Plug-and-play photovoltaic intelligent grid-connected adaptive controller and control method

Abstract

The invention relates to a plug-and-play photovoltaic intelligent grid-connected adaptive controller and a control method. The control method comprises the following steps: collecting reactive power, active power, voltage and current of a power distribution network through a power measurement module of the power distribution network; acquiring the output power of the photovoltaic power generation device and the energy storage device through a new energy power generation power measurement module; the main controller calculates the total network loss of the power distribution network and the voltage drop of each node of the power distribution network through the reactive power, the active power, the voltage and the current of the power distribution network; when the main controller monitors that the total network loss of the power distribution network and the voltage drop of each node of the power distribution network exceed preset values, a control instruction is issued to the reactive compensation switching control module according to a control strategy; and the reactive compensation switching control module controls a corresponding switching switch according to the control instruction, and the energy storage device, the photovoltaic power generation device or the reactive compensation device are connected to the power distribution network, so that the grid-connected stability of the photovoltaic power generation device is ensured, and energy supply in the power distribution network is better coordinated.

Description

Technical Field

[0001] The present application relates to the technical field of distributed photovoltaic grid-connected control, and more specifically, to a plug-and-play photovoltaic intelligent grid-connected adaptive controller and a control method. Background Art

[0002] When considering long-distance transmission of electric energy, due to the complex load types, the coexistence of backup reactive power compensation devices and photovoltaic power generation equipment, and the fact that conventional loads are mainly inductive loads, the reactive power of high-voltage transmission lines increases. Usually, in order to reduce the reactive power of transmission lines and reduce line losses, it is necessary to perform reactive power compensation on the electrical equipment connected to the transmission lines. The capacity of reactive power compensation devices is also increasing with the increase of loads. The increasing capacity of reactive power compensation not only increases equipment investment, but also the area occupied by compensation devices is also increasing. Since the power generated by photovoltaic power generation is active power, in order to give full play to the ability of photovoltaic power generation to compensate for reactive power and reduce the use of reactive power compensation devices, the present invention proposes a plug-and-play photovoltaic intelligent grid-connected adaptive controller and a control method thereof. The method can coordinate and control loads, reactive power compensation devices and photovoltaic power generation, so as to achieve the purpose of using photovoltaic power generation to adjust the reactive power of high-voltage transmission lines, improve remote voltage and reduce line losses.

[0003] Prior art, such as the Chinese patent number "CN116995732A", discloses a photovoltaic grid-connected control device with phase selection grid connection and power regulation functions, which includes a housing and an operating parameter acquisition module installed in the housing, a data processing and control module, a phase selection grid connection execution module, a communication module, a display screen module and a power management module. The present invention obtains operating parameters with high accuracy and is not affected by human factors, thereby greatly improving the accuracy of grid connection; it also ensures the accuracy of the test, meets the test requirements of multi-phase automatic switching, and has good applicability.

[0004] The problem with the above-mentioned prior art is that the control strategy of the device mainly revolves around operating parameter collection, data processing and logical judgment to achieve grid-connected phase conversion and power regulation, and the control strategy is relatively fixed; in a complex power grid environment, such as the presence of multiple distributed power sources and frequent changes in the grid structure, the former may be difficult to respond to various changes quickly and effectively to ensure the stable operation of the power grid due to the inflexible control strategy. Summary of the invention

[0005] In order to solve the above technical problems, the present invention proposes a plug-and-play photovoltaic intelligent grid-connected adaptive controller and a control method.

[0006] The technical solution of the present invention is as follows:

[0007] The present invention provides a control method for a plug-and-play photovoltaic intelligent grid-connected adaptive controller, comprising the following steps:

[0008] Step S1, collecting reactive power, active power, voltage and current of the distribution network through the distribution network power measurement module;

[0009] Step S2, collecting the output power of the photovoltaic power generation device and the energy storage device through the new energy power generation power measurement module;

[0010] Step S3, the main controller calculates the total network loss of the distribution network and the voltage drop of each node of the distribution network through the reactive power, active power, voltage and current of the distribution network;

[0011] Step S4: When the main controller detects that the total network loss of the distribution network and the voltage drop of each node of the distribution network exceed the preset value, the main controller sends a control instruction to the reactive power compensation switching control module according to the control strategy;

[0012] Step S5, the reactive compensation switching control module controls the corresponding photovoltaic end switching switch, energy storage end switching switch or reactive compensation device switching switch according to the control instruction, and connects the energy storage device, photovoltaic power generation device or reactive compensation device to the distribution network.

[0013] As a preferred implementation, in the step of collecting the output power of the photovoltaic power generation device by the new energy power measurement module, the main meteorological influencing factors are first determined by regression analysis and path analysis. The main meteorological influencing factors include solar irradiance, ambient temperature, relative humidity, and wind speed. Then, the predicted values ​​of the main meteorological influencing factors are obtained through weather forecast services, BP neural network models, and wind speed prediction models. Then, an associated data model is established to predict the output power of the photovoltaic power generation device and ensure the grid-connected stability of the photovoltaic power generation device. The associated data model is specifically as follows:

[0014] The main meteorological influencing factors and power generation data of the photovoltaic power generation device are collected in chronological order and stored in the associated data model data table. The structure of each data record in the associated data model data table is t, G, H, T, S, P, FLAG, where t is the data collection time, G is the solar irradiance, H is the relative humidity, T is the ambient temperature, S is the wind speed, P is the output power of the photovoltaic power generation device at time t, and FLAG is the flag bit;

[0015] Select the reference data at time t, the specific requirements are as follows:

[0016]

[0017] Where: ε G , ε H , ε T , ε S It is divided into deviation thresholds of solar irradiance, relative humidity, ambient temperature and wind speed at time t; G ref , Href 、T ref , S ref It is divided into reference values ​​of solar irradiance, relative humidity, ambient temperature and wind speed at different times t;

[0018] The collected data is cleaned, and the cleaning tolerance coefficient calculation formula is:

[0019]

[0020] Where: λ is the data cleaning tolerance coefficient; P is the output power of the photovoltaic power generation device at time t; P ref-avg The average output power of the photovoltaic power generation device during the effective cleaning time;

[0021] in:

[0022]

[0023] Where: P ref-i represents the output power data of the ith photovoltaic power generation device that meets the conditions, and N represents the total number of output power data of the photovoltaic power generation devices that meet the conditions.

[0024] As a preferred implementation, the total network loss of the distribution network is calculated by the following formula:

[0025]

[0026] Where: ΔP LOSS is the total network loss of the distribution network system; P xy , Q xy 、V x and R xy are respectively the active power at the head end, reactive power at the head end, voltage at the head end and branch resistance of the branch directly connected between the xth and yth nodes in the distribution network; Q y is the reactive power of node y; m is the number of nodes in the distribution network.

[0027] As a preferred implementation, the voltage drop of each node of the distribution network is calculated by the following formula:

[0028]

[0029] Where: dV is the voltage drop between nodes x and y; xy V is the branch reactance of the branch directly connected between the xth and yth nodes; x is the voltage at node x.

[0030] As a preferred implementation, the control instruction is sent to the reactive power compensation switching control module according to the control strategy, wherein the control strategy is as follows:

[0031] When the total network loss or voltage drop exceeds the preset value, the photovoltaic power generation device and the energy storage device have sufficient output power reserves. First, consider putting the photovoltaic power generation device into use, and use the active power output of the photovoltaic power generation device to adjust the reactive power, improve the voltage quality, and reduce network loss;

[0032] When the total network loss or voltage drop is still not lower than the preset value after the photovoltaic power generation device is connected, the energy storage device is connected to the distribution network to further provide active power support;

[0033] When the photovoltaic power generation device and the energy storage device are connected to the distribution network, if the total network loss or voltage drop is still not lower than the preset value, the reactive power compensation device will be connected to the distribution network to compensate for the power factor.

[0034] As a preferred implementation, the reactive power compensation device is a three-phase common compensation capacitor, the reactive power compensation device is connected to the vulnerable thyristor switching switch of the distribution network, and the thyristor switching switch control strategy is determined according to the single-channel capacitor compensation model. The specific steps are as follows:

[0035] According to the single-channel capacitor compensation model, the power equation is:

[0036] e s (t)=Re(Eejωt)=|E|cos(ωt+φ);

[0037] According to Kirchhoff's voltage law:

[0038]

[0039] Solve for the capacitor voltage v c (t) and the circuit current:

[0040] V c (t)=|V c |cos(ωt+φ);

[0041]

[0042] Where: i is the current in the single-channel capacitor compensation circuit, R is the equivalent resistance value in the circuit, e s (t) is the amplitude of the power supply voltage, ω is the angular frequency of the power supply voltage, E is the peak voltage, v c (t) is the capacitor terminal voltage, |V c | is the DC voltage component across the capacitor, i1 is the capacitor branch current;

[0043] According to the above formula, the three-phase common compensation capacitor and the power supply voltage are switched when they reach the same peak value, that is, the voltage zero point is detected by the circuit to trigger the thyristor switching switch to turn on.

[0044] As a preferred embodiment, the three-phase common compensation capacitor is connected to the distribution network to compensate the power factor. The power factor is determined by the current value reduced by the reactive component of the total current. The current value reduced by the reactive component of the total current is calculated as follows:

[0045]

[0046] In the formula, I c The current value reduced by the reactive component of the total current; is the current flowing through the inductor I L The reactive current component of: is the line reactive current.

[0047] On the other hand, the present invention also provides a plug-and-play photovoltaic intelligent grid-connected adaptive controller, including: a new energy power generation power measurement module, a main controller, a distribution network power measurement module, a reactive power compensation switching control module, and a reactive power compensation device;

[0048] The output end of the new energy power generation power measurement module is connected to the input end of the main controller, and the input end of the new energy power generation power measurement module is connected to the photovoltaic power generation device and the energy storage device; it is used to measure the output power of the photovoltaic power generation device and the energy storage device;

[0049] The input end of the main controller is connected to the output end of the energy storage device and the photovoltaic power generation device respectively, and the output end of the main controller is connected to the power distribution network; it is used to receive data collected by the new energy power generation power measurement module and the power grid power measurement module, and send control instructions to the device or module corresponding to the reactive power compensation switching control module according to the collected data and control strategy;

[0050] The input end of the power distribution network measurement module is connected to the output end of the main controller, and the output end of the power distribution network measurement module is connected to the input end of the main controller; it is used to collect reactive power, active power, voltage and current of the distribution network;

[0051] The reactive power compensation switching control module input end is connected to the main controller output end, and the reactive power compensation switching control module output end is connected to the reactive power compensation device input end; it is used to control the photovoltaic power generation device, the energy storage device and the reactive power compensation device to be switched on and off according to the control instructions of the main controller;

[0052] The input end of the reactive compensation device is connected to the output end of the reactive compensation switching control module, and the output end of the reactive compensation switching control module is connected to the distribution network; it is used to access the distribution network, reduce the reactive current transmission of the distribution network and improve the power factor value.

[0053] On the other hand, the present invention further provides an electronic device having a computer program stored thereon, wherein when the computer program is executed by a processor, the control method of a plug-and-play photovoltaic intelligent grid-connected adaptive controller as described in any embodiment of the present invention is implemented.

[0054] On the other hand, the present invention also provides a computer-readable medium for storing one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors implement a control method of a plug-and-play photovoltaic intelligent grid-connected adaptive controller as described in any embodiment of the present invention.

[0055] The present invention has the following beneficial effects:

[0056] 1. The main meteorological influencing factors are determined through regression analysis and path analysis. The values ​​of the main meteorological influencing factors are predicted by combining weather forecast services, BP neural network model and wind speed prediction model. The associated data model is established to predict the output power of photovoltaic power generation devices, which ensures the grid-connected stability of photovoltaic power generation devices and helps to better coordinate the energy supply in the distribution network.

[0057] 2. When the total network loss or voltage drop exceeds the preset value and the output power reserve of the photovoltaic power generation device and the energy storage device is sufficient, the photovoltaic power generation device is put into use first, and the active power output is used to adjust the reactive power, improve the voltage quality and reduce the network loss, giving full play to the photovoltaic power generation capacity and meeting the requirements of low-carbon environmental protection.

[0058] 3. If the photovoltaic power generation device and energy storage device still fail to meet the standards after being connected, the reactive power compensation device is connected to compensate the power factor. At this time, the capacity of the reactive power compensation device is small, which improves the efficiency of reactive power compensation, reduces the use of reactive power compensation devices, and reduces equipment investment and floor space.

[0059] 4. The control strategy of the thyristor switching switch is determined by the single-channel capacitor supplement model when the three-phase common compensation capacitor is connected to the distribution network. The switching is performed when the capacitor and the power supply voltage reach the same peak value. The thyristor current zero-crossing natural shutdown function is utilized to avoid current shock and extend the service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0061] Figure 1 This is a schematic diagram of the method flow of Example 1;

[0062] Figure 2 It is the schematic diagram of the plug-and-play photovoltaic intelligent grid-connected adaptive controller;

[0063] Figure 3 It is the switch connection schematic diagram of the plug-and-play photovoltaic intelligent grid-connected adaptive controller;

[0064] Figure 4 It is the principle block diagram of the plug-and-play photovoltaic intelligent grid-connected adaptive controller;

[0065] Figure 5 This is the principle structure diagram of the power measurement module;

[0066] Figure 6 This is the principle block diagram of the reactive power compensation switching control module;

[0067] Figure 7 This is the schematic diagram of the switching circuit of the reactive power compensation device;

[0068] Figure 8 This is the connection diagram of the reactive power compensation device;

[0069] Fig. 9 It is the flow chart of the power prediction algorithm of photovoltaic power generation device;

[0070] Fig.10 The photovoltaic active power diagram under different conditions. DETAILED DESCRIPTION

[0071] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in 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 creative work are within the scope of protection of the present invention.

[0072] It should be understood that the step numbers used in this document are only for convenience of description and are not intended to limit the order in which the steps are executed.

[0073] It should be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0074] The terms “include” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0075] The term "and / or" means and includes any and all possible combinations of one or more of the associated listed items.

[0076] Embodiment 1:

[0077] In order to make the purpose, technical solutions and advantages of the present invention more clear, the following will be combined with the specific embodiments of the present application and refer to the attached Figure 1 , clearly and completely describe the technical solution of the present invention.

[0078] To solve the problems in the prior art, the present invention provides a control method for a plug-and-play photovoltaic intelligent grid-connected adaptive controller, comprising the following steps:

[0079] Step S1, collecting reactive power, active power, voltage and current of the distribution network through the distribution network power measurement module;

[0080] Step S2, collecting the output power of the photovoltaic power generation device and the energy storage device through the new energy power generation power measurement module;

[0081] like Fig. 9 As shown, in the step of collecting the output power of the photovoltaic power generation device by the new energy power measurement module, the main meteorological influencing factors are first determined by regression analysis and path analysis. The main meteorological influencing factors include solar irradiance, ambient temperature, relative humidity, and wind speed. Then, the predicted values ​​of the main meteorological influencing factors are obtained through weather forecast services, BP neural network models, and wind speed prediction models. Then, a related data model is established to predict the output power of the photovoltaic power generation device and ensure the grid-connected stability of the photovoltaic power generation device. The specific related data model is as follows:

[0082] The main meteorological influencing factors and power generation data of the photovoltaic power generation device are collected in chronological order and stored in the associated data model data table. The structure of each data record in the associated data model data table is t, G, H, T, S, P, FLAG, where t is the data collection time, G is the solar irradiance, H is the relative humidity, T is the ambient temperature, S is the wind speed, P is the output power of the photovoltaic power generation device at time t, and FLAG is the flag bit;

[0083] Select the reference data at time t, the specific requirements are as follows:

[0084]

[0085] Where: ε G , ε H , ε T , ε S It is divided into deviation thresholds of solar irradiance, relative humidity, ambient temperature and wind speed at time t; G ref , Href 、T ref , S ref It is divided into reference values ​​of solar irradiance, relative humidity, ambient temperature and wind speed at different times t;

[0086] The collected data is cleaned, and the cleaning tolerance coefficient calculation formula is:

[0087]

[0088] Where: λ is the data cleaning tolerance coefficient; P is the output power of the photovoltaic power generation device at time t; P ref-avg The average output power of the photovoltaic power generation device during the effective cleaning time;

[0089] in:

[0090]

[0091] Where: P ref_i represents the output power data of the ith photovoltaic power generation device that meets the conditions, and N represents the total number of output power data of photovoltaic power generation devices that meet the conditions. The photovoltaic active power diagram under different conditions is as follows Fig.10 shown.

[0092] Step S3, the main controller calculates the total network loss of the distribution network and the voltage drop of each node of the distribution network through the reactive power, active power, voltage and current of the distribution network;

[0093] The total network loss of the distribution network is calculated as follows:

[0094] The connection of inductive loads to the distribution network will lead to an increase in reactive power of the distribution network. The increase in reactive power will lead to an increase in the loss of high-voltage transmission lines. The total network loss of the distribution network system with m nodes can be expressed as:

[0095]

[0096] The direct relationship between the voltage and reactive power of each node is:

[0097]

[0098] From the above formula we can get:

[0099]

[0100] Where: ΔP LOSS is the total network loss of the distribution network system; P xy , Q xy 、V x and R xy are respectively the active power at the head end, reactive power at the head end, voltage at the head end and branch resistance of the branch directly connected between the xth and yth nodes in the distribution network; Qy is the reactive power of node y; m is the number of nodes in the distribution network.

[0101] The voltage drop at each node of the distribution network is calculated by the following formula:

[0102]

[0103] Where: dV is the voltage drop between nodes x and y; xy V is the branch reactance of the branch directly connected between the xth and yth nodes; x is the voltage at node x.

[0104] Step S4: When the main controller detects that the total network loss of the distribution network and the voltage drop of each node of the distribution network exceed the preset value, the main controller sends a control instruction to the reactive power compensation switching control module according to the control strategy;

[0105] The control strategy is as follows:

[0106] When the total network loss or voltage drop exceeds the preset value, the photovoltaic power generation device and the energy storage device have sufficient output power reserves. First, consider putting the photovoltaic power generation device into use, and use the active power output of the photovoltaic power generation device to adjust the reactive power, improve the voltage quality, and reduce network loss;

[0107] When the total network loss or voltage drop is still not lower than the preset value after the photovoltaic power generation device is connected, the energy storage device is connected to the distribution network to further provide active power support;

[0108] When the photovoltaic power generation device and the energy storage device are connected to the distribution network, if the total network loss or voltage drop is still not lower than the preset value, the reactive power compensation device will be connected to the distribution network to compensate for the power factor; but the capacity of the reactive power compensation device used at this time will be very small.

[0109] Step S5, the reactive compensation switching control module controls the corresponding photovoltaic end switching switch, energy storage end switching switch or reactive compensation device switching switch according to the control instruction, and connects the energy storage device, photovoltaic power generation device or reactive compensation device to the distribution network.

[0110] The reactive power compensation device is a three-phase common compensation capacitor. The reactive power compensation device is connected to the easily damaged thyristor switching switch of the distribution network. According to the single-channel capacitor compensation model, the control strategy of the thyristor switching switch is determined. The specific steps are as follows:

[0111] According to the single-channel capacitor compensation model, the power equation is:

[0112] e s (t)=Re(Eejωt)=|E|cos(ωt+φ);

[0113] According to Kirchhoff's voltage law:

[0114]

[0115] Solve for the capacitor voltage v c (t) and the circuit current:

[0116] V c (t)=|V c |cos(ωt+φ);

[0117]

[0118] Where: i is the current in the single-channel capacitor compensation circuit, R is the equivalent resistance value in the circuit, e s (t) is the amplitude of the power supply voltage, ω is the angular frequency of the power supply voltage, E is the peak voltage, v c (t) is the capacitor terminal voltage, |V c | is the DC voltage component across the capacitor, i1 is the capacitor branch current;

[0119] The above formula shows that the voltage of the current and voltage container differ by 90°. When the voltage at the capacitor terminal is the maximum, the current flowing through the capacitor is 0. When the current i in the above formula is 0, the capacitor bears the maximum line voltage. Since the thyristor has the function of natural shutdown when the current passes through zero, there will be no current shock when it is removed and switched. Therefore, the switching is performed when the capacitor and the power supply voltage reach the same peak value, that is, the circuit detects the voltage passing through zero and triggers the thyristor to conduct.

[0120] The three-phase common compensation capacitor is connected to the distribution network to compensate the power factor. The power factor is determined by the current value reduced by the reactive component of the total current. The current value reduced by the reactive component of the total current is calculated as follows:

[0121]

[0122] In the formula, I c The current value reduced by the reactive component of the total current; is the current flowing through the inductor I L The reactive current component of is the line reactive current.

[0123] Embodiment 2:

[0124] like Figure 2 The embodiment shown provides a plug-and-play photovoltaic intelligent grid-connected adaptive controller, characterized in that it includes: a new energy power generation power measurement module, a main controller, a distribution network power measurement module, a reactive power compensation switching control module, and a reactive power compensation device;

[0125] The output end of the new energy power generation power measurement module is connected to the input end of the main controller, and the input end of the new energy power generation power measurement module is connected to the photovoltaic power generation device and the energy storage device; it is used to measure the output power of the photovoltaic power generation device and the energy storage device;

[0126] The input end of the main controller is connected to the output end of the energy storage device and the photovoltaic power generation device respectively, and the output end of the main controller is connected to the distribution network; it is used to receive data collected by the new energy power generation power measurement module and the distribution network power measurement module, and send control instructions to the device or module corresponding to the reactive power compensation switching control module according to the collected data and control strategy;

[0127] The input end of the power distribution network measurement module is connected to the output end of the main controller, and the output end of the power distribution network measurement module is connected to the input end of the main controller; it is used to collect reactive power, active power, voltage and current of the distribution network;

[0128] The reactive power compensation switching control module input end is connected to the main controller output end, and the reactive power compensation switching control module output end is connected to the reactive power compensation device input end; it is used to control the photovoltaic power generation device, the energy storage device and the reactive power compensation device to be switched on and off according to the control instructions of the main controller;

[0129] The input end of the reactive compensation device is connected to the output end of the reactive compensation switching control module, and the output end of the reactive compensation switching control module is connected to the distribution network; it is used to access the distribution network, reduce the reactive current transmission of the distribution network and improve the power factor value.

[0130] In this embodiment: Figure 4 As shown, the main controller includes a communication interface module, a controller microprocessor module, a clock module, an address module, a remote communication interface module, a storage module, a power module, a display module, an energy storage inverter switching drive module, a photovoltaic inverter switching drive module, an energy storage end switching switch, and a photovoltaic end switching switch;

[0131] The input end of the communication interface module is connected to the communication interface of the output end of the controller microprocessor module, and the output end of the communication interface module is respectively connected to the input end of the new energy power generation power measurement module, the power distribution network power measurement module, and the reactive power compensation switching control module;

[0132] The controller microprocessor module adopts STM32 microprocessor chip;

[0133] The communication interface module adopts RS485 communication module;

[0134] The output end of the clock module is connected to the input end I / O port of the controller microprocessor module;

[0135] The clock module uses DS1302 chip to display the test time;

[0136] The output terminal of the address module is connected to the input terminal I / O port of the controller microprocessor module;

[0137] The address module uses a 10-bit DIP switch to set the address;

[0138] The remote transmission communication interface module is connected to the communication interface at the output end of the controller microprocessor module for remote data transmission;

[0139] The remote communication interface module adopts RS485 communication module;

[0140] The storage module input terminal is connected to the controller microprocessor module output terminal I / O port;

[0141] The storage module uses a 128GB storage USB flash drive;

[0142] The output end of the power module is connected to the power end of the controller microprocessor module. The power module adopts a 220VAC to 12VDC switching power module. After passing through a 12VDC to 3.3VDC power conversion module, the electromagnetic compatibility meets the Level 4 requirements.

[0143] The display module uses a color touch LCD screen for parameter settings and data display such as reactive power threshold;

[0144] The input terminals of the energy storage inverter switching drive module and the photovoltaic inverter switching drive module are respectively connected to the I / O ports of the output terminals of the controller microprocessor module;

[0145] The energy storage inverter switching drive module and the photovoltaic inverter switching drive module both use 12VDC intermediate relays;

[0146] like Figure 3 The input ends of the energy storage end switching switch and the photovoltaic end switching switch are respectively connected to the output interfaces corresponding to the energy storage inverter switching drive module and the photovoltaic inverter switching drive module;

[0147] The energy storage end switching switch and the photovoltaic end switching switch both use three-phase AC contactors.

[0148] In this embodiment: Figure 5 As shown, the new energy power generation power measurement module and the distribution network power measurement module both include a phase A voltage sensor, a phase B voltage sensor, a phase C voltage sensor, a phase A current sensor, a phase B current sensor, a phase C current sensor, a power measurement microprocessor module, a power measurement address module, a power measurement power supply module, a power measurement communication module, and a power quality chip;

[0149] The output terminals of the A-phase voltage sensor, the B-phase voltage sensor, the C-phase voltage sensor, the A-phase current sensor, the B-phase current sensor, and the C-phase current sensor are respectively connected to the input terminal of the power quality chip, and the output terminal of the power quality chip is connected to the input I / O port of the power measurement microprocessor module;

[0150] The A-phase voltage sensor, B-phase voltage sensor, and C-phase voltage sensor all use 2mA:2mA current transformers. A 110kΩ resistor is connected in series at the input end to convert the 220VAC voltage signal into a 2mA current signal input by connecting it to the input end of the 2mA:2mA current transformer.

[0151] The A-phase current sensor, B-phase current sensor, and C-phase current sensor all use 5A:5mA current transformers, and connect current signals of any ratio (such as 1000A:5A, 500A:5A, etc.) to the input end of the 5A:5mA current transformer;

[0152] The power quality chip uses the ADE9000 chip. The ADE9000 is a highly accurate, fully integrated multi-phase power and power quality monitoring device. The device has excellent analog performance and a digital signal processing (DSP) core, which can achieve accurate power monitoring over a wide dynamic range. The integrated high-end reference voltage source ensures that the entire channel (including the programmable gain amplifier (PGA) and the analog-to-digital converter (ADC)) achieves low drift over the entire temperature range, and the total drift is less than ±25ppm / ℃ (maximum value). The ADE9000 can measure the total value and fundamental wave of active, reactive, apparent power and energy, providing complete power monitoring functions. Advanced functions such as DIP and SWELL monitoring, frequency, phase angle, voltage total harmonic distortion (VTHD), current total harmonic distortion (ITHD) and power factor measurement can achieve power quality measurement. 1 / 2 cycle rms and 10 cycle rms / 12 cycle rms calculated according to IEC 61000-4-30S class provide instantaneous rms measurements, allowing real-time monitoring.

[0153] The power measurement microprocessor module uses STM32 microprocessor chip;

[0154] The output end of the power measurement address module is connected to the I / O port of the input end of the power measurement microprocessor module. The power measurement address module adopts a 12-bit dip switch for address setting.

[0155] The output end of the power measurement power supply module is connected to the power supply end corresponding to the power measurement microprocessor module. The power measurement power supply module adopts a 220VAC to 12VDC switching power supply module. Through a 12VDC to 3.3VDC power conversion module, the electromagnetic compatibility meets the Level 4 requirements.

[0156] The input end of the power measurement communication module is connected to the corresponding communication interface of the power measurement microprocessor module, and adopts an RS485 communication module.

[0157] In this embodiment: Figure 6 As shown, the reactive compensation switching control module includes a reactive switching control communication module, a reactive switching power supply module, a reactive compensation switching control microprocessor module, and a thyristor + magnetic latching relay component;

[0158] The input end of the reactive power switching control communication module is connected to the communication interface corresponding to the reactive power compensation switching control microprocessor module;

[0159] The reactive power switching control communication module adopts RS485 communication module;

[0160] The reactive power compensation switching control microprocessor module adopts STM32 microprocessor chip;

[0161] The output end of the reactive power switching power supply module is connected to the power supply end corresponding to the reactive power compensation switching control microprocessor module;

[0162] The reactive power switching power module adopts a 220VAC to 12VDC switching power module, and then passes through a 12VDC to 3.3VDC power conversion module, and the electromagnetic compatibility meets the Level 4 requirements;

[0163] The thyristor should be a BTA-100 series bidirectional thyristor with a 1600V high voltage resistance, and the trigger voltage should be screened using an instrument. The trigger voltages of multiple thyristors should be consistent, and the trigger voltage should not be too high, otherwise the current linearity will deteriorate, and a reverse peak absorption resistor should be connected at both ends of the thyristor.

[0164] The input end of the thyristor + magnetic latching relay assembly is connected to the I / O port of the output end of the reactive power compensation switching control microprocessor module, and the output end of the thyristor + magnetic latching relay assembly is connected to the input end of the reactive power compensation device;

[0165] The thyristor + magnetic latching relay assembly adopts a parallel structure of thyristor and magnetic latching relay. The thyristor and magnetic latching relay form the switching switch of the reactive power compensation device. The specific circuit diagram is as follows Figure 7 As shown; in order to reduce the inrush current generated by switching on and off the capacitor of the reactive compensation device, when switching on and off the capacitor of the reactive compensation device, the thyristor is switched at zero point, and the magnetic latching relay is switched after the thyristor is switched at zero point. Due to the parallel structure of the thyristor and the magnetic latching relay, the voltage across the thyristor is zero after the magnetic latching relay is switched on, and the thyristor is automatically turned off.

[0166] In this embodiment: Figure 8As shown, the reactive power compensation device adopts a three-phase common compensation capacitor, that is, three independent capacitors are connected together in a triangle shape, head to tail to form a three-phase common compensation capacitor. When the rated value of the grid line voltage is U, the required capacity of each phase of the three-phase common compensation capacitor is

[0167] Embodiment three:

[0168] This embodiment provides an electronic device having a computer program stored thereon, and when the computer program is executed by a processor, a control method of a plug-and-play photovoltaic intelligent grid-connected adaptive controller as described in any embodiment of the present invention is implemented.

[0169] Embodiment 4:

[0170] This embodiment provides a computer-readable medium for storing one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors implement a control method for a plug-and-play photovoltaic intelligent grid-connected adaptive controller as described in any embodiment of the present invention.

[0171] In the embodiments of the present application, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. Among them, A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c can be represented by: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, c can be single or multiple.

[0172] Those of ordinary skill in the art will appreciate that the various units and algorithm steps described in the embodiments disclosed herein can be implemented in a combination of electronic hardware, computer software, and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0173] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0174] In several embodiments provided in the present application, if any function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory; hereinafter referred to as: ROM), random access memory (Random Access Memory; hereinafter referred to as: RAM), disk or optical disk, and other media that can store program codes.

[0175] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A control method for a plug-and-play photovoltaic intelligent grid-connected adaptive controller, characterized in that: The following steps are involved: Step S1, collecting reactive power, active power, voltage and current of the distribution network through the distribution network power measurement module; Step S2, collecting the output power of the photovoltaic power generation device and the energy storage device through the new energy power generation power measurement module; Step S3, the main controller calculates the total network loss of the distribution network and the voltage drop of each node of the distribution network through the reactive power, active power, voltage and current of the distribution network; Step S4: When the main controller detects that the total network loss of the distribution network and the voltage drop of each node of the distribution network exceed the preset value, the main controller sends a control instruction to the reactive power compensation switching control module according to the control strategy; Step S5, the reactive compensation switching control module controls the corresponding photovoltaic end switching switch, energy storage end switching switch or reactive compensation device switching switch according to the control instruction, and connects the energy storage device, photovoltaic power generation device or reactive compensation device to the distribution network.

2. The control method of a plug-and-play photovoltaic intelligent grid-connected adaptive controller according to claim 1, characterized in that: In the step of collecting the output power of the photovoltaic power generation device by the new energy power generation power measurement module, the main meteorological influencing factors are first determined by regression analysis and path analysis. The main meteorological influencing factors include solar irradiance, ambient temperature, relative humidity, and wind speed. Then, the predicted values ​​of the main meteorological influencing factors are obtained through weather forecast services, BP neural network models, and wind speed prediction models. Then, a related data model is established to predict the output power of the photovoltaic power generation device and ensure the grid-connected stability of the photovoltaic power generation device. The specific related data model is as follows: The main meteorological influencing factors and power generation data of the photovoltaic power generation device are collected in chronological order and stored in the associated data model data table. The structure of each data record in the associated data model data table is t, G, H, T, S, P, FLAG, where t is the data collection time, G is the solar irradiance, H is the relative humidity, T is the ambient temperature, S is the wind speed, P is the output power of the photovoltaic power generation device at time t, and FLAG is the flag bit; Select the reference data at time t, the specific requirements are as follows: Where: ε G , ε H , ε T , ε S It is divided into deviation thresholds of solar irradiance, relative humidity, ambient temperature and wind speed at time t; G ref , H ref , T ref , S ref It is divided into reference values ​​of solar irradiance, relative humidity, ambient temperature and wind speed at different times t; The collected data is cleaned, and the cleaning tolerance coefficient calculation formula is: Where: λ is the data cleaning tolerance coefficient; P is the output power of the photovoltaic power generation device at time t; P ref-avg The average output power of the photovoltaic power generation device during the effective cleaning time; in: Where: P ref-i represents the output power data of the ith photovoltaic power generation device that meets the conditions, and N represents the total number of output power data of the photovoltaic power generation devices that meet the conditions.

3. The control method of a plug-and-play photovoltaic intelligent grid-connected adaptive controller according to claim 1, characterized in that: The total network loss of the distribution network is calculated by the following formula: Where: ΔP LOSS is the total network loss of the distribution network system; P xy , Q xy 、V x and R xy are respectively the active power at the head end, reactive power at the head end, voltage at the head end and branch resistance of the branch directly connected between the xth and yth nodes in the distribution network; Q y is the reactive power of node y; m is the number of nodes in the distribution network.

4. The control method of a plug-and-play photovoltaic intelligent grid-connected adaptive controller according to claim 1, characterized in that: The voltage drop at each node of the distribution network is calculated by the following formula: Where: dV is the voltage drop between nodes x and y; xy V is the branch reactance of the branch directly connected between the xth and yth nodes; x is the voltage at node x.

5. The control method of a plug-and-play photovoltaic intelligent grid-connected adaptive controller according to claim 1, characterized in that: The control instruction is sent to the reactive power compensation switching control module according to the control strategy, wherein the control strategy is specifically as follows: When the total network loss or voltage drop exceeds the preset value, the photovoltaic power generation device and the energy storage device have sufficient output power reserves. The photovoltaic power generation device should be put into use first, and the active power output by the photovoltaic power generation device should be used to adjust the reactive power, improve the voltage quality, and reduce network loss. When the total network loss or voltage drop is still not lower than the preset value after the photovoltaic power generation device is connected, the energy storage device is connected to the distribution network to further provide active power support; When the photovoltaic power generation device and the energy storage device are connected to the distribution network, if the total network loss or voltage drop is still not lower than the preset value, the reactive power compensation device will be connected to the distribution network to compensate for the power factor.

6. The control method of a plug-and-play photovoltaic intelligent grid-connected adaptive controller according to claim 5, characterized in that: The reactive power compensation device is a three-phase common compensation capacitor. The reactive power compensation device is connected to the easily damaged thyristor switching switch of the distribution network. According to the single-channel capacitor compensation model, the control strategy of the thyristor switching switch is determined. The specific steps are as follows: According to the single-channel capacitor compensation model, the power equation is: e s (t)=Re(Eejωt)=|E|cos(ωt+φ); According to Kirchhoff's voltage law: Solve for the capacitor voltage v c (t) and the circuit current: V c (t)=|Vc|cos(ωt+φ); Where: i is the current in the single-channel capacitor compensation circuit, R is the equivalent resistance value in the circuit, e s (t) is the amplitude of the power supply voltage, ω is the angular frequency of the power supply voltage, E is the peak voltage, v c (t) is the capacitor terminal voltage, |V c | is the DC voltage component across the capacitor, i1 is the capacitor branch current; According to the above formula, the three-phase common compensation capacitor and the power supply voltage are switched when they reach the same peak value, that is, the voltage zero point is detected by the circuit to trigger the thyristor switching switch to turn on.

7. The control method of a plug-and-play photovoltaic intelligent grid-connected adaptive controller according to claim 5, characterized in that: The three-phase common compensation capacitor is connected to the distribution network to compensate the power factor. The power factor is determined by the current value reduced by the reactive component of the total current. The current value reduced by the reactive component of the total current is calculated as follows: In the formula, I c The current value reduced by the reactive component of the total current; is the current flowing through the inductor I L The reactive current component of is the line reactive current.

8. A plug-and-play photovoltaic intelligent grid-connected adaptive controller, characterized in that: include: New energy power generation power measurement module, main controller, distribution network power measurement module, reactive power compensation switching control module, reactive power compensation device; The output end of the new energy power generation power measurement module is connected to the input end of the main controller, and the input end of the new energy power generation power measurement module is connected to the photovoltaic power generation device and the energy storage device; it is used to measure the output power of the photovoltaic power generation device and the energy storage device; The input end of the main controller is connected to the output end of the energy storage device and the photovoltaic power generation device respectively, and the output end of the main controller is connected to the power distribution network; it is used to receive data collected by the new energy power generation power measurement module and the power grid power measurement module, and send control instructions to the device or module corresponding to the reactive power compensation switching control module according to the collected data and control strategy; The input end of the power distribution network measurement module is connected to the output end of the main controller, and the output end of the power distribution network measurement module is connected to the input end of the main controller; it is used to collect reactive power, active power, voltage and current of the distribution network; The reactive power compensation switching control module input end is connected to the main controller output end, and the reactive power compensation switching control module output end is connected to the reactive power compensation device input end; it is used to control the photovoltaic power generation device, the energy storage device and the reactive power compensation device to be switched on and off according to the control instructions of the main controller; The input end of the reactive power compensation device is connected to the output end of the reactive power compensation switching control module, and the output end of the reactive power compensation switching control module is connected to the power distribution network; Used to access the distribution network, reduce the reactive current transmission of the distribution network and improve the power factor value.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the control method of the plug-and-play photovoltaic intelligent grid-connected adaptive controller is implemented as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the control method of a plug-and-play photovoltaic intelligent grid-connected adaptive controller is implemented as described in any one of claims 1 to 7.

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