Dear Mr. Guo Weiguo. 20

Squatting and waiting together, I still don't know what the transformer circle means. If the foundation is not solid, knowledge is in the air.

10kv equipment:

10kV cable (incoming + outgoing.

10kV switchgear (incoming line + metering + voltage transformer + outgoing + capacitor.

10kV transformer.

Equipment: Switchgear (incoming line + outgoing line + capacitor +..)

Due to the different cabinet types, the products of various manufacturers are not the same, and the requirements of users are also different, but in general:

KV high-voltage main inlet cabinet, outlet cabinet, capacitor cabinet, high-voltage motor cabinet.

The main structure is the cabinet shell, which contains 1-2 groups of isolation switches, 1 group of circuit breakers, 1-2 groups of current transformers, 1 group of overvoltage absorbers, 1 group of constant current displays, 1 group of electric heaters, some grounding switches, as well as protection devices, temperature and humidity automatic controllers, ammeters, power factor meters, etc.

KV high-pressure metering cabinet.

The main structure is the cabinet shell, which contains 0-1 groups of isolation switches, 1 group of high-precision voltage transformers, 1 group of fuses, 1 group of high-precision current transformers, 1 group of constant current displays, 1 group of electric heaters, as well as temperature and humidity automatic controllers, active and reactive energy meters, etc.

KV high-voltage transformer cabinet.

The main structure is the cabinet shell, which has 1 group of isolation switches, 1 group of fuses, 1 group of lightning arresters, 1 group of constant current displays, 1 group of electric heaters, and some have protection devices, temperature and humidity automatic controllers, voltmeters, etc.

4kV low-voltage total feeder.

The main structure is the cabinet shell, which is equipped with 1-2 groups of isolation switches, 1 group of universal circuit breakers, 1 group plus 1 current transformer, some of which have electric heaters and cooling fans, and there are switch operation buttons and isolation switch operation holes in the cabinet shell, as well as ammeters, voltmeters, power factor meters, etc., and some are also equipped with electric energy meters.

4kV low-voltage outlet cabinet.

The main structure is the cabinet shell, which is equipped with 1-N groups of isolation switches, 1-N groups of low-voltage circuit breakers, N groups or N current transformers, some of which have electric heaters and cooling fans, and there are switch operation buttons and isolation switch operation holes in the cabinet shell, as well as ammeters, voltmeters, power factor meters, etc., and some are also equipped with electric energy meters.

Generally speaking, electricity is from the power line through the high-voltage power cable to the high-voltage incoming switchgear, through the bus of the switchgear, mostly connected by copper bar, and then connected to the transformer through the high-voltage outgoing switchgear outgoing cable, the electric energy drawn from the transformer leads to the low-voltage incoming switchgear through the low-voltage cable, and then leads out of the branch by the low-voltage switchgear for people to use;

10kv cable - high voltage cabinet - 10kv cable - transformer cable (or busbar) - low voltage switchgear

Knowing the electricity consumption for 24 hours a day, you can calculate the average load current of Pingyouzhi on this day, but you can't calculate the maximum load current, and the maximum load current of closed bending needs to be obtained even by meter reading;

If the primary voltage of the main transformer is 35kV and the power factor is , then:

The daily average current is sensitive to i=80000 (

If the primary voltage of the main transformer is 10kV and the power factor is , then:

The average daily current is i=80000 (

I guess your teacher can see it???

I doubt it

I went on a business trip and came back late, sorry.

1. The "standard voltage" of the low-voltage station area is, so the calculation of the voltage qualification rate of the low-voltage station area is subject to this number, that is, the voltage qualification range is 380 (1 7%)V;

2. "Class D voltage monitoring points should be set up at the first and last ends of the representative low-voltage distribution network and some important users". Therefore, the secondary outlet line in the station area is the head end of the low-voltage distribution network, and the 380V user entrance can be regarded as one of the ends, so it should be monitored.

The load capacity ratio is one of the important technical and economic indicators reflecting the power supply capacity of urban grids. The load capacity ratio is too large, and the early investment in power grid construction increases; The load capacity ratio is too small, and the adaptability of the power grid is poor, which affects the power supply.

The substation load ratio is the ratio of the substation capacity (kVA) of the urban network to the corresponding load (kw) on the basis of satisfying the reliability of power supply, which is the index of macroscopic control of the total substation capacity, and is also the basis for the distribution of substation capacity in planning and design. The capacitance load ratio of urban network substation should be calculated according to voltage stratification. The capacity of the step-up substation of a power plant to supply power to the regional distribution network is included in the power substation capacity.

The transformer capacity and load of the substation dedicated to users of the same level voltage network shall be deducted.

The size of the substation capacitance load ratio is related to the calculation parameters, and also related to the location, quantity, and mutual transfer capacity of the distribution points, that is, it is related to the power grid structure, and the estimation formula of the substation capacitance load ratio is:

rs＝ k1·k4/ k2·k3

where rs is the load capacity ratio (kva kw),

k1 is the load dispersion factor

k2 is the average power factor

k3 is the transformer operating rate

k4 is the reserve factor.

220kv power grid, 35 110kv power grid.

The network structure should be strengthened and improved, and the network structure should be established to meet the reliability requirements and reduce the load capacity ratio, so as to improve the economic efficiency of investment. For example, the substation increases the number of main transformers, the secondary power grid increases the ability to transfer loads, improves the power factor, improves the degree of automation, and improves the load of each substation point and the accuracy of the substation capacity configuration.

For two 40MVA main transformers, the calculation of the maximum load of the month is, the load capacity ratio = capacity and the maximum load = is correct. Represents the proportion of the maximum load to the total substation capacity.

With the development of the economy and the gradual advancement of power grid construction, the load capacity ratio will become larger and larger.

Teacher Guo Weiguo is on vacation and will come back another day.