摘要:
The present invention relates to a frequency converter comprising a power part and a control and adjustment part. The frequency converter is characterized in that the control and adjustment part is arranged to be a separate control and adjustment unit separated from the power part and in that the control and adjustment unit forming the control and adjustment part is arranged to be connected to the power part by a telecommunication unit. The telecommunication unit is a wired optic connection or a wireless connection, the control and adjustment part and the power part then being galvanically separated.
摘要:
In an 18-pulse converter system a 3-phase to 9-phase auto transformer with multiple windings per phase is used to power a 9-phase AC to DC converter. The transformer kVA rating is typically about 55% of the DC load kW. Multiple delta connected coils formed around a basic wye connected structure provide a means to circulate the third harmonics of current necessary for proper operation and reduce the amplitude of load current flowing in individual stub windings. The similar current rating required in several of the multiple coils, coupled with reduced amplitude compared to other topologies, facilitates manufacturing of higher power transformers without the need to parallel conductors. The voltage ratio can be selected so as to give an average dc output from an 18-pulse converter which is generally the same as that of a conventional 3-phase bridge rectifier without transformer, however, the topology described is also suitable for step up or step down of voltage as required. Where necessary to further reduce high frequency harmonic currents, a 3-phase ac line reactor may be connected in series with the source of ac power.
摘要:
A system 10 for synchronizing the phase angle of an alternating current power source (“APS”) 12 with the phase angle of a power grid 14. The system 10 provides for reliable synchronization between the phase angle of the APS 12 and the phase angle of the power grid 14 during both normal and abnormal operating conditions.
摘要:
There is provided a frequency voltage converter comprises a first transmission line for transmitting an input signal and a second transmission line provided with a delay line circuit, a third transmission line for transmitting a reference signal and a fourth transmission line provided with a delay line circuit, a mixer circuit, and a locked loop having a control circuit for outputting the same control signal to control portions of both delay line circuits so that the amount of a delay by the delay line circuit reaches one cycle of the reference signal, thereby holding linearity with respect to the frequency of a modulated wave signal and executing frequency voltage conversion even when a center frequency is low.
摘要:
A power-supply voltage frequency control circuit capable of changing a clock frequency in accordance with processing and assuring an operation of a target circuit when supplying a power-supply voltage in accordance therewith, comprising a clock supply circuit capable of supplying a system clock of a plurality of clock frequencies and supplying a system clock having a clock frequency in accordance with a first control signal to a target circuit performing processing in synchronization with the system clock, a power-supply voltage supply circuit for supplying a power-supply voltage of a value in accordance with a second control signal to the target circuit, and a control circuit for outputting the first control signal to the clock supply circuit and a second control signal to the power-supply voltage supply circuit by following an instruction of a frequency change value and a change time from the target circuit.
摘要:
A method is described for controlling a matrix converter which includes nine bi-directional circuit-breakers arranged in a 3×3 switch matrix. A commutation sequence is selected based on detected linked input voltages and a predetermined limit value and compared with a calculated commutation sequence. If these two do not agree, the switching states of the calculated commutation sequence are rearranged into the selected commutation sequence. In this way, it is possible to operate a matrix converter without requiring a precise measurement of the polarity of the input voltages, which eliminates the risk of a commutation short circuit.
摘要:
In an 18-pulse converter system a three-phase to nine-phase auto-transformer with multiple windings per phase is used to power a nine-phase AC to DC converter. The transformer kVA rating is about 55% of the DC load kW. The basic topology is that of a wye connection, but an active delta path is added to allow circulation of the third harmonics necessary for proper operation. The design requires substantially fewer coils than other three-phase to nine-phase auto-transformers. The voltage ratio can be selected so as to give an average DC output from an 18-pulse converter which is generally the same as that of a conventional three-phase bridge rectifier without a transformer. However, the topology described is also suitable for step up or step down of voltage as required. Where necessary to further reduce high frequency harmonic currents, a three-phase ac line reactor may be connected in series with the source of ac power.
摘要:
A system for controlling multiple vehicle includes a twelve volt (12V)/forty-two volt (42V) battery power distribution system that provides direct current. The system converts single phase alternating current to multiple phase alternating current to simultaneously power multiple vehicle systems. A single pulse width modulation generator converts the direct current from the 12V/42V battery power distribution system to alternating current. This provides one power supply path of alternating current, which has a first phase. A splitter device splits the one power supply path of alternating current into three power paths. A lead/lag circuit is used to shift the alternating current of the second path to a second phase different than the first phase of the first power supply path. A second lead/lag circuit for shifts the alternating current of the third path to a third phase different than the first phase or the second phase. This creates a three-phase alternating current power from a single direct current source. The three-phase alternating current is used to power a plurality of induction motors that operate multiple vehicle systems.
摘要:
A magnetic powder core comprises a molded article of a mixture of a glassy alloy powder and an insulating material. The glassy alloy comprises Fe and at least one element selected from Al, P, C, Si, and B, and has a texture primarily composed of an amorphous phase. The glassy alloy exhibits a temperature difference &Dgr;Tx, which is represented by the equation &Dgr;Tx=Tx−Tg, of at least 20 K in a supercooled liquid, wherein Tx indicates the crystallization temperature and Tg indicates the glass transition temperature. The magnetic core precursor is produced mixing the glassy alloy powder with the insulating material, compacting the mixture to form a magnetic core precursor, and annealing the magnetic core precursor at a temperature in the range between (Tg−170) K and Tg K to relieve the internal stress of the magnetic core precursor. The glassy alloy exhibits low coercive force and low core loss.