Frequency Control Ancillary Services Research Articles

Transactive control of community batteries for voltage regulation in distribution systems

With the proliferation of renewable energy sources in distribution systems, the grid operators are posed with the challenge of voltage regulation. Community batteries have significant capabilities in regulating network voltage but such potentials are rarely studied. The literature also lacks insights into how voltage regulation markets should co-exist with other grid service markets, such as battery energy arbitrage service and frequency control ancillary service (FCAS) markets. Therefore, this paper addresses these gaps by proposing a transactive platform for community batteries to trade voltage regulation services with the grid operator while providing other services. First, voltage sensitivity analysis is conducted to construct a voltage regulation demand curve based on the regulation needs of the system. Next, different operating conditions of battery inverters are investigated to model the cost of supplying voltage regulation. Various market-clearing rules are then established to determine the quantity and price of the voltage regulation service traded using the demand and supply curves. Technical analyses indicate that the proposed transactive platform is able to (1) price the voltage regulation service depending on the severity of voltage issues, (2) set a positive/negative regulation price when the system undergoes overvoltage/undervoltage conditions, (3) help battery owners gain considerable extra regulation revenue with proper incentivisation. This research provides guidance to incorporate voltage regulation service with the presence of other grid services and to implement voltage regulation markets to engage community batteries.

Stochastic economic model predictive control for renewable energy and ancillary services trading with storage

The provision of renewable-based ancillary services (AS) is paramount for the stable operation of power systems featuring high renewable penetration. The combined operation of storage with renewables enables aggregators to increase the reliability of their energy and frequency control AS offers. Existing dispatch strategies for the supply of both energy and AS are usually rule-based or involve tracking a technical reference signal, hence economically suboptimal for aggregators. This study proposes a comprehensive decision framework in which first a stochastic optimization derives bids on energy and AS markets, then stochastic economic model predictive control (SEMPC) optimizes the storage dispatch in order to maximize the profit and minimize the storage degradation, as a function of the predicted renewable production and the expected AS activation. The framework is applied to a real-world case study where storage combined with wind power participates in the energy market, the frequency containment market and the frequency restoration reserve market. The SEMPC-based approach increases market revenue by 15% compared to a standard reference-tracking MPC, and reduces storage degradation by 23%. The stochastic formulation lowers the sensitivity of the economic objectives to renewable energy forecast errors, compared to deterministic approaches.

Day-ahead dispatch with carbon trading for multi-regulation participation and emission reduction considering multi-type energy storage

In this work, a day-ahead dispatch optimization model with energy-type, power-type, and composite-type energy storage systems (ESSs) is established to participate in multiple frequency control ancillary services (FCASs), in wind-energy-integrated power systems. This model is designed to better handle the operational uncertainties of wind energy, mitigate operational risks and reduce carbon emissions. Leveraging the complementary features of different types of ESSs, the proposed operation strategies of regulation units can respond to multiple FCASs and achieve the optimal task allocation among different types of resources. Various uncertainty handling approaches are adopted to better cope with the randomness of step disturbances and wind power fluctuations. Furthermore, a new environmental factor is devised in the dispatch objective and the time-of-use carbon-price carbon emission trading (ToU-CET) and ladder-type CET (LT-CET) models are developed. They can incorporate dynamic carbon prices and leverage mechanisms to reduce carbon emissions during daily operations. The effectiveness of the proposed model is verified by case studies, and the decisions can help save energy and reduce carbon emissions in modern power systems with wind power generators with high security and reliability.

Fast Frequency Response for Future Low-Carbon Indian Power System: Challenges and Solutions

India has transitioned from being an energy-deficient nation to an energy-surplus nation. As of July 2023, India’s power system has seen a rapid transformation, with renewable energy, including large hydro, accounting for 40% of the total installed capacity at 177 GW. The ongoing energy transition has not only changed the country’s energy mix but also brought new challenges for system operators. The primary challenge is frequency instability due to the reduction of system inertia and governor-based primary frequency response (PFR) availability by large-scale integration of uncertain renewable energy resources (RES) such as wind and solar photovoltaic generators. Furthermore, the absence of frequency control ancillary services market, inadequate penetration of electric vehicles (EVs) and uncertainty of RES generation enhance the complexity of the frequency response services in the Indian power system. In this context, this paper presents a comprehensive review of the frequency response challenges of the future low-carbon Indian power system and underlines the new potential fast frequency response (FFR) services from advanced energy storage and renewable generation technologies. Such FFR services can be swiftly deployed in low-inertia grids through the integration of energy storage systems and inverter-based resources in a shorter span. Modeling of FFR services in security constraint unit commitment (SCUC) can enhance grid resiliency and facilitate high penetration of RES in the Indian power system without loss of frequency stability.

Research on Grid-Connected Optimal Operation Mode between Renewable Energy Cluster and Shared Energy Storage on Power Supply Side

The renewable energy cluster can reduce the total power deviation of renewable energy stations and also bring cooperative benefits to renewable energy stations. Shared energy storage can assist in tracking the power generation plan of renewable energy and has advantages in the scale of investment, utilization rate, and other aspects. Therefore, this article proposes a study on the grid-connected optimal operation mode between renewable energy cluster and shared energy storage on the power supply side. Firstly, for the complementary characteristics blurring each member’s contribution to the cluster power deviation, an improved Shapley value method is used to build a rational mechanism for apportioning the cluster power deviation penalty. Secondly, based on the Nash negotiation model and allocation mechanism, the revenue model of the renewable energy cluster is constructed, and an improved particle swarm optimization algorithm is proposed to solve the cluster operation strategy. Then, based on the charge and discharge demand of renewable energy cluster, with the goal of maximizing the benefits of shared energy storage, capacity pricing is optimized, as well as capacity allocation and participation in the frequency control auxiliary service market. Finally, the solving process of grid-connected optimal operation mode is proposed, and the rationality of the grid-connected optimal operation strategy between renewable energy cluster and shared energy storage is verified by example analysis. The results indicate that renewable energy cluster and shared energy storage can effectively increase both benefits, and a win-win situation for all parties can be realized. On the one hand, the cooperation mode and allocation mechanism can effectively guarantee the benefit of each renewable energy station. On the other hand, shared energy storage is beneficial for assisting in tracking the power generation plan of renewable energy and reducing the renewable energy power curtailment situation. There also has residual capacity in the shared energy storage system; it can participate in the frequency control ancillary service market, which can improve the capacity utilization rate and benefit of shared energy storage.

A Review of Uncertainties in Power Systems—Modeling, Impact, and Mitigation

A comprehensive review of uncertainties in power systems, covering modeling, impact, and mitigation, is essential to understand and manage the challenges faced by the electric grid. Uncertainties in power systems can arise from various sources and can have significant implications for grid reliability, stability, and economic efficiency. Australia, susceptible to extreme weather such as wildfires and heavy rainfall, faces vulnerabilities in its power network assets. The decentralized distribution of population centers poses economic challenges in supplying power to remote areas, which is a crucial consideration for the emerging technologies emphasized in this paper. In addition, the evolution of modern power grids, facilitated by deploying the advanced metering infrastructure (AMI), has also brought new challenges to the system due to the risk of cyber-attacks via communication links. However, the existing literature lacks a comprehensive review and analysis of uncertainties in modern power systems, encompassing uncertainties related to weather events, cyber-attacks, and asset management, as well as the advantages and limitations of various mitigation approaches. To fill this void, this review covers a broad spectrum of uncertainties considering their impacts on the power system and explores conventional robust control as well as modern probabilistic and data-driven approaches for modeling and correlating the uncertainty events to the state of the grid for optimal decision making. This article also investigates the development of robust and scenario-based operations, control technologies for microgrids (MGs) and energy storage systems (ESSs), and demand-side frequency control ancillary service (D-FCAS) and reserve provision for frequency regulation to ensure a design of uncertainty-tolerance power system. This review delves into the trade-offs linked with the implementation of mitigation strategies, such as reliability, computational speed, and economic efficiency. It also explores how these strategies may influence the planning and operation of future power grids.

The Levelised Cost of Frequency Control Ancillary Services in Australia’s National Electricity Market

Over the period 2016–2021 Australia’s National Electricity Market (NEM) experienced an investment supercycle with 16,000MW of new utility-scale renewable plant commitments in a power system with a peak demand of 35,000MW, and the disorderly loss of 5,000MW of synchronous coal-fired plant. This placed strains on system security, most visibly in the distribution of the power systems’ frequency, requiring material changes to the NEM’s suite of Frequency Control Ancillary Service (FCAS) markets. Utility-scale batteries are ideally suited for FCAS duties, but there is no forward price curve for FCAS markets, nor is there any systematic framework for determining equilibrium prices that might otherwise be used for investment decision-making. In this article, we develop an approach for quantifying long run equilibrium costs and stochastic spot prices in the markets for Frequency Control Ancillary Services, with the intended application being to guide the suitability of utility-scale battery investments under conditions of uncertainty and missing forward FCAS markets.

On static vs. dynamic line ratings in renewable energy zones

Scaling-up Variable Renewable Energy will face critical bottlenecks vis-a-vis requisite transmission hosting capacity. Network developments must navigate the complexity of encroaching on private land, risk disturbing sites of cultural significance, compete with other environmental (i.e. biodiversity) objectives, and endure backlash from directly affected communities. Transmission is costly and post-pandemic supply-chain constraints are sending equipment costs higher. Given time and cost risks, existing transmission networks and successful augmentations need to function at their outer operating envelope. In this article, a Renewable Energy Zone (REZ) is examined by comparing static, seaonal and real-time dynamic line ratings. Historically, seasonal line ratings in the Queensland region of Australia's National Electricity Market reflected the still, hot conditions that characterised critical event maximum demand days. Widespread take-up rates of rooftop solar PV has shifted maximum (grid-supplied) demand to the late-afternoon when wind speeds are rising, which also provides thermal cooling to transmission lines. Optimisation modelling suggests a shift from static to dynamic line ratings for a reference 275 kV radial REZ in Queensland can increase wind hosting capacity from ∼1700 MW to >2800 MW with limited change in the asset base. Dynamically adjusting Frequency Control Ancillary Services further increases VRE hosting capacity.

Bidding strategy of the virtual power plant consisting of thermal loads controlled by thermostats for providing primary frequency control ancillary service

The purpose of this article is to provide a model for the effective use of on/off loads and thermal loads controlled by thermostats (TCL) in providing primary frequency control (PFC). To this end, the mentioned loads have been aggregated in the form of a virtual power plant (VPP), allowing their cumulative capability to be offered as a bid for ancillary services. In order to determine VPP bids, a droop curve similar to the droop curve of traditional power plants has been extracted for VPP, which includes the technical limitations of VPP member loads. In formulating the VPP bidding strategy, the goal is to maximize profits and to use the capabilities of TCLs more effectively; their temperature set point is considered variable, as well as the constraint of compressor lockout, energy consumption level, device’s fire frequency and the duration of their continued response (deployment end) are incorporated in the model. The results of the model are the maximum power that can be provided to the primary frequency ancillary service market and its profit. The presented model has been simulated on a test system including 70 domestic loads in MATLAB software and checked under five different scenarios. According to the obtained results, considering the variable temperature set point for TCL leads to increasing the power of VPP by 7.33%. Moreover, considering compressor lockout constraint and increasing deployment end lead to a 22.4% and 3.54% reduction to the power of VPP respectively.

Economic Viability Assessment of Neighbourhood versus Residential Batteries: Insights from an Australian Case Study

Amidst the evolving paradigms of the contemporary energy landscape, marked by the imperative of sustainability and efficiency, the integration of energy storage has emerged as a transformative strategy that seeks to recalibrate the dynamics of electricity distribution and consumption. However, there remains a pressing need to determine the most economically viable approach for deploying energy storage solutions in residential low-voltage (LV) feeders, especially in rural areas. In this context, this paper presents the results of an economic evaluation of energy storage solutions for a residential LV feeder in a rural town in Australia. Specifically, the study compares the financial viability of a front-of-the-meter (FTM) battery installed on the feeder with that of a fleet of behind-the-meter (BTM) batteries. The FTM battery, with a size of 100 kW/200 kWh, is assumed to be operated by the retailer but owned by the community, with any profits assigned to the community. In this scenario, we studied a battery operating under standard network tariffs and three different trial tariffs that distribution network service providers currently offer in Australia. On the other hand, the fleet of BTM batteries (3 kW, 3.3 kWh) are individually owned by households with solar installations, and their cumulative capacity matches that of the FTM battery. The comparison is based on key economic parameters, including network charges, retail margins, frequency control ancillary service (FCAS) revenues, wholesale energy costs, technology costs associated with community batteries, and net profit or loss for the community, as well as considerations of utility grid arbitrage and solar photovoltaic (PV) self-consumption. The study also assumes different grant levels to assess the impact of subsidies on the economic feasibility for both battery configurations. The findings indicate that, while both require some form of subsidy for profitability, the BTM batteries outperform the FTM battery in terms of economic viability and so would require lower grant support. The FTM battery case finds a need for grants ranging from 75% to 95% to break even, while the BTM fleet requires approximately 50% in grants to achieve a similar outcome. In conclusion, this study highlights the importance of grant support in making energy storage solutions economically feasible. In particular, it highlights how the less mature segment of FTM batteries will need higher support initially if it is to compete with BTM. The outcomes of this study inform decision-making processes for implementing energy storage solutions in similar communities, fostering sustainable and cost-effective energy systems.

Optimal day-ahead large-scale battery dispatch model for multi-regulation participation considering full timescale uncertainties

Grid scale battery integration plays an important role in renewable energy integration and the formation of smart grid. To mitigate the problems of insufficient frequency response and peak regulation capacities faced by modern power grids with high wind energy uptake, a day-ahead optimization dispatch strategy considering operational risks is proposed in this study. In the day-ahead dispatch model, generation units and a large-scale battery energy storage station (LS-BESS) are coordinated to participate in multi-type frequency control ancillary services (FCASs). For optimal performance, scheduling in different timescales and the complementarity between power and energy types of requirements are coordinated, with various service uncertainties considered. Then the conditional value-at-risk theory is utilized to achieve the optimal mix of multiple resources for day-ahead regulation reserves, to realize the minimum operation cost. To tackle the uncertainty of wind power over a large timescale, a robust optimization (RO) approach based on the budget uncertainty set is employed, which considers robustness and economy. This can help avoid over-conservation of the standard RO and enhance the applicability of the decisions made. Simulation studies and comparison analysis of multiple schemes verify the effectiveness of the proposed optimal day-ahead dispatch strategy, which also demonstrate that a LS-BESS participating in multiple FCASs for day-ahead dispatch can help realize secure, reliable, and economic power grid.

Deep reinforcement learning for wind and energy storage coordination in wholesale energy and ancillary service markets

Wind energy has been increasingly adopted to mitigate climate change. However, the variability of wind energy causes wind curtailment, resulting in considerable economic losses for wind farm owners. Wind curtailment can be reduced using battery energy storage systems (BESS) as onsite backup sources. Yet, this auxiliary role may significantly weaken the economic potential of BESS in energy trading. Ideal BESS scheduling should balance onsite wind curtailment reduction and market bidding, but practical implementation is challenging due to coordination complexity and the stochastic nature of energy prices and wind generation. We investigate the joint-market bidding strategy of a co-located wind-battery system in the spot and Regulation Frequency Control Ancillary Service markets. We propose a novel deep reinforcement learning-based approach that decouples the system’s market participation into two related Markov decision processes for each facility, enabling the BESS to absorb onsite wind curtailment while performing joint-market bidding to maximize overall operational revenues. Using realistic wind farm data, we validated the coordinated bidding strategy, with outcomes surpassing the optimization-based benchmark in terms of higher revenue by approximately 25% and more wind curtailment reduction by 2.3 times. Our results show that joint-market bidding can significantly improve the financial performance of wind-battery systems compared to participating in each market separately. Simulations also show that using curtailed wind generation as a power source for charging the BESS can lead to additional financial gains. The successful implementation of our algorithm would encourage co-location of generation and storage assets to unlock wider system benefits.

Virtual Inertia Response and Frequency Control Ancillary Services From Hydrogen Electrolyzers

This paper presents the modeling foundations to study the capabilities of hydrogen electrolyzers (HEs) to provide frequency control ancillary services (FCAS), including virtual inertia and primary and secondary frequency response. To do so, we propose a general, unified HE dynamic model for the electrolyzer stack circuit, power-electronics interface (PEI), and relevant converter-level control loops. The equivalent circuit of the stack is derived from its current transfer function, with poles and zero obtained from its step response characteristics (e.g., rise/settling time). The stack model also considers relevant physical nonlinearities and downstream hydrogen buffer/process operational constraints. The PEI control loops account for stack model parameters, hydrogen production operational constraints, stack temperature dynamics, and active power reference generation strategy for contingency and regulation frequency support services. Further, we propose a virtual synchronous machine (VSM) control approach to study the VSM HE capabilities to also provide virtual inertia response. We apply the modeling to both alkaline and proton exchange membrane (PEM) technologies, including design of appropriate control schemes. Finally, we assess the FCAS performance of alkaline and PEM HEs via dynamic simulation of the Australian south-east interconnection in a 50%-renewable scenario, also discussing comparison and cooperation with battery energy storage systems.

Virtual Power Plant with Renewable Energy Sources and Energy Storage Systems for Sustainable Power Grid-Formation, Control Techniques and Demand Response

As the climate crisis worsens, power grids are gradually transforming into a more sustainable state through renewable energy sources (RESs), energy storage systems (ESSs), and smart loads. Virtual power plants (VPP) are an emerging concept that can flexibly integrate distributed energy resources (DERs), managing manage the power output of each DER unit, as well as the power consumption of loads, to balance electricity supply and demand in real time. VPPs can participate in energy markets, enable self-scheduling of RESs, facilitate energy trading and sharing, and provide demand-side frequency control ancillary services (D-FCAS) to enhance the stability of the system frequency. As a result, studies considering VPPs have become the focus of recent energy research, with the purpose of reducing the uncertainty resulting from RESs distributed in the power grid and improving technology related to energy management system (EMS). However, comprehensive reviews of VPPs considering their formation, control techniques, and D-FCAS are still lacking in the literature. Therefore, this paper aims to provide a thorough overview of state-of-the-art VPP technologies for building sustainable power grids in the future. The review mainly considers the development of VPPs, the information transmission and control methods among DERs and loads in VPPs, as well as the relevant technologies for providing D-FCAS from VPPs. This review paper describes the significant economic, social, and environmental benefits of VPPs, as well as the technological advancements, challenges, and possible future research directions in VPP research.

Stochastic Security-Constrained Economic Dispatch of Load-Following and Contingency Reserves Ancillary Service Using a Grid-Connected Microgrid during Uncertainty

In the context of the growing penetration of renewable power sources in power systems causing probabilistic contingency conditions, a suitable economic dispatch model is decisively needed. There is a lack of research in the field of probabilistic mathematical formulation considering the uncertainties due to the stochastic nature of renewables and contingency occurrence, as it is a very complex problem to be solved. The most appropriate model is the stochastic security-constrained economic dispatch (SSCED) model for optimized economic dispatch decisions during uncertainty. However, because of its complexity, it is rarely employed. This paper attempts to solve the complex SSCED problem in the presence of the uncertainty of resources and probabilistic contingency conditions, which is a novel effort in this regard. The SSCED is carried out over multiple periods to provide the load-following or contingency reserves. In the proposed SSCED, the uncertainty problem is addressed by modeling the stochastic wind energy power source by using “probability transition scenarios”. The uncertainty caused by probabilistic contingency conditions in the dispatch schedule is approximated using a “state-specific transition matrix”. The frequency control reserves in contingency conditions are co-optimized with energy, and stochastic security-constrained economic dispatch is achieved. The efforts are put forward to suggest a new market model in the presence of the uncertainty of renewable energy availability. Case studies are examined to show the potential technical and financial advantages of the proposed SSCED through co-optimization. Grid-connected microgrid owners offer frequency control ancillary services by providing load-following ramping reserves in the normal state and contingency reserves in the state of contingency. The probabilistic contingencies considered are generator failure and an underloading condition. A modified “IEEE 30 bus system” is considered a grid-connected microgrid for testing the proposed SSCED. The results show that the greater the flexibility of the resources, the greater the technical and economic benefits. The increase in ramping flexibility of a wind source results in almost an 8.1% reduction in operational costs compared to the base case. The contingency condition analysis shows that the presence of ramping reserves in the system enhances the power system performance, avoiding the cascading effects that ultimately cause a power system failure.

Assessing the impact of battery storage on Australian electricity markets

This paper empirically examines the impacts of grid-scale battery storage facilities on the frequency control ancillary services (FCAS) market that is used by energy market operators to maintain the frequency of the system within the normal operating band. Using a staggered introduction of grid-scale batteries in two Australian states, our difference-in-differences analysis shows that grid-scale batteries can significantly lower overall FCAS costs. We further show that the reduced FCAS costs are accentuated by the battery storage capacity, and that their impacts are most pronounced in reducing the costs of short-term FCAS markets (such as the regulation and 6-second services). These FCAS markets typically displace more expensive fossil-fuel participation. Given the large scale of both battery and renewable adoption in Australia, our results have policy implications for global energy markets.

Spotlight on the spot market: A review of the indian wholesale electricity market

The Indian Power Exchanges that started in 2008 have remained highly illiquid with less than 10 % liquidity in the day ahead market and short-term contracts after 14 years of operation. The dominance of long-term (25 year) Power Purchase Agreements (PPA) with coal power plants have stifled the wholesale spot market development and may jeopardize the successful integration of 450 GW renewables being targeted for 2030. The coal PPAs are inflexible with a significant take-or-pay provisions and are also more expensive than renewable generation in many cases. Although there has been a recent effort to bring in renewables in the spot market, it took the form of a separate “green” day ahead market rendering the market fragmented. The focus needs to be brought back to a layered integrated spot market which needs to be the fulcrum of all trade be it renewables, cross border trade and eventually frequency control ancillary services products. While contracts are an essential part of any market, their volume, tenure and prices, however, must be informed by spot prices. If India needs to achieve its 450 GW RE target (by 2030), there must be a reform of the thermal PPA regime to bring this generation into the day ahead and real-time spot markets to form a liquid and efficient marketplace.

Feasibility and flexibility regions estimation at TSO–DSO interconnection node using grid structure optimization

Major integration of renewable energy has raised the requirement of frequency and voltage control ancillary services. This necessitates to utilize distributed energy resources for grid flexibility solutions. Aggregated DERs’ flexibility at TSO-DSO node, identified by flexibility operating regions, can provide these services to the grid. Estimating the actual shape of the flexibility region for both slow and fast response systems, is important for real-time applications. However, correct estimation of this region is challenging due to its dependence on various factors, its non-convex shape, and high computational requirements. Proposed novel methodology named ‘Grid Structure Optimization’ can estimate the actual shape of the flexibility region for both slow and fast response systems without any prior shape approximation. The proposed approach is tested on modified IEEE 9 and 33 bus systems considering impacts of Q/P ratio, market dispatch point, cost and type of market. Results highlight the efficacy of this approach for real-time applications as the shape of the region completely avoids the possibility of infeasible points in the region. The results also indicate that the cost willingness is a factor of non-convexity on the feasibility region. Furthermore, the proposed approach is demonstrated to identify DER’s flexibility for contingency-based frequency control ancillary services. • Feasibility and flexibility regions are evaluated at TSO-DSO node using GSO. • True shape of feasibility regions is estimated without any convex approximation. • Effects of market and regulatory factors are highlighted on the feasibility region. • Non-convexity-inducing factors are identified for feasibility region. • Flexibility region of the slow response system is evaluated using GSO.

Optimisation and analysis of battery storage integrated into a wind power plant participating in a wholesale electricity market with energy and ancillary services

This paper examines the optimal performance of a wind farm and an integrated battery storage system in a wholesale electricity market. Participation in both the energy and Frequency Control Ancillary Services (FCAS) markets and imperfect generation forecasting are all considered. This problem is formulated as an optimisation that maximises the Net Present Value (NPV) of the wind farm and the battery while considering different market conditions and technical constraints. It is found that several, more advanced approaches to the integration and control of wind farm-battery systems can yield significant financial benefits to the asset owner by providing useful system services. These are not solely energy and FCAS services since all the considered approaches can also improve the wind farm’s ability to regulate its own power generation. As such, a battery that is integrated with a wind farm can create greater value than a stand-alone battery of the same size offering the same energy and FCAS services. Furthermore, realisation of these opportunities appears to be consistent with a relatively conventional wholesale market framework.

Autonomous vehicle-to-grid design for provision of frequency control ancillary service and distribution voltage regulation

We develop a system-level design for the provision of Ancillary Service (AS) for control of electric power grids by in-vehicle batteries, suitably applied to Electric Vehicles (EVs) operated in a sharing service. An architecture for cooperation between transportation and energy management systems is introduced that enables us to design an autonomous Vehicle-to-Grid (V2G) for the provision of multi-objective AS: primary frequency control in a transmission grid and voltage amplitude regulation in a distribution grid connected to EVs. The design is based on the ordinary differential equation model of distribution voltage, which has been recently introduced as a new physics-based model, and is utilized in this paper for assessing and regulating the impact of spatiotemporal charging/charging of a large population of EVs to a distribution grid. Effectiveness of the autonomous V2G design is evaluated with numerical simulations of realistic models for transmission and distribution grids with synthetic operation data on EVs in a sharing service. In addition, we present a hardware-in-the-loop test for evaluating its feasibility in a situation where inevitable latency is involved due to power, control, and communication equipments.