Real-time control system and method for integration of wind, light, fire and energy storage

Abstract

The invention provides a real-time control system and method for wind-solar-thermal storage integration, and the method comprises the steps: receiving a power grid AGC instruction and the operation parameters of each power generation unit in real time through a comprehensive controller, calculating the deviation power, and carrying out the calculation of the deviation power based on a hierarchical compensation strategy; and the total power is dynamically adjusted through the primary compensation of the new energy unit and the secondary compensation of the energy storage unit in sequence. Wherein the thermal power generating unit is of a double-loop control architecture, and during execution of the layered compensation strategy, the basic power is tracked and adjusted to be within a safe operation interval by constraining the adjustment rate and an instruction. According to the invention, a hierarchical control strategy of primary compensation of a new energy unit and secondary compensation of an energy storage unit is adopted, a power adjustment task is dynamically allocated, so that the response speed of the system is increased, and power deviation is compensated in a short time; the thermal power generating unit adopts a double-loop control framework, the thermal power generating unit is ensured to still operate in a high-efficiency interval when AGC instructions frequently fluctuate by constraining the regulation rate and tracking the instructions, and low load loss and equipment damage are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of control systems and control objects of power generation processes, and in particular to a real-time control system and method for wind, solar, thermal and energy storage integration. Background Art

[0002] At present, some thermal power plants have begun to independently build photovoltaic and / or wind turbines and configure certain energy storage units. In this scenario, photovoltaic / wind power and energy storage are connected at the thermal power grid connection point. Thermal power plants receive the automatic generation control (Automatic Generation Control) instructions from the power grid in a unified manner and have the ability to autonomously allocate power within the field. Different from the previous model of direct dispatch to each unit, it has developed into a new type of power generation entity.

[0003] Among the above power generation forms, the load regulation rate of traditional coal-fired units is slow, and the start-up and shutdown time is long. Its operation mode has certain limitations, but its power generation is relatively stable. Photovoltaic and / or wind power generation relies on solar photovoltaic arrays or wind turbines, does not require fuel consumption, has cheap power generation, and is usually connected to the grid using power electronic equipment, which has a fast load regulation speed. However, photovoltaic or wind power generation will be affected by the environment, such as irradiance, temperature, wind speed, etc., and has a certain volatility. Energy storage units can be charged and discharged at any time, but the storage cost is relatively high.

[0004] Therefore, the common application scenarios of the above-mentioned types of power generation are: as an integrated system, it receives grid dispatch in a unified manner, and the internal configuration is free by the power plant, that is, the integration of wind, solar, thermal and storage. In this scenario, the power plant needs to consider both the load response and the economic efficiency of power generation. Existing integrated control systems are often aimed at integrated energy systems, large new energy bases, virtual power plants and other objects. The internal power generation types are similar, but they are different from new power generation forms in terms of operating modes and power generation targets. There is currently a lack of research on related control methods and control systems, and it is difficult to meet actual production needs.

[0005] In summary, it is also necessary to propose a real-time control method and system for the integration of wind, solar, thermal and storage. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention provides a system and method with a simple control structure, low operating cost and capable of meeting the application requirements of wind, solar, thermal and energy storage integrated scenarios.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows: On the one hand, the present invention provides a real-time control method for wind, solar, thermal and storage integration, which mainly includes the following steps: The integrated controller receives the AGC command of the power grid and the operating parameters of each power generation unit in real time, and calculates the deviation power; in calculating the deviation power, the integrated controller calculates the thermal power reference power based on the AGC command of the power grid; the thermal power reference power is sent to the thermal power controller, and the actual thermal power generation power is obtained through detection; the actual thermal power generation power is sent to the integrated controller, and the deviation power is calculated by the difference comparison method; Based on the hierarchical compensation strategy, the total power is dynamically adjusted through the primary compensation of the new energy unit and the secondary compensation of the energy storage unit in turn to compensate for the deviation power; The thermal power unit adopts a dual-loop control architecture. During the execution of the hierarchical compensation strategy, the basic power is adjusted within a safe operating range by constraining the adjustment rate and tracking the instructions.

[0008] Optionally, calculating the deviation power further includes the following steps: The integrated controller calculates the new energy reference power based on the power grid AGC instruction; The power that the new energy unit should generate is calculated based on the thermal power reference power, the new energy reference power and the actual thermal power generation power.

[0009] Optionally, a total power constraint condition is provided in the dynamic adjustment of the total power, and the formula is: ; In the formula, is the rated power of the thermal power unit, is the rated power of the new energy unit, is the total power commanded by the grid AGC; The formula for the new energy reference power is: ; In the formula, is the new energy reference power; is the reference output coefficient of new energy, and , is the load reduction rate.

[0010] Optionally, the thermal power reference power The formula is: ; The dual-loop control architecture of the thermal power unit is PI control and PID control, wherein the PI control is used to constrain the regulation rate, and the PID control is used to follow the instructions.

[0011] Optionally, the step of adjusting the basic power within the safe operation range includes the following steps: Set the constraints of the thermal power unit as follows: ; Reference output coefficient of thermal power units The formula is: ; After the reference output coefficient of the thermal power unit is input into the thermal power controller, the rate is adjusted through the PI control constraint, and the reference output coefficient of the constrained thermal power unit is obtained. ; Solve the current actual power coefficient of the thermal power unit , the formula is: ; In the formula, is the actual power generation of the thermal power plant; the deviation signal of the thermal power unit is ; The thermal power unit deviation signal is output as the thermal power output coefficient after the PID control ; The thermal power output coefficient is limited, and the limiting processing formula is: ; In the formula, is the actual power coefficient of the thermal power unit in the next period; The actual power coefficient of the thermal power unit in the next period is input into the thermal power controller.

[0012] Optionally, the primary compensation of the new energy unit includes the following steps: Calculate the compensation coefficient of new energy units , the formula is: ; Calculate the output coefficient of new energy units , the formula is: ; The output coefficient of the new energy unit is limited, and the limiting formula is: ; In the formula, is the actual power coefficient of the new energy generator set; and the actual power coefficient of the new energy generator set is input into the Boost controller of the new energy generator set.

[0013] Optionally, the energy storage unit secondary compensation includes the following steps: Calculate the compensation power of the energy storage unit , the formula is: ; In the formula, is the total power of the grid AGC command, is the actual power generation of thermal power, The actual power generated by renewable energy; Set the charging or discharging power of the energy storage unit to ,and .

[0014] On the other hand, the present invention also provides a real-time control system for wind, solar, thermal and energy storage integration, which mainly includes a comprehensive controller, a thermal power controller, a new energy controller and an energy storage controller; The integrated controller is respectively connected to the power grid dispatching system, the thermal power controller, the new energy controller and the energy storage controller, and the integrated controller is also connected to the operation status monitoring devices of the thermal power units, the new energy units and the energy storage units, for collecting the operation parameters of each power generation unit; The thermal power controller is integrated into the thermal power control system and connected to the thermal power unit; The new energy controller is integrated into the new energy control system and connected to the new energy group; The energy storage controller is integrated into the energy storage control system and connected to the energy storage unit.

[0015] Optionally, a PI controller and a PID controller are integrated in the thermal power control.

[0016] Optionally, a limiting module is also connected in series in the output circuits of the PI controller and the PID controller.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The present invention realizes efficient coordinated control of the integrated wind, solar, thermal and energy storage system through a hierarchical compensation strategy and a dual-loop thermal power control architecture; adopts a hierarchical control strategy of primary compensation of new energy units and secondary compensation of energy storage units, and dynamically allocates power regulation tasks to improve the system response speed, and compensates for power deviations in a short time; further, the thermal power units adopt a dual-loop control architecture, and through constraining the regulation rate and instruction tracking, ensure that the thermal power units still operate in the high-efficiency range when the AGC instructions fluctuate frequently, avoiding low-load losses and equipment damage; further, the hierarchical compensation strategy dynamically balances the regulation pressure of new energy and energy storage, and maximizes the proportion of new energy power generation and reduces coal consumption and pollutant emissions while meeting the grid assessment indicators. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1 It is a step diagram of the control method of the present invention; Figure 2 It is the overall control flow chart of the present invention; Figure 3 It is a schematic diagram of the overall structure of the present invention; Figure 4 This is a schematic diagram of the structure of a thermal power controller of the present invention; Figure 5 It is the power response characteristic curve of wind / solar generator set in MPPT mode; Figure 6 is a power response characteristic curve using the strategy of the present invention; Figure 7 It is a comparison diagram of the total power response characteristic curve under the MPPT mode of the wind / photovoltaic generator set and the control condition using the method of the present invention.

[0020] In the figure: 1-first input terminal, 2-PI controller, 3-zero-order holder, 4-PID controller, 5-limiting module, 6-second input terminal, 7-output terminal. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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.

[0022] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0023] It is worth noting that the methods used in the present invention are all conventional methods unless otherwise specified; the raw materials and devices used are all conventional commercially available products, and their sources are not specifically limited unless otherwise specified.

[0024] It should also be noted that in order to facilitate understanding, the method steps in the specific embodiments of the present invention are described in a certain order, but those skilled in the art can change the order of the steps according to actual needs, and therefore this cannot be used as a limiting condition; it should be further noted that in the description of the following specific embodiments, the upper and lower subscripts of each parameter should be understood as distinguishing marks of similar identifications with reference to common interpretations unless otherwise specified, representing the parameters of the device related or corresponding to the subscript, and should not be understood as specific models or special marks.

[0025] On the one hand, if Figure 1 , 2 As shown, the present invention provides a real-time control method for wind, solar, thermal and storage integration, which mainly includes the following steps: The integrated controller receives the grid AGC instructions and the operating parameters of each power generation unit in real time, and calculates the deviation power; specifically, the calculation of the deviation power includes the following steps: Assume the total power constraint condition, the formula is: ; In the formula, is the total power of the grid AGC command, is the rated power of the thermal power unit, It is the rated power of the new energy unit.

[0026] The integrated controller calculates the thermal power reference power based on the grid AGC instruction; among them, the thermal power unit reference output coefficient The formula is: ; Furthermore, in the thermal power controller, the constraints of the thermal power unit are also set as follows: ; Among them, thermal power reference power The formula is: ; In the formula, It is the reference power of new energy.

[0027] The thermal power reference power is sent to the thermal power controller, and the actual thermal power generation power is obtained through detection. The actual thermal power generation power is sent to the integrated controller, and the deviation power is calculated by the difference comparison method.

[0028] Synchronously, the integrated controller also calculates the reference power of renewable energy based on the AGC command of the power grid. The formula for the reference power of renewable energy is: ; In the formula, is the reference output coefficient of new energy, and , is the load shedding rate. In a preferred embodiment, the new energy generator set is a photovoltaic generator set, and the idea of ​​load shedding control is adopted: if the photovoltaic generator set should generate power of; ; In the formula, This design, by replacing the rated power with the maximum power under a specific scenario, not only takes into account the adjustment speed, but also can adjust the real-time accuracy and power generation economy, and cooperates with It can be flexibly set according to empirical values, which determines whether the adjustment margin and output of the photovoltaic group conform to the idea of ​​a better solution.

[0029] The power that the new energy unit should generate is calculated based on the thermal power reference power, the new energy reference power and the actual thermal power generation power, which is the deviation power.

[0030] Based on the hierarchical compensation strategy, the total power is dynamically adjusted through the primary compensation of the new energy unit and the secondary compensation of the energy storage unit to compensate for the deviation power.

[0031] Wherein, the new energy generator set of the present invention is a wind generator set and / or a photovoltaic generator set, and the primary compensation of the new energy generator set includes the following steps: Calculate the compensation coefficient of new energy units , the formula is: ; In the formula, It is the actual power generation capacity of thermal power.

[0032] Calculate the output coefficient of new energy units , the formula is: ; The output coefficient of the new energy unit should be limited, and the limiting formula is: ; In the formula, is the actual power coefficient of the new energy unit; the actual power coefficient of the new energy unit is input into the Boost controller of the new energy unit.

[0033] On the basis of primary compensation, secondary compensation of energy storage unit is also required to achieve more stable output, so the following steps are also included: Calculate the compensation power of the energy storage unit , the formula is: ; In the formula, The actual power generated by renewable energy; Therefore, the charging or discharging power of the energy storage unit is set to ,and .

[0034] In the above process, since the thermal power units provide a relatively large proportion of power, their power generation power is used as the basic power of the power station. In order to stabilize the overall power generation power and avoid the scheduling instructions and multi-system complementary power generation affecting the stability of the basic power, the present invention also designs the thermal power units as a dual-loop control architecture. During the execution of the hierarchical compensation strategy, the basic power is adjusted within a safe operating range through constraint adjustment rate and instruction tracking.

[0035] Furthermore, the dual-loop control architecture of the thermal power unit is PI control and PID control, PI control is used to constrain the adjustment rate, and PID control is used for command tracking. Adjusting the basic power in the safe operating range includes the following steps: After the reference output coefficient of the thermal power unit is input into the thermal power controller, the rate is adjusted through PI control constraints, and the reference output coefficient of the constrained thermal power unit is obtained. ; Solve the current actual power coefficient of thermal power units , the formula is: ; In the formula, the deviation signal of the thermal power unit is ; The deviation signal of the thermal power unit is output as the thermal power output coefficient after PID control ; The thermal power output coefficient is limited, and the limiting formula is: ; In the formula, is the actual power coefficient of the thermal power unit in the next period; The actual power coefficient of the thermal power unit in the next period is input into the thermal power controller.

[0036] In summary, the thermal power reference power guides the thermal power unit to generate electricity under the processing of the thermal power controller, and the thermal power unit obtains the actual power generation of the current thermal power unit. The actual power generation of thermal power is sent to the main controller. The main controller calculates the wind / photovoltaic power to be generated based on the photovoltaic reference power, the thermal power reference power and the actual power generation of thermal power, and sends the wind / photovoltaic power to be generated to the wind / photovoltaic controller. The wind / photovoltaic power to be generated guides the wind / photovoltaic generator unit to generate electricity under the processing of the photovoltaic controller, and the wind / photovoltaic generator unit obtains the actual power generation of the current wind / photovoltaic generator unit and sends it back to the main controller. The main controller calculates the power generation of the energy storage unit based on the AGC total power, the actual power generation of the wind / photovoltaic generator unit, and the actual power generation of the thermal power unit, and sends the power generation of the energy storage unit to the energy storage controller. The energy storage unit fine-tunes the total power generation according to the instructions of the energy storage controller to make the peak regulation more accurate.

[0037] On the other hand, the present invention also provides a real-time control system for wind, solar, thermal and storage integration, which is used to implement the above control method, such as Figure 3 As shown, it mainly includes an integrated controller, a thermal power controller, a new energy controller and an energy storage controller.

[0038] Among them, the integrated controller receives real-time information such as the grid AGC instructions, wind / solar unit power generation, wind / solar unit power forecast, energy storage status, thermal power unit power generation, etc., and generates real-time thermal power unit control instructions, wind / solar unit control instructions, and energy storage control instructions through internal algorithm calculations, and transmits them to the control systems of the corresponding objects to complete the real-time control tasks. At the same time, the integrated controller generates the power response of the entire plant according to the wind / solar power generation, thermal power unit power generation and energy storage status, and uploads it to the grid dispatch via RTU. The integrated controller is connected to the grid dispatch system, thermal power controller, new energy controller and energy storage controller respectively, and the integrated controller is also connected to the operation status monitoring devices of the thermal power units, new energy units and energy storage units to collect the operating parameters of each power generation unit.

[0039] like Figure 4 As shown, the thermal power controller is integrated in the thermal power control system and connected to the thermal power unit, wherein a PI controller 2 and a PID controller 4 are integrated, and the first input terminal 1 is used to receive the thermal power to be generated, which enters the zero-order holder 3 after passing through the PI controller 2, and then is calculated with the actual thermal power received and processed by the second input terminal 6, and the calculation result is input into the PID controller 4, and then through the limiting module 5 to the output terminal 7 to obtain the thermal power reference power.

[0040] The new energy controller is integrated into the new energy control system and connected to the new energy group; specifically, the wind / photovoltaic controller can be implemented by using a PWM generator of a boost circuit.

[0041] The energy storage controller is integrated into the energy storage control system and connected to the energy storage unit; specifically, the energy storage controller can be implemented by a PWM generator of a boost / buck step-up and step-down circuit, and the energy storage unit can be implemented by a hydrogen storage tank or a battery.

[0042] Embodiment 1; As described above, the thermal power controller of this embodiment uses one PI controller and one PID controller. As a conventional controller, the PID controller adjusts the result according to the difference between the reference power and the actual power, and a limiting module needs to be installed at the output end. Among them, the PI controller and the limiting module can be set according to the constraint conditions.

[0043] The specific constraints include: the regulation speed of the thermal power units and the minimum operating load of the thermal power units.

[0044] The architecture and strategy of this embodiment are verified in MATLAB / Simulink software, and the following scenarios are defined: The existing 330MW thermal power units and 120MW photovoltaic power units (new energy units) receive the following instructions: The AGC command power in the first 30 seconds is 420MW; At 30s, the AGC command power suddenly changes to 340MW; At 40s, the AGC command power suddenly changed to 370MW; At 50s, the AGC command power suddenly increased to 330MW; At 60s, the AGC command power suddenly changed to 350MW; At 80s, the AGC command power suddenly changed to 345MW; Furthermore, during the command reception period, the external irradiance fluctuates greatly over time, that is, the photovoltaic output fluctuates by more than 5%.

[0045] thus, Figure 5 is the power response characteristic curve when the photovoltaic generator adopts the MPPT maximum power tracking mode, Figure 6 To adopt the strategy and architecture of the present invention, the output coefficient Power response characteristic curve when set to 0.85.

[0046] Figure 7 The response curves of the traditional method and the strategy of the present invention to the AGC command are shown in Figure 2. By accumulating the errors of the two methods within 100 seconds, the relative error within 100 seconds is calculated, that is, relative error Er = (actual power within 100 seconds - AGC command power within 100 seconds) / AGC command power within 100 seconds. The MPPT mode error is calculated to be Er1 = 2.35%, while the strategy of the present invention is Er2 = 1.13%.

[0047] According to the simulation results, compared with the traditional MPPT tracking method, the system of this embodiment cooperates with the corresponding strategy to greatly improve the adjustment accuracy of the power generation following the instruction and the output stability.

[0048] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A real-time control method for wind, solar, thermal and energy storage integration, characterized by: The steps include: The integrated controller receives the grid AGC instruction and the operating parameters of each power generation unit in real time, and calculates the deviation power; in calculating the deviation power, the integrated controller calculates the thermal power reference power based on the grid AGC instruction; The thermal power reference power is sent to the thermal power controller, and the actual thermal power generation power is obtained through detection; the actual thermal power generation power is sent to the integrated controller, and the deviation power is calculated by the difference comparison method; Based on the hierarchical compensation strategy, the total power is dynamically adjusted through the primary compensation of the new energy unit and the secondary compensation of the energy storage unit in turn to compensate for the deviation power; The thermal power unit adopts a dual-loop control architecture. During the execution of the hierarchical compensation strategy, the basic power is adjusted within a safe operating range by constraining the adjustment rate and tracking the instructions.

2. The real-time control method for wind, solar, thermal and energy storage integration according to claim 1 is characterized by: Calculating the deviation power also includes the following steps: The integrated controller calculates the new energy reference power based on the power grid AGC instruction; The power that the new energy unit should generate is calculated based on the thermal power reference power, the new energy reference power and the actual thermal power generation power.

3. The real-time control method for wind, solar, thermal and energy storage integration according to claim 2 is characterized in that: The total power dynamic regulation is provided with a total power constraint condition, and the formula is: ； In the formula, is the rated power of the thermal power unit, is the rated power of the new energy unit, is the total power commanded by the grid AGC; The formula for the new energy reference power is: ； In the formula, is the new energy reference power; is the reference output coefficient of new energy, and , is the load reduction rate.

4. The real-time control method for wind, solar, thermal and energy storage integration according to claim 3 is characterized by: The thermal power reference power The formula is: ； The dual-loop control architecture of the thermal power unit is PI control and PID control, wherein the PI control is used to constrain the regulation rate, and the PID control is used to follow the instructions.

5. The real-time control method for wind, solar, thermal and energy storage integration according to claim 4 is characterized in that: The step of adjusting the basic power within the safe operation range includes the following steps: Set the constraints of the thermal power unit as follows: ； Reference output coefficient of thermal power units The formula is: ； After the reference output coefficient of the thermal power unit is input into the thermal power controller, the rate is adjusted through the PI control constraint, and the reference output coefficient of the constrained thermal power unit is obtained. ; Solve the current actual power coefficient of the thermal power unit , the formula is: ； In the formula, is the actual power generation of the thermal power plant; the deviation signal of the thermal power unit is ; The thermal power unit deviation signal is output as the thermal power output coefficient after the PID control ; The thermal power output coefficient is limited, and the limiting processing formula is: ； In the formula, is the actual power coefficient of the thermal power unit in the next period; The actual power coefficient of the thermal power unit in the next period is input into the thermal power controller.

6. The real-time control method for wind, solar, thermal and energy storage integration according to claim 5 is characterized by: The primary compensation of the new energy unit includes the following steps: Calculate the compensation coefficient of new energy units , the formula is: ； Calculate the output coefficient of new energy units , the formula is: ； The output coefficient of the new energy unit is limited, and the limiting formula is: ； In the formula, is the actual power coefficient of the new energy generator set; and the actual power coefficient of the new energy generator set is input into the Boost controller of the new energy generator set.

7. The real-time control method for wind, solar, thermal and energy storage integration according to any one of claims 1 to 6, characterized in that: The energy storage unit secondary compensation comprises the following steps: Calculate the compensation power of the energy storage unit , the formula is: ； In the formula, is the total power of the grid AGC command, is the actual power generation of thermal power, The actual power generated by renewable energy; Set the charging or discharging power of the energy storage unit to ,and .

8. A real-time control system for wind, solar, thermal and energy storage integration, characterized by: Including integrated controller, thermal power controller, new energy controller and energy storage controller; The integrated controller is respectively connected to the power grid dispatching system, the thermal power controller, the new energy controller and the energy storage controller, and the integrated controller is also connected to the operation status monitoring devices of the thermal power units, the new energy units and the energy storage units, for collecting the operation parameters of each power generation unit; The thermal power controller is integrated into the thermal power control system and connected to the thermal power unit; The new energy controller is integrated into the new energy control system and connected to the new energy unit; The energy storage controller is integrated into the energy storage control system and connected to the energy storage unit.

9. The real-time control system for wind, solar, thermal and energy storage integration according to claim 8 is characterized by: The thermal power control is integrated with a PI controller and a PID controller.

10. The real-time control system for wind, solar, thermal and energy storage integration according to claim 9 is characterized in that: A limiting module is also serially connected in the output circuits of the PI controller and the PID controller.

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