WO2016190174A1

WO2016190174A1 - Wireless battery system

Info

Publication number: WO2016190174A1
Application number: PCT/JP2016/064668
Authority: WO
Inventors: 孝徳山添; 啓坂部
Original assignee: 株式会社日立製作所
Priority date: 2015-05-28
Filing date: 2016-05-18
Publication date: 2016-12-01
Also published as: JP2018137489A

Abstract

The purpose of the present invention is to provide a wireless battery system that performs a security wireless communication in wireless communication in a battery system of a hybrid car, an electric car, or the like, and that performs a highly versatile wireless communication in wireless communication in a distribution process. In accordance with a change in a signal that a BC transmits to a CC, that is, a change in command type or a change in frequency, the CC performs switching between encryption and decryption of data to be sent from the CC to the BC. Accordingly, the CC is capable of performing both a versatile communication and a security communication.

Description

Wireless battery system

Battery control system

Currently, as global environmental problems are greatly highlighted, in order to prevent global warming, there is a need to reduce carbon dioxide emissions in every situation. About gasoline engine cars, which are a major source of carbon dioxide emissions. Has begun to be replaced by hybrid electric vehicles and electric vehicles.

Large secondary batteries represented by power sources for hybrid electric vehicles and electric vehicles need to have a high output and a large capacity. Therefore, the storage battery module that constitutes them has a plurality of batteries (hereinafter referred to as cells). Are connected in series and parallel.

In addition, lithium ion batteries that are secondary batteries require appropriate use of secondary batteries, such as prevention of high-voltage charging and deterioration of performance due to overdischarge. For this reason, the storage battery module mounted on a hybrid electric vehicle or an electric vehicle has a function of detecting voltage, current, temperature, and the like, which are battery states. FIG. 1 shows a configuration of a storage battery module mounted on a hybrid electric vehicle or an electric vehicle. As shown in FIG. 1, a plurality of cells are connected to a cell controller (hereinafter referred to as CC), and the CC measures the state of the plurality of cells. The plurality of CCs are connected to a battery controller (hereinafter referred to as BC), and the BC acquires the states of the plurality of cells from the plurality of CCs. Further, the BC calculates a state of charge (SOC) and a battery deterioration state (SOH: State of Health) from the acquired states of the plurality of cells, and notifies the upper controller and the like of the calculation result.

FIG. 1 shows general wired communication between BC and CC. CC 100 and BC 200 are connected by wire, and information on CC 100 is transmitted to BC 200 through this wire. In such wired communication, physical connection is required, and thus there are spatial restrictions such as securing a space for providing a communication line. In addition, wiring costs and insulation costs and assembly costs for high voltage countermeasures are required.

On the other hand, Patent Document 1 discloses a technique for reducing the wiring cost, the insulation cost for assuring high voltage, and the assembly cost by changing the CC and BC from wired to wireless.

JP-A-2005-135762

However, if communication between BC and CC is changed from wired to wireless, wireless data may be intercepted from the outside, cell information may be leaked to the outside, and security safety may be reduced. Moreover, there is a possibility that erroneous data is mixed from the outside, the cell state cannot be correctly grasped, and proper battery control cannot be performed.

On the other hand, it is desirable to manage articles such as where and what cells are in the distribution process such as manufacturing, warehouse management, and transportation. In this case, highly versatile wireless communication is required.

An object of the present invention is to provide a wireless battery system that performs wireless communication with security in wireless communication in a battery system such as a hybrid vehicle or an electric vehicle, and performs highly versatile wireless communication in wireless communication in the distribution process. It is.

The features of the present invention are, for example, as follows.

In a wireless battery system in which a battery controller and a plurality of cell controllers communicate wirelessly, data sent from the cell controller to the battery controller is encrypted or non-encrypted according to a signal sent from the battery controller to the cell controller. A wireless battery system that determines whether or not

Further, specific determination means for encryption include, for example, 1) and 2) below.

1) A wireless battery system that determines whether data sent from the cell controller to the battery controller is encrypted or non-encrypted based on a difference in command of a signal sent from the battery controller to the cell controller.

2) A wireless battery system that determines whether data sent from the cell controller to the battery controller is encrypted or unencrypted based on a difference in frequency of a signal sent from the battery controller to the cell controller.

CC changes encryption / non-encryption of data sent from CC to BC according to a change in signal transmitted from BC to CC, that is, change in command type or change in frequency. As a result, the CC can achieve both general-purpose communication and security communication.

According to the present invention, it is possible to provide a communication system for a secondary battery capable of communication according to a change in a situation such as actual use requiring security or distribution requiring versatility.

Configuration diagram of a general in-vehicle storage battery module Configuration diagram of a battery system according to the present invention Wireless time division communication example of the present invention Example of beacon configuration of the present invention Encryption / non-encryption discrimination flowchart using commands of the present invention Encryption / non-encryption configuration diagram of the present invention Encryption / non-encryption configuration diagram of the present invention Encryption / non-encryption discrimination flowchart according to the frequency of the present invention Encryption / non-encryption discrimination configuration diagram according to the frequency of the present invention

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description shows specific examples of the contents of the present invention, and the present invention is not limited to these descriptions. Various modifications by those skilled in the art are within the scope of the technical idea disclosed in this specification. Changes and modifications are possible.

FIG. 2 shows the configuration of the battery system related to Example 1. The battery system 9 includes a CC 100 and a BC 200 attached to a cell group 10 including one or a plurality of cells.

The CC 100 includes one or more measuring devices (sensors) 20 that measure the state (voltage, current, temperature, etc.) of the cell 8, a processing unit 30 that acquires and processes the state information of the cell 8, a radio circuit 40, and radio waves. It comprises an antenna 50 that inputs and outputs. The processing unit 30 includes a power supply circuit 31 that receives power from the cell group 10 to generate an operating voltage, an A / D conversion circuit (ADC) 32 that converts an analog value measured by the measuring instrument 20 into digital data, an A / D A processing circuit (CPU) 33 that outputs data converted by the D conversion circuit (ADC) 32 to the radio circuit, a storage device (memory) 34 that stores individual identification information (unique ID), and the like, and a clock generator 35 Composed.
The clock generator 35 can oscillate by switching between a high-speed clock of about several MHz and a low-speed clock of about several tens of kHz. Further, the processing circuit (CPU) 33 is based on data from the wireless circuit 40 and turns on / off some of the circuits in the wireless circuit 40 and the processing circuit (CPU) 33, and switches the clock frequency of the clock generator 35. Read / write to the storage device (memory) 34 and instructions from the BC 200 can be executed.

BC 200 includes a wireless circuit 210, a processing circuit (CPU) 220, a power supply circuit 230 including a battery, a storage device (memory) 240, and an antenna 250. As for the power supply circuit 230, a battery is incorporated in this embodiment, but power may be supplied from the outside.

FIG. 3 shows a schematic diagram of wireless communication between the BC 200 and the CC 100.

Usually, the BC communicates with one or more CCs and acquires the cell status measured by the CCs. At this time, time-division wireless communication is performed between CC and BC.

First, the BC 200 broadcasts a beacon (B) periodically in order to acquire a cell state from the CC 100. The data content of this beacon (B) is composed of commands and data (FIG. 4). For example, as will be described later, information regarding whether or not to encrypt communication can be entered in the most significant bit of the command (MSB in FIG. 4 represents the most significant bit and LSB represents the least significant bit). In addition, information regarding designation of information instructing transmission to the CC by the BC, for example, designation of “voltage”, “current”, or the like can be entered. Information relating to the ID of the BC or information for identifying the CC when communication is performed with respect to the individual CC can be included in the data.

The information from CC to BC is also composed of commands and data. For example, information indicating what information is to be sent, such as voltage and current, can be included in the command, and specific information can be included in the data. Here, the data communication slot (see FIG. 3) transmitted by each CC is transmitted in a slot assigned in advance to each CC.

Each CC that has received the beacon (B) recognizes the command in the beacon and determines whether or not to encrypt the transmission data in accordance with the command. In this embodiment, the difference between commands is recognized, and it is determined whether or not to encrypt data. In the example of FIG. 5, when the command is 8 bits, the MSB (most significant bit) is determined to be encrypted when the transmission data is “0”, and is determined to be unencrypted when the command is “1”.

Fig. 6 shows the flow structure of CC transmission data encryption. The CC first receives a beacon, recognizes the command, and determines whether to encrypt it. When the transmission data is encrypted, the pseudo-random number generation circuit 303 creates scrambled data using the BC ID (unique number) set in the beacon data as the BC and CC encryption keys.

Next, the encryption unit 304 creates encrypted data that is XORed from the scrambled data and data (transmission data) indicating the state of the cell such as voltage and current. This encrypted data is transmitted to the BC. In the encryption unit 304, the scrambled data and the transmission data may be converted bit by bit based on the XOR, or may be converted into encrypted data as a fixed group.

The BC that has received the encrypted data converts the encrypted data into transmission data for use. The BC has a pseudo-random number generation circuit that operates using the ID of the BC as an encryption key, like the CC. The BC converts the scrambled data created by the pseudo random number generator and the encrypted data received from the CC into transmission data according to the XOR method.

In the first embodiment, the switching between encryption and non-encryption of communication between BC and CC can be changed, for example, before and after the start of battery use. In the distribution stage before the battery is installed on the vehicle or the like, communication is performed without encryption, and after the battery is installed on the vehicle or the like, communication is performed after encryption. By using in this way, it becomes possible to communicate according to changes in the situation such as actual use where security is required and distribution where versatility is required.

In the first embodiment, when the CC receives the BC beacon and determines that the transmission data is encrypted, the BC ID (unique number) set in the BC transmission data is used as the encryption key. In this method, BC transmission data is not set with a BC ID (unique number), and data (such as BC ID) written in advance in the CC storage device (memory) 34 is used as an encryption key ( FIG. 7).

First, the CC determines whether or not to receive and encrypt a beacon as in the first embodiment. When encrypting transmission data, scramble data is created, and encrypted data is created from the created scramble data and transmission data. In the second embodiment, data stored in the CC memory in advance is created as an encryption key for creating scramble data. A method similar to that of the first embodiment can be used as a method for creating encrypted data from scrambled data and transmission data.

In the second embodiment, the ID transmitted from the BC is not used as the encryption key, and the stored information in the CC is used. Therefore, it can be said that the security is higher than that in the first embodiment. However, in this case, it is necessary to put encryption key information in the CC in advance.

Embodiment 3 is an example in which the determination is made based on the frequency of information transmitted by the BC as a method for determining whether or not the CC encrypts transmission data.

Fig. 8 shows the flow of encryption decision.

CC detects the radio frequency transmitted by BC, determines that encryption is performed when the radio frequency is in the 2.4 GHz band, and determines that encryption is not performed when the radio frequency is not in the 2.4 GHz band.

First, CC detects information from BC. Next, it is determined whether the detected information has a frequency in the 2.4 GHz band. If the detected information has a frequency in the 2.4 GHz band, the transmission data is encrypted.

Fig. 9 shows a method for detecting frequencies in the 2.4 GHz band.

In the wireless circuit 210, there are provided two types of filter 401 that resonates at 2.4 GHz and a notch filter 402 that removes a resonance component. The power obtained from the antenna 50 that inputs and outputs power from the BC is passed through these two types of filters.

When the wireless power output from the resonance filter 401 is equal to or greater than a predetermined threshold value, it is determined that the CC transmission data is encrypted. When the wireless power output from the notch filter 402 is equal to or greater than a predetermined threshold, it is determined that the CC transmission data is not encrypted. In the case of this determination method, the output of the resonance filter 401 and the output of the notch filter 402 may be greater than or less than the respective predetermined threshold values. When both the output of the resonance filter 401 and the output of the notch filter 402 are equal to or greater than a predetermined threshold, the CC determines that transmission data is encrypted with emphasis on security. When neither the output of the resonance filter 401 nor the output of the notch filter 402 is less than a predetermined threshold, the CC does not respond because the BC is not transmitting.

As another determination method, for example, the result of comparing the strength of the wireless power output from the resonance filter 401 and the wireless power output from the notch filter 402 can be used for determination of encryption or non-encryption. However, in this case, if there is a lot of noise from the outside and the wireless power output from the resonance filter 401 is equivalent to the wireless power output from the notch filter 402, the determination of encryption or non-encryption is wrong. There is a possibility. For this reason, when determining whether encryption or non-encryption is performed based on the frequency of information received from the BC, it is preferable to independently compare the outputs of the resonance filter 401 and the notch filter 402 with predetermined threshold values. .

The flow after the determination of encryption or non-encryption can use the same flow as in the first and second embodiments.

When comparing the first and second embodiments with the third embodiment, the first and second embodiments, which determine whether encryption or non-encryption is performed by a command, are not affected by noise. Further, it is not necessary to provide a resonance filter 401 or a notch filter 402. On the other hand, since no command is used in the third embodiment, there is an advantage that communication data and a logic circuit can be simplified.

1: storage battery module 4: relay box 5: hybrid controller 6: inverter 7: motor 8: cell 9: battery system 10: one or more battery cell groups 20: one or more measuring instruments for measuring the state of the battery (sensor)
30: Processing unit 31 that acquires and processes battery state information 31: Power supply circuit 32: Detection circuit (A / D converter) that detects the state of a battery cell
33: Processing circuit (CPU)
34: Storage device (memory)
35: Clock generator 36: Power supply circuit 37: Switch (SW)
40: Radio circuit 50: Antenna 60: Wireless power recovery circuit 100: Cell controller (CC)
200: Battery controller (BC)
210: Radio circuit 220: Processing circuit (CPU)
230: Power supply circuit including battery 240: Storage device (memory)
250: Antenna 301: Encryption determination unit 302: Encryption key recognition unit 303: Pseudorandom number generation circuit 304: Encryption unit 305: Initial value Memory data 401: 2.4 GHz band resonance filter (resonance filter)
402: 2.4 GHz band notch filter (notch filter)
403: Amplifier 404: Frequency detection unit

Claims

In a wireless battery system in which a battery controller and a plurality of cell controllers communicate wirelessly,
A wireless battery system that determines whether data to be transmitted from the cell controller to the battery controller is encrypted or unencrypted in response to a signal transmitted from the battery controller to the cell controller.
In claim 1,
The wireless battery system is configured to determine whether the data sent from the cell controller to the battery controller is encrypted or unencrypted based on a difference in a command of a signal sent from the battery controller to the cell controller.
In claim 1,
The wireless battery system is configured to determine whether the data sent from the cell controller to the battery controller is encrypted or unencrypted based on a difference in frequency of a signal sent from the battery controller to the cell controller.
In claim 2 or claim 3,
When it is determined that the data sent from the cell controller to the battery controller is encrypted,
A wireless battery system that encrypts data to be sent from the cell controller to the battery controller using information included in a signal sent from the battery controller to the cell controller as an encryption key.
In claim 2 or claim 3,
A wireless battery system that encrypts data to be sent from the cell controller to the battery controller by using information stored in the cell controller as an encryption key when it is determined that data to be sent from the cell controller to the battery controller is encrypted.
In claim 4 or claim 5,
The cell controller has a pseudo random number generation circuit,
The pseudo-random number generation circuit creates scramble data based on the encryption key, and creates a scrambled data based on information inside the cell that the cell controller sends to the battery controller and the scramble data.
In claim 3,
The cell controller includes a resonance filter that amplifies a signal having a predetermined frequency, and the cell controller sends the signal from the cell controller to the battery controller when the resonance filter receives a signal having the predetermined frequency. A wireless battery system that decides to encrypt data.
In claim 7,
The cell controller has a notch filter that reduces the predetermined frequency;
The cell controller is a wireless battery system that, when the notch filter receives a signal other than the signal of the predetermined frequency for a predetermined amount or more, determines whether to send data sent from the cell controller to the battery controller without encryption.