Automatic generation control (AGC) executes a vital role to supply quality power in an interconnected power system. To cultivate good quality of power supply via preserving area frequency and tie-line power oscillations following consumer's load demand disturbances, the controller designed for AGC of power system should display excellent disturbance rejection expertise. Hence, in this paper, a maiden attempt is made to propose a fuzzy aided integer order proportional integral derivative with filter-fractional order integral (FPIDN-FOI) controller for AGC of multi-area power systems. A more recent intelligent optimization technique termed as imperialist competitive algorithm (ICA) is fruitfully employed for concurrent tuning of various parameters of the proposed controller. It is observed from the simulation results that the proposed FPIDN-FOI controller outperforms the various existing control strategies and PID/PIDN/FPIDN controller designed in the study for five different power system models. Effect of variation in fractional order value of integral on the system performance is analyzed. A sensitivity analysis is conducted to test the robustness of the designed controller under variations in the system parameters, load demands and existence of the system nonlinearities. It is perceived that the proposed controller is robust and executes adequately under variations in system parameters, random load disturbance patterns and nonlinearities.

Improvement in automatic generation control of two-area electric power systems via a new fuzzy aided optimal PIDN-FOI controller.

A paradigm shift in power generation technologies is happening all over the world. This results in replacement of conventional synchronous machines with inertia less power electronic interfaced renewable energy sources (RES). The replacement by intermittent RES, i.e., solar PV and wind turbines, has two-fold effect on power systems: (i) reduction in inertia and (ii) intermittent generation, lead to the degradation of the frequency stability. In modern power system, the frequency regulation (FR) has become one of the most crucial challenges compared to conventional system because the inertia is reduced and both generation and demand are stochastic. The fast responsive energy storage technologies, i.e., battery energy storage, supercapacitor storage technology, flywheel energy storage, and superconducting magnetic energy storage are recognized as viable sources to provide FR in power system with high penetration of RES. The important aspects that are required to understand the applications of rapid responsive energy storage technologies for FR are modeling, planning (sizing and location of storage), and operation (control of storage). This paper comprehensively reviews these important aspects to understand the applications of fast responsive storage technologies more effectively for FR services. In addition, based on the real world experiences this paper highlights the gaps and limitations in the state-of-the-art practices. Moreover, this study also provides recommendations and future directions for researchers working on the applications of storage technologies providing FR services.

A review on rapid responsive energy storage technologies for frequency regulation in modern power systems

In the rapidly expanding size and complexity of the electricity network, automatic generation control (AGC) is contemplated to be the most remarkable option for offering good quality electric power supply to the end users. An AGC system entails highly vigorous, competent and intelligent control technique to deliver a healthy power under stochastic nature of consumers’ power demand. Hence, in this paper, a hybrid fuzzy fractional order proportional integral-fractional order proportional derivative (FFOPI-FOPD) controller is proposed as a new expert control technique to tackle AGC profitably in isolated and interconnected multi-area power systems. A recently developed imperialist competitive algorithm (ICA) is utilized for the optimization of the output gains (KP/KP1/KI/KD) and other parameters such as order of integrator (λ) and differentiator (μ) of FFOPI-FOPD controller exercising integral of squared error criterion. The proposed technique is firstly implemented on 1-area thermal system, then to express its potential and extensibility, the work is extended to 2-area hydro-thermal and 3-area thermal power systems widespread in the literature. The eminence of the method is betokened by comparing the results with the various newly published control methodologies and FPI/FFOPI controller designed in the study via ICA in terms of minimum values of various error criteria and undershoots/overshoots/settling times of frequency and tie-line power deviations following a sudden load demand in an area. The sensitivity analysis substantiates that the suggested controller is robust and performs staunchly under the wide variations in the system parameters, random load pattern and in the company of physical constraints to produce more clean electricity.

A new optimized fuzzy FOPI-FOPD controller for automatic generation control of electric power systems

HVDC tie-link modeling for restructured AGC using a novel fractional order cascade controller

This study highlights an attempt of comparing the performance of several energy storage (ES) devices like battery ES, flywheel ES, capacitive ES, superconducting magnetic ES, ultra-capacitors and redox flow battery (RFB) in automatic generation control under bilateral deregulated scenario. The considered system comprises gas and thermal generations wherein a geothermal power plant (GTPP) is also incorporated. Gas and thermal systems are provided with appropriate generation rate constraints. A new fractional order (FO) cascade controller named as FO proportional-integral-FO proportional-derivative (FOPI-FOPD) is proposed as secondary controller and its performance is compared with commonly used classical controllers. A novel stochastic algorithm, sine cosine algorithm, has been used to optimise controller gains and other parameters. Analyses of dynamic responses reveal the superiority of FOPI-FOPD over others in terms of settling time, peak deviation and magnitude of oscillation. The effect due to GTPP introduction has been examined and the responses disclose that the integration of GTPP leads to better dynamics. Performances of various ES devices in the presence of FOPI-FOPD controller are also compared and dynamic responses of RFB found superior to others. For a more realistic scenario, analysis is done considering time delay and some practical plants of Nevada, USA.

Performance comparison of several energy storage devices in deregulated AGC of a multi-area system incorporating geothermal power plant

This study addresses the impact of ultra-capacitor (UC) on load frequency control of a restructured two-area multi-source system, incorporating conventional thermal and solar thermal power plant (STPP). The thermal system consists of single reheat turbine, appropriate generation rate constraint and governor dead band. Two generating companies and distribution companies are considered in each area. Maiden attempt has been made to use a cascade combination of integer-order (IO) proportional–integral–derivative with filter and fractional-order proportional–derivative (PIDN-FOPD) controller. Performance comparison of some commonly used IO controllers with proposed PIDN-FOPD controller reveals superiority of the latter in terms of peak deviations and settling time in policy schemes like poolco, bilateral and contract violation. A more recent optimisation technique called Whale optimisation algorithm (WOA) is successfully used for simultaneous optimisation of above controllers. Effect of UC using PIDN-FOPD has been studied for above policy schemes and analysis explores that use of UC improves the system dynamics. Sensitivity analysis reveals that WOA optimised PIDN-FOPD gains and system parameters are robust. It is also proved that PIDN-FOPD parameters obtained at nominal distribution companies participation matrix (DPM) are fit enough and parameters need not be optimised for change in DPMs.

https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/iet-gtd.2017.0083

Utilisation of ultra-capacitor in load frequency control under restructured STPP-thermal power systems using WOA optimised PIDN-FOPD controller

The present article deals with automatic generation control of a three-area multi-source thermal-gas (T-G) system with integration of distributed generation (DG), electric vehicles (EVs), and energy storage devices. Each thermal unit is equipped with a single reheat turbine, a generation rate constraint, and a governor dead band. A cascade combination of two degree of freedom proportional-integral-derivative with a filter (2DOF-PIDN) and a fractional order integrator controller [(2DOF-PIDN)-FOI] is proposed as the secondary controller for the system. A meta-heuristic algorithm, whale optimization algorithm, is utilized for simultaneous optimization of gains and other parameters of controllers PIDN, PIDN-FOI, and (2DOF-PIDN)-FOI. Critical observation reveals the superiority of the latter in terms of peak deviations and settling time (ST) for the T-G system under both step load perturbation and random load perturbation. Eigen value analysis is also performed for the T-G system with and without secondary con...

Performance analysis of combination of ultra-capacitor and superconducting magnetic energy storage in a thermal-gas AGC system with utilization of whale optimization algorithm optimized cascade controller

This article deals with automatic generation control (AGC) of an unequal two-area system under deregulated environment. Area-1 comprises distribution generation (DG) and thermal units and area-2 has gas and thermal units. The DG unit comprises wind turbine system (WTS), dish-Stirling solar thermal system (DSTS), aqua electrolyser, fuel cell, diesel generator, and battery energy storage system. A maiden attempt has been made to apply a cascade controller called integer order proportional–integral–derivative with filter (PIDN) cascaded with fractional order integral–derivative (PIDN-FOID) controller and its performance is compared with I, PI, and PIDN controller. Investigation reveals that PIDN-FOID outperforms in terms of peak deviations, settling time, and oscillations in both constant and variable conditions of wind speed and solar insolation. The effect of using WTS, DSTS, both WTS and DSTS on system dynamics is also evaluated and explored that system dynamics improves with integration of these renewable sources. The gains and other parameters are optimised by whale optimisation algorithm. The effect of DC link, redox flow battery, and both on system dynamics is also evaluated in the presence of PIDN-FOID controller and explores that the use of these shows promising dynamic performance. The robustness of controller gains and parameters are tested with change in size of contract.

https://ietresearch.onlinelibrary.wiley.com/doi/epdf/10.1049/iet-gtd.2017.1203

Combined application of redox flow battery and DC link in restructured AGC system in the presence of WTS and DSTS in distributed generation unit

https://onlinelibrary.wiley.com/doi/pdf/10.1002/etep.2646

Arindita Saha

Papers

Utilisation of ultra-capacitor in load frequency control under restructured STPP-thermal power systems using WOA optimised PIDN-FOPD controller

Performance analysis of combination of ultra-capacitor and superconducting magnetic energy storage in a thermal-gas AGC system with utilization of whale optimization algorithm optimized cascade controller

Combined application of redox flow battery and DC link in restructured AGC system in the presence of WTS and DSTS in distributed generation unit

Renewable energy source‐based multiarea AGC system with integration of EV utilizing cascade controller considering time delay

Load frequency control of a wind‐thermal‐split shaft gas turbine‐based restructured power system integrating FACTS and energy storage devices