Power balance regulation method of mppt circuit, power supply device and energy storage power generation system

Abstract

The application provides a power balance regulation method of an MPPT circuit, a power supply device and an energy storage power generation system. An input end of the MPPT circuit is used for connecting a photovoltaic module, and an output end of the MPPT circuit is used for connecting a load. The power balance regulation method comprises the following steps: acquiring an input voltage, an input current and an input power of the input end of the MPPT circuit and acquiring a required power of the load in a current control period; if the input power is greater than the required power, obtaining a current threshold value of the input current based on the input voltage and the required power; determining a current regulation step length according to the input power and the required power; determining a target current of a next control period according to the current threshold value, the current regulation step length and the input current of the current control period; generating a control signal according to the target current and the input voltage and outputting the control signal to the MPPT circuit, and the control signal is used for controlling the MPPT circuit to regulate the input current of the next control period. The application can quickly balance the power of the MPPT circuit, and can avoid the overshoot phenomenon of the current.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy, in particular to a power balance adjustment method of MPPT circuit, a power supply device and an energy storage power generation system. BACKGROUND

[0002] In the related art, an MPPT circuit (MPPT, Maximum Power Point Tracking) is arranged in a device related to photovoltaic, which is used to track the maximum power of the electric energy generated by a photovoltaic module and output the electric energy to a load. However, when the light intensity increases, the output power of the photovoltaic module increases, which may cause the maximum power output by the MPPT circuit to be greater than the required power of the load, and further cause the load to be overloaded and have adverse effects. SUMMARY

[0003] In view of this, the present application provides a power balance adjustment method and a power supply device, which can solve the problem that the load may be overloaded when the light intensity increases.

[0004] The first aspect of the present application provides a power balance adjustment method of MPPT circuit, an input end of the MPPT circuit being used to connect a photovoltaic module, and an output end of the MPPT circuit being used to connect a load; wherein the power balance adjustment method comprises: acquiring an input voltage, an input current and an input power of the input end of the MPPT circuit, and acquiring a required power of the load in a current control period, if the input power is greater than the required power, obtaining a current threshold value of the input current based on the input voltage and the required power, determining a current adjustment step according to the input power and the required power, determining a target current of a next control period according to the current threshold value, the current adjustment step and the input current of the current control period, the target current being less than the input current and greater than or equal to the current threshold value, generating a control signal according to the target current and the input voltage and outputting the control signal to the MPPT circuit, the control signal being used to control the MPPT circuit to adjust the input current of the next control period.

[0005] In the above embodiment, when it is determined that the input power of the MPPT circuit is greater than the required power of the load, the current threshold value of the input current of the MPPT circuit can be determined according to the input voltage of the MPPT circuit and the required power, and then the input current of the MPPT circuit is controlled to gradually adjust to the current threshold value by the current adjustment step size in multiple control periods, so as to gradually reduce the output power of the MPPT circuit to the required power. Even when the maximum power of the photovoltaic module is greater than the required power of the load, the maximum power actually output by the MPPT circuit will not exceed the required power of the load, thereby avoiding the adverse effects that the load may be overloaded and the current is too large. Moreover, the current adjustment step size is determined by the input power and the required power, and the input current of the MPPT circuit is gradually reduced by the current adjustment step size in continuous control periods, so that the input power and the output power of the MPPT circuit can be quickly balanced, and the output current of the MPPT circuit can be prevented from changing too fast to avoid overshoot.

[0006] In one of the embodiments, the input voltage, the input current and the input power of the input end of the MPPT circuit in the current control period are obtained, including: detecting the input voltage and the input current of the input end of the MPPT circuit in the current control period, and obtaining the input power according to the input voltage and the obtained input current.

[0007] In one of the embodiments, the current adjustment step size is determined according to the input power and the required power, including: calculating a first power difference value of the input power and the required power, matching the first power difference value in a preset current step size library to obtain a corresponding current adjustment step size, and the preset current step size library stores preset current adjustment step sizes corresponding to different power difference values.

[0008] In one of the embodiments, the target current of the next control period is determined according to the current threshold value, the current adjustment step size and the input current of the current control period, including: obtaining a first current value output by a current loop of the MPPT circuit, when the first current value is the current threshold value and the input current of the current control period is greater than the current threshold value, the target current of the next control period is obtained by subtracting the current adjustment step size from the input current of the current control period, and when the first current value is the current threshold value and the input current of the current control period is less than or equal to the current threshold value, the current threshold value is determined as the target current of the next control period.

[0009] In one of the embodiments, the method further includes: if the input power is greater than the required power, updating the upper limit of the output of the current loop to the current threshold value, determining the output value of the current loop as the first current value when the output value of the current loop is not greater than the current threshold value, and determining the output value of the current loop as the current threshold value when the output value of the current loop is greater than the current threshold value.

[0010] In one of the embodiments, the power balance adjustment method further comprises: if the input power is less than the demand power, determining a reference voltage of the maximum power point according to a preset MPPT algorithm, generating a second driving signal according to the reference voltage, the input current and the input voltage, and sending the second driving signal to the switch tube of the MPPT circuit in the next control period, the second driving signal being used to drive the switch tube to make the MPPT circuit work at the maximum power point of the photovoltaic module.

[0011] In one of the embodiments, the output end of the MPPT circuit is further connected to the energy storage device, and after the input voltage, the input current and the input power of the input end of the MPTT circuit and the demand power of the load are obtained in the current control period, the power balance adjustment method further comprises: if the input power is greater than the demand power and the energy storage device is not connected or the connected energy storage device does not have charging capability, performing the step of obtaining the current threshold value of the input current based on the input voltage and the demand power. If the input power is greater than the demand power and the energy storage device has charging capability, calculating a second power difference value of the input power and the demand power, and controlling the MPPT circuit to output electric energy to charge the energy storage device according to the second power difference value.

[0012] In one of the embodiments, the output end of the MPPT circuit is further connected to the energy storage device, and the power balance adjustment method further comprises: if the input power is less than the demand power, calculating a third power difference value of the demand power and the input power, and controlling the energy storage device to discharge to jointly supply power to the load with the MPPT circuit.

[0013] The second aspect of the present application provides a power supply device, comprising an MPPT circuit and a controller, the input end of the MPPT circuit being connected to a photovoltaic module, the output end of the MPTT circuit being connected to a load, and the controlled end of the MPPT circuit being connected to the controller. The controller is used to execute any one of the power balance adjustment methods in the above embodiments.

[0014] The third aspect of the present application provides an energy storage power generation system, comprising a photovoltaic module and the above power supply device.

[0015] The fourth aspect of the present application provides a storage medium, the storage medium storing a computer program, when the computer program is executed by the controller, the controller executes any one of the power balance adjustment methods in the above embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a schematic block diagram of the connection of an MPPT circuit, a photovoltaic module and a load provided by the embodiments of the present application.

[0017] Figure 2 is a flowchart of a power balance adjustment method of an MPPT circuit provided by the embodiments of the present application.

[0018] Figure 3 FIG. 1 is a flowchart of a method for acquiring input voltage, input current and input power of an input end of an MPPT circuit according to an embodiment of the present application.

[0019] Figure 4 FIG. 2 is a flowchart of a method for acquiring a current regulation step according to an embodiment of the present application.

[0020] Figure 5 FIG. 3 is a flowchart of a method for determining a target current of a next control period according to an embodiment of the present application.

[0021] Figure 6 FIG. 4 is a flowchart of another method for determining a target current of a next control period according to an embodiment of the present application.

[0022] Figure 7 FIG. 5 is a schematic block diagram of a loop control system outputting a first current value according to an embodiment of the present application.

[0023] Figure 8 FIG. 6 is another schematic block diagram of a loop control system outputting a first current value according to an embodiment of the present application.

[0024] Figure 9 FIG. 7 is a flowchart of a power balance regulation method of a second MPPT circuit according to an embodiment of the present application.

[0025] Figure 10 FIG. 8 is a schematic block diagram of a connection of an MPPT circuit, a photovoltaic module, a load and an energy storage device according to an embodiment of the present application.

[0026] Figure 11 FIG. 9 is a flowchart of a power balance regulation method of a third MPPT circuit according to an embodiment of the present application.

[0027] Figure 12 FIG. 10 is a flowchart of a power balance regulation method of a fourth MPPT circuit according to an embodiment of the present application.

[0028] Figure 13 FIG. 11 is a schematic block diagram of a power supply device according to an embodiment of the present application.

[0029] Figure 14 FIG. 12 is a schematic block diagram of an energy storage power generation system according to an embodiment of the present application. DETAILED DESCRIPTION

[0030] It should be noted that the terms “first”, “second” in the specification and claims of the present application and the drawings are used to distinguish similar objects, and are not used to describe a specific order or sequence.

[0031] It should be noted that the method disclosed in the embodiments of the present application or the method shown in the flowchart includes one or more steps for implementing the method, and the execution order of the steps can be interchanged with each other without departing from the scope of the claims, and some steps can also be deleted.

[0032] Some embodiments will be described below with reference to the accompanying drawings. The embodiments described below and the features in the embodiments can be combined with each other without conflict.

[0033] In the related art, an MPPT circuit is arranged in a photovoltaic related device, an MPPT algorithm is used to track the maximum power point of a photovoltaic module, and the MPPT circuit is controlled to work at the maximum power point to output power to a load, so as to ensure that the photovoltaic module works at the best energy conversion rate.

[0034] However, when the light intensity increases, the output power of the photovoltaic module also increases, which causes the maximum power point of the MPPT circuit to change, and then may cause the power output by the MPTT circuit to the load to be greater than the required power of the load. When the power output by the MPPT circuit to the load is greater than the required power of the load, if the output power of the MPPT circuit and the required power cannot be quickly adjusted to power balance, the load will be in an overload condition, which will reduce the service life of the load and even cause damage to the components in the load.

[0035] The present application provides a power balance adjustment method of an MPPT circuit, a power supply device and an energy storage power generation system, which are used to quickly adjust the output power of the MPTT circuit and the required power to power balance, so as to solve the problem that the load may be overloaded when the light intensity increases.

[0036] Please refer to Figure 1 , Figure 1 A connection schematic block diagram of an MPPT circuit 100 provided by the embodiments of the present application and a photovoltaic module 200 and a load 300 is shown.

[0037] The MPPT circuit 100 includes an input end and an output end. The input end of the MPPT circuit 100 is used to connect the photovoltaic module 200, and the output end of the MPTT circuit 100 is used to connect the load 300. The MPPT circuit 100 is used to receive the photovoltaic voltage input by the photovoltaic module 200, and output the photovoltaic voltage after maximum power point tracking to the load 300.

[0038] It can be understood that the above Figure 1The load 300 in the figure includes, but is not limited to, various electronic devices and power grids. For example, in some scenarios, the output end of the MPPT circuit 100 can be connected to an energy storage device. In other scenarios, the output end of the MPPT circuit 100 can be connected to a DC-DC circuit, an inverter circuit, and a power grid in sequence to form a micro-inverter system to integrate the power generated by the photovoltaic module 200 into the power grid.

[0039] In addition, the MPPT circuit 100 can be controlled by a controller, and the type and position of the controller are not limited in the embodiments of the present application as long as the controller can be connected to the MPPT circuit 100 and control the MPPT circuit 100. For example, in some scenarios, the controller can be a processor of an energy storage device provided with the MPPT circuit. In other scenarios, the controller can also be a microprocessor in the MPPT circuit 100.

[0040] Next, a power balance regulation method of an MPPT circuit provided by an embodiment of the present application will be described in detail. Figure 2 As shown in the figure, the power balance regulation method is applied to the MPPT circuit 100 as shown in the figure. Figure 2 The power balance regulation method specifically includes the following steps. Figure 1

[0041] Step S21: In the current control period, the input voltage, input current, and input power of the input end of the MPPT circuit are acquired, and the demand power of the load is acquired.

[0042] In the embodiments of the present application, the control period can be a given time, that is, the control time of the controller is divided into control periods according to the given time. For example, in the control period, the controller can perform current loop and / or voltage loop regulation control on the MPPT circuit 100 once or multiple times.

[0043] In the current control period, the controller can reserve a certain time in the current control period to collect the input voltage, input current, and input power of the input end of the MPPT circuit, and acquire the demand power of the load. Specifically, for example, the control period can also be subdivided into a sampling period, a deviation calculation period, and a regulation period in time sequence. The controller collects data of the MPPT circuit 100 and the load 300 in the sampling period, calculates the deviation of the to-be-regulated parameter according to the collected data in the deviation calculation period to obtain a deviation value, and adjusts the to-be-regulated parameter according to the deviation value in the regulation period to finally complete the entire loop control of the MPPT circuit 100. The regulation period can also be set before the sampling period, that is, the controller can also use the deviation value generated in the last control period to adjust the to-be-regulated parameter in the regulation period, and then execute the sampling period and the deviation calculation period, which is not limited here. ​

[0044] In some embodiments, the MPPT circuit 100 can further comprise a first interface connected to the input end of the MPPT circuit 100. The photovoltaic module 200 is connected to the MPPT circuit 100 through the first interface, and the first interface is further connected to the controller. In this way, the controller detects the input voltage, the input current and the input power through the first interface. In another example, a detection chip can be further included in the first interface. The detection end of the detection chip is used to detect the pins receiving the current and voltage of the photovoltaic module 200, and the control end of the detection chip is connected to the controller. In this way, the detection chip can detect the input current and the input voltage in the first interface and transmit them to the controller through the control end.

[0045] Similarly, in some embodiments, the MPPT circuit 100 can further comprise a second interface connected to the output end of the MPPT circuit 100. The load 300 is connected to the MPPT circuit 100 through the second interface, and the second interface is further connected to the controller. In this way, the controller communicates with the load 300 through the second interface to obtain the demand power of the load 300.

[0046] Step S22: If the input power is greater than the demand power, the current threshold value of the input current is obtained based on the input voltage and the demand power.

[0047] It can be understood that when the controller determines that the input power of the MPPT circuit 100 is greater than the demand power of the load 300, it can be determined that the power output from the MPPT circuit 100 to the load 300 is greater than the demand power of the load 300, and thus the MPPT circuit 100 needs to be power-regulated.

[0048] The current threshold value is used to limit the input current of the input end of the MPPT circuit 100, so as to limit the input power of the MPPT circuit 100, and thus balance the output power of the MPPT circuit 100 and the demand power of the load 300.

[0049] In the embodiments of the present application, the current threshold value can be obtained by formula (1):

[0050] I1 = P L / V mp Formula (1).

[0051] In the formula, I1 is the current threshold value calculated in the current control period, P L is the demand power of the load 300, and V mp is the input voltage of the MPPT circuit 100 in the current control period.

[0052] Step S23: Determine the current adjustment step according to the input power and the demand power.

[0053] It can be understood that the current adjustment step can be the maximum adjustment value allowed when the input current is adjusted in a control period. In some embodiments, the controller can determine the current adjustment step according to the size of the deviation between the input power and the demand power, that is, the controller can determine the current adjustment step according to the degree of overload of the load 300. In this way, when the input current of the MPPT circuit 100 is adjusted, a suitable current adjustment step can be found to achieve the purpose of quickly adjusting the input current, and using a suitable current adjustment step can also avoid overshooting of the input current.

[0054] Step S24: determining the target current of the next control period according to the current threshold value, the current adjustment step, and the input current of the current control period; the target current is less than the input current and greater than or equal to the current threshold value.

[0055] In the embodiments of the present application, the above-mentioned target current is the input current of the MPPT circuit 100 in the next control period. That is, after the controller obtains the current threshold value and the current adjustment step in the current control period, the input current of the MPPT circuit 100 is adjusted according to the current threshold value and the current adjustment step in the next control period, so that the input current of the MPPT circuit 100 in the next control period reaches the target current.

[0056] For example, in the scenario where the above-mentioned control period is subdivided into an adjustment period, a sampling period, and a deviation calculation period, after the controller obtains the current threshold value and the current adjustment step in the last control period, the input current of the MPPT circuit 100 is first adjusted according to the current threshold value and the current adjustment step in the current adjustment period, and then the power balance judgment of the input power and the demand power is performed through sampling and deviation calculation, and when the power is still unbalanced, the new current threshold value and the new current adjustment step are obtained to continue adjusting the input current of the MPPT circuit 100 in the next control period. Finally, until the input current of the MPPT circuit 100 is less than or equal to the current threshold value, or the input power of the MPPT circuit 100 is not greater than the demand power of the load 300.

[0057] For example, in other embodiments, sampling, deviation calculation, and adjustment can also be performed in parallel in one control period, which is not limited in the present application. For example, the input current is adjusted using the current threshold value and the current adjustment step calculated in the last control period in the current control period. At the same time, after sampling in the current period, the new current threshold value and the new current adjustment step are obtained based on the sampling result, and the new current threshold value and the new current adjustment step will take effect in the adjustment of the next period.

[0058] Step S25: generating a control signal according to the target current and the input voltage and outputting to the MPPT circuit, the control signal being used to control the MPPT circuit to adjust the input current in the next control period.

[0059] It can be understood that the MPPT circuit 100 includes a switch tube, the control signal includes a PWM signal (PWM, Pulse Width Modulation), and the controller generates the control signal (such as the PWM signal) according to the target current and the input voltage, and then outputs to the switch tube of the MPPT circuit 100 in the next control period, so as to control the MPPT circuit 100 to adjust the input current to the target current in the next control period.

[0060] In the embodiments of the present application, when it is determined that the input power of the MPPT circuit 100 is greater than the demand power of the load 300, the current threshold value of the input current of the MPPT circuit 100 is determined according to the input voltage of the MPPT circuit 100 and the demand power, and then the input current of the MPPT circuit 100 is controlled to be gradually adjusted to the current threshold value according to the current adjustment step size in multiple control periods, that is, the output power of the MPPT circuit 100 is gradually reduced to the demand power. Even when the maximum power of the photovoltaic module 200 is greater than the demand power of the load 300, the actual maximum power output by the MPPT circuit 100 will not exceed the demand power of the load 300, thereby avoiding the possibility that the load 300 will be overloaded and the current will be too large to cause adverse effects. Moreover, the current adjustment step size is determined by the input power and the demand power, and the input current of the MPPT circuit 100 is gradually reduced according to the current adjustment step size in continuous control periods, so that the input power and the output power of the MPPT circuit 100 can be quickly balanced, and the output current of the MPPT circuit 100 can be prevented from changing too fast to avoid overshoot.

[0061] Please refer to Figure 3 In some embodiments, the step S21 of obtaining the input voltage, the input current and the input power of the input end of the MPPT circuit in the current control period can include:

[0062] Step S31: detecting the input voltage and the input current of the input end of the MPPT circuit in the current control period.

[0063] Step S32: obtaining the input power according to the input voltage and the obtained input current.

[0064] In the embodiments of the present application, the current sampling circuit and the voltage sampling circuit can also be arranged, the sampling end of the current sampling circuit is connected to the input end of the MPPT circuit 100, and the sampling end of the voltage sampling circuit is connected to the input end of the MPTT circuit 100. The control end of the current sampling circuit and the control end of the voltage sampling circuit are both connected to the controller. In this way, the controller can control the current sampling circuit to collect the current at the input end of the MPPT circuit 100 through the control end of the current sampling circuit, and control the voltage sampling circuit to collect the voltage at the input end of the MPPT circuit 100 through the control end of the voltage sampling circuit, and then obtain the corresponding input power according to the collected current and input voltage at the input end of the MPPT circuit 100.

[0065] Please refer to Figure 4 In some embodiments, the step S23 of determining the current adjustment step length according to the input power and the demand power can include:

[0066] Step S41: calculating a first power difference value between the input power and the demand power.

[0067] Step S42: matching the first power difference value in a preset current step length library to obtain a corresponding current adjustment step length, and the preset current step length library stores preset current adjustment step lengths corresponding to different power difference values.

[0068] In the embodiments of the present application, the above-mentioned first power difference value can represent the degree of power imbalance between the MPPT circuit 100 and the load 300, that is, the greater the first power difference value, the greater the degree of power imbalance between the MPTT circuit 100 and the load 300. It can be understood that, in order to quickly achieve power balance between the MPPT circuit 100 and the load 300 by adjusting the input current, the first power difference value is positively correlated with the current adjustment step length, that is, the greater the first power difference value, the greater the corresponding current adjustment step length. When the first power difference value is small, it indicates that the degree of power imbalance between the MPPT circuit 100 and the load 300 is small, and a relatively small current adjustment step length can avoid overshoot.

[0069] In some embodiments, a memory can also be arranged, the memory is connected to the controller, and the memory stores the above-mentioned current step length library, so that the controller can obtain the corresponding current adjustment step length from the current step length library of the memory after calculating the first power difference value. Alternatively, the memory can also store a relationship function or a relationship curve between the power difference value and the current adjustment step length, and the controller can obtain the corresponding current adjustment step length by substituting the first power difference value into the relationship function or the relationship curve retrieved from the memory and then performing operation. It can be understood that the current adjustment step length corresponding to the power difference value in the above-mentioned preset current step length library, the relationship function, and the relationship curve, etc. can all be obtained through experiments, which are not limited here.

[0070] Referring to Figure 5 In some embodiments, the determining, in step S24, of the target current for the next control period according to the current threshold, the current adjustment step and the input current of the current control period, can include:

[0071] Step S51: obtaining a first current value of the output of the current loop of the MPPT circuit.

[0072] In the embodiments of the present application, the current loop includes the current loop control process of the input current of the MPPT circuit 100, and the controller executes the current loop control process. The first current value at this time is the output value of the current loop. When the controller executes the current loop control program, the input current of the current control period is obtained, and the target current for adjusting the input current of the next control period is obtained by subtracting the current adjustment step from the input current, so as to gradually approach the current threshold by the input current, and gradually approach the demand power by the output power of the MPPT circuit 100.

[0073] Step S52: when the first current value is the current threshold and the input current of the current control period is greater than the current threshold, subtracting the current adjustment step from the input current of the current control period to obtain the target current of the next control period.

[0074] Step S53: when the first current value is the current threshold and the input current of the current control period is less than or equal to the current threshold, determining the current threshold as the target current of the next control period.

[0075] In this embodiment, the target current is the current value that the input current of the MPPT circuit 100 needs to reach in the next control cycle. After obtaining the first current value through the current loop, the controller compares the first current value with the current threshold value to ensure that the first current value does not exceed the current threshold value before comparing the input current with the current threshold value. When it is determined that the input current is greater than the current threshold value, the target current for the next control cycle is obtained by subtracting the current adjustment step size from the input current, thereby avoiding overshoot of the input current of the MPPT circuit 100 and ensuring that the output power of the MPPT circuit 100 and the power demand of the load 300 can reach power balance after multiple control cycles. In traditional control schemes, after determining the current threshold value, the target current is quickly adjusted to the current threshold value, which can easily lead to large current impacts on the load, affecting the load's usage authorization and causing overshoot problems. In this embodiment, after determining that the first current value is the current threshold, the method further determines whether the current input current is greater than the current threshold. If it is greater, the first current value will not be used directly as the target current. Instead, further restrictions will be imposed, and the target current for the next control cycle will be obtained by subtracting the current adjustment step size from the input current. This gradually reduces the target current to the current threshold, achieving a balance between the input power and the load's required power without causing a large current surge.

[0076] Please refer to Figure 6 This is a flowchart illustrating another method for determining the target current of the next control cycle provided in an embodiment of this application. Figure 6 This includes steps S61-S66, and steps S64-S66 are the same as steps S51-S53 described above, and will not be repeated here. Figure 5 compared to, Figure 6 The method shown also includes:

[0077] Step S61: If the input power is greater than the required power, update the upper limit of the current loop output to the current threshold value.

[0078] Step S62: When the output value of the current loop is not greater than the current threshold value, determine the output value of the current loop as the first current value.

[0079] Step S63: When the output value of the current loop is greater than the current threshold value, determine that the output value of the current loop is the current threshold value.

[0080] In some application scenarios, the MPPT circuit 100 can be loop controlled by a voltage loop and a current loop as described above, and the voltage loop and the current loop constitute a loop control system of the MPPT circuit 100. It can be understood that the above-mentioned voltage loop includes a voltage loop control process of the input voltage of the MPPT circuit 100, and the controller executes the voltage loop control process. When the controller runs the above-mentioned voltage loop control program, a given voltage reference value is referred to in the current period, the input voltage of the MPPT circuit 100 is adjusted to approach the given voltage reference value, and an initial current reference value is calculated according to the adjusted input voltage, the initial current reference value is input to the above-mentioned current loop with the input current, and steps S51 to S53 or steps S61 to S66 are executed. In some embodiments, the above-mentioned given voltage reference value includes the rated voltage of the load 300.

[0081] The loop control system can be implemented in a software manner, such as an application program running in the controller. Alternatively, the loop control system of the MPPT circuit 100 can be implemented in a hardware circuit manner, such as adding a loop control circuit in the MPPT circuit 100, which is not limited here.

[0082] Please refer to Figure 7 , the loop control system 700 includes a first voltage loop 710, a current loop 720, and a current limiting module 730.

[0083] The first voltage loop 710 includes a first deviation calculation unit 711 and a first PID unit 712 (PID, Proportion Integral Differential algorithm). The current loop 720 includes a second deviation calculation unit 721 and a second PID unit 722. The current limiting module 730 includes a current limiting unit 731. The first deviation calculation unit 711 is configured to calculate a first deviation value of the input voltage U PV of the MPPT circuit 100 from a given voltage reference value U inref . The first PID unit 712 is configured to calculate the above-mentioned initial current reference value I ref after PID control according to the first deviation value. The second deviation calculation unit 721 is configured to calculate a second deviation value of the input current I of the MPPT circuit 100 from the initial current reference value I ref . The second PID unit 722 is configured to obtain the initial expected value of the input current I PV of the next control period, i.e., the first current value I, according to the second deviation value. The current limiting unit 731 is configured to output I OUT after current limiting of the first current value I according to the above-mentioned current threshold value I1. Specifically, when I OUT= I, when I ≥ I1I OUT = I1.

[0084] In some embodiments, referring to Figure 8 , the loop control system 600 of the first current value includes: a first voltage loop 810, a current loop 820, a current limiting module 830, a second voltage loop 840 and a MIN module 850.

[0085] The first voltage loop 810 includes a first deviation calculation unit 811 and a first PID unit 812. The current loop 820 includes a second deviation calculation unit 821 and a second PID unit 822. The current limiting module 830 includes a current limiting unit 831. The first voltage loop 810, the current loop 820 and the current limiting module 830 are the same as the first voltage loop 710, the current loop 720 and the current limiting module 730 in the loop control system 700 described above, and will not be repeated here. The first voltage loop 810 calculates the first current reference value. Figure 7

[0086] The second voltage loop 840 includes a third deviation calculation unit 841 and a third PID unit 842. The third deviation calculation unit 841 is used to calculate the third deviation value of the output voltage U mp of the MPPT circuit 100 from the output voltage limit value U outref . The third PID unit 842 is used to calculate the second current reference value after PID control according to the third deviation value.

[0087] The MIN module 740 is used to take the minimum value of the first current reference value and the second current reference value as the initial current reference value I ref , and output the initial current reference value to the current loop 820.

[0088] It can be understood that Figure 7 the modules and units in the loop control system 700 shown in Figure 8 and the loop control system 800 shown in can be all or partially implemented by software, hardware, firmware or any combination thereof.

[0089] In some embodiments, the step S25 of generating a control signal according to the target current and the input voltage and outputting it to the MPPT circuit, the control signal being used to control the MPPT circuit to adjust the input current of the next control period can include: (1) determining the voltage reference value of the output voltage of the next control period according to the target current, (2) determining the first duty ratio of the MPPT circuit 100 of the next control period according to the voltage reference value and the input voltage of the current control period, (3) generating the control signal according to the first duty ratio, and sending the control signal to the switch tube of the MPPT circuit 100 in the next control period.

[0090] ​It can be understood that the aforementioned voltage reference value is the expected output voltage of the MPPT circuit 100 in the next control cycle. The controller can calculate the voltage reference value of the MPPT circuit 100's output voltage in the next control cycle by using the target current and the impedance of the MPPT circuit 100. The impedance of the MPPT circuit 100 can be pre-stored in the controller or a memory connected to it.

[0091] In this embodiment of the application, the voltage reference value can be obtained by formula (2):

[0092] U1 = I OUT ×R mp Formula (2).

[0093] In the formula, U1 is the voltage reference value of the output voltage in the next control cycle, and I OUT For the target current, R mp This is the impedance value of MPPT circuit 100.

[0094] The aforementioned first duty cycle refers to the duty cycle of the control signal in the next control cycle of the MPPT circuit 100 that drives the switching transistor. It can be understood that the controller can control the output voltage of the MPPT circuit 100 by transmitting the aforementioned control signal to the control terminal of the switching transistor. Therefore, by modulating the duty cycle of the control signal in the next control cycle to the first duty cycle, the output voltage of the MPPT circuit 100 can be controlled to the aforementioned voltage reference value in the next control cycle.

[0095] In this embodiment of the application, taking the MPPT circuit as a boost circuit as an example, the first duty cycle can be obtained by formula (3):

[0096] D = 1 - U PV / U1 formula (3).

[0097] In the formula, D is the first duty cycle of the MPPT circuit 100 in the next control cycle, and U PV U1 is the input voltage of the MPPT circuit 100 in the current control cycle, and U1 is the voltage reference value of the output voltage in the next control cycle.

[0098] Please refer to Figure 9 , Figure 9 This is a schematic flowchart illustrating the power balance adjustment method for a second MPPT circuit provided in an embodiment of this application. Figure 9 The power balance adjustment method shown includes steps S91-S95, which are related to... Figure 2 Steps S21-S25 shown are the same and will not be repeated here. Figure 9 The power balance adjustment method shown also includes:

[0099] Step S96: If the input power is less than the required power, determine the reference voltage of the maximum power point according to the preset MPPT algorithm.

[0100] Step S97: Generate a second drive signal based on the reference voltage, input current and input voltage, and send the second drive signal to the switching transistor of the MPPT circuit in the next control cycle. The second drive signal is used to drive the switching transistor to make the MPPT circuit work at the maximum power point of the photovoltaic module.

[0101] In this embodiment, when the controller determines that the input power of the PPPT circuit 100 is less than the required power of the load 300, it can determine that the output power of the MPPT circuit 100 cannot meet the required power of the load 300. Therefore, the MPPT circuit 100 can operate normally, that is, it executes the MPPT algorithm to operate at the maximum power point of the photovoltaic module 300. At this time, the controller generates a second drive signal according to the preset MPPT algorithm, and through the second drive signal, makes the MPPT circuit 100 operate at the maximum power point of the photovoltaic module 300, so that the output power of the MPPT circuit 100 meets the requirements of the load 300 as much as possible, reducing the possibility of the load 300 stopping operation due to insufficient power.

[0102] It is understood that the MPPT algorithm may employ existing algorithms in related technologies, and this application does not impose any restrictions on this.

[0103] It is understood that in some embodiments, in Figure 10 In the scenario shown, the output of the MPPT circuit 100 is also used to connect to the energy storage device 400.

[0104] Correspondingly, please refer to the following in this scenario as well. Figure 11 , Figure 11 This is a flowchart illustrating the power balance adjustment method for the third MPPT circuit provided in this application embodiment. Wherein, Figure 10 The steps S111, S113-S115 shown are Figure 2 The steps S21 and S23-S25 shown are the same or similar, and will not be repeated here. Figure 11 The power balance adjustment method shown also includes:

[0105] Step S112: If the input power is greater than the required power and the energy storage device is not connected or the connected energy storage device does not have charging capability, obtain the current threshold value of the input current based on the input voltage and the required power, and execute steps S113-S115.

[0106] Step S116: If the input power is greater than the required power and the energy storage device has charging capability, calculate the second power difference between the input power and the required power.

[0107] It can be understood that the MPPT circuit 100 can further include a third interface connected to the output end of the MPPT circuit 100. The energy storage device 400 is connected to the MPPT circuit 100 through the third interface, and the third interface is also connected to the controller. In this way, the controller can communicate with the energy storage device 400 through the third interface, obtain the charging data of the energy storage device 400, and determine whether the energy storage device 400 has charging capability. For example, the controller obtains the current voltage value of the energy storage device 400 by detecting the voltage-related pin of the energy storage device 400 in the third interface. Whether the energy storage device 400 has charging capability is determined by judging whether the current voltage value is lower than the preset voltage value. In some embodiments, the third interface can also be connected to the second interface.

[0108] Step S117: controlling the MPPT circuit to output power to charge the energy storage device according to the second power difference.

[0109] It can be understood that part of the second power difference output by the MPPT circuit 100 can cause the load 300 to overload, and in the case where the energy storage device 400 has charging capability, receiving part of the second power difference by the energy storage device 400 and storing it can solve the problem that the load 300 may be overloaded.

[0110] For example, in the scenario where the MPPT circuit 100 connects the energy storage device 400 through the third interface, after calculating the second power difference, the controller can control the output end of the MPPT circuit 100 to transmit part of the second power difference to the energy storage device 400 through the third interface, and control the output end of the MPPT circuit 100 to output the required power to the load 300 through the second interface.

[0111] In the embodiments of the present application, by connecting the energy storage device 400 with the output end of the MPPT circuit 100, when the input power is greater than the required power and it is determined that the energy storage device 400 has charging capability, part of the second power difference is received by the energy storage device 400, which can balance the power between the MPPT circuit 100 and the load 300, and storing the excess power by the energy storage device 400 can also ensure that the power is not wasted.

[0112] It can be understood that in the scenario shown in Figure 9 , please refer to Figure 12 , Figure 12 The fourth power balance adjustment method of the MPPT circuit provided in the embodiments of the present application is shown in the flowchart. Among them, Figure 11 The power balance adjustment method shown in the step S121-S125 is the same as the step S111-S115 shown in Figure 11 , and will not be repeated here.Figure 11 The power balance adjustment method shown also includes:

[0113] Step S126: If the input power is less than the demand power, a third power difference between the demand power and the input power is calculated.

[0114] It can be understood that the third power difference is the part of power that the load 300 is lacking to reach the demand power, and that the current output power of the MPPT circuit 100 failing to reach the demand power of the load 300 can cause the load 300 to fail to work normally. By using the energy storage device 400 to participate in power supply for the load 300, the problem that the load 300 can fail to work normally can be solved.

[0115] Step S127: The energy storage device is controlled to discharge according to the third power difference, so as to jointly supply power for the load with the MPPT circuit.

[0116] For example, in the scenario where the MPPT circuit 100 is connected to the energy storage device 400 through the third interface, and the third interface is connected to the second interface, after the controller calculates the third power difference, the controller can transmit the third power difference to the energy storage device 400 through the third interface, so that the energy storage device 400 outputs the output power of the third power difference to the second interface through the third interface, and then the second interface jointly supplies power for the load 300 with the output power of the MPPT circuit 100 and the output power of the energy storage device 400.

[0117] In the embodiment of the present application, by connecting the energy storage device 400 to the output end of the MPPT circuit 100, when the input power is less than the demand power, the energy storage device 400 is used to supplement the part of power that the load 300 is lacking to reach the demand power, so as to avoid the load 300 failing to work normally and improve user experience.

[0118] Please refer to Figure 13 , Figure 13 A schematic block diagram of a power supply device 10 provided in the embodiment of the present application is shown. The power supply device 10 includes an MPPT 100 and a controller 101.

[0119] In the embodiment of the present application, the input end of the MPPT circuit 100 is used to connect a photovoltaic module 200, the output end of the MPPT circuit 100 is used to connect a load 300, and the controlled end of the MPPT circuit 100 is connected to the controller 101. The controller is used to execute the power balance adjustment method in any of the above embodiments.

[0120] Please refer to Figure 14 , Figure 14 A schematic block diagram of an energy storage power generation system 1 provided in the embodiment of the present application is shown. The energy storage power generation system 1 includes a photovoltaic module 20 and the power supply device 10 in the above embodiment.

[0121] It can be understood that the power supply device 10 and the energy storage power generation system 1 provided by the embodiments of the present application can achieve the beneficial effects of the corresponding power balance adjustment method provided above, which will not be repeated here.

[0122] The embodiments of the present application also provide a storage medium, which stores a computer program. When the computer program is executed by a controller, the controller executes the power balance adjustment method in any of the above embodiments.

[0123] The embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the present application.

Claims

1. A method for power balancing regulation of an MPPT circuit, characterized in that, The input end of the MPPT circuit is used for connecting a photovoltaic module, and the output end of the MPPT circuit is used for connecting a load; wherein the power balance adjustment method comprises: acquiring an input voltage, an input current and an input power of the input end of the MPPT circuit in a current control period, and acquiring a demand power of the load; if the input power is greater than the demand power, obtaining a current threshold value of the input current based on the input voltage and the demand power; determining a current adjustment step based on the input power and the demand power; determining a target current of a next control period based on the current threshold value, the current adjustment step and the input current of the current control period; the target current is less than the input current and greater than or equal to the current threshold value; generating a control signal based on the target current and the input voltage and outputting the control signal to the MPPT circuit, the control signal being used for controlling the MPPT circuit to adjust the input current of the next control period; the determining of the current adjustment step based on the input power and the demand power comprises: calculating a first power difference value of the input power and the demand power; matching the first power difference value in a preset current step library to obtain a corresponding current adjustment step; the preset current step library stores preset current adjustment steps corresponding to different power difference values; the determining of the target current of the next control period based on the current threshold value, the current adjustment step and the input current of the current control period comprises: acquiring a first current value output by a current loop of the MPPT circuit; when the first current value is the current threshold value and the input current of the current control period is greater than the current threshold value, subtracting the current adjustment step from the input current of the current control period to obtain the target current of the next control period; when the first current value is the current threshold value and the input current of the current control period is less than or equal to the current threshold value, determining the current threshold value as the target current of the next control period.

2. The power balancing regulation method of claim 1, wherein, the acquiring of the input voltage, the input current and the input power of the input end of the MPPT circuit in the current control period comprises: detecting the input voltage and the input current of the input end of the MPPT circuit in the current control period; and obtaining the input power based on the input voltage and the obtained input current.

3. The power balancing regulation method of claim 1, wherein, the method further comprises: if the input power is greater than the demand power, updating an upper limit of the output of the current loop to the current threshold value; when the output value of the current loop is not greater than the current threshold value, determining the output value of the current loop as the first current value; when the output value of the current loop is greater than the current threshold value, determining the output value of the current loop as the current threshold value.

4. The power balancing regulation method of claim 1, wherein, the power balance adjustment method further comprises: if the input power is less than the demand power, determining a reference voltage of a maximum power point based on a preset MPPT algorithm; A second driving signal is generated according to the reference voltage, the input current and the input voltage, and the second driving signal is sent to a switch tube of the MPPT circuit in a next control period, the second driving signal being used to drive the switch tube to make the MPPT circuit work at the maximum power point of the photovoltaic module.

5. The power balancing regulation method of claim 1, wherein, The output end of the MPPT circuit is also used to connect to an energy storage device, and after the input voltage, the input current and the input power of the input end of the MPPT circuit and the demand power of the load are acquired in a current control period, the power balance adjustment method further comprises: If the input power is greater than the demand power and the energy storage device is not connected or the connected energy storage device does not have charging capability, the step of obtaining the current threshold value of the input current based on the input voltage and the demand power is performed; If the input power is greater than the demand power and the energy storage device has charging capability, a second power difference value between the input power and the demand power is calculated; The output power of the MPPT circuit is controlled according to the second power difference value to charge the energy storage device.

6. The power balancing regulation method of claim 1, wherein, The output end of the MPPT circuit is also used to connect to an energy storage device, and the power balance adjustment method further comprises: If the input power is less than the demand power, a third power difference value between the demand power and the input power is calculated; The energy storage device is controlled to discharge according to the third power difference value to jointly supply power to the load with the MPPT circuit.

7. A power supply device, characterized by comprising: The MPPT circuit and a controller are included, the input end of the MPPT circuit is used to connect to a photovoltaic module, the output end of the MPPT circuit is used to connect to a load, and the controlled end of the MPPT circuit is connected to the controller; wherein the controller is used to perform the power balance adjustment method according to any one of claims 1-6.

8. An energy storage power generation system comprising a photovoltaic module and a power supply device according to claim 7.

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