A passive harmonic elimination cabinet with decentralized switching

Abstract

The invention discloses a distributed switching passive harmonic elimination cabinet comprising one harmonic elimination capacitance compensation active cabinet, two harmonic elimination capacitance compensation linkage cabinets, and an intelligent automatic compensation harmonic elimination controller. The two harmonic elimination capacitance compensation linkage cabinets and one harmonic elimination capacitance compensation active cabinet actuate in a linkage way. The intelligent automatic compensation harmonic elimination controller is installed on a quintic harmonic elimination capacitance compensation active cabinet. The intelligent automatic compensation harmonic elimination controller is composed of a master control element, a detection unit and a human-computer interface. The detection unit and the human-computer interface are connected with the master control element. The detection unit is installed between a power grid and a load. According to the distributed switching passive harmonic elimination cabinet, the intelligent automatic compensation harmonic elimination controller is installed in the passive harmonic elimination cabinet so that utilization rate of capacitors and reactors can be enhanced, great power factor and harmonic elimination effect can be achieved and the design can also be simplified by the aforementioned mode.

Description

technical field [0001] The invention belongs to the field of passive harmonic elimination, in particular to a passive harmonic elimination cabinet for decentralized switching. Background technique [0002] Passive harmonic elimination is based on capacitance compensation, and a matching reactance is connected in series, so that it can filter out specific harmonics while compensating the power factor. [0003] In the traditional design, due to the consideration of the input delay of the original power factor compensator, when fewer circuits are used, the harmonics will concentrate on the first few circuits, and the capacitors of these circuits will be overwhelmed and explode. Therefore, the traditional design is abandoned. The power factor compensator scheme is changed to centralized switching of vacuum contactors. The capacitive reactance components of vacuum contactors will inevitably produce capacitance overcompensation, resulting in overvoltage. Overcompensation means tha...

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Problems solved by technology

[0003] In the traditional design, due to the consideration of the input delay of the original power factor compensator, when fewer circuits are used, the harmonics will concentrate on the first few circuits, and the capacitors of these circuits will be overwhelmed and explode. Therefore, the traditional design is abandoned. The power factor compensator scheme is changed to centralized switching of vacuum contactors. The capacitive reactance components of vacuum contactors will inevitably produce capacitance overcompensation, resulting in overvoltage. Overcompensation means that too many capacitors are connected. The system changed from the original inductive load to the capacitive load, so that the power factor changed from lagging low to leading low. The power supply bureau stipulated that the power factor should be fined if it is lower than 0.9. Originally, I wanted to improve the power factor. Now, due to the emphasis on harmonic elimination Overcompensation due to safety, but it may be lower than the original one. When the vacuum contactor is switched, the peak value of the power supply and the possible high voltage superposition on the capacitor will cause the contacts of the vacuum contactor to be welded and burned. Each vacuum contactor only It can make one kind of harmonic resonate, that is, let one kind of harmonic pass through smoothly, but the harmonics generated by the line will not be one kind, then the harmonic elimination circuit of each harmonic will not be well matched

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