Power coordination control method for photoelectric energy base

Abstract

The invention discloses a power coordination control method for a photoelectric energy base, which is characterized in that the coordination of the whole energy base and the scheduling demand is completed by combining the coordination of scheduling declaration and scheduling instructions with the coordination of energy storage and power generation of an energy storage device of the energy base and a photo-thermal power station by taking solar energy with one day as a period. Compared with a traditional method, the method has the advantages that the daily cycle time period is divided into the photovoltaic energy storage dominant time period and the photo-thermal power generation dominant time period according to the typical daily sunshine condition, and different control strategies are adopted in different time periods. The power control dominant unit is divided into a photo-thermal power generation control dominant unit and an energy storage device control dominant unit according to current time period information, and the power control dominant unit carries out processing according to a two-stage processing method of time period judgment and readjustment in the time period; a power coordination layer of the energy base is provided with a power tracking controller to realize grid-side dispatching power instruction tracking, an energy station layer composed of a photovoltaic power station, an energy storage station and a photo-thermal power station is provided with a branch selection switch, and response is performed according to an energy station access push-out strategy. A photovoltaic power station of the energy station layer adopts a maximum power point control strategy and is realized by a control element in the power station. The photo-thermal station and the energy storage station are respectively provided with a power distribution function so as to coordinate the difference between the calculated value of the power and controller dispatching instruction tracking loop and the real-time power value of the photovoltaic power station, and instruction balance is achieved. And the switching time of different dominant time periods is calculated by adopting a method of rolling superposition calculation and verifying the accuracy to judge the completion of the calculation.

Description

Technical Field

[0001] The invention relates to a photovoltaic energy base, and in particular to a photovoltaic energy base power coordination control method. Background Art

[0002] In the context of centralized development of wind power and photovoltaic power generation, and accelerating the construction of large-scale wind power and photovoltaic base projects focusing on deserts, Gobi and wasteland areas, how to effectively solve the uncertain control of wind and solar resources so that the energy base as a whole can produce stable and reliable energy is an important focus of new energy development and utilization.

[0003] At present, the power coordination strategy of energy bases based on photovoltaic and solar thermal power stations mainly includes: designing and implementing coordination strategies based on the peak-shaving and valley-filling effect of solar thermal power stations, power generation cost targets, power generation revenue targets, etc. These solutions have played a certain role in solving the power coordination planning of the bases. However, the energy base as a whole is still an uncertain power source with large fluctuations to the power grid, which brings great uncertainty to the power call of the power grid.

[0004] Therefore, a coordinated control method for the energy base of a CSP power station is needed to achieve coordination between the overall energy base and the scheduling needs. Summary of the invention

[0005] Based on this, the present invention proposes a power coordination control method for an energy base which is equipped with a photovoltaic power field, an energy storage device and a solar thermal power station with heat storage function. This method uses solar energy with a daily cycle, combined with scheduling declaration and scheduling instruction coordination, and the collaboration of energy base energy storage devices and solar thermal power station energy storage and power generation to complete the coordination of the energy base as a whole and scheduling needs.

[0006] The present invention discloses a photovoltaic energy base power coordination control system, characterized in that the control system comprises a base power coordination layer and an energy station power control layer; wherein the base power coordination layer comprises a power tracking controller, a photovoltaic power station power controller switching switch, a photothermal power station power controller switching switch and its allocation function, and an energy storage device power controller switching switch and its allocation function; the power tracking controller adopts a PID controller, and its calculated output value is connected to the photovoltaic power station, the photothermal power station and the energy storage device in parallel;

[0007] The power control layer of the energy station includes the photovoltaic power station power controller, the solar thermal power station power controller, the energy storage device power controller and their corresponding adjustment mechanisms.

[0008] Optionally, in a preferred example, the base power coordination layer also includes an observer; the input data of the observer are temperature, wind speed and light intensity with time tags, and the data of parameter changes exceeding the set time threshold are sent to the solar thermal power station controller unit as a decision condition for the power control strategy of the solar thermal power station.

[0009] Optionally, in a preferred example, the control system is configured with a photovoltaic power station power prediction function, which calculates the difference between the predicted power value of the photovoltaic power station in a fixed section from the current time of the day and the predicted power value of the photovoltaic power station in a fixed section from the current time of the previous day. If the ratio of the predicted power value of the photovoltaic power station in the fixed section from the current time of the previous day exceeds a set threshold, the excessive disturbance correction control function is started, that is, a disturbance suppression feedforward function is set in front of the corresponding power control loop adjustment mechanism.

[0010] The present application also discloses a control method for a photovoltaic energy base power coordination control system, characterized in that the control method comprises the following steps:

[0011] (1) Obtain the deviation between the dispatching AGC instruction and the total power output of the energy base, which is connected to the power tracking controller of the base power coordination layer;

[0012] (2) The corresponding switching switches of the photovoltaic power station, the solar thermal power station and the energy storage device are turned on or off according to the current time information. The method of turning on or off is based on the subordinate relationship between the current time information and the set photovoltaic energy storage dominant time period and the solar thermal power generation dominant time period. If the current time belongs to the photovoltaic energy storage dominant time period, then execute steps (3) to (4); if the current time belongs to the solar thermal dominant time period, then execute step (5).

[0013] (3) The photovoltaic power station at the energy station layer of the energy base executes the maximum power point control strategy and calculates the power difference adjustment target. The power difference adjustment target Calculated by the following formula:

[0014]

[0015] in, is the target power of the photovoltaic energy storage group, P PV It is the actual power output of the photovoltaic power station.

[0016] (4) The power regulation target of the energy storage device is set equal to the power difference regulation target. When the energy storage device cannot meet the power difference regulation target, it is determined whether the difference meets the minimum economic operation value constraint of the CSP plant. If so, the CSP plant is started to adjust to meet the AGC scheduling instruction; if not, the deviation exceeds the limit and an alarm is issued to guide the adjustment of the power instruction forecast report value for the next time period.

[0017] Optionally, in a preferred example, the reference conditions for determining the start and end times of the photovoltaic energy storage dominant period include: considering the start and stop time requirements of the solar thermal power station.

[0018] (5) The power tracking controller outputs instructions to the power control loop of the CSP station to perform power control.

[0019] Optionally, in a preferred example, the photovoltaic energy storage dominant period is divided into periods I to IV according to the energy relationship. In periods I and IV, photovoltaic power generation alone cannot meet the scheduling requirements, so a photovoltaic power generation + energy storage device power generation strategy is adopted, and the energy storage device is used to supplement power generation; periods II and III are in the stage where photovoltaic power generation exceeds the scheduling requirements, and the excess electric energy is stored in the energy storage device; the calculation of the switching time between the periods adopts a rolling superposition calculation and verifies the matching degree to determine the calculation end time, and the method includes the following steps:

[0020] (a) for t pvs1 Assign an initial value of t0, and calculate the energy storage consumption A2 in the subsequent stage 2 and the energy storage consumption A1 in the previous stage 1.

[0021]

[0022] (b) Calculate the matching degree φ between A1 and A2.

[0023]

[0024] (c) Determine whether the matching degree meets the set requirements. If not, execute step (d);

[0025] If satisfied, the calculation ends.

[0026] (d) After accumulating a fixed step forward from the current calculation time, that is, t j+1 =t j +t1, perform steps (a) to (b) again.

[0027] (e) Determine whether the matching degree meets the set requirements. If not, execute step (f);

[0028] If satisfied, the calculation ends.

[0029] (f) Calculate the current matching degree and compare it with the previous matching degree. If the current matching degree is greater than the previous matching degree, the current calculation time is reduced by a fixed step size, that is, t j+1 =t j -t1, execute step (a) to step (b) again.

[0030] Optionally, in a preferred example, the switching time t pvs1 The determination of the initial value t0 includes the following steps:

[0031]

[0032] Among them, t m is the moment of maximum sunlight intensity, K p It is the historical value of the switching time calculation ratio of q similar prediction curves that start from this calculation and move forward. The q value is selected based on the principle of balancing the calculation time consumption and calculation accuracy; K′=0.4 is selected for the initial calculation.

[0033] Optionally, in a preferred example, the target power of the photovoltaic energy storage group is Calculate by the following steps:

[0034] (a) Calculate the predicted power command P of the photovoltaic power station of the photovoltaic energy storage group PREV for

[0035]

[0036] Where: t v2 The end time of power generation in the operation cycle of the photovoltaic power station is predicted; t v1 K is the start time of power generation in the most recent photovoltaic power station forecast cycle; VS is the reliability coefficient.

[0037] (b) Based on the predicted power command P of the photovoltaic power station PREV The relationship with the AGC instruction is divided into the following cases:

[0038] 1) When P AGCDMIN ≤P AGC -P PREV ≤P AGCDMAX hour,

[0039]

[0040] Where: P AGCDMIN is the minimum allowable deviation of the dispatch instruction (MW); AGCDMAX The maximum allowable deviation of the scheduling instruction (MW).

[0041] 2) When P AGC -P PREV >P AGCDMAX hour,

[0042]

[0043] 3) When P AGC -P PREV <P AGCDMIN hour,

[0044]

[0045] Optionally, in a preferred example, the AGC control instruction received by the power tracking controller is an automatic power generation control instruction issued by the dispatching system, and the instruction is the power forecast data reported to the dispatching system by the energy base. The power forecast is characterized by predicting the corresponding power generation capacity based on the solar irradiation function of the next day, and accumulating the retention value at the end point of the previous day to calculate the total power generation capacity of the next day. Then, according to the matching relationship between the installed capacity of photovoltaic and solar thermal power stations, power values ​​of different dominant time periods are allocated to them.

[0046] Optionally, in a preferred example, the solar thermal power station in the photovoltaic energy base is configured to enter or exit within a period of time before the photovoltaic power station exits or starts, so as to respond to power regulation requirements.

[0047] The main advantages of the present invention are:

[0048] (1) This application is based on a combined power generation energy base consisting of photovoltaic power stations, solar thermal power stations and energy storage devices, and takes the collection, conversion and utilization of solar energy as the starting point of research. It proposes a control scheme for the coordinated collection and conversion of energy by photovoltaic, solar thermal and energy storage in different time periods, as well as tracking and dispatching load instructions. This scheme fully considers the periodicity and volatility of solar energy, organically combines the power regulation of the energy base with the characteristics of energy collection, conversion and storage of the base, and coordinates power within a time period to smooth out the volatility of solar power generation and average the periodic fluctuations of solar energy supply, so that the energy base can automatically adjust the energy stability and optimize the stability of the output power.

[0049] A large number of technical features are recorded in the specification of this application, which are distributed in various technical solutions. If all possible combinations of technical features of this application (i.e., technical solutions) are to be listed, the specification will be too long. In order to avoid this problem, the various technical features disclosed in the above-mentioned invention content of this application, the various technical features disclosed in the various embodiments and examples below, and the various technical features disclosed in the accompanying drawings can be freely combined with each other to form various new technical solutions (these technical solutions are all deemed to have been recorded in this specification), unless the combination of such technical features is technically infeasible. For example, in one example, feature A+B+C is disclosed, and in another example, feature A+B+D+E is disclosed, and features C and D are equivalent technical means that play the same role. Technically, only one can be used, and it is impossible to use them at the same time. Feature E can be combined with feature C technically. Then, the solution of A+B+C+D should not be deemed to have been recorded because it is technically infeasible, and the solution of A+B+C+E should be deemed to have been recorded. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 is a system diagram of an energy base according to the present invention;

[0051] Figure 2 is a schematic diagram of power coordination control according to an embodiment of the present invention;

[0052] Figure 3 is a power coordination control framework diagram according to an embodiment of the present invention;

[0053] Figure 4 is a power command response strategy diagram according to an embodiment of the present invention;

[0054] Figure 5 is a flow chart of solving the switching time according to an embodiment of the present invention; DETAILED DESCRIPTION

[0055] After careful and in-depth research, the inventor has developed for the first time a method that uses solar energy as a reference for a day cycle, combines dispatch declaration and dispatch instruction coordination, focuses on the collaboration of energy base energy storage devices and solar thermal power station energy storage and power generation, and completes the coordination of the energy base as a whole and the dispatch demand. Compared with the traditional method, the present application divides the daily cycle period into photovoltaic energy storage dominant period and solar thermal power generation dominant period according to the sunshine conditions of a typical day, and adopts different control strategies for different periods. The power control dominant unit is divided into two parts: solar thermal power generation control dominant unit and energy storage device control dominant unit according to the current period information. The power control dominant unit is carried out according to the two-level processing method of period judgment and re-adjustment within the period; the power coordination layer of the energy base is equipped with a power tracking controller to realize the grid-side dispatch power instruction tracking, and the energy station layer composed of photovoltaic power station, energy storage station and solar thermal power station is equipped with a branch selection switch to respond according to the energy station access launch strategy. The photovoltaic power station at the energy station layer adopts the maximum power point control strategy, which is realized by the internal control element of the power station. The solar thermal station and the energy storage station are respectively equipped with power allocation functions to coordinate the difference between the power tracking controller dispatch instruction tracking loop calculation value and the real-time power value of the photovoltaic power station to achieve instruction balance. In addition, the switching time of different dominant time periods is calculated by rolling superposition calculation and the accuracy is verified to determine the end of the calculation.

[0056] the term

[0057] Scheduling AGC instructions

[0058] The scheduling AGC instruction proposed in the present invention refers to the energy base as a whole responding to the grid-side automatic generation control (AGC) instruction. The difference between the instruction and the total value of the external power point detection is sent to the dominant unit power controller to calculate the control instruction and guide the action of the dominant unit power control execution unit. In the system of this article, the power control dominant unit is divided into two parts: the solar thermal power generation control dominant unit and the energy storage device control dominant unit according to the current time period information. The power control dominant unit is controlled according to the two-stage processing method of time period judgment and re-adjustment within the time period.

[0059] Example

[0060] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below in conjunction with the accompanying drawings.

[0061] The energy base system involved in this embodiment is as follows: Figure 1 As shown in the figure, the energy base system is equipped with a photovoltaic power plant, an energy storage device and a solar thermal power plant with heat storage function. The photovoltaic power plant consists of n groups of photovoltaic power generation units, and each photovoltaic power generation unit consists of a photovoltaic array, a grid-connected inverter, a circuit breaker, etc. The grid-connected inverter bus in the photovoltaic power generation unit is connected to the field transformer T11 for voltage boosting, and at the same time, it is determined whether to configure the field transformer T21 according to the relationship with the grid voltage. A circuit breaker connected to the energy storage device is set at the photovoltaic array outlet of each photovoltaic power generation unit to complete the access and exit of the energy storage device. The energy storage device is configured on the power supply side to smooth the fluctuation of the output power of the photovoltaic power station, track and dispatch power instructions, and improve the stability, controllability and economy of renewable energy power generation. The solar thermal power station is equipped with a heat storage system to effectively complete the decoupling of heat collection and storage from power generation. The solar thermal power station consists of a concentrated heat collection and storage system and a power generation island of the power station.

[0062] The photovoltaic energy base power coordination control system described in this embodiment is as follows: Figure 3 As shown, it includes a base power coordination layer and an energy station power control layer; wherein, the base power coordination layer includes a power tracking controller, a photovoltaic power station power controller switching switch SW1, a solar thermal power station power controller switching switch SW2 and its allocation function, an energy storage device power controller switching switch SW3 and its allocation function; the power tracking controller adopts a PID controller, and its calculated output value is connected in parallel to the photovoltaic power station, the solar thermal power station and the energy storage device; the energy station power control layer includes a photovoltaic power station power controller, a solar thermal power station power controller, an energy storage device power controller and their corresponding adjustment mechanisms.

[0063] Optionally, in one embodiment, considering that solar energy resources are greatly affected by the weather, an observer formed by temperature, wind speed, and light intensity parameters with time tags is set to correct the adjustment instructions of the CSP plant. Its implementation function is to delay the current moment by t (considering sufficient adjustment time for the CSP plant and the energy storage device), and if the key parameter changes exceed the set threshold, continuous detection is performed and the duration is calculated. In order to ensure reliability, sporadic interruptions caused by signal mutations and other reasons are ignored. The data of the time when the key parameter changes exceed the set threshold is sent to the CSP plant controller unit as a decision condition for its power control strategy.

[0064] Optionally, in one embodiment, the control system is configured with a photovoltaic power station power prediction function, by inputting meteorological data with time tags into the photovoltaic power station power prediction model, when the difference between the photovoltaic power station predicted power value in the 1-minute segment (the numerical value is adjustable) from the current time of the day and the photovoltaic power station predicted power value in the 1-minute segment from the current time of the previous day exceeds the set threshold compared with the photovoltaic power station predicted power value in the 1-minute segment from the current time of the previous day, the excessive disturbance correction control function is started, that is, a disturbance suppression feedforward function is set in front of the corresponding power control loop adjustment mechanism to respond to the impact of changes in the later stage in advance and ensure the stable realization of the main loop control function.

[0065] The main idea of ​​the control method based on the power coordination control system of the photovoltaic energy base in this embodiment is to coordinate and distribute the collected solar radiation energy with a daily operation cycle. The energy from solar radiation is converted in two ways: photovoltaic reaction occurs through photovoltaic elements, generating electric energy for direct external transmission or indirect internal storage and heat transfer through solar radiation energy and molten salt medium, and then converted into the thermal energy of molten salt for storage or power generation. Therefore, according to the solar irradiation function of the next day, the corresponding power generation capacity is predicted, and the retention value at the end point of the previous day is accumulated, and the total power generation capacity of the next day can be calculated. This is also one of the reference standards of the AGC instruction of this application. Specifically, the AGC instruction of this application is dispatched as an automatic power generation control instruction issued by the system, and the instruction is a power prediction data reported to the dispatching system by the energy base. The power prediction is characterized in that the corresponding power generation capacity is predicted according to the solar irradiation function of the next day, and the retention value at the end point of the previous day is accumulated to calculate the total power generation capacity of the next day. According to the matching relationship between the installed capacity of photovoltaic and solar thermal power stations, the power values ​​of different dominant time periods are allocated to them. Then, based on the matching relationship between the installed capacities of photovoltaic and solar thermal power stations, power values ​​for different dominant time periods are allocated and reported to the dispatching system.

[0066] Specifically, the above daily power generation capacity is calculated as

[0067]

[0068] Where: WPRE (t) is the total power generation of the next day; W REM (t-1) is the power reserve of the previous day; α is the coefficient of heat conversion from collector to power; n is the number of photovoltaic modules put into operation; t pve is the time when photovoltaic power generation starts; t pvq It is the moment when photovoltaic power generation stops.

[0069] After calculating the total daily power generation level, the power needs to be allocated according to different dominant time periods. Figure 2 As shown, this application is set and matched according to the characteristics of solar energy in the natural daily cycle. Figure 2 As shown in the figure: t pvm is the starting time of the photovoltaic energy storage dominant period; t tsm is the end time of the photovoltaic energy storage dominant period; t pvs1 is the moment when photovoltaic power generation mode switches to the combined power generation and energy storage mode; t m is the moment of maximum sunlight intensity; t pvs2 It is the moment when photovoltaic power generation switches from the combined power generation and energy storage mode to the power generation mode.

[0070] Specifically, taking the power generation plan for a specific day in the embodiment of the present application as an example, Figure 2 (a) As shown. This application divides the daily cycle into photovoltaic energy storage dominated period and solar thermal power generation dominated period according to the sunshine conditions. Among them, the photovoltaic energy storage dominated period is the operating period with good natural sunshine conditions and strong photovoltaic power generation capacity. In the photovoltaic energy storage dominated period, it is divided into periods I to IV according to the energy relationship, such as Figure 2 (b) As shown. Among them, time periods I and IV are photovoltaic power generation + energy storage device power generation strategies. In this stage, photovoltaic power generation alone cannot meet the power required by the dispatching AGC instructions in the time period; time periods II and III are in the stage where photovoltaic power generation exceeds the power required by the dispatching AGC instructions. Therefore, the energy storage device is in the energy storage strategy at this stage. Since the start and stop of the solar thermal power station takes a certain amount of time, this application achieves seamless connection by crossing the start and stop of the heating power station with the photovoltaic power station, ensuring the connection requirements of the immediate corresponding power regulation.

[0071] Next, we will combine Figure 3 The power coordination control method described in this application is specifically described and explained:

[0072] This application responds to the above-mentioned dispatching AGC instruction as a whole to the photovoltaic energy base. Specifically, it inputs the difference between the dispatching AGC instruction and the total external power detection value into the dominant unit power controller, that is, the power tracking controller mentioned above; then, the power tracking controller adopts a two-level processing method to interact with the corresponding power controller in the power control layer of the energy station, so as to achieve real-time power coordination. Specifically, the first-level processing first performs time period judgment, and the time period judgment is to read the current time and confirm whether the current time is in the photovoltaic energy storage dominant time period or the solar thermal power generation dominant time period and perform corresponding input removal of the photovoltaic power station, solar thermal power station and energy storage device according to the dominant time period;

[0073] After the end time period judgment, the power tracking controller performs secondary processing, namely, the re-adjustment function within the time period. Specifically: during the photovoltaic energy storage-dominated time period, when the deviation between the external output power of the energy base and the AGC instruction exceeds the preset deviation value, the re-adjustment function within the time period is started to adjust the energy storage device. When the energy storage device is adjusted to the maximum control limit and still cannot meet the power control requirements, the system determines whether the CSP station is in operation, and adjusts the power generation of the CSP station according to the operating status of the CSP station to meet the power dispatch requirements of the power grid. When it is not in the photovoltaic energy storage-dominated time period, the AGC function is put into the CSP station.

[0074] Next, we will combine Figure 4 , the response strategy of the power tracking controller is explained in detail:

[0075] like Figure 4 As shown, the power tracking controller starts after receiving the scheduling AGC instruction and the total value of external power detection. It first reads the current time period to determine whether the current time period is dominated by photovoltaic energy storage. If it is the dominant time period of photovoltaic energy storage, the following steps are performed:

[0076] Detect whether the photovoltaic power station is in operation. If not, automatically start the photovoltaic power station and energy storage device, and then start the maximum power control function. The maximum power control function maximizes the use of solar energy to maximize the power of the photovoltaic power station and reduce the amount of abandoned light. The difference between the actual power emitted by the photovoltaic power station and the target power of the photovoltaic energy storage group is calculated as the power difference adjustment target. The power difference adjustment target Calculated by the following formula:

[0077]

[0078] in, is the target power of the photovoltaic energy storage group, P PV It is the actual power output of the photovoltaic power station.

[0079] At the same time, the target power of the photovoltaic energy storage group is calculated as follows:

[0080] (a) Calculate the predicted power command P of the photovoltaic power station of the photovoltaic energy storage group PREV for

[0081]

[0082] Where: t v2 The end time of power generation in the operation cycle of the photovoltaic power station is predicted; t v1 K is the start time of power generation in the most recent photovoltaic power station forecast cycle; VS is the reliability coefficient.

[0083] (b) Based on the predicted power command P of the photovoltaic power station PREV The relationship with the AGC instruction is divided into the following cases:

[0084] 1) When P AGCDMIN ≤P AGC -P PREV ≤P AGCDMAX hour,

[0085]

[0086] Where: P AGCDMIN is the minimum allowable deviation of the dispatch instruction (MW); AGCDMAX The maximum allowable deviation of the scheduling instruction (MW).

[0087] 2) When P AGC -P PREV >P AGCDMAX hour,

[0088]

[0089] 3) When P AGC -P PREV <P AGCDMIN hour,

[0090]

[0091] The power difference adjustment target is smoothed and adjusted by the energy storage or solar thermal power station, and the power adjustment function of the energy storage device is preferentially utilized.

[0092] Therefore, the power difference adjustment target is calculated and used as the power adjustment target of the energy storage device to coordinate the power of the energy storage device. At this time, it is observed whether the power difference adjustment target exceeds the adjustment interval of the energy storage device. Specifically, it is judged whether the adjustment interval of the energy storage device is met according to the following conditions:

[0093] When P PRES<K S ×P AVLS or P AGC -P PREVS >P AGCDMAX When, and meet

[0094] P PRES <K S ×P AVLS hour

[0095] The energy storage device is used to perform power regulation.

[0096] Where: P AGCDMIN is the minimum allowable deviation of the dispatch instruction, MW; P AGCDMAX is the maximum allowable deviation of the scheduling instruction, MW. AVLS P is the power value of external power generation available for the energy storage device, AVLS =P S -P S0 , P S is the total power value of the energy storage device, P S0 K is the critical power residual value of the energy storage device. S is the reliability coefficient of the energy storage device operation.

[0097] If it is exceeded, it is detected whether the solar thermal power station is in operation. If not, it is determined whether the demand power is in the economic operation range of solar thermal power generation. If so, the solar thermal power station is self-started and the automatic power generation control function of the solar thermal power station is started to coordinate power. If not, it is reported that the deviation exceeds the limit and an alarm is issued to guide the adjustment of the power instruction forecast reporting value for the next time period; if it is detected that the solar thermal power station is already in operation, the automatic power generation control function of the solar thermal power station is directly started.

[0098] Specifically, the economic operation range judgment process is as follows:

[0099] The considerations for power differential regulation in CSP plants are as follows: CSP plants can start and stop flexibly, adjust quickly, and the ramp rate can reach 20%P GN / min, considering the start-up and shutdown consumption of the CSP power station, its power generation is calculated as follows:

[0100]

[0101] Where: u is the start and stop variable of the power island, 1 means start, 0 means stop. The power value, W, is required to start the generating island.

[0102] The following constraints exist:

[0103]

[0104] Where: t SUis the start-up time of the CSP plant, t RMIN is the minimum economic operation time of the CSP plant, h.

[0105] If the above constraints are met, it means that it falls within the economic operation range, otherwise it does not fall within the economic operation range.

[0106] Optionally, in a preferred example, the switching time t of the dominant period of the photovoltaic energy base is pvs1 and t pvs2 It is obtained by rolling superposition calculation and verifying the accuracy to determine the end of calculation. The principle is to estimate the energy storage consumption A2 in the subsequent stage 2 to be equivalent to the energy storage consumption A1 in the previous stage 1.

[0107]

[0108] A1≈A2

[0109] Where: K d K is the reliability coefficient considering factors such as equipment status; c is the comprehensive conversion coefficient; P AGC (t) is the scheduling instruction at time t.

[0110] The judgment condition is,

[0111]

[0112] The basic calculation process is as follows Figure 5 As shown: for t pvs1 The initial value is assigned to t0, and the subsequent stage 2 energy storage consumption A2 is calculated to be equivalent to the previous stage 1 energy storage consumption A1, and it is judged whether the matching degree of the two meets the set requirements. If not, the execution time is accumulated forward by a fixed step time segment value, and the calculation is performed again and judged. If it is still not satisfied, the value of the current matching degree is increased and calculated by the size of the previous value to determine whether the switching time value is accumulated forward or reduced backward, until the matching degree judgment value calculation meets the set requirements.

[0113] Optionally, in one embodiment, the switching time t pvs1 The determination of the initial value t0 includes the following steps:

[0114]

[0115] Among them, t m is the moment of maximum sunlight intensity, K p It is the historical value of the switching time calculation ratio of q similar prediction curves that start from this calculation and move forward. The q value is selected based on the principle of balancing the calculation time consumption and calculation accuracy; K′=0.4 is selected for the initial calculation.

[0116] It should be noted that in the invention document of this patent, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including one" do not exclude the existence of other identical elements in the process, method, article or device including the element. In the invention document of this patent, if it is mentioned that an action is performed according to an element, it means that the action is performed at least according to the element, which includes two situations: performing the action only according to the element, and performing the action according to the element and other elements. Expressions such as multiple, multiple, and multiple include 2, 2 times, 2 kinds, and more than 2, more than 2 times, and more than 2 kinds.

[0117] All documents mentioned in the present invention are considered to be included in the disclosure of the present invention as a whole, so that they can be used as the basis for modification when necessary. In addition, it should be understood that the above are only preferred embodiments of this specification and are not used to limit the scope of protection of this specification. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of this specification should be included in the scope of protection of one or more embodiments of this specification.

Claims

1. A photovoltaic energy base power coordination control system, characterized in that: The control system includes a base power coordination layer and an energy station power control layer; wherein the base power coordination layer includes a power tracking controller, a photovoltaic power station power controller switching switch, a solar thermal power station power controller switching switch and its allocation function, and an energy storage device power controller switching switch and its allocation function; the power tracking controller adopts a PID controller, and its calculated output value is connected to the photovoltaic power station, the solar thermal power station and the energy storage device in parallel; The power control layer of the energy station includes the photovoltaic power station power controller, the solar thermal power station power controller, the energy storage device power controller and their corresponding adjustment mechanisms.

2. The control system according to claim 1, characterized in that: The base power coordination layer also includes an observer; the input data of the observer are temperature, wind speed and light intensity with time tags, and the data of parameter changes exceeding the set time threshold are sent to the solar thermal power station controller unit as a decision condition for the power control strategy of the solar thermal power station.

3. The control system according to claim 1, characterized in that: The control system is equipped with a photovoltaic power station power prediction function, which calculates the difference between the predicted power value of the photovoltaic power station in a fixed section from the current time of the day and the predicted power value of the photovoltaic power station in a fixed section from the current time of the previous day. If the ratio of the predicted power value of the photovoltaic power station in the fixed section from the current time of the previous day exceeds the set threshold, the excessive disturbance correction control function is started, that is, a disturbance suppression feedforward function is set in front of the corresponding power control loop adjustment mechanism.

4. A control method applicable to the photovoltaic energy base power coordination control system according to any one of claims 1 to 3, characterized in that: The control method comprises the following steps: (1) Obtaining the deviation between the scheduling AGC instruction and the total power output of the energy base, and inputting it into the power tracking controller of the base power coordination layer; (2) The corresponding switching switches of the photovoltaic power station, the solar thermal power station and the energy storage device are turned on or off according to the current time information; the method of turning on or off is based on the subordinate relationship between the current time information and the set photovoltaic energy storage dominant time period and the solar thermal power generation dominant time period; if the current time belongs to the photovoltaic energy storage dominant time period, then execute steps (3) to (4); if the current time belongs to the solar thermal dominant time period, then execute step (5); (3) The photovoltaic power station at the energy station layer of the energy base executes the maximum power point control strategy and calculates the power difference adjustment target. The power difference adjustment target Calculated by the following formula: in, is the target power of the photovoltaic energy storage group, P PV It is the actual power value emitted by the photovoltaic power station; (4) setting the power regulation target of the energy storage device equal to the power difference regulation target; when the energy storage device cannot meet the power difference regulation target, determining whether the difference meets the minimum economic operation value constraint of the CSP plant; if so, starting the CSP plant to perform regulation to meet the AGC scheduling instruction; if not, executing the deviation exceeding the limit and giving an alarm to guide the adjustment of the power instruction prediction report value for the next time period; (5) The power tracking controller outputs instructions to the power control loop of the CSP station to perform power control.

5. The control method according to claim 4, characterized in that: The reference conditions for determining the start and end times of the photovoltaic energy storage dominant period include: considering the start and stop time requirements of the solar thermal power station.

6. The control method according to claim 4, characterized in that: The photovoltaic energy storage dominant period is divided into periods I to IV according to the energy relationship; in periods I and IV, photovoltaic power generation alone cannot meet the dispatching requirements, so a photovoltaic power generation + energy storage device power generation strategy is adopted, and the energy storage device is used to supplement power generation; periods II and III are in the stage where photovoltaic power generation exceeds the dispatching requirements, and the excess electric energy is stored in the energy storage device; the calculation of the switching time between the periods adopts a rolling superposition calculation and verifies the matching degree to determine the calculation end time, and the method includes the following steps: (a) for t pvs1 Assign an initial value of t0, and calculate the energy storage consumption A2 in the subsequent stage 2 and the energy storage consumption A1 in the previous stage 1; (b) Calculate the matching degree φ between A1 and A2; (c) determining whether the matching degree meets the set requirements; if not, executing step (d); If satisfied, the calculation ends; (d) After accumulating a fixed step forward from the current calculation time, that is, t j+1 =t j +t1, execute step (a) to step (b) again; (e) determining whether the matching degree meets the set requirements; if not, executing step (f); If satisfied, the calculation ends; (f) Calculate the current matching degree and compare it with the previous matching degree. If the current matching degree is greater than the previous matching degree, the current calculation time is reduced by a fixed step size, that is, t j+1 =t j -t1, execute step (a) to step (b) again.

7. The control method according to claim 6, characterized in that: The switching time t pvs1 The determination of the initial value t0 includes the following steps: Among them, t m is the moment of maximum sunlight intensity, K p It is the historical value of the switching time calculation ratio of q similar prediction curves that proceed forward from this calculation as the starting point; the q value is selected based on the principle of balancing the calculation time consumption and calculation accuracy; K′=0.4 is selected for the initial calculation.

8. The control method according to claim 4, characterized in that: The target power of the photovoltaic energy storage group Calculate by the following steps: (a) Calculate the predicted power command P of the photovoltaic power station of the photovoltaic energy storage group PREV for Where: t v2 The end time of power generation in the operation cycle of the photovoltaic power station is predicted; t v1 K is the start time of power generation in the most recent photovoltaic power station prediction cycle; VS is the reliability coefficient; (b) Based on the predicted power command P of the photovoltaic power station PREV The relationship with the AGC instruction is divided into the following cases: 1) When P AGCDMIN ≤P AGC -P PREV ≤P AGCDMAX hour, Where: P AGCDMIN is the minimum allowable deviation of the dispatch instruction (MW); AGCDMAX The maximum allowable deviation of the dispatch instruction (MW); 2) When P AGC -P PREV >P AGCDMAX hour, 3) When P AGC -P PREV <P AGCDMIN hour, 9. The control method according to claim 4, characterized in that: The AGC control instruction received by the power tracking controller is an automatic power generation control instruction issued by the dispatching system, and the instruction takes into account the power forecast data reported to the dispatching system by the energy base; the power forecast predicts the corresponding power generation capacity based on the solar irradiation function of the next day, and accumulates the retention value at the end point of the previous day to calculate the total power generation capacity of the next day; and then allocates power values ​​for different dominant time periods based on the matching relationship between the installed capacities of photovoltaic and solar thermal power stations.

10. The control system according to claim 1, characterized in that: The photothermal power station in the photoelectric energy base is configured to enter or exit within a period of time before the photovoltaic power station exits or starts, in order to respond to the requirements of power regulation.

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