JPH102293A - Dual inverter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide simplified, small-sized, lightweight dual inverters at low cost by eliminating an expensive externally mounting control device provided on the host side in a plurality of inverters which control a plurality of turbo machines. SOLUTION: Two sets of inverters INV1, INV2 respectively corresponding to two sets of turbo machines 5-1, 5-2 provided in parallel are provided, each inverter is built in with a microcomputer fetching a load condition detection value of the turbo machines 5-1, 5-2 to drive control the self connected turbo machines 5-1, 5-2 in accordance with the load condition detection value. Accordingly, the machine is connected to each other by a signal wire S3, each operating condition is connected to each other through the signal wire S3, whether operation is right or not of each inverter INV1, INV2 is determined.

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 turbo machines.

[0002]

2. Description of the Related Art In a turbomachine such as a turbo-type pump or a turbo-type blower, a water supply amount and an air amount are proportional to an operation speed, a water supply pressure and a wind pressure are proportional to a square of the operation speed, and these mechanical outputs are operated. It is proportional to the cube of speed. This indicates that the operation speed can be reduced with a reduction in the load, and there are merits such as energy saving.

Conventionally, a plurality of inverters have been used to control the speed so that the pressures on the discharge sides of a plurality of turbomachines maintain a certain fixed relationship. Is controlled.

When a plurality of turbo machines are driven by a plurality of inverters to control the speed and the number of operating units, it is possible to relatively easily and efficiently control the water supply, air volume, water supply pressure, wind pressure, etc. according to the load fluctuation. . For this reason, it is considered that the speed control by the increasing number of inverters will spread 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 configuration diagram of a water supply device, 1 is a water supply pipe,
2-1 and 2-2 are branch pipes of water distribution 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 for detecting the pressures on the pump suction side and the pump discharge side, respectively, and emit electric signals corresponding to the pressures of the detection units.

FS1 and FS2 are flow switches,
This is a flow switch that is turned on when the amount of water is too small QS shown in FIGS. 2 and 3 described later. CNU is a control device, and an inverter INV that drives the motors 5-1 and 5-2 at a variable speed.
1, INV2 and earth leakage breaker ELB1,
It comprises a power circuit section composed of ELB2, 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 signals (analog amounts) from the pressure sensors 9 and 10 into digital signals, and a water supply system for supplying desired inverter speed command signals to the inverters INV1 and INV2. D / A for 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-described relays 52X1 and 52X2 are provided.

Similarly, the controller CU is shown in FIG.
An input port PIO-2 for reading a set value set by the setting means C so as to operate according to the operation characteristics of the pump shown in FIG. 3, and a contact which 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, INV
Contact I that operates when V2 trips due to overload or the like
An input port PIO-3 for reading the status of NVAL1 and INVAL2 is provided. That is, the CPU stops the pump in response to these failure states, switches to the other pump that is inactive, and instructs the pump to operate, 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. The vertical axis indicates the pressure H, and the horizontal axis indicates the pressure. The amount of water Q is shown. Curve A is a QH performance curve when the pump is driven by the inverter at the operation speed N3, that is, 100% operation speed. Similarly, curves B, C, and D are QH performance curves when the pump is driven at operating speeds of N2, N1, and N0, respectively.

A curve F is a pipeline resistance curve. For example, when the used water amount changes from the water amount Q1 to the water amount Q0, if the water is supplied at a pressure higher than the curve F on the discharge side of the pump, a desired water flow at the terminal faucet is obtained. It shows that pressure can be obtained.
The 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 based on the console CO
Set externally 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, the earth leakage breakers ELB1, EB
When the LB2 is turned on and the control power circuit breaker CB is turned on, the power of the controller CU is established, and the CPU performs initial setting based on a program stored in the memory M in advance, and reads setting information from the setting means C. , The state of the inverter and the earth leakage breaker (no failure) are read from the input port PIO-3, and the pressure sensors 9 and 1 are read.
The signal of 0 is read via the A / D converter. The feedwater pressure corresponds to a change in the operation speed, and stores, for example, a pipeline resistance curve F as load operation control. Thus, the operation preparation is completed.

In this state, when the consumer uses water, the supply water pressure drops. When the water supply pressure drops below the starting pressure HON shown in FIG. 2, the CPU connects the interface I / I via the output port PIO-1. A signal for energizing the relay 52X1 is output, and a signal of the operating speed N1 is output to the inverter INV1 via the D / A converter. Thus, 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 as to be 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 cancels the speed command signal N1 to the inverter INV1 that is currently being output. As a result, the pump 4-1 stops. When the water is used again and the water supply pressure becomes equal to or less than the water supply pressure HON and the starting condition is established, the relay 52
An energizing signal of X2 and a signal of the operating speed N2 are issued, and the other inverter INV2 is driven this time, and the motor 5-2 is driven.
Is driven, and the pump 4-2 starts operating. Thereafter, similarly, the switching control is performed and the alternate operation is performed.

FIG. 3 is a characteristic diagram when two pumps are operated in parallel, and those indicated by the same reference numerals as those in FIG. 2 have the same meaning. That is, as shown in FIG. 2, two pumps are operated alternately one by one, and when the amount of water used further increases, the two pumps are operated.
Pumps 4-1 and 4-2 are simultaneously operated. Pump 1
When the amount of water used becomes Q3 or more while driving on a stand,
Since the operating speed N3 is the highest speed, the water supply capacity is insufficient with one pump, and the water supply pressure drops to HL. As a result, the CPU outputs an energizing signal to the relays 52X1 and 52X2 and issues command signals for the speeds N1 and N2 to each inverter. Thus, two inverters INV1, INV
The two motors 5-1 and 5-2 are simultaneously operated by V2, and the two pumps 4-1 and 4-2 are operated in parallel.
After the parallel operation of the pumps, control based on the signal of the pressure sensor 10 is performed so that the feed water pressure is on the curve F.

In FIG. 3, when the amount of water used decreases, the operation speed changes from N4 to N3, and when the supply water pressure becomes HH, one of the two units stops and operates alone. Japanese Patent Publication No. 5-231332 is a reference for these known examples.

[0015]

The above-mentioned prior art has the following problems. That is, (1) To optimally control the two inverters according to the load, for example, to control the feed water pressure to be on a predetermined load characteristic curve even when the usage amount fluctuates, It is necessary to provide a control unit CU, a relay circuit unit R, and the like. Therefore, the cost of the control panel is increased, and the size and weight are increased.

(2) In order to apply the conventional general-purpose inverter to a turbomachine such as a water supply device configured as a multiplex system and to alternately or parallel operate the inverters, a high-level microcomputer or the like higher than each inverter is required. It is necessary to provide a control device provided to output a command to each inverter. If necessary, a sensor group for detecting the operating state, abnormal state, and load state of the turbomachine must be connected to this control device, and there is a problem that the system becomes highly complicated. Further, in order to perform the alternate operation and the 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 to protect the device from power fluctuations and overload. For this reason, when this protection function operates, the turbo machine cannot be operated. Therefore, it is necessary to check the load state of the turbomachine and the abnormal state of the inverter and perform a retry operation if necessary. For this reason, a control device that issues a command to each inverter higher than the inverter is required. Required.

(4) An indicator is provided on a control panel or the like, and state quantities such as an operating state and an abnormal state, and physical quantities such as a pressure and a frequency are displayed on the indicator. However, the cost of the indicator increases. It is desired to reduce the cost of the device.

An object of the present invention is to provide a dual inverter that does not require an expensive external control device provided above each inverter, and that is simple, small, lightweight, and low in cost.

[0020]

An object of the present invention is to provide a dual inverter including two turbomachines provided in parallel, each having an inverter corresponding to each of the two turbomachines.
The microcomputer incorporates a microcomputer that takes in the load state detection value of the turbo machine and drives and controls the turbo machine connected thereto according to the load state detection value, and is connected to each other by signal wiring and each through the signal wiring. This is achieved by a configuration in which the operating states of the inverters are communicated to determine whether each inverter can be operated.

[0021]

[Function] Because a microcomputer built in each inverter of a dual inverter composed of two identical inverters has a function of executing control based on a sensor detection signal,
There is no need to provide a control device for controlling each inverter above each inverter. Moreover, since the inverters are connected by signal wiring, the inverters can cooperate and control through the signal wiring without a higher-level control device. Furthermore, since the turbomachine control device and the inverter device are provided with a display to display various kinds of information, the cost is reduced as compared with the case where a separate display is provided.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One 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 turbomachine control device according to an embodiment of the present invention is applied to a water supply device, and the same reference numerals are given to the same components as those in FIG. , Its omission. In FIG. 1, the control device C
NU is an earth leakage breaker ELB1, ELB2, inverter INV1, INV2, noise filter 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 inverters INV1 and INV2 described above.

That is, the inverters INV1, INV2
Is the trip signal A of the earth leakage breakers ELB1 and ELB2.
L to the terminal DI via the signal line S1 or the signal line S2.
3, DI4 and flow switch FS1 or FS
2 signal FS1b or FS2b to the signal line S4 or S4
5 to the terminal FWCOM and the pressure sensors 9 and 1
0 signal to terminals AN via signal lines S6 and S7, respectively.
0, AN1, and L are input. The pressure sensors 9 and 1
0 is commonly used by the inverters INV1 and INV2, so that both are connected by a signal line S8. Terminals DI1, DI2, DO1, D of inverters INV1, INV2
O2 is connected by a signal line S3 to exchange signals such as an operation state, a failure state, and an operation request. Further, the signal line S
Steps S9 and S10 output the failure state and operation state of the apparatus to a central monitoring panel and the like.

FIG. 5 and FIG. 6 are flowcharts for explaining the control procedure and operation procedure of a dual inverter device constructed by connecting two inverter devices according to one embodiment of the present invention. FIG. 7 shows the earth leakage breakers ELB1 and ELB.
2, trip operation, inverters INV1, INV2
4 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 unit, which is composed of, for example, 7-segment LEDs or liquid crystal. 14 is R
UN / STOP, that is, a touch switch in the case of instructing operation and stop. Reference numeral 15 denotes, for example, a touch switch for setting operating conditions, and indicates a command. 16,17
Is a touch key for incrementing or decrementing an address when a memory write command is called. Reference numeral 18 denotes a data key for inputting data, for example, alphanumeric characters, and 19 denotes a key for confirming a command operation. Reference numeral 20 denotes a display unit for explaining a state indicated by the display unit 13, which is usually constituted by a nameplate.

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

FIG. 11 is a diagram showing an example of setting the inverter state quantities set in this way. Further, how the inverter is operated is set in accordance with the pump load characteristics shown in FIGS. In addition, which of the two inverters INV1 and INV2 is operated first is set in advance using this setting unit.

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

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

In this example, the first machine is set as the priority machine and the priority operation flag PR10F is set to OFH (in this case, H is 1).
Means hexadecimal. ) 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. If the leakage breakers LB1 and ELB2 are in the trip state, or if the inverters INV1 and INV2
If is in a trip state, the operable flag is reset in step 607. If these are not trip states but normal, set the operable flag in step 609,
If it is in a trip state, it stops at step 608 and executes processing corresponding to this. Further, 603 to 605
In the step, it is determined whether or not there is a parallel operation request. If the request is a parallel operation request, the priority operation flag PR10F is set to 01F.
, Otherwise 01H is masked.

In the interrupt processing INT1 shown in FIG.
Inverter internal state quantity (refer to step 612: measurement of voltage, power supply, pressure, and frequency and display on the display unit according to the command. Detailed display contents are shown in FIG. 8) and check of input / output ports (Refer to step 613:
It monitors the input / output terminals DI1 to D04 and stores the data in the memory) and checks the signals of the sensors (see step 614: monitor AN0, AN1, L, etc. and stores the data in the memory).

Returning to FIG. 5, in step 509, it is determined which inverter or pump is set as the starting machine. For example, the inverter INV1 is a priority unit (priority operation flag PR10F is set to 0FFH) at the initial power-on, and the inverter INV2 is a non-priority unit (priority operation flag PR10F is set to 00H). (0FFH has priority, 01H is parallel operation request, 00H follows). As a result of this determination, the process proceeds to the next step 510, with the inverter INV1 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). Inverter IN
V2 waits at step 509 until the flag becomes 00H since the state of the flag is 00H.

If the pressure signal detected by the pressure sensor 10 in step 510 is equal to or lower than the starting pressure H0N shown in FIGS. 2 and 3, the process proceeds to step 511, where the inverter INV1 and the pump 4-1 are turned on. Start. Hereinafter, the operation according to the load fluctuation is continued under the load condition set for the inverter in step 505 (51).
2,513 steps).

When the amount of used water decreases from such a state, the low water amount detecting means (such as the load current inside the inverter or the flow switch FS1 or FS2) operates. Therefore, in the next step 514, it is determined whether or not the low water amount detecting means detects the low water amount, that is, whether or not the flow switch is OFF if it is a flow switch. As a result of the determination, if the amount of water is small and the stop condition of the pump has been established (it is determined whether or not the stop condition has been established over a period of several minutes in consideration of suppression of the start frequency). The stop processing is executed in step 515. After this, 509
Returning to the step, the subsequent processing is repeated.

By the way, as shown in FIG. 3, when the amount of water used is increased to Q3 or more, it is no longer possible to operate one pump to meet the demand. In this state, a two-unit parallel operation request signal is generated. That is, 60 in FIG.
Priority operation flag PR10F is set to 01 in 3,605 steps
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 feedwater pressure has reached HL or less. Reaches speed N4,
This is the case where the feed water pressure has reached HH or higher. 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 becomes 0.
At 1H, the inverter INV2 and the pump 4-2 are started in the manner described above after the next 510 steps, and the operation is performed in parallel. After the parallel operation, both inverters INV1, I
NV2, pumps 4-1 and 4-2, and motor 5-1
Step 5-2 stops 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, the number of operation request signals is one, and the operation priority is on the first unit. Therefore, the inverters INV1 and No. 1 pump 4-1 operate, and D01 of the signal S3 is changed to the inverter INV2. To declare that the inverter INV1 is operating. Inverter INV2 receives this signal at terminal DI1, and outputs an answerback signal (inverter INV2, No. 2 pump 4-2 is not in an operable state) from terminal D01 to inverter INV1. Inverter INV1 receives this signal at terminal DI1.

There is no operation request signal between times 2 and 3, and the inverter and the pump are stopped. At this time, the operation priority flag PR10F of the inverter INV1 is set to 00H, the operation state signal D01 is set to L, and the inverter INV2
Is set to 0FFH, and the operation 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 is set.
The NV2, No. 2 pump 4-2 is operated, and D01 is set to H to indicate that the pump is operating, and is output to the inverter INV1. In this way, signals are exchanged between the inverter INV1 and the inverter INV2, and alternate operation is performed.

Next, between times 5 and 6, the inverter INV
Consider a case where the inverter or the earth leakage breaker trips while the No. 1 and No. 1 pump 4-1 is operating. Upon tripping, the inverter INV1 immediately stops, and issues a signal that sets the operation state signal D01 to L, the failure state signal D02 to H, and sets the operation priority signal PR10F to 00H. In addition, a timer RE for determining a failure of the inverter INV1 is also provided.
Start SC1, t0 seconds, and forcibly stop timer RE in case of failure
Start ST1 and t1 seconds. In response to these signals, the inverter INV2 sets the operation priority signal PR10F to 0FFH.
And the operation is started with the operation state signal D01 set to H.

At time 6, the operation request signal disappears, the inverter INV2 stops, and the operation state signal D01 is set to L. At time 7, the operation request signal is issued again.
Since T1 and t1 seconds are counting and the failure state signal D02 of the inverter INV1 is in the H state, the inverter INV2 is again activated.
Drives.

Between time 7 and time 8, the inverter IN
The failure forced stop timer REST1, t1 seconds of V1 ends counting, and the failure state signal D02 changes from H to L. At time 8, the inverter INV2 stops, and the operation priority flag PR1
0F is set to 00H, and the inverter INV1 sets this signal to 0FFH. At the time of the operation request at time 9, the inverter INV1 operates. Thereafter, when the inverter INV1 breaks down, the above-mentioned signal is emitted and stopped, the forced stop timer REST1 is started again, and time measurement for t1 seconds is started,
The operation is switched to the operation of the inverter INV2. Hereafter, time 1
The above operation is repeated up to 1.

At time 11, an operation request is issued, and inverter I
When the NV1 operates and trips after the operation, the forced stop time t1 ends at time 12, and three cycles of the failure of the inverse INV1 occur in t0 seconds of the failure determination timer RESC1.
NV1 is regarded as a failure and the operation is disabled, the operation state signal D01 is set to L, the failure state signal D02 is set to H, and the operation priority flag PR10F is set to 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.
A failure signal of c and K0 is issued. After this, the operation of only Unit 2 is performed.

It should be noted that if the operation / failure of the inverter is retried three times within t0 seconds of the failure determination timer RESC1, it is regarded as a failure, and as shown by the broken line at time 11 in FIG.
If it returns to normal, that is, if it returns to normal after less than three retries, it is possible to continue the operation without causing a failure.
Here, the fault means a trip of the earth leakage breakers ELB1 and ELB2 and a trip of the inverters INV1 and INV2. FIG. 7 shows an example of the inverter trip.

The trip of the earth leakage breakers ELB1 and ELB2 will be further described as follows. When the No. 1 earth leakage breaker ELB1 trips, its main power is turned off, and the alarm signal S1 is turned on. 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 state signal D01 is set to L, and the failure state signal D02 is set to H.
And the operation priority signal PR10F is set to 00H. Further, the operation during the pump parallel operation will be described as follows. In FIG. 7, when the inverter INV1 is operating at time 13 and a two-unit operation request signal is output at time 14, the operation priority flag PR10F of the inverter INV2 is set to 01H.
And Then, the processing after step 509 in FIG. 5 is executed, the inverter INV2 operates, and the operation state signal D
A signal with 01 as H is issued.

Next, referring to FIG. 1 and FIG. 9, another countermeasure at the time of failure will be described. When the pressure of the water distribution pipe 1 becomes lower than a specified value (usually 1 to 3.5 kgf / cm 2, which causes a rupture of the pipe or a break in construction, for example, a state where the pressure drops to 0.5 kgf / cm or less), the pump suction side The installed pressure sensor 9 detects this. At this time, the inverter I
The NV1 and the inverter INV2 detect this state based on the signals S6 and S8, and the inverters INV1 and INV2 detect the state.
2 is stopped, and when the water distribution pipe pressure returns to the specified value or more, both inverters can be operated.

In the same manner, when the pressure on the pump discharge side becomes equal to or less than a specified value (for example, reduced to 50% or less of the pressure desired by the water supply system due to pump air biting), the pressure sensor 10 detects this ( The operation disabled state), the signal S7,
In S8, the inverters INV1 and INV2 are stopped, and when they return to the specified value or more, both inverters can be operated. Then, when this abnormal state, that is, when the suction side pressure is reduced, E02 is displayed on the display unit, an H signal is issued from the output port 2 of FIG. 9, the relay X2 is energized, and Kc and K1 are externally connected. Output a signal. When the discharge side pressure decreases, E03 is displayed on the display section, and H is displayed on the output port in FIG.
A signal is issued to activate the relay X3, and the signal K is output to the outside.
c and K2 are output.

The dual inverter according to the embodiment of the present invention described above will be briefly described as follows. Externally mounted inverter, a high-level advanced control device conventionally used, and a relay circuit section housed in the inverter (mostly replaced with microcomputer software in the inverter). The same inverter is composed of two units. , And a dual configuration inverter. Each inverter has a CPU and a storage unit inside, and a display unit and a setting unit are provided on a panel surface thereof. Further, the two inverters are connected by a signal line for transmitting an operation state and a failure state, and are configured to exchange signals with each other. Further, for these inverters, a setting unit sets in advance how the inverter is to be operated or the operation pattern of the load, and sets a priority machine which is operated first. In this way, alternate and parallel operation, retry at abnormal time, and backup operation can be performed.

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

The earth leakage circuit breaker protects the main circuit from short-circuit and the secondary side from earth leakage, shuts off the main circuit, and connects its signal line to the inverter. The inverter drives the turbomachine and is configured as a complete duplex system, and directly takes in signal lines of a pressure sensor for detecting a load state, an underload state detection unit, and a suction-side pressure sensor. Each inverter is equipped with microcomputer software describing a control method and a procedure in advance. When the earth leakage breaker is turned on at the beginning of use, the power of both inverters is established, and the one set in advance as a priority device waits for operation.

When the pressure sensor for detecting the load state detects a preset starting pressure, the standby inverter is started. A sensor that detects an underload condition detects this, and when a preset stop condition is established, the inverter is stopped, and the stopped inverter is made operable by the stop signal of the preceding machine, and started as described above. , Stop. Further, when the pressure sensor for detecting the load state detects the preset parallel operation pressure state,
The suspended inverters are set in an operable state and are operated in parallel.

Further, when the earth leakage breaker trips and the inverter trips, this state is transmitted to each other by a signal line connecting the two inverters, the abnormal side is stopped and switched to the other side, an internal signal is generated, and a retry is performed. . Further, this state is displayed by an error code on a panel display section of the inverter, and a signal is issued to the outside. In addition, the display unit is used to display 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 one inverter, it is possible to perform alternate operation or alternate / parallel operation without the need for an external relay circuit section and higher-level advanced control device. There is an effect that the device can be simplified, small and lightweight, and low cost can be realized. Furthermore, reliability is improved because the number of parts is reduced.

In addition, the short circuit and leakage of the main circuit are monitored by the leakage breaker, and the other failure states on the load side are monitored by the inverter itself due to the change of the internal state quantity of the inverter. Switching operation is possible. Further, since the priority unit can be set externally by the inverter in advance, the operation order is not disturbed (for example, at the time of power recovery). Furthermore, since the retry operation at the time of failure is added, there is an effect that the failure state can be reliably detected.

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

[0057]

According to the present invention, signals are transmitted and received between a plurality of inverters, and the inverters can be operated in a coordinated manner. Therefore, an external control device is not required, and a simple, compact, lightweight, and low cost device can be achieved. Can do.

[Brief description of the drawings]

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

FIG. 2 is an operation characteristic diagram when the pump is operated independently or alternately.

FIG. 3 is an operation characteristic diagram when two pumps are operated in parallel.

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

FIG. 5 is a flowchart showing an operation procedure of the turbomachine control device shown in FIG. 1;

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

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

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

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

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

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

[Description of References] 4-1 and 4-2: pumps each being a turbomachine, 5
-1, 5-2: motor, FS1, FS2: underload detection means, ELB1, ELB2: earth leakage breaker, INV1,
INV2: Inverter.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Kunii 7-1-1 Higashi Narashino, Narashino-shi, Chiba Industrial Equipment Division, Hitachi, Ltd. (72) Inventor Tsunehiro Endo 7-1-1 Higashi-Narashino, Narashino-shi, Chiba No. 1 in the Industrial Equipment Division of Hitachi, Ltd.

Claims (8)

[Claims] 1. A dual inverter having inverters respectively corresponding to two turbo machines provided in parallel, wherein each inverter takes in a load state detection value of the turbo machine and switches the turbo machine connected thereto to the load. It has a built-in microcomputer that drives and controls according to the state detection value, is connected to each other by signal wiring, communicates each operating state via the signal wiring, and determines whether each inverter can be operated. Dual inverter. 2. The turbocharger according to claim 1, wherein the turbomachine is a water supply pump with an electric motor, and the load state detection value is a suction side pressure detection value or a discharge side pressure detection value of the water supply pump. Features a dual inverter. 3. The dual inverter according to claim 1, wherein the turbomachine is a water supply pump with an electric motor, and the load state detection value is a flow rate detection value for each water supply pump. 4. The turbo engine according to claim 1, wherein a priority flag designating a turbo machine to be started next is written into a memory of a built-in inverter connected to the turbo machine via the signal wiring. A dual inverter that starts the machine. 5. The dual inverter according to claim 1, wherein two turbo machines are operated alternately and in parallel. 6. A method according to claim 1, wherein a priority flag for designating a turbo machine to be started first after the power is turned on is set in advance in a memory of a built-in inverter connected to the turbo machine. Characterized by a dual inverter. 7. The dual microcomputer according to claim 1, wherein each microcomputer takes in the load state detection value and performs load control arithmetic processing independently of other microcomputers. Inverter. 8. The dual inverter according to claim 1, further comprising a display unit for displaying a failure when a failure occurs.