Frequency modulation equipment for power system

Abstract

The invention relates to power system frequency modulation equipment in the technical field of power systems, and the power system frequency modulation equipment comprises a controller and power generation equipment, the power generation equipment comprises a generator set, a high-pressure heater and a chemical energy storage device, and a steam turbine regulating valve is arranged on a steam turbine air inlet pipeline in the generator set and is used for regulating the steam inlet amount of a steam turbine; the bidirectional inverter is connected with the output end of the generator set and the chemical energy storage device and used for controlling charging and discharging of the chemical energy storage device; the pneumatic adjusting valve is arranged on an air inlet pipeline of the high-pressure heater and used for indirectly adjusting the steam inlet amount of the steam turbine; the controller comprises: a controller; according to the method, the reserve capacity model is constructed based on the comprehensive cost index and the safe operation index of the system, and the frequency stability of the system after failure is ensured. According to the model, parameters of a new energy generator set and a traditional energy generator set are considered, and a more comprehensive and reliable frequency modulation guarantee is provided.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and more particularly to a frequency regulation device for a power system. Background Art

[0002] With the increasing global demand for clean energy, the proportion of new energy power generation (such as wind power, photovoltaic power generation, etc.) in the power system is getting higher and higher. However, due to the "low inertia" characteristics of new energy power generation, large frequency fluctuations are likely to occur when a fault occurs in the power system. The existing frequency regulation methods, for example, the publicly disclosed invention patent (publication number: CN109742772A) only targets a single type of power generation equipment and cannot effectively cope with the complex situations of multiple types of energy. Therefore, how to achieve fast and accurate frequency regulation in a power system containing multiple types of power generation equipment has become an urgent technical problem to be solved.

[0003] Therefore, we have designed a frequency regulation device for a power system. Summary of the Invention

[0004] In order to overcome the deficiencies in the background art, the present invention discloses a frequency regulation device for a power system.

[0005] To achieve the above invention objective, the present invention adopts the following technical solutions: A frequency regulation device for a power system, comprising a controller and a power generation device. The power generation device includes a generator set, a high-pressure heater, and a chemical energy storage device, and further includes: A steam turbine regulating valve, provided on the steam inlet pipeline of the steam turbine in the generator set, for regulating the steam inlet volume of the steam turbine; A bidirectional inverter, connected to the output end of the generator set and the chemical energy storage device, for controlling the charge and discharge of the chemical energy storage device; A pneumatic regulating valve, provided on the air inlet pipeline of the high-pressure heater, for indirectly regulating the steam inlet volume of the steam turbine; The controller includes: A communication module, for data interaction with the grid dispatching center, receiving AGC dispatching instructions and feeding back the real-time output value; A dynamic model construction module, constructing a system frequency dynamic model during power generation of the power system according to the parameters related to the generator set in the power system; A calculation module, calculating the safe operation index of the power system according to the system frequency dynamic model; A spare capacity model construction module, obtaining the system comprehensive cost index of the power system, and constructing a spare capacity model of the generator set according to the system comprehensive cost index and the safe operation index; A frequency regulation module, performing dual regulation on the system frequency of the power system according to the spare capacity model.

[0006] Preferably, the regulation of the system frequency of the power system by the frequency regulation module includes: When it is detected that the first system frequency change amount within the first predetermined time period of the power system is greater than or equal to the first preset frequency of at least one component, perform a primary frequency adjustment on at least one component, and obtain the second system frequency change amount within the second predetermined time period after the primary frequency adjustment.

[0007] Preferably, the regulation of the system frequency of the power system by the frequency regulation module further includes: When the second system frequency change amount is greater than or equal to the second preset frequency, perform a secondary frequency adjustment on each power supply device.

[0008] Preferably, the primary frequency adjustment includes adjusting the steam turbine control valve and the pneumatic control valve, and controlling the charge and discharge of the chemical energy storage device to achieve the balance of the power system.

[0009] Preferably, the secondary frequency adjustment includes controlling the charge and discharge of the chemical energy storage device through a bidirectional inverter to achieve the balance of the power system.

[0010] Preferably, the generator set includes a new energy generator set and a traditional energy generator set.

[0011] Due to the adoption of the above-mentioned technical solution, the present invention has the following beneficial effects: 1. Build a reserve capacity model based on the comprehensive cost index and safe operation index of the system to ensure the frequency stability of the system after a fault. This model takes into account the parameters of the new energy generator set and the traditional energy generator set, providing a more comprehensive and reliable frequency modulation guarantee; 2. Adopt a dynamic model construction and adaptive adjustment strategy, and continuously optimize the frequency modulation strategy according to the actual operation data, so that the system can better adapt to the complex power environment; 3. Use a bidirectional inverter to drive the chemical energy storage device to charge and discharge, which can respond to the system frequency change within milliseconds, greatly improving the response speed of the system; 4. Quickly respond to the system frequency change through the primary frequency adjustment. When the primary adjustment is not sufficient to stabilize the system, perform a more refined secondary frequency adjustment. This phased frequency modulation strategy can quickly and accurately restore the system frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a structural schematic diagram of the present invention; Figure 2 is a flowchart of the frequency modulation of the present invention.

[0013] In the figure: 100, controller; 101, communication module; 102, dynamic model construction module; 103, calculation module; 104, spare capacity model construction module; 105, frequency regulation module; 200, power generation equipment; 201, generator set; 202, high-pressure heater; 203, chemical energy storage device; 204, steam turbine regulating valve; 205, bidirectional inverter; 206, pneumatic regulating valve. Detailed implementation mode

[0014] The present invention can be explained in detail through the following embodiments. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention. In the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "front", "rear", "left", "right", etc. indicating the orientation or positional relationship, it is only corresponding to the drawings of the present application for the convenience of describing the present invention; it should be understood that if there are terms such as "end", "side", "end part", "side part", "lateral", "longitudinal", etc. indicating the orientation or positional relationship, it is only corresponding to the length and width of the corresponding component, that is, the "end part" indicates the head and tail areas in the length direction of the corresponding component, and the "side part" indicates the head and tail areas in the width direction of the corresponding component; it is for the convenience of describing the present invention rather than indicating or implying that the device or element referred to must have a specific orientation.

[0015] Embodiment 1, in combination with the attached Figure 1-2 , a frequency modulation device for a power system, including a controller 100 and a power generation device 200. The power generation device 200 includes a generator set 201, a high-pressure heater 202 and a chemical energy storage device 203. Further, the generator set 201 includes a new energy generator set and a traditional energy generator set.

[0016] The power generation device 200 further includes: A steam turbine regulating valve 204, which is arranged on the steam inlet pipeline of the steam turbine in the generator set 201 and is used to regulate the steam inlet volume of the steam turbine; A bidirectional inverter 205, which is connected to the output end of the generator set 201 and the chemical energy storage device 203 and is used to control the charge and discharge of the chemical energy storage device 203; A pneumatic regulating valve 206, which is arranged on the air inlet pipeline of the high-pressure heater 202 and is used to indirectly regulate the steam inlet volume of the steam turbine.

[0017] According to requirements, the controller 100 adopts a distributed control system and integrates the AGC (Automatic Generation Control) function so as to be able to obtain the grid dispatching instruction in real time. Specifically, it includes: A communication module 101, which is used for data interaction with the grid dispatching center, receiving the AGC dispatching instruction and feeding back the real-time output value; The dynamic model construction module 102 constructs a system frequency dynamic model during the power generation process of the power system according to the parameters related to the generator set 201 in the power system; The calculation module 103 calculates the safe operation index of the power system according to the system frequency dynamic model; The reserve capacity model construction module 104 obtains the system comprehensive cost index of the power system, and constructs a reserve capacity model of the generator set 201 according to the system comprehensive cost index and the safe operation index; During the process of constructing the reserve capacity model of the generator set 201 as needed, the parameters of the new energy generator set 201 and the traditional energy generator set 201 and the system comprehensive cost index are considered.

[0018] The frequency regulation module 105 regulates the system frequency of the power system according to the reserve capacity model.

[0019] The specific frequency regulation method of this frequency regulation device for the power system is as follows: The dynamic model construction module 102 constructs a system frequency dynamic model during the power generation process of the power system according to the parameters related to the generator set 201 in the power system; according to the system frequency dynamic model of the power system, the calculation module 103 calculates the safe operation index of the power system; the reserve capacity model construction module 104 obtains the system comprehensive cost index of the power system, and constructs a reserve capacity model of the generator set 201 according to the system comprehensive cost index and the safe operation index of the power system, and the frequency regulation module 105 regulates the system frequency of the power system according to the reserve capacity model.

[0020] To improve the frequency regulation accuracy and response speed, preferably, the frequency regulation module 105 has a dual frequency regulation function. The regulation of the system frequency specifically includes: The first stage of frequency regulation is to perform an initial frequency adjustment on at least one component according to the comparison result between the system frequency change amount and the preset frequency threshold; specifically, when it is detected that the first system frequency change amount of the power system within the first predetermined time period is greater than or equal to the first preset frequency of at least one component, an initial frequency adjustment is performed on the at least one component to obtain the second system frequency change amount within the second predetermined time period after the initial frequency adjustment; further, the initial frequency adjustment includes adjusting the steam turbine control valve 204 and the pneumatic control valve 206, and controlling the charge and discharge of the chemical energy storage device 203 to achieve the balance of the power system. Specifically, according to the parameters (such as the high-pressure heater 202, the steam turbine control valve 204, etc.) and the current state of each component, the adjustment actions to be performed are calculated; for the generator set 201, according to its type (new energy or traditional energy) and specific parameters (inertia time constant, damping coefficient, etc.), an appropriate power adjustment amount is determined.

[0021] Specifically, the following formula can be adopted: ; wherein, represents the change in power output to be adjusted for the i-th generator set 201 at time t, and are respectively the inertia time constant and damping coefficient of the i-th generator, is the system frequency deviation, is the rate of change of the system frequency deviation with time.

[0022] According to requirements, the first predetermined time period can be 4, 5, 6 seconds, etc.

[0023] The second frequency regulation is to further finely adjust each power supply device when the change in system frequency still does not meet the requirements. Specifically, when the second change in system frequency is greater than or equal to the second preset frequency, secondary frequency adjustment of each power supply device is performed; further, the secondary frequency adjustment includes controlling the chemical energy storage device 203 to charge and discharge through the bidirectional inverter 205 to achieve a higher-precision balance of the power system.

[0024] The parts not detailed in the present invention are prior arts. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention; therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, aiming to include all changes falling within the meaning and scope of the equivalent elements within the present invention.

Claims

1. A power system frequency modulation device, comprising a controller and a power generation device, wherein the power generation device comprises a generator set, a high-voltage heater and a chemical energy storage device, characterized in that: Also includes: The steam turbine regulating valve is installed on the steam turbine air inlet pipe in the generator set and is used to adjust the steam inlet amount of the steam turbine; A bidirectional inverter is connected to the output end of the generator set and the chemical energy storage device to control the charging and discharging of the chemical energy storage device; The pneumatic regulating valve is installed in the air inlet pipe of the high-pressure heater and is used to indirectly adjust the steam inlet amount of the steam turbine; The controller comprises: Communication module, used to exchange data with the power grid dispatching center, receive AGC dispatching instructions and feedback real-time output values; A dynamic model building module, which builds a system frequency dynamic model of the power system during the power generation process based on the parameters related to the generator sets in the power system; A calculation module calculates the safe operation index of the power system according to the system frequency dynamic model; The spare capacity model building module obtains the system comprehensive cost index of the power system and builds the spare capacity model of the generator set based on the system comprehensive cost index and the safe operation index; The frequency regulation module performs dual regulation on the system frequency of the power system according to the reserve capacity model.

2. The power system frequency modulation device according to claim 1, characterized in that: The frequency regulation module regulates the system frequency of the power system including: When it is detected that a first system frequency change of the power system within a first predetermined time period is greater than or equal to a first preset frequency of at least one component, an initial frequency adjustment is performed on at least one component, and a second system frequency change within a second predetermined time period after the initial frequency adjustment is obtained.

3. The power system frequency modulation device according to claim 2, characterized in that: The frequency regulation module also regulates the system frequency of the power system: When the second system frequency variation is greater than or equal to the second preset frequency, the secondary frequency of each power supply device is adjusted.

4. The power system frequency modulation device according to claim 2, characterized in that: The initial frequency adjustment includes adjusting the turbine regulating valve and the pneumatic regulating valve, and controlling the charging and discharging of the chemical energy storage device to achieve power system balance.

5. The power system frequency modulation device according to claim 3, characterized in that: The secondary frequency adjustment includes controlling the charging and discharging of a chemical energy storage device through a bidirectional inverter to achieve a balance in the power system.

6. The power system frequency modulation device according to claim 1, characterized in that: The generator sets include new energy generator sets and traditional energy generator sets.

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