CN110943603A - Redundant trigger circuit for bypass switch of flexible direct current converter valve - Google Patents
Redundant trigger circuit for bypass switch of flexible direct current converter valve Download PDFInfo
- Publication number
- CN110943603A CN110943603A CN201911292233.2A CN201911292233A CN110943603A CN 110943603 A CN110943603 A CN 110943603A CN 201911292233 A CN201911292233 A CN 201911292233A CN 110943603 A CN110943603 A CN 110943603A
- Authority
- CN
- China
- Prior art keywords
- diode
- thyristor
- cathode
- bypass switch
- trigger 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.)
- Pending
Links
- 239000003990 capacitor Substances 0.000 claims abstract description 65
- 238000004146 energy storage Methods 0.000 claims abstract description 55
- 238000001514 detection method Methods 0.000 claims abstract description 30
- 238000005070 sampling Methods 0.000 claims description 14
- 238000002955 isolation Methods 0.000 claims description 3
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 4
- 230000001960 triggered effect Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/32—Means for protecting converters other than automatic disconnection
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/06—Circuits specially adapted for rendering non-conductive gas discharge tubes or equivalent semiconductor devices, e.g. thyratrons, thyristors
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/32—Means for protecting converters other than automatic disconnection
- H02M1/325—Means for protecting converters other than automatic disconnection with means for allowing continuous operation despite a fault, i.e. fault tolerant converters
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
The invention discloses a redundant trigger circuit for a bypass switch of a soft direct converter valve, which comprises a first charging resistor, a second charging resistor, a first energy storage capacitor, a second energy storage capacitor, a first thyristor, a second thyristor, a first thyristor trigger circuit, a second thyristor trigger circuit, a first diode, a second diode, a third diode, a fourth diode, a bypass switch trigger coil, a second voltage detection circuit and a first voltage detection circuit, wherein the anodes of the first charging resistor and the second charging resistor are connected in parallel to the anode of a power supply, the cathode of the first charging resistor is connected with the first energy storage capacitor and the first voltage detection circuit which are connected in parallel, the cathode of the first charging resistor is connected with the anode of the second thyristor, and the gate of the second thyristor is connected with the second thyristor trigger circuit. The invention has the beneficial effects that: the charging current of the energy storage capacitor is set to be equalized and passes through the bypass switch trigger coil, and the on-off state of the bypass switch trigger coil is detected.
Description
Technical Field
The invention relates to the technical field of power electronics, in particular to a redundant trigger circuit for a bypass switch of a flexible direct current converter valve.
Background
A bridge arm main loop structure of the MMC flexible direct-current transmission converter valve is formed by connecting a plurality of power units in series, and when a single power unit breaks down, a reliable bypass is needed to ensure that equipment continues to operate. At present, a conventional method is to only configure a set of charging resistor, a capacitor, and a thyristor to be connected in series with the trigger coil of the bypass switch, and when the thyristor is triggered to conduct, the capacitor discharges to the trigger coil of the bypass switch, and the bypass switch is triggered to close. The traditional bypass switch trigger circuit cannot detect the on-off state of the bypass switch trigger coil, and the condition that the bypass switch fails to operate is caused when the bypass switch trigger coil fails to open, so that the whole equipment is tripped and stopped, and the reliability is to be improved.
Disclosure of Invention
Aiming at the problems, the invention provides a redundant trigger circuit for a bypass switch of a flexible direct current converter valve, which mainly solves the problems of the background technology, detects the on-off state of a trigger coil of the bypass switch and realizes the redundant trigger function.
In order to solve the technical problems, the technical scheme of the invention is as follows:
a redundant trigger circuit for a bypass switch of a flexible direct current converter valve comprises a first charging resistor, a second charging resistor, a first energy storage capacitor, a second energy storage capacitor, a first thyristor, a second thyristor, a first thyristor trigger circuit, a second thyristor trigger circuit, a first diode, a second diode, a third diode, a fourth diode, a bypass switch trigger coil, a second voltage detection circuit and a first voltage detection circuit, wherein the anodes of the first charging resistor and the second charging resistor are connected in parallel to the anode of a power supply, the cathode of the first charging resistor is connected with the first energy storage capacitor and the first voltage detection circuit which are connected in parallel, the cathode of the first charging resistor is connected with the anode of the second thyristor, the gate of the second thyristor is connected with one end of the second thyristor trigger circuit, the cathode of the second thyristor is connected with the other end of the second thyristor trigger circuit and the anode of the second diode, the negative electrode of the first energy storage capacitor is connected with the negative electrode of the third diode, and in a similar way, the negative electrode of the second charging resistor is connected with the second energy storage capacitor and the second voltage detection circuit which are connected in parallel, the negative electrode of the second charging resistor is connected with the positive electrode of the first thyristor, the gate electrode of the first thyristor is connected with one end of the first thyristor trigger circuit, the negative electrode of the first thyristor is connected with the other end of the first thyristor trigger circuit and the positive electrode of the first diode, the negative electrode of the second energy storage capacitor is connected with the negative electrode of the fourth diode, the positive electrode of the first diode is connected with the negative electrode of the third diode, the positive electrode of the second diode is connected with the negative electrode of the fourth diode, the negative electrode of the first diode and the second diode is connected with one end of the bypass switch trigger coil, and the other end of the bypass switch trigger coil is connected with the negative electrode of the power supply in parallel.
The invention has the beneficial effects that:
1. the redundancy trigger circuit for the bypass switch of the flexible-direct converter valve, which is designed by the invention, realizes the function of detecting the on-off state of the bypass switch trigger coil by setting the charging current of the energy storage capacitor to be uniform and passing through the bypass switch trigger coil.
2. The invention only uses a single power supply to supply power, has low requirement on engineering power supply, adopts a redundant bypass switch trigger circuit and has high reliability.
Drawings
FIG. 1 is a schematic diagram of a redundant trigger circuit for a bypass switch of a soft direct converter valve according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a thyristor trigger circuit in a schematic diagram of a redundant trigger circuit for a bypass switch of a soft direct current converter valve according to an embodiment of the present invention;
fig. 3 is a schematic diagram of a voltage detection circuit for use in a redundant trigger circuit of a bypass switch of a soft dc converter valve according to an embodiment of the present invention.
Wherein: 1. a first charging resistor; 2. a second charging resistor; 3. a first energy storage capacitor; 4. a second energy storage capacitor; 5. a first thyristor; 6. a second thyristor; 7. a first thyristor trigger circuit; 8. a second thyristor trigger circuit; 9. a first diode; 10. a second diode; 11. a third diode; 12. a fourth diode; 13. a bypass switch trigger coil; 14. a second voltage detection circuit; 15. a first voltage detection circuit; 16. an isolation transformer; 17. a rectifier diode; 18. a current limiting resistor; 19. an anti-parallel diode; 20. an up-sampling resistor; 21. a down-sampling resistor; 22. a hysteresis comparator.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer and clearer, the following detailed description of the present invention is provided with reference to the accompanying drawings and detailed description. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some but not all of the relevant aspects of the present invention are shown in the drawings.
According to fig. 1, the present embodiment provides a redundant trigger circuit for a bypass switch of a soft dc converter valve, which includes a first charging resistor 1, a second charging resistor 2, a first energy-storing capacitor 3, a second energy-storing capacitor 4, a first thyristor 5, a second thyristor 6, a first thyristor trigger circuit 7, a second thyristor trigger circuit 8, a first diode 9, a second diode 10, a third diode 11, a fourth diode 12, a bypass switch trigger coil 13, a second voltage detection circuit 14, and a first voltage detection circuit 15, wherein the anodes of the first charging resistor 1 and the second charging resistor 2 are connected in parallel to the anode of a power supply, the cathode of the first charging resistor 1 is connected to the first energy-storing capacitor 3 and the first voltage detection circuit 15 which are connected in parallel, the cathode of the first charging resistor 1 is connected to the anode of the second thyristor 6, the gate of the second thyristor 6 is connected to one end of the second thyristor trigger circuit 8, the cathode of the second thyristor 6 is connected with the other end of the second thyristor trigger circuit 8 and the anode of the second diode 10, the cathode of the first energy-storage capacitor 3 is connected with the cathode of the third diode 11, similarly, the cathode of the second charging resistor 2 is connected with the second energy-storage capacitor 4 and the second voltage detection circuit 14 which are connected in parallel, the cathode of the second charging resistor 2 is connected with the anode of the first thyristor 5, the gate of the first thyristor 5 is connected with one end of the first thyristor trigger circuit 7, the cathode of the first thyristor 5 is connected with the other end of the first thyristor trigger circuit 7 and the anode of the first diode 9, the cathode of the second energy-storage capacitor 4 is connected with the cathode of the fourth diode 12, the anode of the first diode 9 is connected with the cathode of the third diode 11, the anode of the second diode 10 is connected with the cathode of the fourth diode 12, the cathodes of the first diode 9 and the second diode 10 are connected with one end of the bypass switch trigger coil 13, the other end of the bypass switch trigger coil 13 is connected in parallel with the anodes of the third diode 11 and the fourth diode 12 to the negative electrode of the power supply.
The first thyristor trigger circuit 7 and the second thyristor trigger circuit 8 both comprise an isolation transformer 16, a rectifier diode 17, a current limiting resistor 18 and an anti-parallel diode 19, the power transformer 16 receives a trigger signal, one end of the output side of the power transformer drives the first thyristor 5 or the second thyristor 6 through the rectifier diode 17 and the current limiting resistor 18, the anode of the anti-parallel diode 19 is connected with the other end of the output side, and the cathode of the anti-parallel diode 19 is connected with the current limiting resistor 18.
The second voltage detection circuit 14 and the first voltage detection circuit 15 both include an up-sampling resistor 20, a down-sampling resistor 21 and a hysteresis comparator 22, the up-sampling resistor 20 and the down-sampling resistor 21 are connected in series and then connected in parallel at two ends of the first energy storage capacitor 3 or the second energy storage capacitor 4, a connection point between the up-sampling resistor 20 and the down-sampling resistor 21 is connected to an input end of the hysteresis comparator 22, and an output end of the hysteresis comparator 22 is an output end of the voltage detection circuit
The working principle is as follows:
the positive electrode of the power supply supplies power to the first energy storage capacitor 3 through the first charging resistor 1, the first energy storage capacitor 3 will charge gradually to the voltage close to the power supply; the power supply charges the second energy storage capacitor 4 through the second charging resistor 2, and the second energy storage capacitor 4 is gradually charged to a voltage close to the power supply.
The charging path of the first energy storage capacitor 3 is: the positive pole of the power supply passes through the first charging resistor 1, the first energy storage capacitor 3, the first diode 9, the bypass switch trigger coil 13 and the negative pole of the power supply.
The charging path of the second energy storage capacitor 4 is: the positive pole of the power supply passes through the second charging resistor 2, the second energy storage capacitor 4, the second diode 10, the bypass switch trigger coil 13 and the negative pole of the power supply.
The discharge path of the first energy storage capacitor 3 is: the high-voltage switch comprises the upper end of a first energy storage capacitor 3, a second thyristor 6, a second diode 10, a bypass switch trigger coil 13, a third diode 11 and the cathode of the first energy storage capacitor 3.
The discharge path of the second energy storage capacitor 4 is: the upper end of the second energy storage capacitor 4, the first thyristor 5, the first diode 9, the bypass switch trigger coil 13, the fourth diode 12 and the cathode of the second energy storage capacitor 4.
The first energy storage capacitor 3 is connected in parallel with a first voltage detection circuit 15, which can detect the charging voltage state of the first energy storage capacitor 3.
The second energy storage capacitor 4 is connected in parallel with a second voltage detection circuit 14, which can detect the charging voltage state of the second energy storage capacitor 4.
When the bypass switch trigger coil 13 in the circuit is in a conducting state, a redundant trigger circuit for the bypass switch of the flexible direct current converter valve of the embodiment works as follows:
1) before a redundant trigger circuit for a bypass switch of a flexible direct current converter valve is started, the voltage of a first energy storage capacitor 3 and the voltage of a second energy storage capacitor 4 are 0V, a first thyristor trigger circuit 7 and a second thyristor trigger circuit 8 have no trigger signals, and a first thyristor 5 and a second thyristor 6 are in a cut-off state;
2) after the power supply is powered on, the power supply charges the first energy storage capacitor 3 through the first charging resistor 1, the first energy storage capacitor 3, the first diode 9 and the bypass switch trigger coil 13; the power supply charges the second energy storage capacitor 4 through the second charging resistor 2, the second energy storage capacitor 4, the second diode 10 and the bypass switch trigger coil 13.
3) Because the first thyristor 5 and the second thyristor 6 are both in a cut-off state, no current flows, and the voltage of the first energy storage capacitor 3 and the voltage of the second energy storage capacitor 4 are continuously charged to be close to the voltage of the power supply. Via the first voltage detection circuit 15 and the second voltage detection circuit 14, the charging state of the first energy storage capacitor 3 and the second energy storage capacitor 4 can be recognized.
4) When the first thyristor trigger circuit 7 or the second thyristor trigger circuit 8 receives a trigger signal, the first thyristor 5 or the second thyristor 6 is turned on, so that the first energy storage capacitor 3 or the second energy storage capacitor 4 discharges to the bypass switch trigger coil 13 to trigger the bypass switch to be closed.
A redundant trigger circuit for a bypass switch of a limp-to-dc converter valve according to this embodiment operates when the bypass switch trigger coil 13 in the circuit is in an open fault condition as follows:
1) before a redundant trigger circuit for a bypass switch of a flexible direct current converter valve is started, the voltage of a first energy storage capacitor 3 and the voltage of a second energy storage capacitor 4 are 0V, a first thyristor trigger circuit 7 and a second thyristor trigger circuit 8 have no trigger signals, and a first thyristor 5 and a second thyristor 6 are in a cut-off state;
2) after the power supply is powered on, the bypass switch trigger coil 13 is in an open-circuit fault state, the first energy storage capacitor 3 and the second energy storage capacitor 4 cannot be charged, and the voltage is always 0V. Can be identified by the first voltage detection circuit 15 and the second voltage detection circuit 14 and alarms.
The above embodiments are only for illustrating the technical concept and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention accordingly, and not to limit the protection scope of the present invention accordingly. All equivalent changes or modifications made in accordance with the spirit of the present disclosure are intended to be covered by the scope of the present disclosure.
Claims (3)
1. A redundant trigger circuit that is used for gentle straight converter valve bypass switch which characterized in that: comprises a first charging resistor (1), a second charging resistor (2), a first energy storage capacitor (3), a second energy storage capacitor (4), a first thyristor (5), a second thyristor (6), a first thyristor trigger circuit (7), a second thyristor trigger circuit (8), a first diode (9), a second diode (10), a third diode (11), a fourth diode (12), a bypass switch trigger coil (13), a second voltage detection circuit (14) and a first voltage detection circuit (15), wherein the anodes of the first charging resistor (1) and the second charging resistor (2) are connected in parallel to the anode of a power supply, the cathode of the first charging resistor (1) is connected with the first energy storage capacitor (3) and the first voltage detection circuit (15) which are connected in parallel, the cathode of the first charging resistor (1) is connected with the anode of the second thyristor (6), the gate of the second thyristor (6) is connected with one end of the second thyristor trigger circuit (8), the cathode of the second thyristor (6) is connected with the other end of the second thyristor trigger circuit (8) and the anode of the second diode (10), the cathode of the first energy-storing capacitor (3) is connected with the cathode of the third diode (11), similarly, the cathode of the second charging resistor (2) is connected with the second energy-storing capacitor (4) and the second voltage detection circuit (14) which are connected in parallel, the cathode of the second charging resistor (2) is connected with the anode of the first thyristor (5), the gate of the first thyristor (5) is connected with one end of the first thyristor trigger circuit (7), the cathode of the first thyristor (5) is connected with the other end of the first thyristor trigger circuit (7) and the anode of the first diode (9), the cathode of the second energy-storing capacitor (4) is connected with the cathode of the fourth diode (12), the anode of the first diode (9) is connected with the cathode of the third diode (11), the anode of the second diode (10) is connected with the cathode of the fourth diode (12), the cathodes of the first diode (9) and the second diode (10) are connected with one end of the bypass switch trigger coil (13), and the other end of the bypass switch trigger coil (13) is connected with the cathodes of the third diode (11) and the fourth diode (12) in parallel to be connected into a power supply.
2. A redundant trigger circuit for a bypass switch of a soft dc converter valve according to claim 1, wherein: the first thyristor trigger circuit (7) and the second thyristor trigger circuit (8) respectively comprise an isolation transformer (16), a rectifier diode (17), a current-limiting resistor (18) and an anti-parallel diode (19), the power transformer (16) receives a trigger signal, one end of the output side of the power transformer drives the first thyristor (5) or the second thyristor (6) through the rectifier diode (17) and the current-limiting resistor (18), the anode of the anti-parallel diode (19) is connected with the other end of the output side, and the cathode of the anti-parallel diode (19) is connected with the current-limiting resistor (18).
3. A redundant trigger circuit for a bypass switch of a soft dc converter valve according to claim 1, wherein: second voltage detection circuit (14) and first voltage detection circuit (15) all include sampling resistor (20), down sampling resistor (21) and hysteresis comparator (22), parallelly connected at first energy-storing capacitor (3) or second energy-storing capacitor (4) both ends after sampling resistor (20) and down sampling resistor (21) are established ties, go up the tie point between sampling resistor (20) and down sampling resistor (21) and insert the input of hysteresis comparator (22), the output of hysteresis comparator (22) is voltage detection circuit's output.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911292233.2A CN110943603A (en) | 2019-12-13 | 2019-12-13 | Redundant trigger circuit for bypass switch of flexible direct current converter valve |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911292233.2A CN110943603A (en) | 2019-12-13 | 2019-12-13 | Redundant trigger circuit for bypass switch of flexible direct current converter valve |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110943603A true CN110943603A (en) | 2020-03-31 |
Family
ID=69911600
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911292233.2A Pending CN110943603A (en) | 2019-12-13 | 2019-12-13 | Redundant trigger circuit for bypass switch of flexible direct current converter valve |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110943603A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115173690A (en) * | 2022-08-12 | 2022-10-11 | 广东电网有限责任公司广州供电局 | Bypass switch trigger circuit and detection method |
-
2019
- 2019-12-13 CN CN201911292233.2A patent/CN110943603A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115173690A (en) * | 2022-08-12 | 2022-10-11 | 广东电网有限责任公司广州供电局 | Bypass switch trigger circuit and detection method |
| CN115173690B (en) * | 2022-08-12 | 2024-05-24 | 广东电网有限责任公司广州供电局 | Bypass switch trigger circuit and detection method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109546638A (en) | A kind of direct current energy-consuming device and control method | |
| CN109274256B (en) | Power module redundant energy supply circuit based on breakdown diode and control method | |
| CN102222904B (en) | Direct-current dual-circuit power supply for supplying power | |
| CN109742767A (en) | A kind of modularized dc energy-consuming device and control method | |
| CN107634504B (en) | Protection control device, the protection controller of PFC pfc circuit | |
| CN104466918B (en) | A kind of energy-storage battery reverse polarity protection circuit and recognition methods | |
| CN109787264A (en) | A kind of centralization energy-consuming device and its control method | |
| CN106655145A (en) | Battery bus voltage reverse connection protection circuit | |
| CN109546672A (en) | Direct current energy consumption device, system and control method | |
| CN108718077A (en) | A kind of high-pressure thyristor triggering control and state monitoring apparatus and its application process | |
| CN109494752A (en) | A kind of centralization resistance energy-consuming device and its control method | |
| CN109546674A (en) | A kind of bridge-type direct current energy-consuming device and control method | |
| CN103219776A (en) | High-power battery charging device capable of preventing battery reversal | |
| CN209675960U (en) | A kind of preliminary filling protective device | |
| CN110943603A (en) | Redundant trigger circuit for bypass switch of flexible direct current converter valve | |
| CN204290775U (en) | A kind of tri-level circuit of high fault tolerance | |
| CN211508897U (en) | Redundant trigger circuit for bypass switch of flexible direct current converter valve | |
| CN208730807U (en) | Intelligent track electric car ground polarity automatic transfer equipment | |
| CN204144922U (en) | Battery protecting circuit | |
| CN108809085A (en) | A kind of multistage inductive energy storage type pulse power and method of supplying power to | |
| CN206922502U (en) | Power-down protection control circuit and electronic equipment | |
| CN202997559U (en) | Input anti reversal connection protection circuit of solar energy controller | |
| CN203278367U (en) | Large power battery charging device capable of preventing reverse battery | |
| CN217282209U (en) | Open circuit protection device for current transformer | |
| CN109787463A (en) | A kind of chain type direct current energy-consuming device and control method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB02 | Change of applicant information | ||
| CB02 | Change of applicant information |
Address after: 510663 maintenance and test center, building 2, 223, science Avenue, Science City, Luogang District, Guangzhou City, Guangdong Province Applicant after: China Southern Power Grid Corporation Ultra High Voltage Transmission Company Electric Power Research Institute Applicant after: Rongxin Huike Electric Co.,Ltd. Address before: 510663 maintenance and test center, building 2, 223, science Avenue, Science City, Luogang District, Guangzhou City, Guangdong Province Applicant before: MAINTENANCE & TEST CENTRE, CSG EHV POWER TRANSMISSION Co. Applicant before: RONGXIN HUIKO ELECTRIC TECHNOLOGY Co.,Ltd. |