摘要:
A three-phase resonant cyclo-converter including a closed loop control module for controlling the switching frequency of the cyclo-converter, the closed loop control module including: a voltage signal development module arranged to develop a voltage signal representative of a voltage output waveform of the cyclo-converter, a storage module arranged to accumulate voltage signal values for phase portions of the voltage output waveform, where the voltage signal values are based on a voltage error signal and accumulated historical voltage signal values for the same corresponding phase portions, and a switching frequency control module arranged to develop a switching frequency control signal to control the switching frequency of the cyclo-converter based on the accumulated voltage signal values for corresponding phase portions of the voltage output waveform, and a proportional voltage signal based on a difference between the developed voltage signal and a reference voltage signal.
摘要:
A three-phase resonant cyclo-converter comprising a power control module, wherein the power control module is arranged to develop a plurality of repeating switching periods within a cycle, the power control module further arranged to: control the length of a first switching period in the cycle to adjust the power flow, and control the relative length of two or more further switching periods in the cycle to adjust the power factor, wherein the relative length is controlled based on a cross-product of voltage and current values associated with the further switching periods.
摘要:
A three-phase resonant cyclo-converter, the cyclo-converter comprising a feed forward control module arranged to develop a feed forward signal for controlling a switching frequency of the cyclo-converter dependent on conditions of a power supply arranged to provide power to the cyclo-converter.
摘要:
A disturbance, for example, a frequency variation, is generated in at least a portion of the power distribution network. The disturbance may be generated, for example, by an uninterruptible power supply (UPS) or some other component of the power distribution network, such as a switch. At least one node of the network experiencing the disturbance is identified and a topology of the power distribution network is determined responsive to identifying the at least one node. The at least one node may be identified by detecting a voltage-related artifact corresponding to the disturbance. A phase-locked loop (PLL)—based circuit may be used for fast artifact detection. Groups of devices in the network may be identified from the artifacts, and combinatorial optimization techniques may be used to determine connectivity within such groups.
摘要:
Computer systems and methods allow users to annotate content items found in a corpus such as the World Wide Web Annotations, which can include any descriptive and/or evaluative metadata related to a document, are collected from a user and stored in association with that user. Users are able to annotate and view their annotations for any document they encounter while interacting with the corpus, including hits returned in a search of the corpus. Users are also able to search their annotations or to limit searches to documents they have annotated. Metadata from annotations can also be aggregated across users and aggregated metadata applied in generating search results.
摘要:
A bra comprised of separate left and right breast support members where each breast support member comprises a section of flexible sheet material formed to define a concave cavity and having tabs projecting radially outwardly from the cavity rim. Each breast support member defines a rear facing surface encompassing the cavity and tabs, which carries a pressure sensitive adhesive for adhering to a user's skin. The concave cavity constitutes a cup for accommodating the user's breast while the tabs enable the user to readily manipulate the support member for optimally positioning the user's breast relative to the cut of a deep plunge garment.
摘要:
Computer systems and methods allow users to annotate content items found in a corpus such as the World Wide Web. Annotations, which can include any descriptive and/or evaluative metadata related to a document, are collected from a user and stored in association with that user. Users are able to annotate and view their annotations for any document they encounter while interacting with the corpus, including hits returned in a search of the corpus. Users are also able to search their annotations or to limit searches to documents they have annotated. Metadata from annotations can also be aggregated across users and aggregated metadata applied in generating search results.
摘要:
A deployable underwater noise abatement system allowing packing and deploying an organized set of grouped resonators is disclosed. The system allows relatively compact storage and transportation of the noise abatement apparatus when not in use, then, when deployed, the apparatus can be lowered into the water and extended.