A method for discharging a DC intermediate circuit of a converter and a DC intermediate circuit (10) and a converter comprising at least one group of at least two controllable power semiconductor switches (S1, S2, S3, S4, S5, S6, S7, S8) connected in series between two poles (UDC+, UDC-) of the DC…
An electric power source assembly for a vehicle, the power source assembly comprising a plurality of converter unit groups (GC, EC1, MC), each one of which comprises at least one converter unit, each converter unit comprising a plurality of controllable switches (S1 to S6), a first terminal group…
A method and switching arrangement for an inverter, the inverter comprising a positive direct current pole (U DC,P ), a negative direct current pole (U DC,N ), and a neutral direct current pole (M), the arrangement comprising a first controllable switch (S X ) connected between the neutral direct…
A method and an arrangement for preventing slip in a wheeled vehicle having two or more driving wheels that are operated with electric motors. The electric motor of each driving wheel of the vehicle comprises a torque limit applicable to limit torque of the motor, wherein the method comprises, for…
A method and an arrangement for limiting slip in a wheeled vehicle having two or more driving wheels that are operated with electric motors, the method comprising determining a speed (v1, v2, v3, v4) of each of the driving wheels, determining the highest speed (vmax) of the driving wheels…
A method for operating an inverter, and an inverter comprising means (DC+, DC-) for coupling the inverter (10) with a photovoltaic array (20) comprising at least one photovoltaic panel, wherein the inverter (10) further comprises means (11) configured to connect output poles of a photovoltaic array…
The present disclosure discloses a method and an apparatus implementing the method for maximising energy efficiency of an electric drive system comprising an electric motor and a load. In the method, the torque characteristics of the system can be selected from two types of behaviour: linear and…
A method and an arrangement of tracking a maximum power point of a photovoltaic system, in which method an operation point of the photovoltaic system is changed based on the change of operation point and a change of power generated by the photovoltaic system, the method comprising repeatedly…
A method of optimizing one or more starting parameters of a solar power generator system and a solar power generator system, wherein the solar power generator system comprises a solar panel array and a converter for converting power obtained from the panel array. The method comprises measuring an…
A method and an arrangement of detecting islanding operation of a distributed power generator. The method comprises determining a frequency of a grid to which the distributed power generator is connected, measuring a rate of change of the frequency of the grid at an output of the distributed power…
An electrical system having a DC link and a method is such a system. The system comprising a controlled rectifier, an electrical power source connected to the controlled rectifier, the output of the controlled rectifier being connected to the DC link, means for storing electrical energy, at least…
A method and an arrangement of determining starting conditions of a solar converter in a photovoltaic system, the photovoltaic system comprising a photovoltaic panel system having one or more photovoltaic panels, the method comprising determining the open circuit voltage of the photovoltaic panel…
An inverter assembly comprising a DC circuit, inverter means, and control means (CTRL) for controlling the inverter means, the inverter means being multilevel inverter means comprising a first half bridge (HB1) and a second half bridge (HB2), the control means (CTRL) being adapted to provide a…
An aspect of the invention relates to a boost converter module for a solar energy system. The boost converter module comprises input poles (21, 22), output poles (31, 32) and a boost converter unit connected between the input poles (21, 22) and the output poles (31, 32), the input poles (21, 22)…
A method of connecting a plurality of solar panel units to an inverter in an arrangement comprising a plurality of switches. Each switch is configured to connect one of the solar panel units to a DC link of the inverter. The inverter comprises means for controlling a DC link voltage. The method…
A method for controlling transfer of electrical power in island mode in an arrangement comprising a converter and a load connected to the converter through a filter. The method comprises determining voltage reference components for one or more frequency components of an output voltage of the…
An arrangement and a method in connection with a solar energy system. The arrangement comprises solar panels (1) and a converter (2) for converting the DC voltage from the solar panels, which converter is arranged inside a container or a similar closed structure. The arrangement also comprises…
An apparatus for controlling voltages over series-connected DC power supplies (1.1 - 1. m ), comprising an inverter (2) comprising a positive input, a negative input, and means for controlling a voltage between the inputs. The apparatus also comprises a first series connection of two or more…
An alternating current conversion method and system that can adapt to varying voltages of the direct current sources comprise a first and second connection arrangements for the voltage sources (1) such that the direct current can be supplied to the DC/AC converter selectively in the first…
An inverter for supplying a grid, where the inverter comprises a DC link comprising two capacitor units in series and a neutral point (V DC0 ) between the capacitor units, and a first and a second inverter leg. Both inverter legs are connected between the poles (V DC+ and V DC- ) of the DC link and…
An apparatus and a method for controlling energy consumption in a marine vessel having a plurality of energy consuming users and fuel consuming engines are disclosed. According to the invention the apparatus comprises a voyage management tool (2) for planning a route for the marine vessel and for…
An arrangement in connection with an electric drive system, the electric drive system comprising an intermediate circuit (DC), with two or more supply units (S.1-S .n ) and two or more inverter units (I.1-I .n ) connected thereto, and an electric machine (G) having two or more three-phase windings…
An arrangement which comprises two or more energy storage units (1) for electrical energy connected in series, two or more balancing resistor units (2), each balancing resistor unit (2) connected in parallel with one of the energy storage units (1), means (3) for determining a voltage ( U tot )…
An arrangement for controlling frequency converter modules of an electric drive, in which arrangement the frequency converter modules are arranged to control alternatively a first motor (M.1) or several motors (M.2 to M. k ) having less power than the first motor (M.1).
A frequency converter comprising a housing (2), frequency converter means (4) installed in the housing (2), control means (6) for controlling the frequency converter means (4), and user interface means (8) for transmitting control commands from a user to the control means (6). The control means (6)…
A method in connection with a network inverter, an LCL network filter (3) being connected between the network inverter (1) and network (2), and the network inverter being arranged to operate as an active converter of harmonic components of electricity, and the method comprises the steps of forming…
A method in connection with a network converter, and a network converter, the network converter comprising two or more network converter modules coupled in parallel, and first control means for controlling the network converter modules. The method comprises the steps of controlling the network…