You are presented with multiple paper abstracts, alongside the associated literature review and chapter titles. Given the provided information, you are going to do a literature review. Please generate a coherent literature review that synthesizes the content, draws connections between different works, highlights major findings, and identifies any gaps in the existing research.

Literature Review Title: A Review of Architectures and Concepts for Intelligence in Future Electric Energy Systems 
Chapter Title:  B. Central Control Concepts 
1. Abstract of Cited Paper (BIB001):  The widespread installation of distributed generation systems is crucial for making optimal use of renewable energy. However, local distribution networks face voltage fluctuation problems if numerous photovoltaic (PV) systems are connected. Recently, energy storage systems that can be installed at commercial customers have been developed. This paper proposes a concept that solves the voltage fluctuation problem in distribution networks with high penetration of PV systems by using customer-side energy storage systems. The distribution network operator (DNO) is allowed to control the output of the energy storage systems of customers during a specific time period in exchange for a subsidy covering a portion of the initial cost of the storage system. The cost effectiveness of the cooperative operation for both customer and DNO is discussed by numerical simulations based on minute-by-minute solar irradiation data. Our results have clarified the possibilities of making voltage management more economical in distribution networks. 
2. Abstract of Cited Paper (BIB002):  In this paper, a coordinated voltage control scheme utilizing electrical energy storage (EES) is presented, for future distribution networks with large, clustered distributions of low carbon technologies (LCTs) in terms of both feeder and phase location. The benefits of the EES integrated scheme over conventional voltage control schemes are demonstrated by realizing a set of network scenarios on a case study network both in simulation and in network in the loop (NIL) emulation at a smart grid laboratory facility. The case study uses a rigorously validated model of an actual GB distribution network with multiple EES installations. It was found that the EES integrated voltage control scheme is able to provide increased capability over conventional voltage control schemes and increase the value of EES to network operation.

Literature Review:
In contrast to autonomous control, central approaches need a functioning control unit and a communication network. Attached components do not make decisions by their own. An algorithm where storages provide voltage control with OLTC simultaneously on the low-and medium-voltage levels is shown in BIB003 . Single actions are rated based on their costs and impact with offline load flow simulations. A central controller optimizes component behavior based on measurements. The authors in BIB001 discussed a central control algorithm for voltage and frequency control for microgrids based on droop control. The battery storage system is the primary control unit for maintaining both voltage and frequency. It is only active when the microgrid changes to islanding mode. When in islanding mode, the battery ESS (BESS) is coordinated with local DERs over a central control unit. Sugihara et al. BIB002 proposed a central control approach where the distribution system operator (DSO) has direct control access to distributed storage systems at customer sides. Access is granted in exchange of a subsidy for the storage system. The described approach takes advantage of the reactive power compensation abilities of the storage converter. Voltage control facilitated by active power control is not included in the proposed approach. Like other control approaches, the decision foundation is based on characterization of the network via load flow calculations. The authors showed that the described approach allows the DSO to maintain acceptable voltage level on a cheaper base than with other measures. The paradigm of the distributed versus centralized control approaches is in the focus of attention, but the trend toward distribution is clearly identifiable. This is the only way out in such complex systems.