Hybrid energy storage control system with variable coefficient load observer and design method thereof

Abstract

The invention relates to a hybrid energy storage control system with a variable coefficient load observer and a design method thereof; the output end of a hybrid energy storage device is connected respectively to a battery energy storage unit and a supercapacitor energy storage unit; the battery energy storage unit and the supercapacitor energy storage unit are parallelly connected to a direct-current bus respectively through a two-way DC-DC converter; the output end of a variable coefficient finite time load observer is connected to the input end of a hybrid energy storage control device; the variable coefficient finite time load observer uses real-time voltage and real-time current of the direct-current bus as inputs, and outputs load impedance estimated value to the input end of the hybrid energy storage control device; the hybrid energy storage control device controls the energy storage unit and maintains the voltage of the direct-current bus stable. Compared with the prior art, the hybrid energy storage control system has the advantages that finite time precise reconstruction of state is achieved, quick and accurate load state estimation is provided for the hybrid energy storage control device, and control performance of the energy storage system is improved.

Description

technical field [0001] The invention relates to the field of load control, in particular to a hybrid energy storage control system including a variable coefficient load observer and a design method thereof. Background technique [0002] The stability of the DC microgrid operation largely depends on the control performance of the hybrid energy storage system. Since the input variables of the hybrid energy storage control system contain load state feedback information, which is not easy to measure directly, it is necessary to use a load observer to obtain this information. information. However, most of the current load observers are discussed based on the Lyapunov stability sense. The accurate load state information can only be tracked in infinite time and cannot be obtained in limited time, which makes the controller unable to generate fast and accurate information. control law, which in turn affects the control performance of hybrid energy storage. [0003] Since the hybri...

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Problems solved by technology

However, most of the current load observers are based on the discussion of Lyapunov stability. Accurate load status information can only be tracked in infinite time and cannot be obtained in finite time. This makes the controller unable to quickly and accurately generate control law, which in turn affects the hybrid energy storage control performance

[0003] Since the hybrid energy storage system is a time-varying system, in which the load, bus voltage and circuit parameters are all time-varying parameters, the finite-time load observer with constant coefficients cannot observe the load information well

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