146 results about "Reactive power control" patented technology

The invention discloses a distributed power supply-based control method, system, equipment and medium, and relates to the technical field of distributed power supply control, and the method comprises the steps: collecting and preprocessing the real-time data of a distributed power supply, training a prediction model to optimize parameters, obtaining a load demand and power generation capability estimation, and adjusting the power based on a prediction result. Distributing active power according to a total load and a power contribution factor; setting a target power factor to calculate reactive power; monitoring voltage and load changes of a power grid in real time; dynamically selecting and adjusting a reactive power control strategy; and visualizing the running state and backing up the data to a database. Through closed-loop cooperation of data prediction, dynamic power control, value-oriented intelligent operation and maintenance and visual management, the stability, electric energy quality, operation and maintenance economy and management efficiency of the distributed power supply system are comprehensively improved.

The invention relates to the field of power grid voltage reactive power control, and discloses a three-level collaborative power grid voltage reactive power control architecture and control method.The architecture comprises an edge layer, a region layer and a master station layer, the edge layer is deployed at a key node of a power distribution network, and the region layer is deployed at a key node of the power distribution network; quick sensing and response to voltage fluctuation are realized by adopting thousand-time / second-level sampling and millisecond-level local calculation; the regional layer realizes cross-node reactive collaborative optimization based on a digital twinborn model and a federated learning framework; the master station layer constructs a voltage-reactive sensitivity matrix and dynamically adjusts the control weight of the edge layer. According to the control architecture and the control method, the advantages of centralized and distributed control are considered, the problems of response delay, collaborative conflict and data safety of traditional control are solved, the safety, the stability and the economical efficiency of the power grid in a high-proportion new energy access scene are effectively improved, and the control architecture and the control method are suitable for voltage reactive power control of the power grid in a complex region.

The invention discloses a short-time voltage fluctuation suppression method, device and equipment based on partition fluctuation evaluation, and relates to the technical field of power system control. The method comprises the following steps: under a minute-level time scale, taking the comprehensive minimization of active power loss, voltage fluctuation in adjacent time periods and reactive power regulation cost as a target, constructing a multi-period reactive power voltage optimization control model, and obtaining a reference voltage and a reference reactive power control quantity; a power system is partitioned through a modularity-based reactive voltage control robust partitioning algorithm, and influence areas which are mainly influenced by new energy fluctuation are identified on the basis of partitioning. And constructing a partition fluctuation evaluation index and setting a partition optimization event triggering mechanism. And under a short-time scale, constructing a subarea reactive voltage optimization control model based on quadratic programming by utilizing a subarea space decoupling technology, and executing subarea coordination optimization. And correcting the partition reactive voltage optimization control model through a model correction method based on multiple linear regression.

This invention discloses a series-parallel hybrid power flow control method and system, applied in the field of power grid power flow control. The method includes: determining power grid demand information based on key operating data of the transmission network; determining the equivalent active power control quantity of UPFC, the equivalent power flow regulation quantity of SSSC, and the equivalent reactive power control quantity of STATCOM based on the quantification results of the demand information, the first constraint data of the series-parallel hybrid power flow control device, and the second constraint data of the transmission network; and injecting equivalent voltage and equivalent current into the transmission network through the series-parallel connection of UPFC, SSSC, and STATCOM to regulate the key operating data of the transmission network. When power flow control is required in the transmission network, this invention injects controllable voltage and current into the transmission network through UPFC, SSSC, and STATCOM to achieve adaptive control of power flow on transmission network lines.

The present application relates to the technical field of phase modifier control, in particular to a dynamic reactive power control method and system based on a phase modifier, comprising: acquiring real-time voltage deviation of the phase modifier during operation, and calling corresponding pole phase group rearrangement scheme; calculating magnetic density increment of end structure according to phase advance operation depth of the phase modifier, and activating end magnetic circuit optimization control logic when exceeding temperature rise intervention threshold, adjusting the magnetic circuit by simulating magnetic shielding, setting the material properties of the anti-magnetic steel, and introducing equivalent slot impedance; calculating end potential gradient according to the magnetic density increment, and activating end circuit blocking control logic when exceeding circulating current blocking threshold, blocking the circuit anomaly by inserting equivalent insulation sleeve, short-circuiting positioning rib, and laying equivalent insulation sheet; and coupling the output parameters of the two control logics with the pole phase group rearrangement scheme to generate dynamic reactive power distribution instructions. The method can solve the end temperature rise and circulating current discharge problems during the phase advance operation of the phase modifier, and improve the operation stability.

The invention relates to the technical field of power system application, and discloses a unified control method, system, equipment and medium for a flexible interconnection device based on a multi-voltage-level direct-current power distribution network, and the method comprises the steps that the flexible interconnection device is composed of two alternating-current / direct-current converters which are connected back to back, one side adopts direct-current voltage and reactive power control, and the other side adopts direct-current voltage and reactive power control; and the other side adopts active power and reactive power control. Decoupling control is carried out on d-axis current and q-axis current under a synchronous rotating coordinate system, a d-axis current reference value of a PQ side is superposed to a voltage outer ring output of a UdcQ side, and a unified current inner ring reference instruction is generated. According to the method, a feed-forward compensation item is introduced into a current inner loop to offset inter-axis coupling, continuous smooth adjustment of bidirectional power flow can be achieved without switching a control mode, voltage fluctuation of a direct-current bus is effectively restrained, and the dynamic response and global stability of a system are improved.

Embodiments of the application disclose a direct-drive wind turbine low-voltage ride-through control method and related equipment. The method comprises: generating a ride-through high-level signal to activate a low-voltage ride-through mode when a low-voltage ride-through trigger module detects that a current voltage value of a target power grid where a target direct-drive wind turbine is located is lower than a preset reference value; calculating a voltage drop depth according to the current voltage value and the preset reference value; a low-voltage period reactive power control module of a grid-side control system controls the target direct-drive wind turbine to output reactive power to the target power grid to support the power grid according to the voltage drop depth; and an active power control module of a machine-side control system controls output power of the target direct-drive wind turbine according to the voltage drop depth. The direct-drive wind turbine low-voltage ride-through control method overcomes the direct-current voltage overvoltage oscillation defect of the prior art and limits the machine-side electromagnetic power during the wind turbine low-voltage ride-through period from the source.

The invention discloses an AC-DC integrated coupling operation control method for a medium-voltage power distribution system, and relates to the technical field of power distribution networks, and the method comprises the steps: carrying out the power flow analysis of an AC-DC system according to a system operation target, and obtaining a plurality of AC-DC coupling coefficients; obtaining a VSC direct current side voltage reference value by using the alternating current and direct current coupling coefficient and the VSC alternating current side grid connection point voltage effective value; obtaining an AC voltage reference value based on the VSC DC side voltage reference value in combination with AC side reactive power control; and obtaining an AC-DC integrated coupling operation control result by adopting park inverse transformation and a VSC modulation strategy according to the AC voltage reference value. According to the method, the problems of complex converter cooperative control and high system design, analysis and operation difficulty under traditional control are solved, meanwhile, the control of the VSC is unified by the control method, control modes do not need to be allocated to different VSCs under complex working conditions, and dynamic regulation and control of the system are realized while the control complexity is greatly reduced.

This invention discloses a coordinated control strategy for LCC and MMC in DC distribution networks. The strategy employs parallel operation of the LCC and MMC, with their DC sides connected to the same DC bus and simultaneously supplying power to the DC distribution network. When the transmission power is low or power flows in reverse, the LCC is deactivated, and the MMC assumes all the transmission power. When the transmission power is high, the LCC is activated and assumes most of the power. Considering the characteristics of LCC and MMC converter stations, the MMC uses constant DC voltage control and constant reactive power control, while the LCC uses constant DC current or constant DC power control. This invention utilizes the LCC to replace the MMC in assuming part of the transmission power, reducing the number and capacity of MMC devices in the DC distribution network. The coordinated control strategy for steady-state operation of LCC and MMC in the DC distribution network employs parallel operation of the LCC and MMC, with their DC sides connected to the same DC bus and simultaneously supplying power to the DC distribution network.

The invention discloses a virtual synchronous machine control method for improving transient voltage inertia of a grid-connected inverter. The virtual synchronous machine control method comprises an active power control loop and a reactive power control loop with transient voltage inertia. On the basis of a traditional virtual synchronous machine control method, an inertia link is introduced into a reactive power control loop, and a reactive voltage loop is transformed into a second-order system from a first-order system so as to improve the dynamic response of an inverter when the voltage of a power grid drops. According to the invention, the change rate of the output voltage of the grid-connected inverter in the transient process can be effectively reduced, the power angle characteristic, the frequency characteristic and the voltage characteristic of the grid-connected inverter are improved, the negative influence caused by the voltage drop of the power grid is reduced, and the transient stability of the inverter is improved.

The invention provides a matrix converter low-frequency side outer ring reactive power control method and a related device, and the method comprises the steps: carrying out the matching processing based on the obtained operation scene data of the low-frequency side of a matrix converter, determining whether a reactive power control strategy is matched, and if the reactive power control strategy is matched, outputting a reactive power control strategy; if yes, performing coordinate conversion processing on three-phase voltage data and three-phase current data in the operation scene data to obtain voltage conversion data and current conversion data; calculating actual reactive power data based on the voltage conversion data and the current conversion data; performing deviation correction based on the actual reactive power and the obtained reactive power control target data to obtain a deviation correction signal, and performing feed-forward compensation on the reactive power control target data to obtain a feed-forward compensation signal; and performing fusion conversion processing on the feed-forward compensation signal and the deviation correction signal to obtain a control instruction signal, and adjusting the outer loop reactive power of the low-frequency side of the matrix converter based on the control instruction signal. The method improves the operation energy efficiency of the power system.

The invention discloses a double-M3C converter parallel control method for a flexible low-frequency power transmission system, the flexible low-frequency power transmission system comprises two parallel M3C converter stations, the two converters adopt master-slave control, one M3C converter is set as a master converter, the other M3C converter is set as a slave converter, the power frequency side is connected with a three-phase power supply, and the two M3C converter stations are connected in parallel. A low-frequency side receives new energy equivalent to a controlled current source. The method comprises the following steps: determining a master-slave control strategy according to parallel interaction characteristics of the two M3Cs; a grid-connected control method is adopted at the power frequency side of each M3C converter, an inner ring is controlled by alternating current, and an outer ring is controlled by stator module average capacitance voltage and fixed reactive power; the M3C low-frequency side of the master station adopts an alternating-current voltage control strategy; and the M3C low-frequency side of the slave station adopts a current tracking control strategy. According to the invention, high-precision and fast-dynamic-response current-sharing control can be effectively realized, and the parallel operation performance and reliability of the flexible low-frequency power transmission system in scenes of new energy collection and transmission and the like can be remarkably improved.

This invention relates to the field of data management technology, and discloses an Internet of Things (IoT) terminal management method and system. By receiving the total power generated by each IoT terminal in a photovoltaic (PV) power plant, the total output power of the PV power plant is determined. When the active power value generated by the PV power plant or the actual value of the high-voltage busbar of the PV power plant's main transformer is compared with the target value issued by the dispatch center, the active power limit of the inverter is automatically adjusted to bring the current active power or voltage generated by the PV power plant closer to the target value, improving accuracy and control speed, meeting grid demand, enhancing the peak-shaving capability of the IoT system, ensuring that the operation of the new energy power plant and the grid is within a safe and controllable range, and calling upon the planned total output power of the PV power plant, thereby realizing active power control and reactive power control of the PV power plant. It tracks the active power adjustment target value and reactive power adjustment target value issued by the dispatch center, achieving the grid connection technology requirements for high-precision peak-shaving of the PV power plant.

A method for controlling active and reactive powers in grid-tied converters having a grid side and a battery side, in which said grid side supplies an alternative current to said converter whereas the battery side receives a direct current from said converter, said method comprising direct active and reactive power control in ABC frame where no transformation is used, and wherein active power is controlled by controlling the battery charging and discharging currents, and reactive power is controlled by controlling the phase shift between power factor correction current and voltage.

The present application relates to the technical field of power system grid optimization control, in particular to a data-driven grid voltage and reactive power control optimization method and system, which comprises constructing a voltage and reactive power control mathematical model of a three-phase unbalanced grid, taking the minimum node voltage deviation rate, the lowest grid line loss and the optimal three-phase unbalance degree of bus voltage as the optimization goal; using Latin hypercube sampling to cover the photovoltaic-load typical scene of the whole operation condition, combining with the historical operation data of the grid to generate sample data, training the highway neural network combined with the improved NSGA-II algorithm, and obtaining the globally optimal grid voltage and reactive power control strategy through population iteration solution. The present application adopts a data-driven method, replaces the traditional physical model with a proxy model, effectively adapts the uncertainty of new energy access, shortens the single time period decision time to seconds, stabilizes the node voltage and three-phase unbalance degree within the safety limit, and at the same time realizes the minimization of the whole grid loss.

This application discloses a voltage optimization control method, device, terminal, and medium for distribution networks, relating to the field of distribution network technology. By introducing a dynamic zoning adjustment mechanism and an adaptive optimization algorithm, this application achieves deep coupling and synergy between the zoning strategy and the optimization algorithm. This method can effectively address the uncertainties and fluctuations brought about by distributed power source access in distribution networks, improve the reliability of reactive power control, and meet the requirements for efficient and stable operation of distribution networks.

This invention discloses a reactive power control method and system for wind turbine generators based on virtual synchronization technology, belonging to the field of wind power generation technology. First, the control equations of the virtual synchronizer are established based on the synchronous shaft and power angle system. Then, by changing the amplitude and phase angle of the voltage at the grid connection point of the virtual synchronizer, the active and reactive power transmitted by the inverter to the grid are controlled. Finally, the reactive power-voltage droop coefficient of the reactive power control link of the virtual synchronizer is adjusted to achieve the maximum reactive power output of the wind turbine generator. This invention can effectively improve the grid connection characteristics of wind turbine generators, leverage the inertia and damping of the wind turbine generators, and provide strong support for the grid. It can also improve the grid connection performance of wind turbine generators and maximize their reactive power characteristics, showing promising application prospects.

This application provides a method and apparatus for reactive power circulation analysis and control in a grid-connected hybrid renewable energy power station. The method includes: constructing an equivalent model of the grid-connected hybrid renewable energy power station, in which the grid-connected units in the renewable energy power station are equivalent to one equivalent grid-connected unit, connected to the point of common coupling (PCC) via a first line reactor; and the grid-connected units in the renewable energy power station are equivalent to one equivalent grid-connected unit, connected to the PCC via a second line reactor, the PCC being connected to the power grid via a third line reactor; obtaining the reactive power of the grid-connected units and the voltage amplitude of the grid-connected units based on the equivalent model; and limiting the values ​​of the voltage control command for the grid-connected units and the reactive power control command for the grid-connected units by analyzing the reactive power of the grid-connected units and the voltage amplitude of the grid-connected units, so as to ensure that reactive power circulation is suppressed within any given target range of PCC voltage.

The application provides an affine harmonic current calculation method considering new energy harmonic emission characteristics, comprising the following steps: step 1: considering the influence of meteorological conditions, dead zone effect, control time delay and background harmonic, an affine model of harmonic sources of wind power and photovoltaic is established to accurately describe the uncertain harmonic emission characteristics of wind power and photovoltaic; step 2: according to the power characteristics of new energy power generation under the influence of different reactive power control strategies, an affine model of the machine-grid interface of new energy power generation is constructed; step 3: an affine Ybus Gauss iteration algorithm based on reactive power prediction-correction is used to solve the fundamental wave current of the power grid to obtain the operating point of the harmonic source; step 4: an affine overrelaxation iteration method is used to solve the harmonic current equation, and the interval range of the harmonic state quantity is obtained through the alternating iteration of the fundamental wave and the harmonic; the application of the technical scheme can accurately solve the uncertain harmonic current of the new energy power grid, thereby providing a reference for the grid connection planning and harmonic control and suppression of new energy power generation.

This invention discloses a method and system for generating power regulation commands in a multi-station coordinated manner, belonging to the field of new energy power generation control technology. The method includes: acquiring and preprocessing operational data from a large-scale new energy power base; constructing a coordinated optimization model for active and reactive power control commands based on the preprocessed operational data, aiming to minimize the total regulation power error and regulation cost; solving the coordinated optimization model for active and reactive power control commands using a coordinated optimization algorithm based on a preset power regulation level, and generating a strategy table; querying the strategy table according to the received total active power regulation commands, quickly matching and issuing corresponding power station regulation commands to the coordinated control master station and each power station substation; and simultaneously updating the strategy table in real time according to a dynamic update strategy to improve adaptability. This invention achieves coordinated optimization of active and reactive power across multiple power stations, improving the response speed and economy of power regulation while meeting grid frequency, voltage, and line safety constraints.

The invention discloses an energy storage power station active control method combining inertia and droop characteristics. The method comprises the following steps: establishing a mathematical model of an inverter circuit in an energy storage power station according to an electromagnetic characteristic equation of a synchronous generator; calculating the output power of the energy storage power station according to the mathematical model; calculating the output power according to the droop characteristic to obtain a voltage reference value of the output voltage of the inverter circuit; calculating a voltage difference value, and calculating a grid-connected current reference value according to the voltage difference value; and obtaining a reference modulation voltage wave according to the grid-connected current actual value and the grid-connected current reference value, wherein the reference modulation voltage wave is used for modulating the voltage wave of the energy storage power station to realize the balance of the three-phase grid-connected current. According to the method, by simulating a characteristic equation of a synchronous generator, establishing a mathematical model of an energy storage converter and designing active and reactive control outer rings and a voltage and current control inner ring, an energy storage power station can realize self-synchronization grid connection while having external characteristics of a voltage source, and voltage and frequency support is provided for a power grid when necessary.

This invention relates to the field of power system stability control technology, and is a wind power converter control method and system for reducing the risk of transient voltage instability at wind power collection stations. The method includes: establishing a transient voltage model of the wind power collection station in the renewable energy sending-end grid after a DC bipolar blocking fault; establishing a reactive power control model of the wind power converter under the transient voltage control mode based on active power output; and setting transient voltage instability limits for the wind power collection station in the renewable energy sending-end grid after a DC bipolar blocking fault. This invention can fully leverage the rapid reactive power control advantages of the wind power converter when the transient voltage instability risk of the wind power collection station is caused by the UHVDC bipolar blocking in the renewable energy sending-end grid, thereby reducing the peak transient voltage of the wind power collection station, preventing the wind farm units connected to the wind power collection station from tripping and disconnecting from the grid due to high voltage ride-through failure, thus reducing the risk of transient voltage instability at the wind power collection station and improving the transient voltage stability of the system.

The embodiment of the invention provides an automatic shutdown control system and method for a large fuel gas and steam cycle unit, and the system comprises an automatic start-stop control system APS which is used for executing a unit shutdown process comprising a unit load reduction breakpoint and a generator-transformer unit disconnection breakpoint; the coordination control system CCS is connected with the automatic start-stop control system and used for receiving an instruction sent by the APS at the unit load reduction breakpoint and controlling the active power of the unit to be reduced to a first preset threshold value; the reactive power control function group is in communication connection with the APS and the excitation system and is used for receiving an instruction sent by the APS at a unit load reduction breakpoint and controlling the excitation system to reduce the reactive power of the generator to a second preset threshold value; and after the APS is configured to receive a first completion signal indicating that the active power reaches the standard from the CCS and a second completion signal indicating that the reactive power reaches the standard from the reactive control function group at the same time, subsequent generator-transformer group disconnection breakpoint is executed.

The application discloses a hybrid AC-AC converter, comprising: an AC bus on the rectifier side, a converter transformer, a rectifier, an inverter, an AC bus on the inverter side, an AC filter and a DC filter; the rectifier is composed of a high-voltage valve group LCC and a low-voltage valve group MMC, the high-voltage valve group and the low-voltage valve group of the inverter are both in the form of half-bridge sub-module MMC, and a high-power diode valve D is connected in series at the DC outlet of the high-voltage valve group MMC; the rectifier side LCC adopts constant-current control based on the DC voltage of the rectifier side MMC, the rectifier side MMC adopts voltage amplitude-frequency control, and the inverter side MMC adopts constant DC voltage control and constant reactive power control. The application can realize low-frequency transmission of pure new energy power generation bases, well adapt to power fluctuation of the new energy power generation bases, fully utilize the technical maturity of the LCC and the MMC, and reduce engineering cost and power loss compared with a conventional AC-AC converter based on back-to-back MMC.

The invention discloses a multi-network-construction-type converter control method based on active disturbance rejection virtual impedance and a related device, and the method comprises the steps: obtaining a grid-connected reactive instruction, and controlling n actual output currents and n actual output voltages corresponding to n network-construction-type converters through n matching control modules, determining n actual reactive power output powers corresponding to the n network construction type converters based on the n actual output currents and the n actual output voltages, and determining n voltage reference signals based on the n actual reactive power output powers and the n preset reactive power output powers through a reactive power control module, n voltage compensation signals are determined based on the n actual output currents through the active disturbance rejection virtual impedance control module, and the n actual output voltages are adjusted through the voltage and current double-loop control module, so that the n actual output voltages are adjusted to be n target output voltages. According to the embodiment of the invention, the operation stability of the new energy grid-connected system can be improved.

The invention belongs to the technical field of power systems, and particularly discloses a singular perturbation-reactive decoupling-based order reduction method and device for a network construction type converter. According to the invention, the original state space model is converted; on the basis of a singular perturbation strategy, order reduction processing is carried out according to target variable characteristics; order reduction processing is carried out on a voltage dynamic equation in a reactive power control outer ring, reactive power decoupling is carried out in the mode that a voltage state variable is introduced into an active power control state equation, and a differential equation based on the phase angle relation is established. Through the above mode, aiming at the electromagnetic dynamic process of the fast subsystem, order reduction processing is carried out on the electromagnetic dynamic state variable based on the singular perturbation strategy, order reduction processing is carried out on the voltage dynamic equation in the reactive power control outer loop, high-order dynamic items are eliminated, main dynamic characteristics in the state space are reserved, the model order and the solving complexity are obviously reduced, and the reliability of the system is improved. Therefore, the model order can be systematically reduced on the premise of ensuring key dynamic characteristics and stability analysis precision.

According to the voltage reactive power control system and method, the storage medium and the computing equipment provided by the invention, the reactive power control parameters of the own equipment in the future preset time period are independently calculated through the power transmission network and each power distribution network, so that distributed solution is realized, and the problem of large communication and computing burden is avoided. And each flexible DC converter iteratively optimizes and adjusts the reactive output power of the flexible DC converter itself by measuring the difference value between the real-time voltage and the reference voltage at the power distribution network in real-time operation in the future preset time period through the reference voltage output by the power distribution network in the future preset time period and in combination with the regulation and control weight and sensitivity parameters, so that the reactive output power of the flexible DC converter is optimized and adjusted. Accurate cooperative reactive power control can be carried out and reactive power required by a power grid system can be fairly shared with other flexible direct current converters without communication with other flexible direct current converters, so that the overall utilization rate of reactive power resources is improved, the abrasion of the flexible direct current converters is reduced, the operation stability of the power grid system is guaranteed, and the service life of the power grid system is prolonged. And the real-time response to the reactive power demand of the power grid system is realized.

A dynamic frequency coordination control method combining frequency synchronous control in VSC-HVDC and bilateral FLC in LCC-HVDC includes: when a disturbance occurs in a system, the frequency synchronous control in VSC-HVDC is preferentially used to stabilize a grid frequency, and a power adjustment output by the frequency synchronous control in VSC-HVDC is taken as an activation criterion for the bilateral FLC control in LCC-HVDC; when the power adjustment exceeds a preset limiting range and a system frequency deviation exceeds a control dead zone of the bilateral FLC control in LCC-HVDC, the bilateral FLC control in LCC-HVDC is used to determine and output the power adjustment for LCC-HVDC; based on the power adjustment for LCC-HVDC, an additional reactive power control of VSC-HVDC is utilized to provide additional reactive power to LCC-HVDC to regulate a voltage stability of a grid.

The invention discloses a power distribution network layered voltage control method, a medium and equipment. According to the method, firstly, a reactive power-voltage model of distributed photovoltaic and electric vehicle energy storage is constructed, and in consideration of differences of EV battery capacities and states of charge (SoC), a voltage adjustment degree consistency principle is proposed and reactive power output of the EV is corrected. On the basis, reactive power changes of the PV and the EV and tap changes of an on-load tap changing transformer (OLTC) are comprehensively considered, multi-time-step-scale MPC optimization is used for achieving centralized control, and the correcting value of the PV steady-state VQ characteristic and the reactive power control adjusting quantity of the EV are calculated. And the PV and EV access points perform local control on a local unit after receiving the regulating variable of the upper layer, so as to ensure that the voltage of each node of the active power distribution network does not exceed the limit. According to the method, the PV and the EV can be cooperated to participate in active power distribution network voltage control, the adjustable margin of the battery capacity of each EV node is ensured to be reduced according to a consistency principle, and the adjustment frequency of the OLTC tap during voltage fluctuation is reduced.

The invention discloses a reactive power operational range calculation method for a power grid commutation high-voltage direct-current transmission system, and the method comprises the steps: analyzing the reactive power characteristics of the power grid commutation high-voltage direct-current system and the operation limiting conditions of a direct-current system, and calculating a trigger angle, a turn-off angle, direct-current voltage and direct-current of the power grid commutation high-voltage direct-current transmission system; reactive power operable ranges under different working conditions in a power grid commutation high-voltage direct-current system can be obtained by respectively changing alternating-current bus voltages of a rectification side and an inversion side; the technical problem that dynamic and steady-state reactive power support is difficult to provide for an alternating current system because the reactive power adjustable range under different operation conditions is not considered in the reactive power control of the current converter consumed by the existing power grid commutation high-voltage direct current power transmission system is solved.