JP2010063308A - Load controller and load control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a load controller and a load control method which can bring a load back to a normal operating state in a short time as much as possible when the load operates differently from a desired operation due to the occurrence of an earthquake. <P>SOLUTION: When a vibration sensor detects the occurrence of an earthquake (S2), a load controller stores a load control state at the moment in a memory (S3). When an earthquake sensor detects the termination of the earthquake (S5), the load controller reads out the stored load control state (S6) and compares it with a current load control state. If there is a difference between the two load control states, the load controller instructs an output circuit to supply power or stop power to a relay circuit to bring the load back to the load control state at earthquake detection (S8). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a load control device and a load control method having control functions such as power supply to a load, interruption, protection, and monitoring.

The invention disclosed in Patent Document 1 discloses a seismic sensor unit that is incorporated in a distribution board together with a breaker and prevents a secondary disaster such as an electric fire by blocking the breaker when a large earthquake occurs. When the magnitude of the earthquake exceeds a predetermined value, the distribution board branch breaker is shut off instantaneously. In the case of a larger earthquake, the distribution board branch breaker is shut off instantaneously and after a certain period of time Shut off the main breaker. As a result, energization of the lighting circuit or the like continues for a certain time, so that evacuation and the like are facilitated.
Japanese Patent Laid-Open No. 10-336885

  A load control device such as a closed switchboard includes an electromagnetic contactor and an auxiliary relay in order to supply, cut off, and protect power to the load. When an earthquake occurs, the vibration may cause these main contacts and auxiliary contacts to be in a state different from the original open / close state, and the load may be abnormally stopped or started. When an important load that cannot be stopped even if an earthquake occurs is stopped due to the earthquake, an operation for restarting the load for each circuit in the load control device is required immediately after the earthquake ends. Moreover, when the load which should be stopped if an earthquake occurs, the operation which stops a load for every circuit in a load control apparatus immediately after the end of an earthquake is needed.

  However, in factories and business offices, workers are not always monitoring the load control device, and when an earthquake occurs, the workers are chased by other work or the workers are evacuated. It may be possible to delay restarting or stopping.

  The present invention has been made in view of the above circumstances, and its purpose is to be able to return to a normal operating state in a short time as much as possible even when the operating state of the load is different from the intended state due to the occurrence of an earthquake. And a load control method are provided.

  In order to achieve the above object, a load control device according to a first aspect of the present invention includes a load control means for controlling the operation of the load, a vibration detection means for detecting the vibration of the main body of the apparatus, and a vibration detected by the vibration detection means. When the occurrence of an earthquake is detected by the earthquake detection means, the storage means, and the earthquake detection means for detecting the occurrence and termination of an earthquake based on the above, the load control state of the load control means at the time of the occurrence of the earthquake is stored in the memory And when the end of the earthquake is detected by the earthquake detection means, the load control state is read from the storage means, and the load control means is caused to return to the read load control state. Means.

  The load control device according to claim 2 stores the load control state for the latest predetermined length of the load control means, the vibration detection means, the earthquake detection means, the storage means, and the load control means. When the occurrence of an earthquake is detected by the state storage means and the earthquake detection means, the load control state for a predetermined length stored in the state storage means is stored in the storage means, and the earthquake detection means When the end is detected, a state return is performed by reading the load control state at a predetermined point in the load control state for the predetermined length from the storage unit and causing the load control unit to return to the read load control state. And a control means.

  The load control method according to claim 9, wherein a first step of detecting vibration and detecting occurrence of an earthquake based on the vibration, and load control at the time of detecting the occurrence of an earthquake or immediately before the occurrence of the earthquake is detected. A second step for storing the state, a third step for detecting the vibration and detecting the end of the earthquake based on the vibration, and a return to the load control state for storing the load control state when the end of the earthquake is detected. And a fourth step.

  According to the present invention, even if an earthquake occurs and the load is different from the intended operation, the load can be operated in the state before the earthquake immediately after the earthquake ends. Can be kept to a minimum.

(First embodiment)
A first embodiment according to the present invention will be described below with reference to FIGS.
FIG. 2 shows an electrical configuration of one unit of a load control device stored in a closed switchboard used as a control center. The closed switchboard sequentially accommodates a plurality of load control devices 1 that are individualized for each unit in the vertical direction. Each load control device 1 supplies, interrupts, protects, and monitors power to the motor 2 connected thereto. Etc. are to be controlled.

  The load control device 1 includes a main circuit 3, an auxiliary circuit 4, and a control circuit unit 5. The main circuit 3 is formed between a three-phase power bus 6 and a motor 2 as a load. The main circuit 3 includes a circuit breaker 7 for wiring and a current transformer for detecting a main circuit current. 8. A magnetic contactor 9 (main contact 9a) and a zero-phase current transformer 10 for detecting a zero-phase current (ground fault current) are provided.

  A primary winding of the transformer 11 is connected between any two phases of the main circuit 3 on the load side of the circuit breaker 7 for wiring (the power source side of the main contact 9a of the electromagnetic contactor 9). This transformer 11 has two secondary windings, one system is used to generate the drive power for the auxiliary circuit unit 5 via the control power supply lines 12 and 13, and the other one system is controlled. It is used for the operation of the auxiliary circuit 4 via the power lines 14 and 15.

  In the auxiliary circuit 4, a control coil 9 b of the electromagnetic contactor 9 is connected between the control power line 14 and the output terminal 16 of the control circuit unit 5. A first auxiliary contact 9 c is connected between the control power line 14 and the first input terminal 17 of the control circuit unit 5. The first auxiliary contact 9 c is a normally open contact that is closed by energizing the control coil 9 b, and outputs an answer back signal for confirming the open / closed state of the main contact 9 a to the control circuit unit 5.

  Between the control power supply line 14 and the second input terminal 18 of the control circuit unit 5, a start operation switch 19, a stop operation switch 20 and a contact 21 constituting a part of the interlock circuit are connected in series. . A normally open second auxiliary contact 9d of the magnetic contactor 9 is connected to the start operation switch 19 in parallel.

  In the control circuit unit 5, an excitation circuit 22 a and a contact circuit 22 b constituting the relay circuit 22 are connected between the second input terminal 18 and the control power supply line 15 and between the output terminal 16 and the control power supply line 15, respectively. Has been. The excitation circuit 22a is actually composed of a resistance voltage dividing circuit, a filter capacitor, a control coil of a miniature relay that is excited according to the voltage across the voltage dividing resistor, and the contact circuit 22b is the above-described miniature relay. It is comprised from the normally open type contact.

  The control circuit unit 5 is mainly composed of a microcomputer as shown in FIG. The CPU 23 executes a load control program stored in a rewritable nonvolatile memory (flash memory) (not shown) and a state return control program shown in FIG. The load control program is a basic program that performs processing such as power interruption (start / stop) to the motor 2, protection, and monitoring. As will be described in detail later, the state return control program is a program for performing processing to return the load control state to the state at the time of occurrence of the earthquake after the end of the earthquake when the occurrence of the earthquake is detected.

  The memory 24 is a storage unit in which a load control state is written when an earthquake occurrence is detected, and includes a RAM, an EEPROM, and the like. The current detection circuit 25 A / D converts each output signal of the current transformer 8 and the zero-phase current transformer 10 and outputs the result to the CPU 23. The input circuit 26 inputs the answer back signal from the first input terminal 17 and inputs a start control signal given from the second input terminal 18 to the excitation circuit 22a. Inputs load control status such as energized status and monitor signal. Based on an output command from the CPU 23, the output circuit 27 energizes the excitation circuit 22a through a path different from the start control signal, and also changes the state of various contacts (not shown) and the energization state of the control coil. Output a signal. The vibration sensor 28 is a vibration detection unit composed of an acceleration sensor or the like, and outputs a signal corresponding to the magnitude of vibration to the CPU 23. The vibration sensor 28 is disposed inside the control circuit unit 5.

  The load control state refers to the operation state of the motor 2, for example, the start / stop state of the motor 2, the rotational speed, the acceleration / deceleration, and the like. Furthermore, in the load control device 1 for creating the state. This refers to the excitation state of the control coil, the contact open / close state, and the like.

  The load control means referred to in the present invention is necessary for processing such as power interruption (start / stop), protection, monitoring to the motor 2 based on the load control program in the configuration of the load control device 1. The basic composition.

Next, the operation of the load control device 1 in normal times when no earthquake is detected will be described.
When the circuit breaker 7 is turned on and the start operation switch 19 is turned on, the excitation circuit 22a in the control circuit unit 5 is activated, and the contact circuit 22b is closed and controlled accordingly. The coil 9b is excited. As a result, the main contact 9a of the electromagnetic contactor 9 is closed, power is supplied from the power supply bus 6 to the motor 2, and the motor 2 is started. At this time, when the second auxiliary contact 9d is closed, a self-holding circuit is formed in the auxiliary circuit 4, and power is continuously supplied from the power supply bus 6 to the motor 2 even when the start operation switch 19 is returned to the OFF state. The first auxiliary contact 9c is closed in response to the closing of the main contact 9a of the electromagnetic contactor 9, and an answer back signal is given to the input circuit 26 of the control circuit unit 5.

  When the stop device switch 20 is operated or the contact 21 constituting a part of the interlock circuit is opened, the self-holding state formed in the auxiliary circuit 4 is taken, whereby the main contact 9a of the electromagnetic contactor 9 is taken. Is opened, power supply from the power supply bus 6 to the motor 2 is stopped, and the motor 2 is stopped.

  Next, the operation of the load control device 1 when an earthquake occurs will be described using the flowchart of the state return control program shown in FIG. The CPU 23 that executes this state return control program corresponds to the state return control means in the present invention.

  The CPU 23 of the control circuit unit 5 detects the occurrence of an earthquake based on the output signal of the vibration sensor 28 in steps S1 and S2. That is, the output signal of the vibration sensor 28 is input in step S1, and the output signal of the vibration sensor 28 is compared with the threshold value in step S2. Then, it is determined that an earthquake has occurred when the output signal of the vibration sensor 28 exceeds the threshold value. The vibration corresponding to the threshold value does not change the open / closed state of each contact in the load control device 1. When the CPU 2 detects an earthquake, the CPU 2 proceeds to step S3 and writes the current load control state (here, answerback signal) in the memory 24. On the other hand, if no earthquake is detected, the process returns to step S1.

  CPU23 judges whether the end of an earthquake was detected based on the output signal of vibration sensor 28 at Steps S4 and S5. That is, in step S4, it is determined whether or not the output signal of the vibration sensor 28 has become lower than the threshold value. When the output signal of the vibration sensor 28 is lower than the threshold value, the CPU 23 detects the end of the earthquake (determined as YES), proceeds to step S6, and sets the load control state (answerback signal) written in step S3. Read from the memory 24. In step S7, it is determined whether or not the current load control state and the read load control state at the time of earthquake detection are the same.

If the CPU 23 determines that the load control state is different (NO), the CPU 23 performs a return process to the read load control state (at the time of earthquake detection) in step S8. That is, when the answerback signal is on (contact 9c is closed) when the earthquake is detected but the current answerback signal is off (contact 9c is opened), the CPU 23 is excited by the output circuit 27. The circuit 22a is energized, the main contact 9a is closed, and the motor 2 is started. On the other hand, if the current answerback signal is on (contact 9c is closed) even though the answerback signal is off (contact 9c is opened) when an earthquake is detected, the CPU 23 causes the output circuit 27 to The energization to the excitation circuit 22a is stopped, and the contact circuit 22b is opened. At this time, energization to the control coil 9b of the electromagnetic contactor 9 is also stopped, the main contact 9a is opened, and the motor 2 is stopped.
When the CPU 23 determines that the load control state is the same (YES) in step S7, the CPU 23 returns to step S1 and repeats the series of operations described above.

  As described above, the load control device 1 according to the first embodiment detects the occurrence of an earthquake with the vibration sensor 28 in the built-in control circuit unit 5 and stores the load control state at that time in the memory 24. When the earthquake sensor 28 detects the end of the earthquake, the stored load control state is read out and compared with the current load control state. If there is a difference, the output circuit 27 is instructed to energize or cut off the relay circuit 22. Return to the load control state when the occurrence of an earthquake is detected.

Therefore, even if the load control state changes due to the vibration of the earthquake, it is possible to automatically return to the normal load control state before the occurrence of the earthquake immediately after the end of the earthquake, and the influence of the earthquake can be minimized. .
The threshold value used for the determination of the occurrence and termination of an earthquake is set to a value that does not change the switching state of each contact in the load control device 1. For this reason, even when the vibration sensor 28 detects an earthquake, the normal load control state before the contact open / close state changes can be stored.

If an EEPROM is used for the memory 24, the memory 24 can store the load control state even when a power failure occurs due to an earthquake, and automatically returns to the normal load control state before the earthquake occurs after power recovery. it can.
The CPU 23 can set the open / close state of the contact circuit 22 b of the relay circuit 22 via the output circuit 27. For this reason, the CPU 23 can control energization or disconnection of the control coil 9b of the electromagnetic contactor 9, and can set the open / close state of the main contact 9a.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 corresponds to FIG. 1 according to the first embodiment, and is a flowchart of a state return control program representing state return control means. In FIG. 4, the same processing steps as those in FIG. The configuration of the load control device according to the present embodiment (corresponding to the load control device 1 in the first embodiment) is basically the same as that of the first embodiment, and the main circuit 3, auxiliary circuit 4 and It consists of a control circuit unit 5.

  The memory 24 has a memory area 24a (not shown) and a memory area 24b (not shown), and the CPU (corresponding to the CPU 23 in the first embodiment) is always the latest predetermined length as the state storage means. Is stored in the memory area 24a, and in parallel with this, the state return program shown in FIG. 4 is executed. When the occurrence of an earthquake is detected, the load control state for a predetermined length up to the present (at the time of earthquake detection) stored in the memory area 24a is read in step S24, and stored in the memory area 24b. Then, after the end of the earthquake is detected, the load control state at a predetermined time out of the predetermined length stored in the memory area 24b is read in step S25. Then, the process of step S7, 8 is performed, it returns to step S1 and repeats a series of operation | movement mentioned above.

In the present embodiment, since the load control state for the latest predetermined length is always stored in the memory area 24a, it is possible to return the load control device to the load control state that has been traced back from the time of the earthquake detection after the earthquake ended. Become. In this case, among the plurality of load control states stored in the memory area 24b, the load control state that is one sampling before the latest one is the one immediately before the earthquake detection. By reading the load control state at this time, it is possible to return to the normal load control state closest to the time of earthquake detection.
Also, by reading the load control state at the sampling point further retroactively from the latest one, it is possible to return to the normal load control state before the occurrence of the earthquake with high accuracy.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 5 corresponds to FIG. 1 according to the first embodiment, and is a flowchart of a state return control program representing state return control means. In FIG. 5, the same processing steps as those in FIG. The configuration of the load control device according to the present embodiment (corresponding to the load control device 1 in the first embodiment) is basically the same as that of the first embodiment, and the main circuit 3, auxiliary circuit 4 and It consists of a control circuit unit 5.

  In step S31, whether or not to return the load control state to the load control device after the earthquake ends is input. Then, in step S32 after the earthquake is detected, it is determined whether or not the load control device performs a return operation after the earthquake ends.

  If it is input at step 31 that the load control device performs a return operation after the end of the earthquake, YES is determined at step 32 and the processing from step S3 is performed. If it is input in step S31 that the load control device does not return after the earthquake ends, NO is determined in step S32, and the load control device performs a stop process of the motor 2 as a load in step S33.

  Thus, in the load control device according to the present embodiment, when the earthquake ends, the load control device can be added with a function of selecting in advance whether or not to return to the load control state at the time of occurrence of the earthquake. . This makes it possible to cope with a situation where the load control state should not be restored after the end of the earthquake depending on how the motor 2 is used.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 6 corresponds to FIG. 3 according to the first embodiment, and is a block diagram illustrating a configuration of a control circuit unit of the load control device (corresponding to the load control device 1 in the first embodiment) according to the present embodiment. . FIG. 7 corresponds to FIG. 1 according to the first embodiment, and is a flowchart of a state return control program representing state return control means. In FIG. 7, the same processing steps as those in FIG.

  The configuration of the load control device according to the present embodiment is basically the same as that of the first embodiment, and includes the main circuit 3, the auxiliary circuit 4, and the control circuit unit 5 shown in FIG. As shown in FIG. 6, the control circuit unit 5 includes a communication device 41 connected to the CPU 23. The communication device 41 is configured to be able to communicate with the host monitoring board 42 of the load control device. And the communication apparatus 41 will transmit to the CPU 23 that there was an earthquake early warning, if the earthquake early warning from the high-order monitoring panel 42 was received.

  As shown in FIG. 7, the CPU 23 determines whether or not an earthquake early warning has been received in step S41. Until the earthquake early warning is received, the determination in step S41 is NO and the determination as to whether or not the earthquake early warning has been received is repeated. When earthquake early warning is received, judgment of Step S41 becomes YES and processing after Step S1 is performed.

  The earthquake early warning here is to predict the arrival of an earthquake, and examples include the national instantaneous warning system of the Ministry of Internal Affairs and Communications, but are not limited to this and are provided by local governments, private companies, etc. Earthquake early warning may be used. Moreover, the earthquake early warning which detects the P wave of an earthquake wave and forecasts that an S wave arrives after that may be sufficient.

  Thus, by receiving the earthquake early warning, it is possible to make sure that the vibration sensed by the vibration sensor 28 of the load control device is due to the earthquake. For example, vibration when a person or an object collides with the load control device is not erroneously recognized as a vibration caused by an earthquake, and the state return control means such as the vibration sensor 28 of the load control device is effectively and efficiently set in a ready state. can do.

The present invention is not limited to the embodiments described above and shown in the drawings, and the following modifications or expansions are possible.
Although the load control device taking the motor 2 as a load as an example in each of the embodiments described above, the load is not limited to this and may be an electromagnetic solenoid or the like.
Moreover, in each said embodiment, although the vibration sensor 28 has shown the example incorporated in the control circuit unit 5, it is not restricted to this, You may attach to the main body of a load control apparatus, or a closed switchboard main body. .

The flowchart of the state return control program which shows operation | movement when the earthquake of the load control apparatus which concerns on 1st Embodiment generate | occur | produces. Electrical configuration diagram of load control device Block diagram showing the configuration of the control circuit unit of the load control device FIG. 1 equivalent view according to the second embodiment FIG. 1 equivalent view according to the third embodiment FIG. 3 equivalent diagram according to the fourth embodiment 1 equivalent diagram

Explanation of symbols

In the drawings, 1 is a load control device, 2 is a motor (load), 3 is a main circuit, 4 is an auxiliary circuit, 5 is a control circuit unit (load control means), 23 is a CPU (load control means, earthquake detection means, state) (Return control means), 24 is a memory (storage means, state accumulation means), 28 is a vibration sensor (vibration detection means), and 41 is a communication device (reception means).

Claims (9)

Load control means for controlling the operation of the load;
Vibration detecting means for detecting vibration of the apparatus body;
An earthquake detection means for detecting the occurrence and termination of an earthquake based on the vibration detected by the vibration detection means;
Storage means;
When the occurrence of an earthquake is detected by the earthquake detection means, the load control state of the load control means at the time of the occurrence of the earthquake is stored in the storage means, and when the end of the earthquake is detected by the earthquake detection means, State return control means for reading the load control state from the storage means, and causing the load control means to return to the read load control state;
A load control device comprising: Load control means for controlling the operation of the load;
Vibration detecting means for detecting vibration of the apparatus body;
An earthquake detection means for detecting the occurrence and termination of an earthquake based on the vibration detected by the vibration detection means;
Storage means;
State accumulation means for storing a load control state for the latest predetermined length of the load control means;
When the occurrence of an earthquake is detected by the earthquake detection means, the load control state for a predetermined length stored in the state storage means is stored in the storage means, and the end of the earthquake is detected by the earthquake detection means. And a state return control means for reading out a load control state at a predetermined point in the load control state for the predetermined length from the storage means, and causing the load control means to return to the read load control state,
A load control device comprising:   The load control apparatus according to claim 2, wherein the load control state at the predetermined time is immediately before the occurrence of an earthquake by the earthquake detection means.   When the end of the earthquake is detected, the state return control unit compares the load control state of the load control unit at the time of detection of the end of the earthquake with the load control state read from the storage unit, and both states are different. 4. The load control device according to claim 1, wherein the load control unit causes the load control unit to return to the load control state read from the storage unit. 5.   The load control device according to any one of claims 1 to 4, wherein the state return control means is configured to be able to stop the state return control operation accompanying the occurrence and end of an earthquake.   6. The state return control means causes the load control means to stop the load when an occurrence of an earthquake is detected when the state return control operation is in a stopped state. The load control device described in 1.   Receiving means for receiving an earthquake early warning that is distributed by predicting the occurrence of an earthquake at the installation location of the apparatus main body, and the earthquake detecting means detects the occurrence and termination of the earthquake on the condition that the earthquake early warning is received. The load control device according to claim 1, wherein the load control device detects the load control device.   The load control device according to claim 1, wherein the load control state is an open / close state of a contact built in the load control means. A first step of detecting vibration and detecting the occurrence of an earthquake based on the vibration;
A second step of storing the load control state at the time of the occurrence of the earthquake or immediately before the occurrence of the earthquake when the occurrence of the earthquake is detected;
A third step of detecting vibration and detecting the end of the earthquake based on the vibration;
A load control method comprising a fourth step of returning the load control state to the stored load control state when the end of the earthquake is detected.

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