Traction battery

Abstract

The invention relates to the field of energy accumulator design. A traction battery for a highly automated autonomous vehicle includes: a housing in which modules connected in series are mounted; a heating system comprising a heating mat disposed between the modules; and a control system. The modules are arranged in two layers. Each module includes lithium iron phosphate-based rechargeable cells interconnected in series that are electrically isolated from each other. And the control system comprises a temperature sensor and a humidity sensor which are arranged on each module, a voltmeter for each battery cell in the module, and a current sensor for loading and unloading the power supply module. The invention makes it possible to increase the nominal voltage and operating temperature range during discharge, and to provide safer maintenance of the traction battery.

Description

[0001] Field of the Invention The present invention relates to the field of electrical engineering, namely to a traction battery based on lithium iron phosphate cells for unmanned highly automated vehicles (HAVs), designed to collect and store electrical energy for performing movement and powering low current on-board computers.

[0002] background Many different types of traction batteries with different energy storage chemistries are known from the prior art.The proposed traction battery based on lithium iron phosphate cells has several advantages over similar solutions.

[0003] A device is known (RU137774 U1, B60H1 / 00, published on 27.02.2014) for protecting a vehicle battery from excessive cooling. It comprises a heat-insulating housing, a temperature sensor, a heater and a control unit, the output of which is connected to the supply circuit of the heater. The control unit comprises a timer and a button, and the temperature sensor of the battery housing is connected to the timer control input via the button.

[0004] The disadvantage of this solution is that it requires an external power supply, which means that the process of heating the battery is limited by the technical conditions of the unit, its charging and chemical composition.

[0005] A thermally protected lithium-ion rechargeable battery is known (RU140037 U1, H01M10 / 44, published on 27.04.2014), comprising a heating element installed in the housing of a battery module, and a series-connected electrical energy storage device with an integrated hierarchical electronic control system. The control system consists of temperature sensors and balancing devices installed on the energy storage units, which are interconnected and connected to a control unit via a bidirectional information communication channel, while the battery module control unit contains an electronic key connected to an end-to-end isolated direct current (DC) power exchange line.

[0006] The disadvantages of this technical solution include the need to install an electrical energy storage device, which also requires an additional control module for data collection and analysis.

[0007] A rechargeable automotive battery is known from the prior art (RU 2713618 C2, H01M10 / 653, published on 05.02.2020). It is used as a prototype and comprises a battery module having a plurality of stacked battery cells and, at least in one intermediate region between two adjacent battery cells, a heat conducting element (film or steel sheet).

[0008] The prototype's shortcomings include the inability to quickly replace battery cells and the lack of sensors and control boards to regulate temperatures inside and outside the battery. Summary of the invention

[0009] The proposed technical solution solves the task of creating a traction battery based on lithium iron phosphate cells for unmanned HAVs.

[0010] The technical result of the claimed invention is an increase in the rated voltage and operating temperature range during discharge, as well as the possibility of rapid replacement of battery modules, as well as increased assembly integrity, repair and maintenance of the traction battery.

[0011] The technical result claimed is achieved due to the fact that the traction battery comprises a housing with modules connected in series and a heating system formed by heating mats between the modules, wherein the modules in the housing are arranged in two layers and each module is formed by iron phosphate battery cells connected in series, electrically isolated from each other; furthermore, the housing comprises a control system having on each module a temperature sensor, a humidity sensor, a voltmeter for each cell in the module, a current sensor and an upper and lower power supply module.

[0012] The technical solution used in the claimed battery allows monitoring and control of essential parameters of each cell and module. The series connection of cells in modules and two-layer structures leads to an increase in the rated voltage, which is necessary to provide power to all vehicle systems.

[0013] BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 A model of a traction battery is shown, where 1 is the traction battery 2 is the battery control board 3 is the upper power module 4 is the lower power module 5 is the controller central board 6 is a housing.

[0014] The housing consists of battery modules (1) mounted in two layers and connected in series, each battery module containing 12 lithium iron phosphate battery cells also connected in series. Each cell is connected to a control board (2) by electrical contacts; the data from the control board is transmitted to the central board (5) of the control module to monitor the parameters of each cell (voltage, temperature, resistance, state of charge, etc.). The cell control board (2) is powered by energy obtained from the battery modules (1). The controller central board (5) is responsible for monitoring the battery charge level by collecting and analyzing information from each battery module (1). An electric shock protection system, a short circuit protection system and a humidity control system are also installed inside the battery. The upper power module (3) serves as a positive line contactor and the lower power module (4) serves as a negative line contactor. Thus, the + and - lines are separated from each other, allowing the battery to be safely assembled, repaired and maintained (no short circuit is possible).

[0015] The battery comprises a heating system for the modules to charge the battery at sub-zero temperatures and to prevent degradation of the battery during charging at sub-zero temperatures. The temperature is recorded via at least two temperature sensors in each battery module (1) during discharge / charging, which provides more accurate temperature control. The values ​​of all parameters (voltage, temperature, charge) are sent to a connected computer via a network interface.

[0016] Detailed description of the invention Battery condition monitoring is performed using a traction battery monitoring and control system installed as part of the battery. To achieve optimal voltage and energy consumption during HAV operation, the battery is designed as follows: 12 lithium iron phosphate battery cells with a rated voltage of 3.2 V are combined into one module, and 16 modules are installed in two layers and connected sequentially (see Figure 1 ). Inside the battery, there is a control module for tracking the parameters (voltage, temperature, resistance, charge, etc.) of each cell in each of the 16 modules; a shock protection system, a short circuit protection system, and a humidity control system are also installed inside the housing. The 16 modules are arranged in two layers and connected in series in order to increase the rated voltage. The traction battery has a heating system for the modules (and, accordingly, the cells) to charge the battery at sub-zero temperatures and to prevent the cells from deteriorating during charging at sub-zero temperatures. Inside the battery, there are humidity sensors, current and voltage sensors that provide extensive information about the battery. This ensures continuous integrity monitoring and prevents high voltage breakdown on the housing due to water entering the high voltage contacts.

[0017] The electric shock protection system works together with the battery layer control system. The upper and lower power modules are installed, where the upper power module is used as a positive line contactor and the lower power module is used as a negative line contactor (which allows design optimization). Therefore, the + line and the - line are separated from each other, which avoids short circuits and increases the safety of battery assembly, repair and maintenance.

[0018] The assembled battery has the following characteristics: rated voltage 614V, capacity 105 Ah. The design allows charging each battery layer simultaneously by an external DC power supply. The advantages of this embodiment are the self-balancing of each cell (a process that occurs due to the equalization of the potential on each cell), and the possibility of rapid replacement of battery modules. In order to track the parameters of each cell (voltage, temperature, current, charge, errors, capacity of each cell), a cell monitoring board is installed in the module, which allows monitoring of any individual cell and the system as a whole. The system is monitored via a network interface for each of the two layers.

[0019] The chemical composition of the cells, which make up the battery module (cathodes based on lithium iron phosphate), allows to carry out discharge processes with currents up to 2C, where C is the capacity of the entire system, in a temperature range of -20°C to +55°C, which in turn offers the opportunity to operate the HAV at subzero temperatures without switching on the heating system. In order to carry out charging in a temperature range below 0°C (up to 1C), the battery modules and, respectively, the cells, are provided with a heating system formed by heating pads located between the modules. When an external current source is connected, the heating is activated during charging, which avoids the need for additional batteries.

[0020] The claimed traction battery based on lithium iron phosphate cells is used as an energy source for unmanned HAVs.

[0021] The claimed technical solution meets the requirements of industrial applicability, and the claimed solution can be used in any ground unmanned HAV.

Claims

1. A traction battery for an unmanned highly automated vehicle, comprising: A housing having modules connected in series; a heating system formed by heating mats located between the modules; wherein the modules are arranged in two layers in the housing, and each module is formed by lithium iron phosphate battery cells connected in series and electrically isolated from each other; The housing includes a monitoring system, which is composed of a temperature sensor and a humidity sensor installed on each module, a voltmeter for each battery cell in the module, a current sensor, and upper and lower power modules.

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