CN114301036B - Cascaded multi-level converter and on-load and off-load starting method thereof - Google Patents
Cascaded multi-level converter and on-load and off-load starting method thereof Download PDFInfo
- Publication number
- CN114301036B CN114301036B CN202111627857.2A CN202111627857A CN114301036B CN 114301036 B CN114301036 B CN 114301036B CN 202111627857 A CN202111627857 A CN 202111627857A CN 114301036 B CN114301036 B CN 114301036B
- Authority
- CN
- China
- Prior art keywords
- current
- load
- starting
- power
- direct
- 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.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 48
- 239000003990 capacitor Substances 0.000 claims abstract description 35
- 238000005070 sampling Methods 0.000 claims description 18
- 238000010586 diagram Methods 0.000 description 9
- 238000004590 computer program Methods 0.000 description 7
- 230000006870 function Effects 0.000 description 4
- 230000003111 delayed effect Effects 0.000 description 3
- 230000009466 transformation Effects 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
Landscapes
- Inverter Devices (AREA)
- Rectifiers (AREA)
Abstract
The invention discloses a cascading type multilevel converter and a loaded and unloaded starting method thereof, which comprises a starting cabinet and a power cabinet, wherein the power cabinet is connected into a power grid through the starting cabinet; the starting cabinet comprises a main circuit breaker, a pre-charging resistor and a pre-charging switch, wherein the pre-charging resistor and the pre-charging switch are connected in series and then connected with the main circuit breaker in parallel; the power cabinet comprises power units which are connected in series in multiple stages, alternating current sides of adjacent power units are connected in series, direct current sides of the power units are capacitors, and the alternating current sides and the direct current sides are connected through a full bridge or half bridge circuit. The advantages are that: firstly unlocking the pulse and then closing the main breaker, so that the precharge resistor plays a role in limiting current during the unlocking pulse, and current impact on equipment during the unlocking pulse is greatly avoided; the on-load starting method greatly avoids impact current brought to equipment when the main breaker is closed; the no-load starting method can reduce the current impact on equipment when the main breaker is closed.
Description
Technical Field
The invention relates to a cascading type multilevel converter and a loading and unloading starting method thereof, belonging to the technical field of power transmission and transformation.
Background
The cascade multilevel converter is generally formed by connecting a plurality of power units in series, wherein the direct current side of the power units is a capacitor, and the equipment can normally work only after the direct current side capacitor is charged when the equipment is started up and reaches the rated voltage.
In order to charge the capacitor at the direct current side, the cascaded multilevel converter is generally provided with a starting cabinet, the capacitor is precharged through a precharge resistor, then the resistor is short-circuited by combining a main breaker, the capacitor is directly connected with a power grid, and the capacitor is charged to a rated value through controllable rectification after unlocking pulse to finish starting. In this process, both the unlocking pulse and the merging of the main circuit breaker are accompanied by complex and rapid transient processes, which bring about a small current surge to the device. Such current surge can be avoided in theory, but is not easy to do in practice.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a cascading type multi-level converter and an on-load and off-load starting method thereof.
In order to solve the technical problems, the invention provides a cascading type multi-level converter, which comprises a starting cabinet and a power cabinet, wherein the power cabinet is connected to a power grid through the starting cabinet;
the starting cabinet comprises a main circuit breaker, a pre-charging resistor and a pre-charging switch, wherein the pre-charging resistor and the pre-charging switch are connected in series and then connected with the main circuit breaker in parallel;
the power cabinet comprises power units which are connected in series in multiple stages, alternating current sides of adjacent power units are connected in series, direct current sides of the power units are capacitors, and the alternating current sides and the direct current sides are connected through a full bridge or half bridge circuit.
A method for starting up cascade multilevel converter on load includes:
the main circuit breaker is controlled to be in an open state, the precharge switch is closed, and the power grid charges a direct-current side capacitor of the cascade multilevel converter for a preset time through the precharge switch and the precharge resistor;
after the precharge is completed, unlocking a power unit pulse of the power unit, and controlling the output current of the power cabinet to slowly increase from a set smaller value to a pre-sampling calculated current reference value containing equipment load current after unlocking;
closing a main breaker in the process of increasing the output current, and then opening a precharge switch;
after the precharge is completed, the power unit pulse of the power unit is unlocked, the voltage of the DC capacitor is continuously increased after the power unit is unlocked until the DC voltage reaches a set value, meanwhile, the output current is increased to the current reference value, the cascade multilevel converter enters a working state, and the starting is completed.
Further, the predetermined time period is not less than 2.5 times of the product of the total capacitance value of the direct-current side capacitor and the resistance value of the pre-charging resistor.
Further, the time of the main circuit breaker is zero when the output current of the cascade multilevel converter passes through after one period of the unlocking pulse.
Further, the minimum output current that sets the smaller value to 0 or that causes the cascaded multilevel converter to not be excessively modulated.
Further, the output current of the control power cabinet after unlocking slowly increases from a set smaller value to a pre-sampling calculated current reference value containing the equipment load current, and the method comprises the following steps:
the pre-sampled calculated current reference value containing the device load current is multiplied by a coefficient that slowly increases from a constant between 0, 1) to 1.
Further, the sampling the calculated current reference value containing the device load current includes:
sampling direct-current side voltage data, load current data to be compensated and alternating-current power grid voltage data, and calculating a current reference value containing equipment load current according to the direct-current side voltage data, the load current data to be compensated and the alternating-current power grid voltage data.
A cascade multi-level converter no-load starting method comprises the following steps:
the main circuit breaker is controlled to be in an open state, the precharge switch is closed, and the power grid charges a direct-current side capacitor of the cascade multilevel converter for a preset time through the precharge switch and the precharge resistor;
after the precharge is completed, unlocking the power unit pulse of the power unit, and controlling the power cabinet to calculate an idle current reference value for the pre-sampling after unlocking;
after unlocking pulse for a certain time, switching on the main breaker when the output current of the cascade multilevel converter passes zero, and then switching off the precharge switch;
after the power unit pulse of the power unit is unlocked, the power cabinet outputs current, the output current boosts the direct-current side capacitor, and when the voltage of the direct-current side capacitor reaches a set value, starting is completed.
Further, the predetermined time period is not less than 2.5 times of the product of the total capacitance value of the direct-current side capacitor and the resistance value of the pre-charging resistor.
Further, the main breaker is combined in the process of increasing the output current, and the main breaker comprises:
and after the unlocking pulse is delayed for a preset time, closing the main circuit breaker at the zero crossing moment of the output current.
Further, the sampling calculates an idle current reference value, including:
and sampling the direct-current side voltage data and the alternating-current power grid voltage data, and calculating to obtain an idle current reference value according to the direct-current side voltage data and the alternating-current power grid voltage data.
A computer readable storage medium storing one or more programs, the one or more programs comprising instructions, which when executed by a computing device, cause the computing device to perform any of the methods.
A computing device, comprising,
one or more processors, memory, and one or more programs, wherein one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs comprising instructions for performing any of the methods.
The invention has the beneficial effects that:
the application provides two cascaded multi-level converter starting strategies which can meet two different working conditions of on-load starting and no-load starting.
(1) In the two strategies, the pulse is unlocked firstly, and then the main breaker is closed, so that the pre-charging resistor plays a role in limiting current during the unlocking pulse, and current impact on equipment during the unlocking pulse is avoided greatly.
(2) In the on-load starting strategy, the output current of the equipment is slowly increased, and the main circuit breaker is closed when the output current is smaller, so that the pressure difference at two ends of the main circuit breaker is small, and the impact current brought to the equipment when the main circuit breaker is closed is greatly avoided.
(3) In the no-load starting strategy, the time of equipment load current input is delayed, so that the current of a starting loop can be kept at a small value, and the effect of reducing current impact on equipment when a main breaker is closed is also achieved.
(4) After the unlocking pulse, the main circuit breaker and the bypass pre-charging circuit are timely closed, so that the heating of the pre-charging resistor can be reduced, and the capacity requirement of the pre-charging resistor is lowered.
Drawings
FIG. 1 is a schematic diagram of a circuit topology of a cascaded multilevel converter according to the present invention;
FIG. 2 is a flow chart of the on-load start-up of the cascaded multilevel converter of the present invention;
FIG. 3 is a graph showing waveforms of reference current and output current during on-load start of the cascaded multilevel converter of the present invention;
FIG. 4 is a waveform diagram of DC side capacitor voltage during on-load start of the cascaded multilevel converter according to the present invention;
FIG. 5 is a flow chart of the idle starting of the cascaded multilevel converter according to the present invention;
FIG. 6 is a graph showing waveforms of reference current and output current of the cascaded multilevel converter of the present invention during idle start;
FIG. 7 is a waveform diagram of DC side capacitor voltage during idle start of the cascaded multilevel converter of the present invention;
in fig. 1-7, 1, a starting cabinet; 1-1, a main breaker; 1-2, a precharge switch; 1-3, pre-charging resistor; 2. a power cabinet; 2-1, a power unit; 2-1-1, direct current side capacitance.
Detailed Description
The invention is further described below with reference to the accompanying drawings. The following examples are only for more clearly illustrating the technical aspects of the present invention, and are not intended to limit the scope of the present invention.
In a specific embodiment 1, a cascaded multi-level converter is shown in fig. 1, and includes a starting cabinet 1 and a power cabinet 2, wherein the power cabinet 2 is connected to a power grid through the starting cabinet 1; the starting cabinet 1 comprises a main circuit breaker 1-1, and a precharge resistor 1-3 and a precharge switch 1-2 are connected in series and then connected with the main circuit breaker 1-1 in parallel; the power cabinet 2 comprises power units 2-1 which are connected in series in multiple stages, the power units 2-1 are connected in series through an alternating current side, a direct current side is a capacitor 2-1-1, and the alternating current side and the direct current side are connected through a full bridge or half bridge circuit.
The control object of the cascaded multilevel converter is output current when the cascaded multilevel converter is started; when in on-load starting, sampling direct-current side voltage data, load current data to be compensated and alternating-current power grid voltage data, and obtaining a current reference value containing equipment load current through phase locking, coordinate transformation and other calculation processes; the on-load strategy process is shown in fig. 2, the output current waveform of the cascaded multilevel converter is shown in fig. 3, the capacitor voltage waveform is shown in fig. 4, and the on-load starting method of the cascaded multilevel converter comprises the following specific steps:
(1) Firstly, precharging, wherein the main circuit breaker 1-1 is in an open state, the precharge switch 1-2 is closed, and a power grid charges a direct-current side capacitor 2-1-1 of the cascade multilevel converter through the precharge switch 1-2 and the precharge resistor 1-3; as can be seen from FIG. 3, the cascade multilevel converter is in an uncontrolled rectifying state, and the charging current can be adjusted by adjusting the resistance of the precharge resistors 1-3, which is easy to limit.
(2) After the precharge is finished, the power unit 2-1 unlocks the pulse and controls the output current to slowly increase from a set smaller value; the smaller value set here is 0; as can be seen from fig. 3, the output current of the cascaded multilevel converter has a certain impact when unlocking the pulse, but is limited to a very low level.
(3) The main breaker 1-1 is closed in the output current increasing process, the time of closing the main breaker 1-1 is selected when the output current crosses zero, the voltage at two ends of the main breaker is lower, and the current impact when the main breaker 1-1 is closed is smaller. After the main breaker switch 1-1 is closed, the precharge switch 1-2 is opened; as can be seen from fig. 3, there is also some current surge when the main breaker is closed, but the current surge is limited to be small.
(4) The voltage of the direct-current side capacitor 2-1-1 reaches the set value, and the starting is completed, namely, the voltage of the direct-current side capacitor 2-1-1 reaches around 900V in fig. 4. At this time, as shown in fig. 3, the output current is increased to the reference value calculated by sampling, and the cascaded multilevel converter enters an operating state.
As can be seen from fig. 4, in the whole starting process, the capacitor voltage at the direct current side is slowly increased to the set value, and the increasing process is smooth, has no excessive fluctuation and is in line with expectations.
In a specific embodiment 2, the cascaded multilevel converter structure is the same as that of embodiment 1. The control object of the cascaded multilevel converter is output current when the cascaded multilevel converter is started; when no-load is started, sampling direct-current side voltage data and alternating-current power grid voltage data, and obtaining a no-load current reference value through phase locking, coordinate transformation and other calculation processes; the no-load strategy process is shown in fig. 5, the output current waveform of the cascaded multilevel converter is shown in fig. 6, the capacitor voltage waveform is shown in fig. 7, and the no-load starting method of the cascaded multilevel converter comprises the following specific steps:
(1) Firstly, precharging, wherein the main circuit breaker 1-1 is in an open state, the precharge switch 1-2 is closed, and a power grid charges a direct-current side capacitor 2-1-1 of the cascade multilevel converter through the precharge switch 1-2 and the precharge resistor 1-3; as can be seen from FIG. 3, the cascade multilevel converter is in an uncontrolled rectifying state, and the charging current can be adjusted by adjusting the resistance of the precharge resistors 1-3, which is easy to limit.
(2) After the precharge is finished, the power unit 2-1 unlocks the pulse and controls the output current to be a reference value calculated by sampling; as can be seen from fig. 6, the output current of the cascaded multi-level converter has a certain impact when unlocking the pulse, but is limited to a very low level.
(3) After 20ms of unlocking pulse (), the main breaker 1-1 is closed at the moment when the output current crosses zero, and then the precharge switch 1-2 is opened. As can be seen from fig. 6, since the device output current is small, the voltage across the main breaker 1-1 is low when it is closed, and there is some current surge when the main breaker is closed, but the current surge is limited to be small.
(4) The voltage of the direct-current side capacitor 2-1-1 reaches a set value, and the starting is completed, namely, when the voltage of the direct-current side capacitor is stabilized near 900V as shown in FIG. 7;
(5) After the start-up is completed, as shown in fig. 6, the reference value of the output current of the cascaded multilevel converter is made to include the device load current, and the cascaded multilevel converter is put into an operating state.
As can be seen from fig. 7, during the whole starting process, the capacitor voltage at the direct current side is slowly increased to the set value, and the increasing process is smooth, has no excessive fluctuation and is in line with expectations.
The invention provides a cascading type multi-level converter starting strategy, and provides two strategies of loading starting and unloading starting aiming at two working conditions of loading and unloading, in the two strategies, the pulse is unlocked firstly, and then the main breaker is closed, so that the pre-charge resistor plays a role in limiting current when the pulse is unlocked, and the current impact on equipment when the pulse is unlocked is avoided greatly; in the on-load starting strategy, the output current of the equipment is slowly increased, and the main circuit breaker is closed when the output current is smaller, so that the pressure difference between two ends of the main circuit breaker is small, and the impact current brought to the equipment when the main circuit breaker is closed is greatly avoided; in the no-load starting strategy, the time of equipment load current input is delayed, so that the current of a starting loop is kept at a small value, and the effect of reducing the impact current is also achieved; after the unlocking pulse, the main circuit breaker and the bypass pre-charging circuit are timely closed, so that the heating of the pre-charging resistor can be reduced, and the capacity requirement of the pre-charging resistor is lowered.
The corresponding invention also provides a computer readable storage medium storing one or more programs, the one or more programs comprising instructions, which when executed by a computing device, cause the computing device to perform any of the methods.
The corresponding invention also provides a computing device comprising,
one or more processors, memory, and one or more programs, wherein one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs comprising instructions for performing any of the methods.
It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
The foregoing is merely a preferred embodiment of the present invention, and it should be noted that modifications and variations could be made by those skilled in the art without departing from the technical principles of the present invention, and such modifications and variations should also be regarded as being within the scope of the invention.
Claims (9)
1. A method for starting up cascade multilevel converter in load or idle state is characterized in that,
the cascading type multi-level converter comprises a starting cabinet (1) and a power cabinet (2), wherein the power cabinet (2) is connected into a power grid through the starting cabinet (1);
the starting cabinet (1) comprises a main circuit breaker (1-1), a pre-charging resistor (1-3) and a pre-charging switch (1-2), wherein the pre-charging resistor (1-3) and the pre-charging switch (1-2) are connected in series and then connected with the main circuit breaker (1-1) in parallel;
the power cabinet (2) comprises a plurality of stages of power units (2-1) which are connected in series, the alternating current sides of the adjacent power units (2-1) are connected in series, the direct current side of the power unit (2-1) is a capacitor (2-1-1), and the alternating current side and the direct current side are connected through a full bridge or half bridge circuit;
the method comprises the following steps: a loaded starting method and an unloaded starting method;
the on-load starting method comprises the following steps:
the main circuit breaker (1-1) is controlled to be in an open state, the precharge switch (1-2) is closed, and the power grid charges the direct-current side capacitor (2-1-1) of the cascading type multilevel converter for a preset time through the precharge switch (1-2) and the precharge resistor (1-3);
after the precharge is completed, unlocking the power unit pulse of the power unit (2-1), and controlling the output current of the power cabinet (2) to slowly increase from a set value to a current reference value which is calculated by pre-sampling and contains equipment load current after unlocking;
closing the main breaker (1-1) during the output current increase, and then opening the precharge switch (1-2);
after the precharge is finished, unlocking the power unit pulse of the power unit (2-1), and continuously increasing the voltage of the direct current capacitor after unlocking until the direct current voltage reaches a set value, increasing the output current to the current reference value, enabling the cascade multilevel converter to enter a working state, and finishing starting;
the no-load starting method comprises the following steps:
the main circuit breaker (1-1) is controlled to be in an open state, the precharge switch (1-2) is closed, and the power grid charges the direct-current side capacitor (2-1-1) of the cascading type multilevel converter for a preset time through the precharge switch (1-2) and the precharge resistor (1-3);
after the precharge is completed, unlocking the power unit pulse of the power unit (2-1), and controlling the power cabinet (2) to calculate an idle current reference value for the pre-sampling after unlocking;
after unlocking pulse for a certain time, switching on the main breaker (1-1) when the output current of the cascade multilevel converter passes zero, and then switching off the precharge switch (1-2);
after the power unit pulse of the unlocking power unit (2-1), the power cabinet (2) outputs current which boosts the direct-current side capacitor (2-1-1), and when the voltage of the direct-current side capacitor (2-1-1) reaches a set value, the starting is completed
The output current of the control power cabinet (2) after unlocking slowly increases from a set value to a pre-sampling calculated current reference value containing equipment load current, and the method comprises the following steps:
the pre-sampled calculated current reference value containing the device load current is multiplied by a coefficient that slowly increases from a constant between 0, 1) to 1.
2. The on-load and off-load starting method of the cascaded multilevel converter according to claim 1, wherein the predetermined time period is not less than 2.5 times of the product of the total capacitance value of the direct current side capacitor (2-1-1) and the resistance value of the precharge resistor (1-3).
3. The on-load and off-load starting method of the cascaded multilevel converter according to claim 1, wherein the time of the main circuit breaker (1-1) is zero when the output current of the cascaded multilevel converter passes through after one period of the unlocking pulse.
4. The method of claim 1, wherein the set value is 0 or a minimum output current that does not cause the cascaded multilevel converter to be overmodulated.
5. The method for on-load and off-load starting of a cascaded multilevel converter according to claim 1, wherein the sampling the calculated current reference value comprising the device load current comprises:
sampling direct-current side voltage data, load current data to be compensated and alternating-current power grid voltage data, and calculating a current reference value containing equipment load current according to the direct-current side voltage data, the load current data to be compensated and the alternating-current power grid voltage data.
6. The on-load and off-load starting method of a cascaded multilevel converter according to claim 1, wherein the main circuit breaker (1-1) is incorporated during an output current increasing process, comprising:
after the unlocking pulse is preset for delay time, the main breaker (1-1) is closed at the zero crossing moment of the output current.
7. The method of claim 1, wherein the sampling calculates an idle current reference value, comprising:
and sampling the direct-current side voltage data and the alternating-current power grid voltage data, and calculating to obtain an idle current reference value according to the direct-current side voltage data and the alternating-current power grid voltage data.
8. A computer readable storage medium storing one or more programs, wherein the one or more programs comprise instructions, which when executed by a computing device, cause the computing device to perform any of the methods of claims 1-7.
9. A computing device, comprising,
one or more processors, memory, and one or more programs, wherein one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs comprising instructions for performing any of the methods of claims 1-7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111627857.2A CN114301036B (en) | 2021-12-28 | 2021-12-28 | Cascaded multi-level converter and on-load and off-load starting method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111627857.2A CN114301036B (en) | 2021-12-28 | 2021-12-28 | Cascaded multi-level converter and on-load and off-load starting method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114301036A CN114301036A (en) | 2022-04-08 |
| CN114301036B true CN114301036B (en) | 2024-03-26 |
Family
ID=80970665
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111627857.2A Active CN114301036B (en) | 2021-12-28 | 2021-12-28 | Cascaded multi-level converter and on-load and off-load starting method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114301036B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103337969A (en) * | 2013-04-15 | 2013-10-02 | 湖南大学 | Method for MMC type VSC-HVDC system precharge control |
| CN103532418A (en) * | 2013-04-18 | 2014-01-22 | 中国矿业大学 | SVG submodule capacitor pre-charging strategy based on MMC |
| CN104953608A (en) * | 2014-03-26 | 2015-09-30 | 常勇 | DC-side pre-charging starting method for modular multi-level converter type high-voltage DC power transmission system connected with passive network |
| CN111313451A (en) * | 2019-11-29 | 2020-06-19 | 国网天津市电力公司电力科学研究院 | Medium-voltage direct-current power distribution network starting method based on half-bridge MMC |
| CN112039104A (en) * | 2020-07-16 | 2020-12-04 | 南京东博智慧能源研究院有限公司 | Starting method of hybrid multi-terminal direct-current power transmission system |
| CN113300620A (en) * | 2021-05-08 | 2021-08-24 | 许继集团有限公司 | Starting method and system of modular multilevel matrix converter |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3026803A1 (en) * | 2014-11-25 | 2016-06-01 | Alstom Technology Ltd | Start-up of HVDC converters |
-
2021
- 2021-12-28 CN CN202111627857.2A patent/CN114301036B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103337969A (en) * | 2013-04-15 | 2013-10-02 | 湖南大学 | Method for MMC type VSC-HVDC system precharge control |
| CN103532418A (en) * | 2013-04-18 | 2014-01-22 | 中国矿业大学 | SVG submodule capacitor pre-charging strategy based on MMC |
| CN104953608A (en) * | 2014-03-26 | 2015-09-30 | 常勇 | DC-side pre-charging starting method for modular multi-level converter type high-voltage DC power transmission system connected with passive network |
| CN111313451A (en) * | 2019-11-29 | 2020-06-19 | 国网天津市电力公司电力科学研究院 | Medium-voltage direct-current power distribution network starting method based on half-bridge MMC |
| CN112039104A (en) * | 2020-07-16 | 2020-12-04 | 南京东博智慧能源研究院有限公司 | Starting method of hybrid multi-terminal direct-current power transmission system |
| CN113300620A (en) * | 2021-05-08 | 2021-08-24 | 许继集团有限公司 | Starting method and system of modular multilevel matrix converter |
Non-Patent Citations (2)
| Title |
|---|
| 刘璇 ; 李琦 ; 乐波 ; 宋强 ; .DFIG风场并网柔直***的启动策略研究.电力电子技术.2016,(第11期),全文. * |
| 张航 ; 李耀华 ; 高范强 ; 李子欣 ; 罗龙 ; 胡钰杰 ; 王平 ; 张宸宇 ; .级联矩阵型交直流电力电子变压器预充电策略.电工电能新技术.2020,(第06期),全文. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114301036A (en) | 2022-04-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101540583B (en) | Motor controller | |
| CN103308869B (en) | Modular multi-level multi-terminal flexible direct-current transmission system starting characteristics test method | |
| CN109193795A (en) | EMU parallel connection auxiliary converter synchronous SS (soft start) networking control strategy | |
| JP5717189B2 (en) | Phase advance capacitor controller | |
| Selim et al. | Fast quasi‐static time‐series analysis and reactive power control of unbalanced distribution systems | |
| CN114884078A (en) | High-voltage direct-hanging system integrating reactive compensation and energy storage | |
| CN114301036B (en) | Cascaded multi-level converter and on-load and off-load starting method thereof | |
| EP3298682B1 (en) | Method and device for damping voltage harmonics in a multilevel power converter | |
| CN110544953A (en) | Method and system for checking steady-state voltage after extra-high voltage direct current fault | |
| CN107465360B (en) | Harmonic circulating current eliminating method and device for modular multilevel converter | |
| Shah et al. | Power quality improvement using ultra capacitor based dynamic voltage restorer with real twisting sliding mode control | |
| CN111654034A (en) | Park level voltage sag layered and graded treatment system and method and terminal equipment | |
| CN112152237A (en) | Transformer area power quality management method and system based on multi-DFACTS device coordination control | |
| JP2018148664A (en) | Reactive power compensator and control system of the same | |
| CN109193689B (en) | Voltage reactive power regulation time interval dividing method and device | |
| CN113852067B (en) | Method, system, storage medium and equipment for controlling seamless switching between off-grid and on-grid | |
| CN110568775A (en) | Data center load control method and device, server and storage medium | |
| CN110838716B (en) | Transformer starting impact current suppression system and method | |
| CN109995057B (en) | UPS current equalizing method and equipment | |
| Wang | Multi-mode tri-state operation of a 4-switch bidirectional DC-DC converter for interfacing a supercapacitor to a DC grid | |
| Liu et al. | Predictive direct power control for rectifier stage of solid state transformer | |
| CN108288909A (en) | Method and apparatus for bus voltage ripple control | |
| Choi et al. | Current sharing algorithm for parallel operation of single phase UPS inverters using predictive current control | |
| CN103199550A (en) | Capacitor voltage balance control method of cascade reactive power compensation device | |
| Sorokin et al. | Power factor corrector for bipolar unbalanced load and asymmetrical three-phase power supply |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |