Power Distribution Unit Research Articles

Powerful Delivery

As Power Demands in Electric Vehicles Continue to Increase, so must the Capabilities of the Power Distribution Units

Single event latch-up detection for nano-satellite external solar radiation mitigation system

This paper presents the single event latch-up (SEL) detection for nano-satellite external solar radiation mitigation system. In this study, the SEL detection analysis was conducted using circuit test and simulation. An electrical power subsystem (EPS) is a part of all CubeSat bus subsystems and it comprises solar arrays, rechargeable batteries, and a power control and distribution unit (PCDU). In order to extract the maximum power generated by the solar arrays, a peak power tracking topology is required. This may lead to the SEL with the presence of high voltage produced by solar. To overcome the SEL problems, the circuit test and simulation must be done so that the flow of SEL will be easily detected and mitigate. The method that been used are by using microcontroller, the SEL will be created in the certain time. The programable integrated circuit (PIC) are used to mitigate SEL effect. It indicates that, the SEL occur very fast in certain time. When the simulation is conducted by using SPENVIS, the result shows, only single event upset (SEU) was affected on UiTMSAT-1.

Analysis and design of energy storage capacity of AC-DC hybrid power distribution unit with energy storage to improve the reliability of power grid

Based on the development of AC-DC distribution network, a new AC-DC distribution device with energy storage structure is designed in this paper. This paper first analyzes the existing AC-DC power distribution equipment and network reliability assessment methods. On this basis, the design is put forward, the energy storage link is placed at the DC high voltage side. The constraints of energy storage as an critical load backup power supply are defined and the mathematical model is established. In this paper the timing Monte Carlo method is used to calculate the reliability of the device and the power grid. The model in this paper can be applied to a variety of distribution network structure and energy storage scenarios, with high accuracy. It is concluded that the AC-DC distribution unit has remarkable effect in improving reliability.

Reliability Analysis of Internal Power Supply Architecture of Data Centers in Terms of Power Losses

The number of data centers and the energy demand are increasing globally with the development of information and communication technology (ICT). The data center operators are facing challenges to limit the internal power losses and the unexpected outages of the computational resources or servers. The power losses of the internal power supply system (IPSS) increase with the increasing number of servers that causes power supply capacity shortage for the devices in IPSS. The aim of this paper is to address the outage probability of the computational resources or servers due to the power supply capacity shortage of the power distribution units (PDUs) in the IPSS. The servers outage probability at rack-level defines the service availability of the data center since the servers are the main computational resource of it. The overall availability of the IPSS and the power consumption models of the IPSS devices are also presented in this paper. Quantitative studies are performed to show the impacts of the power losses on the service availability and the overall availability of the IPSS for two different IPSS architectures, which are equivalent to the Tier I and Tier IV models of the data center.

Solar Power Generation System for the Canadian Space Agency STRATOS Program

This paper discusses the design and application of solar photovoltaics (PV) under aerospace conditions. The application of solar PV that is addressed is the Power Distribution Unit (PDU) for the Canadian Space Agency’s (CSA) stratospheric balloon (STRATOS) program. The PDU utilizes four 1 kWh Battery Unit (BUs) that have been sized with volume and weight restrictions in mind. Without the capacity to provide enough energy to support multi-day missions, they are thus supplemented by the solar power generation subsystem presented in this paper. The power generation sub-system includes a bespoke solar panel design and a centralized Maximum Power Point Tracking (MPPT) power conversion unit to maximize the power output of solar panels. The centralized unit can accommodate up to eight solar panels, each consisting of nine individual C60 SunPower solar cells. The centralized MPPT unit consists of two MPPT controllers, each controller supporting up to four solar panels. The MPPT unit is modular and can be easily integrated to the CSA’s existing intelligent Battery Management System (BMS).

A Novel Reliability Index to Assess the Computational Resource Adequacy in Data Centers

The energy demand of data centers is increasing globally with the increasing demand for computational resources to ensure the quality of services. It is important to quantify the required resources to comply with the computational workloads at the rack-level. In this paper, a novel reliability index called loss of workload probability is presented to quantify the rack-level computational resource adequacy. The index defines the right-sizing of the rack-level computational resources that comply with the computational workloads, and the desired reliability level of the data center investor. The outage probability of the power supply units and the workload duration curve of servers are analyzed to define the loss of workload probability. The workload duration curve of the rack, hence, the power consumption of the servers is modeled as a function of server workloads. The server workloads are taken from a publicly available data set published by Google. The power consumption models of the major components of the internal power supply system are also presented which shows the power loss of the power distribution unit is the highest compared to the other components in the internal power supply system. The proposed reliability index and the power loss analysis could be used for rack-level computational resources expansion planning and ensures energy-efficient operation of the data center.

IBM z15: Improved data center density and energy efficiency, new system packaging, and modeling

The IBM z15 is designed to meet the requirements of a range of data centers, while reducing costs through increased density, configuration flexibility, and cooling efficiency. The z15 is a continuation and broadening of the physical transformation of the mainframe that began with the IBM z14 ZR1/LR1, which introduced the new “true 19-in” frame. A maximum configuration z15 delivers greater than 30% additional compute capacity per watt than z14, and maintains approximately the same maximum system footprint, while enabling significant floor space reduction for most configurations. The z15 introduces the choice of integrated 2N power using either intelligent power distribution units or bulk power, also supporting most data centers including hot/cold-aisle containment, raised-floor and nonraised-floor, and top and bottom-exit I/O and power. The z15 supports the ASHRAE A3 (fourth edition) environment, providing efficiency advantages by reducing humidification requirements. The z15 maintains the value of a system that is preconfigured/pretested before shipping. Innovations in packaging, I/O cabling, controls, and testing are put in the context of the latest data center trends. The capabilities of new tools to estimate power, weight, airflow, heat extracted to water for water-cooled systems as well as 3-D and computational fluid dynamics models to aid in the planning for the system are described.

Analysis of Electrical Model of Data Center Power System

The electrical structure of the power distribution system in data center is generally a tree-like structure, with fewer branches closer to the power supply side and more branches closer to the load side. In this article, the electrical topology structure diagram is established, and the structure of power distribution network between 10kV input line and power distribution units is discussed. In the electrical structure of power system, 10kV distribution cabinets and 400V distribution cabinets are connected with electrical equipment such as electrical cable, transformer or enclosed busbar. By analysing the equivalent impedance model of equipment above, the theoretical impedance values are obtained.

An Electric Drive for a Drilling Rig Top Drive System

The operation of a drilling rig top drive system (TDS) in drilling practice at a great depth or during the construction of a drill pipe stand in the case of failure of one of two motors is considered. In the existing kinematic scheme of most domestic and foreign TDSs, the two motors are mechanically rigidly connected to the drive shaft through a gear reduction unit. It is proposed to replace the gearbox with rigid mechanical connections with a double planetary gear reducer and, thereby, ensure the operation of the electric drive with two independent mechanical channels. Such a kinematic scheme with independent mechanical channels makes it possible to provide the drilling rig operation at great depths in the case of failure of one of the drives and when constructing pipes when disassembling the drilling string. Due to a wider range of torque control for each of the two channels, in the case of failure of one of the drives, the proposed scheme implements the indicated operating modes at a reduced speed, avoiding expensive downtime. The static mechanical characteristics of the TDS for the existing and proposed systems are presented. The calculation of the mechanical converter providing the required gear ratios for each of the mechanical channels is performed. The operation of the control system and power distribution unit of two drives is considered.

Experimental Description of Information Technology Equipment Reliability Exposed to a Data Center Using Airside Economizer Operating in Recommended and Allowable ASHRAE Envelopes in an ANSI/ISA Classified G2 Environment

Abstract Airside economizers lower the operating cost of data centers by reducing or eliminating mechanical cooling. It, however, increases the risk of reliability degradation of information technology (IT) equipment due to contaminants. IT Equipment manufacturers have tested equipment performance and guarantee the reliability of their equipment in environments within ISA 71.04-2013 severity level G1 and the ASHRAE recommended temperature-relative humidity (RH) envelope. IT Equipment manufacturers require data center operators to meet all the specified conditions consistently before fulfilling warranty on equipment failure. To determine the reliability of electronic hardware in higher severity conditions, field data obtained from real data centers are required. In this study, a corrosion classification coupon experiment as per ISA 71.04-2013 was performed to determine the severity level of a research data center (RDC) located in an industrial area of hot and humid Dallas. The temperature-RH excursions were analyzed based on time series and weather data bin analysis using trend data for the duration of operation. After some period, a failure was recorded on two power distribution units (PDUs) located in the hot aisle. The damaged hardware and other hardware were evaluated, and cumulative corrosion damage study was carried out. The hypothetical estimation of the end of life of components is provided to determine free air-cooling hours for the site. There was no failure of even a single server operated with fresh air-cooling shows that using evaporative/free air cooling is not detrimental to IT equipment reliability. This study, however, must be repeated in other geographical locations to determine if the contamination effect is location dependent.

An innovative monitoring and maintenance model for the INFN CNAF Tier-1 data center infrastructure

During the last years we have carried out a renewal of the Building Management System (BMS) software of our data center with the aim of improving the data collection capability. Considering the complex physical distribution of the technical plants and the limits of the actual building hosting our center, a system that simply monitors and collects all the necessary information and provides alarms only in case of major failures has proven to be unsatisfactory. In 2017 we suffered a major flood due to one main water pipeline failure in the public street. After this disastrous event, clearly far beyond our control, we were however forced to reconsider completely the physical site robustness of our building in addition to the current monitoring and alarm system capabilities. It was clear that in some specific cases, alerts should be triggered hours or days before the actual main problem arises in order to allow efficient human intervention and proper escalation process. This paradigm could be easily applied to almost all the infrastructure components in our site, mainly the electric power distribution and continuity systems as well as the whole cooling devices. For this reason, in parallel to a consistent increase in the sensor widespread distribution of our BMS data collector system, a study of a predictive maintenance approach applicability to our site has been started. Predictive maintenance techniques aims at prevent unexpected infrastructure components failures or major events with the study of the whole monitoring data collection and the creation of appropriate statistical models with the help of big data analysis and machine learning techniques. An improvement in the Power Distribution Units (PDUs) monitoring in our site and the introduction of a dedicated network of water leak sensors were the first steps for increasing the data collection information at our disposal. With sufficient monitoring statistical information stored in our BMS system a preliminary and exploratory predictive data analysis proof of concept could be constructed. This could lead to the model building phase and the creation of a prototype with the aim of forecasting future infrastructure main failure events and forthcoming error conditions. The general idea is, conceivably, an approach to the predictive maintenance model where it would be possible to introduce scheduled corrective actions for the purpose of preventing potential failures in the next future and increasing the site overall reliability.

Study on the deflection control of suspended tubular bus in 750kV transformer substation

Because of the large span between bus bars and the big diameter and heavy weight of tubular buses, it has been a difficult issue to control the deflection of buses for the 750kV power distribution unit. Based on the hanging test on suspended tubular buses and the actual conditions in spot, finite models were established with different support types and rigidities to simplify the true hanging points and provide an effective reference for the optimization design of suspended tubular buses.

Numerical Model to Calculate Magnetization AC Losses for Superconducting Strip used for Current Transport Applications in Electric Aircrafts

High Temperature Superconducting (HTS) tapes are being proposed in the current transportation applications in electric aircrafts due to their capacities to carry large currents with low losses and higher efficiencies. Many systems are involved in the aircraft power distribution units and each component has its own magnetic field which may affect the working of surrounding systems. It has been found from many studies that perpendicular field has significant effect on the critical current of the HTS tape. In the present study, effort has been made to develop a numerical code through which magnetization AC losses due to external magnetic field are evaluated for YBCO superconductor. Calculated values are compared with Halse-Brandt model and it has been found that with the increase in the index value ‘n’, the results are approaching the Halse-Brandt model.

RF Near-Field Coupling System Using Reverse PDN and Considering Electromagnetic Effects

One of the more intriguing applications of wireless power transfer is power delivery for low-power Internet of Things (IoT) devices. By utilizing RF near-field coupling (NFC), an improved combination of small receiver coil area and system efficiency can be achieved, as is ideal for wireless charging for low-power IoT platforms. However, utilizing high efficiency RF NFC comes with a cost—various electromagnetic effects can lead to detuning of the resonant frequency if not properly modeled. In addition, integrating power regulation with high frequency ac–dc conversion can create large ripple voltage supply to a power distribution unit (PDU). This paper investigates the system level issues that arise in efficient, regulated RF NFC systems for milliwatt-scale output power. A method for modeling the various electromagnetic, frequency detuning effects is presented, as well as a selection process for the circuit component values in the design. Furthermore, a reverse power distribution network is designed to integrate the rectifier with a PDU, introducing a target impedance and phase considerations for an RF rectifier. The modeling and integration solutions are experimentally verified through two different RF NFC systems. The systems have measured peak efficiency of 68.4% at 3.3 V output and 58.6% for 1 V output with less than 100 mm $^2$ receiver coil area, demonstrating a unique combination of small coil area and high efficiency compared to other NFC systems to better support low-power IoT devices.

RF Wireless Power Transfer Using Integrated Inductor

Wireless power transfer (WPT) is an ideal power delivery solution for many light-load applications, such as for the Internet of Things. A regulated solution for WPT may utilize a power distribution unit (PDU). Previous works have designed planar inductors for integration with switched-inductor buck regulators, but these inductors will not be as efficient for light-load applications. This paper reevaluates the inductor loss for light-load applications by taking into account the frequency spectrum of the inductor current. Using this revised analysis, a planar inductor with screen printed NiZn ferrite epoxy composite magnetic core is designed for an RF near-field coupling system with 1–10-mW load power. In measurement with a 6-MHz buck converter, the PDU with designed inductor demonstrated up to 3% improved efficiency compared to surface-mount technology inductor in the pulse-frequency modulation mode and pulsewidth modulation mode. The designed embedded inductor was subsequently demonstrated in an integrated, compact RF near-field coupling system with peak 43% system efficiency.

An energy-efficient cloud system with novel dynamic resource allocation methods

In the last decade, cloud computing has brought enormous changes to people’s lives. Cloud computing gives a client-driven computational model. In this case, the pay-per-use model enables a flexible method of deploying and sharing distributed services and resources. Furthermore, computational resources are progressively reassembled and insulated to give various types of services. Current solutions on how to efficiently utilize energy consumption are inadequate. Thus, we propose two methods to tackle the problem, which are the dynamic resource allocation method and the energy saving method, respectively. In this work, we firstly deployed an infrastructure platform based on OpenStack to actualize the proposed approach with live migration of virtual machines (VMs). Secondly, we allocated the dynamic resources and proposed the energy saving algorithm. Thirdly, we monitor the power distribution unit status to record the energy consumption of the system. Finally, in the experiments, we found that the proposed algorithms cannot just accomplish the proficient use of VMs’ resources but also thrift the energy usage of physical machines. Our experimental results demonstrate about 39.89% of energy is saved from 20 VCPUs of 20 GB memory.

Online monitoring of high‐voltage switchgear installation

The high-voltage distribution device is an important part of the power supply system which shoulders the dual tasks of control and protection. The function of the high-voltage distribution device is closely related to the safe operation of the power supply system. The condition monitoring of high-voltage distribution device can detect the specific parts of the fault in a timely and effective way which can improve the stability of the system. The mechanical vibration signal of circuit breaker body in mine high-voltage distribution device is a rich information carrier which contains a large number of device operating status information. Using modern information processing technology, the special parameters of mechanical faults are extracted from vibration signals, which have very important practical significance. Based on the analysis of the common mechanical faults in the high-voltage power distribution unit, a set of online vibration signal processing system with perfect function and reliable operation has been developed, which provides the technical guarantee for the reliable operation of the high-voltage power distribution unit.

Power electronic transformer with adaptive PLL technique for voltage-disturbance ride through

The power electronic transformer (PET) has recently emerged as a type of power converter. It features the basic functions of power conversion and isolation as well as additional functions related to power quality control. A novel PET for a distribution grid called a flexible power distribution unit is proposed in this paper, and the energy exchange mechanism between the network and the load is revealed. A 30 kW 600 VAC/220 VAC/110 VDC medium-frequency isolated prototype is developed and demonstrated. This paper also presents key control strategies of the PET for electrical distribution grid applications, especially under grid voltage disturbance conditions. Moreover, stability issues related to the grid-connected three-phase PET are discussed and verified with an impedance-based analysis. The PET prototype is tested, and it passes the voltage-disturbance ride-through function. The experimental results verify the power quality control abilities of the PET.

An intelligent remote control system for ECEI on EAST

An intelligent remote control system based on a power distribution unit (PDU) and Arduino has been designed for the electron cyclotron emission imaging (ECEI) system on Experimental Advanced Superconducting Tokamak (EAST). This intelligent system has three major functions: ECEI system reboot, measurement region adjustment and signal amplitude optimization. The observation region of ECEI can be modified for different physics proposals by remotely tuning the optical and electronics systems. Via the remote adjustment of the attenuation level, the ECEI intermediate frequency signal amplitude can be efficiently optimized. The remote control system provides a feasible and reliable solution for the improvement of signal quality and the efficiency of the ECEI diagnostic system, which is also valuable for other diagnostic systems.

A joint measurement of efficiency and effectiveness for ranking power distribution units in Iran: integrated data envelopment analysis approach

In recent years, data envelopment analysis (DEA) has been widely used to assess both technical efficiency and technical effectiveness. Although a number of studies have focused on performance evaluation of power distribution units, this sort of studies are rare in Iran. This paper proposes an integrated slack-based measure (ISBM) approach to measure both technical efficiency and technical effectiveness of Iranian's power distribution units. The proposed SBM-DEA model represents both non-storable features of power distribution industry and production technologies in a unified framework. The proposed approach not only measures technical efficiency and effectiveness of power distribution units, but also estimates overall efficiency of distribution units.