A higher control unit 1 generates a command current i* based on a command value. A model predictive control unit 2 sets a plurality of assumed voltage vectors for each switching cycle of an output voltage, divides the switching cycle of the output voltage into two periods according to a ratio between a dead time and the switching cycle of the output voltage, calculates a predicted current of the assumed voltage vector for each of the two periods obtained by the two-dividing, determines an evaluation function between the assumed voltage vector and the predicted current, sets the assumed voltage vector which has highest evaluation function result, as a command voltage vector. A gate signal g for outputting a voltage expressed by the command voltage vector from the power converter is output. The power converter is driven and controlled based on the gate signal.

A higher control unit 1 generates a command current i* based on a command value. A model predictive control unit 2 sets a plurality of assumed voltage vectors for each switching cycle of an output voltage, divides the switching cycle of the output voltage into two periods according to a ratio between a dead time and the switching cycle of the output voltage, calculates a predicted current of the assumed voltage vector for each of the two periods obtained by the two-dividing, determines an evaluation function between the assumed voltage vector and the predicted current, sets the assumed voltage vector which has highest evaluation function result, as a command voltage vector. A gate signal g for outputting a voltage expressed by the command voltage vector from the power converter is output. The power converter is driven and controlled based on the gate signal.

Systems and methods for providing AC power to a power grid using renewable energy sources as well as energy storage devices. A control system controls multiple DC/DC converters that are coupled to renewable energy sources as well as to one or more energy storage devices. The control system also controls the charge/discharge of the energy storage devices. Each DC/DC converter control block in the control system automatically detects whether to perform MPPT on the renewable energy source or to control the discharge of the energy storage devices. Each DC/DC converter control block ensures that power from the renewable energy source or from the energy storage device is converted and provided to the power grid.

The present invention relates to a method for obtaining switching angles (α.sub.1, . . . , α.sub.i), and to an associated conversion system. In the method, possible values (IM) are established for a modulation index, within a predetermined range of values (R) and divided into a plurality of segments (S.sub.1, . . . , S.sub.j); a value is obtained for each of the switching angles (α.sub.1, . . . , α.sub.i) in each segment (S.sub.1, . . . , S.sub.j) and for each of the possible values (IM); a switching curve (SC) is formed for each switching angle (α.sub.1, . . . , α.sub.i) over the entire range (R); and the height or amplitude and the slope of each switching curve (SC) at a possible value shared by two segments (S.sub.1, . . . , S.sub.j) are considered constant.

A frequency converter module includes a frequency control management module. An input port of the frequency conversion control management module is electrically connected to an input port of a power supply module. The power accuracy monitoring module includes an initial power measuring module, a power prediction correction module, and an actual power display storage module. An output port of the initial power measuring module is electrically connected to an input port of the power prediction correction module. An output port of the power prediction correction module is electrically connected to an input port of the actual power display storage module.

There is provided a power conversion device capable of effectively reducing a surge voltage generated by a parasitic inductance of a circuit. The power conversion device 1 is configured to operate a motor 8 driving a compression mechanism 7 of an electric compressor 16 by means of a three-phase inverter circuit 28 having a plurality of switching elements 18A to 18F. The power conversion device calculates a surge voltage value of each phase from a parasitic inductance of the circuit and phase currents iu, iv, and iw of the motor 8 to derive a phase in which the surge voltage value becomes maximum, and suppresses the switching of the switching elements 18A-18F of the phase having the maximum surge voltage value by a discontinuous modulation method.

A switching element driving method executed in a switching element driving device including a plurality of switching elements and a driving circuit configured to drive the plurality of switching elements, the switching element driving method including: detecting temperatures of the plurality of switching elements; calculating a switching determination temperature that serves as a reference for changing switching speeds of the switching elements from the plurality of detected temperatures; and changing the switching speeds of all the switching elements based on the switching determination temperature.

A switching element driving method executed in a switching element driving device including a plurality of switching elements and a driving circuit configured to drive the plurality of switching elements, the switching element driving method including: detecting temperatures of the plurality of switching elements; calculating a switching determination temperature that serves as a reference for changing switching speeds of the switching elements from the plurality of detected temperatures; and changing the switching speeds of all the switching elements based on the switching determination temperature.

A converter and a method of operating a converter. The converter comprising a DC link capacitor, an upper arm (S1) and a lower arm (S4) with switching cells in series, an upper switch (S2) and a lower switch (S3). The upper switch (S2) and the lower switch (S3) are connected together and the connection point forming an output voltage terminal (a). The converter comprising further an upper valve component and a lower valve component, which are arranged such that the upper valve component allows current from the center point of the DC link capacitor towards the upper arm and the lower valve component allows current from the lower arm towards center point of the DC link capacitor. A current path through the upper valve component or the lower valve component comprises inductance to form a resonance circuit.

A converter and a method of operating a converter. The converter comprising a DC link capacitor, an upper arm (S1) and a lower arm (S4) with switching cells in series, an upper switch (S2) and a lower switch (S3). The upper switch (S2) and the lower switch (S3) are connected together and the connection point forming an output voltage terminal (a). The converter comprising further an upper valve component and a lower valve component, which are arranged such that the upper valve component allows current from the center point of the DC link capacitor towards the upper arm and the lower valve component allows current from the lower arm towards center point of the DC link capacitor. A current path through the upper valve component or the lower valve component comprises inductance to form a resonance circuit.