CN-122001036-A - Reactive power dynamic cooperative allocation method for full-field loss reduction and voltage stabilization-oriented wind turbine generator set

CN122001036ACN 122001036 ACN122001036 ACN 122001036ACN-122001036-A

Abstract

The invention relates to the technical field of wind power grid-connected control, and discloses a dynamic cooperative distribution method of reactive power of a wind turbine generator set for full-field loss reduction and voltage stabilization. The reactive power distribution strategy aims to solve the technical problem that the existing reactive power distribution strategy is difficult to consider the transient stability of the grid-connected point voltage and the internal operation economy of a station under a complex current collection system. The invention analyzes reactive reserve space of a unit by collecting full-field synchronous parameters, screens an allocation initial value with minimum total loss based on full-path impedance and voltage sensitivity, calculates compensation quantity by utilizing response time lag to generate a cooperative instruction, realizes full-field action synchronization, and performs online parameter deviation correction and safety relay allocation by combining voltage slope monitoring. The grid-connected voltage control method and the grid-connected voltage control device improve grid-connected voltage control precision, reduce system electric energy loss and guarantee safe operation of converter equipment.

Inventors

SUN WENXIA
LI HAIWEN
YU GUANGYONG
WANG LIYAN
LIU HENG

Assignees

甘肃龙源新能源有限公司
龙源(敦煌)新能源发展有限公司

Dates

Publication Date: 20260508
Application Date: 20260202

Claims (10)

1. A dynamic cooperative allocation method of reactive power of a wind turbine generator set for full-field loss reduction and voltage stabilization is characterized by comprising the following steps: s1, acquiring electrical parameters and weather forecast data of a unit output end, a collection branch point, a booster station bus and a grid connection point in a wind power plant, and evaluating a reactive power adjustable space of a full-field unit in a next control period; s2, extracting the physical impedance of a full path from the output end of the unit to the grid-connected point through a collection branch point and a booster station bus, analyzing the voltage sensitivity and the branch loss weight of the unit, and screening a group of data with the lowest heating loss value of a full-field current collecting line as a reactive distribution instruction initial value of the unit through a power balance relation in reactive output combination of the grid-connected point voltage fluctuation within a rated allowable deviation range; S3, identifying inherent communication delay and hardware response time lag of the unit converter, and generating a cooperative action instruction by superposing millisecond-level time compensation quantity at the transmission time point of the reactive power distribution instruction initial value; and S4, sending the cooperative action instruction to the unit converter, monitoring the change slope of the voltage of the grid-connected point, and correcting the impedance calculation parameter in the power balance relation on line according to the difference value of the voltage change slope and a preset feedback index.
2. The dynamic collaborative distribution method for reactive power of a full-field loss reduction and voltage stabilization-oriented wind turbine generator system according to claim 1 is characterized in that the electrical parameter acquiring process in the step S1 is that voltage vectors, current vectors and active and reactive power values are acquired by synchronous phasor measuring devices arranged at the output end of the wind turbine generator system and corresponding nodes according to a unified time reference.
3. The dynamic collaborative distribution method for reactive power of a wind turbine generator set facing full-field loss reduction and voltage stabilization according to claim 1 is characterized in that the process of evaluating the reactive power adjustable space in the step S1 is that the upper limit of active power determined by combining weather forecast data is calculated according to the geometric difference between the total bearing capacity limit value of a current active operating point of a current transformer of the wind turbine generator set and the geometric difference between the current active operating point of the current transformer, and the limit of the temperature rise of the current transformer by considering the environmental temperature.
4. The dynamic collaborative distribution method for reactive power of a wind turbine generator set facing full-field loss reduction and voltage stabilization according to claim 1 is characterized in that the process of analyzing voltage sensitivity and branch loss weight in the step S2 is that electric parameters of the full-path physical impedance at all connection nodes are summarized, a mapping relation of grid-connected point voltage along with reactive power output variation of the wind turbine generator set is established, voltage sensitivity is obtained by calculating the variation ratio of the grid-connected point voltage to reactive power output of the wind turbine generator set, and heating loss of all transformer branches and collector lines under unit reactive power current is calculated to be used as the branch loss weight.
5. The dynamic collaborative distribution method of reactive power of a wind turbine generator set facing full-field loss reduction and voltage stabilization according to claim 4, wherein the process of calculating the reactive power distribution command initial value in the step S2 is to calculate corresponding full-field total loss values one by utilizing a power balance relation of full-field power transmission according to different reactive power output combinations in a reactive power reserve allowance range under the condition that the grid-connected point voltage is in a rated allowable deviation range, and screen out a group of output data minimizing the full-field total loss values from the output data, and lock the output data as the reactive power distribution command initial value corresponding to the wind turbine generator set.
6. The dynamic cooperative allocation method for reactive power of a full-field loss reduction and voltage stabilization-oriented wind turbine generator set according to claim 1 is characterized in that the process of identifying inherent communication delay and hardware response time lag in the step S3 is that a control system sends a test step signal to a converter of the wind turbine generator set, records the time difference of current change from the signal to the output end of the converter and takes the time difference as a correction reference of the hardware response time lag.
7. The dynamic collaborative distribution method of the reactive power of the wind turbine generator set facing full-field loss reduction and voltage stabilization according to claim 1 is characterized in that the process of superimposing millisecond-level time compensation in the step S3 is that a hardware response time lag value of the turbine generator set converter is extracted, the turbine generator set converter with the largest response time lag value is selected as a reference device, response time lag deviation of the turbine generator set converter relative to the reference device is calculated, and the response time lag deviation is used as waiting time length to be implanted into a transmission time sequence of the reactive power distribution command initial value.
8. The method for dynamically and cooperatively distributing reactive power of a full-field loss-reducing and voltage-stabilizing wind turbine generator set according to claim 1 is characterized in that the step S4 of monitoring the change slope of the grid-connected point voltage comprises the steps of obtaining a voltage sequence of the grid-connected point voltage in a continuous sampling period in a preset observation window after the cooperative action instruction is executed, and obtaining the voltage fluctuation amplitude in unit time by means of differential calculation.
9. The method for dynamically and cooperatively distributing reactive power of a wind turbine generator set for full-field loss reduction and voltage stabilization according to claim 1, wherein the process of online correction of impedance calculation parameters in the step S4 is that if the voltage change slope is smaller than an expected slope, the actual value of the full-path physical impedance is determined to be larger than a set value in a power balance relation, and the impedance value in the power balance relation is synchronously increased according to a deviation ratio.
10. The method for dynamically and cooperatively distributing reactive power of a wind turbine generator set facing full-field loss reduction and voltage stabilization according to claim 9, wherein after the impedance calculation parameter is corrected online in the step S4, the method further comprises the steps of checking the voltage of a machine end of the converter of the wind turbine generator set after the cooperative action instruction is executed, locking reactive power output of a current wind turbine generator set and stopping correction of the impedance calculation parameter when the voltage of the machine end exceeds a preset safety value interval, generating reactive power instruction deviation amount according to the reactive power instruction deviation amount, and redistributing the reactive power instruction deviation amount to other wind turbine generator sets in the safety value interval according to the sequence of high voltage sensitivity to low voltage sensitivity.

Description

Reactive power dynamic cooperative allocation method for full-field loss reduction and voltage stabilization-oriented wind turbine generator set Technical Field The invention relates to the technical field of wind power grid-connected control, in particular to a full-field loss reduction and voltage stabilization oriented wind turbine reactive power dynamic collaborative distribution method. Background In the current large-scale wind farm operation practice, reactive power regulation by using a converter configured by a wind turbine generator system has become an important means for maintaining the voltage stability of grid-connected points. The traditional distribution mode generally adopts an empirical distribution strategy based on the static voltage support requirement or the distribution according to the equal proportion of capacity, and aims to meet the basic control requirement of grid dispatching on grid-connected point voltage. However, with the continuous expansion of the installed scale of wind farms and the complexity of the topology of the current collection system, the conventional reactive power distribution approach faces multiple substantial technical challenges in practical applications. The wind power generation system has the advantages that the span of the current collecting circuit in the wind power plant is huge, the distributed impedance difference between each unit and the grid-connected point is obvious, the reactive current generated by the remote unit is always caused to be unnecessarily active in long-distance transmission due to simple equal-proportion distribution, and the voltage fluctuation at the machine end is easy to be out of limit. The method is also limited by the differences of hardware performance, communication protocols and physical distances of converters in different batches, and each unit has obvious non-synchronism when receiving and executing instructions, and the differences of response time lags are extremely easy to induce concussion of parallel network voltage in the transient regulation process. In addition, physical parameters such as cable impedance have time variability under the influence of environmental temperature and operation working condition, and a preset static model is difficult to accurately describe a complex energy flow rule. Therefore, how to ensure the accurate stability of the grid-connected point voltage in the millisecond transient process and the action synchronization of the whole-field unit under the fluctuating wind power resource and the complex topological environment and effectively consider the real-time operation loss and the equipment safety of the internal current collection network becomes a key problem to be solved in the field. Disclosure of Invention The present invention has been made in view of the above-described problems occurring in the prior art. Therefore, in order to solve the technical problem that the existing reactive power distribution strategy is difficult to consider the transient stability of the grid-connected point voltage and the internal operation economy of the station under the complex current collection system, the invention provides a dynamic cooperative distribution method for the reactive power of the wind turbine generator, which is oriented to full-field loss reduction and voltage stabilization. In order to solve the technical problems, the invention provides the following technical scheme: the invention provides a dynamic cooperative allocation method of reactive power of a wind turbine generator set for full-field loss reduction and voltage stabilization, which comprises the following steps, S1, acquiring electrical parameters and weather forecast data of a unit output end, a collection branch point, a booster station bus and a grid connection point in a wind power plant, and evaluating a reactive power adjustable space of a full-field unit in a next control period; s2, extracting the physical impedance of a full path from the output end of the unit to the grid-connected point through a collection branch point and a booster station bus, analyzing the voltage sensitivity and the branch loss weight of the unit, and screening a group of data with the lowest heating loss value of a full-field current collecting line as a reactive distribution instruction initial value of the unit through a power balance relation in reactive output combination of the grid-connected point voltage fluctuation within a rated allowable deviation range; S3, identifying inherent communication delay and hardware response time lag of the unit converter, and generating a cooperative action instruction by superposing millisecond-level time compensation quantity at the transmission time point of the reactive power distribution instruction initial value; and S4, sending the cooperative action instruction to the unit converter, monitoring the change slope of the voltage of the grid-connected point, and correcting the impedanc