Wind-solar-storage combined operation system and control method thereof

Abstract

The invention relates to a wind-solar-energy-storage combined operation system and a control method thereof, the wind-solar-energy-storage combined operation system comprises two layers of architectures, the first layer of architecture comprises an in-situ EMS which is an in-situ EMS configured in a wind-solar-energy-storage same-field power station and is used for receiving an instruction issued by a station control level AGC / AVC host or fast frequency modulation and completing wind-solar-energy-storage total power control in situ; and the second-layer architecture comprises a photovoltaic inverter, a fan converter and an energy storage converter, and is used for receiving an instruction issued by the in-situ EMS and achieving self-coordination control of total output by adjusting output modes of a photovoltaic system, an energy storage system and a wind power system. According to the method, the in-situ EMS is configured in the field of the wind-solar-storage same-field power station, the response time of the wind-solar-storage same-field system can be greatly shortened through operation of the in-situ EMS, the response speed of the system is increased, and meanwhile the operation reliability and stability of the wind-solar-storage same-field power station are improved.

Description

Technical Field

[0001] The present invention belongs to the field of photovoltaic technology, and in particular relates to a wind-solar-storage combined operation system and a control method thereof. Background Art

[0002] As for the utilization of renewable energy, photovoltaic and wind power are the most mature technologies and are also regarded as the most promising renewable energy utilization technologies in the future. Both wind energy resources and light resources are intermittent and unstable. However, from a macro perspective, in some regions of the world, wind energy resources and light resources have a relatively large consistency in geographical distribution. For example, my country's "Three North Regions" are both rich in wind energy resources and rich in solar energy resources, which are suitable for the construction of large-scale wind farms and photovoltaic power stations. In these areas, we can make full use of the geographical overlap and temporal complementarity of wind and solar energy to build wind-solar complementary power stations. On this basis, we can configure energy storage systems to make the overall output area of ​​the power station stable, and also reduce investment and improve efficiency.

[0003] The overall architecture of the traditional wind, solar and storage system is the station-level EMS (Energy Management System). System, energy management system) centrally manages photovoltaic system, wind power system and energy storage system, which consists of four layers of architecture. The first layer is the station control level EMS, which receives the instructions issued by the dispatching AGC / AVC host and completes the control of the photovoltaic, wind power and energy storage systems of the whole station; the second layer is the photovoltaic power generation unit host, wind power generation unit host and energy storage unit host, which receive the instructions issued by the station control level EMS and complete the instruction distribution and issuance of the local photovoltaic communication control unit and wind power communication control unit; the third layer is the local photovoltaic communication control unit, wind power communication control unit and energy storage communication control unit, which receive the instructions issued by the photovoltaic power generation unit host, wind power generation unit and energy storage unit respectively, and complete the instruction distribution and issuance of photovoltaic inverter, wind turbine converter and energy storage converter; the fourth layer is the photovoltaic inverter, wind turbine converter and energy storage converter, which receive the instructions issued by the photovoltaic power generation unit host, wind power generation unit and energy storage unit, and complete the output adjustment of photovoltaic inverter, wind turbine converter and energy storage converter, such as Figure 3 As shown in the figure, in the traditional wind, photovoltaic and energy storage system, the station-level EMS centrally manages the wind power system, photovoltaic system and energy storage system. According to the light power forecast, AGC / AVC system, wind power output, photovoltaic output, energy storage system charge status, etc., the station-level EMS sends instructions to the photovoltaic system, wind power system and energy storage system to control the overall output. There are many control logic links in the traditional control strategy, resulting in a long response time, which is not conducive to the reliable and stable operation of the power station. Summary of the invention

[0004] The purpose of the present invention is to provide a wind, solar and energy storage combined operation system and a control method thereof in order to solve the above problems.

[0005] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0006] A wind, solar and storage joint operation system includes a two-layer architecture. The first layer of the architecture includes an on-site EMS, which is an EMS configured on-site at a power station with wind, solar and storage, and is used to receive instructions issued by a station-level AGC / AVC host or a fast frequency modulation to complete the total power control of wind, solar and storage on-site;

[0007] The second layer architecture includes photovoltaic inverters, wind turbine converters and energy storage converters, which are used to receive instructions issued by the local EMS and achieve self-coordinated control of the total output by adjusting the output modes of the photovoltaic system, energy storage system and wind power system.

[0008] A wind, photovoltaic and energy storage combined operation system also includes a communication control unit, which includes the local EMS and a data acquisition device. The data acquisition device, the photovoltaic inverter, the wind turbine converter and the energy storage converter are all communicatively connected to the data acquisition device.

[0009] As a further optimization scheme of the present invention, the data acquisition device is connected to the station control level AGC / AVC host and the fast frequency modulation communication through the optical fiber ring network switch of the power station monitoring system interval layer.

[0010] As a further optimization solution of the present invention, the data acquisition device includes a PLC power carrier module, the photovoltaic inverter includes a plurality of string inverters, and the plurality of string inverters are all communicatively connected to the PLC power carrier module.

[0011] As a further optimization solution of the present invention, the data acquisition device is communicatively connected with the box-type transformer watt-hour meter and the box-type transformer measurement and control device.

[0012] As a further optimization solution of the present invention, the station control-level AGC / AVC host and the fast frequency modulation have interlocking control, and the local EMS only receives instructions issued by one of them at any time.

[0013] A control method for a wind-solar-storage combined operation system, comprising:

[0014] Calculate the rated power P1 of the preset multiple of the box-type transformer and the command power P2 issued by the AGC / AVC host or fast frequency modulation of the local EMS receiving station control level, and take the minimum value of the two as the maximum grid connection point power Pmax of the subarray;

[0015] The power of the box-type transformer grid connection point collected in real time by the local EMS is Ppcc, and the charging power is Pcharge;

[0016] The charging or discharging of the energy storage system is controlled based on the numerical relationship between Ppcc and Pmax.

[0017] As a further optimization scheme of the present invention, controlling the charging or discharging of the energy storage system based on the numerical relationship between Ppcc and Pmax includes the following:

[0018] If Ppcc>Pmax, the energy storage system starts charging;

[0019] If Ppcc<Pmax, the energy storage system starts discharging, and the discharge power is Pdischarge.

[0020] As a further optimization solution of the present invention, if Ppcc>Pmax, the energy storage system starts charging including the following:

[0021] If the difference between the two is greater than the rated power Prate of the energy storage system, the energy storage system will charge according to the rated power and start to prioritize limiting the photovoltaic power until the power is zero; if the grid-connected power Ppcc of the box transformer is still greater than the maximum allowable grid-connected power Pmax of the subarray, the wind power will be limited so that the grid-connected power Ppcc of the box transformer is equal to the maximum allowable grid-connected power Pmax of the subarray;

[0022] If the battery is fully charged, the energy storage system charging power is 0, and the photovoltaic power is limited first until the power is zero; if the grid-connected power of the box transformer is still greater than the maximum allowable grid-connected power Pmax of the subarray, the wind power is limited so that the grid-connected power Ppcc is equal to the maximum allowable grid-connected power Pmax of the subarray;

[0023] If the difference between the two is less than the rated power of the energy storage system, the energy storage system will be charged according to the difference power, and the photovoltaic and wind power systems will not be limited.

[0024] As a further optimization scheme of the present invention, if Ppcc<Pmax, the energy storage system starts to discharge, and the discharge power is Pdischarge, including the following contents:

[0025] If the difference between the two is greater than the rated power Prate of the energy storage system, the energy storage system will discharge according to the rated power, and the photovoltaic and wind power systems will not be limited in power generation;

[0026] If the battery is in an empty state, the energy storage system discharge power is 0, and the photovoltaic and wind power systems are unlimited;

[0027] If the difference between the two is less than the rated power of the energy storage system, the energy storage system will discharge according to the difference power, and the photovoltaic and wind power systems will not be limited.

[0028] The beneficial effects of the present invention are:

[0029] The present invention configures a local EMS on site at the wind, solar and energy storage power station, collects information such as photovoltaic inverters, wind turbine converters, energy storage converters, wind, solar and energy storage supporting 35kV booster transformer measurement and control devices and electric meters, and the local EMS can directly receive instructions issued by the AGC / AVC system to adjust the output of the photovoltaic system and the energy storage system to achieve self-coordinated control of the total wind and solar output. The operation of the local EMS system can greatly reduce the response time of the wind, solar and energy storage system, improve the system response speed, and at the same time improve the reliability and stability of the wind, solar and energy storage power station. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic diagram of the system structure in an embodiment of the present invention;

[0031] Figure 2 is a flow chart of a control strategy of a wind-solar-storage combined operation system in an embodiment of the present invention;

[0032] Figure 3 This is the communication block diagram of the traditional wind, solar and storage system. DETAILED DESCRIPTION

[0033] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0034] like Figure 1 As shown in the figure, a wind, solar and energy storage joint operation system is composed of a two-layer architecture. The first layer is the local EMS, which receives the instructions issued by the station-level AGC / AVC host or fast frequency modulation, and completes the total power control of wind, solar and energy storage on site; the second layer is the photovoltaic inverter, wind turbine converter, and energy storage converter, which receive the instructions issued by the local EMS and achieve self-coordinated control of the total output by adjusting the output mode of the photovoltaic system, energy storage system, and wind power system.

[0035] The station-level AGC / AVC host and the fast frequency modulation have interlocking control, and the local EMS only receives instructions from one of them at any time.

[0036] The system also includes a communication control unit, which includes the local EMS and a data acquisition device. The data acquisition device, the photovoltaic inverter, the wind turbine converter and the energy storage converter are all communicatively connected to the data acquisition device.

[0037] The data acquisition device is connected to the station control-level AGC / AVC host and the fast frequency modulation communication through the power station monitoring system interval layer optical fiber ring network switch; the data acquisition device includes a PLC power carrier module, the photovoltaic inverter includes a plurality of string inverters, and the plurality of string inverters are all connected to the PLC power carrier module in communication; the data acquisition device is connected to the box-type transformer watt-hour meter and the box-type transformer measurement and control device in communication.

[0038] like Figure 2 As shown, the control method of the wind-solar-storage combined operation system includes:

[0039] (1) Calculate 1.1 times the rated power P1 of the box-type transformer and the command power P2 issued by the AGC / AVC host or fast frequency modulation of the local EMS receiving station control level, and take the minimum value of the two as the maximum grid-connected point power Pmax of the sub-array.

[0040] (2) The grid-connected power of the box-type transformer collected in real time by the local EMS is Ppcc, and the charging power is Pcharge.

[0041] 1) If Ppcc>Pmax, the energy storage system starts charging.

[0042] ① If the difference between the two is greater than the rated power Prate of the energy storage system, the energy storage system will charge according to the rated power and start to prioritize limiting the photovoltaic power until the power is zero. If the grid-connected power of the box transformer is still greater than the maximum allowable grid-connected power Pmax of the subarray, the wind power will be limited to make the grid-connected power Ppcc equal to the maximum allowable grid-connected power Pmax of the subarray;

[0043] ② If the battery is fully charged, the energy storage system charging power is 0, and the photovoltaic power is limited first until the power is zero. If the grid-connected power of the box transformer is still greater than the maximum allowable grid-connected power Pmax of the subarray, the wind power is limited so that the grid-connected power Ppcc is equal to the maximum allowable grid-connected power Pmax of the subarray.

[0044] ③ If the difference between the two is less than the rated power of the energy storage system, the energy storage system will be charged according to the difference power, and the photovoltaic and wind power systems will not be limited.

[0045] 2) If Ppcc<Pmax, the energy storage system starts to discharge, and the discharge power is Pdischarge.

[0046] ① If the difference between the two is greater than the rated power Prate of the energy storage system, the energy storage system will discharge according to the rated power, and the photovoltaic and wind power systems will not be limited;

[0047] ② If the battery is in an empty state, the energy storage system discharge power is 0, and the photovoltaic and wind power systems are unlimited;

[0048] ③ If the difference between the two is less than the rated power of the energy storage system, the energy storage system will discharge according to the difference power, and the photovoltaic and wind power systems will not be limited.

[0049] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A wind, solar and energy storage combined operation system, characterized in that: It includes two layers of architecture. The first layer includes the local EMS, which is the EMS configured on-site in the same power station as the wind, solar and storage. It is used to receive instructions issued by the station-level AGC / AVC host or fast frequency modulation to complete the total power control of wind, solar and storage on-site. The second layer architecture includes photovoltaic inverters, wind turbine converters and energy storage converters, which are used to receive instructions issued by the local EMS and achieve self-coordinated control of the total output by adjusting the output modes of the photovoltaic system, energy storage system and wind power system.

2. A wind-solar-storage combined operation system according to claim 1, characterized in that: It also includes a communication control unit, which includes the local EMS and a data acquisition device. The data acquisition device, the photovoltaic inverter, the wind turbine converter and the energy storage converter are all communicatively connected to the data acquisition device.

3. A wind, solar and energy storage combined operation system according to claim 2, characterized in that: The data acquisition device is connected to the station control level AGC / AVC host and the fast frequency modulation communication through the optical fiber ring network switch of the power station monitoring system interval layer.

4. A wind-solar-storage combined operation system according to claim 2, characterized in that: The data acquisition device includes a PLC power carrier module, the photovoltaic inverter includes a plurality of string inverters, and the plurality of string inverters are all communicatively connected to the PLC power carrier module.

5. The wind-solar-storage combined operation system according to claim 2, characterized in that: The data acquisition device is communicatively connected with the box-type transformer watt-hour meter and the box-type transformer measurement and control device.

6. The wind-solar-storage combined operation system according to claim 1, characterized in that: The station-level AGC / AVC host and the fast frequency modulation have interlocking control, and the local EMS only receives instructions from one of them at any time.

7. A control method for a wind-solar-storage combined operation system according to any one of claims 1 to 6, characterized in that: include: Calculate the rated power P1 of the preset multiple of the box-type transformer and the command power P2 issued by the AGC / AVC host or fast frequency modulation of the local EMS receiving station control level, and take the minimum value of the two as the maximum grid connection point power Pmax of the subarray; The power of the box-type transformer grid connection point collected in real time by the local EMS is Ppcc, and the charging power is Pcharge; The charging or discharging of the energy storage system is controlled based on the numerical relationship between Ppcc and Pmax.

8. The wind, solar and energy storage combined operation system according to claim 7, characterized in that: Controlling the charging or discharging of the energy storage system based on the numerical relationship between Ppcc and Pmax includes the following: If Ppcc>Pmax, the energy storage system starts charging; If Ppcc<Pmax, the energy storage system starts discharging, and the discharge power is Pdischarge.

9. A wind, solar and energy storage combined operation system according to claim 8, characterized in that: If Ppcc>Pmax, the energy storage system starts charging including the following: If the difference between the two is greater than the rated power Prate of the energy storage system, the energy storage system will charge according to the rated power and start to prioritize limiting the photovoltaic power until the power is zero; if the grid-connected power Ppcc of the box transformer is still greater than the maximum allowable grid-connected power Pmax of the subarray, the wind power will be limited so that the grid-connected power Ppcc of the box transformer is equal to the maximum allowable grid-connected power Pmax of the subarray; If the battery is fully charged, the energy storage system charging power is 0, and the photovoltaic power is limited first until the power is zero; if the grid-connected power of the box transformer is still greater than the maximum allowable grid-connected power Pmax of the subarray, the wind power is limited so that the grid-connected power Ppcc is equal to the maximum allowable grid-connected power Pmax of the subarray; If the difference between the two is less than the rated power of the energy storage system, the energy storage system will be charged according to the difference power, and the photovoltaic and wind power systems will not be limited.

10. The wind, solar and energy storage combined operation system according to claim 8, characterized in that: If Ppcc<Pmax, the energy storage system starts to discharge, and the discharge power is Pdischarge, which includes the following contents: If the difference between the two is greater than the rated power Prate of the energy storage system, the energy storage system will discharge according to the rated power, and the photovoltaic and wind power systems will not be limited in power generation; If the battery is in an empty state, the energy storage system discharge power is 0, and the photovoltaic and wind power systems are unlimited; If the difference between the two is less than the rated power of the energy storage system, the energy storage system will discharge according to the difference power, and the photovoltaic and wind power systems will not be limited.

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