Parallel current-sharing control method for energy storage converter based on power series decoupling

Abstract

The invention provides a parallel current-sharing control method for an energy storage converter based on power series decoupling. The parallel current-sharing control method comprises the following steps: firstly, acquiring current actually-measured active power Pi and reactive power Qi and comparing the current actually-measured active power Pi and the reactive power Qi with reference power commands Prefi and Qrefi to obtain device recirculation active power PHi and reactive power QHi; secondly, carrying out PI control to obtain d-axis component delta Vdi1 and q-axis component delta Vqi1 ofinitial adjustment quantity of output voltage; thirdly, constructing a coefficient matrix K according to equivalent parallel resistance and inductive reactance of PCS devices, multiplying the coefficient matrix K by the d-axis component delta Vdi1 and q-axis component delta Vqi1 of the initial adjustment quantity of the output voltage to obtain final adjustment quantities delta Vdi and delta Vqi of the output voltage; finally, superimposing a specified value Vd, q_set of the output voltage with the final adjustment quantities of the output voltage to obtain an output voltage directive value Vd, qrefi of the current PCS device; carrying out closed-loop control on the output voltage so as to control average active power and the reactive power of each PCS device. According to the parallel current-sharing control method for the energy storage converter based on the power series decoupling, disclosed by the invention, the influence from the deviation of actual parallel equivalent resistanceis considered, so that the current-sharing control precision and the current-sharing dynamic response speed are improved.

Description

technical field [0001] The invention belongs to the technical field of electric energy storage systems, and in particular relates to a decoupling control method when energy storage converters operate in parallel. Background technique [0002] When the microgrid operates independently, the energy storage system maintains the stability of the common bus voltage amplitude and frequency. Energy storage converters are the core components of energy storage systems. In order to meet the needs of large-scale energy storage, modular parallel technology is an effective method. [0003] Large-scale energy storage systems will be equipped with a centralized controller to monitor the operating status of each energy storage unit. The centralized controller is used to realize the synchronization of multiple energy storage devices, and at the same time, the power outer loop is fine-tuned through communication, ignoring the coupling between the circulating power; the cross-decoupling scheme...

AI Technical Summary

Problems solved by technology

The centralized controller is used to realize the synchronization of multiple energy storage devices, and at the same time, the power outer loop is fine-tuned through communication, ignoring the coupling between the circulating power; the cross-decoupling scheme based on the circulating power can ensure better static uniformity. current accuracy, but also ignores the effect of shunt impedance changes on decoupling performance

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