公开(公告)号：US20210373065A1

公开(公告)日：2021-12-02

申请号：US17290284

申请日：2019-08-22

Applicant: HITACHI, LTD.

Inventor： Kazuhisa TAKAMI ,  Shoji YOSHIDA ,  Mitsuyasu KIDO ,  Tatsuya MARUYAMA

IPC: G01R31/12 ,  G01R31/14 ,  G01R31/52

Abstract: A partial discharge detection apparatus includes low-speed and high-speed AD converters. The low-speed AD converter converts an analog signal of an AC waveform flowing through a power cable into a digital signal. The high-speed AD converter converts an analog signal of a partial discharge current into a digital signal. The analog signal is in a plurality of Nyquist frequency domains defined for each of two different types of sampling frequencies. The partial discharge is detected by a partial-discharge-detection digital signal processing unit based on the maximum value or the sum of a current value obtained from the digital signal of the partial discharge current obtained by the conversion of the high-speed AD converter, for each phase of the AC waveform, which is obtained from the digital signal of the AC waveform flowing in the power cable. The digital signal is obtained by the conversion of the low-speed AD converter.

公开(公告)号：US20220131681A1

公开(公告)日：2022-04-28

申请号：US17600154

申请日：2020-02-13

Applicant: Hitachi, Ltd.

Inventor： Tatsuya MARUYAMA ,  Mitsuyasu KIDO ,  Shoji YOSHIDA ,  Kazuhisa TAKAMI ,  Takamichi ENDO

IPC: H04L7/00 ,  H04L7/04

Abstract: In the related art, since there is a difference in communication delay time in a round-trip communication path due to packet clogging in a network configuration using a network relay device, there is a problem that time cannot be synchronized. In order to solve the above problem, in the present invention, a time synchronization unit 131 is controlled by the time synchronization control unit 130 to perform time synchronization once, delays of an egress path and an ingress path of the time packet on the basis of the synchronization time are calculated, and time synchronization processing is executed using a time of the time packet in a case where the calculated values are equal to each other.

公开(公告)号：US20160360497A1

公开(公告)日：2016-12-08

申请号：US15172315

申请日：2016-06-03

Applicant: Hitachi, Ltd.

Inventor： Tatsuya MARUYAMA ,  Tsutomu YAMADA ,  Mitsuyasu KIDO ,  Shouji YOSHIDA ,  Kazuhisa TAKAMI

IPC: H04W56/00 ,  H04W72/12

CPC classification number: H04W56/001 ,  H04L47/36 ,  H04L47/628 ,  H04L49/3072 ,  H04L51/04 ,  H04L65/608 ,  H04N21/45457 ,  H04N21/6437

Abstract: There is provided a communication control device including: a real-time communication status extraction unit that acquires a communication timing of real-time data; a dynamic fragment size determination unit that acquires a fragment size of sending data which can be sent until the communication timing acquired by the real-time communication status extraction unit; a fragment processing unit that fragments non-real-time data to have at least a fragment size which is equal to or less than the fragment size acquired by the dynamic fragment size determination unit; and a communication unit that sends the non-real-time data, which is fragmented by the fragment processing unit, before the communication timing of the real-time data.

Abstract translation: 提供了一种通信控制装置，包括：实时通信状态提取单元，其获取实时数据的通信定时; 动态片段大小确定单元，其获取可以发送的发送数据的片段大小，直到由所述实时通信状态提取单元获取的通信定时; 片段处理单元，其将非实时数据分段成至少具有等于或小于由所述动态片段大小确定单元获取的片段大小的片段大小; 以及通信单元，其在实时数据的通信定时之前发送由片段处理单元分段的非实时数据。