Recently, dc electric springs (dc-ESs) have been proposed to realize voltage regulation and power quality improvement in microgrids. This paper establishes a distributed cooperative control framework for multiple dc-ESs microgrid presents the small-signal stability analysis of system. The primary level implements droop coordinate operations dc-ESs. secondary is based on consensus algorithm regulate dc-bus reference, incorporating state-of-charge (SOC) balance among With design, can achieve...

With the increasing complexity of power grid and concerns on major blackouts, there is an urgent need for efficient effective tool to assess system structural vulnerability. To tackle this challenge, paper proposes a maximum flow-based complex network approach identify critical lines in system. The proposed method consists two steps. First, modeled as graph with edges (transmission lines, transformers, etc.) nodes (buses, substations, etc.). scenarios are identified by using principal...

Since wind generation is one of the most mature renewable energy technologies, it will have greatest share future portfolio. Due to special characteristics generation, best choice for grid connection infrastructure still not completely understood. In light practical project experience, this paper explores feasibility using HVDC transmission technology, especially multi-terminal (MTDC), as preferable solutions solve interconnection issue. The mainly focuses on application hybrid MTDC...

Following a converter outage in Multiterminal dc (MTDC) for offshore wind farm integration, the conventional droop control shares power mismatch to minimize impact on generation with fixed coefficient; however, it may easily lead overloading and large voltage deviation. The paper proposes fuzzy logic based adaptive controller, which utilizes available capacity of converters update coefficient. It can make compromise between deviation sharing. Furthermore, coefficient change stability MTDC...

This paper proposes a novel double-fed induction generator based wind-energy conversion system (WECS), which incorporates dynamic voltage restorer (DVR) and energy storage system. The DVR is in series with the output terminal of wind turbine (WTG) parallel to dc link WTG ESS. control scheme WECS designed suppress power fluctuations compensate grid disturbances, turn improve fault ride through capability penetration level. Finally, performance this investigated under various operation...

In recent years, the subsynchronous oscillation (SSO), which occurs in direct‐drive permanent magnetic synchronous generators (D‐PMSGs)‐based wind farm, has great impact on stability of power system. The different parameters and operation conditions D‐PMSGs lead to interaction (SSI) among D‐PMSGs. What is more, SSI will influence SSO characteristics system D‐PMSGs‐based farm integrated AC network. Here, considering difference or eigenvalue analysis, based small‐signal state‐space model two...

In the distribution network fault management, service restoration is a very important component. When occurs, it necessary to restore power these deenergized loads as soon possible. The problem could be formulated multilevel, multi-objective optimization with constraints [1].

This paper studies the feasibility of segmenting large power system interconnections with AC link using energy storage technology, similar to DC link, for improving dynamic stability. Firstly, segmentation validity interconnected technology is proved in terms theoretical analysis, and then a simple effective control strategy proposed. Moreover, influences device location capacity on proposed method are discussed detail. The effectiveness verified by simulations two systems.

In this paper, a multiagent system-based wide-area protection and control scheme is proposed to deal with the long-term voltage instability-induced cascading trips. Based on sensitivity analysis between relay operation margin power system state variables, an optimal emergency strategy defined adjust states timely prevent unexpected order supervise process further minimize load loss, agent-based adopted monitor of distributed controllers strategy. A hybrid simulation platform based LabVIEW...

This study presents a non‐linear adaptive control (NAC) for the energy storage system (ESS) embedded dynamic voltage restorer (DVR) in enhancing low‐voltage ride through (LVRT) capability of wind farms. The proposed NAC features perturbation observer to estimate and then compensate real whole system, including parameter uncertainties, measurement noise, external disturbances such as different grid faults intermittent power. It can achieve an robust without requiring accurate model full‐state...

Calculation of the complex torque coefficient for multi-machine system subsynchronous resonance (SSR) assessment had been proven a hard task. In this paper concept frequency domain port-equivalence conductance matrix (CPCM) is introduced to model individual component which represents relationship between terminal voltage and current in domain, overall power can be established easily. Thus coefficients generator unit under investigation calculated SSR assessment. The advantages proposed...

This paper taps on the participation ability of Electric Vehicles Aggregator (EVA) in Load Frequency Control (LFC). The focus here is EVA complete provision LFC using Vehicle-to-Grid technology. possible however it faces two main challenges. first one post-disturbance oscillations frequency when there a time delay system. To cope with these approaches are suggested. One application constraints designing model predictive control for LFC. Whereas other emulated inertial and droop support from...

Inland all-electric ship is receiving more and attention due to its advantages in terms of low carbon, energy conservation, flexibility operation mode. However, extensive promotion application are held back by various problems such as long charging time, high cost supplement, environmental factors, etc. In addition, the complexity electric fleet also poses a challenge optimal operation. Hence, an voyage scheduling model inland fleet, with departure time speed each decision variables, firstly...

In recent years, many large onshore wind farms are constructed or under construction all over the world. northwest region of China, planned capacity has reached 20GW in total. However, locations those very remote and far away from load centers, their distance to centers beyond 1000km. Therefore, it's primary importance address issues concerned with bulk power transmission long distance. This paper is aimed at development application using line-commutated converter based multi-terminal HVDC...

In this paper, a multi-agent system based wide area protection scheme is proposed in order to prevent long term voltage instability induced cascading events. The distributed relays and controllers work as device agent which not only executes the normal function automatically but also can be modified fulfill extra according external requirements. control center designed highest level MAS coordinate all lower agents disturbance. A hybrid simulation platform with MATLAB RTDS set up demonstrate...

Construction of the linearized state-space model is key step eigenvalue analysis for SSO study power systems with large-scale renewable generation (RPG) integrated. This paper proposes a novel method to construct state matrix AC/DC hybrid system RPG within discrete-time domain. The continuous-time each component as well units in system, discretized together their corresponding control. equation then represented by an equivalent circuit consisting parallel historical current and conductance....

With the extensive use of PMUs in power system, how to implement optimal PMU placement for complete system observability is becoming more and significant. Against simple genetic algorithm, easy fall into local minima, this paper proposed a effective adaptive aimed at determining PMUs. The algorithm provides crossover mutation probability iterations has better convergence global search ability than confirmed many practical applications. Generally speaking, minimum problem multiple solutions,...

In order to prevent long term voltage instability and induced cascading events, a load shedding strategy based on the sensitivity of relay operation margin powers is discussed proposed in this paper. The critical impedance backup defined identify runtime emergent states related system component. Based analysis between power state variables, an optimal applied adjust timely before unwanted operation. Load dynamics taken into account compensate amount calculation. And multi-agent technology...

The subsynchronous resonance (SSR) of a double-fed induction generator (DFIG) and its suppression method are studied in this paper. SSR may be aroused by the interaction between series-compensated transmission lines. This paper proposes an expression electrical damping for assessing stability based on complex torque method. is derived linearizing DFIG model at operating point. When mechanical neglected, can used to calculate whether positive or negative judge stability. quantitatively...

Most cascaded blackouts are caused by unexpected backup relay operations due to low voltage or overload state post fault load restoration dynamics. If such can be sensed and adjusted appropriately before those actions, system stability might sustained. This paper proposed a control protection cooperation strategy prevent instability. The multi-agent technology is applied for the implementation; criteria based on wide area measured impedances defined choose strategy, as tap changer adjusting...

Assuming that all electric vehicles (EVs) integrated to the grid are managed by aggregators, it is possible make full use of controllability charging EVs. Based on this, load each EV aggregator defined as one optimal scheduling variables in unit commitment (UC) model. This can be accomplished assessing upper and lower limit different scenarios, which simulated Monte Carlo method. According a UC model proposed for coordination aggregators wind generation, considering owner's requirement,...

This paper presents a new Maximum Power Loss Sensitivity (MPLS) method and Modified Plant Growth Simulation Algorithm (MPGSA) to find the optimal placement size of Distributed Generation (DG). study aims reduce total power loss improve voltage profile. The proposed solution has two steps: first, MPLS is used select position DG. Second, MPGSA capacity DG then applied on an IEEE 33-bus system. However, this proposal can be implemented for renewable non-renewable DGs. results algorithm were...

The Central China Power Grid (CCPG) and North (NCPG) are connected together by a single AC ultra‐high‐voltage (UHV) transmission link. When suffering power disturbances, oscillation with high magnitude long period would happen on the UHV tie‐line, which may affect synchronous stable operation of interconnected two grids. This study proposes novel emergency control scheme for high‐voltage direct current (HVDC) in CCPG to suppress peak value oscillation. Based two‐machine equivalent model,...