Abb Schweiz Ag

Abb Power Grids Switzerland Ag

Abb Technology Ltd

Hitachi Energy Ltd

Hitachi Energy Switzerland Ag

Robert Saers

Ritwik Majumder

Lars Liljestrand

RongRong Yu

Jesper Magnusson

Zhao Wang

Yao Liang Chen

Bertil Berggren

Tord Bengtsson

Frans Dijkhuizen

Tor Laneryd

Nilanga Abeywickrama

Tomas Tengner

Subrat Sahoo

Antonis Marinopoulos

Jonas Hedberg

Giovanni Velotto

Xiaoxia Yang

Ebrahim Shayesteh

Bertil Samuelsson

Anders Brokvist

Rongrong Yu

Marko Viitala

Cathy-Yao Chen

One embodiment is a system comprising a medium voltage direct current (MVDC) link electrically coupling a first AC-DC converter and a second AC-DC converter. The first AC-DC converter is electrically coupled with a first alternating current (AC) feeder. The second AC-DC converter electrically coupled with a second AC feeder. A battery charger electrically coupled with the MVDC link via a converterless connection. A first electronic controller is operatively coupled with the first AC-DC converter. A second electronic controller is operatively coupled with the second AC-DC converter. During operation of the battery charger to charge a battery the first electronic controller is configured to control power flow between the first AC feeder and the second AC feeder and the second electronic controller is configured to control the voltage of the MVDC link.

MVDC link-powered battery chargers and operation thereof

A method can be used for determining resiliency in a microgrid that includes a number of assets. The method includes obtaining status data about devices used to control the assets as well as about communication resources of this control, determining, based on the status data, the health and availability of each asset to assist each of a plurality of functions for handling disruptive events in the microgrid, determining a resiliency index of the microgrid in performing the plurality of functions, providing the resiliency index to a control system of the microgrid, comparing, in the control system, the resiliency index with a least one threshold, and changing the control of the microgrid if any of the thresholds is crossed.

Resiliency determination in a microgrid

A cooling system for a high voltage electromagnetic induction device, includes: at least one duct filled with a first coolant and surrounded by a second coolant, each being routed along a direction of natural convection; at least one group of fans, each fan of the group being mounted along a respective duct of the at least one duct along the direction of natural convection and being configured to blow for the-second-coolant-forced cooling; at least one group of electric motors, each electric motor being configured to operate a respective fan of the at least one group of fans; at least one group of switches, each switch being configured to control a respective electric motor of the at least one group of electric motors. A method of cooling a high voltage electromagnetic induction device is also provided. By using the option of operating fans with higher cooling rate, because of the less fans are operating, the predetermined cooling capacity can be reached with lower power consumption.

Cooling system and cooling method

The present application discloses a method to optimize operation of a transformer cooling system, the corresponding cooling system, and a method to determine the capacity of Variable Frequency Drives (VFD) that are used in the transformer cooling system. The method comprises: preprocessing the initial data input by user; collecting the on-line data, and calculating the optimized control command to meet the requirement of the transformer loss, top-oil temperature variation and noise; and executing the control actions by controlling a controllable switch and/or sending a control command to a VFD. Compared with the existing prior arts, the proposed solutions are much more intuitive and practical in the field of the cooling system.

Method to optimize operation of a transformer cooling system, the corresponding system and a method to determine the VFD capacity

A method for controlling power in a microgrid that includes power sources, loads and at least one connection to a main grid where a transformer is arranged to transfer electric power between the microgrid and the main grid is disclosed. The method includes: monitoring the power balance within the microgrid; monitoring the transformer, including monitoring the transformer temperature; and detecting a need for overloading the transformer based on the power balance within the microgrid. Especially, the method includes: determining a load profile for the transformer based on the power balance within the microgrid; determining a prognosis of the transformer temperature based on the load profile; and determining a schedule for power control of the microgrid, which determining of a schedule for power control includes analyzing the prognosis of the transformer temperature.

Power control of microgrid wherein detecting a need for overloading a transformer based on power balance within the microgrid

A method of determining phasor components of a periodic waveform, wherein the method includes: a) sampling the periodic waveform, b) determining a frequency spectrum of the sampled periodic waveform by means of a frequency transform utilizing a Gaussian window function, wherein a ratio ndefined by the duration of the sampling of the periodic waveform divided by the width parameter of the Gaussian window function is at least 5, c) selecting a region of the frequency spectrum containing a frequency peak defined by a group of consecutive frequency bins each being defined by a frequency value and a magnitude value, and d) determining phasor components of the periodic waveform based on the group of consecutive frequency bins.

Method and system for determining phasor components of a periodic waveform

A passive electronic fuse for protecting a DC application in the event of a fault includes a first leg including a first winding of a mutual inductor and a switch device connected in series, a second leg including a second winding of the mutual inductor. The first leg and the second leg are connected in parallel and a self-inductance of the second winding is lower than a self-inductance of the first winding. The second leg further includes a capacitor connected in series with the second winding of the mutual inductor, and the switch device is a thyristor or a switch device with switching properties of a thyristor.

Passive electronic fuse for protecting a DC application

An apparatus is arranged to break an electrical current. The apparatus includes: a mechanical switch leg including a first winding of a mutual inductor and a mechanical switch connected in series; a semiconductor switch leg including a second winding of the mutual inductor and a semiconductor switch connected in series; and an overvoltage protection circuit. The mechanical switch leg and the semiconductor switch leg are connected in parallel and a self inductance of the second winding is lower than a self inductance of the first winding. A corresponding DC circuit breaker and AC current limiter are also presented.

Apparatus arranged to break an electrical current

Growing community of inventors

Västerås, Sweden

Robert Saers