CN102495363B - Method for distinguishing shutting of +/-800 kV extra-high voltage direct-current valve group - Google Patents
Method for distinguishing shutting of +/-800 kV extra-high voltage direct-current valve group Download PDFInfo
- Publication number
- CN102495363B CN102495363B CN201110327009.XA CN201110327009A CN102495363B CN 102495363 B CN102495363 B CN 102495363B CN 201110327009 A CN201110327009 A CN 201110327009A CN 102495363 B CN102495363 B CN 102495363B
- Authority
- CN
- China
- Prior art keywords
- valve group
- current
- signal
- power
- locking
- 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
Images
Landscapes
- Direct Current Feeding And Distribution (AREA)
- Electrically Driven Valve-Operating Means (AREA)
Abstract
The invention provides a method for distinguishing the shutting of a 800 kV extra-high voltage direct-current valve group. A direct-current power transmission system is composed of two poles and each pole is composed of two 400 kV valve groups; each valve group corresponds to a relevant converter transformer; a stable control device is used for collecting three-phase current and three-phase voltage of the converter transformer; when the following three conditions are met, a valve group shutting or emergent stopping signal sent by a direct-current pole control system is received and the valve group is confirmed to have faults and the valve group is shut by time delay; and the three conditions are as follows: (1) a mutational volume starting of changes of current or power of the converter transformer is carried out; (2) after the mutational volume starting, a current real-time power Pdck of the converter transformer is less than 'a stopping threshold constant value, namely a stopping power constant value of the direct-current valve group' Pdcstop; after a direct-current system has the pole shutting, the Pdck (Pdcstop) is judged; and (3) before the mutational volume starting, a power Pdc_ of the converter transformer at a previous moment is more than a pre-set operation threshold constant value, namely 'a run power constant value of the direct-current valve group' Pdcrun.
Description
Technical field
The present invention relates to the method for discrimination of DC transmission system DC valve group locking in a kind of electric system.
Background technology
In the HVDC (High Voltage Direct Current) transmission system remote high-power transmission of electricity of electric system at home, large-sized connection electrified wire netting, be widely used.HVDC (High Voltage Direct Current) transmission system transmission power is large, after DC system fault or locking, causes larger power transfer or system power uneven, and serious threat is to the safe and stable operation of electrical network.
According to the regulation of China < < guiding rules of power system safety and stability > >, as electric system, bear the second level safety and stability standard of large disturbance ability, while there is bipolar fault in DC power transmission line, can take necessary control measure by safety stabilization control system, guarantee the stable operation of electrical network.Therefore, the feature of necessary researching DC valve group locking, proposes reliable straight-wavy valve group locking criterion, and applies it in electricity net safety stable controlling system.When there is straight-wavy valve group locking fault, by safety and stability control device, sentence exactly and the locking of straight-wavy valve group, thereby take urgent effective measures, ensure the safety of electrical network.
At present, the method for discrimination for the locking of DC transmission system valve group does not also have disclosing of better scheme;
Summary of the invention
The present invention seeks to: safety stabilization control system or the device of the method for discrimination of a kind of DC transmission system valve group locking for electric system are provided, can fast, reliably differentiate straight-flow system valve group locking fault, for safety stabilization control system or device fast, accurately take to stablize the reliable guarantee of providing of control measure.Make full use of valve group block signal, valve group that DC pole control system provides and throw and stop the electric parameters that signal and the change of current become and combine, proposed the method for discrimination of a kind of straight-wavy valve group locking.
Technical scheme of the present invention is: DC transmission system DC valve group locking method of discrimination, DC transmission system is comprised of two levels, each utmost point is comprised of 2 400kV valve groups, the corresponding corresponding change of current of each valve group becomes, stability control device gathers three-phase current and the three-phase voltage that the change of current becomes, it is characterized in that: the locking of valve group or the emergency outage signal when following three conditions are satisfied, received, exist fault and the locking of valve group through this valve group of delay confirmation
(1) Sudden Changing Rate of the electric current that the change of current becomes or the variation of power starts, and Sudden Changing Rate initiating element comprises 2 elements: jump-value of current initiating element, chugging measure moving, and in these 2 elements, any one starting thinks that Sudden Changing Rate initiating element moves.
1) jump-value of current starting
Δi＝i
k-i
k-24
|Δi|≥ΔI
S
Divide judgment by phase current, arbitrary mutually continuous three sampled points meet above formula, make device enter starting state.In above formula, Δ i represents each difference of phase currents, i
krepresent current current sampling data, i
k-24represent 1 week wavefront current sampling data, Δ I
srepresent that jump-value of current starts definite value, by user, adjusted, this definite value is adjusted by avoiding the curent change causing due to the normal fluctuation of system, considers certain nargin, should be more than or equal to the primary side rated current of 0.03 times of CT simultaneously, avoid because measuring error causes device Fraquent start.
2) chugging amount starts
ΔP＝P
t-P
t-Δt
|ΔP|≥ΔP
S
Continuous three sampled points meet above formula, make device enter starting state.In above formula, Δ P represents chugging amount, P
trepresent current active power value, P
t-Δ trepresent the front active power value of Δ t, Δ P
sfor " power variation startup definite value ", by user, adjusted.Δ t represents chugging amount start-up time, by user, to be adjusted.This definite value is adjusted by avoiding the active power variation causing due to the normal fluctuation of system, consider certain nargin, the minimum setting valve of this definite value should be more than or equal to TA primary side rated current, the rated voltage of 0.01 times simultaneously, active power factor is the active power of this element of correspondence in 1 situation, avoids device Fraquent start.
Chugging amount Δ start-up time t adjusted as 0.1-0.5 second; The peak power 1.1～1.5 that " stoppage in transit threshold definite value " adjusted and become into every utmost point change of current; " valve group put into operation power definite value " adjusted and become 0.5～0.9 times of the minimum power that puts into operation for every utmost point change of current.
(2) the current power Pdck that after Sudden Changing Rate startup, the change of current becomes is less than the stoppage in transit threshold definite value Pdcstop of setting, and after the locking of the straight-flow system generation utmost point (Sudden Changing Rate starts rear), judges Pdck < Pdcstop;
(3) the power P dc_ that before Sudden Changing Rate startup, the 200ms change of current constantly becomes is greater than the operation threshold definite value Pdcrun of setting, and meeting of this condition is mainly that before the locking of confirmation valve group, electric parameters will meet the condition putting into operation;
(4) when above-mentioned three conditions are satisfied, receive the locking of valve group or the emergency outage signal that DC pole control system sends, the form sending valve group locking of utmost point control system by switching value or emergency outage signal be to safety and stability control device, and safety and stability control device receives that this valve group of delay confirmation through 5ms exists fault and the locking of valve group after this signal;
(5) in order to identify more reliably, exactly the whether locking of the direct current utmost point; the criterion that only relies on above-described electric parameters is sufficient not; the expression valve group locking that provides in conjunction with DC control and protection system or the switching value signal of emergency outage are preferably also provided, use 3 to open into signal indication here:
1) valve group blocking leaves into signal: when straight-wavy valve group is during in normal operating condition, this opens into signal is 1, if the locking of straight-wavy valve group or stop transport after, this opens into signal is 0.
2) valve group released state leaves into signal: when straight-wavy valve group is during in normal operating condition, this opens into signal is 0, if the locking of straight-wavy valve group or stop transport after, this opens into signal is 1.
3) valve group emergency outage leaves into signal: when DC control protection action, direct current is changed to blocking by running status, and this is opened into signal and is 1 and keeps a period of time (being generally less than 1s).
Open into speak to oneself the respectively contact of output of DC pole control system of signal for above-mentioned 3, monitor these open into signal circuit, judge whether to occur abnormal, thereby guarantee that the locking of valve group sentences and accurately and reliably.
When all meeting, above five conditions sentence the locking of valve group.
The present invention makes full use of valve blocking signal, valve that DC pole control system provides and throws and stop electric parameters that signal and the change of current become and combine and proposed the criterion of a whole set of HVDC pole blocking, generally after HVDC pole blocking, 20ms can sentence in left and right, for taking as early as possible steady control means to win the valuable time.
The invention has the beneficial effects as follows: the present invention fully utilizes the signals such as valve group locking of direct current utmost point power, DC operation state and DC pole control system, can be after the locking of straight-flow system generation valve group fast, reliably differentiate, for stabilizing control system takes to stablize the reliable basis of providing of control measure fast.The method can not be mistaken for the locking of valve group when straight-flow system is normally moved, and after the locking of generation valve group, can reliably differentiate.Along with being constructed and put into operation of China ± 800kV extra-high voltage direct-current transmission project, the AC/DC parallel operation electrical network of large capacity long distance power delivery is more and more, the electricity net safety stable problem of bringing after straight-wavy valve locking is also more and more outstanding, as gordian technique wherein, the method for discrimination of DC transmission system valve group locking is the important guarantee of power network safety operation.The present invention makes full use of valve group block signal, valve group that DC pole control system provides and throws and stop the electric parameters that signal and the change of current become and combine, and has proposed the method for discrimination of a set of straight-wavy valve locking.The present invention can differentiate straight-flow system valve group locking fault fast, accurately and reliably, fast, accurately takes control measure reliable basis is provided for safety stabilization control system.
Accompanying drawing explanation
Fig. 1: straight-wavy valve group locking discrimination principles logic diagram.
In figure: Pdcstop: straight-wavy valve group outages power definite value;
Pdcrun: the straight-wavy valve group power definite value that puts into operation;
Valve group emergency outage leaves into signal: the locking of the valve group that DC pole control system sends or emergency outage signal, and this signal is a pulse signal, pulse width is about hundreds of ms;
Valve group blocking signal: the blocking signal of the valve group that DC pole control system sends;
Valve group released state signal: the released state signal of the valve group that DC pole control system sends.
Embodiment
2 of 800kV DC transmission system each utmost points in are extremely composed in series by the valve group of 2 400kV, and corresponding 2 changes of current of each valve group become, and therefore 4 corresponding 4 changes of current of valve group become.Logic is differentiated in straight-wavy valve group locking shown in Fig. 1, adopts three-phase current, the voltage of 4 converter power transformers of full stabilization control device access of the present invention, and the switching value such as the operation of straight-wavy valve group, shut down condition and straight-wavy valve group emergency outage signal.
The embodiment of the Sudden Changing Rate initiating element shown in Fig. 1 is as described below:
Device gathers in the mode of digital sample three-phase current, the three-phase voltage that the change of current becomes, and sampling rate was 1200 point/seconds, every cycle (20ms) sampling 24 points, and device calculates three-phase electricity flow valuve, three-phase voltage value, active power value by digital algorithm.Sudden Changing Rate initiating element comprises 2 elements: jump-value of current initiating element, chugging measure moving, in these 2 elements, any one starting thinks that Sudden Changing Rate initiating element moves, Sudden Changing Rate initiating element is sensitiveer, and the starting time is not more than 10ms (being greater than 1ms), and representative value is 5ms.Power calculation is slower for Sudden Changing Rate initiating element, and the response time is about 10ms～20ms." valve group emergency outage leaves into signal " opens into broadening 100ms, for escaping the asynchronous of device Sudden Changing Rate element and power calculation.。
In Fig. 1, Pdc_ and Pdck are respectively power and the current realtime power of the Sudden Changing Rate prestart 200ms that the change of current that device gathers becomes, and Pdcrun is " valve group put into operation power definite value ", adjust and become 0.7 times of the minimum power that puts into operation for every utmost point change of current; Pdcstop is " after the locking of valve group outages power fixed " value, adjusts as 1.3 times of the peak powers of the change of current change of the max cap. after every utmost point locking.
Device adopts all-wave fourier algorithm to calculate in real time change of current change performance number corresponding to valve group, generally after a cycle (20ms), just can accurately calculate DC power Pdck corresponding to current valve group, after the starting of device Sudden Changing Rate element, device is given Pdc_ by the Pdck value of 200ms before starting constantly, in device starting process (being generally 8s), the value of Pdc_ no longer changes, device judge that Pdc_ > Pdcrun is whether satisfied, its objective is for differentiate this valve group before locking whether in the state of putting into operation;
Meanwhile, device judges that the change of current corresponding to current straight-wavy valve group becomes power P dck < Pdcstop and whether meet.Its objective is in order to differentiate this valve group electric parameters and whether meet the power under barring condition.
In order to identify reliably, exactly the whether locking of the direct current utmost point; the criterion that only relies on above-described electric parameters is inadequate; the expression valve group locking that provides in conjunction with DC control and protection system or the switching value signal of emergency outage are also provided, use 3 to open into signal indication here:
Valve group blocking leaves into signal: when straight-wavy valve group is during in normal operating condition, this opens into signal is 1, if the locking of straight-wavy valve group or stop transport after, this opens into signal is 0.
Valve group released state leaves into signal: when straight-wavy valve group is during in normal operating condition, this opens into signal is 0, if the locking of straight-wavy valve group or stop transport after, this opens into signal is 1.
Valve group emergency outage leaves into signal: when DC control protection action, direct current is changed to blocking by running status, and this is opened into signal and is 1 and keeps a period of time (being generally less than 1s).
Open into speak to oneself the respectively contact of output of DC pole control system of signal for above-mentioned 3.
Whether " valve group emergency outage leaves into warning alert " opens entry loop for detection of " valve group emergency outage leaves into signal " abnormal.From above, " valve group emergency outage leaves into signal " opened and is less than 1s into the time that only may connect.From the logic of Fig. 1, if surpass 2s when " valve group emergency outage leaves into signal " continues to connect, think that this opens entry loop abnormal.
Whether " valve group running status is left into warning " opens entry loop for detection of " valve group blocking leaves into signal " and " valve group released state leaves into signal " two abnormal.Straight-wavy valve group is when running status, and the former opens, and the latter is closed; Straight-wavy valve group is when blocking, and the former is closed, and the latter opens.From the logic of Fig. 1, when opening into connection simultaneously or the closed lasting 5s of surpassing of while for these two, think that opening entry loop for these two must have one extremely.
Report to the police after any action, can not differentiate the locking of straight-wavy valve group for these two.If after the locking of straight-wavy valve group but sentenced, then send warning, on this straight-wavy valve group locking judgement nothing impact.
Claims (2)
1. DC transmission system DC valve group locking method of discrimination, DC transmission system is comprised of two levels, each utmost point is comprised of 2 400kV valve groups, the corresponding corresponding change of current of each valve group becomes, stability control device gathers three-phase current and the three-phase voltage that the change of current becomes, it is characterized in that: when following three conditions are satisfied, and receive and through this valve group of delay confirmation, have fault and the locking of valve group by the locking of valve group or the emergency outage signal that DC pole control system sends:
(1) Sudden Changing Rate of the electric current that the change of current becomes or the variation of power starts;
Sudden Changing Rate starting element comprises 2 elements: jump-value of current starting element, chugging amount start, in these 2 elements, any one startup thinks that Sudden Changing Rate starting element moves, continuous three sampled points meet the following same form arbitrarily, make device enter starting state:
1) jump-value of current starts
Δi＝i
k－i
k-24
｜Δi｜≥ΔI
S
Divide judgment by phase current, arbitrary mutually continuous three sampled points meet above formula, make device enter starting state; In above formula, Δ i represents each difference of phase currents, i
krepresent current current sampling data, i
k-24represent 1 week wavefront current sampling data, Δ I
srepresent that jump-value of current starts definite value, is adjusted by user;
2) chugging amount starts
ΔP＝P
t－P
t-△t
｜ΔP｜≥ΔP
S
In above formula, Δ P represents chugging amount, P
trepresent current active power value, P
t-△ trepresent the front active power value of △ t, Δ P
sfor power variation starts definite value, by user, adjusted; △ t represents chugging amount start-up time, by user, to be adjusted;
(2) the stoppage in transit threshold definite value that the current realtime power Pdck that after Sudden Changing Rate startup, the change of current becomes is less than setting is straight-wavy valve group outages power definite value Pdcstop; After the straight-flow system amount of undergoing mutation starts, judge Pdck<Pdcstop;
(3) to start the operation threshold definite value that power P dc_ that the change of current of previous moment becomes is greater than setting be the straight-wavy valve group power definite value Pdcrun that puts into operation to Sudden Changing Rate;
The expression valve group locking providing in conjunction with DC control and protection system or the switching value signal of emergency outage, used three and open into signal indication:
1) valve group blocking leaves into signal: when straight-wavy valve group is during in normal operating condition, this opens into signal is 1, if the locking of straight-wavy valve group or stop transport after, this opens into signal is 0;
2) valve group released state leaves into signal: when straight-wavy valve group is during in normal operating condition, this opens into signal is 0, if the locking of straight-wavy valve group or stop transport after, this opens into signal is 1;
3) valve group emergency outage leaves into signal: when DC control protection action, direct current is changed to blocking by running status, and this is opened into signal and is 1 and keeps a period of time, and it is less than 1s;
Open the contact that comes from respectively the output of DC pole control system into signal for above-mentioned three, monitor that these are opened into signal circuit, to judge whether to occur abnormal, when abnormal, sentence the locking of valve group;
Described chugging amount △ start-up time t adjusted as 0.1-0.5 second; Chugging amount △ start-up time t adjusts by avoiding the active power variation causing due to the normal fluctuation of system; Stoppage in transit threshold fixed value adjusting is 1.1～1.5 times of the peak power that becomes of every utmost point change of current; The valve group power fixed value adjusting that puts into operation is 0.5～0.9 times that every utmost point change of current becomes the minimum power that puts into operation.
2. DC transmission system DC valve group locking method of discrimination as claimed in claim 1, is characterized in that:
Δ I
srepresent that jump-value of current starts definite value, by user, adjusted, this definite value is adjusted by avoiding the curent change causing due to the normal fluctuation of system, is more than or equal to the primary side rated current of 0.03 times of CT.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110327009.XA CN102495363B (en) | 2011-10-25 | 2011-10-25 | Method for distinguishing shutting of +/-800 kV extra-high voltage direct-current valve group |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110327009.XA CN102495363B (en) | 2011-10-25 | 2011-10-25 | Method for distinguishing shutting of +/-800 kV extra-high voltage direct-current valve group |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102495363A CN102495363A (en) | 2012-06-13 |
| CN102495363B true CN102495363B (en) | 2014-04-23 |
Family
ID=46187203
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201110327009.XA Active CN102495363B (en) | 2011-10-25 | 2011-10-25 | Method for distinguishing shutting of +/-800 kV extra-high voltage direct-current valve group |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102495363B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102721858A (en) * | 2012-07-05 | 2012-10-10 | 中国电力工程顾问集团东北电力设计院 | Quick electric power measurement method for DC power-end alternating current system |
| CN104035024B (en) * | 2014-06-10 | 2017-01-18 | 宁波长壁流体动力科技有限公司 | Sudden stop lock switch detection circuit |
| CN104849534B (en) * | 2015-05-14 | 2018-02-23 | 中国南方电网有限责任公司超高压输电公司检修试验中心 | A kind of method for realizing voltage measurement abnormality detection in direct current station control system |
| CN106093761B (en) * | 2016-06-06 | 2018-09-11 | 中国南方电网有限责任公司超高压输电公司 | Extra-high voltage direct-current by-pass switch position judging method and device |
| CN109494692B (en) * | 2018-10-31 | 2022-07-01 | 中国电力科学研究院有限公司 | Method and system for acquiring fault measure quantity of direct current bipolar line of flexible direct current power grid |
| CN110380441B (en) * | 2019-07-19 | 2021-01-22 | 国电南瑞科技股份有限公司 | Stability control criterion method and device for identifying locking and restarting states of extra-high voltage direct current |
| CN112202192B (en) * | 2020-01-03 | 2022-12-13 | 南京南瑞继保工程技术有限公司 | Method for judging operation and locking of direct-current valve bank for flexible direct-current stable control |
| CN112217221B (en) * | 2020-10-12 | 2023-06-27 | 国网福建省电力有限公司 | Manual emergency shutdown control method for double-end flexible direct-current transmission converter station |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4168463A (en) * | 1977-03-22 | 1979-09-18 | Siemens Aktiengesellschaft | Arrangement for the synthetic testing of tripolar high-voltage circuit breakers |
| CN1808821A (en) * | 2005-12-15 | 2006-07-26 | 南京南瑞继保电气有限公司 | Trip discrimination method for pure electric power system |
| CN1808158A (en) * | 2005-12-15 | 2006-07-26 | 南京南瑞继保电气有限公司 | Pole block comprehensive distinguishing method for DC power transmission system |
| CN1877945A (en) * | 2006-06-29 | 2006-12-13 | 南京南瑞继保电气有限公司 | Short trouble protective method for converter valve assembly |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2666946B2 (en) * | 1988-02-18 | 1997-10-22 | 株式会社東芝 | Capacitor switching performance test equipment |
-
2011
- 2011-10-25 CN CN201110327009.XA patent/CN102495363B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4168463A (en) * | 1977-03-22 | 1979-09-18 | Siemens Aktiengesellschaft | Arrangement for the synthetic testing of tripolar high-voltage circuit breakers |
| CN1808821A (en) * | 2005-12-15 | 2006-07-26 | 南京南瑞继保电气有限公司 | Trip discrimination method for pure electric power system |
| CN1808158A (en) * | 2005-12-15 | 2006-07-26 | 南京南瑞继保电气有限公司 | Pole block comprehensive distinguishing method for DC power transmission system |
| CN1877945A (en) * | 2006-06-29 | 2006-12-13 | 南京南瑞继保电气有限公司 | Short trouble protective method for converter valve assembly |
Non-Patent Citations (5)
| Title |
|---|
| ±800kV特高压直流输电换流阀组低压加压试验方法探讨和应用;朱奕帆等;《华东电力》;20101130;第38卷(第11期);全文 * |
| ±800kV特高压直流输电系统解锁/闭锁研究;李少华等;《电力系统保护与控制》;20100316;第38卷(第06期);全文 * |
| JP平1-210873A 1989.08.24 |
| 朱奕帆等.±800kV特高压直流输电换流阀组低压加压试验方法探讨和应用.《华东电力》.2010,第38卷(第11期), |
| 李少华等.±800kV特高压直流输电系统解锁/闭锁研究.《电力系统保护与控制》.2010,第38卷(第06期), |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102495363A (en) | 2012-06-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102495363B (en) | Method for distinguishing shutting of +/-800 kV extra-high voltage direct-current valve group | |
| CN107069682B (en) | A kind of HVDC transmission line back-up protection method based on DC control system | |
| CN101478150B (en) | Intelligent diagnosis method and apparatus for power transmission and distribution line state | |
| US10106036B2 (en) | Protecting a power supply including a plurality of batteries in parallel against an external short-circuit | |
| CN103618377A (en) | Automatic bus transfer equipment system and automatic bus transfer method used for transformer substation to which small power supply is connected | |
| CN103412207A (en) | Photovoltaic grid connected inverter island detection method based on negative sequence current injection | |
| CN104362599A (en) | Method for protecting low-voltage bus of intelligent substation | |
| CN102136726B (en) | Method and device for detecting operation mode of convertor station | |
| CN106684822A (en) | Transformer dead-zone fault protection method and breaker failure protection method | |
| CN103336205A (en) | Island effect detection system and method during simultaneous injection of two harmonic current | |
| CN109638813A (en) | A kind of circuit that realizing power grid self-healing and control method | |
| CN202737463U (en) | Active filtering device with energy-saving, consumption-reducing and harmonic-treating functions | |
| CN103762612B (en) | Live access method for multi-terminal flexible direct current transmission system through disconnecting switch | |
| CN105717426A (en) | Insulation monitoring device and method capable of preventing buses from misoperation | |
| CN204694790U (en) | A kind of Hall element fault monitoring device being applicable to nuclear power plant's ups system | |
| CN204012701U (en) | A kind of one-phase earthing failure in electric distribution network identification controller | |
| CN105637605B (en) | Controlled closing device and its application method | |
| Ma et al. | On-load automatic voltage regulation system designed via thyristor for distribution transformer | |
| CN109031044A (en) | A kind of dispatching terminal substation low current single-phase earthing automatic route selection method | |
| CN208874279U (en) | A kind of improved breaker body unbalanced three-phase lines outlet loop | |
| CN111224376A (en) | Low-voltage distribution network electric shock protection method and protection device | |
| CN107147099B (en) | Arc grounding over-voltage suppressing method and system | |
| CN109103846A (en) | It is a kind of based on than mutually and than width principle pumping energy reactor protection method and system | |
| CN109546649A (en) | A kind of fault comprehensive control method of polymorphic power quality controlling device | |
| CN105892452B (en) | The calibration equipment and method of calibration of extra-high voltage station breaker same period control device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |