Patent Description:
In a battery system, a battery management system (BMS) may be divided into several modes according to a cycle of measuring a voltage, a current, a temperature, and the like.

The measuring cycle of the BMS may be used as an indicator for diagnosing whether the BMS is normally operating. However, in order to check the measuring cycle of the BMS, efforts such as displaying a specific signal on a screen by using equipment such as an oscilloscope and manipulating the screen and the equipment are required, and the work therefor may take excessive time.

Korean Patent Application Publication <CIT> relates to a battery management system diagnosis method executed by a battery management system controlling and inspecting a battery module. The method includes: a first step of determining whether or not a battery management system is abnormal by comparing a first condition of a battery, which is calculated through a first algorithm determining a battery condition by using at least one first element among the voltage, temperature and current of the battery, to a second condition of the battery, which is calculated through a second algorithm determining a battery condition by using an element different from the first element; and a second step of determining whether or not the battery management system is abnormal by determining whether or not the process of calculating the second condition of the battery through the second algorithm is normally operated if the first condition and the second condition are equal.

United States Patent Application Publication <CIT> relates to an electrical current measurement circuit. The electrical current measurement circuit is configured to receive a sense current proportionally related to an electrical current of interest to continuously charge a capacitor to a sense voltage. The electrical current measurement circuit is configured to determine whether the sense voltage reaches a predefined voltage threshold and reduce the sense voltage to below the predefined voltage threshold in response to the sense voltage reaching the predefined voltage threshold. The electrical current measurement circuit counts each occurrence of the sense voltage reaching the predefined voltage threshold and quantifies the electrical current based on a total count of the sense voltage reaching the predefined voltage threshold during the predefined measurement period.

Chinese Patent Application Publication <CIT> relates to a battery pack diagnostic apparatus including a communication port, a measurer, and a controller. The communication port provides an electrical connection between the battery pack diagnostic apparatus and a battery management system. The measurer is electrically connected to an output terminal of the battery pack and is configured to measure a voltage and a current of the battery pack. The controller is configured to obtain a first measurement value with respect to a voltage and a current of the battery pack from the battery management system. The controller is further configured to obtain a second measurement value with respect to a second voltage and a second current of the battery pack from the measurer. The controller analyzes a state of the battery pack based on the first measurement value and the second measurement value.

Korean Patent Application Publication <CIT> relates to a system for diagnosing a state of a battery pack. The system for diagnosing a state of a battery pack is configured to comprise: an on board charger receiving power from an external charging device and converting the received power into a power for charging a battery pack to charge the battery pack; and a battery management system monitoring a state of the battery pack and diagnosing the state of the battery pack through control of the on board charger.

United States Patent Application Publication <CIT> relates to a method for detecting a malfunction of a battery control system including a plurality of sensors intended to measure separate physical quantities of the battery, the method including the following steps: a) reading output values of the sensors; and b) determining, by means of a processing unit, whether the read values are consistent with a physical phenomenon conditioning relationships between at least two of the quantities.

The present disclosure has been made in an effort to provide a measuring device that may check a measuring cycle of a BMS.

The present disclosure has been made in an effort to provide a diagnostic system and a diagnostic method that may diagnose whether a BMS is normally operating according to a measuring cycle of the BMS.

An embodiment provides a measuring device, including: a voltage measurer measuring a voltage from a node on a wire connected to a battery management system (BMS); and a controller that receives the measured voltage signal from the voltage measurer to derive a voltage value, counts the number of times the voltage value reaches a reference voltage during a measuring period, and determines a state of the BMS as one of a normal state of a first mode, a normal state of a second mode, and an abnormal state based on the number of times.

The wire may be a wire connected to one end of a thermistor. The first mode is a power mode in which the BMS measures a temperature from the thermistor at a cycle of a first period. The second mode is a power mode in which the BMS measures the temperature from the thermistor at a cycle of a second period longer than the first period.

When the number of times is within a first range in which a value obtained by dividing the measuring period by the first period and multiplied by <NUM> is a minimum value and a value obtained by adding <NUM> to the minimum value is a maximum value, the controller may determine the state of the BMS as the normal state of the first mode.

When the number of times is within a second range in which a value obtained by dividing the measuring period by the second period and multiplied by <NUM> is a minimum value and a value obtained by adding <NUM> to the minimum value is a maximum value, the controller may determine the state of the BMS as the normal state of the second mode.

The controller may determine the state of the BMS as the abnormal state when the number is not within the first and second ranges.

Another embodiment provides a diagnostic system, including: a measuring device that measures a voltage from a node on a wire connected to a battery management system (BMS), derives a voltage value from the measured voltage signal, counts the number of times the voltage value reaches a reference voltage during a measuring period, and determines a state of the BMS as one of a normal state of a first mode, a normal state of a second mode, and an abnormal state based on the number of times; and an output device that receives a signal indicating the state of the BMS from the measuring device, and outputs a diagnostic result including the state of the BMS based on the signal indicating the state of the BMS.

When the number of times is within a first range in which a value obtained by dividing the measuring period by the first period and multiplied by <NUM> is a minimum value and a value obtained by adding <NUM> to the minimum value is a maximum value, the measuring device may determine the state of the BMS as the normal state of the first mode.

When the number of times is within a second range in which a value obtained by dividing the measuring period by the second period and multiplied by <NUM> is a minimum value and a value obtained by adding <NUM> to the minimum value is a maximum value, the measuring device may determine the state of the BMS as the normal state of the second mode.

The measuring device may determine the state of the BMS as the abnormal state when the number is not within the first and second ranges.

The output device may include a display that visually outputs the diagnostic result.

Another embodiment provides a diagnostic method, including: measuring a voltage from a node on a wire connected to a battery management system (BMS); deriving a voltage value based on the measured voltage and counting the number of times the voltage value reaches a reference voltage during a measuring period; determining whether the number of times is within a first or second range; and determining the state of the BMS as one of a normal state of a first mode, a normal state of a second mode, and an abnormal state based on the determined result.

The first range may be a range in which a value obtained by dividing the measuring period by the first period and multiplied by <NUM> is a minimum value and a value obtained by adding <NUM> to the minimum value is a maximum value.

The determining of the state of the BMS as one of the normal state of the first mode, the normal state of the second mode, and the abnormal state: may include determining, when the number of times is within the first range, the state of the BMS as the normal state of the first mode.

The second range may be a range in which a value obtained by dividing the measuring period by the second period and multiplied by <NUM> is a minimum value and a value obtained by adding <NUM> to the minimum value is a maximum value.

The determining of the state of the BMS as one of the normal state of the first mode, the normal state of the second mode, and the abnormal state: may include determining, when the number of times is within the second range, the state of the BMS as the normal state of the second mode.

The determining of the state of the BMS as one of the normal state of the first mode, the normal state of the second mode, and the abnormal state may include determining the state of the BMS as the abnormal state when the number is not within the first and second ranges.

The diagnostic method may further include outputting a diagnostic result including the state of the BMS determined as one of the normal state of the first mode, the normal state of the second mode, and the abnormal state.

The outputting of the diagnostic result may include visually outputting the state of the BMS and the number of times through a display.

According to the present disclosure, it is possible to diagnose whether a BMS normally operates by checking a measuring cycle of the BMS.

According to the present disclosure, it is possible to improve accuracy of mode determination by determining a power mode of a BMS based on a measuring cycle of the BMS.

Hereinafter, embodiments disclosed in the present specification will be described in detail with reference to the accompanying drawings, and in the present specification, the same or similar constituent elements will be denoted by the same or similar reference numerals, and a redundant description thereof will be omitted. The terms "module" and/or "unit, portion, or part" representing constituent element used in the following description are used only in order to make understanding of the specification easier, and thus, these terms do not have meanings or roles that distinguish them from each other by themselves. In addition, in describing embodiments of the present specification, when it is determined that a detailed description of the well-known art associated with the present disclosure may obscure the gist of the present disclosure, it will be omitted. Further, the accompanying drawings are provided only in order to allow embodiments disclosed in the present specification to be easily understood and are not to be interpreted as limiting the present specification, and it is to be understood that the present disclosure includes all modifications, equivalents, and substitutions without departing from the scope of the present disclosure.

Terms including ordinal numbers such as first, second, and the like will be used only to describe various constituent elements, and are not to be interpreted as limiting these constituent elements. The terms are only used to differentiate one constituent element from other constituent elements.

In the present application, it should be understood that the term "include", "comprise", "have", or "configure" indicates that a feature, a number, a step, an operation, a constituent element, a part, or a combination thereof described in the specification is present, but does not exclude a possibility of presence or addition of one or more other features, numbers, steps, operations, constituent elements, parts, or combinations, in advance.

A program implemented as a set of instructions embodying a control algorithm necessary for controlling another component may be installed in a component for controlling another component under a specific control condition among components according to an embodiment. A control component may generate output data by processing input data and stored data according to the installed program. The control component may include a non-volatile memory for storing a program and a memory for storing data.

<FIG> illustrates a block diagram of a diagnostic system according to an embodiment.

Referring to <FIG>, a system <NUM> (hereinafter referred to as a "diagnostic system") for diagnosing a battery management system (BMS) is connected to a battery system including the BMS to measure a voltage at a connected node, diagnose a state of the BMS based on the measured voltage value, and output a screen displaying the diagnosed result. The diagnostic system <NUM> may include a measuring device <NUM> and an output device <NUM>.

The measuring device <NUM> may measure a voltage at a node ND, and may transmit a result of diagnosing the state of the BMS based on the measured voltage to the output device <NUM>. Here, the node ND may be a node on a wire connected to the BMS. The measuring device <NUM> may include a voltage measurer <NUM>, a controller <NUM>, and a communicator <NUM>.

The voltage measurer <NUM> may measure a voltage from the node ND, and may generate a signal (hereinafter referred to as a "voltage signal") representing the measured voltage to transmit it to the controller <NUM>.

The controller <NUM> may derive a voltage value based on the voltage signal received from the voltage measurer <NUM>. Deriving the voltage value may comprise the step of outputting a voltage value that has a positive level at the times when a voltage signal is measured at the node ND. The controller <NUM> may determine whether the voltage value reaches a trigger level indicating a predetermined reference voltage during a predetermined measuring period, may count the number of times the voltage value reaches the trigger level (for example, determine the number of times the voltage value crosses the trigger level), and may determine a state of the BMS based on a count result for a predetermined measuring period. For example, the predetermined measuring period may be <NUM> seconds.

The state of the BMS may be either a normal state indicating a normally operating state or an abnormal state indicating a non-normal operating state. The normal state may be a normal state of one of a plurality of power modes according to a cycle in which the BMS measures a voltage, a temperature, a current, and the like of the battery. Hereinafter, for convenience of description, it is assumed that the plurality of power modes are modes according to a cycle in which the BMS measures the temperature of the battery through a thermistor.

In the embodiment, the plurality of power modes may include a first mode and a second mode. The first mode is a mode in which the BMS periodically measures the temperature through the thermistor every first period. That is, in the first mode, the BMS may repeat an operation of measuring the temperature through the thermistor at a time interval of the first period. The first mode may be referred to as an active or normal mode. The second mode is a mode in which the BMS periodically measures the temperature through the thermistor every second period. That is, in the second mode, the BMS may repeat an operation of measuring the temperature through the thermistor at a time interval of the second period. The second mode may be referred to as a sleep or standby mode. Here, the second period may be longer than the first period. For example, the first period may be <NUM> second, and the second period may be <NUM> seconds.

In the embodiment, the controller <NUM> may determine the state of the BMS as a normal state in the first mode, a normal state in the second mode, or an abnormal state, based on the count result.

For example, the controller <NUM> may determine a first range in which a value obtained by dividing a predetermined measuring period by the first period and multiplied by <NUM> is taken as a minimum value, and a value obtained by adding <NUM> to the minimum value is taken as a maximum value; and when the count result during the predetermined measuring period is within the first range, the controller <NUM> may determine the state of the BMS as a normal state in the first mode in which the voltage measuring cycle is the first period. The controller <NUM> may determine a second range in which a value obtained by dividing a predetermined measuring period by the second period and multiplied by <NUM> is taken as a minimum value, and a value obtained by adding <NUM> to the minimum value is taken as a maximum value; and when the count result during the predetermined measuring period is within the second range, the controller <NUM> may determine the state of the BMS as a normal state in the second mode in which the voltage measuring cycle is the second period. The controller <NUM> may determine the state of the BMS as the abnormal state when the count result during the predetermined measuring period is not within the first range or the second range.

The communicator <NUM> may transmit and receive signals to and from an external device such as the output device <NUM> through wired or wireless communication with the external device.

The output device <NUM> may output a diagnosed result based on the signal received from the measurer <NUM>. The output device <NUM> may include a display that visually outputs the diagnosed result. In addition, the output device may include a speaker that outputs the diagnosed result as sound. The diagnosed result may include information indicating the number of times the voltage value measured by the measurer <NUM> reaches the trigger level and/or the state of the BMS.

Hereinafter, a state in which the diagnostic system <NUM> is connected to a wire connected to a BMS will be described with reference to <FIG>.

<FIG> is a block diagram for explaining a battery system to which the voltage measurer of <FIG> is connected.

A battery system <NUM> may include a battery pack <NUM>, a BMS <NUM>, a thermistor <NUM>, and relays <NUM> and <NUM>.

An external device <NUM> may include a load such as an inverter and a converter, and/or a charging device. When the external device <NUM> is a charging device, respective ends of the battery system <NUM> are connected to the charging device, so that the battery system <NUM> may be charged by receiving power from the charging device. When the external device <NUM> is a load, respective ends of the battery system <NUM> are connected to the load, so that power supplied by the battery pack <NUM> may be discharged through the load.

The battery pack <NUM> may generate a voltage measuring signal VS indicating a cell voltage of each of a plurality of battery cells <NUM> to <NUM> to transmit it to the BMS <NUM>. The BMS <NUM> may obtain a voltage measuring signal VS from the battery pack <NUM> through a pin P1.

The battery pack <NUM> may include a plurality of battery cells <NUM> to <NUM>. Although <FIG> illustrates that the number of a plurality of battery cells <NUM> to <NUM> is three, the present disclosure is not limited thereto, and the battery pack <NUM> may be implemented with <NUM> or more battery cells connected in series, a plurality of battery cells in which two or more battery cells connected in parallel are connected in series, or two or more battery cells connected in parallel.

The thermistor <NUM> may sense the pack temperature of the battery pack <NUM> to generate a temperature measuring signal TS, and may transmit the temperature measuring signal TS to the BMS <NUM>. Here, the temperature measuring signal TS may indicate a voltage value determined according to the measured temperature. One end of the thermistor <NUM> is connected to pin P2, and the other end of the thermistor <NUM> is connected to the ground. The BMS <NUM> may obtain the temperature measuring signal TS from the thermistor <NUM> through a pin P2.

One end of each of the relays <NUM> and <NUM> is connected to the battery pack <NUM>, and the other end of each of the relays <NUM> and <NUM> is connected to at least one component of an external device <NUM>. Closing and opening of the relays <NUM> and <NUM> may be controlled according to relay control signals RCS1 and RCS2 supplied from the BMS <NUM>.

The node ND may be disposed on a wire connected between one end of the thermistor <NUM> and the pin P2. The voltage measurer <NUM> may be electrically connected to the node ND to measure the voltage of the node ND, and may generate a voltage signal representing the measured voltage.

The BMS <NUM> may periodically receive the temperature measuring signal TS according to a predetermined measuring cycle. The predetermined measuring cycle may be determined according to the state of the BMS <NUM>. The predetermined measuring cycle may include the first period in the first mode, the second period in the second mode, and the like.

When the BMS <NUM> performs an operation of reading the temperature measuring signal TS from the thermistor <NUM> through the pin P2, the voltage of the node ND may be changed. The voltage measurer <NUM> may measure the changed voltage of the node ND.

Hereinafter, a method of diagnosing the state of the BMS based on the voltage measured by the diagnostic system <NUM> will be described with reference to <FIG>.

<FIG> illustrates a flowchart of a diagnostic method according to an embodiment.

The voltage measurer <NUM> may start measuring the voltage from the node ND (S1), and may transmit the measured voltage signal to the controller <NUM>.

The controller <NUM> may derive a voltage value based on the voltage signal and count the number of times the derived voltage value reaches the trigger level during a predetermined measuring period (S2). The controller <NUM> may generate a value indicating the number of times the trigger level is reached (hereinafter referred to as a "count value"). Hereinafter, steps S2 and S3 will be described with reference to <FIG> and <FIG>.

<FIG> and <FIG> illustrate waveform diagrams of the voltage signals derived by the controller in step S2.

The voltage signal may reach a trigger level VT once or more during a predetermined measuring period. The trigger level VT may indicate an arbitrary voltage value among values between highest and lowest values of the voltage values measured during the predetermined measuring period.

According to the waveform diagram shown in <FIG>, the controller <NUM> may count the number of times a voltage value v reaches the trigger level VT from a start time point t1 of a predetermined measuring period P to an end time point t2 of the measuring period P. The voltage value v reaches the trigger level VT at time points t103, t104, t105, t106, t107, t108, t109, t110, t111, and t112. Accordingly, referring to <FIG>, the count value is <NUM> times.

In addition, according to the waveform diagram shown in <FIG>, the controller <NUM> may count the number of times the voltage value v reaches the trigger level VT from a start time point t3 of the measuring period P to an end time point t4 of the measuring period P. The voltage value v reaches the trigger level VT at time points t203 and t204. Accordingly, referring to <FIG>, the count value is <NUM> times.

When the predetermined measuring period P ends, the controller <NUM> may determine whether the count value is within the first range or the second range (S3). In the controller <NUM>, information of the first and second periods indicating the measuring cycle of each of the first and second modes may be previously stored. Alternatively, the controller <NUM> may receive information indicating the first and second periods from the BMS <NUM> through the communicator <NUM>.

The first range may be a range in which the BMS <NUM> normally operates corresponding to a case in which the measuring cycle of the BMS <NUM> is the first period. The first range may be, as shown in Equation <NUM> below, a range equal to or greater than a value obtained by dividing the measuring period P by the first period and multiplied by <NUM> and less than a value obtained by adding <NUM> to a value obtained by dividing the measuring period P by the first period and multiplied by <NUM>.

Here, P is a measuring period for counting the number of times, T1 is the first period corresponding to the first mode of the BMS <NUM>, and Count is a value counted by the controller <NUM>. Units of P and T1 may both be seconds.

For example, when the first period T1 is <NUM> second and the measuring period P is <NUM> seconds, the first range is a range in which the count value is <NUM> or more and <NUM> or less. In the example of <FIG>, since the count value is <NUM> times, the controller <NUM> may determine that the count value is within the first range.

The second range may be a range in which the BMS <NUM> normally operates corresponding to a case in which the measuring cycle of the BMS <NUM> is the second period. As shown in Equation <NUM> below, the second range may be a range equal to or greater than a value obtained by dividing the measuring period P by the second period and multiplied by <NUM> and less than a value obtained by adding <NUM> to a value obtained by dividing the measuring period P by the second period and multiplied by <NUM>.

Here, P is a measuring period for counting the number of times, T2 is the second period corresponding to the first mode of the BMS <NUM>, and Count is a value counted by the controller <NUM>. Units of P and T2 may both be seconds.

For example, when the second period T2 is <NUM> seconds and the measuring period P is <NUM> seconds, the second range is a range in which the count value is <NUM> or more and <NUM> or less. In the example of <FIG>, since the count value is <NUM> times, the controller <NUM> may determine that the count value is within the second range.

The reason that the value obtained by adding <NUM> to the minimum value in each of the first and second ranges is determined as the maximum value is because when the voltage value at the start time point and/or the end time point of the measuring period P is the same as the trigger level, the count value may exceed a value obtained by dividing the measuring period P by the first or second period T1 or T2 even when the BMS <NUM> is in a normal state.

For example, in <FIG>, it is assumed that the start time point of the measuring period P is t102 and the end time point of the measuring period P is t122. The voltage value reaches the trigger level VT at time points t102, t103, t104, t105, t106, t107, t108, t109, t110, t111, and t112. Accordingly, the count value is <NUM> times.

In addition, for example, in <FIG>, it is assumed that the start time point of the measuring period P is t202 and the end time point of the measuring period P is t204. The voltage value reaches the trigger level VT at time points t202, t203, and t204. Accordingly, the count value is <NUM> times.

When the count value is within the first range, the controller <NUM> may determine the state of the BMS <NUM> as the normal state of the first mode (S4). When the count value is within the second range, the controller <NUM> may determine the state of the BMS <NUM> as the normal state of the second mode (S5). When the count value is not within the first and second ranges, the controller <NUM> may determine the state of the BMS <NUM> as the abnormal state (S6).

A voltage value being above the trigger level may indicate that the BMS is performing a measurement. In the normal state in which the BMS <NUM> normally operates, since the measuring cycle is the first or second period, the count value is within the first or second range. When the count value is not within the first and second ranges, since the measuring cycle of the BMS <NUM> is different from the first or second period, the controller <NUM> may determine that the BMS <NUM> is in an abnormal state.

In <FIG>, the state in which the BMS <NUM> normally operates is illustrated as a normal state of one of the first mode and the second mode, but the present disclosure is not limited thereto. The normal state of the BMS <NUM> may include respective normal states of two or more modes in which the BMS <NUM> operates at different cycles.

The controller <NUM> may determine the state of the BMS <NUM> through one of steps S4 to S6 and generate a signal indicating the determined state of the BMS <NUM> (hereinafter referred to as a "BMS state signal"). The BMS state signal may include information indicating a count value. The communicator <NUM> may transmit the BMS state signal to the output device <NUM>.

The output device <NUM> may receive the BMS state signal. The output device <NUM> may output a diagnostic result including a count value and information representing a state of the BMS <NUM> based on the BMS state signal (S7). The output device <NUM> may visually output the diagnostic result through a display. The output device <NUM> may provide a screen displaying the diagnostic result through an application and the like installed in the output device <NUM>.

A user may check the state of the BMS <NUM> through the output device <NUM> and, when the BMS <NUM> is in an abnormal state, may take countermeasures for the abnormal state.

Claim 1:
A measuring device (<NUM>), comprising:
a voltage measurer (<NUM>) configured to measure a voltage from a node (ND) on a wire connected to a battery management system (BMS); and
a controller (<NUM>) configured to receive the measured voltage signal from the voltage measurer to derive a voltage value, to count the number of times the voltage value reaches a reference voltage during a measuring period, and to determine a state of the BMS as one of a normal state of a first mode, a normal state of a second mode, and an abnormal state based on the number of times.