JP2010114977A - Streetlight power supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for reducing the transmission loss and the transmission cost when supplying power to streetlights for illuminating such roads as freeways. <P>SOLUTION: Power used for streetlights within a given zone is boosted to a high voltage altogether and transmitted to relay power substation points in order to reduce the heat-related loss. Furthermore, streetlights are each provided with an electric double layer capacitor, whereby the portion of electricity to be consumed at night is charged quickly utilizing night-time electric power in order to reduce the transmission cost. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a system and method for reducing power transmission loss by reducing power transmission loss by transmitting power for night consumption in a very short time when power is transmitted to a street light for road lighting such as an expressway. It is about.

To reduce transmission loss when transmitting power energy to remote locations such as thermal power, nuclear power, hydropower, wind power, etc., there are many AC / DC selective power transmission, reactive power control associated with AC phase, transformer materials during voltage conversion, etc. Measures have been taken. In addition, various measures such as daytime peak power avoidance and demand network optimization adjustment, which are issues as the demand increases, have been taken, but it is said that there is still a loss of 5-10% for remote transmission. ing. Furthermore, even in facilities that use constant power within a specific time, power is transmitted continuously throughout the day.

A similar problem arises when a department in a general office once receives power from a power plant and then transmits it to a facility in a specific area at a remote location. For example, the power of street lamps used for road lighting along the highway by an organization that manages and operates an expressway is transmitted to a large number of lighting lights every night over long distances. Power transmission loss. There are similar power consumption issues in urban lighting managed by municipalities, maintenance of broadcast radio waves in mountainous frontiers, and management of civil engineering facilities such as dams.

Various measures have been taken as described above to reduce transmission loss from power plants to remote urban demand layers, but as a more efficient power reduction method, captive support for consumer equipment A method of using a secondary battery as a power source has been proposed.
For example, in Patent Document 1, suppression and retention of voltage fluctuations that occur in response to fluctuations in urban demand load, detection of reactive power and active power associated with phase fluctuations, reduction of distribution current by adjusting optimum values, suppression of daytime peak currents, A system using a secondary battery has been proposed for leveling the normal electric energy. Patent Document 2 proposes a method for controlling in real time by adding supply and demand power operation and systematic system operation in addition to the above system to achieve the above target.
Patent Publication 2006-225380 Patent Publication 2006-067469

The proposed system system detects the fluctuating voltage and current in response to loads that fluctuate constantly, such as urban power and factories, determines the superiority or inferiority of reactive current and active current, and discharges and charges from secondary batteries. It is intended to reduce the circulating current as much as possible while selecting. In addition, in order to monitor the power consumption in real time for the purpose of increasing the usage efficiency of the secondary battery, the equipment uses and makes full use of command generators and current drivers that look at many detectors, electronic arithmetic circuits, switching machines, etc. There are many types and quantities. Since secondary batteries use chemical batteries such as lead-acid batteries and lithium ion batteries, the memory effect of charge and discharge remains, the product life is short, and maintenance costs are required, and the spread is not progressing. In order to cope with load fluctuations by constructing a large number of monitoring systems as proposed in the power reduction method for street lamp power supply, a large number of large-capacity secondary batteries are required and a large installation cost is required. There are no conventional highway lighting street lights equipped with storage batteries.

The conventional power transmission method used for night illumination on expressways is to energize 100 or 200V AC all night long to individual street lamps installed over a long distance directly from the command power conversion station (substation). A 500 W to 1 KW sodium lamp and a high-pressure mercury lamp are continuously lit. The power consumption and transmission loss associated with long-time lighting cannot be overlooked.
Recently, power is generated by attaching solar cells to street lamps for remote lighting and remote islands where power lines do not pass, roads and gardens in tourist areas, and the power is stored in power storage devices (mostly secondary storage batteries) attached to street lamps. An illuminating device is used for discharging the light.
Although it is a desirable deployment method that complements generators such as thermal power, nuclear power, and hydropower through the use of eco-energy, problems remain when used as power for highway lighting. In other words, a large-area solar cell of several square meters is required for power generation, which requires equipment costs. In addition, power generation is unstable because it depends on the weather, and stable and reliable lighting such as highway lighting is obtained. Is unsuitable.

In this patent, in order to reduce the power transmission loss of lighting power for highways and the like, a power storage device is charged in advance in the power storage device, and the power is discharged sequentially at night. In the current highway and street lighting, the individual power consumption is as low as 1 kW or less, and the power standards are exactly the same. Therefore, there is almost no load fluctuation during use and the control current is small. As proposed in Patent Documents 1 and 2, there is no need to control the power transmission to the city area by finely and precisely detecting the current voltage and controlling a large number of electronic circuit devices. Since it is not the purpose, the power storage device used in this patent may be any device that has a simple control function and performs a simple charge / discharge operation without maintenance.

As a method of reducing heat loss during power transmission, the power of street lamps used in a certain area is collectively sent to a relay substation at one time, reducing power transmission loss and shortening power transmission time. The transmission loss is reduced by increasing the voltage and transmitting at a high voltage to reduce the current to reduce heat generation. The time zone for power transmission is a time zone certified as nighttime power, and the power transmission is completed in a shorter time. At the relay substation, the voltage of the received power is stepped down, and the AC-DC converted direct current is supplied to each street light. In the street lamp, a control device is installed that introduces a supplied current into the power storage device and performs a switching operation so as to discharge from the power storage device to the street light source. This control device also has a voltage and current control function for maintaining stable lighting. As a power storage device that stores electric power, an electric double layer capacitor is used to enable rapid charging in a short time.

If the electric power used for the street lamp for night road lighting is boosted to a high voltage and transmitted to the relay substation, the amount of current can be reduced and heat loss is suppressed. In addition, since power can be stored in the power storage device at once in a short time, heat loss due to energization for a long time can be reduced. Inexpensive power is used by charging the power storage device within the night power certification time. If power supply with a power storage device is performed in a place that is lit day and night like in a tunnel lighting, the power consumed in the daytime can be charged in a short time using the nighttime power and discharged for lighting in the daytime. Covering daytime lighting with nighttime electricity is cheaper than using daytime electricity. In addition, in the era when shortage of summer power is regarded as a problem due to an increase in power demand, the use of nighttime electricity will suppress the use of daytime electricity as much as possible, contributing to power leveling by leading to a so-called peak shift. It will be.

When an electric double layer capacitor is used in the power storage device, the advantages over the conventional storage battery can be obtained. For example, since rapid charging is possible, the required amount of power can be stored in a short time. Rapid charging is difficult with conventional chemical battery charging, and if it is charged with a large current at once, it may be damaged or the service life may be impaired. The electric double layer capacitor can be charged quickly and can be used up until the amount of stored electricity decreases and discharge becomes impossible. Further, since there is no chemical change, the service life is semi-permanent, and maintenance such as electrolyte injection and storage device replacement is unnecessary.
As described above, the use of this patent not only reduces the cost of electric power users, but also contributes to the country's effective energy utilization policy, and has great social significance.

The present invention relates to a street lamp power supply method, which is a method that enables efficient power transmission and shortening of power transmission time. First, the connection relationship of the main power distribution path, the equipment used, and the operation time will be described. Normally, when transmitting power from a power plant to a remote location, power is transmitted at 380,000 V, 525,000 V, and 1 million V, but when it is sold to businesses in the city, it is 10,000 V or less. The source power received by the power supply command center 1 of the business entity such as an expressway from the electric power company is boosted by a voltage step-up transformer in the command station, and passes through the primary transmission line 11 to the relay substations 20, 21 at remote locations.・ ・ Transmitted to 20 + n. At the relay substations 20, 21,... 20 + n that have received power, the voltage is stepped down, and then the street lamps 30, 31,... 30 + n and 40, 41,. Power is supplied to 40 + n, 50, 51,... 50 + n.

Each street lamp is provided with a current / voltage controller 3, an electric double layer capacitor 4, and an illumination light source 5. Power transmission from the power supply command station 1 to each relay substation is not performed during the day. The electric power supplied to the street light from the relay substation enters the voltage controller provided in the street light, charges the electric double layer capacitor 4 through the transmission line 12 for a short time of night power, and illuminates the charged power. It is sent to the light source 5 and turned on at night. Use energy-saving equipment with remarkable development as the illumination light source. Conventionally, a sodium lamp is used, but it is preferable to use a high-frequency fluorescent lamp or LED (light emitting diode) that consumes less power.

A specific example suitable for the street lamp power supply system will be described below along the power supply path for the highway lighting.
FIG. 1 is a block diagram showing a power distribution system. At the power supply command center 1 of the office that has received power from the power station, the power used by the lighting lamps under the jurisdiction of the power station is boosted by a voltage step-up transformer and relayed through a primary transmission line 11 at a remote location. Power is transmitted to the bases 20, 21, 20 + n. In the highway lighting, lighting lights are installed over a total number of 100 km, and inside the tunnels. The power supply command station 1 does not directly connect and transmit power to individual lighting lamps, but transmits power to street lamps through the secondary power transmission lines 12 via the relay substations 20, 21... 20 + n. The relay substation is a base that divides roadsides as appropriate and transforms all the illumination lights in the section to supply power. For example, the relay substation 20 is connected to illumination lamps 30, 31,. Similarly, the lamps 40, 41,... 40 + n are connected to the relay substation 21, and the lamps 50, 51, .. 50 + n are connected to the relay substation 22. The divided section of the relay substation is equivalent to, for example, a section within the service area interval, and 800 lamps are built within the distance of about 40 km.

Since the current lighting power using sodium lamps is 500 W to 1 KW per unit, the consumption of the entire expressway is very large. The power handled by one relay substation installed in this patent is about several hundred kW. (In the evening, it is lighted for over 16 hours and is over 10,000 KW).
If this light source is replaced with an LED, the power consumption per lamp becomes 1/15 to 1/30, so the power consumption per relay substation base can be reduced to 100 KW or less. At the relay substation, the electric power received at a high voltage is reduced to several tens of volts, AC-DC converted, and direct current power is supplied to each illumination lamp. Each illuminating lamp is provided with an electric double layer capacitor 4, and a light source of 30W per unit is turned on overnight to store more power than is consumed. The lighting time for one night is 16 hours as 16: 00 to 8:00. Since the power consumption is 480 Wh, this charging is performed with a charging voltage of 24 V and energization equivalent to 120 A × 10 min.

FIG. 2 shows a block diagram of an illumination part provided in the illuminating lamp.
The electric power entered from the power transmission line 12 enters the controller 3 and is connected to the electric double layer capacitor 4 in the charging mode and charged there (charge amount is 480 Wh in 16 hours in the case of LED 30W). The time for power transmission from the power supply command center 1 is to transmit the total amount of power consumed at night in all jurisdictions of one expressway in a short time. At the relay substations 20, 21,... 2 n that have received power, the voltage is reduced to a voltage suitable for the power storage device possessed by each lighting lamp, and the lighting lamps 30, 40,. Sent to 50 ...

The charging mode is performed according to the following procedure. When the nighttime power certification time is 10 hours (22: 00-08: 00), the power is sent from the power supply command station 1 through the relay substations 20, 21,. 30 ..., 40 ..., 50 ... At this time, the current input terminal from the outside is connected to the electric double layer capacitor 4 in the controller 3 by the instruction signal from the power supply command station 1, and charging starts. When the battery is fully charged for about 10 minutes before 8:00 in the morning, the power transmission from the power supply command station 1 is completed, and the connection with the electric double layer capacitor 4 is released in the controller 3 by this power transmission stop. When this charging time is over, the electric power of the electric double layer capacitor charged until the start of lighting in the evening is preserved as it is in the daytime.

The lighting mode is performed according to the following procedure. During the daytime, there is no power supply or lighting, and at dusk, for example, in the winter, a lighting signal from the power supply command center is transmitted through the relay substations 20, 21,... . .. 30 + n, 40... 50, and in the controller 3 in the illuminating lamp, the terminal of the electric double layer capacitor 4 is connected to the terminal of the light source, and the output of the electric double layer capacitor 4 is the light source 5 It is discharged and lights up. Since the voltage of the electric double layer capacitor 4 decreases when discharge starts, the current controller 3 controls the current so that the illuminance of the light source becomes constant.

In addition, although the instruction | indication of a lighting start was performed from the electric power supply command center 1, the following methods may be sufficient. For example, the darkening time may suddenly change depending on the weather in a remote location. Therefore, even if a blinking instruction is issued using a sky illumination sensor installed at the relay substations 20, 21,. good.
Thus, the lighting continues until it becomes bright the next morning through the night, and the controller 3 changes to the charging mode when the power supply from the power supply command station 1 is started again, and is turned off.

This patent uses a power relay substation and electric double layer capacitor power storage device to reduce power transmission loss when power is supplied for long-distance road lighting over a long distance such as an expressway, and it can transmit power at night time in a short time. Therefore, the possibility of use is great. It can be used not only for expressways but also for streetlight lighting systems that are managed by local governments in various regions, and it can also be used for reducing power for monitoring civil engineering construction facilities such as wireless relay facilities and dams in remote mountainous areas. The utility value is very wide.

Plock diagram showing power distribution system Block diagram of lighting components provided in lighting

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electric power supply command center 11 ... Primary transmission line 12 ... Secondary transmission line 20, 21, ... 20 + n ... Power relay substation 3 ... Controllers 30, 31, ... · 30 + n ··· Lighting lamps 40 and 41 belonging to the substation relay base 20 · · · 40 + n · · · Lighting lamps 50 and 51 belonging to the substation relay base 21 · · · 50 + n · · · Lighting lamp 4 belonging to the substation relay base 21 .... Electric double layer capacitor 5 ... Light source

Claims (5)

When power is supplied to a street light for street lighting installed in a distant place such as an expressway, each street light for street lighting has a power storage device with charge / discharge capability, and an input that is connected to the power storage device and supplied with power Equipped with a controller that has the ability to control both the voltage and current and the output voltage and current to the street light. The power storage device is charged in a short time with all the power consumed by night lighting, and the power storage device is discharged at night. A street lamp power supply system characterized by lighting by lighting. 2. The street lamp power supply system according to claim 1, wherein a light source of the street lamp for road illumination uses an LED or a high-frequency fluorescent lamp. When distributing the power supply for lighting to a remote area, the power is boosted to a high voltage to the relay substation that has jurisdiction over a specific section, and the power that is stepped down to the desired voltage is received at each substation that receives the power. 2. The street lamp power feeding system according to claim 1, wherein the street lamp group is fed with power. 2. The street lamp power supply system according to claim 1, wherein the power storage device installed in the street lamp for street lighting is an electric double layer capacitor. The control device performs charging to the power storage device for power supplied in the daytime according to an instruction from the power supply command center, blocking charging, discharging from the power storage device to the light source in the evening, and blocking emission to the morning light source. 2. The street lamp power supply system according to claim 1, further comprising reporting a lighting condition of the street lamp to a power source power command center.

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