A Three-phase Voltage Unbalance Compensation Method for Traction Power Supply System Considering the Effect of Wind Farm

Abstract

The invention discloses a three-phase voltage unbalance compensation method for a traction power supply system considering the influence of a wind farm. Wind farm-grid voltage unbalance propagation model; establish traction power supply system-grid voltage unbalance propagation model; based on the above steps, solve the reference current of the compensation device that meets the three-phase voltage unbalance compensation target; The mathematical relationship between the three-phase voltage unbalance compensation reference current of the power supply system and the traction transformer branch and the power flow controller branch is used to solve the traction transformer branch current equation; according to the power balance relationship and the traction transformer branch current equation, the power flow controller branch is calculated. The reference current of the road is used to design the corresponding controller; the invention avoids the problem of unsatisfactory compensation effect caused by the existing compensation method, can match the actual compensation effect of the traction power supply system with the compensation target, optimize the compensation capacity of the traction power supply system, and can simultaneously Reduce the compensation capacity of the traction power supply system and save investment.

Description

technical field

[0001] The invention relates to the technical field of electric energy quality control for traction power supply systems of electrified railways, in particular to a three-phase voltage unbalance compensation method for traction power supply systems considering the influence of wind farms. Background technique

[0002] my country will focus on building an electrified railway network in western China. The 25kV power frequency single-phase traction power supply system is the only power source for high-speed EMUs and heavy-duty freight trains. Power quality problems represented by unbalanced three-phase voltage will affect the power system. Safe, reliable and efficient operation. On the other hand, the western region of my country is an important wind power base in China, and more than 32GW of wind turbines are installed in this area. This makes it possible for large-scale wind farms and traction power supply systems to be connected to the same grid point of comm...

Examples

Embodiment

[0097] The topological structure of the embodiment in the present invention is as figure 1 shown. The parameters of the traction power supply system are shown in Table 1.

[0098] Table 1. Traction power supply system parameters

[0099]

[0100]

[0101] The installed capacity of the wind farm is 100MVA, and the parameters of a single 1.5MW wind turbine are shown in Table 2.

[0102] Table 2. Parameters of a single 1.5MW wind turbine

[0103]

[0104] The grid transmission line unit impedance matrix is ​​shown below.

[0105]

[0106] In order to verify the effectiveness of the proposed method, three simulation cases are set up. From Case 1 to Case 2, the three-phase voltage unbalance control target is 2%, and the traction load is stepped from 15MVA to 30MVA; from Case 2 to Case 3, The traction load is 30MVA, and the three-phase voltage unbalance control target is stepped from 2% to 4%.

[0107] Table 3. Simulation study settings

[0108]

[0109] image...

technical field

[0001] The invention relates to the technical field of electric energy quality control for traction power supply systems of electrified railways, in particular to a three-phase voltage unbalance compensation method for traction power supply systems considering the influence of wind farms. Background technique

[0002] my country will focus on building an electrified railway network in western China. The 25kV power frequency single-phase traction power supply system is the only power source for high-speed EMUs and heavy-duty freight trains. Power quality problems represented by unbalanced three-phase voltage will affect the power system. Safe, reliable and efficient operation. On the other hand, the western region of my country is an important wind power base in China, and more than 32GW of wind turbines are installed in this area. This makes it possible for large-scale wind farms and traction power supply systems to be connected to the same grid point of comm...

Examples

Embodiment

[0097] The topological structure of the embodiment in the present invention is as figure 1 shown. The parameters of the traction power supply system are shown in Table 1.

[0098] Table 1. Traction power supply system parameters

[0099]

[0100]

[0101] The installed capacity of the wind farm is 100MVA, and the parameters of a single 1.5MW wind turbine are shown in Table 2.

[0102] Table 2. Parameters of a single 1.5MW wind turbine

[0103]

[0104] The grid transmission line unit impedance matrix is ​​shown below.

[0105]

[0106] In order to verify the effectiveness of the proposed method, three simulation cases are set up. From Case 1 to Case 2, the three-phase voltage unbalance control target is 2%, and the traction load is stepped from 15MVA to 30MVA; from Case 2 to Case 3, The traction load is 30MVA, and the three-phase voltage unbalance control target is stepped from 2% to 4%.

[0107] Table 3. Simulation study settings

[0108]

[0109] image...

Images