A multi-machine PQ coordination synchronous control method for LCUs with different regulation rates
By recalculating the PQ parameters and establishing the PQ power regulation model within the AGC/AVC controller of the hydropower plant, the problem of regulation imbalance caused by different regulation rates of each unit in the hydropower plant was solved, and stable multi-unit PQ coordinated synchronous control was achieved, improving the regulation accuracy and stability of the generator units.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HUANENG LANCANG RIVER HYDROPOWER CO LTD
- Filing Date
- 2023-03-14
- Publication Date
- 2026-08-04
AI Technical Summary
The different active and reactive power regulation rates of each unit in the hydropower plant lead to problems such as unbalanced AGC/AVC program allocation, active power oscillation, inadequate load regulation, and deviation of the plant's actual power generation from the load curve.
This paper presents a multi-unit PQ coordinated synchronous control method using LCUs with different regulation rates. By setting automatic/manual parameter adjustment inputs in the AGC/AVC controller, the PQ parameters are recalculated based on deviations from the unit load regulation index. Combined with tests on the governor and excitation regulation rate of the hydroelectric generator set, a PQ power regulation and response regulation function model is established, the parameter set is optimized, and the optimal regulation accuracy and the minimum restricted operating range are achieved to perform multi-unit PQ coordinated synchronous control.
It improves the stability of power generation control, avoids load fluctuations and mis-adjustments and mis-controls, optimizes the regulation rate, and ensures the accuracy of power output and accident assessment.
Smart Images
Figure CN116224797B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of multi-machine PQ coordinated synchronization control of LCUs, and more specifically, to a multi-machine PQ coordinated synchronization control method for LCUs with different adjustment rates. Background Technology
[0002] Currently, due to phased construction or phased renovations, the active and reactive power regulation rates of each unit in a hydropower plant vary. This leads to problems such as imbalanced distribution, active power oscillations, inadequate load regulation, and deviations from the overall plant load curve when the AGC / AVC program performs active and reactive power regulation. Therefore, we propose an improvement: a multi-unit PQ coordinated synchronous control method using LCUs with different regulation rates. Summary of the Invention
[0003] The purpose of this invention is to address the problem arising from the different regulation rates of various generating units in a hydropower plant, and to develop a multi-unit PQ coordinated synchronous control method applicable to LCUs with different regulation rates. This method aims to achieve optimal regulation accuracy, minimum power regulation oscillation, and the fewest restrictions on operating areas based on the PQ power regulation function and response regulation function of different generating units under AGC / AVC control. To achieve the above-mentioned objective, this invention provides the following technical solution: A multi-machine PQ coordinated synchronous control method for LCUs with different regulation rates, step 1: In the current AGC / AVC controller, set an automatic / manual parameter adjustment entry, so that the PQ parameters can be recalculated and adjusted according to the deviation of the unit load regulation index; Step 2: Based on the speed regulation rate test of the hydroelectric generator set governor, the excitation regulation rate test, and the statistical analysis of the actual power generation adjustment rate under the AGC / AVC control of the hydroelectric generator set, a dynamic automatic selection model for the active and reactive PID function parameters of different generator sets under AGC / AVC control is obtained. Based on the actual adjustment rate under different heads and different distributed loads, different parameter sets are obtained. Step 3: Based on the PQ power regulation function and response regulation function of different generator sets under AGC / AVC control, and with the objectives of optimal regulation accuracy, minimum PQ power regulation oscillation, and minimum restricted operating area operation, establish a PQ regulation response model for hydraulic generator sets under AGC / AVC control. Step 4: When dispatching loads, determine the optimal AGC / AVC allocation of units and the optimal parameter set based on the maximum regulation rate of the hydroelectric generator set and the optimal unit coordination under different water heads, and carry out multi-unit PQ coordinated synchronous control of LCUs with different regulation rates.
[0004] As a preferred technical solution of the present invention, step 4 involves programming to implement a joint load regulation strategy based on the maximum regulation rate of the hydroelectric generator set under different head conditions, and to implement command regulation command security verification and PQ power stability protection functions.
[0005] As a preferred technical solution of the present invention, in step 1, the PQ adjustment parameters are adjusted by the AGC / AVC controller. Based on the load adjustment feedback and the preset adjustment indicators, including adjustment rate, adjustment accuracy and response time, the parameters are compared and recalculated. The parameters are then reset automatically or manually so that the indicators approach the target indicators.
[0006] As a preferred technical solution of the present invention, in step 2, the energy storage output of the PQ regulation response model is zero, and the regulation rate deficit is calculated in combination with the upper and lower limits of the allowed frequency; the switching power range is calculated in combination with the energy storage output constraint of the PQ regulation response model.
[0007] As a preferred technical solution of the present invention, in step 2, the allowable deviation of the adjustment rate of the PQ adjustment response model is combined with the adjustment constraint of the PQ operation energy storage to adjust the range of the adjustment rate load.
[0008] As a preferred technical solution of the present invention, in step 3, the PQ power adjustment function under AGC / AVC control sets the multi-machine PQ energy storage power of the LCU, and the PQ energy storage power allocation adjustment function PQ coordinates and synchronizes control.
[0009] As a preferred technical solution of the present invention, in step 3, the DC bus voltage between the AGC / AVC controller and the AGC / AVC distributor converter is the target voltage of the converter, and the duty cycle of the switching transistors in the AGC / AVC distributor converter is controlled to keep the converter constant.
[0010] As a preferred technical solution of the present invention, in step 4, a single-pole AGC / AVC distributor or a bipolar DC-AGC / AVC distributor is connected to the PQ coordinated power grid, and one of the functions of the PQ coordinated system is configured as rate regulation.
[0011] As a preferred technical solution of the present invention, step 4, the multi-machine PQ coordination and synchronization control of the LCU, is used to perform secondary quantization on the LCU and to import the PQ coordination and synchronization control to adjust the different rates of all the coding units divided in the LCU.
[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: In this invention, an automatic / manual parameter adjustment input is set within the AGC / AVC controller. This allows for recalculation and adjustment of PQ parameters after deviations from the unit's load regulation index. Based on tests of the hydroelectric generator governor's regulation rate, excitation regulation rate, and statistical analysis of the actual power regulation rate under AGC / AVC control, a dynamic automatic selection model for active and reactive power PID function parameters under AGC / AVC control is derived for different generator sets. Different parameter sets are obtained based on the actual regulation rates under different heads and load distributions. Based on the PQ power regulation function and response regulation function of different generator sets under AGC / AVC control, a PQ regulation response model for hydroelectric generator sets under AGC / AVC control is established with the goals of optimal regulation accuracy, minimum PQ power regulation oscillation, and minimal restricted operating area operation. After the implementation of a multi-unit PQ coordinated synchronous control method with different regulation rates (LCUs) in hydroelectric power plants, the stability of power generation control can be improved, avoiding load fluctuations, mis-regulation, and mis-control, thus preventing power generation and accident assessments. Overshoot control and regulation rate are optimized. Attached Figure Description
[0013] Figure 1 The flowchart for determining the PQ conditional response model and parameter set selection provided by this invention; Figure 2 The flowchart of multi-machine PQ coordinated synchronization control for LCUs with different adjustment rates provided by this invention. Detailed Implementation
[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are specific implementations of the present invention and are not limited to all embodiments.
[0015] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely illustrates some embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. It should be noted that, in the absence of conflict, the embodiments and features and technical solutions in the embodiments of the present invention can be combined with each other. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0016] Example 1: Please refer to Figure 1-2A multi-machine PQ coordinated synchronous control method for LCUs with different regulation rates, step 1: In the current AGC / AVC controller, set an automatic / manual parameter adjustment entry, so that the PQ parameters can be recalculated and adjusted according to the deviation of the unit load regulation index; Step 2: Based on the speed regulation rate test of the hydroelectric generator set governor, the excitation regulation rate test, and the statistical analysis of the actual power generation adjustment rate under the AGC / AVC control of the hydroelectric generator set, a dynamic automatic selection model for the active and reactive PID function parameters of different generator sets under AGC / AVC control is obtained. Based on the actual adjustment rate under different heads and different distributed loads, different parameter sets are obtained. Step 3: Based on the PQ power regulation function and response regulation function of different generator sets under AGC / AVC control, and with the objectives of optimal regulation accuracy, minimum PQ power regulation oscillation, and minimum restricted operating area operation, establish a PQ regulation response model for hydraulic generator sets under AGC / AVC control. Step 4: When dispatching loads, determine the optimal AGC / AVC allocation of units and the optimal parameter set based on the maximum regulation rate of the hydroelectric generator set and the optimal unit coordination under different water heads, and carry out multi-unit PQ coordinated synchronous control of LCUs with different regulation rates.
[0017] In step 4, the program implements a joint load regulation strategy based on the maximum regulation rate of the hydroelectric generator unit under different head conditions, and implements command regulation command security verification and PQ power stability protection functions.
[0018] In step 1, the PQ adjustment parameters are adjusted by the AGC / AVC controller. The load adjustment feedback and preset adjustment indicators, including adjustment rate, adjustment accuracy and response time, are compared and the parameters are recalculated. The parameters are then reset automatically or manually to make the indicators approach the target indicators.
[0019] In step 2, the energy storage output of the PQ regulation response model is zero. Combined with the upper and lower limits of the allowed frequency, the regulation rate deficit is calculated. Combined with the energy storage output constraint of the PQ regulation response model, the switching power range is calculated.
[0020] In step 2, the allowable deviation of the adjustment rate of the PQ regulation response model is combined with the regulation constraints of the PQ energy storage operation to adjust the range of the adjustment rate load.
[0021] In step 3, the PQ power regulation function under AGC / AVC control sets the multi-machine PQ energy storage power of the LCU, and the PQ energy storage power distribution regulation function is used for PQ coordinated synchronization control.
[0022] In step 3, the DC bus voltage between the AGC / AVC control and the AGC / AVC distributor converter is the target voltage of the converter. The duty cycle of the switching transistors in the AGC / AVC distributor converter is controlled to keep the converter constant.
[0023] In step 4, a unipolar AGC / AVC distributor or a bipolar DC-AGC / AVC distributor is connected to the PQ coordinated power grid, and one of the functions of the PQ coordinated system is configured to regulate the rate.
[0024] In step 4, the multi-machine PQ coordination and synchronization control of the LCU is used to perform secondary quantization on the LCU, and the PQ coordination and synchronization control is used to adjust the different rates of all the coding units divided in the LCU.
[0025] Working Principle: In the process of using this invention, Step 1: Within the current AGC / AVC controller, an automatic / manual parameter adjustment entry is set. This allows for recalculation and adjustment of PQ parameters based on deviations in the unit's load regulation index. Step 2: Based on tests of the hydroelectric generator governor's regulation rate, excitation regulation rate, and statistical analysis of the actual power generation adjustment rate under AGC / AVC control, a dynamic automatic selection model for the active and reactive power PID function parameters of different generator units under AGC / AVC control is derived. This model is then used to determine the actual adjustment rate under different heads and load distributions. Step 1: Different parameter sets are derived based on the PQ power regulation function and response regulation function of different generator sets under AGC / AVC control. The goal is to achieve optimal regulation accuracy, minimum PQ power regulation oscillation, and minimal restricted operating area operation. Step 2: When dispatching loads, the optimal number of generator sets and the optimal parameter set for AGC / AVC allocation are selected based on the maximum regulation rate and optimal unit coordination under different water heads. Multi-unit PQ coordinated synchronous control with LCUs at different regulation rates is then implemented. Step 3: The load regulation strategy based on the maximum regulation rate of the generator sets under different water heads is implemented through programming. The system also includes command regulation command security verification and PQ power stability protection functions. In Step 1, the PQ regulation parameters are adjusted by the AGC / AVC controller. The load regulation feedback is compared with preset regulation indicators, including regulation rate, regulation accuracy, and response time. Parameters are recalculated and reset automatically or manually to bring the indicators closer to the target indicators. In step 2, the energy storage output of the PQ regulation response model is zero. Combined with the upper and lower limits of the allowed frequency, the regulation rate deficit is calculated. The switching power range is calculated based on the energy storage output constraint of the PQ regulation response model. In step 2, the allowable deviation of the PQ regulation rate is adjusted, combined with the regulation constraint of the PQ operating energy storage, to determine the range of the regulation rate load. In step 3, the PQ power regulation function under AGC / AVC control sets the multi-machine PQ energy storage power of the LCU, and the PQ energy storage power distribution regulation function is PQ coordinated synchronous control. In step 3, the DC bus voltage between the AGC / AVC control and the AGC / AVC distributor converter is the converter target. The duty cycle of the switching transistors in the AGC / AVC distributor converter is controlled to keep the converter constant. In step 4, a unipolar AGC / AVC distributor or a bipolar DC-AGC / AVC distributor is connected to the PQ coordinated grid, and one of the functions of the PQ coordinated system is configured as the regulation rate. In step 4, the multi-machine PQ coordination and synchronization control of the LCU is used to perform secondary quantization on the LCU, and the PQ coordination and synchronization control is used to adjust the different rates of all the coding units divided in the LCU.
[0026] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described herein. Although the present invention has been described in detail with reference to the above embodiments, the present invention is not limited to the specific embodiments described above. Therefore, any modifications or equivalent substitutions to the present invention, as well as all technical solutions and improvements that do not depart from the spirit and scope of the invention, are covered within the scope of the claims of the present invention.
Claims
1. A multi-machine PQ coordinated synchronous control method for LCUs with different adjustment rates, characterized in that, Includes the following steps; Step 1: Set up an automatic or manual parameter adjustment entry in the current AGC / AVC controller. When the unit load adjustment index deviates from the preset adjustment index, including adjustment rate, adjustment accuracy, and response time, the PQ parameter will be recalculated and adjusted. Step 2: Based on the speed regulation rate test of the hydroelectric generator set governor, the excitation regulation rate test, and the statistical analysis of the actual power generation adjustment rate under the AGC / AVC control of the hydroelectric generator set, a dynamic automatic selection model for the active and reactive PID function parameters of different generator sets under AGC / AVC control is obtained. Based on the actual adjustment rate under different heads and different distributed loads, different parameter sets are obtained. Step 3: Based on the PQ power regulation function and response regulation function of different generator sets under AGC / AVC control, and with the objectives of optimal regulation accuracy, minimum PQ power regulation oscillation, and minimum restricted operating area operation, establish a PQ regulation response model for hydraulic generator sets under AGC / AVC control. Step 4: After receiving the load command issued by the dispatcher, first determine the current head condition, and then dynamically select the optimal AGC / AVC allocation unit number and corresponding parameter set according to the maximum regulation rate of the hydroelectric generator unit and the principle of optimal unit coordination. Perform multi-machine PQ coordinated synchronous control on LCUs with different regulation rates to achieve accurate and stable response to the load command.
2. The multi-machine PQ coordinated synchronization control method for LCUs with different adjustment rates according to claim 1, characterized in that, Step 4 involves programming to implement a joint load regulation strategy based on the maximum regulation rate of the hydroelectric generator set under different head conditions, and to implement command regulation command security verification and PQ power stability protection functions.
3. The multi-machine PQ coordinated synchronization control method for LCUs with different adjustment rates according to claim 2, characterized in that, In step 1, the PQ adjustment parameters are adjusted by the AGC / AVC controller. Based on the load adjustment feedback and the preset adjustment indicators, including adjustment rate, adjustment accuracy, and response time, the parameters are compared and recalculated. The parameters are then reset automatically or manually to make the indicators approach the target indicators.
4. The multi-machine PQ coordinated synchronization control method for LCUs with different adjustment rates according to claim 3, characterized in that, In step 2, the energy storage output of the PQ regulation response model is zero. Combined with the upper and lower limits of the allowed frequency, the regulation rate deficit is calculated. Combined with the energy storage output constraint of the PQ regulation response model, the switching power range is calculated.
5. The multi-machine PQ coordinated synchronization control method for LCUs with different adjustment rates according to claim 4, characterized in that, In step 2, the allowable deviation of the adjustment rate of the PQ adjustment response model is combined with the adjustment constraint of PQ energy storage operation to adjust the range of the adjustment rate load.
6. The multi-machine PQ coordinated synchronization control method for LCUs with different adjustment rates according to claim 5, characterized in that, In step 3, the PQ power adjustment function under AGC / AVC control sets the multi-machine PQ energy storage power of the LCU, and the PQ energy storage power allocation adjustment function PQ coordinates and synchronizes the control.
7. The multi-machine PQ coordinated synchronization control method for LCUs with different adjustment rates according to claim 6, characterized in that, In step 3, the DC bus voltage between the AGC / AVC controller and the AGC / AVC distributor converter is the target voltage of the converter. The duty cycle of the switching transistors in the AGC / AVC distributor converter is controlled to keep the converter constant.
8. The multi-machine PQ coordinated synchronization control method for LCUs with different adjustment rates according to claim 7, characterized in that, In step 4, a single-pole AGC / AVC distributor or a bipolar DC-AGC / AVC distributor is connected to the PQ coordinated power grid, and one of the functions of the PQ coordinated system is configured to regulate the rate.
9. A multi-machine PQ coordinated synchronization control method for LCUs with different adjustment rates according to claim 8, characterized in that, Step 4, the multi-machine PQ coordination and synchronization control of the LCU, is used to perform secondary quantization on the LCU and to import the PQ coordination and synchronization control to adjust the different rates of all the coding units divided in the LCU.