Control method for auxiliary frequency modulation of thermal power generating unit

Abstract

The invention relates to the technical field of thermal power generating unit frequency modulation, and discloses a control method for auxiliary frequency modulation of a thermal power generating unit. According to the method, related data of a thermal power generating unit are collected, the standard output power, the stable load requirement, the system standard frequency and the standard unit operating temperature of the generating unit are calculated according to the collected data, calculated values are judged, and whether the thermal power generating unit needs frequency modulation or not is analyzed; the deviation between the current system frequency and the target frequency and the power adjustment amount are calculated, and control instructions are generated according to the power adjustment amount and include up-regulation and down-regulation of the output power of the generator set, sending of the control instructions to the generator set and completion of auxiliary frequency modulation of the thermal power generating unit; the control instruction is issued to complete automatic frequency modulation, so that the adjustment time is shortened, the problem of untimely frequency modulation caused by human factors is avoided, and meanwhile, the frequency modulation accuracy is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of frequency regulation of thermal power generation units, and in particular to a control method for auxiliary frequency regulation of thermal power generation units. Background Art

[0002] Thermal power units are devices that generate heat by burning fossil fuels such as coal, natural gas or oil, and then convert the heat into mechanical energy through steam or gas turbines, and finally drive generators to generate electricity. Thermal power units are widely used in power systems and are responsible for providing baseload power and peak-shaving power to meet the continuous and instantaneous power demand of the power grid. The core of power system operation is to ensure the balance between power generation and load, especially the stability of frequency. When power generation is insufficient to supply the load, the system frequency decreases. Conversely, when power generation exceeds the load, the frequency increases. Frequency fluctuations may cause damage to power equipment or unstable operation. Therefore, frequency regulation of thermal power units is a necessary measure to ensure the stability of the power system. At the same time, due to changes in electricity demand, such as peak and trough time periods, thermal power units need to adjust the output power according to the instantaneous load to maintain frequency stability. This frequency regulation capability helps the power system better cope with various operating conditions.

[0003] In traditional frequency regulation methods, operators need to regularly monitor system frequency, load demand and unit status, and determine whether frequency regulation is needed based on these data. This process often relies on manual experience and judgment. This manual adjustment is not only time-consuming, but may also lead to untimely response and inaccurate frequency regulation due to human factors. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the deficiencies in the prior art, the present invention provides a control method for auxiliary frequency regulation of a thermal power unit, which has the characteristics of collecting output power, load demand, system frequency, unit operating temperature and unit environmental humidity data of the thermal power unit, calculating the standard output power, stable load demand, system standard frequency and standard unit operating temperature of the generator set according to the above collected data, judging the calculated values, analyzing whether the thermal power unit needs frequency regulation, and when the thermal power unit determines that frequency regulation is needed, calculating the deviation between the current system frequency and the target frequency, analyzing the changing trend of the frequency deviation, calculating the power adjustment amount, generating a control instruction according to the power adjustment amount, including increasing and decreasing the output power of the generator set, sending the control instruction to the generator set, completing the auxiliary frequency regulation of the thermal power unit, and completing the automatic frequency regulation by calculating and analyzing the relevant parameters of the thermal power unit and issuing the control instruction, thereby reducing the adjustment time, avoiding the problem of untimely frequency regulation due to human factors, and improving the accuracy of frequency regulation, thereby solving the above problems.

[0006] (II) Technical solution

[0007] To achieve the above object, the present invention provides the following technical solution: a control method for auxiliary frequency regulation of a thermal power unit, comprising the following steps:

[0008] S1. Collect the output power, load demand, system frequency, unit operating temperature and unit ambient humidity data of the thermal power unit;

[0009] S2, calculate the standard output power, stable load demand, system standard frequency and standard unit operating temperature of the generator set according to the data collected in S1, and judge the calculated values ​​to analyze whether the thermal power unit needs frequency regulation;

[0010] S3. When the thermal power unit determines that frequency regulation is required, the deviation between the current system frequency and the target frequency is calculated, the changing trend of the frequency deviation is analyzed, and the power adjustment amount is calculated;

[0011] S4, generating a control instruction according to the power adjustment amount, including increasing or decreasing the output power of the generator set;

[0012] S5. Send the control command to the generator set to complete the auxiliary frequency regulation of the thermal power unit.

[0013] Preferably, the formula for calculating the standard output power of the generator set by S2 is as follows:

[0014] P st =Fdxl*Rllz*LHV

[0015] In the formula, P st It represents the standard output power of the generator set, Fdxl represents the power generation efficiency, which is obtained through the unit performance test, Rllz represents the fuel flow, which is obtained by real-time monitoring of the fuel flow consumed by the unit through the flow meter, and LHV represents the lower heating value, which is obtained through the standard fuel data table.

[0016] Preferably, the formula for calculating the stable load demand in S2 is as follows:

[0017] D(t)=a+b1*D(t-1)+b2*D(t-2)+...+b n *D(tn)+∈

[0018] In the formula, D(t) represents the stable load demand, D(t-1), D(t-2), ..., D(tn) represent the historical load data, which are extracted from the historical database of the power dispatching center, and a, b1, b2, ..., b n represents the regression coefficient, which is obtained by statistical analysis using historical load data; ∈ represents the error term, which is obtained by statistical analysis.

[0019] Preferably, the formula for calculating the standard frequency of the S2 system is as follows:

[0020] f(t)=Edgl+K f *(Fdzg-D(t))

[0021] In the formula, f(t) represents the system standard frequency, Edgl represents the rated power, which is obtained from the grid standard specification, and K f It represents the control gain, which is obtained through the analysis of the system dynamic characteristics. Fdzg represents the total power generated, which is obtained in real time through the monitoring system of the generator set.

[0022] Preferably, the formula for calculating the standard unit operating temperature by S2 is as follows:

[0023]

[0024] In the formula, Bywd represents the standard unit operating temperature, Hjwd represents the ambient temperature, which is obtained in real time through the temperature sensor, Jzsw represents the unit design temperature rise, which is obtained through the unit's technical documents, Dqsc represents the current output power, which is obtained through the power dispatching center, and Glbh represents the temperature change caused by power, which is obtained through the unit's historical data analysis.

[0025] Preferably, the conditions for S2 to determine whether the thermal power unit needs frequency modulation are as follows:

[0026] When the generator set standard output power P st If it is greater than the stable load demand D(t), it means that the output needs to be reduced and the frequency of power generation regulation needs to be reduced;

[0027] When the generator set standard output power P st Less than the stable load demand D(t), indicating the need to increase the output to maintain frequency and power supply;

[0028] When the system standard frequency is less than the frequency threshold, it means that the system frequency is low and the generator set needs to increase its output to increase the frequency and meet the load demand;

[0029] When the system standard frequency is greater than the frequency threshold, it means that the system frequency is high and the generator set needs to reduce output to prevent the frequency from being too high;

[0030] When the standard unit operating temperature exceeds the unit design temperature threshold, it indicates that the unit temperature is abnormal and the load needs to be reduced or cooling needs to be increased;

[0031] When any of the above conditions is met, the thermal power unit needs to be frequency modulated.

[0032] Preferably, the formula for calculating the deviation between the current system frequency and the target frequency in S3 is as follows:

[0033] Ploc=Dqpl-f(t)

[0034] In the formula, Ploc represents the deviation between the current system frequency and the target frequency, Dqpl represents the current system frequency, and f(t) represents the system standard frequency.

[0035] Preferably, the formula for calculating the power adjustment amount in S3 is as follows:

[0036] Gltz=Pxxs*Ploc

[0037] In the formula, Gltz represents the power adjustment amount, and Pxxs represents the frequency response coefficient of the system, which is obtained through the power dispatching center database.

[0038] Preferably, the S4 generates a control instruction for increasing the output power of the generator set and a control instruction for decreasing the output power of the generator set according to the power adjustment amount as follows:

[0039] When Gltz is greater than 0, a control instruction to increase the output power needs to be generated;

[0040] When Gltz is less than 0, a control instruction to reduce the output power needs to be generated.

[0041] Preferably, the S5 sends the control instructions to the generator set through the Modbus communication protocol, and uses the SCADA system to monitor the response of the generator set in real time and track the changes in output power and system frequency.

[0042] Compared with the prior art, the present invention provides a control method for auxiliary frequency regulation of a thermal power unit, which has the following beneficial effects:

[0043] The present invention collects data on the output power, load demand, system frequency, unit operating temperature and unit environmental humidity of the thermal power unit, calculates the standard output power, stable load demand, system standard frequency and standard unit operating temperature of the generator set according to the collected data, judges the calculated values, analyzes whether the thermal power unit needs frequency modulation, and when the thermal power unit determines that frequency modulation is needed, calculates the deviation between the current system frequency and the target frequency, analyzes the changing trend of the frequency deviation, calculates the power adjustment amount, generates a control instruction according to the power adjustment amount, including increasing and decreasing the output power of the generator set, sends the control instruction to the generator set, completes the auxiliary frequency modulation of the thermal power unit, calculates and analyzes the relevant parameters of the thermal power unit, and sends the control instruction to complete the automatic frequency modulation, reduces the adjustment time, avoids the problem of untimely frequency modulation due to human factors, and improves the accuracy of frequency modulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic diagram of the steps of the method of the present invention. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] In traditional frequency regulation methods, operators need to regularly monitor system frequency, load demand and unit status, and judge whether frequency regulation is needed based on these data. This process often relies on manual experience and judgment. This manual adjustment is not only time-consuming, but may also lead to untimely response and inaccurate frequency regulation due to human factors. Therefore, a control method for auxiliary frequency regulation of thermal power units is proposed. Please refer to Figure 1 , the method comprises the following steps:

[0047] S1. Collect the output power, load demand, system frequency, unit operating temperature and unit ambient humidity data of the thermal power unit;

[0048] High-precision sensors and transmitters are used to obtain the output power of the unit in real time. Power analysis instruments are used to form a dynamic power monitoring model while ensuring data accuracy. In order to adapt to the fluctuation of power grid load, data from the power dispatching center is accessed to monitor and analyze system load requirements in real time to ensure that the generator set can flexibly respond to instantaneous load changes. In order to ensure the safe and stable operation of the unit, advanced temperature sensors are equipped to monitor the operating temperatures of key components of the unit, such as turbines, boilers and generators, through temperature control probes, and upload data to the central control system in real time. In terms of unit environmental humidity monitoring, ambient air humidity information is collected through environmental monitoring instruments to prevent equipment corrosion or affect the combustion efficiency of the unit due to excessive environmental humidity. All these data are summarized and analyzed through an integrated industrial Internet platform to form an integrated monitoring system.

[0049] S2, calculate the standard output power, stable load demand, system standard frequency and standard unit operating temperature of the generator set according to the data collected in S1, and judge the calculated values ​​to analyze whether the thermal power unit needs frequency regulation;

[0050] The calculation formula for the standard output power of the generator set is as follows:

[0051] P st =Fdxl*Rllz*LHV

[0052] By ensuring a balance between output power and load demand and reducing frequency fluctuations, it helps maintain system stability and reduces the risk of large-scale power failures. In the formula, Pst It represents the standard output power of the generator set, Fdxl represents the power generation efficiency, which is obtained through the performance test of the unit, Rllz represents the fuel flow, which is obtained by real-time monitoring of the fuel flow consumed by the unit through the flow meter, and LHV represents the lower heating value, which is obtained through the standard fuel data table. The calculation of the standard output power provides a clear benchmark value for the dispatcher, so that he can flexibly adjust the power generation strategy in the face of sudden load changes and improve the efficiency of power dispatching;

[0053] The formula for steady load demand is as follows:

[0054] D(t)=a+b1*D(t-1)+b2*D(t-2)+...+b n *D(tn)+∈

[0055] The calculation of stable load demand helps to maintain the dynamic balance between power generation and load, reduce the frequent start and stop of units, and extend the service life of equipment. In the formula, D(t) represents the stable load demand, D(t-1), D(t-2), ..., D(tn) represent the load history data, which are extracted from the historical database of the power dispatching center. a, b1, b2, ..., b n represents the regression coefficient, which is obtained by statistical analysis using the load data of previous years. ∈ represents the error term, which is obtained by statistical analysis. By predicting the load demand, the operating status of the generator set can be judged in advance, so as to formulate corresponding adjustment strategies to ensure the reliability of power supply.

[0056] The calculation formula of the system standard frequency is as follows:

[0057] f(t)=Edgl+K f *(Fdzg-D(t))

[0058] The setting of the system standard frequency can serve as the basis for the safe operation of the power system to prevent equipment damage and system instability caused by frequency anomalies. In the formula, f(t) represents the system standard frequency, Edgl represents the rated power, which is obtained through the grid standard specification, and K f It represents the control gain, which is obtained through the analysis of the system dynamic characteristics. Fdzg represents the total power generation, which is obtained in real time through the monitoring system of the generator set. By accurately calculating the standard frequency, the deviation of the current frequency can be accurately determined, and the corresponding adjustment plan can be formulated to perform auxiliary frequency regulation more effectively.

[0059] The calculation formula for the standard unit operating temperature is as follows:

[0060]

[0061] By monitoring and adjusting the operating temperature of the unit, it is possible to effectively prevent equipment failure caused by overheating, reduce the risk of accidents, and thus improve the operating safety of the equipment. In the formula, Bywd represents the standard unit operating temperature, Hjwd represents the ambient temperature, which is obtained in real time through the temperature sensor, Jzsw represents the unit design temperature rise, which is obtained through the technical documents of the unit, Dqsc represents the current output power, which is obtained through the power dispatching center, and Glbh represents the temperature change caused by power, which is obtained through the analysis of the unit's historical data. Maintaining the standard operating temperature of the unit helps to achieve optimal fuel utilization efficiency, improve the overall efficiency of cogeneration, and thus reduce operating costs;

[0062] The conditions for judging whether a thermal power unit needs frequency regulation are as follows:

[0063] When the generator set standard output power P st If it is greater than the stable load demand D(t), it means that the output needs to be reduced and the frequency of power generation regulation needs to be reduced;

[0064] When the generator set standard output power P st Less than the stable load demand D(t), indicating the need to increase the output to maintain frequency and power supply;

[0065] When the system standard frequency is less than the frequency threshold, it means that the system frequency is low and the generator set needs to increase its output to increase the frequency and meet the load demand;

[0066] When the system standard frequency is greater than the frequency threshold, it means that the system frequency is high and the generator set needs to reduce output to prevent the frequency from being too high;

[0067] When the standard unit operating temperature exceeds the unit design temperature threshold, it indicates that the unit temperature is abnormal and the load needs to be reduced or cooling needs to be increased;

[0068] When any of the above conditions is met, the thermal power unit needs frequency regulation;

[0069] S3. When the thermal power unit determines that frequency regulation is required, the deviation between the current system frequency and the target frequency is calculated, the changing trend of the frequency deviation is analyzed, and the power adjustment amount is calculated;

[0070] The calculation formula for the deviation between the current system frequency and the target frequency is as follows:

[0071] Ploc=Dqpl-f(t)

[0072] Calculating the deviation between the current system frequency and the target frequency is an important step in judging the state of the power system. Accurate frequency deviation calculation provides a reference for the frequency regulation mechanism, enabling the generator set to respond quickly according to actual needs and dynamic conditions, optimize the adjustment speed and amplitude, and ensure that the frequency returns to the target. In the formula, Ploc represents the deviation between the current system frequency and the target frequency, Dqpl represents the current system frequency, and f(t) represents the system standard frequency. By calculating the frequency deviation, the health of the power system can be monitored in real time, frequency anomalies can be discovered in time, and instability or failure of the power system can be prevented.

[0073] The power adjustment amount is calculated as follows:

[0074] Gltz=Pxxs*Ploc

[0075] Power adjustment is a key parameter that determines the response of the generator set to load changes. By calculating the required power adjustment, the generator set can match the load demand in a more cost-effective way, minimize fuel consumption, and optimize the overall economic benefits. In the formula, Gltz represents the power adjustment, and Pxxs represents the frequency response coefficient of the system, which is obtained from the database of the power dispatching center. After calculating the reasonable power adjustment, the generator set can be smoothly adjusted to avoid equipment wear and efficiency loss caused by frequent start and stop, thereby improving the service life and maintenance cycle of the unit;

[0076] S4, generating a control instruction according to the power adjustment amount, including increasing or decreasing the output power of the generator set;

[0077] The control instructions for increasing and decreasing the output power of the generator set are as follows:

[0078] When Gltz is greater than 0, a control instruction to increase the output power needs to be generated;

[0079] When Gltz is less than 0, a control instruction to reduce the output power needs to be generated;

[0080] S5, sending the control command to the generator set to complete the auxiliary frequency regulation of the thermal power unit;

[0081] The generated control instructions are verified and optimized by the dispatch center to ensure their efficiency and safety in actual operation. In this process, the modern communication technology Modbus protocol is used to ensure that the control instructions can be transmitted to the control system of the generator set in real time and accurately. The DCS distributed control system equipped inside the generator set will receive these instructions and quickly parse their content, such as whether the power output needs to be increased or decreased. According to the content of the instructions, the control system will adjust the unit in real time by adjusting the fuel valve, steam flow or generator excitation current. In order to ensure the timeliness and accuracy of the response, the generator set monitors the data in real time through the SCADA system for self-feedback adjustment to ensure rapid response in the case of rapid changes in demand.

[0082] By calculating and analyzing the relevant parameters of the thermal power units and issuing control instructions to complete automatic frequency regulation, the adjustment time is reduced, the problem of untimely frequency regulation caused by human factors is avoided, and the accuracy of frequency regulation is improved.

[0083] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A control method for auxiliary frequency regulation of a thermal power unit, It is characterized in that The following steps are involved: S1. Collect the output power, load demand, system frequency, unit operating temperature and unit ambient humidity data of the thermal power unit; S2, calculate the standard output power, stable load demand, system standard frequency and standard unit operating temperature of the generator set according to the data collected in S1, and judge the calculated values ​​to analyze whether the thermal power unit needs frequency regulation; S3. When the thermal power unit determines that frequency regulation is required, the deviation between the current system frequency and the target frequency is calculated, the changing trend of the frequency deviation is analyzed, and the power adjustment amount is calculated; S4, generating a control instruction according to the power adjustment amount, including increasing or decreasing the output power of the generator set; S5. Send the control command to the generator set to complete the auxiliary frequency regulation of the thermal power unit.

2. A control method for auxiliary frequency regulation of a thermal power unit according to claim 1, Features: The formula for calculating the standard output power of the generator set by S2 is as follows: P st =Fdxl*Rllz*LHV In the formula, P st It represents the standard output power of the generator set, Fdxl represents the power generation efficiency, which is obtained through the unit performance test, Rllz represents the fuel flow, which is obtained by real-time monitoring of the fuel flow consumed by the unit through the flow meter, and LHV represents the lower heating value, which is obtained through the standard fuel data table.

3. A control method for auxiliary frequency regulation of a thermal power unit according to claim 2, Features: The formula for calculating the stable load demand of S2 is as follows: D(t)=a+b 1 *D(t-1)+b 2 *D(t-2)+...+b n *D(t-n)+∈ In the formula, D(t) represents the stable load demand, D(t-1), D(t-2), ..., D(tn) represent the historical load data, which are extracted from the historical database of the power dispatching center, and a, b 1 、b 2 , ..., b n represents the regression coefficient, which is obtained by statistical analysis using historical load data; ∈ represents the error term, which is obtained by statistical analysis.

4. A control method for auxiliary frequency regulation of a thermal power unit according to claim 3, Features: The formula for calculating the standard frequency of the S2 system is as follows: f(t)=Edgl+K f *(Fdzg-D(t)) In the formula, f(t) represents the system standard frequency, Edgl represents the rated power, which is obtained from the grid standard specification, and K f It represents the control gain, which is obtained through the analysis of the system dynamic characteristics. Fdzg represents the total power generated, which is obtained in real time through the monitoring system of the generator set.

5. A control method for auxiliary frequency regulation of a thermal power unit according to claim 4, Features: The formula for calculating the standard unit operating temperature by S2 is as follows: In the formula, Bywd represents the standard unit operating temperature, Hjwd represents the ambient temperature, which is obtained in real time through the temperature sensor, Jzsw represents the unit design temperature rise, which is obtained through the unit's technical documents, Dqsc represents the current output power, which is obtained through the power dispatching center, and Glbh represents the temperature change caused by power, which is obtained through the unit's historical data analysis.

6. A control method for auxiliary frequency regulation of a thermal power unit according to claim 5, Features: The conditions for S2 to determine whether the thermal power unit needs frequency modulation are as follows: When the generator set standard output power P st If it is greater than the stable load demand D(t), it means that the output needs to be reduced and the frequency of power generation regulation needs to be reduced; When the generator set standard output power P st Less than the stable load demand D(t), indicating the need to increase the output to maintain frequency and power supply; When the system standard frequency is less than the frequency threshold, it means that the system frequency is low and the generator set needs to increase its output to increase the frequency and meet the load demand; When the system standard frequency is greater than the frequency threshold, it means that the system frequency is high and the generator set needs to reduce output to prevent the frequency from being too high; When the standard unit operating temperature exceeds the unit design temperature threshold, it indicates that the unit temperature is abnormal and the load needs to be reduced or cooling needs to be increased; When any of the above conditions is met, the thermal power unit needs to be frequency modulated.

7. A control method for auxiliary frequency regulation of a thermal power unit according to claim 6, Features: The formula for calculating the deviation between the current system frequency and the target frequency in S3 is as follows: Ploc=Dqpl-f(t) In the formula, Ploc represents the deviation between the current system frequency and the target frequency, Dqpl represents the current system frequency, and f(t) represents the system standard frequency.

8. A control method for auxiliary frequency regulation of a thermal power unit according to claim 7, Features: The formula for calculating the power adjustment amount in S3 is as follows: Gltz=Pxxs*Ploc In the formula, Gltz represents the power adjustment amount, and Pxxs represents the frequency response coefficient of the system, which is obtained through the power dispatching center database.

9. A control method for auxiliary frequency regulation of a thermal power unit according to claim 8, Features: The method in which S4 generates a control instruction for increasing the output power of the generator set and a control instruction for decreasing the output power of the generator set according to the power adjustment amount is as follows: When Gltz is greater than 0, a control instruction to increase the output power needs to be generated; When Gltz is less than 0, a control instruction to reduce the output power needs to be generated.

10. A control method for auxiliary frequency regulation of a thermal power unit according to claim 9, Features: The S5 sends control instructions to the generator set through the Modbus communication protocol, and uses the SCADA system to monitor the response of the generator set in real time and track the changes in output power and system frequency.

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