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Central Banks in major industrialized economies have struggled to keep inflation within their target ranges since the global financial crisis. The periods of missing inflation and deflation experienced in the post-crisis era have led to doubts about the traditional Fisher effect as a crucial component of the policy reaction function. We explore the NeoFisherian theory, which suggests an alternative causal relationship between the policy rate and inflation. We focus on the USA, UK, and EU and apply wavelet coherence analysis to examine the time–frequency lead–lag comovements on data spanning from January 2007 to March 2023. Our findings indicate increasing NeoFisherian dynamics, notably post-2013 taper tantrum, implying that Central Banks in industrialized economies have misunderstood monetary policy dynamics. [ABSTRACT FROM AUTHOR]

The Under-Frequency Load Shedding (UFLS) scheme is an emergency measure in place to prevent system collapse in the event of a large generation deficit relative to demand at any moment in time. However, the effectiveness of traditional UFLS schemes may be compromised as network power flows change due to the growth of distributed generation (DG) and a reduction in system inertia. This study has shown some of the issues affecting the UFLS protection system with rising installed capacities of DG in the Great Britain power system. Simulation results show how the effectiveness of the scheme is challenged with current and future expected DG installed capacities and the risk of over shedding demand due to the scheme’s current settings is evaluated. Many proposed improvements to traditional load shedding schemes are based on upgrades to network monitoring and communication systems, which are not yet fully available. This study evaluates more readily available solutions, including relocation of under-frequency relays and reducing the time delay of the scheme, which may provide interim improvements to the UFLS scheme, based on a case study in GB. [ABSTRACT FROM AUTHOR]

The reduced inertia levels in low-carbon power grids necessitate explicit constraints to limit frequency’s nadir and rate of change during scheduling. This can result in significant curtailment of renewable energy due to the minimum generation of thermal plants that are needed to provide frequency response (FR) and inertia. Additional consideration of fast FR, a dynamically reduced largest loss and under frequency load shedding (UFLS) allows frequency security to be achieved more cost effectively. This paper derives a novel constraint from the swing equation to contain the frequency nadir using all of these services. The expected cost of UFLS is found probabilistically to facilitate its comparison to the other frequency services. We demonstrate that this constraint can be accurately and conservatively approximated for moderate UFLS levels with a second order cone (SOC), resulting in highly tractable convex problems. Case studies performed on a Great Britain 2030 system demonstrate that UFLS as an option to contain single plant outages can reduce annual operational costs by up to $\pounds $ 559 m, 52% of frequency security costs. The sensitivity of this value to wind penetration, abundance of alternative frequency services, UFLS amount and cost is explored. [ABSTRACT FROM AUTHOR]

This letter analyzes the difficulty of estimating power system inertia under ambient conditions using the Center-of-Inertia (CoI) system model. We show that the main obstacle to doing this is a difficulty in detecting a peak in the Power Spectral Density (PSD) of the frequency trace. This is due to a combination of two factors: (i) the Ornstein-Uhlenbeck (OU) process with a high mean-reversion time, which models the load disturbance and is mathematically equivalent to a low-pass filter with a high time constant; (ii) the CoI dominant mode is highly damped. This observation also explains why it is possible to estimate system inertia under ambient conditions using wide-area PMU measurements by exploiting information about inter-area oscillations which have lower damping than the dominant mode of the CoI model. We validated those findings by using the PSD of the actual 2-hour frequency trace for Great Britain from 00:00 to 02:00 of January 01, 2019. [ABSTRACT FROM AUTHOR]

In Part I of this paper we have introduced the closed-form conditions for guaranteeing regional frequency stability in a power system. Here we propose a methodology to represent these conditions in the form of linear constraints and demonstrate their applicability by implementing them in a generation-scheduling model. This model simultaneously optimises energy production and ancillary services for maintaining frequency stability in the event of a generation outage, by solving a frequency-secured Stochastic Unit Commitment (SUC). We consider the Great Britain system, characterised by two regions that create a non-uniform distribution of inertia: England in the South, where most of the load is located, and Scotland in the North, containing significant wind resources. Through several case studies, it is shown that inertia and frequency response cannot be considered as system-wide magnitudes in power systems that exhibit inter-area oscillations in frequency, as their location in a particular region is key to guarantee stability. In addition, securing against a medium-sized loss in the low-inertia region proves to cause significant wind curtailment, which could be alleviated through reinforced transmission corridors. In this context, the proposed constraints allow to find the optimal volume of ancillary services to be procured in each region. [ABSTRACT FROM AUTHOR]

This paper establishes some stylized facts of the long-run relationship between growth and labor shares using historical data for the USA (1898–2010), the United Kingdom (1856–2010), and France (1896–2010). Performing individual country time–frequency analysis, we demonstrate the existence of long-term cycles in labor share of 30–50 years explaining a major part of the variance in the data. Further, the impact of labor share on growth changes sign with the frequency considered from negative at high frequencies to positive at low frequencies. Finally, the positive coefficient associated with the labor share at low frequencies increases over time. [ABSTRACT FROM AUTHOR]

The undergoing transition from conventional to converter-interfaced renewable generation leads to significant challenges in maintaining frequency stability due to declining system inertia. In this paper, a novel control framework for Synthetic Inertia (SI) provision from Wind Turbines (WTs) is proposed, which eliminates the secondary frequency dip and allows the dynamics of SI from WTs to be analytically integrated into the system frequency dynamics. Furthermore, analytical system frequency constraints with SI provision from WTs are developed and incorporated into a stochastic system scheduling model, which enables the provision of SI from WTs to be dynamically optimized on a system level. Several case studies are carried out on a Great Britain 2030 power system with different penetration levels of wind generation and inclusion of frequency response requirements in order to assess the performance of the proposed model and analyze the influence of the improved SI control scheme on the potential secondary frequency dip. The results demonstrate that the inclusion of SI provision from WTs into Unit Commitment (UC) can drastically impact the overall system costs. [ABSTRACT FROM AUTHOR]

Power-hardware-in-the-loop (PHIL) is a vital technique for realistic testing of prototype systems. While the application of power electronics-based amplifiers to enable PHIL capability has been widely reported, the use of motor-generator (MG) sets as the PHIL interfaces has not been fully investigated. This article presents the realization of the first MW-scale PHIL setup using an MG set as the power amplifier, which offers a promising solution for testing novel systems for the integration of distributed energy resources. Uniquely, this article presents a methodology that introduces augmented frequency and phase control loops that can be integrated to commercially-available MG set's existing frequency controller for precise frequency and phase tracking. Internal model control is used for the controllers design and tuning. The developed control algorithm is tested in a MW-scale MG set that couples a Great Britain (GB) transmission network model simulated in a real time simulator to an 11 kV distribution network. Experimental results are presented, which demonstrate that the proposed control methodology is highly effective in maintaining the synchronization between the simulated and physical systems, thereby capable of enabling the MG set as a PHIL interface. [ABSTRACT FROM AUTHOR]

The reduced level of system inertia in low-carbon power grids increases the need for alternative frequency services. However, simultaneously optimizing the provision of these services in the scheduling process, subject to significant uncertainty, is a complex task given the challenge of linking the steady-state optimization with frequency dynamics. This paper proposes a novel frequency-constrained stochastic unit commitment model which, for the first time, co-optimizes energy production along with the provision of synchronized and synthetic inertia, enhanced frequency response, primary frequency response and a dynamically-reduced largest power infeed. The contribution of load damping is modeled through a linear inner approximation. The effectiveness of the proposed model is demonstrated through several case studies for Great Britain's 2030 power system, which highlight the synergies and conflicts among alternative frequency services, as well as the significant economic savings and carbon reduction achieved by simultaneously optimizing all these services. [ABSTRACT FROM AUTHOR]

• A realistic case study of overvoltage amplification in a 400 kV network is analysed and presented. • Energisation and fault inception involving new cables, led to overvoltage values at remote nodes that are close to switching withstand voltage. • Time and frequency domains analysis explained the causes of amplification. • Surge arresters are effective mitigation option for overvoltage amplification. The paper investigates overvoltage propagation in a 400 kV network within the National Grid Electricity Transmission system in the UK. The studies were triggered by a replacement project for two parallel 400 kV cables and the installation of an additional one. The network in the vicinity of the cables has historical issues of flashover and circuit breaker failures. Electromagnetic transient studies were performed to simulate energisation and fault inception and clearance for the three new cables to examine compliance against overvoltage standards and limits. Studies were performed using the DIgSILENT analysis tool. Studies show that due to resonance in a specific frequency range, switching overvoltage propagated and amplified at remote nodes to a level close to the equipment's rated switching voltage. As mitigation, surge arresters with characteristics different from the National Grid recommended surge arresters were proposed and found suitable to bring the overvoltage values within the design limits for temporary overvoltage. [ABSTRACT FROM AUTHOR]

Electricity demand forecasts are needed for decisions regarding generation dispatch for lead times as short as just a few minutes. Imbalance between generation and demand causes deviation of the system frequency from its target, which in Great Britain is 50 Hz. This, in turn, causes a change in demand, due largely to motor loads. For Great Britain, the change is estimated to be 2.5% of demand per 1 Hz of frequency deviation from its target. This can be used to calculate the demand that would have occurred if frequency had been at 50 Hz. Modeling and forecasting the resulting frequency-corrected demand provides a better basis for dispatching generation. This paper evaluates methods for forecasting frequency-corrected demand up to 10 min ahead. We introduce an exponential smoothing model that, like the system operator's proposed Kalman filter approach, jointly models frequency and demand. We also evaluate a set of univariate methods applied directly to the series of frequency-corrected demand. These methods have not previously been considered for lead times less than 10 min. In our empirical analysis, the best results were produced by a seasonal exponential smoothing method applied directly to the series of frequency-corrected demand. [ABSTRACT FROM AUTHOR]

In this article, wavelet tools and economic sentiment indicators are used to study the similarity and synchronization of economic cycles in the eurozone. The time-varying and frequency-varying patterns of business cycles synchronization are assessed and the impact of the creation of the European monetary union ( EMU) in 1999 is tested. Among several results, it is found that: the EMU is associated with a significant increase in the similarity and synchronization of the economic sentiment in the eurozone; and the hard-peg of its currency to the euro led to a comparable effect on Denmark's economic sentiment after 1999, different from what happened in the United Kingdom. [ABSTRACT FROM AUTHOR]

This paper makes three contributions. First we present a technique by which the monetary transmission mechanism of Germany, France, the UK and the Eurozone can be decomposed into its component cycles, compared across economies and across time. As a result, we found that the individual data generating processes have varied over time. Second we show that Germany has now converged on the rest of Europe and not vice versa, although Germany had dominated monetary policy making in Europe for many years. Third, we show that the UK as an outsider has behaved like a peripheral EMU country, even when EMU was not in place. In other words, the transmission mechanisms of Germany and the UK were fundamentally different. Hence, when that German monetary policy dominated Europe in a way that was not in line with the rest of Europe, never mind the UK, it is no surprise that the UK eventually left the ERM (1992). The current financial crisis may enforce the trend of convergence of the transmission mechanism. But there have been signs of a divergence between core and periphery, to some extent involving the UK, so this general convergence, as opposed to tighter convergence in the core, may not last. [ABSTRACT FROM AUTHOR]

The dating of a possible European business cycle has been inconclusive. At this stage, there is no consensus on the existence of such a cycle, or of its periodicity and amplitude, or of the relationship of individual member countries to that cycle. Yet cyclical convergence is the key consideration for countries that wish to be members of the currency union. The confusion over whether and to what degree the UK is converging on the cycles of its European partners, or whether its cycle is more in line with the US, is one example of this lack of consensus. Moreover, countries will vary in the components and characteristics that make up their output cycles at any moment, as well as in the state of their cycle. In this paper we show how to decompose a business cycle into a time-frequency framework. This allows us to decompose movements in output, both at the European level and in member countries, into their component cycles and allows those component cycles (and the coherence between them) to vary in their importance and cyclical characteristics. That then allows us to determine if the inconclusive convergence results obtained so far have appeared because member countries have some cycles in common, but diverge at other frequencies. [ABSTRACT FROM AUTHOR]