JP2010053821A - Pump system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pump system capable of restraining power consumption at a low level. <P>SOLUTION: The pump system used for transport of river water and agricultural water comprises a transformer 7 for reducing voltage of power supplied from a power system, a plurality of electric motors M operating by receiving power supply from the transformer 7, a plurality of pumps P respectively connected with the plurality of electric motors M, a plurality of auxiliary devices operating by receiving the power supply, and an operation control section 12 for controlling an operation of the pump system. The operation control section 12 has a function for switching a normal operation mode supplying power to all the plurality of the auxiliary devices and a power saving mode supplying power to only a part of the plurality of auxiliary devices. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pump system (pump station) used for transferring river water and agricultural water.

  Pump systems for transferring river water and agricultural water are often used during the rainy season and agricultural work season, and are often out of operation at other times. Especially in large pump systems, the pump capacity (drainage) and the number of pumps are determined based on the maximum expected rainfall. The frequency of operation (number of operating pumps) varies from year to year.

  The pump system includes various instruments, a space heater for preventing condensation, an operation state display lamp, and the like as ancillary equipment of the pump. Since these auxiliary devices are always supplied with electric power regardless of the operation state of the pump, useless electric power is consumed in the off season when the pump is hardly operated. In addition, when operating with a small number of pumps, there is a problem that the efficiency of the transformer in the pump system decreases. In other words, in a pump system with a large total amount of power used, such as a pump system having a drive with a large output, a transformer with a large capacity corresponding to the maximum power used is used for the transformer that steps down the power supplied from the power system. ing. In general, when the current flowing through the transformer is small relative to the capacity of the transformer, that is, when the power used is small, the efficiency of the transformer deteriorates due to the characteristics of the transformer. Therefore, if a small number of pumps are operated, the power consumption efficiency deteriorates, and the maintenance cost (power consumption cost) increases due to the supply of more power than necessary.

  The present invention has been made in view of the above-described conventional problems, and an object thereof is to provide a pump system that can keep power consumption low.

  In order to achieve the above-described object, according to one aspect of the present invention, in a pump system that transfers liquid, a transformer that steps down power supplied from a power system, and receives power supplied from the transformer operates. A plurality of electric motors, a plurality of pumps respectively connected to the plurality of electric motors, a plurality of auxiliary devices that operate by receiving power supply, and an operation control unit that controls the operation of the pump system, The operation control unit has a function of switching between a normal operation mode for supplying power to all of the plurality of auxiliary devices and a power saving mode for supplying power to only some of the plurality of auxiliary devices. .

In a preferred aspect of the present invention, when the pump system is operated in the power saving mode, a start command to the electric motor related to an auxiliary device that is not supplied with electric power among the plurality of auxiliary devices is issued. An interlock mechanism for rejecting is provided.
In a preferred aspect of the present invention, the transformer is a plurality of transformers, and the plurality of electric motors are electrically connected to any one of the plurality of transformers, respectively, and the primary side of the plurality of transformers And the circuit breaker is each installed in the secondary side, It is characterized by the above-mentioned.

A preferred aspect of the present invention is characterized by further comprising a bus bar that connects secondary sides of the plurality of transformers, and a connection breaker that blocks connection by the bus bar.
In a preferred aspect of the present invention, the plurality of auxiliary devices are configured to be supplied with power from any of the plurality of transformers.
In a preferred aspect of the present invention, the transformer includes a main transformer and a sub-transformer having a smaller capacity than the main transformer, and the main transformer and the sub-transformer are connected in parallel to each other. The main transformer is used when the pump system is operated in the normal operation mode, and the sub-transformer is used when the pump system is operated in the power saving mode. It is characterized by.

  According to the present invention, in a quiet operation period in which only some of the plurality of electric motors are operating, switching from the normal operation mode to the power saving mode allows power supply to some of the auxiliary equipment that is not required. Can be stopped. Therefore, it is possible to reduce the amount of electric power used in the off season to the minimum necessary, and to reduce the running cost.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic diagram showing a pump system according to a first embodiment of the present invention. As shown in FIG. 1, the pump system includes a plurality of pumps P that pump up water in the suction water tank 1 and a plurality of electric motors M that respectively drive the pumps P. In the example shown in FIG. 1, six pumps P and six electric motors M are provided. Each pump P is connected to an electric motor M through a speed reducer 4.

  The pump system includes a power receiving / distributing device 6 connected to the power system, a main transformer 7 for stepping down power from the power receiving / distributing device 6, and a plurality of pumps connected to the main transformer 7 to control the operation of each electric motor M. Motor controller 8 (six in this example), on-site transformer 10 for further stepping down the output power of main transformer 7, and distribution control unit for distributing output power of on-site transformer 10 to various auxiliary devices described later 11 and an operation control unit 12 that controls the operation of the pump system. The operation control unit 12 is connected to the power distribution control unit 11.

  As shown in FIG. 1, the motor control unit 8 is connected to each motor M, and controls a control panel for controlling the operation of each motor M such as starting and stopping (normal stop, emergency stop at the time of failure, etc.) In addition, a rotation speed control device (an inverter device, a Serbius device, etc.) for controlling the rotation speed of the electric motor M is included.

  In addition to the electric motor M described above, the pump system includes various auxiliary devices that operate by receiving power supply. This accessory device includes, for example, a motor 21 that operates a discharge valve 20 disposed on the discharge side of the pump P, a full water detector 22 that detects whether or not the inside of the pump P is filled with water, A motor 24 that drives a vacuum pump 23 that discharges the air and introduces priming water, a motor 26 that drives a gear pump 25 that circulates lubricating oil in the speed reducer 4, a water fall detector 28 that detects water fall in the pump P, A water level meter 29 for measuring the water level in the suction water tank 1 is provided. In addition to these, although not shown in FIG. 1, a ventilation fan, a space heater for preventing condensation, a water level meter of a discharge water tank, a bearing thermometer, a pressure sensor, an operation state display lamp, a failure display lamp, and various instruments A measurement value display, a monitoring camera, and the like are provided as accessory devices. These auxiliary devices are connected to the power distribution control unit 11 described above, and the operation of the auxiliary devices is controlled by the operation control unit 12 described above.

  In this pump system, the number of pumps P to be operated is determined according to the required amount of drainage. Therefore, not all the pumps P are always operated, some of them are operated, or none of the pumps P may be operated. Therefore, the pump system according to the present embodiment can be operated in a power saving mode in which power is supplied only to a predetermined accessory device in order to suppress power consumption. Hereinafter, the operation mode switching function of the pump system will be described.

  The operation control unit 12 described above has two types of changeover switches for switching the operation mode of the pump system. As shown in FIG. 2A, the first changeover switch is a control mode changeover switch 31 for switching the operation control of the pump P between the interlocking mode and the single mode. In the interlocking mode, the motor M that drives the pump P and incidental devices related to the operation of the pump P are interlocked and controlled by the operation control unit 12 based on a preset control flow until the pump P starts. In the single mode, the electric motor M that drives the pump P and the incidental devices related to the operation of the pump P are not controlled by the operation control unit 12 and are operated and stopped manually. Mode. In the single mode, each accessory device is operated and stopped by manual operation, and even if the interlock control function fails, the pump P can be finally operated manually.

  As shown in FIG. 2B, the second changeover switch is an operation mode changeover switch 32 that switches the operation of the various accessory devices described above between the normal operation mode and the power saving mode. The normal operation mode is a mode in which power is supplied to all the above-mentioned auxiliary devices and is in an operable state, and the power saving mode is an electric power that can be operated only to a predetermined auxiliary device. This mode is supplied. The table shown in FIG. 3 shows an example of a list of auxiliary devices to which power is supplied in the normal operation mode and the power saving mode. The power supply device (operable accessory device) in the power saving mode is preferably set as appropriate depending on the operation method of the pump system and the installation environment (temperature, humidity, etc.).

  In the off season when a large amount of drainage is not required, the power consumption can be reduced by switching to the power saving mode to stop the supply of power to the auxiliary equipment that is not substantially used. In case of sudden rain such as abnormal weather, it is possible to switch from the power saving mode to the normal operation mode only by operating the mode switch at the discretion of the operator (operator). It is not necessary to return the circuit breakers of the individual auxiliary devices that have been stopped, and the pump system can be immediately returned to a state where normal operation is possible. That is, it is possible to promptly respond to sudden rain, and to provide a highly reliable pump system that can prevent inundation damage due to a delay in return (pump start delay).

  Here, since various instruments such as a water level meter and a thermometer are not operating in the power saving mode, if the suspended pump P is started in this state, a serious failure occurs in the pump P, the electric motor M, or the like. There is a fear. Therefore, in order to prevent such a failure, the control unit 11 or 12 includes an interlock mechanism that rejects a start command (operation) of the electric motor M related to an auxiliary device to which power is not supplied. This interlock mechanism is a mechanism that links the power supply state of the accessory device with the starting condition of the motor M, and in order to start the motor M, it is necessary to supply power to the accessory device. Therefore, in order to start the motor M that is not operating, it is necessary to switch from the power saving mode to the normal operation mode. By providing such an interlock mechanism, the operation safety of the pump system can be ensured.

  Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a schematic view showing a pump system according to the second embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the element which is the same as that of 1st Embodiment, or respond | corresponds, and the overlapping description is abbreviate | omitted. In this embodiment, the plurality of electric motors M are divided into a plurality of groups, and a plurality of main transformers are provided corresponding to the respective groups. Electric power is supplied to the motors M of each group from the corresponding main transformer. In the example shown in FIG. 4, the plurality of electric motors M are divided into two groups (three electric motors M per group), and two main transformers 7A and 7B for supplying electric power to these groups are provided. It has been. These main transformers 7A and 7B have a smaller capacity than the main transformer 7 according to the first embodiment. That is, the main transformers 7A and 7B each have a capacity sufficient to drive the three electric motors M.

  Motor control units 8A and 8B are connected to the main transformers 7A and 7B, respectively, and electric power is supplied to the motors M of each group via the motor control units 8A and 8B. The operation (start, stop, rotational speed, etc.) of each motor M is controlled by motor control units 8A and 8B. In-house transformers 10A and 10B are connected to the main transformers 7A and 7B, respectively. A distribution control unit 11 is connected to the on-site transformers 10A and 10B, and an operation control unit 12 is connected to the distribution control unit 11.

  Circuit breakers 30 are provided on the primary and secondary sides of the main transformer 7A. Similarly, circuit breakers 30 are also provided on the primary side and the secondary side of the main transformer 7B. In the off season when a large amount of drainage is not required, the circuit breaker 30 provided on the primary side or the secondary side of one of the two main transformers 7A and 7B is opened. Thereby, it is possible to cope with the operation / operation of a small number of electric motors M with a smaller number of main transformers than during normal operation.

In general, as shown in FIG. 5, when the load current is small, the efficiency of the transformer is deteriorated. In FIG. 5, the copper loss is a load loss, and is a resistance loss when a current flows through the primary winding and the secondary winding of the transformer. Iron loss is no-load loss, and represents loss due to hysteresis and eddy currents in the transformer core. The efficiency of the transformer can be obtained from the following equation.
Transformer efficiency = output / (output + no-load loss + load loss)

  In the off-season when the pump is hardly operated, the efficiency of the transformer deteriorates due to a decrease in power consumption, so that the power corresponding to the loss of the transformer is wasted. Moreover, even if there is no load on the secondary side of the transformer (no load state), the amount of power for iron loss is consumed. Therefore, in the off season, the circuit breaker 30 provided on the primary side or the secondary side of one of the plurality of transformers (one of the main transformers 7A and 7B in the example shown in FIG. 4). Is opened. As a result, the load factor of the transformer is increased, the efficiency of the transformer is improved, and wasteful power consumption can be reduced.

  As shown in FIG. 4, the motor control units 8A and 8B connected to the secondary sides of the main transformers 7A and 7B are connected to each other by a bus 35, and the bus 35 is electrically connected by the bus 35. The connection circuit breaker 36 which interrupts | blocks is provided. Normally, the connection breaker 36 is opened, and the connection breaker 36 is closed when one of the main transformers 7A, 7B fails. For example, in the example shown in FIG. When the second electric motor M fails, the main transformer 7A can operate only the two electric motors M even though the main transformer 7A has a capacity for operating the three electric motors M. Therefore, by closing the connection breaker 36, one of the three motors M connected to the failed main transformer 7B can be operated by the main transformer 7A. It is possible to make the best use of the ability.

  Thus, it is effective to close the connection breaker 36 when either of the main transformers 7A and 7B fails. However, it is not preferable to always keep the connection breaker 36 closed. This is because when the motor M or wiring arranged on the secondary side of the main transformers 7A and 7B malfunctions and an excessive current is applied to the wiring system, both the transformers 7A and 7B located at the upper level break down. This is because there is a risk of losing. For this reason, the connection breaker 36 is opened during normal operation, and the connection breaker 36 is closed when one of the main transformers 7A, 7B fails.

  It is preferable that power is supplied to the auxiliary equipment from any of the main transformers 7A and 7B. If comprised in this way, it will become possible to change alternately the main transformers 7A and 7B to be suspended in a quiet period periodically (for example, every year), and the operating frequency of the main transformers 7A and 7B will be leveled. By suppressing unilateral deterioration, the life of the main transformers 7A and 7B can be extended. Also in this embodiment, it is preferable to provide the above-described interlock mechanism.

  Next, a third embodiment of the present invention will be described. FIG. 6 is a schematic view showing a pump system according to the third embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the element which is the same as that of 1st Embodiment, or respond | corresponds, and the overlapping description is abbreviate | omitted. In this embodiment, the main transformer 7 and the subtransformer 7C are provided in parallel with each other. The capacity of the sub-transformer 7C is set smaller than the capacity of the main transformer 7. More specifically, the main transformer 7 has sufficient capacity to drive all the motors M, while the sub-transformer 7C has only capacity to drive some of the motors M. is doing. In addition, when it is not necessary to drive the pump P in the off-season, the sub-transformer 7C is a transformer having only a capacity for driving maintenance and management equipment (lighting, ventilation, etc.).

  The power receiving / distributing device 6 includes a transformer changeover switch (transformer operation mode changeover switch) (not shown) that switches between the main transformer 7 and the sub-transformer 7C. This transformer changeover switch may be operated in conjunction with the above-described operation mode changeover switch (second changeover switch). Specifically, when the second changeover switch is switched to the normal operation mode, a circuit breaker (not shown) on the primary side or the secondary side of the sub-transformer 7C is activated, and the output power of the power receiving and distributing device 6 is changed to the main transformer 7 Only from the sub-transformer 7C. In this case, the output power of the power receiving / distributing device 6 is stepped down only by the main transformer 7, and power is sent from the main transformer 7 to the motor controller 8 connected to the secondary side. On the other hand, when the second changeover switch is switched to the power saving mode, the circuit breaker (not shown) on the primary side or the secondary side of the main transformer 7 is activated, and the output power of the power receiving / distributing device 6 is transmitted only from the sub transformer 7C. The main transformer 7 is not interposed. In this case, the output power of the power receiving / distributing device 6 is stepped down by the sub-transformer 7C. Therefore, by switching the operation mode to the power saving mode in the low season, not only the power supply to the auxiliary equipment is limited, but also the transformer can be operated with high efficiency. The transformer changeover switch described above may be provided in the power distribution control unit 11 or the operation control unit 12 in place of the power receiving / distributing device 6. Also in this embodiment, it is preferable to provide the above-described interlock mechanism.

  The embodiment described above is described for the purpose of enabling the person having ordinary knowledge in the technical field to which the present invention belongs to implement the present invention. Various modifications of the above embodiment can be naturally made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Therefore, the present invention should not be limited to the described embodiments, but should be the widest scope according to the technical idea defined by the claims.

It is a mimetic diagram showing the pump system concerning a 1st embodiment of the present invention. FIG. 2A is a diagram showing a control mode changeover switch for switching the operation control of the pump between the interlocking mode and the single mode, and FIG. 2B shows the operation of the accessory device in the normal operation mode. It is a figure which shows the operation mode switching switch switched between electric power modes. It is a table | surface which shows an example of the list | wrist of the incidental apparatus with which electric power is supplied at the time of normal operation mode and power saving mode. It is a schematic diagram which shows the pump system which concerns on the 2nd Embodiment of this invention. It is a graph which shows the efficiency of a transformer. It is a schematic diagram which shows the pump system which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Suction water tank 4 Reducer 6 Power receiving / distributing device 7 Main transformer 8 Electric motor control part 10 In-house transformer 11 Distribution control part 12 Operation control part 20 Discharge valve 21, 24, 26 Motor 22 Full detector 30 Breaker 31 Control mode switching Switch 32 Operation mode changeover switch 35 Bus 36 Connection breaker

Claims (6)

In a pump system for transferring liquid,
A transformer that steps down the power supplied from the power system;
A plurality of electric motors that operate in response to the supply of electric power from the transformer;
A plurality of pumps respectively connected to the plurality of electric motors;
A plurality of ancillary devices that operate upon receiving power supply;
An operation control unit for controlling the operation of the pump system,
The operation control unit has a function of switching between a normal operation mode for supplying power to all of the plurality of auxiliary devices and a power saving mode for supplying power only to a part of the plurality of auxiliary devices. To pump system.   When the pump system is operated in the power saving mode, an interlock mechanism that rejects a start command to the electric motor related to an auxiliary device that is not supplied with electric power among the auxiliary devices is provided. The pump system according to claim 1. The transformer is a plurality of transformers;
The plurality of electric motors are electrically connected to any of the plurality of transformers,
The pump system according to claim 1 or 2, wherein circuit breakers are respectively installed on the primary side and the secondary side of the plurality of transformers. A bus connecting the secondary sides of the plurality of transformers;
The pump system according to claim 3, further comprising a connection breaker that cuts off the connection by the bus.   The pump system according to claim 3, wherein the plurality of auxiliary devices are configured to be supplied with power from any of the plurality of transformers. The transformer is composed of a main transformer and a sub-transformer having a smaller capacity than the main transformer,
The main transformer and the sub-transformer are connected in parallel with each other,
The main transformer is used when the pump system is operating in the normal operation mode,
The pump system according to claim 1, wherein the sub-transformer is used when the pump system is operated in the power saving mode.

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