A thermal management system and thermal management method for electric forklift battery

Abstract

This disclosure provides a thermal management system for an electric forklift battery, comprising an ambient temperature detection module, an operating status module, a heating and cooling module, and a thermal management control module. The ambient temperature detection module and the operating status module are respectively connected to the thermal management control module, which is in turn connected to the heating and cooling module. The ambient temperature detection module includes a temperature sensor located near the electric forklift battery, which detects the ambient temperature of the electric forklift battery. The operating status module includes a battery management system, a voltage sensor, and a current sensor. The battery management system detects the voltage and current of the electric forklift battery using the voltage and current sensors, respectively. The heating and cooling module includes N independent heating and cooling units, which heat or cool the environment in which the electric forklift battery is located. The thermal management control module includes a pump motor controller that controls the heating and cooling module to heat or cool.

Description

Technical Field

[0001] The present disclosure relates to the technical field of electric forklift battery thermal management, and in particular to an electric forklift battery thermal management system and a thermal management method thereof. Background Art

[0002] The electric forklift motor drive system consists of a travel motor and a travel motor controller, a pump motor and a pump motor controller. The travel motor is responsible for driving the forklift to move, and the pump motor is responsible for driving the hydraulic pump to operate to achieve lifting and steering of the forklift. Normally, the pump motor and the pump motor controller are running when the forklift is lifting materials, and are idle at other times. In other words, the working process of the pump motor and the pump motor controller is intermittent.

[0003] Electric forklift batteries are mostly lead-acid batteries or lithium-ion batteries. The normal temperature range inside electric forklift batteries is small, and both low and high temperatures can easily cause the battery's performance to decline or decay; since electric forklifts often work in harsh environments, in order to improve battery life, reliability and safety of electric forklifts, it is very important to implement thermal management on electric forklift batteries.

[0004] Most electric forklift batteries have independent thermal management systems, which have independent temperature collection components, control components, heating or cooling components, and also contain many electrical switches and cumbersome control logic to adapt to large ambient temperature changes. This electric forklift battery thermal management system has a complex structure and high application cost. Summary of the invention

[0005] In view of the above technical problems in the related art, the present disclosure proposes an electric forklift battery thermal management system, which can overcome the above deficiencies in the prior art.

[0006] To achieve the above technical objectives, the technical solution of the present disclosure is implemented as follows:

[0007] The first object of the present disclosure is to provide an electric forklift battery thermal management system, which includes an ambient temperature detection module, an operating status module, a heating and cooling module and a thermal management control module, wherein the ambient temperature detection module and the operating status module are respectively connected to the thermal management control module, and the thermal management control module is connected to the heating and cooling module;

[0008] The ambient temperature detection module includes a temperature sensor adjacent to the electric forklift battery, and the temperature sensor is used to detect the ambient temperature of the electric forklift battery;

[0009] The operating status module includes a battery management system, a voltage sensor and a current sensor. The battery management system detects the voltage and current of the electric forklift battery through the voltage sensor and the current sensor respectively;

[0010] The heating and cooling module includes N mutually independent heating and cooling units, and the heating and cooling units are used to heat or cool the environment in which the electric forklift battery is located;

[0011] The thermal management control module includes a pump motor controller, which controls the heating and cooling module to perform heating or cooling based on the ambient temperature of the electric forklift battery and the operating information of the electric forklift battery and the pump motor.

[0012] Preferably, the pump motor controller includes a microprocessor, a capacitor, a DC positive bus, a DC negative bus and an N-phase bridge inverter circuit; each phase of the N-phase bridge inverter circuit corresponds to a heating and cooling unit and is connected to the pump motor to drive the heating and cooling unit to operate; the temperature sensor is connected to the microprocessor through a first communication line, so as to send the detection result to the microprocessor; the battery management system is connected to the microprocessor through a second communication line, and the battery management system transmits the detected voltage and current of the electric forklift battery to the microprocessor.

[0013] Preferably, each phase of the N-phase bridge inverter circuit includes an upper bridge arm power device and a lower bridge arm power device connected and matched with each other, and the connection between the upper bridge arm power device and the lower bridge arm power device of each phase constitutes the bridge arm midpoint of the phase;

[0014] The capacitor output positive electrode is connected to the DC positive bus and the output negative electrode is connected to the DC negative bus. The negative power supply end of each heating and cooling unit is connected to the DC negative bus and the positive power supply end is connected to the midpoint of the bridge arm of the corresponding phase.

[0015] Preferably, the upper arm power device or the lower arm power device is preferably a MOSFET or an IGBT.

[0016] Preferably, N=3, so the N-phase bridge inverter circuit is a 3-phase bridge inverter circuit. Similarly, the heating and cooling module includes 3 heating and cooling units.

[0017] Preferably, the three-phase bridge inverter circuit specifically includes a first-phase upper bridge arm power device, a first-phase lower bridge arm power device, a second-phase upper bridge arm power device, a second-phase lower bridge arm power device, a third-phase upper bridge arm power device, and a third-phase lower bridge arm power device;

[0018] Wherein, the connection point of the first phase upper bridge arm power device and the first phase lower bridge arm power device constitutes the midpoint of the first phase bridge arm; the connection point of the second phase upper bridge arm power device and the second phase lower bridge arm power device constitutes the midpoint of the second phase bridge arm; the connection point of the third phase upper bridge arm power device and the third phase lower bridge arm power device constitutes the midpoint of the third phase bridge arm;

[0019] The heating and cooling module correspondingly includes a first heating and cooling unit, a second heating and cooling unit and a third heating and cooling unit; the positive power supply end of the first heating and cooling unit is connected to the midpoint of the first phase bridge arm through a wire, the positive power supply end of the second heating and cooling unit is connected to the midpoint of the second phase bridge arm through a wire, and the positive power supply end of the third heating and cooling unit is connected to the midpoint of the third phase bridge arm through a wire.

[0020] When in use, when the first-phase upper bridge arm power device is turned on, the first heating and cooling unit operates; when the second-phase upper bridge arm power device is turned on, the second heating and cooling unit operates; when the third-phase upper bridge arm power device is turned on, the third heating and cooling unit operates; when the first-phase upper bridge arm power device is turned off, the first heating and cooling unit does not operate; when the second-phase upper bridge arm power device is turned off, the second heating and cooling unit does not operate; when the third-phase upper bridge arm power device is turned off, the third heating and cooling unit does not operate. In other words, by controlling the upper bridge arm power device, the upper bridge arm power device, and the upper bridge arm power device, the first heating and cooling unit, the second heating and cooling unit, and the third heating and cooling unit can be controlled to operate respectively.

[0021] Preferably, the microprocessor connects the first phase upper bridge arm power device, the first phase lower bridge arm power device, the second phase upper bridge arm power device, the second phase lower bridge arm power device, the third phase upper bridge arm power device, and the third phase lower bridge arm power device through control lines, respectively, so as to control the conduction or cutoff of each power device.

[0022] Preferably, the three-phase stator winding of the pump motor is connected to the midpoint of the first phase bridge arm, the midpoint of the second phase bridge arm and the midpoint of the third phase bridge arm respectively through wires, the positive output of the electric forklift battery is connected to the DC positive bus, and the negative output of the electric forklift battery is connected to the DC negative bus.

[0023] The second object of the present disclosure is to provide a thermal management method adopted by the electric forklift battery thermal management system in the first object, which comprises the following steps:

[0024] S1: Check whether the pump motor is running;

[0025] S2: If the pump motor is running, the microprocessor does not control the heating and cooling module and jumps to S8; otherwise, continue to S3;

[0026] S3: When it is detected that the pump motor is not running, the ambient temperature detection module obtains the ambient temperature of the electric forklift battery, the operating state module obtains the voltage and current of the electric forklift battery, the microprocessor controls the first phase lower bridge arm power device, the second phase lower bridge arm power device and the third phase lower bridge arm power device to be cut off, and the microprocessor calculates the internal temperature of the electric forklift battery based on the ambient temperature, voltage and current;

[0027] S4: If the internal temperature is within the normal internal temperature range, the microprocessor controls the first phase upper bridge arm power device, the second phase upper bridge arm power device and the third phase upper bridge arm power device to be turned off, that is, the heating and cooling module is controlled not to work, and jumps to S8; otherwise, continue to S5;

[0028] S5: If the internal temperature is 1-5°C higher or lower than the normal internal temperature of the electric forklift battery, the microprocessor controls the first phase upper bridge arm power device to turn on, and the first heating and cooling unit operates; otherwise, continue to S6;

[0029] S6: If the internal temperature of the electric forklift battery is 6-10°C higher or lower than the normal internal temperature of the electric forklift battery, the microprocessor controls the first-phase upper bridge arm power device and the second-phase upper bridge arm power device to be turned on, and the first heating and cooling unit and the second heating and cooling unit operate; otherwise, continue to S7;

[0030] S7: If the internal temperature of the electric forklift battery is higher or lower than the normal internal temperature of the electric forklift battery by more than 11°C, the microprocessor controls the first-phase upper bridge arm power device, the second-phase upper bridge arm power device and the third-phase upper bridge arm power device to be turned on, and the first heating and cooling unit, the second heating and cooling unit and the third heating and cooling unit are operated;

[0031] S8: End.

[0032] Preferably, in S3, the microprocessor may use the internal resistance energy consumption and the thermal network of the electric forklift battery to calculate the internal temperature.

[0033] Beneficial effects: The electric forklift battery thermal management system and thermal management method provided by the present invention utilize the upper arm power device in the three-phase bridge inverter circuit of the pump motor controller to control the heating and cooling unit in the heating and cooling module, which can solve the problems of complex structure and high application cost of the electric forklift battery thermal management system in the background technology; at the same time, during the operation of the electric forklift, the internal temperature of the electric forklift battery can be kept within a normal range, which is beneficial to extending the service life of the electric forklift battery and improving the safety and reliability of the electric forklift battery.

[0034] During operation, the thermal management system disclosed herein calculates the internal temperature of the electric forklift battery according to the operating status of the electric forklift battery and the ambient temperature. Based on the internal temperature of the electric forklift battery, the power device in the pump motor controller controls the operation of the heating and cooling module, thereby realizing thermal management of the electric forklift battery.

[0035] The thermal management system disclosed in the present invention has a simple structure and low application cost. At the same time, during the operation of the electric forklift, the internal temperature of the electric forklift battery can be kept within a normal range, which is beneficial to extending the service life of the electric forklift battery and improving the safety and reliability of the electric forklift battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 A functional block diagram of a battery thermal management system for an electric forklift provided according to an embodiment of the present application;

[0038] Figure 2 This is a schematic diagram of the structure of an electric forklift battery thermal management system according to an embodiment of the present application;

[0039] Figure 3 The present invention is an execution logic diagram of a thermal management method provided according to an embodiment of the present application.

[0040] In the figure: 10, electric forklift battery thermal management system; 100, ambient temperature detection module; 101, temperature sensor; 200, operating status module; 201, battery management system; 202, voltage sensor; 203, current sensor; 300, heating and cooling module; 400, thermal management control module; 401, microprocessor; 402, first phase upper bridge arm power device; 403, first phase lower bridge arm power device; 404, second phase upper bridge arm power device; 405, second phase Lower bridge arm power device; 406, third phase upper bridge arm power device; 407, third phase lower bridge arm power device; 408, capacitor; 409, first phase bridge arm midpoint; 410, second phase bridge arm midpoint; 411, third phase bridge arm midpoint; 412, DC positive bus; 413, DC negative bus; 414--419, conductor; 420, first communication line; 421, second communication line; 422--427: control line; 500, electric forklift battery; 600, pump motor. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present disclosure.

[0042] like Figure 1-3 As shown, in order to facilitate the understanding of the above technical solutions of the present disclosure, the above technical solutions of the present disclosure are described in detail below through specific usage methods.

[0043] The first object of the present disclosure is to provide an electric forklift battery thermal management system, which includes an ambient temperature detection module 100, an operating status module 200, a heating and cooling module 300 and a thermal management control module 400, wherein the ambient temperature detection module 100 and the operating status module 200 are respectively connected to the thermal management control module 400, and the thermal management control module 400 is connected to the heating and cooling module 300;

[0044] The ambient temperature detection module 100 includes a temperature sensor 101 adjacent to the electric forklift battery 500, and the temperature sensor 101 is used to detect the ambient temperature of the electric forklift battery 500;

[0045] The operation status module 200 includes a battery management system 201, a voltage sensor 202 and a current sensor 203. The battery management system 201 detects the voltage and current of the electric forklift battery 500 through the voltage sensor 202 and the current sensor 203 respectively;

[0046] The heating and cooling module 300 includes N mutually independent heating and cooling units, and the heating and cooling units are used to heat or cool the environment in which the electric forklift battery 500 is located;

[0047] The thermal management control module 400 includes a pump motor controller. The pump motor controller controls the heating and cooling module 300 to perform heating or cooling based on the ambient temperature of the electric forklift battery 500 and the operating information of the electric forklift battery 500 and the pump motor 600 .

[0048] In a specific embodiment, the pump motor controller includes a microprocessor 401, a capacitor 408, a DC positive bus 412, a DC negative bus 413 and an N-phase bridge inverter circuit; each phase of the N-phase bridge inverter circuit corresponds to a heating and cooling unit and is connected to the pump motor 600 to drive the heating and cooling unit to operate; the temperature sensor 101 is communicated with the microprocessor 401 through a first communication line 420, so as to send the detection result to the microprocessor 401; the battery management system 201 is communicated with the microprocessor 401 through a second communication line 421, and the battery management system 201 transmits the detected voltage and current of the electric forklift battery 500 to the microprocessor 401.

[0049] In a specific embodiment, each phase of the N-phase bridge inverter circuit includes an upper bridge arm power device and a lower bridge arm power device connected and matched with each other, and the connection between the upper bridge arm power device and the lower bridge arm power device of each phase constitutes the bridge arm midpoint of the phase;

[0050] The positive output of capacitor 408 is connected to the DC positive bus 412 and the negative output is connected to the DC negative bus 413. The negative power supply end of each heating and cooling unit is connected to the DC negative bus 413 and the positive power supply end is connected to the midpoint of the bridge arm of the corresponding phase.

[0051] In a specific embodiment, the upper arm power device or the lower arm power device is preferably a MOSFET or an IGBT.

[0052] In a specific embodiment, N=3, so the N-phase bridge inverter circuit is a 3-phase bridge inverter circuit. Similarly, the heating and cooling module 300 includes 3 heating and cooling units.

[0053] In a specific embodiment, the three-phase bridge inverter circuit specifically includes a first-phase upper bridge arm power device 402, a first-phase lower bridge arm power device 403, a second-phase upper bridge arm power device 404, a second-phase lower bridge arm power device 405, a third-phase upper bridge arm power device 406, and a third-phase lower bridge arm power device 407;

[0054] Wherein, the connection between the first-phase upper bridge arm power device 402 and the first-phase lower bridge arm power device 403 constitutes the first-phase bridge arm midpoint 409; the connection between the second-phase upper bridge arm power device 404 and the second-phase lower bridge arm power device 405 constitutes the second-phase bridge arm midpoint 410; the connection between the third-phase upper bridge arm power device 406 and the third-phase lower bridge arm power device 407 constitutes the third-phase bridge arm midpoint 411;

[0055] The heating and cooling module 300 correspondingly includes a first heating and cooling unit 301, a second heating and cooling unit 302 and a third heating and cooling unit 303; the positive power supply end of the first heating and cooling unit 301 is connected to the midpoint 409 of the first phase bridge arm through a wire 417, the positive power supply end of the second heating and cooling unit 302 is connected to the midpoint 410 of the second phase bridge arm through a wire 418, and the positive power supply end of the third heating and cooling unit 303 is connected to the midpoint 411 of the third phase bridge arm through a wire 419.

[0056] When in use, when the first-phase upper bridge arm power device 402 is turned on, the first heating and cooling unit 301 operates; when the second-phase upper bridge arm power device 404 is turned on, the second heating and cooling unit 302 operates; when the third-phase upper bridge arm power device 406 is turned on, the third heating and cooling unit 301 operates; when the first-phase upper bridge arm power device 402 is turned off, the first heating and cooling unit 301 does not operate; when the second-phase upper bridge arm power device 404 is turned off, the second heating and cooling unit 302 does not operate; when the third-phase upper bridge arm power device 406 is turned off, the third heating and cooling unit 303 does not operate. In other words, by controlling the upper bridge arm power device 402, the upper bridge arm power device 404 and the upper bridge arm power device 406, the first heating and cooling unit 301, the second heating and cooling unit 302 and the third heating and cooling unit 303 can be controlled to operate respectively.

[0057] In a specific embodiment, the microprocessor 401 connects the first phase upper bridge arm power device 402, the first phase lower bridge arm power device 403, the second phase upper bridge arm power device 404, the second phase lower bridge arm power device 405, the third phase upper bridge arm power device 406, and the third phase lower bridge arm power device 407 through control lines, thereby controlling the conduction or cutoff of each power device. Figure 2 As shown, the microprocessor 401 controls the lines (422-427) to connect the power devices 402-407 respectively, thereby controlling the conduction or cutoff of each power component.

[0058] In a specific embodiment, the three-phase stator winding of the pump motor 600 is connected to the first phase bridge arm midpoint 409, the second phase bridge arm midpoint 410 and the third phase bridge arm midpoint 411 respectively through the wires (414, 415, 416), the positive output of the electric forklift battery 500 is connected to the DC positive bus 412, and the negative output of the electric forklift battery 500 is connected to the DC negative bus 413. Figure 2 As shown, the three-phase stator winding of the pump motor 600 is connected to the first phase bridge arm midpoint 409, the second phase bridge arm midpoint 410 and the third phase bridge arm midpoint 411 respectively through wires 414, 415, 416).

[0059] The second object of the present disclosure is to provide a thermal management method adopted by the electric forklift battery thermal management system in the first object, which comprises the following steps:

[0060] S1: Detect whether the pump motor 600 is running;

[0061] S2: If the pump motor 600 is running, the microprocessor 401 does not control the heating and cooling module 300 and jumps to S8; otherwise, continue to S3;

[0062] S3: When it is detected that the pump motor 600 is not running, the ambient temperature detection module 100 obtains the ambient temperature of the electric forklift battery 500, the operating state module 200 obtains the voltage and current of the electric forklift battery 500, and the microprocessor 401 controls the first-phase lower bridge arm power device 403, the second-phase lower bridge arm power device 405, and the third-phase lower bridge arm power device 407 to be turned off. On the other hand, the microprocessor 401 calculates the internal temperature of the electric forklift battery 500 based on the ambient temperature, voltage, and current;

[0063] S4: If the internal temperature is within the normal internal temperature range, the microprocessor 401 controls the first phase upper bridge arm power device 402, the second phase upper bridge arm power device 404 and the third phase upper bridge arm power device 406 to be turned off, that is, the heating and cooling module 300 is controlled not to work, and jumps to S8; otherwise, continue to S5;

[0064] S5: If the internal temperature is 1-5°C higher or lower than the normal internal temperature of the electric forklift battery, the microprocessor 401 controls the first phase upper bridge arm power device 402 to turn on, and the first heating and cooling unit 301 operates; otherwise, continue to S6;

[0065] S6: If the internal temperature of the electric forklift battery is 6-10°C higher or lower than the normal internal temperature of the electric forklift battery, the microprocessor 401 controls the first-phase upper bridge arm power device 402 and the second-phase upper bridge arm power device 404 to be turned on, and the first heating and cooling unit 301 and the second heating and cooling unit 302 operate; otherwise, continue to S7;

[0066] S7: If the internal temperature of the electric forklift battery is higher or lower than the normal internal temperature of the electric forklift battery by more than 11°C, the microprocessor 401 controls the first-phase upper bridge arm power device 402, the second-phase upper bridge arm power device 404 and the third-phase upper bridge arm power device 406 to be turned on, and the first heating and cooling unit 301, the second heating and cooling unit 302 and the third heating and cooling unit 303 are in operation;

[0067] S8: End.

[0068] In a specific embodiment, in S3 , the microprocessor 401 may calculate the internal temperature using the internal resistance energy consumption and the thermal network of the electric forklift battery 500 .

[0069] Specific working principle: Figure 1 As shown, the electric forklift battery thermal management system 10 includes: an ambient temperature detection module 100 , an operating status module 200 , a heating and cooling module 300 and a thermal management control module 400 .

[0070] like Figure 2As shown, the ambient temperature detection module 100 includes a temperature sensor 101 , which is installed near the electric forklift battery 500 , and can detect the ambient temperature of the electric forklift battery 500 , and send the detection result to the microprocessor 401 through the first communication line 420 .

[0071] Among them, the operating status module 200 includes a battery management system 201, a voltage sensor 202 and a current sensor 203. The battery management system 201 can detect the voltage of the electric forklift battery 500 through the voltage sensor 202 and detect the current of the electric forklift battery 500 through the current sensor 203; the battery management system 201 sends the detected voltage and current of the electric forklift battery 500 to the microprocessor 401 through the second communication line 421.

[0072] The heating and cooling module 300 includes a first heating and cooling unit 301, a second heating and cooling unit 302 and a third heating and cooling unit 303, and the three heating and cooling units work independently of each other. The negative power supply ends of the first heating and cooling unit 301, the second heating and cooling unit 302 and the third heating and cooling unit 303 are connected to the DC negative bus 413. The positive power supply end of the first heating and cooling unit 301 is connected to the first phase bridge arm midpoint 409 in the three-phase bridge inverter circuit of the pump motor controller through a wire 417; the positive power supply end of the second heating and cooling unit 302 is connected to the second phase bridge arm midpoint 410 in the three-phase bridge inverter circuit of the pump motor controller through a wire 418; the positive power supply end of the third heating and cooling unit 303 is connected to the third phase bridge arm midpoint 411 in the three-phase bridge inverter circuit of the pump motor controller through a wire 419. Wires 417-419 are all different wires.

[0073] In addition, the thermal management control module 400 at least includes a pump motor controller, specifically including: a microprocessor 401, a first-phase upper bridge arm power device 402, a first-phase lower bridge arm power device 403, a second-phase upper bridge arm power device 404, a second-phase lower bridge arm power device 405, a third-phase upper bridge arm power device 406, a third-phase lower bridge arm power device 407, a capacitor 408, a DC positive bus 412, and a DC negative bus 413. The power devices 402-407 form a three-phase bridge inverter circuit, wherein the connection point between the first-phase upper bridge arm power device 402 and the first-phase lower bridge arm power device 403 is the first-phase bridge arm midpoint 409; the connection point between the second-phase upper bridge arm power device 404 and the second-phase lower bridge arm power device 405 is the second-phase bridge arm midpoint 410; and the connection point between the third-phase upper bridge arm power device 406 and the third-phase lower bridge arm power device 407 is the third-phase bridge arm midpoint 411. Preferably, the power devices 402-407 are MOSFETs; optionally, the power devices 402-407 are IGBTs. The positive output of the capacitor 408 is connected to the DC positive bus 412, and the negative output of the capacitor 408 is connected to the DC negative bus 413. In addition, the microprocessor 401 controls the conduction or cutoff of the power devices 402-407 through different control lines 422-427.

[0074] In addition, the three-phase stator winding of the pump motor 600 is connected to the first phase bridge arm midpoint 409, the second phase bridge arm midpoint 410 and the third phase bridge arm midpoint 411 in the thermal management control module 400 through wires 414, 415 and 416 respectively. The positive output of the electric forklift battery 500 is connected to the DC positive bus 412, and the negative output of the electric forklift battery 500 is connected to the DC negative bus 413. Wires 414-416 are all different wires.

[0075] Further, based on the electrical connection relationship between each module or each component or each component unit in the above-mentioned electric forklift battery thermal management system, it can be understood that when the first-phase upper bridge arm power device 402 is turned on, the first heating and cooling unit 301 operates; when the second-phase upper bridge arm power device 404 is turned on, the second heating and cooling unit 302 operates; when the third-phase upper bridge arm power device 406 is turned on, the third heating and cooling unit 301 operates; when the first-phase upper bridge arm power device 402 is turned off, the first heating and cooling unit 301 does not operate; when the second-phase upper bridge arm power device 404 is turned off, the second heating and cooling unit 302 does not operate; when the third-phase upper bridge arm power device 406 is turned off, the third heating and cooling unit 303 does not operate. In other words, by controlling the upper bridge arm power device 402, the upper bridge arm power device 404 and the upper bridge arm power device 406, it is possible to control whether the first heating and cooling unit 301, the second heating and cooling unit 302 and the third heating and cooling unit 303 operate respectively.

[0076] To facilitate those skilled in the art to further understand the electric forklift battery thermal management system provided in the embodiment of the present application, the electric forklift battery thermal management method provided in the embodiment of the present application is described below with reference to the accompanying drawings.

[0077] like Figure 3 As shown, the electric forklift battery thermal management method adopts the above-mentioned electric forklift battery thermal management system, and the method includes the following steps:

[0078] In step S1: firstly, whether the pump motor 600 is running is detected;

[0079] In step S2, when the pump motor 600 is running, the microprocessor 401 does not perform any intentional control on the heating and cooling module.

[0080] In step S3, when the pump motor 600 is not running, the microprocessor 401 calculates the internal temperature of the electric forklift battery based on the ambient temperature of the battery obtained from the battery ambient temperature detection module, the battery voltage and the battery current obtained from the battery operation status module. Optionally, the internal temperature of the electric forklift battery can be calculated using the internal resistance energy consumption of the electric forklift battery and the electric forklift battery thermal network. The microprocessor 401 controls the first phase lower bridge arm power device 403, the second phase lower bridge arm power device 405 and the third phase lower bridge arm power device 407 to be turned off, and on this basis, continues to S4.

[0081] In step S4, if the internal temperature of the electric forklift battery is within the normal internal temperature range of the electric forklift battery, the microprocessor 401 controls the first phase upper bridge arm power device 402, the second phase upper bridge arm power device 404 and the third phase upper bridge arm power device 406 to be cut off, and the heating and cooling module does not work.

[0082] In step S5, if the internal temperature of the electric forklift battery is 1-5°C higher or lower than the normal internal temperature of the electric forklift battery, the microprocessor 401 controls the first phase upper bridge arm power device 402 to be turned on, and the first heating and cooling unit 301 operates.

[0083] In step S6, if the internal temperature of the electric forklift battery is 6-10°C higher or lower than the normal internal temperature of the electric forklift battery, the microprocessor 401 controls the first phase upper bridge arm power device 402 and the second phase upper bridge arm power device 404 to be turned on, and the first heating and cooling unit 301 and the second heating and cooling unit 302 operate.

[0084] In step S7, if the internal temperature of the electric forklift battery is higher or lower than the normal internal temperature of the electric forklift battery by more than 11°C, the microprocessor 401 controls the first-phase upper bridge arm power device 402, the second-phase upper bridge arm power device 404 and the third-phase upper bridge arm power device 406 to be turned on, and the first heating and cooling unit 301, the second heating and cooling unit 302 and the third heating and cooling unit 303 are running.

[0085] In step S8, the process ends.

[0086] It should be noted that the aforementioned explanation of the embodiment of the electric forklift battery thermal management system is also applicable to the electric forklift battery thermal management method of this embodiment, and will not be repeated here.

[0087] To sum up, through the unique design of the present invention, the electric forklift battery thermal management system and thermal management method provided by the present invention utilize the upper arm power device in the three-phase bridge inverter circuit of the pump motor controller to control the heating and cooling unit in the heating and cooling module, which can solve the problems of complex structure and high application cost of the electric forklift battery thermal management system in the background technology; at the same time, during the operation of the electric forklift, the internal temperature of the electric forklift battery can be kept within a normal range, which is beneficial to extending the service life of the electric forklift battery and improving the safety and reliability of the electric forklift battery.

[0088] The above description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A thermal management method for an electric forklift battery thermal management system, The electric forklift battery thermal management system comprises an ambient temperature detection module (100), an operating status module (200), a heating and cooling module (300) and a thermal management control module (400); the ambient temperature detection module (100) and the operating status module (200) are respectively connected to the thermal management control module (400), and the thermal management control module (400) is connected to the heating and cooling module (300); The ambient temperature detection module (100) comprises a temperature sensor (101) adjacent to the electric forklift battery (500), wherein the temperature sensor (101) is used to detect the ambient temperature of the electric forklift battery (500); The operating status module (200) comprises a battery management system (201), a voltage sensor (202) and a current sensor (203); the battery management system (201) detects the voltage and current of the electric forklift battery (500) respectively through the voltage sensor (202) and the current sensor (203); The heating and cooling module (300) comprises N mutually independent heating and cooling units, and the heating and cooling units are used to heat or cool the environment in which the electric forklift battery (500) is located; The thermal management control module (400) includes a pump motor controller, which controls the heating and cooling module (300) to perform heating or cooling based on the ambient temperature of the electric forklift battery (500) and the operation information of the electric forklift battery (500) and the pump motor (600); The pump motor controller comprises a microprocessor (401), a capacitor (408), a DC positive bus (412), a DC negative bus (413) and an N-phase bridge inverter circuit; each phase of the N-phase bridge inverter circuit corresponds to one of the heating and cooling units and is connected to the pump motor (600) to drive the heating and cooling units to operate; the temperature sensor (101) is connected to the microprocessor (401) in communication via a first communication line (420), thereby sending the detection result to the microprocessor (401); the battery management system (201) is connected to the microprocessor (401) in communication via a second communication line (421), and the battery management system (201) sends the detected voltage and current of the electric forklift battery (500) to the microprocessor (401); Each phase of the N-phase bridge inverter circuit comprises an upper bridge arm power device and a lower bridge arm power device that are connected and matched with each other, and the connection between the upper bridge arm power device and the lower bridge arm power device of each phase constitutes the bridge arm midpoint of the phase; the capacitor (408) output positive electrode is connected to the DC positive bus (412) and the output negative electrode is connected to the DC negative bus (413), and the negative power supply end of each heating and cooling unit is connected to the DC negative bus (413) and the positive power supply end is connected to the bridge arm midpoint of the corresponding phase; Said N=3, so said N-phase bridge inverter circuit is a 3-phase bridge inverter circuit, and similarly said heating and cooling module (300) comprises 3 said heating and cooling units; The three-phase bridge inverter circuit specifically comprises a first-phase upper bridge arm power device (402), a first-phase lower bridge arm power device (403), a second-phase upper bridge arm power device (404), a second-phase lower bridge arm power device (405), a third-phase upper bridge arm power device (406), and a third-phase lower bridge arm power device (407); in, The connection point between the first-phase upper bridge arm power device (402) and the first-phase lower bridge arm power device (403) forms the first-phase bridge arm midpoint (409); the connection point between the second-phase upper bridge arm power device (404) and the second-phase lower bridge arm power device (405) forms the second-phase bridge arm midpoint (410); and the connection point between the third-phase upper bridge arm power device (406) and the third-phase lower bridge arm power device (407) forms the third-phase bridge arm midpoint (411); The heating and cooling module (300) correspondingly comprises a first heating and cooling unit (301), a second heating and cooling unit (302) and a third heating and cooling unit (303); the positive power supply end of the first heating and cooling unit (301) is connected to the midpoint (409) of the first phase bridge arm via a wire, the positive power supply end of the second heating and cooling unit (302) is connected to the midpoint (410) of the second phase bridge arm via a wire, and the positive power supply end of the third heating and cooling unit (303) is connected to the midpoint (411) of the third phase bridge arm via a wire. It is characterized by comprising the following steps: S1: Detecting whether the pump motor (600) is running; S2: If the pump motor (600) is running, the microprocessor (401) does not control the heating and cooling module (300) and jumps to S8; otherwise, continue to S3; S3: When it is detected that the pump motor (600) is not running, the ambient temperature detection module (100) obtains the ambient temperature of the electric forklift battery (500), the operating state module (200) obtains the voltage and current of the electric forklift battery (500), the microprocessor (401) controls the first phase lower bridge arm power device (403), the second phase lower bridge arm power device (405) and the third phase lower bridge arm power device (407) to be turned off, and the microprocessor (401) calculates the internal temperature of the electric forklift battery (500) based on the ambient temperature, voltage and current; S4: If the internal temperature is within the normal internal temperature range, the microprocessor (401) controls the first phase upper bridge arm power device (402), the second phase upper bridge arm power device (404) and the third phase upper bridge arm power device (406) to be turned off, that is, the heating and cooling module (300) is controlled not to work, and the process jumps to S8; otherwise, the process continues to S5; S5: If the internal temperature is 1-5°C higher or lower than the normal internal temperature of the electric forklift battery, the microprocessor (401) controls the first phase upper bridge arm power device (402) to be turned on, and the first heating and cooling unit (301) operates; otherwise, continue to S6; S6: If the internal temperature of the electric forklift battery is 6-10° C. higher or lower than the normal internal temperature of the electric forklift battery, the microprocessor (401) controls the first-phase upper bridge arm power device (402) and the second-phase upper bridge arm power device (404) to be turned on, and the first heating and cooling unit (301) and the second heating and cooling unit (302) to operate; otherwise, continue to S7; S7: If the internal temperature of the electric forklift battery is higher or lower than the normal internal temperature of the electric forklift battery by more than 11°C, the microprocessor (401) controls the first-phase upper bridge arm power device (402), the second-phase upper bridge arm power device (404) and the third-phase upper bridge arm power device (406) to be turned on, and the first heating and cooling unit (301), the second heating and cooling unit (302) and the third heating and cooling unit (303) to operate; S8: End.

2. The thermal management method according to claim 1, It is characterized in that In S3, the microprocessor (401) calculates the internal temperature using the internal resistance energy consumption and the thermal network of the electric forklift battery (500).

3. The thermal management method according to claim 1, It is characterized in that The upper bridge arm power device or the lower bridge arm power device is a MOSFET or an IGBT.

4. The thermal management method according to claim 1, It is characterized in that The microprocessor (401) is connected to the first-phase upper bridge arm power device (402), the first-phase lower bridge arm power device (403), the second-phase upper bridge arm power device (404), the second-phase lower bridge arm power device (405), the third-phase upper bridge arm power device (406), and the third-phase lower bridge arm power device (407) respectively through control lines, thereby controlling the conduction or cutoff of each power device.

5. The thermal management method according to claim 1, It is characterized in that The three-phase stator winding of the pump motor (600) is respectively connected to the midpoint of the first phase bridge arm (409), the midpoint of the second phase bridge arm (410) and the midpoint of the third phase bridge arm (411) through conductive wires; the positive output electrode of the electric forklift battery (500) is connected to the DC positive bus (412); and the negative output electrode of the electric forklift battery (500) is connected to the DC negative bus (413).

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