A power conversion device included in a self-excited DC power transmission system connected to an AC system includes a self-excited converter and a control device. The control device includes: a storage to store first vibration information and a first control parameter of the self-excited converter in association with each other for each of a plurality of pieces of first vibration information, a vibration detector to detect a vibration component of an AC voltage of the AC system; a determination unit to determine whether first similar vibration information similar to first detected vibration information including the vibration component of the AC voltage of the detected AC system exists in the plurality of pieces of first vibration information; and a setting unit to set the first control parameter associated with the first similar vibration information as a new control parameter of the self-excited converter when the first similar vibration information exists.

A power conversion device included in a self-excited DC power transmission system connected to an AC system includes a self-excited converter and a control device. The control device includes: a storage to store first vibration information and a first control parameter of the self-excited converter in association with each other for each of a plurality of pieces of first vibration information, a vibration detector to detect a vibration component of an AC voltage of the AC system; a determination unit to determine whether first similar vibration information similar to first detected vibration information including the vibration component of the AC voltage of the detected AC system exists in the plurality of pieces of first vibration information; and a setting unit to set the first control parameter associated with the first similar vibration information as a new control parameter of the self-excited converter when the first similar vibration information exists.

A device and a method for providing an electrical current to an electrical load is disclosed. In particular, the device comprises a memory storage device for storing a plurality of ideal voltage waveforms; an electronic controller arranged in data communication with the memory storage device, the electronic controller operable to select one of the plurality of ideal voltage waveforms to compute a reference voltage and a switching period based on a predetermined rule; and an electronic switch arranged to receive the switching period to switch the electronic switch between an on state and an off state, wherein the electrical current is calculated based on a function of the reference voltage and the switching period of the electronic switch.

A multi-phase power converter includes two or more multi-phase, bi-directional, multi-level, switching power converter subcircuits, connected in parallel at respective AC and DC sides, so as to provide a multi-channel, bi-directional, multi-level configuration. The AC sides of the switching converter subcircuits are directly coupled to one another and to a multi-phase AC input via series interface reactors, and the DC sides of the switching converter subcircuits are directly connected to one another and to a common split-capacitor bank at each level of the multi-level outputs of the switching converter subcircuits. A control circuit is configured to selectively control one or more switching semiconductor devices in each of the switching converter subcircuits. In some embodiments, the control circuit includes a closed-loop zero-sequence controller and a zero-sequence generator configured to eliminate circulating current among the switching converter subcircuits and to balance voltages across levels of the common split-capacitor bank.

A multi-phase power converter includes two or more multi-phase, bi-directional, multi-level, switching power converter subcircuits, connected in parallel at respective AC and DC sides, so as to provide a multi-channel, bi-directional, multi-level configuration. The AC sides of the switching converter subcircuits are directly coupled to one another and to a multi-phase AC input via series interface reactors, and the DC sides of the switching converter subcircuits are directly connected to one another and to a common split-capacitor bank at each level of the multi-level outputs of the switching converter subcircuits. A control circuit is configured to selectively control one or more switching semiconductor devices in each of the switching converter subcircuits. In some embodiments, the control circuit includes a closed-loop zero-sequence controller and a zero-sequence generator configured to eliminate circulating current among the switching converter subcircuits and to balance voltages across levels of the common split-capacitor bank.

A hybrid power plant is characterized by a substantially constant load on generators regardless of momentary swings in power load. Short changes in power load are accommodated by DC components such as capacitors, batteries, resistors, or a combination thereof. Resistors are used to consume power when loads in the power plant are generating excess power. Capacitors are used to store and deliver power when the loads in the power plant demand additional power. Reducing rapid changes in power load as seen by the generators allows the generators to operate at higher efficiencies and with reduced emissions. Additionally, power plants employing combinations of generators, loads, and energy storage devices have increased dynamic performance.

A hybrid power plant is characterized by a substantially constant load on generators regardless of momentary swings in power load. Short changes in power load are accommodated by DC components such as capacitors, batteries, resistors, or a combination thereof. Resistors are used to consume power when loads in the power plant are generating excess power. Capacitors are used to store and deliver power when the loads in the power plant demand additional power. Reducing rapid changes in power load as seen by the generators allows the generators to operate at higher efficiencies and with reduced emissions. Additionally, power plants employing combinations of generators, loads, and energy storage devices have increased dynamic performance.

The disclosure relates to a line commutated converter, LCC, for a high-voltage direct current, HVDC, power converter. The LCC comprises at least one bridge circuit for connection to at least one terminal of a DC system. Each bridge circuit comprises at least two arms, and each arm is associated with a phase of an AC system. Each arm comprises one or more upper thyristor valves and one or more lower thyristor valves connected in series, and a branch extending from between the upper and lower thyristor valves. Each arm further comprises a parallel capacitor module comprising at least one parallel capacitor being connected in parallel between at least one pair of branches comprising a first branch and a second branch wherein during commutation of a flow of current in the first branch to a flow of current in the second branch, the at least one parallel capacitor is configured to discharge current in to the second branch in the same direction as the flow of current in the second branch.

A modular intermediate circuit for a power converter has at least two or more intermediate circuit capacitor modules connected in parallel and in a chain, each intermediate circuit capacitor module having a first terminal, a second terminal, and at least one first intermediate circuit capacitor, which is electrically connected with the first terminal and the second terminal. First terminals of the intermediate circuit capacitor modules each following immediately one after another in the chain are connected in each case through a first low-resistance, high-inductance connection and a first high-resistance, low-inductance connection that is connected in parallel thereto. Second terminals of the intermediate circuit capacitor modules each following immediately one after another in the chain are connected in each case through a second low-resistance, high-inductance connection and a second high-resistance, low-inductance connection that is connected in parallel thereto. A converter circuit, an energy converter, and a vehicle are also disclosed.

A modular intermediate circuit for a power converter has at least two or more intermediate circuit capacitor modules connected in parallel and in a chain, each intermediate circuit capacitor module having a first terminal, a second terminal, and at least one first intermediate circuit capacitor, which is electrically connected with the first terminal and the second terminal. First terminals of the intermediate circuit capacitor modules each following immediately one after another in the chain are connected in each case through a first low-resistance, high-inductance connection and a first high-resistance, low-inductance connection that is connected in parallel thereto. Second terminals of the intermediate circuit capacitor modules each following immediately one after another in the chain are connected in each case through a second low-resistance, high-inductance connection and a second high-resistance, low-inductance connection that is connected in parallel thereto. A converter circuit, an energy converter, and a vehicle are also disclosed.