H02H 7/04
Emergency protective circuit arrangements specially adapted for specific types of electric machines
Official title: for transformers
H02H7/04 (Emergency protective circuit arrangements specially adapted for specific types of electric machines) appears on 324 US grants and 289 published applications in this corpus.
Search patents in H02H- Granted patents
- 324
- Published applications
- 289
- Assignees
- 182
- Inventors
- 770
- Latest grant
- 11 Aug 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 3 | 0 |
| 1977 | 2 | 0 |
| 1978 | 1 | 0 |
| 1979 | 2 | 0 |
| 1980 | 5 | 0 |
| 1981 | 2 | 0 |
| 1982 | 2 | 0 |
| 1983 | 3 | 0 |
| 1984 | 2 | 0 |
| 1985 | 3 | 0 |
| 1986 | 2 | 0 |
| 1987 | 5 | 0 |
| 1988 | 3 | 0 |
| 1989 | 3 | 0 |
| 1990 | 2 | 0 |
| 1991 | 2 | 0 |
| 1992 | 4 | 0 |
| 1993 | 1 | 0 |
| 1994 | 1 | 0 |
| 1995 | 2 | 0 |
| 1996 | 2 | 0 |
| 1997 | 4 | 0 |
| 1998 | 7 | 0 |
| 1999 | 4 | 0 |
| 2000 | 1 | 0 |
| 2001 | 2 | 2 |
| 2002 | 7 | 2 |
| 2003 | 4 | 3 |
| 2004 | 6 | 9 |
| 2005 | 5 | 3 |
| 2006 | 2 | 2 |
| 2007 | 4 | 8 |
| 2008 | 4 | 4 |
| 2009 | 3 | 8 |
| 2010 | 4 | 6 |
| 2011 | 10 | 10 |
| 2012 | 3 | 8 |
| 2013 | 11 | 16 |
| 2014 | 7 | 10 |
| 2015 | 11 | 21 |
| 2016 | 12 | 9 |
| 2017 | 13 | 31 |
| 2018 | 16 | 9 |
| 2019 | 22 | 23 |
| 2020 | 17 | 14 |
| 2021 | 17 | 21 |
| 2022 | 23 | 25 |
| 2023 | 25 | 13 |
| 2024 | 19 | 11 |
| 2025 | 7 | 13 |
| 2026 | 2 | 8 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Adaptive combined approach for intelligent transformer dissolved gas alarm detection11 Aug 2026US 12,704,491 B2GE Vernova Infrastructure Technology LLC
- Reducing transformer inrush current14 Apr 2026US 12,603,494 B2ABB Schweiz AG
- High-impedance differential protection using a diversity of signals16 Sep 2025US 12,418,168 B2Schweitzer Engineering Laboratories, Inc.
- Reducing transformer inrush current9 Sep 2025US 12,413,069 B2ABB Schweiz AG
- Fault handling system of solid-state transformer12 Aug 2025US 12,388,251 B2Huawei Digital Power Technologies Co., Ltd.
- Power receiving and transforming equipment leakage current/stray current digital safety control system13 Aug 2026US 2026/0237996 A1Technomirai Co., Ltd.
- Quotient differential protection for electric power delivery systems9 Jul 2026US 2026/0196823 A1Schweitzer Engineering Laboratories, Inc.
- A fault discrimination and a current transformer saturation detection for a differential protection system25 Jun 2026US 2026/0180308 A1Hitachi Energy Ltd
- System and method for monitoring load usage on an electrical transformer28 May 2026US 2026/0146898 A1Eskom Holdings SOC Limited
- Transformer protection using distributed energy resources9 Apr 2026US 2026/0100574 A1Itron, Inc.
Most cited
By later US patents
- Method for determining wear and other characteristics of electrodes in high voltage equipment118US 6,448,758 B1General Electric Company · 2002
- Differential protection device of a power transformer110US 5,784,233 AEcole Superieure d'Electricite Supelec · 1998
- Method and system for providing protective relay functions93US 5,592,393 ABeckwith Electric Co., Inc. · 1997
- Method and apparatus for monitoring transformers83US 4,654,806 AWestinghouse Electric Corp. · 1987
- Method and device for testing differential protection relays or differential protection relay systems68US 6,396,279 B1Omicron Electronics GmbH · 2002