A method of operating a thyristor-based line-commutated multi-phase power converter on a multi-phase AC voltage connection point, which is supplied by an AC voltage network. Between the AC voltage connection point and an AC voltage connection of the power converter, a series circuit of modules is arranged for each phase. Each of the series circuits has a first electronic switching element, a second electronic switching element, and an electric energy storage device. The voltages of the phases of the AC voltage connection point are measured and, if an undervoltage is detected on a phase of the AC voltage connection point, an additional voltage adding to the voltage of that phase is generated by way of the series circuit of modules allocated to that phase in such a way that the voltage of that phase is increased, at least temporarily.

The converter includes a plurality of input lines and one or more output lines. Each input line is connected to a group of supply circuits and the supply circuits of each group are connected to different output lines. The electric generator comprises a stator and a rotor. The stator has a plurality of windings. Each winding has a plurality of phases. Each phase comprises bars connected in series. The phases have a first connection at one end, a second connection at the other end and a third connection in an intermediate position between the first and the second connection.

A converter configured to supply an energy consuming element during an operating phase and may charge a capacitor during a pre-charging phase prior to the operating phase. The converter may have a power factor correction circuit having the capacitor and thyristors. The converter may also have a control system configured to control the pre-charging phase. The control system may have a control unit configured to, during the operating phase, detect the state of charge of the capacitor, and generate a control signal configured to control the thyristors as a function of the state of charge of the capacitor.

A converter configured to supply an energy consuming element during an operating phase and may charge a capacitor during a pre-charging phase prior to the operating phase. The converter may have a power factor correction circuit having the capacitor and thyristors. The converter may also have a control system configured to control the pre-charging phase. The control system may have a control unit configured to, during the operating phase, detect the state of charge of the capacitor, and generate a control signal configured to control the thyristors as a function of the state of charge of the capacitor.

In one example, a circuit includes an alternating current (AC) voltage source, a voltage rail, a reference rail, a first capacitor, a second capacitor, and a switching unit. The AC voltage source is configured to supply voltage in a first direction during a first half of a cycle and supply voltage in a second direction during a second half of the cycle. During a first state of the circuit, the voltage in the first direction supplied by the AC voltage source charges the first capacitor and the voltage in the second direction supplied by the AC voltage source charges the first capacitor. During a second state of the circuit, the voltage in the first direction supplied by the AC voltage source charges the first capacitor and the voltage in the second direction supplied by the AC voltage source charges the second capacitor.

The invention relates to an energizing circuit of at least one magnetizing coil of an operational brake, the energizing circuit being configured for energizing the magnetizing coil, which energizing circuit comprises a rectifying bridge connected to the supply network, the output terminals of the rectifying bridge being connectable/connected to the input points of the magnetizing coil,

characterized in that the energizing circuit comprises at least one reduced voltage circuit or external DC supply, whose outputs are connectable via to the to the input points of the magnetizing coil via a controllable operation switch of the energizing circuit. The patent application also comprises claims for a passenger conveyor and for a method.

A power converter including a compressor as a load includes a compensation current output (80) allowing compensation current (Ic), which compensates for leakage current (Ia), to flow. A controller (50) receives a detection signal from a rotational speed sensor (55) which senses the rotational speed of the compressor (CM). When the rotational speed has increased to a set rotational speed at which the leakage current (Ia) is lower than or equal to its limiting value (Lmax) (e.g., the limiting value specified under the Electrical Appliances and Materials Safety Act or by the IEC) in a state where the compensation current output (80) is off, the compensation current output (80) is switched from an on state to an off state. This may reduce the leakage current from the compressor with low power loss.

A method and apparatus for modulating a load by means of control command obtained by varying conduction angle of AC voltage is provided. Under normal operation, conduction angle of AC is approximate to 180 degrees. When a state change command of the load is to be executed, the angle of conduction angle is changed by a conduction angle modulation circuit of control end. After a conduction angle detection circuit of the load end detects the conduction angle, a control unit decodes the information of the conduction angle, and controls the load to perform a corresponding operation. The method and apparatus do not need to add an extra control wiring for the load, and may use the conduction angle of an AC power supply to effectively perform multifunctional modulations on the load with existing power lines, and the defect of a low power commonly found in a traditional dimmer is overcome.

A power converter and an air conditioner having the same, in which the power converter includes a rectifying unit configured to rectify an input AC current and an interleave converter that has a plurality of converters and that is configured to convert rectified output from the rectifying unit to DC power and output the converted DC power. The power converter also includes a capacitor connected to an output terminal of the interleave converter, and a converter controller configured to control the interleave converter. The converter controller controls the interleave converter by calculating a load level of both terminals of the capacitor and changing a number of operating converters in the plurality of converters of the interleave converter based on the determined load level of both terminals of the capacitor.

Disclosed is a rectifying device provided with a standby power reduction function. When a voltage of unsmoothed DC power, which is output from a rectifying unit that rectifies AC power, is lowered to be equal to or smaller than a discharge reference voltage at a time around a zero-crossing point of the AC power, the present invention can instantaneously discharge a capacitor, which has been charged with the unsmoothed DC power, to be synthesized with the unsmoothed DC power, and thus supply stable DC power to a load without using an electrolytic capacitor. In particular, the present invention can adjust a resistance value of a surge prevention switch connected in series with the capacitor to control a current amount flowing through the capacitor, and thus can prevent a surge voltage from being generated when charging and discharging the capacitor.