CN103730906A - Method for coordination control over restraint in mixed direct-current transmission phase-commutation failure - Google Patents
Method for coordination control over restraint in mixed direct-current transmission phase-commutation failure Download PDFInfo
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Abstract
The invention discloses a method for coordination control over restraint in a mixed direct-current transmission phase-commutation failure and belongs to the field of power transmission and distribution. According to the technical scheme, fixed direct-current voltage control and fixed alternating-current voltage control are adopted by rectification side VSC and inversion side LCC comprises the step that on the basis of a basic control strategy of fixed direct-current control of a VDCOL, a VDVOL is added to the rectification side VSC. A fault detecting point is set on the inversion side LCC of a mixed direct-current transmission system and according to fault information detected by the detecting point, whether the VDVOL is started by the rectification side VSC or not is determined; if the VDVOL of the rectification side VSC is started, on-line control over the mixed direct-current transmission system is achieved according to parameter set of the VDVOL. The method for coordination control over the restraint in the mixed direct-current transmission phase-commutation failure has the advantages that when the inversion side LCC of the mixed direct-current transmission system breaks down, the VDVOL of the rectification side VSC is started, a reference value of direct-current voltage is reduced, the resistance capacity on the phase-commutation failure of the mixed direct-current transmission system can be effectively improved, and the fault recovery speed of the system is increased.
Description
Technical field
The invention belongs to power transmission and distribution technical field, relate in particular to a kind of control method for coordinating that suppresses Hybrid HVDC commutation failure.
Background technology
Traditional LCC-HVDC transmission capacity is large, electric pressure is high has obtained extensive approval, and in the highest transmission capacity and the highest voltage level of building VSC-HVDC engineering, also reached respectively 2 * 1000MW and 500kV at present, although the capacity of the two and electric pressure also have certain gap, but consider current situation and the prospect of VSC-HVDC, in conjunction with the Hybrid HVDC of LCC-HVDC and VSC-HVDC, will there is future in engineering applications.The rectification side the present invention relates to is the Hybrid HVDC that VSC, inversion side are LCC, in the grid-connected scheme of remote offshore wind farm, has unique advantage and competitiveness, is a kind of mixed structure with extensive prospect.Generation of electricity by new energy at present especially develops rapidly with wind power generation, VSC is without additional commutation voltage, can control flexibly ac bus voltage, this type of Hybrid HVDC needs additional commutation voltage while having overcome LCC connection wind energy turbine set, VSC investment, the shortcoming that loss is large, both advantages of reasonable combination, although commutation failure may occur its inversion side, can reduce the probability of its generation by certain measure.
Commutation failure is when two valves of inverter carry out commutation, because commutation process is failed to carry out complete, or after the valve breakdown of estimating to turn-off, during reverse voltage, fail to recover blocking ability, when the voltage being added on this valve is timing,, having there is to switch phase in conducting again immediately, makes to estimate that the valve of opening turn-offs again.According to the Mathematical Modeling of Hybrid HVDC system and operation characteristic, the present invention has designed a kind of control method for coordinating that rectification side is the VSC inversion side Hybrid HVDC commutation failure that is LCC that suppresses, it is the constant DC voltage control that rectification side VSC adopts, determining alternating voltage controls, inversion side LCC comprises current limiting low-voltage and controls (Voltage Dependent Current Order Limiter, on the basis of the Baseline Control Strategy of constant DC current control VDCOL), at rectification side VSC, add low voltage limit pressure-controlled (Voltage Dependent Voltage Order Limiter, VDVOL).The coordination control strategy of design can effectively improve the defensive ability/resistance ability of Hybrid HVDC system to commutation failure, and can accelerate the fault recovery speed of system.
Summary of the invention
The present invention is directed to rectification side is that the Hybrid HVDC system commutation failure fault that VSC inversion side is LCC is studied, and has proposed a kind of control method for coordinating that suppresses this type of Hybrid HVDC commutation failure.It is characterized in that, the constant DC voltage control adopting at rectification side VSC, determine alternating voltage control, on the basis of the Baseline Control Strategy of the constant DC current control that inversion side LCC comprises VDCOL, in rectification side, VSC adds VDVOL, specifically comprises the following steps:
Step 1: the parameter of the VDVOL of design rectification side VSC;
Step 2: the inversion side LCC in Hybrid HVDC system arranges malfunction monitoring point, the fault message monitoring according to monitoring point, determines whether rectification side VSC starts VDVOL;
Step 3: the VDVOL that starts rectification side VSC if determine controls, and, according to the parameter setting of VDVOL in step 1, Hybrid HVDC system is carried out to On-line Control.
In step 1, according to the Mathematical Modeling of Hybrid HVDC system and operation characteristic, the direct voltage reference value of rectification side VSC should be linear with inversion side LCC ac bus voltage.For prevention commutation failure, by emulation and network analysis, consider after certain nargin and scope range of the fluctuation of voltage, determine the relation of rectification side VSC direct voltage and inversion side LCC ac bus voltage, i.e. each breakover point of VDVOL and parameter setting.
In step 2, at the inversion side LCC of Hybrid HVDC system, malfunction monitoring point is set, whether Real-Time Monitoring inversion side LCC ac bus breaks down.Whether the fault message monitoring according to monitoring point, break down and make inversion side LCC ac bus voltage drop, determines whether that the VDVOL that starts rectification side VSC controls.If monitor, inversion side LCC breaks down and ac bus voltage drops to the limit value that starts VDVOL, starts VDVOL and controls.
In step 3, the VDVOL that starts rectification side VSC if determine controls, and according to the VDVOL parameter in step 1, arranges, and reduces the direct voltage reference value that rectification side VSC determines direct voltage, and Hybrid HVDC system is carried out to On-line Control.
The invention has the beneficial effects as follows, when Hybrid HVDC system inversion side LCC breaks down, according to the detected fault message in monitoring point, the VDVOL that starts rectification side VSC controls, reduce direct voltage reference value, the defensive ability/resistance ability of Hybrid HVDC system to commutation failure can be effectively improved, and the fault recovery speed of system can be accelerated.
Accompanying drawing explanation
Fig. 1 is that rectification side provided by the invention is the Hybrid HVDC system diagram that VSC inversion side is LCC;
Fig. 2 is a kind of control block diagram that suppresses the control method for coordinating rectification side VSC of Hybrid HVDC commutation failure provided by the invention;
Fig. 3 is a kind of control block diagram that suppresses the control method for coordinating inversion side LCC of Hybrid HVDC commutation failure provided by the invention;
Fig. 4 be a kind of VDVOL provided by the invention external characteristic curve figure (with
k vDVOL =2.5 is example).
Embodiment
Below in conjunction with accompanying drawing, preferred embodiment is elaborated.Should be emphasized that following explanation is only exemplary, rather than in order to limit the scope of the invention and to apply.
Hybrid HVDC system as shown in Figure 1, the control block diagram of a kind of control method for coordinating both sides that suppress Hybrid HVDC commutation failure that provide of the present invention design is as shown in Figures 2 and 3: Fig. 2 is rectification side VSC control block diagram, and Fig. 3 is inversion side LCC control block diagram.The constant DC voltage control adopting at rectification side VSC, determine alternating voltage and control, on the basis of the Baseline Control Strategy of the constant DC current control that inversion side LCC employing comprises VDCOL, in rectification side, VSC adds VDVOL, specifically comprises the following steps:
Step 1: the parameter of the VDVOL of design rectification side VSC
According to the Mathematical Modeling of Hybrid HVDC system and operation characteristic, from following formula:
The direct voltage of inversion side LCC
u d2 for:
Direct current
i dc for:
The direct voltage of rectification side VSC
u d1 with inversion side LCC ac bus voltage
u 2 pass be:
It is rectification side VSC direct voltage
u d1 reference value should with inversion side LCC ac bus voltage
u 2 linear.For prevention commutation failure, in conjunction with emulation, determine
u d1 with
u 2 relation as follows, the parameter designing of VDVOL is with reference to formula:
By emulation and network analysis, consider after certain nargin and scope range of the fluctuation of voltage, determine each breakover point and the parameter setting of VDVOL, when
u 2 while dropping to a certain degree,
u d1 continue to decline and can not suppress the generation of commutation failure, and uneconomical.
With
k vDVOL =2.5 is example, and the parameter designing that obtains VDVOL is shown below, and VDVOL external characteristic curve as shown in Figure 4.
Step 2: the inversion side LCC in Hybrid HVDC system arranges malfunction monitoring point, the fault message monitoring according to monitoring point, determines whether rectification side VSC starts VDVOL;
Inversion side LCC in Hybrid HVDC system arranges malfunction monitoring point, and whether Real-Time Monitoring inversion side LCC ac bus breaks down, if break down, sends signal.Whether the fault message monitoring according to monitoring point, break down and make inversion side LCC ac bus voltage drop, determines whether that the VDVOL that starts rectification side VSC controls.If monitor, inversion side LCC breaks down and ac bus voltage drops to the limit value that starts rectification side VDVOL, starts VDVOL and controls.
Step 3: start rectification side VDVOL if determine and control,, according to the parameter setting of VDVOL in step 1, Hybrid HVDC system is carried out to On-line Control
If determine, start rectification side VDVOL and control, according to the VDVOL parameter in step 1, arrange, reduce the direct voltage reference value that rectification side VSC determines direct voltage, Hybrid HVDC system is carried out to On-line Control.Effectively to improve the defensive ability/resistance ability of Hybrid HVDC system to commutation failure, and the fault recovery speed of quickening system
The above; be only the present invention's embodiment preferably, but protection scope of the present invention is not limited to this, is anyly familiar with in technical scope that those skilled in the art disclose in the present invention; the variation that can expect easily or replacement, within all should being encompassed in protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of claim.
Claims (4)
1. a control method for coordinating that suppresses Hybrid HVDC commutation failure, it is characterized in that: the constant DC voltage control adopting at rectification side VSC, determine alternating voltage control, inversion side LCC comprises current limiting low-voltage and controls (Voltage Dependent Current Order Limiter, on the basis of the Baseline Control Strategy of constant DC current control VDCOL), at rectification side VSC, add low voltage limit pressure-controlled (Voltage Dependent Voltage Order Limiter, VDVOL), the parameter of the VDVOL of design rectification side VSC; Inversion side LCC in Hybrid HVDC system arranges malfunction monitoring point, and the fault message monitoring according to monitoring point determines whether rectification side VSC starts VDVOL; The VDVOL that starts rectification side VSC if determine controls, and, according to the parameter setting of VDVOL in step 1, Hybrid HVDC system is carried out to On-line Control, the parameter of design inversion side VDVOL according to claim 1.
2. it is characterized in that: according to the Mathematical Modeling of Hybrid HVDC system and operation characteristic, the direct voltage reference value of rectification side VSC should be linear with inversion side LCC ac bus voltage, for prevention commutation failure, by emulation and network analysis, consider after certain nargin and scope range of the fluctuation of voltage, determine the relation of rectification side VSC direct voltage and inversion side LCC ac bus voltage, i.e. each breakover point of VDVOL and parameter setting.
3. the inversion side in Hybrid HVDC system according to claim 1 arranges malfunction monitoring point, it is characterized in that: the inversion side LCC in Hybrid HVDC system arranges malfunction monitoring point, whether Real-Time Monitoring inversion side LCC ac bus breaks down, the fault message monitoring according to monitoring point, whether break down and make inversion side LCC ac bus voltage drop, determine whether that the VDVOL that starts rectification side VSC controls, if monitor, inversion side LCC breaks down and ac bus voltage drops to the limit value that starts VDVOL, starts VDVOL and controls.
4. if definite startup rectification side VDVOL according to claim 1 controls, according to the parameter of VDVOL, Hybrid HVDC system is carried out to On-line Control, it is characterized in that: the VDVOL that starts rectification side VSC if determine controls, according to the VDVOL parameter in step 1, arrange, reduce the direct voltage reference value that rectification side VSC determines direct voltage, Hybrid HVDC system is carried out to On-line Control.
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Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103986179A (en) * | 2014-05-26 | 2014-08-13 | 中国南方电网有限责任公司电网技术研究中心 | Control method of alternating-direct-current voltage signal mixing weighting type low-voltage current-limiting unit based on wide-area measuring system |
| CN104167755A (en) * | 2014-07-07 | 2014-11-26 | 中国南方电网有限责任公司电网技术研究中心 | Method for determining single-phase short circuit area causing commutation failure |
| CN104269890A (en) * | 2014-09-26 | 2015-01-07 | 华北电力大学 | Control method and system for extra-high-voltage direct current layering access mode |
| CN105548661A (en) * | 2016-02-02 | 2016-05-04 | 中国南方电网有限责任公司超高压输电公司 | Method for monitoring extra high voltage DC power transmission system DC line voltage fluctuation |
| CN105870908A (en) * | 2015-01-21 | 2016-08-17 | 国家电网公司 | Method and device for suppressing commutation failure during DC line fault restart period |
| CN106160023A (en) * | 2015-04-17 | 2016-11-23 | 华北电力大学 | A kind of Hybrid HVDC receiving end weak mains frequency cooperative control method |
| CN106208127A (en) * | 2016-08-19 | 2016-12-07 | 华北电力大学 | The HVDC transmission system emulation modelling method analyzed for sub-synchronous oscillation |
| CN107306030A (en) * | 2017-06-11 | 2017-10-31 | 天津大学 | A kind of control method for suppressing the continuous commutation failure of direct current transportation |
| CN108711877A (en) * | 2018-06-14 | 2018-10-26 | 南方电网科学研究院有限责任公司 | Inhibit mixed DC system in parallel that the method and device of continuous commutation failure occurs |
| CN110620396A (en) * | 2019-10-17 | 2019-12-27 | 重庆大学 | Self-adaptive low-voltage current limiting control method for LCC direct current transmission system |
| CN110994641A (en) * | 2019-11-13 | 2020-04-10 | 中国电力科学研究院有限公司 | Method for inhibiting large-amplitude power oscillation of direct-current transmission project |
| CN113178895A (en) * | 2021-06-11 | 2021-07-27 | 盛东如东海上风力发电有限责任公司 | Offshore wind power alternating current fault ride-through cooperative control method and device and storage medium |
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Cited By (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103986179A (en) * | 2014-05-26 | 2014-08-13 | 中国南方电网有限责任公司电网技术研究中心 | Control method of alternating-direct-current voltage signal mixing weighting type low-voltage current-limiting unit based on wide-area measuring system |
| CN104167755A (en) * | 2014-07-07 | 2014-11-26 | 中国南方电网有限责任公司电网技术研究中心 | Method for determining single-phase short circuit area causing commutation failure |
| CN104269890A (en) * | 2014-09-26 | 2015-01-07 | 华北电力大学 | Control method and system for extra-high-voltage direct current layering access mode |
| CN105870908A (en) * | 2015-01-21 | 2016-08-17 | 国家电网公司 | Method and device for suppressing commutation failure during DC line fault restart period |
| CN105870908B (en) * | 2015-01-21 | 2018-10-26 | 国家电网公司 | Inhibit the method and device of commutation failure during a kind of DC line fault recovery sequence |
| CN106160023A (en) * | 2015-04-17 | 2016-11-23 | 华北电力大学 | A kind of Hybrid HVDC receiving end weak mains frequency cooperative control method |
| CN106160023B (en) * | 2015-04-17 | 2019-01-25 | 华北电力大学 | A kind of Hybrid HVDC receiving end weak grid frequency cooperative control method |
| CN105548661B (en) * | 2016-02-02 | 2019-02-26 | 中国南方电网有限责任公司超高压输电公司 | A kind of monitoring method of extra-high voltage DC transmission system DC line voltage distribution fluctuation |
| CN105548661A (en) * | 2016-02-02 | 2016-05-04 | 中国南方电网有限责任公司超高压输电公司 | Method for monitoring extra high voltage DC power transmission system DC line voltage fluctuation |
| CN106208127A (en) * | 2016-08-19 | 2016-12-07 | 华北电力大学 | The HVDC transmission system emulation modelling method analyzed for sub-synchronous oscillation |
| CN107306030A (en) * | 2017-06-11 | 2017-10-31 | 天津大学 | A kind of control method for suppressing the continuous commutation failure of direct current transportation |
| CN108711877A (en) * | 2018-06-14 | 2018-10-26 | 南方电网科学研究院有限责任公司 | Inhibit mixed DC system in parallel that the method and device of continuous commutation failure occurs |
| CN110620396A (en) * | 2019-10-17 | 2019-12-27 | 重庆大学 | Self-adaptive low-voltage current limiting control method for LCC direct current transmission system |
| CN110620396B (en) * | 2019-10-17 | 2020-12-22 | 重庆大学 | Self-adaptive low-voltage current limiting control method for LCC direct current transmission system |
| CN110994641A (en) * | 2019-11-13 | 2020-04-10 | 中国电力科学研究院有限公司 | Method for inhibiting large-amplitude power oscillation of direct-current transmission project |
| CN113178895A (en) * | 2021-06-11 | 2021-07-27 | 盛东如东海上风力发电有限责任公司 | Offshore wind power alternating current fault ride-through cooperative control method and device and storage medium |
| CN113178895B (en) * | 2021-06-11 | 2023-09-22 | 盛东如东海上风力发电有限责任公司 | Marine wind power alternating current fault ride-through cooperative control method and device and storage medium |
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