A regulator rectifier device and a method for regulating an output voltage of the same which takes input from three phase alternating current voltage generating device with each phase including a positive cycle and a negative cycle. A first rectifying unit with a first gate terminal, connected to the generating device to rectify the positive cycle of said three phase alternating current voltage. A second rectifying unit with a second gate terminal, connected to said generating device to rectify the negative cycle of said three phase alternating current voltage, wherein said second rectifying unit switches between rectification mode and shunt mode depending on the load condition. And a controlling unit configured to control said second rectifying unit by a gate control signal, said controlling unit outputs said gate control signal based on an output voltage of said regulator rectifier device with respect to a first predefined voltage in battery connected condition or third predefined voltage in battery-less condition and said positive cycle and said negative cycle of each phase of said three phase alternating current voltage from said generating device, said gate control signal enables said second rectifying unit to switch between rectification mode and shunt mode by controlling the second gate terminal of said second rectifying unit, wherein said gate control signal switches said second rectifying unit into shunt mode when the output voltage of said regulator rectifier device is greater than said first predefined voltage in battery connected condition or third predefined voltage in battery-less condition and thereby continuing the shunting of said second rectifying unit as long as said positive cycle of corresponding phase of said three phase alternating current voltage exists.

A power supply system for an arc furnace, suitable for converting voltage of a three-phase electric power network into power supply voltage for the arc furnace, has an indirect AC/AC converter having a converter input and a converter output, and a matching apparatus having a matching transformer having a secondary side connectable to the arc furnace and a primary side operatively connected to the converter output. An input transformer group, inserted between the indirect AC/AC converter and the three-phase electric power network, has an input transformer primary side connectable to the three-phase electric power system, an input transformer secondary side connected to the converter input, a first input transformer and a second input transformer. Each of the first and second input transformers has three mutually displaced groups of secondary windings, each of which has a winding for each phase corresponding to a phase of the three-phase electric power network.

A voltage converter includes a voltage conversion circuit, a pulse width modulation (PWM) signal generating module, a feedback controlling module, and a subtractor. The voltage conversion circuit is configured to convert an input voltage to an output voltage according to a PWM signal. The PWM signal generating module is configured to generate the PWM signal according to a control signal. The feedback controlling module is configured to generate the control signal according to a feedback signal. The subtractor is configured to subtract a first reference voltage by the output voltage, to generate the feedback signal. The phase of an AC component of the first reference voltage is substantially opposite to the phase of the input voltage.

The invention relates to a three-phase boost rectifier circuit and a control method thereof, and an uninterrupted power supply, which contains at least first battery packs BAT+, second battery packs BAT−, and a boost rectifier module; the boost rectifier module comprises a first bidirectional thyristor SCR1, a second bidirectional thyristor SCR2, a third bidirectional thyristor SCR3, a fourth bidirectional thyristor SCR6, a first unidirectional thyristor SCR4, a second unidirectional thyristor SCR5, a first inductor L1, a second inductor L2, a third inductor L3, a three-phase fully controlled rectifier bridge, a first capacitor C1 and a second capacitor C2. The invention can ensure the balance of positive and negative bus's voltage without the balancing device under battery operated boost mode, while improving the efficiency and reliability of the battery operated boost mode.

The present disclosure provides a three-phase AC/DC converter aiming for low input current harmonic. The converter includes an input stage for receiving a three-phase AC input voltage, an output stage for at least one load, and one or more switching conversion stages, each stage including a plurality of half bridge modules. The switches in each module operate with a substantially fixed 50% duty cycle and are connected in a specific pattern to couple a DC-link and a neutral node of the input voltage. The AC/DC converter further includes one or more controllers adapted to vary the switching frequency of the switches in the switching conversion stages based on at least one of load voltage, load current, input voltage, and DC-link voltage. The converter can also include one or more decoupling stages, such as, inductive components adapted to decouple the output stage from the switching conversion stages.

A switching power source device includes a plurality of power source circuits including a first power source circuit corresponding to a first phase of an external power source, and a second power source circuit corresponding to a second phase of the external power source that is different from the first phase; a first switching circuit capable of switching between a plurality of connection modes including a first mode of connecting the second power source circuit to the first phase in parallel with the first power source circuit, and a second mode of connecting the second power source circuit to the second phase; a memory; and a hardware processor coupled to the memory, the hardware processor being configured to open and close a switching element included in the first power source circuit and a switching element included in the second power source circuit, in different phases in the first mode.

Provided are a three-phase AC/DC converter disposed between a three-phase AC power supply and a light emitting diode group, the converter including a three-phase full bridge circuit in which pairs of switching elements are connected in parallel between DC buses for the three phases of the three-phase AC power supply; reactors connecting connection portions between the switching elements and corresponding phases of the three-phase AC power supply; a smoothing capacitor on the output side of the three-phase full bridge circuit; a DC voltage detection means; a power supply voltage phase detection means; and a pulse width modulation means for outputting pulse width modulation signals of the switching elements, wherein the pulse width modulation means outputs the pulse width modulation signals based on a power supply voltage phase and an output voltage between the DC buses.

A frequency converter with a rectifier on an input side and a backup capacitor arranged downstream of the rectifier. Input-side phases of the rectifier feed the backup capacitor via multiple half-bridges of the rectifier. The input-side phases are connected to grid-side phases of a multiphase supply grid via a pre-circuit. Each grid-side phase is connected to an input-side phase within the pre-circuit via a phase capacitor. Each grid-side phase is additionally directly connected to another input-side phase within the pre-circuit via a switch and the grid-side phases are short-circuited with the input-side phases when the switches are closed. Each phase capacitor connects two grid-side phases or two input-side phases together. The frequency converter has a control apparatus which keeps the switches open when pre-charging the backup capacitor and closes the switches when a specified charge state of the backup capacitor is reached.

A frequency converter includes a rectifier on an input side and a support capacitor downstream of the rectifier. Input-side phases of the rectifier feed the backup capacitor via multiple half-bridges of the rectifier. The half-bridges have active switching elements and the rectifier is designed as a recovery rectifier. The input-side phases are connected to grid-side phases of a multiphase supply grid via an upstream circuit. Each grid-side phase is connected to one of the input-side phases within the upstream circuit via a respective phase capacitor. A control facility controls the active switching elements when a first charge state of the support capacitor is reached and input-side phase voltages are applied to the input-side phases via the active switching elements. Voltages running in the opposite direction to the grid-side phase voltages are applied to the grid-side phases to which the input-side phases are connected via the phase capacitors.

A frequency converter with a rectifier on an input side and a backup capacitor arranged downstream of the rectifier. Input-side phases of the rectifier feed the backup capacitor via multiple half-bridges of the rectifier. The input-side phases are connected to grid-side phases of a multiphase supply grid via a pre-circuit. Each grid-side phase is connected to an input-side phase within the pre-circuit via a phase capacitor. Each grid-side phase is additionally directly connected to another input-side phase within the pre-circuit via a switch and the grid-side phases are short-circuited with the input-side phases when the switches are closed. Each phase capacitor connects two grid-side phases or two input-side phases together. The frequency converter has a control apparatus which keeps the switches open when pre-charging the backup capacitor and closes the switches when a specified charge state of the backup capacitor is reached.