CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the priority of International Application No. PCT/EP2017/078494, filed on Nov. 7, 2017, which claims priority to GB Application No. 1618971.4, filed Nov. 10, 2016, the entire contents of each of which are fully incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to an energy storage and utilization system based on smart battery units. In particular, the invention relates to anomaly detection of the smart battery units within the ecosystem.

BACKGROUND

In a system containing a large number of swappable battery units (e.g. a system of battery units for electric vehicles which can be swapped at service stations, as an alternative to recharging from an external power supply), there is a need to provide a valuation of the battery units. This is because the value of the battery units themselves is likely to be much higher than the value of the energy stored therein—for example, a brand new battery unit with a high capacity would clearly be more valuable than a several-year-old battery unit with a small percentage of its operating capacity remaining.

GB 2518248 describes how values can be assigned in such a system. In summary, state information is reported by the battery units to a central valuation service, which uses the state information (along with hardware information and historical state information previously reported by that unit) to determine a valuation for the unit. The valuation may be a monetary value, or a series of ratings (e.g. scores out of 5 for each of reliability, charge capacity, peak output power, etc). The valuation relies on the battery units periodically sending the state information to the valuation service. The state information may include electrical performance data of the battery unit (e.g. capacity, number of charge/discharge cycles, peak current), administrative data of the battery unit (e.g. software version, hardware version, and which electric tank it is associated with), and/or environmental factors (e.g. temperature, sudden acceleration).

Also other devices of the ecosystem measure and send log data of multiple variables, such as temperature, power output, et cetera to the centralized computer system. The devices in the system have also known relationship, for example a battery unit is inside one electric tank, which is controlled by one ETCU and is powering one electric car. A battery unit may also be inside a storage silo of the service station. The identifications of the battery units, ETCUs, electric vehicles and service stations are known and registered in the system.

Interfaces between the smart battery units and centralized computer system are secured but there is always a certain risk that the smart battery units can be tampered or the transmission can be attacked and log data would not be correct. Since the usage history data of the smart battery unit has direct correlation to the resale value of the smart battery unit, there is clear monetary incentive to manipulate the usage history to look better than it has actually been. False data could either be inserted by the battery units themselves, or by a “man-in-the-middle” attack, for example where the state information is transmitted via the electric car. Similarly, the electric tank may falsely report some data—e.g. if there is an environmental factor measured at the tank but not by the battery units, then falsely reporting the value of this factor would raise the value of all battery units in the tank.

SUMMARY

This invention defines anomaly detection methods which can be used to find out fraudulent log data. The data collected from the different parts of the system is likely to also have some kind of relationships. The relationship may be between same types of units (for example temperature of different battery units in the same tank is in the same range) or between different types of units (for example power output of electric tank and power input of the electric vehicle should be equal). By comparing the data collected from the different units, the relationships can be found and patterns emerge. In case of abnormal patterns are emerging it is an indication of some type of unwanted action in the system.

Anomaly detection can be done in all levels of the system not only in the centralized computer system. The electric tank control unit also collects the usage data from the battery units located in the tank. Same applies also to the service station control unit which locally collects data from the battery units located inside the storage silos of the service station.

Some detected anomalies may be caused by system malfunction instead of fraudulent manipulation of the data. In these cases anomaly detection functionality and the automated reactions based on findings can be used to protect the system and the users and make it safer.

According to an aspect, there is provided a method of detecting reporting of false electrical performance data by battery units operating within an energy storage and supply system comprising a tank containing a plurality of randomly packed battery units, the tank having electrical contacts for either drawing energy from battery units or supplying energy to battery units within the tank during normal use. Data reporting energy claimed to have been extracted from or supplied to the battery unit is received from each of the battery units. The actual total energy extracted from or supplied to the plurality of battery units is measured. The reported data and the measured data are compared to determine whether or not the battery units are reporting false electrical performance data.

According to a further aspect, there is provided apparatus configured to detect reporting of false electrical performance data by battery units operating within an energy storage and supply system comprising a tank containing a plurality of randomly packed battery units, the tank having electrical contacts for either drawing energy from battery units or supplying energy to battery units within the tank during normal use. The apparatus comprises a communication unit and an anomaly detection unit. The communication unit is configured to communicate with the battery units and the electrical storage and supply system. The anomaly detection unit is configured to, for each of the battery units:receive from each of the battery units, data reporting energy claimed to have been extracted from or supplied to the battery unit;measure the actual total energy extracted from or supplied to the plurality of battery units; andcompare the reported data and the measured data to determine whether or not the battery units are reporting false electrical performance data.

According to a further aspect, there is provided a method of detecting false state information reported by a battery unit, wherein the battery unit comprises a reporting system configured to measure and report state information of the battery unit. The method is performed at a monitoring system configured to receive reports from a plurality of battery units. A log of state information reported by the battery unit is inspected in order to determine whether or not there is a change in state information which is inconsistent with normal operation of the battery unit. If there is a change in state information which is inconsistent with normal operation of the battery unit, then it is determined that the battery unit has reported false state information.

According to a further aspect, there is provided apparatus configured to detect false data reported by battery units, wherein each battery unit comprises a reporting system configured to measure and report state information of the battery unit. The apparatus comprises a communication unit, and an anomaly detection unit. The communications unit is configured to communicate with the battery units. The anomaly detection unit is configured to, for each battery unit:receive state information reported by the battery unit;inspect a log of state information reported by the battery unit in order to determine whether or not there is a change in state information which is inconsistent with normal operation of the battery unit;if there is a change in state information which is inconsistent with normal operation of the battery unit, then determine that the battery unit has reported false data.

According to a further aspect, there is provided a method of detecting false state information reported by battery units, wherein each battery unit comprises a reporting system configured to measure and report state information of the battery unit. The method is performed at a monitoring system. Reported state information is received from each of a plurality of battery units and other devices. State information reported by each battery unit is compared with state information reported by one or more devices external to the battery unit which were in proximity to the battery unit or in electrical contact with the battery unit at the time the state information was monitored. If the state information reported by the battery unit is inconsistent with the state information of the device external to the battery unit, then it is determined that the battery unit has reported false state information.

According to a further aspect, there is provided apparatus configured to detect false data reported by battery units, wherein each battery unit comprises a reporting system configured to measure and report state information of the battery unit. The apparatus comprises a communications unit and an anomaly detection unit. The communications unit is configured to communicate with the battery units and other devices. The anomaly detection unit is configured to:receive state information reported the battery units and other devices; for each battery unit:compare state information reported by the battery unit with state information reported by a device external to the battery unit which was in proximity to the battery unit or electrical contact with the battery unit at the time the state information was monitored;if the state information reported by the battery unit is inconsistent with the state information of the other device, then determine that the battery unit has reported false data.

According to a further aspect, there is provided a method of detecting tampering with an energy storage and supply system, the energy storage and supply system comprising an electric tank and a plurality of battery units, wherein the plurality of battery units are randomly packed within the electric tank. Locations and/or identities of the plurality of battery units within the electric tank at a first time are compared to locations and/or identities of the plurality of battery units within the tank at a second time. It is determined whether or not there has been an authorised replacement or servicing of battery units within the tank between said first and second time. If the locations and/or identities of the plurality of battery units within the tank have changed between the first and second time, and there has been no authorised replacement or servicing, then it is determined that the energy storage and supply system has been tampered with.

Further embodiments are presented in claim2et seq.

