Storage battery direct current charging control method, charging management module and mobile power supply

Abstract

The invention discloses a storage battery direct current charging control method, a charging management module and a mobile power supply. The mobile power supply comprises a charging management module, a charging module and a battery. The storage battery direct-current charging control method is applied to a charging management module in a mobile power supply, and comprises the following steps: firstly, detecting the internal resistance value of a charger, identifying the type of the charger according to the internal resistance value, then controlling a pulse width modulation signal of the charging module, and detecting the maximum charging power of a charger power supply; and finally, according to the identified charger type, selecting a charging control strategy to control the charging module to charge the storage battery by using the maximum charging power. According to the invention, the storage battery can be automatically adapted to different DC charging power supply types, different control modes are adopted for different charging power supplies, unique requirements of different charging power supplies are met, and efficient charging of the storage battery under various charging power supplies is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic circuits, and in particular to a battery direct current charging control method, a charging management module and a mobile power source. Background Art

[0002] In modern society, batteries, as energy storage carriers, are widely used in many fields such as outdoor mobile power supplies, electric vehicles, energy storage power stations, communication base stations, etc., providing power guarantee for the stable operation of various equipment. In the use of batteries, the charging link is very important, and its efficiency and quality directly affect the performance and service life of the battery.

[0003] For outdoor mobile power supplies, there are generally only two charging methods for DC power supplies for charging batteries in outdoor mobile power supplies on the market: power adapters and photovoltaic power supplies. However, when charging with a power adapter, due to the differences in output rated voltage and output rated power of power adapters produced by different manufacturers, and the output power of the power adapter is relatively fixed, if the control strategy cannot accurately match the adapter power with the battery requirements, the charging current may be too small when the battery power is low and needs to be quickly replenished, extending the overall charging time; and when the battery is close to full power, the charging current is not reduced in time, resulting in an increased risk of battery overcharging and affecting battery life. When charging with a photovoltaic power supply, the photovoltaic power supply is affected by environmental factors such as light intensity and temperature, and the output voltage and current fluctuate greatly. Traditional control strategies are difficult to track these changes in real time, and charging interruptions due to voltage fluctuations are prone to occur, or when the light is strong, the high output power of the photovoltaic power supply cannot be reasonably utilized, resulting in low charging efficiency and failure to fully utilize solar energy resources.

[0004] In summary, the existing battery DC charging control strategies have serious deficiencies. On the one hand, these strategies are difficult to automatically adapt to different DC charging power supplies. Different DC charging power supplies have differences in output voltage, current characteristics, power, etc. Traditional control strategies cannot be flexibly adjusted according to these differences, resulting in the inability to fully utilize the charging performance of the battery when using different charging power supplies. On the other hand, the existing charging control strategies do not adopt differentiated control methods for different charging power supplies. A single control strategy cannot meet the unique needs of different charging power supplies and cannot achieve efficient charging of batteries under various charging power supplies. Summary of the invention

[0005] The purpose of the present invention is to provide a battery DC charging control method, a charging management module and a mobile power supply, which can enable the battery to automatically adapt to different DC charging power supply types, and adopt differentiated control methods for different charging power supplies to meet the unique requirements of different charging power supplies, and realize efficient charging of the battery under various charging power supplies.

[0006] To achieve the above objectives, an embodiment of the present invention provides a battery DC charging control method, which is applied to a charging management module in a mobile power supply, wherein the mobile power supply also includes a charging module and a battery; the battery DC charging control method includes:

[0007] Detecting the internal resistance value of the charger, and identifying the type of the charger according to the internal resistance value; wherein the charger types include power adapters and photovoltaic power chargers;

[0008] Controlling the pulse width modulation signal of the charging module to detect the maximum charging power of the charger;

[0009] According to the identified charger type, a charging control strategy is selected to control the charging module to charge the battery using the maximum charging power.

[0010] In an optional embodiment, detecting the internal resistance value of the charger and identifying the type of the charger according to the internal resistance value includes:

[0011] When it is detected that a power source is connected, detecting and recording the open circuit voltage of the charging module;

[0012] driving the charging module to operate at a first operating current, detecting and recording an operating voltage of the charging module when operating at the first operating current;

[0013] Calculating an internal resistance value of the charger according to the open circuit voltage, the operating current and the operating voltage;

[0014] If the internal resistance value is less than a first threshold value, the charger type is identified as a power adapter; if the internal resistance value is greater than the first threshold value, the charger type is identified as a photovoltaic power charger.

[0015] In an optional embodiment, the first threshold is 0.3 ohms.

[0016] In an optional embodiment, the controlling the pulse width modulation signal of the charging module to detect the maximum charging power of the charger includes:

[0017] gradually increasing the pulse width modulation signal of the charging module to increase the working current of the charging module;

[0018] Detecting and recording the operating voltage and corresponding operating current of the charging module under different operating currents;

[0019] Calculate the current charging power according to the corresponding working voltage and the corresponding working current;

[0020] When the current charging power decreases as the pulse width modulation signal increases, the maximum charging power and the corresponding maximum charging current and maximum charging voltage are obtained.

[0021] In an optional embodiment, the selecting, according to the identified charger type, a charging control strategy to control the charging module to charge the battery using the maximum charging power includes:

[0022] When the charger type is a power adapter, a PID closed-loop control algorithm is used to control the charging module to charge the battery using the maximum charging power;

[0023] When the charger type is a photovoltaic power charger, a PID closed-loop control algorithm is used in combination with an asymmetric, variable step size and an uninterrupted trial method to control the charging module to charge the battery with the maximum charging power.

[0024] In an optional embodiment, when the charger type is a power adapter, a PID closed-loop control algorithm is used to control the charging module to charge the battery using the maximum charging power, including:

[0025] When the charger type is a power adapter, a PID closed-loop control algorithm is used to control the working current of the charging module to stably operate at the maximum charging current;

[0026] Detecting the operating temperature of the charging module;

[0027] If the operating temperature of the charging module exceeds a first set temperature, the charging power of the charging module is reduced. When the operating temperature of the charging module is steadily reduced, the charging module is controlled to charge the battery with the maximum charging power.

[0028] In an optional embodiment, when the charger type is a photovoltaic power charger, a PID closed-loop control algorithm is used in combination with an asymmetric, variable step size, and uninterrupted trial method to control the charging module to charge the battery with the maximum charging power, including:

[0029] When the charger type is a photovoltaic power charger, a PID closed-loop control algorithm is used in combination with an asymmetric, variable step size, and an uninterrupted trial method to adjust the pulse width modulation signal, so as to control the working voltage of the charging module to stably operate at the maximum charging voltage;

[0030] After each adjustment of the pulse width modulation signal, detecting the operating temperature of the charging module;

[0031] If the operating temperature of the charging module exceeds the second set temperature, the charging power of the charging module is reduced. When the operating temperature of the charging module is steadily reduced, the charging module is controlled to charge the battery according to the maximum charging power.

[0032] In an optional embodiment, the PID closed-loop control algorithm is combined with an asymmetric, variable step size and an uninterrupted trial method to adjust the pulse width modulation signal to control the working voltage of the charging module to stably operate at the maximum charging voltage, including:

[0033] Detecting the operating voltage of the charging module;

[0034] If the working voltage is greater than the maximum charging voltage, the pulse width modulation signal is increased; wherein, when the difference between the working voltage and the maximum charging voltage is greater than a preset threshold, the pulse width modulation signal is greatly increased for testing, and when the difference between the working voltage and the maximum charging voltage is less than the preset threshold, the pulse width modulation signal is slightly increased for testing;

[0035] If the working voltage is less than the maximum charging voltage, the pulse width modulation signal is greatly reduced to test.

[0036] To achieve the above objectives, an embodiment of the present invention further provides a charging management module, which is used to execute the battery DC charging control method as described in any one of the above items.

[0037] To achieve the above objectives, an embodiment of the present invention further provides a mobile power source, comprising a charging module, a storage battery and the charging management module as described above; the charging module comprises a buck-boost converter;

[0038] The charging management module is used to control the charging module to charge the battery.

[0039] Compared with the prior art, the battery DC charging control method provided by the embodiment of the present invention can simply and efficiently determine the power type of the charger by detecting the internal resistance of the charger power supply; after accurately identifying the charger type, the actual power supply capacity of the charger can be understood by detecting and recording the maximum charging power of the charger, and the charging module can be operated within the maximum power range allowed by the charger according to the maximum charging power, thereby making full use of the power output of the charger and improving the charging efficiency; finally, according to the detected power type of the charger, different control strategies are adaptively selected to control the charger to charge the battery with the maximum power, so that the charger can charge the battery with the highest efficiency. The present invention can make the battery automatically adapt to different DC charging power supply types, and adopt differentiated control methods for different charging power supplies to meet the unique needs of different charging power supplies, and realize efficient charging of the battery under various charging power supplies. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solution of the present invention, the drawings used in the implementation mode will be briefly introduced below. Obviously, the drawings described below are only some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 It is a structural block diagram and charging schematic diagram of a mobile power supply provided by an embodiment of the present invention;

[0042] Figure 2 is a flow chart of a battery DC charging control method provided by an embodiment of the present invention;

[0043] Figure 3 is a characteristic curve diagram of a power adapter provided by an embodiment of the present invention;

[0044] Figure 4 is a characteristic curve diagram of a photovoltaic power charger provided by an embodiment of the present invention;

[0045] Figure 5 is a schematic diagram of a flow chart of identifying a charger type provided by an embodiment of the present invention;

[0046] Figure 6 is a schematic diagram of a flow chart of detecting the maximum charging power of a charger provided by an embodiment of the present invention;

[0047] Figure 7 This is a schematic diagram of a charging control flow of a power adapter provided by an embodiment of the present invention;

[0048] Figure 8 The present invention provides a schematic diagram of a charging control process of a photovoltaic power charger. DETAILED DESCRIPTION

[0049] 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.

[0050] It should be noted that when an element is referred to as being "connected to" another element, it can be directly connected to another element or indirectly connected to the other element. It is understandable that the "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if the connected circuits, modules, units, etc. have the transmission of electrical signals or data to each other. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first" and "second" can explicitly or implicitly include one or more of the features. "At least one" means one or more, and "multiple" means two or more.

[0051] See also Figure 1 , Figure 1 1 is a structural block diagram and charging schematic diagram of a mobile power supply provided by an embodiment of the present invention. Figure 1 As shown, the mobile power supply includes a charging management module, a charging module and a battery, which reveals the composition and interconnection relationship of each key component inside the mobile power supply, as well as the process of electric energy flowing therein.

[0052] like Figure 1 As shown in the figure, the mobile power supply mainly consists of three core parts, namely the charging management module, the charging module and the battery. As the "MCU" of the entire mobile power supply, the charging management module is used to execute the battery DC charging control strategy to regulate the working state of the charging module. Under the precise regulation of the charging management module, it processes and converts the electric energy input by the charger, and charges the battery according to the set strategy using the maximum charging power detected. The battery, as the mobile power supply, is the energy core of the entire device. It is responsible for receiving and storing the electric energy transmitted from the charging module. When the external device needs electricity, it releases the stored electric energy to power the external device and meet the user's power needs in different scenarios.

[0053] However, the current battery DC charging control strategy has serious deficiencies. Therefore, an embodiment of the present invention provides a battery DC charging control method, which is applied to the charging management module of the mobile power supply. Figure 2, the battery DC charging control method comprises:

[0054] S1. Detecting the internal resistance value of the charger, and identifying the type of the charger according to the internal resistance value; wherein the charger types include power adapters and photovoltaic power chargers;

[0055] It should be noted that currently, the main charging methods for batteries in outdoor mobile power supplies on the market are power adapters and photovoltaic power chargers. Therefore, the embodiment of the present invention mainly identifies the type of charger, whether it is a power adapter or a photovoltaic power charger. Among them, most chargers such as power adapters are connected to a transformer through a thick power cord, which is then transformed and rectified to output stable direct current. Photovoltaic power chargers are devices that use the solar photovoltaic effect to convert solar energy into electrical energy and provide charging functions for various devices or batteries.

[0056] In an optional embodiment, detecting the internal resistance value of the charger and identifying the type of the charger according to the internal resistance value includes:

[0057] When it is detected that a power source is connected, detecting and recording the open circuit voltage of the charging module;

[0058] driving the charging module to operate at a first operating current, detecting and recording an operating voltage of the charging module when operating at the first operating current;

[0059] Calculating an internal resistance value of the charger according to the open circuit voltage, the operating current and the operating voltage;

[0060] If the internal resistance value is less than the first threshold, the charger type is identified as a power adapter; if the internal resistance value is greater than the first threshold, the charger type is identified as a photovoltaic power charger. Preferably, the first threshold is 0.3 ohms.

[0061] It should be noted that the inventors have studied the characteristic curves of most power adapters and photovoltaic power chargers currently on the market and found that there is a relatively obvious difference between the internal resistance of the power adapter and the internal resistance of the photovoltaic charger.

[0062] See also Figure 3-4 , Figure 3 is a characteristic curve diagram of a power adapter provided by an embodiment of the present invention, Figure 4 It is a characteristic curve diagram of the photovoltaic power charger provided by an embodiment of the present invention.

[0063] like Figure 3As shown in the figure, the IU curve of the power adapter charger is a straight line within a certain range, indicating that the current I is approximately proportional to the voltage U. According to Ohm's law (R = U / I), the inverse of the slope of the straight line reflects the internal resistance to a certain extent, and the internal resistance is relatively stable as a constant. Therefore Figure 3 The greater the slope of the IU curve, the smaller the internal resistance of the power adapter. The PU curve of the power adapter charger is a parabola (within a certain range), from P = U2 / R, when the resistance R is a constant, the power is proportional to the square of the voltage.

[0064] like Figure 4 As shown, the IU curve of the photovoltaic power charger is a curve, which means that the current I and the voltage U are not in a simple linear relationship, that is, as the voltage changes, its equivalent internal resistance (affected by factors such as the characteristics of the photovoltaic cell) changes continuously. Figure 4 The smaller the slope of the IU curve, the greater the internal resistance of the photovoltaic power charger. The PU curve of the photovoltaic power charger is a curve that rises first and then falls, indicating that the relationship between power and voltage is not simply proportional to the square of the voltage. Its internal resistance changes with the working state, which is obviously different from the internal resistance characteristics of the power adapter charger.

[0065] Furthermore, although the internal resistance of the power adapter and the photovoltaic power charger is not absolutely fixed, based on the obvious difference between the internal resistance of the power adapter and the internal resistance of the photovoltaic charger, the inventors have conducted actual measurements on a large number of power adapters and photovoltaic power chargers on the market, and obtained a large amount of empirical data indicating that basically the internal resistance of the power adapter is relatively small, below 0.3 ohms, while the internal resistance of the photovoltaic power charger is relatively large, above 0.3 ohms.

[0066] It should be noted that in the embodiment of the present invention, this preset internal resistance threshold is not a conventionally known value in the art. Generally, if you want to obtain the internal resistance value of the charger, you need to measure it through a special instrument, which means that if you need to measure the internal resistance of the charger through the internal resistance value before charging the device, you need to add additional software or hardware devices. Therefore, in general, those skilled in the art will not identify the charger based on the internal resistance of the charger. However, by studying the internal resistance value law of the charger, the embodiment of the present invention only needs to measure the voltage and current of the charger, without adding additional software or hardware devices, and without using special instruments to identify the type of charger during charging, so that the charging strategy and parameters can be automatically adjusted during subsequent charging, thereby improving charging efficiency and extending battery life, while also enhancing the compatibility and stability of the entire charging system.

[0067] See also Figure 5 , Figure 5 FIG. 1 is a flow chart of identifying the type of charger provided by an embodiment of the present invention. Figure 1 and Figure 5As shown, the charger is connected to the mobile power supply in the dotted box through the charging interface. When the charging management module detects that a charging power supply is connected, the charging management module starts power supply identification, and detects and records the open circuit voltage Voc at the same time. Then the charging management module drives the charging module to work at a specific working current I1 (for example, 1A), detects and records the working voltage V1 at 1A, and then calculates the internal resistance of the charging power supply according to the formula R=(Voc-V1) / I1. If the internal resistance R is less than the threshold value Rth (such as 0.3 ohms), it is determined to be charged using a power adapter. If the internal resistance is greater than the threshold value, it is determined to be charged using a photovoltaic power charger.

[0068] S2, controlling the pulse width modulation signal of the charging module to detect the maximum charging power of the charger;

[0069] In an optional embodiment, the controlling the pulse width modulation signal of the charging module to detect the maximum charging power of the charger includes:

[0070] gradually increasing the pulse width modulation signal of the charging module to increase the working current of the charging module;

[0071] Detecting and recording the operating voltage and corresponding operating current of the charging module under different operating currents;

[0072] Calculate the current charging power according to the corresponding working voltage and the corresponding working current;

[0073] When the current charging power decreases as the pulse width modulation signal increases, the maximum charging power of the charger and the corresponding maximum charging current and maximum charging voltage are obtained.

[0074] See also Figure 6 , Figure 6 FIG. 1 is a flow chart of detecting the maximum charging power of a charger provided by an embodiment of the present invention. Figure 6As shown, in the specific implementation, the charging management module will first gradually increase the pulse width modulation (PWM) signal of the charging module in a step-by-step manner. The change of the pulse width modulation signal will directly affect the working state of the charging module. By increasing the signal, the working current of the charging module can be steadily increased. In the process of the continuous change of the working current of the charging module, the charging management module will detect and record in real time and accurately the working voltage Vi and the corresponding working current Ii values ​​of the charging module under different working currents. Then, each set of corresponding working voltage and working current data is detected, and the electrical calculation formula (Pi=Vi*Ii) is used to calculate the current charging power. When the charging power decreases with the increase of the pulse width modulation signal PWM, it means that the maximum charging power has been reached, or the charging power has reached the set rated charging power, then the maximum charging power Pmax and the corresponding maximum charging current Imax and maximum charging voltage Vmax are recorded.

[0075] It is worth noting that the method for detecting the maximum charging power in the embodiment of the present invention does not rely on a specific type of charger, is applicable to a variety of charger power sources, and can be dynamically detected according to different charger characteristics, so that the charging system can be compatible with different devices and improve versatility.

[0076] S3. According to the identified charger type, select a charging control strategy to control the charging module to charge the battery using the maximum charging power.

[0077] Specifically, the selecting, according to the identified charger type, a charging control strategy to control the charging module to charge the battery using the maximum charging power includes:

[0078] When the charger type is a power adapter, a PID closed-loop control algorithm is used to control the charging module to charge the battery using the maximum charging power;

[0079] When the charger type is a photovoltaic power charger, a PID closed-loop control algorithm is used in combination with an asymmetric, variable step size and an uninterrupted trial method to control the charging module to charge the battery with the maximum charging power.

[0080] In an optional embodiment, when the charger type is a power adapter, a PID closed-loop control algorithm is used to control the charging module to charge the battery using the maximum charging power, including:

[0081] When the charger type is a power adapter, a PID closed-loop control algorithm is used to control the working current of the charging module to stably operate at the maximum charging current;

[0082] Detecting the operating temperature of the charging module;

[0083] If the operating temperature of the charging module exceeds a first set temperature, the charging power of the charging module is reduced. When the operating temperature of the charging module is steadily reduced, the charging module is controlled to charge the battery with the maximum charging power.

[0084] See also Figure 7 , Figure 7 The present invention provides a schematic diagram of a power adapter charging control process.

[0085] For example, Figure 7 As shown, if the charger type is a power adapter, first detect in real time whether the working current I of the charger is working at the maximum charging current Imax, compare the detected working current I with the maximum charging current Imax, if I is less than Imax, increase the duty cycle of the PWM signal to increase the output power; if I is greater than or equal to Imax, reduce the duty cycle of the PWM signal to reduce the output power. This step uses the PID control principle to adjust the working current so that the charging current works stably at Imax. At the same time, no matter whether the previous step is to increase or decrease PWM, it will then determine whether the temperature of the charging module is too high at this time. If the temperature is not too high, return to the current detection step and continue the cyclic monitoring; if the temperature is too high, reduce PWM and reduce the charging power. When the charging module is stably reduced, resume charging at the maximum charging power.

[0086] In an optional embodiment, when the charger type is a photovoltaic power charger, a PID closed-loop control algorithm is used in combination with an asymmetric, variable step size, and uninterrupted trial method to control the charging module to charge the battery with the maximum charging power, including:

[0087] When the charger type is a photovoltaic power charger, a PID closed-loop control algorithm is used in combination with an asymmetric, variable step size, and an uninterrupted trial method to adjust the pulse width modulation signal, so as to control the working voltage of the charging module to stably operate at the maximum charging voltage;

[0088] After each adjustment of the pulse width modulation signal, detecting the operating temperature of the charging module;

[0089] If the operating temperature of the charging module exceeds the second set temperature, the charging power of the charging module is reduced. When the operating temperature of the charging module is steadily reduced, the charging module is controlled to charge the battery according to the maximum charging power.

[0090] It should be noted that the biggest difference between "using a PID closed-loop control algorithm to control the working current of the charging module to work stably at the maximum charging current" and "using a PID closed-loop control algorithm combined with an asymmetric, variable step size and an uninterrupted trial method to adjust the pulse width modulation signal to control the working voltage of the charging module to work stably at the maximum charging voltage" is the different control purposes. The former is to stabilize the current Imax, and the latter is to stabilize the voltage Vmax. Because the working characteristics of the power adapter and the photovoltaic charger are different, the power adapter can achieve the maximum charging power by stabilizing the current Imax, and the photovoltaic charger can achieve the maximum charging power by stabilizing the voltage Vmax.

[0091] In an optional embodiment, the PID closed-loop control algorithm is combined with an asymmetric, variable step size and an uninterrupted trial method to adjust the pulse width modulation signal to control the working voltage of the charging module to stably operate at the maximum charging voltage, including:

[0092] Detecting the operating voltage of the charging module;

[0093] If the working voltage is greater than the maximum charging voltage, the pulse width modulation signal is increased; wherein, when the difference between the working voltage and the maximum charging voltage is greater than a preset threshold, the pulse width modulation signal is greatly increased for testing, and when the difference between the working voltage and the maximum charging voltage is less than the preset threshold, the pulse width modulation signal is slightly increased for testing;

[0094] If the working voltage is less than the maximum charging voltage, the pulse width modulation signal is greatly reduced to test.

[0095] It should be noted that there is asymmetry in the regulation logic after the working voltage is compared with the maximum charging voltage. When the working voltage is greater than the maximum charging voltage, the pulse width modulation (PWM) signal is increased; and when the working voltage is less than the maximum charging voltage, the PWM signal is reduced. In these two cases, the regulation direction is completely opposite, and it is not a symmetrical regulation mode, which reflects the asymmetric characteristics.

[0096] When the working voltage is greater than the maximum charging voltage, the PWM signal will be adjusted with different amplitudes according to the distance from the maximum charging voltage. When the distance is far, the amplitude will be increased to a greater extent, and when the distance is close, the amplitude will be increased to a smaller extent. The adjustment step size changes dynamically with the difference between the two. When the working voltage is less than the maximum charging voltage, if the working voltage is continuously less than the maximum charging voltage, the PWM signal will be reduced to a greater extent to test, which is different from the adjustment amplitude and method when it is greater than the maximum charging voltage, which also reflects that the step size is variable according to the actual situation.

[0097] The entire probing process is a continuous loop of judgment and adjustment. As long as the charging module is in operation, the working voltage and the maximum charging voltage are continuously compared, and the PWM signal is adjusted accordingly based on the comparison result. This process of comparison and adjustment never stops, constantly probing to find the most suitable PWM signal to stabilize the working current at an ideal state and achieve the maximum charging power.

[0098] It should be noted that when the working voltage is greater than the maximum charging voltage Vmax and is far from Vmax, it indicates a large voltage deviation. If a small PWM change amount is used for adjustment, since the duty cycle change amplitude is small, the adjustment effect on the working voltage will be very weak, and it may take a long time to adjust the voltage to a reasonable range, unable to effectively respond to the problem of excessive voltage in a timely manner. By choosing a large PWM change amount for probing, the duty cycle of the PWM signal can change significantly, thereby having a more significant adjustment effect on the voltage or power in the circuit. In this way, the working voltage can be changed more quickly and adjusted towards a direction close to Vmax to correct the excessive voltage deviation in a timely manner.

[0099] See Figure 8 , Figure 8 is a schematic diagram of the charging control process of a photovoltaic power charger provided by an embodiment of the present invention. As Figure 8 shown, the detected working voltage V is compared with the maximum charging voltage Vmax. If V > Vmax, the duty cycle of the pulse width modulation (PWM) signal is increased. If V ≤ Vmax, the duty cycle of the PWM signal is decreased; when V > Vmax, it is further determined whether the difference between V and Vmax is greater than the set threshold Vth. If V - Vmax > Vth, PWM is increased significantly. If V - Vmax ≤ Vth, PWM is increased slightly; when V < Vmax, regardless of whether Vmax - V is less than the set threshold Vth, PWM is decreased significantly; after each adjustment of PWM, it is determined whether the temperature of the charging module is too high. If the temperature is not too high, the process returns to the step of detecting voltage V and continues to loop. If the temperature is too high, after decreasing PWM, it returns to the step of detecting voltage V and continues to loop.

[0100] It should be noted that although the PID algorithm is a relatively mature control algorithm, in the existing PID algorithms, in the charging control strategies that can be compatible with both power adapters and photovoltaic chargers, there is no use of the control method of "using the PID closed-loop control algorithm combined with asymmetric, variable step size, and continuous probing methods to adjust the pulse width modulation signal". In some current traditional power control methods, even if the PID control is used, it only simply controls a single target, either controlling a stable current or a stable voltage, and mostly adjusts the PWM drive only by judging a fixed voltage threshold. However, the embodiment of the present invention adopts a PID closed-loop control that can quickly adjust according to real-time feedback. Combined with asymmetric and variable step size probing, when the output of the photovoltaic power supply changes, it can dynamically track and maintain the maximum charging power, improve the utilization rate of photovoltaic electric energy, enable the storage battery to be charged quickly and fully, make the working voltage of the charging module stable at an appropriate value, avoid large voltage fluctuations, ensure charging stability, and extend the service life of the storage battery and the charging device; this method can cope with changes in factors such as the output voltage of the photovoltaic power supply and the ambient temperature. When the voltage fluctuates or the temperature is abnormal, it can flexibly adjust the PWM to ensure the normal operation of the charging module, improve the adaptability of the system under different working conditions, and solve the problem of slow dynamic adjustment speed in the existing public technologies.

[0101] As Figure 1 shown, the embodiment of the present invention also provides a mobile power supply, including a charging module, a storage battery, and a charging management module; the charging module includes a buck-boost converter (Buck-Boost).

[0102] The charging management module is used to execute the storage battery DC charging control method described in any one of the above embodiments to control the charging module to charge the storage battery.

[0103] It should be noted that a charging management module provided by the embodiment of the present invention is used to execute all the process steps of the storage battery DC charging control method in the above embodiment, and the working principles and beneficial effects of the two correspond one by one, so they will not be elaborated here.

[0104] In summary, a storage battery DC charging control method, a charging management module, and a mobile power supply provided by the embodiment of the present invention first detect the internal resistance value of the charger, identify the charger type according to the internal resistance value, then control the pulse width modulation signal of the charging module, detect the maximum charging power of the charger power supply, and finally select a charging control strategy according to the identified charger type to control the charging module to charge the storage battery using the maximum charging power.

[0105] The embodiment of the present invention detects the internal resistance of the charger power supply, and determines the charger type, power adapter or photovoltaic power charger according to the internal resistance of the charger. Only one voltage detection and current detection are needed to calculate the internal resistance value to obtain the type of the charger input source, which is simpler and more efficient than the disclosed technology. After accurately identifying the charger type, the charging management can understand the actual power supply capacity of the charger by detecting and recording the maximum charging power of the charger, and can make the charging module work within the maximum power range allowed by the charger according to this maximum charging power, so as to make full use of the power output of the charger and improve the charging efficiency. Finally, according to the detected charger type, different control strategies are adaptively selected to control the charger to charge the battery with the maximum power, so as to achieve the highest efficiency of the charger to charge the battery. The present invention can flexibly and freely match the battery with power adapters or photovoltaic power chargers with different charging voltages and different charging powers, so that the battery can be flexibly matched with different chargers for charging, enhance the compatibility and versatility of the charging management module, and improve the practicality of the product and user satisfaction.

[0106] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A battery DC charging control method, characterized in that: A charging management module applied to a mobile power source, wherein the mobile power source further comprises a charging module and a battery; The battery DC charging control method comprises: Detecting the internal resistance value of the charger, and identifying the type of the charger according to the internal resistance value; wherein the charger types include power adapters and photovoltaic power chargers; Controlling the pulse width modulation signal of the charging module to detect the maximum charging power of the charger; According to the identified charger type, a charging control strategy is selected to control the charging module to charge the battery using the maximum charging power.

2. The battery DC charging control method according to claim 1, characterized in that: The detecting the internal resistance value of the charger and identifying the type of the charger according to the internal resistance value includes: When it is detected that a power source is connected, detecting and recording the open circuit voltage of the charging module; driving the charging module to operate at a first operating current, detecting and recording an operating voltage of the charging module when operating at the first operating current; Calculating an internal resistance value of the charger according to the open circuit voltage, the operating current and the operating voltage; If the internal resistance value is less than a first threshold value, the charger type is identified as a power adapter; if the internal resistance value is greater than the first threshold value, the charger type is identified as a photovoltaic power charger.

3. The battery DC charging control method according to claim 2, characterized in that: The first threshold is 0.3 ohms.

4. The battery DC charging control method according to claim 1, characterized in that: The controlling the pulse width modulation signal of the charging module to detect the maximum charging power of the charger includes: gradually increasing the pulse width modulation signal of the charging module to increase the working current of the charging module; Detecting and recording the operating voltage and corresponding operating current of the charging module under different operating currents; Calculate the current charging power according to the corresponding working voltage and the corresponding working current; When the current charging power decreases as the pulse width modulation signal increases, the maximum charging power of the charger and the corresponding maximum charging current and maximum charging voltage are obtained.

5. The battery DC charging control method according to claim 4, characterized in that: The step of selecting a charging control strategy according to the identified charger type to control the charging module to charge the battery using the maximum charging power includes: When the charger type is a power adapter, a PID closed-loop control algorithm is used to control the charging module to charge the battery using the maximum charging power; When the charger type is a photovoltaic power charger, a PID closed-loop control algorithm is used in combination with an asymmetric, variable step size and an uninterrupted trial method to control the charging module to charge the battery with the maximum charging power.

6. The battery DC charging control method according to claim 5, characterized in that: When the charger type is a power adapter, a PID closed-loop control algorithm is used to control the charging module to charge the battery using the maximum charging power, including: When the charger type is a power adapter, a PID closed-loop control algorithm is used to control the working current of the charging module to stably operate at the maximum charging current; Detecting the operating temperature of the charging module; If the operating temperature of the charging module exceeds a first set temperature, the charging power of the charging module is reduced. When the operating temperature of the charging module is steadily reduced, the charging module is controlled to charge the battery with the maximum charging power.

7. The battery DC charging control method according to claim 5, characterized in that: When the charger type is a photovoltaic power charger, a PID closed-loop control algorithm is used in combination with an asymmetric, variable step size, and uninterrupted trial method to control the charging module to charge the battery with the maximum charging power, including: When the charger type is a photovoltaic power charger, a PID closed-loop control algorithm is used in combination with an asymmetric, variable step size, and an uninterrupted trial method to adjust the pulse width modulation signal, so as to control the working voltage of the charging module to stably operate at the maximum charging voltage; After each adjustment of the pulse width modulation signal, detecting the operating temperature of the charging module; If the operating temperature of the charging module exceeds the second set temperature, the charging power of the charging module is reduced. When the operating temperature of the charging module is steadily reduced, the charging module is controlled to charge the battery according to the maximum charging power.

8. The battery DC charging control method according to claim 7, characterized in that: The PID closed-loop control algorithm is combined with an asymmetric, variable step size and an uninterrupted trial method to adjust the pulse width modulation signal to control the working voltage of the charging module to stably operate at the maximum charging voltage, including: Detecting the operating voltage of the charging module; If the working voltage is greater than the maximum charging voltage, the pulse width modulation signal is increased; wherein, when the difference between the working voltage and the maximum charging voltage is greater than a preset threshold, the pulse width modulation signal is greatly increased for testing, and when the difference between the working voltage and the maximum charging voltage is less than the preset threshold, the pulse width modulation signal is slightly increased for testing; If the working voltage is less than the maximum charging voltage, the pulse width modulation signal is greatly reduced to test.

9. A charging management module, characterized in that: The charging management module is used to execute the battery DC charging control method according to any one of claims 1 to 8.

10. A mobile power source, characterized in that: It comprises a charging module, a battery and a charging management module as claimed in claim 9; the charging module comprises a buck-boost converter; The charging management module is used to control the charging module to charge the battery.

Images