JP2021010255A - Electrical device, control method for electrical device, and control program - Google Patents

Abstract

To provide an electrical device that can quickly detect a true undervoltage.SOLUTION: An electrical device (air conditioner) 1 includes a plug 10, a fuse 11, a varistor 12, a rectifier circuit 13, a smoothing capacitor 14, a DC/DC converter 15, a motor driver 16, a control device 17, and resistors R1 and R2. The control device 17 measures a voltage related to a direct current from the smoothing capacitor 14, and when it is determined that the voltage is equal to or less than a predetermined threshold value, the control device instructs the motor driver 16 to operate the motor, and after a lapse of a predetermined period, when it is determined again that the voltage is equal to or less than the predetermined threshold value, the control device determines that the voltage is a true undervoltage.SELECTED DRAWING: Figure 1

Description

The present invention relates to an electrical device including a converter that converts an input alternating current into a direct current.

Generally, a rated input voltage is specified for an electric device, and if the input voltage is low, it may not operate properly. For this reason, many electric devices have an undervoltage detection function that determines that the input voltage is undervoltage when the input voltage is equal to or less than a predetermined voltage, outputs an alarm, or stops the operation. .. For example, in Patent Document 1, when a voltage detection signal indicating that the output voltage output from the power supply unit is equal to or lower than a predetermined voltage is taken from the low voltage detection circuit, an alarm is output and the compressor is stopped. A control device for stopping the air conditioner is disclosed.

Japanese Unexamined Patent Publication No. 2001-304651

In general, electrical equipment that converts alternating current from a commercial power source into direct current and uses it includes various capacitors. Therefore, even if the alternating current from the commercial power supply is cut off due to, for example, a power failure or the user removing the plug from the outlet, the DC voltage is gradually reduced by the capacitor. Therefore, when the electric device has the undervoltage detection function, if the DC voltage becomes a predetermined voltage or less, the undervoltage is erroneously detected, which is not desirable.

On the other hand, in Patent Document 1, a counter is operated every time it is determined that the output voltage from the power supply unit is low, and when the counter reaches a predetermined number of times, an alarm is output and an air conditioner is used. A control device for controlling the stoppage is disclosed. By using such a control device, if the DC voltage becomes close to zero and the operation of the electric device is stopped before the counter reaches a predetermined number of times, it is possible to prevent the false detection of the undervoltage.

However, it takes about 1 minute from the interruption of the alternating current to the stop of the operation of the electric device. For this reason, when a true undervoltage is input to the electrical device, it will continue to be input for at least one minute, which is not desirable.

One aspect of the present invention is to provide an electric device or the like capable of quickly detecting a true undervoltage.

In order to solve the above problems, the electric device according to one aspect of the present invention is an electric device including a converter that converts an input alternating current into a direct current, and a load and a control device that operates by the direct current. The control device includes a measuring unit that measures a voltage related to the alternating current or the direct current, a detecting unit that detects that the voltage is a true undervoltage, and a load control unit that controls the load. When the detection unit determines that the voltage is equal to or lower than a predetermined threshold, the detection unit instructs the load control unit to operate the load, and after a predetermined period of time, the voltage is equal to or lower than the predetermined threshold. When it is determined again, it is characterized in that it is determined that the voltage is a true undervoltage.

According to one aspect of the present invention, there is an effect that a true undervoltage can be detected quickly.

It is a circuit diagram which shows the main part structure of the air conditioner which concerns on one Embodiment of this invention. It is a block diagram which shows the schematic structure of the control device of the said air conditioner. It is a flowchart which shows the flow of process of the undervoltage detection in the said control device. It is a circuit diagram which shows the main part structure of the air conditioner which concerns on another embodiment of this invention. It is a flowchart which shows the flow of process of the undervoltage detection in the control device of the air conditioner. It is a circuit diagram which shows the main part structure of the air conditioner which concerns on other embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail. For convenience of explanation, the members having the same functions as the members shown in each embodiment are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

[Embodiment 1]
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 3.

(Overview of air conditioner)
FIG. 1 is a circuit diagram showing a main configuration of an air conditioner (air conditioner) according to the present embodiment. As shown in FIG. 1, the air conditioner 1 (electrical equipment) includes a plug 10, a fuse 11, a varistor 12, a rectifier circuit 13 (converter), a smoothing capacitor 14 (converter), a DC / DC converter 15, and a motor driver 16. , Control device 17, and resistors R1 and R2.

The plug 10 is a connection component that is detachably attached to an outlet (not shown) to receive alternating current from a commercial power source via the outlet. The fuse 11 and the varistor 12 are circuits for protecting the air conditioner 1 from an excessive voltage. When the AC voltage input from the plug 10 exceeds a predetermined voltage higher than the rated input voltage (for example, 200V), the resistance value of the varistor 12 drops rapidly and the fuse 11 is blown to protect the subsequent circuit. ..

The rectifier circuit 13 converts alternating current from the plug 10 into direct current. The smoothing capacitor 14 smoothes the DC voltage from the rectifier circuit 13. The rectifier circuit 13 and the smoothing capacitor 14 function as an AC / DC converter (converter) that converts an AC voltage into a DC voltage.

The DC / DC converter 15 converts the DC voltage from the smoothing capacitor 14 (hereinafter, referred to as “first DC voltage”) into another DC voltage (hereinafter, referred to as “second DC voltage”). It is a thing. The DC / DC converter 15 applies a second DC voltage to various devices connected to the subsequent stage, such as the motor driver 16 and the control device 17, to supply DC power.

The motor driver 16 drives various motors (loads) provided in the air conditioner 1. Examples of the above motor include an indoor fan motor, an outdoor fan motor, a compressor motor, and the like. A first DC voltage may be applied to the motor, or a second DC voltage may be applied to the motor.

The control device 17 controls the operation of each part of the air conditioner 1. The details of the control device 17 will be described later.

The resistors R1 and R2 are for dividing the first DC voltage. The divided DC voltage (hereinafter referred to as "third DC voltage") is applied to the control device 17. Since the resistors R1 and R2 are used for voltage measurement as described later, it is desirable that they have high resistance.

In the present embodiment, the control device 17 measures the third DC voltage, and when it is determined that the third DC voltage is equal to or less than a predetermined threshold value, the control device 17 instructs the motor driver 16 to operate the motor. Then, when it is determined again that the third DC voltage is equal to or less than the predetermined threshold value after the elapse of the predetermined period, it is determined that the voltage input from the plug 10 is a true undervoltage.

According to the above configuration, when the third DC voltage is equal to or less than a predetermined threshold value, the motor operates. As a result, when the alternating current from the commercial power supply is cut off, the first to third DC voltages drop rapidly, and the operation of the air conditioner 1 including the control device 17 stops in about a few seconds. Therefore, the predetermined period until it is determined again that the third DC voltage is equal to or less than the predetermined threshold value can be set short, and as a result, the true undervoltage can be quickly detected. It is desirable to change the predetermined period depending on the load of the operating motor or the like.

(Overview of control device)
FIG. 2 is a block diagram showing a schematic configuration of the control device 17. As shown in FIG. 1, the control device 17 includes a control unit 20, a storage unit 21, and a notification unit 22.

The control unit 20 controls the operation of each unit of the control device 17, and is composed of, for example, a computer device composed of a CPU (Central Processing Unit), an arithmetic processing unit such as a dedicated processor, and the like. The control unit 20 comprehensively controls the operation of each unit of the control device 17 by reading and executing a control program for executing various controls in the control device 17 stored in the storage unit 21. The details of the control unit 20 will be described later.

The storage unit 21 stores various data used in the control device 17, and includes a RAM (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disk Drive), and the like.

The notification unit 22 notifies the user based on the instruction from the control unit 20. Examples of notifications performed by the notification unit 22 include light emission using a light emitting element such as an LED (light emitting diode), sound output using a speaker, information display / output using a display, and wireless communication. Information may be transmitted using a communication device.

(Details of control device)
Next, the details of the control unit 20 in the control device 17 will be described. As shown in FIG. 2, the control unit 20 includes a voltage measurement unit 23 (measurement unit), an undervoltage detection unit 24 (detection unit), an operation instruction unit 25 (load control unit), and a notification instruction unit 26. ..

The voltage measuring unit 23 measures the third DC voltage divided by the resistors R1 and R2. The voltage measuring unit 23 sends the measured value of the third DC voltage to the undervoltage detecting unit 24. The undervoltage detection unit 24 detects that the AC voltage and the first DC voltage are true undervoltages based on the measured values of the third DC voltage from the voltage measurement unit 23. The operation instruction unit 25 instructs various devices in the air conditioner 1 to operate. The notification instruction unit 26 instructs the notification unit 22 to notify.

In the present embodiment, when the undervoltage detection unit 24 determines that the measured value of the third DC voltage is equal to or less than a predetermined threshold value, it instructs the operation instruction unit 25 to instruct at least one of the various motors in the air conditioner 1. The motor driver 16 is instructed to drive (for example, a motor for an indoor fan). When the alternating current from the commercial power source is cut off, the electric power is consumed by driving the motor, so that the first to third DC voltages drop rapidly. Then, after a few seconds, the control device 17 is stopped, and the operation of the air conditioner 1 is stopped.

Next, the undervoltage detection unit 24 waits for a predetermined period (for example, 5 seconds, 10 seconds, etc.), and then performs the above determination again. When the undervoltage detection unit 24 redetermines that the measured value of the third DC voltage is equal to or less than a predetermined threshold value, AC is input to the plug 10, so that the AC voltage and the first DC voltage are changed. Judge that it is a true undervoltage.

At this time, the undervoltage detection unit 24 instructs the operation instruction unit 25 to stop the operation of various devices in the air conditioner 1. This makes it possible to prevent improper operation of electrical equipment due to a true undervoltage.

Further, the undervoltage detection unit 24 instructs the notification unit 26 to give an undervoltage alarm to the notification unit 22. As a result, it is possible to give an undervoltage alarm to the user, and it is possible to prevent an undervoltage false alarm due to the interruption of alternating current from the commercial power source.

(Undervoltage detection processing)
FIG. 3 is a flowchart showing the flow of the undervoltage detection process (detection step) in the control device 17 having the above configuration. First, the voltage measuring unit 23 measures the third DC voltage (measurement step). Next, as shown in FIG. 3, the undervoltage detection unit 24 determines whether or not the measured value of the third DC voltage is equal to or less than a predetermined threshold value (S10). When the measured value is larger than the threshold value, the process returns to step S10 and the above operation is repeated. On the other hand, when the measured value is equal to or less than the threshold value, the operation instruction unit 25 instructs the motor driver 16 to operate the motor if the motor is not operating (S11) (S12).

Next, after waiting for a predetermined period (S13), the undervoltage detection unit 24 redetermines whether or not the measured value of the third DC voltage is equal to or less than a predetermined threshold value (S14). When the measured value is larger than the above threshold value, the undervoltage detection unit 24 determines that the AC voltage and the first DC voltage from the plug 10 are only a temporary voltage drop and are not true undervoltages. Then, the operation instruction unit 25 returns the operation of the air conditioner 1 to the original state (S15). That is, the operation instruction unit 25 instructs the motor driver 16 to stop the motor when the motor is operated in step S12.

On the other hand, when the measured value is equal to or less than the threshold value, the undervoltage detection unit 24 determines that the AC voltage and the first DC voltage from the plug 10 are true undervoltages (S16). Then, the operation instruction unit 25 instructs various devices in the air conditioner 1 to stop the operation (S17), and the notification instruction unit 26 instructs the notification unit 22 to give an undervoltage alarm (S18).

(Additional notes)
In the present embodiment, the voltage measuring unit 23 measures the third DC voltage divided by the resistors R1 and R2, but further calculates the AC voltage or the first DC voltage from the measured value of the third DC voltage. You may. In this case, the predetermined threshold value used by the undervoltage detection unit 24 may be changed to a predetermined threshold value corresponding to the AC voltage or the first DC voltage.

[Embodiment 2]
Next, another embodiment of the present invention will be described with reference to FIGS. 4 and 5.

FIG. 4 is a circuit diagram showing a main configuration of the air conditioner 1 according to the present embodiment. Compared to the air conditioner 1 shown in FIGS. 1 and 2, the air conditioner 1 shown in FIG. 4 has a resistor R3 (load), a relay 30, a diode D1, and an inverter 31 added, and an operation instruction of the control device 17. The operation in the part 25 is different, and the other configurations are the same. In FIG. 4, the motor driver 16 in FIG. 1 is omitted. Further, the configuration of the control device 17 of the present embodiment is the same as the configuration of the control device 17 shown in FIG.

The resistor R3 and the relay 30 are provided after the DC / DC converter 15, and the switch portion of the resistor R3 and the relay 30 is connected in series between the power line 32 on the non-grounded side and the power line 33 on the grounded side. There is. Further, the coil portion of the relay 30 and the diode D1 are connected in parallel, the cathode side of the diode D1 is connected to the power line 32 on the non-grounded side, and the anode side of the diode D1 is connected to the control device 17 via the inverter 31. Has been done.

In the present embodiment, the operation instruction unit 25 of the control device 17 energizes the resistor R3 instead of driving the motor when the measured value of the third DC voltage is equal to or less than a predetermined threshold value. Specifically, the operation instruction unit 25 outputs an H (high) level signal to the inverter 31. At this time, since the output of the inverter 31 becomes the L (low) level, the coil portion of the relay 30 is energized, the switch portion is turned on, and the resistor R3 is energized. As a result, when the alternating current from the commercial power source is cut off, the power is consumed by the resistor R3, so that the first to third DC voltages drop rapidly. Then, after a few seconds, the control device 17 is stopped, and the operation of the air conditioner 1 is stopped.

Therefore, the air conditioner 1 of the present embodiment can exhibit the same effect as the air conditioner 1 of the above embodiment. That is, even if it is an electric device that converts alternating current into direct current and is used without a motor, by providing the control device 17, the relay 30, the resistors R1 to R3, and the like in the present embodiment, The same effect as that of the air conditioner 1 of the above embodiment can be obtained. Since the resistor R3 is used as a load, it is desirable that the resistor has a low resistance.

FIG. 5 is a flowchart showing the flow of the process (detection step) of the undervoltage detection in the control device 17 of the air conditioner 1. The process shown in FIG. 5 is different from the process shown in FIG. 3 in that step S30 is provided instead of steps S11 and S12 and step S31 is provided instead of step S18. Other processing is the same.

In step S30, the operation instruction unit 25 energizes the resistor R3 as described above. Further, in step S31, the operation instruction unit 25 stops the energization of the resistor R3. Specifically, the operation instruction unit 25 outputs an L level signal to the inverter 31. At this time, since the output of the inverter 31 becomes H level, the coil portion of the relay 30 is not energized, the switch portion is turned off, and the energization of the resistor R3 is stopped.

[Embodiment 3]
Next, another embodiment of the present invention will be described with reference to FIG.

FIG. 6 is a circuit diagram showing a main configuration of the air conditioner 1 according to the present embodiment. The air conditioner 1 shown in FIG. 6 is different from the air conditioner 1 shown in FIGS. 1 and 2 in that a diode D2, resistors R4 to R6, and an electrolytic capacitor C1 are provided instead of the resistors R1 and R2. Other configurations are the same.

The diodes D2 and resistors R4 to R6 are connected in series between the power lines between the varistor 12 and the rectifier circuit 13. The connection point between the resistors R5 and R6 is connected to the positive electrode of the electrolytic capacitor C1 and the control device 17. The negative electrode of the electrolytic capacitor C1 is grounded.

With the above configuration, the AC voltage is semi-rectified by the diode D2, divided by the resistors R4 to R6, smoothed by the electrolytic capacitor C1, and applied to the control device 17 as a third DC voltage, and the control device 17 Measured at. Since the resistors R4 to R6 are used for voltage measurement, it is desirable that they have a high resistance.

According to this embodiment, it can be understood that the third DC voltage used for voltage measurement can be obtained not only from the first DC voltage but also from the AC voltage.

(Additional notes)
In the above embodiment, the air conditioner 1 is used, but the present invention is not limited to these. Any electrical equipment including an AC / DC converter (rectifier circuit 13 and smoothing capacitor 14) that converts alternating current input from a commercial power source into direct current, and a load and control device that operates by the direct current can be used. ..

Further, in the above embodiment, the motor and the resistor R3 are used as the load for consuming electric power, but the present invention is not limited to these. Any circuit element or circuit that consumes power can be utilized.

[Example of realization by software]
The control block (particularly the control unit 20) of the control device 17 may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or may be realized by software.

In the latter case, the control device 17 includes a computer that executes instructions of a program that is software that realizes each function. The computer includes, for example, at least one processor (control device) and at least one computer-readable recording medium that stores the program. Then, in the computer, the processor reads the program from the recording medium and executes it, thereby achieving the object of the present invention. As the processor, for example, a CPU (Central Processing Unit) can be used. As the recording medium, a "non-temporary tangible medium", for example, a ROM (Read Only Memory) or the like, a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. Further, a RAM (Random Access Memory) for expanding the above program may be further provided. Further, the program may be supplied to the computer via an arbitrary transmission medium (communication network, broadcast wave, etc.) capable of transmitting the program. It should be noted that one aspect of the present invention can also be realized in the form of a data signal embedded in a carrier wave, in which the above program is embodied by electronic transmission.

[Summary]
The electric device according to the first aspect of the present invention is an electric device including a converter that converts an input alternating current into a direct current, and a load and a control device that operates by the direct current, and the control device is the AC or the control device. A measuring unit for measuring a voltage related to direct current, a detecting unit for detecting that the voltage is a true undervoltage, and a load control unit for controlling the load are provided, and the detecting unit has the voltage. When it is determined that the voltage is equal to or lower than the predetermined threshold, the load control unit is instructed to operate the load, and when it is determined again that the voltage is equal to or lower than the predetermined threshold after the elapse of the predetermined period, the voltage is true. It is judged that the voltage is undervoltage.

According to the above configuration, the load operates when the voltage related to AC or DC is equal to or less than a predetermined threshold value. As a result, when the alternating current from the commercial power supply is cut off, the voltage drops rapidly, and the operation of the electric equipment including the control device stops in about a few seconds. Therefore, the predetermined period until it is determined again that the voltage is equal to or less than the predetermined threshold value can be set short, and as a result, the true undervoltage can be quickly detected.

In the electric device according to the second aspect of the present invention, in the first aspect, the control device further includes a notification unit that notifies the user, and the detection unit states that the voltage is a true undervoltage. If it is determined, the notification unit may be instructed to give an undervoltage alarm. In this case, the undervoltage alarm can be given to the user, and the undervoltage false alarm due to the interruption of the alternating current from the commercial power source can be prevented.

In the electric device according to the third aspect of the present invention, in the first or second aspect, the control device stops the operation of the electric device when the detection unit determines that the voltage is a true undervoltage. You may. In this case, it is possible to prevent improper operation of the electric device due to a true undervoltage.

The load is preferably a resistor or a motor that consumes a large amount of power.

The method for controlling an electric device according to the fourth aspect of the present invention is a method for controlling an electric device including a converter that converts an input alternating current into a direct current and a load and a control device that operate by the direct current. The apparatus includes a measurement step of measuring the AC or DC voltage and a detection step of detecting that the voltage is a true undervoltage, and the detection step includes the voltage. When it is determined that is equal to or less than a predetermined threshold, the load is controlled to operate, and when it is determined again that the voltage is equal to or less than a predetermined threshold after a predetermined period has elapsed, the voltage is a true undervoltage. It is a control method that determines that there is. In this case, the same effect as that of the first aspect is obtained.

The control device according to each aspect of the present invention may be realized by a computer. In this case, the control device is realized by the computer by operating the computer as each part (software element) included in the control device. The control program of the control device and the computer-readable recording medium on which it is recorded also fall within the scope of the present invention.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

1 Air conditioner (electrical equipment)
10 Plug 11 Fuse 12 Varistor 13 Rectifier circuit (converter)
14 Smoothing capacitor (converter)
15 DC / DC converter 16 Motor driver 17 Control device 20 Control unit 21 Storage unit 22 Notification unit 23 Voltage measurement unit (measurement unit)
24 Undervoltage detector (detector)
25 Operation instruction unit (load control unit)
26 Notification indicator 30 Relay 31 Inverter 32, 33 Power line

Claims (6)

An electric device including a converter that converts an input alternating current into a direct current, and a load and a control device that operates by the direct current.
The control device is
A measuring unit that measures the voltage related to the AC or DC, and
A detector that detects that the voltage is a true undervoltage,
It is equipped with a load control unit that controls the load.
When the detection unit determines that the voltage is equal to or lower than a predetermined threshold value, the detection unit instructs the load control unit to operate the load, and after a predetermined period of time elapses, if the voltage is equal to or lower than the predetermined threshold value again. An electrical device characterized in that when it is determined, the voltage is determined to be a true undervoltage. The control device further includes a notification unit that notifies the user.
The electrical device according to claim 1, wherein the detection unit instructs the notification unit to give an alarm for the undervoltage when it determines that the voltage is a true undervoltage. The electric device according to claim 1 or 2, wherein the control device stops the operation of the electric device when the detection unit determines that the voltage is a true undervoltage. The electrical device according to any one of claims 1 to 3, wherein the load is a resistor or a motor. A control program for operating a computer as an electric device according to any one of claims 1 to 3, wherein the computer functions as a detection unit. A method for controlling an electric device including a converter that converts an input alternating current into a direct current and a load and a control device that are operated by the direct current.
A measurement step in which the control device measures the AC or DC voltage.
The control device includes a detection step of detecting that the voltage is a true undervoltage.
The detection step controls the load to operate when it is determined that the voltage is equal to or lower than a predetermined threshold value, and when it is determined again that the voltage is equal to or lower than a predetermined threshold value after a lapse of a predetermined period, the detection step is described. A method of controlling electrical equipment, characterized in that the voltage is determined to be a true undervoltage.

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