CN204835522U - Transformer dc magnetic biasing electric current suppression device - Google Patents
Transformer dc magnetic biasing electric current suppression device Download PDFInfo
- Publication number
- CN204835522U CN204835522U CN201520598803.1U CN201520598803U CN204835522U CN 204835522 U CN204835522 U CN 204835522U CN 201520598803 U CN201520598803 U CN 201520598803U CN 204835522 U CN204835522 U CN 204835522U
- Authority
- CN
- China
- Prior art keywords
- transformer
- magnetic bias
- bias current
- restraining device
- current restraining
- 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.)
- Withdrawn - After Issue
Links
Landscapes
- Emergency Protection Circuit Devices (AREA)
Abstract
The utility model discloses a transformer dc magnetic biasing electric current suppression device, the device is including nonlinearity (PTC) thermistor, zinc oxide resistance, two ball electrodes of controllable gap, current sensor, voltage sensor, digital monitoring ware and remote monitering system, zinc oxide resistance is parallelly connected with nonlinearity (PTC) thermistor for protection nonlinearity (PTC) thermistor prevents that transformer neutral point voltage is too high, distance between the two ball electrodes of controllable gap can be adjusted as required, adjusted, this device simple structure, volume are very little, simple to operate, fund input are less, do not need controlgear, ground connection mode when not changing transformer normal operating, this device has easy operation, has the influence basically, can effectively reduce characteristics such as circuit short -circuit current line protection.
Description
Technical field
The utility model relates to operation of power networks control technology, more particularly, relates to a kind of transformer DC magnetic bias current restraining device.
Background technology
In recent years, along with rapid economic development, energy demand increases fast, and remote, high-capacity direct current power transmission engineering develops rapidly.When DC line one pole take the earth as loop operation, huge direct current is formed loop with the earth, flows through and can have an impact to neighbouring AC system from the earth.When one pole take the earth as loop operation, can form potential difference between AC Substation, direct current will flow through Transformer Winding by transformer neutral point and transmission line, make transformer occur bias phenomenon.The zone of saturation that in AC network, neutral-point solid ground transformer is operated in excitation curve can cause that its vibration is violent, noise poly-ly rises, overheated and ac grid voltage resultant distortion rate significantly raises, and can cause the damage of transformer time serious.
DC magnetic bias current can be summarized as follows the impact of transformer:
(1) noise increases,
(2) on the impact of voltage waveform,
(3) transformer copper loss increases,
(4) Transformers Iron Loss increases,
Direct current grounding pole earth current has following features to substation transformer impact: the time uncertain (fault or occur between turn(a)round), action time short (several hours), earth current amplitude large (upper kiloampere), positive-negative polarity is uncertain, affects large feature to transformer.At present, kiowatt has recognized the seriousness that direct current grounding pole earth current affects substation transformer at home.Present stage has the method and apparatus of multiple suppression transformer DC magnetic bias current, mainly contains electric capacity and seals in the method and apparatus such as small resistor, reverse dc, potential compensation every straight, neutral point.
Utility model content
The purpose of this utility model is: provide a kind of occupation of land less, cost is very low, there is not the impact on each side such as system overvoltage, insulation coordination, relaying protections, also there is not the device of the risk causing system resonance; Meanwhile, do not deposit power electronics equal controller, decrease the equipment caused because of power electronic equipment fault and be failure to actuate or the transformer DC magnetic bias current restraining device of misoperation.
To achieve these goals, the utility model provides a kind of transformer DC magnetic bias current restraining device, between transformer neutral point and earth point, be provided with non-linear thermistor, described non-linear temperature-sensitive resistant series is connected between transformer neutral point and earth point.
Further, described transformer DC magnetic bias current restraining device is also provided with ZnO resistors, and described ZnO resistors and described non-linear temperature-sensitive resistor coupled in parallel, be serially connected with between described transformer neutral point and earth point.
Further, described transformer DC magnetic bias current restraining device is also provided with control gap two ball electrode, and described control gap two ball electrode and described non-linear temperature-sensitive resistor coupled in parallel, be serially connected with between described transformer neutral point and earth point.
Further, described transformer DC magnetic bias current restraining device is also provided with control gap two ball electrode, and described control gap two ball electrode is in parallel with described non-linear thermistor and ZnO resistors, is serially connected with between described transformer neutral point and earth point.
Further, described transformer DC magnetic bias current restraining device is also provided with current sensor, and for measuring neutral point current, described current sensor is serially connected with between described transformer DC magnetic bias current restraining device and earth point.
Further, described transformer DC magnetic bias current restraining device is also provided with voltage sensor, and for measuring described transformer DC magnetic bias current restraining device voltage, described voltage sensor is connected between described transformer neutral point and earth point.
Further, described transformer DC magnetic bias current restraining device is also provided with digital monitor system, for monitoring described current sensor, voltage sensor, grasp equipment running status, described digital monitor system is connected with described current sensor, voltage sensor respectively.
Further, described transformer DC magnetic bias current restraining device is also provided with long distance control system, and for remote monitoring and regulate and control each equipment operation condition, described long distance control system is connected with described digital monitor system.
Whether electric capacity is that isolated DC is relatively more thorough every straight device advantage, by switch control rule by electric capacity and spark gap bypass, also very convenient.Shortcoming is that package unit is comparatively complicated, takes up an area more, cost very high (up to 1,000,000 RMB), realizes difficulty still comparatively large, and for each side such as system overvoltage, insulation coordination to affect X factor more, check difficulty.In addition, seal in electric capacity and also likely cause system resonance.With electric capacity compared with the straight device; this device (nonlinear resistance is every straight device) is not owing to having bulky capacitor, and take up an area less, cost is very low; there is not the impact on each side such as system overvoltage, insulation coordination, relaying protections, there is not the risk causing system resonance yet.Meanwhile, this device does not deposit power electronics equal controller, decreases the equipment caused because of power electronic equipment fault and is failure to actuate or misoperation.In addition, this device can also reduce line short circuit current.
Between neutral point and earth mat, seal in a resistance is the small resistor of several ohm, and the direct current that neutral point can be made to flow into obviously reduces, and reaches acceptable degree in engineering.Neutral point seals in impedance and creates impact to system zero order parameter, and then also can have influence on adjusting of zero-sequenceprotection.The shortcoming of this scheme cannot offset direct current completely to flow into from neutral point, but due to its definite conception, be relatively easy to realize, also less on the impact of system.Compared with small resistor device, the resistance of this device (nonlinear resistance is every straight device) can increase with the increase of electric current, greatly can reduce DC magnetic bias current, even, can reach the basic effect eliminating DC magnetic bias current.Meanwhile, under normal circumstances (without earth current impact), nonlinear resistance is very little, not influential system Zero sequence parameter, does not affect adjusting of zero-sequenceprotection.
Reverse dc and the complexity of the device involved by potential compensation method, be difficult to realize, present stage there is no application.And this device has that structure is simple, volume is very little, easy for installation, fund input is less, do not change earthing mode when transformer normally runs, on route protection without advantages such as impacts, be beneficial in engineering and apply.
On transformer DC magnetic bias current size, this device action situation, nonlinear resistance, voltage can be sent to grid operating monitoring department in real time, and grid operating monitoring department can grasp the ruuning situation of transformer and this device in real time.
This device, compared with other devices, has very large advantage: this apparatus structure is simple, volume is very little, easy for installation, fund input is less, do not need control appliance, do not change earthing mode when transformer normally runs, on route protection substantially without affecting, effectively can reducing the features such as line short circuit current.
Accompanying drawing explanation
Fig. 1 is the structural representation of a kind of transformer DC magnetic bias current restraining device of the utility model.
Embodiment
In order to make the purpose of this utility model, technical scheme and Advantageous Effects thereof more clear, below in conjunction with the drawings and specific embodiments, the utility model is further elaborated.Should be understood that, the embodiment described in this specification is only used to explain the utility model, is not intended to limit the utility model.
Refer to Fig. 1, a kind of transformer DC magnetic bias current restraining device of the utility model, operation principle of the present utility model: the composition structure of this system refers to Fig. 1, the functional requirements description of critical piece: non-linear (PTC) thermistor, non-linear (PTC) thermistor temp and room temperature is close, resistance very little (being less than 1 ohm), flow through the electric current of non-linear (PTC) thermistor larger time, thermistor causes temperature to rise due to heating power increase, and resistance can sharply increase.ZnO resistors is in parallel with non-linear (PTC) thermistor, for the protection of non-linear (PTC) thermistor, prevents transformer neutral point overtension.Distance between the ball electrode of control gap two can adjust as required, adjust.CT is current sensor, for measuring neutral point current, can measure direct current, alternating current.PT is voltage sensor, for measuring neutral point current, can measure direct current, alternating voltage.Digital monitor and long distance control system measure electric current, magnitude of voltage for monitoring CT, PT, grasp equipment running status.
Concrete principle of device is as follows:
This device is loaded on transformer neutral point, when transformer normally works, the electric current flowing through transformer neutral point is very little, non-linear (PTC) thermistor temp and room temperature is close, resistance very little (being less than 1 ohm), series connection can not hinder electric current to pass through in circuit, transformer neutral point is equivalent to, through very little grounding through resistance, even can think direct ground connection.Now; if there is AC system short trouble; short trouble zero-sequence current will flow through non-linear (PTC) thermistor; because fault generation non-linear hour (PTC) thermistor resistance is less be equivalent to the direct ground connection of system, this device does not affect circuit Control protection definite value.The flowing continuously through of short trouble zero-sequence current thereupon, non-linear (PTC) thermistor causes temperature to rise due to heating power increase, resistance can sharply increase, and therefore, non-linear (PTC) thermistor can also play the effect of limit value short circuit current.
When DC transmission engineering is run for circuit type with one pole the earth, direct current earth current will flow into AC system by transformer neutral point, the electric current now flowing through non-linear (PTC) thermistor is larger, thermistor causes temperature to rise due to heating power increase, resistance can sharply increase, by transformer centerline current limit in lower level, will greatly reduce the earth current flowing into AC system, most of earth current will be propagated in soil.Now, if there is AC system short trouble, because the resistance of the impact of earth current non-linear (PTC) thermistor is very large, the effect of limiting short-circuit current will be played.But now transformer is equivalent to through large grounding through resistance, although can not have an impact by power line main protection, can produce certain impact owing to changing system zero sequence resistance on zero sequence current protection.When DC transmission engineering is recovered normally to run with bipolar balance mode, direct current earth current disappears, and the resistance of non-linear (PTC) thermistor can return to rapidly original level.
In above-mentioned situation, when short circuit current effect, when the overvoltage at non-linear (PTC) thermistor two ends is larger, exceed ZnO resistors (lightning arrester) operating valve value, ZnO resistors will action leakage current, reduces transformer neutral point overvoltage.The ball gap of controllable distance is for the protection of non-linear (PTC) thermistor and ZnO resistors; prevent the not operating transformer neutral point voltage caused of ZnO resistors excessive; when transformer neutral point voltage is excessive; the disruptive discharge of ball gap forms discharge path, reduces transformer neutral point overvoltage.
The announcement of book according to the above description, the utility model those skilled in the art can also carry out suitable change and amendment to above-mentioned execution mode.Therefore, the utility model is not limited to embodiment disclosed and described above, also should fall in the protection range of claim of the present utility model modifications and changes more of the present utility model.In addition, although employ some specific terms in this specification, these terms just for convenience of description, do not form any restriction to the utility model.
Claims (8)
1. a transformer DC magnetic bias current restraining device, is characterized in that: between transformer neutral point and earth point, be provided with non-linear thermistor, and described non-linear temperature-sensitive resistant series is connected between transformer neutral point and earth point.
2. transformer DC magnetic bias current restraining device according to claim 1, it is characterized in that, described transformer DC magnetic bias current restraining device is also provided with ZnO resistors, described ZnO resistors and described non-linear temperature-sensitive resistor coupled in parallel, be serially connected with between described transformer neutral point and earth point.
3. transformer DC magnetic bias current restraining device according to claim 1, it is characterized in that, described transformer DC magnetic bias current restraining device is also provided with control gap two ball electrode, described control gap two ball electrode and described non-linear temperature-sensitive resistor coupled in parallel, be serially connected with between described transformer neutral point and earth point.
4. transformer DC magnetic bias current restraining device according to claim 2, it is characterized in that, described transformer DC magnetic bias current restraining device is also provided with control gap two ball electrode, described control gap two ball electrode is in parallel with described non-linear thermistor and ZnO resistors, is serially connected with between described transformer neutral point and earth point.
5. according to described transformer DC magnetic bias current restraining device arbitrary in Claims 1-4, it is characterized in that, described transformer DC magnetic bias current restraining device is also provided with current sensor, for measuring neutral point current, described current sensor is serially connected with between described transformer DC magnetic bias current restraining device and earth point.
6. transformer DC magnetic bias current restraining device according to claim 5, it is characterized in that, described transformer DC magnetic bias current restraining device is also provided with voltage sensor, for measuring described transformer DC magnetic bias current restraining device voltage, described voltage sensor is connected between described transformer neutral point and earth point.
7. transformer DC magnetic bias current restraining device according to claim 6, it is characterized in that, described transformer DC magnetic bias current restraining device is also provided with digital monitor system, for monitoring described current sensor, voltage sensor, grasp equipment running status, described digital monitor system is connected with described current sensor, voltage sensor respectively.
8. transformer DC magnetic bias current restraining device according to claim 7, it is characterized in that, described transformer DC magnetic bias current restraining device is also provided with long distance control system, for remote monitoring and regulate and control each equipment operation condition, described long distance control system is connected with described digital monitor system.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520598803.1U CN204835522U (en) | 2015-08-10 | 2015-08-10 | Transformer dc magnetic biasing electric current suppression device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520598803.1U CN204835522U (en) | 2015-08-10 | 2015-08-10 | Transformer dc magnetic biasing electric current suppression device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204835522U true CN204835522U (en) | 2015-12-02 |
Family
ID=54693081
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201520598803.1U Withdrawn - After Issue CN204835522U (en) | 2015-08-10 | 2015-08-10 | Transformer dc magnetic biasing electric current suppression device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204835522U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105048435A (en) * | 2015-08-10 | 2015-11-11 | 中国南方电网有限责任公司电网技术研究中心 | Suppression device for direct-current biasing current of transformer and control method |
-
2015
- 2015-08-10 CN CN201520598803.1U patent/CN204835522U/en not_active Withdrawn - After Issue
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105048435A (en) * | 2015-08-10 | 2015-11-11 | 中国南方电网有限责任公司电网技术研究中心 | Suppression device for direct-current biasing current of transformer and control method |
| CN105048435B (en) * | 2015-08-10 | 2018-09-18 | 中国南方电网有限责任公司电网技术研究中心 | A kind of transformer DC magnetic bias current restraining device and control method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9396866B2 (en) | Blocker of geomagnetically induced currents (GIC) | |
| CN204012678U (en) | A kind of power distribution network multimode ground protection system | |
| CN105140897A (en) | Protection method suitable for low resistance grounding system single phase grounding fault | |
| CN105954624A (en) | Detection device | |
| CN105048435B (en) | A kind of transformer DC magnetic bias current restraining device and control method | |
| CN103368155B (en) | Capacitance DC (Direct Current) blocking on-off controllable bridge circuit for inhibiting DC magnetic bias of transformer | |
| CN205123243U (en) | Lightning protection surge protector | |
| CN203180510U (en) | Combined overvoltage protector of resistance capacitance lightening arrester | |
| CN204835522U (en) | Transformer dc magnetic biasing electric current suppression device | |
| CN105048437B (en) | A kind of combined type neutral ground composite control apparatus | |
| CN207339261U (en) | A kind of overvoltage protection device for preventing high pressure from sealing in electrification display | |
| CN201674222U (en) | Drainage device for protecting cathode of buried metal pipeline | |
| RU171479U1 (en) | Resistive grounding device | |
| CN202949205U (en) | Lightning arrester overvoltage protection device with variable voltage ratio | |
| CN204333940U (en) | A kind of intelligence revises nonlinear resistance type resonance eliminator | |
| CN106159932A (en) | 10kV neutral grounding by small resistance complexes | |
| CN103560484B (en) | Three current transformer on-line monitoring multipoint earthing of clamping piece of transformer current control devices | |
| CN106684850B (en) | High-tension transformer earth neutral system | |
| CN204835520U (en) | Dc magnetic biasing electric current suppression device of transformer | |
| CN204794020U (en) | Transformer system | |
| CN205195251U (en) | Control cabinet with collection that GIS equipment coordination used | |
| CN204290298U (en) | A kind of power transformer neutral point direct current current limliting and every stream device | |
| CN105186473B (en) | A kind of restraining device of DC magnetic bias current for transformer high-voltage winding | |
| CN103124063B (en) | Arrester overvoltage protection device with variable voltage ratio and implementation method | |
| Škuletić et al. | Analysis of surge protection performance in low-voltage AC systems with capacitive load |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| AV01 | Patent right actively abandoned |
Granted publication date: 20151202 Effective date of abandoning: 20180918 |
|
| AV01 | Patent right actively abandoned |