JP3355441B2 - Emergency generator power system in sewerage facility - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an emergency power generator having a gas turbine, a diesel engine, a gas engine, and a gasoline engine as a prime mover and installed in a sewerage facility.

In a sewage system, during a heavy rain, a preliminary sewage pump (including a sewage pump in a divided flow system; the same applies hereinafter) is operated without losing the machine according to an increase in inflow of sewage to secure pumping capacity. It is very important.
If the sewage pump is operated incorrectly and the sewage overflows from the pipeline, it will cause extremely serious damage to urban functions and the environment such as flooding of roads and flooding of houses.

By the way, since heavy rains are caused by lightning and typhoons, there is always the danger of sudden power outages (including instantaneous voltage drops; the same applies hereinafter) in commercial power systems. Also,
In recent years, the occurrence of concentrated torrential rain caused by urban climate change, the so-called heat island phenomenon, has also become remarkable. Under these circumstances, it is a problem that sewage pumps, which are fully operating during heavy rainfall, may stop due to a sudden power outage. Some sewage facilities need to be reconsidered and dealt with again.

[0004]

2. Description of the Related Art As a countermeasure for this, a method of temporarily storing inflow water and a method of operating a sewage pump have been considered. However, in an electric power system, in order to shorten a recovery time in case of a sudden power failure, a bus line is required. Is a double bus consisting of a commercial power bus and a self-generated bus, and some load feeders are equipped with an electric switching disconnector to automate the switching operation. However, once the sewage pump is stopped, it will take one time between restart and full opening of the discharge valve.
It takes several minutes per unit, so it takes at least ten minutes to complete the operation of all units. In addition, if a device malfunction or erroneous operation occurs during the recovery process, the time may be even longer. Considering that, even with the above-mentioned most powerful electric power system, if sewage flows in a large amount in a short period of time, there is a concern that pumping will not catch up relatively, and the risk of flooding will not be completely eliminated.

In order to solve this problem drastically, during heavy rainfall, important loads such as sewage pumps (including monitoring control devices and lighting equipment, etc .; the same applies hereafter) are transferred to an independent operation by an emergency generator without interruption. The best measure is to prevent the effects of a sudden power outage of the commercial power system (hereafter referred to as standby operation). However, according to the conventional wisdom, the emergency generator is stipulated by law to be used in the event of a power outage in the commercial power system. Regarding this, it is said that the connection between the emergency generator and the commercial power system is prohibited by law, and such a method has not been implemented. ｛For example, Toshiba's “Electrical Equipment for Waterworks Handbook”, Vol. 6, pages 45-48,
Pp. 113-126, pp. 123, 209-220, 3
See pages 95-409. ｝

[Problems to be solved by the invention]

However, a detailed study of the relevant laws and regulations reveals the following. Gas turbines, diesel engines,
Regarding the operation of emergency generators with gas or gasoline engines as the prime mover, the law on air pollution control stipulates, in principle, that “strict guidance should be given to the categories of regular or emergency use”. On the other hand, as an exception,
"Emergency facilities and facilities that are used for highly public purposes and building facilities must be carefully considered so that the work related to the facilities can be carried out smoothly."
｛“Enforcement of a Cabinet Order Revision of Part of the Enforcement Order of the Air Pollution Control Act”
, Notice of the Air Quality Bureau of the Environment Agency, ⇒ "Ditto," dated November 6, 1987, 3rd and 5th of the Taikan No. 235, and "Handling of Emergency Facilities," November 6, 1987 See Date, Kankandai No. 237, Notification of Air Quality Control Division, Air Quality Control Bureau, Environment Agency III. Therefore, in the sewage facilities, if appropriate measures are taken, there is room to operate the emergency generator before the sudden interruption of the commercial power system.

[0007] As for the interconnection between the emergency generator and the commercial power system , Article 61 of the Electrical Equipment Technical Standards can be read as if the interconnection is prohibited at first glance. It calls for the need to install a device that disconnects the service line when reverse power is generated, and does not prohibit interconnection.解説 Refer to “Technical Standards for Electrical Equipment”, Public Utilities Division, Agency for Natural Resources and Energy, 1998 edition, p.88｝.

[0008] Accordingly, the object of the present invention, based on the above conclusions, is to make the policy of notification from the Environment Agency's Air Conservation Bureau described in paragraph 0006 that the aim is to achieve both harmonization and harmony between air pollution prevention and smooth operation of sewerage facilities. It aims to provide a power system for sewage facilities that completely prevents flood damage caused by sudden power outages during heavy rains.

[0010]

Means for Solving the Problems Differences between the emergency generator (1)
As a measure to prohibit legal regular operation and secure it externally , use a prohibition lock device (17) with this power system.
In the system. This device locks the emergency generator (1) so that it cannot operate under normal load during normal times.
When heavy rains occur, data on inflow water and weather
Flood potential (a new indicator of flood risk)
Index), and only when the value exceeds the expected value
The lock is automatically released to enable actual load operation.

Power receiving equipment and an emergency generator so that the grid interconnection does not adversely affect the commercial power system.
Is the “Guidelines for Technical Requirements for Interconnection to the Grid” ｛Notice of the Public Utilities Division, Agency for Natural Resources and Energy, dated August 1, 1986, last revised March 10, 1998. Based on 上 の, take necessary measures on facilities, including consultation with power companies.

As a method for transferring the important load of the sewage facility from the commercial power system to the emergency generator system, the emergency generator (1) and the commercial power system are temporarily linked, and the emergency generator ( By shifting the load to 1) and solving the interconnection,
Use a method of uninterrupted power. Similarly, in the method of returning from the emergency generator system to the commercial power system, the emergency generator (1) and the commercial power system are temporarily linked, the load is shifted to the commercial power system side, and then the interconnection is released. By doing so, a method of performing uninterrupted power is adopted. An automatic load shifter (18) for this purpose is installed in this power system.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
It consists of a lock device and a lock release device. The lock device is a relay with a contact, which normally opens the a contact to shut off the input circuit of the automatic load shift device (18) and lock.

The unlocking device is an arithmetic device. The lock release device calculates the flood potential described in the next paragraph using the operational data and weather data of the sewerage facility as the input automatic signal, and attaches the lock relay described in the preceding paragraph when the flood potential ≥ the set value. Close the a-contact and release the lock. Also, as a method of unlocking,
It is also possible to directly input an external signal such as an electric power company, local government authority, or a private weather forecasting company as an automatic signal and unlock the system.

Here, the flood potential is a concept representing the degree of risk of flood caused by a sudden power outage. The factors that determine the flood potential (P) are the sewage pump well water level (L), the sewage pump well water level change rate (dL / dt), the number of operating sewage pumps (N), the amount of pumped water (Q), and the upstream main flow rate (F). ), Rainfall (R), rainfall intensity (Ri), lightning (Ln)
. Qualitatively speaking, a state with high flood potential means that the number of operating sewage pumps is greater than normal, the sewage pump well water level and its rising rate are both large, and the upstream main flow, rainfall, and rainfall intensity are all large. And there is a lightning strike. In this state, the inflow rate exceeds the pumping rate,
This indicates that the margin of sewage storage is reduced and the risk of flooding is high, and that the inflow of water continues to increase and lightning is expected to continue. Is high. In other words, this means that the need for standby operation and the urgency are high.

The signal input of the factors described in the preceding paragraph to be taken into the unlocking device can be obtained from various existing measuring instruments of the sewerage facility. If higher accuracy and accuracy are required for inflow forecasting, rainfall runoff analyzers and inflow forecasting devices using the latest radar rain gauges, and thunderstorm forecasting systems from private weather forecasting companies, etc. can be adopted.

The calculation method of the flood potential and the numerical value setting of the unlock are based on the specificity of the sewerage facility by quantitatively grasping the correlation while referring to the sewage inflow pattern and the results of the operation data and the weather data. The most appropriate.

The automatic load shift device (18) comprises a sequence controller, an automatic synchronizer, and an automatic load adjusting device. The sequence controller starts operation when the service prohibition lock is released, the operator inputs a standby operation command, and the emergency generator (1) is started. First, the automatic synchronizer verifies the voltage and phase between the self-generated bus (5) and the emergency generator (1), turns on the power generation circuit breaker (4), and switches the emergency generator (1) to commercial power. Connect to the grid. Next, the automatic load adjuster increases the load on the emergency generator (1) in response to the input signal of the power generation circuit breaker (4), and when the power flow of the bus communication circuit breaker (15) becomes zero. Then, the busbar circuit breaker (15) is cut off and the interconnection is released. Thus, the critical load (6) enters the standby operation state by the emergency generator (1).

When the operator inputs a normal operation return command after the heavy rain stops and the service prohibition lock is engaged, the sequence controller starts operating on condition that there is no power failure in the commercial power system. First, the automatic synchronizer verifies the voltage and phase of the private power generation bus (5) and the commercial power bus (12), synchronously turns on the bus communication breaker (15), and uses the emergency generator (1) for commercial power. Link with power supply system. Next, the automatic load adjuster reduces the load on the emergency generator (1),
When the power flow of the power generation circuit breaker (4) becomes zero, the power generation circuit breaker (4) is cut off to disconnect the interconnection. Thus, the important load (6) returns to the power supply from the commercial power system and returns to the normal state. Finally, the emergency generator stops.

If the commercial power system stops due to an accident or the like during normal times, the emergency power generator (1) is started up after the power failure is detected, and the actual load can be operated.

FIG. 1 shows the case where the receiving voltage of the commercial power system is extraordinarily high and the emergency generator (1) is high, or the case where the receiving voltage is high and the emergency generator (1) is low. As shown, the basics do not change even when the receiving voltage is high and the emergency generator (1) is high.

In the case of retrofitting existing equipment, the emergency generator must be equipped with a damper winding according to the technical guidelines for grid connection, and if the short-circuit capacity of the grid is insufficient, the breaker must be renewed or limited. Note that a flow reactor must be installed.

[0023]

Effect of the invention: Effect of preventing flood damage. In this power system, even if a sudden power outage occurs during a heavy rain, there is no interruption and stagnation of the pumping function as in the conventional power system.
The possibility of flood damage during heavy rain as described in paragraph 0004 can be completely eliminated.

Effects of power cost reduction. Sewage pumps in sewage facilities operate only about one-third of all units during normal times, and all units operate only during several to several dozen heavy rainfalls a year. This causes peak power generation and lowers the annual load factor. However, in this power system, the peak power is cut as a result, so the contract power can be reduced and the power cost can be reduced. (There is a trial calculation of 10 million yen / year for a facility with a contract power of 5 MW.)

Effects of reducing equipment costs. This power system
Compared with the electric power system described in paragraph 0004, there is no need for a double bus and an electric switching disconnector, so that the equipment cost can be reduced. It is particularly effective when it is necessary to improve sewerage facilities in response to changes in the urban environment as described in paragraph 0003. (In a facility of contract power 5MW class,
Remodeling costs are 7 to 7 compared to the power system described in paragraph 0004.
There is a trial calculation example that only one-eighth is needed. )

Effects of labor saving and improvement of safety. There is no power system switching due to a sudden power failure during heavy rain and no restart operation of important load equipment, which helps to save labor for operators, and there is no risk of operator erroneous operation or behavioral disaster, and high safety. .

[Brief description of the drawings]

FIG. 1 is a power system diagram showing a facility configuration of a power system.

FIG. 2 is a control flow chart showing an operation function of the power system.

[Explanation of symbols]

 1. Emergency generator. 2,3,7,8,9,10,14 Instrument transformer. 4 Power generation breaker. 5 Self-generated bus. 6 Important load. 11 Power receiving circuit breaker. 12 Commercial power bus. 13 General load. 15 Bus breaker. 16 Protection relay device. 17 Locking device for normal use. 18 Automatic load shifter.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H02J 9/08 E03F 5/22 F04B 49/00

Claims (2)

(57) [Claims] An emergency power generation facility using an internal combustion engine as a prime mover
Including commercial power receiving equipment and important loads, commercial power
If this happens, start the emergency generator and restart the critical load.
Power system of emergency generators in
And the power system further includes a prohibition locking device.
The emergency prohibition locking device is provided with the emergency
Lock the electric machine with a prohibition lock to prevent the emergency
In addition to prohibiting actual load operation of the generator,
Indicates the degree of flood risk caused by a sudden power outage.
When the “R” exceeds the set value, the lock is released and
Actual load operation of the emergency generator without waiting for a commercial power outage
Emergency in sewerage facilities characterized by enabling
Generator power system. 2. The power system further comprises an automatic load shifter.
The emergency power generator, including the device, the generator breaker, and the bus breaker.
After the start-up, the electric
Automatically synchronize the generator breaker and connect it to the commercial power system.
The power generation output is increased and the critical load is shifted to the emergency generator side.
And the power flow of the bus breaker becomes zero
When the bus becomes
When the service prohibition lock device returns to the locked state,
The bus load breaker is automatically synchronized by the automatic load shifter.
To reduce the power generation output,
The critical load is completely shifted to the commercial power grid side,
When the power flow of the generator breaker becomes zero,
2. The device according to claim 1, wherein the device is automatically shut down and stopped.
Power system for emergency generators in the sewerage facilities mentioned.