The present invention relates to a power conversion device and an air conditioner comprising the same. The power conversion device according to one embodiment of the present invention comprises: a rectification unit for rectifying input alternating current power; a boost converter for boosting power rectified from the rectification unit and outputting the same; a dc-end capacitor connected to an output end of the boost converter; an inductor current detection unit for detecting an inductor current flowing in an inductor within the boost converter; a dc-end voltage detection unit for detecting voltages of both ends of the dc-end capacitor; and a control unit for controlling the boost converter, wherein the control unit generates and outputs a converter switching control signal by performing proportional resonant control for a duty command value of a switching element within the boost converter, on the basis of the detected inductor current and dc-end voltage. Therefore, a harmonic current component flowing through a dc-end capacitor induced by a ripple component of an input voltage can be reduced.

The present invention relates to a power conversion device and an air conditioner comprising the same. The power conversion device according to one embodiment of the present invention comprises: a rectification unit for rectifying input alternating current power; a boost converter for boosting power rectified from the rectification unit and outputting the same; a dc-end capacitor connected to an output end of the boost converter; an inductor current detection unit for detecting an inductor current flowing in an inductor within the boost converter; a dc-end voltage detection unit for detecting voltages of both ends of the dc-end capacitor; and a control unit for controlling the boost converter, wherein the control unit generates and outputs a converter switching control signal by performing proportional resonant control for a duty command value of a switching element within the boost converter, on the basis of the detected inductor current and dc-end voltage. Therefore, a harmonic current component flowing through a dc-end capacitor induced by a ripple component of an input voltage can be reduced.

A system, including: a plurality of load commutated inverters (LCIs) connected in parallel, wherein each LCI includes: a source bridge for converting an alternating current (AC) voltage to a direct current (DC) voltage, wherein the source bridge includes at least one current switching device; a load bridge for converting the DC voltage from the source bridge to a variable frequency AC voltage; and a DC link coupling the source bridge to the load bridge; wherein each LCI includes a respective current regulator for controlling the at least one current switching device in the source bridge of the LCI to generate a current in the DC link.

A system, including: a plurality of load commutated inverters (LCIs) connected in parallel, wherein each LCI includes: a source bridge for converting an alternating current (AC) voltage to a direct current (DC) voltage, wherein the source bridge includes at least one current switching device; a load bridge for converting the DC voltage from the source bridge to a variable frequency AC voltage; and a DC link coupling the source bridge to the load bridge; wherein each LCI includes a respective current regulator for controlling the at least one current switching device in the source bridge of the LCI to generate a current in the DC link.

A load commutated converter interconnects an AC power grid with an AC load and comprises a grid-side converter, a DC link and a load-side converter. A method for controlling the load commutated converter comprises: determining a gridside firing angle for the grid-side converter; determining a load-side firing angle for the load-side converter; determining a grid voltage of the AC power grid; modifying the grid-side firing angle and/or the load-side firing angle based on the grid voltage, such that when an undervoltage condition in the AC power grid occurs, the operation of the load commutated converter is adapted to a change in the grid voltage; and applying the grid-side firing angle to the grid-side converter and the load-side firing angle to the load-side converter.

A load commutated converter interconnects an AC power grid with an AC load and comprises a grid-side converter, a DC link and a load-side converter. A method for controlling the load commutated converter comprises: determining a gridside firing angle for the grid-side converter; determining a load-side firing angle for the load-side converter; determining a grid voltage of the AC power grid; modifying the grid-side firing angle and/or the load-side firing angle based on the grid voltage, such that when an undervoltage condition in the AC power grid occurs, the operation of the load commutated converter is adapted to a change in the grid voltage; and applying the grid-side firing angle to the grid-side converter and the load-side firing angle to the load-side converter.

A system includes multiple electrical nodes connected in series to a primary power source via transmission lines. Each node includes a power converter that can receive first power from the primary power source or another upstream node. The power converter can change a voltage level and/or a frequency of the first power. Each node also includes a high-speed synchronous rotating machine (HSRM), which includes an inertial storage flywheel, a rotating excitation assembly, stator windings, and a synchronous motor coupled to an induction generator. The HSRM can boost a voltage level between an input and output to compensate for a voltage drop of the first power. At least one of the nodes further includes an inductive power coupler to electrically couple the node to a mobile power source that provides second power to the node and receives a portion of the first power from the node using contactless inductive power transfer. The system includes a combination of AC and DC power transmission techniques and associated bidirectional power converters.

In a method for generating with a modular multilevel power converter (M2C) having a plurality of sub-modules a frequency-variable output voltage, the sub-modules are switched on and off to generate from an input voltage discrete voltage steps approximating an approximately sinusoidal alternating output voltage having a first angular frequency located between a zero frequency and a second angular frequency, and the input voltage is controlled or regulated as a function of the first angular frequency so as to be located between a lower angular frequency, which is equal to or greater than the zero frequency, and a third angular frequency, such that the input voltage increases with increasing first angular frequency, thereby reducing capacitor complexity in the power converter.

In a method for generating with a modular multilevel power converter (M2C) having a plurality of sub-modules a frequency-variable output voltage, the sub-modules are switched on and off to generate from an input voltage discrete voltage steps approximating an approximately sinusoidal alternating output voltage having a first angular frequency located between a zero frequency and a second angular frequency, and the input voltage is controlled or regulated as a function of the first angular frequency so as to be located between a lower angular frequency, which is equal to or greater than the zero frequency, and a third angular frequency, such that the input voltage increases with increasing first angular frequency, thereby reducing capacitor complexity in the power converter.

A high voltage/ultrahigh voltage direct current transmission inverter side frequency control implementing method includes: transmitting a deviation between the inverter side power grid frequency and rated frequency to the inverter side frequency controller, wherein the frequency controller regulates and outputs a modulation quantity by adopting self-adaptive parameters according to different operation conditions; when the interstation communication is normal, the modulation quantity output of the inverter side frequency controller causes the rectifier side and the inverter side to form a new power/current order through the interstation communication; when the interstation communication is abnormal, converting the inverter side to current control from voltage control and converting the rectifier side to voltage control from current control; superposing the modulation quantity output of the inverter side frequency controller to the power/current order of the inverter side, changing the size of the transmission power to realizing the inverter side frequency control.