CN103731019A - Over modulation method of modular multi-level converter station - Google Patents
Over modulation method of modular multi-level converter station Download PDFInfo
- Publication number
- CN103731019A CN103731019A CN201310643852.8A CN201310643852A CN103731019A CN 103731019 A CN103731019 A CN 103731019A CN 201310643852 A CN201310643852 A CN 201310643852A CN 103731019 A CN103731019 A CN 103731019A
- Authority
- CN
- China
- Prior art keywords
- voltage
- common
- modulation
- current
- mode
- 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.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 34
- 239000003990 capacitor Substances 0.000 claims abstract description 6
- 238000006243 chemical reaction Methods 0.000 claims description 42
- 210000000635 valve cell Anatomy 0.000 claims description 6
- 230000005540 biological transmission Effects 0.000 abstract description 10
- 238000010586 diagram Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000001105 regulatory effect Effects 0.000 description 3
- 230000001052 transient effect Effects 0.000 description 3
- 238000000205 computational method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
Images
Abstract
The invention discloses an over modulation method of a modular multi-level converter station. The over modulation method of the modular multi-level converter station is used for direct-current transmission. The modular multi-level converter station comprises a plurality of valve units, a charging resistor and a knife switch used for a bypass charging resistor, and each valve unit comprises a capacitor. After the converter station is unlocked, a Udc, the capacitor voltage of a bridge arm, an average value Ucap and alternating current modulation voltages (Ua, Ub and Uc) generated by a current controller of the converter station are set according to the current direct current voltage, and the minimum common-mode voltages Un capable of being overlaid to the alternating current modulation voltages are worked out, so that after the minimum common-mode voltages Un are overlaid, the modulation voltages (Uan=Ua-Un, Ubn=Ub-Un, and Ucn=Uc-Un) of all phases are in a permissible range as much as possible; when the compensation effect is the same after overlaying, the common-mode voltage is small as soon as possible. Through the method, when uncontrolled charging of the converter station is finished, due to the fact that the capacitor voltage of the bridge arm is low, the alternating current modulation voltages capable of being output will be obviously improved, and starting impact current is further lowered; when the system operates stably, due to the facts that the capacitor voltage of the bridge arm has been raised and the overlaid modulation voltages are zero, the stable operation of the system is not affected.
Description
Technical field
The invention belongs to flexible DC power transmission system control technology field, relate in particular to the start-up course of current conversion station in DC transmission system.
Background technology
Voltage-source type DC transmission system, be also referred to as flexible DC power transmission system, having current conversion station and meritoriously/idle can independently control, not need huge alternating current filter, can support Power Grid Black to start, support to advantages such as weak net power supply such as island/wind energy turbine set, is solve regional new-energy grid-connected and dissolve the effective method of problem.Modular multi-level converter is one of main method realizing voltage-source type DC transmission system at present; but the control resist technology of modular multilevel current conversion station is complicated; especially start-up course, easily causes large impulse current, has affected the reliability of system.
The startup that solves at present modular multilevel current conversion station has two kinds of methods: a kind of method is to increase the leakage reactance of AC transformer and the brachium pontis reactance of converter, suppress inrush current, the method has increased the cost of current conversion station, increase the stable state pressure drop in transformer and brachium pontis reactance, be unfavorable for the optimization of current conversion station system; Another kind method [1] is by bridge arm module being divided into two groups, respectively every group being charged, can obtaining higher charging voltage, after charging completes, because total brachium pontis capacitance voltage and apparently higher than line voltage has been avoided too large impulse current; [2] method is similar, and by the bridge arm module of bypass some, the brachium pontis that has repeated to bypass disparate modules charges, and can obtain equally higher brachium pontis capacitance voltage, thereby reduces inrush current; [1] and the method for [2] all obviously increased the loss of charging resistor, make charging and start-up course too complexity.
For improving the reliability and stability of modular multilevel current conversion station start-up course, need to a kind ofly can obviously reduce inrush current, can not affect again the control method of the steady operation outside startup.
Summary of the invention
A kind of ovennodulation method that the object of this invention is to provide modular multilevel current conversion station for direct current transportation, the method can not change simply not controlled charging circuit, impulse current in the time of reducing release to greatest extent again does not also affect normal steady operation simultaneously.
For achieving the above object, the present invention realizes by the following technical solutions:
Technical solution of the present invention is for the modular multilevel current conversion station for direct current transportation, described modular multilevel current conversion station, as shown in Figure 1, comprise a plurality of valve cells, charging resistor, for the disconnecting link of bypass charging resistor, each valve cell comprises capacitor.Current conversion station is in start-up course, at controlled charging not, finish after by-pass knife switch closure, according to current direct voltage, set the AC regulating voltage (Ua of the current controller generation of Udc, brachium pontis capacitance voltage and mean value Ucap, current conversion station, Ub, Uc), calculate the minimum common-mode voltage Un that can be superimposed upon on AC regulating voltage, make to superpose after this common-mode voltage Un, the modulation voltage of every phase (Uan=Ua-Un, Ubn=Ub-Un, Ucn=Uc-Un) is as far as possible all in allowed band.By this method, when just release of current conversion station, because brachium pontis capacitance voltage is lower, obviously improved the AC regulating voltage that can export; After system stable operation, because brachium pontis capacitance voltage raises, the common-mode voltage of stack is zero, does not affect the steady operation of system.Meanwhile, if because the fluctuation of AC network, the modulation voltage that accidentally need to exceed normal range (NR) comes stabling current to control, current conversion station also can the suitable common-mode voltage of instantaneous stack, improve instantaneous modulation voltage, and after the fluctuation of system disappears, automatically common-mode voltage is adjusted into 0.The detailed process that Un calculates as shown in Figure 3 and Figure 5.
Compared with prior art, the invention has the beneficial effects as follows:
(1) modular multilevel current conversion station starting method provided by the invention, can effectively avoid the impulse current in start-up course, improves the reliability of current conversion station.
(2) modular multilevel current conversion station starting method provided by the invention can, in simply not controlled charging release at once after completing of current conversion station, need to not controlled outward by plus in charging process.
(3) modular multilevel current conversion station starting method provided by the invention, does not affect the steady operation after current conversion station release.
(4) modular multilevel current conversion station starting method provided by the invention, can, in the moment of AC network fluctuation, improve instantaneous modulation voltage scope, the ability of the anti-grid disturbance of raising system equally.
Accompanying drawing explanation
Fig. 1 is modular multilevel current conversion station structure chart.
Fig. 2, according to the present invention, compensates the three-phase modulations voltage schematic diagram after front and compensation under different situations.
Fig. 2 a modulation voltage is when positive direction surpasses restriction; Fig. 2 b modulation voltage is when negative direction surpasses restriction; Fig. 2 c modulation voltage is within limited field time.
Fig. 3 is for a kind of computational methods of the common-mode voltage that compensates.
The schematic diagram that Fig. 4 is added to common-mode voltage on modulation voltage.
Fig. 5 is for the another kind of computational methods of the common-mode voltage that compensates.
Embodiment
Below in conjunction with the accompanying drawings and the specific embodiments the technical scheme of invention is elaborated.
Figure 1 shows that a modular multilevel current conversion station, comprising the disconnecting link of 6 brachium pontis, charging resistor, bypass charging resistor.When normal operation, by controlling conducting, the off state of the valve cell on brachium pontis, can control the voltage of brachium pontis output, thereby control the electric current that current conversion station flows to AC network.Normally in service, the capacitance voltage of each brachium pontis and Ucap are apparently higher than the voltage of AC network, make to control after the break-make of valve cell on brachium pontis, can arbitrarily control the instantaneous voltage (Uan of brachium pontis output, Ubn, Ucn) a little more than or lower than the voltage of AC network, thereby the transient current that makes current conversion station flow to AC network increases or is less; By constantly detecting current conversion station, flow to the electric current of AC network, and control brachium pontis output voltage according to the size of transient current, can allow the electric current of current conversion station maintain in desired value always.
But, before the complete current conversion station release of controlled charging not, capacitance voltage on 6 brachium pontis and Ucap all with alternating voltage peak sizableness, in order to control current conversion station, flow to the transient current of AC network, needed brachium pontis output voltage (Ua, Ub, Uc) tends to exceed the modulation voltage restriction of brachium pontis, as Fig. 2 (a) with (b), in other words at this moment current conversion station in ovennodulation state.Current controlled in order to allow, according to the present invention, the common common mode component Un that can superpose on three-phase modulations voltage, makes within three-phase modulations voltage after compensation is positioned at the modulation voltage restriction of brachium pontis as far as possible.This common mode component must meet:
1. allow as far as possible within the restriction of the modulation voltage of revised three-phase modulations voltage in brachium pontis
2. in 1 all common mode components of meeting the demands, select minimum common mode component.As Fig. 2 (a) with (b)
3., if the three-phase modulations voltage while not adding common mode component was located in limited field originally, this common mode component should be 0.As shown in Fig. 2 (c).
1,, according to current brachium pontis capacitance voltage and mean value Ucap and direct voltage Udc, calculate current modulation voltage restriction Ulim
Ulim=min(Ucap,Ucap-Udc/2)
2, calculate maximum maxU and the minimum value minU in three-phase modulations voltage (Ua, Ub, Uc)
Within if the maximum in 3 three-phase modulations voltages (Ua, Ub, Uc) and minimum value are all positioned at modulation voltage restriction, for the common-mode voltage Un=0 compensating
If the maximum in 4 three-phase modulations voltages (Ua, Ub, Uc) and minimum value are all over modulation voltage restriction, for the common-mode voltage Un=0 compensating
If the maximum maxU in 5 three-phase modulations voltages (Ua, Ub, Uc) has surpassed modulation voltage restriction, and minimum value minU is within modulation voltage restriction, as shown in Fig. 2 (a), calculates the common-mode voltage for compensating:
Un=min(maxU-Ulim,minU+Ulim)
If the maximum maxU in 6 three-phase modulations voltages (Ua, Ub, Uc) is within modulation voltage restriction, and minimum value minU has surpassed modulation voltage restriction, as shown in Fig. 2 (b), calculates the common-mode voltage for compensating:
Un=max(maxU-Ulim,minU+Ulim)
7, revise three-phase modulations voltage, as shown in Figure 4
Uan=Ua–Un
Ubn=Ub–Un
Ucn=Uc–Un
In above realization, when three-phase modulations voltage all surpasses current modulation voltage restriction in positive negative direction, the common mode correction voltage calculating is 0.
Another kind of implementation method of the present invention is, when three-phase modulations voltage all surpasses current modulation voltage restriction in positive negative direction, adjusts common mode correction voltage, makes revised modulation voltage in positive negative direction, exceed the amplitude of restriction equal.Specific implementation as shown in Figure 5, is described below:
1,, according to current brachium pontis capacitance voltage and mean value Ucap and direct voltage Udc, calculate current modulation voltage restriction Ulim
Ulim=min(Ucap,Ucap-Udc/2)
2, calculate maximum maxU and the minimum value minU in three-phase modulations voltage (Ua, Ub, Uc)
3, calculate the common-mode voltage Un0 that makes modulation voltage Symmetrical
Un0=(maxU+minU)/2
If the maximum maxU in 4 Un0>0 and three-phase modulations voltage (Ua, Ub, Uc) has surpassed modulation voltage restriction, calculate the common-mode voltage for compensating:
Un=min(maxU-Ulim,Un0)
5 otherwise, if the minimum value minU in Un0<0 and three-phase modulations voltage (Ua, Ub, Uc) has surpassed modulation voltage restriction, calculate the common-mode voltage for compensating:
Un=max(minU+Ulim，Un0)
6 otherwise, set Un0=0
7, revise three-phase modulations voltage, as shown in Figure 4
Uan=Ua–Un
Ubn=Ub–Un
Ucn=Uc-Un
In addition, in voltage-source type direct-current transmission converter station design, direct voltage rated value generally with brachium pontis capacitance voltage and rated value equate.In this case, can simplify and think that Udc=Ucap in service also sets up, thereby above modulation voltage limit calculation is reduced to:
Ulim=Ucap/2
It is example that the block diagram of two kinds of different implementation methods is take in the present invention, has introduced concrete implementation step and technological thought, can not limit protection scope of the present invention with this.Protection scope of the present invention is as the criterion with the protection range of claim.
[1] Wang Guangzhu. a kind of system and method .N201210350682.2012-12-19. of modular multilevel converter electric capacity grouping precharge
[2] Yao Weizheng, Wu Jinlong, He Qinglian, etc. a kind of starting method .CN201210462977.2013-03-13. of modular multilevel flexible DC power transmission converter
Claims (7)
1. for the ovennodulation method of the modular multilevel current conversion station of direct current transportation, described current conversion station adopts modularization multi-level converter, comprise a plurality of valve cells, in each valve cell, contain capacitor, current conversion station AC comprises charging resistor and the by-pass knife switch in parallel with charging resistor, current controller at current conversion station produces after three-phase modulations voltage, and the common-mode voltage that superposes on three-phase modulations voltage, is characterized in that:
A) allow as far as possible within the modulation voltage of three-phase modulations voltage in brachium pontis restriction after compensation;
B) in all common-mode voltages that meet the demands a), select minimum common-mode voltage;
C), if the three-phase modulations voltage while not superposeing common-mode voltage was located in limited field originally, this common-mode voltage should be 0.
2. the ovennodulation method of the modular multilevel current conversion station for direct current transportation according to claim 1, is characterized in that: first according to current brachium pontis capacitance voltage and and direct voltage calculate modulation voltage restriction.
3. the ovennodulation method of the modular multilevel current conversion station for direct current transportation according to claim 1, it is characterized in that: when the brachium pontis capacitance voltage rated value of current conversion station is designed to equate with direct voltage rated value, using current brachium pontis capacitance voltage and half as modulation voltage, limit.
4. the ovennodulation method of the modular multilevel current conversion station for direct current transportation according to claim 1, is characterized in that: when three-phase modulations voltage all surpasses current modulation voltage restriction in positive negative direction, the common-mode voltage of setting for compensating is 0.
5. the ovennodulation method of the modular multilevel current conversion station for direct current transportation according to claim 1, it is characterized in that: when three-phase modulations voltage all surpasses current modulation voltage restriction in positive negative direction, adjust common-mode voltage, the amplitude that makes modulation voltage after compensation exceed modulation voltage restriction in positive negative direction equates.
6. the ovennodulation method of the modular multilevel current conversion station for direct current transportation according to claim 4, is characterized in that: following steps are followed in the calculating for the common-mode voltage that compensates:
Step 1: calculate maximum maxU and minimum value minU in three-phase modulations voltage (Ua, Ub, Uc)
Step 2: if within the maximum in three-phase modulations voltage (Ua, Ub, Uc) and minimum value be all positioned at modulation voltage restriction, for the common-mode voltage Un=0 compensating
Step 3: if the maximum in three-phase modulations voltage (Ua, Ub, Uc) and minimum value are all over modulation voltage restriction, for the common-mode voltage Un=0 compensating
Step 4: if the maximum maxU in three-phase modulations voltage (Ua, Ub, Uc) has surpassed modulation voltage restriction, and minimum value minU is within modulation voltage restriction, calculates the common-mode voltage for compensating:
Un=min(maxU-Ulim,minU+Ulim)
Step 5: if the maximum maxU in three-phase modulations voltage (Ua, Ub, Uc) is within modulation voltage limits, and minimum value minU has surpassed modulation voltage restriction, calculates the common-mode voltage for compensating:
Un=max(maxU-Ulim,minU+Ulim)?。
7. the ovennodulation method of the modular multilevel current conversion station for direct current transportation according to claim 5, is characterized in that: following steps are followed in the calculating for the common-mode voltage that compensates:
Step 1: calculate maximum maxU and minimum value minU in three-phase modulations voltage (Ua, Ub, Uc)
Step 2: calculate the common-mode voltage Un0 that makes modulation voltage Symmetrical
Un0=(maxU+minU)/2
Step 3: if the maximum maxU in Un0>0 and three-phase modulations voltage (Ua, Ub, Uc) has surpassed modulation voltage restriction, calculate the common-mode voltage for compensating:
Un=min(maxU-Ulim,Un0)
Step 4: otherwise, if the minimum value minU in Un0<0 and three-phase modulations voltage (Ua, Ub, Uc) has surpassed modulation voltage restriction, calculate the common-mode voltage for compensating:
Un=max(minU+Ulim，Un0)
Step 5: otherwise, set the common-mode voltage Un=0 for compensating.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310643852.8A CN103731019B (en) | 2013-12-03 | 2013-12-03 | A kind of overmodulation method of modular multilevel current conversion station |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310643852.8A CN103731019B (en) | 2013-12-03 | 2013-12-03 | A kind of overmodulation method of modular multilevel current conversion station |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103731019A true CN103731019A (en) | 2014-04-16 |
| CN103731019B CN103731019B (en) | 2015-12-30 |
Family
ID=50454989
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310643852.8A Active CN103731019B (en) | 2013-12-03 | 2013-12-03 | A kind of overmodulation method of modular multilevel current conversion station |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103731019B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1527454A (en) * | 2003-02-04 | 2004-09-08 | ��ķ�ɷ�����˾ | Limiting circuit and motor driver using the same limiting circuit |
| CN101359881A (en) * | 2008-09-26 | 2009-02-04 | 清华大学 | Pulse width modulation method based on minimum common mode transient voltage superimposed |
| CN201774458U (en) * | 2010-07-22 | 2011-03-23 | 荣信电力电子股份有限公司 | MMC (modular multilevel converter)-based transformerless four-quadrant topological structure of high-voltage variable frequency power source |
| CN102013691A (en) * | 2010-07-22 | 2011-04-13 | 荣信电力电子股份有限公司 | Battery energy storage topology structure without transformer based on MMC modularized multi-level inverter |
| CN102025166A (en) * | 2010-07-22 | 2011-04-20 | 荣信电力电子股份有限公司 | Power-generating interconnected topological structure of transformerless water-turbine generator |
-
2013
- 2013-12-03 CN CN201310643852.8A patent/CN103731019B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1527454A (en) * | 2003-02-04 | 2004-09-08 | ��ķ�ɷ�����˾ | Limiting circuit and motor driver using the same limiting circuit |
| CN101359881A (en) * | 2008-09-26 | 2009-02-04 | 清华大学 | Pulse width modulation method based on minimum common mode transient voltage superimposed |
| CN201774458U (en) * | 2010-07-22 | 2011-03-23 | 荣信电力电子股份有限公司 | MMC (modular multilevel converter)-based transformerless four-quadrant topological structure of high-voltage variable frequency power source |
| CN102013691A (en) * | 2010-07-22 | 2011-04-13 | 荣信电力电子股份有限公司 | Battery energy storage topology structure without transformer based on MMC modularized multi-level inverter |
| CN102025166A (en) * | 2010-07-22 | 2011-04-20 | 荣信电力电子股份有限公司 | Power-generating interconnected topological structure of transformerless water-turbine generator |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103731019B (en) | 2015-12-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103986136B (en) | A kind of novel and multifunctional fault current limiting system and its control method that technology is stored up based on light | |
| TWI522767B (en) | Photovoltaic power generation system | |
| EP2191550B1 (en) | Statcom system for providing reactive and/or active power to a power network | |
| US20140056041A1 (en) | Power generation system, power converter system, and methods of operating a power converter system | |
| CN111934330B (en) | Active energy control method for offshore wind power under alternating current fault through flexible direct grid-connected system | |
| US10998723B1 (en) | Large-scale photovoltaic DC series boost grid-connected system with power balancer | |
| CA3080015A1 (en) | Voltage and current control method and device for direct-current transmission system | |
| CN107196312B (en) | L C network switch parallel connection type unified power quality controller and control method thereof | |
| CN101951178A (en) | Method used for balancing three phases of direct current side voltages of chain power regulating device | |
| WO2020082762A1 (en) | Pwm method, modulator and system for three-level rectifier suppressing common mode voltage | |
| Naqvi et al. | A PV-battery system resilient to weak grid conditions with regulated power injection and grid supportive features | |
| CN111786396B (en) | Phase-change failure suppression method for high-voltage direct-current transmission system based on energy storage type chained STATCOM | |
| CN104993533A (en) | Modular multilevel converter inter-bridge-arm energy balance control method | |
| JP6113556B2 (en) | Reactive power compensator | |
| Wang et al. | Series and shunt DC electric springs | |
| CN113394819B (en) | Coordination control method and system for island offshore wind power plant hybrid direct current grid-connected system | |
| Nithya et al. | Multimode inverter control strategy for LVRT and HVRT capability enhancement in grid connected solar PV system | |
| CN104201683A (en) | Flexible direct-current transmission system coupled transformer tap adjusting method | |
| Guerrero et al. | Parallel operation of uninterruptible power supply systems in microgrids | |
| CN105790300A (en) | Hybrid DC transmission-based fan grid-connected system | |
| CN203608080U (en) | Start control device based on flexible DC power transmission multi-level converter | |
| CN104104104A (en) | Method of automatic switching between power generation mode and SVG mode for photovoltaic inverter | |
| KR101281079B1 (en) | Photoelectric cell system with improved power quality and operating method of it | |
| CN113013917B (en) | Hybrid phase synchronization controller and control method for power electronic converter | |
| CN103731019A (en) | Over modulation method of modular multi-level converter station |
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 | ||
| C56 | Change in the name or address of the patentee | ||
| CP01 | Change in the name or title of a patent holder |
Address after: Guangzhou City, Guangdong province Yuexiu District 510080 Dongfeng East Road, No. 8, 6 water Kong Guangdong building Patentee after: Research Institute of Southern Power Grid Co., Ltd. Patentee after: Monternet Rongxin Technology Group Limited by Share Ltd Address before: Guangzhou City, Guangdong province Yuexiu District 510080 Dongfeng East Road, No. 8, 6 water Kong Guangdong building Patentee before: Research Institute of Southern Power Grid Co., Ltd. Patentee before: Rongxin Power Electronic Co., Ltd. |
|
| EE01 | Entry into force of recordation of patent licensing contract | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Application publication date: 20140416 Assignee: Rong / electric technology limited liability company Assignor: Monternet Rongxin Technology Group Limited by Share Ltd Contract record no.: 2017210000040 Denomination of invention: Over modulation method of modular multi-level converter station Granted publication date: 20151230 License type: Common License Record date: 20171212 |
|
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20200212 Address after: Guangzhou City, Guangdong province Yuexiu District 510080 Dongfeng East Road, No. 8, 6 water Kong Guangdong building Co-patentee after: Rong / electric technology limited liability company Patentee after: ELECTRIC POWER RESEARCH INSTITUTE, CHINA SOUTHERN POWER GRID Address before: Guangzhou City, Guangdong province Yuexiu District 510080 Dongfeng East Road, No. 8, 6 water Kong Guangdong building Co-patentee before: Monternet Rongxin Technology Group Limited by Share Ltd Patentee before: ELECTRIC POWER RESEARCH INSTITUTE, CHINA SOUTHERN POWER GRID |
|
| CP01 | Change in the name or title of a patent holder | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 510080 Guangdong Province, Guangzhou, Guangdong province Yuexiu District Dongfeng Road East 6, 8, Guangdong Electric Building Patentee after: China Southern Power Grid Research Institute Co.,Ltd. Patentee after: Rongxin Huike Electric Co.,Ltd. Address before: 510080 Guangdong Province, Guangzhou, Guangdong province Yuexiu District Dongfeng Road East 6, 8, Guangdong Electric Building Patentee before: China Southern Power Grid Research Institute Co.,Ltd. Patentee before: RONGXIN HUIKE ELECTRIC TECHNOLOGY Co.,Ltd. |