Wireless communication method in battery pack and master BMS providing the same

Abstract

The present invention relates to a wireless communication method in a battery pack and a master BMS for providing the method, and the master BMS according to the present invention, which performs wireless communication with a slave BMS according to a frequency hopping method in a battery pack, includes: a communicator for receiving first channel scanning information generated by scanning a plurality of channels belonging to a frequency bandwidth used in wireless communication by a device set outside the battery pack; a channel analyzer for generating second channel scanning information by scanning channels belonging to the frequency bandwidth; a storage unit for storing a reference signal-to-noise ratio (SNR) value regarding wireless communication; and a control unit for selecting a frequency hopping channel used in the frequency hopping method based on the first channel scanning information, and calculating the signal strength of the selected frequency hopping channel based on the second channel scanning information and the reference SNR value.

Description

Technical Field

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Korean Patent Application No. 10-2020-0121337 filed on September 21, 2020, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.

[0003] The present invention relates to a wireless communication method in a battery pack, and more particularly to a wireless communication method and a master BMS providing the method. Background Art

[0004] A battery pack, particularly a medium to large battery pack used in a vehicle or ESS, may include a plurality of battery modules having a multi-module structure in which the battery modules are coupled in series and / or in parallel to increase the capacity and / or output of the battery pack.

[0005] Multi-structure battery packs can be implemented in various forms, depending on circuit logic or PCB configuration. In this case, the battery management system (BMS) typically uses a multi-slave structure to improve monitoring and control efficiency. The multi-slave structure is configured for multiple slave BMSs to cover the multiple battery modules configuring the battery pack, and is configured for the master BMS to control the multiple slave BMSs as a whole.

[0006] In a conventional battery pack, a wired communication method is used between a master BMS and slave BMSs, but there are many problems such as a complicated communication link. Therefore, many attempts have been made to use a wireless communication method between a master BMS and slave BMSs in a battery pack.

[0007] However, wireless communication methods also have drawbacks, the most prominent of which is battery power consumption. When transmitting and receiving battery information data within a battery pack, communication accuracy is crucial. The master BMS assumes the worst-case scenario and sets the maximum signal transmission power for data transmission. Wireless communication with multiple slave BMSs is performed at this predetermined signal transmission power level, potentially resulting in excessive power consumption over time.

[0008] That is, the slave BMS is electrically connected to the battery module and can receive power from the battery module and perform wireless communication. Data is transmitted and received at the maximum signal transmission power that considers the worst case without reflecting actual external noise, so the power of the battery module may drop sharply.

[0009] Therefore, a communication method is needed for transmitting / receiving data with optimal signal transmission power when performing wireless communication between a master BMS and multiple slave BMSs in a battery pack, thereby reducing power consumption of the battery module and reducing interference caused by external noise. Summary of the Invention

[0010] Technical issues

[0011] The present invention is conceived with the object of providing a wireless communication method in a battery pack for selecting a plurality of frequency hopping channels for a frequency hopping method based on noise intensity and noise type of each channel measured outside the battery pack, and a master BMS for providing the method.

[0012] Another object of conceiving the present invention is to provide a wireless communication method in a battery pack for calculating signal transmission power (TP) of each frequency hopping channel based on noise intensity of the channel measured in the battery pack, and a master BMS for providing the method.

[0013] Another object of conceiving the present invention is to provide a wireless communication method in a battery pack for generating a frequency hopping sequence based on a plurality of frequency hopping channels and a signal transmission power calculated for each frequency hopping channel, and performing wireless communication between a master BMS and a slave BMS according to the frequency hopping sequence, and a master BMS for providing the method.

[0014] Technical Solution

[0015] An embodiment of the present invention provides a master battery management system (BMS), which serves as a master BMS that performs wireless communication with a slave BMS according to a frequency hopping method in a battery pack, including: a communicator for receiving first channel scanning information generated by a device arranged outside the battery pack scanning a plurality of channels belonging to a frequency bandwidth used in wireless communication; a channel analyzer for generating second channel scanning information by scanning channels belonging to the frequency bandwidth; a storage unit for storing a reference signal-to-noise ratio (SNR) value regarding wireless communication; and a control unit for selecting a frequency hopping channel used in the frequency hopping method based on the first channel scanning information, and calculating the signal strength of the selected frequency hopping channel based on the second channel scanning information and the reference SNR value.

[0016] The first channel scanning information may include first noise intensities of respective channels, and the control unit may compare the first noise intensities with a reference value and select a channel having a first noise intensity less than the first reference value from among the channels as a frequency hopping channel.

[0017] The first channel scanning information may include a first noise type and a first noise intensity of each channel, and the control unit may compare the first noise intensity with a reference value and select a channel having a first noise intensity less than the first reference value and not including noise predetermined as the first noise type from among the channels as a frequency hopping channel.

[0018] The second channel scanning information may include second noise strength of each channel, and the control unit may calculate a signal strength satisfying a reference SNR value with respect to the second noise strength and set the calculated signal strength as the signal strength of the frequency hopping channel.

[0019] The control unit may generate a hopping sequence of a frequency hopping method based on the frequency hopping channel and the signal strength of the frequency hopping channel, and perform synchronization with the slave BMS based on the hopping sequence, thereby being arranged in the same hopping channel simultaneously with the slave BMS.

[0020] The frequency bandwidth may include a frequency bandwidth to which the Industrial-Scientific-Medical (ISM) band belongs.

[0021] Another embodiment of the present invention provides a wireless communication method in a battery pack, as a method for a master battery management system (BMS) to perform wireless communication with a slave BMS according to a frequency hopping method in the battery pack, including: receiving first channel scanning information generated by scanning a plurality of channels belonging to a frequency bandwidth used in wireless communication by a device outside the battery pack; selecting a frequency hopping channel used in the frequency hopping method based on the first channel scanning information; calculating the signal strength of the frequency hopping channel based on second channel scanning information generated by scanning the channels belonging to the frequency bandwidth in the battery pack and a reference signal-to-noise ratio (SNR) value for wireless communication; and generating a frequency hopping sequence of the frequency hopping method based on the frequency hopping channel and the signal strength of the frequency hopping channel.

[0022] Selecting the frequency hopping channel may include comparing first noise intensities of channels included in the first channel scanning information with a reference value, and selecting a channel having a first noise intensity less than the first reference value from among the channels as the frequency hopping channel.

[0023] Selecting a frequency hopping channel may include comparing first noise intensities of respective channels included in the first channel scanning information with a reference value, and selecting a channel having a first noise intensity less than the first reference value as the frequency hopping channel from channels that do not include noise of a first noise type predetermined to be included in the first channel scanning information.

[0024] Calculating the signal strength of the frequency hopping channel may include calculating a signal strength satisfying a reference SNR value among second noise strengths of the frequency hopping channel included in the second channel scanning information, and setting the calculated signal strength as the signal strength of the frequency hopping channel.

[0025] The wireless communication method may further include, after generating a frequency hopping sequence of the frequency hopping method, performing synchronization with the slave BMS based on the frequency hopping sequence, thereby being simultaneously positioned in the same frequency hopping channel as the slave BMS.

[0026] Beneficial effects

[0027] The present invention can avoid interference issues with other communication protocols such as Bluetooth or Wi-Fi that co-use the Industrial-Scientific-Medical (ISM) band by selecting a frequency hopping channel for wireless communication between a master BMS and a slave BMS based on noise intensity and / or noise type measured outside the battery pack.

[0028] The present invention can reduce unnecessary power consumption of wireless communication between a master BMS and a slave BMS by calculating the optimal signal transmission power of each frequency hopping channel based on noise intensity measured in a battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A system for providing a wireless communication method in a battery pack according to an embodiment is shown.

[0030] Figure 2 Show Figure 1 The configuration of the main BMS is shown.

[0031] Figure 3 A flow chart illustrating a wireless communication method in a battery pack according to an embodiment. DETAILED DESCRIPTION

[0032] Hereinafter, the embodiments disclosed in this specification will be described in detail with reference to the accompanying drawings. In this specification, the same or similar components are represented by the same or similar reference numerals, and their repeated description will be omitted. For the components used in the following description, the terms "module" and "unit" are used only to make the specification easier. Therefore, these terms themselves do not have the meaning or function of distinguishing them from each other. When describing the embodiments of this specification, when it is determined that the detailed description of the known technology associated with the present invention may confuse the main points of the present invention, it will be omitted. The accompanying drawings are provided only to make the embodiments disclosed in this specification easy to understand, and should not be interpreted as limiting the spirit disclosed in this specification, and it should be understood that the present invention includes all modifications, equivalents and alternatives without departing from the scope and spirit of the invention.

[0033] Terms including ordinal numbers, such as "first," "second," etc., are only used to describe various components and should not be construed as limiting these components. These terms are only used to distinguish one component from other components.

[0034] It should be understood that when a component is referred to as being “connected” or “coupled” to another component, it can be directly connected or coupled to the other component or connected or coupled to the other component through other components interposed therebetween. On the other hand, it should be understood that when a component is referred to as being “directly connected or coupled” to another component, it can be connected or coupled to the other component without other components interposed therebetween.

[0035] It should be further understood that the terms “including” or “having” used in this specification specify the existence of the stated features, numbers, steps, operations, components, parts or a combination thereof, but do not exclude the existence or addition of one or more other features, numbers, steps, operations, components, parts or a combination thereof.

[0036] Figure 1 A system for providing a wireless communication method in a battery pack according to an embodiment is shown.

[0037] Reference Figure 1 , a system for providing a wireless communication method in a battery pack includes an external terminal 1 and a vehicle system 2 .

[0038] External terminal 1 may be a portable terminal owned by a driver who has boarded a vehicle. For example, when the driver enters the vehicle and turns on vehicle system 2, external terminal 1 and vehicle system 2 may communicate wirelessly using a predetermined communication module. The communication module may be a communication module such as Bluetooth, Wi-Fi, or Zigbee.

[0039] The external terminal 1 can scan multiple channels within a frequency bandwidth and measure the noise type and noise intensity of the channels to generate first channel scanning information. For example, when the vehicle system 2 is turned on, the external terminal 1 can include an application for generating the first channel scanning information for each predetermined period or in real time and transmitting it to the vehicle system 2.

[0040] According to an embodiment, the frequency bandwidth may include the Industrial-Scientific-Medical (ISM) bandwidth. The ISM bandwidth is a frequency bandwidth allocated to the industrial, scientific, and medical fields and can be used without an additional license. Common ISM bandwidths are established worldwide as 900 MHz, 2.4 GHz, and 5.7 GHz bandwidths. For example, Bluetooth and Zigbee use one frequency bandwidth (2.4 GHz), and Wi-Fi uses two frequency bandwidths (2.4 GHz and 5 GHz).

[0041] The ISM bandwidth is used by various wireless communication devices, leading to performance degradation due to communication interference. To prevent communication interference, communication protocols such as Bluetooth, Wi-Fi, and Zigbee that use the ISM bandwidth perform communication using a frequency hopping method. Frequency hopping refers to a communication method that divides the frequency bandwidth in use into multiple channels with predetermined bandwidths, rapidly moves between the channels according to a specific pattern (hereinafter referred to as a frequency hopping sequence), and divides and transmits data.

[0042] The vehicle system 2 includes a control device 10 and a battery pack 20 .

[0043] The control device 10 generally controls the vehicle system 2 , and may be, for example, an electronic control unit (ECU), but is not limited thereto.

[0044] According to an embodiment, the control device 10 may include a first communication device for performing wireless communication with the external terminal 1 and a second communication device for performing vehicle communication with the battery pack 20. The first communication device may include a wireless communication module such as Bluetooth, Wi-Fi, or Zigbee. The second communication device may include a vehicle communication module such as a controller area network (CAN), a local interconnect network (LIN), or FlexRay for communication within the vehicle.

[0045] The control device 10 may receive the first channel scanning information from the external terminal 1 through the first communication module, and may transmit the first channel scanning information to the battery pack 20 through the second communication module.

[0046] The battery pack 20 includes a master battery management system (BMS) 100 and a slave battery management system 200 .

[0047] In addition to the master BMS 100 and the slave BMS 200, the battery pack also includes a plurality of battery modules (not shown). Each battery module includes a plurality of battery cells electrically connected in series. For example, the battery pack can be installed on a vehicle to supply power and drive an electric motor, or can supply power to operate various electronic devices such as an audio unit or an air conditioner. Here, the vehicle can be an electric vehicle (EV) or a hybrid electric vehicle (HEV or PHEV) that receives driving power from the battery pack.

[0048] The battery pack 20 communicates with various external electronic devices using a vehicle communication method such as CAN, LIN, or FlexRay. In some embodiments, the electronic devices in the battery pack 20 can communicate using a wireless communication method that conforms to a frequency hopping method. In some embodiments, a master BMS 100 is installed in the battery pack 20. It can communicate with the external control device 10 using a vehicle communication method such as CAN communication, and can communicate with an internal slave BMS 200 using a wireless communication method such as a frequency hopping method. The slave BMS 200 is installed in the battery pack 20. It may not communicate directly with the outside world, but can communicate with the master BMS 100 using a wireless communication method that conforms to a frequency hopping method.

[0049] The performance of wireless communications is determined not by absolute signal strength but by the ratio of signal strength to noise strength—that is, relative signal strength. The average power of a signal (transmission power) is altered by amplifiers and attenuators, and noise is added to the signal, degrading transmission characteristics. Therefore, it is difficult to use average power as a performance indicator for wireless communications. In other words, the performance of wireless communications can be determined by the signal-to-noise ratio (SNR).

[0050] The SNR is a metric used to quantitatively indicate the influence of noise on a signal carrying information. It shows how high the signal power level is compared to the noise level. In other words, signals often coexist with noise. The effect of noise on a signal can be quantified using the signal-to-noise ratio.

[0051] (Equation 1)

[0052]

[0053] Equation 1 calculates the SNR. S is the average signal transmission power, P N is the average noise power, and the unit of SNR may be decibel (dB). Referring to Equation 1, SNR indicates that the effect of noise decreases as the value increases.

[0054] For example, the optimal SNR level for audio may be equal to or greater than 40 dB (preferably 60 dB), and the optimal SNR level for video may be equal to or greater than 45 dB (preferably 55 dB). According to an embodiment, when the master BMS 100 and the slave BMS 200 transmit and receive data to and from each other, the optimal SNR level may be set by an upper-layer control device such as the control device 10.

[0055] The master BMS 100 can collectively control multiple slave BMSs 200_1, 200_2, ..., 200_N. For example, the master BMS 100 can wirelessly communicate with the slave BMSs 200 to receive battery information and transmit instructions. The battery information may include information measured by the slave BMSs 200 (e.g., cell current, cell voltage, cell temperature, etc.) and information estimated by the slave BMSs 200 (e.g., SOC (State of Charge) and SOH (State of Health)).

[0056] According to an embodiment, the master BMS 100 may generate a frequency hopping sequence and perform wireless communication with the slave BMS 200 according to the frequency hopping sequence. For example, the master BMS 100 may select a plurality of frequency hopping channels to be used in the frequency hopping method from a plurality of channels CH_1 to CH_N existing in the ISM bandwidth as a frequency bandwidth used in wireless communication, and may calculate the signal strength of each frequency hopping channel to generate a frequency hopping sequence.

[0057] The frequency hopping method is a communication method for preventing deterioration in communication quality due to signal interference with another communication device using the same frequency bandwidth, namely, the ISM bandwidth. Specifically, the frequency hopping method divides the frequency bandwidth into a plurality of channels of different frequencies, divides data while changing channels, and transmits the divided data.

[0058] For example, when the ISM bandwidth is divided into ten channels, namely, the first channel CH_1 to the tenth channel CH_10, the master BMS 100 changes the channels to the first channel CH_1, the third channel CH_3, the eighth channel CH_8, etc., according to a predetermined pattern, divides the data, and transmits the divided data, thereby reducing or resolving mutual interference between signals. The predetermined pattern may be a frequency hopping sequence.

[0059] The master BMS 100 can select a channel with a noise intensity equal to or less than a reference value from among multiple channels belonging to the frequency bandwidth as a frequency hopping channel. For example, among the ten divided channels from the first channel CH_1 to the tenth channel CH_10 in the ISM bandwidth, the master BMS 100 can discard the channel with a high noise power density and select a channel with a noise power density equal to or less than a reference value as the frequency hopping channel. The noise in this example includes all signals except the data transmitted and received between the master BMS 100 and the slave BMS 200. For example, it can include signals transmitted via a channel via Bluetooth, Wi-Fi, or Zigbee.

[0060] When the outer shell of the battery pack 20 is made of metal, some noise existing outside the battery pack 20 is blocked and is not transmitted into the battery pack 20. That is, the inside of the battery pack 20 is affected by the external noise, and it is difficult to clearly distinguish the type and intensity of the external noise in the battery pack 20. According to an embodiment, the master BMS 100 may select a frequency hopping channel based on the first channel scanning information generated by scanning the frequency bandwidth outside the battery pack 20. Figure 2 and Figure 3 Provide a detailed description.

[0061] The master BMS 100 can calculate the signal strength for transmitting and receiving data on the frequency-hopping channel based on the noise intensity of the channel selected as the frequency-hopping channel and a predetermined signal-to-noise ratio (SNR). Signal strength can be time-averaged signal power and can be determined by the data transmission device. For example, when the predetermined signal strength is high, the slave BMS 200 must receive a large amount of power from the battery module to transmit data to the master BMS 100.

[0062] According to an embodiment, the master BMS 100 may substitute the noise intensity and SNR into Equation 1 to calculate the signal intensity. The noise intensity may be the noise power, and the signal intensity may be the signal transmission power. For example, when the frequency hopping channels have different noise powers, the master BMS 100 may calculate the signal transmission power of each frequency hopping channel.

[0063] The frequency hopping channel is used for wireless communication in the battery pack 20, so according to an embodiment, the master BMS 100 can scan the frequency bandwidth in the battery pack 20 to generate second channel scanning information, and calculate the signal transmission power based on the noise power of the frequency hopping channel included in the second channel scanning information. That is, the master BMS 100 can preferably calculate the signal transmission power based on the noise power measured in the environment where wireless communication is performed. Then, unnecessary power consumption can be reduced. Figure 2 and Figure 3 Provide a detailed description.

[0064] The slave BMS 200 is a system that is electrically connected to a battery module (not shown) and measures and manages the status of the battery module. For example, the slave BMS 200 can predict the state of charge (SOC) of a battery cell and perform cell balancing. According to an embodiment, the slave BMS 200 can perform wireless communication with the master BMS 100 based on a frequency hopping sequence.

[0065] The slave BMS 200 receives power for transmitting data from the battery module. For example, when a large signal transmission power is set, the power used to perform wireless communication (for example, transmitting battery information from the BMS 200 to the master BMS 100) also becomes larger. Then, the battery module may be discharged quickly.

[0066] Figure 2 Show Figure 1 The configuration of the main BMS is shown.

[0067] Reference Figure 2 , the master BMS 100 includes a communicator 110 , a channel analyzer 130 , a storage unit 150 , and a control unit 170 .

[0068] The communicator 110 may include a first communication module for communicating with the control device 10 and a second communication module for communicating with the slave BMS 200 .

[0069] The first communication module may communicate with the control device 10 to receive first channel scan information through the control of the control unit 170, and may store the first channel scan information in the storage unit 150. For example, the first communication module may include a vehicle communication module such as a controller area network (CAN), a local interconnect network (LIN), or FlexRay for communication in a vehicle.

[0070] The first channel scanning information may be generated by the external terminal 1 located outside the battery pack 20. For example, the first channel scanning information may include first noise types and first noise powers for respective ten channels of the first channel CH_1 to the tenth channel CH_10 included in the ISM bandwidth.

[0071] The second communication module may perform wireless communication with the slave BMS 200 according to a frequency hopping sequence under the control of the control unit 170. The frequency hopping sequence may be generated by the control unit 170 and may be stored in the storage unit 150.

[0072] The channel analyzer 130 may scan a plurality of channels of a frequency bandwidth and may measure a second noise type and a second noise power of the channels to generate second channel scan information. For example, when the vehicle system 2 is turned on, the channel analyzer 130 may generate the second channel scan information and transmit it to the control unit 170 for a predetermined period of time or in real time. The frequency bandwidth may be an ISM bandwidth.

[0073] The second channel scan information may be generated by the channel analyzer 130 located inside the battery pack 20. For example, the second channel scan information may include the second noise type and the second noise power for the ten channels from the first channel CH_1 to the tenth channel CH_10 included in the ISM bandwidth. According to an embodiment, the first channel scan information and the second channel scan information are generated outside and inside the battery pack 20, respectively, so the first noise power and the second noise power of the first channel CH_1 to the tenth channel CH_10 may be different from each other.

[0074] The signal according to the embodiment may include data transmitted and received between the master BMS 100 and the slave BMS 200, and the noise may include signals transmitted and received by other devices than the master BMS 100 and the slave BMS 200. Therefore, the measurement signals of the respective channels included in the first channel scanning information and the second channel scanning information may be noise.

[0075] The storage unit 150 may store a reference SNR value that serves as a reference for determining the performance of wireless communication performed in the battery pack 20. The storage unit 150 may store first channel scanning information received from the control device 10 through the first communication module and second channel scanning information generated by the channel analyzer 130.

[0076] According to an embodiment, the control device 10 may predetermine a minimum SNR, that is, a reference SNR value (e.g., 5 dB), for data transmitted and received between the master BMS 100 and the slave BMS 200. For example, the control unit 170 may transmit data to the slave BMS 200 using a signal transmission power that allows the reference SNR value to be at least 5 dB.

[0077] The control unit 170 selects a plurality of frequency hopping channels based on the first channel scanning information, and calculates the signal strength of each frequency hopping channel based on the second channel scanning information and a reference SNR value to generate a frequency hopping sequence.

[0078] The control unit 170 may select a plurality of frequency hopping channels to be used in the frequency hopping method from among a plurality of channels CH_1 to CH_N existing in the ISM bandwidth based on the first noise type and the first noise power measured outside the battery pack 20 .

[0079] For example, based on the first channel scanning information, among the first channel CH_1 to the tenth channel CH_10 existing in the ISM bandwidth, the channels having the first noise power equal to or less than the reference value may be the first channel CH_1, the third channel CH_3, and the eighth channel CH_8. The control unit 170 may select the first channel CH_1, the third channel CH_3, and the eighth channel CH_8 as frequency hopping channels.

[0080] For another example, the control unit 170 may select, as a frequency hopping channel, a channel having a first noise power equal to or less than a reference value and not including a specific noise type from among the first channel CH_1 to the tenth channel CH_10 existing in the ISM bandwidth. That is, when noise (Bluetooth, Wi-Fi, Zigbee, etc.) uses a channel having a low power density according to the first noise, the control unit 170 may not select the corresponding channel as a frequency hopping channel.

[0081] The control unit 170 may calculate the signal transmission power of each frequency hopping channel based on the second noise power measured in the battery pack 20 and the reference SNR value.

[0082] When the signal transmission power of the data actually transmitted is high, that is, when the SNR value, which is the ratio of the signal transmission power to the noise power, increases, the receiving side can clearly understand the signal. However, the case where data is transmitted with a signal transmission power exceeding the appropriate level provides wireless communication performance that is not much different from the case where data is transmitted with the optimal signal transmission power, but has the disadvantage of using a lot of the power of the battery module to transmit data from the BMS 200. According to an embodiment, the control unit 170 may calculate the signal transmission power of the data transmitted and received in the battery pack 20 based on a second noise power measured inside the battery pack 20, rather than a first noise power measured outside the battery pack 20.

[0083] For example, the control unit 170 may extract the second noise power of the frequency hopping channel included in the second channel scanning information, and may calculate the signal transmission power of the frequency hopping channel by substituting the extracted second noise power into Equation 1. When the first channel CH_1, the third channel CH_3, and the eighth channel CH_8 are selected as the frequency hopping channels, the second noise power of each of the first channel CH_1, the third channel CH_3, and the eighth channel CH_8 may be extracted from the second channel scanning information, and the extracted second noise power may be substituted into Equation 1 to calculate the signal transmission power of the first channel CH_1, the third channel CH_3, and the eighth channel CH_8.

[0084] The control unit 170 may generate a frequency hopping sequence based on the selected frequency hopping channels and the signal transmission power of each frequency hopping channel. For example, the control unit 170 may configure the first channel CH_1, the third channel CH_3, the first channel CH_1, the eighth channel CH_8, and the third channel CH_3 into a set. The frequency hopping sequence may be configured in the order of repeating the channel set.

[0085] Figure 3 A flow chart illustrating a wireless communication method in a battery pack according to an embodiment.

[0086] The following will refer to Figures 1 to 3 A wireless communication method in a battery pack and a master BMS providing the method are described.

[0087] The master BMS 100 may receive first channel scanning information generated by the external terminal 1 located outside the battery pack 20 through the control device 10 ( S110 ).

[0088] The external terminal 1 may scan a plurality of channels belonging to a frequency bandwidth for wireless communication in the battery pack 20 to generate first channel scan information and may transmit the first channel scan information to the control device 10. The control device 10 may transmit the first channel scan information to the master BMS 100.

[0089] External terminal 1 may be a portable terminal owned by a driver entering a vehicle. For example, when the driver enters the vehicle and turns on vehicle system 2, external terminal 1 and vehicle system 2 may communicate wirelessly using a predetermined communication module. The communication module may be a communication module such as Bluetooth, Wi-Fi, or Zigbee.

[0090] The external terminal 1 may scan a plurality of channels of a frequency bandwidth and may measure a first noise type and a first noise intensity of each channel to generate first channel scanning information. The frequency bandwidth may include an Industrial-Scientific-Medical (ISM) bandwidth. The ISM bandwidth is a frequency bandwidth allocated to the industrial, scientific, and medical fields and may be used without an additional license.

[0091] For example, the first channel scanning information may include first noise types and first noise powers of respective ten channels of a first channel CH_1 to a tenth channel CH_10 included in the ISM bandwidth.

[0092] The master BMS 100 may select a frequency hopping channel for the frequency hopping method based on the first channel scan information ( S130 ).

[0093] According to an embodiment, the master BMS 100 may compare the first noise intensity of each channel included in the first channel scan information with a reference value and select a channel having a first noise intensity less than the first reference value from among a plurality of channels as a frequency hopping channel.

[0094] For example, based on the first channel scanning information, among the first channel CH_1 to the tenth channel CH_10 existing in the ISM bandwidth, the channels having the first noise power equal to or less than the reference value may be the first channel CH_1, the third channel CH_3, and the eighth channel CH_8. The master BMS 100 may select the first channel CH_1, the third channel CH_3, and the eighth channel CH_8 as frequency hopping channels.

[0095] According to another embodiment, the master BMS 100 may compare the first noise intensity of each channel included in the first channel scan information with a reference value, and select, from among the channels, a channel having a first noise intensity less than the first reference value and not including predetermined noise in the first noise type included in the first channel scan information as a frequency hopping channel.

[0096] For example, when scanning the first channel information, among the first to tenth channels CH_1 through CH_10 in the ISM bandwidth, the channels having the first noise power equal to or less than the reference value may be the first channel CH_1, the third channel CH_3, and the eighth channel CH_8. The predetermined noise type is the Bluetooth protocol, and the Bluetooth protocol may use the third channel CH_3 based on the first channel scanning information. The master BMS 100 may select the first channel CH_1 and the eighth channel CH_8 as frequency hopping channels.

[0097] The master BMS 100 may calculate the signal strength of the frequency hopping channel based on the reference SNR value regarding wireless communication and the second channel scanning information ( S150 ).

[0098] The master BMS 100 may scan a plurality of channels belonging to a frequency bandwidth in the battery pack 20 to generate second channel scanning information. The second channel scanning information may include a second noise intensity of the channel.

[0099] The master BMS 100 may calculate a signal strength satisfying a reference SNR value of a second noise strength of the frequency hopping channel included in the second channel scan information, and may determine the calculated signal strength as the signal strength of the frequency hopping channel.

[0100] For example, the master BMS 100 may substitute the second noise intensity and the reference SNR value of the first channel CH_1 selected as the frequency hopping channel into Equation 1 and may calculate the signal strength of the first channel CH_1. The master BMS 100 may substitute the second noise intensity and the reference SNR value of the third channel CH_3 selected as the frequency hopping channel into Equation 1 and may calculate the signal strength of the third channel CH_3. The master BMS 100 may substitute the second noise intensity and the reference SNR value of the eighth channel CH_8 selected as the frequency hopping channel into Equation 1 and may calculate the signal strength of the eighth channel CH_8.

[0101] The master BMS 100 may generate a hopping sequence of a frequency hopping method based on the frequency hopping channels and signal strengths of the frequency hopping channels ( S170 ).

[0102] The master BMS 100 can set the order so that the first channel CH_1, the third channel CH_3, and the eighth channel CH_8 as frequency hopping channels can have any pattern. For example, the master BMS 100 can configure the first channel CH_1, the third channel CH_3, the first channel CH_1, the eighth channel CH_8, and the third channel CH_3 as a channel set. The master BMS 100 can generate a frequency hopping sequence in the order of repeating the channel set. That is, the frequency hopping sequence can be repeated in the order of the first channel CH_1, the third channel CH_3, the first channel CH_1, the eighth channel CH_8, the third channel CH_3, the first channel CH_1, the third channel CH_3, the first channel CH_1, the eighth channel CH_8, the third channel CH_3, the first channel CH_1, the third channel CH_3, the first channel CH_1, the eighth channel CH_8, and the third channel CH_3, and can be set to transmit and receive data according to the signal transmission power of each channel.

[0103] The master BMS 100 may perform synchronization with the slave BMS 200 based on the frequency hopping sequence, so it may be simultaneously located in the same frequency hopping channel as the slave BMS 200 ( S190 ).

[0104] In order to receive data from the slave BMS 200, the master BMS 100 must be tuned to a specific frequency at a specific time by using the same frequency hopping sequence as that used when transmitting data from the slave BMS 200. That is, when synchronized with the slave BMS 200 based on the frequency hopping sequence, the master BMS 100 can utilize the data transmitted from the slave BMS 200.

[0105] While the invention has been described in connection with what are presently considered to be practical embodiments, it should be understood that the invention is not limited to the disclosed embodiments, but on the contrary is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A master battery management system (BMS), serving as a master BMS that performs wireless communication with a slave BMS according to a frequency hopping method in a battery pack, comprising: a communicator configured to receive first channel scanning information generated by a device disposed outside the battery pack scanning a plurality of channels belonging to a frequency bandwidth used in the wireless communication; a channel analyzer configured to generate second channel scanning information by scanning channels belonging to the frequency bandwidth; a storage unit, the storage unit being configured to store a reference signal-to-noise ratio (SNR) value regarding the wireless communication; as well as a control unit configured to select a frequency hopping channel used in the frequency hopping method based on the first channel scanning information, and calculate a signal strength of the selected frequency hopping channel based on the second channel scanning information and the reference SNR value, The control unit generates a frequency hopping sequence of the frequency hopping method based on the frequency hopping channel and the signal strength of the frequency hopping channel.

2. The master BMS according to claim 1, wherein The first channel scanning information includes the first noise intensity of each channel, and The control unit compares the first noise intensity with a reference value and selects a channel having a first noise intensity smaller than the reference value from among the channels as the frequency hopping channel.

3. The master BMS according to claim 1, wherein The first channel scanning information includes a first noise type and a first noise intensity of each channel, and The control unit compares the first noise intensity with a reference value and selects a channel having a first noise intensity smaller than the reference value and not including noise predetermined as the first noise type from among the channels as the frequency hopping channel.

4. The master BMS according to claim 1, wherein The second channel scanning information includes the second noise intensity of each channel, and The control unit calculates a signal strength that satisfies the reference SNR value based on the second noise strength, and sets the calculated signal strength as the signal strength of the frequency hopping channel.

5. The master BMS according to claim 1, wherein The control unit performs synchronization with the slave BMS based on the frequency hopping sequence, thereby being arranged in the same frequency hopping channel as the slave BMS at the same time.

6. The master BMS according to claim 1, wherein The frequency bandwidth includes a frequency bandwidth to which an Industrial-Scientific-Medical (ISM) band belongs.

7. A wireless communication method in a battery pack, as a method for a master battery management system (BMS) to perform wireless communication with a slave BMS according to a frequency hopping method in a battery pack, comprising: receiving first channel scanning information generated by a device external to the battery pack scanning a plurality of channels belonging to a frequency bandwidth used in the wireless communication; selecting a frequency hopping channel used in the frequency hopping method based on the first channel scanning information; calculating a signal strength of the frequency hopping channel based on second channel scanning information generated by scanning channels belonging to the frequency bandwidth in the battery pack and a reference signal-to-noise ratio (SNR) value regarding the wireless communication; as well as A frequency hopping sequence of the frequency hopping method is generated based on the frequency hopping channels and signal strengths of the frequency hopping channels.

8. The wireless communication method according to claim 7, wherein Selecting the frequency hopping channel includes: The first noise intensity of the channels included in the first channel scanning information is compared with a reference value, and a channel having a first noise intensity less than the reference value is selected from among the channels as the frequency hopping channel.

9. The wireless communication method according to claim 7, wherein Selecting the frequency hopping channel includes: Comparing the first noise intensity of each channel included in the first channel scanning information with a reference value, and selecting a channel with a first noise intensity less than the reference value from channels that do not include noise of a first noise type predetermined to be included in the first channel scanning information as the frequency hopping channel.

10. The wireless communication method according to claim 7, wherein Calculating the signal strength of the frequency hopping channel includes: A signal strength satisfying the reference SNR value among the second noise strength of the frequency hopping channel included in the second channel scanning information is calculated, and the calculated signal strength is set as the signal strength of the frequency hopping channel.

11. The wireless communication method according to claim 10, further comprising: After generating the frequency hopping sequence of the frequency hopping method, Synchronization is performed with the slave BMS based on the frequency hopping sequence, thereby being simultaneously positioned in the same frequency hopping channel as the slave BMS.

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