CN201174580Y - Monitoring circuit of converter transformer cooling system - Google Patents
Monitoring circuit of converter transformer cooling system Download PDFInfo
- Publication number
- CN201174580Y CN201174580Y CNU200820076554XU CN200820076554U CN201174580Y CN 201174580 Y CN201174580 Y CN 201174580Y CN U200820076554X U CNU200820076554X U CN U200820076554XU CN 200820076554 U CN200820076554 U CN 200820076554U CN 201174580 Y CN201174580 Y CN 201174580Y
- Authority
- CN
- China
- Prior art keywords
- control
- cooling
- side winding
- programmable controller
- circuit
- 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.)
- Expired - Fee Related
Links
Images
Landscapes
- Control Of Temperature (AREA)
Abstract
The utility model discloses a monitoring circuit for a cooling system of a convertor transformer, belonging to the power transmission and distribution technical field. The circuit is used for solving the problem of cooling the convertor transformer. The utility model adopts the technical proposal that the circuit consists of a switching signal input circuit, a simulating signal input circuit, a programmable controller and an executive circuit. Output ends of the switching signal input circuit and the simulating signal input circuit are connected with the input end of the programmable controller. The executive circuit consists of a cooler control contactor. Control coils of the contactor are connected with the output end of the programmable controller. Contacts of each contractor are connected with a blower or an oil pump in the cooler. Compared with the control circuit of the prior convertor transformer cooling system, the circuit is complete in control function, high in operational reliability, and can meet the requirement of the direct current transformer for the cooling system.
Description
Technical field
The utility model relates to a kind of supervisory circuit that is used for direct current electric transmission and transformation converter transformer cooling system, belongs to the power transmission and distribution technical field.
Background technology
Cooling system is an important component part of transformer, to the important role in safe operation of transformer.The quality of transformer cooling system performance depends on its control system to a great extent, the cooling control system of conventional AC transformer only utilizes simple relay circuit to finish control to cooling system self, its circuit structure is simple, function singleness, reliability is low, can't implement monitoring to transformer effectively, its control signal can not reflect the variation of transformer load and operation conditions in real time, and because the load variations dielectric, hot spot temperature of winding and the pasta variation of temperature situation that cause, also fail to take into full account the control features of converter transformer.
At present, the direct current electric transmission and transformation technology starts to walk, and converter transformer is had higher requirement to the Performance And Reliability of cooling system, and traditional converter transformer cooling system supervisory circuit has been difficult to meet the demands.
Summary of the invention
The purpose of this utility model be to provide a kind of operational reliability, controlled function perfect, be suitable for the converter transformer cooling system supervisory circuit that the direct current electric transmission and transformation system uses.
The alleged problem of the utility model realizes with following technical proposals:
A kind of converter transformer cooling system supervisory circuit, form by switching signal input circuit, analog signal input circuit, programmable controller PLC and executive circuit, the input of the output termination programmable controller PLC of described switching signal input circuit and analog signal input circuit, described executive circuit is made of the cooler control contactor, the control coil of contactor connects the output of programmable controller PLC, and the contact of each contactor connects blower fan or the oil pump in the cooler.
Above-mentioned converter transformer cooling system supervisory circuit, described switching signal input circuit is formed set button Ks and reset button K by one-level cooling control two-position relay J1, secondary cooling control relay J2, three grades of cooling control relay J3, one-level cold oil surface temperature K switch t1, one-level cooling net side winding temperature K switch t2, one-level cooling valve side winding temperature K switch t3, secondary cold oil surface temperature K switch t4, secondary cooling net side winding temperature K switch t5 and secondary cooling valve side winding temperature K switch t6
RIt is the control switch of one-level cooling control two-position relay J1, the control coil of common control secondary cooling control relay J2 after the normally opened contact J2-2 of described secondary cooling control relay J2 connects with one-level cold oil surface temperature K switch t1, simultaneously, also be attempted by on the described control loop after one-level cooling net side winding temperature K switch t2 and the one-level cooling valve side winding temperature K switch t3 parallel connection, the control coil of three grades of cooling control relay J3 of common control after the normally opened contact J3-2 of described three grades of cooling control relay J3 connects with secondary cold oil surface temperature K switch t4, simultaneously, also be attempted by in the described control loop after secondary cooling net side winding temperature K switch t5 and the secondary cooling valve side winding temperature K switch t6 parallel connection; I4.0, I4.1, I4.2 are respectively three switching signal input ports of programmable controller PLC, and the normally opened contact J3-1 of the normally opened contact J1-1 of described one-level cooling control two-position relay J1, a normally opened contact J2-1, the three grades of cooling control relay J3 of secondary cooling control relay J2 is serially connected in respectively in the input circuit of three switching signal input ports of described programmable controller PLC.
Above-mentioned converter transformer cooling system supervisory circuit, described analog signal input circuit is by current on line side instrument transformer CT1, current on valve side instrument transformer CT2, voltage on valve side instrument transformer PT and four temperature sensors are formed, the signal output part of described current on line side instrument transformer CT1 connects the PEW256 end of programmable controller PLC through converter T1, the signal output part of described current on valve side instrument transformer CT2 is held through the PEW260 that converter T2 meets programmable controller PLC, and the signal output part of described voltage on valve side instrument transformer PT connects the PEW268 end of programmable controller PLC through converter T3; Described four temperature sensors are respectively net side winding temperature transducer Rt1, valve side winding temperature transducer Rt2, transformer oil surface temperature transducer Rt3 and environment temperature sensor Rt4, a their end ground connection, the other end connect PEW258, PEW262, PEW264 and the PEW266 end of programmable controller PLC respectively.
Above-mentioned converter transformer cooling system supervisory circuit, described cooler control contactor comprises four power contactors and three fan contactors, the normally opened contact of four power contactors is controlled the current supply circuit of four coolers respectively, its control coil is connected to Q0.4, Q0.5, Q0.6 and the Q0.7 end of programmable controller PLC respectively, the control coil of three fan contactors is connected to Q0.0, Q0.1 and the Q0.2 end of programmable controller PLC respectively, and four normally opened contacts of each fan contactor are controlled a fan in four coolers respectively.
Above-mentioned converter transformer cooling system supervisory circuit, the closed temperature set point of described one-level cold oil surface temperature K switch t1, one-level cooling net side winding temperature K switch t2, one-level cooling valve side winding temperature K switch t3, secondary cold oil surface temperature K switch t4, secondary cooling net side winding temperature K switch t5, secondary cooling valve side winding temperature K switch t6 is separately positioned on 30 ℃～40 ℃, 55 ℃～65 ℃, 55 ℃～65 ℃, 41 ℃～50 ℃, 66 ℃～75 ℃, 66 ℃～75 ℃ according to the concrete running status of converter transformer.
The utility model utilizes the switching signal input circuit to gather the temperature switch signal and the manual control signal of transformer diverse location, utilize analog signal input circuit to gather the temperature analog signal of transformer diverse location and transformer voltage, current signal in real time, programmable controller PLC analyzes the various signals of being gathered, and, control the operation of each cooler to executive circuit output control signal.This supervisory circuit is implemented Multistage Control according to different situations to cooler, has improved control performance, has improved the control effect.Adopt the space signal of analog signal, improved the reliability of supervisory circuit as the temperature switch signal.Control circuit with traditional converter transformer cooling system is compared, and the utility model controlled function is perfect, operational reliability is high, can satisfy the requirement of converter transformer to cooling system.
Description of drawings
Fig. 1 is the electric theory diagram of converter transformer cooling system supervisory circuit;
Fig. 2 is the electrical schematic diagram of switching signal input circuit;
Fig. 3 is an electrical schematic diagram of the present utility model;
Fig. 4 is the electrical schematic diagram of cooler major loop.
Each symbol is among the figure: J1, one-level cooling control two-position relay, J1-1, the normally opened contact of one-level cooling control two-position relay J1, J2, secondary cooling control relay, J2-1, J2-2, the normally opened contact of secondary cooling control relay J2, J3, three grades of cooling relays, J3-1, J3-2, the normally opened contact of three grades of cooling relay J 3, Kt1, one-level cold oil surface temperature switch (being used to measure the pasta temperature), Kt2, one-level cooling net side winding temperature switch (being used to measure net side winding temperature), Kt3, one-level cooling valve side winding temperature switch (being used to measure valve side temperature), Kt4, secondary cold oil surface temperature switch (being used to measure the pasta temperature), Kt5, secondary cooling net side winding temperature switch (being used to measure net side winding temperature), Kt6, secondary cooling valve side winding temperature switch (being used to measure valve side winding temperature), Ks, the set button, K
RReset button, CT1, the current on line side instrument transformer, CT2, the current on valve side instrument transformer, PT, the voltage on valve side instrument transformer, Rt1, net side winding temperature transducer, Rt2, valve side winding temperature transducer, Rt3, transformer oil surface temperature transducer, Rt4, environment temperature sensor, T1, T2, the T3 converter, JL1, the first Cooler Power contactor, JL2, the second Cooler Power contactor, JL3, the 3rd Cooler Power contactor, JL4, the 4th Cooler Power contactor, JL1-1, the normally opened contact of the first Cooler Power contactor, JL2-1, the normally opened contact of the second Cooler Power contactor, JL3-1, the normally opened contact of the 3rd Cooler Power contactor, JL4-1, the normally opened contact of the 4th Cooler Power contactor, JF1, the first fan contactor, JF2, the second thermantidote contactor, JF3, the three fan contactor, JF1-1, JF1-2, JF1-3, JF1-3, the normally opened contact of the first fan contactor, JF2-1, JF2-2, JF2-3, JF2-4, the normally opened contact of the second thermantidote contactor, JF3-1, JF3-2, JF3-3, JF3-4, the normally opened contact of three fan contactor, PLC, programmable controller, LQ1, first cooler, LQ2, second cooler, LQ3, the 3rd cooler, LQ4, the 4th cooler, MF11, MF12, MF13, the first cooler fan, MF21, MF22, MF23, the second cooler fan, MF31, MF32, MF33, the 3rd cooler fan, MF41, MF42, MF43, the 4th cooler fan, MP1, the first cooler oil pump, MP2, the second cooler oil pump, MP3, the 3rd cooler oil pump, MP4, the 4th cooler oil pump.
Embodiment
This supervisory circuit is implemented three grades of cooling controls according to the two-stage temperature signal to cooler.Implement one-level cooling control by one-level cooling control two-position relay, one-level cold oil surface temperature K switch t1, one-level cooling net side winding temperature K switch t2 and one-level cooling valve side winding temperature K switch t3 gather secondary cooling control temperature signal, and secondary cold oil surface temperature K switch t4, secondary cooling net side winding temperature K switch t5 and secondary cooling valve side winding temperature K switch t6 gather three grades of cooling control temperature signals.(alleged valve side is a finger direct current network side in the utility model; The net side is a finger AC network side.)
Referring to Fig. 2, J1 is an one-level cooling control two-position relay, when set button Ks presses, its normally opened contact J1-1 closure, give programmable controller PLC input cooler starting-up signal, if the temperature of each temperature monitoring point is all less than one-level chilling temperature value at this moment, then programmable controller PLC implements one-level cooling control to cooler, as reset button K
RWhen pressing, its normally opened contact J1-1 opens, and gives programmable controller PLC input cooler off signal.
When net side winding temperature is increased to the closed temperature of one-level cooling net side winding temperature K switch t2 or valve side winding temperature when being increased to the closed temperature of one-level cooling valve side winding temperature K switch t3, one-level cooling net side winding temperature K switch t2 or one-level cooling valve side winding temperature K switch t3 closure, the control coil of secondary cooling control relay J2 is got, its normally opened contact J2-1, the J2-2 closure, give programmable controller PLC input one-level coolant temperature signal, if the temperature of each temperature monitoring point is all less than secondary chilling temperature value at this moment, then programmable controller PLC implements secondary cooling control to cooler.Because the pasta variation of temperature generally lags behind than the variation of winding temperature, the back pasta temperature that raises winding temperature also can rise thereupon, make one-level cold oil surface temperature K switch t1 closure, when winding temperature is reduced to less than one-level chilling temperature value, the pasta temperature may be still greater than one-level chilling temperature value, though this moment Kt2, Kt3 disconnects, but one-level cold oil surface temperature K switch t1 is in closure state, the normally opened contact J2-2 of secondary cooling control relay J2 also is in closure state, secondary cooling control relay J2 is kept closed, reduce until the pasta temperature, one-level cold oil surface temperature K switch t1 disconnects.
When net side winding temperature is increased to the closed temperature of secondary cooling net side winding temperature K switch t5 or valve side winding temperature when being increased to the closed temperature of secondary cooling valve side winding temperature K switch t6, secondary cooling net side winding temperature K switch t5 or secondary cooling valve side temperature switch Kt6 closure, the control coil of three grades of cooling relay J 3 is got, its normally opened contact J3-1, J3-2 closure, give programmable controller PLC input secondary coolant temperature signal, programmable controller PLC implements three grades of cooling controls to cooler.Because the pasta temperature is littler than winding temperature decrease speed, when winding temperature is reduced to less than secondary chilling temperature value, the pasta temperature may be still greater than secondary chilling temperature value, though this moment, Kt5, Kt6 disconnected, but secondary cold oil surface temperature K switch t4 still is in closure state, three grades of cooling relay J 3 are kept closed, and reduce until the pasta temperature, and secondary cold oil surface temperature K switch t4 disconnects.
Referring to Fig. 3, the effect of T1, T2, T3 converter is the signal that the curtage signal transformation that current on line side instrument transformer CT1, current on valve side instrument transformer CT2, voltage on valve side instrument transformer PT are exported is complementary for the input with PLC.Temperature analog signal and switching value signal that current on line side instrument transformer CT1, current on valve side instrument transformer CT2, voltage on valve side instrument transformer PT and four temperature sensors are gathered participate in control simultaneously, when temperature analog signal surpassed one-level, secondary chilling temperature set point, programmable controller PLC implemented secondary, three grades of cooling controls to cooler equally.Two kinds of signals are equipped with mutually, have improved the reliability of supervisory circuit.
Referring to Fig. 4, each cooler comprises an oil pump and three fans, and when the power contactor of cooler was closed, its oil pump was entry into service, and each fan will just be worked when the power contactor of cooler and fan contactor are closed simultaneously.
During one-level cooling control, three cooler runnings, each cooler has two fan works.
During secondary cooling control, three cooler runnings, three fans of each cooler are all worked.
During three grades of controls, four coolers all turn round, and three fans of each cooler are all worked.
The model of programmable controller PLC is SM331 8XAI, certainly, also can select other model.
Each temperature switch is provided with two pairs of contacts, during concrete enforcement, in order further to improve reliability of the present utility model, two pairs of contacts of each temperature switch should be inserted two independently in the temperature signal collection loop, and the signal of being gathered is input programmable logic controller PLC simultaneously.
Claims (5)
1, a kind of converter transformer cooling system supervisory circuit, it is characterized in that, it is made up of switching signal input circuit, analog signal input circuit, programmable controller (PLC) and executive circuit, the input of the output termination programmable controller (PLC) of described switching signal input circuit and analog signal input circuit, described executive circuit is made of the cooler control contactor, the control coil of contactor connects the output of programmable controller (PLC), and the contact of each contactor connects blower fan or the oil pump in the cooler.
2, according to the described converter transformer cooling system of claim 1 supervisory circuit, it is characterized in that, described switching signal input circuit is by one-level cooling control two-position relay (J1), secondary cooling control relay (J2), three grades of cooling control relays (J3), one-level cold oil surface temperature switch (Kt1), one-level cooling net side winding temperature switch (Kt2), one-level cooling valve side winding temperature switch (Kt3), secondary cold oil surface temperature switch (Kt4), secondary cooling net side winding temperature switch (Kt5) and secondary cooling valve side winding temperature switch (Kt6) are formed set button (Ks) and reset button (K
R) be the control switch of one-level cooling control two-position relay (J1), the control coil of common control secondary cooling control relay (J2) after a normally opened contact (J2-2) of described secondary cooling control relay (J2) is connected with one-level cold oil surface temperature switch (Kt1), simultaneously, also be attempted by on the described control loop after one-level cooling net side winding temperature switch (Kt2) and the parallel connection of one-level cooling valve side winding temperature switch (Kt3), the control coil of common three grades of cooling control relays of control (J3) after a normally opened contact (J3-2) of described three grades of cooling control relays (J3) is connected with secondary cold oil surface temperature switch (Kt4), simultaneously, also be attempted by in the described control loop after secondary cooling net side winding temperature switch (Kt5) and the parallel connection of secondary cooling valve side winding temperature switch (Kt6); I4.0, I4.1, I4.2 are respectively three switching signal input ports of programmable controller (PLC), and a normally opened contact (J2-1) of a normally opened contact (J1-1) of described one-level cooling control two-position relay (J1), secondary cooling control relay (J2), a normally opened contact (J3-1) of three grades of cooling control relays (J3) are serially connected in respectively in the input circuit of three switching signal input ports of described programmable controller (PLC).
3, according to the described converter transformer cooling system of claim 2 supervisory circuit, it is characterized in that, described analog signal input circuit is by current on line side instrument transformer (CT1), current on valve side instrument transformer (CT2), voltage on valve side instrument transformer (PT) and four temperature sensors are formed, the signal output part of described current on line side instrument transformer (CT1) connects the PEW256 end of programmable controller (PLC) through converter (T1), the signal output part of described current on valve side instrument transformer (CT2) is held through the PEW260 that converter (T2) connects programmable controller (PLC), and the signal output part of described voltage on valve side instrument transformer (PT) connects the PEW268 end of programmable controller (PLC) through converter (T3); Described four temperature sensors are respectively net side winding temperature transducer (Rt1), valve side winding temperature transducer (Rt2), transformer oil surface temperature transducer (Rt3) and environment temperature sensor (Rt4), a their end ground connection, the other end connect PEW258, PEW262, PEW264 and the PEW266 end of programmable controller (PLC) respectively.
4, according to the described converter transformer cooling system of claim 3 supervisory circuit, it is characterized in that, described cooler control contactor comprises four power contactors and three fan contactors, the normally opened contact of four power contactors is controlled the current supply circuit of four coolers respectively, its control coil is connected to the Q0.4 of programmable controller (PLC) respectively, Q0.5, Q0.6 and Q0.7 end, the control coil of three fan contactors is connected to the Q0.0 of programmable controller (PLC) respectively, Q0.1, with the Q0.2 end, four normally opened contacts of each fan contactor are controlled a fan in four coolers respectively.
5, according to claim 2,3 or 4 described converter transformer cooling system supervisory circuits, described one-level cold oil surface temperature switch (Kt1), one-level cooling net side winding temperature switch (Kt2), one-level cooling valve side winding temperature switch (Kt3), secondary cold oil surface temperature switch (Kt4), secondary cooling net side winding temperature switch (Kt5), the closed temperature set point of secondary cooling valve side winding temperature switch (Kt6) is separately positioned on 30 ℃～40 ℃ according to the concrete running status of converter transformer, 55 ℃～65 ℃, 55 ℃～65 ℃, 41 ℃～50 ℃, 66 ℃～75 ℃, 66 ℃～75 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU200820076554XU CN201174580Y (en) | 2008-03-19 | 2008-03-19 | Monitoring circuit of converter transformer cooling system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU200820076554XU CN201174580Y (en) | 2008-03-19 | 2008-03-19 | Monitoring circuit of converter transformer cooling system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201174580Y true CN201174580Y (en) | 2008-12-31 |
Family
ID=40201708
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU200820076554XU Expired - Fee Related CN201174580Y (en) | 2008-03-19 | 2008-03-19 | Monitoring circuit of converter transformer cooling system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201174580Y (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102722193A (en) * | 2012-06-25 | 2012-10-10 | 甘景福 | Method for slowing down aging of solid insulation of oil-paper insulating transformer |
| CN103095282A (en) * | 2013-02-05 | 2013-05-08 | 中国能源建设集团广东省电力设计研究院 | Optimized connector device of direct current control and protection system and converter transformer and implementation method thereof |
| CN104238590A (en) * | 2013-06-09 | 2014-12-24 | 成都昊地科技有限责任公司 | Novel intelligent cooling device of transformer |
| CN105575616A (en) * | 2016-01-27 | 2016-05-11 | 国网山西省电力公司运城供电公司 | Automatic cooling system for transformer |
| CN110517849A (en) * | 2019-07-29 | 2019-11-29 | 江苏星驰变压器有限公司 | A kind of oil-immersed type transformer and its detection method for reducing cooling oil convective resistance and work condition state |
| CN110957109A (en) * | 2019-11-25 | 2020-04-03 | 国网四川省电力公司广安供电公司 | Oil-immersed self-cooling transformer cooling system |
-
2008
- 2008-03-19 CN CNU200820076554XU patent/CN201174580Y/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102722193A (en) * | 2012-06-25 | 2012-10-10 | 甘景福 | Method for slowing down aging of solid insulation of oil-paper insulating transformer |
| CN102722193B (en) * | 2012-06-25 | 2014-02-19 | 甘景福 | Method for slowing down aging of solid insulation of oil-paper insulating transformer |
| CN103095282A (en) * | 2013-02-05 | 2013-05-08 | 中国能源建设集团广东省电力设计研究院 | Optimized connector device of direct current control and protection system and converter transformer and implementation method thereof |
| CN103095282B (en) * | 2013-02-05 | 2015-06-03 | 中国能源建设集团广东省电力设计研究院有限公司 | Optimized connector device of direct current control and protection system and converter transformer and implementation method thereof |
| CN104238590A (en) * | 2013-06-09 | 2014-12-24 | 成都昊地科技有限责任公司 | Novel intelligent cooling device of transformer |
| CN105575616A (en) * | 2016-01-27 | 2016-05-11 | 国网山西省电力公司运城供电公司 | Automatic cooling system for transformer |
| CN110517849A (en) * | 2019-07-29 | 2019-11-29 | 江苏星驰变压器有限公司 | A kind of oil-immersed type transformer and its detection method for reducing cooling oil convective resistance and work condition state |
| CN110957109A (en) * | 2019-11-25 | 2020-04-03 | 国网四川省电力公司广安供电公司 | Oil-immersed self-cooling transformer cooling system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN201174580Y (en) | Monitoring circuit of converter transformer cooling system | |
| CN201156681Y (en) | Intelligent power distribution system | |
| CN102130462B (en) | Intelligent electrical load unbalance compensation device | |
| CN101286654A (en) | Energy saver for intelligent control of power system load transfer | |
| CN103267893B (en) | Balanced distribution intelligent electric meter | |
| CN206564487U (en) | A kind of switching circuit of the mother of two inlet wire of low-tension switch cabinet one | |
| CN103248257B (en) | Single-module seamless thermal input and ablation control method in parallel inverter power supply | |
| CN201774496U (en) | Intelligent economizer for hydraulic press | |
| CN200996874Y (en) | Intelligent monitor of cooler for large transformer | |
| CN201536254U (en) | Protector for power transformer | |
| CN205583704U (en) | Not balancing control system of change secondary side is joined in marriage in low district of presenting a theatrical performance as last item on a programme | |
| CN105305474B (en) | A kind of network load Fast-Balance regulating system and its control method | |
| CN101609990A (en) | Intelligent three-phase electricity-saving protection controller | |
| CN110829583A (en) | Power supply switching monitoring device of main transformer cooler | |
| CN202663123U (en) | Programmable logic controller (PLC)-based iron alloy smelting electric arc furnace low voltage reactive compensation device | |
| CN109660178B (en) | Efficient motion control system and method for motor under constant-frequency working condition | |
| CN211777945U (en) | Circulating pump frequency conversion cabinet | |
| CN106469902A (en) | 10KV phase-loss low-voltage intelligent tripping protection device | |
| CN201639541U (en) | Phase adjusting transformer monitoring circuit | |
| CN201869151U (en) | Intelligent control system with failure isolation for economic operation of transformer | |
| CN203177326U (en) | Control device for automatic frequency conversion water replenishing of heat exchanger unit | |
| CN205489034U (en) | Block terminal device of oven | |
| CN209860600U (en) | Low-voltage reactive dynamic compensation device | |
| CN212930388U (en) | Central air conditioning frequency conversion control system | |
| CN203445598U (en) | Overload protection circuit of refrigerating unit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Assignee: Tianwei Baobian (Qinhuangdao) Transformer Co., Ltd. Assignor: Baoding Tianwei Group Co., Ltd. Contract fulfillment period: 2009.4.20 to 2015.8.20 Contract record no.: 2009130000088 Denomination of utility model: Monitoring circuit of converter transformer cooling system Granted publication date: 20081231 License type: Exclusive license Record date: 20090623 |
|
| LIC | Patent licence contract for exploitation submitted for record |
Free format text: EXCLUSIVE LICENSE; TIME LIMIT OF IMPLEMENTING CONTACT: 2009.4.20 TO 2015.8.20; CHANGE OF CONTRACT Name of requester: TIANWEI BAOBIAN( QINHUANGDAO )TRANSFORMER CO., LTD Effective date: 20090623 |
|
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20081231 Termination date: 20130319 |