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Journal ArticleDOI

A Transformerless Intelligent Power Substation: A three-phase SST enabled by a 15-kV SiC IGBT

TL;DR: The solid-state transformer (SST) is a promising power electronics solution that provides voltage regulation, reactive power compensation, dc-sourced renewable integration, and communication capabilities, in addition to the traditional step-up/stepdown functionality of a transformer as mentioned in this paper.
Abstract: The solid-state transformer (SST) is a promising power electronics solution that provides voltage regulation, reactive power compensation, dc-sourced renewable integration, and communication capabilities, in addition to the traditional step-up/step-down functionality of a transformer. It is gaining widespread attention for medium-voltage (MV) grid interfacing to enable increases in renewable energy penetration, and, commercially, the SST is of interest for traction applications due to its light weight as a result of medium-frequency isolation. The recent advancements in silicon carbide (SiC) power semiconductor device technology are creating a new paradigm with the development of discrete power semiconductor devices in the range of 10-15 kV and even beyond-up to 22 kV, as recently reported. In contrast to silicon (Si) IGBTs, which are limited to 6.5-kV blocking, these high-voltage (HV) SiC devices are enabling much simpler converter topologies and increased efficiency and reliability, with dramatic reductions of the size and weight of the MV power-conversion systems.
Citations
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Journal ArticleDOI
Xuan Zhang1, He Li1, Lixing Fu1, Mico Perales, John Wu, Jin Wang1 
TL;DR: In this paper, a 15kV silicon carbide (SiC) MOSFET gate drive is presented, which features high commonmode (CM) noise immunity, small size, light weight, and robust yet flexible protection functions.
Abstract: This paper presents a 15kV silicon carbide (SiC) MOSFET gate drive, which features high common-mode (CM) noise immunity, small size, light weight, and robust yet flexible protection functions. To enhance the gate-drive power reliability, a power over fiberbased isolated power supply is designed to replace the traditional design based on isolation transformer. It delivers the gate-drive power by laser light via optical fiber over a long distance (>1 m), so a high isolation voltage (>20 kV) is achieved, and the circuit size and weight are reduced. More importantly, it eliminates the parasitic CM capacitance coupling the power stage and control stage, and thus eradicates the control signal distortion caused by high dv/dt in switching transients of the high-voltage SiC devices. In addition, the gate-drive circuit design integrates comprehensive protection functions, including the overcurrent protection, undervoltage/overvoltage lockout, active miller clamping, soft turn off, and fault report. The overcurrent protection responds within 400 ns. The experimental results from a 15kV double-pulse tester are presented to validate the design.

117 citations


Cites background from "A Transformerless Intelligent Power..."

  • ...In traditional designs, the isolation is implemented with transformers [3], [9], [20]–[24]....

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Journal ArticleDOI
31 Dec 2016
TL;DR: In this paper, the benefits of silicon carbide (SiC) based power electronics for converters and systems, as well as their ability in enabling new applications are discussed, and challenges and research trends on the design and application of SiC power electronics are also discussed.
Abstract: This paper overviews the silicon carbide (SiC) technology. The focus is on the benefits of SiC based power electronics for converters and systems, as well as their ability in enabling new applications. The challenges and research trends on the design and application of SiC power electronics are also discussed

117 citations


Cites background from "A Transformerless Intelligent Power..."

  • ...Similar to SSTs, SSFCLs and SSCBs can be realized by both Si and SiC devices....

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  • ...Also, as discussed above, SiC based converter, such as SST, are being developed for shipboard and train as well....

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  • ...Also note that some equipment, such as SST, SSFCL, and SSCB, are not limited to utility application but can be leveraged to any applications with electric power system, such as shipboard, electrified train....

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  • ...SiC devices can improve and impact power electronics in several ways [2]: 1) At converter level, through substituting Si devices directly or simplifying circuit topologies, SiC devices can improve converter efficiency, reduce cooling needs, and reduce active and passive component numbers and size, with their high voltage, low loss and fast switching capabilities; 2) At system level, SiC based converters can have better dynamic performance and more system functionalities as a result of their high frequency capability and high control bandwidth enabled by fast switching speed, and 3) SiC can enable new applications, such as high-efficiency high-density solid-state transformers (SST) and high speed motor drives....

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  • ...7 shows a prototype SST based on 10-kV, 120-...

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Journal ArticleDOI
TL;DR: In this paper, a voltage balance control strategy based on dual active bridge (DAB) dc/dc converters in a power electronic traction transformer (PETT) is proposed.
Abstract: In this paper, a voltage balance control strategy based on dual active bridge (DAB) dc/dc converters in a power electronic traction transformer (PETT) is proposed. Based on this strategy, the output-parallel DAB converters can be equivalent to an input-series-output-parallel system. Furthermore, a PETT starting control method is put forward, which can effectively avoid risks of overcurrent and overvoltage in the PETT starting process. In order to carry out the controller design and system stability analysis, three different kinds of mathematical models of DAB converters are set up. The first model is related to a single DAB converter, the second model reflects the equivalent relation between an output-parallel DAB system and a single DAB converter in terms of the output-voltage control loop, and the third model indicates that the voltage balance control system based on DAB converters is a multiinput-multioutput system. Due to the nonzero off-diagonal elements of the controlled plant, there is a mutual effect between different control loops, which is defined as “interaction” in the multivariable feedback control theory. The stability of the voltage balance control system is made up of two parts, including the stability of each single-input-single-output (SISO) control loop and the influence of the interaction on the system stability. The research is carried out to measure the intensity of the interaction in this paper, and a criterion directly based on the controlled plant is proposed to predict the influence of the interaction, which can obviously simplify the system stability analysis. Considering the particular traction onboard application, a new control structure toward the voltage balance controller is introduced. Based on the new structure, the controller is designed and the stability of the SISO system is analyzed. Finally, a five-cell PETT prototype with rated power of 30 kW is taken to carry out further research, and the experiment results verify the effectiveness and correctness of the proposed algorithms.

106 citations


Cites background from "A Transformerless Intelligent Power..."

  • ...Erenow, there are many similar researches, not only in traction onboard application, but also in the utility gird application, and the concepts such as solid-state transformer [8], universal and flexible power management [9], power electronic transformer [10], smart energy router [11], [12], single-phase solid-state power substation [13], medium-frequency transformer link [14], and transformerless intelligent power substation [15] were proposed in succession....

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Journal ArticleDOI
TL;DR: This paper presents predictive current-mode control for a single-phase high-frequency transformer-isolated dual-active bridge dc-to-dc converter and demonstrates that the application of the predictive control algorithm can remove transient dc offset from the current in high- frequencies isolation transformer within one switching cycle.
Abstract: This paper presents predictive current-mode control for a single-phase high-frequency transformer-isolated dual-active bridge dc-to-dc converter. The predictive control algorithm increases the bandwidth of the current loop of the converter which enables tracking of the current reference within one switching cycle. The paper further demonstrates that the application of the predictive control algorithm can remove transient dc offset from the current in high-frequency isolation transformer within one switching cycle. Direct control of the converter current protects the transformer from saturation even at transient conditions. The control algorithm has been implemented on an experimental setup and transient tests have been performed to validate controller performance. Since the predictive control algorithm is dependent on the measured value of the leakage inductance of the transformer, a compensator has been implemented to improve the parameter insensitivity of the proposed controller.

95 citations

Journal ArticleDOI
TL;DR: In the current configuration, transformers are passive devices that do not enable dc systems to connect or interface the electric grid with other energy grids.
Abstract: Increasing decentralized energy production challenges the distribution grid [1], [2], and, in many countries, power generation and consumption are spatially separated, meaning that energy must be transferred over a long distance [3]. This calls for novel ways to transfer power to the loads without overloading grid feeders and to connect new intelligent loads and storage [4], which typically form the actual electric grid hybrid (ac and dc) and couple with other energy networks (multimodal) [5]. In the current configuration, transformers are passive devices that do not enable dc systems to connect or interface the electric grid with other energy grids.

95 citations


Cites background from "A Transformerless Intelligent Power..."

  • ...Conversely, a nonmodular system is based on a single power converter and usually takes advantage of high-voltage, wide-bandgap semiconductors [17], [18]....

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  • ...For the semiconductors, Silicon Carbide (SiC) MOSFETs with very low on resistance (RDS(on)) have been used....

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  • ...Special devices with high-voltage capability, such as 10 kV SiC metal-oxide– semiconductor field-effect transistor (MOSFET) [18] or 15 kV SiC MOSFET [17], are needed to handle the MV level in the power converter....

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References
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Journal ArticleDOI
02 Oct 1988
TL;DR: In this paper, three DC/DC converter topologies suitable for high power-density high power applications are presented, which operate in a soft-switched manner, making possible a reduction in device switching losses and an increase in switching frequency.
Abstract: Three DC/DC converter topologies suitable for high-power-density high-power applications are presented. All three circuits operate in a soft-switched manner, making possible a reduction in device switching losses and an increase in switching frequency. The three-phase dual-bridge converter proposed is shown to have the most favorable characteristics. This converter consists of two three-phase inverter stages operating in a high-frequency six-step mode. In contrast to existing single-phase AC-link DC/DC converters, lower turn-off peak currents in the power devices and lower RMS current ratings for both the input and output filter capacitors are obtained. This is in addition to smaller filter element values due to the higher-frequency content of the input and output waveforms. Furthermore, the use of a three-phase symmetrical transformer instead of single-phase transformers and a better utilization of the available apparent power of the transformer (as a consequence of the controlled output inverter) significantly increase the power density attainable. >

2,056 citations


"A Transformerless Intelligent Power..." refers methods in this paper

  • ...Modular 3L-NPC Converter for TIPS Based on the switching loss measurements, the hardswitching frequency limits of the 15-kV SiC IGBT were evaluated and demonstrated on a 10-kV dc–dc boost converter [10]....

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  • ...The AFEC dc bus (22 kV) is converted to a LV-side dc bus (800 V) using an HF dc-link, enabled by a three-phase dual active bridge converter (DABC) [10]....

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Book
01 Jan 2006
TL;DR: In this article, the authors present a model for high-power switchings with SCR rectifiers and demonstrate how to use SCR Rectifiers to control high power switchings.
Abstract: Preface. Part One Introduction. 1. Introduction. 1.1 Introduction. 1.2 Technical Requirements and Challenges. 1.3 Converter Configurations. 1.4 MV Industrial Drives. 1.5 Summary. References. Appendix. 2. High-Power Semiconductor Devices. 2.1 Introduction. 2.2 High-Power Switching Devices. 2.3 Operation of Series-Connected Devices. 2.4 Summary. References. Part Two Multipulse Diode and SCR Rectifiers. 3. Multipulse Diode Rectifiers. 3.1 Introduction. 3.2 Six-Pulse Diode Rectifier. 3.3 Series-Type Multipulse Diode Rectifiers. 3.4 Separate-Type Multipulse Diode Rectifiers. 3.5 Summary.(c) References. 4. Multipulse SCR Rectifiers. 4.1 Introduction. 4.2 Six-Pulse SCR Rectifier. 4.3 12-Pulse SCR Rectifier. 4.4 18- and 24-Pulse SCR Rectifiers. 4.5 Summary. References. 5. Phase-Shifting Transformers. 5.1 Introduction. 5.2 Y/Z Phase-Shifting Transformers. 5.3 /Z Transformers. 5.4 Harmonic Current Cancellation. 5.5 Summary. Part Three Multilevel Voltage Source Converters. 6. Two-Level Voltage Source Inverter. 6.1 Introduction. 6.2 Sinusoidal PWM. 6.3 Space Vector Modulation. 6.4 Summary. References. 7. Cascaded H-Bridge Multilevel Inverters. 7.1 Introduction. 7.2 H-Bridge Inverter. 7.3 Multilevel Inverter Topologies. 7.4 Carrier Based PWM Schemes. 7.5 Staircase Modulation. 7.6 Summary. References. 8. Diode-Clamped Multilevel Inverters. 8.1 Introduction. 8.2 Three-Level Inverter. 8.3 Space Vector Modulation. 8.4 Neutral-Point Voltage Control. 8.5 Other Space Vector Modulation Algorithms. 8.6 High-Level Diode-Clamped Inverters. 8.7 Summary. References. Appendix. 9. Other Multilevel Voltage Source Inverters. 9.1 Introduction. 9.2 NPC/H-Bridge Inverter. 9.3 Multilevel Flying-Capacitor Inverters. 9.4 Summary. References. Part Four PWM Current Source Converters. 10. PWM Current Source Inverters. 10.1 Introduction. 10.2 PWM Current Source Inverter. 10.3 Space Vector Modulation. 10.4 Parallel Current Source Inverters. 10.5 Load-Commutated Inverter (LCI). 10.6 Summary. References. Appendix. 11. PWM Current Source Rectifiers. 11.1 Introduction. 11.2 Single-Bridge Current Source Rectifier. 11.3 Dual-Bridge Current Source Rectifier. 11.4 Power Factor Control . 11.5 Active Damping Control. 11.6 Summary. References. Appendix. Part Five High-Power AC Drives. 12. Voltage Source Inverter-Fed Drives. 12.1 Introduction. 12.2 Two-Level VBSI-Based MV Drives. 12.3 Neutral-Point Clamped (NPC) Inverter-Fed Drives. 12.4 Multilevel Cascaded H-Bridge (CHB) Inverter-Fed Drives. 12.5 NPC/H-Bridge Inverter-Fed Drives. 12.6 Summary. References. 13. Current Source Inverter-Fed Drives. 13.1 Introduction. 13.2 CSI Drives with PWM Rectifiers. 13.3 Transformerless CSI Drive for Standard AC Motors. 13.4 CSI Drive with Multipulse SCR Rectifier. 13.5 LCI Drives for Synchronous Motors. 13.6 Summary. References. 14. Advanced Drive Control Schemes. 14.1 Introduction. 14.2 Reference Frame Transformation. 14.3 Induction Motor Dynamic Models. 14.4 Principle of Field-Oriented Control (FOC). 14.5 Direct Field-Oriented Control. 14.6 Indirect Field-Oriented Control. 14.7 FOC for CSI-Fed Drives. 14.8 Direct Torque Control. 14.9 Summary. References. Abbreviations. Appendix Projects for Graduate-Level Courses. P. 1 Introduction. P. 2 Sample Project. P. 3 Answers to Sample Project. Index. About the Author.

1,870 citations


"A Transformerless Intelligent Power..." refers background in this paper

  • ...Also, it cannot be too close to the dominant lower-order harmonics, like the fifth and seventh, to prevent harmonics being amplified in the supply [18]....

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Journal ArticleDOI
TL;DR: In this article, a transformerless intelligent power substation (TIPS) is proposed as a three-phase SST interconnecting a 13.8 kV distribution grid with a 480 V utility grid.
Abstract: Medium-voltage (MV) SiC devices have been developed recently which can be used for three-phase MV grid tie applications. Two such devices, 15 kV SiC insulated-gate bipolar transistor (IGBT) and 10 kV SiC MOSFET, have opened up the possibilities of looking into different converter topologies for the MV distribution grid interface. These can be used in MV drives, active filter applications, or as the active front end converter for solid-state transformers (SSTs). The transformerless intelligent power substation (TIPS) is one such application for these devices. TIPS is proposed as a three-phase SST interconnecting a 13.8 kV distribution grid with a 480 V utility grid. It is an all SiC device-based multistage SST. This paper focuses on the advantages, design considerations, and challenges associated with the operation of converters using these devices keeping TIPS as the topology of reference. The efficiency of the TIPS topology is also calculated using the experimentally measured loss data of the devices and the high-frequency transformer. Experimental results captured on a developed prototype of TIPS along with its measured efficiency are also given.

307 citations


"A Transformerless Intelligent Power..." refers background in this paper

  • ...L2 ^ h This results in 90 mH for L1 and 180 mH for L2 [17]....

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Journal ArticleDOI
TL;DR: Development of 15-kV SiC IGBTs and their impact on utility applications is discussed, and the need for power semiconductor devices with high-voltage, high- frequency, and high-temperature operation capability is growing.
Abstract: The need for power semiconductor devices with high-voltage, high- frequency, and high-temperature operation capability is growing, especially for advanced power conversion and military applications, and hence the size and weight of the power electronic system are reduced. Development of 15-kV SiC IGBTs and their impact on utility applications is discussed.

252 citations


"A Transformerless Intelligent Power..." refers background in this paper

  • ...Background Si-based power semiconductor devices have been widely used for several decades over a wide range of voltage and power levels [1]....

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