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Article
Publication date: 15 February 2024

Yumin He, Tingyun Gu, Bowen Li, Yu Wang, Dongyuan Qiu, Yang Zhang and Peicheng Qiu

Electric spring (ES) is a demand response method that can stabilize the voltage of critical loads and improve power quality, especially in a weak power grid with a high proportion…

Abstract

Purpose

Electric spring (ES) is a demand response method that can stabilize the voltage of critical loads and improve power quality, especially in a weak power grid with a high proportion of renewable energy sources. Most of existing ESs are implemented by voltage-source inverter (VSI), which has some shortcomings. For example, the DC-link capacitor limits the service life of ES, and the battery is costly and hard to recycle. Besides, conventional VSI cannot boost the voltage, which limits the application of ES in high-voltage occasions. This study aims to propose a novel scheme of ES to solve the above problems.

Design/methodology/approach

In this work, an ES topology based on current-source inverter (CSI) without a battery is presented, and a direct current control strategy is proposed. The operating principles, voltage regulation range and parameter design of the proposed ES are discussed in detail.

Findings

The proposed ES is applicable to various voltage levels, and the harmonics are effectively suppressed, which have been validated via the experimental results in both ideal and distorted grid conditions.

Originality/value

An ES topology based on battery-less CSI is proposed for the first time, which reduces the cost and prolongs the service time of ES. A novel control strategy is proposed to realize the functions of voltage regulation and harmonic suppression.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 43 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 10 September 2018

Yuvaraja T. and K. Ramya

The purpose of studying the low voltage direct current (DC) microgrid, which uses computerised control system techniques, an orderly coordination control stratagem considering…

Abstract

Purpose

The purpose of studying the low voltage direct current (DC) microgrid, which uses computerised control system techniques, an orderly coordination control stratagem considering optimisation of a hybrid energy storage system (HESS) was projected in this paper.

Design/methodology/approach

The projected control stratagem was divided into three levels: topmost power dispatch level, transitional bus voltage regulation level and bottommost converter control level.

Findings

At the topmost power dispatch level, the cost of system stability was introduced, which is related with state of charge and discharging power of HESS.

Originality/value

Furthermore, the cost of system stability and HESS depreciation was compared with commercial price, and HESS switches its operating mode to discharge more at higher price or charge more at lower price to ensure the DC microgrid in economic operation. At the transitional bus voltage regulation level, DC bus gesturing is used as a control signal to achieve an autonomous decentralised operation of DC microgrid. The Matlab/Simulink simulation inveterate that the economical and autonomous decentralised operation can be achieved through the control stratagem.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 37 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 2 November 2015

Jian-Xin Shen, Dong-Min Miao and Mengjia Jin

The purpose of this paper is to focus on various control strategies for permanent magnet synchronous generator (PMSG) systems, in order to stabilize the dc link output voltage

Abstract

Purpose

The purpose of this paper is to focus on various control strategies for permanent magnet synchronous generator (PMSG) systems, in order to stabilize the dc link output voltage over a wide operation speed range.

Design/methodology/approach

Two control methods, namely, the flux regulation control (FRC) which adjusts the stator flux linkage and then indirectly stabilize the dc link voltage, and the direct voltage control (DVC) which directly stabilize the dc link voltage by regulating the power angle, are proposed in this paper. Both methods can be realized by either approach of the conventional space vector pulse width modulation (SVPWM) or the proposed single voltage vector modulation (SVVM).

Findings

The FRC can optimize the field in the PMSG, however, the realization is complicated. The DVC need not estimate and regulate the stator flux linkage, hence is easy to implement. On the other hand, the SVPWM can provide smooth armature current and dc link voltage, while the SVVM applies only one voltage vector during each control cycle, hence, is simple to realize and requires the minimum switching on the PWM rectifier. All cross-combinations between the two control methods and the two realization approaches work well.

Originality/value

The proposed FRC and DVC methods are simpler than the conventional field oriented control, while the proposed SVVM is a novel and efficient approach to generate the PWM status. Optimal cross-combination, either of SVPWM-FRC, SVVM-FRC, SVPWM-DVC and SVVM-DVC, can be chosen to satisfy the system characters and requirements.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 34 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 6 September 2022

Lijian Quan and Guohui Zeng

In the event of a DC short-circuit fault in a flexible DC power grid, the high peak value of the fault current puts forward more stringent requirements on the DC circuit breaker…

53

Abstract

Purpose

In the event of a DC short-circuit fault in a flexible DC power grid, the high peak value of the fault current puts forward more stringent requirements on the DC circuit breaker. The existing fault current cutoff mainly focuses on changing the topology structure. To suppress the development of fault current and reduce the investment cost of the DC grid, this paper aims to propose a dual-loop active current-limiting control based on energy difference.

Design/methodology/approach

Firstly, the equivalent circuit at fault is established, and the parameters related to the fault current are analyzed. Then, the relationship between the output voltage change of the bridge arm and the difference between the AC and DC energy is deduced. Finally, the experimental results are discussed on the real-time simulation platform Opal-RT.

Findings

The proposed current-limiting measures can greatly reduce the fault current, reduce the breaking current of the circuit breaker and increase the capacitor voltage during the fault period, which is beneficial to the stability of the AC system. It is verified that the proposed method is also applicable to a certain high-resistance fault.

Originality/value

This paper applies the method of AC fault to DC fault and deduces the relationship between energy difference and voltage variation corresponding to different step lengths based on digital simulation. In addition, two variables are used as control structure parameters to reduce the probability of system misoperation.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 42 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 5 September 2016

Anan Zhang, Shi Chen, Fan Zhang, Xuliang Zhang, Hongwei Li and Xue Gong

It is very indispensable for the various control centers of multi-transmission system owners (TSOs) grids to coordinate their reactive power optimization (RPO) efforts. However…

Abstract

Purpose

It is very indispensable for the various control centers of multi-transmission system owners (TSOs) grids to coordinate their reactive power optimization (RPO) efforts. However, such coordinated equilibrium point is comparatively hard to achieve unless one TSO control center could obtain all grids’ information in detail, which may lead to confidential issue and heavy communicating load. The purpose of this paper is to propose a solution to optimizing the reactive power control efforts among multi-TSOs grids with a mathematic interconnection model and reasonable communication cost.

Design/methodology/approach

Based on the interconnected power network equation, the stability-related optimum reactive power injection and the power-loss-related optimum reactive power injection were derived, respectively. Furthermore, according to the decomposition-and-coordination-based computing methodology, a coordinated RPO model for interconnected TSOs was designed, taking into consideration both the static voltage stability and economy.

Findings

The extreme values for the indicator L of power grid voltage stability and active power loss function were found and proved to be minimums. According to these extreme values, an expression for the reactive power injection at interconnected nodes between TSOs grids was obtained, and a coordinated strategy of RPO was established, which could take the static voltage stability and economy into consideration without confidential concern.

Originality/value

The existence of minimum values for indicator L of voltage stability and power loss was demonstrated, respectively. And the method presented in this paper can ensure the safety of information among different TSO grids, i.e. avoiding confidential issues. In particular, the coordinated control method can be implemented on the local power grid without knowing all of the parameters of its interconnection.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 35 no. 5
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 3 January 2017

Kosei Shinoda, Xavier Guillaud, Seddik Bacha, Abdelkrim Benchaib and Bruno Francois

Self-commuted voltage source converter (VSC) can significantly extend the flexibility and operability of an HVDC system and be used to implement the concept of multi-terminal HVDC…

Abstract

Purpose

Self-commuted voltage source converter (VSC) can significantly extend the flexibility and operability of an HVDC system and be used to implement the concept of multi-terminal HVDC (MTDC) grid. To take full advantage of MTDC systems, its overall behaviour must be characterized in quasi static and dynamic states. Based on the numerous literatures, a dedicated two-level VSC model and its local controllers and DC grid voltage regulators are developed for this purpose. Furthermore, the requirement of the system to guarantee all the physical constrains must be well assessed and concrete demonstrations must be provided by numerical simulations.

Design/methodology/approach

First, a two-level VSC model and its local controllers and DC grid voltage regulators are developed. Then, DC cable models are investigated and their characteristics are assessed in the frequency domain. Those developed models are combined to form a three-terminal HVDC grid system on Matlab/Simulink platform. To analyze the stability of this electrical system, the dynamics of the system against variations of power dispatch are observed.

Findings

To analyze the stability of this electrical system, the dynamics of the system against variations of power dispatch are observed. The differences in the DC grid voltage dynamics and the power flow of the converter stations coming from the embedded primary controls are analysed, and the technical requirements for both cases are assessed.

Originality/value

In this paper, the dynamic stability of an MTDC system has been analysed and assessed through an adequate simulation model, including its control scheme and the cable models. The interest of the improved PI model for cables is highlighted.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 36 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 August 2004

Renuganth Varatharajoo and Mohamad Tarmizi Ahmad

Flywheels can serve not only as attitude control devices, but also as energy storage devices, thereby eliminating the need for conventional batteries. Hence, a combined energy and…

Abstract

Flywheels can serve not only as attitude control devices, but also as energy storage devices, thereby eliminating the need for conventional batteries. Hence, a combined energy and attitude control system (CEACS) consisting of a double counter rotating flywheel assembly is proposed for small satellites in this paper. The energy level in CEACS depends mainly on the flywheels' speeds. Therefore, a specific flywheel energy management strategy has to be implemented to take into account the limitations of the flywheels, which has not been established until today.

Details

Aircraft Engineering and Aerospace Technology, vol. 76 no. 4
Type: Research Article
ISSN: 0002-2667

Keywords

Article
Publication date: 16 December 2021

D. Naveen Kilari, A. Hema Sekhar, N. Sudhakar Reddy and N.P. Dharani

This paper aims to provide a permanent magnet synchronous generator (PMSG) wind turbine, which feeds electric power (AC) to the power grid. The converter, located on the machine…

Abstract

Purpose

This paper aims to provide a permanent magnet synchronous generator (PMSG) wind turbine, which feeds electric power (AC) to the power grid. The converter, located on the machine side, is used to produce the full amount of wind power. Research on wind energy conversion system (WECS) is carried out in this study using a direct wind turbine in MATLAB with constant and variable speeds.

Design/methodology/approach

This paper is about WECS using PMSG and is connected to a grid of two serial converters with common DC connections.

Findings

This paper aims to provide the value of DC connection voltage at its base, regardless of the wind speed alterations, the inverter's output ac voltage can be kept constant.

Originality/value

This paper aims to provide a Hill Climb Search maximum power point tracking (MPPT) algorithm is an effective control system for extracting maximum energy, also called voltage control, pitch control, phase-locked loop (PLL) controls, from a wind turbine. Using the Fuzzy controller, the grid side converter is controlled.

Details

International Journal of Intelligent Unmanned Systems, vol. 11 no. 1
Type: Research Article
ISSN: 2049-6427

Keywords

Article
Publication date: 16 April 2020

Nikhil Pachauri

In a power system, the purpose of automatic voltage regulator (AVR) is the voltage control of synchronous generator. Power system stability and security depends on the AVR.

Abstract

Purpose

In a power system, the purpose of automatic voltage regulator (AVR) is the voltage control of synchronous generator. Power system stability and security depends on the AVR.

Design/methodology/approach

The present work is concentrated on the precise terminal voltage control of AVR system and simultaneously maintaining the stability of the system. Therefore, an optimal proportional–integral–derivative (PID) controller is proposed. An optimization technique inspired from Mother Nature, i.e. water cycle algorithm (WCA) is used to evaluate the optimum parameter values of PID controller leading to WCA-tuned PID (WCA-PID). The performance of WCA-PID is compared with other controller reported in the literature.

Findings

Simulation results show that WCA-PID regulates the terminal voltage more preciously and accurately in comparison to other controller. Further, it is more robust toward parametric uncertainty, set-point tracking and disturbance rejection in comparison to other controller reported in the literature.

Originality/value

The work is not published anywhere else.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 39 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 May 2020

Jailsingh Bhookya and Ravi Kumar Jatoth

This paper aims to get the optimal controller parameters of fractional order proportional integral derivative (FOPID)/proportional integral derivative (PID) i.e. Kp, Ki, Kd, λ and…

Abstract

Purpose

This paper aims to get the optimal controller parameters of fractional order proportional integral derivative (FOPID)/proportional integral derivative (PID) i.e. Kp, Ki, Kd, λ and µ for designing controller in automatic voltage regulator (AVR) system.

Design/methodology/approach

A novel method is proposed to get the optimal controller parameters for designing controller in AVR system using improved Jaya algorithm (IJA). The time domain objective and regular integral error objectives are used to design the controller to estimate the performance of the AVR system based on optimal tuning FOPID/PID controller.

Findings

The proposed method captures time domain objective of the FOPID/PID controller design and demonstrates effective transient response and better control action. The efficient tuning of FOPID controller results in high superiority of control efforts.

Practical implications

The simulations of IJA-based FOPID/PID controller design method are performed in MatLab tool and compared with several methods in the recent state of the art and the same are observed to be robust for the AVR system.

Originality/value

The developed optimal FOPID/PID controller tuning using IJA optimization method is totally a new approach for the AVR system in the literature.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 39 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

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