Real-world lithium battery charging matching control circuit and method based on high-altitude and cold environment

Abstract

This invention discloses a lithium battery charging matching control circuit and method for vehicles operating in high-altitude and cold environments. The circuit includes a lithium battery, a power generation system, a main power distribution box, an external power interface, diodes, and cables. The lithium battery provides starting power for special vehicles and also powers the electrical equipment used in combat readiness operations. Under generator operating conditions, it suppresses voltage fluctuations in the power grid. The power generation system controls the engine to operate at a constant speed under both driving and stationary conditions, providing a stable power supply to the vehicle's electrical equipment. The main power distribution box provides a parallel interface for the lithium battery and power generation system. The diodes provide emergency power to the lithium battery management system. The external power interface is used to connect to an external power source. Cables are used for power transmission, signal transmission, and bus signal transmission. This invention improves the rapid charging capability of lithium batteries at low temperatures and enhances the stability of the vehicle's power generation system.

Description

Technical Field

[0001] This invention belongs to the technical field of automatic control, specifically relating to a charging matching control circuit and method for lithium batteries in vehicles operating in high-altitude and cold environments. Background Technology

[0002] To improve the starting capability of special vehicles in high-altitude and frigid environments, and the energy storage power supply capability under intelligent combat readiness conditions, the original lead-acid batteries of some special vehicles have been replaced by lithium batteries. Lithium batteries have the characteristics of high energy density and strong low-temperature discharge capability. The application of lithium batteries has improved the mobility of special vehicles in high-altitude and frigid environments and provided a relatively abundant power reserve for combat readiness duties. However, compared with lead-acid batteries, lithium batteries require more management and control of charging and discharging to ensure the safety of lithium battery use and extend its lifespan. Therefore, it is necessary to design a low-temperature charging and discharging control circuit for lithium batteries used in high-altitude and frigid environments to ensure the safe application of lithium batteries. Summary of the Invention

[0003] In view of this, the present invention provides a charging matching control circuit and method for lithium batteries in vehicles operating in high-altitude and cold environments.

[0004] The technical solution for implementing the present invention is as follows:

[0005] Based on the lithium battery charging matching control circuit of a real vehicle in high-altitude and cold environment, including lithium battery, power generation system, main power distribution box, external power interface, diodes and cables;

[0006] Lithium batteries provide starting power for special vehicles and power the electrical equipment used by special vehicles in combat readiness and duty; and suppress voltage fluctuations in the power grid for special vehicles when the generator is working.

[0007] The power generation system controls the engine to operate at a constant speed under special vehicle driving conditions or special vehicle stationary conditions, providing a stable power supply for the vehicle's electrical equipment.

[0008] The main distribution box provides parallel interfaces for lithium batteries and the power generation system;

[0009] Diodes provide emergency power to the lithium battery management system;

[0010] The external power interface is used to connect to an external power source;

[0011] Cables are used for power transmission, signal transmission, and bus signal transmission.

[0012] Furthermore, the lithium battery includes a battery pack, a management module, a main contactor, a heating contactor, a current sensor, a temperature sensor, and an emergency charging interface. The battery pack is used for energy storage and output. The management module is used to collect data on individual cell voltage, temperature, and current, as well as to upload battery SOC, total voltage, individual cell voltage, current, and alarm information. The main contactor is used for controlling the main circuit, and the heating contactor is used for controlling the heating circuit. The current sensor is used to test the current in the battery's main circuit. The temperature sensor is used to collect battery temperature data. The emergency charging interface is directly connected to the vehicle's main power distribution box for emergency power supply to the lithium battery.

[0013] Furthermore, the power generation system consists of a generator and a generator controller; the generator converts mechanical energy into electrical energy, and the generator controller detects the generator output voltage and adjusts the generator excitation current to maintain voltage stability within the generator speed range of 1900rpm to 4900rpm, as well as voltage stability from no-load to rated load. The generator controller has voltage stabilization and voltage regulation functions.

[0014] The method for matching and controlling the charging of lithium batteries in high-altitude and cold environments, and the method for matching and controlling the power generation system and lithium batteries under low-temperature conditions, are as follows:

[0015] When the vehicle is in operation, the lithium battery is charged by the on-board generator. When the temperature of the lithium battery is ≤0℃, the generator speed is ≥3000rpm, and the terminal voltage of the lithium battery is ≥27V, the internal heating circuit of the lithium battery is connected and the main circuit of the lithium battery is disconnected. That is, the internal heating contactor K2 of the lithium battery is closed and the main circuit contactor K1 is disconnected.

[0016] When the lithium battery temperature is ≥10℃, or the lithium battery terminal voltage is ≤25.5V, or the generator speed is ≤2000rpm, the lithium battery heating circuit is turned off and the main circuit is turned on. That is, the internal heating contactor K2 of the lithium battery is opened and the main contactor K1 is closed. This can realize the rapid charging of the lithium battery after heating, and also ensure the stability of the vehicle's power grid.

[0017] Furthermore, the specific matching control method for the power generation system and lithium battery under normal operating conditions is as follows:

[0018] When 0℃ < lithium battery temperature < 45℃, and the lithium battery charging current ≥ 160A, the generator controller automatically adjusts the generator excitation current to reduce the generator output voltage, thereby reducing the lithium battery charging current. When the lithium battery terminal voltage ≤ 25.5V, the generator controller no longer adjusts the excitation current. When the lithium battery charging current < 140A, the generator controller automatically adjusts the generator excitation current to increase the generator output voltage, thereby increasing the lithium battery charging current and keeping it within the range of 140A to 160A as much as possible. When the lithium battery terminal voltage ≥ 29V, the generator controller no longer adjusts the excitation current.

[0019] Furthermore, the specific matching control method for the high-temperature power generation system and the lithium battery is as follows:

[0020] When the lithium battery temperature is ≥45℃ and the lithium battery charging current is ≥80A, the generator controller automatically adjusts the generator excitation current to reduce the generator output voltage, thereby reducing the lithium battery charging current. When the lithium battery terminal voltage is ≤25.5V, the generator controller no longer adjusts the excitation current. When the lithium battery charging current is <60A, the generator controller automatically adjusts the generator excitation current to increase the generator output voltage, thereby increasing the lithium battery charging current and keeping it within the range of 60A to 80A as much as possible. When the lithium battery terminal voltage is ≥29V, the generator controller no longer adjusts the excitation current.

[0021] Beneficial effects:

[0022] 1. This invention improves the safety and lifespan of lithium batteries through constant current control of the charging current, and ensures the relative stability of the vehicle's power grid through voltage control. It meets the requirements for power grid characteristics in GJB298-1987.

[0023] 2. This invention provides an external emergency power supply for lithium batteries, ensuring the reliability of the power supply to the lithium battery management system when the lithium battery capacity is low.

[0024] 3. This invention enables control of lithium battery charging current under low temperature, normal temperature and high temperature conditions, thereby improving the safety and service life of lithium batteries. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the control circuit of the present invention. Detailed Implementation

[0026] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] This invention provides a lithium battery charging matching control circuit based on a real vehicle in a high-altitude and cold environment, such as... Figure 1As shown, it mainly includes lithium batteries, a power generation system, a main power distribution box, an external power interface, diodes, and cables.

[0028] Lithium batteries: Lithium batteries are energy storage power sources, primarily used to provide starting power for special vehicles and power the electrical equipment used by these vehicles during combat readiness operations. They also suppress voltage fluctuations in the power grid and improve grid voltage quality when the generator is operating.

[0029] The lithium battery internally includes a battery pack, management module, main contactor, heating contactor, current sensor, temperature sensor, and emergency charging interface. The battery pack is used for energy storage and output. The management module can acquire individual cell voltage, temperature, and current data, and upload battery SOC, total voltage, individual cell voltage, current, and alarm information. The main contactor controls the main circuit, and the heating contactor controls the heating circuit. The current sensor measures the current in the battery's main circuit; the temperature sensor acquires the battery temperature; and the emergency charging interface can be directly connected to the vehicle's main power distribution box to provide emergency power to the lithium battery.

[0030] The main function of the power generation system is to provide a stable power supply to the vehicle's electrical equipment when the engine is operating at a constant speed, whether the vehicle is in motion or stationary.

[0031] The power generation system consists of a generator and a generator controller. The generator converts mechanical energy into electrical energy. The generator controller detects the generator output voltage and adjusts the generator excitation current to maintain voltage stability within the generator speed range of 1900 rpm to 4900 rpm, as well as voltage stability from no-load to rated load. The generator controller has voltage stabilization and voltage regulation functions.

[0032] Main distribution box: The main function of the main distribution box is to provide parallel interfaces for lithium batteries and power generation systems.

[0033] Diode: The main function of a diode is to provide emergency power for the lithium battery management system.

[0034] External power interface: The main function of this interface is to connect an external power source.

[0035] Cables: Cables mainly include power transmission cables, signal transmission cables, and bus signal transmission cables.

[0036] The method for matching and controlling the charging of lithium batteries in real vehicles in high-altitude and cold environments is as follows:

[0037] 1. Matching control of low-temperature power generation system and lithium battery

[0038] When the vehicle is in operation, the lithium battery is charged by the on-board generator. When the temperature of the lithium battery is ≤0℃, the generator speed is ≥3000rpm, and the terminal voltage of the lithium battery is ≥27V, the internal heating circuit of the lithium battery is connected and the main circuit of the lithium battery is disconnected. That is, the internal heating contactor K2 of the lithium battery is closed and the main circuit contactor K1 is disconnected.

[0039] When the lithium battery temperature is ≥10℃, or the lithium battery terminal voltage is ≤25.5V, or the generator speed is ≤2000rpm, the lithium battery heating circuit is shut off and the main circuit is connected. That is, the internal heating contactor K2 of the lithium battery is disconnected, and the main contactor K1 is closed. This enables rapid charging of the lithium battery after heating, while also ensuring the stability of the vehicle's power grid.

[0040] 2. Matching control of power generation system and lithium battery under normal operating conditions

[0041] When 0℃ < lithium battery temperature < 45℃, and the lithium battery charging current ≥ 160A, the generator controller automatically adjusts the generator excitation current to reduce the generator output voltage, thereby reducing the lithium battery charging current. When the lithium battery terminal voltage ≤ 25.5V, the generator controller's excitation current is no longer adjusted. When the lithium battery charging current < 140A, the generator controller automatically adjusts the generator excitation current to increase the generator output voltage, thereby increasing the lithium battery charging current and keeping it within the 140A~160A range as much as possible. When the lithium battery terminal voltage ≥ 29V, the generator controller's excitation current is no longer adjusted.

[0042] 3. Matching control of high-temperature power generation system and lithium battery

[0043] When the lithium battery temperature is ≥45℃ and the lithium battery charging current is ≥80A, the generator controller automatically adjusts the generator excitation current to reduce the generator output voltage, thereby reducing the lithium battery charging current. When the lithium battery terminal voltage is ≤25.5V, the generator controller's excitation current is no longer adjusted. When the lithium battery charging current is <60A, the generator controller automatically adjusts the generator excitation current to increase the generator output voltage, thereby increasing the lithium battery charging current and keeping it within the 60A-80A range as much as possible. When the lithium battery terminal voltage is ≥29V, the generator controller's excitation current is no longer adjusted.

[0044] Emergency power supply

[0045] The lithium battery is equipped with an emergency power supply interface, which is connected to the vehicle's main power distribution box. The positive terminal of the generator and the external power supply interface are also connected to the vehicle's main power distribution box. When the voltage of the lithium battery is lower than the operating voltage of the lithium battery management system, closing the vehicle's main switch will not work the lithium battery. In this case, an external power supply needs to be connected to the external power supply interface. After closing the vehicle's main switch, the internal contactor of the lithium battery will automatically close, thus charging the lithium battery.

[0046] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A control method of a charging matching control circuit for a lithium battery in a high-altitude and cold environment, the circuit comprising a lithium battery, a power generation system, a main distribution box, an external power supply interface, a diode, and a cable; The lithium battery provides a starting power supply for a special vehicle and provides a power supply for the electrical equipment of the special vehicle in a combat state; and under the working condition of the generator, the voltage fluctuation of the power grid of the special vehicle is suppressed; The power generation system controls the engine to work in a constant speed condition under the driving condition of the special vehicle or the stationary condition of the special vehicle, and provides a stable power supply for the electrical equipment of the vehicle; The main distribution box provides a parallel interface for the lithium battery and the power generation system; The diode provides an emergency power supply for the lithium battery management module; The external power supply interface is used for connecting an external power supply; The cable is used for power transmission, signal transmission, and bus signal transmission; characterized in that The matching control method of the power generation system and the lithium battery under a low-temperature working condition is as follows: Under the driving condition of the vehicle, the lithium battery is charged by the vehicle-mounted generator; when the temperature of the lithium battery is less than or equal to 0℃, the rotating speed of the generator is greater than or equal to 3000 rpm, and the terminal voltage of the lithium battery is greater than or equal to 27V, the internal heating circuit of the lithium battery is turned on, and the main circuit of the lithium battery is cut off, that is, the internal heating contactor of the lithium battery is closed, and the main contactor is disconnected; When the temperature of the lithium battery is greater than or equal to 10℃, or the terminal voltage of the lithium battery is less than or equal to 25.5V, or the rotating speed of the generator is less than or equal to 2000 rpm, the lithium battery heating circuit is turned off, and the main circuit of the lithium battery is turned on, that is, the internal heating contactor of the lithium battery is disconnected, and the main contactor is closed; both the rapid charging of the lithium battery after heating and the stability of the vehicle power grid can be ensured; Under the condition that the temperature of the lithium battery is greater than 0℃ and less than 45℃, when the charging current of the lithium battery is greater than or equal to 160A, the generator controller automatically adjusts the excitation current of the generator to reduce the output voltage of the generator, thereby reducing the charging current of the lithium battery; when the terminal voltage of the lithium battery is less than or equal to 25.5V, the excitation current of the generator controller is no longer adjusted; when the charging current of the lithium battery is less than 140A, the generator controller automatically adjusts the excitation current of the generator to increase the output voltage of the generator, thereby increasing the charging current of the lithium battery, and the charging current of the lithium battery is controlled in the range of 140A to 160A; when the terminal voltage of the lithium battery is greater than or equal to 29V, the excitation current of the generator controller is no longer adjusted; Under the condition that the temperature of the lithium battery is greater than 45℃, when the charging current of the lithium battery is greater than or equal to 80A, the generator controller automatically adjusts the excitation current of the generator to reduce the output voltage of the generator, thereby reducing the charging current of the lithium battery; when the terminal voltage of the lithium battery is less than or equal to 25.5V, the excitation current of the generator controller is no longer adjusted; when the charging current of the lithium battery is less than 60A, the generator controller automatically adjusts the excitation current of the generator to increase the output voltage of the generator, thereby increasing the charging current of the lithium battery, and the charging current of the lithium battery is controlled in the range of 60A to 80A; when the terminal voltage of the lithium battery is greater than or equal to 29V, the excitation current of the generator controller is no longer adjusted.

2. The control method according to claim 1, characterized by, The lithium battery comprises a battery pack, a management module, a main contactor, a warming contactor, a current sensor, a temperature sensor and an emergency charging interface; the battery pack is used for electric energy storage and electric energy output; the management module is used for realizing single cell voltage acquisition, temperature acquisition, current acquisition and uploading of battery SOC, total voltage, single cell voltage, current and alarm information; the main contactor is used for control of a main circuit of the lithium battery, and the warming contactor is used for control of a warming circuit; the current sensor is used for testing of current of the main circuit of the lithium battery; the temperature sensor is used for acquisition of battery temperature; and the emergency charging interface is directly connected to a main power distribution box of a real vehicle and is used for emergency power supply of the lithium battery.

3. The control method according to claim 1 or 2, characterized by, The power generation system is composed of a generator and a generator controller; the generator is used for converting mechanical energy into electric energy; the generator controller adjusts the excitation current of the generator by detecting the output voltage of the generator, so that the voltage is stabilized when the rotating speed of the generator is in the range of 1900 rpm to 4900 rpm, and the voltage is stabilized when the load is in the range of no load to rated load; and the generator controller has voltage stabilizing control and voltage regulating control functions.

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