A control method for energy storage converter topology with fault ride-through capability

Abstract

The invention discloses a control method for an energy storage converter topology with fault ride-through capability, wherein the converter topology includes three phase units, and each phase unit includes an upper bridge arm, a lower bridge arm, an upper bridge arm inductor, The lower bridge arm inductance, the upper and lower bridge arms of the three phase units are composed of half-bridge sub-modules and full-bridge energy storage sub-modules mixed in series; the method is to determine each phase bridge arm according to the output command voltage waveform of each phase. The modulated wave of each half-bridge sub-module and the similar full-bridge energy storage sub-module in each phase bridge arm is compared with the carrier wave and modulation wave of each sub-module to generate a control signal, which controls each sub-module in each phase bridge arm to input or cut off. The above-mentioned energy storage converter with fault ride-through capability can increase the inertia of the new energy system, and the charging and discharging current of the battery used for energy storage is smooth, and the voltage level is low, which ensures the efficient operation and safety of the battery. At the same time, it has the capability of DC side fault ride-through, and can still store energy when the DC side is faulty.

Description

technical field [0001] The invention belongs to the technical field of electrical automation equipment, and in particular relates to a control method for an energy storage converter topology with fault ride-through capability. Background technique [0002] In the existing technology, the sub-module with energy storage function directly connects the battery next to the capacitor of the sub-module, so that the battery can withstand the pulsating current of one or two times the power frequency, which has great impact on the efficient operation of the battery and the cost of the whole life cycle. Unfavorable; at the same time, the sub-module capacitor voltage in actual working conditions is generally greater than 1500V voltage level. For high-rate batteries represented by lithium-ion batteries, based on the balance of battery state of charge and fault protection, it is difficult to achieve in terms of cost and safety. Such a high series voltage. In addition, this sub-module wit...

AI Technical Summary

Problems solved by technology

In the event of a DC fault, DC fault ride-through is realized by blocking a part of the sub-modules, and provides reactive power support for the grid through another part of the sub-modules; this patent realizes fault ride-through by blocking the sub-modules and cooperating with the full bridge module and the clamping single sub-module, only Has the ability to ride through faults, but does not have the energy storage function in the event of a fault

Images