Control method of intelligent charging device for lead-acid battery of lifting working platform

Abstract

The invention discloses a control method of an intelligent charging device for a lead-acid battery of a lifting working platform. The voltage of the lead-acid storage battery is measured through a BMS of a lithium battery, and the current electric quantity of the lead-acid storage battery is obtained. When the electric quantity of the lead-acid storage battery is lower than the electric quantity needing to be charged, the BMS awakens the lithium battery to discharge outwards, meanwhile, the BMS awakens the switch K1 to be powered on and closed, the lithium battery converts 80V direct current into 12V direct current through the DCDC to charge the lead-acid storage battery, after the electric quantity of the lead-acid storage battery reaches the set electric quantity, the lithium battery stops charging the lead-acid storage battery, meanwhile, the BMS awakens the switch K2 to be powered off and disconnected, and the BMS enters a dormant state. According to the method, the lithium battery BMS is automatically awakened in a timed mode, the battery is automatically awakened when the electric quantity of the lead-acid storage battery is low, the lithium battery is used for charging the battery, and charging is stopped under the condition that the lead-acid storage battery is fully charged or the electric quantity of the lithium battery is low; therefore, the purposes that the lead-acid battery of the vehicle is not lack of electricity and the lithium battery is not damaged after being placed for a long time are achieved.

Description

Technical Field

[0001] The invention relates to the field of lead-acid battery charging control, and in particular to a control method for an intelligent lead-acid battery charging device for a lifting work platform. Background Art

[0002] With the rapid development of society and the further strengthening of the country's requirements for safe construction, the number of mobile lifting work platforms is increasing. At the same time, with the soaring international oil prices, the cost of mobile lifting work platforms driven by diesel engines is getting higher and higher, and it can no longer meet market demand. With the rapid development of the new energy industry, electric mobile lifting work platforms have become the mainstream, and most of the vehicles currently on the market are electric.

[0003] At present, the emergency battery charger is cancelled to reduce costs and avoid the problem of contact adhesion of the slow charging contactor of the lithium battery in the charging process that occurred in the early stage. The built-in DCDC of the lithium battery is cancelled to reduce the cost of the lithium battery. The lithium battery is mostly used and does not directly power the control circuit. Instead, the control circuit is charged by the lead-acid battery (including the BMS of the lithium battery). The lithium battery charges the lead-acid battery through an external DCDC. This also causes the lithium battery as the main power to be unable to output voltage independently, and relies on the lead-acid battery to wake up the BMS of the lithium battery. When the storage time is long and the lead-acid battery is depleted, the entire system cannot be started. Even if the lithium battery still has a high power, it cannot be discharged. It is necessary to use a 12V charger to charge the lead-acid battery separately before continuing to use the vehicle. It is more cumbersome to use, which seriously affects the customer's user experience and efficiency. Summary of the invention

[0004] In view of the above-mentioned technical deficiencies, the object of the present invention is to provide a control method for an intelligent charging device for lead-acid batteries of a lifting work platform, which automatically wakes up the lead-acid battery through a lithium battery BMS timed automatic wake-up program, and charges it through the lithium battery when the lead-acid battery is low. Moreover, the charging is stopped when the lead-acid battery is full or the lithium battery is low, so as to achieve the purpose of not depleting the lead-acid battery when the vehicle is placed for a long time, and not damaging the lithium battery when placed for a long time.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] The present invention provides a control method for a lead-acid battery intelligent charging device for a lifting work platform, wherein the charging device comprises a lithium battery that provides 80V direct current for a DCDC and a vehicle power system, the DCDC is connected to the lead-acid battery and provides 12V of electricity for it; the lithium battery is connected to a BMS and performs control signal transmission, and the BMS is connected to a vehicle control system and performs control signal transmission; the lead-acid battery provides 12V direct current for the BMS and the vehicle control system;

[0007] When the BMS detects that the lead-acid battery is low in power, the vehicle power supply stops, or the lithium battery charging stops, the DCDC control terminal of the BMS outputs a high level to close the DCDC, and the lithium battery starts to charge the lead-acid battery; the method steps are specifically as follows:

[0008] First, if the lithium battery power SOC B At the set value SOC 3 If the above conditions are met, the BMS will wake up regularly according to the set time;

[0009] After the BMS wakes up, the lead-acid battery voltage U and the lithium battery power SOC are obtained. B Then, according to the relationship diagram between the lead-acid battery terminal voltage OCV and the charge SOC, the lead-acid battery charge SOC at this time is determined. A ;

[0010] If SOC A Greater than or equal to the required charging power SOC 1 , then return to wait for the lithium battery BMS to wake up again and repeat the above process;

[0011] If SOC A Less than the required charging capacity SOC 1 , then judge SOC B And protect the lithium battery SOC 3 Relationship:

[0012] If SOC B Less than or equal to the protection lithium battery power SOC 3 The lithium battery BMS will stop waking up regularly until the next time the lithium battery is charged. The lithium battery power SOC B Greater than the protection lithium battery SOC 3 , the battery BMS resumes regular wake-up;

[0013] If SOC B Greater than the protection lithium battery SOC 3 , the lithium battery starts to charge the lead-acid battery, and when SOC A Greater than the saturation charge SOC of the lead-acid battery 2 When the battery is fully charged, the charging is terminated and the battery returns to wait for the lithium battery BMS to wake up periodically and repeat the above process. Otherwise, the lithium battery will continue to charge the lead-acid battery.

[0014] Preferably, the lithium battery is charged by connecting a lithium battery charger to a 220V / 380V AC power supply, and a switch K1 is provided between the lithium battery and the lithium battery charger; a switch K2 is provided between the lithium battery and the vehicle power system. When the switch K2 is closed and the BMS is awakened, the lithium battery starts to supply power to the vehicle power system.

[0015] Preferably, the lithium battery is connected to the BMS via an internal signal line to transmit control signals, and the BMS is connected to the vehicle control system via a CAN line to transmit control signals.

[0016] Preferably, the external DCDC is replaced with a lithium battery built-in DCDC, which has the advantages of convenient maintenance and replacement, low cost, no restrictions on installation size, greater power, and faster charging speed for lead-acid batteries.

[0017] Preferably, the switches K1 and K2 are electromagnetic switches, and their closing is controlled by the BMS.

[0018] The beneficial effects of the present invention are:

[0019] 1. It can automatically recharge the vehicle's lead-acid battery through a lithium battery to prevent the lithium battery from being unable to power the vehicle because the lead-acid battery is depleted and the lithium battery's BMS cannot be awakened.

[0020] 2. Changes are made based on the existing electrical components of the existing vehicles. There is no need to add electrical components to the vehicle, only the BMS program needs to be changed. It has the advantages of simple modification and low cost.

[0021] 3. The vehicle uses a lead-acid battery intelligent charging device and strategy, which has the advantages of no need for mobile signal transmission, simplicity, reliability, and is not affected by the location of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A schematic diagram of the internal connection relationship of a lead-acid battery intelligent charging device for a lifting work platform provided by an embodiment of the present invention;

[0024] Figure 2 It is the relationship diagram between the terminal voltage OCV and the charge SOC of the lead-acid battery;

[0025] Figure 3 The present invention is a schematic diagram of a control method of a lead-acid battery intelligent charging device for a lifting work platform. DETAILED DESCRIPTION

[0026] 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.

[0027] like Figures 1 to 3 As shown, a control method for an intelligent charging device for a lead-acid battery of a lifting work platform,

[0028] The charging device includes a lithium battery that provides 80V DC power to the DCDC and the vehicle power system. The DCDC is connected to the lead-acid battery and provides 12V power to it. The lithium battery is connected to the BMS and transmits control signals. The BMS is connected to the vehicle control system and transmits control signals. The lead-acid battery provides 12V DC power to the BMS and the vehicle control system.

[0029] When the BMS detects that the lead-acid battery is low in power, the vehicle power supply stops, or the lithium battery charging stops, the DCDC control terminal of the BMS outputs a high level to close the DCDC, and the lithium battery starts to charge the lead-acid battery; the method steps are specifically as follows:

[0030] First, if the lithium battery power SOC B At the set value SOC 3 If the above conditions are met, the BMS will wake up regularly according to the set time;

[0031] After the BMS wakes up, the lead-acid battery voltage U and the lithium battery power SOC are obtained. B Then, according to the relationship diagram between the lead-acid battery terminal voltage OCV and the charge SOC provided by the battery manufacturer, determine the lead-acid battery charge SOC at this time. A ;

[0032] If SOC A Greater than or equal to the required charging power SOC 1 , then return to wait for the lithium battery BMS to wake up again and repeat the above process;

[0033] If SOC A Less than the required charging capacity SOC 1 , then judge SOC B And protect the lithium battery SOC 3 Relationship:

[0034] If SOC B Less than or equal to the protection lithium battery power SOC 3 The lithium battery BMS will stop waking up regularly until the next time the lithium battery is charged. The lithium battery power SOC BGreater than the protection lithium battery SOC 3 , the battery BMS resumes regular wake-up;

[0035] If SOC B Greater than the protection lithium battery SOC 3 , the lithium battery starts to charge the lead-acid battery, and when SOC A Greater than the saturation charge SOC of the lead-acid battery 2 When the battery is fully charged, the charging is terminated and the battery returns to wait for the lithium battery BMS to wake up periodically and repeat the above process. Otherwise, the lithium battery will continue to charge the lead-acid battery.

[0036] The lithium battery is charged by connecting a lithium battery charger to a 220V / 380V AC power supply. A switch K1 is provided between the lithium battery and the lithium battery charger. A switch K2 is provided between the lithium battery and the vehicle power system. When the switch K2 is closed and the BMS is awakened, the lithium battery starts to supply power to the vehicle power system.

[0037] The lithium battery is connected to the BMS via an internal signal line to transmit control signals, and the BMS is connected to the vehicle control system via a CAN line to transmit control signals.

[0038] The switches K1 and K2 are electromagnetic switches, and their closing is controlled by the BMS.

[0039] The present invention adopts the above scheme and stops charging when the lead-acid battery is full or the lithium battery is low in power, so as to achieve the purpose of not depleting the lead-acid battery when the vehicle is placed for a long time, and not damaging the lithium battery when placed for a long time; the present invention can be achieved by simply modifying the BMS program of the lithium battery, and has the advantages of simple modification and low cost; in the present invention, the strategy of using the BMS to wake up periodically and allow the lithium battery to charge the lead-acid battery through logical judgment has the advantages of not requiring mobile signal transmission, being simple and reliable, and not being affected by the location of the vehicle.

[0040] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A control method for a lead-acid battery intelligent charging device for a lifting work platform, characterized in that: The charging device includes a lithium battery that provides 80V DC power to the DCDC and the vehicle power system. The DCDC is connected to the lead-acid battery and provides 12V power to it. The lithium battery is connected to the BMS and transmits control signals. The BMS is connected to the vehicle control system and transmits control signals. The lead-acid battery provides 12V DC power to the BMS and the vehicle control system. When the BMS detects that the lead-acid battery is low in power, the vehicle power supply stops, or the lithium battery charging stops, the DCDC control terminal of the BMS outputs a high level to close the DCDC, and the lithium battery starts to charge the lead-acid battery; the method steps are specifically as follows: First, if the lithium battery power SOC B When the SOC is above the set value SOC3, the BMS wakes up periodically according to the set time; After the BMS wakes up, the lead-acid battery voltage U and the lithium battery power SOC are obtained. B Then, according to the relationship diagram between the lead-acid battery terminal voltage OCV and the charge SOC, the lead-acid battery charge SOC at this time is determined. A ; If SOC A If it is greater than or equal to the required charging power SOC1, it returns to wait for the lithium battery BMS to wake up again and repeats the above process; If SOC A If it is less than the required charging capacity SOC1, then determine SOC B Relationship with protecting lithium battery power SOC3: If SOC B If the lithium battery power SOC is less than or equal to the protection lithium battery power SOC3, the lithium battery BMS will end the periodic wake-up until the next lithium battery charging. B When the power level of the lithium battery is greater than SOC3, the battery BMS resumes regular wake-up. If SOC B If the SOC is greater than the protection lithium battery power SOC3, the lithium battery starts to charge the lead-acid battery, and when SOC A When the charge is greater than the saturation charge SOC2 of the lead-acid battery, charging is terminated and the battery returns to wait for the lithium battery BMS to wake up periodically and repeat the above process. Otherwise, the lithium battery will not charge the lead-acid battery.

2. The control method of the intelligent charging device for lead-acid batteries of a lifting work platform according to claim 1, characterized in that: The lithium battery is charged by connecting a lithium battery charger to a 220V / 380V AC power supply. A switch K1 is provided between the lithium battery and the lithium battery charger. A switch K2 is provided between the lithium battery and the vehicle power system. When the switch K2 is closed and the BMS is awakened, the lithium battery starts to supply power to the vehicle power system.

3. The control method of the intelligent charging device for lead-acid batteries of a lifting work platform as claimed in claim 2, characterized in that: The lithium battery is connected to the BMS via an internal signal line to transmit control signals, and the BMS is connected to the vehicle control system via a CAN line to transmit control signals.

4. The control method of the intelligent charging device for lead-acid batteries of a lifting work platform according to claim 1, characterized in that: External DCDC replaces the built-in DCDC of lithium battery.

5. The control method of the intelligent charging device for lead-acid batteries of a lifting work platform as claimed in claim 4, characterized in that: The switches K1 and K2 are electromagnetic switches, and their closing is controlled by the BMS.

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