According to the annual meeting of the national road lighting to get the figures , the national rural road lighting ( excluding enterprises , ports, airports , highways, inter-provincial highways ) total number of lamps 3 million , plus the ports, roads and other places a total of about 400 more than ten thousand . Intensified in recent years due to different lighting construction , substantial increase in the total number of lamps and lighting , coastal provinces increased by about 12 % to 15% , by 2002 , the country will be the total number of lamps and lighting lamps more than 12 million . To market the largest amount of 250W HPS do the calculation based on the annual consumption of each sodium fee : 250 × 1.15 ( inductive ballast power consumption ) × 11.5h ÷ 1000 × 365天× 0.7元/ h = 845元. Saving rate of 25 % per annum, each bulb can save electricity 211.2 yuan per year , 12 million light festivals electricity bill of around 2.5 billion.
First, the reasons for the high tariff
    First of all, the main purpose of lighting the vehicle , pedestrian safety, travel, outdoor lighting main purpose is to beautify the urban landscape , to give people a warm and harmonious atmosphere for relaxation . Flow, traffic flow after the 0:00 has been significantly reduced, and this time it is electricity trough grid voltage increases , the lamp brighter than ShangBanYe Therefore, this period of light utilization is very low, if no measures are taken at any time to adjust illumination, will waste considerable power .
    Secondly , road lighting directly connected with the electricity grid , according to the test , each power supply point of the transformer output voltage greater than the rated voltage of 220V, 250V up some more, so that the output power greatly increased.
    Again, as lamps, light source selection is not appropriate, the same amount of energy consumption efficiency of light generated significantly reduced , the cable material and the size of a direct impact on the size of the loss of the power supply line . In addition, currently used mainly inductive ballast , because there is not enough emphasis on reactive power compensation , reactive power increased significantly.
Second, energy-saving measures
    One , to ensure that the function and effect of the premise, reasonable adjustments to lighting quantity and time. Road lighting should fully promote night light , primary and secondary roads to implement the dual loop -powered, full- nightlights loops and sub- loops night lights , night lights unconditional provision of specialized circuits can be single -phase power supply at night , but it should be changed to keep the entire three-phase equilibrium ; slip road industrial area and living area , road width narrower street lights using night mode unilateral change . City lights generally only in the public more time on outdoor activities .
    Second, the selection of the light source with high luminous efficiency . Energy sources depends largely on its luminous efficiency, but the choice of the light source can not simply starting from the light effect , but according to CRI , service life, starting characteristics considered, rational use . Choose a light source principle : to minimize the use of incandescent lamps ; promote the use of thin fluorescent lamps and compact fluorescent lamps ; gradually reducing the use of high-pressure mercury lamp , in particular, should not be free to use the self-ballasted high-pressure mercury lamp ; actively promote the high-pressure sodium , a metal halide lamp .
    Third, the selection of high quality and efficient lighting . Performance is critical for energy-saving lamps , mainly lighting efficiency and light distribution role. Lighting efficiency is under specified conditions lighting luminous flux emitted FL with all the light fixture outside lit the lamp total luminous flux emitted by the ratio of FS , with the "h" , ie h = FL / FS. Generally , h with lampshade material reflectance and transmittance is proportional to open depends on the efficiency lighting fixtures opening area S0 and reflection area S ratio and the shape of the reflector . To minimize the loss of light in the fixture , S0 / S bigger the better . The shape of the main reflector lights in the shade caused by multiple reflections within . Therefore, choosing lamps should consider the following aspects : should be a higher utilization factor ; reasonable choice lamp light ; preferred block plate lamps ; Try to choose lamps without attachments ; try to use lamps with a high retention rate .
    Fourth, all the transformer output voltage detection, downshift , so that the output voltage ratings. If it is not reduced, the motor can be used to step down provincial energy . After testing , the provincial electrical power saving rate of 11 percent to 23 percent.
    Fifth, the circuit reactive power compensation, compensation and centralized single lamp can be compensated in two ways. Compensation is in every single light lamp capacitance in parallel with a capacitor to compensate appropriately , both to reduce the lighting circuit reactive power, low-voltage lighting circuits can also reduce the energy loss and voltage loss. Also, because the line current is reduced , you can use a smaller cross-section of the wire . Single lamp compensation experience : 250, 400W HPS compensation capacitor capacitance values ​​were 30, 50UF. Centralized compensation capacitor is mounted on the power distribution unit focused , the advantage of simple installation , reliable operation , high utilization , the disadvantage is not to reduce the voltage on the low voltage line loss and power consumption, can only play on the grid reactive power compensation effect ; In addition , you must install discharges.
    Sixth, promote the use of electronic ballasts. Electronic ballast exchange
- DC - AC converter , the 50HZ AC by DC rectifier filter becomes stable , and then converted into a high-frequency DC current as the lamp current. Since gas discharge lamp having a negative volt-ampere characteristics , while at high frequencies becomes positive volt-ampere characteristics , so that the lamp can be started normally . Compared with inductive ballast , has the following advantages: energy consumption of inductive ballast bulb itself of 10% to 15% , the electronic ballast itself very low energy consumption , and exercise and power output characteristics.
    Seven , three-phase power transformers to ensure basic balance . If the three-phase current imbalance will increase line losses . Assuming three phase current per phase I, lead resistance is R, then the line loss is W1 = 312R; if three-phase current imbalance , namely I, 1.5I, 0.5I, then W2 = 12R + (1.5I) 2R + (0.5I) 2R = 3.512R, apparently line losses increase .
    Eight , reducing wear and tear on the supply line . According to the formula S = I / In [ where S is the cable cross-sectional area (mm2), I was lights load current (A), In the economic current density (A/mm2)] Select the cable cross-section , so that resistance to a reasonable value , thus reduce line losses .
    Nine , the choice of high-tech energy-saving products, such as provincial motor, regulator electronic ballasts , energy saving lamps microcomputer meter, single lamp power controller.