Industry News

Discussion on Energy Saving Design of High Pole Lamp Lighting System in Hongqiao Airport

2020-06-22
1 Introduction

  With the development of the times, the pace of modernization is accelerating, the contradiction between energy supply and demand is more and more prominent, and the requirements for energy saving and green lighting are becoming more urgent and higher. Energy conservation has become an urgent and important task for us. Local governments have also clarified annual energy conservation and consumption reduction targets in government work reports. With the rapid development of power electronics technology, many companies with their own energy-saving technologies have grown like mushrooms after the elimination of some old technologies.
  At present, in the lighting energy-saving technology, many methods can be adopted in the lighting control loop. Many energy-saving manufacturers also "mysteriously" expressed their product technology routes and product performances, such as midnight light control, traditional electromagnetic shift control by time , Traditional electromagnetic fixed buck control, no matter whether they are for commercial purposes, whether they are objective, rational, and correct expression, there is no doubt that everyone has begun to feel the energy crisis and has invested money, research technology, and developed products.
  This time, the design of the high pole lighting in the construction of the west section of Hongqiao Airport is also a big project. Due to the large number of high pole lights, large lighting power, and long lighting time, the consumption of electrical energy is a very large data. Therefore, to reduce the consumption of electrical energy by high pole lights without affecting the brightness of the apron lighting. Indispensable, it should attract enough attention and thinking.

2 Control loop system analysis

  As shown in Figure 1, this high pole lamp control loop system has three ways to control the high pole lamp, namely: manual control mode, microcomputer remote control mode, clock control mode, and the control of the high pole lamp lighting can be selected through the SA switch the way.
  The lamps on each base pole lamp in the west area of Hongqiao Airport are divided into two circuits, called the midnight circuit and the full night circuit. That is, the lights on the midnight circuit need to be turned off after lighting for a period of time. The lights stay on at night. There are many kinds of lights on each base pole lamp, which are divided into 7 lights, 9 lights, and 12 lights. There are 3 lights on the all-night circuit, and the rest are on the mid-night circuit. The switches of these two circuits respectively control the attraction and separation of contacts K M 1 and K M 2 through the gains and losses of the coils K M 1 and K M 2 of the relay, that is, the opening and closing of the control switches K M 1 and K M 2.

2.1 Manual control
  When the SA transfer switch reaches the local control gear, the two points 5 and 6 in Figure 1 are turned on, and the indicator H L1 is lit, indicating that the high pole light control is manual control at this time. When the manual buttons SB1 and SB2 are pressed, the coils K M 1 and K M 2 are energized, then the contacts
KM 1 and KM 2 are closed, and by going through the 02 → 04 → 18 → 05 and 02 → 06 → 19 → 07 lines, the midnight mode and the full night mode are lit together, and the indicators H L2 and H L3 are also lit; When the SBS1 and SBS2 buttons are pressed, the circuit coil that was originally disconnected is de-energized, the contacts are separated, and the lights of the circuit are turned off at midnight.


Figure 1 High pole lamp secondary circuit control wiring diagram

2.2 Clock control
  When the SA switch is switched to clock control, the two points 7 and 8 in the figure are turned on, and the indicator H L6 lights up. At this time, the high pole lamp is controlled by the clock. In this control mode, there is a fixed clock to control the switch 1H on and off. When the fixed clock is closed for 1H at the set time, the coil of the contactor K A and the delay relay SJ are energized at the same time, then the K A contact is closed. By going through the 13 → 15 → 05 → KM 1 coil → N line, the coil KM 1 is energized to make the contact of the contactor KM 1 close, so the light of the midnight circuit lights up; the same is true for the all night circuit Light up together. Since the delay relay SJ is opened for delay, the SJ contact will be automatically opened after the delay time, and the KM 1 coil will be de-energized, so the contact of the KM contactor will also be opened. The lights are turned off accordingly, leaving only one full-night circuit light on.

2.3 Microcomputer remote control
  SA has two gears for remote control. Remote 1 can turn on the 3, 4 and 1, 2 circuits, and remote 2 can only turn on the 1 and 2 circuits. The microcomputer control mainly sends commands through remote control to control the attraction and disconnection of the contacts M M 1 and M M 2 so that the coils K M 1 and K M 2 are energized and de-energized, and then the lights of the midnight circuit and the full night circuit are controlled.

3 Analysis of energy saving plan

  Since there are two circuits per base high pole lamp, namely the midnight circuit and the full night circuit, the energy saving effect can be achieved by closing a circuit when the high pole lamp is operated, and the consumption of electric energy can be reduced.
  There are a total of three circuits in the high pole lamp control system. The manual control part is generally used to maintain a single base high pole lamp and check the circuit. In normal operation, if you put the manual position, since the high pole lights are independent under manual control, it is a very laborious and tedious work to go on and off on a site-by-site basis. Therefore, only the two loops of fixed clock control and microcomputer control are analyzed below.

3.1 Using a fixed clock to control energy saving
  The control mode of this mode is mainly to turn on the lights of the midnight circuit through the fixed clock within the time set by the case, and to disconnect the lights of the midnight circuit after a delay time of the delay relay, and finally set by pressing the fixed clock Turn off the lights of the circuit all night.
  Initially, the clock control mode was operated for a period of time when the west section of Hongqiao Airport was just completed. After a few months of operation, it can save energy, and the investment cost is relatively low. When a fault occurs, it will not be individually lit, and there will be no large-area bright. However, at the same time, there are many problems, such as:
(1) The delay time of the delay relay is not long enough. Closing the midnight circuit early affects the apron lighting slightly. Because the maximum delay time is 6h, it turns off at 11:30 after it lights up at 5:30 in the evening; however, there are still many airport flights at this time, and it needs a stronger light brightness. It is better in summer, and the opening time is compared late. This control loop is more suitable for street lighting
Bright.
(2) Each base high pole lamp is separate, decentralized and relatively independent. Since the fixed clocks are installed on each base pole lamp, they are only controlled by their own fixed clocks, and the time of each fixed clock is different, which results in inconsistent lighting conditions.
(3) It cannot be controlled centrally or at any time. When it encounters some bad weather and needs to be turned on or off immediately, it cannot be done. It can only be turned on manually one by one on site.


3.2 Microcomputer remote control energy saving scheme

1) Status of microcomputer remote control system
After some minor problems occurred when using the fixed clock control mode, the remote control was started. Through microcomputer remote control, send M M 1 and M M 2 contact pull-in and open commands to control the midnight circuit and the full night circuit. Although centralized control and single lamp monitoring are achieved, when using the microcomputer remote control mode, it is found that the original control principle diagram cannot achieve the energy saving effect after closing the midnight circuit. It can only control to open or close the half-night circuit at the same time.
2) Control loop optimization
By studying the secondary control circuit of the high pole lamp, it is found that after the computer sends the command to open the midnight circuit at the same time, the contacts of the AC contactors K M 1 and K M 2 are closed. When a command to close the midnight circuit is sent after a period of time, that is, to open the M M 1 contact, the K M 1 contact needs to be opened. However, at the moment when MM 1 is disconnected, although the 08 → 05 → N line is not conducting, the KM 1 coil is de-energized, and there is a short delay in the opening of the contact, but according to the control circuit diagram, the circuit can go through 10 → 07→ 19 → 06 → 02 → 04 → 18 → 05 → N line, the coil KM 1 is energized again, so that the contact KM 1 cannot be opened and the midnight circuit cannot be closed. Similarly, the all-night circuit cannot be closed, and only two circuits can be opened and closed at the same time.
  If it is disconnected between SBS1 and SBS2, the function of closing a loop can be achieved at any time. According to the control diagram in Figure 1, a manual switch is installed (as shown in the dark thick dotted box in Figure 2). When the high pole lamp control mode is in the microcomputer In remote control mode, turn off the switch; in local control or fixed clock control mode, close the switch. In addition, because the remote control 2 mode in Figure 1 is useless, the indicator is also useless. Remove it to install a manual switch with 3 pairs of contacts (normally open, normally closed, power indicator) with light source indication. This is economical, cost-saving, and simple, with only one switch added.
  After using the microcomputer remote control mode, the operation is very simple, and it is easy to control the high pole lamp. It can also monitor the lighting status of the high pole lights in real time, which can be controlled by both groups and single lights, and can be controlled at any time, truly realizing automatic remote control. However, it has some shortcomings. The cost of using this equipment is higher than that of fixed clock control.


Figure 2 The secondary control circuit diagram after adding the index light switch

4 Analysis of the light pattern at half-night

4.1 The effect of turning on the lights at midnight
  The high pole lights in the west area of Hongqiao Airport are illuminated in a half-night mode. The microcomputer sends a switch signal to control the high pole lamp, and turn off some lights on each base high pole lamp in the middle of the night to achieve energy saving effect. The high-pressure sodium lamps on each base pole lamp are 1000W, at least 7 lamps, and some have 9 lamps and 12 lamps. The consumption of ballast, capacitor and trigger in each lamp circuit is negligible, as shown in Figure 3 As shown. The lighting time of each base pole lamp is from 6pm to 6am the next day, a total of 12h, which consumes a lot of electricity every night. Turn off the lights on the midnight circuit after 1 am in the middle of the night, that is, only 3 lights on each base pole lamp. For a rough calculation, assuming that there are (7+9+12)/3=9 lights per base on all high pole lights, then there are 6 lights that only light up for 7h every night, 5h is off, so (6/9) ×(5/12)≈ 0.28, it can be concluded that nearly 28% of electricity is saved, which will be a considerable number.
  In the second half of the night, only the lights of the full night circuit are turned on. After selecting a few base pole lights to test the brightness of the lights, the data in the following table is obtained. Based on the above data, it can be calculated that the average value of the light intensity is 21.3lx, and the uniformity (average value/minimum value) is 1.72. According to the regulations of the Fourth Edition of Annex 14 Airport of Civil Aviation, the light intensity of high pole lights on the apron is not less than 20lx, and the uniformity is not more than 4. Therefore, the energy-saving scheme using the midnight lamp mode effectively meets the regulations and requirements.

Light intensity table of high pole lamp on 276


4.2 Insufficient lighting at midnight
  Since the high pole lamp is powered by a three-phase line (see Figure 4), after turning off some of the lamps after midnight (see Figure 3), each lamp is powered by one phase, so that the power of each phase is different due to the extinction of the lamp Drop, but it is impossible to fully achieve three-phase balance in the distribution network, because:
(1) Due to the unbalanced three-phase voltage, the voltage on the light-loaded phase line will be higher than the rated voltage, and therefore will have different degrees of damage to the high pole lamp. In actual operation, after six months of maintenance statistics from March to August 2011, a total of 16 1000W lamps, a ballast, and a trigger were damaged, and the damage was still very small.
(2) The three-phase total power imbalance reduces the power supply efficiency of the superior power supply system. Three-phase unbalance will cause voltage on the neutral line, that is, current will be generated through the neutral line, increasing the power loss of the transmission line, that is, P=3I2 R, the greater the zero-sequence current I, the greater the line loss P. After midnight, there are only 3 1000W and 2 400W (irradiation service lane) left per base. After the average distribution to each phase, the zero sequence current will not be very large, and the line loss is not very obvious.


Figure 3  Wiring diagram of high-pressure sodium lamp with trigger



Figure 4 High pole lamp primary circuit wiring diagram

4.3 Advantages of turning on the lights at midnight
  Since half-night control is only through the control of the suction and opening of the contacts of the two circuits, there is no need to adjust the voltage and move the equal technology, as long as the feedback signal of the two circuit contactor contacts is opened or closed, you can understand To the lighting state of the on-site high pole lamp,
And because the circuit is very simple, it is relatively simple to control, convenient to maintain, high in reliability, and low in cost. In addition, after a rough calculation, the energy saving efficiency of lighting in this way is very considerable, which greatly reduces the consumption of electrical energy. The light intensity of the high pole light on the apron lighting in the middle of the night using the mid-night lighting mode also meets the regulations, and there is no insufficient or uneven illumination.

5 Conclusions and prospects

  This paper introduces the three control loops of the high pole light system through the analysis and research of the high pole light control system of Hongqiao Airport, and analyzes the advantages and disadvantages of each control loop. The lighting system adopts the energy-saving mode of midnight lights. Although there are some shortcomings, it achieves energy saving effects under the requirements of light intensity, which effectively reduces the power consumption in the middle of the night when the airport is operating. At the same time, the control loop is simple, low in cost, and strong in reliability. It is an economical and practical lighting system.
  At present, the objective requirements and calls for lighting system power saving are getting higher and higher, and the country's policy on this is also very clear. Although currently due to the limitations of energy-saving technical conditions, energy-saving technology has not been fully implemented and the best energy-saving effect has not been achieved, but With the rapid development of power electronics technology, I hope and believe that a more feasible route will be explored in technology, which is more suitable for the long-term development of lighting energy saving.