The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper presents operation of a Doubly Fed Induction Generator (DFIG) to extract oscillatory power from ocean wave energy converter (WEC). DFIG has the advantage of generating power at both sub-synchronous and super-synchronous speed with only slip power to be handled by power converter at rotor side. At super-synchronous speed the rotor generates slip power along with the stator to take the net...
Recently, Voltage Source Converter (VSC) based High Voltage Direct Current (HVDC) transmission systems have gained more attention. In this paper, a control method for a modular VSC based HVDC transmission system with high frequency isolation referred to as high frequency isolated modular converter is proposed. In the high frequency isolated modular converter configuration, several floating DC capacitors...
Using 6.5 kV Silicon (Si) IGBTs, high voltage high power DC to DC converters are realized either by multi-level converters or series connected devices based two level converters or modular multi-level converter using series connected devices two level converter as building blocks. The introduction of high voltage SiC devices (10 kV to 20 kV) reduces the component count significantly while improving...
The Solid State Transformer (SST) enables intelligent integration of renewable resources with the grid. The rectifier, grid tie inverter and black start modes of SST operation are discussed in this paper. A previous study [3], did a preliminary investigation of the black start capabilities of the SST. This paper further investigates the control structures and validates them through PSCAD simulations...
The advent of medium voltage blocking SiC devices has resulted in the development of 3-phase Solid State Transformers (SSTs) to inter-connect the 13.8 kV distribution grid with the 480 V utility grid. One such 3-phase SST is the Transformerless Intelligent Power Substation (TIPS). TIPS is tied with the 13.8 kV grid through an ac-dc Front End Converter (FEC) stage. The isolation stage is a dc-dc Dual...
This paper investigates application of temperature sensitive ferrofluids (TSFF) in the thermal management of electric machines as the cooling and dielectric media for end winding section of these systems. The goal is to exploit the thermal and magnetic characteristics of TSMFs such that not only the fluid will circulate over the end winding of an electric machine, but also existing thermal and magnetic...
Multi-terminal DC grid can be embedded in meshed AC grid to increase power transmission capability and control power flow of AC grid. In addition to economic benefits especially in congested areas, the proposed solution can provide back-up for the AC grid and enhance power transmission capacity and flexibility. From the supervisory control point of view, a control algorithm is required to set the...
Solid State Transformer (SST) average models are needed to enable system and protection studies. This paper focuses on fine tuning existing average models to replicate their switching counterparts and also discusses and validates control modifications required for successful grid integration. A 3 phase test system comprised of Substation SSTs and load SSTs of different ratings has been developed in...
This paper discusses about a multi-port solid state transformer (SST) which can be used as an inter-grid power flow controller. The objective of the converter is to integrate renewable energy sources with the existing grid along with controlled power flow between the grids. As an example, this paper describes a three terminal isolated SST with an integrated battery bank connected to it. The energy...
The advent of Silicon Carbide (SiC) devices has made possible high switching frequency operation of PWM power converters. In this paper, SiC devices are compared in detail with Si devices in a high power (1 MW) DC -DC converter application. The converter is designed as the building block for traction drives which requires it to operate at high power, high input voltage (11 kV) and low output voltage...
Silicon Carbide (SiC) has wider band gap compared to Silicon (Si) and hence MOSFET made in SiC has considerably lower drift region resistance, which is a significant resistive component in high-voltage power devices. Due to low on-state resistance combined with its inherently low switching loss, SiC MOSFET is an excellent candidate for high power converter design. With its lower power loss and operation...
In this paper, a Reverse Blocking IGBT is compared with various other combinations of switches and diodes keeping Current Source based Converter application in mind. The devices are tested under Reverse Voltage Commutation, Switch Overlap (turn on at non-zero current but zero voltage), Hard Switching, and Zero Current Switching condition. Test Circuits have been constructed and tested at various voltage...
There are applications like railway traction system where power converters for HVAC to MVDC or MDAC to LVDC are required with a high power/weight ratio. The conventional way is to use heavy line frequency or medium frequency transformers followed by a controlled rectifier. The availability of high voltage SiC devices has made it possible to raise the switching frequency to higher value and hence the...
This paper presents extensive experimental switching characteristics of a state-of-the-art 15 kV SiC N-IGBT (0.32 cm2 active area) up to 10 kV, 10 A and 175°C. The influence of the thermal resistance of the module package, cooling mechanism, and the increased energy loss with temperature are investigated for determining the switching frequency limits of the IGBT. Detailed FEM analysis is conducted...
High voltage high power semiconductor devices are being used for grid integration of renewable energy sources. 1200V, 100A SiC Mosfets, 10 kV SiC Mosfets and 10kV SiC JBS Diodes have proven to be beneficial for high voltage application. High Voltage SiC devices enable high switching frequency operation thus reducing size of passive elements. Scope of this paper focuses on an alternative approach for...
Recently, medium voltage SiC devices have been developed which can be used for grid tie applications at medium voltage. Two such devices − 15 kV SiC IGBT and 10 kV SiC MOSFET have opened up the possibility of looking into different converter topologies for medium voltage distribution grid interface. These can be used in medium voltage drives, active filter applications or as the active front end converter...
The advent of the 15kV SiC IGBT device has made a single series stage medium-voltage (MV) and high-frequency (HF) DC-DC Dual Active Bridge (DAB) converter application viable. The Y: Y/Δ three-phase DAB is a high-power isolated DC-DC converter based on three-level neutral-point clamped (NPC) on the MV side. A MV/HF transformer used in the DAB, has significant parasitic capacitances, which cause ringing...
The integrated gate commutated thyristor (IGCT) and the press-pack power diodes are successfully applied in medium-voltage Neutral Point Clamped (NPC) converters in the power range from hundreds of kW to tenth of MW. Responsible for driving key processes in various industries, the requirements of reliability and high availability of these converters are absolutely relevant, since its repair or replacement...
The PWM-controlled Voltage Source Converters (VSCs) are commonly used in industrial and utility applications. In spite of superior features of fast voltage regulation and stable DC-link voltage, PWM-controlled VSCs have the major drawback of being sensitive to the grid disturbances especially the unbalanced conditions and system faults. Unbalanced input voltage generates large negative sequence current...
This paper proposes a simple control scheme to eliminate the lower order harmonics in the line currents of the Front End Converter (FEC) of a 100 kVA Transformerless Intelligent Power Substation (TIPS) connected to the medium voltage (13.8 kV) grid through an LCL filter. Due to medium voltage (13.8 kV) and low power (100 kVA) specification for the FEC, the control technique needs to be specially designed...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.