CN110739714B - Online smooth switching method for isolated island and networking mode of soft direct current converter valve - Google Patents
Online smooth switching method for isolated island and networking mode of soft direct current converter valve Download PDFInfo
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- 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
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- H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
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- 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
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Abstract
A soft direct current converter valve island and networking mode online smooth switching method comprises an active instruction switching module, a reactive instruction switching module, a power control module, a voltage control module and a current control module. The output end of the voltage control module is respectively added with the power grid feedforward current and then connected with the input end of the current control module after the limiting link, and the current control module outputs a dq axis voltage modulation signal finally of the converter valve. The stability of the soft direct current converter valve in the island and networking operation mode switching process can be improved.
Description
Technical Field
The invention relates to the technical field of flexible direct-current transmission converter valve control, in particular to an island and networking mode online smooth switching method of a flexible direct-current converter valve.
Background
The flexible direct-current transmission converter valve is widely applied to the fields of asynchronous interconnection of power grids, large-scale new energy grid connection of wind power and the like, the converter valve generally adopts a modularized multi-level structure, a plurality of power modules are connected in series to form 1 bridge arm of the converter valve, 6 bridge arms of the converter valve are symmetrical, and each power module is formed by connecting full-control power devices (IGBT, IEGT) in a half-bridge or full-bridge mode. The flexible direct-current transmission converter valve can be connected with a weak alternating-current system, power is supplied to a passive network, and penetrating power of new energy sources such as wind power and the like, which are accessed into a power grid, is improved. Along with the continuous progress of the flexible direct current transmission technology, the current flexible direct current technology has been developed to a multi-terminal system, a plurality of converter stations are connected in parallel with the same direct current bus, such as a three-terminal flexible direct current system in south Australia, and the like, and each converter station at each terminal is operated in a coordinated manner, and has various control modes and operation schemes, including pure direct current line operation, parallel operation of alternating current lines and direct current lines, double-terminal operation, three-terminal operation and the like. According to different operation requirements, the converter station is required to realize the switching of an online control mode, if an alternating current system is disconnected during the parallel operation of alternating current-direct current lines, the converter valve is separated from a power grid and is required to be automatically converted into an island operation mode, and conversely, the alternating current system is recovered, and the converter valve is required to be operated in a networking mode again.
In the island and networking operation switching process, the switching of the control modes of the network side alternating current switch and the converter valve is required to be closely matched, but delay and uncertainty exist in the switching-on time of the alternating current breaker, the switching-on of the control mode and other processes in actual engineering, and large disturbance generally exists in the system switching process to cause the switching failure of the system operation mode to trip, so that the system stability is affected. The reference 'MMC-HVDC networking and island operation state conversion strategy' proposes a double closed loop droop controller, the droop characteristic of active power-frequency is utilized to obtain the synchronous phase of a power grid, the unified control structure of networking to island network is realized without control mode switching, but in the switching process from networking to island, the alternating-current side of a converter valve is disconnected from the power grid, and the grid-connected power is instantaneously reduced to zero. The output power of the converter valve is unchanged, so that the load voltage and the frequency can be suddenly changed due to unbalanced power, and the output voltage can be fluctuated during switching, so that the power supply quality of the load is affected. The control mode conversion method can be further improved.
Disclosure of Invention
In order to solve the technical problems in the background art, the invention provides the island and networking mode online smooth switching method of the soft direct current converter valve, which can improve the stability of the soft direct current converter valve in the island and networking operation mode switching process.
In order to achieve the above purpose, the invention is realized by adopting the following technical scheme:
an online smooth switching method for a soft direct current converter valve island and a networking mode, the method comprising the following steps: the system comprises an active instruction switching module, a reactive instruction switching module, a power control module, a voltage control module and a current control module; second active given signal P at output end of active instruction switching module ref2 And a second reactive given signal Q at the output end of the reactive instruction switching module ref2 Respectively with the active given input end P of the power control module ref And reactive power given input terminal Q ref Is connected with the d-axis voltage given signal U at the output end of the power control module dref And q-axis voltage given signal U qref Is connected with the input end of the voltage control module to synchronize the phase calculated value theta cal A first d-axis current given signal I at the output end of the voltage control module is connected with the input end of the active instruction switching module dref1 And a first q-axis current given signal I qref1 Respectively with the feedforward current I of the power grid gd And I gq After addition, the current is subjected to amplitude limiting I and amplitude limiting II and then is connected with the input end I of the current control module dref2 And I qref2 The current control module outputs a final d-axis and q-axis voltage modulation signal V of the converter valve dref And V qref 。
The input quantity of the active instruction switching module comprises: first active given signal P ref1 Grid phase theta PLL Synchronous phase θ output by power control module cal And control mode signalThe method comprises the steps of carrying out a first treatment on the surface of the The output is a second active given signal; the control mode signal has two signal values of 0 and 1, and is connected with a control end S of the mode selection switch, when the control end is 0, an output end Out of the mode selection switch is connected with a first input end In1 of the mode selection switch, and when the control end is 1, the output end Out of the mode selection switch is connected with a second input end In2 of the mode selection switch; the first input end In1 of the mode selection switch and the input quantity first active power given signal P of the active instruction switching module ref1 A second input end In2 of the mode selection switch is connected with the output end of the phase regulator PI1, and the power grid phase theta PLL Synchronous phase θ with power module output cal The difference value is connected with the input end of the phase regulator PI1 after sine calculation sin; output second active given signal P ref2 The output end Out of the mode selection switch is connected; the phase regulator PI1 is a proportional-integral regulator.
The input quantity of the reactive power instruction switching module comprises: AC voltage amplitude given signal E ref Ac voltage amplitude feedback signal E fbk First passive power given signal Q ref1 And a control mode signal; the output quantity is the second reactive given signal Q ref2 The method comprises the steps of carrying out a first treatment on the surface of the The control mode signal has two signal values of 0 and 1, and is connected with the control end of the mode selection switch, when the control end is 0, the output end Out of the mode selection switch is connected with the first input end In1 of the mode selection switch, and when the control end is 1, the output end Out of the mode selection switch is connected with the second input end In2 of the mode selection switch; the first input end In1 of the mode selection switch and the input quantity first passive given signal Q of the reactive power instruction switching module ref1 A second input end In2 of the mode selection switch is connected with the output end of the voltage amplitude regulator PI2, and an alternating voltage amplitude given signal E ref And an alternating voltage amplitude feedback signal E fbk Is connected with the input end of the voltage amplitude regulator PI 2; output second reactive given signal Q ref2 The output end Out of the mode selection switch is connected; the voltage amplitude regulator PI2 is a proportional-integral regulator.
Input of the power control moduleThe amounts include: active power given signal P ref Active power feedback signal P fbk Reactive power given signal Q ref Reactive power feedback signal Q fbk The method comprises the steps of carrying out a first treatment on the surface of the The output quantity includes: d-axis voltage given signal U dref Q-axis voltage given signal U qref And a synchronous phase calculation value θ cal The method comprises the steps of carrying out a first treatment on the surface of the Active power given signal P ref And an active power feedback signal P fbk The difference value is connected with the Kp input end of the active power regulator, and the Kp output end of the active power regulator is connected with the rated angular frequency omega of the power grid 0 The sum is connected with the input end of the integrator, and the output end theta of the integrator cal The phase input end of the coordinate transformation module is connected with the phase input end of the coordinate transformation module; reactive power given signal Q ref And reactive power feedback signal Q fbk The difference value of (a) is connected with the input end of a reactive power regulator PI4, and the output end of the reactive power regulator is connected with the amplitude input end of the Kp-dq coordinate conversion module; kp-dq coordinate transformation realizes transformation from polar coordinates to synchronous rotation coordinates, and a first output end and a second output end of the Kp-dq coordinate transformation module are respectively connected with an output quantity d-axis voltage given signal U of the power control module dref And q-axis voltage given signal U qref Are connected; wherein the active power regulator Kp is a proportional regulator.
The input quantity of the voltage control module comprises: d-axis voltage given signal U output by power control module dref And q-axis voltage given signal U qref And d-axis voltage feedback signal U dfbk And q-axis voltage feedback signal U qfbk The method comprises the steps of carrying out a first treatment on the surface of the The output quantity is a first d-axis current given signal I dref1 And a first q-axis current given signal I qref1 The method comprises the steps of carrying out a first treatment on the surface of the d-axis voltage given U qref And d-axis voltage feedback U dfbk Is connected with the input end of the d-axis voltage regulator PI5, and the q-axis voltage is given by U qref And q-axis voltage feedback U qfbk The difference value of the voltage regulator is connected with the input end of the q-axis voltage regulator PI6, and the output end of the d-axis voltage regulator PI5 and the output end of the q-axis voltage regulator PI6 are respectively connected with a first d-axis current given signal I of the output end of the voltage control module dref1 And a first q-axis current given signal I qref1 Is connected with each other.
The current control moduleThe inputs include: second d-axis current given signal I dref2 And a second q-axis current given signal I qref2 And d-axis current feedback signal I at alternating current side of converter valve dfbk And q-axis current feedback signal I qfbk The method comprises the steps of carrying out a first treatment on the surface of the The output signal comprises d-axis voltage modulation signal V dref And q-axis voltage modulation signal V qref The method comprises the steps of carrying out a first treatment on the surface of the Second d-axis current given signal I dref2 And a d-axis current feedback signal I at the alternating-current side of the converter valve dfbk The difference is connected with the input end of the d-axis current regulator PI7, and the second q-axis current is given by the signal I qref2 And the current feedback signal I of the q-axis of the alternating-current side of the converter valve qfbk The difference is connected with the input end of the q-axis current regulator PI 8; the output signals of the d-axis current regulator PI7 and the q-axis current regulator PI8 are respectively connected with the output quantity d-axis voltage modulation signal V of the current control module dref And q-axis voltage modulation signal V qref Connecting; the d-axis modulation signal and the q-axis modulation signal are converted from the conventional synchronous rotation coordinate to the static coordinate to obtain the three-phase control signal of the converter valve.
Compared with the prior art, the invention has the beneficial effects that:
1. according to the control method of the converter valve, the AC voltage phase of the converter valve is adjusted by utilizing the deviation of active power, and the phase-locked loop and the power grid in the traditional control strategy are not depended on synchronization during steady operation, so that the stability of the converter valve when the converter valve is connected into a weak AC system can be improved.
2. The feedforward control quantity of the power grid current is introduced into the given signal of the current control, the alternating current voltage regulator only outputs the given signal of the load current, the feedforward current of the power grid is instantaneously reduced to 0 after the converter valve is off-grid, the power unbalance degree of the transient process can be improved in the process of networking to island conversion, and the current impact is reduced.
3. The networking and island control mode is switched and arranged on the outer ring, the modulation signal mutation can be avoided in the switching process, the switching process and the switching position time sequence of the alternating current breaker do not need to be strictly matched, and the power control ring has the inertia energy to keep the stable operation of the system in a short time under the two control modes.
Drawings
FIG. 1 is a block diagram of a converter valve island and networking control mode switching control method of the present invention;
FIG. 2 is a schematic diagram of an active command switching module according to the present invention;
FIG. 3 is a schematic diagram of a reactive command switching module according to the present invention;
FIG. 4 is a schematic diagram of a power control module according to the present invention;
FIG. 5 is a schematic diagram of a voltage control module according to the present invention;
fig. 6 is a schematic diagram of a current control module according to the present invention.
Detailed Description
The following detailed description of the embodiments of the invention is provided with reference to the accompanying drawings.
As shown in fig. 1, an online smooth switching method for a island and a networking mode of a soft direct current converter valve, the method comprises the following steps: the system comprises an active instruction switching module, a reactive instruction switching module, a power control module, a voltage control module and a current control module; second active given signal P at output end of active instruction switching module ref2 And a second reactive given signal Q at the output end of the reactive instruction switching module ref2 Respectively with the active given input end P of the power control module ref And reactive power given input terminal Q ref Is connected with the d-axis voltage given signal U at the output end of the power control module dref And q-axis voltage given signal U qref Is connected with the input end of the voltage control module to synchronize the phase calculated value theta cal A first d-axis current given signal I at the output end of the voltage control module is connected with the input end of the active instruction switching module dref1 And a first q-axis current given signal I qref1 Respectively with the feedforward current I of the power grid gd And I gq After addition, the current is subjected to amplitude limiting I and amplitude limiting II and then is connected with the input end I of the current control module dref2 And I qref2 The current control module outputs a final d-axis and q-axis voltage modulation signal V of the converter valve dref And V qref 。
As shown in fig. 2, the input amounts of the active command switching module include: first active given signal P ref1 Grid phase theta PLL Synchronous phase θ output by power control module cal And a control mode signal; the output is a second active given signal; the control mode signal has two signal values of 0 and 1, and is connected with a control end S of the mode selection switch, when the control end is 0, an output end Out of the mode selection switch is connected with a first input end In1 of the mode selection switch, and when the control end is 1, the output end Out of the mode selection switch is connected with a second input end In2 of the mode selection switch; the first input end In1 of the mode selection switch and the input quantity first active power given signal P of the active instruction switching module ref1 A second input end In2 of the mode selection switch is connected with the output end of the phase regulator PI1, and the power grid phase theta PLL Synchronous phase θ with power module output cal The difference value is connected with the input end of the phase regulator PI1 after sine calculation sin; output second active given signal P ref2 The output end Out of the mode selection switch is connected; the phase regulator PI1 is a proportional-integral regulator.
As shown in fig. 3, the input amounts of the reactive instruction switching module include: AC voltage amplitude given signal E ref Ac voltage amplitude feedback signal E fbk First passive power given signal Q ref1 And a control mode signal; the output quantity is the second reactive given signal Q ref2 The method comprises the steps of carrying out a first treatment on the surface of the The control mode signal has two signal values of 0 and 1, and is connected with the control end of the mode selection switch, when the control end is 0, the output end Out of the mode selection switch is connected with the first input end In1 of the mode selection switch, and when the control end is 1, the output end Out of the mode selection switch is connected with the second input end In2 of the mode selection switch; the first input end In1 of the mode selection switch and the input quantity first passive given signal Q of the reactive power instruction switching module ref1 A second input end In2 of the mode selection switch is connected with the output end of the voltage amplitude regulator PI2, and an alternating voltage amplitude given signal E ref And an alternating voltage amplitude feedback signal E fbk Is connected with the input end of the voltage amplitude regulator PI 2; output second reactive given signal Q ref2 The output end Out of the mode selection switch is connected; the voltage amplitude regulator PI2 is a proportional-integral regulator.
The networking mode is set when the control mode signal is 0, and the island mode is set when the control mode signal is 1.
As shown in fig. 4, the input amounts of the power control module include: active power given signal P ref Active power feedback signal P fbk Reactive power given signal Q ref Reactive power feedback signal Q fbk The method comprises the steps of carrying out a first treatment on the surface of the The output quantity includes: d-axis voltage given signal U dref Q-axis voltage given signal U qref And a synchronous phase calculation value θ cal The method comprises the steps of carrying out a first treatment on the surface of the Active power given signal P ref And an active power feedback signal P fbk The difference value is connected with the Kp input end of the active power regulator, and the Kp output end of the active power regulator is connected with the rated angular frequency omega of the power grid 0 The sum is connected with the input end of the integrator, and the output end theta of the integrator cal The phase input end of the coordinate transformation module is connected with the phase input end of the coordinate transformation module; reactive power given signal Q ref And reactive power feedback signal Q fbk The difference value of (a) is connected with the input end of a reactive power regulator PI4, and the output end of the reactive power regulator is connected with the amplitude input end of the Kp-dq coordinate conversion module; kp-dq coordinate transformation realizes transformation from polar coordinates to synchronous rotation coordinates, and a first output end and a second output end of the Kp-dq coordinate transformation module are respectively connected with an output quantity d-axis voltage given signal U of the power control module dref And q-axis voltage given signal U qref Are connected; wherein the active power regulator Kp is a proportional regulator.
As shown in fig. 5, the input amounts of the voltage control module include: d-axis voltage given signal U output by power control module dref And q-axis voltage given signal U qref And d-axis voltage feedback signal U dfbk And q-axis voltage feedback signal U qfbk The method comprises the steps of carrying out a first treatment on the surface of the The output quantity is a first d-axis current given signal I dref1 And a first q-axis current given signal I qref1 The method comprises the steps of carrying out a first treatment on the surface of the d-axis voltage given U qref And d-axis voltage feedback U dfbk Is connected with the input end of the d-axis voltage regulator PI5, and the q-axis voltage is given by U qref And q-axis voltage feedback U qfbk Is connected with the input end of the q-axis voltage regulator PI6, and the output end of the d-axis voltage regulator PI5 and the output end of the q-axis voltage regulator PI6 are respectivelyA first d-axis current given signal I connected with the output end of the voltage control module dref1 And a first q-axis current given signal I qref1 Is connected with each other.
As shown in fig. 6, the current control module inputs include: second d-axis current given signal I dref2 And a second q-axis current given signal I qref2 And d-axis current feedback signal I at alternating current side of converter valve dfbk And q-axis current feedback signal I qfbk The method comprises the steps of carrying out a first treatment on the surface of the The output signal comprises d-axis voltage modulation signal V dref And q-axis voltage modulation signal V qref The method comprises the steps of carrying out a first treatment on the surface of the Second d-axis current given signal I dref2 And a d-axis current feedback signal I at the alternating-current side of the converter valve dfbk The difference is connected with the input end of the d-axis current regulator PI7, and the second q-axis current is given by the signal I qref2 And the current feedback signal I of the q-axis of the alternating-current side of the converter valve qfbk The difference is connected with the input end of the q-axis current regulator PI 8; the output signals of the d-axis current regulator PI7 and the q-axis current regulator PI8 are respectively connected with the output quantity d-axis voltage modulation signal V of the current control module dref And q-axis voltage modulation signal V qref Connecting; the d-axis modulation signal and the q-axis modulation signal are converted from the conventional synchronous rotation coordinate to the static coordinate to obtain the three-phase control signal of the converter valve.
The above examples are implemented on the premise of the technical scheme of the present invention, and detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to the above examples. The methods used in the above examples are conventional methods unless otherwise specified.
Claims (3)
1. The method for online smooth switching of the isolated island and the networking mode of the soft direct current converter valve is characterized by comprising the following steps of: the system comprises an active instruction switching module, a reactive instruction switching module, a power control module, a voltage control module and a current control module; second active given signal P at output end of active instruction switching module ref2 And a second reactive given signal Q at the output end of the reactive instruction switching module ref2 Is respectively connected with an active given input end and a reactive given input end of the power control module, and d-axis voltage given signal U of the output end of the power control module dref And q-axis voltage given signal U qref Is connected with the input end of the voltage control module to synchronize the phase calculated value theta cal A first d-axis current given signal I at the output end of the voltage control module is connected with the input end of the active instruction switching module dref1 And a first q-axis current given signal I qref1 Respectively with the feedforward d-axis current I of the power grid gd And grid feed-forward q-axis current I gq After addition, the first and second amplitude limiting signals are respectively subjected to amplitude limiting and second amplitude limiting to output a second d-axis current given signal I dref2 And a second q-axis current given signal I qref2 The current control module outputs the final d and q axis voltage modulation signals V of the converter valve dref And V qref ；
The input quantity of the active instruction switching module comprises: first active given signal P ref1 Grid phase theta PLL Synchronous phase calculation value theta output by power control module cal And a control mode signal; the output quantity is the second active given signal P ref2 The method comprises the steps of carrying out a first treatment on the surface of the The control mode signal has two signal values of 0 and 1, and is connected with a control end S of the mode selection switch, when the control end is 0, an output end Out of the mode selection switch is connected with a first input end In1 of the mode selection switch, and when the control end is 1, the output end Out of the mode selection switch is connected with a second input end In2 of the mode selection switch; the first input end In1 of the mode selection switch and the first input active given signal P of the active instruction switching module ref1 A second input end In2 of the mode selection switch is connected with the output end of the phase regulator PI1, and the power grid phase theta PLL Synchronous phase calculation value theta output by power control module cal The difference value of (2) is connected with the input end of the phase regulator PI1 after sinusoidal calculation; the output terminal Out of the mode selection switch outputs a second active given signal P ref2 The method comprises the steps of carrying out a first treatment on the surface of the The phase regulator PI1 is a proportional-integral regulator;
the input quantity of the reactive power instruction switching module comprises: AC voltage amplitude given signal E ref Ac voltage amplitude feedback signal E fbk First passive given signal Q ref1 And a control mode signal; conveying deviceThe output is the second reactive given signal Q ref2 The method comprises the steps of carrying out a first treatment on the surface of the The control mode signal has two signal values of 0 and 1, and is connected with the control end of the mode selection switch, when the control end is 0, the output end Out of the mode selection switch is connected with the first input end In1 of the mode selection switch, and when the control end is 1, the output end Out of the mode selection switch is connected with the second input end In2 of the mode selection switch; the first input end In1 of the mode selection switch and the input quantity first passive given signal Q of the reactive power instruction switching module ref1 A second input end In2 of the mode selection switch is connected with the output end of the voltage amplitude regulator PI2, and an alternating voltage amplitude given signal E ref And an alternating voltage amplitude feedback signal E fbk Is connected with the input end of the voltage amplitude regulator PI 2; the output end Out of the mode selection switch outputs a second reactive given signal Q ref2 The method comprises the steps of carrying out a first treatment on the surface of the The voltage amplitude regulator PI2 is a proportional-integral regulator;
the input quantity of the power control module comprises: second active given signal P ref2 Active power feedback signal P fbk Second reactive given signal Q ref2 Reactive power feedback signal Q fbk The method comprises the steps of carrying out a first treatment on the surface of the The output quantity includes: d-axis voltage given signal U dref Q-axis voltage given signal U qref And a synchronous phase calculation value θ cal The method comprises the steps of carrying out a first treatment on the surface of the Second active given signal P ref2 And an active power feedback signal P fbk Is connected with the input end of the active power regulator Kp, and the output signal of the active power regulator Kp is connected with the rated angular frequency omega of the power grid 0 The sum is connected with the input end of the integrator, and the synchronous phase calculated value theta output by the output end of the integrator cal The phase input end of the Kp-dq coordinate transformation module is connected with the phase input end of the Kp-dq coordinate transformation module; second reactive given signal Q ref2 And reactive power feedback signal Q fbk The difference value of the (a) is connected with the input end of a reactive power regulator PI4, and the output end of the reactive power regulator PI4 is connected with the amplitude input end of the Kp-dq coordinate conversion module; the Kp-dq coordinate transformation module is used for transforming polar coordinates into synchronous rotation coordinates and outputting d-axis voltage given signals U dref And q-axis voltage given signal U qref The method comprises the steps of carrying out a first treatment on the surface of the Wherein the active power regulator Kp is proportional toAnd a regulator.
2. The method for online smooth switching of the island and the networking mode of the soft direct current converter valve according to claim 1, wherein the input quantity of the voltage control module comprises the following steps: d-axis voltage given signal U output by power control module dref And q-axis voltage given signal U qref And d-axis voltage feedback signal U dfbk And q-axis voltage feedback signal U qfbk The method comprises the steps of carrying out a first treatment on the surface of the The output quantity is a first d-axis current given signal I dref1 And a first q-axis current given signal I qref1 The method comprises the steps of carrying out a first treatment on the surface of the d-axis voltage given signal U qref And d-axis voltage feedback U dfbk Is connected to the input of the d-axis voltage regulator PI5, and the q-axis voltage gives a signal U qref And q-axis voltage feedback U qfbk The difference value of the voltage regulator is connected with the input end of the q-axis voltage regulator PI6, and the d-axis voltage regulator PI5 and the q-axis voltage regulator PI6 respectively output a first d-axis current given signal I dref1 And a first q-axis current given signal I qref1 。
3. The method for online smooth switching between the island and the networking mode of the soft direct current converter valve according to claim 1, wherein the input quantity of the current control module comprises the following steps: second d-axis current given signal I dref2 And a second q-axis current given signal I qref2 And d-axis current feedback signal I at alternating current side of converter valve dfbk And q-axis current feedback signal I qfbk The method comprises the steps of carrying out a first treatment on the surface of the The output signal comprises d-axis voltage modulation signal V dref And q-axis voltage modulation signal V qref The method comprises the steps of carrying out a first treatment on the surface of the Second d-axis current given signal I dref2 And a d-axis current feedback signal I at the alternating-current side of the converter valve dfbk The difference is connected with the input end of the d-axis current regulator PI7, and the second q-axis current is given by the signal I qref2 And the current feedback signal I of the q-axis of the alternating-current side of the converter valve qfbk The difference is connected with the input end of the q-axis current regulator PI 8; d-axis current regulator PI7 and q-axis current regulator PI8 output d-axis voltage modulation signal V, respectively dref And q-axis voltage modulation signal V qref The method comprises the steps of carrying out a first treatment on the surface of the The d-axis and q-axis voltage modulation signals are converted from synchronous rotation coordinates to static coordinatesThe three-phase control signal of the converter valve can be obtained.
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| CN113394809B (en) * | 2021-06-24 | 2022-07-22 | 南方电网科学研究院有限责任公司 | Flexible direct current island control method, device and medium based on power grid structure type |
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| CN103414182B (en) * | 2013-06-04 | 2016-06-29 | 南方电网科学研究院有限责任公司 | A kind of flexible direct current power transmission system is from the smooth-switching method transferring islet operation side by side to |
| CN103401259B (en) * | 2013-07-25 | 2015-11-18 | 南方电网科学研究院有限责任公司 | A kind of energy-storage system seamless switching control method |
| CN103647286A (en) * | 2013-11-15 | 2014-03-19 | 许继集团有限公司 | Modularization multi-level converter island switching control method |
| CN103928946B (en) * | 2014-05-07 | 2015-10-21 | 湖南大学 | A kind of three-phase dual mode inverter take over seamlessly control method |
| CN104078997A (en) * | 2014-06-26 | 2014-10-01 | 许继电气股份有限公司 | Photovoltaic grid-connected inverter grid-disconnecting mode and grid-connecting mode switching control method |
| JP5985775B1 (en) * | 2016-03-18 | 2016-09-06 | 田淵電機株式会社 | Isolated operation detection device and isolated operation detection method |
| CN107612044A (en) * | 2017-09-27 | 2018-01-19 | 南方电网科学研究院有限责任公司 | A kind of switching method and device of micro-capacitance sensor island mode and grid-connect mode |
| CN109980676B (en) * | 2017-12-28 | 2021-06-25 | 北京天诚同创电气有限公司 | Microgrid control system and microgrid |
| CN110061529B (en) * | 2019-04-19 | 2022-12-06 | 合肥工业大学 | Smooth switching control method of flexible multi-state switch |
| CN110048455B (en) * | 2019-04-24 | 2021-06-01 | 湖南大学 | Droop control inverter with weak grid fault ride-through capability and control method thereof |
| CN110034586A (en) * | 2019-05-10 | 2019-07-19 | 中国石油大学(华东) | A kind of MMC-HVDC island-grid active/passive method for handover control |
| CN110233500B (en) * | 2019-06-24 | 2023-05-05 | 上海电力学院 | Method for switching virtual synchronous generator off-grid to grid connection |
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