Bus Agent Research Articles

Designing a Website-Based Bus Ticketing System for Ria Sari Bus Agents

Ria Sari Bus Ticket Agent is a night ticket agent that serves the various regions in Indonesia. Currently, the agent still uses a manual system to record bus ticket sales. Agents still write prospective passenger data and calculate agent commissions manually. In addition, sometimes agents forget about passenger orders that have been booked long ago. This usually happens during the Eid season and long vacations. This bus agent also does not have a recap of sales reports every month, so it does not know the commission earned each month. This study has a solution in a website-based ticket sales information system developed using Laravel, PHP, XAMPP, and MySQL. The purpose of the study is to design and develop a website-based bus ticketing system for Ria Sari Bus Ticket Agent. The testing of the system is conducted by interviews with the owner and users of the system. The result shows all features and menus available in this system are working properly and in accordance with the access rights of each user. The owner and users are satisfied and perceived helpful in using the system.

Automatic Self-Adaptive Local Voltage Control Under Limited Reactive Power

The increasing proliferation of distributed energy resources has posed new challenges to Volt/VAr control problems in distribution networks. To this end, this paper proposes an automatic self-adaptive local voltage control (ASALVC) by locally controlling VAr outputs of distributed energy resources. In this ASALVC strategy, each bus agent can locally and dynamically adjust its voltage droop function in accordance with time-varying system changes. The voltage droop function is associated with the bus-specific time-varying slope and intercept, which can be locally updated, merely based on local voltage measurements, without requiring communication. Stability, convergence, and optimality properties of this local voltage control are analytically established. In addition, the online implementation of ASALVC is further proposed to address the real-time system changes by adjusting VAr outputs of DERs online. Numerical test cases are performed to validate and demonstrate the effectiveness and superiority of ASALVC.

Optimizing the Scheduling of Electrified Public Transport System in Malta

In this paper, we describe a comparative analysis of a bus route scheduling problem as part of timetable trips. We consider the current uptake of electric buses as a viable public transportation option that will eventually phase out the diesel-engine-based buses. We note that, with the increasing number of electric buses, the complexity related to the scheduling also increases, especially stemming from the charging requirement and the dedicated infrastructure behind it. The aim of our comparative study is to highlight the brevity with which a multi-agent-system-based scheduling method can be helpful as compared to the classical mixed-integer linear-programming-based approach. The multi-agent approach we design is centralized with asymmetric communication between the master agent, the bus agent, and the depot agent, which makes it possible to solve the multi-depot scheduling problem in almost real time as opposed to the classical optimizer, which sees a multi-depot problem as a combinatorial heuristic NP-hard problem, which, for large system cases, can be computationally inefficient to solve. We test the efficacy of the multi-agent algorithm and also compare the same with the MILP objective designed in harmony with the multi-agent system. We test the comparisons first on a small network and then extend the scheduling application to real data extracted from the public transport of the Maltese Islands.

A multi-agent framework for scheduling fully electrified public transport

This paper describes a framework for scheduling electric buses with the aim of minimizing their overall operational costs as well as the required fleet. The scheduling problem of electric buses comes with several real-time constraints such as the location of the charging stations, number of time-tabled trips, the distance between the depots, etc. The main objective is to minimize the running costs of the electric buses on the road network while satisfying the underlying constraints. The cooperative multi-agent model segregates the scheduling problem into a master agent and a bus agent through asymmetric communication, and this decentralized approach allows the scheduling to happen in a real-time scenario. The proposed scheme is tested on the public transport network of the Maltese Islands.

Online Voltage Control for Unbalanced Distribution Networks Using Projected Newton Method

This paper proposes an online voltage control strategy of distributed energy resources (DERs), based on the projected Newton method (PNM), for unbalanced distribution networks. The optimal Volt/VAr control (VVC) problem is formulated as an optimization program, with the goal of maintaining the voltage profile across the network by coordinating the VAr outputs of DERs. To overcome the slow convergence rate of conventional gradient-based methods, a PNM-based solution algorithm is developed to solve this VVC problem. It utilizes a non-diagonal symmetric positive definite matrix, developed from the Hessian matrix of the objective, to scale the gradient, and thus a fast convergence performance can be expected in this Newton-like algorithm. Moreover, taking advantage of the instantaneous feedback of voltage measurements, the online implementation of the PNM-based VVC is further designed to deal with fast system variations. In this online PNM-based VVC scheme, each bus agent communicates the instantaneous voltage measurements to the central agent, and the central agent communicates the VAr output commands of DERs back to each bus agent. The fast convergence performance of PNM results in a stronger capability to track the system variations in real time. Finally, numerical case studies are performed to validate the effectiveness, superiority, and scalability of the proposed method.

A Completely Distributed Economic Dispatching Strategy Considering Capacity Constraints

For islanded microgrids integrating distributed generators (DGs) with different generation cost and capacity, economic dispatch (ED) is its one of the key performance attributes and challenges. This paper proposes a completely distributed control strategy with improved reliability, flexibility and voltage quality for DC microgrids. Only depending on a sparse communication graph and neighbor information, the output power of each DG is adjusted to obtain global economic optimization while meeting the load demands and its capacity constraint by switching its control mode between distributed dispatch based on dynamic consensus algorithm and constant power control smoothly. The bus voltage is recovered accurately by construct a shortest communication line between bus agent and one DG to obtain the bus voltage. The stability and convergence of the proposed scheme have been analyzed. Simulation test has verified the feasibility and validity of the proposed control strategy.

Distributed optimal active power dispatch with energy storage units and power flow limits in smart grids

Dynamic optimal active power dispatch with energy storage units and power flow limits is an important problem in smart grids. This problem is usually described as a convex optimization model. In our model, not only the conventional equality and inequality constraints, energy storage units’ constraints and power flow constraints are considered, but also the energy storage units’ operational costs and the power price of the main grid are considered in the total costs. To solve this problem, a fully distributed algorithm based on the alternating direction method of multipliers (ADMM), the projected gradient method and the average consensus is proposed. The proposed algorithm can obtain the optimal output power settings of the energy storage units, distributed generators and the main grid for different demand loads with different initial states. In the proposed algorithm, firstly, the dispatch problem is decomposed into multiple subproblems on the basis of the alternating direction method of multipliers; then the subproblems can be solved according to the projected gradient method and the average consensus algorithm. In order to apply the projected gradient method, every bus is equipped with a bus agent which is responsible for information communication and the output power optimization calculation. Simulation studies demonstrate the effectiveness of the proposed algorithm. .

Distributed Load Sharing of an Inverter-Based Microgrid With Reduced Communication

This paper presents a fully distributed power sharing control strategy for a microgrid with integration of multiple inverter-based intermittent distributed generators (IDGs) using a need-based aperiodic data transmission scheme. The control objective is to maintain the supply-demand balance of active power. According to the proposed control strategy, each bus in a microgrid has an associated bus agent. First, it is shown that by controlling the utilization levels of IDGs to a common value, which can be calculated using the total available power and total demands, the supply-demand balance can be maintained. Subsequently, we propose a multiagent system (MAS)-based discovery algorithm to discover the global microgrid information. Compared with most existing MAS-based load sharing studies, the proposed algorithm is capable of reducing data communication requirements since the agent only broadcasts its state to its neighbors when an event occurs. Furthermore, the distances between neighbor agents have been considered in the threshold of event condition to improve its efficiency in reducing data communication. Finally, the effectiveness of the proposed scheme is validated on the Canadian urban distribution system.

A Voltage Control Method for a Distributed Line Feeder by means of Multiagent Approach

SUMMARYThis paper proposes a method for the coordinated control of power factor by means of a multiagent approach. The proposed multiagent system consists of two types of agent: single feeder agent (F_AG) and bus agent (B_AG). In the proposed system, an F_AG plays as an important role, which decides the power factors of all distributed generators by executing the load flow calculations repeatedly. The voltage control strategies are implemented as the class definition of Java into the system. In order to verify the performance of the proposed method, it has been applied to a typical distribution model system. The simulation results show that the system is able to control very violent fluctuation of the demands and the photovoltaic (PV) generations.

配電線フィーダの自己完結型電圧制御方式

This paper proposes a self-contained voltage control method for distribution line feeders. The proposed system consists of two types of agent: feeder agent (F_AG) and bus agent (B_AG). The F_AG plays as an important role, which decides the power factors of all distributed generators by executing the load flow calculations repeatedly. The voltage control strategies are implemented as the class definition of Java into the system. In order to verify the performance of the proposed method, it has been applied to a distribution model system. The simulation results show that the system is able to control very violent fluctuation of the demands and the photovoltaic generations (PVs).

System Modeling and Simulation of Intentionally Islanded Reconfigurable Microgrid

Microgrid reconfiguration plays important role in improving continuity of power supply especially in the event of fault within the power grid or microgrid connected to the medium voltage distribution network. Due to the fault in power grid, intentional islanding through static switch is one possible solution while, fault within the microgrid emphasizes microgrid reconfiguration to recover maximum affected loads in each isolated zone. This paper presents multiagent system based (MAS) approach in order to withstand stably and autonomously in the event of fault within microgrid or power grid. MAS approach includes negotiation agent (NA) for the entire microgrid and bus agent (BA) for each bus within each zone. NA is responsible for selecting a Dominant-BA from each zone and prioritizing the zones by using region weight coefficient (RWC) method. Zone having excessive power will recombine with the zone having lesser power for maintaining power quality of sensitive and less sensitive loads, while normal loads are shed.

An Overview of Staged-bus Operation in Cities

In developing countries, demand for passenger travel is higher, due to economic growth. Government policy encourages people to use public transportation instead of their private carsto reduce of traffic congestion and air pollution. In the city areas, bus networks are the major part of the public transportation system because they are easily accessible and cheaper compared to other types of public transportation. In this study revelation of details of bus operation included different agents is studied. Bus operations, during provision of their service, have interaction with three main agents: bus agent, passenger agent and traffic agent. Study of the influence of each agent in bus operation is presented in this study, using the macroscopic way.

Fully Distributed Coordination of Multiple DFIGs in a Microgrid for Load Sharing

When wind power penetration is high, the available generation may be more than needed, especially for wind-powered microgrids working autonomously. Because the maximum peak power tracking algorithm may result in a supply-demand imbalance, an alternative algorithm is needed for load sharing. In this paper, a fully distributed control scheme is presented to coordinate the operations of multiple doubly-fed induction generators (DFIGs) in a microgrid. According to the proposed control strategy, each bus in a microgrid has an associated bus agent that may have two function modules. The global information discovery module discovers the total available wind generation and total demand. The load sharing control module calculates the generation reference of a DFIG. The consensus-based algorithm can guarantee convergence for microgrids of arbitrary topologies under various operating conditions. By controlling the utilization levels of DFIGs to a common value, the supply-demand balance can be maintained. In addition, the detrimental impact of inaccurate and outdated predictions of maximum wind power can be alleviated. The generated control references are tracked by coordinating converter controls and pitch angle control. Simulation results with a 5-DFIG microgrid demonstrate the effectiveness of the proposed control scheme.

Distributed architecture for real-time coordination of bus holding in transit networks

A distributed control approach based on multiagent negotiation is presented, wherein stops and buses act as agents that communicate in real-time to achieve dynamic coordination of bus dispatching at various stops. The negotiation between a Bus Agent and a Stop Agent is conducted based on marginal cost calculations. We present optimality conditions for the formulated problem, using a negotiation algorithm, which we derive, to coordinate bus holding at various stops. A comparison between the negotiation algorithm and other simple bus control strategies such as on-schedule and even-headway strategies made through simulations verifies the robustness and efficiency of our negotiation strategy to different transit environments, involving both stationary passenger arrivals as well as a variety of nonstationary passenger arrivals.

Field programmable gate array-based PCI interface for a coprocessor system

This paper presents the design and implementation of a field programmable gate array (FPGA)-based PCI bus interface for a general purpose parallel neurocomputer, which is hosted by a personal computer. The basic background of the PCI bus and a detailed discussion of applicable FPGA design considerations are given. With FPGA, critical implementation factors are the realization of fast-enough state machines and efficient resource allocation. Emphasis is placed on presenting how to allocate resources efficiently from the VHDL hardware description language. Related to the overall implementation, PCI bus agent initialization and configuration from the operating system are considered.