A method and device for controlling reactive power of a photovoltaic power station

Abstract

The present invention relates to a method and device for reactive power control of a photovoltaic power station, comprising: determining a reactive power adjustment value of the photovoltaic power station based on a reactive power adjustment instruction received by the photovoltaic power station; and adjusting the reactive power output by each photovoltaic inverter unit and each energy storage unit in the photovoltaic power station based on the reactive power adjustment value of the photovoltaic power station. The technical solution provided by the present invention can utilize the excellent reactive power adjustment capabilities of the photovoltaic inverter and energy storage system of the photovoltaic power station to achieve a steady-state reactive power control function of the photovoltaic power station through coordinated control of the AVC system. It does not need to consider whether the SOC of the energy storage system is within the normal range, the amount of active power, or the charge and discharge status, and can perform reactive support according to a constant power factor.

Description

Technical Field

[0001] The present invention relates to the technical field of reactive voltage control of photovoltaic power stations, and in particular to a reactive power control method and device for a photovoltaic power station. Background Art

[0002] Currently, most PV power stations in actual operation are equipped with dynamic reactive power supplementation devices (SVGs) that account for 20-30% of the installed capacity of the PV power station in accordance with the requirements of the power grid company. The reactive power and voltage regulation of the PV power station mainly rely on SVGs. At the same time, as the price of energy storage batteries continues to decline, many PV power stations are equipped with energy storage systems of a certain capacity, but these systems can only play the role of peak load shifting. This solution does not truly utilize the reactive power regulation capabilities of the PV inverter and energy storage battery, and the configured SVGs increase the initial construction cost and subsequent maintenance costs.

[0003] Numerous patents and literature have examined the use of inverters and SVGs in conjunction with reactive voltage regulation in photovoltaic power plants, as well as the use of photovoltaic inverters alone. The core concept of these patents is to directly collect the reactive power target values ​​of the photovoltaic power plant issued by the dispatcher, or the reactive power values ​​converted from the grid connection point voltage, and then use algorithms such as particle swarm optimization and multi-objective dynamic optimization to distribute reactive power between the photovoltaic inverter and SVG devices. There is also literature examining the use of energy storage systems alone for reactive voltage control in new energy power plants. The core algorithm is a reactive power control strategy for battery energy storage systems based on control variables such as the current maximum allowable reactive power value of the battery energy storage and the current maximum allowable reactive power characteristic value, achieving coordinated control and real-time distribution of the energy storage system's reactive power. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a photovoltaic power station that can utilize the good reactive power regulation capabilities of the photovoltaic inverter and energy storage system, and realize the steady-state reactive power control function of the photovoltaic power station through the coordinated control of the AVC system.

[0005] The purpose of the present invention is achieved by adopting the following technical solutions:

[0006] The present invention provides a method for controlling reactive power in a photovoltaic power station, wherein the method comprises:

[0007] Determining a reactive power regulation value of the photovoltaic power station according to a reactive power regulation instruction received by the photovoltaic power station;

[0008] The reactive power output by each photovoltaic inverter unit and each energy storage unit in the photovoltaic power station is adjusted according to the reactive power adjustment value of the photovoltaic power station.

[0009] Preferably, determining the reactive power regulation value of the photovoltaic power station according to the reactive power regulation instruction received by the photovoltaic power station includes:

[0010] The reactive power regulation value Q of the photovoltaic power station is determined as follows: a :

[0011] Q a =Q g -Q c

[0012] In the above formula, Q g is the reactive power target value in the reactive power regulation instruction of the photovoltaic power station; Q c The current value of reactive power collected by the photovoltaic power station.

[0013] Preferably, regulating the reactive power output by each photovoltaic inverter unit and each energy storage unit in the photovoltaic power station according to the reactive power regulation value of the photovoltaic power station includes:

[0014] Calculating the reactive power that the photovoltaic inverter and the energy storage system need to output respectively according to the reactive power adjustment value of the photovoltaic power station;

[0015] The reactive power that the photovoltaic inverter and the energy storage system need to output is distributed to each photovoltaic inverter unit and each energy storage unit accordingly.

[0016] Furthermore, the reactive power required to be output by the photovoltaic inverter and the energy storage system is calculated according to the reactive power adjustment value of the photovoltaic power station, including:

[0017] When the reactive power adjustment value of the photovoltaic power station Q a When the reactive power adjustment value Q of the photovoltaic power station is greater than zero, a Less than the upper limit of the reactive power output of the photovoltaic inverter Q PV-max , then let the reactive power value Q output by the photovoltaic inverter be PV Equal to the reactive power regulation value Q of the photovoltaic power station a , the reactive power value Q output by the energy storage system ST Equal to zero; if the photovoltaic power station reactive power adjustment value Q a Greater than the upper limit of the reactive power output of the photovoltaic inverter Q PV-max And it is less than the upper limit of the reactive power output of the energy storage system Q ST-max The upper limit of reactive power output by the photovoltaic inverter Q PV-max The sum of the photovoltaic inverter output reactive power value Q PV Equal to the upper limit of the reactive power output of the photovoltaic inverter Q PV-max , the energy storage system outputs reactive power value Q ST Equal to the reactive power regulation value Q of the photovoltaic power station a The reactive power value Q output by the photovoltaic inverter PV If the reactive power adjustment value of the photovoltaic power station Qa Greater than the upper limit of the reactive power output of the photovoltaic inverter Q PV-max The upper limit of reactive power output of energy storage system Q ST-max The sum of the photovoltaic inverter output reactive power value Q PV Equal to the upper limit of the reactive power output of the photovoltaic inverter Q PV-max , the energy storage system outputs reactive power value Q ST-Σ Equal to the upper limit of reactive power output of the energy storage system Q ST-max ;

[0018] When the reactive power adjustment value of the photovoltaic power station Q a When the reactive power adjustment value Q of the photovoltaic power station is less than zero, a The absolute value of is less than the lower limit of the reactive power output of the photovoltaic inverter Q PV-min , then the photovoltaic inverter outputs a reactive power value Q PV Equal to the reactive power regulation value Q of the photovoltaic power station a , the energy storage system outputs reactive power value Q ST Equal to zero; if the photovoltaic power station reactive power adjustment value Q a The absolute value of is greater than the lower limit of the reactive power output of the photovoltaic inverter Q PV-min And it is less than the lower limit of the reactive power output of the photovoltaic inverter Q PV-min and the lower limit value Q of reactive power output of energy storage system ST-min The sum of the photovoltaic inverter output reactive power value Q PV Equal to the negative lower limit of the PV inverter output reactive power Q PV-min , the energy storage system outputs reactive power value Q ST Equal to the negative reactive power regulation value Q of the photovoltaic power station a The reactive power value Q output by the photovoltaic inverter PV If the reactive power adjustment value of the photovoltaic power station Q a The absolute value of is greater than the lower limit of the reactive power output of the photovoltaic inverter Q PV-min The lower limit value of reactive power output by the energy storage system Q ST-min The sum of the photovoltaic inverter output reactive power value Q PV Equal to the negative lower limit of the PV inverter output reactive power Q PV-min , the energy storage system outputs reactive power value Q ST Equal to the negative lower limit of reactive power output of the energy storage system Q ST-min .

[0019] Furthermore, the upper limit value Q of reactive power that can be output by the photovoltaic inverter in the photovoltaic power station is determined as follows: PV-max :

[0020]

[0021] In the above formula, Q PVmax-i is the upper limit of reactive power that can be output by the i-th photovoltaic inverter unit in the photovoltaic power station; ΔQ M The reactive power loss value of the main transformer; ΔQ V is the reactive power loss value of the photovoltaic box transformer; ΔQ L is the reactive power loss value of the photovoltaic collection line; N is the total number of photovoltaic inverter units in the photovoltaic power station;

[0022] The upper limit value Q of reactive power that can be output by the energy storage system in the photovoltaic power station is determined by the following formula: ST-max ;

[0023]

[0024] In the above formula, Q ST max-j is the upper limit of reactive power that can be output by the j-th energy storage unit in the photovoltaic power station; ΔQ S is the reactive power loss value of the energy storage box; ΔQ SL is the reactive loss value of the energy storage collection line; M is the total number of energy storage units in the photovoltaic power station;

[0025] The lower limit value Q of reactive power that can be output by the photovoltaic inverter in the photovoltaic power station is determined by the following formula: PV-min :

[0026]

[0027] In the above formula, Q PV min-i is the lower limit of reactive power that can be output by the i-th photovoltaic inverter unit in the photovoltaic power station;

[0028] The lower limit value Q of reactive power that can be output by the energy storage system in the photovoltaic power station is determined by the following formula: ST-min :

[0029]

[0030] In the above formula, Q ST min-j is the lower limit of the reactive power that can be output by the j-th energy storage unit in the photovoltaic power station.

[0031] Furthermore, the reactive power required to be output by the photovoltaic inverter and the energy storage system is distributed to each photovoltaic inverter unit and each energy storage unit, including:

[0032] When the reactive power adjustment value of the photovoltaic power station Q a When it is greater than zero, the process of distributing the reactive power output by the photovoltaic inverter to each photovoltaic inverter unit includes:

[0033] Step 1: Initialize the preset reactive power output value of the PV inverter unit The number of dispatchable photovoltaic inverter units in a photovoltaic power station is B=N:

[0034] Step 2: Determine whether there is a photovoltaic inverter unit that meets the first constraint condition among the B photovoltaic inverter units. If so, set the reactive power output by the photovoltaic inverter unit that meets the first constraint condition to be equal to its respective maximum output reactive power; otherwise, set the reactive power output by the B photovoltaic inverter units to be equal to Q PV-a And end the operation;

[0035] Step 3: Update the preset reactive power output value of the photovoltaic inverter unit The number of dispatchable photovoltaic inverter units in the photovoltaic power station B=BF, and return to step 2;

[0036] Among them, the first constraint condition is: Q PV-a >Q PV max-i ;Q PV max-i is the upper limit of reactive power that can be output by the i-th photovoltaic inverter unit in the photovoltaic power station; Q CPVmax-z is the maximum reactive power that can be output by the z-th photovoltaic inverter unit that meets the first constraint condition; F is the number of photovoltaic inverter units that meet the first constraint condition;

[0037] The process of distributing the reactive power output by the energy storage system to each energy storage unit includes:

[0038] Step 4: Initialize the preset reactive power output value of the energy storage unit The number of dispatchable energy storage units in a photovoltaic power station is L=M:

[0039] Step 5: Determine whether there is an energy storage unit that meets the second constraint condition among the L energy storage units. If so, set the reactive power output by the energy storage unit that meets the second constraint condition to be equal to its respective maximum output reactive power; otherwise, set the reactive power output by the L energy storage units to be equal to Q ST-a And end the operation;

[0040] Step 6: Update the preset reactive power output value of the energy storage unit The number of dispatchable energy storage units in the photovoltaic power station L=LH, and return to step 2;

[0041] Among them, the second constraint condition is: Q ST-a >Q ST max-j ;Q ST max-j is the upper limit of reactive power that can be output by the j-th energy storage unit in the photovoltaic power station; Q CSTmax-C is the maximum reactive power that can be output by the c-th energy storage unit that meets the second constraint; H is the number of energy storage units that meet the second constraint;

[0042] When the reactive power adjustment value of the photovoltaic power station Q a When the reactive power output by the photovoltaic inverter is less than zero, the process of distributing the reactive power output by the photovoltaic inverter to each photovoltaic inverter unit includes:

[0043] Step 7: Initialize the preset reactive power output value of the PV inverter unit The number of dispatchable photovoltaic inverter units in a photovoltaic power station is B=N:

[0044] Step 8: Determine whether there is a photovoltaic inverter unit that meets the third constraint condition among the B photovoltaic inverter units. If so, set the reactive power output by the photovoltaic inverter unit that meets the third constraint condition to be equal to the negative value of its respective minimum output reactive power; otherwise, set the reactive power output by the B photovoltaic inverter units to be equal to Q PV-a And end the operation;

[0045] Step 9: Update the preset reactive power output value of the photovoltaic inverter unit The number of dispatchable photovoltaic inverter units in the photovoltaic power station B=BG, and return to step 2;

[0046] The third constraint condition is: PV-a |>Q PV min-i ;Q PV min-i is the lower limit of reactive power that can be output by the i-th photovoltaic inverter unit in the photovoltaic power station; Q CPV min-s is the minimum reactive power output by the s-th photovoltaic inverter unit that meets the third constraint; G is the number of photovoltaic inverter units that meet the second constraint;

[0047] The process of distributing the reactive power output by the energy storage system to each energy storage unit includes:

[0048] Step 10: Initialize the preset reactive power output value of the energy storage unit The number of dispatchable energy storage units in a photovoltaic power station is L=M:

[0049] Step 11: Determine whether there is an energy storage unit that meets the fourth constraint condition among the L energy storage units. If so, set the reactive power output by the energy storage unit that meets the fourth constraint condition to be equal to the negative value of its respective minimum output reactive power value; otherwise, set the reactive power output by the L energy storage units to be equal to Q ST-a And end the operation;

[0050] Step 12: Update the preset reactive power output value of the energy storage unit The number of dispatchable energy storage units in the photovoltaic power station L=LU, and return to step 2;

[0051] The fourth constraint condition is: ST-a|>Q ST min-j ;Q ST min-j is the lower limit of reactive power that can be output by the j-th energy storage unit in the photovoltaic power station; Q CST min-v is the minimum reactive power that can be output by the vth energy storage unit that meets the fourth constraint; U is the number of energy storage units that meet the fourth constraint.

[0052] The present invention provides a reactive power control device for a photovoltaic power station, wherein the device comprises:

[0053] Determination module: used to determine the reactive power adjustment value of the photovoltaic power station according to the reactive power adjustment instruction received by the photovoltaic power station;

[0054] The regulating module is used to regulate the reactive power output by each photovoltaic inverter unit and each energy storage unit in the photovoltaic power station according to the reactive power regulation value of the photovoltaic power station.

[0055] Preferably, the determining module is used to:

[0056] The reactive power regulation value Q of the photovoltaic power station is determined as follows: a :

[0057] Q a =Q g -Q c

[0058] In the above formula, Q g is the reactive power target value in the reactive power regulation instruction of the photovoltaic power station; Q c The current value of reactive power collected by the photovoltaic power station.

[0059] Preferably, the adjustment module includes:

[0060] Adjustment unit: used for calculating the reactive power that the photovoltaic inverter and the energy storage system need to output respectively according to the reactive power adjustment value of the photovoltaic power station;

[0061] Distribution unit: used to distribute the reactive power required to be output by the photovoltaic inverter and the energy storage system to each photovoltaic inverter unit and each energy storage unit.

[0062] Furthermore, the adjustment unit is used to:

[0063] When the reactive power adjustment value of the photovoltaic power station Q a When the reactive power adjustment value Q of the photovoltaic power station is greater than zero, a Less than the upper limit of the reactive power output of the photovoltaic inverter Q PV-max , then let the reactive power value Q output by the photovoltaic inverter be PV Equal to the reactive power regulation value Q of the photovoltaic power station a, the reactive power value Q output by the energy storage system ST Equal to zero; if the photovoltaic power station reactive power adjustment value Q a Greater than the upper limit of the reactive power output of the photovoltaic inverter Q PV-max And it is less than the upper limit of the reactive power output of the energy storage system Q ST-max The upper limit of reactive power output by the photovoltaic inverter Q PV-max The sum of the photovoltaic inverter output reactive power value Q PV Equal to the upper limit of the reactive power output of the photovoltaic inverter Q PV-max , the energy storage system outputs reactive power value Q ST Equal to the reactive power regulation value Q of the photovoltaic power station a The reactive power value Q output by the photovoltaic inverter PV If the reactive power adjustment value of the photovoltaic power station Q a Greater than the upper limit of the reactive power output of the photovoltaic inverter Q PV-max The upper limit of reactive power output of energy storage system Q ST-max The sum of the photovoltaic inverter output reactive power value Q PV Equal to the upper limit of the reactive power output of the photovoltaic inverter Q PV-max , the energy storage system outputs reactive power value Q ST-Σ Equal to the upper limit of reactive power output of the energy storage system Q ST-max ;

[0064] When the reactive power adjustment value of the photovoltaic power station Q a When the reactive power adjustment value Q of the photovoltaic power station is less than zero, a The absolute value of is less than the lower limit of the reactive power output of the photovoltaic inverter Q PV-min , then the photovoltaic inverter outputs a reactive power value Q PV Equal to the reactive power regulation value Q of the photovoltaic power station a , the energy storage system outputs reactive power value Q ST Equal to zero; if the photovoltaic power station reactive power adjustment value Q a The absolute value of is greater than the lower limit of the reactive power output of the photovoltaic inverter Q PV-min And it is less than the lower limit of the reactive power output of the photovoltaic inverter Q PV-min and the lower limit value Q of reactive power output of energy storage system ST-min The sum of the photovoltaic inverter output reactive power value Q PV Equal to the negative lower limit of the PV inverter output reactive power Q PV-min , the energy storage system outputs reactive power value Q ST Equal to the negative reactive power regulation value Q of the photovoltaic power station a The reactive power value Q output by the photovoltaic inverter PV If the reactive power adjustment value of the photovoltaic power station Q aThe absolute value of is greater than the lower limit of the reactive power output of the photovoltaic inverter Q PV-min The lower limit value of reactive power output by the energy storage system Q ST-min The sum of the photovoltaic inverter output reactive power value Q PV Equal to the negative lower limit of the PV inverter output reactive power Q PV-min , the energy storage system outputs reactive power value Q ST Equal to the negative lower limit of reactive power output of the energy storage system Q ST-min .

[0065] Furthermore, the upper limit value Q of reactive power that can be output by the photovoltaic inverter in the photovoltaic power station is determined as follows: PV-max :

[0066]

[0067] In the above formula, Q PVmax-i is the upper limit of reactive power that can be output by the i-th photovoltaic inverter unit in the photovoltaic power station; ΔQ M The reactive power loss value of the main transformer; ΔQ V is the reactive power loss value of the photovoltaic box transformer; ΔQ L is the reactive power loss value of the photovoltaic collection line; N is the total number of photovoltaic inverter units in the photovoltaic power station;

[0068] The upper limit value Q of reactive power that can be output by the energy storage system in the photovoltaic power station is determined by the following formula: ST-max ;

[0069]

[0070] In the above formula, Q ST max-j is the upper limit of reactive power that can be output by the j-th energy storage unit in the photovoltaic power station; ΔQ S is the reactive power loss value of the energy storage box; ΔQ SL is the reactive loss value of the energy storage collection line; M is the total number of energy storage units in the photovoltaic power station;

[0071] The lower limit value Q of reactive power that can be output by the photovoltaic inverter in the photovoltaic power station is determined by the following formula: PV-min :

[0072]

[0073] In the above formula, Q PV min-i is the lower limit of reactive power that can be output by the i-th photovoltaic inverter unit in the photovoltaic power station;

[0074] The lower limit value Q of reactive power that can be output by the energy storage system in the photovoltaic power station is determined by the following formula: ST-min :

[0075]

[0076] In the above formula, Q ST min-j is the lower limit of the reactive power that can be output by the j-th energy storage unit in the photovoltaic power station.

[0077] Furthermore, the allocation unit is used to:

[0078] When the reactive power adjustment value of the photovoltaic power station Q a When it is greater than zero, the process of distributing the reactive power output by the photovoltaic inverter to each photovoltaic inverter unit includes:

[0079] Step 1: Initialize the preset reactive power output value of the PV inverter unit The number of dispatchable photovoltaic inverter units in a photovoltaic power station is B=N:

[0080] Step 2: Determine whether there is a photovoltaic inverter unit that meets the first constraint condition among the B photovoltaic inverter units. If so, set the reactive power output by the photovoltaic inverter unit that meets the first constraint condition to be equal to its respective maximum output reactive power; otherwise, set the reactive power output by the B photovoltaic inverter units to be equal to Q PV-a And end the operation;

[0081] Step 3: Update the preset reactive power output value of the photovoltaic inverter unit The number of dispatchable photovoltaic inverter units in the photovoltaic power station B=BF, and return to step 2;

[0082] Among them, the first constraint condition is: Q PV-a >Q PV max-i ;Q PV max-i is the upper limit of reactive power that can be output by the i-th photovoltaic inverter unit in the photovoltaic power station; Q CPVmax-z is the maximum reactive power that can be output by the z-th photovoltaic inverter unit that meets the first constraint condition; F is the number of photovoltaic inverter units that meet the first constraint condition;

[0083] The process of distributing the reactive power output by the energy storage system to each energy storage unit includes:

[0084] Step 4: Initialize the preset reactive power output value of the energy storage unit The number of dispatchable energy storage units in a photovoltaic power station is L=M:

[0085] Step 5: Determine whether there is an energy storage unit that meets the second constraint condition among the L energy storage units. If so, set the reactive power output by the energy storage unit that meets the second constraint condition to be equal to its respective maximum output reactive power; otherwise, set the reactive power output by the L energy storage units to be equal to Q ST-a And end the operation;

[0086] Step 6: Update the preset reactive power output value of the energy storage unit The number of dispatchable energy storage units in the photovoltaic power station L=LH, and return to step 2;

[0087] Among them, the second constraint condition is: Q ST-a >Q ST max-j ;Q ST max-j is the upper limit of reactive power that can be output by the j-th energy storage unit in the photovoltaic power station; Q CSTmax-C is the maximum reactive power that can be output by the c-th energy storage unit that meets the second constraint; H is the number of energy storage units that meet the second constraint;

[0088] When the reactive power adjustment value of the photovoltaic power station Q a When the reactive power output by the photovoltaic inverter is less than zero, the process of distributing the reactive power output by the photovoltaic inverter to each photovoltaic inverter unit includes:

[0089] Step 7: Initialize the preset reactive power output value of the PV inverter unit The number of dispatchable photovoltaic inverter units in a photovoltaic power station is B=N:

[0090] Step 8: Determine whether there is a photovoltaic inverter unit that meets the third constraint condition among the B photovoltaic inverter units. If so, set the reactive power output by the photovoltaic inverter unit that meets the third constraint condition to be equal to the negative value of its respective minimum output reactive power; otherwise, set the reactive power output by the B photovoltaic inverter units to be equal to Q PV-a And end the operation;

[0091] Step 9: Update the preset reactive power output value of the photovoltaic inverter unit The number of dispatchable photovoltaic inverter units in the photovoltaic power station B=BG, and return to step 2;

[0092] The third constraint condition is: PV-a |>Q PV min-i ;Q PV min-i is the lower limit of reactive power that can be output by the i-th photovoltaic inverter unit in the photovoltaic power station; Q CPV min-s is the minimum reactive power output by the s-th photovoltaic inverter unit that meets the third constraint; G is the number of photovoltaic inverter units that meet the second constraint;

[0093] The process of distributing the reactive power output by the energy storage system to each energy storage unit includes:

[0094] Step 10: Initialize the preset reactive power output value of the energy storage unit The number of dispatchable energy storage units in a photovoltaic power station is L=M:

[0095] Step 11: Determine whether there is an energy storage unit that meets the fourth constraint condition among the L energy storage units. If so, set the reactive power output by the energy storage unit that meets the fourth constraint condition to be equal to the negative value of its respective minimum output reactive power value; otherwise, set the reactive power output by the L energy storage units to be equal to Q ST-a And end the operation;

[0096] Step 12: Update the preset reactive power output value of the energy storage unit The number of dispatchable energy storage units in the photovoltaic power station L=LU, and return to step 2;

[0097] The fourth constraint condition is: ST-a |>Q ST min-j ;Q ST min-j is the lower limit of reactive power that can be output by the j-th energy storage unit in the photovoltaic power station; Q CST min-v is the minimum reactive power that can be output by the vth energy storage unit that meets the fourth constraint; U is the number of energy storage units that meet the fourth constraint.

[0098] Compared with the closest prior art, the present invention has the following beneficial effects:

[0099] The control method and device provided by the present invention determine the reactive power adjustment value of the photovoltaic power station according to the reactive power adjustment instruction received by the photovoltaic power station, and adjust the reactive power output by each photovoltaic inverter unit and each energy storage unit in the photovoltaic power station according to the reactive power adjustment value of the photovoltaic power station, with priority given to adjusting the reactive capacity of the photovoltaic inverter. If necessary, it is adjusted simultaneously with the energy storage system without considering whether the SOC of the energy storage system is within the normal range, the size of the active power and the charge and discharge status. Reactive support can be performed according to a constant power factor and the initial investment in the construction of the photovoltaic power station can be reduced. The control method and device provided by the present invention can also be extended to photovoltaic storage power stations, wind storage and wind-solar storage power stations, giving full play to the reactive adjustment capability of the wind-solar inverter and the flexible reactive support characteristics of the energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0100] Figure 1 This is a flow chart of a reactive power control method for a photovoltaic power station provided by the present invention;

[0101] Figure 2 This is a structural diagram of a reactive power control device for a photovoltaic power station provided by the present invention. DETAILED DESCRIPTION

[0102] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0103] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only 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 making creative efforts shall fall within the scope of protection of the present invention.

[0104] The present invention provides a method for controlling reactive power in a photovoltaic power station. The purpose is to maintain the control mode of the AVC system of the photovoltaic power station, utilize the reactive power regulation capability of the photovoltaic inverter itself, give full play to the reactive power control characteristics of the PCS of the existing energy storage system of the photovoltaic power station, coordinate the adjustable capacity of the photovoltaic inverter and the energy storage PCS according to the voltage fluctuation in the steady state, meet the dispatching requirements for the reactive power and voltage of the photovoltaic power station, replace or partially replace the dynamic reactive power compensation equipment such as SVG configured in the photovoltaic power station, and reduce the initial investment in the construction of the photovoltaic power station. Figure 1 As shown, the method includes:

[0105] Determining a reactive power regulation value of the photovoltaic power station according to a reactive power regulation instruction received by the photovoltaic power station;

[0106] The reactive power output by each photovoltaic inverter unit and each energy storage unit in the photovoltaic power station is adjusted according to the reactive power adjustment value of the photovoltaic power station.

[0107] Specifically, determining the reactive power adjustment value of the photovoltaic power station according to the reactive power adjustment instruction received by the photovoltaic power station includes:

[0108] The reactive power regulation value Q of the photovoltaic power station is determined as follows: a :

[0109] Q a =Q g -Q c

[0110] In the above formula, Q g is the reactive power target value in the reactive power regulation instruction of the photovoltaic power station; Q c The current value of reactive power collected by the photovoltaic power station.

[0111] Specifically, adjusting the reactive power output by each photovoltaic inverter unit and each energy storage unit in the photovoltaic power station according to the reactive power adjustment value of the photovoltaic power station includes:

[0112] Calculating the reactive power that the photovoltaic inverter and the energy storage system need to output respectively according to the reactive power adjustment value of the photovoltaic power station;

[0113] The reactive power that the photovoltaic inverter and the energy storage system need to output is distributed to each photovoltaic inverter unit and each energy storage unit accordingly.

[0114] Furthermore, the reactive power required to be output by the photovoltaic inverter and the energy storage system is calculated according to the reactive power adjustment value of the photovoltaic power station, including:

[0115] When the reactive power adjustment value of the photovoltaic power station Q a When the reactive power adjustment value Q of the photovoltaic power station is greater than zero, a Less than the upper limit of the reactive power output of the photovoltaic inverter Q PV-max , then let the reactive power value Q output by the photovoltaic inverter be PV Equal to the reactive power regulation value Q of the photovoltaic power station a , the reactive power value Q output by the energy storage system ST Equal to zero; if the photovoltaic power station reactive power adjustment value Q a Greater than the upper limit of the reactive power output of the photovoltaic inverter Q PV-max And it is less than the upper limit of the reactive power output of the energy storage system Q ST-max The upper limit of reactive power output by the photovoltaic inverter Q PV-max The sum of the photovoltaic inverter output reactive power value Q PV Equal to the upper limit of the reactive power output of the photovoltaic inverter Q PV-max , the energy storage system outputs reactive power value Q ST Equal to the reactive power regulation value Q of the photovoltaic power station a The reactive power value Q output by the photovoltaic inverter PV If the reactive power adjustment value of the photovoltaic power station Q a Greater than the upper limit of the reactive power output of the photovoltaic inverter Q PV-max The upper limit of reactive power output of energy storage system Q ST-max The sum of the photovoltaic inverter output reactive power value Q PV Equal to the upper limit of the reactive power output of the photovoltaic inverter Q PV-max , the energy storage system outputs reactive power value Q ST-Σ Equal to the upper limit of reactive power output of the energy storage system Q ST-max ;

[0116] When the reactive power adjustment value of the photovoltaic power station Q a When the reactive power adjustment value Q of the photovoltaic power station is less than zero, a The absolute value of is less than the lower limit of the reactive power output of the photovoltaic inverter Q PV-min , then the photovoltaic inverter outputs a reactive power value Q PV Equal to the reactive power regulation value Q of the photovoltaic power station a , the energy storage system outputs reactive power value Q STEqual to zero; if the photovoltaic power station reactive power adjustment value Q a The absolute value of is greater than the lower limit of the reactive power output of the photovoltaic inverter Q PV-min And it is less than the lower limit of the reactive power output of the photovoltaic inverter Q PV-min and the lower limit value Q of reactive power output of energy storage system ST-min The sum of the photovoltaic inverter output reactive power value Q PV Equal to the negative lower limit of the PV inverter output reactive power Q PV-min , the energy storage system outputs reactive power value Q ST Equal to the negative reactive power regulation value Q of the photovoltaic power station a The reactive power value Q output by the photovoltaic inverter PV If the reactive power adjustment value of the photovoltaic power station Q a The absolute value of is greater than the lower limit of the reactive power output of the photovoltaic inverter Q PV-min The lower limit value of reactive power output by the energy storage system Q ST-min The sum of the photovoltaic inverter output reactive power value Q PV Equal to the negative lower limit of the PV inverter output reactive power Q PV-min , the energy storage system outputs reactive power value Q ST Equal to the negative lower limit of reactive power output of the energy storage system Q ST-min .

[0117] Furthermore, the upper limit value Q of reactive power that can be output by the photovoltaic inverter in the photovoltaic power station is determined as follows: PV-max :

[0118]

[0119] In the above formula, Q PVmax-i is the upper limit of reactive power that can be output by the i-th photovoltaic inverter unit in the photovoltaic power station; ΔQ M The reactive power loss value of the main transformer; ΔQ V is the reactive power loss value of the photovoltaic box transformer; ΔQ L is the reactive power loss value of the photovoltaic collection line; N is the total number of photovoltaic inverter units in the photovoltaic power station;

[0120] The upper limit value Q of reactive power that can be output by the energy storage system in the photovoltaic power station is determined by the following formula: ST-max ;

[0121]

[0122] In the above formula, Q STmax-j is the upper limit of reactive power that can be output by the j-th energy storage unit in the photovoltaic power station; ΔQ S is the reactive power loss value of the energy storage box; ΔQ SLis the reactive loss value of the energy storage collection line; M is the total number of energy storage units in the photovoltaic power station;

[0123] The lower limit value Q of reactive power that can be output by the photovoltaic inverter in the photovoltaic power station is determined by the following formula: PV-min :

[0124]

[0125] In the above formula, Q PV min-i is the lower limit of reactive power that can be output by the i-th photovoltaic inverter unit in the photovoltaic power station;

[0126] The lower limit value Q of reactive power that can be output by the energy storage system in the photovoltaic power station is determined by the following formula: ST-min :

[0127]

[0128] In the above formula, Q ST min-j is the lower limit of the reactive power that can be output by the j-th energy storage unit in the photovoltaic power station.

[0129] Furthermore, the reactive power required to be output by the photovoltaic inverter and the energy storage system is distributed to each photovoltaic inverter unit and each energy storage unit, including:

[0130] When the reactive power adjustment value of the photovoltaic power station Q a When it is greater than zero, the process of distributing the reactive power output by the photovoltaic inverter to each photovoltaic inverter unit includes:

[0131] Step 1: Initialize the preset reactive power output value of the PV inverter unit The number of dispatchable photovoltaic inverter units in a photovoltaic power station is B=N:

[0132] Step 2: Determine whether there is a photovoltaic inverter unit that meets the first constraint condition among the B photovoltaic inverter units. If so, set the reactive power output by the photovoltaic inverter unit that meets the first constraint condition to be equal to its respective maximum output reactive power; otherwise, set the reactive power output by the B photovoltaic inverter units to be equal to Q PV-a And end the operation;

[0133] Step 3: Update the preset reactive power output value of the photovoltaic inverter unit The number of dispatchable photovoltaic inverter units in the photovoltaic power station B=BF, and return to step 2;

[0134] Among them, the first constraint condition is: Q PV-a >Q PV max-i ;Q PV max-i is the upper limit of reactive power that can be output by the i-th photovoltaic inverter unit in the photovoltaic power station; QCPVmax-z is the maximum reactive power that can be output by the z-th photovoltaic inverter unit that meets the first constraint condition; F is the number of photovoltaic inverter units that meet the first constraint condition;

[0135] The process of distributing the reactive power output by the energy storage system to each energy storage unit includes:

[0136] Step 4: Initialize the preset reactive power output value of the energy storage unit The number of dispatchable energy storage units in a photovoltaic power station is L=M:

[0137] Step 5: Determine whether there is an energy storage unit that meets the second constraint condition among the L energy storage units. If so, set the reactive power output by the energy storage unit that meets the second constraint condition to be equal to its respective maximum output reactive power; otherwise, set the reactive power output by the L energy storage units to be equal to Q ST-a And end the operation;

[0138] Step 6: Update the preset reactive power output value of the energy storage unit The number of dispatchable energy storage units in the photovoltaic power station L=LH, and return to step 2;

[0139] Among them, the second constraint condition is: Q ST-a >Q S Tmax-j ;Q ST max-j is the upper limit of reactive power that can be output by the j-th energy storage unit in the photovoltaic power station; Q CSTmax-C is the maximum reactive power that can be output by the c-th energy storage unit that meets the second constraint; H is the number of energy storage units that meet the second constraint;

[0140] When the reactive power adjustment value of the photovoltaic power station Q a When the reactive power output by the photovoltaic inverter is less than zero, the process of distributing the reactive power output by the photovoltaic inverter to each photovoltaic inverter unit includes:

[0141] Step 7: Initialize the preset reactive power output value of the PV inverter unit The number of dispatchable photovoltaic inverter units in a photovoltaic power station is B=N:

[0142] Step 8: Determine whether there is a photovoltaic inverter unit that meets the third constraint condition among the B photovoltaic inverter units. If so, set the reactive power output by the photovoltaic inverter unit that meets the third constraint condition to be equal to the negative value of its respective minimum output reactive power; otherwise, set the reactive power output by the B photovoltaic inverter units to be equal to Q PV-a And end the operation;

[0143] Step 9: Update the preset reactive power output value of the photovoltaic inverter unit The number of dispatchable photovoltaic inverter units in the photovoltaic power station B=BG, and return to step 2;

[0144] The third constraint condition is: PV-a |>Q PV min-i ;Q PV min-i is the lower limit of reactive power that can be output by the i-th photovoltaic inverter unit in the photovoltaic power station; Q CPV min-s is the minimum reactive power output by the s-th photovoltaic inverter unit that meets the third constraint; G is the number of photovoltaic inverter units that meet the second constraint;

[0145] The process of distributing the reactive power output by the energy storage system to each energy storage unit includes:

[0146] Step 10: Initialize the preset reactive power output value of the energy storage unit The number of dispatchable energy storage units in a photovoltaic power station is L=M:

[0147] Step 11: Determine whether there is an energy storage unit that meets the fourth constraint condition among the L energy storage units. If so, set the reactive power output by the energy storage unit that meets the fourth constraint condition to be equal to the negative value of its respective minimum output reactive power value; otherwise, set the reactive power output by the L energy storage units to be equal to Q ST-a And end the operation;

[0148] Step 12: Update the preset reactive power output value of the energy storage unit The number of dispatchable energy storage units in the photovoltaic power station L=LU, and return to step 2;

[0149] The fourth constraint condition is: ST-a |>Q ST min-j ;Q ST min-j is the lower limit of reactive power that can be output by the j-th energy storage unit in the photovoltaic power station; Q CST min-v is the minimum reactive power that can be output by the vth energy storage unit that meets the fourth constraint; U is the number of energy storage units that meet the fourth constraint.

[0150] The present invention also provides a photovoltaic power station reactive power control device, such as Figure 2 As shown, the device includes:

[0151] Determination module: used to determine the reactive power adjustment value of the photovoltaic power station according to the reactive power adjustment instruction received by the photovoltaic power station;

[0152] The regulating module is used to regulate the reactive power output by each photovoltaic inverter unit and each energy storage unit in the photovoltaic power station according to the reactive power regulation value of the photovoltaic power station.

[0153] Specifically, the determining module is used to:

[0154] The reactive power regulation value Q of the photovoltaic power station is determined as follows: a :

[0155] Q a =Q g -Q c

[0156] In the above formula, Q g is the reactive power target value in the reactive power regulation instruction of the photovoltaic power station; Q c The current value of reactive power collected by the photovoltaic power station.

[0157] Specifically, the adjustment module includes:

[0158] Adjustment unit: used for calculating the reactive power that the photovoltaic inverter and the energy storage system need to output respectively according to the reactive power adjustment value of the photovoltaic power station;

[0159] Distribution unit: used to distribute the reactive power required to be output by the photovoltaic inverter and the energy storage system to each photovoltaic inverter unit and each energy storage unit.

[0160] In the optimal embodiment of the present invention, priority is given to adjusting the reactive capacity of the photovoltaic inverter, and when necessary, it is adjusted simultaneously with the energy storage system.

[0161] Furthermore, the adjustment unit is used to:

[0162] When the reactive power adjustment value of the photovoltaic power station Q a When the reactive power adjustment value Q of the photovoltaic power station is greater than zero, a Less than the upper limit of the reactive power output of the photovoltaic inverter Q PV-max , then let the reactive power value Q output by the photovoltaic inverter be PV Equal to the reactive power regulation value Q of the photovoltaic power station a , the reactive power value Q output by the energy storage system ST Equal to zero; if the photovoltaic power station reactive power adjustment value Q a Greater than the upper limit of the reactive power output of the photovoltaic inverter Q PV-max And it is less than the upper limit of the reactive power output of the energy storage system Q ST-max The upper limit of reactive power output by the photovoltaic inverter Q PV-max The sum of the photovoltaic inverter output reactive power value Q PV Equal to the upper limit of the reactive power output of the photovoltaic inverter Q PV-max , the energy storage system outputs reactive power value Q ST Equal to the reactive power regulation value Q of the photovoltaic power station a The reactive power value Q output by the photovoltaic inverter PVIf the reactive power adjustment value of the photovoltaic power station Q a Greater than the upper limit of the reactive power output of the photovoltaic inverter Q PV-max The upper limit of reactive power output of energy storage system Q ST-max The sum of the photovoltaic inverter output reactive power value Q PV Equal to the upper limit of the reactive power output of the photovoltaic inverter Q PV-max , the energy storage system outputs reactive power value Q ST-Σ Equal to the upper limit of reactive power output of the energy storage system Q ST-max ;

[0163] When the reactive power adjustment value of the photovoltaic power station Q a When the reactive power adjustment value Q of the photovoltaic power station is less than zero, a The absolute value of is less than the lower limit of the reactive power output of the photovoltaic inverter Q PV-min , then the photovoltaic inverter outputs a reactive power value Q PV Equal to the reactive power regulation value Q of the photovoltaic power station a , the energy storage system outputs reactive power value Q ST Equal to zero; if the photovoltaic power station reactive power adjustment value Q a The absolute value of is greater than the lower limit of the reactive power output of the photovoltaic inverter Q PV-min And it is less than the lower limit of the reactive power output of the photovoltaic inverter Q PV-min and the lower limit value Q of reactive power output of energy storage system ST-min The sum of the photovoltaic inverter output reactive power value Q PV Equal to the negative lower limit of the PV inverter output reactive power Q PV-min , the energy storage system outputs reactive power value Q ST Equal to the negative reactive power regulation value Q of the photovoltaic power station a The reactive power value Q output by the photovoltaic inverter PV If the reactive power adjustment value of the photovoltaic power station Q a The absolute value of is greater than the lower limit of the reactive power output of the photovoltaic inverter Q PV-min The lower limit value of reactive power output by the energy storage system Q ST-min The sum of the photovoltaic inverter output reactive power value Q PV Equal to the negative lower limit of the PV inverter output reactive power Q PV-min , the energy storage system outputs reactive power value Q ST Equal to the negative lower limit of reactive power output of the energy storage system Q ST-min .

[0164] Furthermore, the upper limit value Q of reactive power that can be output by the photovoltaic inverter in the photovoltaic power station is determined as follows: PV-max :

[0165]

[0166] In the above formula, Q PVmax-i is the upper limit of reactive power that can be output by the i-th photovoltaic inverter unit in the photovoltaic power station; ΔQ M The reactive power loss value of the main transformer; ΔQ V is the reactive power loss value of the photovoltaic box transformer; ΔQ L is the reactive power loss value of the photovoltaic collection line; N is the total number of photovoltaic inverter units in the photovoltaic power station;

[0167] The upper limit value Q of reactive power that can be output by the energy storage system in the photovoltaic power station is determined by the following formula: ST-max ;

[0168]

[0169] In the above formula, Q STmax-j is the upper limit of reactive power that can be output by the j-th energy storage unit in the photovoltaic power station; ΔQ S is the reactive power loss value of the energy storage box; ΔQ SL is the reactive loss value of the energy storage collection line; M is the total number of energy storage units in the photovoltaic power station;

[0170] The lower limit value Q of reactive power that can be output by the photovoltaic inverter in the photovoltaic power station is determined by the following formula: PV-min :

[0171]

[0172] In the above formula, Q PVmin-i is the lower limit of reactive power that can be output by the i-th photovoltaic inverter unit in the photovoltaic power station;

[0173] The lower limit value Q of reactive power that can be output by the energy storage system in the photovoltaic power station is determined by the following formula: ST-min :

[0174]

[0175] In the above formula, Q STmin-j is the lower limit of the reactive power that can be output by the j-th energy storage unit in the photovoltaic power station.

[0176] Furthermore, the allocation unit is used to:

[0177] When the reactive power adjustment value of the photovoltaic power station Q a When it is greater than zero, the process of distributing the reactive power output by the photovoltaic inverter to each photovoltaic inverter unit includes:

[0178] Step 1: Initialize the preset reactive power output value of the PV inverter unit The number of dispatchable photovoltaic inverter units in a photovoltaic power station is B=N:

[0179] Step 2: Determine whether there is a photovoltaic inverter unit that meets the first constraint condition among the B photovoltaic inverter units. If so, set the reactive power output by the photovoltaic inverter unit that meets the first constraint condition to be equal to its respective maximum output reactive power; otherwise, set the reactive power output by the B photovoltaic inverter units to be equal to Q PV-a And end the operation;

[0180] Step 3: Update the preset reactive power output value of the photovoltaic inverter unit The number of dispatchable photovoltaic inverter units in the photovoltaic power station B=BF, and return to step 2;

[0181] Among them, the first constraint condition is: Q PV-a >Q PV max-i ;Q PV max-i is the upper limit of reactive power that can be output by the i-th photovoltaic inverter unit in the photovoltaic power station; Q CPVmax-z is the maximum reactive power that can be output by the z-th photovoltaic inverter unit that meets the first constraint condition; F is the number of photovoltaic inverter units that meet the first constraint condition;

[0182] The process of distributing the reactive power output by the energy storage system to each energy storage unit includes:

[0183] Step 4: Initialize the preset reactive power output value of the energy storage unit The number of dispatchable energy storage units in a photovoltaic power station is L=M:

[0184] Step 5: Determine whether there is an energy storage unit that meets the second constraint condition among the L energy storage units. If so, set the reactive power output by the energy storage unit that meets the second constraint condition to be equal to its respective maximum output reactive power; otherwise, set the reactive power output by the L energy storage units to be equal to Q ST-a And end the operation;

[0185] Step 6: Update the preset reactive power output value of the energy storage unit The number of dispatchable energy storage units in the photovoltaic power station L=LH, and return to step 2;

[0186] Among them, the second constraint condition is: Q ST-a >Q ST max-j ;Q ST max-j is the upper limit of reactive power that can be output by the j-th energy storage unit in the photovoltaic power station; Q CSTmax-C is the maximum reactive power that can be output by the c-th energy storage unit that meets the second constraint; H is the number of energy storage units that meet the second constraint;

[0187] When the reactive power adjustment value of the photovoltaic power station Q a When the reactive power output by the photovoltaic inverter is less than zero, the process of distributing the reactive power output by the photovoltaic inverter to each photovoltaic inverter unit includes:

[0188] Step 7: Initialize the preset reactive power output value of the PV inverter unit The number of dispatchable photovoltaic inverter units in a photovoltaic power station is B=N:

[0189] Step 8: Determine whether there is a photovoltaic inverter unit that meets the third constraint condition among the B photovoltaic inverter units. If so, set the reactive power output by the photovoltaic inverter unit that meets the third constraint condition to be equal to the negative value of its respective minimum output reactive power; otherwise, set the reactive power output by the B photovoltaic inverter units to be equal to Q PV-a And end the operation;

[0190] Step 9: Update the preset reactive power output value of the photovoltaic inverter unit The number of dispatchable photovoltaic inverter units in the photovoltaic power station B=BG, and return to step 2;

[0191] The third constraint condition is: PV-a |>Q PV min-i ;Q PV min-i is the lower limit of reactive power that can be output by the i-th photovoltaic inverter unit in the photovoltaic power station; Q CPV min-s is the minimum reactive power output by the s-th photovoltaic inverter unit that meets the third constraint; G is the number of photovoltaic inverter units that meet the second constraint;

[0192] The process of distributing the reactive power output by the energy storage system to each energy storage unit includes:

[0193] Step 10: Initialize the preset reactive power output value of the energy storage unit The number of dispatchable energy storage units in a photovoltaic power station is L=M:

[0194] Step 11: Determine whether there is an energy storage unit that meets the fourth constraint condition among the L energy storage units. If so, set the reactive power output by the energy storage unit that meets the fourth constraint condition to be equal to the negative value of its respective minimum output reactive power value; otherwise, set the reactive power output by the L energy storage units to be equal to Q ST-a And end the operation;

[0195] Step 12: Update the preset reactive power output value of the energy storage unit The number of dispatchable energy storage units in the photovoltaic power station L=LU, and return to step 2;

[0196] The fourth constraint condition is: ST-a|>Q ST min-j ;Q ST min-j is the lower limit of reactive power that can be output by the j-th energy storage unit in the photovoltaic power station; Q CST min-v is the minimum reactive power that can be output by the vth energy storage unit that meets the fourth constraint; U is the number of energy storage units that meet the fourth constraint.

[0197] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0198] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, 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 device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0199] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0200] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0201] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A method for controlling reactive power of a photovoltaic power station, characterized in that: The method comprises: Determining a reactive power regulation value of the photovoltaic power station according to a reactive power regulation instruction received by the photovoltaic power station; Adjusting the reactive power output by each photovoltaic inverter unit and each energy storage unit in the photovoltaic power station according to the reactive power adjustment value of the photovoltaic power station; The step of adjusting the reactive power output by each photovoltaic inverter unit and each energy storage unit in the photovoltaic power station according to the reactive power adjustment value of the photovoltaic power station includes: Calculating the reactive power that the photovoltaic inverter and the energy storage system need to output respectively according to the reactive power adjustment value of the photovoltaic power station; Distributing the reactive power required to be output by the photovoltaic inverter and the energy storage system to each photovoltaic inverter unit and each energy storage unit; The step of calculating the reactive power that each of the photovoltaic inverter and the energy storage system needs to output according to the reactive power adjustment value of the photovoltaic power station includes: When the reactive power adjustment value of the photovoltaic power station When the reactive power adjustment value of the photovoltaic power station is greater than zero, Less than the upper limit of the reactive power output of the photovoltaic inverter , then let the reactive power value output by the photovoltaic inverter be Equal to the reactive power regulation value of the photovoltaic power station , the reactive power value output by the energy storage system Equal to zero; if the reactive power adjustment value of the photovoltaic power station Greater than the upper limit of the PV inverter output reactive power And it is less than the upper limit of the reactive power output of the energy storage system The upper limit of reactive power output of photovoltaic inverter The sum of the PV inverter output reactive power is Equal to the upper limit of the reactive power output of the photovoltaic inverter , the energy storage system outputs reactive power value Equal to the reactive power regulation value of the photovoltaic power station and the reactive power value output by the photovoltaic inverter If the reactive power adjustment value of the photovoltaic power station Greater than the upper limit of the PV inverter output reactive power The upper limit of reactive power output of the energy storage system The sum of the PV inverter output reactive power is Equal to the upper limit of the reactive power output of the photovoltaic inverter , the energy storage system outputs reactive power value Equal to the upper limit of the reactive power output of the energy storage system ; When the reactive power adjustment value of the photovoltaic power station When the reactive power adjustment value of the photovoltaic power station is less than zero, The absolute value of the reactive power output by the photovoltaic inverter is less than the lower limit of the reactive power output by the photovoltaic inverter. , then the photovoltaic inverter outputs reactive power value Equal to the reactive power regulation value of the photovoltaic power station , the energy storage system outputs reactive power value Equal to zero; if the reactive power adjustment value of the photovoltaic power station The absolute value of the reactive power output by the photovoltaic inverter is greater than the lower limit of the reactive power output by the photovoltaic inverter And less than the lower limit of the reactive power output of the photovoltaic inverter The lower limit of reactive power output of the energy storage system The sum of the PV inverter output reactive power is Equal to the negative lower limit of the reactive power output of the photovoltaic inverter , the energy storage system outputs reactive power value Equal to the negative reactive power regulation value of the photovoltaic power station and the reactive power value output by the photovoltaic inverter If the reactive power adjustment value of the photovoltaic power station The absolute value of the reactive power output by the photovoltaic inverter is greater than the lower limit of the reactive power output by the photovoltaic inverter The lower limit of reactive power output of the energy storage system The sum of the PV inverter output reactive power is Equal to the negative lower limit of the reactive power output of the photovoltaic inverter , the energy storage system outputs reactive power value Equal to the negative lower limit of the reactive power output of the energy storage system ; The step of distributing the reactive power required to be output by the photovoltaic inverter and the energy storage system to each photovoltaic inverter unit and each energy storage unit includes: When the reactive power adjustment value of the photovoltaic power station When it is greater than zero, the process of distributing the reactive power output by the photovoltaic inverter to each photovoltaic inverter unit includes: Step 1: Initialize the preset reactive power output value of the PV inverter unit , the number of dispatchable photovoltaic inverter units in the photovoltaic power station : Step 2: Judgment Is there a photovoltaic inverter unit that meets the first constraint condition among the photovoltaic inverter units? If so, let the reactive power output by the photovoltaic inverter unit that meets the first constraint condition be equal to the maximum reactive power that can be output by each of them; otherwise, let The reactive power output by each photovoltaic inverter unit is equal to And end the operation; Step 3: Update the preset reactive power output value of the photovoltaic inverter unit , the number of dispatchable photovoltaic inverter units in the photovoltaic power station , and return to step 2; The first constraint condition is: ; For photovoltaic power station The upper limit of reactive power that can be output by each photovoltaic inverter unit; To meet the first constraint The maximum reactive power that can be output by each photovoltaic inverter unit; is the number of photovoltaic inverter units that meet the first constraint; The process of distributing the reactive power output by the energy storage system to each energy storage unit includes: Step 4: Initialize the preset reactive power output value of the energy storage unit ; Number of dispatchable energy storage units in a photovoltaic power station : Step 5: Judgement Is there an energy storage unit that meets the second constraint condition among the energy storage units? If so, let the reactive power output by the energy storage unit that meets the second constraint condition be equal to the maximum reactive power that can be output by each of them; otherwise, let The reactive power output by each energy storage unit is equal to And end the operation; Step 6: Update the preset reactive power output value of the energy storage unit , the number of dispatchable energy storage units in the photovoltaic power station , and return to step 2; The second constraint condition is: ; For photovoltaic power station The upper limit of reactive power that can be output by each energy storage unit; To meet the second constraint The maximum reactive power that can be output by each energy storage unit; is the number of energy storage units that meet the second constraint; When the reactive power adjustment value of the photovoltaic power station When the reactive power output by the photovoltaic inverter is less than zero, the process of distributing the reactive power output by the photovoltaic inverter to each photovoltaic inverter unit includes: Step 7: Initialize the preset reactive power output value of the PV inverter unit ; Number of dispatchable photovoltaic inverter units in a photovoltaic power station : Step 8: Judgement Is there a photovoltaic inverter unit that meets the third constraint condition among the photovoltaic inverter units? If so, let the reactive power output by the photovoltaic inverter unit that meets the third constraint condition be equal to the negative value of its respective minimum output reactive power value; otherwise, let The reactive power output by each photovoltaic inverter unit is equal to And end the operation; Step 9: Update the preset reactive power output value of the photovoltaic inverter unit , the number of dispatchable photovoltaic inverter units in the photovoltaic power station , and return to step 2; The third constraint condition is: ; For photovoltaic power station The lower limit of reactive power that can be output by each photovoltaic inverter unit; To meet the third constraint The minimum reactive power that can be output by each photovoltaic inverter unit; is the number of PV inverter units that meet the second constraint; The process of distributing the reactive power output by the energy storage system to each energy storage unit includes: Step 10: Initialize the preset reactive power output value of the energy storage unit ; Number of dispatchable energy storage units in a photovoltaic power station : Step 11: Judgement Is there an energy storage unit that meets the fourth constraint condition among the energy storage units? If so, let the reactive power output by the energy storage unit that meets the fourth constraint condition be equal to the negative value of its respective minimum reactive power output value; otherwise, let The reactive power output by each energy storage unit is equal to And end the operation; Step 12: Update the preset reactive power output value of the energy storage unit , the number of dispatchable energy storage units in the photovoltaic power station , and return to step 2; The fourth constraint condition is: ; For photovoltaic power station The lower limit of reactive power that can be output by each energy storage unit; To meet the fourth constraint The minimum reactive power that can be output by each energy storage unit; is the number of energy storage units that meet the fourth constraint.

2. The method according to claim 1, wherein The determining of the reactive power adjustment value of the photovoltaic power station according to the reactive power adjustment instruction received by the photovoltaic power station includes: Determine the reactive power regulation value of the photovoltaic power station as follows: : In the above formula, The reactive power target value in the reactive power regulation instruction of the photovoltaic power station; The current value of reactive power collected by the photovoltaic power station.

3. The method according to claim 1, wherein The upper limit of reactive power output by the photovoltaic inverter in the photovoltaic power station is determined by the following formula: : In the above formula, For photovoltaic power station The upper limit of reactive power that can be output by each photovoltaic inverter unit; is the reactive loss value of the main transformer; is the reactive power loss value of the PV box transformer; is the reactive loss value of the photovoltaic collection line; is the total number of PV inverter units in the PV power station; The upper limit of reactive power output by the energy storage system in the photovoltaic power station is determined by the following formula: ; In the above formula, For photovoltaic power station The upper limit of reactive power that can be output by each energy storage unit; is the reactive power loss value of the energy storage box; is the reactive power loss value of the energy storage collection line; is the total number of energy storage units in the PV power station; The lower limit of reactive power output by the photovoltaic inverter in the photovoltaic power station is determined by the following formula: : In the above formula, For photovoltaic power station The lower limit of reactive power that can be output by each photovoltaic inverter unit; The lower limit of reactive power output by the energy storage system in the photovoltaic power station is determined by the following formula: : In the above formula, For photovoltaic power station The lower limit of reactive power that can be output by an energy storage unit.

4. A reactive power control device for a photovoltaic power station, characterized in that: The device comprises: Determination module: used to determine the reactive power adjustment value of the photovoltaic power station according to the reactive power adjustment instruction received by the photovoltaic power station; Regulation module: used for regulating the reactive power output by each photovoltaic inverter unit and each energy storage unit in the photovoltaic power station according to the reactive power regulation value of the photovoltaic power station; The adjustment module includes: Adjustment unit: used for calculating the reactive power that the photovoltaic inverter and the energy storage system need to output respectively according to the reactive power adjustment value of the photovoltaic power station; Distribution unit: used to distribute the reactive power required to be output by the photovoltaic inverter and the energy storage system to each photovoltaic inverter unit and each energy storage unit; The regulating unit is used for: When the reactive power adjustment value of the photovoltaic power station When the reactive power adjustment value of the photovoltaic power station is greater than zero, Less than the upper limit of the reactive power output of the photovoltaic inverter , then let the reactive power value output by the photovoltaic inverter be Equal to the reactive power regulation value of the photovoltaic power station , the reactive power value output by the energy storage system Equal to zero; if the reactive power adjustment value of the photovoltaic power station Greater than the upper limit of the PV inverter output reactive power And it is less than the upper limit of the reactive power output of the energy storage system The upper limit of reactive power output of photovoltaic inverter The sum of the PV inverter output reactive power is Equal to the upper limit of the reactive power output of the photovoltaic inverter , the energy storage system outputs reactive power value Equal to the reactive power regulation value of the photovoltaic power station and the reactive power value output by the photovoltaic inverter If the reactive power adjustment value of the photovoltaic power station Greater than the upper limit of the PV inverter output reactive power The upper limit of reactive power output of the energy storage system The sum of the PV inverter output reactive power is Equal to the upper limit of the reactive power output of the photovoltaic inverter , the energy storage system outputs reactive power value Equal to the upper limit of the reactive power output of the energy storage system ; When the reactive power adjustment value of the photovoltaic power station When the reactive power adjustment value of the photovoltaic power station is less than zero, The absolute value of the reactive power output by the photovoltaic inverter is less than the lower limit of the reactive power output by the photovoltaic inverter. , then the photovoltaic inverter outputs reactive power value Equal to the reactive power regulation value of the photovoltaic power station , the energy storage system outputs reactive power value Equal to zero; if the reactive power adjustment value of the photovoltaic power station The absolute value of the reactive power output by the photovoltaic inverter is greater than the lower limit of the reactive power output by the photovoltaic inverter And less than the lower limit of the reactive power output of the photovoltaic inverter The lower limit of reactive power output of the energy storage system The sum of the PV inverter output reactive power is Equal to the negative lower limit of the reactive power output of the photovoltaic inverter , the energy storage system outputs reactive power value Equal to the negative reactive power regulation value of the photovoltaic power station and the reactive power value output by the photovoltaic inverter If the reactive power adjustment value of the photovoltaic power station The absolute value of the reactive power output by the photovoltaic inverter is greater than the lower limit of the reactive power output by the photovoltaic inverter The lower limit of reactive power output of the energy storage system The sum of the PV inverter output reactive power is Equal to the negative lower limit of the reactive power output of the photovoltaic inverter , the energy storage system outputs reactive power value Equal to the negative lower limit of the reactive power output of the energy storage system ; The distribution unit is used to: When the reactive power adjustment value of the photovoltaic power station When it is greater than zero, the process of distributing the reactive power output by the photovoltaic inverter to each photovoltaic inverter unit includes: Step 1: Initialize the preset reactive power output value of the PV inverter unit , the number of dispatchable photovoltaic inverter units in the photovoltaic power station : Step 2: Judgment Is there a photovoltaic inverter unit that meets the first constraint condition among the photovoltaic inverter units? If so, let the reactive power output by the photovoltaic inverter unit that meets the first constraint condition be equal to the maximum reactive power that can be output by each of them; otherwise, let The reactive power output by each photovoltaic inverter unit is equal to And end the operation; Step 3: Update the preset reactive power output value of the photovoltaic inverter unit , the number of dispatchable photovoltaic inverter units in the photovoltaic power station , and return to step 2; The first constraint condition is: ; For photovoltaic power station The upper limit of reactive power that can be output by each photovoltaic inverter unit; To meet the first constraint The maximum reactive power that can be output by each photovoltaic inverter unit; is the number of photovoltaic inverter units that meet the first constraint; The process of distributing the reactive power output by the energy storage system to each energy storage unit includes: Step 4: Initialize the preset reactive power output value of the energy storage unit ; Number of dispatchable energy storage units in a photovoltaic power station : Step 5: Judgement Is there an energy storage unit that meets the second constraint condition among the energy storage units? If so, let the reactive power output by the energy storage unit that meets the second constraint condition be equal to the maximum reactive power that can be output by each of them; otherwise, let The reactive power output by each energy storage unit is equal to And end the operation; Step 6: Update the preset reactive power output value of the energy storage unit , the number of dispatchable energy storage units in the photovoltaic power station , and return to step 2; The second constraint condition is: ; For photovoltaic power station The upper limit of reactive power that can be output by each energy storage unit; To meet the second constraint The maximum reactive power that can be output by each energy storage unit; is the number of energy storage units that meet the second constraint; When the reactive power adjustment value of the photovoltaic power station When the reactive power output by the photovoltaic inverter is less than zero, the process of distributing the reactive power output by the photovoltaic inverter to each photovoltaic inverter unit includes: Step 7: Initialize the preset reactive power output value of the PV inverter unit ; Number of dispatchable photovoltaic inverter units in a photovoltaic power station : Step 8: Judgement Is there a photovoltaic inverter unit that meets the third constraint condition among the photovoltaic inverter units? If so, let the reactive power output by the photovoltaic inverter unit that meets the third constraint condition be equal to the negative value of its respective minimum output reactive power value; otherwise, let The reactive power output by each photovoltaic inverter unit is equal to And end the operation; Step 9: Update the preset reactive power output value of the photovoltaic inverter unit , the number of dispatchable photovoltaic inverter units in the photovoltaic power station , and return to step 2; The third constraint condition is: ; For photovoltaic power station The lower limit of reactive power that can be output by each photovoltaic inverter unit; To meet the third constraint The minimum reactive power that can be output by each photovoltaic inverter unit; is the number of PV inverter units that meet the second constraint; The process of distributing the reactive power output by the energy storage system to each energy storage unit includes: Step 10: Initialize the preset reactive power output value of the energy storage unit ; Number of dispatchable energy storage units in a photovoltaic power station : Step 11: Judgement Is there an energy storage unit that meets the fourth constraint condition among the energy storage units? If so, let the reactive power output by the energy storage unit that meets the fourth constraint condition be equal to the negative value of its respective minimum reactive power output value; otherwise, let The reactive power output by each energy storage unit is equal to And end the operation; Step 12: Update the preset reactive power output value of the energy storage unit , the number of dispatchable energy storage units in the photovoltaic power station , and return to step 2; The fourth constraint condition is: ; For photovoltaic power station The lower limit of reactive power that can be output by each energy storage unit; To meet the fourth constraint The minimum reactive power that can be output by each energy storage unit; is the number of energy storage units that meet the fourth constraint.

5. The device according to claim 4, characterized in that The determining module is configured to: Determine the reactive power regulation value of the photovoltaic power station as follows: : In the above formula, The reactive power target value in the reactive power regulation instruction of the photovoltaic power station; The current value of reactive power collected by the photovoltaic power station.

6. The device according to claim 4, characterized in that The upper limit of reactive power output by the photovoltaic inverter in the photovoltaic power station is determined by the following formula: : In the above formula, For photovoltaic power station The upper limit of reactive power that can be output by each photovoltaic inverter unit; is the reactive loss value of the main transformer; is the reactive power loss value of the PV box transformer; is the reactive loss value of the photovoltaic collection line; is the total number of PV inverter units in the PV power station; The upper limit of reactive power output by the energy storage system in the photovoltaic power station is determined by the following formula: ; In the above formula, For photovoltaic power station The upper limit of reactive power that can be output by each energy storage unit; is the reactive power loss value of the energy storage box; is the reactive power loss value of the energy storage collection line; is the total number of energy storage units in the PV power station; The lower limit of reactive power output by the photovoltaic inverter in the photovoltaic power station is determined by the following formula: : In the above formula, For photovoltaic power station The lower limit of reactive power that can be output by each photovoltaic inverter unit; The lower limit of reactive power output by the energy storage system in the photovoltaic power station is determined by the following formula: : In the above formula, For photovoltaic power station The lower limit of reactive power that can be output by an energy storage unit.

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