JP3317069B2 - Motor control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor control device for controlling a motor by causing a control operation means to execute a program.

[0002]

2. Description of the Related Art In a motor control device which controls a motor by causing a control arithmetic unit to execute a program, when power is lost due to a power failure or the like, the control arithmetic unit operates except for a system having an uninterruptible power supply. Therefore, the control calculation means performs a power failure process such as outputting a stop signal to the motor during a few milliseconds during which the power supply of the motor control device itself can be held, and then resets to an initial state. However, in the case of a short-term power outage, the motor or a device operated by the motor generally has a large inertia and a large time constant of deceleration, so that when the power is restored, it is possible to continue the operation before the power failure. Often. Therefore, in the case of a short-time power failure such as an instantaneous power failure in which the motor or the system can continue to operate sufficiently, it is desirable that the motor control device restarts the control that has been continued at the same time as the power is restored.

FIG. 3 shows an example of a motor control device which continues the previous control when the power failure is within the allowable range when the short-time power failure is recovered. FIG. 3A is a diagram illustrating a portion related to a power failure process of the motor control device. In the figure,
A is a motor control device, and the motor control device A includes a control operation unit 2, a power failure time detection circuit 1, and a power failure time detection circuit 1.
And a current amplifier circuit composed of a differential amplifier OP and a resistor R5 for inputting a terminal voltage Vc of the power failure time detection circuit 1 to a terminal T1 of the control operation means 2 for charging the power supply. . GND is a power supply bus connected to a negative electrode which is a reference voltage of a DC power supply for supplying electric power to the motor control device A, and Vcc is a power supply bus connected to the positive electrode.

FIG. 3 (b) shows a block diagram of the inside of the control operation means 2 shown in FIG. 3 (a). In the figure, reference numeral 2 denotes a control operation means.
Program storage means 22, data storage means 23, nonvolatile data storage means 24, first input / output circuit 25, second input / output circuit 2
6. It comprises operation signal input means 27. SB is control operation means 2
Is a signal bus for transmitting a signal between the respective parts constituting.
The first input / output circuit 25 and the second input / output circuit 26 are connected to a motor or a peripheral circuit of the motor, the first input / output circuit 25 inputs / outputs digital signals, and the second input / output circuit 26 inputs / outputs analog signals. Input and output. The non-volatile data storage means 24 is a storage means for storing data to be referred to when the control operation unit 21 executes a program, and for storing data generated by the control operation unit to be retained even during a power failure. The means 23 is a storage means for temporarily storing data generated when the instruction of the control operation unit 21 is executed or data to be referred to. The control operation unit 21 executes a system program and a motor control program stored in the program storage unit 22, and controls the motor to be controlled to the first input / output circuit 25 and the second input / output circuit 25.
Control is performed via the input / output circuit 26.

As shown in FIG. 3A, the power failure time detection circuit 1 is a power failure time detection circuit (hereinafter referred to as a CR circuit 1) composed of a parallel circuit of a resistor R and a capacitor C. Since the input resistance of the differential amplifier OP is much higher than the resistance R and the resistance R1 of the capacitor C, the resistance R1 and the diode R1 are connected to the resistance R1 while the motor control device A is operating normally. It is charged to the voltage Vvm divided by the series circuit of the diode D1 and the resistor R. The terminal voltage Vc of the capacitor C is input to the input terminal of the differential amplifier OP via the resistor R5, and a voltage equal to the input voltage is output from the differential amplifier OP to the input terminal T1 of the control operation means 2. . The terminal T1 is one of the terminals of the second input / output circuit 26 shown in FIG. 3 (b). The terminal T1 is a binary signal corresponding to the input voltage by the A / D converter inside the second input / output circuit 26. And is read by the control calculation means 2 via the signal bus SB.

FIG. 4 is a graph showing the discharge characteristics of the CR circuit 1 shown in FIG. 3. The horizontal axis represents time, and the vertical axis represents the terminal voltage Vc of the CR circuit 1 shown in FIG. The terminal voltage of the CR circuit 1 with respect to the passage of time with the time of occurrence of a power failure as time 0
6 is a graph showing a change in Vc. The graph shows the following equation (1)
Can also be represented by

[0007]

(Equation 1)

Vc = Vcm * exp (-t / T) where Vc is the time measured with the time of occurrence of a power failure as time 0.
The terminal voltage of the capacitor C at t ", Vcm is the terminal voltage of the capacitor C at time 0, the charging voltage of the CR circuit 1, and T is the capacitance C of the capacitor C (unit farad).
Is multiplied by the resistance value R (unit ohm) of the resistor R, "*" is a multiplication operator. Next, referring to FIG. 3 and FIG. explain. In the motor control device A, an allowable limit time TL for determining whether to restart the operation before the power failure after the power is restored or to wait for a new start as a reset is determined in advance in accordance with the characteristics of the control target. Is substituted into the time t of the formula (1), and the obtained value is set as the allowable limit voltage VL. Data corresponding to the allowable limit voltage VL is stored in the non-volatile storage means 24 or the program storage means 22, and the power is restored after the power failure. Sometimes, the terminal voltage of the CR circuit 1 is measured. If the measured voltage is greater than or equal to the permissible limit voltage VL, the operation before the power failure is continued.

[0009]

In a motor control device that controls a motor by causing a control arithmetic unit to execute a program, a power outage is allowed if the restart of operation continued before the power outage is permitted when the power is restored after the power outage. It is desirable to continue the previous operation. Therefore, in an example of a conventional motor control device, as described above, a power failure time detection that discharges from the time of the power failure occurs in an allowable limit time that is determined by adapting to the characteristics of the control target and that represents a limit time in which operation can be continued. The voltage reached by the terminal voltage of the circuit is stored in the storage means of the motor control device as an allowable limit voltage, and when the power is restored after the power failure, the terminal of the power failure time detection circuit is restored when the power is restored. The voltage is measured, and if the measured voltage is greater than or equal to the permissible limit voltage, the operation before the power failure is continued. If the measured voltage is smaller than the allowable limit voltage, a stop signal is output to the control target, and the operation is reset to wait for a start operation to restart the operation.

However, in the motor control device of the type in which the above-mentioned power failure time is obtained from the discharge characteristics of the power failure time detection circuit charged during operation, the power failure time depends on the state of the power supply in which the motor control device is installed. Since the voltage of the power supply charging the capacitor of the detection circuit is not necessarily a constant value, the allowable limit voltage of the power failure time stored in advance in the motor control device is the power failure time detection circuit in the installed state. The value may be considerably different from the voltage corresponding to the allowable limit time determined from the discharge characteristics. In addition, if the value of the allowable limit voltage is set to a high value and the voltage at the time of the occurrence of the power failure is low, the motor control device may determine that the allowable limit time has been exceeded even in the case of an extremely short-time instantaneous power failure.

In view of the circumstances described above, an object of the present invention is to provide a motor control device of a type in which a power outage time is obtained from a discharge characteristic of a power outage time detection circuit charged during operation. It is an object of the present invention to provide a motor control device in which the influence on the measurement of the power outage time due to the environment is reduced.

[0012]

According to the present invention, there is provided, in accordance with the present invention, an operation signal input unit, a control operation unit, a nonvolatile storage unit for storing a value of a reference allowable limit voltage, A power failure time detection circuit consisting of a capacitor and a resistor that is normally charged with the power supply voltage and discharged at the time of power failure is provided.When the power failure recovers, the terminal voltage of the power failure time detection circuit representing a voltage corresponding to the power failure time is measured. A motor control device that determines whether or not to continue the operation of the control target by comparing the value with the allowable limit voltage value, wherein a switch that controls charging and discharging of the power failure time detection circuit by a signal from the control arithmetic unit. A circuit and a reference discharge characteristic creating program executed by the control arithmetic means, wherein the control arithmetic means is configured to execute the control discharge operation at a predetermined time via the operation signal input means. By inputting the operation signal and executing the reference discharge characteristic creation program, the switch circuit is controlled to charge the power failure time detection circuit with the power supply voltage of the electric motor control device. The discharge of the time detection circuit is started, the change in the terminal voltage of the power failure time detection circuit with respect to the passage of time during the discharge is measured, and the measured value is stored as the reference discharge characteristic in the nonvolatile storage means. A reference allowable limit voltage value corresponding to a control target of the motor control device can be stored in the non-volatile storage means via the operation signal input means. At this point, the control calculation means executes the power failure processing program, and uses the measured value of the terminal voltage of the power failure time detection circuit as the actual charging voltage, When the power failure is recovered, the terminal voltage of the power failure time detection circuit is measured, and the actual discharge characteristic and the actual allowable limit voltage are calculated from the reference discharge characteristic and the actual charge voltage. It is characterized in that a limit allowable voltage value is compared with a measured value of the terminal voltage of the power failure time detection circuit at the time of the recovery from the power failure, and it is determined whether or not the operation of the controlled object is continued.

[0013]

[0014]

The motor control device of the present invention, when a signal for instructing the start of execution of the reference discharge characteristic creation program is input to the control calculation means at a predetermined time, for example, when the motor control device is shipped from a factory, The means executes a reference discharge characteristic creation program. The control operation means first charges the power failure time detection circuit with the power supply voltage of the motor control device via the switch circuit, and outputs the control signal to the power failure time detection circuit to start discharging when the power failure time detection circuit is charged. Then, the terminal voltage of the power failure time detection circuit during the discharge is measured in accordance with the passage of time, and the measurement result is stored in the nonvolatile storage means.

Further, in the motor control device according to the second aspect, when a value of the reference allowable limit voltage is inputted through the operation signal input means, the value is stored in the nonvolatile storage means. Further, in the motor control device according to the third aspect, at the time of occurrence of a power failure during operation, the control calculation means executes a power failure processing program, and uses the measured value of the terminal voltage of the power failure time detection circuit as an actual charging voltage. Stored in the sex storage means. When the power failure recovers, the terminal voltage of the power failure time detection circuit at this time is measured, and the actual discharge characteristics and the actual allowable limit voltage are calculated from the reference discharge characteristics and the actual charging voltage stored in the non-volatile storage means when the power failure is detected. Then, the actual allowable limit voltage value is compared with the measured value of the terminal voltage of the power failure time detection circuit at the time of the recovery from the power failure to determine whether or not to continue the operation of the controlled object.

[0016]

FIG. 1 is an explanatory view of a motor control device according to one embodiment of the present invention. FIG. 1A is a block diagram showing the inside of the electric motor control device A1. The electric motor control device A1 comprises a control operation means 2, a nonvolatile storage means 3, a power failure time detection circuit 1 comprising a capacitor C and a resistor R. In the following description, the terminal voltage of the capacitor C, which is the terminal voltage of the CR circuit 1, is input, a voltage equal to this voltage is output, and a resistor R5 is input to the terminal T1 of the control operation means. And a current amplifier circuit including a differential amplifier OP and a switch circuit 4. Among the components constituting the motor control device A1 shown in FIG. 1A, the components having the same reference numerals as those constituting the motor control device A shown in FIG. 3 are the same as those shown in FIG. Therefore, the individual description of the same reference numerals is omitted. GND is a power supply bus connected to a negative electrode which is a reference voltage of a DC power supply for supplying electric power to the motor control device A, and Vcc is a power supply bus connected to the positive electrode.

The non-volatile storage means 3 is a storage means, for example, which is made of a RAM whose power is guaranteed by a battery and which retains the stored contents even when the power is lost, and which is controlled via the signal bus SB. And exchange data. Switch circuit 4
Is a circuit composed of transistors TR1, TR2 and resistors R1, R2, R3, R4. In this circuit, when the voltage input to the base of the transistor TR1 is an L level voltage corresponding to 0 of a binary signal, the impedance between the emitter and the collector of the transistor TR1 is practically almost open. And the current flowing into the transistor TR1 through the resistor R2 disappears.
The current that reaches the saturation value flowing through R2 flows, falls to an impedance equivalent to the fact that the emitter and collector of the transistor TR2 are practically closed, and the capacitor C is charged via the resistor R3 and the transistor TR2. You.
When the voltage input to the base of the transistor TR1 is an H-level voltage corresponding to 1 of a binary signal, the impedance between the emitter and the collector of this transistor becomes a practically close value, and the transistor TR2 Applied to the base of the transistor TR2 has a high impedance corresponding to the fact that the emitter and the collector of the transistor TR2 are practically opened, and the voltage between the switch circuit 4 and the CR circuit 1 becomes low. Be cut off. When the connection between the switch circuit 4 and the CR circuit 1 is cut off, the capacitor C is charged because the input terminal of the differential amplifier OP to which the other terminal of the CR circuit is connected via the resistor R5 has a very high impedance. The discharged charges are discharged only through the resistor R.

In FIG. 1B, the discharge start time of the CR circuit 1 is set to "0 second" at the origin of time measurement, time is plotted on the horizontal axis, and the terminal voltage Vc of the capacitor C is plotted on the vertical axis. 4 is a graph showing the relationship between the elapsed time t and the terminal voltage Vc of the capacitor C. In the figure, a curve Vcs is a curve representing a relationship between time t and voltage Vcs, which is a standard discharge characteristic when the capacitor C is charged to the reference charge voltage value Vcsm, and a curve Vc
Is a curve representing the relationship between time t, which is the actual discharge characteristic, and voltage Vc when the battery is charged to the actual charging voltage Vcm, which is the charging voltage at the place where the motor control device A1 is installed.

At the final stage of testing when the motor control device A1 is shipped from the factory, or at the site where the motor control device A1 is installed, the motor control device A1 stores the program storage means 22 (see FIG. When a signal prompting execution of the reference discharge characteristic creation program stored in (b) of FIG. 1 is input, the control calculation means 2 executes the reference discharge characteristic creation program and first executes the terminal T2 (FIG. 1). (a)) to the switch circuit 4 to send an L level signal,
The R circuit 1 is charged up to the reference voltage value Vcsm. Next, an L-level signal is transmitted to the switch circuit 4, the CR circuit 1 is cut off from the switch circuit 4, and the electric charge of the capacitor C is transferred to the resistor R.
The terminal voltage of the CR circuit 1 is input from the terminal T1 every time the predetermined time elapses, and is stored in the nonvolatile storage means 3. Table 1 shows an example of the stored values.

[0020]

[Table 1]

In this example, as shown in the table, the time "0"
That is, the value of the reference charging voltage Vcsm, which is the charging voltage at the time of completion of charging, is 4.6 V, and the terminal voltage of the capacitor C becomes 4.16 V at the time when the discharging time has elapsed 0.1 second, and when 1 second has elapsed,
It is shown to be 1.69V. The data obtained by the processing described above is similar to the calculated reference discharge characteristics, but in practice this value is referred to as the reference discharge characteristics.
It is stored in the nonvolatile storage means 3 as Vcs and used.

The electric motor control device A1 is installed at the site where the control target is located, and before the electric motor control device A1 starts operation, the operation can be performed in accordance with the characteristics of the control target, following the operation before the power outage when the power outage is recovered. The allowable limit time TSR, which is the limit value of the power outage time, is determined. After the allowable limit time TSR is determined, the allowable limit voltage VSR of the voltage value at which the terminal voltage of the CR circuit 1 at the time of discharging reaches the allowable limit time TSR is calculated in the reference discharge characteristic Vcs, and this value is stored in the nonvolatile storage means. 3 is stored.

When the motor control device A1 starts operation and detects a power failure in the middle of the operation, the motor control device A1 stores the power failure processing program stored in the program storage means 22 of the control calculation means in the control calculation means 2. Is executed, and the terminal voltage of the CR circuit 1 immediately after the detection of the power failure is input and stored in the nonvolatile storage unit 3. Since the stored value is a time sufficiently smaller than the time constant of the CR circuit, it can be practically regarded as the actual charging voltage Vcm of the voltage that charged the CR circuit. Once the actual charge voltage Vcm is determined, the actual discharge characteristic, which is the discharge characteristic when the charge voltage is the actual charge voltage Vcm, is
As is apparent from Equation 1, the reference discharge characteristics are created by converting the ratio of (actual charge voltage Vcm / reference charge voltage Vcsm) in the direction of the vertical axis. For example, (actual charging voltage Vcm
/ Reference charge voltage Vcsm) is 0.95, the actual discharge characteristic at time "0" is the measured value of 4.37V, and after 0.1 seconds, the reference characteristic Vcs has the value of (actual charge voltage Vcm / reference charge voltage Vcsm) of 0. .
It becomes 3.95V which is the value which multiplied 95.

When the power failure is recovered, the motor control device A1 causes the control operation means 2 to execute the power failure processing program at the time of the recovery. By executing the power failure processing program, the control operation means 2 first sets the terminal voltage of the CR circuit 1 to the power failure recovery voltage V1 while keeping the switch circuit in the open state.
Enter as Next, as described above, an actual discharge characteristic is created from the reference discharge characteristic, the actual charge voltage Vcm, and the reference charge voltage Vcsm, and the reference allowable limit voltage VSR stored in advance in the nonvolatile storage means is set to (the actual charge The actual allowable limit voltage VCR is obtained by multiplying the value of (voltage Vcm / reference charging voltage Vcsm). Then, the previously input power failure recovery voltage V1 is compared with the actual allowable limit voltage VCR. As shown in Fig. 1 (b), the actual discharge characteristics fall to the right on the graph.
If V1 is greater than or equal to the actual permissible limit voltage VCR, the outage time is equal to or shorter than the permissible limit time TSR,
If it is smaller, it means that the allowable time limit TSR is exceeded.
Therefore, when the power failure recovery time voltage V1 is greater than or equal to the actual allowable limit time, the motor control device A1 resumes control of the control target following the power failure, and transmits a stop signal to the control target when it is smaller, The state is reset.

FIG. 2 is a flowchart showing the operation of the motor control device A1 described above. In the figure, processing F1
Process F8 is a flowchart showing the process at the time of shipment of the motor control device or at the time after the motor control device A1 is installed at the site where the control target is located.
F19 to F19 are flowcharts showing processing in the motor control device A1 when a power failure occurs.

When the motor control device is shipped or when the motor control device A1 is installed at the site where the control target is located, the control calculation means of the motor control device A1 executes the process starting from the process F1. The control calculation means 2 of the motor control device A1 determines the operation mode set in the motor control device A1 in the process F1, and proceeds to the process F2 when in the shipping mode, and enters the shipping mode when not in the shipping mode. Wait for it to be set. In the process F2, the switch circuit 4
(See (a) of FIG. 1), the charging of the capacitor is started, the process proceeds to the process F3, and the completion of the charging of the capacitor is monitored in the process F3. Completion of charging is detected by sequentially and continuously inputting the terminal voltage of the CR circuit 1.
When the charging is completed, the process proceeds to step F4, in which the terminal voltage of the CR circuit at this time is stored in the storage means in the control calculation means 2 as the reference voltage Vcsm. Next, the process proceeds to process F5, where the switch circuit 4 is opened. As a result of the switch opening 4 being opened, the CR circuit 1 is disconnected from the input / output circuit for the current with the outside, and the electric charge of the capacitor C is discharged from the resistor R. In the process F6, the control calculation means 2 of the motor control device A1 measures the terminal voltage of the CR circuit 1 at predetermined time intervals, for example, at 0.1 second intervals, and stores the measurement result in the storage means in the control calculation means 2 as a reference characteristic. I do. Next, in a process F7, the reference charge voltage and the reference discharge characteristic previously stored in the control calculation means 2 are stored in the nonvolatile storage means 3. Although the case where the process F8 is performed subsequent to the process F7 is shown, the process is completed up to the process F7,
Only the process F8 may be performed again. In process F8, when the reference allowable limit time TSR is input to the motor control device A1, the control calculation means 2 executes the reference discharge characteristic creation program, and calculates the reference allowable limit voltage VSR corresponding to the reference allowable limit time TSR. It is calculated and stored in the non-volatile storage means 3.

If a power failure is detected, the control operation means 2 enters a process F10 and immediately sets the terminal voltage of the CR circuit 4 to the actual charging voltage Vcm (see FIG. 1 (b)). To be stored. Next, the process proceeds to step F11, in which data required when the operation is automatically restarted is stored in the non-volatile storage unit 3, and the process proceeds to step F12 to interrupt the process by the control calculation unit 2. When the recovery from the power failure is detected, the control calculation means 2 starts the process from the process F13, and in the process F13, determines whether or not the mode is the shipping mode. The terminal voltage of the CR circuit is measured as the power failure recovery voltage V1 (see FIG. 1 (b)). Next, the process proceeds to processing F15, in which the actual discharge characteristics are obtained from the actual charge voltage Vcm and the reference discharge characteristics measured previously, and the actual allowable limit voltage VCR is obtained from the actual charge voltage Vcm, the actual discharge characteristics, and the reference allowable limit voltage VSR. Calculate and compare the voltage at recovery from power failure V1 with the actual allowable limit voltage VCR at F16 and F17.
If V1 is larger than the actual allowable limit voltage VCR, the process proceeds to step F18, in which the operation restart data stored in the non-volatile storage means 3 is restored in step F11, and the control before the power failure is continued.
If the power failure recovery voltage V1 is lower than the actual allowable limit voltage VCR, the process proceeds to step 19 to reset the circuit and wait for the next operation restart operation signal.

[0028]

As described above, the present invention is provided with a power failure processing program, and when a power failure occurs during operation, the control arithmetic means executes the power failure processing program, and executes the power failure processing program to determine the terminal voltage of the power failure time detection circuit. The measured value is stored in the nonvolatile storage means as the actual charging voltage, and at the time when the power failure is recovered, the terminal voltage of the power failure time detection circuit is measured,
The actual discharge characteristic and the actual allowable limit voltage are calculated from the reference discharge characteristic and the actual charge voltage, and the actual limit allowable voltage value is compared with the measured value of the terminal voltage of the power failure time detection circuit terminal at the time of the recovery from the power failure. Therefore, it is determined whether or not to continue the operation of the controlled object. Therefore, a power failure processing program is provided. When a power failure occurs during operation, the control operation means executes the power failure processing program, and executes the power failure time detection circuit. Is stored in the non-volatile storage means as the actual charge voltage, and when the power failure is recovered, the terminal voltage of the power failure time detection circuit is measured, and the actual discharge characteristic and the actual allowable limit are determined from the reference discharge characteristic and the actual charge voltage. A voltage is calculated, and the actual limit allowable voltage value is compared with the measured value of the terminal voltage of the power failure time detection circuit terminal at the time of recovery from the power failure to determine whether or not to continue the operation of the controlled object. Therefore, the actual discharge characteristics that may be referred to after the power failure recovery,
The actual allowable limit voltage, which is a criterion for determining whether or not to operate the controlled object following the operation before the power failure after recovery from the power failure, is based on the actual condition during operation, and therefore, the motor with high measurement accuracy of the power failure time A control device can be provided.

[0029]

[0030]

[Brief description of the drawings]

FIG. 1 is an explanatory view of an embodiment of a motor control device according to the invention described in claim 1, wherein (a) is a block diagram of the motor control device, and (b) shows discharge characteristics of a power failure time detection circuit. Figure

FIG. 2 is a flowchart showing the operation of the motor control device shown in FIG.

FIG. 3 is an explanatory diagram of an example of a conventional motor control device;
(a) is a block diagram of the motor control device, and (b) is a block diagram of the control calculation means.

FIG. 4 is a diagram showing discharge characteristics of the power failure time detection circuit shown in FIG. 3;

[Explanation of symbols]

 A1 Motor control unit 1 Power failure time detection circuit 2 Control operation means 3 Non-volatile storage means 4 Switch circuit OP Differential amplifier TSR Allowable limit time Vcsm Reference charge voltage Vcm Actual charge voltage VSR Reference allowance voltage VCR Actual allowable limit voltage

Claims (1)

(57) [Claims] 1. An operation signal input means, a control operation means,
Non-volatile storage means for storing the value of the reference allowable limit voltage,
A power failure time detection circuit consisting of a capacitor and a resistor that is normally charged with the power supply voltage and discharged at the time of power failure is provided.When the power failure recovers, the terminal voltage of the power failure time detection circuit representing a voltage corresponding to the power failure time is measured. A motor control device that determines whether or not to continue the operation of the control target by comparing the value with the allowable limit voltage value, wherein a switch that controls charging and discharging of the power failure time detection circuit by a signal from the control arithmetic unit. And a reference discharge characteristic creation program executed by the control operation means. The control operation means receives an operation signal at a predetermined time via the operation signal input means, and outputs the reference discharge characteristic creation program. By executing the above, the switch circuit is controlled to charge the power failure time detection circuit with the power supply voltage of the motor control device. There initiate the discharge of the power failure time detection circuit from Upon completion, discharged change in the terminal voltage of the power failure time detecting circuit over time in the course determined, the nonvolatile storage means as the reference discharge characteristic of the measured values And a control pair of the motor control device.
The reference allowable limit voltage value corresponding to the
Storing in the non-volatile storage means via the input means
Power failure processing program, and
At the time of power generation, the control operation means
To measure the terminal voltage of the power failure detection circuit
The value is stored as the actual charging voltage in the nonvolatile storage means,
At the time when the power is restored,
The voltage is measured, and the voltage is measured based on the reference discharge characteristics and the actual charging voltage.
Calculate the discharge characteristics and the actual allowable limit voltage.
Voltage value and the power outage time detection circuit terminal at the time of the power outage recovery
Compare the measured voltage to continue operation of the controlled object
An electric motor control device, characterized in that it is determined whether or not this is the case.