Discussion on the environmental protection operation method of street lamp weakening voltage
The difference between an autotransformer and an ordinary transformer is that the primary and secondary coils of the autotransformer not only have magnetic contact, but also electrical connection. Therefore, when the output voltage adjustment range is not large, its capacity is small, so consumption The material is small, the cost is low, and the efficiency is high. The biggest advantage of this type of product is that it overcomes the defects of the harmonic generation of the thyristor chopper type product, realizes the sine wave output of the voltage, and has simple structure and function, and high reliability. There are two methods currently applied, namely fixed tapping mode and continuous adjusting mode. (1) Fixed multi-speed auto-coupled buck. Since the core component is a multi-tap transformer, the transformation ratio is fixed. Generally, there are 3 to 5 buck taps on the secondary side, which are reduced by 5V, 10V, 15V, and 20V respectively. Once the terminal is fixed, the voltage is reduced. . When the grid voltage fluctuates, the output voltage of the regulating device will also fluctuate up and down, so that the working voltage of the lighting is in an unstable fluctuation state, and the electric power cannot be protected. When the grid voltage is high, the power saving rate is not optimal; when the grid voltage is low, undervoltage may occur, causing the lamps to fail to light normally, and thus reducing the life of the lamps, which is the biggest safety defect of such control devices. (2) Continuously adjust the auto-coupled buck. It can adjust the output voltage by brushing the surface of the coil smoothly or rolling, changing the ratio of the coil. The advantage is that stepless smooth adjustment can be realized, and the adjustment precision is high. However, since the brush adjustment circuit is in the main circuit, the current is large, the brush is easily contacted, and a spark is generated, causing contact wear. Intelligent lighting power savers From the perspective of the first two types of power-saving products, they have their own advantages and disadvantages. The reason why they cannot be used in large quantities is because they have technical defects. The advantage of the thyristor (phase control) type is that it can accurately control the output voltage in real time to meet the optimal value of the lighting power. The disadvantage is that the voltage cannot achieve sine wave output and there is harmonic pollution. The advantage of the auto-coupled buck type is that it can achieve the voltage sine wave output, but it can not achieve the automatic and precise control of the voltage. It can only fix the voltage drop, and can not boost and stabilize the voltage. Defects are relatively ideal lighting energy-saving products. The working principle of the intelligent lighting control device adopts the microcomputer control system, the real-time acquisition output, the input voltage signal is compared with the optimal lighting voltage, and the automatic adjustment is performed through calculation, thereby ensuring the output of the optimal lighting system operating voltage. The intelligent lighting control device has the following characteristics: (1) Optimize the power quality, save lighting power, and stabilize the optimal working voltage. The control device can adjust and output the optimal lighting working voltage in real time according to the actual needs of the user site, and can stabilize it within ±2%, effectively improve the power quality, thereby achieving 10% to 40% of power saving; (2) multiple time periods Energy efficient operation. According to the actual lighting needs of the user, the control device can also set the multi-time energy-saving voltage setting through the program, so as to meet the needs of different light sources and different time of the user, to achieve the optimal illumination state and maximum power saving rate; (3) real-time voltage regulation and control Pressure. Where the voltage fluctuates greatly, such as a factory with more electrical equipment, the voltage fluctuation reaches ±15%; the power supply voltage of the street lamp will reach 250V in the middle of the night. The high-stability optimal lighting voltage of the intelligent control device can extend the life of the electric light source by 2 to 4 times and reduce the operation and maintenance cost of the lighting by 30% to 50%. Most of these products use a compensation transformer to adjust the voltage. (1) Principle of compensating transformer regulating voltage: See 2 for the principle of compensating transformer regulating voltage. The output of the compensating regulator is sinusoidal without harmonic interference. Its transformer capacity is only the capacity of the part to be adjusted. Therefore, it can control larger capacity output with smaller capacity, high output efficiency, convenient adjustment and strong overload capability. Suitable for applications in large and medium power applications. (2) See Figure 3 for the principle of matrix regulator. This type of regulator has multiple sets of compensation transformers in the circuit. By adjusting different relay contacts, different voltage combinations can be obtained at the output. In the figure, the output can be equal to the input minus u 1, or subtract u. 2, or subtract (u 1+u 2). When the number of compensation transformers is enough, the required adjustment precision can be obtained. The disadvantage is that the voltage adjustment is stepped. When the number of compensation transformers is small, the voltage of the first adjustment may jump, the circuit is complicated, and there is contact switching. When switching the primary coil of a large inductor, overvoltage and inrush current are easily generated, which will make the operation unstable. (3) The non-contact compensation type voltage regulator replaces the relay contact in Fig. 3 with a thyristor, and the thyristor operates in a fully conducting state, so no harmonics are generated. The thyristor AC voltage regulator is a new-generation AC voltage regulator developed for the current unstable voltage and frequent mutation of most power grids. It integrates microcomputer measurement and control, thyristor non-contact switch and transformer technology. In one, it has the characteristics of large capacity, small size, fast response and no noise. The problem that needs to be solved is that the street lamp buck power saving has only been proposed in recent years. There is still a lot of work to be done to better apply it: (1) It is necessary to verify the relationship between the output luminous flux of the light source and the input voltage through experiments. In theory, the power of the load and its input voltage are squared, that is, the input voltage is reduced by 10%, the power consumed by the load is reduced by 20%, and the luminous flux should be reduced by 20%. However, the existing energy-saving products consider that the gas discharge lamp is different from the incandescent lamp, the voltage is reduced by 10%, the light output is only reduced by 7% to 10%, which needs to be verified by experiments; (2) verifying the illumination and input voltage of the light source on the road. (3) The influence of the light source on the start-up voltage and the relationship with the life when the input voltage is lowered, whether it is beneficial to reduce the voltage at the start-up; (4) Study the method of adjusting the input voltage of the light source and adjust the efficiency of the power supply, currently There are many forms of energy-saving products, there are contacts, there is no contact, there is a level of pressure regulation, there is stepless pressure regulation, the accuracy of the pressure regulation is appropriate, must be selected through research and test suitable for street lighting The way.
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