CN112736957A - Harmonic compensation type flexible direct current converter and control method - Google Patents
Harmonic compensation type flexible direct current converter and control method Download PDFInfo
- Publication number
- CN112736957A CN112736957A CN202011545581.9A CN202011545581A CN112736957A CN 112736957 A CN112736957 A CN 112736957A CN 202011545581 A CN202011545581 A CN 202011545581A CN 112736957 A CN112736957 A CN 112736957A
- Authority
- CN
- China
- Prior art keywords
- converter
- controller
- current
- harmonic compensation
- harmonic
- 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
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/01—Arrangements for reducing harmonics or ripples
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2203/00—Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
- H02J2203/20—Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/40—Arrangements for reducing harmonics
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Supply And Distribution Of Alternating Current (AREA)
Abstract
The invention discloses a harmonic compensation type flexible direct current converter and a control method, and relates to the field of power transmission and distribution of a power system. This flexible direct current converter of harmonic compensation type is including active power control and harmonic compensation two parts, this converter is on the one hand through the outer loop decide the active power transmission of power control assurance converter, on the other hand carries out predictive analysis through the harmonic of controlling converter or diode rectifier access direct current transmission system mutually, as this flexible direct current converter of harmonic compensation type's control command, control flexible direct current converter after with the stack of active control command value, make flexible direct current converter in active power transmission, need not to dispose extra filter equipment just can compensate the harmonic of mixing direct current transmission system access point, with the whole electric energy quality who promotes mixing direct current transmission system. The invention is suitable for the design and manufacture of the flexible direct current converter and the harmonic compensation control of a direct current transmission system comprising the voltage source converter.
Description
Technical Field
The invention relates to the field of power transmission and distribution of a power system, in particular to a harmonic compensation type flexible direct current converter and a control method.
Background
The characteristic that energy bases and load centers in China are distributed reversely in space prompts urgent needs of large-scale optimal allocation of energy resources. Due to the advantage of long-distance large-capacity power transmission, the direct-current power transmission technology plays an important role in the process of energy resource optimal configuration. However, the use of a large number of converters and the power electronics of the power system make the power system nonlinear, so that the harmonic problem of the power system is increasingly prominent.
Currently, the method for engineering dealing with the harmonic of the hybrid dc power transmission system is to configure a filter. The types of filters are: passive filters, active filters and hybrid filters. The passive filter has the advantages of simple structure, low cost, high operation reliability, low operation cost and the like, is widely applied to harmonic control, but has a harmonic filtering rate of only 80% generally and limited reactive compensation for fundamental waves. The active filtering depends on a power electronic device, and generates a group of harmonic phasors which are equal to the system amplitude and opposite to the system phase when detecting the system harmonic, so that the system harmonic is offset, and the waveform of the system harmonic is sinusoidal. The active filtering can filter out harmonic waves and can also dynamically compensate reactive power. Its advantages are quick response and high filtering speed up to 95% or more. Compared with a passive filter, the active filter has a good treatment effect, can mainly filter multiple times of higher harmonics and cannot cause resonance. However, the active filter has the disadvantages of high price, small capacity and very limited improvement on harmonic waves. No matter the passive filter or the active filter is an additional device configured for inhibiting system harmonic waves, the structure of the system is complicated, the occupied area of the converter is increased, the site selection and the engineering cost of the converter are greatly influenced, and the method is particularly obvious in the open sea wind power direct current transmission project.
Disclosure of Invention
Aiming at the defects or improvement requirements of the prior art, the invention provides a harmonic compensation type flexible direct current converter and a control method, so that a hybrid direct current power transmission system does not need to be additionally provided with a filtering device, the problems of large occupied area, unsatisfactory filtering effect, high investment and limited capacity of an active filter technology in the prior passive filtering technology are solved, and the economy of the hybrid direct current power transmission system is greatly improved.
In order to achieve the above object, according to one aspect of the present invention, there is provided a harmonic compensation type flexible dc converter, which is applied to a hybrid dc power transmission system using flexible dc power transmission, and can compensate harmonic voltage or current of the hybrid dc power transmission system by outputting harmonic voltage while ensuring active power transmission, the converter includes an active power controller, an inner loop current controller, a first amplitude limiting link, a harmonic compensation controller, a second amplitude limiting link, and a third amplitude limiting link.
The output of an active power controller is used as the input of an inner loop current controller, wherein the active power controller is used for regulating the active transmission of the flexible direct current converter, the inner loop current controller is used for ensuring the tracking of the output current of the converter and the ring current suppression inside the converter, a modulation signal output by the inner loop current controller is connected with the first amplitude limiting link, and the first amplitude limiting link is used for limiting the amplitude of the modulation signal;
harmonic components of a phase control converter or a diode rectifier in the hybrid direct-current power transmission system are input to a harmonic compensation controller, harmonic compensation control quantity output by the harmonic compensation controller is connected with the second amplitude limiting link, and the second amplitude limiting link is used for limiting amplitude of the harmonic compensation control quantity;
the control quantity of the current converter obtained by superposing the output quantity of the active power controller or the inner ring current controller or the first amplitude limiting link and the output quantity of the harmonic compensator is input into a third amplitude limiting link, the third amplitude limiting link is used for limiting the amplitude of the control quantity, and the control quantity of the current converter after modulation is used for harmonic compensation of the voltage and the current of a control point and is used for improving the electric energy quality of the hybrid direct-current transmission system.
Preferably, the active power controller comprises: any one of an active power proportional-integral controller, an active power proportional controller, an active power fuzzy logic controller, an active power neural network controller, an active power repetitive controller and active power model predictive control.
Preferably, the inner loop current controller includes: any one of an inner loop current proportional-integral controller, an inner loop current proportional controller, an inner loop current fuzzy logic controller and an inner loop current neural network controller.
Preferably, the harmonic compensation controller includes: any one of a harmonic compensation proportional-integral controller, a harmonic compensation proportional controller, a harmonic compensation fuzzy logic controller, a harmonic compensation neural network controller, a harmonic compensation repetitive controller and a harmonic compensation model predictive control.
Preferably, the converter outer ring control can adopt any one of active type or reactive type control quantity or adopt the two types simultaneously, and can complete the harmonic compensation of any point of the hybrid direct-current transmission system.
By establishing a mathematical model for the hybrid direct-current power transmission system, the harmonic condition of any point of the system can be calculated numerically, and the harmonic condition is taken as a basis and a control reference to control the harmonic compensation type flexible direct-current converter to generate harmonic voltage or current with the same amplitude and opposite phase with the previous harmonic at the point, so that the harmonic compensation is completed, and the electric energy quality of the hybrid direct-current power transmission system is improved.
As another aspect of the present invention, the present invention provides a method for controlling a harmonic compensation type flexible dc converter, including the steps of:
s1, taking the output quantity of an active power controller as an input reference value of an inner ring current controller;
s2, carrying out predictive analysis on harmonic components of a phase control converter or a diode rectifier in the hybrid direct-current power transmission system, using the harmonic components as input quantities of a harmonic compensation controller, and generating corresponding harmonic compensation control quantities;
s3, overlapping the output quantity of the active power controller or the inner ring current controller or the first amplitude limiting link and the output quantity of the harmonic compensator to the control quantity of the converter;
and S4, modulating the control quantity of the current converter, and ensuring the active power transmission of the current converter and the harmonic compensation of the voltage and the current of a control point so as to improve the electric energy quality of the hybrid direct-current power transmission system.
Preferably, the harmonic compensation control method provided by the invention can be applied to any voltage source converter such as a two-level converter, a three-level converter and a modular multi-level converter.
Preferably, the harmonic compensation type flexible direct current converter and the control system thereof provided by the invention can be applied to any hybrid direct current transmission system comprising a voltage source type converter, and can perform harmonic compensation on the hybrid direct current transmission system in a unipolar, bipolar and pseudo-bipolar main connection mode of the system.
Compared with the prior art, the harmonic compensation type flexible direct current converter and the control method thereof provided by the invention can compensate the harmonic of the hybrid direct current transmission system while ensuring the transmission of active power, do not need to be provided with an additional filtering device, simplify the design of the system, improve the quality of electric energy and greatly reduce the cost and the volume of the hybrid direct current transmission system.
Drawings
Fig. 1 is a schematic diagram of a prior art parallel hybrid dc transmission system;
FIG. 2 is a control schematic diagram of a harmonic compensation type flexible DC circulator according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of the AC side of the rectification side of the hybrid DC transmission system;
fig. 4 is a schematic diagram of active power transmission of a hybrid dc power transmission system by connecting an LCC and an MMC in parallel;
FIG. 5 is a schematic diagram of a hybrid DC power transmission system with LCC connected in series with MMC for connecting a pseudo bipolar system for active power transmission;
FIG. 6 is a schematic diagram of a hybrid DC power transmission system with LCC connected in series with MMC for active power transmission by bipolar system wiring;
FIG. 7 is a schematic diagram of a hybrid DC power transmission system with LCC in series with MMC for active power transmission with single pole system wiring;
FIG. 8 is a schematic diagram of a hybrid DC power transmission system with a single LCC in series with multiple parallel MMCs for power transmission;
FIG. 9 is a schematic diagram of active power transmission of a hybrid DC power transmission system from DR in parallel with MMC;
FIG. 10 is a schematic diagram of a hybrid DC power transmission system with DR in series with MMC for active power transmission with pseudo bipolar system wiring;
FIG. 11 is a schematic diagram of a hybrid DC power transmission system with DR connected in series with MMC for active power transmission with bipolar system wiring;
FIG. 12 is a schematic diagram of a hybrid DC power transmission system with active power transmission from DR and MMC connected in series, wired for monopolar system;
FIG. 13 is a schematic diagram of an embodiment of a hybrid DC power transmission system employing a harmonic compensation type flexible DC converter;
fig. 14 shows net-side ac current actual values of the inverter MMC;
fig. 15 shows the net-side ac current actual value of the inverter LCC;
FIG. 16 shows the actual value of the grid AC current;
fig. 17 shows the actual value of the active power transmission of the converter LCC;
fig. 18 shows the real value of the active power transmission of the inverter MMC.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
The invention provides a harmonic compensation type flexible direct current converter which is used for active power transmission of a direct current transmission system, can be used as an active filter for compensating harmonic waves of a hybrid direct current transmission system, and can reduce the use of passive filtering of the hybrid direct current transmission system, thereby reducing the engineering construction cost and the occupied space, improving the filtering effect and improving the electric energy quality of the hybrid direct current transmission system. The active power control device comprises an active power controller, an inner ring current controller, a first amplitude limiting link, a harmonic compensation controller, a second amplitude limiting link and a third amplitude limiting link.
The output of an active power controller is used as the input of an inner loop current controller, wherein the active power controller is used for regulating the active transmission of the flexible direct current converter, the inner loop current controller is used for ensuring the tracking of the output current of the converter and the ring current suppression inside the converter, a modulation signal output by the inner loop current controller is connected with the first amplitude limiting link, and the first amplitude limiting link is used for limiting the amplitude of the modulation signal;
harmonic components of a phase control converter or a diode rectifier in the hybrid direct-current power transmission system are input to a harmonic compensation controller, harmonic compensation control quantity output by the harmonic compensation controller is connected with the second amplitude limiting link, and the second amplitude limiting link is used for limiting amplitude of the harmonic compensation control quantity;
the control quantity of the current converter obtained by superposing the output quantity of the active power controller or the inner ring current controller or the first amplitude limiting link and the output quantity of the harmonic compensator is input into a third amplitude limiting link, the third amplitude limiting link is used for limiting the amplitude of the control quantity, and the control quantity of the current converter after modulation is used for harmonic compensation of the voltage and the current of a control point and is used for improving the electric energy quality of the hybrid direct-current transmission system.
The physical meanings of the main variables or abbreviations involved in the examples of the present invention are listed in table 1 below.
TABLE 1
| Name of variable | Physical significance |
| LCC | Phase-changing current converter for power grid |
| MMC | Modular multilevel converter |
| DR | Diode converter |
| Us | Network voltage |
| is1 | Network current |
| is2 | Network side alternating current of power grid phase-change converter |
| is3 | Network side alternating current of modular multilevel converter |
| PLCC | Actual value of active power of power grid commutation converter |
| PMMC | Actual active power value of modular multilevel converter |
| M | Controller output modulation ratio |
Fig. 1 is a schematic diagram of a conventional parallel hybrid dc power transmission system. The LCC and the MMC are connected in parallel and are jointly accessed into the hybrid direct-current power transmission system to transmit active power. And a passive filter is configured at the LCC to filter the harmonic waves of the LCC and provide reactive compensation. The problems are that firstly, the passive filter has limited filtering effect and improves the harmonic condition of the system. Secondly, the occupied area of the passive filter is large and is about one third of that of the convertor station, so that the construction cost and the design difficulty are improved, and the characteristic is particularly obvious in the construction of open sea wind power.
Fig. 2 is a control schematic diagram of a harmonic compensation type flexible dc converter according to an embodiment of the present invention, and the output quantity of an active power controller is used as an input reference value of an inner-loop current controller, wherein the active power controller is used for adjusting the active transmission of the flexible dc converter, and the inner-loop current controller is used for ensuring the tracking of the output current of the converter on the reference value and the loop current suppression inside the converter;
carrying out predictive analysis on harmonic components of the hybrid direct-current power transmission system, using the harmonic components as input quantities of a harmonic compensation controller, and generating corresponding harmonic compensation control quantities;
superposing the modulation signal of the inner ring current controller and the modulation signal of the harmonic compensator to obtain the control quantity of the current converter;
the control quantity of the current converter is modulated, active power transmission of the current converter and harmonic compensation of voltage and current of a control point are ensured, and therefore the electric energy quality of the hybrid direct-current transmission system is improved.
Fig. 3 is a schematic diagram of an ac terminal on a rectification side of a hybrid dc power transmission system, where the ac terminal may include only one ac system, or may be any combination of an ac power grid, a wind power island, and a photovoltaic base. The combination method comprises the following steps: the system comprises an alternating current power grid + wind power island, an alternating current power grid + photovoltaic base, a wind power island + photovoltaic base and an alternating current power grid + wind power island + photovoltaic base.
Fig. 4 is a schematic diagram of active power transmission of a hybrid dc power transmission system in another embodiment in which an LCC and an MMC are connected in parallel, the number of the LCC and the MMC is not limited to one, and the MMC can compensate for harmonics of the LCC while transmitting the active power without configuring an additional filtering device.
Fig. 5 is a schematic diagram of a hybrid dc power transmission system in another embodiment, in which an LCC is connected in series with an MMC to connect a pseudo bipolar system for active power transmission, the number of the LCC and the MMC is not limited to one, and the MMC can compensate for harmonics of the LCC while transmitting active power without configuring an additional filtering device.
Fig. 6 is a schematic diagram of a hybrid dc power transmission system in another embodiment, in which an LCC and an MMC are connected in series to connect a bipolar system for active power transmission, the number of the LCC and the MMC is not limited to one, and the MMC can compensate for harmonics of the LCC while transmitting active power without configuring an additional filtering device.
Fig. 7 is a schematic diagram of a hybrid dc power transmission system in another embodiment, in which an LCC is connected in series with an MMC to connect a single-pole system for active power transmission, the number of the LCC and the MMC is not limited to one, and the MMC can compensate for harmonics of the LCC while transmitting active power without configuring an additional filtering device.
Fig. 8 is a schematic diagram of power transmission performed by connecting an LCC and an MMC of a hybrid dc power transmission system in series in another embodiment, where the LCC and the MMC of the cascaded converter valve of the embodiment may be formed by connecting a plurality of converters in parallel, and the MMC may perform harmonic compensation on the hybrid dc power transmission system by using harmonic compensation control.
Fig. 9 is a schematic diagram of active power transmission of a hybrid dc power transmission system in which DR and MMC are connected in parallel in another embodiment, the number of the DR and MMC is not limited to one, and the MMC can compensate for the harmonic of DR while transmitting the active power without configuring an additional filtering device.
Fig. 10 is a schematic diagram of another embodiment of a hybrid dc power transmission system in which a DR and an MMC are connected in series to connect a pseudo bipolar system for active power transmission, the numbers of the DR and the MMC are not limited to one, and the MMC can compensate for the harmonic of the DR while transmitting the active power without configuring an additional filtering device.
Fig. 11 is a schematic diagram of active power transmission performed by connecting a DR and an MMC in series in a hybrid dc power transmission system for a bipolar system connection according to another embodiment, the numbers of the DR and the MMC are not limited to one, and the MMC can compensate for the harmonic of the DR while transmitting the active power without configuring an additional filtering device.
Fig. 12 is a schematic diagram of another embodiment of a hybrid dc power transmission system connected in series by a DR and an MMC and wired for a unipolar system to perform active power transmission, where the numbers of the DR and the MMC are not limited to one, and the MMC can compensate for the harmonic of the DR while transmitting the active power without configuring an additional filtering device.
The flexible direct-current transmission system shown in fig. 13 is used for simulation test of effectiveness of the harmonic compensation type flexible direct-current converter provided by the invention on active power transmission and harmonic compensation of the system. The LCC and the MMC are connected in parallel and jointly accessed into the hybrid direct-current power transmission system to transmit active power, wherein the capacities of the LCC and the MMC are both 800MVA, and the direct-current end voltages of the LCC and the MMC are both 400 KV. The LCC adopts constant direct current control, and the MMC adopts constant active power and harmonic compensation control. And at the moment t being 3.0s, the MMC harmonic compensation control is put into operation, and compensation harmonics which are equal in amplitude and opposite in phase to the previous harmonics are generated at a compensation point.
Fig. 14 shows the net-side ac current actual value of the inverter MMC. It can be seen that after the harmonic compensation control is put into operation at the time of 3s, the converter MMC generates a corresponding harmonic alternating current on the network side.
Fig. 15 shows the net-side ac current actual values of the inverter LCC. It can be seen that the converter LCC always generates harmonic alternating current on the network side before and after the harmonic compensation control is put into operation.
Fig. 16 shows the actual value of the ac current of the grid. It can be seen that the harmonic compensation control is not put into operation before 3s, the grid current contains a large amount of harmonics, and the harmonic current of the grid current is compensated after the harmonic compensation control is put into operation at the moment of 3 s.
Fig. 17 shows the actual value of the active power transmission of the converter LCC. It can be seen that after the harmonic compensation control is put into operation at the 3s moment, the converter LCC can still ensure constant transmission of active power.
Fig. 18 shows the real value of the active power transmission of the inverter MMC. It can be seen that after the harmonic compensation control is put into operation at the moment of 3s, the converter MMC can still ensure the constant transmission of active power.
It will be appreciated by those skilled in the art that the foregoing is only a preferred embodiment of the invention, and is not intended to limit the invention, such that various modifications, equivalents and improvements may be made without departing from the spirit and scope of the invention.
Claims (9)
1. A harmonic compensation type flexible direct current converter is applied to a hybrid direct current transmission system and is characterized by comprising an active power controller, an inner ring current controller, a first amplitude limiting link, a harmonic compensation controller, a second amplitude limiting link and a third amplitude limiting link;
the output of the active power controller is used as the input of the inner loop current controller, the active power controller is used for regulating the active transmission of the converter, the inner loop current controller is used for ensuring the tracking of the output current of the converter on a reference value and the suppression of the ring current in the converter, the modulation signal output by the inner loop current controller is connected with the first amplitude limiting link, and the first amplitude limiting link is used for limiting the amplitude of the modulation signal;
harmonic components of a phase control converter or a diode rectifier in the hybrid direct-current power transmission system are input to a harmonic compensation controller, harmonic compensation control quantity output by the harmonic compensation controller is connected with the second amplitude limiting link, and the second amplitude limiting link is used for limiting amplitude of the harmonic compensation control quantity;
the control quantity of the current converter obtained by superposing the output quantity of the active power controller or the inner ring current controller or the first amplitude limiting link and the output quantity of the harmonic compensator is input into a third amplitude limiting link, the third amplitude limiting link is used for limiting the amplitude of the control quantity, and the control quantity of the current converter after modulation is used for harmonic compensation of the voltage and the current of a control point and is used for improving the electric energy quality of the hybrid direct-current transmission system.
2. The harmonic compensation type flexible dc converter according to claim 1, wherein the active power controller comprises: any one of an active power proportional-integral controller, an active power proportional controller, an active power fuzzy logic controller, an active power neural network controller, an active power repetitive controller and active power model predictive control.
3. The harmonic compensation type flexible dc converter according to claim 1, wherein the inner loop current controller comprises: any one of an inner loop current proportional-integral controller, an inner loop current proportional controller, an inner loop current fuzzy logic controller and an inner loop current neural network controller.
4. The harmonic compensation flexible dc converter of claim 1 wherein the harmonic compensation controller comprises: any one of a harmonic compensation proportional-integral controller, a harmonic compensation proportional controller, a harmonic compensation fuzzy logic controller, a harmonic compensation neural network controller, a harmonic compensation repetitive controller and a harmonic compensation model predictive control.
5. The harmonic compensation type flexible dc converter according to claim 1, wherein the outer loop of the harmonic compensation type flexible dc converter can adopt either one or both of active control quantity and reactive control quantity.
6. The harmonic compensation type flexible direct current converter according to claim 1, wherein a mathematical model is established for the hybrid direct current transmission system, and a harmonic condition at any point of the system can be predicted and analyzed, and with this as a reference, the harmonic compensation type flexible direct current converter is controlled to generate a harmonic voltage or current at the point, which has the same amplitude and opposite phase with the previous harmonic at the point, so as to complete harmonic compensation and improve the power quality of the hybrid direct current transmission system.
7. A control method based on the harmonic compensation type flexible direct current converter of any one of claims 1 to 6 is characterized by comprising the following steps:
s1, taking the output quantity of an active power controller as an input reference value of an inner ring current controller;
s2, carrying out predictive analysis on harmonic components of a phase control converter or a diode rectifier in the hybrid direct-current power transmission system, using the harmonic components as input quantities of a harmonic compensation controller, and generating corresponding harmonic compensation control quantities;
s3, overlapping the output quantity of the active power controller or the inner ring current controller or the first amplitude limiting link with the output quantity of the harmonic compensator to obtain the control quantity of the converter;
and S4, modulating the control quantity of the current converter, and ensuring the active power transmission of the current converter and the harmonic compensation of the voltage and the current of a control point so as to improve the electric energy quality of the hybrid direct-current power transmission system.
8. The control method according to claim 7, wherein the harmonic compensation control method is applicable to any voltage source converter such as a two-level converter, a three-level converter, a modular multilevel converter, etc.
9. The control method according to claim 7, wherein the harmonic compensation type flexible DC converter and the control system thereof can be applied to any hybrid DC power transmission system comprising a voltage source type converter, and the harmonic compensation can be carried out on the hybrid DC power transmission system for a system unipolar, bipolar and pseudo bipolar main connection modes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011545581.9A CN112736957A (en) | 2020-12-24 | 2020-12-24 | Harmonic compensation type flexible direct current converter and control method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011545581.9A CN112736957A (en) | 2020-12-24 | 2020-12-24 | Harmonic compensation type flexible direct current converter and control method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112736957A true CN112736957A (en) | 2021-04-30 |
Family
ID=75605044
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011545581.9A Pending CN112736957A (en) | 2020-12-24 | 2020-12-24 | Harmonic compensation type flexible direct current converter and control method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112736957A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104269861A (en) * | 2014-10-13 | 2015-01-07 | 国家电网公司 | Electromagnetic looped network reactive power ring current optimal control method based on flexible looped network controller |
| CN106451516A (en) * | 2016-08-27 | 2017-02-22 | 许继集团有限公司 | DC fault crossing method for hybrid multiterminal HVDC system |
| CN107196540A (en) * | 2017-07-20 | 2017-09-22 | 云南电网有限责任公司电力科学研究院 | A kind of modularization multi-level converter direct current harmonic suppressing method |
| CN112054537A (en) * | 2020-09-25 | 2020-12-08 | 国家电网有限公司 | Active filter for simultaneously compensating reactive power and controlling harmonic wave and control and design method |
-
2020
- 2020-12-24 CN CN202011545581.9A patent/CN112736957A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104269861A (en) * | 2014-10-13 | 2015-01-07 | 国家电网公司 | Electromagnetic looped network reactive power ring current optimal control method based on flexible looped network controller |
| CN106451516A (en) * | 2016-08-27 | 2017-02-22 | 许继集团有限公司 | DC fault crossing method for hybrid multiterminal HVDC system |
| CN107196540A (en) * | 2017-07-20 | 2017-09-22 | 云南电网有限责任公司电力科学研究院 | A kind of modularization multi-level converter direct current harmonic suppressing method |
| CN112054537A (en) * | 2020-09-25 | 2020-12-08 | 国家电网有限公司 | Active filter for simultaneously compensating reactive power and controlling harmonic wave and control and design method |
Non-Patent Citations (1)
| Title |
|---|
| 崔康生: ""混合直流异步联网***谐波抑制措施研究"", 《中国优秀博硕士学位论文全文数据库(硕士)工程科技Ⅱ辑》 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Zhang et al. | Three‐phase four‐leg flying‐capacitor multi‐level inverter‐based active power filter for unbalanced current operation | |
| CN104201910A (en) | Sub-module capacitance voltage balance control method for three-phase modular multilevel converter applicable to VSC-HVDC (voltage source converter-high voltage direct current) | |
| CN107070258B (en) | A kind of control method of single-phase more current levels sources current transformer and current transformer | |
| CN105391313A (en) | Control method of modular multi-level current converter | |
| CN104201909A (en) | Three-phase modularized multi-level converter for VSC-HVDC (voltage source converter-high voltage DC) and carrier phase-shifting modulation method of converter | |
| CN103441512B (en) | Reactive-load compensation (MMC-STATCOM) method based on modular multi-level converter | |
| CN106877371B (en) | A kind of control method of the modular multi-level converter with energy-storage function | |
| CN109787265A (en) | A kind of flexible HVDC transmission system control method for coordinating stabilized new energy and go out fluctuation | |
| CN105141144A (en) | Suppression method for bus voltage fluctuation in high-voltage frequency converter | |
| CN110829870B (en) | Control method of modular multilevel converter in low-frequency operation state | |
| CN106877726A (en) | A kind of control method of the accumulation energy type converter topology with fault ride-through capacity | |
| CN109194171A (en) | A kind of MMC optimization method substantially reducing submodule capacitor's capacity | |
| CN214409146U (en) | Power module test platform | |
| CN111756045B (en) | Three-in-one power electronic compensation transformer substation | |
| Martinez-Rodrigo et al. | Calculation of the number of modules and the switching frequency of a modular multilevel converter using near level control | |
| CN106936151B (en) | Method for determining operation interval of flexible direct-current transmission system | |
| CN111030483A (en) | Power electronic transformer and control method | |
| CN112736957A (en) | Harmonic compensation type flexible direct current converter and control method | |
| CN109347352A (en) | Cascade converter submodule capacitor voltage balance control method | |
| Lova Lakshmi et al. | TLBO algorithm for multi-level inverter-based multi-terminal HVDC system in grid-tied photovoltaic power plant | |
| Sharmeela et al. | Multi-level distribution STATCOM for voltage sag and swell reduction | |
| CN116073690B (en) | MMC energy storage system mixed modulation method | |
| Chaturvedi et al. | Multi-pulse converters as a viable solution for power quality improvement | |
| Verne et al. | Predictive control of a back to back diode clamped multilevel converter | |
| Diggavi et al. | Performance analysis of VSC-MMC Based Hybrid HVDC transmission system |
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 |