A comparison of low cost wireless communication methods for remote control of grid-tied converters

Remote control of grid tied converters has become important with an increasing number of grid connected energy storage systems. Hence, it is crucial point for utilities to outline the requirements of the communication methods and to find the best communication infrastructure to handle the remotely located converters in a reliable and cost effective manner throughout the operation. The purpose of this study is to come up with a low cost wireless communication solution for remote controlled converters. Focusing on low cost, this letter studies about three communication methods which can be applicable to control the remote converters. All three methods are being tested to find out the suitability for data communication. Then this paper provides a comparison of all three methods with cost, measured range and the data rate. And conclude that LoRa is the solution with the highest potential for this application from the compared methods

Optimization and modeling of a stand-alone wind/PV hybrid energy system

Microwave repeaters are one of the main energy consumers in the telecommunication industry. These repeaters are powered using diesel generators and batteries, particularly when they are located in remote areas. Diesel generators require higher maintenance cost and for remote sites this cost will be more due to the added oil transportation cost. The aim of this paper to optimize and model a hybrid energy system for a microwave repeater located in Mulligan, Labrador, Canada. The hybrid system is a combination of wind, solar, diesel generation and batteries. Hybrid Optimization Model for Electric Renewable (HOMER) software is used for the sizing, and sensitivity analysis is performed in order to obtain the most feasible configuration of a hybrid renewable energy system. The proposed hybrid system is finally modeled in SIMULINK and results are presented to demonstrate the system performance

Optimization and a comparison between renewable and non-renewable energy systems for a telecommunication site

The renewable energy based hybrid energy system is one of better solutions to reduce the environment pollution. Renewable energy offers power supply for locations that are remotely located and also allows economical way of producing power for small power applications. The objective of this paper is to optimize and compare a non-renewable energy system with a renewable energy system for a remotely located telecommunication site in Mulligan, Labrador in Canada. The current system is operated using a diesel generator and batteries and the proposed system expects to integrate a hybrid wind and solar energy system into the existing diesel generator and batteries. Hybrid Optimization Model for Electric Renewable (HOMER) software is used to obtain the most feasible configuration of a hybrid renewable energy system. The results show the hybrid renewable energy system is cost effective. The proposed system significantly reduces the running time of diesel generator and this helps to reduce the emission level. Moreover, it is expected that the proposed system will help the BellAliant Company to provide uninterrupted power for their sites in remote areas of Labrador

Micro-grid system based on renewable power generation units

Micro-grid system is currently a conceptual solution to fulfill the commitment of reliable power delivery for future power systems. Renewable power sources such as wind and hydro offer the best potential for emission free power for future micro-grid systems. This paper presents a micro-grid system based on wind and hydro power sources and addresses issues related to operation, control, and stability of the system. The micro-grid system investigated in this paper represents a case study in Newfoundland, Canada. It consists of a small hydro generation unit and a wind farm that contains nine variable-speed, double-fed induction generator based wind turbines. Using Matlab/Simulink, the system is modeled and simulated to identify the technical issues involved in the operation of a micro-grid system based on renewable power generation units. The operational modes, technical challenges and a brief outline of conceptual approaches to addressing some of the technical issues are presented for further investigation

CKF-Based Visual Inertial Odometry for Long-Term Trajectory Operations

The estimation error accumulation in the conventional visual inertial odometry (VIO) generally forbids accurate long-term operations. Some advanced techniques such as global pose graph optimization and loop closure demand relatively high computation and processing time to execute the optimization procedure for the entire trajectory and may not be feasible to be implemented in a low-cost robotic platform. In an attempt to allow the VIO to operate for a longer duration without either using or generating a map, this paper develops iterated cubature Kalman filter for VIO application that performs multiple corrections on a single measurement to optimize the current filter state and covariance during the measurement update. The optimization process is terminated using the maximum likelihood estimate based criteria. For comparison, this paper also develops a second solution to integrate VIO estimation with ranging measurements. The wireless communications between the vehicle and multiple beacons produce the ranging measurements and help to bound the accumulative errors. Experiments utilize publicly available dataset for validation, and a rigorous comparison between the two solutions is presented to determine the application scenario of each solution

Vision Analysis of Pack Ice for Potential Use in a Hazard Warning and Avoidance System

Ships travelling through pack ice are exposed to collisions that can result in structural damage to the hull. The GEM project at Memorial University has developed ice-ship interaction simulation software that allows study of the impact forces applied on a ship when it maneuvers through pack ice [1]. Such capability is useful in order to predict the collisions that would potentially affect the structural integrity and operational performance of ships and floating offshore structures. GEM is capable of simulating transit through complex pack ice formations at a rate much faster than real time. If hyper-real time simulation were available in a real operational setting, with actual ice, it would permit a variety of benefits, including general operational planning. If the near field ice information were sufficiently accurate, GEM could also be used in a “feed forward” near-field hazard warning and avoidance system (HWAS)

LiDAR and Vision Based Pack Ice Field Estimation for Aided Ship Navigation

Ships travelling through pack ice are exposed to structural damage in the hull due to collisions with ice-floe. GEM simulation environment, a Memorial University project, is an ice-ship interaction software that allows the study of the impact forces applied on a ship, when it maneuvers through pack ice [1]. At a rate much faster than the real-time, GEM is capable of simulating ship navigation through complex pack ice formations. Such a tool is beneficial in predicting hazardous collisions that affect structural integrity and operational performance of ships and floating offshore structures