Battery discharge voltage matching method applied to inverter system

Abstract

The present invention relates to a battery discharge voltage matching method applied to an inverter system, comprising: after a machine is started for operating in a power-on state, by means of PWM, an MOSFET is driven to work; at the same time, a control circuit cyclically collects voltage of a battery pack and compares same with a voltage set value of a minimum discharge voltage protection register, and when discharge voltage of the battery pack is less than the voltage set value of the minimum discharge voltage protection register, driving the MOSFET by means of PWM is immediately stopped to enter an operational display screen in a protected state; and different minimum discharge voltage protection values are set on a control program on the basis of the types of different battery packs, and when a corresponding minimum discharge voltage protection value is set by means of the operational display screen, and when the control circuit detects that the voltage of the battery pack returns to normal, by means of PWM, the MOSFET is driven to work again. The problems of the influence of over-discharge of a battery pack on the service life thereof, and abnormal turn-off of an inverter due to the battery pack (provided with a protection board) stopping power supply prior to inverter protection are solved.

Description

A battery discharge voltage matching method applied in inverter system Technical Field

[0001] The present invention relates to the technical field of inverter protection, and in particular to a battery discharge voltage matching method applied in an inverter system. Background Art

[0002] Currently, the low-voltage protection voltage of off-grid energy storage inverters on the market is a simple matching scheme, often designed based on the characteristics of traditional lead-acid battery packs (discharge cut-off voltage of approximately 9.5-10V). However, with the recent significant cost reductions in battery packs such as lithium iron phosphate (LiFePO4) batteries (discharge cut-off voltage of approximately 11.1V) and ternary lithium batteries (discharge cut-off voltage of approximately 10.4V), they have become widely used in both off-grid and grid-connected energy storage inverters. Different battery types have different discharge cut-off voltage requirements. If battery packs of different specifications and types do not match the inverter's low-voltage protection parameters, they can lead to various problems, including over-discharge, shortening battery life, battery packs (with built-in protection boards) stopping power before the inverter protection function is activated, causing abnormal inverter shutdown, impacting user experience, and reducing battery utilization. Therefore, a technical solution has long been desired for inverters that allow for the flexible setting of the minimum discharge voltage protection value to match the battery pack voltage.

[0003] Currently, no products on the market have been found that can set the minimum voltage discharge protection parameters for battery packs. This project has filled the market gap by setting optional parameters in the inverter embedded software to meet various discharge cut-off voltage requirements. Summary of the Invention

[0004] The purpose of the present invention is to provide a battery discharge voltage matching method for use in an inverter system to solve various problems such as battery overdischarge, which affects the service life, and the battery pack (with its own protection board) stops supplying power before the inverter protection, causing abnormal inverter shutdown, affecting user use and low battery pack utilization. At the same time, it can provide the minimum discharge voltage requirements for various battery pack types.

[0005] The object of the present invention is achieved like this:

[0006] A battery discharge voltage matching method applied to an inverter system includes the following steps: setting different minimum discharge voltage protection values ​​according to different battery pack types in a control program of the inverter, displaying battery pack type options on an operation display screen of the inverter, and selecting and setting the minimum discharge voltage protection value of the battery pack according to the battery pack type options;

[0007] Alternatively, the inverter control program is provided with a setting range of the minimum discharge voltage protection value, and the inverter operation display screen displays the selected setting value of the minimum discharge voltage protection value, so that the user can freely select and set the minimum discharge voltage protection value of the battery pack on the inverter operation display screen;

[0008] Alternatively, the inverter's main control board MCU module is connected to a control terminal via Bluetooth or WiFi; the control terminal's operation display screen displays battery pack type options and / or displays a selected setting value of the minimum discharge voltage protection value, allowing the user to set the minimum discharge voltage protection value of the battery pack through the control terminal;

[0009] The selected set minimum discharge voltage protection value is stored in the minimum discharge voltage protection register. After the machine is powered on and started, it drives the MOSFET tube to work through PWM. The control circuit simultaneously cyclically collects the battery pack voltage and compares it with the set voltage value. When the discharge voltage of the battery pack is less than or equal to the voltage setting value of the minimum discharge voltage protection register, the PWM drive of the MOSFET tube is immediately turned off and the operation display screen enters the protection state; when the operation display screen does not move, the control circuit detects that the battery pack voltage has returned to the specified condition value and drives the MOSFET tube to work again through PWM.

[0010] After the machine is powered on and started running, the control program first reads the setting data of the EEPROM programmable read-only register into the register; the control program starts the PWM drive MOSFET tube to work; the control circuit cyclically collects the battery pack voltage through the voltage data collector. If the battery pack voltage is greater than or equal to the voltage setting value of the minimum discharge voltage protection register, the machine operates normally.

[0011] When the discharge voltage of the battery pack approaches the voltage setting value of the minimum discharge voltage protection register, the alarm module of the inverter is triggered to issue an alarm prompt, notifying the user to prepare to turn off the PWM drive of the MOSFET tube.

[0012] The control program is provided with an operation number setting program during the screen processing setting process, and the operation number setting program records the operation number of the operation display screen.

[0013] The inverter's operation display screen displays the display interface of the corresponding functional position according to the number of operations, and the timer on the control program reads the operation seconds. When there is no operation within the operation time range set by the control program, the inverter's operation display screen exits the set display interface state after the corresponding time, and the control program updates the selected preset parameter value to the minimum discharge voltage protection register to achieve the purpose of changing the minimum discharge voltage protection value. At the same time, the set parameter value is saved to the EEPROM for the next time the machine is turned on to read and use the set minimum discharge voltage protection value.

[0014] By counting the number of times the display screen or button is tapped and touched, when the operation is stopped, the control program enters the corresponding function option according to the number of times the operation is touched, and displays the corresponding function option display interface on the operation display screen. Among them, after entering the battery pack type selection function interface, multiple groups of preset minimum discharge voltage protection values ​​in the control program code can be cyclically read by tapping and touching, and the currently selected battery pack type is displayed in the form of a sub-option code on the operation display screen to set the minimum discharge voltage protection value.

[0015] According to the discharge characteristics of different types of battery packs, the battery pack name, sub-option code, and display letters are preset in the battery pack type setting item program; a variety of minimum discharge voltage protection values ​​are set according to the discharge characteristics of different types of battery packs, and are selected and set in the control program.

[0016] Specifically:

[0017] According to the discharge characteristics of different types of battery packs, the battery pack type setting item program presets 9.5V for lead-acid battery packs, sub-option code H1, and the letters ACID; 11.1V for ternary lithium battery packs, sub-option code H2, and the letters NCM; and 10.4V for lithium iron phosphate battery packs, sub-option code H3, and the letters LFP. Multiple minimum discharge voltage protection values ​​are set according to the discharge characteristics of different types of battery packs, and are selected and set in the control program.

[0018] The control program uses a combination of letters and numbers to represent the corresponding function options. When you tap the touch button, a prompt will be displayed at the corresponding position on the operation display. After entering the battery pack type selection function, letters, numbers, and letters are used as combination option codes to represent the minimum discharge voltage protection value of different types of battery packs; and the function item code, the currently selected battery pack type sub-item code, and letters are displayed on the operation display. Different codes will be displayed as the selection is made through corresponding operations.

[0019] When the user freely selects and sets the minimum discharge voltage protection value of the battery pack on the operation display screen of the inverter or control terminal, the user can step by step increase or decrease the minimum discharge voltage protection value of the battery pack by triggering the button until it is adjusted to the minimum discharge voltage protection value of the matching battery pack.

[0020] The control terminal is a mobile phone, tablet computer, laptop computer, desktop computer or a remote control with an operation display screen.

[0021] The beneficial effects of the present invention are as follows:

[0022] After the machine is powered on and started, it drives the MOSFET tube through PWM. The control circuit simultaneously cyclically collects the battery pack voltage and compares it with the voltage setting value of the minimum discharge voltage protection register. When the discharge voltage of the battery pack is lower than the voltage setting value of the minimum discharge voltage protection register, the PWM drive of the MOSFET tube is immediately turned off to enter the protection state operation display screen. The control program has different minimum discharge voltage protection values ​​according to the type of battery pack. After setting the corresponding minimum discharge voltage protection value through the operation display screen, the control circuit detects that the battery pack voltage has returned to normal and then drives the MOSFET tube again through PWM to solve the problems of battery pack over-discharge, affecting service life, battery pack (with built-in protection board) stopping power supply before inverter protection, causing abnormal shutdown of the inverter, affecting user use and low battery pack utilization rate. At the same time, it can provide the minimum discharge voltage requirements of multiple battery pack types and the inverter can freely set the minimum discharge voltage protection value to match the battery pack voltage value. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG1 is a push-pull DC / DC boost inverter circuit according to an embodiment of the present invention.

[0024] FIG2 is a schematic diagram of a control flow of a method for setting a battery pack type according to an embodiment of the present invention. Implementation Method

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] Referring to Figures 1 and 2, a battery discharge voltage matching method for an inverter system is characterized by comprising the following steps: setting different minimum discharge voltage protection values ​​according to different battery pack types in the inverter control program, displaying battery pack type options on the inverter operation display screen, and selecting and setting the minimum discharge voltage protection value of the battery pack according to the battery pack type options;

[0027] Alternatively, the inverter control program is provided with a setting range of the minimum discharge voltage protection value, and the inverter operation display screen displays the selected setting value of the minimum discharge voltage protection value, so that the user can freely select and set the minimum discharge voltage protection value of the battery pack on the inverter operation display screen;

[0028] Alternatively, the inverter's main control board MCU module is connected to a control terminal via Bluetooth or WiFi; the control terminal's operation display screen displays battery pack type options and / or displays a selected setting value of the minimum discharge voltage protection value, allowing the user to set the minimum discharge voltage protection value of the battery pack through the control terminal;

[0029] The selected set minimum discharge voltage protection value is stored in the minimum discharge voltage protection register. After the machine is powered on and started, it drives the MOSFET tube to work through PWM. The control circuit simultaneously cyclically collects the voltage of battery pack 1 and compares it with the set voltage value. When the discharge voltage of battery pack 1 is less than or equal to the voltage setting value of the minimum discharge voltage protection register, the PWM drive of the MOSFET tube is immediately turned off and the operation display screen enters the protection state; when the operation display screen does not operate, the control circuit detects that the voltage of battery pack 1 has recovered to the specified condition value and drives the MOSFET tube to work again through PWM.

[0030] There are two ways to set the minimum discharge voltage protection value of the battery pack: a mobile phone app and the inverter itself.

[0031] The first method is to set it through the mobile phone APP. You can directly enter the discharge voltage protection parameters you want to match on the APP, and send them to the inverter Bluetooth receiving module through the mobile phone Bluetooth port. The inverter receives the data through the serial port of the Bluetooth receiving module.

[0032] The second method is to use the inverter's touch switches in conjunction with the LCD display to set data. In the normal interface, the number of times the touch switch is pressed is counted. When the click stops, the corresponding function option is entered based on the number of presses. The program structure is shown in Figure 2. The program uses F+number to represent a function. Pressing the touch switch will display a prompt such as F1 or F2 on the LCD screen.

[0033] After entering the discharge voltage parameter setting, the currently adjusted discharge voltage protection value will flash on the LCD screen. By tapping the touch switch, the value can be adjusted in 0.1V increments until it matches the discharge voltage protection value of the battery. The timer will exit after 5 seconds of no action. Customers can flexibly adjust the voltage of multiple battery packs in series according to system requirements.

[0034] After the machine is powered on and started running, the control program first reads the setting data of the EEPROM programmable read-only register into the register; the control program starts the PWM drive MOSFET tube to work; the control circuit cyclically collects the voltage of battery pack 1 through the voltage data collector. If the voltage of battery pack 1 is greater than or equal to the voltage setting value of the minimum discharge voltage protection register, the machine operates normally.

[0035] When the discharge voltage of the battery pack 1 approaches the voltage setting value of the minimum discharge voltage protection register, the alarm module of the inverter is triggered to issue an alarm prompt.

[0036] The control program is provided with an operation number setting program during the screen processing setting process, and the operation number setting program records the operation number of the operation display screen.

[0037] The inverter's operation display screen displays the display interface of the corresponding functional position according to the number of operations, and the timer on the control program reads the operation seconds. When there is no operation within the operation time range set by the control program, the inverter's operation display screen exits the set display interface state after the corresponding time, and the control program updates the selected preset parameter value to the minimum discharge voltage protection register to achieve the purpose of changing the minimum discharge voltage protection value. At the same time, the set parameter value is saved to the EEPROM for the next time the machine is turned on to read and use the set minimum discharge voltage protection value.

[0038] By counting the number of times the display screen or button is tapped and touched, when the operation is stopped, the control program enters the corresponding function option according to the number of times the operation is touched, and displays the corresponding function option display interface on the operation display screen. Among them, after entering the battery pack type selection function interface, multiple groups of preset minimum discharge voltage protection values ​​in the control program code can be cyclically read by tapping and touching, and the currently selected battery pack type is displayed in the form of a sub-option code on the operation display screen to set the minimum discharge voltage protection value.

[0039] According to the discharge characteristics of different types of battery packs, the battery pack type setting item program presets 9.5V for lead-acid battery packs, sub-option code H1, and the letters ACID; 11.1V for ternary lithium battery packs, sub-option code H2, and the letters NCM; and 10.4V for lithium iron phosphate battery packs, sub-option code H3, and the letters LFP. Multiple minimum discharge voltage protection values ​​are set according to the discharge characteristics of different types of battery packs, and are selected and set in the control program.

[0040] The control program uses a combination of letters and numbers to represent the corresponding function options. When you tap the touch button, a prompt will be displayed at the corresponding position on the operation display. After entering the battery pack type selection function, letters, numbers, and letters are used as combination option codes to represent the minimum discharge voltage protection value of different types of battery packs; and the function item code, the currently selected battery pack type sub-item code, and letters are displayed on the operation display. Different codes will be displayed as the selection is made through corresponding operations.

[0041] Specifically:

[0042] The circuit structure, as shown in Figure 1, uses a push-pull DC / DC boost inverter circuit. After powering on, the MOSFET is driven by PWM. Simultaneously, the battery pack voltage is cyclically sampled and compared with the value set in the minimum discharge voltage protection register. If the voltage falls below the set value, the MOSFET's PWM drive is immediately shut off, entering a protection state. The circuit restarts after detecting that the voltage has returned to normal.

[0043] The program structure is shown in Figure 2. F+numbers are used in the program to represent a certain function. When the touch switch is pressed, a prompt will be displayed somewhere on the LCD screen, such as F1 and F2. After entering the battery pack type selection function, the option code format of H+numbers+English letters is used to represent the minimum discharge voltage protection value of different types of battery packs. The LCD screen also displays the function item code+the sub-item code of the currently selected battery pack type+letters, such as F3+H1+ACID, where H1+ACID is the sub-option code and will display different codes as the selection is made.

[0044] In the project, based on the discharge characteristics of different types of battery packs, the battery pack type setting program presets a variety of minimum discharge voltage protection values, including lead-acid battery pack (9.5V): sub-option code H1, displayed as ACID; ternary lithium battery pack (11.1V): sub-option code H2, displayed as NCM; lithium iron phosphate battery pack (10.4V): sub-option code H3, displayed as LFP.

[0045] Under normal conditions, the system counts the number of times the touch switch is pressed. When you stop pressing, the system enters the corresponding function based on the number of times. When entering the battery pack type setting (minimum discharge voltage protection value setting), pressing the touch switch cycles through multiple preset minimum discharge voltage protection values ​​in the code. The currently selected battery pack type is displayed on the screen using the sub-option code. After 5 seconds of inactivity, the system exits and updates the selected preset parameter value to the minimum discharge voltage protection register, achieving the desired minimum discharge voltage protection value. The set parameter value is also saved to EEPROM for retrieval the next time the device is turned on.

[0046] When the user freely selects and sets the minimum discharge voltage protection value of the battery pack on the operation display screen of the inverter or control terminal, the user can step by step increase or decrease the minimum discharge voltage protection value of the battery pack by triggering the button until it is adjusted to the minimum discharge voltage protection value of the matching battery pack.

[0047] Specifically: The minimum discharge voltage protection value is cyclically adjusted within the supported operating range. During adjustment, the LCD screen flashes to display the currently adjusted minimum discharge voltage protection value. By tapping the touch switch, the value is stepped by 0.1V each time until the discharge voltage protection value of the equipped battery is adjusted to match. For example: The minimum discharge voltage of a 4-string ternary lithium battery pack is about 2.75Vx4=11V, but the cut-off discharge voltage of the built-in discharge protection board of different manufacturers will have a deviation of plus or minus a few tenths of a volt. The cyclic step adjustment using the above method can better adapt to the matching of most manufacturers. Customers can flexibly adjust the voltage of multiple battery packs after superposition in series according to system requirements.

[0048] The control terminal is a mobile phone, tablet computer, laptop computer, desktop computer or a remote control with an operation display screen.

[0049] The above is a preferred embodiment of the present invention, which illustrates and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A battery discharge voltage matching method applied in an inverter system, characterized in that: The following steps are involved: The inverter control program sets different minimum discharge voltage protection values ​​according to different battery pack types. The inverter operation display screen displays the battery pack type options. Select and set the minimum discharge voltage protection value of the battery pack according to the battery pack type options. Alternatively, the control program of the inverter is provided with a setting range of the minimum discharge voltage protection value, and the operation display screen of the inverter displays the selected setting value of the minimum discharge voltage protection value, so that the user can freely select and set the minimum discharge voltage protection value of the battery pack on the operation display screen of the inverter; Alternatively, the inverter's main control board MCU module is connected to a control terminal via Bluetooth or WiFi; the control terminal displays the battery type option and / or the selected setting value of the minimum discharge voltage protection value on the operation display screen of the control terminal, so that the user can set the minimum discharge voltage protection value of the battery pack through the control terminal; The selected set minimum discharge voltage protection value is stored in the minimum discharge voltage protection register. After the machine is powered on and started, the MOSFET tube is driven to work through PWM. The control circuit simultaneously cyclically collects the voltage of the battery pack (1) and compares it with the set voltage value. When the discharge voltage of the battery pack (1) is less than or equal to the voltage setting value of the minimum discharge voltage protection register, the PWM drive of the MOSFET tube is immediately turned off and the operating display screen enters the protection state. When the operating display screen does not operate, the control circuit detects that the voltage of the battery pack (1) has recovered to the specified condition value and drives the MOSFET tube to work again through PWM.

2. The battery discharge voltage matching method used in the inverter system according to claim 1, characterized in that: After the machine is powered on and started, the control program first reads the setting data of the EEPROM programmable read-only register into the register; the control program starts the PWM drive MOSFET tube to work; the control circuit cyclically collects the voltage of the battery pack (1) through the voltage data collector. If the voltage of the battery pack (1) is greater than or equal to the voltage setting value of the minimum discharge voltage protection register, the machine operates normally.

3. The battery discharge voltage matching method used in the inverter system according to claim 1, characterized in that: When the discharge voltage of the battery pack (1) approaches the voltage setting value of the minimum discharge voltage protection register, the alarm module of the inverter is triggered to issue an alarm prompt.

4. The battery discharge voltage matching method used in the inverter system according to claim 1, characterized in that: The control program is provided with an operation number setting program in the process of screen processing setting, and the operation number setting program records the operation number of the operation display screen.

5. The battery discharge voltage matching method used in the inverter system according to claim 4, characterized in that: The inverter's operation display screen displays the display interface of the corresponding functional position according to the number of operations, and the timer on the control program reads the operation seconds. When there is no operation within the operation time range set by the control program, the inverter's operation display screen exits the set display interface state after the corresponding time, and the control program updates the selected preset parameter value to the minimum discharge voltage protection register to achieve the purpose of changing the minimum discharge voltage protection value. At the same time, the set parameter value is saved to the EEPROM for the next time the machine is turned on to read and use the set minimum discharge voltage protection value.

6. The battery discharge voltage matching method used in the inverter system according to claim 5, characterized in that: By counting the number of times the display screen or button is tapped and touched, when the operation is stopped, the control program enters the corresponding function option according to the number of times the operation is touched, and displays the corresponding function option display interface on the operation display screen. Among them, after entering the battery pack type selection function interface, multiple groups of preset minimum discharge voltage protection values ​​in the control program code can be cyclically read through tapping operations, and the currently selected battery pack type is displayed in the form of a sub-option code on the operation display screen to set the minimum discharge voltage protection value.

7. The battery discharge voltage matching method used in the inverter system according to claim 6, characterized in that: According to the discharge characteristics of different types of battery packs, the battery pack name, sub-option code, and display letters are preset in the battery pack type setting item program; a variety of minimum discharge voltage protection values ​​are set according to the discharge characteristics of different types of battery packs, and are selected and set in the control program.

8. The battery discharge voltage matching method used in an inverter system according to claim 6, characterized in that: In the control program, a combination of letters and numbers is used to represent the corresponding function options. When the touch button is pressed, a prompt will be displayed at the corresponding position on the operation display screen. After entering the battery pack type selection function, letters, numbers, and letters are used as a combination of option codes to represent the minimum discharge voltage protection value of different types of battery packs; and the function item code, the currently selected battery pack type sub-item code, and letters are displayed on the operation display screen. Different codes will be displayed as the selection is made through corresponding operations.

9. The battery discharge voltage matching method used in the inverter system according to claim 1, characterized in that: When the user freely selects and sets the minimum discharge voltage protection value of the battery pack on the operation display screen of the inverter or control terminal, the user can increase or decrease the minimum discharge voltage protection value of the battery pack step by step by triggering the button until it is adjusted to the minimum discharge voltage protection value of the matching battery pack.

10. The battery discharge voltage matching method used in an inverter system according to claim 1, characterized in that: The control terminal is a mobile phone, tablet computer, laptop computer, desktop computer or a remote controller with an operation display screen.

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