Self-adaptive power energy storage converter control method and system

Abstract

The invention discloses a power-adaptive energy storage converter control method and system. According to the method, the problems of overvoltage and undervoltage of a grid-connected point and overcharge and overdischarge of an energy storage battery can be effectively solved by controlling adaptive charge and discharge of the energy storage battery. Firstly, grid-connected point voltage is sampled for effective value processing, a grid voltage effective value feedback signal Ugfrms is obtained and sent to the inverted input end of a voltage error amplifier, and a grid voltage reference Uref is sent to the in-phase end of the voltage error amplifier. The output Ue of the voltage error amplifier is subjected to a positive and negative amplitude limiting link to obtain Ue1, and the Ue1 is sent to one input end of the multiplier. And the charge state signal Soc of the energy storage battery is subjected to range judgment to obtain a state signal J, and the state signal J is sent to the other input end of the multiplier. And the output Iref of the multiplier and the charging current sampling signal Ibf of the energy storage battery are respectively sent to the non-inverting input end and the inverting input end of the current regulator. The output of the current regulator serves as a modulation signal and is sent to the PWM modulator.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage converter control, and in particular to a method and system for controlling an energy storage converter with adaptive power. Background Art

[0002] With the development of my country's new energy layout, a series of distributed renewable energy power generation systems such as wind power generation and photovoltaic power generation are booming. According to the "Several Opinions on Promoting the Healthy Development of the Photovoltaic Industry" and other relevant policies, photovoltaic power generation should be developed in a decentralized manner, with local consumption as the main focus. Therefore, the number and capacity of distributed photovoltaic power generation in medium and low voltage distribution networks are also growing rapidly. Among them, affected by weather factors, grid voltage overvoltage or undervoltage is the main factor limiting photovoltaic access capacity. Based on the demand of the majority of users for the power quality of the distribution network, the overvoltage and undervoltage of the grid connection point of the photovoltaic inverter has become a problem that needs to be solved urgently.

[0003] Configuring an energy storage system is the most effective solution to this problem. Energy storage batteries can not only solve the problem of over-limit and drop in the grid-connected point voltage of photovoltaic inverters caused by the randomness of new energy, but also greatly improve the utilization rate of new energy and avoid the problem of wind or light abandonment. However, the introduction of energy storage systems makes the power transmission control of photovoltaic grid-connected systems complicated, especially the charging and discharging strategy of energy storage battery systems. Traditional energy storage converter control takes the DC bus voltage as the control target. This solution cannot effectively solve the over-voltage and under-voltage problems of the grid voltage, and the over-discharge and over-charge of energy storage batteries will cause energy waste and reduce the life of energy storage batteries, affecting the interests of distributed photovoltaic owners. Therefore, there is an urgent need for an adaptive power control method for energy storage converters, which can autonomously control the size of the charging and discharging current according to the grid voltage, effectively suppress the problem of over-voltage and under-voltage of the grid, and autonomously set the battery charging and discharging range, greatly improving the battery life. Summary of the invention

[0004] Purpose of the invention: In order to overcome the problem of overvoltage and undervoltage of the power grid, the present invention provides an adaptive power energy storage converter control method, which can autonomously control the size of the charging and discharging current according to the level of the power grid voltage, and can effectively suppress the problem of overvoltage and undervoltage of the power grid. At the same time, the battery charging and discharging range can be autonomously set, which greatly improves the battery life. Based on this, the present invention also provides an adaptive power energy storage converter control system.

[0005] Technical solution: According to a first aspect of the present invention, a method for controlling an energy storage converter with adaptive power is provided, the method comprising the following steps:

[0006] S1 converts the low voltage distribution network voltage U g After voltage sampling coefficient H gThe effective value U of the low-voltage distribution network voltage sampling is obtained by the operation processing of the effective value module RMS. gf_rms ;

[0007] S2 sets the grid voltage reference U ref The effective value U of the low voltage distribution network voltage sampling gf_rms The voltage error signal U is sent to the non-inverting terminal and the inverting terminal of the voltage error amplifier respectively, and the output is the voltage error signal U e And obtain the limiting voltage error signal U through the positive and negative limiting links e1 ;

[0008] S3 detects the state of charge Soc of the energy storage battery and performs range determination on it to obtain a state signal J;

[0009] S4 combines the state signal J with the limit voltage error signal U e1 The current reference signal I is sent to the two input terminals of the multiplier to obtain the current reference signal I ref ;

[0010] S5 converts the current reference signal I ref The charging current I of the energy storage battery b The sampling signal I bf , respectively as the positive input and negative input of the current regulator, outputting the modulation signal; wherein the sampling signal I bf is the charging current I of the energy storage battery b Through the current sampling coefficient H i Afterwards,

[0011] S6 sends the modulation signal generated by the current regulator to the PWM modulator to generate a corresponding control PWM signal, completes the regulation control of the bidirectional converter, and thus realizes the adaptive charge and discharge control of the energy storage battery.

[0012] Further, including:

[0013] The effective value U of the low-voltage distribution network voltage sampling gf_rms It is expressed as:

[0014]

[0015] Where N is the low voltage distribution network voltage U g The number of sampling points within one power frequency cycle, and M power frequency cycles are used as the calculation limit, M ≥ 2.

[0016] Further, including:

[0017] In step S2, the amplitude limiting voltage error signal U is obtained through the positive and negative amplitude limiting link. e1 ,include:

[0018] Limiting voltage error signal U e1 The upper and lower limits are expressed as: e1max , -U e1min , and the energy storage battery charging current I in step S5 b Size limitation and the current sampling factor H i The design complies with the following relationship, so as to realize the self-setting of the maximum current of charge and discharge:

[0019] When the energy storage battery is charged:

[0020] When the energy storage battery is discharged:

[0021] Further, including:

[0022] In step S3, the Soc range is determined by:

[0023]

[0024] Among them, Soc min With Soc max They are the minimum and maximum setting values ​​of Soc, which are used to avoid over-discharge and over-charge of the energy storage battery.

[0025] On the other hand, the present invention also provides an adaptive power energy storage converter control system, which is used to implement the adaptive power energy storage converter control method described above, and specifically includes a grid-connected unit, an energy storage unit and a control unit, wherein the bidirectional converter output of the grid-connected unit is connected to the energy storage unit to complete the storage and release of electric energy, and the control unit includes a voltage error amplifier, a multiplier, a current regulator and a PWM modulator;

[0026] The voltage of the low-voltage distribution network is sampled for effective value processing to obtain an effective value feedback signal of the grid voltage, and the effective value feedback signal is sent to the inverting input terminal of the voltage error amplifier, and the grid voltage reference is sent to the non-inverting terminal of the voltage error amplifier. The output of the voltage error amplifier is passed through a positive and negative limiting link to obtain a limited voltage error amplified signal and sent to an input terminal of the multiplier;

[0027] At the same time, the state of charge signal of the energy storage unit is range-determined to obtain a state signal, and is sent to the other input end of the multiplier. The output of the multiplier and the charging current sampling signal of the energy storage unit are respectively sent to the non-inverting input end and the inverting input end of the current regulator. The output of the current regulator is used as a modulation signal and sent to the PWM modulator to generate a corresponding control PWM signal to complete the regulation and control of the bidirectional converter, thereby realizing adaptive charging and discharging control of the energy storage battery.

[0028] Further, including:

[0029] The grid-connected unit includes a photovoltaic array, a boost converter, an energy storage battery, a bidirectional converter, a grid-connected inverter and a filter;

[0030] The photovoltaic array is connected to the input of the boost converter as the output; the output of the boost converter is connected to the input of the grid-connected inverter and the input of the bidirectional converter; the output of the grid-connected inverter is connected to the filter to complete the grid connection of photovoltaic power generation.

[0031] Further, including:

[0032] The energy storage unit includes an energy storage battery.

[0033] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0034] (1) Low cost, only voltage detection hardware needs to be added to the grid connection point;

[0035] (2) Simple implementation, requiring only the detection of the grid connection point voltage to be introduced into the loop control of the energy storage converter;

[0036] (3) Adaptive control: When the grid connection point is overvoltage, the energy storage battery enters the charging mode. The charging current will increase with the increase of overvoltage, absorbing excess electric energy, thereby effectively suppressing the overvoltage. When the grid connection point is undervoltage, the energy storage battery enters the discharging mode. The discharge current will increase with the increase of undervoltage, releasing sufficient electric energy, thereby effectively suppressing the undervoltage.

[0037] (4) The battery state of charge can be set autonomously. The battery state of charge can be charged and discharged only when the battery is in the specified state, thus avoiding overcharging and over-discharging of the battery and effectively extending the battery life. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic diagram of the control structure of the energy storage converter with adaptive power according to an embodiment of the present invention;

[0039] Figure 1 The main symbol name in: H i ——Current sampling coefficient, H g ——voltage sampling coefficient, RMS——effective value calculation, Soc——energy storage battery charge state, I b ——Energy storage battery charging current, I bf ——sampling value of energy storage battery charging current; J——energy storage battery status, U e ——Grid voltage error method value, U e1 ——Grid voltage error amplification limit value, U g ——Grid voltage, U gf_rms——effective value of grid voltage, I ref ——Energy storage battery charging current benchmark;

[0040] Figure 2 The waveform diagram of the adaptive power energy storage converter control scheme according to the embodiment of the present invention, wherein (a) is a grid overvoltage working state diagram, (b) is a grid undervoltage working state diagram, (c) is a Soc exceeding the upper limit state diagram, and (d) is a Soc below the lower limit state diagram;

[0041] Figure 3 This is a flow chart of the adaptive power energy storage converter control method described in an embodiment of the present invention. DETAILED DESCRIPTION

[0042] 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.

[0043] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0044] Example 1

[0045] The present invention proposes an adaptive power control method for energy storage converters. When the voltage at the photovoltaic inverter grid connection point is too high, the energy storage battery will be adaptively controlled to charge and absorb excess electric energy, thereby effectively suppressing the rise of the grid voltage; when the voltage at the photovoltaic inverter grid connection point is too low, the energy storage battery will be adaptively controlled to discharge and release electric energy, thereby effectively compensating for the drop of the grid voltage. At the same time, in order to avoid overcharging or over-discharging of the energy storage battery, the present invention can self-set the upper limit of the charge and discharge of the energy storage battery Soc and the size of the charge and discharge current, greatly improving the operating life of the energy storage battery.

[0046] like Figure 3 As shown, the present invention provides an adaptive power energy storage converter control method, the method comprising the following steps:

[0047] S1 converts the low voltage distribution network voltage U g After voltage sampling coefficient H g The effective value U of the low-voltage distribution network voltage sampling is obtained by the operation processing of the effective value module RMS. gf_rms .

[0048] This embodiment does not limit the effective value module RMS, and an effective value chip can be used, or calculation can be performed in the program. If calculation is performed in the program, the calculation formula is:

[0049]

[0050] Where N is the low voltage distribution network voltage U g The number of sampling points in one power frequency cycle, and M power frequency cycles are used as the calculation limit, M ≥ 2, the purpose is to improve the stability of control. When there is a disturbance in the system, the smaller M is, the more likely it is that the calculated U gf_ms The larger the change, the larger the system adjustment amount, and thus the more unstable the system output. Therefore, it is most preferred that M=3 is selected in this embodiment, and thus it is expressed as:

[0051]

[0052] Where N is the grid voltage U g The number of sampling points within one power frequency cycle is 3 power frequency cycles in order to improve the stability of control.

[0053] S2 sets the grid voltage reference U ref The effective value U of the low voltage distribution network voltage sampling gf_rms The voltage error signal U is sent to the non-inverting terminal and the inverting terminal of the voltage error amplifier respectively, and the output is the voltage error signal U e And through the positive and negative limiting links, the limiting voltage error signal U is obtained e1 .

[0054] This embodiment does not limit the specific model of the voltage error amplifier, which can be linear or nonlinear.

[0055] S3 detects the state of charge Soc of the energy storage battery, performs range determination on it, and obtains a state signal J.

[0056] Specifically, the Soc range determination in step S3 is carried out in the following manner:

[0057]

[0058] Among them, Soc min With Soc max They are the minimum and maximum setting values ​​of Soc, which are used to avoid over-discharge and over-charge of the energy storage battery.

[0059] S4 combines the state signal J with the limit voltage error signal U e1 The current reference signal I is sent to the two input terminals of the multiplier to obtain the current reference signal I ref ;

[0060] S5 converts the current reference signal I ref The charging current I of the energy storage battery b The sampling signal Ibf , respectively as the positive input and negative input of the current regulator, outputting the modulation signal; wherein the sampling signal I bf is the charging current I of the energy storage battery b Through the current sampling coefficient H i Then get it.

[0061] In this embodiment, in order to realize the autonomous setting of the charge and discharge thresholds and avoid overcharging and over-discharging of the energy storage battery, the following contents need to be set:

[0062] The output voltage upper limit U of the positive and negative limit link in step S2 e1max With lower limit -U e1min , and the energy storage battery charging current I in step S5 b Size Limit and Sampling Factor H i The design should meet the following relationship:

[0063]

[0064] This embodiment does not impose any restrictions on the upper and lower limits, which can be determined according to the maximum charge and discharge current to be designed. Specifically: through a reasonable current sampling coefficient H i The upper limit U of the positive and negative limit link e1max With lower limit -U e1min With the design, you can set the maximum charge and discharge current independently.

[0065] S6 sends the modulation signal generated by the current regulator to the PWM modulator to generate a corresponding control PWM signal, completes the regulation control of the bidirectional converter, and thus realizes the adaptive charge and discharge control of the energy storage battery.

[0066] Therefore, this control method can effectively solve the problem of too high or too low voltage at the grid connection point, and at the same time can effectively prevent overcharging or over-discharging of the energy storage battery, thereby improving the stability of the grid voltage and the life of the energy storage battery.

[0067] When the voltage at the grid-connected point of the photovoltaic inverter is too high, the voltage error amplifier will output a negative value with an upper limit, and the current of the energy storage battery will track the negative value, so that the energy storage battery is charged, and the maximum charging current is limited by the upper limit of the negative value; when the voltage at the grid-connected point of the photovoltaic inverter is too low, the voltage error amplifier will output a positive value with an upper limit, and the current of the energy storage battery will track the positive value, so that the energy storage battery is discharged, and the maximum discharging current is limited by the upper limit of the positive value; at the same time, in order to avoid overcharging or over-discharging of the energy storage battery, the present invention uses the Soc range determination link. When the Soc exceeds the specified range, the current reference of the energy storage battery is made 0, that is, charging and discharging are no longer performed, which effectively avoids overcharging and over-discharging of the energy storage battery and greatly improves the life of the energy storage battery.

[0068] This embodiment does not limit the specific model of the current regulator, which may be a P controller or a PI controller.

[0069] On the other hand, the present invention also provides an adaptive power energy storage converter control system, which is used to implement the method described in Example 1, specifically including: a photovoltaic array, a boost converter, an energy storage battery, a bidirectional converter, a grid-connected inverter, a filter, a voltage error amplifier, a multiplier, a current regulator, and a PWM modulator.

[0070] The photovoltaic array serves as the output terminal and is connected to the input terminal of the boost converter;

[0071] The output end of the boost converter is connected to the input end of the grid-connected inverter and the input end of the bidirectional converter; the output end of the grid-connected inverter is connected to the filter to complete the grid connection of photovoltaic power generation;

[0072] The output of the bidirectional converter is connected to the energy storage battery to complete the storage and release of electrical energy.

[0073] The grid point voltage is sampled and processed for effective value to obtain the grid voltage effective value feedback signal, which is sent to the inverting input of the voltage error amplifier, and the grid voltage reference is sent to the non-inverting end of the voltage error amplifier. The output of the voltage error amplifier is passed through the positive and negative limiting links to obtain a limited voltage error amplified signal and sent to one input of the multiplier.

[0074] The state signal of the energy storage battery is determined by the range and sent to the other input of the multiplier. The output of the multiplier and the charging current sampling signal of the energy storage battery are sent to the in-phase input and the inverting input of the current regulator respectively. The output of the current regulator is sent to the PWM modulator as a modulation signal. By controlling the bidirectional converter, the energy storage battery can be adaptively charged and discharged according to the voltage of the grid connection point, effectively solving the problem of too high and too low voltage at the grid connection point.

[0075] Below Figure 1 The specific working principle of the present invention is mainly described, and the corresponding circuit key waveforms are shown in Figure 2 .

[0076] First, the invention performs effective value processing on the sampled grid-connected point voltage to obtain the grid voltage effective value feedback signal U gf_rms , and send it to the inverting input of the voltage error amplifier, the grid voltage reference U ref The output of the voltage error amplifier is U e Get U through the positive and negative limiting links e1The state signal Soc of the energy storage battery is range-determined to obtain the state signal J and sent to the other input of the multiplier. The output I ref The charging current sampling signal I bf The output of the current regulator is sent to the PWM modulator as a modulation signal. By controlling the bidirectional converter, the energy storage battery can be adaptively charged and discharged according to the grid voltage, effectively solving the problem of too high or too low grid voltage.

[0077] This application effectively solves the problem of unstable grid voltage caused by the connection of a large number of new energy sources to the grid. It can not only prevent the grid voltage from exceeding the limit, but also prevent the grid voltage from dropping, greatly improving the stability of the grid voltage. This application also effectively solves the problem of overcharging and over-discharging of energy storage batteries in current energy storage systems. This application can avoid overcharging and over-discharging of energy storage batteries by independently setting the charge and discharge thresholds, greatly improving the service life of energy storage batteries and reducing the operation and maintenance costs of energy storage batteries.

[0078] like Figure 2 In the simulation shown, the upper limit of Soc is set to 80% and the lower limit is set to 20%. Figures a, b, c, and d are the simulation waveforms corresponding to the initial Soc of the battery being 50%, 50%, 84.5%, and 12%, respectively.

[0079] from Figure 2 From the waveform shown in (a), it can be seen that when the effective value of the grid connection point voltage exceeds 220V (i.e., it is in an overvoltage state), it can be seen that the energy storage battery is in a charging state, absorbing excess energy and suppressing the further rise of the grid voltage. Moreover, it can be seen from the waveform shape that the more the grid voltage exceeds 220V, the greater the charging current.

[0080] from Figure 2 It can be seen from the waveform shown in (b) that when the effective value of the grid connection point voltage is lower than 220V (i.e., it is in an undervoltage state), it can be seen that the energy storage battery is in a discharge state, releasing electrical energy to compensate the grid and suppressing the grid voltage from further dropping. Moreover, it can be seen from the shape of the waveform that the more the grid voltage is lower than 220V, the greater the discharge current.

[0081] from Figure 2 It can be seen from (c) that when Soc exceeds the upper limit, the charging and discharging current of the energy storage battery is always maintained at around 0, and no more charging is performed to avoid overcharging of the battery;

[0082] from Figure 2 It can be seen from (d) that when Soc is lower than the lower limit, the charging and discharging current of the energy storage battery is maintained at around 0, and no more discharge is performed to avoid over-discharge.

[0083] It can be seen from the above that this control method can realize adaptive charge and discharge control of energy storage batteries when working: when the grid voltage is higher than the reference value, the energy storage battery enters the charging mode, and the charging current increases with the increase of the grid voltage, absorbing excess electric energy to suppress the rise of the grid voltage; when the grid voltage is lower than the reference value, the energy storage battery enters the discharge mode, and the discharge current increases with the decrease of the grid voltage, releasing enough electric energy to suppress the grid voltage drop. Therefore, when the energy storage battery Soc is not within the set range, this method can prevent the battery from continuing to discharge or charge, avoiding overcharging and over-discharging of the battery.

[0084] It should be noted that since the storage medium provided in the embodiment of the present application is the storage medium used to implement the method of the embodiment of the present application, based on the method introduced in the embodiment of the present application, the person skilled in the art can understand the specific structure and deformation of the storage medium, so it is not repeated here. All storage media used in the method of the embodiment of the present application belong to the scope of protection of this application.

[0085] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0086] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks 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 processes in the flowchart and / or block diagram. 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.

[0087] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate 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 1A function specified in one or more boxes.

[0088] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions 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.

[0089] It should be noted that in the claims, any reference signs placed between parentheses shall not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claim. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The invention may be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The use of the words first, second, and third etc. does not indicate any order. These words may be interpreted as names.

[0090] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0091] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

[0092] The above are only preferred 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 method for controlling an energy storage converter with adaptive power, characterized in that: The method comprises the following steps: S1 converts the low voltage distribution network voltage U g After voltage sampling coefficient H g The effective value U of the low-voltage distribution network voltage sampling is obtained by the operation processing of the effective value module RMS. gf_rms ; S2 sets the grid voltage reference U ref The effective value U of the low voltage distribution network voltage sampling gf_rms The voltage error signal U is sent to the non-inverting terminal and the inverting terminal of the voltage error amplifier respectively, and the output is the voltage error signal U e And through the positive and negative limiting links, the limiting voltage error signal U is obtained e1 ; S3 detects the state of charge Soc of the energy storage battery and performs range determination on it to obtain a state signal J; S4 combines the state signal J with the limit voltage error signal U e1 The current reference signal I is sent to the two input terminals of the multiplier to obtain the current reference signal I ref ; S5 converts the current reference signal I ref The charging current I of the energy storage battery b The sampling signal I bf , respectively as the positive input and negative input of the current regulator, outputting the modulation signal; wherein the sampling signal I bf is the charging current I of the energy storage battery b Through the current sampling coefficient H i Afterwards, S6 sends the modulation signal generated by the current regulator to the PWM modulator to generate a corresponding control PWM signal, completes the regulation control of the bidirectional converter, and thus realizes the adaptive charge and discharge control of the energy storage battery.

2. The adaptive power energy storage converter control method according to claim 1, characterized in that: The effective value U of the low-voltage distribution network voltage sampling gf_rms It is expressed as: Where N is the low voltage distribution network voltage U g The number of sampling points within one power frequency cycle, and M power frequency cycles are used as the calculation limit, M ≥ 2.

3. The adaptive power energy storage converter control method according to claim 1, characterized in that: In step S2, the amplitude limiting voltage error signal U is obtained through the positive and negative amplitude limiting link. e1 ,include: Limiting voltage error signal U e1 The upper and lower limits are expressed as: e1max , -U e1min , and the energy storage battery charging current I in step S5 b Size limitation and the current sampling factor H i The design complies with the following relationship, so as to realize the self-setting of the maximum current of charge and discharge: When the energy storage battery is charged: When the energy storage battery is discharged:

4. The adaptive power energy storage converter control method according to claim 1, characterized in that: In step S3, the Soc range is determined by: Among them, Soc min With Soc max They are the minimum and maximum setting values ​​of Soc, which are used to avoid over-discharge and over-charge of the energy storage battery.

5. An adaptive power energy storage converter control system, characterized in that: The system is used to implement the adaptive power energy storage converter control method based on any one of claims 1-4, specifically comprising a grid-connected unit, an energy storage unit and a control unit, wherein the bidirectional converter output of the grid-connected unit is connected to the energy storage unit to complete the storage and release of electric energy, and the control unit comprises a voltage error amplifier, a multiplier, a current regulator and a PWM modulator; The voltage of the low-voltage distribution network is sampled for effective value processing to obtain an effective value feedback signal of the grid voltage, and the effective value feedback signal is sent to the inverting input terminal of the voltage error amplifier, and the grid voltage reference is sent to the non-inverting terminal of the voltage error amplifier. The output of the voltage error amplifier is passed through a positive and negative limiting link to obtain a limited voltage error amplified signal and sent to an input terminal of the multiplier; At the same time, the state of charge signal of the energy storage unit is range-determined to obtain a state signal, and is sent to the other input end of the multiplier. The output of the multiplier and the charging current sampling signal of the energy storage unit are respectively sent to the non-inverting input end and the inverting input end of the current regulator. The output of the current regulator is used as a modulation signal and sent to the PWM modulator to generate a corresponding control PWM signal to complete the regulation and control of the bidirectional converter, thereby realizing adaptive charging and discharging control of the energy storage battery.

6. The adaptive power energy storage converter control system according to claim 5, characterized in that: The grid-connected unit includes a photovoltaic array, a boost converter, an energy storage battery, a bidirectional converter, a grid-connected inverter and a filter; The photovoltaic array is connected to the input of the boost converter as the output; the output of the boost converter is connected to the input of the grid-connected inverter and the input of the bidirectional converter; the output of the grid-connected inverter is connected to the filter to complete the grid connection of photovoltaic power generation.

7. The adaptive power energy storage converter control system according to claim 5, characterized in that: The energy storage unit includes an energy storage battery.

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