Multi-grid-connected-mode photovoltaic standby participated station transient power angle control method and device

Abstract

The invention provides a transient power angle control method and device for a multi-grid-connected-mode photovoltaic standby participated station. The method comprises the following steps: creating time sequences of respective direct current side active power parameters and alternating current side active power parameters of a grid-constructing inverter, a grid-following inverter and discharge power parameters of battery energy storage; determining influence factors of the direct current side active power parameter, the alternating current side active power parameter and the discharge power parameter at the next moment; determining a DC side active power predicted value, an AC side active power parameter predicted value and a discharge power parameter predicted value at the next moment based on the influence factor; performing normalization processing on the DC side active power prediction value, the AC side active power parameter prediction value and the discharge power parameter prediction value; determining a transient power angle index prediction value at the next moment based on each normalized value; and controlling parameters of a network-constructing inverter, a network-following inverter and battery energy storage based on the transient power angle index predicted value, thereby improving the stability of the power system.

Description

Technical Field

[0001] The present invention relates to the technical field of transient power angle control of a photovoltaic standby station, and in particular to a method and device for controlling transient power angle of a photovoltaic standby station in multiple grid-connected modes. Background Art

[0002] In recent years, new energy generation represented by photovoltaics has developed rapidly, and the capacity of access to the power grid has continued to increase, reducing the use of fossil energy and environmental pollution. With the continuous increase in the penetration rate of photovoltaic systems in the power grid and the development of photovoltaic inverter technology, photovoltaic systems have begun to assume more grid support functions, including voltage and frequency support, which makes photovoltaic systems also participate in the stability and transient response of the power system to some extent.

[0003] Since the photovoltaic system itself does not have the traditional concept of "transient power angle" (because the photovoltaic system does not generate electricity through a rotating rotor like a synchronous generator, and does not have a physical rotor that participates in the synchronous operation of the power system), the transient power angle stability of new energy stations has not yet been fully quantified and evaluated, which limits the effective participation of new energy stations in the stability control of the power system. Summary of the invention

[0004] The present invention provides a method and device for controlling transient power angle of a station with photovoltaic standby participation in multiple grid-connected modes, so as to solve the technical problem in the prior art that the transient power angle change trend cannot be accurately predicted, resulting in the inability to maintain the stability of the power system.

[0005] On the one hand, the present invention provides a method for controlling transient power angle of a station with photovoltaic standby participation in multiple grid-connected modes, comprising:

[0006] Obtain the DC side active power parameters and AC side active power parameters of the grid-connected inverter and grid-following inverter of the photovoltaic standby participating station in the multi-grid mode, as well as the discharge power parameters of the battery energy storage, which are used to determine the transient power angle index of the station;

[0007] Creating respective time series of the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter, and the discharge power parameters of the battery energy storage;

[0008] Based on each of the time series, determining the influencing factors of the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter and the discharge power parameters of the battery energy storage at the next moment;

[0009] Based on the influencing factors, determining the DC side active power prediction value and AC side active power parameter prediction value and battery energy storage discharge power parameter prediction value of each of the grid-forming inverter and the grid-following inverter at the next moment;

[0010] Normalizing the DC side active power prediction value and AC side active power parameter prediction value of the grid-forming inverter and the grid-following inverter, and the battery energy storage discharge power parameter prediction value, to obtain their corresponding normalized values;

[0011] Based on the normalized values, determining a predicted value of a transient power angle index of a station in which photovoltaic standby participates in a multi-grid-connected mode at the next moment;

[0012] Based on the predicted value of the transient power angle index, the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter and the discharge power parameters of the battery energy storage are controlled.

[0013] According to a method for controlling transient power angle of a station with photovoltaic standby in multiple grid-connected modes provided by the present invention, the formula for determining the transient power angle index of the station is as shown in the following formula (1) based on the DC side active power parameters and AC side active power parameters of the grid-connected inverter and the grid-following inverter of the photovoltaic standby station and the discharge power parameters of the battery energy storage. The time series can be as shown in the following formula (2):

[0014]

[0015] Among them, TSPA SUE is the transient power angle index of the station; T 1 ,T 2 ,K,T n ,K,T k are the moments in a fixed time interval, where k is a natural number, indicating the kth moment; n is a natural number, indicating the nth moment, and n is from 1 to k; T n Total active power on the AC side of the grid-connected photovoltaic inverter at all times; T n Total active power on the DC side of the grid-connected photovoltaic inverter at any given moment; P rpAC,max T 1 ,T 2 ,K,T n ,K,T k The maximum value of the total active power on the AC side of the grid-connected photovoltaic inverter at these k fixed time intervals; P rpDC,max T 1 ,T 2 ,K,T n ,K,T kThe maximum active power on the DC side of the grid-connected photovoltaic inverter at these k fixed time intervals; T n Always follow the total active power on the AC side of the grid-connected photovoltaic inverter; T n The total active power on the DC side of the grid-connected photovoltaic inverter at all times; P ctAC,max T 1 ,T 2 ,K,T n ,K,T k The maximum active power of the AC side of the grid-connected photovoltaic inverter at these k fixed time intervals; P ctDC,max T 1 ,T 2 ,K,T n ,K,T k The maximum active power of the DC side of the grid-connected photovoltaic inverter at these k fixed time intervals; T n Battery energy storage discharge power at any moment; P bes,max T 1 ,T 2 ,K,T n ,K,T k The maximum discharge power of the battery energy storage during these k fixed time intervals.

[0016] According to a method for controlling transient power angle of a station with photovoltaic standby participation in multiple grid-connected modes provided by the present invention, the influencing factor is shown in the following formula (3):

[0017]

[0018] in, For the T n The influence factors of the DC side active power parameters and AC side active power parameters of the grid-type inverter and grid-following inverter of the multi-grid-connected photovoltaic standby and the station at the next moment, as well as the battery energy storage discharge power parameters, on the DC side active power parameters and AC side active power parameters of the grid-type inverter and grid-following inverter of the station participating in the multi-grid-connected photovoltaic standby at the next moment; P rpDC,min is the total active power of the DC side of the grid-connected inverter at T 1 ,T 2 ,K,T n ,K,T k The minimum value of the measured values ​​at these k fixed time intervals; P rpAC,max is the total active power on the AC side of the grid-connected inverter at T 1 ,T 2 ,K,T n ,K,T kThe maximum value of the measured value at these k fixed time intervals; P ctDC,min is the total active power on the DC side of the grid-following inverter at T 1 ,T 2 ,K,T n ,K,T k The minimum value of the measured values ​​at these k fixed time intervals; P ctAC,max is the total active power on the AC side of the grid-following inverter at T 1 ,T 2 ,K,T n ,K,T k The maximum value of the measured value at these k fixed time intervals; P bes,max The battery energy storage discharge power at T 1 ,T 2 ,K,T n ,K,T k The maximum value of the measured values ​​at these k fixed time intervals.

[0019] According to a method for controlling transient power angle of a station with photovoltaic standby in multiple grid-connected modes provided by the present invention, the DC side active power prediction value and AC side active power parameter prediction value of the grid-connected inverter and the grid-following inverter, as well as the battery energy storage discharge power parameter prediction value are shown in the following formula (4):

[0020]

[0021] in, T k+1 The predicted value of the total active power on the DC side of the grid-connected inverter at every moment; T k+1 The predicted value of the total active power on the AC side of the grid-connected inverter at all times; T k+1 Always follow the predicted value of the total active power on the DC side of the grid-connected inverter; T k+1 Always follow the predicted value of the total active power on the AC side of the grid-type inverter; T k+1 The predicted value of battery energy storage discharge power at the moment.

[0022] According to a method for controlling transient power angle of a station with photovoltaic standby participating in multiple grid-connected modes provided by the present invention, the corresponding normalized values ​​are shown in the following formula (5):

[0023]

[0024] in, T k+1 Normalized value of the total active power prediction value of the DC side of the grid-connected inverter at each moment; Tk+1 Normalized value of the total active power prediction value of the AC side of the grid-connected inverter at any moment; T k+1 The normalized value of the total active power prediction value of the DC side of the grid-type inverter at all times; T k+1 The normalized value of the total active power prediction value of the AC side of the grid-type inverter at all times; T k+1 The normalized value of the predicted battery energy storage discharge power at the moment.

[0025] According to a method for controlling transient power angle of a station with photovoltaic standby participation in multiple grid-connected modes provided by the present invention, the predicted value of the transient power angle index of the station is shown in the following formula (6):

[0026]

[0027] in, Indicates the predicted value of the station transient power angle index.

[0028] According to a method for controlling transient power angle of a station with photovoltaic standby participation in multiple grid-connected modes provided by the present invention, based on the predicted value of the transient power angle index, the DC side active power parameters and AC side active power parameters of the grid-connecting inverter and the grid-following inverter, and the discharge power parameters of the battery energy storage are controlled, including:

[0029] If the predicted value of the transient power angle index is greater than or equal to a preset threshold, the discharge power of the multi-grid-connected mode photovoltaic backup and the station active power or the battery energy storage is increased;

[0030] If the predicted value of the transient power angle index is less than the threshold, the grid-mode photovoltaic backup and the station active power or the discharge power of the battery energy storage is reduced.

[0031] According to a method for controlling transient power angle of a station with photovoltaic backup participation in multiple grid-connected modes provided by the present invention, the preset threshold is 0.43.

[0032] For ease of understanding, the present invention is described in more detail below. Assume that the fixed time interval is 10 minutes, and 5 measurement moments are selected, that is, k is 5. That is, at the fixed time interval T 1 ,T 2 ,T 3 ,T 4 ,T 5 The measured active power value of the DC side of the grid-connected inverter is obtained by At a fixed time interval T 1 ,T 2 ,T 3 ,T 4 ,T 5The measured active power value of the AC side of the grid-connected inverter is obtained by At a fixed time interval T 1 ,T 2 ,T 3 ,T 4 ,T 5 Measuring the active power value of the DC side of the grid-following inverter At a fixed time interval T 1 ,T 2 ,T 3 ,T 4 ,T 5 Measuring the active power value of the AC side of the grid-following inverter At a fixed time interval T 1 ,T 2 ,T 3 ,T 4 ,T 5 Measuring the discharge power of battery energy storage Based on all the above-mentioned measured values, the active power parameters of the DC and AC sides of the photovoltaic backup and station grid-connected mode and the grid-following inverter and the battery energy storage discharge power parameter time series are established as shown below (7):

[0033]

[0034] When k is 5, the impact factors obtained include

[0035] When k is 5, k is the current moment, and k+1 is the next moment. The above formula (4) is converted into the following formula (8):

[0036]

[0037] in, T 6 The predicted value of the total active power on the DC side of the grid-connected inverter at every moment; T 6 The predicted value of the total active power on the AC side of the grid-connected inverter at all times; T 6 Always follow the predicted value of the total active power on the DC side of the grid-connected inverter; T 6 Always follow the predicted value of the total active power on the AC side of the grid-type inverter; T 6 The predicted value of battery energy storage discharge power at the moment.

[0038] When k is 5, the result of formula (5) is as shown in formula (9):

[0039]

[0040] in, T 6 Normalized value of the total active power prediction value of the DC side of the grid-connected inverter at each moment; T 6 Normalized value of the total active power prediction value of the AC side of the grid-connected inverter at any moment; T 6 The normalized value of the total active power prediction value of the DC side of the grid-type inverter at all times; T 6 The normalized value of the total active power prediction value of the AC side of the grid-type inverter at all times; T 6 The normalized value of the predicted battery energy storage discharge power at the moment.

[0041] When k is 5, the result of formula (6) is as shown in formula (10):

[0042]

[0043] On the other hand, the present invention also provides a transient power angle control device for a station with photovoltaic standby participation in multiple grid-connected modes, comprising:

[0044] An acquisition module is used to acquire the DC side active power parameters and AC side active power parameters of the grid-connected inverter and the grid-following inverter of the photovoltaic standby participating station in the multi-grid mode, which are used to determine the transient power angle index of the station, and the discharge power parameters of the battery energy storage;

[0045] A time series module is used to create time series of the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter, and the discharge power parameters of the battery energy storage;

[0046] An influence factor module, based on each of the time series, determines the influence factors of the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter and the discharge power parameters of the battery energy storage at the next moment;

[0047] A first prediction module determines, based on the influencing factor, a DC side active power prediction value and an AC side active power parameter prediction value of each of the grid-forming inverter and the grid-following inverter and a battery energy storage discharge power parameter prediction value at the next moment;

[0048] A normalization module normalizes the DC side active power prediction value and AC side active power parameter prediction value of the grid-forming inverter and the grid-following inverter, and the battery energy storage discharge power parameter prediction value, to obtain respective corresponding normalized values;

[0049] The second prediction module determines, based on the normalized values, a predicted value of a transient power angle index of a station in which photovoltaic standby participates in a multi-grid mode at a next moment;

[0050] A control module controls the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter, and the discharge power parameters of the battery energy storage, based on the predicted value of the transient power angle index.

[0051] On the other hand, the present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method for controlling transient power angle of a station involving photovoltaic standby in multiple grid-connected modes as described above is implemented.

[0052] The method and device for controlling transient power angle of a station with photovoltaic standby in multiple grid-connected modes provided by the present invention create respective time series of active power parameters of the DC side and the AC side of the grid-connecting inverter and the grid-following inverter, and the discharge power parameters of the battery energy storage; based on the respective time series, determine the influencing factors of the active power parameters of the DC side and the AC side of the grid-connecting inverter and the grid-following inverter, and the discharge power parameters of the battery energy storage at the next moment; based on the influencing factors, determine the predicted values ​​of the active power of the DC side and the AC side of the grid-connecting inverter and the grid-following inverter, and the predicted values ​​of the discharge power parameters of the battery energy storage at the next moment; The DC side active power prediction values ​​and AC side active power parameter prediction values ​​of the grid-forming inverter and the grid-following inverter, as well as the battery energy storage discharge power parameter prediction values ​​are normalized to obtain their corresponding normalized values; based on the normalized values, the transient power angle index prediction value of the station in which the photovoltaic standby participates in the multi-grid mode at the next moment is determined; based on the transient power angle index prediction value, the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter, as well as the battery energy storage discharge power parameters, are controlled, thereby achieving accurate prediction of the transient power angle change trend, enabling the new energy station to effectively participate in the power system stability control, thereby improving the stability of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0054] Figure 1It is a flow chart of a method for controlling transient power angle of a station with photovoltaic standby participation in multiple grid-connected modes provided by an embodiment of the present invention;

[0055] Figure 2 It is a structural schematic diagram of a transient power angle control device for a station with photovoltaic standby participation in multiple grid-connected modes provided by an embodiment of the present invention;

[0056] Figure 3 It is a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings 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.

[0058] Figure 1 It is a flow chart of a method for controlling transient power angle of a station with photovoltaic standby participating in multiple grid-connected modes provided by an embodiment of the present invention.

[0059] See also Figure 1 The method for controlling transient power angle of a station with multi-grid-connected mode photovoltaic backup participating may include the following steps.

[0060] 101. Obtain the DC side active power parameters and AC side active power parameters of the grid-connected inverter and grid-following inverter of the photovoltaic standby participating station and the discharge power parameters of the battery energy storage for determining the transient power angle index of the station in the multi-grid mode.

[0061] In this step, the calculation relationship between the transient power angle index of the site participating in the multi-grid-connected mode photovoltaic standby and the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter and the discharge power parameters of the battery energy storage can be pre-defined.

[0062] 102. Create time series for the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter, as well as the discharge power parameters of the battery energy storage.

[0063] In this step, the calculation formula of the transient power angle index of the photovoltaic standby participating station is determined by the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter, and the discharge power parameters of the battery energy storage, as shown in the following formula (1):

[0064]

[0065] The time series can be expressed as follows:

[0066]

[0067] Among them, TSPA SUE is the transient power angle index of the station; T 1 ,T 2 ,K,T n ,K,T k are the moments in a fixed time interval, where k is a natural number, indicating the kth moment; n is a natural number, indicating the nth moment, and n is from 1 to k; T n Total active power on the AC side of the grid-connected photovoltaic inverter at all times; T n Total active power on the DC side of the grid-connected photovoltaic inverter at any given moment; P rpAC,max T 1 ,T 2 ,K,T n ,K,T k The maximum value of the total active power on the AC side of the grid-connected photovoltaic inverter at these k fixed time intervals; P rpDC,max T 1 ,T 2 ,K,T n ,K,T k The maximum active power on the DC side of the grid-connected photovoltaic inverter at these k fixed time intervals; T n Always follow the total active power on the AC side of the grid-connected photovoltaic inverter; T n The total active power on the DC side of the grid-connected photovoltaic inverter at all times; P ctAC,max T 1 ,T 2 ,K,T n ,K,T k The maximum active power of the AC side of the grid-connected photovoltaic inverter at these k fixed time intervals; P ctDC,max T 1 ,T 2 ,K,T n ,K,T k The maximum active power of the DC side of the grid-connected photovoltaic inverter at these k fixed time intervals; T n Battery energy storage discharge power at any moment; P bes,max T 1 ,T 2 ,K,T n ,K,T kThe maximum discharge power of the battery energy storage during these k fixed time intervals.

[0068] 103. Based on each time series, determine the influencing factors of the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter and the discharge power parameters of the battery energy storage at the next moment.

[0069] In this step, the impact factor is as shown in the following formula (3):

[0070]

[0071] in, For the T n The influence factors of the DC side active power parameters and AC side active power parameters of the grid-type inverter and grid-following inverter of the multi-grid-connected photovoltaic standby and the station at the next moment, as well as the battery energy storage discharge power parameters, on the DC side active power parameters and AC side active power parameters of the grid-type inverter and grid-following inverter of the station participating in the multi-grid-connected photovoltaic standby at the next moment; P rpDC,min is the total active power of the DC side of the grid-connected inverter at T 1 ,T 2 ,K,T n ,K,T k The minimum value of the measured values ​​at these k fixed time intervals; P rpAC,max is the total active power on the AC side of the grid-connected inverter at T 1 ,T 2 ,K,T n ,K,T k The maximum value of the measured value at these k fixed time intervals; P ctDC,min is the total active power on the DC side of the grid-following inverter at T 1 ,T 2 ,K,T n ,K,T k The minimum value of the measured values ​​at these k fixed time intervals; P ctAC,max is the total active power on the AC side of the grid-following inverter at T 1 ,T 2 ,K,T n ,K,T k The maximum value of the measured value at these k fixed time intervals; P bes,max The battery energy storage discharge power at T 1 ,T 2 ,K,T n ,K,T kThe maximum value of the measured values ​​at these k fixed time intervals. The next moment is generally the moment after the current moment. In general, moment k can be regarded as the current moment, and moment k+1 can be regarded as the next moment.

[0072] 104. Based on the influencing factors, determine the DC side active power prediction value and AC side active power parameter prediction value of the grid-forming inverter and the grid-following inverter, as well as the battery energy storage discharge power parameter prediction value at the next moment.

[0073] In this step, the DC side active power prediction value and AC side active power parameter prediction value of the grid-forming inverter and the grid-following inverter, as well as the battery energy storage discharge power parameter prediction value are shown in the following formula (4):

[0074]

[0075] in, T k+1 The predicted value of the total active power on the DC side of the grid-connected inverter at every moment; T k+1 The predicted value of the total active power on the AC side of the grid-connected inverter at all times; T k+1 Always follow the predicted value of the total active power on the DC side of the grid-connected inverter; T k+1 Always follow the predicted value of the total active power on the AC side of the grid-type inverter; T k+1 The predicted value of battery energy storage discharge power at the moment.

[0076] 105. Normalize the DC side active power prediction value and AC side active power parameter prediction value of the grid-building inverter and the grid-following inverter, and the battery energy storage discharge power parameter prediction value to obtain their corresponding normalized values.

[0077] In this step, the corresponding normalized values ​​are shown in the following formula (5):

[0078]

[0079] in, T k+1 Normalized value of the total active power prediction value of the DC side of the grid-connected inverter at each moment; T k+1 Normalized value of the total active power prediction value of the AC side of the grid-connected inverter at any moment; T k+1 The normalized value of the total active power prediction value of the DC side of the grid-type inverter at all times; T k+1The normalized value of the total active power prediction value of the AC side of the grid-type inverter at all times; T k+1 The normalized value of the predicted battery energy storage discharge power at the moment.

[0080] 106. Based on each normalized value, determine the predicted value of the transient power angle index of the station with photovoltaic backup participation in the multi-grid mode at the next moment.

[0081] In this step, the predicted value of the station transient power angle index is shown in the following formula (6):

[0082]

[0083] in, Indicates the predicted value of the transient power angle index of the station.

[0084] 107. Based on the predicted value of the transient power angle index, the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter as well as the discharge power parameters of the battery energy storage are controlled.

[0085] In this embodiment, time series of the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter and the discharge power parameters of the battery energy storage are created; based on each time series, the influencing factors of the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter and the discharge power parameters of the battery energy storage at the next moment are determined; based on the influencing factors, the DC side active power prediction values ​​and AC side active power parameter prediction values ​​and the battery energy storage discharge power parameter prediction values ​​of the grid-forming inverter and the grid-following inverter at the next moment are determined; The DC side active power prediction values ​​and AC side active power parameter prediction values ​​of the respective inverters and the battery energy storage discharge power parameter prediction values ​​are normalized to obtain their corresponding normalized values; based on the normalized values, the transient power angle index prediction value of the station in which the photovoltaic standby participates in the multi-grid mode at the next moment is determined; based on the transient power angle index prediction value, the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter and the battery energy storage discharge power parameters are controlled, so as to achieve accurate prediction of the transient power angle change trend, enable the new energy station to effectively participate in the power system stability control, and thus improve the stability of the power system.

[0086] In one embodiment of the present specification, based on the transient power angle index prediction value, controlling the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter and the discharge power parameters of the battery energy storage may include:

[0087] If the predicted value of the transient power angle index is greater than or equal to the preset threshold, the discharge power of the multi-grid-connected mode photovoltaic backup and the station active power or battery energy storage is increased;

[0088] If the predicted value of the transient power angle index is less than the threshold, the grid-mode photovoltaic backup and the station active power or the discharge power of the battery energy storage is reduced.

[0089] In this embodiment, the magnitude relationship between the transient power angle index prediction value and the preset threshold value can be compared. If the transient power angle index prediction value is greater than or equal to the preset threshold value, the discharge power of the multi-grid mode photovoltaic standby and the station active power or battery energy storage is increased, and if the transient power angle index prediction value is less than the threshold value, the discharge power of the grid mode photovoltaic standby and the station active power or battery energy storage is reduced, thereby maintaining the stability of the power grid system.

[0090] In one embodiment of the present specification, the preset threshold value can be set, for example, to any value between 0.4 and 0.5, and 0.43 can be preferably set.

[0091] In summary, the method of the present invention monitors the active power parameters of the DC and AC sides of the grid-forming and grid-following inverters of the multi-grid-connected mode photovoltaic standby and the station in real time, and predicts the predicted values ​​of the parameters at the next moment, and calculates the predicted value of the transient power angle index of the station in which the multi-grid-connected mode photovoltaic standby participates according to the obtained monitoring parameters and the predicted values ​​of the parameters at the next moment, and adjusts the active power parameters of the DC and AC sides of the grid-forming and grid-following inverters of the multi-grid-connected mode photovoltaic standby and the station and the battery energy storage discharge power in real time according to the calculation results, thereby improving the transient power angle stability of the station in which the multi-grid-connected mode photovoltaic standby participates, and ensuring the stability of the power system under the multi-grid-connected mode.

[0092] Based on the same general inventive concept, the present invention also protects a transient power angle control device for a station with multiple grid-connected modes and photovoltaic standby participation, such as Figure 2 As shown, Figure 2 It is a structural schematic diagram of a station transient power angle control device with participation of photovoltaic standby in multiple grid-connected modes provided by an embodiment of the present invention. The station transient power angle control device with participation of photovoltaic standby in multiple grid-connected modes provided by the present invention is described below. The station transient power angle control device with participation of photovoltaic standby in multiple grid-connected modes described below and the station transient power angle control method with participation of photovoltaic standby in multiple grid-connected modes described above can be referred to each other.

[0093] The transient power angle control device for a station with photovoltaic backup participating in multiple grid-connected modes includes an acquisition module 201, a time series module 202, an influencing factor module 203, a first prediction module 204, a normalization module 205, a second prediction module 206 and a control module 207.

[0094] The acquisition module 201 acquires the DC side active power parameters and AC side active power parameters of the grid-connected inverter and the grid-following inverter of the photovoltaic standby participating station for determining the transient power angle index of the station in the multi-grid mode, and the discharge power parameters of the battery energy storage;

[0095] The time series module 202 creates a time series of the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter, and the discharge power parameters of the battery energy storage;

[0096] The influencing factor module 203 determines the influencing factors of the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter and the discharge power parameters of the battery energy storage at the next moment based on each of the time series;

[0097] The first prediction module 204 determines the DC side active power prediction value and AC side active power parameter prediction value of the grid-forming inverter and the grid-following inverter, and the battery energy storage discharge power parameter prediction value at the next moment based on the influencing factor;

[0098] The normalization module 205 normalizes the DC side active power prediction value and the AC side active power parameter prediction value and the battery energy storage discharge power parameter prediction value of the grid-forming inverter and the grid-following inverter to obtain their corresponding normalized values;

[0099] The second prediction module 206 determines the predicted value of the transient power angle index of the station in which the photovoltaic standby participates in the multi-grid mode at the next moment based on the normalized values;

[0100] The control module 207 controls the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter, and the discharge power parameters of the battery energy storage, based on the transient power angle index prediction value.

[0101] Figure 3 Schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. Figure 3 As shown, the electronic device may include: a processor 310, a communication interface 320, a memory 330 and a communication bus 340, wherein the processor 310, the communication interface 320 and the memory 330 communicate with each other through the communication bus 340. The processor 310 may call the logic instructions in the memory 330 to execute the transient power angle control method of the site with the participation of photovoltaic standby in multiple grid-connected modes.

[0102] In addition, the logic instructions in the above-mentioned memory 330 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0103] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the transient power angle control method of the station with the participation of multi-grid-connected mode photovoltaic standby provided by the above methods.

[0104] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the transient power angle control method for a station with multi-grid-connected mode photovoltaic standby participation provided by the above-mentioned methods.

[0105] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0106] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for controlling transient power angle of a station with photovoltaic standby in multiple grid-connected modes, characterized in that: include: Obtain the DC side active power parameters and AC side active power parameters of the grid-connected inverter and grid-following inverter of the photovoltaic standby participating station in the multi-grid mode, as well as the discharge power parameters of the battery energy storage, which are used to determine the transient power angle index of the station; Creating respective time series of the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter, and the discharge power parameters of the battery energy storage; Based on each of the time series, determining the influencing factors of the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter and the discharge power parameters of the battery energy storage at the next moment; Based on the influencing factors, determining the DC side active power prediction value and AC side active power parameter prediction value and battery energy storage discharge power parameter prediction value of each of the grid-forming inverter and the grid-following inverter at the next moment; Normalizing the DC side active power prediction value and AC side active power parameter prediction value of the grid-forming inverter and the grid-following inverter, and the battery energy storage discharge power parameter prediction value, to obtain their corresponding normalized values; Based on the normalized values, determining a predicted value of a transient power angle index of a station in which photovoltaic standby participates in a multi-grid-connected mode at the next moment; Based on the predicted value of the transient power angle index, the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter and the discharge power parameters of the battery energy storage are controlled.

2. The method for controlling transient power angle of a station with photovoltaic standby participation in multiple grid-connected modes according to claim 1, characterized in that: The formula for determining the transient power angle index of the station is shown in the following formula (1) based on the DC side active power parameters and AC side active power parameters of the grid-connecting inverter and grid-following inverter of the photovoltaic standby station and the discharge power parameters of the battery energy storage. The time series can be shown in the following formula (2): Among them, TSPA SUE is the transient power angle index of the station; T1, T2, K, T n ,K,T k are the moments in a fixed time interval, where k is a natural number, indicating the kth moment; n is a natural number, indicating the nth moment, and n is from 1 to k; T n Total active power on the AC side of the grid-connected photovoltaic inverter at all times; T n Total active power on the DC side of the grid-connected photovoltaic inverter at any given moment; P rpAC,max is T1, T2, K, T n ,K,T k The maximum value of the total active power on the AC side of the grid-connected photovoltaic inverter at these k fixed time intervals; P rpDC,max is T1, T2, K, T n ,K,T k The maximum active power on the DC side of the grid-connected photovoltaic inverter at these k fixed time intervals; T n Always follow the total active power on the AC side of the grid-connected photovoltaic inverter; T n The total active power on the DC side of the grid-connected photovoltaic inverter at all times; P ctAC,max is T1, T2, K, T n ,K,T k The maximum active power of the AC side of the grid-connected photovoltaic inverter at these k fixed time intervals; P ctDC,max is T1, T2, K, T n ,K,T k The maximum active power of the DC side of the grid-connected photovoltaic inverter at these k fixed time intervals; T n Battery energy storage discharge power at any moment; P bes,max is T1, T2, K, T n ,K,T k The maximum discharge power of the battery energy storage during these k fixed time intervals.

3. The method for controlling transient power angle of a station with photovoltaic standby participation in multiple grid-connected modes according to claim 2, characterized in that: The impact factor is shown in the following formula (3): in, For the T n The influence factors of the DC side active power parameters and AC side active power parameters of the grid-type inverter and grid-following inverter of the multi-grid-connected photovoltaic standby and the station at the next moment, as well as the battery energy storage discharge power parameters, on the DC side active power parameters and AC side active power parameters of the grid-type inverter and grid-following inverter of the station participating in the multi-grid-connected photovoltaic standby at the next moment; P rpDC,min The total active power of the DC side of the grid-type inverter is T1, T2, K, T n ,K,T k The minimum value of the measured values ​​at these k fixed time intervals; P rpAC,max The total active power of the AC side of the grid-type inverter is T1, T2, K, T n ,K,T k The maximum value of the measured value at these k fixed time intervals; P ctDC,min The total active power of the DC side of the grid-following inverter is T1, T2, K, T n ,K,T k The minimum value of the measured values ​​at these k fixed time intervals; P ctAC,max The total active power of the AC side of the grid-following inverter is T1, T2, K, T n ,K,T k The maximum value of the measured value at these k fixed time intervals; P bes,max The battery energy storage discharge power is T1, T2, K, T n ,K,T k The maximum value of the measured values ​​at these k fixed time intervals.

4. The method for controlling transient power angle of a station with photovoltaic standby participation in multiple grid-connected modes according to claim 3 is characterized in that: The DC side active power prediction value and AC side active power parameter prediction value of the grid-forming inverter and the grid-following inverter, as well as the battery energy storage discharge power parameter prediction value are shown in the following formula (4): in, T k+1 The predicted value of the total active power on the DC side of the grid-connected inverter at every moment; T k+1 The predicted value of the total active power on the AC side of the grid-connected inverter at all times; T k+1 Always follow the predicted value of the total active power on the DC side of the grid-connected inverter; T k+1 Always follow the predicted value of the total active power on the AC side of the grid-type inverter; T k+1 The predicted value of battery energy storage discharge power at the moment.

5. The method for controlling transient power angle of a station with photovoltaic standby participation in multiple grid-connected modes according to claim 4 is characterized in that: The corresponding normalized values ​​are shown in the following formula (5): in, T k+1 Normalized value of the total active power prediction value of the DC side of the grid-connected inverter at each moment; T k+1 Normalized value of the total active power prediction value of the AC side of the grid-connected inverter at any moment; T k+1 The normalized value of the total active power prediction value of the DC side of the grid-type inverter at all times; T k+1 The normalized value of the total active power prediction value of the AC side of the grid-type inverter at all times; T k+1 The normalized value of the predicted battery energy storage discharge power at the moment.

6. The method for controlling transient power angle of a station with photovoltaic standby participation in multiple grid-connected modes according to claim 5, characterized in that: The predicted value of the station transient power angle index is shown in the following formula (6): in, Indicates the predicted value of the transient power angle index of the station.

7. The method for controlling transient power angle of a station with photovoltaic standby participation in multiple grid-connected modes according to claim 6, characterized in that: Based on the transient power angle index prediction value, controlling the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter and the discharge power parameters of the battery energy storage, including: If the predicted value of the transient power angle index is greater than or equal to a preset threshold, the discharge power of the multi-grid-connected mode photovoltaic backup and the station active power or the battery energy storage is increased; If the predicted value of the transient power angle index is less than the threshold, the grid-mode photovoltaic backup and the station active power or the discharge power of the battery energy storage is reduced.

8. The method for controlling transient power angle of a station with photovoltaic standby participation in multiple grid-connected modes according to claim 7, characterized in that: The preset threshold is 0.

43.

9. A transient power angle control device for a station with photovoltaic standby participation in multiple grid-connected modes, characterized in that: include: An acquisition module is used to acquire the DC side active power parameters and AC side active power parameters of the grid-connected inverter and the grid-following inverter of the photovoltaic standby participating station in the multi-grid mode, which are used to determine the transient power angle index of the station, and the discharge power parameters of the battery energy storage; A time series module is used to create time series of the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter, and the discharge power parameters of the battery energy storage; An influence factor module, based on each of the time series, determines the influence factors of the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter and the discharge power parameters of the battery energy storage at the next moment; A first prediction module determines, based on the influencing factor, a DC side active power prediction value and an AC side active power parameter prediction value of each of the grid-forming inverter and the grid-following inverter and a battery energy storage discharge power parameter prediction value at the next moment; A normalization module normalizes the DC side active power prediction value and AC side active power parameter prediction value of the grid-forming inverter and the grid-following inverter, and the battery energy storage discharge power parameter prediction value, to obtain respective corresponding normalized values; The second prediction module determines, based on the normalized values, a predicted value of a transient power angle index of a station in which photovoltaic standby participates in a multi-grid mode at a next moment; A control module controls the DC side active power parameters and AC side active power parameters of the grid-forming inverter and the grid-following inverter, and the discharge power parameters of the battery energy storage, based on the predicted value of the transient power angle index.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the method for controlling transient power angle of a station with the participation of photovoltaic backup in multiple grid-connected modes as described in any one of claims 1 to 8 above is implemented.

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