Photovoltaic-photothermal combined power generation regional power grid voltage coordination control method and system

Abstract

The present application relates to photovoltaic-photothermal combined power generation regional power grid voltage coordination control method and system, including: the photovoltaic-photothermal combined power generation regional power grid is divided into multiple sub-regions;According to the voltage information of the leading node in each sub-region, the voltage regulation instruction value of the leading node in each sub-region is determined;The reactive power control instruction value of the reactive power source of the photovoltaic power station and the voltage control instruction value of the photothermal power station in each sub-region are determined by using the voltage regulation instruction value of the leading node in each sub-region;The output reactive power of the reactive power source of the photovoltaic power station and the terminal output voltage of the photothermal power station in each sub-region are controlled by using the reactive power control instruction value of the reactive power source of the photovoltaic power station and the voltage control instruction value of the photothermal power station in each sub-region respectively.The technical scheme provided by the present application carries out unified coordination control on the dispersed multiple reactive power compensation devices and synchronous generator sets, realizes the nearby balance of reactive power and voltage regulation, and avoids the local power grid voltage oscillation caused by the respective control of multiple solar power stations.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solar power generation, in particular to a photovoltaic-photothermal combined power generation regional power grid voltage coordinated control method and system. BACKGROUND

[0002] Large-scale solar power generation access to the power system brings new challenges to the safe operation of the power grid, and solar-thermal power generation has the advantages of long-time heat storage, stable and reliable power output, so that photothermal-photovoltaic combined power generation will become one of the main modes of large-scale solar power generation base development and construction in the future. Solar photovoltaic power generation is connected to the grid through power electronic inverters, and the current installed capacity of photovoltaic power stations is smaller than that of conventional units, so it is connected to the grid through multiple access points. Due to the limited reactive power regulation capacity of the power station itself, SVC and SVG dynamic reactive power compensation devices are usually configured. Solar-thermal power generation is connected to the grid through steam turbine generators, but the capacity of a single unit is also much smaller than that of conventional units, and in a large-scale photovoltaic-photothermal combined power generation region, there will be photovoltaic power station groups and photothermal power station groups distributed at different access points. Therefore, it is necessary to uniformly schedule and coordinately control the dispersed multiple reactive power compensation devices and synchronous generators to achieve local reactive power balance and voltage regulation, and to avoid local grid voltage oscillation caused by individual control of multiple solar power stations. SUMMARY

[0003] In view of the deficiencies of the prior art, the purpose of the present application is to provide a photovoltaic-photothermal combined power generation regional power grid voltage coordinated control method and system, which adopts three-level voltage coordinated control in different regions, and takes the dominant node voltage as the control target, so as to uniformly schedule and coordinately control the dispersed multiple reactive power compensation devices and synchronous generators.

[0004] The purpose of the present application is achieved by using the following technical solutions:

[0005] The photovoltaic-photothermal combined power generation regional power grid voltage coordinated control method provided by the present application improves in that it comprises:

[0006] dividing the photovoltaic-photothermal combined power generation regional power grid into multiple sub-regions;

[0007] determining the voltage regulation instruction value of the dominant node in each sub-region according to the voltage information of the dominant node in each sub-region;

[0008] determining the reactive power control instruction value of the reactive power source of the photovoltaic power station and the voltage control instruction value of the photothermal power station in each sub-region by using the voltage regulation instruction value of the dominant node in each sub-region;

[0009] The reactive power control instruction value of the reactive power source of the photovoltaic power station and the voltage control instruction value of the photothermal power station are used to control the reactive power of the output of the reactive power source of the photovoltaic power station and the terminal output voltage of the photothermal power station in each sub-region.

[0010] Preferably, the photovoltaic-photothermal combined power generation regional power grid is divided into a plurality of sub-regions, comprising:

[0011] The photovoltaic-photothermal combined power generation regional power grid is clustered based on the electrical distance between the voltage nodes in the photovoltaic-photothermal combined power generation regional power grid, and a clustering result is obtained.

[0012] The voltage nodes in one cluster in the clustering result are divided into a sub-region.

[0013] The voltage nodes include the grid-connected voltage nodes of the photovoltaic power station and the grid-connected voltage nodes of the photothermal power station.

[0014] Further, the electrical distance between the voltage nodes in the photovoltaic-photothermal combined power generation regional power grid is determined according to the following formula:

[0015]

[0016] Wherein, a, b ∈ B, B is a set of voltage nodes, D ab is the electrical distance between voltage node a and voltage node b, S ab is the reactive voltage sensitivity of the change of the reactive power of voltage node b to the voltage of voltage node a, S bb is the reactive voltage sensitivity of the change of the reactive power of voltage node b to the voltage of voltage node b, S ba is the reactive voltage sensitivity of the change of the reactive power of voltage node a to the voltage of voltage node b, S aa is the reactive voltage sensitivity of the change of the reactive power of voltage node a to the voltage of voltage node a.

[0017] Preferably, the determination process of the dominant node in the sub-region comprises:

[0018] The dominant coefficients of all voltage nodes in the sub-region are determined according to the sum of the electrical distances between any voltage node in the sub-region and the remaining voltage nodes in the sub-region.

[0019] The voltage node with the smallest dominant coefficient in the sub-region is selected as the dominant node in the sub-region.

[0020] Further, the voltage information includes a voltage set value and a real-time voltage value.

[0021] Further, the setting process of the voltage set value comprises:

[0022] The optimal voltage value of the leading node for making each subarea steady-state operation is obtained by using a power system flow calculation method, and the optimal voltage value is taken as the voltage setting value of the leading node in the corresponding subarea.

[0023] Preferably, the voltage regulation instruction value of the leading node in each subarea is determined according to the voltage information of the leading node in each subarea, and the method comprises the following steps:

[0024] The voltage regulation instruction value of the leading node in the ith subarea is determined according to the following formula

[0025]

[0026] wherein, i∈[1,N], N is the total number of subareas of the power generation area division, is the voltage setting value of the leading node in the ith subarea, is the real-time voltage value of the leading node in the ith subarea.

[0027] Preferably, the reactive power control instruction value of the reactive power source of the photovoltaic power station and the voltage control instruction value of the photo-thermal power station in each subarea are determined by using the voltage regulation instruction value of the leading node in each subarea, and the method comprises the following steps:

[0028] The total reactive power regulation amount of the leading node in the ith subarea is determined according to the following formula

[0029]

[0030] The reactive power control instruction value of the photovoltaic power station and the reactive power control instruction value of the photo-thermal power station in the ith subarea are obtained by carrying out quadratic programming analysis on the total reactive power regulation amount of the leading node in the ith subarea based on the voltage and reactive power sensitivity of the power station in the ith subarea, wherein the power station comprises a photovoltaic power station and a photo-thermal power station;

[0031] The reactive power control instruction value of the kth reactive power source in the lth photovoltaic power station in the ith subarea is determined according to the following formula

[0032]

[0033] The voltage control instruction value of the mth photo-thermal power station in the ith subarea is determined according to the following formula

[0034]

[0035] wherein, i∈[1, N], N is the total number of sub-regions of the power generation region division, l∈[1, L], L is the total number of photovoltaic power stations in the i-th sub-region, m∈[1, M], M is the total number of photo-thermal power stations in the i-th sub-region, k∈[1, K], K is the total number of reactive power sources in the l-th photovoltaic power station in the i-th sub-region, is the voltage regulation instruction value of the dominant node in the i-th sub-region, is the reactive power control instruction value of the m-th photo-thermal power station in the i-th sub-region, is the reactive power control instruction value of the l-th photovoltaic power station in the i-th sub-region, is the reactive power capacity value of the k-th reactive power source in the l-th photovoltaic power station in the i-th sub-region, is the total reactive power capacity value of the l-th photovoltaic power station in the i-th sub-region, K P1 and K P2 is the reactive power voltage proportional adjustment coefficient, K I1 and K I2 is the reactive power voltage integral adjustment coefficient.

[0036] Further, the reactive power control instruction value of the photovoltaic power station and the reactive power control instruction value of the photo-thermal power station in each sub-region and the total reactive power regulation amount of the dominant node in the corresponding sub-region satisfy the following constraint condition:

[0037]

[0038] wherein, i∈[1, N], N is the total number of sub-regions of the power generation region division, l∈[1, L], L is the total number of photovoltaic power stations in the i-th sub-region, m∈[1, M], M is the total number of photo-thermal power stations in the i-th sub-region, is the total reactive power regulation amount of the dominant node in the i-th sub-region, is the reactive power control instruction value of the l-th photovoltaic power station in the i-th sub-region, is the reactive power control instruction value of the m-th photo-thermal power station in the i-th sub-region.

[0039] Preferably, the respective photovoltaic power station and photo-thermal power station in each sub-region are controlled by using the reactive power control instruction value of the reactive power source of the photovoltaic power station and the voltage control instruction value of the photo-thermal power station in each sub-region, including:

[0040] The reactive power output value Qj of the j-th reactive power source in the l-th photovoltaic power station in the i-th sub-region is determined according to the following formula: i,RPj :

[0041]

[0042] The machine terminal voltage output value V of the hth photo-thermal power station in the ith sub-region is determined according to the following formula i,CSPh :

[0043]

[0044] wherein j [1, K], K is the total number of reactive power sources in the lth photovoltaic power station in the ith sub-region, h [1, M], M is the total number of photo-thermal power stations in the ith sub-region, is the current reactive power value of the jth reactive power source in the lth photovoltaic power station in the ith sub-region, is the reactive power control instruction value of the jth reactive power source in the lth photovoltaic power station in the ith sub-region, is the current voltage value of the hth photo-thermal power station in the ith sub-region, is the voltage control instruction value of the hth photo-thermal power station in the ith sub-region;

[0045] The output of the jth reactive power source in the lth photovoltaic power station in the ith sub-region is controlled to have a reactive power of Q i,RPj ;

[0046] The machine terminal output voltage of the hth photo-thermal power station in the ith sub-region is controlled to be V i,CSPh .

[0047] The photovoltaic-photo-thermal combined power generation regional power grid voltage coordination control system provided by the application has the improvement that it comprises:

[0048] A partition module is configured to divide the photovoltaic-photo-thermal combined power generation regional power grid into a plurality of sub-regions;

[0049] A first calculation module is configured to determine voltage regulation instruction values of dominant nodes in each sub-region according to voltage information of the dominant nodes in each sub-region;

[0050] A second calculation module is configured to determine reactive power control instruction values of reactive power sources of photovoltaic power stations and voltage control instruction values of photo-thermal power stations in each sub-region by using the voltage regulation instruction values of the dominant nodes in each sub-region;

[0051] A control module is configured to control the reactive power of the output of the reactive power sources of the photovoltaic power stations and the machine terminal output voltage of the photo-thermal power stations in each sub-region by using the reactive power control instruction values of the reactive power sources of the photovoltaic power stations and the voltage control instruction values of the photo-thermal power stations in each sub-region, respectively.

[0052] Compared with the closest prior art, the application has the beneficial effects that:

[0053] (1) The technical scheme provided by the present application divides the photovoltaic-photothermal combined power generation regional power grid into multiple sub-regions; determines the voltage regulation instruction value of the dominant node in each sub-region according to the voltage information of the dominant node in each sub-region; determines the reactive power control instruction value of the reactive power source of the photovoltaic power station and the voltage control instruction value of the photothermal power station in each sub-region by using the voltage regulation instruction value of the dominant node in each sub-region; controls the output reactive power of the reactive power source of the photovoltaic power station and the terminal output voltage of the photothermal power station in each sub-region by using the reactive power control instruction value of the reactive power source of the photovoltaic power station and the voltage control instruction value of the photothermal power station in each sub-region respectively; ensures the local balance and the overall network balance of the reactive power, ensures the stability of the grid voltage, and increases the system operation economy and safety by performing reactive power optimization or dynamic voltage control through static or changing the reactive power output of the new energy plant.

[0054] (2) The technical scheme provided by the present application is beneficial to unified scheduling and coordinated control of the dispersed multiple reactive power compensation devices and synchronous generator sets, realizes the nearby balance of reactive power and voltage regulation, and avoids local grid voltage oscillation caused by the respective control of multiple solar power stations. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 is a flow chart of the photovoltaic-photothermal combined power generation regional power grid voltage coordinated control method;

[0056] Figure 2 is a structural diagram of the photovoltaic-photothermal combined power generation regional power grid voltage coordinated control system. DETAILED DESCRIPTION

[0057] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0058] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0059] The photovoltaic-photothermal combined power generation regional power grid voltage coordinated control method provided by the present application, as shown in Figure 1 , comprises:

[0060] Step 101, dividing the photovoltaic-photothermal combined power generation regional power grid into multiple sub-regions;

[0061] Step 102, determining the voltage regulation instruction value of the dominant node in each sub-region according to the voltage information of the dominant node in each sub-region;

[0062] Step 103, determining the reactive power control instruction value of the reactive power source of the photovoltaic power station and the voltage control instruction value of the photo-thermal power station in each sub-region by using the voltage regulation instruction value of the dominant node in each sub-region;

[0063] Step 104, controlling the output of the reactive power of the reactive power source of the photovoltaic power station and the terminal output voltage of the photo-thermal power station in each sub-region by using the reactive power control instruction value of the reactive power source of the photovoltaic power station and the voltage control instruction value of the photo-thermal power station in each sub-region, respectively.

[0064] Preferably, the photovoltaic-photo-thermal combined power generation regional power grid is divided into a plurality of sub-regions, including:

[0065] Step A1, performing cluster analysis on the photovoltaic-photo-thermal combined power generation regional power grid based on the electrical distance between the voltage nodes in the photovoltaic-photo-thermal combined power generation regional power grid to obtain a cluster result;

[0066] Step A2, dividing the voltage nodes in a cluster in the cluster result into a sub-region;

[0067] Preferably, the voltage nodes include the grid-connected voltage nodes of the photovoltaic power station and the grid-connected voltage nodes of the photo-thermal power station.

[0068] Further, the electrical distance between the voltage nodes in the photovoltaic-photo-thermal combined power generation regional power grid is determined according to the following formula:

[0069]

[0070] Wherein, a, b ∈ B, B is a set of voltage nodes, D ab is the electrical distance between the voltage node a and the voltage node b, S ab is the reactive voltage sensitivity of the change of the reactive power of the voltage node b to the voltage of the voltage node a, S bb is the reactive voltage sensitivity of the change of the reactive power of the voltage node b to the voltage of the voltage node b, S ba is the reactive voltage sensitivity of the change of the reactive power of the voltage node a to the voltage of the voltage node b, S aa is the reactive voltage sensitivity of the change of the reactive power of the voltage node a to the voltage of the voltage node a.

[0071] Preferably, the determination process of the dominant node in the sub-region includes:

[0072] According to the sum of the electrical distances between any voltage node in the sub-region and the remaining voltage nodes in the sub-region, the dominant coefficient of all voltage nodes in the sub-region is determined;

[0073] The voltage node with the smallest dominant coefficient in the sub-region is selected as the dominant node in the sub-region.

[0074] Further, the voltage information comprises: a voltage setting value and a real-time voltage value.

[0075] Further, the setting process of the voltage setting value comprises:

[0076] An optimal voltage value of the leading node for steady operation of each sub-region is obtained by using a power system flow calculation method, and the optimal voltage value is taken as the voltage setting value of the leading node in the corresponding sub-region.

[0077] Preferably, the voltage regulation instruction value of the leading node in each sub-region is determined according to the voltage information of the leading node in each sub-region, comprising:

[0078] The voltage regulation instruction value of the leading node in the i th sub-region is determined according to the following formula

[0079]

[0080] Wherein, i∈[1,N], N is the total number of sub-regions of the power generation region division, is the voltage setting value of the leading node in the i th sub-region, is the real-time voltage value of the leading node in the i th sub-region.

[0081] In the embodiment of the present application, the reactive power capacity and real-time voltage of the leading node in each sub-region are analyzed by using the power system flow calculation method, the voltage value of the leading node in each sub-region is obtained, and the voltage value of the leading node in each sub-region is taken as the voltage setting value of the leading node in each sub-region;

[0082] After determining the voltage regulation instruction value of the leading node in each sub-region according to the voltage information of the leading node in each sub-region, the power grid dispatching center automatically issues the voltage regulation instruction value of the leading node to each sub-region automatic voltage control substation through the communication system.

[0083] Preferably, the reactive power control instruction value of the reactive power source of the photovoltaic power station and the voltage control instruction value of the photo-thermal power station in each sub-region are determined by using the voltage regulation instruction value of the leading node in each sub-region, comprising:

[0084] Step B1, the total reactive power regulation amount of the leading node in the i th sub-region is determined according to the following formula

[0085]

[0086] Step B2, based on the voltage and reactive power sensitivity of the power station in the ith sub-region, the total reactive power adjustment amount of the dominant node in the ith sub-region is analyzed by quadratic programming, and the reactive power control instruction value of the photovoltaic power station and the reactive power control instruction value of the photo-thermal power station in the ith sub-region are obtained, wherein the power station includes: photovoltaic power station and photo-thermal power station;

[0087] Step B3, the reactive power control instruction value of the kth reactive power source in the lth photovoltaic power station in the ith sub-region is determined as follows

[0088]

[0089] Step B4, the voltage control instruction value of the mth photo-thermal power station in the ith sub-region is determined as follows

[0090]

[0091] In the formula, i∈[1,N], N is the total number of sub-regions of power generation region division, l∈[1,L], L is the total number of photovoltaic power stations in the ith sub-region, m∈[1,M], M is the total number of photo-thermal power stations in the ith sub-region, k∈[1,K], K is the total number of reactive power sources in the lth photovoltaic power station in the ith sub-region, is the voltage regulation instruction value of the dominant node in the ith sub-region, is the reactive power control instruction value of the mth photo-thermal power station in the ith sub-region, is the reactive power control instruction value of the lth photovoltaic power station in the ith sub-region, is the reactive power capacity value of the kth reactive power source in the lth photovoltaic power station in the ith sub-region, is the total reactive power capacity value of the lth photovoltaic power station in the ith sub-region, K P1 and K P2 is the proportional adjustment coefficient of reactive power and voltage, K I1 and K I2 is the integral adjustment coefficient of reactive power and voltage.

[0092] Further, the reactive power control instruction value of the photovoltaic power station and the reactive power control instruction value of the photo-thermal power station in each sub-region satisfy the following constraint conditions between the total reactive power adjustment amount of the dominant node in the corresponding sub-region:

[0093]

[0094] In the formula, i∈[1,N], N is the total number of sub-regions of power generation region division, l∈[1,L], L is the total number of photovoltaic power stations in the ith sub-region, m∈[1,M], M is the total number of photo-thermal power stations in the ith sub-region, a total reactive power regulation amount of the dominant node in the ith sub-region, a reactive power control instruction value of the lth photovoltaic power station in the ith sub-region, a reactive power control instruction value of the mth photo-thermal power station in the ith sub-region.

[0095] In the embodiment of the present application, the power station voltage reactive power sensitivity is the sensitivity of the power station grid point voltage change to the power station reactive power, which can be obtained by calculating the partial derivative of the node voltage to the reactive power according to the system active power, the reactive power, the actual data of each node voltage and the grid parameters recorded by the system active power, the reactive power, the actual data of each node voltage and the grid parameters recorded by the data acquisition and monitoring control system of each sub-region in real time.

[0096] Preferably, the output reactive power of the reactive power source of the photovoltaic power station in each sub-region and the terminal output voltage of the photo-thermal power station are controlled by using the reactive power control instruction value of the reactive power source of the photovoltaic power station and the voltage control instruction value of the photo-thermal power station in each sub-region respectively, comprising:

[0097] Step C1, determining the reactive power output value Q of the jth reactive power source in the lth photovoltaic power station in the ith sub-region according to the following formula i,RPj :

[0098]

[0099] Step C2, determining the terminal voltage output value V of the hth photo-thermal power station in the ith sub-region according to the following formula i,CSPh :

[0100]

[0101] wherein j∈[1,K], K is the total number of reactive power sources in the lth photovoltaic power station in the ith sub-region, h∈[1,M], M is the total number of photo-thermal power stations in the ith sub-region, a current reactive power value of the jth reactive power source in the lth photovoltaic power station in the ith sub-region, a reactive power control instruction value of the jth reactive power source in the lth photovoltaic power station in the ith sub-region, a current voltage value of the hth photo-thermal power station in the ith sub-region, a voltage control instruction value of the hth photo-thermal power station in the ith sub-region;

[0102] Step C3, controlling the output reactive power of the jth reactive power source in the lth photovoltaic power station in the ith sub-region to be Q i,RPj ; and controlling the terminal output voltage of the hth photo-thermal power station in the ith sub-region to be V i,CSPh .

[0103] In the embodiment of the present application, each sub-area automatic regulation substation issues reactive power control instruction values of reactive power sources of photovoltaic power stations in each sub-area to the photovoltaic power stations in each sub-area through a communication system, controls reactive power current output through a reactive power current controller, and further controls reactive power output of grid-connected inverters, static reactive power compensation devices and dynamic reactive power compensation devices in the photovoltaic power stations; and issues voltage control instruction values of the photothermal power stations to the photothermal power stations in each sub-area, controls excitation current output through a unit excitation control system, and further controls machine terminal voltage output of the synchronous generator units of the photothermal power stations.

[0104] The photovoltaic-photothermal combined power generation regional power grid voltage coordination control system provided by the present application comprises: Figure 2

[0105] A partition module is configured to divide the photovoltaic-photothermal combined power generation regional power grid into a plurality of sub-areas.

[0106] A first calculation module is configured to determine voltage regulation instruction values of dominant nodes in each sub-area according to voltage information of the dominant nodes.

[0107] A second calculation module is configured to determine reactive power control instruction values of reactive power sources of photovoltaic power stations in each sub-area and voltage control instruction values of photothermal power stations by using the voltage regulation instruction values of the dominant nodes in each sub-area.

[0108] A control module is configured to control output reactive power of the reactive power sources of the photovoltaic power stations in each sub-area and machine terminal output voltage of the photothermal power stations by using the reactive power control instruction values of the reactive power sources of the photovoltaic power stations and the voltage control instruction values of the photothermal power stations in each sub-area, respectively.

[0109] In the embodiment of the present application, the photovoltaic-photothermal combined power generation regional power grid voltage coordination control system is processed as follows:

[0110] First, the photovoltaic-photothermal combined power generation regional power grid is divided into a plurality of sub-areas, including:

[0111] The photovoltaic-photothermal combined power generation regional power grid is subjected to cluster analysis based on electrical distances between voltage nodes in the photovoltaic-photothermal combined power generation regional power grid, and a cluster result is obtained.

[0112] Voltage nodes in one cluster in the cluster result are divided into one sub-area.

[0113] The voltage nodes include grid-connected voltage nodes of photovoltaic power stations and grid-connected voltage nodes of photothermal power stations.

[0114] The electrical distance D between voltage node a and voltage node b in the photovoltaic-photothermal combined power generation regional power grid is determined according to the following formula: ab : ​

[0115]

[0116] wherein a, b e B, B is a set of voltage nodes, S ab is a reactive voltage sensitivity of a reactive power change of the voltage node b to the voltage of the voltage node a, S bb is a reactive voltage sensitivity of a reactive power change of the voltage node b to the voltage of the voltage node b, S ba is a reactive voltage sensitivity of a reactive power change of the voltage node a to the voltage of the voltage node b, S aa is a reactive voltage sensitivity of a reactive power change of the voltage node a to the voltage of the voltage node a.

[0117] Secondly, the process of determining the dominant node in the sub-region comprises:

[0118] determining the dominant coefficient of all voltage nodes in the sub-region according to the sum of the electrical distance between any voltage node in the sub-region and the rest of the voltage nodes in the sub-region;

[0119] selecting the voltage node with the smallest dominant coefficient in the sub-region as the dominant node in the sub-region.

[0120] The voltage information comprises: a voltage set value and a real-time voltage value.

[0121] The process of setting the voltage set value comprises:

[0122] adopting a power system flow calculation method to obtain the optimal voltage value of the dominant node for the steady-state operation of each sub-region, and taking the optimal voltage value as the voltage set value of the dominant node in the corresponding sub-region.

[0123] determining the voltage regulation instruction value of the dominant node in each sub-region according to the voltage information of the dominant node in each sub-region, comprising:

[0124] determining the voltage regulation instruction value of the dominant node in the i-th sub-region according to the following formula

[0125]

[0126] wherein i e [1, N], N is the total number of sub-regions of the power generation region division, is the voltage set value of the dominant node in the i-th sub-region, is the real-time voltage value of the dominant node in the i-th sub-region.

[0127] Then, the reactive power control instruction value of the reactive power source of the photovoltaic power station and the voltage control instruction value of the photo-thermal power station in each sub-region are determined by using the voltage regulation instruction value of the dominant node in each sub-region, comprising:

[0128] The total reactive power regulation amount of the dominant node in the i-th sub-region is determined according to the following formula

[0129]

[0130] The total reactive power regulation amount of the dominant node in the i-th sub-region is analyzed by quadratic programming based on the voltage-reactive power sensitivity of the power station in the i-th sub-region, to obtain the reactive power control instruction value of the photovoltaic power station and the reactive power control instruction value of the photo-thermal power station in the i-th sub-region, wherein the power station includes: a photovoltaic power station and a photo-thermal power station;

[0131] The reactive power control instruction value of the k-th reactive power source in the l-th photovoltaic power station in the i-th sub-region is determined according to the following formula

[0132]

[0133] The voltage control instruction value of the m-th photo-thermal power station in the i-th sub-region is determined according to the following formula

[0134]

[0135] In the formula, i∈[1,N], N is the total number of sub-regions of power generation region division, l∈[1,L], L is the total number of photovoltaic power stations in the i-th sub-region, m∈[1,M], M is the total number of photo-thermal power stations in the i-th sub-region, k∈[1,K], K is the total number of reactive power sources in the l-th photovoltaic power station in the i-th sub-region, is the voltage regulation instruction value of the dominant node in the i-th sub-region, is the reactive power control instruction value of the m-th photo-thermal power station in the i-th sub-region, is the reactive power control instruction value of the l-th photovoltaic power station in the i-th sub-region, is the reactive power capacity value of the k-th reactive power source in the l-th photovoltaic power station in the i-th sub-region, is the total reactive power capacity value of the l-th photovoltaic power station in the i-th sub-region, K P1 and K P2 is the reactive power voltage proportional regulation coefficient, K I1 and K I2 is the reactive power voltage integral regulation coefficient.

[0136] The reactive power control instruction value of the photovoltaic power station and the reactive power control instruction value of the photo-thermal power station in each sub-region satisfy the following constraint condition between the total reactive power regulation amount of the dominant node in the corresponding sub-region:

[0137]

[0138] wherein, i∈[1, N], N is the total number of sub-regions of the power generation region division, l∈[1, L], L is the total number of photovoltaic power stations in the i-th sub-region, m∈[1, M], M is the total number of photo-thermal power stations in the i-th sub-region, is the total reactive power regulation amount of the dominant node in the i-th sub-region, is the reactive power control instruction value of the l-th photovoltaic power station in the i-th sub-region, is the reactive power control instruction value of the m-th photo-thermal power station in the i-th sub-region.

[0139] Finally, the reactive power of the output of the reactive power source of the photovoltaic power station in each sub-region and the terminal output voltage of the photo-thermal power station are controlled by using the reactive power control instruction value of the reactive power source of the photovoltaic power station and the voltage control instruction value of the photo-thermal power station in each sub-region, respectively, including:

[0140] The reactive power output value Q of the j-th reactive power source in the l-th photovoltaic power station in the i-th sub-region is determined according to the following formula i,RPj :

[0141]

[0142] The terminal voltage output value V of the h-th photo-thermal power station in the i-th sub-region is determined according to the following formula i,CSPh :

[0143]

[0144] wherein, j∈[1, K], K is the total number of reactive power sources in the l-th photovoltaic power station in the i-th sub-region, h∈[1, M], M is the total number of photo-thermal power stations in the i-th sub-region, is the current reactive power value of the j-th reactive power source in the l-th photovoltaic power station in the i-th sub-region, is the reactive power control instruction value of the j-th reactive power source in the l-th photovoltaic power station in the i-th sub-region, is the current voltage value of the h-th photo-thermal power station in the i-th sub-region, is the voltage control instruction value of the h-th photo-thermal power station in the i-th sub-region;

[0145] The reactive power of the output of the j-th reactive power source in the l-th photovoltaic power station in the i-th sub-region is controlled to be Q i,RPj .

[0146] The terminal output voltage of the h-th photo-thermal power station in the i-th sub-region is controlled to be V i,CSPh .

[0147] In the embodiment of the present application, the four modules in the photovoltaic-photothermal combined power generation regional power grid voltage coordinated control system can be contained in one system to realize unified coordinated control of the photovoltaic-photothermal combined power generation regional power grid, sub-regions, and photovoltaic power stations and photothermal power stations in the sub-regions; or the modules can be arranged in different regions according to their functions, that is, the zoning module and the first calculation module are arranged in the dispatching master station in the photovoltaic-photothermal combined power generation regional power grid, the second calculation module is arranged in each dispatching substation in each sub-region, and the corresponding control module is configured in each photovoltaic power station and each photothermal power station in each sub-region.

[0148] Those skilled in the art will understand that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage, etc.) containing computer-usable program code.

[0149] The present application is described with reference to flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, as well as combinations of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing apparatus to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing apparatus produce a device that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in the flow or flows and / or blocks Figure 1 The functions specified in the flow or flows and / or blocks

[0150] These computer program instructions can also be stored in a computer-readable memory that can direct the computer or other programmable data processing apparatus to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including instruction devices that implement the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in the flow or flows and / or blocks Figure 1 The functions specified in the flow or flows and / or blocks

[0151] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus, so that a series of operation steps are performed on the computer or other programmable data processing apparatus to produce a computer-implemented process, so that the instructions executed on the computer or other programmable data processing apparatus provide a device for implementing the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in the flow or flows and / or blocksFigure 1 the steps of the functions specified in the one or more blocks.

[0152] It should be noted that the above-mentioned embodiments are only used to illustrate the technical solutions of the present application, but not to limit the present application. Although the present application has been described in detail with reference to the above-mentioned embodiments, those skilled in the art should understand that the specific embodiments of the present application can be modified or equivalent replacements without departing from the spirit and scope of the present application, and any modifications or equivalent replacements should be covered in the protection scope of the claims of the present application.

Claims

1. A method for coordinated control of photovoltaic-photothermal combined power generation regional grid voltage, characterized in that, The method comprises: dividing the photovoltaic-photothermal combined power generation regional power grid into a plurality of sub-regions; determining voltage regulation instruction values of dominant nodes in each sub-region according to voltage information of the dominant nodes; determining reactive power control instruction values of reactive power sources of photovoltaic power stations and voltage control instruction values of photothermal power stations in each sub-region by using the voltage regulation instruction values of the dominant nodes in each sub-region; controlling reactive power output of the reactive power sources of the photovoltaic power stations and machine terminal output voltage of the photothermal power stations in each sub-region by using the reactive power control instruction values of the reactive power sources of the photovoltaic power stations and the voltage control instruction values of the photothermal power stations in each sub-region respectively; wherein the dividing of the photovoltaic-photothermal combined power generation regional power grid into a plurality of sub-regions comprises: performing clustering analysis on the photovoltaic-photothermal combined power generation regional power grid based on electrical distances between voltage nodes in the photovoltaic-photothermal combined power generation regional power grid to obtain a clustering result; dividing voltage nodes in one clustering cluster in the clustering result into one sub-region; wherein the voltage nodes comprise grid-connected voltage nodes of photovoltaic power stations and grid-connected voltage nodes of photothermal power stations; determining the electrical distances between the voltage nodes in the photovoltaic-photothermal combined power generation regional power grid according to the following formula: wherein D ab is the electrical distance between voltage node a and voltage node b in the photovoltaic-photothermal combined power generation regional power grid, a, b ∈ B, B is a voltage node set, S ab is the reactive voltage sensitivity of the voltage node b reactive power change to the voltage of the voltage node a, S bb is the reactive voltage sensitivity of the voltage node b reactive power change to the voltage of the voltage node b, S ba is the reactive voltage sensitivity of the voltage node a reactive power change to the voltage of the voltage node b, S aa is the reactive voltage sensitivity of the voltage node a reactive power change to the voltage of the voltage node a.

2. The method of claim 1, wherein, the determination process of the dominant nodes in the sub-region comprises: determining dominant coefficients of all voltage nodes in a sub-region according to a sum of electrical distances between any voltage node in the sub-region and the remaining voltage nodes in the sub-region; selecting a voltage node with the smallest dominant coefficient in the sub-region as a dominant node in the sub-region.

3. The method of claim 1, wherein, The voltage information comprises a voltage set value and a real-time voltage value.

4. The method of claim 3, wherein, The setting process of the voltage set value comprises: obtaining optimal voltage values of the dominant nodes for steady-state operation of each sub-region by using a power system flow calculation method, and taking the optimal voltage values as voltage set values of the dominant nodes in the corresponding sub-region.

5. The method of claim 1, wherein, The determination of the voltage regulation instruction values of the dominant nodes in each sub-region according to the voltage information of the dominant nodes comprises: The voltage regulation command value of the dominant node in the i-th region is determined by the following expression wherein i ∈ [1, N], N is the total number of sub-regions of the power generation region division, Vset,i is the voltage set value of the dominant node in the i-th sub-region, Vreal,i is the real-time voltage value of the dominant node in the i-th sub-region.

6. The method of claim 1, wherein, The determination of the reactive power control instruction values of the reactive power sources of the photovoltaic power stations and the voltage control instruction values of the photothermal power stations in each sub-region by using the voltage regulation instruction values of the dominant nodes in each sub-region comprises: The total reactive power regulation amount of the dominant node in the i-th sub-region is determined as follows performing optimization analysis on total reactive power adjustment amounts of the dominant nodes in the i th sub-region based on voltage and reactive power sensitivities of power stations in the i th sub-region by using a quadratic programming algorithm to obtain reactive power control instruction values of photovoltaic power stations in the i th sub-region and reactive power control instruction values of photothermal power stations in the i th sub-region; The reactive power control command value of the kth reactive power source in the lth photovoltaic power plant in the ith sub-region is determined by the following formula The voltage control command value of the mth photo-thermal power plant in the ith sub-region is determined by the following formula In the formula, i ∈ [1, N], N is the total number of sub-regions of power generation area division, l ∈ [1, L], L is the total number of photovoltaic power stations in the i th sub-region, m ∈ [1, M], M is the total number of photo-thermal power stations in the i th sub-region, k ∈ [1, K], K is the total number of reactive power sources in the l th photovoltaic power station in the i th sub-region, is the voltage regulation instruction value of the dominant node in the i th sub-region, is the reactive power control instruction value of the m th photo-thermal power station in the i th sub-region, is the reactive power control instruction value of the l th photovoltaic power station in the i th sub-region, is the reactive power capacity value of the k th reactive power source in the l th photovoltaic power station in the i th sub-region, is the total reactive power capacity value of the l th photovoltaic power station in the i th sub-region, K P1 and K P2 is the reactive power voltage proportional adjustment coefficient, K I1 and K I2 is the reactive power voltage integral adjustment coefficient.

7. The method of claim 6, wherein, The reactive power control instruction values of the photovoltaic power stations and the reactive power control instruction values of the photothermal power stations in each sub-region and total reactive power adjustment amounts of the dominant nodes in the corresponding sub-region satisfy the following constraint condition: wherein, i∈[1, N], N is the total number of sub-regions of the power generation region division, l∈[1, L], L is the total number of photovoltaic power stations in the i th sub-region, m∈[1, M], M is the total number of photo-thermal power stations in the i th sub-region, is the total reactive power regulation amount of the dominant node in the i th sub-region, is the reactive power control instruction value of the l th photovoltaic power station in the i th sub-region, is the reactive power control instruction value of the m th photo-thermal power station in the i th sub-region.

8. The method of claim 1, wherein, The control of the reactive power output of the reactive power sources of the photovoltaic power stations and the machine terminal output voltage of the photothermal power stations in each sub-region by using the reactive power control instruction values of the reactive power sources of the photovoltaic power stations and the voltage control instruction values of the photothermal power stations in each sub-region respectively comprises: The reactive power output value Q of the jth reactive power source in the ith sub-area within the lth photovoltaic power station is determined by the following formula i,RPj : The machine terminal voltage output value V of the hth photo-thermal power plant in the ith sub-region is determined by the following formula i,CSPh : wherein, j∈[1,K], K is the total number of reactive power sources in the lth photovoltaic power station in the ith sub-region, h∈[1,M], M is the total number of photo-thermal power stations in the ith sub-region, is the current reactive power value of the jth reactive power source in the lth photovoltaic power station in the ith sub-region, is the reactive power control instruction value of the jth reactive power source in the lth photovoltaic power station in the ith sub-region, is the current voltage value of the hth photo-thermal power station in the ith sub-region, is the voltage control instruction value of the hth photo-thermal power station in the ith sub-region. The reactive power of controlling the output of the jth reactive power source in the ith sub-area in the lth photovoltaic power station is Q i,RPj ; The machine terminal output voltage of the hth photo-thermal power station in the ith sub-region is V i,CSPh .

9. A photovoltaic-photothermal combined power generation regional grid voltage coordination control system, characterized in that, The system comprises: a sub-region module configured to divide the photovoltaic-photothermal combined power generation regional power grid into a plurality of sub-regions; a first calculation module configured to determine voltage regulation instruction values of dominant nodes in each sub-region according to voltage information of the dominant nodes; The second calculation module is configured to determine the reactive power control instruction value of the reactive power source of the photovoltaic power station and the voltage control instruction value of the photo-thermal power station in each sub-region according to the voltage regulation instruction value of the dominant node in each sub-region; The control module is configured to control the output of the reactive power of the reactive power source of the photovoltaic power station and the terminal output voltage of the photo-thermal power station in each sub-region according to the reactive power control instruction value of the reactive power source of the photovoltaic power station and the voltage control instruction value of the photo-thermal power station in each sub-region, respectively. The photovoltaic-thermal combined power generation regional power grid is divided into a plurality of sub-regions, including: performing clustering analysis on the photovoltaic-thermal combined power generation regional power grid based on the electrical distance between the voltage nodes in the photovoltaic-thermal combined power generation regional power grid to obtain a clustering result; dividing the voltage nodes in one clustering cluster in the clustering result into one sub-region; The voltage nodes include the grid-connected voltage nodes of the photovoltaic power station and the grid-connected voltage nodes of the photo-thermal power station. The electrical distance between the voltage nodes in the photovoltaic-thermal combined power generation regional power grid is determined according to the following formula: wherein D ab is the electrical distance between voltage node a and voltage node b in the photovoltaic-photothermal combined power generation regional power grid, a, b ∈ B, B is a voltage node set, S ab is the reactive voltage sensitivity of the voltage node b's reactive power change to the voltage of the voltage node a, S bb is the reactive voltage sensitivity of the voltage node b's reactive power change to the voltage of the voltage node b, S ba is the reactive voltage sensitivity of the voltage node a's reactive power change to the voltage of the voltage node b, S aa is the reactive voltage sensitivity of the voltage node a's reactive power change to the voltage of the voltage node a.

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