An Optimal Design Method for External Grid Connection Scheme of Electrified Railway

Abstract

The invention discloses an optimal design method for an external grid access scheme of an electrified railway, comprising the following steps: acquiring load process data and grid data of a traction substation; constructing a database of an external grid access scheme, and establishing a three-phase equivalent of the traction substation Model; construct a unified model of three-phase grid-traction power supply system, solve the positive and negative sequence voltage distribution on each bus; calculate the effective apparent power of the traction substation; pre-evaluate the limit of the voltage unbalance that is allowed to be injected into the public grid ; Calculate the capacity of the full-line compensation device; establish the objective function of the optimization model; construct the constraint conditions of the voltage unbalance degree of each bus; solve the optimization model to complete the optimal design of the external grid access scheme of the electrified railway; the present invention can obtain a reasonable external The grid access scheme avoids the problems caused by the lack of subjective experience of designers; at the same time, it can reduce the compensation capacity of the compensation device and save investment.

Description

technical field

[0001] The invention relates to the field of optimal design of a traction power supply system, in particular to an optimal design method for an external grid connection scheme of an electrified railway. Background technique

[0002] The 25kV power frequency single-phase traction power supply system is the core component of the electrified railway. However, as more and more high-speed railway lines are put into operation, the power quality problems caused by the traction power supply system in the public grid are becoming more and more prominent, especially the problem of voltage imbalance. This problem is particularly prominent in the central and western regions of China where the power grid structure is weak. Therefore, in the design stage of the traction power supply system, it is necessary to focus on how to solve the voltage imbalance problem generated by it, and at the same time meet the requirements of economy.

[0003] The external grid connection sc...

Examples

Embodiment

[0091] The topological structure of the embodiment in the present invention is as figure 1 shown. Comparing three external power grid access schemes, the combination u of the traction transformer wiring form in each traction substation is shown in Table 2.

[0092] Table 2. Traction transformer wiring combination u

[0093]

[0094] The commutation combination w of each traction substation is shown in Table 3

[0095] Table 3. Alternative Commutation Combination w

[0096]

[0097] The parameters of the three-phase power grid are shown in Table 4.

[0098] Table 4. Three-phase grid parameters

[0099]

[0100] After programming calculation, the calculation results are shown in Table 5.

[0101] Table 5. Calculation results

[0102]

[0103] Table 4 shows the calculation results of three external grid access schemes; according to Table 4, it can be known that the external grid access scheme f(w 2 ,u 2 ) is the global optimal scheme, the capacity of the negat...

technical field

[0001] The invention relates to the field of optimal design of a traction power supply system, in particular to an optimal design method for an external grid connection scheme of an electrified railway. Background technique

[0002] The 25kV power frequency single-phase traction power supply system is the core component of the electrified railway. However, as more and more high-speed railway lines are put into operation, the power quality problems caused by the traction power supply system in the public grid are becoming more and more prominent, especially the problem of voltage imbalance. This problem is particularly prominent in the central and western regions of China where the power grid structure is weak. Therefore, in the design stage of the traction power supply system, it is necessary to focus on how to solve the voltage imbalance problem generated by it, and at the same time meet the requirements of economy.

[0003] The external grid connection sc...

Examples

Embodiment

[0091] The topological structure of the embodiment in the present invention is as figure 1 shown. Comparing three external power grid access schemes, the combination u of the traction transformer wiring form in each traction substation is shown in Table 2.

[0092] Table 2. Traction transformer wiring combination u

[0093]

[0094] The commutation combination w of each traction substation is shown in Table 3

[0095] Table 3. Alternative Commutation Combination w

[0096]

[0097] The parameters of the three-phase power grid are shown in Table 4.

[0098] Table 4. Three-phase grid parameters

[0099]

[0100] After programming calculation, the calculation results are shown in Table 5.

[0101] Table 5. Calculation results

[0102]

[0103] Table 4 shows the calculation results of three external grid access schemes; according to Table 4, it can be known that the external grid access scheme f(w 2 ,u 2 ) is the global optimal scheme, the capacity of the negat...

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