Metal-air battery control method

Abstract

The application discloses a metal-air battery control method, which comprises the following steps: battery starting, determining starting tracking voltage; bus current slow starting; sampling battery parameters, including sampling current voltage, current and calculating current power; judging whether the current voltage is greater than the starting tracking voltage; when the current voltage is greater than the starting tracking voltage, continuing to execute the bus current slow starting; when the current voltage is less than or equal to the starting tracking voltage, judging whether the current power is the maximum output power; when the current power is the maximum output power, continuing to execute the sampling battery parameter step; when the current power is not the maximum output power, adjusting the load until the current power reaches the maximum output power. The application can detect the output power of the metal-air battery in real time, predict the possible maximum output power of the metal-air battery under the current working condition by using a certain control algorithm, and change the current impedance condition to meet the maximum output power requirement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air cell, more particularly, the present application relates to a metal air cell control method. BACKGROUND

[0002] The output characteristics of the metal air cell change nonlinearly with various factors, and the output capacity of the cell changes with temperature and time, etc. Currently, most of the systems are directly connected to the power conversion device for constant power discharge output, which cannot fully exert the maximum output power of the metal air cell. SUMMARY

[0003] In view of the deficiencies of the prior art, the present application innovatively provides a metal air cell control method, which can real-time regulate and control the output of the metal air cell to increase the output power of the cell.

[0004] To achieve the above technical purposes, the present application discloses a metal air cell control method, comprising:

[0005] starting the cell and determining a starting tracking voltage;

[0006] slowly starting the bus current;

[0007] sampling the cell parameters, including sampling the current voltage, current and calculating the current power;

[0008] judging whether the current voltage is greater than the starting tracking voltage;

[0009] when the current voltage is greater than the starting tracking voltage, continuing to execute the slowly starting the bus current,

[0010] when the current voltage is less than or equal to the starting tracking voltage, judging whether the current power is the maximum output power;

[0011] when judging that the current power is the maximum output power, continuing to execute the sampling cell parameters step,

[0012] when judging that the current power is not the maximum output power, adjusting the load until the current power reaches the maximum output power.

[0013] Further, the starting tracking voltage is 0.75-0.8 times the open circuit voltage.

[0014] Further, when the current voltage is less than or equal to the starting tracking voltage, first judging whether the current voltage is less than a lower voltage limit value,

[0015] when the current voltage is less than the lower voltage limit value, reducing the load until the current power reaches the maximum output power;

[0016] When the current voltage is greater than or equal to the lower limit value of the voltage, the step of judging whether the current power is the maximum output power is performed.

[0017] Further, when the current power values calculated by the two adjacent detection points are the same, the current power is the maximum output power.

[0018] Further, the adjusting the load includes increasing the load or decreasing the load, the increasing the load includes increasing the current, and the decreasing the load includes decreasing the current.

[0019] Further, the current power is not the maximum output power includes: the current power is increased, and the current power is decreased.

[0020] Further, when the current power is increased, it is judged whether the current current is increased,

[0021] When it is judged that the current current is increased, the current is continuously controlled to be increased until the current power is the maximum output power.

[0022] When it is judged that the current current is unchanged or decreased, the current is continuously controlled to be decreased until the current power is the maximum output power.

[0023] Further, when the current power is decreased, it is judged whether the current current is increased,

[0024] When it is judged that the current current is increased, the current is controlled to be decreased until the current power is the maximum output power.

[0025] When it is judged that the current current is unchanged or decreased, the current is controlled to be increased until the current power is the maximum output power.

[0026] Further, when the current is increased, the current is controlled to be increased by a fixed increasing amplitude,

[0027] When the current is decreased, the current is controlled to be decreased by a fixed decreasing amplitude.

[0028] The present application has the following beneficial effects:

[0029] In the present application, the output power of the metal-air battery is detected in real time by tracking the maximum output power control strategy of the metal-air battery, a certain control algorithm is used to predict the possible maximum output power output of the metal-air battery under the current working condition, and the current impedance condition is changed to meet the requirement of the maximum output power output. In this way, even if the output power of the metal-air battery is reduced, the system can still run in the best state under the current working condition. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1P-U curves of the metal-air battery under different environments are shown;

[0031] Figure 2 A flow chart of the metal-air battery control method of the first embodiment of the present application is shown;

[0032] Figure 3 A flow chart of the metal-air battery control method of the second embodiment of the present application is shown;

[0033] Figure 4 A flow chart of the metal-air battery control method of the third embodiment of the present application is shown. DETAILED DESCRIPTION

[0034] The metal-air battery control method provided by the present application is explained and described in detail below in combination with the accompanying drawings.

[0035] The output power of the metal-air battery is easily affected by the concentration, flow rate, air amount, and temperature of the electrolyte, and its own output characteristics are a nonlinear process varying with multiple factors, and its output power is often not easy to control, and it cannot be output at the maximum output power.

[0036] In order to enable the metal-air battery to output as much electric energy as possible, the present application studies the metal-air battery control method, and realizes the maximum output power output of the metal-air battery under different conditions through the maximum output power tracking control, improves the discharging capacity and discharging efficiency of the metal-air battery, and meets the power supply task requirements as a reserve power source.

[0037] The maximum output power tracking of the metal-air battery is a dynamic self-optimization process, and through the control of the change of the terminal voltage of the metal-air battery, it can intelligently output the maximum output power under different conditions, Figure 1 P-U curves of the metal-air battery under different environments are shown, and the control target of the maximum output power tracking of the metal-air battery is to make the metal-air battery work at point A or point C, when the battery works on the left side of point A or point C, with the increase of the terminal voltage of the battery, the output power of the battery will increase, and when the battery works on the right side of point A or point C, with the increase of the terminal voltage of the battery, the output power of the battery will decrease, and the decreasing rate on the right side is much greater than the increasing rate on the left side.

[0038] The system works at point A, that is, works on curve 1, when the metal-air battery discharge characteristic curve becomes curve 2, if the maximum output power tracking control of the metal-air battery is not added, the system will work at point B according to the current power output, and at this time, the maximum output power point of the system is at point C, thus a large part of energy will be inevitably lost, and the system will become unstable, which is the importance of the maximum output power tracking control of the metal-air battery. The maximum output power tracking control of the metal-air battery is added, so that the system can stably work near the maximum output power point under any external conditions, and the system can efficiently and stably provide power to the load.

[0039] The maximum output power tracking control idea of the metal-air battery is as follows: the voltage U and the current I output by the metal-air battery are detected, multiplied to obtain power P, and then it is judged whether the output power of the metal-air battery at this time reaches the maximum, if not, the pulse width is adjusted, the output duty cycle D is modulated, the voltage and the current are changed, real-time sampling is performed again, and it is judged whether the duty cycle needs to be changed. Through such an optimization process, the metal-air battery can always work at the maximum output power point, so as to fully utilize the output energy of the metal-air battery. In addition, from the perspective of system characteristics, the metal-air battery can be regarded as a constant voltage source combined with a constant current source, which has strong nonlinearity. The capacitor on both sides of the bus is used as an energy storage element, and the sudden increase of the load capacity will inevitably cause the drop of the DC side voltage, so that the current system working point crosses the maximum output power point and enters the constant current source region. For the voltage type load, the sudden increase of power will inevitably cause the increase of the bus current to compensate for the drop of the voltage at the power source end. At this time, the working point is in the constant current source region, and a small current change will cause a sharp drop of the bus voltage. The drop of the voltage will further increase the current, and so on, which will eventually lead to the collapse of the bus voltage. Therefore, the maximum output power tracking control of the metal-air battery is very necessary.

[0040] The metal-air battery control method of the present application is described in detail in combination with specific embodiments as follows: Figure 2 As shown in the figure, the present application provides a metal-air battery control method, which comprises the following steps:

[0041] Starting the battery, determining the starting tracking voltage U;

[0042] Slowly starting the bus current, and gradually increasing the current value;

[0043] Sampling the battery parameters, including sampling the current voltage U pv (k) and the current I pv (k) of the battery, and calculating the current power P pv (k), that is, P pv (k) = U pv (k) * I pv(k);

[0044] Determine the current voltage U pv (k) Whether it is greater than the starting tracking voltage U;

[0045] When the current voltage U pv (k) If the current is greater than the starting tracking voltage U, the bus current soft start will continue.

[0046] When the current voltage U pv (k) When the current power P is less than or equal to the starting tracking voltage U, determine that... pv (k) Is it the maximum output power?

[0047] When determining the current power P pv When (k) represents the maximum output power, continue with the step of sampling battery parameters.

[0048] When determining the current power P pv (k) If the output power is not at its maximum, adjust the load until the current power P is reached. pv (k) reaches maximum output power.

[0049] The starting tracking voltage U is 0.75 to 0.8 times the open-circuit voltage U. oc In this embodiment, the starting tracking voltage U = 0.79U oc When the current power values ​​calculated from two adjacent detection points are the same, then the current power is the maximum output power, i.e., P. pv (k)=P pv When (k-1), the current power is determined to be the maximum output power.

[0050] like Figure 3 As shown, when the current voltage is less than or equal to the start tracking voltage, the current voltage U is first determined. pv (k) Whether it is less than the lower voltage limit, which is the battery's cutoff voltage. When the current voltage U pv (k) When the voltage is less than the lower limit, adjust the load, specifically by reducing the load until the current power reaches the maximum output power; when the current voltage U pv (k) When the voltage lower limit is greater than or equal to the voltage lower limit, the step of determining whether the current power is the maximum output power is executed.

[0051] Adjusting the load includes increasing the load or decreasing the load, wherein increasing the load includes increasing the current, and decreasing the load includes decreasing the current.

[0052] In this embodiment, the metal-air battery control method of this application, such as Figure 4 As shown, the specific steps include the following:

[0053] Start the battery, sample the open circuit voltage U of the metal fuel cell oc , and determine the start tracking voltage U=0.79U oc .

[0054] Slowly increase the current value to improve the battery load, and then sample the current voltage U pv (k) pv (k) and calculate the current power P pv (k) pv (k) = U pv (k) * I pv (k) pv (k) is greater than the start tracking voltage U. When the current voltage U pv (k) is greater than the start tracking voltage U, continue to perform the bus current slow start, continue to increase the current value, and continue to sample. When the current voltage U pv (k) is less than or equal to the start tracking voltage U, determine whether the current voltage U pv (k) is less than the lower limit of the voltage, and when the current voltage U pv (k) is less than the lower limit of the voltage, adjust the load, specifically reduce the load to the current power to reach the maximum output power, and further reduce the current value to ensure the normal operation of the battery. Preferably, the current value is reduced in the form of I = I pv (k) - A, where I pv (k) is the current value, and A is the amplitude of the current reduction, preferably A is in the range of 1 / 1000 of the rated current value to 1 / 500 of the rated current value.

[0055] When the current voltage is greater than or equal to the lower limit of the voltage, perform the step of determining whether the current power is the maximum output power. Specifically, when the current power values calculated by two adjacent detection points are the same, the current power is the maximum output power, that is, P pv (k) = P pv (k-1). pv (k) is the maximum output power, that is, P pv (k) = P pv (k-1), the current output is maintained, and the battery data is continuously sampled, that is, the above determination process is continued. When the current power P pv (k) is not the maximum output power, determine whether the current power P pv (k) is increasing, that is, whether the current power satisfies P pv (k) > P pv (k-1).

[0056] If the above condition is met, i.e. the current power P pv (k) is increased, the current sample value is analyzed to determine whether the current is increased, i.e. whether the current satisfies I pv (k) > I pv (k-1), when the condition is met, the current is continuously increased to increase the power until the maximum output power is reached. Preferably, the current value is increased in the manner of I = I pv (k) + B, wherein I pv (k) is the current value, and B is the amplitude of the current increment. Preferably, the value of B ranges from 1 / 1000 of the rated current value to 1 / 500 of the rated current value. Further, the values of A and B can be the same or different, i.e. the amplitude of the current decrement and the amplitude of the current increment can be the same or different.

[0057] When it is determined that the current is unchanged or decreased, the current is continuously controlled to be decreased until the current power is the maximum output power. Preferably, the current value is decreased in the manner of I = I pv (k) - A, wherein I pv (k) is the current value, and A is the amplitude of the current decrement.

[0058] If the current power P pv (k) is decreased, the current sample value is analyzed to determine whether the current is increased, i.e. whether the current satisfies I pv (k) > I pv (k-1), when the condition is met, the current is continuously controlled to be decreased until the current power is the maximum output power. Preferably, the current value is decreased in the manner of I = I pv (k) - A, wherein I pv (k) is the current value, and A is the amplitude of the current decrement. When the current sample value does not satisfy the above condition, the current is continuously increased to increase the power until the maximum output power is reached. Preferably, the current value is increased in the manner of I = I pv (k) + B, wherein I pv (k) is the current value, and B is the amplitude of the current increment.

[0059] When the current is increased, the current is controlled to be increased at a fixed increment, and when the current is decreased, the current is controlled to be decreased at a fixed decrement. The amplitude of the current adjustment is controlled to avoid affecting the output stability of the battery due to large amplitude adjustment of the current.

[0060] In the application, the output power of the metal-air battery is detected in real time by tracking the maximum output power control strategy of the metal-air battery, a certain control algorithm is used to predict the possible maximum output power output of the metal-air battery under the current working condition, and the current impedance condition is changed to meet the requirement of maximum output power output. In this way, even if the output power of the metal-air battery decreases, the system can still run in the best state under the current working condition.

[0061] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0062] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0063] In the description of the present application, the description of the terms "the present embodiment", "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are contained in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in at least one embodiment or example. In addition, those skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of different embodiments or examples without contradiction.

[0064] In addition, the terms "first", "second", etc. are used only for the purpose of description, and should not be understood as indicating or implying relative importance or a specific number of the technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0065] The above is only the preferred embodiment of the present application, and is not used to limit the present application. Any modification, equivalent replacement and simple improvement made on the essential content of the present application shall be included in the protection scope of the present application.

Claims

1. A metal-air battery control method characterized by comprising: The method comprises: battery starting, determining a starting tracking voltage; bus current slow starting; sampling battery parameters, including sampling current voltage, current and calculating current power; judging whether the current voltage is greater than the starting tracking voltage, the starting tracking voltage being 0.75-0.8 times open circuit voltage; when the current voltage is greater than the starting tracking voltage, continuing to execute the bus current slow starting, when the current voltage is less than or equal to the starting tracking voltage, judging whether the current power is maximum output power; when judging that the current power is maximum output power, continuing to execute the sampling battery parameters step, when judging that the current power is not maximum output power, adjusting load until the current power reaches maximum output power.

2. The metal-air battery control method according to claim 1, characterized by, when the current voltage is less than or equal to the starting tracking voltage, first judging whether the current voltage is less than a voltage lower limit value, when the current voltage is less than the voltage lower limit value, reducing load to current power reaching maximum output power; when the current voltage is greater than or equal to the voltage lower limit value, executing the step of judging whether the current power is maximum output power.

3. The metal-air battery control method according to claim 2, characterized by, the current power is maximum output power when the current power values calculated by two adjacent detection points are the same.

4. The metal-air battery control method according to claim 3, characterized by, The adjusting load comprises increasing load or reducing load, the increasing load comprises increasing current, and the reducing load comprises reducing current.

5. The metal-air battery control method according to claim 4, characterized by, The current power being not maximum output power comprises the current power increasing and the current power reducing.

6. The metal-air battery control method according to claim 5, wherein when the current power is increasing, judging whether the current is increasing, when judging that the current is increasing, continuing to control current increasing until the current power is maximum output power; when judging that the current is not increasing or is reducing, continuing to control current reducing until the current power is maximum output power.

7. The metal-air battery control method according to claim 5, characterized by, when the current power is reducing, judging whether the current is increasing, when judging that the current is increasing, controlling current reducing until the current power is maximum output power; when judging that the current is not increasing or is reducing, controlling current increasing until the current power is maximum output power.

8. The metal-air battery control method according to claim 6 or 7, characterized by, The current is increasing at a fixed increasing amplitude, The current is reducing at a fixed reducing amplitude.

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