This paper present a coordinated allocation and control of Step voltage regulators (SVRs) and Static Var Compensators (SVCs) for voltage deviations in case distributed generations are installed in distribution networks. In the proposed method, the reactive tabu search (RTS) with multiple structures and functions has been applied to the coordination. Firstly, the locations of SVRs are selected optimally and secondly the tap positions of SVRs are optimized by the RTS. Finally, the locations of SVC are decided to brash up the voltage profile in the distribution network.The proposed method enables us to take account of the installation cost of both SVR and SVC as an economic criterion, the upper and lower limit of voltage at each node and also the upper limit of line currents as constraints. By applying the proposed method to a practical distribution test system, it is verified that this method is efficient to allocate SVRs and SVCs at the minimum cost and regulate the system voltages within an appropriate value after introducing distributed generations into the distribution system.
Keywords: expansion planning of distribution network, combinatorial optimization, reactive tabu search, SVC, SVR This paper presents a cooperative allocation method of Step Voltage Regulators (SVRs) and Static Var Compensators (SVCs) in case of some distributed generators (DGs) are installed to distribution system. In the proposed method, the Reactive Tabu Search (RTS) with multiple structures and functions has been applied. Firstly, the allocations of SVRs are selected optimally and secondly the tap positions of SVRs are optimized by the RTS. Finally, the locations of SVC are decided to brush up the voltage profile in the distribution network. The proposed method enables us to take account of the installation cost of both SVR and SVC as an economic criterion, the upper and lower limit of voltage at each node and also the upper limit of line currents as constraints. By applying the proposed method to a practical distribution test system, it is verified that this method is efficiency to allocate SVRs and SVCs at the minimum cost and to regulate the system voltages within an appropriate value after introducing distributed generators into a distribution system.In this paper, we applied to a simple radial distribution test system as shown in Fig. 1 and Fig. 2 to verify the efficient of proposal method. This test system is assumed to have two distributed generators for the sake of simplicity. Also, it assumes that the expansion and investment for voltage control equipment are required for the original test system by reason of the increase in loads. The optimal investment for voltage control equipment is solved by the proposed RTS with multiple structures procedure. Two optimization approach were assumed for examining this proposal method and making comparative study. Case 1 is the conventional expansion planning, which does not take connected distributed generators into consideration, and case 2 is proposal method. Figure 1. shows the result of conventional expansion planning and Fig. 2 shows the result of proposal expansion planning. In Fig. 1, the system has three SVRs and two SVC. The other hand, the system has two SVRs and one SVC in Fig. 2. Figure 3 show the voltage profile of both case 1 and case 2 before and after DGs stop. In both two cases, the voltage profile is kept within the reference value of voltage. From these result, proposal method enable us to regulate the system and decrease the investment cost of allocating the voltage control equipment effecively.In this simulation study, though,the system was not so big, this proposal method can decrease the investement cost more when the larger distribution system is applied the proposal expansion planningn method, which consider the connecting DGs and allocate cooperativly. In the future, it is more important to develop more sophisticated approaches to optimize locations and installation capacities of power system controllers to regulate the voltage deviations after introducing many distributed generations.
SUMMARYThis paper presents a method for cooperative allocation of step voltage regulators (SVRs) and static var compensators (SVCs) when some distributed generators (DGs) are installed in a distribution system. In the proposed method, reactive tabu search (RTS) with multiple structures and functions is applied. First, the allocations of the SVRs are selected optimally and then the tap positions of the SVRs are optimized by the RTS. Finally, the locations of the SVC are chosen in order to enhance the voltage profile in the distribution network. The proposed method enables us to take account of the installation cost of both SVRs and SVCs as an economic criterion, of the upper and lower voltage limit at each node, and also of the upper limit of line currents as constraints. By applying the proposed method to a practical distribution test system (IEEE 34 Node Test Feeder Model), it is verified that this method is efficient in allocating SVRs and SVCs at minimum cost and in regulating the system voltages within an appropriate range after introducing DGs into the distribution system.
The paper first describes the mechanism of the inadequate motion of a transformer's tap changer. We then outline the original fuzzy expert AVQC automatic Voltage and Reactive control) method in use at Tohoku Electric Power Company. We propose improved fuzzy expert and neural network methods to prevent unnecessary tap changer actions. In order to validate the improved method, simulations of tap changer behavior under various operating conditions were conducted. The results of the simulations and analyses are also presented. In the last section, we briefly recommend prudence in utilizing on-load tap changers under critical operating conditions in terms of transient stability of a power system. Index Term ---Voltage and reactive power control, Power system control, Fuzzy expert, Neural network control and BP algorithm, Power systems analysis I. LNTRODUCTION Voltage and reactive power control facilities, such as static condensers, shunt reactors, and SVR (Static Voltage Regulator) for EHV and UHV power systems, are not only expensive, but also limited in terms of available control capability. The control of voltage and reactive control of EHV and UHV bulk power transmission networks depend on the control capacity of large-scale generator units and on-load tap changers of transformers at EHV or UHV substations. In Tohoku Electric Power Company, all step-up transformers of large generating units at thermal and nuclear power stations have been equipped with on-load tap changers since 1968. The tap changers are locally operated by the conventional AVQC system. T. Minakawa and E. Monma are with the
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.