Accuracy Improvement Method of Energy Storage Utilization with DC Voltage Estimation in Large-Scale Photovoltaic Power Plants

Abstract

In regard to electric devices, currently designed large-scale distributed generation systems require a precise prediction strategy based on the composition of internal component owing to an environmental fluctuating condition and forecasted power variation. A number of renewable resources, such as solar or marine based energies, are made up of a low voltage direct current (DC) network. In addition to actively considering a power compensation plan, these generation systems have negative effects, which can be induced to a connected power system. When a storage is connected to a DC-based generation system on an inner network along with other generators, a precise state analysis plan should back the utilization process. This paper presents a cooperative operating condition, consisting of the shared DC section, which includes photovoltaic (PVs) and energy storage devices. An active storage management plan with voltage-expectation is introduced and compared via a commercialized electro-magnetic transient simulation tool with designed environmental conditions. Owing to their complexity, the case studies were sequentially advanced by dividing state analysis verification and storage device operation.

Practical Application Study for Precision Improvement Plan for Energy Storage Devices Based on Iterative Methods

“…As mentioned earlier, the main focus of this paper is to check control constraint of the accuracy improvement plan. A more detailed description of the structure can be found in [13]. In order to explain the ESS operation plan, a DC power flow method applied on two topologies is described in Section 3.…”

“…In a PV system, a current flows through the cathode for grounding. According to [13], a method was used to eliminate the current leakage in consideration of ground impedance. Since this study examined the impact of computational load with a focus on a previously used method of deriving current expectation based on real-time power output, the detailed resistance component between each PV module is applied to the admittance matrix.…”

“…In a PV based hybrid DC system, which adopts a storage application, to perform precise control in a region where there is a number of DESs, a compensatory calculation process for each signal may be necessary. With regards to this, a proposal about a voltage calculation method based on a power flow analysis that considers the current flow between the PV modules is presented in [13], with detailed description of a practical ESS application. The possible voltage fluctuations generated between cables which were reported in [14,15] was reflected and analyzed in [13].…”

“…Focusing on a distribution network, the voltage impact was established and analyzed to check the availability of additional signal compensation plan. The ESS model configurations, including control topologies, are composed as in [13] to implement a reasonable case design.…”

A State-Space Approach to the Modelling and Control of the Neutral Leg of a Four Legs, Three-Phase Inverter

“…Indeed, inverters must be used to interface DC sources [1] (e.g. photovoltaics [2,3] and storage systems) with the AC grid. Moreover, inverters could also be used to interface AC sources (e.g., wind-turbines [4,5] or hydro-turbines) to the AC grid.…”