1 Urban roads are generally divided into: express roads, main roads, secondary trunk roads, branch roads and residential roads. The secondary trunk roads and below account for more than 2/3 of the length of the roads in the entire city, and the electricity consumption of street lighting is correspondingly large. This article focuses on energy conservation issues for secondary roads and below. 2Using time relay and intermediate relay to realize the function of barrier lighting Urban road lights generally adopt double-sided symmetrical arrangement, double-sided asymmetric arrangement and single-sided arrangement. Night street lights use the second half of the street light to illuminate the light to save energy. The main control method is to increase the distribution cable and use the night light and the midnight light. They are connected to different cable lines and can save energy by turning off a part of the street lamps. The author completes the function of lighting off the light through the time relay connected to the street light circuit and the controller of the intermediate relay, and achieves better energy saving effect. Usually the road light source is a high pressure sodium lamp. The street light is controlled by a microcomputer street light controller. The controller has the functions of time control, light control, time control and light control. The street light is turned on at night, the dawn is turned off, and some street lights are turned off in the middle of the night. The street lamps are arranged symmetrically on both sides (or one-sided arrangement). In the base of the street lamp pole, a set of time relays for delaying the turn-off and the controller of the intermediate relay are set every other time (the time relay is delayed after about 6h). The function of electricity, the intermediate relay functions to disconnect the street light current. Due to different regions, the time relay setting time can be long or short). In the evening, the street lights are all on. After about 6 hours, the street lights of the controllers with time relays and intermediate relays are extinguished due to the delayed power failure. The street lights without the time relay and intermediate relay controller are always on until after dawn. The microcomputer street light controller controls the power off and the street light stops working. When designing and installing the street lamp, it is necessary to consider the three-phase distribution balance of the load, and the street lamp should be set to the controller of the time relay and the intermediate relay according to the double-sided (one-side) asymmetric (light-separated lamp) all night. In this way, after turning off a part of the street light, the brightness of the road can be made as uniform as possible. For example, if a road is east-west, the road is 30m wide, 700m long. The motorway is 15m wide, and the sidewalks are 4m wide. The green belts on both sides are 3.5m wide. According to the road lighting design standards, they are symmetrically set on both sides of the motor vehicle road. A street lamp with a height of 10 m and a horizontal spacing of about 35 m. There are 21 street lamps on the south and north sides, numbered N1, N2, N3, ..., N21, S1, S2, S3, ..., S21 (see Figure 1). In the latter half of the night (after 6 hours), turn off N2, N4, N6...N20, S1, S3, S5...S21. See 1. The relay components of the controller are selected from the SS-60 type time relay of the Xuji Group and the intermediate relay of the DZJ-10 type. The working principle is shown in 2. 3 technical economic comparison Generally, the method of separating and extinguishing lights is used to save energy, which has a certain effect. However, each side of the lamp must be laid with two cables to control the night light and the front half of the night light respectively, which will increase the amount of street light power cable, in the street lamp project. Increased investment and caused waste. With the street light of the controller with time relay and intermediate relay, only one cable is needed on each side to solve the energy-saving function of the above-mentioned light-off. Taking the above-mentioned 700m long road as an example, the controller using the time relay and the intermediate relay and the effect of using the increased power cable to control the separation lamp to light off and energy saving are comparatively analyzed from the perspective of technical economy. According to the comparison of three-phase power supply, the YJV-0.6/1kV5×16mm 2 XLPE power cable is more than 50526 yuan than the controller with time relay and intermediate relay (the calculation process is omitted); according to the single-phase power supply, YJV- is adopted. The 0.6/1kV 3×16mm 2 XLPE power cable has an investment of 27,580 yuan more than the controller with time relay and intermediate relay (the calculation process is omitted). In summary, the method of using time relay and intermediate relay is more energy-saving, material saving, simple control, safe and reliable, less investment, less maintenance and long service life than using power cable to control the light. The downside is the use of traditional, mechanical components, such as a modern integrated time relay and intermediate relay made of integrated controller, energy saving effect will be better. 4 Problems and suggestions The interval lighting is realized by the controller with time relay and intermediate relay, which is easy to install and manage, and the energy saving effect is remarkable. However, in the latter half of the night, because a part of the street light is turned off, the power supply voltage of the street lamp that is lit overnight will increase, which will inevitably affect the service life of the street lamp that is lit overnight, resulting in an increase in maintenance costs. Through many years of experience in designing street lamps, the author suggests to study the production of special dedicated street lamp transformers with on-load automatic regulation voltage, which can solve the problem that the street lamp service life is affected by the increase of the street lamp power supply voltage. Cassava Dregs Separator,Cassava Processing Machine,Cassava Processing Equipment,Cassava Milling Machine Hunan Furui Mechanical and Electrical Equipment Manufacturing Co., Ltd. , https://www.thresher.nl