A multi-pulse line-interphase transformer converter includes an electric part that includes magnetic components configured to be connected to a three-phase AC grid, and an electric part that includes a multi-phase voltage system configured to be connected to a common DC capacitor. The electric part splits each AC grid phase n times into two phases, resulting in a plurality of intermediate phases at an internal interface, each intermediate phase corresponding to a pulse of the multi-pulse line-interphase transformer converter. The intermediate phases are connected to the multi-phase voltage system. The multi-phase voltage system comprises bridges with actively controlled switches. The bridges are connected in parallel to the common DC capacitor.

This power conversion device includes: a rectification circuit; an inverter circuit having a full-bridge configuration, and having a DC capacitor, and first and second legs each of which has two switching elements connected in series to each other; a transformer; and a control circuit for controlling operation of the inverter circuit, wherein the control circuit controls an ON period for the first leg, thereby controlling increase/decrease in current flowing through a first rectification circuit from an AC input, and controls an ON period for the second leg and a phase shift amount between the ON period for the first leg and the ON period for the second leg, thereby controlling voltage of the DC capacitor to be constant. Thus, it becomes possible to achieve high-power-factor control and output power control at the same time by a single stage of full-bridge inverter circuit.

In a power conversion device in a configuration in which a plurality of power converter cells has serially connected outputs and includes a converter and an inverter as components, when a load is light, the cells also operate with a light load, and efficiency is reduced. A power conversion device has a plurality of power converter cells. The outputs of the cells are connected in series. The device has a controller that controls the cells. The cells each have a converter that converts an externally inputted power supply voltage and generates a DC link voltage and an inverter that converts the DC link voltage into an alternating current voltage and outputs the current. The controller stops a converter in some of the cells depending on power supply electric power or load electric power. The inverter continues to operate using a link capacitor as a power supply.

A power transmission network includes an AC electrical system, an AC transmission link from the AC electrical system to AC-DC converter(s), and a control system. AC-DC converter(s) include an AC connecting point connected to the AC transmission link and a DC connecting point for connection to a DC transmission link. The control system operates each AC-DC converter in an AC voltage control mode as an AC slack bus to control a magnitude and/or a frequency of an AC voltage of the AC transmission link at a steady-state value and facilitating a power transfer between its connecting points to accommodate power generated or supplied to the AC electrical system. The control system further operates each AC-DC converter in a protection mode to protect each AC-DC converter from an overvoltage and/or an overcurrent.

A system for generation and distribution of high voltage direct current (HVDC) within a contained power domain named POD and methods for making and using the same. The system and methods efficiently power Information Technology racks deployed to a data center environment, advantageously providing features and functions highly desirable for a specific application.

A series compensation device suitable to double-circuit lines is disclosed. The device includes one series transformer and one converter. One converter and dual-circuit transmission lines are respectively connected to three windings of one series transformer. In the solution provided in the present application, the device can be independently installed in a power transmission system to be used as a static synchronous series compensator, and can also be used as a component of a unified power flow controller, a convertible static compensator, an interline power flow controller and a unified power quality conditioner to be connected to a power transmission system device in series. The device can save the capacity of a converter, improve the application efficiency of the series compensation device, and reduce the cost and area occupation.

Some embodiments may include a multi-stage converter comprising: a branch connected between a positive busbar and a negative busbar; and a control device. The branch has two arms connected in series. The arms each comprise a series circuit including a plurality of two-pole submodules, an energy store, and a communication connection to the control device. The communication connection transmits state of charge of the energy store and a switching instruction for the respective submodule. For at least a subset of the submodules, the communication connection comprises a common communication connection with a plurality of insulation paths having an insulation capability in each case of at most 5 kV.

A method and a device for controlling a voltage-controlled power semiconductor switch that can be switched off again, which has a first and a second connection and a control connection and which is conductive in the switched on state between the first and the second connection is provided. Firstly, a first control voltage comprising a first value is applied to the control connection to switch on the power semiconductor switch. Subsequently, conditions are detected, which indicate the progress of the switch-on procedure of the power semiconductor switch. As soon as conditions are detected, which are indicative of the fact that the switch-on procedure is deemed to be complete, a second control voltage comprising a second value higher than the first value is applied to the control connection to operate the power semiconductor switch in the conductive state with a higher control voltage to reduce its conduction losses.

A method and a device for controlling a voltage-controlled power semiconductor switch that can be switched off again, which has a first and a second connection and a control connection and which is conductive in the switched on state between the first and the second connection is provided. Firstly, a first control voltage comprising a first value is applied to the control connection to switch on the power semiconductor switch. Subsequently, conditions are detected, which indicate the progress of the switch-on procedure of the power semiconductor switch. As soon as conditions are detected, which are indicative of the fact that the switch-on procedure is deemed to be complete, a second control voltage comprising a second value higher than the first value is applied to the control connection to operate the power semiconductor switch in the conductive state with a higher control voltage to reduce its conduction losses.

A bidirectional DC converter assembly includes two serially-arranged DC/DC converters. The first converter is a buck (or a buck/boost) converter to be connected to a high-voltage (HV) level of an electric vehicle. The second converter is a series resonant switching converter to be connected to a low-voltage (LV) of the vehicle. The series resonant switching converter of the second converter is formed by a DC/AC converter, a transformer, and an AC/DC converter, which are serially arranged in the stated order between the first converter and the LV level. A bidirectional peak current controller is associated with the first converter. The peak current controller is realized by a current measurement at an inductor of the first converter. The peak current controller uses the coil current value, which is modified with an offset value and thus has a constant sign, as a set point in controlling the first converter.