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Preparation for Electrical Engineers: compensation transformer lighting voltage stabilizing and energy-saving device

1. Summary

with the obvious acceleration of urbanization, the scale of street lamp system is also growing. The operation cost of street lamps has caused great pressure on local finance. The total number of street lamps in China is about 12million, and the annual power consumption is 43.9 billion kwh. Based on the average electricity price of 0.65 yuan, the annual expenditure is 28.5 billion yuan. Electricity is very unstable due to the tight power supply

the first midnight coincides with the peak of power consumption, the voltage is low, the street lamps are relatively dim, and even stroboscopic phenomenon occurs. After midnight, the line voltage rises sharply, and in some areas it can reach 250V. As a result, the lighting is extremely bright, and even glare appears, so that the bulbs with a design life of 5 years have been damaged in less than 1 year. Based on the ownership of 30000 street lamps, the annual replacement cost is as high as 3.6 million yuan (the replacement cost of each lamp is 120 yuan)

7. Cooler: the crud of air-cooled cooler should be cleared regularly; If water cooling is adopted, regularly inspect whether the cooling copper pipe has cracks and water leakage; The old street lamp control only considered on, off and some protection. Now, the state has stipulated to adopt energy-saving equipment for the lighting of high-grade highways. For the old street lamps, the state also vigorously advocates energy-saving transformation

the illuminance of the gas discharge lamp commonly used at present does not decrease proportionally when it is reduced within the allowable range, that is, the illuminance changes little. The moderate use of reduced voltage can not only ensure the lighting quality, but also greatly save power consumption and considerable electricity expenses. However, it should be economical and reliable, with a long service life. Remember that this day, the street lamps should be regulated by the pollution-free adjustable power supply

some of the traditional sliding contact voltage regulators, AC contactor switching, magnetic saturation voltage regulators, phase controlled voltage regulators and other methods have slow response speed, mechanical contacts are easy to be damaged, and the degree of automation is low; Some are inefficient; Some output waveforms are distorted greatly, which often causes serious pollution to electricity

based on the most simple, mature and highly reliable transformer technology, the introduction of microcomputer as an intelligent control unit, and the use of advanced modern power semiconductor devices as contactless control compensation transformer type lighting voltage stabilization and energy-saving device has been tested by the market. It is playing an increasingly important role in the field of lighting

2. Principle of compensation transformer type lighting voltage stabilizing and energy saving device

compensation transformer type lighting voltage stabilizing and energy saving device is to connect a set of transformer coils in series in the main circuit, and use the potential generated by it to superimpose with the main power supply, so as to change the output voltage value. Since the transformer is not directly used for power supply, but only for compensation (about 30% of the total power supply voltage), the power and volume of the transformer can also be reduced to 30%, which can save a lot of copper wires, iron cores and other materials

the primary winding of the compensation transformer is connected with each tap of the multi tap transformer by the electronic power component, which undertakes two tasks:

(1) connect and disconnect the taps according to the instructions of the microcomputer

(2) subdivide the voltage according to the instructions of the microcomputer, that is, adjust the conduction degree and change the amplitude of the superimposed voltage to increase the voltage series and the accuracy of each stage. If the tap of each stage is 5V, within the range of 5V, we can divide it into 1v/gear 5 levels. Because it is realized by changing the conductivity of electronic components, the phase and other parameters do not change, so the sinusoidal waveform will not be changed

in addition to the key technology of reasonable parameter calculation and design of the transformer, the microcomputer analyzes and judges the output signal fed back, and immediately makes the instruction of opening and closing the electronic switch. The electronic switch is synchronized (in phase) with the power supply and continuously turns on and off with the instruction of the microcomputer. There must be no misleading or non conduction. If misguided conduction or non conduction occurs, the output voltage waveform will be distorted and high-order harmonics will be generated, which in turn will feed back wrong information to the microcomputer. Eventually, the system crashed. At present, few people in China can master this technology. Therefore, there are few excellent contactless products

3. Functions of compensation transformer type lighting voltage stabilizing and energy saving device

with an economic, reliable, harmonic free, contactless voltage regulating device, there is a foundation to make lighting lamps work in the best state and meet people's requirements for lighting energy saving

the opening and closing of lamps can be controlled according to the sunshine curve and by using mature common methods such as astronomical clock, optical control switch, PLC, remote control device, etc

4. Lighting regulation system

compensation transformer type with the introduction of its new high viscosity bio based extrusion grade grilamid1 sxe4281 and grilamid2 sxe4282, the lighting voltage stabilizing energy-saving device and low-voltage power distribution form a complete lighting regulation system. It is divided into three parts:

(1) light switch and energy-saving time control

(2) main circuit protection and control part

(3) emergency and maintenance bypass part

the integrated (PC level) automatic transfer switch (ATSE) usually does not consume electricity, and the material selected for the contact system has fully considered the problem of long-term idleness and non oxidation. Therefore, the integrated (PC level) automatic transfer switch (ATSE) is required in places with high reliability requirements such as fire protection, and contactor type, circuit breaker type and electric load switch type are not allowed