JP3367598B2 - Dual inverter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dual inverter for driving and controlling a plurality of turbomachines.

[0002]

2. Description of the Related Art In turbo machines such as turbo pumps and turbo blowers, the amount of water supplied and the amount of air are proportional to the operating speed, the pressure of water supplied and the wind pressure are proportional to the square of the operating speed, and the mechanical output of these is It is proportional to the cube of speed. This indicates that the operating speed can be reduced as the load amount is reduced, and there is a merit that energy can be saved.

Conventionally, a plurality of inverters are used to perform speed control so that pressures on the discharge sides of a plurality of turbomachines maintain a certain relationship, and control of the operating sequence of these plurality of inverters and turbomachines and the number of operating machines are performed. Control of.

When a plurality of turbomachines are driven by a plurality of inverters to control the speed and the number of operating machines, the water supply, the air volume, the water supply pressure, the wind pressure, etc. can be controlled relatively easily and efficiently. . For this reason, it is considered that speed control by inverters will become more popular in the future.

As an example of a conventional turbomachine, an example in which an inverter is used in a water supply device will be described with reference to FIGS. FIG. 4 is a block diagram of the water supply device, 1 is a water supply pipe,
2-1, 2-2 are water distribution pipe branch pipes, 3-1, 3-2, 3-
3, 3-4 are gate valves, 4-1 and 4-2 are pumps, 5-
1, 5-2 is an electric motor, 6-1 and 6-2 are check valves, 7 is a water supply pipe, 8 is a pressure tank having an air reservoir inside,
Reference numerals 9 and 10 denote pressure sensors that detect the pressures on the pump suction side and the pump discharge side, respectively, and emit electric signals according to the pressure of the detection unit.

FS1 and FS2 are flow switches,
It is a flow switch that is turned on when the amount of water is too small QS shown in FIGS. CNU is a control device, which is an inverter INV that drives the electric motors 5-1 and 5-2 at a variable speed.
1, INV2 and earth leakage breaker ELB1, which protects against earth leakage
The ELB 2 includes a power circuit section, a relay circuit section R, and a controller CU. Relay circuit R
Is a transformer TR, a stabilized power supply Z, and a relay 52X.
1, 52X2 and an interface I / O with the controller CU.

The controller CU is an arithmetic processing unit CPU
(Hereinafter abbreviated as CPU), an A / D converter for converting the signals (analog amount) from the pressure sensors 9 and 10 into digital signals, and the water supply system to the inverters INV1 and INV2. D / A commanding N1 and N2
A converter, a power supply terminal E for supplying power to the controller CU, and an output port PIO-1 for transmitting a signal S4 to the interface I / O for driving the above-mentioned relays 52X1 and 52X2 are provided.

Similarly, the controller CU is shown in FIG.
An input port PIO-2 for reading the set value set by the setting means C so as to operate according to the operating characteristics of the pump shown in FIG. 3, and a contact that operates when each of the earth leakage breakers ELB1 and ELB2 trips due to earth leakage or the like. EL
BAL1, ELBAL2 and inverters INV1, IN
Contact I that operates when V2 trips due to overload
It has an input port PIO-3 for reading the states of NVAL1 and INVAL2. That is, the CPU stops the pump according to these failure states, commands the other pump to be stopped and operates, and executes its operation control.

FIG. 2 is an operation characteristic diagram when one pump is operated alone or two pumps are alternately operated by the water supply device described above, and the pressure H is plotted on the vertical axis and the horizontal axis is plotted on the horizontal axis. The amount of water Q is shown. A curve A is a Q-H performance curve when the pump is driven by the inverter at the operating speed N3, that is, the operating speed of 100%. Similarly, curves B, C, and D are Q-H performance curves when the pump is driven at operating speeds of N2, N1, and N0, respectively.

The curve F is a pipe resistance curve. For example, when the amount of water used changes from the water amount Q1 to the water amount Q0, if water is supplied at a pressure higher than the curve F on the discharge side of the pump, a desired end faucet can be obtained. It shows that pressure can be obtained.
The above-mentioned inverters INV1 and INV2 control the set conditions, for example, how long the acceleration / deceleration time is and what value V / F (output voltage / output frequency characteristic) rotates. These conditions are console CO
It is externally set by NS1 and CONS2. That is,
The water supply device operates the pump on the curve F along O3 → O2 → O1 → O0.

In FIG. 4, earth leakage breakers ELB1, E
When LB2 is turned on and the control power breaker CB is turned on, the power of the controller CU is established, and the CPU makes initial settings based on the program stored in the memory M in advance and reads the setting information from the setting means C. , The status of the inverter and the earth leakage breaker (not broken) is read from the input port PIO-3, and the pressure sensor 9, 1 is read.
The 0 signal is read through the A / D converter. The water supply pressure corresponds to the change in the operating speed, and, for example, the pipeline resistance curve F is stored as the load operating control. The operation preparation is completed in this way.

Under this condition, when the customer uses water, the water supply pressure drops, and when the water pressure drops below the starting pressure HON shown in FIG. 2, the CPU sends the interface I / O through the output port PIO-1. A signal for energizing the O relay 52X1 is output, and a signal of the operating speed N1 is output to the inverter INV1 via the D / A converter. As a result, the inverter INV1 is started and the electric motor 5-1 is driven. After the operation, the water supply pressure is controlled based on the signal of the pressure sensor 10 so that the water supply pressure is on the curve F. When the amount of water used decreases and the pump stop condition is established, the CPU deactivates the relay 52X1 and releases the speed command signal N1 to the inverter INV1 that is currently output. As a result, the pump 4-1 is stopped. When the water is used again and the supply pressure becomes less than HON and the starting condition is established, the relay 52
The energizing signal of X2 and the signal of operating speed N2 are issued, and this time the other inverter INV2 is driven to drive the electric motor 5-2.
Is driven, and the pump 4-2 starts operating. Thereafter, similarly, switching control is performed and alternate operation is performed.

FIG. 3 is a characteristic diagram when two pumps are operated in parallel, and those denoted by the same reference numerals as those in FIG. 2 have the same meaning. That is, as shown in FIG. 2, two pumps are alternately operating one by one, and when the amount of water used further increases,
The pumps 4-1 and 4-2 of the table are operated at the same time. Pump 1
If the amount of water used exceeds Q3 while operating on a stand,
Since the operating speed N3 is the maximum speed, the water supply capacity is insufficient with one pump, and the water supply pressure decreases to HL. As a result, the CPU outputs an energizing signal to the relays 52X1 and 52X2 and also issues a command signal of speeds N1 and N2 to each inverter. Thus two inverters INV1, IN
Two electric motors 5-1 and 5-2 are simultaneously operated by V2, and two pumps 4-1 and 4-2 are operated in parallel.
After the parallel operation of the pumps, control is performed based on the signal of the pressure sensor 10 so that the feed water pressure is on the curve F.

In FIG. 3, when the amount of water used decreases, the operating speed changes from N4 to N3, and the water supply pressure becomes HH, one of the two units stops and the unit operates independently. As a publicly known example of these, Japanese Patent Publication No. Hei 5-231332 is referred to.

[0015]

The above-mentioned prior art has the following problems. That is, (1) In order to optimally control the two inverters according to the load, for example, in order to control the water supply pressure so as to be on a predetermined load characteristic curve even if the usage amount changes, the It is necessary to provide the control unit CU, the relay circuit unit R, and the like. Therefore, the cost of the control panel increases, and the size and weight also increase.

(2) In order to apply the conventional general-purpose inverter to a turbomachine such as a water supply system composed of multiple systems to operate the inverters alternately or in parallel, a high-level microcomputer or the like is installed above each inverter. It is necessary to provide a control device provided with the configuration to output a command to each inverter. If necessary, a sensor group for detecting an operating state, an abnormal state, and a load state of the turbomachine must be connected to this control device, which causes a problem that the system becomes highly complex. Further, in order to perform alternate operation or parallel operation, it is necessary to interlock the inverters with each other, detect these states, and output an operation command.

(3) The inverter has a built-in trip function for protecting the device from fluctuations in power supply and overload. Therefore, if this protection function operates, the turbomachine cannot be operated. Therefore, it is necessary to check the load condition of the turbomachinery and the abnormal condition of the inverter, and perform the retry operation if necessary.For this purpose, the control device that issues a command to each inverter above the inverter is also required. Will be needed.

(4) An indicator is provided on a control panel or the like, and the physical quantities such as operating condition, abnormal condition, etc., physical quantities such as pressure, frequency, etc. are displayed on this indicator, but the cost of this indicator is high, It is desired to reduce the cost of the device.

It is an object of the present invention to provide a dual inverter which does not require an external expensive control device provided on the upper side of each inverter, and is simple, compact, lightweight and low in cost.

[0020]

SUMMARY OF THE INVENTION The above object is to provide a dual inverter equipped with inverters corresponding to two turbomachines provided in parallel.
With a built-in microcomputer for driving and controlling in response the connected turbomachine self capture the load state detection value of the turbomachine to the load state detection value, are connected to each other by a signal line, via the signal line , Next to start
A priority flag that specifies the machine is connected to the turbomachine.
Write to the built-in inverter built-in memory
It is achieved by starting it .

[0021]

Since the microcomputer built in each inverter of the dual inverter composed of two identical inverters has the function of executing the control based on the sensor detection signal,
It is not necessary to provide a control device that supervises each inverter above each inverter. Moreover, since the respective inverters are connected by the signal wiring, the respective inverters can cooperate with each other to control through the signal wiring even without a host controller. Further, since the turbo machine control device and the inverter device themselves are provided with an indicator to display various information, the cost is reduced as compared with the case where the indicator is provided separately.

[0022]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram showing an example in which a turbo machine control device according to an embodiment of the present invention is applied to a water supply device, and the same components as those of the configuration of FIG. , Omit it. In FIG. 1, the control device C
NU is a leakage breaker ELB1, ELB2, inverters INV1, INV2, noise filters ZCL0, ZC
L1 and ZCL2 are provided. This is because the relay circuit unit R and the control device (both hardware and software) CU shown in FIG. 4 are incorporated in the above-described inverters INV1 and INV2.

That is, the inverters INV1 and INV2
Is the trip signal A of the earth leakage breakers ELB1 and ELB2.
L to terminal DI via signal line S1 or signal line S2
3 and DI4, flow switch FS1 or FS
2 signal FS1b or FS2b to signal line S4 or S
Input to the terminal FWCOM via the pressure sensor 9 and 1
0 signal through the signal lines S6 and S7 respectively to the terminal AN
Input to 0, AN1, and L. The pressure sensors 9 and 1
Since 0 is commonly used for the inverters INV1 and INV2, the both are connected by a signal line S8. Inverters INV1, INV2 terminals DI1, DI2, DO1, D
A signal line S3 is connected between O2 to exchange signals such as an operating state, a fault state, and an operating request. Furthermore, the signal line S
In 9 and S10, the failure state and the operating state of this device are output to a central monitoring panel or the like.

FIGS. 5 and 6 are flow charts for explaining the control procedure and the operating procedure of the dual inverter device constructed by connecting two inverter devices according to the embodiment of the present invention. Further, FIG. 7 shows the leakage breakers ELB1 and ELB.
2 trip operation, inverter INV1, INV2
3 is a timing chart for explaining the operation at the time of trip and the alternate operation operation.

FIG. 8 shows the panel surface of the inverter shown in FIG. 1 in detail. Reference numeral 13 denotes a display portion, which is composed of, for example, a 7-segment LED or liquid crystal. 14 is R
For example, a touch switch is used to instruct UN / STOP, that is, operation and stop. Reference numeral 15 denotes, for example, a touch switch when setting the driving condition, which indicates a command. 16, 17
Is a touch key for incrementing or decrementing an address when calling a memory write command. Reference numeral 18 is a data key for entering data, such as alphanumeric data, and 19 is a key for confirming a command operation. Reference numeral 20 is a display unit for explaining the state shown by the display unit 13, and is usually composed of a name plate.

FIG. 10 is a diagram for explaining the touch key function described above, and the function of each touch key is as follows. (1) Depress the command key "C" 15. As a result, the letter “C” lights up on the “a” of the display unit 13. (2) The memory address is designated by the alphanumeric key 18. As a result, the designated address is displayed in the “B” and “C” of the display unit 13. (3) Depress the confirm key "R" 19. As a result, the set value corresponding to the above (1) and (2) is displayed on the display unit 13 as “a”.
Default values are displayed in "b" and "c". (4) The default value displayed in (3) above can be corrected with the touch keys 15, 16, 17, 18, 19 as necessary.

FIG. 11 is a diagram showing a setting example of the inverter state quantity set in this way. Further, how to operate the inverter is also set according to the pump load characteristics shown in FIGS. In addition, which of the two inverters INV1 and INV2 is to be operated first is set in advance using this setting unit.

FIG. 9 shows an external output section S of the signal shown in FIG.
9 and S10 are shown in detail, for example, the inverter I
When NV1 and INV2 trip due to some trouble, the internal CPU outputs a signal of "H" to its output port 1.
As a result, the relay X1 is energized, and the signal terminals Kc and K0
An ON signal indicating a failure is output to. Similarly, the signal terminals Kc and K1 output, for example, a signal indicating a decrease in inflow pressure, and the signal terminals Kc and K2 output a signal, for example, indicating a discharge pressure decrease.

Next, the driving operation will be described in detail with reference to FIGS. Earth leakage breaker ELB1, shown in FIG.
When ELB2 is turned on, inverters INV1, INV2
When the power source is established (see steps 501 to 503 in FIG. 5), the display unit 13 displays, for example, “000”.
In step 504 of FIG. 5, it is confirmed whether or not the key switch 14 is pressed. If NO, the process proceeds to step 505,
If YES, go to step 506. The key switch 14 is a RUN / STOP (run / stop) command switch, and means a run command at the first time and a stop command when pressed again. In step 506, the key switch 15
Press to confirm whether the above-mentioned various conditions such as operating conditions are set. As a result of the confirmation, if it is set, the process proceeds to step 508, and if not, the process proceeds to step 505. In steps 505 to 507, the various settings described above are performed.

Further, in this example, the priority operation flag PR10F is set to OFH (in this case, H is 1
It means a hexadecimal number. ) And Unit 2 is set to 00H (artificial setting). Thereafter, the process proceeds to step 508, and the interrupt processing routine shown in FIG. 6 is permitted.

In the interrupt processing INT0 shown in FIG. 6A, the internal state is checked as shown in steps 601 to 604, and if the earth leakage breakers LB1 and ELB2 are in the trip state, or if the inverters INV1 and INV2 are in the trip state.
If is a trip state, the operable flag is reset in step 607. If these are normal but not tripped, set the operable flag in 609 steps,
If it is in the trip state, the operation is stopped in step 608 and the corresponding process is executed. Furthermore, 603 to 605
In the step, it is judged whether or not there is a parallel operation request, and if the parallel operation request is made, the priority operation flag PR10F is set to 01F.
, And otherwise mask 01H.

In the interrupt processing INT1 shown in FIG. 6 (b),
Check the inverter internal state quantity (see step 612: measure voltage, power supply, pressure, frequency and display on the display according to the command. Detailed display contents are shown in Fig. 8) and check the input / output ports (See step 613:
The input / output terminals DI1 to D04 are monitored and the data is stored in the memory), and the signals of each sensor are checked (see step 614: AN0, AN1, L, etc. are monitored and the data are stored in the memory).

Returning to FIG. 5, in step 509, it is determined which inverter or pump is set as the starter. For example, the inverter INV1 is a priority machine (priority operation flag PR10F is set to 0FFH) and the inverter INV2 is a non-priority machine (priority operation flag PR10F is set to 00H) when the power is initially turned on. (0FFH has priority, 01H requests parallel operation, and 00H follows). As a result of this determination, the inverter INV1 is set as the starting machine (because the priority operation flag PR10F in FIG. 5 is in the state of 0FFH, which will be described in detail later), the process proceeds to the next step 510. Inverter IN
Since the flag state is 00H, V2 waits in 509 steps until it becomes 0FFH.

In the inverter INV1, if the pressure signal detected by the pressure sensor 10 in step 510 is less than the starting pressure H0N shown in FIGS. 2 and 3, the process proceeds to step 511, in which the inverter INV1 and the pump 4-1 are operated. To start. Thereafter, the operation according to the load fluctuation is continued under the load condition set in the inverter in step 505 (51
2,513 steps).

When the amount of water used decreases from such a state, the small amount of water detecting means (the load current inside the inverter, the flow switch FS1 or FS2, etc.) operates. Therefore, in the next step 514, it is determined whether or not the small water amount detecting means detects the small amount of water, that is, if it is a flow switch, it is turned off. As a result of the determination, if the amount of water is small and the pump stop condition is established (taking into account the suppression of the start frequency, it is determined whether or not the stop condition is established by taking several minutes). Stop processing is executed in step 515. After this, 509
The process returns to the step and the subsequent processing is repeated.

By the way, as shown in FIG. 3, when the amount of water used increases to Q3 or more, it is no longer possible to meet the demand demand by operating one pump. In this state, a two-unit parallel operation request signal is generated. That is, 60 in FIG.
In step 3,605, the priority operation flag PR10F is set to 01.
Set to H. In FIG. 3, the parallel operation request condition is, for example, a case where the inverter operation speed is suitable for the maximum speed N3 and the water supply pressure reaches HL or less, and the parallel operation request cancellation condition is the minimum inverter operation speed. Reaching speed N4,
This is the case where the water supply pressure reaches HH or higher, and in this case, 01H of the priority operation flag PR10F is masked.

When such a parallel condition is satisfied, the inverter INV2 set as the follower determines in step 509 that the priority operation flag PR10F is 0.
It is 1H, and after the following 510 steps, the inverter INV2 and the pump 4-2 are started in the manner described above, and the parallel operation is performed. After parallel operation, both inverters INV1, I
NV2, pumps 4-1, 4-2, and motor 5-1,
5-2 is stopped when the stop conditions are established in steps 512 to 513 described above.

Next, using the time chart of FIG.
The alternate operation and the operation at the time of abnormality will be described. At time 1 in FIG. 7, since there is only one operation request signal and the operation priority is the No. 1 machine, the inverters INV1 and No. 1 pump 4-1 are operated, and among the signals S3, the D01 is changed to the inverter INV2. To the inverter INV1 to declare that it is in operation. The inverter INV2 receives this signal at the terminal DI1 and outputs an answer-back signal (that the inverter INV2, No. 2 pump 4-2 is not in an operable state) from the terminal D01 to the inverter INV1. The inverter INV1 receives this signal at the terminal DI1.

Between times 2 and 3, there is no operation request signal, and the inverter and pump are stopped. At this time, the driving priority flag PR10F of the inverter INV1 is set to 00H, the driving state signal D01 is set to L, and the inverter INV2 is set.
The driving priority flag PR10F is set to 0FFH, and the driving state signal D01 is set to L.

Next, when an operation request signal is input at time 3, the inverter I whose operation priority flag PR10F is 0FFH
The NV2, No. 2 pump 4-2 is in operation, and D01 is set to H indicating that it is in operation, and output to the inverter INV1. In this way, signals are exchanged between the inverter INV1 and the inverter INV2, and the alternating operation is performed.

Next, between the times 5 and 6, the inverter INV is
Consider a case where the inverter or the earth leakage breaker trips while the No. 1 and No. 1 pumps 4-1 are operating. When the inverter trips, the inverter INV1 immediately stops, and outputs a signal that sets the operation status signal D01 to L, the failure status signal D02 to H, and the operation priority signal PR10F to 00H. Also, in addition, a timer RE for failure determination of the inverter INV1
Starts SC1, t0 seconds, and forced stop timer RE at failure
Start ST1, t1 seconds. In response to these signals, the inverter INV2 sets the operation priority signal PR10F to 0FFH.
The driving state signal is set to D01 and the driving is started.

At time 6, the operation request signal disappears, the inverter INV2 stops, and the operation state signal D01 becomes L. At time 7, the operation request signal is issued again, but the above-mentioned forced stop timer RES when the inverter INV1 fails
Since the failure status signal D02 of the inverter INV1 is in the H state while T1 and t1 seconds are being timed, the inverter INV2 is restarted.
Will drive.

Between times 7 and 8 the above-mentioned inverter IN
V1 failure forced stop timer REST1, t1 seconds are timed, and failure status signal D02 goes from H to L. At time 8, the inverter INV2 stops and the driving priority flag PR1
0F is set to 00H, and on the contrary, the inverter INV1 sets this signal to 0FFH. At the time of operation request at time 9, the inverter INV1 operates. After that, when the inverter INV1 fails, the above-mentioned signal is emitted and stopped, the forced stop timer REST1 is activated again, and the timing of t1 seconds is started,
Switch to the operation of the inverter INV2. Below, time 1
The above operation is repeated until 1.

There is an operation request at time 11, and the inverter I
When the NV1 operates and also trips after the operation, the forced stop time t1 ends at time 12, and a failure of the inverse INV1 occurs for 3 cycles in t0 seconds of the failure determination timer RESC1.
NV1 is regarded as a failure and is in an inoperable state, the operation status signal D01 is L, the failure status signal D02 is H, and the operation priority flag PR10F is 00H. In addition, E01 is displayed on the display unit of FIG. 8, a signal of H is output to the output port 1 of the CPU shown in FIG. 9, the relay X1 is energized, and K is output to the outside.
The fault signal of c and K0 is emitted. After this, only Unit 2 will be operated.

Incidentally, if the operation / fault of the inverter is retried three times within t0 seconds of the fault judgment timer RESC1, it is regarded as a fault, and as indicated by a broken line at time 11 in FIG.
If it returns to normal, that is, if it returns to normal after less than 3 retries, it is not considered as a failure and the operation can be continued.
The failure mentioned here means a trip of the earth leakage breakers ELB1 and ELB2 and a trip of the inverters INV1 and INV2, but FIG. 7 shows an example of the inverter trip.

The trip of the earth leakage breakers ELB1 and ELB2 will be described below. When the No. 1 earth leakage breaker ELB1 trips, the main power source of the circuit breaker ELB1 is turned off and the alarm signal S1 is input. The control power of the inverter INV1 is supplied to the terminals R1 and R2 via the circuit protector CP1. Based on the alarm signal S1, the operation status signal D01 is L and the failure status signal D02 is H.
And the driving priority signal PR10F is set to 00H. Further, the operation during parallel operation of the pumps will be described as follows. In FIG. 7, when the inverter INV1 is operating at time 13 and the two-vehicle operation request signal is output at time 14, the operation priority flag PR10F of the inverter INV2 is set to 01H.
And Then, the processes after step 509 in FIG. 5 are executed to operate the inverter INV2, and the operation state signal D
A signal in which 01 is H is emitted.

Next, with reference to FIG. 1 and FIG. 9, other measures in case of failure will be described. When the pressure of the water supply pipe 1 falls below a specified value (usually 1 to 3.5 kgf / cm ² , pipe rupture or construction water interruption, for example, 0.5 kgf / cm ² or less) The pressure sensor 9 installed on the side detects this. At this time, the inverter I
The NV1 and the inverter INV2 detect this state by the signals S6 and S8, and the inverters INV1, INV
When 2 is stopped and the water supply pipe pressure returns to the specified value or higher, both inverters can be operated.

In the same manner, when the pressure on the pump discharge side becomes equal to or lower than a prescribed value (for example, it drops to 50% or less of the pressure desired by the water supply system due to biting of the pump air), the pressure sensor 10 detects this ( Inoperable state), signal S7,
By S8, the inverters INV1 and INV2 are stopped, and both inverters can be operated after returning to the specified value or more. Then, in this abnormal state, that is, when the suction side pressure decreases, E02 is displayed on the display unit, the H signal is issued from the output port 2 of FIG. 9, the relay X2 is energized, and the external Kc and K1 Output a signal. When the discharge side pressure drops, E03 is displayed on the display and H is displayed on the output port of FIG.
Send a signal to energize relay X3 and signal K to the outside.
c, K2 are output.

The dual inverter according to the embodiment of the present invention described above will be briefly described below. For the external installation of the inverter, the higher-level advanced control device that was conventionally used and the relay circuit part are housed inside the inverter (most are replaced with microcomputer software inside the inverter). , Inverter with dual configuration. Each inverter has a CPU and a storage unit inside, and a display unit and a setting unit are provided on its panel surface. Further, the two inverters are connected by a signal line for transmitting an operating state and a fault state, and are configured to exchange signals with each other. Further, these inverters are set in advance by a setting unit to set how to operate the inverters or load operation patterns, and to set which one is to be operated first. In this way, alternate and parallel operation, retry at the time of abnormality and backup operation can be performed.

Further, the operating state and the fault state are displayed on the display section of the inverter. In particular, pressure, current, frequency, voltage, etc. are displayed as error codes for the details of failures. Further, the pressure sensor for detecting the suction side pressure state and the load state can be shared by the two inverters.

The earth leakage breaker is designed to protect the main circuit from short-circuiting and to prevent leakage on the secondary side, cut off the main circuit, and connect the signal line to the inverter. The inverter drives the turbomachine and is constituted by a complete duplex system, and directly takes in signal lines of a pressure sensor for detecting a load state, an underload state detecting means, and a suction side pressure sensor. Each inverter is equipped with microcomputer software that describes a control method and procedure in advance. At the beginning of use, when the earth leakage breaker is turned on, the power supplies of both inverters are established, and the one set as a priority machine in advance stands by for operation.

When the pressure sensor for detecting the load state detects the preset starting pressure, the inverter on standby is started. The sensor that detects the underload condition detects this, and when the preset stop condition is established, the inverter is stopped, and the inactive inverter is made operable by the stop signal of the preceding machine and started in the same manner as described above. , Stop. Furthermore, if the pressure sensor that detects the load state detects the preset parallel operation pressure state,
Inverters that are not in operation are ready for operation and operate in parallel.

Further, when the earth leakage breaker trips or the inverter trips, this state is transmitted to each other by a signal line connecting both inverters, stopping the abnormal side and switching to the other side, generating an internal signal and retrying. . Further, this state is displayed by an error code on the panel display section of the inverter, and a signal is issued to the outside. In addition, the display unit is used to display the values of pressure, current, voltage and frequency.

Thus, according to the embodiment of the present invention, 2
Since the control circuit, operation procedure, and control contents are stored in the inverter of the stand, alternate operation or alternate / parallel operation can be performed without the need for an external relay circuit unit and higher-level advanced control device There is an effect that the device is simplified, small-sized and lightweight, and low cost can be realized. Further, since the number of parts is reduced, reliability is improved.

Further, the main circuit is short-circuited and short-circuited by an earth leakage breaker, and other fault conditions on the load side are monitored by the inverter itself due to changes in the internal state quantity of the inverter. Switching operation is possible. Further, since the priority machine can be externally set in advance by the inverter, the operation sequence is not disturbed (at the time of restoration from power failure, etc.). Furthermore, since the retry operation at the time of failure is added, there is an effect that the failure state can be detected reliably.

Furthermore, since the operating status and the failure status are displayed using the display section of the inverter, it is possible to realize a simple and low cost. Furthermore, since the pressure sensor for detecting the load state and the pressure sensor for detecting the suction side pressure can be shared by the two inverters, it is simple and inexpensive. Furthermore, since the failure backup is taken by the system configuration of the complete multiplex system (double system in the embodiment),
There is an effect that the reliability can be further improved.

[0057]

According to the present invention, signals can be transmitted and received between a plurality of inverters so that they can be operated in cooperation with each other. Therefore, an external control device is not required, and the device is simple, compact, lightweight, and low in cost. It can be done.

[Brief description of drawings]

FIG. 1 is a configuration diagram in which a turbo machine control device according to an embodiment of the present invention is applied as a water supply device.

FIG. 2 is an operation characteristic diagram when the pumps are operated individually or alternately.

FIG. 3 is an operation characteristic diagram during parallel operation of two pumps.

FIG. 4 is an overall configuration diagram of a conventional water supply system.

5 is a flowchart showing an operating procedure of the turbomachine controller shown in FIG.

6 is a flowchart showing a control method of the turbomachine controller shown in FIG.

FIG. 7 is a timing chart showing the control operation of the dual inverter.

FIG. 8 is a detailed view of a display unit and a setting unit of the inverter.

FIG. 9 is an external output circuit diagram showing a failure state of the inverter.

FIG. 10 is a functional explanatory diagram of an inverter display unit and a setting unit.

FIG. 11 is a diagram showing a setting example of an inverter internal state quantity.

[Explanation of symbols]

4-1 and 4-2 ... Pumps and 5 that are turbomachines, respectively
-1, 5-2 ... Motor, FS1, FS2 ... Underload detection means, ELB1, ELB2 ... Earth leakage breaker, INV1,
INV2 ... Inverter.

Front page continued (72) Inventor Takayuki Oshiga 7-1-1 Higashi Narashino, Narashino City, Chiba Prefecture Industrial Equipment Division, Hitachi, Ltd. (72) Inventor Hiroshi Kunii 7-1-1 Higashi Narashino, Narashino City, Chiba Stocks Company Hitachi, Ltd. Industrial Equipment Division (72) Inventor Tsunehiro Endo 7-1-1 Higashi Narashino, Narashino City, Chiba Prefecture Hitachi Industrial Equipment Division (72) Inventor Toshi Honma 7-1-1 Higashi Narashino, Narashino City, Chiba Prefecture No. 1 Hitachi Industrial Co., Ltd. (56) References JP-A-6-261596 (JP, A) JP-A-3-93494 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H02P 7/74 F04D 15/00 H02M 7/48

Claims (7)

(57) [Claims] 1. A dual inverter having an inverter corresponding to each of two turbomachines provided in parallel, wherein each inverter fetches a load state detection value of the turbomachine and connects the turbomachine connected to itself to the load. with a built-in microcomputer for driving and controlling in response to the state detection value, are connected to each other by a signal line, via the signal line, the following
The priority flag that specifies the turbo machine to
Write to memory with built-in inverter connected to robot machine
A dual inverter characterized by activating the turbomachine . 2. A have your <br/> dual inverter of claim 1, wherein a water supply pump with the turbomachine motor, load state detection value, the suction side of the pressure detection value of the water supply pump Or a dual inverter characterized in that it is a pressure detection value on the discharge side. 3. A have your <br/> dual inverter according to claim 1, wherein it is a water supply pump with the turbomachine motor, load state detection value is the flow rate detection value for each water supply pump A dual inverter featuring. 4. The device according to any one of claims 1 to 3.
In Interview al inverter, dual inverter, characterized in <br/> be operated or parallel operation alternately turbomachine two above. 5. A device according to any one of claims 1 to 4.
In the dual inverter , priority is given to the turbomachinery that starts first after the power is turned on.
In the inverter where the flag was previously connected to the turbomachine
A dual inverter, which is set in the memory of the warehouse . 6. The device according to any one of claims 1 to 5.
In the dual inverter , each microcomputer fetches the load state detection value and
A dual inverter that features load control calculation processing independent of the microcomputer . 7. The device according to any one of claims 1 to 6.
In Interview al inverter, dual inverter, characterized in that it comprises a display unit for performing fault indication when a fault occurs.