introduction
Today's industrial plants generally have large working areas, and there are many street lamps. Generally, high-pressure sodium lamps are used, and the power consumption of the lamps is very large, resulting in unstable power supply voltage and large fluctuation range. Especially in the middle of the night, the voltage is usually as high as 250V or more, resulting in a very high bulb loss rate (up to 60% or more). In order to save energy, reduce waste and reduce costs, it is necessary to carry out energy-saving renovation.
1. Analysis of energy saving reform
1.1 Power supply status
In order to avoid various losses during the transmission process and the adverse effect of the end voltage of the line on the power supply equipment, the power supply department applies the voltage 10% higher than the nominal voltage to the user (with a single-phase 220V standard). Let the voltage be an example, the actual supply voltage is 220+22010%=242V) to ensure that the voltage at the far end of the power supply line will not be lower than 220-22010%=198V. Therefore, most of the voltage on the power supply line will be equal to or higher than the nominal voltage (220V). The standard conversion ratio of user transformers in China is 10kV/0.4kV, but the actual supply voltage of 10kV high-voltage lines is 11kV (10+1010%=11kV), so the single-phase actual output voltage at the low-voltage end can reach up to 254V (0.4V/10V11kV/ 1.732=254V).
1.2 Power consumption status
The normal operating voltage range (single phase, phase voltage) of lighting electrical equipment (lamps) is 220 (110%) V (ie 198V~242V). In general, the supply voltage of a city or region increases with the reduction of the electricity load in the area. This phenomenon is particularly prominent in industrial areas.
Especially in the middle of the night, the power supply voltage will be 10% to 15% higher than the normal value of 220V.
Most of the lighting lines supply power to the luminaire without reactive power compensation. The power factor is extremely low, and the reactive power and reactive power loss caused by the reactive power loss and reactive current of the circuit are relatively large, resulting in great waste of electrical energy.
1.3 Feasibility and power saving analysis
The formula for calculating the power consumption of the luminaire during operation is:
Where P - the electric power consumed by the bulb; U - the voltage supplied to the bulb; R - the impedance of the bulb.
Once the bulb has been shipped, its impedance R has been determined. Therefore, changing the supply voltage supplied to the luminaire, the electric power consumed by the luminaire will rapidly decrease as the square of the supply voltage drops.
Pin Header,Smd Pin Header,Double Row Pin Connector,Environmentally Friendly Pin Headers
Shenzhen Jinyicheng Electronci Technology Co.,Ltd. , https://www.jycconnector.com