CN111211544B - Valve side main equipment configuration and transformer grounding system and use method thereof - Google Patents
Valve side main equipment configuration and transformer grounding system and use method thereof Download PDFInfo
- Publication number
- CN111211544B CN111211544B CN202010078829.9A CN202010078829A CN111211544B CN 111211544 B CN111211544 B CN 111211544B CN 202010078829 A CN202010078829 A CN 202010078829A CN 111211544 B CN111211544 B CN 111211544B
- Authority
- CN
- China
- Prior art keywords
- transformer
- current
- valve
- circuit breaker
- breaker
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 11
- 238000004804 winding Methods 0.000 claims abstract description 15
- 239000003990 capacitor Substances 0.000 claims abstract description 4
- 238000005520 cutting process Methods 0.000 claims description 6
- 230000008569 process Effects 0.000 claims description 2
- 230000005540 biological transmission Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 238000002955 isolation Methods 0.000 description 2
- 230000007935 neutral effect Effects 0.000 description 2
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
- H02H7/268—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured for dc systems
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/04—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for transformers
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
The invention relates to a valve side main equipment configuration and transformer grounding system and a use method thereof, which are characterized by comprising a transformer: the transformer adopts a three-winding type; the grid side winding adopts a star connection mode, and the grid side is connected with a variable grid side alternating current circuit breaker through a third current transformer and a first lightning arrester; the valve side winding adopts a star connection mode, and the valve side is sequentially connected with a fifth current transformer, a third lightning arrester, a capacitor voltage transformer, a grounding switch, a connecting transformer valve side breaker, a starting circuit and a seventh current transformer in series; the seventh current transformer is also connected with an upper bridge arm reactor and a lower bridge arm reactor in parallel, and the upper bridge arm reactor and the lower bridge arm reactor are connected with the current converter in the valve hall area through corresponding sleeves.
Description
Technical Field
The invention relates to a valve side main equipment configuration and transformer grounding system and a use method thereof, belonging to the technical field of flexible direct current transmission.
Background
Compared with a conventional direct current mode, the flexible direct current mode has the advantages of no need of providing phase-change current on an alternating current side, no need of reactive compensation, no problem of phase-change failure, capability of quickly and independently controlling active power and reactive power, high output voltage waveform quality and the like, and is an effective solution for realizing access and transmission of various energy sources such as large-scale wind power, photovoltaic and pumped storage. In recent years, China has been put into operation or started to plan design in succession with navigatan engineering, mansion engineering, Luxi engineering, Yubei engineering, Zhang Bei engineering, Wudongde engineering and Baihe beach engineering, and the wide application prospect of flexible direct current transmission is verified.
The neutral point of the converter transformer is grounded through a large resistor, and the grounding scheme is a common grounding scheme of a symmetrical unipolar flexible direct-current system, zero potential clamping is realized by utilizing the wiring characteristics of the transformer, a star-shaped reactor is not required to be additionally configured, and wiring is simple and clear. When the flexible direct current transmission project breaks down, the current converter needs to be locked and the alternating current incoming line breaker needs to be opened. In the design of the engineering scheme, the failure protection scheme of the alternating current incoming line breaker which is suitable for the characteristics of the symmetrical unipolar flexible direct current engineering needs to be researched. However, the above grounding scheme has the following two disadvantages: 1) when a single-phase earth fault (or a direct-current single-pole earth fault) occurs on the valve side and the alternating-current incoming line breaker fails, the traditional alternating-current breaker failure protection detection is difficult to start because the fault current is small; 2) when direct current bipolar short circuit trouble and exchange the inlet wire circuit breaker malfunctioning back, the malfunctioning protection action time of traditional interchange circuit breaker is too long, is difficult to satisfy VSC (voltage source converter) valve requirement.
Disclosure of Invention
In view of the above problems, an object of the present invention is to provide a valve side master configuration and transformer grounding system that is convenient to detect and meets the requirements of a VSC valve, and a method of using the same.
In order to achieve the purpose, the invention adopts the following technical scheme: a valve side master configuration and transformer grounding system comprising a transformer: the transformer adopts a three-winding type, and a third winding of the transformer adopts a triangular connection mode; the grid side winding of the transformer adopts a star connection mode, and is grounded through three first current transformers connected in parallel and a second current transformer; the network side of the transformer is connected with a network side alternating current breaker through a third current transformer and a first lightning arrester; a valve side winding of the transformer is grounded through a fourth current transformer, a grounding resistor and a sixth current transformer which are connected in parallel in sequence in a star-shaped connection mode, and the grounding resistor is further connected with a bypass breaker and a second lightning arrester in parallel; a valve side of the transformer is sequentially connected with a fifth current transformer, a third lightning arrester, a capacitor voltage transformer, a grounding switch, a connecting transformer valve side breaker, a starting circuit and a seventh current transformer in series; the seventh current transformer is further connected with an upper bridge arm reactor and a lower bridge arm reactor in parallel, and the upper bridge arm reactor and the lower bridge arm reactor are connected with the current converter in the valve hall area through corresponding sleeves.
Furthermore, the starting loop is formed by connecting an eighth current transformer, a starting resistor and the first isolating switch in series and then connecting the eighth current transformer, the starting resistor and the first isolating switch in parallel with the second isolating switch.
Furthermore, the first isolating switch is an isolating switch with double ground knives, and the second isolating switch is an isolating switch with single ground knife.
Furthermore, the first to fifth current transformers adopt electromagnetic current transformers, and the sixth to eighth current transformers adopt electronic current transformers.
A use method based on valve side main equipment configuration and a transformer grounding system is characterized by comprising the following steps: 1) charging a current converter in the valve hall area, and cutting off a starting resistor after the charging is finished; 2) when the converter in the valve hall area operates in a steady state, only the connecting variable valve side circuit breaker is connected into a main loop, so that the connecting variable valve side circuit breaker serves as a backup of the connecting variable network side alternating current circuit breaker; 3) when the grounding switch has a fault, tripping off the AC circuit breaker at the side of the connecting transformer network and the circuit breaker at the side of the connecting transformer valve at the same time; 4) after a fixed time delay, the bypass circuit breaker is closed, so that the failure protection of the alternating current circuit breaker can detect the failure of the alternating current incoming line circuit breaker.
Further, the specific process of cutting off the starting resistor in the step 1) is as follows: and closing the second isolating switch and breaking the first isolating switch.
Due to the adoption of the technical scheme, the invention has the following advantages:
1. the invention carries out optimization and adjustment on the basis of the traditional grounding system and has the advantages of small number of newly added equipment, clear function, compact configuration, optimized occupied area, higher economy and the like.
2. The grounding system has the characteristics of simple and easy steps, clearness and the like in use, and can effectively solve the problems that the traditional alternating current circuit breaker is difficult to detect in failure protection and the traditional converter valve is difficult to bear due to long action time.
3. According to the invention, the alternating current incoming line breaker and the connecting variable valve side breaker are simultaneously tripped, so that failure removal caused by failure of the alternating current incoming line breaker is prevented, the starting resistance bypass breaker is used as a backup of the alternating current breaker, the problem of failure protection of the alternating current breaker can be solved, and the flexible direct current circuit breaker can be widely applied to the technical field of flexible direct current power transmission.
Drawings
FIG. 1 is a schematic diagram of a prior art grounding system;
fig. 2 is a schematic structural diagram of the grounding system of the present invention.
Detailed Description
The present invention is described in detail below with reference to the attached drawings. It is to be understood, however, that the drawings are provided solely for the purposes of promoting an understanding of the invention and that they are not to be construed as limiting the invention.
As shown in fig. 1, a schematic diagram of a valve-side main device configuration and a transformer grounding system in the prior art is shown, in which a transformer valve-side neutral point is connected to ground via a large resistor, however, the prior art grounding system has the following two disadvantages:
1) if a single-phase earth fault (direct-current single-pole earth fault) occurs on the valve side and the alternating-current incoming line breaker fails, the fault current flowing through the alternating-current incoming line breaker after the converter is locked is small (100-200A), and the traditional alternating-current breaker failure protection is difficult to start;
2) if when the bipolar short-circuit trouble of direct current and exchange the inlet wire circuit breaker malfunctioning, the withstand time of VSC valve only satisfies subordinate's alternating current circuit breaker and clears away the trouble in 200ms, and traditional alternating current circuit breaker failure protection needs 450ms through tripping subordinate's circuit breaker, can't satisfy the VSC valve requirement.
The invention optimizes and adjusts the defects, and as shown in fig. 2, compared with the conventional grounding scheme, the invention mainly has the following differences:
1) the original starting resistor bypass breaker Q1 is moved to the position of an isolating switch Q11 between the original starting resistor R1 and the coupling transformer, and the grounding switch Q23 is moved to the position of a grounding switch Q21;
2) an isolating switch Q11 (grounding switches are respectively Q21 and Q22) with double grounding knives is moved to the valve side of a serial loop of an original starting resistor R1;
3) a bypass breaker Q2 is connected beside the grounding resistor R2 in parallel;
4) a single-pole isolating switch Q12 (the grounding switch is Q24) is added to a bypass loop of the starting resistor R1.
Therefore, the valve-side main equipment configuration and transformer grounding system provided by the invention comprises a transformer, an arrester A, electromagnetic current transformers T1-T5, electronic current transformers T6-T8, an arrester V0, an arrester AV, a capacitor voltage transformer PT, a connection transformer-side breaker Q1, a bypass breaker Q2, an upper arm reactor L1, a lower arm reactor L2 and a grounding resistor R2, wherein a starting loop is formed by connecting the electronic current transformers T7, the starting resistor R1 and an isolating switch Q11 (grounding switches are Q21 and Q22 respectively) in series and then connecting the isolating switch Q12 (the grounding switch is Q24) in parallel.
The transformer adopts a three-winding type, and a third winding of the transformer adopts a triangular connection mode and is used for providing power supply in a station.
The grid side winding of the transformer adopts a star connection mode, and is grounded through three electromagnetic current transformers T1 connected in parallel through an electromagnetic current transformer T2. The network side of the transformer is connected with a lightning arrester A through an electromagnetic current transformer T3 and is connected with a network side alternating current breaker Q3.
The valve side winding of the transformer adopts a star connection mode, is grounded through three electromagnetic current transformers T4, a grounding resistor R2 and an electronic current transformer T6 which are connected in parallel in sequence, and the grounding resistor R2 is also connected with a bypass breaker Q2 and a lightning arrester V0 in parallel. The valve side of the transformer is sequentially connected with an electromagnetic current transformer T5, a lightning arrester AV, a capacitance voltage transformer PT, a grounding switch Q23, a connecting transformer side breaker Q1, a starting circuit and an electronic current transformer T8 in series. The electronic current transformer T8 is also connected in parallel to an upper arm reactor L1 and a lower arm reactor L2, and the upper arm reactor L1 and the lower arm reactor L2 are connected to the converter in the valve hall area by a corresponding bushing X1 and a bushing X2.
The lightning arrester is used for protecting equipment under operation impact or lightning impact, and the isolating switch and the grounding switch are used for realizing electrical isolation of the equipment and providing an obvious electrical isolation point for equipment maintenance; the breaker is used for quickly isolating faults and cutting off a fault current path; the current transformer is used for measuring the current of the relevant position and providing a measured value for control and protection.
The following describes in detail the valve side main equipment configuration and the method of using the transformer grounding system according to the present invention by specific embodiments:
1) and (4) charging the converter in the valve hall area, closing the isolating switch Q12 after the charging is finished, and cutting off the starting resistor R1 by opening the isolating switch Q11.
2) When the converter in the valve hall area operates in a steady state, only the connecting transformer side circuit breaker Q1 is connected into the main circuit, so that the connecting transformer side circuit breaker Q1 is used as a backup of the connecting transformer side alternating current circuit breaker Q3.
3) When the grounding switch Q23 between the transformer in the valve hall area and the connecting transformer side circuit breaker Q1 breaks down, the connecting transformer side AC circuit breaker Q3 and the connecting transformer side circuit breaker Q1 are simultaneously tripped, so that failure of fault clearing caused by failure of the AC circuit breaker is prevented.
4) After a fixed time delay, the bypass breaker Q2 is closed so that the ac inlet line breaker failure can be detected by the conventional ac breaker failure protection.
The above embodiments are only used for illustrating the present invention, and the structure, connection mode, manufacturing process, etc. of the components may be changed, and all equivalent changes and modifications performed on the basis of the technical solution of the present invention should not be excluded from the protection scope of the present invention.
Claims (2)
1. A method of using a valve-side master configuration and transformer grounding system, comprising:
1) charging a current converter in the valve hall area, and cutting off a starting resistor after the charging is finished;
2) when the converter in the valve hall area operates in a steady state, only the connecting variable valve side circuit breaker is connected into a main loop, so that the connecting variable valve side circuit breaker serves as a backup of the connecting variable network side alternating current circuit breaker;
3) when the grounding switch has a fault, tripping off the AC circuit breaker at the side of the connecting transformer network and the circuit breaker at the side of the connecting transformer valve at the same time;
4) after fixed time delay, the bypass circuit breaker is closed, so that the failure of the alternating current incoming line circuit breaker can be detected by the alternating current circuit breaker failure protection;
the valve side master configuration and transformer grounding system includes a transformer:
the transformer adopts a three-winding type, and a third winding of the transformer adopts a triangular connection mode;
the grid side winding of the transformer adopts a star connection mode, and is grounded through three first current transformers connected in parallel and a second current transformer; the network side of the transformer is connected with a network side alternating current breaker through a third current transformer and a first lightning arrester;
a valve side winding of the transformer is grounded through a fourth current transformer, a grounding resistor and a sixth current transformer which are connected in parallel in sequence in a star-shaped connection mode, and the grounding resistor is further connected with a bypass breaker and a second lightning arrester in parallel; a valve side of the transformer is sequentially connected with a fifth current transformer, a third lightning arrester, a capacitor voltage transformer, a grounding switch, a connecting transformer valve side breaker, a starting circuit and a seventh current transformer in series; the seventh current transformer is also connected with an upper bridge arm reactor and a lower bridge arm reactor in parallel, and the upper bridge arm reactor and the lower bridge arm reactor are connected with a current converter in a valve hall area through corresponding sleeves;
the starting loop is formed by connecting an eighth current transformer, a starting resistor and a first isolating switch in series and then connecting a second isolating switch in parallel;
the first isolating switch is an isolating switch with double ground knives, and the second isolating switch is an isolating switch with a single ground knife.
2. The method for using the valve side main equipment configuration and the transformer grounding system according to claim 1, wherein the specific process of cutting off the starting resistor in the step 1) is as follows: and closing the second isolating switch and breaking the first isolating switch.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010078829.9A CN111211544B (en) | 2020-02-03 | 2020-02-03 | Valve side main equipment configuration and transformer grounding system and use method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010078829.9A CN111211544B (en) | 2020-02-03 | 2020-02-03 | Valve side main equipment configuration and transformer grounding system and use method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111211544A CN111211544A (en) | 2020-05-29 |
| CN111211544B true CN111211544B (en) | 2021-07-27 |
Family
ID=70789905
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010078829.9A Active CN111211544B (en) | 2020-02-03 | 2020-02-03 | Valve side main equipment configuration and transformer grounding system and use method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111211544B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114038283A (en) * | 2021-11-19 | 2022-02-11 | 广东电网有限责任公司 | Flexible direct current distribution network steady state and transient state off-line simulation and training system |
| CN115173379A (en) * | 2022-08-17 | 2022-10-11 | 国网经济技术研究院有限公司 | Symmetrical monopole flexible direct current grounding system and grounding parameter selection method thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106300330A (en) * | 2015-05-15 | 2017-01-04 | 国网智能电网研究院 | A kind of THE UPFC fault case traversing method |
| CN109119975A (en) * | 2018-08-22 | 2019-01-01 | 许继集团有限公司 | A kind of failure protection method of the breaker of direct current system and its start-up course |
| CN109347134A (en) * | 2018-11-09 | 2019-02-15 | 国家电网有限公司 | Bipolar flexible direct-current power grid polar line electric main wiring system and online maintenance method |
| CN110011285A (en) * | 2019-04-25 | 2019-07-12 | 国家电网有限公司 | Grounding system and method for high-voltage high-capacity flexible direct current engineering |
| CN110247560A (en) * | 2019-07-10 | 2019-09-17 | 南方电网科学研究院有限责任公司 | Flexible direct current converter station valve hall and converter valve inlet wire system |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7961481B2 (en) * | 2007-11-20 | 2011-06-14 | Leadtrend Technology Corp. | Pulse width modulation control circuit applied to charge output capacitor |
| CN108832607B (en) * | 2018-06-20 | 2019-12-13 | 国家电网公司 | Insulation matching method and system for symmetrical bipolar flexible direct current engineering converter station |
-
2020
- 2020-02-03 CN CN202010078829.9A patent/CN111211544B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106300330A (en) * | 2015-05-15 | 2017-01-04 | 国网智能电网研究院 | A kind of THE UPFC fault case traversing method |
| CN109119975A (en) * | 2018-08-22 | 2019-01-01 | 许继集团有限公司 | A kind of failure protection method of the breaker of direct current system and its start-up course |
| CN109347134A (en) * | 2018-11-09 | 2019-02-15 | 国家电网有限公司 | Bipolar flexible direct-current power grid polar line electric main wiring system and online maintenance method |
| CN110011285A (en) * | 2019-04-25 | 2019-07-12 | 国家电网有限公司 | Grounding system and method for high-voltage high-capacity flexible direct current engineering |
| CN110247560A (en) * | 2019-07-10 | 2019-09-17 | 南方电网科学研究院有限责任公司 | Flexible direct current converter station valve hall and converter valve inlet wire system |
Non-Patent Citations (1)
| Title |
|---|
| 柔性直流背靠背换流站阀厅电气设备布置设计;王丽杰等;《电力勘测设计》;20190731(第7期);第1-2节 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111211544A (en) | 2020-05-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Dang et al. | An adaptive protection method for the inverter dominated microgrid | |
| CN106655120A (en) | Intelligent ground protection method and system for neutral point of power distribution network | |
| Rahman et al. | DC fault protection strategy considering DC network partition | |
| CN111211544B (en) | Valve side main equipment configuration and transformer grounding system and use method thereof | |
| CN109347134B (en) | Bipolar flexible direct-current power grid polar line electric main wiring system and online maintenance method | |
| CN107785884A (en) | A kind of more level active compensation devices of three-phase four-arm and control method | |
| CN114089122B (en) | Fault distance measurement method based on direct current breaker structure multiplexing | |
| CN113156251B (en) | Ground fault simulation experiment table for non-effective grounding system | |
| Ruffing | HVDC grid protection based on fault blocking converters | |
| CN105471389A (en) | Fault crossing detection system and method of photovoltaic power station/photovoltaic inverter | |
| Li et al. | Control and protection system design of zhangbei VSC-HVDC grid | |
| Rahman et al. | DC fault protection of multi-terminal HVDC systems using DC network partition and DC circuit breakers | |
| Gatta et al. | Modelling of battery energy storage systems under faulted conditions: Assessment of protection systems behaviour | |
| CN110661488B (en) | Photovoltaic power generation low-voltage ride-through detection device compatible with double voltage levels | |
| Yao et al. | Studies of coordinated zone protection strategy for DC grid | |
| Jennett et al. | Protection of converter dense power systems | |
| CN113595040A (en) | Annular direct-current micro-grid single-ended current type distance measurement method based on control and protection cooperation | |
| CN206283246U (en) | A kind of many electrode difference protection power distribution automation equipment of use magnetic control fast chopper | |
| Li et al. | Research on DC Distribution Network Protection Technology | |
| CN215682123U (en) | Neutral point grounding device on converter transformer valve side | |
| Kheirollahi et al. | Optimal coordination of ultrafast solid-state circuit breakers in DC microgrids | |
| CN101764389B (en) | Anti-overvoltage measurement and control system and method | |
| Wenjing et al. | Research on protection configuration of AC/DC hybrid distribution network in industrial park | |
| CN217882828U (en) | Main transformer protection device and system of traction substation transformer substation | |
| CN111162558B (en) | Main wiring system of back-to-back symmetrical single-pole flexible-straight system and selection method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |