A fuel cell control method

Abstract

The present invention discloses a control method for a fuel cell system, comprising the following steps: S1. Monitor the state of charge (SOC) of the lithium battery pack 锂电池 and the forklift demand power P 需求 . When P 需求 ≥ min(P 满载行驶 , P 小时能耗 ) or SOC 锂电池 ≤ 30%, start the fuel cell; S2. Monitor the forklift demand power P 需求 . If P 需求 ≤ P 净 , then execute step S3; if P 需求 > P 净 , then execute step S4; S3. The fuel cell power generation system supplies power to the load, and at the same time monitors the SOC of the lithium battery pack. If the SOC of the lithium battery pack is lower than the charging threshold, then charge the lithium battery pack at the same time; S4. The fuel cell power generation system and the lithium battery pack jointly supply power to the load; S5. When P 需求 = 0 and SOC 锂电池 > 85%, P 输出 = 0 or when P 需求 < min(P 满载行驶 , P 小时能耗 ) and 30% < SOC 锂电池 ≤ 85%, P 输出 = 0, and the fuel cell power generation system stops working.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and specifically to a fuel cell control method. Background Art

[0002] In the existing fuel cell power generation system, due to frequent start-stop, the service life of the fuel cell power generation system is affected; the lithium battery pack is charged and discharged at a high-rate current under different temperatures and different SOC conditions, resulting in the reduction of the service life of the lithium battery pack. Summary of the Invention

[0003] The purpose of the present invention is to provide a fuel cell control method to solve the problems raised in the above background art.

[0004] To achieve the above purpose, the present invention provides the following technical solutions:

[0005] A fuel cell system control method includes the following steps:

[0006] S1. Monitor the state of charge SOC of the lithium battery pack 锂电池 and the forklift demand power P 需求 . When P 需求 ≥min(P 满载行驶 , P 小时能耗 ) or SOC 锂电池 ≤30%, start the fuel cell;

[0007] S2. Monitor the forklift demand power P 需求 . If P 需求 ≤P 净 , then execute step S3; if P 需求 >P 净 , then execute step S4;

[0008] S3. The fuel cell power generation system supplies power to the load, and at the same time monitors the SOC of the lithium battery pack. If the SOC of the lithium battery pack is lower than the charging threshold, the lithium battery pack is charged simultaneously;

[0009] S4. The fuel cell power generation system and the lithium battery pack supply power to the load together;

[0010] S5. When P 需求 =0 and SOC 锂电池 >85% or when P 输出 =0 or when P 需求 <min(P 满载行驶 , P 小时能耗 ) and 30%<SOC 锂电池 ≤85%, P 输出 =0, and the fuel cell power generation system stops working;

[0011] Wherein: P需求 : Demand power of counterbalanced forklift

[0012] P 满载行驶 : Maximum speed driving power of counterbalanced forklift with full load on flat ground

[0013] P 小时能耗 : Average power of 1-hour energy consumption test condition of counterbalanced forklift

[0014] P 净 : Maximum net output power of fuel cell power generation system

[0015] P 输出 : Output power of fuel cell power generation system

[0016] SOC 锂电池 : State of charge of lithium battery.

[0017] As a further solution of the present invention: The charging threshold in S3 is SOC 锂电池 = 85%.

[0018] As a further solution of the present invention: In S3, when the fuel cell power generation system supplies power to the load alone:

[0019] If SOC 锂电池 ≤30% and 0 < P 需求 ≤P 净 , P 输出 = P 净 = P 需求 + P 充 ;

[0020] If 30% < SOC 锂电池 ≤85% and min(P 满载行驶 , P 小时能耗 )≤P 需求 ≤P 净 , P 输出 ≤P 净 = P 需求 + P 充 , P 充 = I 充 * U 充 ;

[0021] If SOC 锂电池 > 85% and min(P 满载行驶 , P 小时能耗 )≤P 需求 ≤P 净 , P 输出 = P 需求 ;

[0022] Wherein: P 充 : Charging power of fuel cell power generation system to lithium battery

[0023] I 充 : The charging current of the fuel cell power generation system to the lithium battery, I 充 shall meet the requirements of Condition 4

[0024] U 充 : The charging voltage of the fuel cell power generation system to the lithium battery.

[0025] As a further solution of the present invention: In S3, the fuel cell power generation system charges the lithium battery pack:

[0026] When P 需求 = 0 and 25% ≤ SOC 锂电池 < 50% and 35°C ≤ T 锂电池 < 55°C, I 充 = 1C;

[0027] When P 需求 = 0 and 25% ≤ SOC 锂电池 < 50% and 15°C ≤ T 锂电池 < 35°C, I 充 = 6C;

[0028] When P 需求 = 0 and 25% ≤ SOC 锂电池 < 50% and 0°C ≤ T 锂电池 < 15°C, I 充 = 1C;

[0029] When P 需求 = 0 and 50% ≤ SOC 锂电池 ≤ 85% and 35°C ≤ T 锂电池 < 55°C, I 充 = 0.5C;

[0030] When P 需求 = 0 and 50% ≤ SOC 锂电池 ≤ 85% and 15°C ≤ T 锂电池 < 35°C, I 充 = 1.5C;

[0031] When P 需求 = 0 and 50% ≤ SOC 锂电池 ≤ 85% and 15°C ≤ T 锂电池 < 35°C, I 充 = 0.5C;

[0032] When P 需求 = 0 and SOC 锂电池 > 85%, I 充 = 0C;

[0033] When 30% < SOC 锂电池≤85% and min(P 满载行驶 , P 小时能耗 ) ≤ P 需求 ≤ P 净 , P 输出 = P 需求 + I 充 * U 充

[0034] where: T 锂电池 : the temperature of the lithium battery cell

[0035] C: the rate current.

[0036] As a further solution of the present invention: when the fuel cell power generation system and the lithium battery pack jointly supply power to the load, P 净 + P 锂 = P 需求 ;

[0037] where P 锂 : the output power of the lithium battery pack.

[0038] As a further solution of the present invention: when the state of charge SOC of the lithium battery pack 锂电池 > 30%, and P 需求 < min(P 满载行驶 , P 小时能耗 ), at this time, the load is powered by the lithium battery pack alone, P 锂 = P 需求 , where: P 锂 : the output power of the lithium battery.

[0039] As a further solution of the present invention: when the whole forklift brakes, the lithium battery pack is charged by the braking energy, P 锂充 = P 输出 + P 制动 ,

[0040] where P 锂充 : the charging power of the lithium battery pack

[0041] P 制动 : the charging power of the braking current.

[0042] Compared with the prior art, the beneficial effects of the present invention are:

[0043] 1. Adopt a control method for starting and stopping the fuel cell power generation system based on the SOC of the lithium battery pack and the power demand of the forklift, avoid frequent starting and stopping, and improve the service life of the fuel cell system;

[0044] 2. Adopt a control method for the charge and discharge current of the lithium battery pack based on the SOC and temperature of the lithium battery pack, avoid large current charging under high temperature and high SOC of the lithium battery, and improve the service life of the lithium battery pack. Detailed implementation manner

[0045] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0046] A fuel cell system control method includes the following steps:

[0047] S1. Monitor the state of charge SOC of the lithium battery pack 锂电池 and the forklift demand power P 需求 . When P 需求 ≥min(P 满载行驶 , P 小时能耗 ) or SOC 锂电池 ≤30%, start the fuel cell;

[0048] S2. Monitor the forklift demand power P 需求 . If P 需求 ≤P 净 , then execute step S3; if P 需求 >P 净 , then execute step S4;

[0049] S3. The fuel cell power generation system supplies power to the load. When the fuel cell power generation system supplies power to the load alone:

[0050] If SOC 锂电池 ≤30% and 0<P 需求 ≤P 净 , P 输出 =P 净 =P 需求 +P 充 ;

[0051] If 30%<SOC 锂电池 ≤85% and min(P 满载行驶 , P 小时能耗 )≤P 需求 ≤P 净 , P 输出 ≤P 净 =P 需求 +P 充 , P 充 =I 充 *U 充 ;

[0052] If SOC 锂电池 >85% and min(P 满载行驶 , P 小时能耗 )≤P 需求≤P 净 ,P 输出 =P 需求 ;

[0053] Monitor the SOC of the lithium battery pack simultaneously. If the SOC of the lithium battery pack is lower than the charging threshold, in this embodiment, the charging threshold is SOC 锂电池 =85%. Then charge the lithium battery pack simultaneously. When the fuel cell power generation system charges the lithium battery pack:

[0054] When P 需求 =0 and 25%≤SOC 锂电池 <50% and 35℃≤T 锂电池 <55℃, I 充 =1C;

[0055] When P 需求 =0 and 25%≤SOC 锂电池 <50% and 15℃≤T 锂电池 <35℃, I 充 =6C;

[0056] When P 需求 =0 and 25%≤SOC 锂电池 <50% and 0℃≤T 锂电池 <15℃, I 充 =1C;

[0057] When P 需求 =0 and 50%≤SOC 锂电池 ≤85% and 35℃≤T 锂电池 <55℃, I 充 =0.5C;

[0058] When P 需求 =0 and 50%≤SOC 锂电池 ≤85% and 15℃≤T 锂电池 <35℃, I 充 =1.5C;

[0059] When P 需求 =0 and 50%≤SOC 锂电池 ≤85% and 15℃≤T 锂电池 <35℃, I 充 =0.5C;

[0060] When P 需求 =0 and SOC 锂电池 >85%, I 充 =0C;

[0061] When 30%<SOC 锂电池 ≤85% and min(P 满载行驶 , P 小时能耗) ≤ P 需求 ≤ P 净 ,P 输出 = P 需求 + I 充 * U 充 。

[0062] S4. When the fuel cell power generation system and the lithium battery pack jointly supply power to the load, when the fuel cell power generation system and the lithium battery pack jointly supply power to the load, P 净 + P 锂 = P 需求 。

[0063] When the state of charge SOC of the lithium battery pack 锂电池 > 30%, and P 需求 < min(P 满载行驶 ,P 小时能耗 ), at this time, the lithium battery pack supplies power to the load alone, P 锂 = P 需求 ,

[0064] S5. When P 需求 = 0 and SOC 锂电池 > 85%, P 输出 = 0 or when P 需求 < min(P 满载行驶 ,P 小时能耗 ) and 30% < SOC 锂电池 ≤ 85%, P 输出 = 0, and the fuel cell power generation system stops working;

[0065] When the forklift truck is braked as a whole, the lithium battery pack is charged by the braking energy, P 锂充 = P 输出 + P 制动 ,

[0066] Wherein:

[0067] P 需求 : The required power of the counterbalanced forklift

[0068] P 满载行驶 : The maximum speed driving power of the counterbalanced forklift when fully loaded on flat ground

[0069] P 小时能耗 : The average power of the counterbalanced forklift in the 1-hour energy consumption test condition

[0070] P 净 : The maximum net output power of the fuel cell power generation system

[0071] P 输出 : The output power of the fuel cell power generation system

[0072] SOC 锂电池: State of Charge of Lithium Battery

[0073] P 充 : Charging Power of Lithium Battery by Fuel Cell Power Generation System

[0074] I 充 : Charging Current of Lithium Battery by Fuel Cell Power Generation System

[0075] U 充 : Charging Voltage of Lithium Battery by Fuel Cell Power Generation System

[0076] T 锂电池 : Temperature of Lithium Battery Cell

[0077] C: Rate Current

[0078] P 锂 : Output Power of Lithium Battery Pack

[0079] P 锂充 : Charging Power of Lithium Battery Pack

[0080] P 制动 : Charging Power of Braking Current.

[0081] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, in any regard, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be encompassed within the present invention.

[0082] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A fuel cell system control method, characterized in that, Including the following steps: S1. Monitor the state of charge (SOC) of the lithium battery pack 锂电池 and the required power P of the forklift 需求 . When P 需求 ≥ min(P 满载行驶 , P 小时能耗 ) or SOC 锂电池 ≤ 30%, start the fuel cell; S2. Monitor the required power P of the forklift 需求 ; If P 需求 ≤P 净 , then execute step S3; If P 需求 >P 净 , then execute step S4; S3. The fuel cell power generation system supplies power to the load and simultaneously monitors the SOC of the lithium battery pack. If the SOC of the lithium battery pack is lower than the charging threshold, the lithium battery pack is charged simultaneously. The charging threshold is SOC 锂电池 = 85%; When the fuel cell power generation system supplies power to the load alone: If SOC 锂电池 ≤ 30% and 0 < P 需求 ≤ P 净 , P 输出 = P 净 = P 需求 + P 充 ; If 30% < SOC 锂电池 ≤ 85% and min(P 满载行驶 , P 小时能耗 ) ≤ P 需求 ≤ P 净 , P 输出 ≤ P 净 = P 需求 + P 充 , P 充 = I 充 * U 充 ; If the SOC 锂电池 > 85% and min(P 满载行驶 , P 小时能耗 ) ≤ P 需求 ≤ P 净 , P 输出 = P 需求 ; The fuel cell engine system charges the lithium battery pack: When P 需求 = 0 and 25% ≤ SOC 锂电池 < 50% and 35°C ≤ T 锂电池 < 55°C, I 充 = 1C; When P 需求 = 0 and 25% ≤ SOC 锂电池 < 50% and 15°C ≤ T 锂电池 < 35°C, I 充 = 6C; When P 需求 = 0 and 25% ≤ SOC 锂电池 < 50% and 0°C ≤ T 锂电池 < 15°C, I 充 = 1C; When P 需求 = 0 and 50% ≤ SOC 锂电池 ≤ 85% and 35°C ≤ T 锂电池 < 55°C, I 充 = 0.5C; When P 需求 = 0 and 50% ≤ SOC 锂电池 ≤ 85% and 15°C ≤ T 锂电池 < 35°C, I 充 = 1.5C; When P 需求 = 0 and 50% ≤ SOC 锂电池 ≤ 85% and 15°C ≤ T 锂电池 < 35°C, I 充 = 0.5C; When P 需求 = 0 and SOC 锂电池 > 85%, I 充 = 0C; When 30% < SOC 锂电池 ≤ 85% and min(P 满载行驶 , P 小时能耗 ) ≤ P 需求 ≤ P 净 , P 输出 = P 需求 + I 充 * Ucharge Where: T 锂电池 : the temperature of the lithium battery cell; C: rate current; P 充 : Charging power of the fuel cell power generation system for the lithium battery; I 充 : Charging current of the fuel cell power generation system to the lithium battery; U 充 : Charging voltage of the fuel cell power generation system for the lithium battery; S4. The fuel cell power generation system and the lithium battery pack supply power to the load together; S5. When P 需求 = 0 and SOC 锂电池 > 85%, P 输出 = 0 or when P 需求 < min(P 满载行驶 , P 小时能耗 ) and 30% < SOC 锂电池 ≤ 85%, P 输出 = 0, and the fuel cell power generation system stops working; Where: P 需求 : Balanced counterbalanced forklift demand power P 满载行驶 : Maximum speed driving power of counterbalanced forklift with full load on flat ground P 小时能耗 : Average power of the counterbalanced forklift in the 1-hour energy consumption test condition P 净 : Maximum net output power of the fuel cell power generation system P 输出 : Output power of fuel cell power generation system SOC 锂电池 : State of Charge of a lithium battery.

2. The fuel cell system control method according to claim 1, characterized in that, When the fuel cell power generation system and the lithium battery pack jointly supply power to the load, P 净 +P 锂 =P 需求 ; Where P 锂 : Output power of the lithium battery pack.

3. The fuel cell system control method according to claim 1, characterized in that, The state of charge (SOC) of the lithium battery pack 锂电池 When it is > 30%, and P 需求 < min(P 满载行驶 , P 小时能耗 ), at this time, the load is powered by the lithium battery pack alone, and P 锂 = P 需求 , where: P 锂 : The output power of the lithium battery.

4. The fuel cell system control method according to claim 1, characterized in that, When the forklift is braked as a whole, the lithium battery pack is charged by the braking energy, P 锂充 = P 输出 + P 制动 , Where P 锂充 : Charging power of the lithium battery pack P 制动 : Charging power of braking current.