CN204794032U - Fault handling circuit and converter of converter braking circuit - Google Patents
Fault handling circuit and converter of converter braking circuit Download PDFInfo
- Publication number
- CN204794032U CN204794032U CN201520175547.5U CN201520175547U CN204794032U CN 204794032 U CN204794032 U CN 204794032U CN 201520175547 U CN201520175547 U CN 201520175547U CN 204794032 U CN204794032 U CN 204794032U
- Authority
- CN
- China
- Prior art keywords
- frequency converter
- braking circuit
- circuit
- controller
- converter
- 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
- 238000001514 detection method Methods 0.000 abstract description 9
- 230000007547 defect Effects 0.000 abstract description 3
- 238000000034 method Methods 0.000 description 15
- 230000001143 conditioned effect Effects 0.000 description 9
- 230000000694 effects Effects 0.000 description 4
- 239000000853 adhesive Substances 0.000 description 3
- 230000001070 adhesive effect Effects 0.000 description 3
- 230000005611 electricity Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 230000004807 localization Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000009790 rate-determining step (RDS) Methods 0.000 description 1
Landscapes
- Inverter Devices (AREA)
Abstract
The utility model discloses a fault handling circuit and converter of converter braking circuit. This fault handling circuit includes the controller, and wherein, the controller includes voltage detecting end and control pin, and the voltage detecting end is connected with the dc bus of braking circuit respectively, and control pin is connected with the gate pole of brakeing the brake pipe in the circuit. The utility model discloses improve traditional detection method and only can realize the comprehensive detection to the trouble of converter braking circuit to a certain defect that the component carries out fault detection and makes the reply in the braking circuit to can more effective protection converter system, avoid taking place incident and loss of property.
Description
Technical field
The utility model relates to frequency converter field, especially, relates to a kind of fault logic circuits and frequency converter of frequency converter braking circuit.
Background technology
Transducer drive motor, when motor braking, the decelerate of motor makes regenerated energy feed back on the DC bus of frequency converter by the inverter circuit of frequency converter, causes busbar voltage to raise.When busbar voltage exceedes limit value, frequency converter may be caused to damage.
Therefore, in converter circuit, add braking circuit, as shown in Figure 1, brake resistance R1, diode D7 and IGBT brake pipe Q7 form frequency converter braking circuit jointly.When motor braking, Q7 conducting, by R1 place in circuit, makes the form that the regenerated energy feeding back to frequency changer direct current bus flows through R1 generation heat with electric current consume.Thus play the effect of protection frequency converter, and shorten the braking time of motor.
When braking circuit breaks down, the potential safety hazard of frequency convertor system can be caused equally.When brake resistance R1 or IGBT brake pipe Q7 opens a way, then braking circuit does not access converter circuit, does not play the effect of braking protection, frequency converter may be caused to damage.And when Q7 is short-circuited, then Q7 conducting always, makes R1 be in "on" position always, long heating power may cause R1 to burn and may initiation fire.
In correlation technique, for how judging that braking circuit breaks down, and not yet provides solution at present.
Utility model content
The utility model provides a kind of fault logic circuits of frequency converter braking circuit and comprises the frequency converter of fault logic circuits of frequency converter braking circuit, for detecting and process the fault of braking circuit.
On the one hand, the utility model provides a kind of fault logic circuits of frequency converter braking circuit, comprise controller, wherein, described controller comprises: voltage detecting end and control pin, described voltage detecting end is connected with the DC bus of described frequency converter braking circuit respectively, and described control pin is connected with the gate pole of the brake pipe in described frequency converter braking circuit.
The fault logic circuits of frequency converter braking circuit also comprises:
Relay, is connected with described controller, under the control of the controller conducting or shutoff;
Contactor, one end of described contactor is connected with one end of described relay, and the other end of described contactor is connected with the live wire end controlling power supply, and the zero line side of described control power supply is connected with the other end of described relay, wherein, described control power supply is that described contactor is powered.
Described contactor comprises: multiple main contact, magnet exciting coil and auxiliary contact;
Wherein, described multiple main contact is electrically connected with multiple electric currents of alternating current respectively and controls conducting and the shutoff of described multiple electric current phase respectively, and described alternating current is input to the frequency converter be connected with described frequency converter braking circuit; One end of described magnet exciting coil is connected with the live wire end of described control power supply, and the other end of described magnet exciting coil is connected with one end of described auxiliary contact; The other end of described auxiliary contact is connected with one end of described relay.
It is inner that described relay is integrated in described controller.
The fault logic circuits of frequency converter braking circuit also comprises: the first switch and second switch;
Wherein, described first switch is connected in series between described auxiliary contact and described relay;
Described second switch is connected in the two ends of described auxiliary contact in parallel.
On the other hand, the utility model provides a kind of frequency converter, and described frequency converter comprises the fault logic circuits of frequency converter braking circuit as above.
In the scheme that the utility model provides, by the DC bus-bar voltage of controller Measurement for Inverter, and control conducting and the shutoff of brake pipe; By the amplitude of variation of frequency changer direct current bus voltage after calculating brake pipe turn-on and turn-off, judge whether braking circuit breaks down.After judgement braking circuit breaks down, automatically can cut off AC power input, thus avoid causing frequency convertor system damaging or occurring security incident.This programme can detect the fault differentiating braking circuit all sidedly, compensate for the defect that prior art detected object is incomplete.
Accompanying drawing explanation
Accompanying drawing described herein is used to provide further understanding of the present utility model, and form a application's part, schematic description and description of the present utility model, for explaining the utility model, is not formed improper restriction of the present utility model.In the accompanying drawings:
Fig. 1 is traditional converter circuit figure comprising braking circuit;
The converter circuit figure comprising controller that Fig. 2 provides for the utility model
The converter circuit figure comprising fault logic circuits that Fig. 3 provides for the utility model.
Embodiment
Hereinafter also describe the utility model in detail with reference to accompanying drawing in conjunction with the embodiments.It should be noted that, when not conflicting, the embodiment in the application and the feature in embodiment can combine mutually.
The utility model provides a kind for the treatment of circuit of frequency converter braking circuit fault, and Fig. 2 is the converter circuit figure comprising controller 1, Fig. 3 is the converter circuit figure comprising fault logic circuits.
As shown in Figure 2, for universal frequency converter circuit, six diode D1 to D6 are divided into three groups, two Diode series often in group, the diode of three groups of series connection accesses three-phase alternating current electrical input R, S and T respectively, and is got up by the diodes in parallel that three groups are connected, composition rectifier circuit.First electric capacity C1 is connected with the second electric capacity C2, and in parallel with above-mentioned rectifier circuit, form the rectifying part of frequency converter.Three-phase alternating current input, after the rectification of above-mentioned rectifying part, is converted into direct current.After brake resistance R1 is in parallel with diode D7, be connected to the collector electrode of IGBT brake pipe Q7, composition frequency converter braking circuit.Between the DC bus of above-mentioned braking circuit parallel connection access frequency converter.Six IGBT pipe Q1 to Q6 connect to form inversion circuit between two, and connect three-phase alternating current output U, V and W, for driving the motor of frequency converter rear end.
The treatment circuit of the frequency converter braking circuit fault that the utility model provides comprises controller 1, wherein, above-mentioned controller 1 comprises voltage detecting end and controls pin 2, above-mentioned voltage detecting end is connected with the DC bus of braking circuit respectively, and above-mentioned control pin 2 is connected with the gate pole of the brake pipe in braking circuit.
Above-mentioned voltage detecting end V+ and V-connects two DC buss of braking circuit respectively, for detecting DC bus-bar voltage.Above-mentioned control pin 2 is connected with the gate pole of IGBT brake pipe Q7, sends low and high level signal with the conducting of control Q7 and shutoff for controller 1.
As shown in Figure 3, the treatment circuit of braking circuit fault also comprises control power supply, contactor, relay K 4, first K switch 3 and second switch K2.Above-mentioned control power supply is that above-mentioned contactor is powered.Above-mentioned contactor comprises three main contact K1M, auxiliary contact K1NO and magnet exciting coil K1; Above-mentioned three main contact K1M are connected on three electric current phase R, S and T of the alternating current of frequency converter, to control conducting and the shutoff of three electric current phases; One end of magnet exciting coil K1 is connected with the live wire 3 of above-mentioned control power supply, the other end is connected with one end of above-mentioned auxiliary contact K1NO, the other end of auxiliary contact K1NO is connected with one end of above-mentioned first K switch 3, the other end of the first K switch 3 is connected with one end of above-mentioned relay K 4, and the other end of relay K 4 is connected with the zero line 4 of above-mentioned control power supply; Above-mentioned second switch K2 is connected in parallel on the two ends of auxiliary contact K1NO.Wherein the normality of relay K 4 is closure state, and by the conducting of above-mentioned controller 1 control relay and shutoff.
Preferably, it is inner that relay K 4 is integrated in above-mentioned controller 1, and two electric connecting terminals of relay K 4 can realize by the mode of controller 1 two pins.
In above-mentioned contactor, three main contact K1M and auxiliary contact K1NO realize linking mechanically, that is, when above-mentioned magnet exciting coil K1 is energized, and three main contact K1M adhesive conductings, and auxiliary contact K1NO adhesive conducting thereupon; And when magnet exciting coil K1 power-off, three main contact K1M disconnect, and auxiliary contact K1NO disconnects thereupon.
Add the first K switch 3 in circuit and second switch K2 is powering on and power operation for ease of frequency convertor system, wherein the first K switch 3 is normalities is closed switch, and second switch K2 is the switch that normality is off.In specific implementation, the corresponding frequency converter cut-off button of above-mentioned first K switch 3, the corresponding frequency converter power on buttons of second switch K2.When frequency converter is in the state be not energized, in magnet exciting coil K1, no current flows through, and three main contact K1M and auxiliary contact K1NO are all in off-state, and the first K switch 3 is in closure state, and second switch K2 is in off-state.Now operator presses power on buttons, that is, closed by second switch K2, and connect between the live wire 3 of above-mentioned control power supply and zero line 4 and conduct electricity, magnet exciting coil K1 is energized, then three main contact K1M and auxiliary contact K1NO adhesive; Even if now operator stops pressing power on buttons, second switch K2 recovers off-state, and due to the self-locking action of auxiliary contact K1NO, circuit still keeps connecting, frequency convertor system energising work.When needs are by frequency convertor system power-off, operator presses cut-off button, that is, the first K switch 3 disconnected, and is turned off between the live wire 3 of above-mentioned control power supply and zero line 4, magnet exciting coil K1 power-off, and three main contact K1M and auxiliary contact K1NO all disconnect; Even if now operator stops pressing cut-off button, the first K switch 3 recovers closure state, and due to the self-locking action of auxiliary contact K1NO, circuit still keeps turning off, and frequency convertor system quits work.
Treatment circuit below in conjunction with above-mentioned frequency converter braking circuit fault illustrates the detection and process that how to realize braking circuit fault.
The detection of braking circuit fault and process are comprised the following steps:
First detecting step: frequency converter have alternating current input but under the state of non-drive motors, in the first moment, controller 1 detects the first voltage V1 between the DC bus of described braking circuit.
Conducting step: above-mentioned controller 1 controls the brake pipe in conducting braking circuit.
Second detecting step: in the second moment, above-mentioned controller 1 detects the second voltage V2 between the DC bus of braking circuit, wherein, differs the first preset duration between the second moment with above-mentioned first moment.
Turn off step: above-mentioned controller 1 controls to turn off the above-mentioned brake pipe in braking circuit.
3rd detecting step: in the 3rd moment, above-mentioned controller 1 detects the tertiary voltage V3 between the DC bus of braking circuit, wherein, differs the second preset duration between the 3rd moment with above-mentioned second moment.
Determining step: when the numerical value of | V1-V3|/V3 meets first pre-conditioned, and | the numerical value of V2-V3|/V3 meet second pre-conditioned time, determine that above-mentioned braking circuit breaks down.
Wherein, first is pre-conditionedly: 0≤| V1-V3|/V3<N1, N1≤1; Second is pre-conditionedly: 0≤| V2-V3|/V3<N2, N2≤1.
In above-mentioned second detecting step, if open fault appears in the brake resistance R1 in braking circuit or brake pipe Q7, then the conducting of Q7 does not make to form path between DC bus yet, and there will not be pressure drop, now V2 should be equal with V1.And if there is the fault of IGBT brake pipe Q7 short circuit in braking circuit, then no matter Q7 conducting whether, between DC bus, one forms path straight through braking circuit, so no matter Q7 conducting or shutoff, DC bus-bar voltage all can keep stable, also there will not be pressure drop, that is, V2 is still equal with V1.So when the element brake resistance R1 in braking circuit and brake pipe Q7 does not all break down, when Q7 conducting, form path between DC bus by brake resistance R1 and IGBT brake pipe Q7, electric current flows through R1 and Q7 and produces pressure drop, and namely the value of V2 is less than the value of V1.
In above-mentioned 3rd detecting step, brake pipe Q7 closes and has no progeny, and no longer forms path between DC bus, then the pressure drop that Q7 conducting is formed disappears, and the value of V3 should be equal with the value of V1.
For above-mentioned first pre-conditioned, calculating | the value of V1-V3|/V3 is to judge the intensity of variation of V3 relative to V1, from description before, in theory or ideally, should meet V1=V3; So when | when the value of V1-V3|/V3 is less than a certain threshold value N1, illustrate in this testing process, the power supply fluctuation of frequency convertor system is little, can not impact fault detect; And work as | when the value of V1-V3|/V3 is greater than this threshold value N1, think in this testing process, there is fluctuation and fluctuate excessive in the power supply of frequency convertor system, the result that have impact on fault detect judges, now will be understood that this detect invalid and not by this detection record for once effectively to detect.
And for above-mentioned second pre-conditioned, calculating | the value of V2-V3|/V3 is to judge the intensity of variation of V2 relative to V3, from description before, when the element of braking circuit does not break down, owing to producing pressure drop, V2 < V3 should be met; So when | when the value of V2-V3|/V3 is less than a certain threshold value N2, think that obvious change does not occur DC bus-bar voltage, illustrates in braking circuit to there is fault before and after brake pipe Q7 conducting, need to investigate one by one brake resistance R1 and brake pipe Q7, with the localization of faults; And work as | when the value of V2-V3|/V3 is greater than this threshold value N2, think that V2 creates obvious change relative to V3, illustrate that braking circuit element normally acts on to there is not fault in braking circuit.
Above-mentioned threshold value N1 and N2 freely can determine according to the operating mode of frequency convertor system and parameter, preferably, and N1=N2=1%.Meanwhile, the first above-mentioned preset duration and the second preset duration also freely can be determined according to the operating mode of frequency convertor system and operating intervals, and preferably, the first preset duration is 50 milliseconds, and the second preset duration is 50 milliseconds.
For ensureing the accuracy of testing result, the causing trouble that affects being subject to site environment is avoided to judge by accident, further comprising the steps of:
Rate-determining steps: control to repeat above-mentioned first detecting step to determining step N3 time, the number of times broken down is N4, wherein N4≤N3.
Determining step: judge that whether the numerical value of above-mentioned N4/N3 meet the 3rd pre-conditioned, if judged result is yes, determine that braking circuit breaks down.
Wherein the 3rd is pre-conditionedly: 0<N5<N4/N3≤1.
Break step: when determining that braking circuit breaks down, disconnects the alternating current input of frequency converter.
Alternatively, counter can be introduced record the number of times performing detection and the number of times determining to break down respectively in above-mentioned controller 1.Such as, use counter CT1 record to perform the number of times detected, use CT2 record to determine the number of times broken down.When meet first pre-conditioned or second pre-conditioned time, that is, 0<N1≤| V1-V3|/V3 or 0<N2≤| V2-V3|/V3, this hour counter CT1 record numerical value add 1, and CT2 record numerical value do not increase; When first and second pre-conditioned all meet time, that is, 0≤| V1-V3|/V3<N1 and 0≤| the numerical value of V2-V3|/V3<N2, this hour counter CT1 and CT2 record all adds 1.After so repeating to detect several times, counter CT1 obtains detecting times N 3, and counter CT2 obtains the times N 4 that breaks down, and wherein N3 and N4 must meet N4≤N3.Calculate the value of N4/N3, when this ratio is higher than a certain threshold value N5, when namely meeting the 3rd pre-conditioned 0<N5<N4/N3≤1st, then think in testing process repeatedly, the number of times that fault occurs has reached higher ratio, can determine to have occurred fault in braking circuit, get rid of the possibility of erroneous judgement.
Above-mentioned threshold value N5 also freely can determine according to the operating mode of frequency convertor system and parameter, preferably, and N5=90%.
After determining that braking circuit breaks down, control above-mentioned relay K 4 by above-mentioned controller 1 and disconnect.From description before, when relay K 4 disconnects, the supply line of above-mentioned contactor is cut off, then above-mentioned magnet exciting coil K1 power-off, thus above-mentioned main contact K1M all disconnects with auxiliary contact K1NO and contacting, achieve the alternating current input cutting off frequency convertor system, thus avoid frequency convertor system to damage.
Each detecting step need have alternating current input but carry out under the state of non-drive motors at frequency converter above, because detect under the state of frequency converter band live machine, braking circuit can be made also to become the load of above-mentioned rectifying part, namely, rectifying part needs to drive three fractional load of braking circuit, Converting Unit and motor, the load capacity of rectifying part can be exceeded, thus may rectifying part be damaged.
In like manner, if in process fault detection, frequency converter receives the instruction of drive motors, then controller 1 immediately termination failure detect and turn off above-mentioned IGBT brake pipe Q7, otherwise also can damage rectifying part because making rectifying part band carry overweight.
Controller in the utility model, resistance, diode, IGBT pipe, contactor, relay, switch and electric capacity can adopt the electronic component in correlation technique, it does not all have the restriction of model or kind, and user can select the electronic component of respective model or kind according to concrete applied environment.It should be noted that, any simple substitute to technical scheme in the utility model or equivalent replacement still belong in protection range of the present utility model.
The treatment circuit of the frequency converter braking circuit fault that the utility model provides is by controlling conducting and the shutoff of brake pipe, and detect the intensity of variation of DC bus-bar voltage, achieve the complete detection of the fault to frequency converter braking circuit, improve in prior art and only can carry out fault detect for elements some in braking circuit, detect and monitoring comprehensive, other element fault cannot be detected and make the defect of reply.Thus can more effective protection frequency convertor system, avoid security incident and property loss occur.
It should be noted that, in this article, term " comprises ", " comprising " or its any other variant are intended to contain comprising of nonexcludability, thus make to comprise the process of a series of key element, method, article or equipment and not only comprise those key elements, but also comprise other key elements clearly do not listed, or also comprise by the intrinsic key element of this process, method, article or equipment.It should be noted that, these technique effects are not that above-mentioned all execution modes have, and some technique effect is that some preferred implementation just can obtain.
The foregoing is only preferred embodiment of the present utility model, be not intended to limit protection range of the present utility model.All do within spirit of the present utility model and principle any amendment, equivalent replacement, improvement etc., be all included in protection range of the present utility model.
Claims (6)
1. the fault logic circuits of a frequency converter braking circuit, it is characterized in that, comprise controller, wherein, described controller comprises: voltage detecting end and control pin, described voltage detecting end is connected with the DC bus of described frequency converter braking circuit respectively, and described control pin is connected with the gate pole of the brake pipe in described frequency converter braking circuit.
2. the fault logic circuits of frequency converter braking circuit according to claim 1, is characterized in that, also comprise:
Relay, is connected with described controller, conducting or shutoff under the control of described controller;
Contactor, one end of described contactor is connected with one end of described relay, and the other end of described contactor is connected with the live wire end controlling power supply, and the zero line side of described control power supply is connected with the other end of described relay, wherein, described control power supply is that described contactor is powered.
3. the fault logic circuits of frequency converter braking circuit according to claim 2, is characterized in that,
Described contactor comprises: multiple main contact, magnet exciting coil and auxiliary contact;
Wherein, described multiple main contact is electrically connected with multiple electric currents of alternating current respectively and controls conducting and the shutoff of described multiple electric current phase respectively, and described alternating current is input to the frequency converter be connected with described frequency converter braking circuit; One end of described magnet exciting coil is connected with the live wire end of described control power supply, and the other end of described magnet exciting coil is connected with one end of described auxiliary contact; The other end of described auxiliary contact is connected with one end of described relay.
4. the fault logic circuits of frequency converter braking circuit according to claim 2, is characterized in that, it is inner that described relay is integrated in described controller.
5. the fault logic circuits of frequency converter braking circuit according to claim 3, is characterized in that, also comprise:
First switch and second switch;
Wherein, described first switch is connected in series between described auxiliary contact and described relay;
Described second switch is connected in the two ends of described auxiliary contact in parallel.
6. a frequency converter, is characterized in that, described frequency converter comprises the fault logic circuits of the frequency converter braking circuit according to any one of claim 1-5.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201520175547.5U CN204794032U (en) | 2015-03-26 | 2015-03-26 | Fault handling circuit and converter of converter braking circuit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201520175547.5U CN204794032U (en) | 2015-03-26 | 2015-03-26 | Fault handling circuit and converter of converter braking circuit |
Publications (1)
Publication Number | Publication Date |
---|---|
CN204794032U true CN204794032U (en) | 2015-11-18 |
Family
ID=54534015
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN201520175547.5U Expired - Fee Related CN204794032U (en) | 2015-03-26 | 2015-03-26 | Fault handling circuit and converter of converter braking circuit |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN204794032U (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106159905A (en) * | 2015-03-26 | 2016-11-23 | 控制技术有限公司 | The fault logic circuits of converter braking circuit, method and apparatus and converter |
-
2015
- 2015-03-26 CN CN201520175547.5U patent/CN204794032U/en not_active Expired - Fee Related
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106159905A (en) * | 2015-03-26 | 2016-11-23 | 控制技术有限公司 | The fault logic circuits of converter braking circuit, method and apparatus and converter |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN102820771A (en) | Soft start device and soft start method of converter equipment | |
AU2018372887B2 (en) | Multi-source power supply circuit detection method, system, and device | |
CN107121630A (en) | The self checking method and device of a kind of active short-circuit protection circuit of electric machine control system | |
CN104953806A (en) | Power-consumption-free bypass apparatus of cascaded-power-unit-based high-voltage inverter and control method thereof | |
CN103746570A (en) | Rectifier and electric power equipment | |
CN103311903A (en) | Switch device and power generation system thereof | |
CN104953546A (en) | Protection detection device for photovoltaic assembly or power system as well as control method of protection detection device | |
CN202218006U (en) | Grounding fault detecting and protecting device of solar photovoltaic inverter | |
KR101091636B1 (en) | Power cable short detection method of motor | |
CN203415956U (en) | Frequency converter system protection device | |
CN207967914U (en) | A kind of voltage protection of photovoltaic parallel in system | |
CN204794032U (en) | Fault handling circuit and converter of converter braking circuit | |
CN109789796B (en) | Rectifier, electric drive system and method for charging an electrical energy store | |
CN201616661U (en) | Three-phase alternating current motor automatic phase-conversion default-phase protecting instrument | |
CN102832798B (en) | One powers on buffer control circuit and control method thereof | |
CN107919655B (en) | Control circuit, control method and air conditioner | |
CN114069696B (en) | Method and equipment for enhancing reliability of micro-grid silicon controlled rectifier off-grid switching device | |
CN106159905A (en) | The fault logic circuits of converter braking circuit, method and apparatus and converter | |
CN202931210U (en) | Power supply unit for testing of electric locomotive | |
CN201204570Y (en) | AC contactless control switch | |
CN103376389A (en) | Fault electric arc judgment system for low-voltage line and judgment method thereof | |
CN208226558U (en) | A kind of motor protective circuit | |
CN105071249A (en) | Intelligent low voltage power distribution box | |
CN105656297A (en) | Discharging method of direct driving type wind turbine generator system converter direct-current bus | |
CN217305438U (en) | Limit working condition test platform of alternating current switch device |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
C14 | Grant of patent or utility model | ||
GR01 | Patent grant | ||
CP01 | Change in the name or title of a patent holder |
Address after: British Powys Patentee after: Nideke Control Technology Co. Ltd. Address before: British Powys Patentee before: Control Tech Ltd |
|
CF01 | Termination of patent right due to non-payment of annual fee | ||
CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20151118 Termination date: 20200326 |