Two Stop-and-Go Gate Driving to Reduce Switching Loss and Switching Noise in Automotive IGBT Modules

A new active gate driving method of “two stop-and-go gate driving (2S&G)” is proposed to reduce both the switching loss (ELOSS) and the collector current overshoot (IOVERSHOOT) in the turn-on of automotive IGBT modules. 2S&G includes two gate current zeros during turn-on and has only two parameters for a digital gate driver, which means low test cost for parameter optimization. Five different gate driving methods, including the conventional single-step gate driving (CSG), the conventional one stop-and-go gate driving [1], and digital gate drivings with 100 ns × 4 slots and 20 ns × 20 slots, are compared in the double pulse test using a 6-bit digital gate driver IC at 300 V and 150 A, and the proposed 2S&G showed the best performance. Compared with CSG, the proposed 2S&G reduces ELOSS by 42 % under IOVERSHOOT-aligned condition and reduces IOVERSHOOT by 18 % under ELOSS-aligned condition.

ON MODELLING PIEZOELECTRIC TRANSDUCER

Piezoelectric transducers are the key to APT systems. Choosing, designing, and optimizing the piezoelectric transducer is particularly important to improve the performance of the APT system. Therefore, this paper first lists the application of piezoelectric transducer materials’ development, its advantages, and disadvantages. Secondly, while some behaviors of piezoelectric transducers require a more stereoscopic three-dimensional analysis, their basic behaviors can be described by a one-dimensional model of piezoelectric transducers. Therefore, this paper analyzes and compares several one-dimensional equivalent circuits of piezoelectric transducers and summarizes these models’ application range and value, which will significantly improve the efficiency of designing and optimizing piezoelectric transducers.

Manipulation of Actual Demand in Electric Vehicles (MAD EV): A Cyber Security Perspective

This paper defines and analyses a specific cybersecurity risk for EVs, which we refer to as Manipulation of Actual Demand. This attack involves coordinated charging of a large number of EVs across multiple charging stations to disrupt the power grid. We provide a detailed analysis and quantification of the impact of this unique cyber-attack on the smart grid in terms of demand-side load. The findings of our analysis guide future considerations on cybersecurity risks of coordinated EV charging and their mitigation. We have made a comparison between Home EV chargers and Fast EV chargers via simulation. The results indicate the EV demand load threshold required to disrupt normal power grid operations

Design and Experimental Validation of a Novel Integrated Three-Phase Inductor For Vienna PFC Rectifier

Miniaturization of the electromagnetics plays a critical role in power converter design since they dominate the overall size and weight. This paper proposes a super-compact three-phase inductor design using integrated technique, contributing to higher power density of the Vienna power factor correction (PFC) rectifier. A novel symmetrical magnetic mechanism is introduced and the equivalent magnetic circuit is modeled to evaluate the corresponding inductance network. A variety of the magnetic materials has been studied comprehensively to investigate the most suitable material in this research. Moreover, a close-loop iterative framework is formulated by coupling the analytical expression and 3D FEM-based numerical model to address the relevant parameters of the investigated inductor design. Furthermore, a prototype incorporating the proposed configuration is fabricated and extensive experiments are being performed in a 6kW/29kHz Vienna PFC circuit to validate the design. During testing exploration, an upgraded inductance measurement approach exploiting single-phase setup is proposed for the measurement of a three-phase inductor. Obtained results are quite comparable with FEM simulations and in-circuit inductance deduction. With the support of the experimental results, the effectiveness of the proposed design has been validated with 48% size reduction compared to the conventional counterparts without compromising any thermal performance or filtering capability.

Impact of standardized methods applied for conducted EMI estimation on optimal volume of EMC filter in a single-leg inverter system

– In order to estimate the influence of standard measurement conditions on filter design, this paper discusses the impact of the absence of the line impedance stabilization network (LISN) on conducted emissions and consequently on the optimized volume of passive EMC filter in a single-leg inverter system fed by a DC source.
– addressing the problem of using the LISN in a more critical case (DC sources and DC grids) compared to state of art (AC grids)
-The enhanced two-probe HF impedance measurement method with a new setup allows accurate measuring in higher frequencies compared to state of art (until 50 MHz compared to 30 MHz from state of art)
– comparison of filter volume designed for each case and showing the increase in volume related to this problem.

Stochastic Approach to Modelling Emissions of Multiple Power Electronic Converters

This paper aims to describe the effects of time delays ∆t on the statistical quantification of the common mode current caused by multiple converters operating within the same grid. For this purpose, a circuit simulation and the Polynomial Chaos (PC) method are used to create a surrogate model of the grid. The switching-on time ∆t of each converter is considered as a random variable following a uniform distribution. The resulting model allows to depict a distribution of the common mode current for selected harmonics of the switching frequency. The results provided by the model can be used by the EMC and power engineers to account for the uncertainty caused by the operation of several identical converters.

Power Reserve Control Methods for Grid-Connected Photovoltaic Power Plants: A Review

Solar penetration is steadily increasing to provide power generation as the world turns to clean and sustainable solutions to meet the rising energy demand. Consequently, grid codes and standards are constantly evolving with new requirements such as constant power injection into the grid and power reserve control (PRC) to provide grid support. As a result, existing control techniques in photovoltaic (PV) systems, such maximum power point tracking (MPPT) and flexible power point tracking (FPPT) algorithms, need to be modified to provide such functionalities. Constant power injection, achieved by FPPT, mitigates the problem of solar intermittency, whereas PRC can provide frequency response capability to the grid-connected PV power plants. PRC methods are able to determine the maximum available power which indicates the dispatchable power reserve magnitude while performing FPPT. PRC methods can be broadly classified as estimation and measurement-based. In this paper, a review of PRC methods followed by a comparative discussion on the basis of complexity, ease of implementation, accuracy, and additional hardware requirement of these methods is done.

Decoupled Three-Phase Coil Array

Proposes a three-phase IPT coupler which achieves mutual decoupling of its three coils whilst retaining simple geometry and a modular structure facilitate ease of construction.

On routing tolerant to power supply failure of a cabinet of a torus-based supercomputer

Supercomputers are massively parallel systems as they include hundreds of thousands of compute nodes. Power management is key to such machinery: nodes are gathered into cabinets, with a consumption of 15 to 20 kW per cabinet in the case of the IBM Blue Gene/L, for a grand total of more than 1 MW (1.2 MW for the IBM Blue Gene/L). Failure of the power supply unit of one cabinet would thus trigger a sudden and massive increase of the number of faulty compute nodes. Conventional approaches to fault tolerance in such interconnection networks are able to cope with only a few faulty nodes or edges, thus not tolerant to such cabinet power supply failure. In this paper, recognising that torus-based interconnects are very popular, we are going to propose and evaluate a particular node organisation into cabinets and a routing algorithm that is capable of dealing with such failure scenario in an n-dimensional torus.

Multi-Ports Unified Power Quality Conditioner for Active Distribution Network

This paper proposes a novel multi-ports unified power quality controller.The whole UPQC can fulfill the following functions. One is to reduce the voltage deviation in each feeder and another is to balance the output power of the
transformers and maintain the successful operation of parallel supply. The detailed coordinated power control method has been proposed for maintaining the stability of the dc-link voltage either.