie, the allowable values ​​of frequency and duty, both have values ​​within a certain range.

[0054] (Step S201) The master open-phase waveform analysis unit 113 finds the frequency based on the time difference between the change points. For example, suppose that four transition points a to d are obtained per cycle in the pulse waveform shown in Figure 2(c). In this case, the frequency of the master open-phase waveform can be calculated by calculating the time difference between a and b, and then calculating the reciprocal of the time difference.

[0055] (Step S202) The master open-phase waveform analyzer 113 sets the allowable values ​​of the frequency (third frequency) and duty (third duty), which are the first allowable values, in a memory (not shown). In this case, the master phase loss waveform analysis unit 113 may accept and set the frequency and duty tolerance values ​​set by the user, or may automatically acquire and set the preset frequency and duty tolerance values. The tolerance here is, as in the above, a percentage of the tolerance for the frequency and duty cycle obtained by the master open-phase waveform determination unit 114 through sampling.

[0056] (Step S203) The master open-phase waveform analyzer 113 determines whether the frequency is within the allowable range. In this case, if the master open phase waveform analyzer 113 determines that the frequency calculated in step S201 is within the allowable range of frequencies set in step S202 (step S203: Yes), the process proceeds to step S204. On the other hand, if the master open phase waveform analyzer 113 determines that the frequency calculated in step S201 is not within the allowable range of frequencies set in step S202 (step S203: No), the process proceeds to step S207. The master open-phase waveform analyzer 113 can determine whether the frequency obtained in step S201 is within the allowable percentage by checking whether the deviation of the frequency is within the allowable percentage.

[0057] (Step S204) The master open-phase waveform analyzer 113 calculates the duty. In this case, the master open-phase waveform analyzer 113 can obtain the duty cycle, which is the pulse width, by determining the time difference between a and b in the pulse waveform shown in FIG. 2(c) in the same manner as above.

[0058] (Step S205) The master open-phase waveform analyzer 113 determines whether the obtained duty is within an allowable value. In this case, if the master open phase waveform analyzer 113 determines that the duty calculated in step S204 is within the allowable range of duty set in step S202 (step S205: Yes), the process proceeds to step S206. On the other hand, if the master open phase waveform analyzer 113 determines that the duty calculated in step S204 is not within the allowable range of duty set in step S202 (step S205: No), the process proceeds to step S207. The allowable value here is a duty (third duty) that is set manually or automatically. As above, the duty (third duty) is the allowable deviation amount for the pulse width (first duty) of the master open-phase waveform expressed as a percentage, and by checking whether the deviation amount of the duty calculated in step S204 is within the allowable percentage, it can be determined whether the calculated duty is within the allowable value.

[0059] (Step S206) The master open-phase waveform analyzer 113 determines the frequency (first frequency) and duty (first duty) that are the first characteristics.

[0060] (Step S207) The master open-phase waveform analyzer 113 outputs an error.

[0061] Next, the polling open-phase waveform determination process will be described with reference to Fig. 7. In the following description, determination based on binarized values ​​is based on negative logic, as in the above.

[0062] (Step S301) The polling open-phase waveform determination unit 116 full-wave rectifies each phase voltage and sets the binarized value in a memory (not shown). In this case, when the AC voltage is single-phase as shown in FIG. 2(a), the polling open-phase waveform determination unit 116 full-wave rectifies the AC voltage from the input power supply 200 as shown in FIG. 2(b), samples it at a fixed sampling period (for example, 400 usec) based on the above-mentioned fixed threshold value (for example, 100 V), and sets the binarized value in a memory (not shown). In addition, in the case of three phases, the polling open-phase waveform determination unit 116 full-wave rectifies the AC voltage from the input power supply 200 as shown in FIG. 3(a), samples it at a fixed sampling period (for example, 400 usec) based on the above-mentioned fixed threshold value (for example, 100 V), and sets the binarized value in a memory (not shown).

[0063] (Step S302) The polling open-phase waveform determination unit 116 determines whether there is a change in voltage level between the previous time and the current time. In this case, similarly to the above, if the sampled value is 0 and the next sampled value is 1, the polling open phase waveform determination unit 116 determines that there is a change in the voltage level (step S302: Yes), and proceeds to step S303. On the other hand, if the sampled value is 0 and the next sampled value is also 0, the polling open phase waveform determination unit 116 determines that there is no change in the voltage level (step S302: No), and proceeds to step S308.

[0064] (Step S303) The polling open-phase waveform determination unit 116 records 1 at N (N=1), which indicates a single-phase change, in the arrangement of a ring buffer (not shown).

[0065] (Step S304) The polling open-phase waveform determination unit 116 determines whether N≧5. In this case, if N is less than 5, the polling open phase waveform determining unit 116 determines that N≧5 is not satisfied (step S304: No), and proceeds to step S301. On the other hand, if N is 5 or more, the polling open phase waveform determining unit 116 determines that N≧5 (step S304: Yes), and proceeds to step S305. Here, N=5 corresponds to five points a to e (change points) indicating the rising and falling edges of a pulse obtained by sampling by polling open-phase waveform determination unit 116, for example, as described above.

[0066] (Step S305) The polling phase loss waveform analysis unit 115 analyzes the polling phase loss waveform. In addition, when the polling phase loss waveform analysis unit 115 analyzes the polling phase loss waveform, if either or both of the frequency and duty are not within the allowable values, an error is output, the details of which will be explained later with reference to FIG. 8.

[0067] (Step S306) The polling open phase waveform determination unit 116 determines whether the analysis result of the polling open phase waveform is normal. In this case, if the polling phase loss waveform analysis unit 115 described later analyzes that both the frequency and duty are within the allowable values, the polling phase loss waveform determination unit 116 determines that the analysis result of the polling phase loss waveform is normal (step S306: Yes), and proceeds to step S301. In contrast, if the polling phase loss waveform analysis unit 115 analyzes that either or both of the frequency and the duty are not within the allowable values, the polling phase loss waveform determination unit 116 determines that the analysis result of the polling phase loss waveform is not normal (step S306: No), and proceeds to step S307.

[0068] (Step S307) In step S406, if the main control unit 110 determines that the analysis result of the master phase loss waveform is not normal based on the error output by the polling phase loss waveform determination unit 116 when the polling phase loss waveform analysis unit 115 described below analyzes that either or both of the frequency and duty are not within the allowable values, the main control unit 110 notifies the monitor 120 of the error via the monitor control unit 117.

[0069] (Step S308) The polling open-phase waveform determination unit 116 determines whether the voltage level is LOW. In this case, as shown in FIG. 3(e), if the sampled values ​​are all 1, the polling open phase waveform determiner 116 determines that the voltage level is LOW using negative logic (step S308: Yes), and proceeds to step S309. In contrast, if the sampled value is 0 in step S302 and the next sampled value is also 0, the polling open phase waveform determination unit 116 determines that the voltage level is HIGH using negative logic (step S308: No), and proceeds to step S310.

[0070] (Step S309) The polling open-phase waveform determination unit 116 counts LOW.

[0071] (Step S310) The polling open-phase waveform determination unit 116 counts HIGH.

[0072] (Step S311) The polling open-phase waveform determination unit 116 determines whether M, which is the total number of LOW count values ​​and HIGH count values, is greater than a specified number (for example, 200). In this case, if the polling open-phase waveform determination unit 116 determines that M, which is the total number of LOW count values ​​and HIGH count values, is greater than the specified number of times (step S311: Yes), the process proceeds to step S312. On the other hand, if the polling open-phase waveform determination unit 116 determines that M, which is the total number of LOW count values ​​and HIGH count values, is not greater than the specified number of times (step S311: No), the process proceeds to step S301.

[0073] (Step S312) The polling open-phase waveform determination unit 116 determines whether the LOW count value is greater than the HIGH count value. In this case, if the polling open phase waveform determination unit 116 determines that the LOW count value is greater than the HIGH count value (step S312: Yes), the process proceeds to step S313. On the other hand, if the polling open phase waveform determination unit 116 determines that the LOW count value is not greater than the HIGH count value (step S312: No), the process proceeds to step S307.

[0074] (Step S313) The polling phase loss waveform determination unit 116 determines whether the master phase loss waveform is three phases. In this case, when the input voltage set by the single-phase / three-phase setting unit 112 is three-phase, the polling phase loss waveform determination unit 116 determines that the master phase loss waveform is three-phase (step S313: Yes), and proceeds to step S301. In contrast, when the input voltage set by the single-phase / three-phase setting unit 112 is single-phase, the polling phase loss waveform determination unit 116 determines that the master phase loss waveform is not three-phase (step S313: No), and proceeds to step S307.

[0075] Next, the polling open phase waveform analysis process will be described with reference to Fig. 8. Note that the second allowable values ​​described below, namely, the allowable values ​​of frequency and duty, are assumed to have a certain range of values, similar to the above.

[0076] (Step S401) The polling open phase waveform analysis unit 115 finds the frequency based on the time difference between the change points. Here, similarly to the above, for example, in the pulse waveform shown in Figure 2(c), four change points a to d are obtained per period. In this case, similarly to the above, for example, the time difference between a and b is found, and then the reciprocal of the found time difference is found, thereby making it possible to find the frequency of the polling open-phase waveform.

[0077] (Step S402) The polling open phase waveform analyzer 115 sets the second allowable values, ie, the frequency (fourth frequency) and the duty (fourth duty), in a memory (not shown). In this case, the polling open phase waveform analysis unit 115 may accept and set the frequency and duty tolerance values ​​set by the user, or may automatically accept and set the preset frequency and duty tolerance values.

[0078] (Step S403) The polling open-phase waveform analysis unit 115 determines whether the frequency is within the allowable range. In this case, if the polling open phase waveform analyzer 115 determines that the frequency calculated in step S401 is within the allowable range of frequencies set in step S402 (step S403: Yes), the process proceeds to step S404. On the other hand, if the polling open phase waveform analyzer 115 determines that the frequency calculated in step S401 is not within the allowable range of frequencies set in step S402 (step S403: No), the process proceeds to step S407. The polling open phase waveform analyzer 115 can determine whether the frequency obtained in step S401 is within the allowable percentage by checking whether the deviation of the frequency obtained in step S401 is within the allowable percentage.

[0079] (Step S404) The polling open phase waveform analysis unit 115 determines the duty. In this case, the polling open phase waveform analyzer 115 can obtain the duty cycle, which is the pulse width, by determining the time difference between a and b in the pulse waveform shown in FIG. 2(c) in the same manner as above.

[0080] (Step S405) The polling open phase waveform analysis unit 115 determines whether the obtained duty is within an allowable value. In this case, if the polling open phase waveform analyzer 115 determines that the duty calculated in step S404 is within the allowable range of duty set in step S402 (step S405: Yes), the process proceeds to step S406. On the other hand, if the polling open phase waveform analyzer 115 determines that the duty calculated in step S404 is not within the allowable range of duty set in step S402 (step S405: No), the process proceeds to step S407. The polling open phase waveform analyzer 115 can determine whether the determined duty is within the allowable value by checking whether the deviation amount of the duty calculated in step S404 is within the allowable percentage.

[0081] (Step S406) The polling open-phase waveform analysis unit 115 outputs the analysis result indicating that the waveform is normal.

[0082] (Step S407) The polling open phase waveform analysis unit 115 outputs an error.

[0083] As described above, in this embodiment, the master phase loss waveform analysis unit 113 (first analysis unit) analyzes whether the power from the input power source 200 deviates from the first allowable value based on the value sampled under certain conditions, and the master phase loss waveform determination unit 114 (phase loss waveform determination unit) samples the power under certain conditions, and if the analysis result by the master phase loss waveform analysis unit 113 (first analysis unit) is normal, determines a master phase loss waveform (first phase loss waveform) including the first characteristic obtained from the sampled value. Furthermore, the polling phase loss waveform analysis unit 115 (second analysis unit) compares the first characteristic with a second characteristic of the polling phase loss waveform (second loss phase waveform) obtained from values ​​sampled under certain conditions after the master phase loss waveform (first loss phase waveform) is determined, and analyzes whether the second characteristic deviates from a second allowable value with respect to the first characteristic, and the polling phase loss waveform determination unit 116 (loss phase waveform determination unit) samples the power under certain conditions after the master phase loss waveform (first loss phase waveform) is determined, and determines that the analysis result by the polling phase loss waveform analysis unit 115 (second analysis unit) does not deviate from the second allowable value as normal, and the main control unit 110 notifies an error when the master phase loss waveform determination unit 114 (loss phase waveform determination unit) determines that there is an abnormality and when the polling phase loss waveform determination unit 116 (loss phase waveform determination unit) determines that there is an abnormality.

[0084] This allows the first missing phase waveform, which serves as an indicator of the operational stability of the servo amplifier 100, to be determined, so that it is possible to confirm whether the servo amplifier 100 is in a state where it will not malfunction before starting operation of the servo amplifier 100.

[0085] Furthermore, since the master phase loss waveform is determined based on a first tolerance value that is set manually or automatically, and the normality or abnormality of the polling phase loss waveform that is compared with the first phase loss waveform is determined based on a second tolerance value, it is possible to easily set parameters for the servo amplifier 100. Furthermore, since the normality or abnormality of the master phase loss waveform is determined, and the normality or abnormality of the polling phase loss waveform is determined, it is possible to prevent forgetting to set parameters, and further, it is possible to reliably avoid malfunctions of the servo amplifier 100 due to fluctuations in the input power supply 200. This is particularly effective in avoiding malfunctions of the servo amplifier 100 when a transformer with variations in transformation accuracy is used. [Explanation of symbols]

[0086] 100 Servo Amplifier 110 Main control unit 111 signal line 112 Single-phase / three-phase setting section 113 Master phase loss waveform analysis unit 114 Master phase loss waveform determination unit 115 Polling open-phase waveform analysis section 116 Polling open-phase waveform determination unit 117 Monitor control section 120 monitors 200 Input power 300 motor L1, L2, L3, U, V, W terminals a~e Change points

Claims

1. a first analysis unit that analyzes whether or not the power from the input power supply deviates from a first allowable value based on a value sampled under certain conditions, and outputs an error if the value deviates; a missing phase waveform determination unit that samples the power under the certain conditions, and determines a first missing phase waveform including a first characteristic obtained from the sampled value when the analysis result by the first analysis unit is normal; a second analysis unit that compares the first characteristic with a second characteristic of a second open phase waveform obtained from values ​​sampled under the certain conditions after the first open phase waveform is determined, analyzes whether the second characteristic deviates from a second allowable value with respect to the first characteristic, and outputs an error if there is a deviation; an open-phase waveform determination unit that samples the power under certain conditions after determining the first open-phase waveform, and determines that the power is normal if the analysis result by the second analysis unit does not deviate from the second allowable value; a main control unit that notifies an error when the open phase waveform determination unit determines that an abnormality has occurred based on the error output from the first analysis unit and when the open phase waveform determination unit determines that an abnormality has occurred based on the error output from the second analysis unit, the certain conditions include a certain threshold and a certain sampling period; the first characteristic includes a first frequency and a first duty; the second characteristic includes a second frequency and a second duty; the first allowable value includes a third frequency and a third duty that are set manually or automatically; the second allowable value includes a fourth frequency and a fourth duty that are set manually or automatically, the missing phase waveform determination unit binarizes the power using the constant threshold value and the constant sampling period; the first analysis unit determines the first frequency and the first duty cycle based on a time difference between a timing at which the sampled value switches from LOW to HIGH and a timing at which the sampled value switches from HIGH to LOW, and analyzes whether or not any or all of the first frequency and the first duty cycle deviates from any or all of the third frequency and the third duty cycle; the open-phase waveform determination unit binarizes the power using the constant threshold value and the constant sampling period; The second analysis unit obtains the second frequency and the second duty cycle based on the time difference between the timing at which the sampled value switches from LOW to HIGH and the timing at which the sampled value switches from HIGH to LOW, and analyzes whether or not any or all of the second frequency and the second duty cycle deviates from any or all of the fourth frequency and the fourth duty cycle. A servo amplifier characterized by:

2. the third frequency and the third duty have values ​​within a certain range, The fourth frequency and the fourth duty have values ​​within a certain range.

2. The servo amplifier according to claim 1.

3. A method for determining a phase loss waveform to check and avoid malfunctions of a servo amplifier and to set parameters, comprising: a step of analyzing by a first analysis unit whether or not the power from the input power supply deviates from a first allowable value based on a value sampled under certain conditions, and outputting an error if the power deviates; a step of sampling the power under the certain conditions by a loss-phase waveform determination unit, and determining a first loss-phase waveform including a first characteristic obtained from the sampled value when the analysis result by the first analysis unit is normal; a step of comparing, by a second analysis unit, the first characteristic with a second characteristic of a second open phase waveform obtained from values ​​sampled under the certain conditions after the first open phase waveform is determined, analyzing whether the second characteristic deviates from a second allowable value with respect to the first characteristic, and outputting an error if there is a deviation; a step of sampling the power under a certain condition by an open-phase waveform determination unit after determining the first open-phase waveform, and determining that the power is normal if the analysis result by the second analysis unit does not deviate from the second allowable value; a step of notifying an error by a main control unit when the open phase waveform determination unit determines that an abnormality has occurred based on the error output from the first analysis unit and when the open phase waveform determination unit determines that an abnormality has occurred based on the error output from the second analysis unit, the certain conditions include a certain threshold and a certain sampling period; the first characteristic includes a first frequency and a first duty; the second characteristic includes a second frequency and a second duty; the first allowable value includes a third frequency and a third duty that are set manually or automatically; the second allowable value includes a fourth frequency and a fourth duty that are set manually or automatically, a step of binarizing the power by the missing phase waveform determination unit using the constant threshold value and the constant sampling period; a step of determining the first frequency and the first duty cycle based on the time between the timing when the sampled value switches from LOW to HIGH and the timing when the sampled value switches from HIGH to LOW by the first analysis unit, and analyzing whether or not any or all of the first frequency and the first duty cycle deviates from any or all of the third frequency and the third duty cycle; a step of binarizing the power by the open-phase waveform determination unit using the constant threshold value and the constant sampling period; and a step of determining, by the second analysis unit, the second frequency and the second duty cycle based on the time between the timing at which the sampled value switches from LOW to HIGH and the timing at which the sampled value switches from HIGH to LOW, and analyzing whether or not any or all of the second frequency and the second duty cycle deviates from any or all of the fourth frequency and the fourth duty cycle. A method for determining a missing phase.

4. the third frequency and the third duty have values ​​within a certain range, The fourth frequency and the fourth duty have values ​​within a certain range.

4. The method for determining a missing phase according to claim 3.

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