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The regenerative ABS is developed to avoid slip and to regenerate energy using two types of braking: friction and motor. This paper discusses the experimental results of combining the two types of braking which are applied to a quarter-electric vehicle model. The control algorithm is developed using sliding mode control (SMC), where continuous action is performed to produce motor braking torque while discrete action is performed to produce hydraulic braking torque (friction). Furthermore, the proposed control system also implements control coordination to distribute braking torque, enhances the occurrence of the non-slip process, and generates energy for vehicle batteries. From the experimental results, it is concluded that the slip ratio value can be used to obtain the optimum conditions for the braking process, where the hydraulic torque as the cause of the slip, is limited through the braking distribution algorithm. The proposed control system produces a response with a brake speed of 2 m/s and a 3.39% increase in battery SOC.

The regenerative ABS is developed to avoid slip and to regenerate energy using two types of braking: friction and motor. This paper discusses the experimental results of combining the two types of braking which are applied to a quarter-electric vehicle model. The control algorithm is developed using sliding mode control (SMC), where continuous action is performed to produce motor braking torque while discrete action is performed to produce hydraulic braking torque (friction). Furthermore, the proposed control system also implements control coordination to distribute braking torque, enhances the occurrence of the non-slip process, and generates energy for vehicle batteries. From the experimental results, it is concluded that the slip ratio value can be used to obtain the optimum conditions for the braking process, where the hydraulic torque as the cause of the slip, is limited through the braking distribution algorithm. The proposed control system produces a response with a brake speed of 2 m/s and a 3.39% increase in battery SOC. [ABSTRACT FROM AUTHOR]

This paper introduces the concept of adaptive coordination of damping controllers for enhancing power system stability. The coordination uses phasor measurement units (PMUs) to adapt to different disturbances by selecting the switching status (on/off) of damping controllers that minimizes an energy-based dynamic performance measure. This dynamic performance measure, referred to as total action (TA), uses a physical interpretation of excited modes rather than fixed targeted modes as in the traditional damping control design. The coordination is formulated as a binary integer programming problem, which is solved by using the total action sensitivity (TAS). The concept of oscillation energy and the implementation of the adaptive coordination scheme is tested in the western North America power system (wNAPS). The results show that the proposed adaptive control scheme can improve oscillation damping for different short-circuit locations even in the presence of large communication delays.

In modern medium voltage distribution grids, voltage and reactive power (Volt/VAr) control can effectively be achieved using the time delayed responses of on-load tap changer, line voltage regulators, capacitor banks and distributed generation (DG) units. The timely coordination among different Volt/VAr control (VVC) devices can be assured through online control processes and updating the control parameters (i.e. set-points) of VVC devices. This is essential for efficient operation of the distribution grids while achieving steady-state voltage recovery and other control objectives such as loss minimisation; as the control interactions among VVC devices and Volt/VAr support DG units caused by poor coordination can lead to operational conflicts. In this article, a novel control approach is proposed for updating VVC set-points for eliminating operational interactions between different voltage regulating devices; thereby, minimising power losses in a network. The proposed strategy has been tested on a practical distribution system derived from the state of New South Wales, Australia, and the simulation results are reported. The results have demonstrated that the interactions among VVC devices and Volt/VAr support DG units can be avoided while minimising power losses, with the implementation of the proposed strategy. [ABSTRACT FROM AUTHOR]

With more photovoltaic (PV) systems being integrated into distribution networks, power utilities are facing many challenges in both planning and operation. Network operators are concerned with PV variability and associated necessity of voltage regulation, control coordination, reserve adequacy and dispatch constraints. While to address the obligatory connection agreement, it is vital for PV farm owners to accurately estimate PV variability and then provide the most cost‐effective compensation method. In the literature, PV variability of different scales has been investigated over the last 20 years. However, little has focused on output fluctuations of PV systems with long‐term and high‐resolution recorded data at a low‐voltage distribution feeder level where voltage regulation has become a serious issue. This is particularly true in Australia, where PV penetration is growing in many states and is expected to grow further in the near future. This study utilises the data of a distributed 1.2 MWp PV system in the University of Queensland recorded over the last three years with 1‐min resolution to analyse the statistical characteristics of PV power variability. The results from this study will provide very useful information for both power utilities and solar farm owners regarding network operation and future PV system development. [ABSTRACT FROM AUTHOR]

The responses of multiple distributed generation (DG) units and voltage regulating devices, such as tap changers and capacitor banks, for correcting the voltage may lead to operational conflicts and oscillatory transients, where distribution systems are subjected to network reconfiguration and availability of the DG units. Therefore, coordinated voltage control is required to minimize control interactions, while accounting for the impact of structural changes associated with the network. This paper proposes a strategy for coordinating the operation of multiple voltage regulating devices and DG units in medium voltage (MV) distribution systems, under structural changes and DG availability, for effective voltage control. The proposed strategy aids to minimize the operational conflicts by allowing voltage regulating devices to operate in accordance with the priority scheme designed based on the electrical-distance between voltage regulating devices and DG units, while maximizing the voltage support by the DG units. The proposed coordination scheme is designed to enact with an aid of a substation centered distribution management system for online voltage control. The control actions of proposed coordination strategy are tested on a MV distribution system, derived from the state of New South Wales, Australia, through simulations, and results are reported. [ABSTRACT FROM PUBLISHER]

The concept of an intelligent environment-friendly vehicle (i-EFV) is proposed in this paper. It integrates three components, i.e., clean-energy powertrain, electrified chassis, and intelligent information interaction devices. By employing such technologies as structure sharing, data fusion, and control coordination, more comprehensive performances are achievable, in terms of traffic safety, fuel efficiency, and environmental protection. Based on its definition and configuration, some key technologies, including design for resource effectiveness, driving environment identification, and coordinated control, are studied. As a basic application, a platform of an intelligent hybrid electric vehicle (i-HEV), which incorporates a hybrid powertrain with adaptive cruise control, has been designed and implemented. Both simulation and experimental results demonstrated that the i-EFV performed better than a conventional vehicle. [ABSTRACT FROM PUBLISHER]

This paper presents an optimal allocation method for flexible ac transmission system (FACTS) devices for market-based power systems considering congestion relief and voltage stability. The purpose of the FACTS devices installation is to provide benefit for all entities accomplished by both minimizing annual device investment cost and maximizing annual benefit defined as difference between expected security cost (ESC) with and without FACTS devices installation. Different from previous approaches, the proposed method accurately evaluates the annual cost and benefits obtainable by FACTS devices installation by formulating a large-scale optimization problem that contains power flow analyses for a large number of system states representing annual power system operations. In addition, dynamic state transitions caused by specified contingencies are also simulated in the optimization problem to evaluate the effect of FACTS control actions as well as the other coordinated controls. The expected cost consists of operating cost under normal and contingency states along with their related probabilities to occur. Maximizing social welfare is the objective for normal state while minimizing compensations for generations re-scheduling and load shedding as well as maximizing social welfare are the objectives in case of contingency. Although installation cost of FACTS devices is required, they are useful as cost free means, which can reduce effectively the annual costs for generations re-scheduling and load shedding. [ABSTRACT FROM PUBLISHER]