JP3686471B2 - Three-phase motor drive device and its utilization device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In the present invention, when a three-phase motor is operated by a three-phase power source provided through a relay circuit, the operation of opening the relay circuit is performed, but a failure of the relay circuit causes the 3 This invention relates to a three-phase motor drive device having a configuration for releasing the overoperation when the phase motor continues to operate (referred to as overoperation in the present invention), and more particularly to a device in which the overoperation is dangerous. is there.
[0002]
Examples of such a three-phase motor drive device include a crane device that moves and operates dangerous substances, and a combustible gas pressurizing and supplying device that pressurizes combustible gas, for example, natural gas, and supplies it to a required container.
[0003]
As the latter device, for example, a combustible gas pressurizing and supplying device 100 as shown in FIG. 6 is well known. In FIG. 6, the pump 11 driven by the three-phase electric motor 10 pressurizes the combustible gas 13 stored in the storage tank 12, for example, natural gas, and presses the required container 14 through the connection line 14 </ b> A. For example, the fuel is supplied to the fuel cylinder of the automobile 15.
[0004]
The relay circuit 16 for operating the three-phase motor 10 by the three-phase power source 17 has a [normal type configuration] and an [overoperation release type configuration] as shown in FIG. In the configuration], one three-pole single-throw type for opening and closing the three-phase electric circuit of the three-phase power source 17, that is, the three-circuit simultaneous opening and closing type relay 16X is connected to the relay driving circuit 16XA, for example, a transistor switching circuit However, in such a configuration, the contact of the relay 16X may be welded by an arc or the like during contact / separation operation. When this welding occurs, the relay 16X is actually controlled to open the electric circuit, but the contact of the relay 16X is not opened and the electric circuit remains closed. 10 over-acts, the supply pressure of the combustible gas 13 becomes abnormally high, causing a gas leakage accident and, consequently, a risk of causing a gas explosion accident.
[0005]
Therefore, in the [over-operation release type configuration], the relay circuit 16 is configured to drive two three-circuit simultaneous opening / closing type relays 16X and 16Y by the relay drive circuits 16XA and 16YA, respectively, and one relay 16X is always closed, and the operation of the three-phase motor 10 is operated and stopped only by the other relay 16Y. When an overoperation occurs, the relay 16X is opened to release the overoperation. doing.
[0006]
[Problems to be solved by the invention]
In the conventional [over-operation release type configuration] as described above, since a large relay circuit using two three-circuit simultaneous opening / closing relays is required, the apparatus cannot be provided with a small size and low cost. Therefore, there is a problem that provision of such an inconvenient device is desired.
[0007]
[Means for Solving the Problems]
With this invention for driving a three-phase motor for more OPERATION three-phase power source as described above Therefore predetermined object, according to the over-operation the above object based on an abnormality in relay circuit of the three-phase power supply In the three-phase motor drive device provided with a release function for releasing the over-operation described above in order to be dangerous,
[0008]
A first relay circuit that closes the one-phase circuit of the three-phase power source at all times or before the above operation, and the remaining two-phase circuit of the three-phase power source for each operation and stop of the operation. Relay circuit arranging means for providing a second relay circuit for opening and closing;
An overoperation detecting means for detecting the presence or absence of the overoperation when the second relay circuit is opened;
[0009]
A first configuration provided with an over-operation stop means for opening the first relay circuit and stopping the over-operation when the over-operation is detected by the detection;
[0010]
The over-operation detecting means in the first configuration detects the presence or absence of the over-operation, and detects the presence of the over-operation in the two-phase electric circuit between the second relay circuit and the three-phase motor. The presence or absence of at least one of the currents, or the voltage between the two-phase circuit and the one-phase circuit between the second relay circuit and the three-phase motor. A second configuration for detecting by the presence or absence of at least one of the voltages;
[0011]
It drives the pump to pressurize the combustible gas by a three-phase electric motor for driving the 3-phase power source, a flammable gas pressurized feed device provided with a release function for releasing the excessive operation of the three-phase electric motor of the ,
A third configuration provided with the relay circuit arrangement means similar to the first configuration, the over-operation detection means, and the over-operation stop means;
The above-described problem is solved by a fourth configuration in which the over-operation detecting means in the third configuration is configured similarly to the second configuration .
[0012]
DETAILED DESCRIPTION OF THE INVENTION
As an embodiment of the present invention, an example in which the present invention is applied to a configuration in which the three-phase motor driving device 100 is configured by the combustible gas pressurizing and supplying device of FIG. 6 will be described.
[0013]
【Example】
Examples will be described below with reference to FIGS. 1 to 5, the parts denoted by the same reference numerals as those in FIGS. 6 and 7 are parts having the same functions as the parts having the same reference numerals described in FIGS. 6 and 7. 1 to 5 are portions having the same functions as the portions having the same reference numerals described in any of FIGS.
[0014]
[Detection of overoperation]
The following three methods are conceivable as a method for detecting an over-operation state.
In the first detection method, the voltage is applied to the electric circuit between the relay circuit 16 and the three-phase motor 10 even though the relay circuit 16 is opened. Since it is in operation, it is a method for determining whether or not there is a voltage in this electric circuit, and this determination method is called “voltage determination”.
The
[0015]
In the second detection method, although the operation of opening the relay circuit 16 is performed, the fact that the three-phase motor 10 is operating means that a current is flowing through the electric path of the three-phase motor 10. Therefore, this determination method is called “current determination”.
[0016]
In the third detection method, although the relay circuit 16 is opened, the three-phase motor 10 is operating because the rotor of the three-phase motor 10 is rotating. Therefore, this determination method is referred to as “rotation determination”.
[0017]
“Rotation determination” can be determined by, for example, mechanically or electrically detecting the rotational speed of the rotating shaft of the three-phase electric motor 10 or a portion driven by the rotating shaft. Further, in the case where the three-phase motor 10 is subjected to dynamic braking, it can also be detected by the current flowing through the dynamic braking circuit.
[0018]
[First embodiment]
First, the first embodiment will be described with reference to FIGS. 1, 2, 4, and 5. FIG. In FIG. 1, the relay circuit 16 opens and closes a three-phase power source 17 that operates the three-phase motor 10, that is, a three-phase AC power source, for example, an AC 200 V circuit 18. The control unit 70 controls the relay circuit 16 and the like based on the pressurization operation condition set by the setting operation unit 75 and the detection signal detected by the pressure detector D1 for the supply pressure of the combustible gas 13. The pressurized combustible gas is supplied to the container 14.
[0019]
As shown in FIG. 2, the relay circuit 16 includes a relay circuit 161 for opening and closing the one-phase electric circuit 18A of the electric circuit 18, and a relay circuit for opening and closing the remaining two-phase electric circuits 18B and 18C. 162.
[0020]
The relay circuit 161 is, for example, a one-pole single-throw type, that is, a one-circuit open / close type relay 161A, for example, a plunger-type relay, that is driven by a drive circuit 161B, for example, a transistor switching circuit. The relay circuit 162 is a circuit that drives, for example, a two-pole single-throw type, that is, a two-circuit open / close type relay 162A, for example, a plunger-type relay, by a drive circuit 162B, for example, a transistor switching circuit. The drive circuits 161A and 162B are controlled by the control unit 70. The drive circuits 161A and 162B are supplied with a DC power source, for example, DC 24V, obtained from the three-phase power source 17 through a rectifier circuit (not shown) as an operating power source. Then, the relay circuit 161 is used for releasing the overoperation, and the relay circuit 162 is used for operation control and stop control with respect to the operation of the three-phase motor 10.
[0021]
The over-operation detection unit 20 is a part that detects an over-operation state by the above “voltage discrimination”. In this embodiment, the two-voltage detection circuits 21 and 22 open the relay circuit 162 to form a three-phase circuit. When a voltage is applied to the electrical path between the relay circuit 16 and the three-phase motor 10 even though a time enough for the motor 10 to stop, for example, about one second has elapsed, the three-phase motor 10 It is determined that the device is overoperating.
[0022]
That is, the voltage detection circuits 21 and 22 are respectively connected between the one-phase electric circuit 18A of the electric circuit 18 between the relay circuit 16 and the three-phase motor 10 and the remaining two-phase electric circuits 18B and 18C. A circuit for detecting a voltage, for example, the voltage detection circuit 21 compares a predetermined voltage VA with a reduced voltage value obtained by dividing each of the high-resistance voltage dividing circuits provided between the electric circuit 18A and the electric circuit 18B. The voltage detection signal D11A is obtained by the operational amplifier circuit to be detected, and the voltage detection circuit 22 is also a circuit for obtaining the voltage detection signal D12A in the same manner between the electric circuit 18A and the electric circuit 18C.
[0023]
The control unit 70 is a control unit mainly using a control processing function (hereinafter referred to as CPU) by a microcomputer, for example, a control unit using a commercially available CPU board (CPU / B). For example, as shown in FIG. In addition, data based on each detection signal obtained by detecting the state of each unit and each operation signal input by operating the setting operation unit 75 is taken as input data from the input / output port and stored in the work memory 73, for example, the RAM. In addition to storing the data, the respective units obtained by performing the required control processing are controlled based on these data, the processing memory 72, for example, the control processing flow program stored in advance in the ROM and the data such as the reference value. A control signal is output from the input / output port.
[0024]
In addition to measuring the time required for the control process by the clock circuit 74, the display unit 76 is configured to display necessary items among the operation state, control state, and setting state of each unit. The operation of the three-phase motor 10 by the relay circuit 16 and the release of the overoperation are controlled by a control processing flow as shown in FIG.
[0025]
The processing flow of FIG. 5 is configured as a subroutine of a main control processing routine that performs control processing of the entire apparatus, and is configured to shift to the control processing flow of FIG. 5 every 2 seconds, for example. Generally, before the operation of the three-phase motor 10, for example, when starting the operation of the entire apparatus, the electric circuit 18A is closed by the relay circuit 161, and thereafter, the operation and stop of the three-phase motor 10 are performed. Is performed only by the relay circuit 162, and the relay circuit 161 is configured to be opened when there is an overoperation or when the operation of the entire apparatus is stopped.
[0026]
[Explanation of control processing flow]
Hereinafter, the control processing flow of FIG. 5 will be described.
In step SP1, command data is fetched and the process proceeds to the next step SP2.
[0027]
In step SP2, it is determined whether or not to start the operation of the entire apparatus. When the operation of the entire apparatus is started, the process proceeds to the next step SP3, and otherwise, the process proceeds to step SP4.
[0028]
In step SP3, the relay circuit 161 used for canceling the overoperation is set as a relay circuit that is closed in advance, the relay circuit 161 is closed, and the process proceeds to the next step SP4.
[0029]
In step SP4, it is determined whether or not to stop the operation of the entire apparatus. If it is a command to stop the operation of the entire apparatus, the process proceeds to step S11, and if not, the process proceeds to the next step SP5. When stopping the operation of the entire device, the main control processing routine instructs to stop the operation of the entire device after giving a command to stop the operation of the three-phase motor 10 first.
[0030]
In step SP5, it is determined whether or not the operation of the three-phase motor 10 is started. When the operation of the three-phase motor 10 is started, the process proceeds to the next step SP6, and otherwise, the process proceeds to step SP7.
[0031]
◆ In step SP6, the relay circuit 162 used for the operation control and stop control of the operation of the three-phase motor 10 is followed and closed, and the relay circuit 162 is closed and the main control processing routine is predetermined. Move to the step part.
[0032]
In step SP7, it is determined whether or not to stop the operation of the three-phase motor 10. When the operation of the three-phase motor 10 is stopped, the process proceeds to the next step SP8. Otherwise, the process proceeds to a predetermined step part of the main control processing routine.
[0033]
◆ In step SP8, the relay circuit 162 that has been closed later is opened, and the process proceeds to the next step SP. That is, in this state, the relay circuit 161 that has been closed in advance is held in the closed state.
[0034]
In step SP9, after the relay circuit 162 is opened in step SP8, after a predetermined time TA, for example, about 2 seconds has passed, detection data for detecting an over-operation state, that is, the voltage detection signal D11A. D12A is taken in and the process proceeds to the next step SP10.
[0035]
Here, as the value of the predetermined time TA, in a normal state, the time from when the power supplied to the three-phase motor 10 is turned off until the rotation speed of the three-phase motor 10 becomes about ½ is tested in advance. The time value obtained in this manner is stored in the processing memory 72, and the clock circuit 74 measures the elapsed time and determines it.
[0036]
In step SP10, it is determined whether or not an over-operation occurs based on the detection data of the voltage detection signals D11A and D12A. When over-operation occurs, the process proceeds to SP12, and when not, the process proceeds to a predetermined step in the main control process routine.
[0037]
The above “voltage discrimination” here is discriminated based on whether at least one of the data of the voltage detection signals D11A and D12A has been obtained. The value of the predetermined value VA to be compared by the operational amplifier circuit is normal. In the state, the value obtained by previously experimenting with the value at the time when the predetermined time TA has elapsed is stored in the processing memory 72.
[0038]
In addition, since the two contact contacts of the relay 162A in the relay circuit 162, that is, the contact a that opens and closes the electric circuit 18B and the contact b that opens and closes the electric circuit 18C can hardly be simultaneously welded, Since it may be considered that only one of the contacts b is welded, data indicating that the predetermined value VA is exceeded is obtained in at least one of the voltage detection signals D11A and D12A.
[0039]
In step SP11, the relay circuit 161 closed in advance is opened, and the process proceeds to a predetermined step position of the main control processing routine. In this state, the relay circuit 162 that has been closed afterward is already held open.
[0040]
In step SP12, the relay circuit 161 closed in advance is opened, and the process proceeds to the next step SP13. In this state, one of the contact a and the contact b of the relay 162A in the relay circuit 162 that is closed later is welded, but either the electric circuit 18B or the electric circuit 18C is connected by the non-welded contact. In order to open, the two electric circuits of the opened electric circuit and the electric circuit 18A in which the relay circuit 161 is opened are opened and the three-phase motor 10 is stopped, so that the overoperation is released.
[0041]
In step SP13, the display unit 76 is made to display a warning that there is an abnormality in the relay circuit 16 and a warning sound such as a buzzer if necessary, and then proceeds to the next step SP14.
[0042]
In step SP14, it is determined whether or not the operation worker has input data for canceling maintenance by operating a predetermined operation key of the setting operation unit 75. When maintenance release data is input, the routine proceeds to a predetermined step location of the main control processing routine. Otherwise, this step SP14 is repeated.
[0043]
[Second Embodiment]
Next, a second embodiment will be described with reference to FIG. 1, FIG. 3, FIG. 4, and FIG. In this embodiment, the configuration of the relay circuit 16 of FIG. 2 in the first embodiment is changed as shown in FIG. 3, and over-operation is discriminated by “current discrimination”.
[0044]
In FIG. 3, the relay circuit 16 includes two one-pole single-throw type, that is, one-circuit open / close type relays 162 </ b> A <b> 1 and 162 </ b> A <b> 2, for example, plunger-type relays, respectively. Each of the driving circuits 162B1 and 162B2, for example, a circuit driven by a transistor switching circuit. Therefore, it can be configured by combining three of the same relays 161A and driving circuit 161B.
[0045]
The control processing operation is the same as the control for the drive circuit 162B shown in FIG. 2, and if the drive circuits 162B1 and 162B2 in the relay circuit 16 shown in FIG. By executing the control process as described above as it is, the relay circuit 16 can be controlled in the same manner as in the first embodiment.
[0046]
Further, the over-operation detecting unit 20 in FIG. 3 performs operational amplification for detecting the detected currents of the current transformers D13 and D14 provided in the electric paths 18B and 18C by comparing them with current detection circuits 23 and 24, for example, a predetermined value IA. The above “current discrimination” is performed by obtaining the current detection signals D13A and D14A detected by the circuit.
[0047]
Therefore, the value of the predetermined value IA can be obtained by storing the value obtained by previously experimenting with the value at the time when the predetermined time TA has elapsed in the normal state in the processing memory 72. As in the case of “voltage determination” in the embodiment, it is possible to determine whether or not an overoperation has occurred. Therefore, the determination in step SP10 of the control processing flow of FIG. By performing the control process flow of FIG. 5 as it is, it is possible to perform the control for the overoperation in the same manner as in the first embodiment.
[0048]
[Third embodiment]
Next, a third embodiment will be described with reference to FIGS. In this embodiment, the relay circuit 161 of FIG. 2 in the first embodiment and the second embodiment and the relay 161A of the relay circuit 161 in the relay circuit 16 of FIG. The contact contact is closed by the above, and only when the drive circuit 161B is operated, the contact contact is changed so that the contact contact is opened, whereby steps SP1 to SP4 and step SP11 in the control processing flow of FIG. 5 are performed. In addition to making it unnecessary, by performing control processing so that the relay circuit 161 is opened only at step SP12, control processing of operation power operation of the target three-phase motor 10 and cancellation of over-operation can be performed. It is what I did.
[0049]
[Summary of Configuration of Example]
To summarize the configuration of each of the above embodiments,
Predetermined object by a three-phase motor 10 to more OPERATION three-phase power source 17, for example, drives the pump 11 to compress the combustible gas 13, the above object relay circuit of the three-phase power source 17 In the three-phase motor drive device 100 provided with a release function for releasing the overoperation described above, because there is a danger due to overoperation based on 16 abnormalities,
[0050]
For example, the first circuit which closes the one-phase electric circuit 18A of the three-phase power source 17 before the above-described operation at all times as in the relay circuit 161 in the [third embodiment] or, for example, as in step SP3. The second relay circuit 161 that opens and closes the remaining two-phase electric circuits 18B and 18C of the three-phase power source 17 for each operation and stop of the operation as in step SP6 and step SP8, for example. Relay circuit arrangement means for providing the electric circuit 162;
[0051]
For example, as in step SP10, when opening the second relay circuit 162 described above, for example, by excessive movement detection unit 20, and the over-movement detecting means for detecting the presence or absence of the over-operation,
When there is an overoperation by the above detection, for example, as in step SP12, the first relay circuit 161 is opened to provide an overoperation stop means for stopping the overoperation. And the configuration of
[0052]
The over-operation detecting means in the first configuration detects the presence or absence of the over-operation, for example, the second relay circuit 162 and the above-mentioned as in the over-operation detection unit 20 of FIG. The presence / absence of at least one of the currents in the two-phase electric circuits 18B and 18C with the three-phase motor 10 or the second operation as in the over-operation detection unit 20 in FIG. Detected by the presence or absence of at least one of the voltages between the two-phase electric circuits 18B and 18C between the relay circuit 162 and the three-phase motor 10 and the one-phase electric circuit 18A. A second configuration as described above,
[0053]
By a three-phase electric motor 10 to drive the 3-phase power source 17 drives the pump 11 to pressurize the combustible gas 13, the combustible gas under pressure having a release function for releasing the excessive operation of the three-phase motor 10 of the In the supply device,
A third configuration provided with the relay circuit arrangement means similar to the first configuration, the over-operation detection means, and the over-operation stop means;
The over-operation detecting means in the third configuration is configured as a fourth configuration configured in the same manner as the second configuration .
[0054]
[Modification]
The present invention can be carried out with the following modifications.
(1) The operation part for moving and operating the dangerous substance is applied to a crane device that is driven by the three-phase motor 10.
(2) Instead of the drive circuit 162B1 and drive circuit 162B2 of the relay circuit 162 in the configuration of FIG. 3, the relay 162A1 and the relay 162A1 are configured to be driven by one drive circuit.
[0055]
【The invention's effect】
According to the present invention, the relay operation of the one-phase circuit among the three-phase power circuits that operate the three-phase motor is always closed or closed before operation, and only the remaining two-phase circuits are opened and closed. Since the three-phase motor is being operated by this, the contact of the relay circuit that is normally or closed before the operation is caused by a spark during the relay operation for the operation / stop of the three-phase motor. Since contact welding does not occur, it is possible to reliably release over-operation by simply opening the relay circuit that is closed at all times or before operation, and it is closed at all times or before operation. Since the relay circuit can be completed with only one phase electric circuit, there is a feature that a small and inexpensive three-phase motor drive device having an over-operation release function can be provided.
[Brief description of the drawings]
In the drawings, FIGS. 1 to 5 show an embodiment of the present invention, and FIGS. 6 and 7 show the prior art. The contents of each figure are as follows.
1 is an overall block configuration diagram. FIG. 2 is an essential block configuration diagram. FIG. 3 is an essential block configuration diagram. FIG. 4 is an essential block configuration diagram. Block diagram [Fig. 7] Main block diagram [Explanation of symbols]
10 Three-phase motor 11 Pump (object)
12 Storage tank 13 Combustible gas 14 Container (cylinder)
14A Pipe 15 Car 16 Relay circuit 17 Three-phase power supply 18 Electric circuit 18A Electric circuit 18B Electric circuit 18C Electric circuit 20 Overoperation detection unit 21 Voltage detection circuit 22 Voltage detection circuit 23 Current detection circuit 24 Current detection circuit 70 Control unit 71 Input / output port 72 Processing memory 73 Work memory 74 Clock circuit 75 Setting operation unit 76 Display (alarm) unit 100 Three-phase motor drive device (combustible gas pressurization supply device)
161 Relay circuit 161A Relay 161B Drive circuit 162 Relay circuit 162A Relay 162A1 Relay 162B1 Drive circuit 162A2 Relay 162B2 Drive circuit a Contact contact b Contact contact D1 Pressure detector D11A Voltage detection signal D12A Current detection signal D13A Current detection signal D13A signal

Claims (4)

Drives the more 3-phase motor for OPERATION Therefore predetermined object in a three-phase power supply, to accompany the risk of the object due to the abnormality in the over-operation of the relay circuit before Symbol 3-phase power supply, the over A three-phase motor drive device provided with a release function for releasing operation,
A first relay circuit that closes the one-phase circuit of the three-phase power source at all times or before the operation, and a second relay circuit that opens and closes the remaining two-phase circuit of the three-phase power source every time the operation is stopped and operated A relay circuit arrangement means for providing a relay circuit of
Over-operation detecting means for detecting the presence or absence of the over-operation when the second relay circuit is opened;
An over-operation stop unit that opens the first relay circuit and stops the over-operation when the over-operation is detected by the detection.   The over-operation detecting means detects the presence / absence of the over-operation by the presence / absence of at least one of the currents in the two-phase electric circuit between the second relay circuit and the three-phase motor; or 2. The detection according to claim 1, wherein the detection is based on the presence / absence of at least one of a voltage between the two-phase circuit and the one-phase circuit between the second relay circuit and the three-phase motor. Three-phase motor drive device. Drives the pump to pressurize the combustible gas by a three-phase electric motor for driving the 3-phase power source, a flammable gas pressurized feed device provided with a release function for releasing the excessive operation of the 3-phase motor,
A first relay circuit that closes the one-phase circuit of the three-phase power source at all times or before the operation, and a second relay circuit that opens and closes the remaining two-phase circuit of the three-phase power source every time the operation is stopped and operated A relay circuit arrangement means for providing a relay circuit of
Over-operation detecting means for detecting the presence or absence of the over-operation when the second relay circuit is opened;
Wherein when there is the over operation by the detection, the first open relay circuit, wherein the combustible gas pressurized pressure supply apparatus characterized by comprising an over operation stopping means for stopping excessive operation. The over-operation detecting means detects the presence / absence of the over-operation, the presence / absence of at least one of the currents of the two-phase electric circuit between the second relay circuit and the three-phase motor; or 4. The detection according to claim 3, wherein the detection is based on the presence or absence of at least one of a voltage between the two-phase electric circuit and the one-phase electric circuit between the second relay circuit and the three-phase electric motor. combustible gas pressurized pressure supply device.

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