In this paper, we report on two analyses that support the need to reform processes for transmission and generator interconnection planning in the US. The first develops methodologies to quantify the multiple benefits of transmission and applies these methodologies in two sample transmission projects. Using 40 years of weather data, a methodology is developed to examine resilience to extreme weather events. Extensive sensitivity analysis is conducted across renewable energy and fossil-fuelled generator levels, gas prices, and load growth rates, to examine risk mitigation. Loss-of-load expectation analysis is used to examine resource adequacy benefits. Adjusted production cost, emissions, and enablement of high-quality renewable resources are also quantified. These methodologies are applied to two types of example transmission projects in ERCOT (Electric Reliability Council of Texas) to demonstrate a value-stacking approach. The second investigates cost savings for new generator interconnections through a proactive planned approach. A proactive planned approach can study larger numbers of projects or even look forward to anticipate projects due to public policies and may be able to right-size transmission facilities for the longer term rather than sequentially building many small facilities. In this analysis, we compare generator interconnection costs across three different levels of proactiveness in MISO (Midcontinent ISO) and SPP (Southwest Power Pool) to understand the importance of a proactive, planned approach for generator interconnection.

Grid-forming inverter-based resources are gaining attention as a viable mechanism for supporting significantly higher penetration of renewables as conventional synchronous generators are being retired or displaced in bulk power systems [1]. Because grid-forming resources emulate some of the physical characteristics of synchronous machines via control algorithms, this technology may help alleviate growing concerns related to decreasing inertia and reducing system strength in power grids. This paper is related to recent technology development of dual-fed wind-turbine technology with grid-forming capability.

Offshore energy hubs connect large amounts of offshore wind to a hub from where the generation can be transmitted to onshore, potentially linking to multiple surrounding countries. The benefits of such hubs, and the related meshed offshore grid to connect them, have been investigated in the North Sea. The system-wide impacts of offshore energy hubs in the Baltic Sea are less studied; however, the region is seeing increased interest in offshore wind development. This paper uses detailed offshore wind generation simulations and energy system optimisation to investigate the cost-effectiveness of offshore energy hubs in the Baltic Sea in different scenarios towards 2050. The results show that the largest deployment of offshore energy hubs occurs when the energy system is highly electrified. The strongest development of the offshore energy hubs occurs in the southern part of the Baltic Sea.

Transient stability is an essential property of electrical power systems. It describes the ability of the system to maintain synchronous operation of all generators. Classically, transient stability of individual generators is analyzed based on possible loss of synchronism after near short-circuit faults. In contrast, this paper considers transient stability of generator groups as a potential instability phenomenon in future grid scenarios. We investigate and analyze relevant factors of influence and countermeasures and modeling aspects to consider when studying the phenomenon. Based thereon we discuss the effectiveness of possible countermeasures. The main focus of this paper is to provide a better understanding of the underlying dependencies within the power system and their impact on the stability itself.

In conventional wide-area control schemes, the actuators are typically the power system stabilizers of synchronous machines. The control action, in this case, can not directly act upon the power-angle relationship of the machines. In this context, the gridforming control for power converters offers the opportunity of an effective wide-area control: grid-forming converters present in fact a direct formulation of the power-angle control law, and therefore the possibility of directly acting upon it. The paper proposes an extension of the grid-forming control, including a specific additional control action based on a remote frequency signal. The proposed concept is proved with a simple representative system, and then demonstrated with two application cases, the standard IEEE 39-bus system and the European power system. The results indicate that the proposed participation of grid-forming converters in the wide-area control leads to a considerable improvement of the dynamic characteristics of the system.

This paper addresses the issue of limiting currents of grid-forming converter systems in the event of a grid fault. Because power electronics are not capable of feeding in an unlimited amount of fault current, the control method must ensure that the current limits are not exceeded. The most trivial approach is to switch to current-controlled mode in case of a grid fault. This makes the fault current very easily controllable but can also lead to instabilities under certain circumstances, as this work shows. A second approach, which allows the grid-forming properties to be kept, is compared. The simulation results are obtained through experiments in a Hardware-in-the-Loop (HIL) test system. The analysation of the results yields to a better understanding of requirements for grid-forming current limitations for Fault-Right-Through (FRT) operations.

A concern from a grid owner perspective is how so-called hybrid power park (HPP) will influence the power quality (PQ) in their distribution grid. This project studies how PQ and on-load tap-changer operations are affected by a solar-wind HPP located in a Swedish municipality. PQ measurements were performed in ten-minute intervals during 2021 for relevant PQ parameters in wind and photovoltiaics (PV) power parks and a low-voltage substation all connected to the same 10/130 kV transformer and compared to two other load-dominated transformers. Results show that 'events' (i.e., deviations from PQ standards) were more common when measured at the connection points of the parks (130-132 events) than in a than in a load-dominated transformer (70 events). Events are slightly more likely when PV power generation dominates. However, only a few (sag) events may require the grid operator to act. Overall there are less tap changing operations in the transformer in which the HPP is connected compared to in a load-dominated transformer. This is probably due to a broader bandwidth in the tap-changer of the HPP transformer, which may cause future problems downstream. In conclusion, the grid operator should presently not be worried that the HPP will increase PQ issues.

With the shutdown of conventional power plants as part of the decarbonisation of the energy system, new capacities for system services are needed. Therefore, according to the EU's Electricity Balancing Guideline from 2017, Demand Response is to be integrated non-discriminatorily into the joint European mechanism for procurement of system services, which is currently being developed.

In Germany, the procurement of system services was last adjusted in 2020, so that flexibility options available at short notice can participate recently. This offers a new marketing option for industrial flexibility options. Expected revenues in this balancing energy market are higher than in the continuous intraday market. Nevertheless, the introduction of the balancing energy market has not fulfilled its objective of increasing competition and the costs for balancing energy are immense. However, complex analyses are necessary for optimised marketing in the balancing energy market, compared to the intraday market, where the attractiveness of flexibility marketing is also increasing.

In this paper, it is shown, that the prequalification mechanism for participation in the german energy balancing markets is currently too high, a hurdle for industrial demand response. Within the framework of European procurement, it must be possible to intensively integrate modern virtual power plants.

Meeting Canada's emission reduction targets requires a fundamental shift, not only in the infrastructure underpinning the supply and delivery of energy services, but also in the institutional frameworks that govern policy and investment decisions. Stakeholders' engagement in the energy transition is gaining momentum, but a communication gap between experts and decision makers is impeding the impact of model-based decarbonization analyses. This represents a substantial missed opportunity. We present three case studies that adopt a two-pronged strategy to co-create and co-deliver model-based insights. The first prong entails the development of an integrated energy modelling suite that provides a holistic perspective of energy systems that spans sectors, spatial-temporal scales, and energy vectors. The second prong entails a model implementation process, in which stakeholders and researchers co-develop 'Scenario Bundles' to analyze a particular project, policy, or target through a series of collaborative activities. We present three case studies, at the federal, inter-provincial and municipal scales respectively, that apply these two prongs in distinct stakeholder-driven modelling projects. We conclude with a critical analysis of the role of modelling and stakeholder engagement in effective decision making.

In recent years, more and more wind turbine manufacturers have been using test benches, such as the Dynamic Nacelle Testing Laboratory at Fraunhofer IWES in Bremerhaven, to test and optimize their turbines. To further accelerate the test phases, Fraunhofer IWES, together with the project partners Nordex Energy SE & Co. KG and Vestas Wind Systems A/S, has built a new test bench for grid compliance testing of reduced systems, consisting of the generator, the converter, and the transformer plus control as well as protection system. The HiL-GridCoP project demonstrated the comparability of test bench measurements on a wind turbine equipped with a doubly-fed induction generator with field measurements performed using a fault ride-through container. The aim of this paper is to present some of the key findings related to the electrical commissioning and test execution. The focus is on the grid simulator and on its impedance simulation functionality. It is discussed which limitations may be caused by specific test bench components and which issues might affect the test results. Finally, some measurements of voltage dips are presented to verify the test bench's comparability with field tests so that the full electrical certification can be carried out next.