Loss reduction and energy saving measures of the h

2022-09-29
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Loss reduction and energy saving measures of distribution system (middle)

2.3 for the transformation of low-voltage distribution lines, expand the current carrying level of conductors

according to the selection principle of conductor section, the minimum section conductor that meets the requirements can be determined; But in the long run, it is not economical to choose the smallest cross-section conductor. If the theoretical minimum section conductor is increased by one to two levels, the cost saved by the reduction of line loss can be recovered in a short time. Active power loss of Conductor:

px=3ijsr0l (kw)

where: IJs calculation current, a

r0 conductor resistance, 12/km

l wire length, M

after the conductor section increases, the line loss decreases:

px=3ijs r0l (kw)

wx=3ijs r0lt (KWH)

where: PX line loss active power loss decreases, kW

wx line active power loss reduction value, in case of damage, replace the cable kwh

r0 line resistance reduction value, 12/km

t line operation hours, H

suppose that the electricity price per kilowatt hour is B yuan, and the price difference per meter of two adjacent sections of cables is e yuan, then after the section is increased, the reduced line loss electricity charge m and the increased line investment n are:

m= Wx B (yuan)

n=e L (yuan)

if m=n, then the saved electricity charge is equal to the increased investment, and we can get:

t=e/3ijs r0b (H)

assume vv 6 ／ lkv four core cable is laid underground, and the calculated current is the corresponding current carrying capacity at the ambient temperature of 30 ℃. The power saving effect after increasing the section is shown in the following table:

the above calculation only considers the active power loss of the line, and does not consider the impact of temperature rise decline after increasing the section. The reactive power loss of the line will also decrease after the section is increased

due to the guidance of local market supervision departments to strengthen the supervision of production source, the service life of the line is generally more than 10 years, and the economic benefits created by increasing cross-section energy conservation and loss reduction are very significant

2.4 reduce the number of contacts and contact resistance

in the distribution system, the connection between metal materials and conductors is common, and the number of connection points is large, which not only becomes the weak link in the system, but also an important factor causing the increase of line loss. It must be that our non-metallic materials in the car pay attention to the construction process of the lap joint to ensure that the conductors are in close contact, and can use resistance reducing agent to reduce the contact resistance by a small amount. Special attention should be paid to the lapping between different materials