High-speed railway unbalance compensation topological system based on neutral section passing load linear regulation

Abstract

The invention provides a high-speed railway unbalance compensation topological system based on neutral section passing load linear regulation. The system comprises two parts consisting of a neutral section passing power supply topological structure and an unbalance compensation topological structure. The neutral section passing power supply topological structure is a three-phase topological structure, each phase of the topological structure comprises two parts consisting of an upper bridge arm and a lower bridge arm. The unbalance compensation topological structure is a single-phase structureand is formed by connection of a magnetic controllable reactor (MCR) and a third harmonic filter branch and a fifth harmonic filter branch in parallel to form a magnetically controlled static reactivecompensation module (MSVC). Compared to the prior art, the high-speed railway unbalance compensation topological system can perform bidirectional current taking according to the actual conditions ofthe traction networks at two sides to maintain the linear change relation of energy absorbed from the traction power supply arms at the two sides and maintain the constant energy summation to allow atrain to pass through the neutral section region without outage and to track and respond to the change of the traction load in real time so as to complete the effective compensation of the negative sequence current with no need for access of a transformer.

Description

technical field [0001] The invention belongs to the technical field of power electronics and relates to a high-speed railway unbalance compensation topology system based on linear regulation of excessive phase load. Background technique [0002] In my country's current power grid model, when there is a higher-level power grid, the lower-level power grid is often no longer operated in a loop. Therefore, when 110kV or 220kV is used to supply power to the traction transformer, unilateral power supply or radial power supply is often used. . When using this power supply method, the voltage difference between adjacent power supply arms is very large, and the power supply arms of different voltage phases cannot be directly connected, so there is an isolation section between the two-phase power supply arms, which needs to pass through the isolation link every 20-30km For electrical isolation, it is generally called an electrical phase separation area in the traction power supply sys...

AI Technical Summary

Problems solved by technology

The problem of electric phase separation and automatic over-phase separation has been seriously restricting the safe and reliable operation of high-speed and heavy-duty trains. In order to eliminate the problems of overvoltage and over-current during the process of over-phase separation, it is necessary to install a complex automatic over-phase separation device

However, this compensation method cannot quickly track and respond to sudden load changes, so it cannot effectively compensate the negative sequence current of the system; RPC consists of two single-phase voltage source inverters with a back-to-back structure based on turn-off thyristors (GTOs). The compensation method uses RPC to transfer active power, the value of the transferred active current is half of the load current, and the transfer direction is from the side with a small load to the side with a large load. In this way, both sides equal traction load power, thereby eliminating negative sequence currents

When this method is used for negative sequence compensation, since the voltage and current level that the RPC can withstand is low and the reliability is not strong, it is necessary to connect the circuit through a transformer at both ends of the RPC, which not only greatly increases the cost of the device, but also makes the active Increased compensation capacity and device footprint, leading to application limitations

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