Detection and Mitigation of Cyberattacks on Volt-Var Control

Cyberattacks are becoming more frequent, and attackers can use different mechanisms, such as denial of service (DoS) and false data injection (FDI). Furthermore, multiple attack types can be launched simultaneously, known as hybrid attacks, to cause more damage. Volt-Var control algorithms are widely used in the distribution system to maintain the voltage within a nominal range. This work uses an artificial neural network (ANN)-based method to detect and mitigate hybrid cyberattacks on the Volt-VAr control algorithm.Comment: Accepted by CIGRE Symposium Australia, 202

Impact of controllable superconducting series reactor in transient recovery voltage of circuit breaker

Series reactors as fault current limiters (FCLs) are extensively employed to enhance power grid protection issues. Utilizing superconducting technology is a viable solution to approach FCLs toward commercializing. The concern of transient recovery voltage (TRV) of the circuit breaker becomes more considerable due to FCL’s high stored energy in the case of fault current limiting mode. This paper firstly focuses on the analysis of TRV under the presence of an inductive-based superconducting fault current limiter (SFCL) installed in a power grid, and then it investigates the impact of a controllable superconducting series reactor (CSSR) in TRV of the circuit breaker. The obtained results show that the synchronous operation of a CSSR with a circuit breaker substantially declines TRV

Impact of controllable superconducting series reactor in transient recovery voltage of circuit breaker

Series reactors as fault current limiters (FCLs) are extensively employed to enhance power grid protection issues. Utilizing superconducting technology is a viable solution to approach FCLs toward commercializing. The concern of transient recovery voltage (TRV) of the circuit breaker becomes more considerable due to FCL’s high stored energy in the case of fault current limiting mode. This paper firstly focuses on the analysis of TRV under the presence of an inductive-based superconducting fault current limiter (SFCL) installed in a power grid, and then it investigates the impact of a controllable superconducting series reactor (CSSR) in TRV of the circuit breaker. The obtained results show that the synchronous operation of a CSSR with a circuit breaker substantially declines TRV

The Use of System in the Loop, Hardware in the Loop, and Co-modeling of Cyber-Physical Systems in Developing and Evaluating New Smart Grid Solutions

This paper deals with two issues: development of some advanced smart grid applications, and implementation of advanced testbeds to evaluate these applications. In each of the development cases, the role of the testbeds is explained and evaluation results are presented. The applications cover the synchrophasor systems, interfacing of microgrids to the main grid, and cybersecurity solutions. The paper hypothesizes that the use of the advanced testbeds is beneficial for the development process since the solution product-to-market cycle may be shortened due to early real-life demonstrations. In addition, solution users’ feedback to the testbed demonstration can be incorporated at an early stage when making the changes is not as costly as doing it at more mature development stages

Direct current power system stabilizers for HVDC grids: Current status

A power system stabilizer (PSS) is a control system integrated into the control structure of specific generation units within AC grids. It monitors current, voltage, and machine shaft speed. Analysing these variables, the PSS generates appropriate control signals to the voltage regulator unit, aiming to damp system oscillations. With the advancement of high-voltage direct current (HVDC) overlaid high-voltage alternative current (HVAC) grids, it is anticipated that direct current power system stabilizers (DC-PSS) will be developed to perform a similar role as their AC counterparts. DC-PSS will be responsible for monitoring and controlling DC voltage levels, ensuring stable operations. This paper focuses on DC-PSS in HVDC grids, designed to ensure stable operation and mitigate voltage fluctuations. Unlike conventional AC power systems, HVDC includes only DC voltage and power. The input signal for DC-PSS is the variations in DC voltage, and the output signal is proportional to the power changes at the specific bus where the DC-PSS is installed, aiming to minimize DC voltage oscillations. These characteristics pose significant challenges in DC-PSS. The paper addresses the challenges and highlights issues such as inertia and low-frequency oscillations associated with DC-PSS. Various control methods are presented and a comparison is made among these methods

Facilitating the transition to an inverter dominated power system : experimental evaluation of a non-intrusive add-on predictive controller

The transition to an inverter-dominated power system is expected with the large-scale integration of distributed energy resources (DER). To improve the dynamic response of DERs already installed within such a system, a non-intrusive add-on controller referred to as SPAACE (set point automatic adjustment with correction enabled), has been proposed in the literature. Extensive simulation-based analysis and supporting mathematical foundations have helped establish its theoretical prevalence. This paper establishes the practical real-world relevance of SPAACE via a rigorous performance evaluation utilizing a high fidelity hardware-in-the-loop systems test bed. A comprehensive methodological approach to the evaluation with several practical measures has been undertaken and the performance of SPAACE subject to representative scenarios assessed. With the evaluation undertaken, the fundamental hypothesis of SPAACE for real-world applications has been proven, i.e., improvements in dynamic performance can be achieved without access to the internal controller. Furthermore, based on the quantitative analysis, observations, and recommendations are reported. These provide guidance for future potential users of the approach in their efforts to accelerate the transition to an inverter-dominated power system

Load frequency control in variable inertia systems

Conventional load frequency control primarily relies on large synchronous generation units to ensure regulation of the system frequency. However, its performance deteriorates as the system parameters, including inertia and droop coefficients, deviate from original system design. This letter proposes an augmented load frequency control (ALFC) to ensure robust frequency regulation under diurnal variations in system parameters that are expected in the future, renewables-rich power system. The superior performance of ALFC is demonstrated by several case studies, and its stability is assessed by small-signal analysis

An improved nine‐level switched capacitor‐based inverter with voltage boosting capability and limitation of capacitor current spikes for PV applications

To proceed to a net zero carbon world and to mitigate the environmental challenges associated with it, integration speed of renewable energy sources such as photovoltaic (PV) systems has been increased around the world. Here, an improved switched-capacitor based nine-level inverter is introduced for PV applications. This topology has several benefits such as, voltage boosting feature, using a single DC source, reduction of capacitor charging current spike and extendable input voltage. This inverter produces nine-level output voltage waveform using single power supply. This topology, using identical two capacitors in parallel with a single DC source, can boost the input voltage. In this inverter to limit spike current of capacitor charging mode, an inductor is placed in the charging path of capacitors with a parallel diode. The power losses and overall efficiency analysis of the improved inverter are considered. To verify the accurate performance of inverter under a step change on power flows, simulation results are obtained by MATLAB/Simulink software and presented. To highlight the benefits of the inverter, a comparison of improved topology with most recent topologies is performed. Finally, to verify the feasibility and performance of the improved inverter, experimental results of a 770 W grid-tied prototype are presented