Voltage Management System Research Articles

An Optimal Parameterized Fractional-Order PID Controller for the Single Phase Grid Integrated with Solar and Wind System

The hybrid solar/wind power systems are the best renewable energy sources because of their complementary nature. The generation of electricity from wind and solar photovoltaic (PV) systems is greatly reliant on the weather. Their intermittent nature causes output fluctuations. As a result, the need for rapid compensation for energy transmission and distribution systems is becoming increasingly critical. In this article, an optimal parameterized Fractional Order Proportional Integral Derivative (FOPID) controller for a hybrid renewable energy system integrated with a single-phase grid. An amalgamation of solar PV and wind is presented as a way to provide continuous power from alternate sources. Furthermore, it is planned to design a robust output voltage management system that utilizes a FOPID controller for the output voltage regulation of the hybrid system integrated with the grid. A novel Randomly Updated Path Finder Algorithm (RU-PF) is proposed to optimize the FOPID gains. Hence, the proposed FOPID-based control for the single-phase grid connected to PV and wind system is simulated in MATLAB/Simulink, and their performance is examined. In particular, the fitness of the proposed RU-PF algorithm is 5.06%, 1.32%, 7.41%, and 0.88% superior to the extant PSO, FF, WOA, and PFA algorithms at the 25th iteration.

Cooperative voltage management by demand resources and fair payoff allocation for distribution systems

This paper proposes a socially acceptable framework for the realization of efficient voltage management by cooperation among consumers in electric distribution systems where the frequent voltage variation problem is caused by large amounts of photovoltaic (PV) generation systems. In the proposed framework, the profit maximization problem of the coalition under the constraints to suppress the voltage variations caused by PVs is formulated as a linear programming problem, and the payoff allocation among consumers is provided using a solution concept from cooperative game theory called the core. The proposed method efficiently computes the payoff allocation in the nonempty core to accomplish the cooperative voltage management system. Unlike most related works, this paper employs cooperative game theory to explicitly address incentives for cooperation with the consumers. Although the computation for finding an allocation in the core generally requires a significant amount of time, this paper demonstrates that the allocation can be efficiently calculated by using the dual optimal solution of a formulated linear programming problem. The proposed method is validated by computational experiments on a large-scale distribution system model in which consumers with demand resources (including PVs and controllable loads) are connected.

Implementation and Application of Voltage Management System to Physical Power System for Stable and Robust Operation

The paper describes implementation and application of voltage management system (VMS) to a physical power system for bringing stable and robust operation. The VMS has a role of balancing reactive power generation of the generators, which are controlled by the VMS. The VMS consists of continuous voltage controller (CVC) and discrete voltage controller (DVC). Those are used to maintain the system voltage within stable range. Especially, the CVC induces a supplementary signal to automatic voltage regulator (AVR) to balance reactive power generation of all involved generators. In the paper, the physical application of the VMS is described and the important considerations are introduced. Also, the paper shows the results of the stable application of the VMS.

Field Implementation of Voltage Management System (VMS) into Jeju Power System in Korea

This paper presents the results of field tests on Voltage Management System (VMS) using hybrid voltage control, which utilizes coordinated controls of various reactive power resources such as generators, FACTS and switched shunt devices to regulate the pilot bus voltage in a voltage control area. It also includes the results of performance test on RTDS-based test bed in order to validate the VMS before installing it in Jeju power system. The main purpose of the system is adequately to regulate the reactive power reserve of key generators in a normal condition with coordination of discrete shunt devices such as condensers and reactors so that the reserves can avoid voltage collapse in emergency state in Jeju system. Field tests in the automatic mode of VMS operation are included in steady-states and transient states. Finally, by the successful operation of VMS in Jeju power system, the VMS is proved to effectively control system voltage profiles in steady-state condition, increase system MVAR reserves and improve system reliability for pre- and post-contingency.

Design of Advanced Voltage Management System Including Manual Operation Mode via Real-Time Digital Simulator

This paper presents the design of the advanced voltage management system (AVMS) including manual operation mode in order to control reactive power generation in a practical power system. The existing secondary voltage controller (SVC) has a demerit occurring as a large transient phenomenon shortly after the SVC begins to work. This malfunction results from the difference of the operation statuses before and after the SVC operates. For solving the problem and implementing the voltage control safely, the AVMS including the manual operation mode is developed by Korea Electric Power Corporation. Aside from the fact that the AVMS overcomes the drawback, it can also execute the coordination control of both continuous voltage controller (CVC) and discrete voltage controller (DVC). The CVC controls reactive power generation sources such as generator and flexible ac transmission system devices which can generate reactive power continuously and linearly. On the other hand, the DVC controls the discrete reactive power sources such as switched shunt capacitors and reactors. The performances of the proposed AVMS are carried out by time-domain simulation in the Jeju Island power system with real-time digital simulator.

Systematic Design of Coordination Control between Damping Controller and SVC via Digital Simulator

AbstractThis paper describes a method to design an external controller for secondary voltage controller (SVC) and tune both controllers in order to improve transient stability with real-time simulation. Recently, Korea Electric Power Corporation (KEPCO) has developed a novel voltage management system (VMS), a kind of SVCs, and installed in Jeju Island. It has been operated successfully to balance reactive power reserve of the controlled generators and enhance the voltage stability. However, the VMS has an inherent demerit in short-term recovery after a disturbance such as load change and tripping transmission line occurs. In this paper, after having a discussion related to the demerit in detail, an external controller is proposed. Also, a method to tune the external controller for reducing the bad reaction of the VMS is implemented with real-time digital simulator (RTDS) which is a fully digital power system simulator in real-time. The performance is evaluated by time-domain simulation.

Studies of a High Voltage Management System in Electric Vehicles

Vehicle safety is one of the most important design elements for all types of vehicles designed for use on public streets or roadways. Compared with traditional vehicles, besides other safety issues to be considered, a new issue that is the high voltage management problem should be taken in consideration very carefully in the electric vehicle development. This paper analyses the high voltage system in the electric vehicle and proposed a high voltage management system which implements several functions like power-up and power-down control of the high voltage system, high-voltage-circuit interlock protection, protection of electric leakage of the HV system etc. Because of the high voltage management, the electrical safety goals could be achieved and the protection of human being from high voltage hazardous becomes possible.

Development and Installation of Voltage Management System for Voltage and Reactive Power Control of Wide Area System

KEPCO proposes enhanced voltage management system that is a coordinate voltage control system between the hierarchical voltage control system and the slow voltage control system. It has been installing in Jeju island. VMS consists of a master controller, CVC (Continuous Voltage Controller) and DVC (Discrete Voltage Controller). CVC consists of main controller, FDMU (Field Data Measurement Unit) and several RPDs (Reactive Power Dispatcher). CVC has a control scheme with AVRs of generator to maintain the voltage of a pilot bus in a power system, DVC has a control scheme with static reactive power sources, like a shunt capacitor, a shunt reactor, ULTC and so on, to maintain the reactive power reserve of a power system and a master controller is executed to recover reactive power margin of a power system through coordinated control between CVC and DVC.