Repayment and decompression techniques are used in large areas of sports to illuminate the illusion

In the experiment, the high-pressure sodium lamp and the metal halide lamp of the experimental object were respectively connected to the grid, and the voltage applied to the light source was adjusted, and the voltage value, the current value, the power value and the corresponding illuminance were recorded at the same time. The experimental circuit is shown as 2-1. 2-1 (a) is used to measure power, voltage and current, and 2-1 (b) is used to measure illuminance. During the measurement of the illuminance, it is measured at a distance of 1 m from the light source.

Through experiments, the corresponding illuminance, power and energy efficiency ratios of the high pressure sodium lamp and the metal halide lamp in the range of 242V to 187V were obtained. As shown in 2-2(a) and (b).

Wherein, the abscissa of the curve is the value of the voltage, and the ordinate is the value of the illuminance, power and energy efficiency ratio. a is the illuminance curve, b is the power curve, and c is the energy efficiency ratio curve.

In the analysis curve of high-pressure sodium lamp and metal halide lamp, when the voltage is lowered, the illuminance decreases almost linearly, and the power gradually decreases, but the luminous energy efficiency ratio tends to increase with the decrease of voltage. The high-pressure sodium lamp has the lowest energy efficiency ratio at 234V, while the metal halide lamp has the lowest energy efficiency ratio at 231V. The electro-optic characteristics of the two lamps are similar. From the perspective of luminaire energy efficiency, while reducing the illuminance, the improvement of energy efficiency ratio is not the only energy-saving goal pursued. However, for stadium lighting, dimming reduces illumination is a functional requirement. While the dimming reduces the illuminance, the metal halide lamp reduces the power by 15% when the illuminance is reduced by 22.4%. That is to say, while meeting the dimming control of the stadium, energy saving can also be achieved. The high-pressure sodium lamp reduces power by 15% when the illuminance is reduced by 26%. Therefore, when the same electric power is reduced by 15%, the dimming range of the metal halide lamp is smaller than that of the high pressure sodium lamp.

According to the characteristics and requirements of the venue lighting, combined with the above experimental research and analysis of the two commonly used venue light source technical indicators, the lamps used in this study are high pressure sodium lamps.

In stadium lighting, different grid voltages must have different transformers to choose from. But using too many transformers is not advisable and is not cost effective. Here is a simple method that achieves both regulation and accuracy.

Considering that a decimal number can always be represented by a finite bit binary, such as: 10=8+2=(1010)2 15=8+4+2+1=(1111)2

(3-1) 28=16+8+2+4=(111100)2 In this way, if there is a transformer with a secondary side rated voltage of 2 0, 2 1..., the corresponding transformer can be put into all the grid voltages U i . , so that the output U 0 does not change. The principle of input transformer selection is to convert the deviation of U 0 and U i into binary, and 1 represents the input of the corresponding transformer.

In the lighting system, the fluctuation of the grid voltage is generally -15% to 10% of the rated voltage, that is, the variation range does not exceed 33V, and the deviation of the smaller voltage (about 5% of the rated voltage) is allowed for the low-voltage user power system. Therefore, the selection of 4, 8, 16V three sets of transformers can meet the requirements. The main circuit (phase A) is shown as -1.

Working principle: (3-2) where ki(i=1,2,3)=10 U 0=U 1―ko(ki×16+k 2×8+k 3×4)-2 thyristor trigger circuit with optocoupler input Connected to the I/O port of the microprocessor. When the optocoupler MOC3083 receives a low level signal, the optocoupler is turned off. Take the current from the A1 end to the B1 end as an example. At this time, the current reaches the B1 terminal through the diode D 1 and the resistors R 5 , R 6 and R 7 . Since the resistance of the R 6 is large, the resistance connected to the trigger end of the thyristor is divided. The voltage is small enough to trigger the thyristor and the thyristor is in an open state. When the microprocessor will send a high level signal to the optocoupler MOC3083, the optocoupler is turned on, R 6 is shorted, and the voltage divider connected to the thyristor trigger terminal is large, triggering the thyristor to turn on. The MOC3083 has a zero-crossing detection function, so it can be more reliable zero-crossing triggering.

The software design of the control circuit The control program of the dimming energy-saving system mainly consists of several parts. (1) Initialization. This includes setting the interrupt mode; defining the initial values ​​of all registers in the program; defining the number of firing angles and the registers associated with the firing angle; defining the state of the input and output ports; defining the A/D conversion related memory bits and associated register states. (2) The main program part. Mainly loop detection, loop take and pulse. Including current synchronization signal level determination, trigger level signal, LED flashing program. (3) Voltage adjustment truth table. According to the deviation value between the voltage set value and the feedback voltage output value, the electronic switch that needs to be turned on, that is, the thyristor, is read in the truth table. Therefore, the transformer group with different inputs is cut and operated to achieve the purpose of voltage regulation. (4) Interrupt service subroutine. Includes A/D conversion interrupts and external interrupts.

The power factor dynamic compensation circuit is designed in the stadium lighting energy-saving system. Due to the wide application of inductive loads such as gas discharge lamps, there is a large amount of reactive power in the power grid, which makes the power factor of the power grid extremely low, which greatly affects Safe and efficient operation of the grid and power systems. Therefore, improving the power factor of the power grid makes the reactive power basically balance in place, reducing line loss and improving voltage quality is a very important task. The traditional power factor compensation device lacks effective automatic control means, the reaction speed is slow, the regulation is insensitive, and the compensation precision is low. In operation, over-compensation or under-compensation often occurs. When U 1 ≥ U 0 is not present, K n is turned on, K m is turned off, k 0=1; when U 1 ≤ U 0, K m is turned on, and K n is turned off. , k 0=-1.

Ordinary thyristors are solid-state switches that only allow current to flow in one direction. When they are connected in anti-parallel, they can be controlled to increase the AC voltage by controlling their turn-on logic. A balanced current is obtained by appropriate control methods to make its performance more stable. In order to absorb the instantaneous energy generated during the operation of the thyristor and the transient voltage shock, a buffer circuit is connected in parallel on each of the opposite parallel thyristors. The buffer circuit is composed of a resistor and a capacitor in series, and the buffer circuit can simultaneously reduce the voltage rise rate dV of the thyristor device. /dt, to prevent false triggering and protect the thyristor from damage.

Thyristor group K 1 and K 2 control the input of 16V transformer, K 3 and K 4 control 8V transformer, K 5 and K 6 control 4V transformer, take 1 for conduction, and 0 for disconnection. For example, when U 1 is higher than the rated voltage U 0 , the values ​​of each coefficient and the state of the thyristor are shown in Table 3-1.

3-1 trigger state table adjustment voltage k 0 k 1 k 2 k 3 K m K n K 1 K 2 K 3 K 4 K 5 K 6 0V 4V 8V 12V 16V 20V 24V 28V is shown in Table 3-1: (1) The adjustable voltage system is 4V, 8V, 12V, 16V, 20V, 24V, 28V, allowing the grid voltage to be: 220±28V, and the variation range is 13% of the rated voltage, which can fully adapt to the voltage change of the low-voltage lighting system. (2) The maximum deviation is ±2V, which is less than 1% of the rated voltage, and the accuracy is high. (3) Voltage regulation is not continuous adjustment, it is only when the electricity reaches a certain amplitude. (4) The turn-on and turn-off of the thyristor is directly controlled by the single-chip microcomputer, so the control is accurate and the reliability is very high.

When the power supply voltage U i is higher than the rated voltage U 0 , the voltage regulator can be used to achieve energy saving. The secondary side of the transformer absorbs excess energy and is coupled through the transformer. The energy is fed back to the grid from the primary side, and the transformer itself does not consume energy. In the energy saving of lighting, it is the use of this energy conversion to achieve the purpose of energy saving.

Indoor Fiber Termination Box can be supplied empty or fully loaded with adapters and pigtails. Meanwhile they are often deployed in FTTH applications for connecting feeder and distribution cables. The indoor fiber terminal box provides efficient cable connections between outside plant cables and equipment inside the buildings and communications facilities . Indoor Fiber Termination Box can be wall mounted or pole mounted and provides various accessories to avoid any unexpected damage to the fiber.

Indoor Fiber Termination Box

Indoor Fiber Termination Box,Fiber Termination Box,Fiber Optic Termination Box,Fiber Optic Box

Foclink Co., Ltd , http://www.scfiberpigtail.com