Additional Relay Research Articles

Comparison of Configurable Modular Two-Level and Three-Level Isolated Bidirectional DC–DC Converters for Super-Capacitor Charging in DC Shore Power Systems

Compared to the AC counterpart, the DC shore power system provides a significant advantage of efficient power supply from renewable sources to ships and onshore loads. Super-capacitors serve as key energy storage units in such a system to buffer the power fluctuations and collect the regenerative energy. However, the ultra-wide voltage range of super-capacitors imposes a significant challenge in the topology selection and efficiency optimization of the interfacing isolated bidirectional DC–DC converter. To tackle this challenge, this paper analyzes and compares two promising converter topologies, which are a configurable modular two-level dual-active bridge (CM-2L-DAB) and a three-level dual-active bridge (3L-DAB). To facilitate an ultra-wide voltage range, extended phase-shift (EPS) modulation in conjunction with the topology reconfiguration is analyzed for the CM-2L-DAB, while a hybrid modulation scheme is proposed for the 3L-DAB. A unified design approach is provided for both topologies, which also yields to the power loss modeling. On this basis, the CM-2L-DAB and 3L-DAB are thoroughly compared in terms of the modulation schemes, current stress, soft-switching operation, power conversion efficiency, material usage, closed-loop control scheme, and reliability. A prominent conclusion can be drawn that the CM-2L-DAB provides a higher efficiency than the 3L-DAB over the whole voltage range, but it relies on additional relays to reconfigure its topology which results in lower reliability and dynamic performance than the 3L-DAB.

Effects of N levels on land productivity and N2O emissions in maize-soybean relay intercropping.

Relay intercropping of maize and soybean can improve land productivity. However, the mechanism behind N2O emissions in this practice remains unclear. A two-factor randomized block field trial was conducted to reveal the mechanism of N2O emissions in a full additive maize-soybean relay intercropping. Factor A was three cropping systems - that is, monoculture maize (Zea mays L.), monoculture soybean (Glycine max L. Merr.) and maize-soybean relay intercropping. Factor B was different N supply, containing no N, reduced N and conventional N. Differences in N2O emissions, soil properties, rhizosphere bacterial communities and yield advantage were evaluated. The land equivalent ratio was 1.55-2.44, and the cumulative N2O emission ( ) was notably lower by 60.2% in intercropping than in monoculture, respectively. Reduced N declined without penalty on the yield advantages. The relay intercropping shifted soil properties - for example, soil organic matter, total N, and protease activity - and improved the soil microorganism community - for example, Proteobacteria and Acidobacteria. Intercropping reduced by directly suppressing nirS- and amoA-regulated N2O generation during soil N cycling, or nirS- and amoA-mediated soil properties shifted to reduce indirectly. Reduced N directly reduced by decreasing soil N content and reducing soil microorganism activities to alleviate N2O produced in soil N cycling. Conducting a full additive maize-soybean relay intercropping with reduced nitrogen supply provides a way to alleviate N2O emissions without the penalty on the yield advantage by changing rhizosphere bacterial communities and soil N cycling. © 2024 Society of Chemical Industry.

Simple and low-cost microscopy setup for 3D particle field measurement using incoherent illumination and open-source hardware.

The quantification of 3D particle field is of interest for a vast range of fields. While in-line particle holography (PH) can provide high-resolution measurements of particles, it suffers from speckle noise. Plenoptic imaging (PI) is less susceptible to speckle noises, but it involves a trade-off between spatial and angular resolution, rendering images with low resolution. Here, we report a simple microscopy setup with the goals of getting the strengths of both techniques. It is built with off-the-shelf and cost-effective components including a photographic lens, a diaphragm, and a CCD camera. The cost of the microscopy setup is affordable to small labs and individual researchers. The pupil plane of the proposed setup can be mechanically accessible, allowing us to implement pupil plane modulation and increase the depth of field (DOF) without requiring any additional relay lenses. It also allows us to understand the working principle of pupil plane modulation clearly, benefiting microscopy education. It illuminates the sample (particles) using diffuse white light, and thus avoids the problem of speckle noise. It captures multiple perspective images via pupil plane modulation, without requiring trading off angular and spatial resolution. We validate the setup with 2D and 3D particle samples. RESEARCH HIGHLIGHTS: We report a simple and cost-effective microscopy setup with the goals of getting the strengths of plenoptic imaging and in-line particle holography. It is built with off-the-shelf and cost-effective components. The cost of the microscopy setup is affordable to small labs and individual researchers. The pupil plane of the proposed setup can be mechanically accessible, allowing us to implement pupil plane modulation and increase the DOF without requiring any additional relay lenses. It also allows us to understand the working principle of pupil plane modulation clearly, benefiting microscopy education. It illuminates the sample (particles) using diffuse white light, and thus avoids the problem of speckle noise. It captures multiple perspective images via pupil plane modulation, without requiring trading off angular and spatial resolution. We validate the setup with 2D and 3D particle samples.

Интеллектуальные функции управления в микропроцессорных системах централизации

Trends in the development of computer-based interlocking systems are considered. The main emphasis when creating them is on achieving safety indicators no worse than those of relay analogues. The subsequent steps of improving the systems determined the directions of expansion of information support and automation of management. The main advantage of computer systems was the software implementation of a number of traditional functions that required the installation of additional relay equipment. The use of digital joints between the components of the system makes it possible to design a distributed structure of the computer-based interlocking systems on the basis of standard equipment, ensuring the rational use of computing power. Modern intelligent technologies as part of the tasks solved in the computer-based interlocking systems provide not only the choice of the best technological solutions for the organization of the station, but also allow you to exclude incorrect actions of personnel, free them from performing routine operations.

A Reconfigurable Half-Bridge Compensation Topology-Based WPT System With Constant Current and Constant Voltage Outputs

A reconfigurable half-bridge compensation topology is proposed in this brief for automatic guided vehicles (AGV) wireless charging system. Considering the cost and reliability, a simple and reconfigurable structure without extra passive element and additional relay is developed, the reconfigurable topology could realize the shift from inductor-capacitor-capacitor-inductor-capacitor-capacitor (LCC-LCC) topology to series-inductor-capacitor-capacitor (S-LCC) topology, and further achieve load-independent constant current (CC) and constant voltage (CV) outputs, full design freedom for current and voltage gain. Accompanying with a special switching strategy of mode transition, the proposed reconfigurable circuit could realize smooth cutting off of inductor current without spike across switch. Moreover, module of zero-current could be saved in the proposed topology. The proposed circuit has less switches and could achieve zero phase angle (ZPA) operating and zero voltage switching (ZVS) in the whole charging process, which allows the lower cost and power losses. An experimental prototype is established to validate the feasibility of the reconfigurable half-bridge compensation topology and switching strategy.

Feasibility of seismic wave communication using electromagnetic vibrator under strong environmental noise interference: Field experimental research.

Although various wired or wireless communication facilities play a significant role in underground mine production monitoring and disaster warning, some communication nodes will be damaged when an accident occurs, resulting in unreliable emergency communications. Due to the excellent transmission characteristics of seismic waves in the earth channel, there is no need for the seismic wave communication system to set up relay nodes. Since seismic waves are not easily disturbed by the external environment, they can be used as a new type of emergency communication carrier to realize information transmission. However, under strong background noise interference in a real environment, the feasibility of seismic wave communication using an electromagnetic vibrator is not yet known. Therefore, a field experiment research on electromagnetic vibrator seismic wave communication was conducted. First, the model of electromagnetic vibrator seismic wave communication was established. In addition, the on-off keying modulation method, the cross-correlation segment threshold demodulation method, and the noise suppression method based on the time-frequency characteristics of the carrier were introduced. Finally, an electromagnetic vibrator seismic wave communication system was built, and binary data communication up to 72m without deploying additional relay nodes was achieved successfully. The experimental results illustrate the feasibility of the electromagnetic vibrator seismic wave communication under strong background noise interference in a real environment. Furthermore, combined with the characteristics of the seismic wave, the time-frequency slice filtering can significantly improve the signal-to-noise ratio of the seismic wave and can further increase the communication distance with respect to the traditional methods.

Learning Curve and Long-Term Outcomes of Thoracic Endovascular Repair With the Relay Stent-Graft

Purpose: To define the learning curve of a widely employed stent-graft for thoracic endovascular repair (TEVAR) by analyzing procedural variables and their impact on long-term outcomes. Materials and Methods: Standard TEVARs for each major aortic thoracic disease were included excluding procedures using thoracoabdominal, arch fenestrated/branched devices and/or chimneys. The primary outcome was the learning curve analysis using the cumulative sum chart method. The secondary outcomes, presented as early (Q1–Q2) versus latest (Q3–Q4) quartiles of experience, were 30-day major adverse events (MAEs); procedural details (additional maneuvers, operative and fluoroscopy time, and contrast volume); 30-day clinical success; endoleak; aorta-related reintervention; and overall and aorta-related survival. Results: Between November 2005 and September 2021, 220 consecutive TEVAR procedures involving the Relay endograft (Terumo Aortic, Sunrise, FL, USA) were performed and included in the present analysis. The mean follow-up was 4.5 ± 3.9 years. The learning curve was reached after 10 patients. Secondary outcomes improved significantly over experience. Thirty-day MAE occurrence was 14.5% versus 11.8% (p=0.550). Additional maneuvers (p=0.009), access-vessel additional maneuvers (p=0.010), operative time (p=0.004), Relay Plus (p=0.001), and implantation of multiple stent-grafts (p=0.034) were independent risk markers for MAEs. Operative time (125.9 ± 66.7 vs 86.7 ± 48.5 minutes, p<0.001), contrast volume (185.4 ± 112.8 vs 140.5 ± 88.2 mL, p=0.003), and fluoroscopy time (12.4 ± 12.7 vs 8.8 ± 7.5 minutes, p=0.017) decreased significantly. Late endoleak occurrence was 19.5% with a nonsignificant reduction (21.8% vs 17.3%, p=0.395). Fluoroscopy time (hazard ratio [HR]=1.0; 95% confidence interval [CI]=1.0–1.1; p=0.008), contrast volume (HR=1.0; 95% CI=1.0–1.1; p=0.018), and type III aortic arch (HR=3.3; 95% CI=1.7–6.4; p<0.001) were independent risk markers for endoleak. Fluoroscopy time (HR=1.0; 95% CI=1.0–1.1; p=0.032) and type III aortic arch (HR=3.6; 95% CI=1.7–7.4; p=0.001) confirmed their significant association in a multivariable analysis. Conclusion: In a high-volume center with a consistent previous endovascular experience, the Relay graft presented satisfactory long-term results with a short learning curve supporting its reliability. Clinical Impact The manuscript addresses the understanding of how many TEVAR procedures with a currently implanted device have been required to reach the learning curve for an endovascular skilled center. Our TEVAR experience with the Relay stent-graft (Terumo Aortic) demonstrated that ten implantations were required to achieve the device-related learning curve. The fifteen-year analyzed period showed that intraoperative learning-related variables were associated with long-term clinical outcomes and both improved over time. The Relay stent-graft presented satisfactory long-term results along with a short learning curve in a high-volume endovascular center supporting its ongoing implantation.

Analysis and Design of Enhanced Distributed Fountain Codes in Multiple Access Networks with Cooperative Relay

Distributed fountain coding plays an important role in rateless code research. The reliability and effectiveness of these coding schemes are increasingly challenged with the growing applications. In this paper, a novel multiple-access network with cooperative relay is presented, and a novel enhanced distributed fountain coding scheme for this network is proposed. The overall degree distributions are derived, and the asymptotic decoding performance is analyzed theoretically by employing the And-Or tree method. On this basis, a design method using joint iterative optimization algorithms is proposed to optimize the degree distributions of the sources and relays. Simulation results show that the proposed enhanced distributed fountain codes outperform the existing generalized distributed fountain codes (GDFC) and have a good performance on both lossless and lossy channels. It reveals that the proposed codes can provide unequal error protection (UEP) property for different sources by introducing the extra cooperative relay. The performance improvement is not restricted to the sources connected to the cooperative relay but applies to all sources. With the additional relay, the proposed codes are able to overcome the effects of bad channel conditions caused by terrain, obstacles, and so on, to avoid communication interruptions and improve the reliability of the network.

A New Method to Determine the Optimal Location and Amount of Shed Load in Multi-Stage Under Frequency Load Shedding Using DIgSILENT

Under-frequency load shedding (UFLS) appears to be an effective approach to preventing cascading outages that includes various methods. In recent years, much research has been done in the field of dynamic schemes. However, these schemes are less commonly used due to their disadvantages such as the inability to calculate the optimal shed load amount, the need to additional relays or communication infrastructures, etc. In contrast, static UFLS schemes are more common due to their simplicity, efficiency, fast implementation, as well as the unnecessity of additional equipment. However, how to determine the load shedding (LS) location and amount in static methods seems to be still challenging. Furthermore, conventional methods have a major drawback because of over shedding. In order to solve this problem, in this paper, a new static method is proposed to determine the location and amount of optimal LS based on co-simulation of DIgSILENT and MATLAB software. The system dynamics is simulated in DIgSILENT and optimization using imperialist competitive algorithm (ICA) runs in MATLAB. This co-simulation makes it possible to take advantage of both pieces of software. The results of the simulation on the IEEE 39-Bustest system in several scenarios clearly demonstrate the efficiency of the proposed method.

Reliable and Seamless Communications of Networked IAV in Container Terminal Using UAV Technology

Abstract Managing container loading and unloading operations at a container terminal using Intelligent Autonomous Vehicle (IAV) is challenging, especially at intersections in the yard, which are often inevitable. For ensuring efficient and accident-free management of these intersections, the IAV must cooperate by exchanging messages. Due to signal obstruction at these intersections, indirect communication is established through an additional relay node to ensure reliable communication. This paper proposes distributed approach using Unmanned Aerial Vehicle (UAV) connectivity to avoid collision and deadlock between IAV at intersections. Due to the obstacles formed by stacked containers blocking the radio transmissions, the proposed algorithm automatically switches the ongoing communication through the UAV to ensure successful communication at intersections. Thus, the idea of introducing UAV as communication relay in a container terminal is an interesting solution that we have adopted in this work. Simulation techniques are used to evaluate our proposal. The obtained results confirm that our UAV-based approach ensures reliable communication and automated intersections management in the yard while further ensuring the safety of IAV traffic.

Large device to device communication network including airborne drones for emergency scenarios

AbstractIn the case of emergency scenarios communication infrastructure might be destroyed, impairing communication abilities in the disaster area. In such situation device‐to‐device (D2D) communication networking plays an essential role to overcome the communication loss. To provide a reliable communication network, D2D devices are combined with airborne drones. The D2D devices provide a relay service while being able to transmit their own data. The airborne drones offer additional relay functionality and provide considerably reduced latency compared with D2D communication networks without any airborne drones. In this article, we will illustrate a large dynamic communication network (LDCN) and demonstrate its feasibility for even more than 64 000 D2D communication devices in the case of realistic channel conditions including path loss and fading. It will be shown that the illustrated LDCN is truly infrastructure‐less, that is, no infrastructure or backbone or base station functionality need to be reinstalled. Therefore, the airborne drones do not take over any coordination services. The illustrated LDCN has a simple packet switching architecture and since all communication is localized it is robust and fully flexible. In addition, no specific radio interface or preferred multiple access scheme such as code division multiple access or time division multiple access are required.

A hybridization strategy using equal and unequal clustering schemes to mitigate idle listening for lifetime maximization of wireless sensor network

The main focus in the designing of wireless sensor networks (WSNs) applications and protocols is minimizing energy dissipation while at the same time maximizing the network lifetime. In this paper, we investigate the idle listening and hotspot problems with respect to the clustering routing technique in WSNs. Some of the studies in clustering centered around equal clustering scheme while others were based on unequal clustering scheme. Equal clustering scheme avoids inter-cluster idle listening as the intra-cluster data collection can be completed at the same time across all clusters in the network but lead to hotspot problem due to additional traffic relay experienced by cluster heads near the base station. Similarly, unequal clustering addresses hotspot problem but lead to inter-cluster idle listening due to the use of global network-wide intra-cluster collection among clusters of unequal sizes and densities. In this paper we proposed a zone-based clustering scheme referred to as hybrid equal and unequal clustering (HEUC) that jointly address inter-cluster idle listening and hotspot problems to maximize the lifetime of WSNs. To achieve this, the network area is firstly partitioned into zones. The size of clusters in the same zone is designed to be equal and cluster size increases across zones as the distance from the BS increases. Secondly, the density of nodes deployed in each cluster per zone is obtained in such a way that the distribution of nodes in zones away from BS increases according to the radius increase in clusters across the zones. Thirdly, a deterministic deployment strategy is used to deploy nodes into various clusters. Fourthly, we implement a zone-wise intra-cluster data collection strategy that allows intra-cluster data collection to be completed at once to address inter-cluster idle listening. Lastly, a multihop routing is used for data forwarding to BS. The result shows that our proposed HEUC has 38% and 51% lifetime improvement against EBULRP and AECR respectively.

Monitoring the Ocean Environment Using Robotic Systems: Advancements, Trends, and Challenges

AbstractScientists are able to gain a substantial understanding of various environmental processes (e.g., physical, chemical, or biological parameters) through environmental sensing and monitoring. Most of these monitoring scenarios involve large environmental space and require a considerable amount of work and time for collecting the required data. Realizing the associated human effort, the data collection process was automated, to some extent, by providing wireless communication capabilities to the sensors. However, with the sensing environments increasing demographically, the location of the sensors moved far apart, necessitating additional relay nodes. This made data collection time consuming and complex. In order to simplify the effort towards data collection by reducing the human involvement to a minimum and to reduce power requirement of the sensors for data transmission, thereby increasing their life, use of marine robotic systems has been experimented with successfully. This article aims to discuss the advancements, trends, and challenges of marine robotic systems for environmental monitoring.

Towards optimal wireless sensor network lifetime in three dimensional terrains using relay placement metaheuristics

In wireless sensor networks, sensor nodes located close to the base station or sink are more susceptible to energy loss, leading to premature disconnection of the network or energy holes. This is due to the fact that all traffic is forwarded towards the sink, increasing the workloads for these closer nodes. One solution for this issue is to shorten the hop distance a sensor’s data has to travel until reaching the sink, by deploying additional relay nodes. This paper considers the problem of optimal relay node placement for maximizing the network lifetime of wireless sensor networks in three-dimensional terrains. We first design a mathematical model of the problem and reformulate it as a mixed-integer programming model to provide a basis for finding lower bound solutions. We divide the problem into two phases and show that the second phase can be solved exactly using an algorithm based on maximum flow and binary search. We then propose a local search algorithm for the first phase, utilizing the exact algorithm to create full solutions. Experimental validation on 3D datasets has been carried out to demonstrate the performance of our algorithms.

Crop Productivity and Nutrients Recovery in Maize–Soybean Additive Relay Intercropping Systems Under Subtropical Regions in Southwest China

Limited arable land area and deteriorating soil health in smallholder farmers’ fields of subtropical regions in China have led to an urgent demand for sustainable production practices with greater land productivity and nutrients use efficiency. A group of field experiments at three locations (Yaan, Lezhi and Renshou) in two consecutive years of 2012–2013 were conducted to study crop production and nutrients recovery of maize (Zea mays L.) and soybean (Glycine max (L.) Merr.) in monocropping and additive relay intercropping systems. The results showed that the total crop yields of the 2:2 maize-to-soybean wide-narrow row spacing planting pattern (RIwn) were significantly higher than that of the 1:1 maize-to-soybean equal row spacing planting pattern (RIe), and the average land equivalent ratios (LER) of the grain yield were 1.79 and 1.49 for the RIwn and RIe, respectively. The nitrogen (N), phosphorus (P) and potassium (K) recovery efficiency calculated by the ratios of crop nutrients removed and fertilizer input indicated that the RIwn had a higher nutrients recovery than the RIe due to proper spacing between maize and soybean rows and higher soybean yield in RIwn. In terms of the amount of fertilizer applied, based on this experiment, P should be reduced in maize plantings and increased in soybean plantings to maintain the balance of soil P. Considering the higher temperatures during the soybean vegetative growth phase, N fertilizer inputs should be controlled to prevent excessive soybean growth. In addition, excess K was taken up in the crop biomass, maybe the straw should be returned to the field to maintain soil K fertility sustainable for the long term.

Non-Communication Based Time-Current-Voltage Dual Setting Directional Overcurrent Protection for Radial Distribution Systems With DG

This paper proposes a novel protection scheme equipped with time current voltage dual setting directional overcurrent relays for radial distribution systems with (distributed generation) DG without the need of communication assistance. The proposed protection scheme is formulated as a nonlinear programming problem where the main objective is to determine the optimal relay forward and reverse settings to minimize the relay overall operating times. The proposed scheme, based on the time current voltage dual settings directional overcurrent relay, is applied to the IEEE 33-bus radial distribution system with synchronous-based DG and its performance is compared against the conventional protection schemes that rely on both standard overcurrent relays and time current voltage directional overcurrent relays (proposed in the literature). The results show that, for radial distribution systems, the proposed scheme is capable of mitigating protection coordination failure due to DG reverse fault currents (a limitation in overcurrent relays), does not require communication (a limitation for meshed distribution systems) and does not require additional relays (a limitation in directional overcurrent relays) and thus making such relays more suitable for protecting radial distribution systems with DG.

Adaptive cluster-based relay-node placement for disjoint wireless sensor networks

Wireless sensor networks are formed with very small sensor devices with limited energy and short transmission range. Sensors are randomly deployed in remote areas with harsh conditions. Due to this, their distribution are non-uniform. In a hostile environment, the occurring of large scale failure is very often and it creates partitions of different sizes in the network. Restoring the network connectivity is very crucial for network functioning. Typically sensors are static and communication is bi-directional and we need to reconnect the network with the additional relay sensor nodes. After reconnecting the network, overhead on relays is very high and thus it consumes more energy and high computational power. Optimal number of relay nodes required for reconnecting the network is an NP-hard problem. Here, we proposed a new heuristic approach called adaptive Cluster-based Relay Placement Algorithm. Our approach is to reconnecting the networks based on finding the nearest partitions using their centroids. Using the proposed algorithm, relays are placed on the denser part of the partitions and number of required relays are also minimum. It reduces the network recovery time and increases the network lifetime. Through simulation, we show that the proposed algorithm performs better than the existing approaches.

Automated control of distributed generation enabled power districts

The paper presents the results of integrating distributed generation (DG) facilities in the distribution grids and internal grids of industrial enterprises. It proves such locations require many more additional relay protection and automation devices, including emergency controls; the cost of such systems is on par with that of a DG facility. The paper presents the prerequisites for equipping DG-enabled power districts with routine and emergency controls (REC). It substantiates the use of phasor measurement units as REC sensors in low- and medium-voltage grids. Presented herein are the fundamental principles behind, and functionality of, REC. The paper proves feasible using offline-computed parameters to implement a REC system for further transition to online software-based computing of steady states and transients.

Yield advantage and nitrogen fate in an additive maize-soybean relay intercropping system

Sustainable agricultural development is urgently required to satisfy future food demands while decreasing environmental costs. Intercropping can increase per-unit farmland productivity through a resource-efficient utilization. However, the fate of N in intercropping systems remains unclear. To study the yield advantages and the fate of N in additive maize–soybean relay intercropping (IMS) systems, we quantified crop yield, soil N transformation abilities, soil bacterial abundances, and the fate of 15N. This study was conducted using three planting patterns, namely, monoculture maize (Zea mays L.) (MM), monoculture soybean (Glycine max L. Merr.) (MS), and IMS, and two N application rates, specifically, no N and applied N (N1, 45 and 135 kg N ha−1 for MS and MM, correspondingly; and N for the IMS, which was the sum of the monocultures). Results showed that a higher per-unit farmland productivity and a lower land use intensity are attained in the intercropping system than in the corresponding monocultures. In addition, land equivalent ratio (LER) ranges from 1.85 to 2.20. Moreover, the fate of 15N showed that the N uptake and residual are the highest, whereas N loss in the IMS is the lowest among all planting patterns. Intercropping had an increased N use efficiency by increasing N utilization efficiency, rather than N uptake efficiency. The abundance of ammonia oxidizer and denitrifier indicated that IMS improves the structure of soil microorganisms. Furthermore, the transformation abilities of soil N denoted that intercropping strengthens ammonifying and nitrifying capacities to increase soil N residual while decreasing ammonia volatilization and N2O emission. Finally, the greenhouse warming potential and gas intensity of N2O were significantly lower in the IMS than in the corresponding monocultures. In summary, the IMS system provides an environmentally friendly approach to increasing farmland productivity.

Single-Phase Bidirectional On-Board Charger Using Starter Generator System in Hybrid Electric Vehicles

This paper presents the design and control methods of a single-phase bidirectional on-board charger (OBC) using a hybrid starter generator (HSG) and an inverter in a hybrid electric vehicle (HEV). In an HEV, there are a number of components, including the combustion engine, transmission, traction motor, motor controller, OBC, and HSG system. The proposed design reconfigures the HSG system to provide battery-charging capability instead of a conventional OBC based on the use of additional power relays. As a result, the number of power converters is effectively reduced through the replacement of the conventional OBC, and, thus, the power density is increased. This paper also proposes a control method for enabling not only battery charging but also a reactive power support depending on the grid command. Compared with a conventional reactive power compensation method, the proposed method has an advantage because it is located near the principal reactive power source. The simulation and experimental results verify the validity and feasibility of the proposed bidirectional OBC design and its control methods.