A control method for railway purification power supply to improve continuous operation ability under inrush current

Abstract

The invention relates to a control method for improving the continuous operation capability of a railway purification power supply under an impact current, including active control loop processing, auxiliary control loop processing, unbalance suppression loop processing, and normalized modulation processing. Through the active control loop processing, the control gain is increased when the current is small and large, and the tracking speed is improved. Under the impact current, the control gain is reduced, and the voltage change rate is reduced to reduce the probability of the drive device turning off the IGBT; through the auxiliary control loop processing, the increase The control accuracy of the output voltage is improved; the output voltage of each phase is adjusted to suppress the unbalanced voltage when the three-phase currents are inconsistent through the unbalanced suppression loop processing; the DC voltage is normalized through the normalized modulation processing, so that the engineering Modulation processing; therefore, the control method of the present invention can realize stable control under various currents, especially under the impact current, reduce the probability of driver protection action, and improve the ability of continuous operation.

Description

technical field [0001] The invention belongs to the technical field of electrified railway power supply, and in particular relates to a control method for improving the continuous operation capability of a railway purification power supply under inrush current. Background technique [0002] Railway purification power supply is a new type of power supply device that has gradually emerged in recent years. It converts the 27.5kV voltage used by railway locomotives into a voltage suitable for railway power 10kV. These existing railway purification power supplies use power electronic converter technology to achieve rectification and inversion, and use controllable inverter technology to achieve stable output voltage, which is not affected by 27.5kV side voltage fluctuations and harmonics. However, the applicant found that: the 10kV side of the railway power contains multiple feeders, often including station feeders, self-closing lines, and through lines, and each feeder contains ...

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Problems solved by technology

However, the applicant found that: the 10kV side of the railway power contains multiple feeders, often including station feeders, self-closing lines, and through lines, and each feeder contains many transformers. When the impact current flows through the power electronic converter of the purification power device, on the one hand, because the current capacity of the IGBT device is limited, it is impossible to increase the flow capacity of the IGBT regardless of the cost. At the same time, limited by the development of IGBT devices, IGBT devices that can flow thousands of amperes of current are immature. When the current reaches a certain level that the IGBT can flow through the device, the driving device will turn off the IGBT to protect the IGBT from overcurrent damage; On the one hand, when the purification power supply device is subjected to a current impact, the huge impact current will cause a huge voltage drop on the impedance of the filter and the isolation transformer, and the huge voltage change rate will act on the filter to aggravate the impact current.

For the above problems, the extremely large inrush current caused the protection action of the driver, turned off the IGBT, caused the shutdown of the purification power supply device, and reduced the ability of continuous operation

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