A power converter is capable to convert an electrical input power into a bipolar output power and to deliver the bipolar output power to at least two independent plasma processing chambers. The power converter includes: a power input port for connection to an electrical power delivering grid, at least two, preferably more than two, power output ports each for connection to one of the plasma process chambers, and a controller configured to control the power converter to deliver the bipolar output power to the power output ports, using one or more control parameters selected from a list comprising: power, voltage, current, excitation frequency, and threshold for protective measures, such that at least one of the control parameters at a first power output port is different from the corresponding control parameter at a different power output port.

A power converter is capable to convert an electrical input power into a bipolar output power and to deliver the bipolar output power to at least two independent plasma processing chambers. The power converter includes: a power input port for connection to an electrical power delivering grid, at least two, preferably more than two, power output ports each for connection to one of the plasma process chambers, and a controller configured to control the power converter to deliver the bipolar output power to the power output ports, using one or more control parameters selected from a list comprising: power, voltage, current, excitation frequency, and threshold for protective measures, such that at least one of the control parameters at a first power output port is different from the corresponding control parameter at a different power output port.

An indirect matrix converter includes a rectifier module, an inverter module, and a control unit. The rectifier module includes three parallel-connected T-type bridge arms, and each T-type bridge arm includes a bidirectional switch and a power bridge arm. The power bridge arm includes a first switch and a second switch connected to the first switch in series. One end of the bidirectional switch is coupled to a first AC power source, and the other end thereof is coupled to a common contact between the first switch and the second switch. The control unit outputs a plurality of control signals to control the rectifier module and the inverter module, so that the first AC power source is converted into a second AC power source, or the second AC power source is converted into the first AC power source.

A converter system includes a rectifier, a DC link stage and an inverter connected in series. A control unit includes a slow reference frame angle determination unit that generates a slow reference frame angle θ.sub.r,slow representing an angle that is slowly following a grid phase deviation, and a fast Phase Locked Loop generating a fast reference frame angle θ.sub.r,fast representing an angle that is fast following a grid phase deviation. The control unit uses the slow reference frame angle θ.sub.r,slow and the fast reference frame angle θ.sub.r,fast to control the rectifier output current, and the fast reference frame angle θ.sub.r,fast to control the inverter output voltage and to synchronize the inverter output voltage with the grid voltage.

A converter system includes a rectifier, a DC link stage and an inverter connected in series. A control unit includes a slow reference frame angle determination unit that generates a slow reference frame angle θ.sub.r,slow representing an angle that is slowly following a grid phase deviation, and a fast Phase Locked Loop generating a fast reference frame angle θ.sub.r,fast representing an angle that is fast following a grid phase deviation. The control unit uses the slow reference frame angle θ.sub.r,slow and the fast reference frame angle θ.sub.r,fast to control the rectifier output current, and the fast reference frame angle θ.sub.r,fast to control the inverter output voltage and to synchronize the inverter output voltage with the grid voltage.

Embodiments of present disclosure relate to an apparatus and a method for controlling a delta-connected cascaded multilevel converter. The apparatus (100) for controlling a delta-connected cascaded multilevel converter (110) comprises: a converter controller (102) configured to: receive current signals indicating phase currents flowing through respective phase arms of the converter (110); determine a harmonic current signal indicating a circulating current of the converter (110) from the current signals; and generate, based on the determined harmonic current signal and a reference current signal, a harmonic voltage signal to cause an amplitude of the circulating current flowing through the phase arms of the converter (110) to be a predetermined amplitude.

The invention comprises a method, including the steps of: providing an inductor core and longitudinally joining a first electrical turn section to a second electrical turn section to form at least part of an electrical turn of a winding about the inductor core and optionally including at least one of the steps of: (1) additive manufacturing, casting, stamping from metal stock, cutting material, and/or bending metal to form the first electrical turn section and/or (2) welding and/or mechanically joining the first electrical turn section to the second electrical turn section.

An induction heating apparatus includes a working coil; an inverter configured to perform switching operation to thereby apply a resonance current to the working coil; and a controller configured to provide a control signal with a fixed frequency to the inverter to thereby control the switching operation. The controller changes a pulse width of the control signal based on a predetermined cycle that is set based on a temperature of the inverter.

An induction heating apparatus includes a working coil; an inverter configured to perform switching operation to thereby apply a resonance current to the working coil; and a controller configured to provide a control signal with a fixed frequency to the inverter to thereby control the switching operation. The controller changes a pulse width of the control signal based on a predetermined cycle that is set based on a temperature of the inverter.

An apparatus for modular AC to AC frequency conversion is disclosed. An input AC source is configured to generate an input AC voltage at a first frequency. At least one primary low frequency (LF) conversion stage is configured to generate a DC voltage, and comprises a first pair of metal-oxide-semiconductor field effect transistors (MOSFETs). At least one primary high frequency (HF) conversion stage is configured to generate the DC voltage, and comprises a first pair of high electron mobility transistors (HEMTs). At least one secondary LF conversion stage is configured to receive the DC voltage and generate an output AC voltage at a second frequency, and comprises a second pair of MOSFETs. At least one secondary HF conversion stage is configured to receive the DC voltage and generate the output AC voltage at the second frequency, and comprises a second pair of HEMTs.