CN110888069A - Current detection method and device for power battery - Google Patents
Current detection method and device for power battery Download PDFInfo
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Abstract
The invention provides a detection method and a device of a power battery, wherein a loop of the power battery is provided with a plurality of current sensors which are respectively used for collecting output current of the power battery, after sampling current values of the current sensors in each sampling period are obtained, current estimated values of the power battery in the sampling period are obtained through the current sampling current values and measurement precision estimated values of the current sensors determined in the previous sampling, namely the current estimated values are fusion estimated values after integrating the sampling values of the current sensors and the measurement precision, meanwhile, the measurement precision estimated values of the current sensors in the current sampling period are estimated according to the current estimated values and the sampling current values, and the measurement precision is dynamically adjusted in real time to be used for estimating the current of the power battery in the next sampling period. The method effectively improves the detection precision of the current of the power battery.
Description
Technical Field
The invention relates to the field of new energy automobiles, in particular to a current detection method and device for a power battery.
Background
With the continuous reduction of traditional energy and the continuous improvement of environmental protection consciousness, new energy automobile has gained a long-standing development, and new energy automobile is as the source of power by the power battery package, and the running state of car has been decided to the state of battery package.
The current value of the power battery is an important parameter of a battery pack and an important input parameter of a Battery Management System (BMS), the current value is used in an estimation algorithm of many parameters of the power battery, the current value is generally acquired by a current sensor, and the sampling precision of the current value directly influences the accuracy of estimation of all parameters of the power battery in the BMS. Currently, the accuracy of the current sampling value is improved mainly by selecting a current sensor with higher accuracy, which increases the cost of the system, and the improvement of the accuracy on hardware is limited, which increases the cost of the system.
Disclosure of Invention
In view of this, the present invention provides a method for detecting a power battery, which improves the detection accuracy of the current of the power battery.
In order to achieve the purpose, the invention has the following technical scheme:
a current detection method for a power battery is characterized in that M current sensors are arranged in a loop of the power battery, and each current sensor is used for collecting output current of the power battery, and the method comprises the following steps:
obtaining a sampling error value E of the mth current sensor before the power battery outputs current to the load0mAs an initial measurement accuracy estimate e0mM is from 1 to M, M is more than or equal to 2;
after the power battery outputs current to a load, sequentially obtaining the current estimated value IR of the power battery in the kth sampling periodkK starting from 1, obtaining said current estimate IRkThe method comprises the following steps:
respectively obtaining current sampling values I of the mth current sensor in the kth sampling periodkmM is from 1 to M;
the current sampling value I according to the m current sensorkmAnd an estimate e of the measurement accuracy in the k-1 th sampling period(k-1)mObtaining the current estimated value IR of the power battery in the kth sampling periodkWhen k is 1, the measurement accuracy of the 0 th sampling periodThe estimated value is an estimated value e of the initial measurement precision0m；
By said current estimation value IRkThe current sampling value IkmAnd an estimate e of the measurement accuracy for the k-1 th sampling period(k-1)mObtaining the measurement accuracy estimated value e of the mth current sensor in the kth sampling periodkmAnd M is from 1 to M.
Optionally, the obtaining a sampling error value of each current sensor before the power battery outputs current to the load includes:
obtaining current sampling values of an mth current sensor at different sampling moments before the power battery outputs current to a load, wherein M is from 1 to M;
respectively obtaining sampling error values of the mth current sensor according to current sampling values of the mth current sensor at different sampling moments to serve as initial measurement precision estimated values e0m。
Optionally, the current estimation value IR of the power battery in the k sampling period is obtainedkThe method comprises the following steps:
obtaining the current estimated value IR of the power battery in the kth sampling period by adopting a fusion algorithmk。
Optionally, the fusion algorithm is a mean algorithm, a least squares algorithm, or a minimum mean square error algorithm.
Optionally, said passing said current estimation value IRkThe current sampling value IkmAnd an estimate e of the measurement accuracy of the k-1 th sampling period(k-1)mObtaining the measurement precision estimated value e of the mth current sensor in the kth sampling periodkmThe method comprises the following steps:
by the current sampling value IkmAnd said current estimate IRkObtaining the sampling error value E of the m current sensor in the k sampling periodkm；
Obtaining the sampling error value EkmAnd said measurement accuracy estimate e(k-1)mTaking the average value as the estimated value e of the measurement precision of the k-th sampling periodkm。
A current detection device of a power battery, wherein M current sensors are arranged in a loop of the power battery, and each current sensor is used for collecting the output current of the power battery, and the device comprises:
an initial measurement accuracy estimation unit for obtaining a sampling error value E of the mth current sensor before the power battery outputs current to the load0mAs an initial measurement accuracy estimate e0mM is from 1 to M, M is more than or equal to 2;
the current estimation unit is used for sequentially obtaining the current estimation value IR of the power battery in the kth sampling period after the power battery outputs current to a loadkK starting from 1, the current estimation unit comprising:
a current sampling value acquisition unit for respectively acquiring current sampling values I of the m current sensor in the k sampling periodkmM is from 1 to M;
a current estimated value acquisition unit for acquiring a current sampled value I according to the m-th current sensorkmAnd an estimate e of the measurement accuracy in the k-1 th sampling period(k-1)mObtaining the current estimated value IR of the power battery in the kth sampling periodkWhen k is 1, the measurement accuracy estimate of the 0 th sampling period is the initial measurement accuracy estimate e0m；
A measurement accuracy obtaining unit for passing the current estimation value IRkThe current sampling value IkmAnd an estimated value e of the measurement accuracy of the k-1 sampling period(k-1)mObtaining the estimated value e of the measurement precision of the mth current sensor in the kth sampling periodkmAnd M is from 1 to M.
Optionally, in the initial measurement accuracy estimation unit, the obtaining a sampling error value of each current sensor before the power battery outputs a current to a load includes:
obtaining current sampling values of an mth current sensor at different sampling moments before the power battery outputs current to a load, wherein M is from 1 to M;
respectively obtaining sampling error values of the mth current sensor according to current sampling values of the mth current sensor at different sampling moments to be used as initial measurement accuracy estimationCalculated value e0m。
Optionally, in the current estimated value obtaining unit, the current estimated value IR of the power battery at the k-th sampling period is obtainedkThe method comprises the following steps:
obtaining the current estimated value IR of the power battery in the kth sampling period by adopting a fusion algorithmk。
Optionally, the fusion algorithm is a mean algorithm, a least squares algorithm, or a minimum mean square error algorithm.
Optionally, in the measurement accuracy obtaining unit, the current estimated value IR is passed throughkThe current sampling value IkmAnd an estimate e of the measurement accuracy of the k-1 th sampling period(k-1)mObtaining the measurement precision estimated value e of the mth current sensor in the kth sampling periodkmThe method comprises the following steps:
by the current sampling value IkmAnd said current estimate IRkObtaining the sampling error value E of the m current sensor in the k sampling periodkm；
Obtaining the sampling error value EkmAnd said measurement accuracy estimate e(k-1)mTaking the average value as the estimated value e of the measurement precision of the k-th sampling periodkm。
The detection method and the device for the power battery provided by the embodiment of the invention are characterized in that a plurality of current sensors are arranged in a loop where the power battery is arranged and are respectively used for collecting the output current of the power battery, after the sampling current value of each current sensor in each sampling period is obtained, the current estimated value of the power battery in the sampling period is obtained through each current sampling value and the measurement precision estimated value of each current sensor determined in the previous sampling, namely, the current estimation value is a fused estimation value after integrating the sampling values of the current sensors and the measurement accuracy, and at the same time, and estimating the measurement precision estimated value of each current sensor in the current sampling period according to the current estimated value and each sampling current value, and dynamically adjusting the measurement precision in real time so as to be used for estimating the current of the power battery in the next sampling period. In the method, the measurement accuracy estimation value of each current sensor in each sampling period is adjusted in real time, so that the accuracy of the measurement accuracy estimation value is ensured, meanwhile, the current value of the power battery in each sampling period is the estimation value obtained according to the sampling current value of each current sensor and the measurement accuracy estimation value, and the detection accuracy of the current of the power battery is effectively improved by estimating through multiple current values.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 shows a schematic structural diagram of a power cell circuit according to an embodiment of the invention;
FIG. 2 is a flow chart illustrating a method for detecting current of a power battery according to an embodiment of the invention;
fig. 3 shows a schematic structural diagram of a current detection device of a power battery according to an embodiment of the invention.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described and will be readily apparent to those of ordinary skill in the art without departing from the spirit of the present invention, and therefore the present invention is not limited to the specific embodiments disclosed below.
As described in the background art, the current value of the power battery is an important input parameter in the BMS system, and is used in an estimation algorithm of many other parameters related to the power battery, and the detection accuracy of the current value directly affects the accuracy of estimation of other parameters. At present, the accuracy of current detection of the power battery is improved mainly by improving the measurement accuracy of hardware of the current sensor, and the improvement of the accuracy of the hardware is always limited, and the cost of the system is increased.
The current value of the power battery in each sampling period is an estimated value obtained according to the sampling current value and the measurement precision estimated value of each current sensor, and estimation is carried out through multiple current values, so that the detection precision of the current of the power battery is effectively improved.
In order to better understand the technical solution of the present application, the power battery circuit is first described. The power battery is a power battery pack for a vehicle, and a plurality of battery cells are usually connected in series and parallel to serve as a power source of a motor vehicle, and the power battery provides high voltage electricity, as shown in fig. 1, a relay switch 16 is usually connected in series at an output end of a power battery 10, and whether the power battery outputs current to a load is controlled by opening and closing the relay switch.
In the present application, referring to fig. 1, a plurality of current sensors 12-1, 12-2 are disposed in a loop of a power battery 10, one or more current sensors may be disposed at one or both ends of the power battery 10, the current sensors 12-1, 12-2 are connected to a BMS through sampling lines, and the BMS obtains a sampled current value of each current sensor 12-1, 12-2 through the sampling lines, and the sampled current value may be further used for estimation of the power battery current or estimation of other parameters.
In the present application, after further estimation is performed by the sampled current value of each current sensor, the current value of the power battery in each sampling period is obtained, and the method will be described in detail below with reference to a flowchart.
Referring to fig. 2, in step S101, a sampling error value of each current sensor before the power battery outputs current to the load is obtained, and the sampling error value is used as an initial measurement accuracy estimation value.
As mentioned above, a relay switch is usually connected in series to the output end of the power battery, and the power battery is controlled to output current to the load by closing the relay switch, before the switch is closed, the loop where the power battery is located is in an open circuit state, and theoretically, the current sampling value collected by each current sensor should be 0.
The sampling error value of each current sensor before the power battery outputs current to the load may be a theoretical sampling precision of the current sensor, where the sampling precision is a precision of sensor hardware itself, and is usually determined at the time of sensor factory shipment and is a fixed precision value.
In a more preferred embodiment of the present application, the current sampling value of each current sensor before the power battery outputs current to the load can be used for determining. Specifically, obtaining a sampling error value of each current sensor before the power battery outputs current to the load includes:
obtaining a plurality of current sampling values of all current sensors at different sampling moments before the power battery outputs current to a load; and respectively obtaining sampling error values of the current sensors through the sum of current sampling values of the current sensors at different sampling moments, taking the sampling values as initial measurement precision estimated values, and using the estimated values for estimating the current value of the power battery in a first sampling period after the power battery outputs current to a load subsequently.
If M current sensors are arranged in the loop of the power battery to respectively collect the output current of the power battery, and M is more than or equal to 2, for convenience of description, the M current sensors are respectively referred to as M-th sensors, and M is from 1 to M. For each current sensor, respectively obtaining current sampling values of the current sensor at each sampling moment, wherein the current sampling value of the m-th sensor in the ith sampling period is marked as xmiI is from 1 to n and M is from 1 to M. It can be known that when the loop of the power battery is in an open circuit state, the power battery does not output current to the load, and theoretically, each powerThe current sampling value collected by the current sensor is 0, and the current sampling value obtained in the state is related to the measurement accuracy of the current sampling value, so that the sampling error value of the current sensor can be determined by the current sampling value in the open-circuit state.
In this embodiment, the current sampling values of a plurality of sampling periods are collected, and sampling error values of each current sensor can be respectively obtained according to the current sampling values of each current sensor at different sampling times, and the sampling error values are taken as initial measurement accuracy estimated values, and the initial measurement accuracy estimated values can be represented by the following expression:
e0m＝f(xm1,xm2....xmn) (1)
wherein e is0mIs an initial measurement accuracy estimation value of the m current sensor, xm1,xm2....xmnThe current sampling values of the m-th current sensor in each sampling period before the power battery outputs current to the load are n sampling periods in total.
The sampling error value can be estimated by the current sampling values of a plurality of sampling periods, for example, the sampling error value can be obtained by summing the current sampling values and then calculating the average value; the current sampling values may be processed to remove abnormal data, where the abnormal data may be, for example, the maximum value and the minimum value of the current sampling values, or the current sampling values that exceed the normal threshold range, and then the current sampling values after the abnormal data is removed are summed and averaged to obtain the sampling error value.
In step S102, after the power battery outputs current to the load, the current estimated value IR of the power battery in the k sampling period is obtained in sequencekK starts at 1.
It is understood that, when the current is sampled, the sampled value of each sampling period is obtained in turn, and the number of periods is continuously increased, that is, the k value is increased by 1 after the current estimation of each sampling period is completed.
After the power battery outputs current to the load, namely the relay switch is closedAnd in the state, the loop of the power battery is in a closed state. Specifically, at each sampling period, the current estimation value IR of the power battery is obtainedkComprises the following steps.
S1021, respectively obtaining current sampling values I of the m current sensor in the k sampling periodkmAnd M is from 1 to M.
S1022, sampling value I of current according to m current sensorkmAnd an estimate e of the measurement accuracy during the k-1 th sampling period(k-1)mObtaining the current estimated value IR of the power battery in the kth sampling periodk。
S1023, by said current estimation IRkAnd the current sampling value IkmObtaining the measurement precision estimated value e of the mth current sensor in the kth sampling periodkmAnd M is from 1 to M.
After the power battery outputs current to the load, the current sensor starts to collect the output current of the power battery, and the current sampling value of each sampling period can be obtained through the current sensor.
For convenience of description and understanding, each sampling period is referred to as a kth sampling period, a current sampling value of each current sensor in the kth sampling period is referred to as a current sampling value I of an m-th sensorkmIn the kth sampling period, the measurement accuracy of the mth sensor is estimated and designated as ekmAnd M is from 1 to M. The current estimate for the power cell for the kth sampling period is denoted as IRkThe calculation formula is as follows:
IRk＝f[Ik1,Ik2.....Ikm,e(k-1)1,e(k-1)2....e(k-1)m](2)
wherein, Ik1,Ik2.....Ikm,e(k-1)1For the current sample value of the kth sample period of each sensor, e(k-1)2....e(k-1)mIs an estimated value of the measurement accuracy of the k-1 th sampling period of each current sensor.
In a specific application, the algorithm for obtaining the current estimation value of the power battery may be a sensor fusion algorithm, for example, a mean algorithm, a least square algorithm, or a minimum mean square error algorithm.
The measurement accuracy estimate of the m-th sensor in the k-th sampling period is denoted as ekmThe calculation formula is as follows:
ekm＝f[Ik1,Ik2.....Ikm,e(k-1)1,e(k-1)2....e(k-1)m,IRk](3)
wherein, Ik1,Ik2.....Ikm,e(k-1)1For the current sample value of the kth sample period of each sensor, e(k-1)2....e(k-1)mAnd IRk is the current estimated value of the power battery in the k sampling period for the measurement precision estimated value of the k-1 sampling period of each current sensor.
In a particular application, the measurement accuracy estimate for the sampling period may be obtained by a statistical or other algorithm. Specifically, in this embodiment, the current sampling value I is first passed throughkmAnd said current estimate IRkObtaining the sampling error value E of the m current sensor in the k sampling periodkm(ii) a Obtaining the sampling error value EkmAnd said measurement accuracy estimate e(k-1)mIs taken as the measurement accuracy estimation value e of the k-th sampling periodkm。
In the embodiment of the application, the current sampling value obtained by the current sensor is not directly used as the current value of the power battery, but the current estimated value of the power battery is obtained through further calculation, and the current estimated value is used as the estimation application of the BMS to various states of the battery. Specifically, in each sampling period, the current estimated value of the power battery in the sampling period is estimated according to the current sampling value of each current sensor and the measurement accuracy estimated value obtained in the previous sampling period, meanwhile, the measurement accuracy estimated value of each current sensor is updated in each sampling period, the measurement accuracy estimated value of each current sensor in the current sampling period is obtained through calculation according to the current sampling value obtained in the current sampling period, the current estimated value obtained through calculation and the measurement accuracy estimated value in the previous sampling period, and the measurement accuracy estimated value is used for calculating the current estimated value of the power battery in the next sampling period.
Therefore, the estimated value of the measurement accuracy of each current sensor in each sampling period is adjusted in real time, so that the accuracy of the estimated value of the measurement accuracy is ensured, and meanwhile, the current value of the power battery in each sampling period is an estimated value obtained according to the sampled current value of each current sensor and the estimated value of the measurement accuracy, and is estimated through multiple current values, so that the detection accuracy of the current of the power battery is effectively improved.
In order to facilitate understanding of the scheme, the following will describe a method for obtaining the current estimation value of the power battery by taking two sampling periods as an example.
First, current sample values of the respective current sensors in the 1 st sampling period are obtained.
In the 1 st sampling period, the current sampling value I of the m-th sensor1mAnd M is from 1 to M.
Then, the current sampling value I of each current sensor is obtained according to the 1 st sampling period1mAnd an initial measurement accuracy estimate e0mObtaining the current estimated value IR of the power battery in the 1 st sampling period1。
Meanwhile, the current sampling value I of each current sensor is obtained according to the 1 st sampling period1mInitial measurement accuracy estimate e0mAnd the current estimate IR of the power battery for the 1 st sampling period1Obtaining the estimated value e of the measurement precision of each current sensor in the 1 st sampling period1m。
Then, in the 2 nd sampling period, the current sampling value of each current sensor in the 2 nd sampling period is obtained.
In the 2 nd sampling period, the current sampling value I of the m-th sensor2mAnd M is from 1 to M.
Similarly, the current sampling value I of each current sensor is obtained according to the 2 nd sampling period2mAnd an estimate e of the measurement accuracy for the 1 st sampling period1mObtaining the current estimated value IR of the power battery in the 2 nd sampling period2。
Meanwhile, the current sampling value I of each current sensor is obtained according to the 2 nd sampling period 2m1 st miningMeasurement accuracy estimation value e of sample period1mAnd the current estimate IR of the power cell for the 2 nd sampling period2Obtaining the estimated value e of the measurement precision of each current sensor in the 2 nd sampling period2m。
For each subsequent sampling period, the same method as that in each period is adopted to obtain the current estimation value and the measurement precision estimation value of the sampling period, and details are not repeated here.
In addition, the present invention provides a current detection apparatus for a power battery, which implements the method, where a loop in which the power battery is located is provided with M current sensors, and each current sensor is used for collecting an output current of the power battery, and as shown in fig. 3, the method includes:
an initial measurement accuracy estimation unit 200 for obtaining a sampling error value E of the mth current sensor before the power battery outputs current to the load0mAs an initial measurement accuracy estimate e0mM is from 1 to M, M is more than or equal to 2;
a current estimation unit 210, configured to obtain estimated current values IR of the power battery in the kth sampling period in sequence after the power battery outputs current to a loadkK starts from 1, the current estimation unit 210 includes:
a current sampling value obtaining unit 2101 for respectively obtaining current sampling values I of the mth current sensor in the kth sampling periodkmM is from 1 to M;
a current estimated value acquisition unit 2102 for acquiring a current sampled value I from the m-th current sensorkmAnd an estimate e of the measurement accuracy in the k-1 th sampling period(k-1)mObtaining the current estimated value IR of the power battery in the kth sampling periodkWhen k is 1, the measurement accuracy estimate of the 0 th sampling period is the initial measurement accuracy estimate e0m；
A measurement accuracy acquisition unit 2103 for passing the current estimation value IRkThe current sampling value IkmAnd an estimate e of the measurement accuracy of the k-1 th sampling period(k-1)mObtaining the measurement precision estimated value e of the mth current sensor in the kth sampling periodkmAnd M is from 1 to M.
Further, in the initial measurement accuracy estimation unit 200, the obtaining a sampling error value of each current sensor before the power battery outputs a current to a load includes:
obtaining current sampling values of an mth current sensor at different sampling moments before the power battery outputs current to a load, wherein M is from 1 to M;
respectively obtaining sampling error values of the mth current sensor according to current sampling values of the mth current sensor at different sampling moments to serve as initial measurement precision estimated values e0m。
Further, in the estimated current value obtaining unit 2102, the estimated current value IR of the power battery in the k-th sampling period is obtainedkThe method comprises the following steps:
obtaining the current estimated value IR of the power battery in the kth sampling period by adopting a fusion algorithmk。
Further, the fusion algorithm is a mean algorithm, a least square algorithm or a minimum mean square error algorithm.
Further, in the measurement accuracy obtaining unit 2103, the current estimation value IR is passed throughkThe current sampling value IkmAnd an estimate e of the measurement accuracy of the k-1 th sampling period(k-1)mObtaining the measurement accuracy estimated value e of the mth current sensor in the kth sampling periodkmThe method comprises the following steps:
by the current sampling value IkmAnd said current estimate IRkObtaining the sampling error value E of the m current sensor in the k sampling periodkm；
Obtaining the sampling error value EkmAnd said measurement accuracy estimate e(k-1)mTaking the average value as the estimated value e of the measurement precision of the k-th sampling periodkm。
The embodiments in the present specification are described in a progressive manner, and the same and similar parts among the embodiments are referred to each other, and each embodiment focuses on different points from other embodiments. In particular, for the system embodiment, since it is substantially similar to the method embodiment, the description is relatively simple, and for the relevant points, reference may be made to the partial description of the method embodiment. The above-described system embodiments are merely illustrative, wherein the modules or units described as separate parts may or may not be physically separate, and the parts displayed as modules or units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
The foregoing is only a preferred embodiment of the present invention, and although the present invention has been disclosed in the preferred embodiments, it is not intended to limit the present invention. Those skilled in the art can make many possible variations and modifications to the disclosed embodiments, or modify equivalent embodiments, using the methods and techniques disclosed above, without departing from the scope of the claimed invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the protection scope of the technical solution of the present invention, unless the contents of the technical solution of the present invention are departed.
Claims (10)
1. A current detection method of a power battery is characterized in that M current sensors are arranged in a loop of the power battery, and each current sensor is used for collecting output current of the power battery, and the method comprises the following steps:
obtaining a sampling error value E of the mth current sensor before the power battery outputs current to the load0mAs an initial measurement accuracy estimate e0mM is from 1 to M, M is more than or equal to 2;
after the power battery outputs current to the load, the k sampling period is obtained in sequenceCurrent estimate IR of the force cellkK starting from 1, obtaining said current estimate IRkThe method comprises the following steps:
respectively obtaining current sampling values I of the mth current sensor in the kth sampling periodkmM is from 1 to M;
the current sampling value I according to the m current sensorkmAnd an estimate e of the measurement accuracy in the k-1 th sampling period(k-1)mObtaining the current estimated value IR of the power battery in the kth sampling periodkWhen k is 1, the measurement accuracy estimate of the 0 th sampling period is the initial measurement accuracy estimate e0m；
By said current estimation value IRkThe current sampling value IkmAnd an estimate e of the measurement accuracy of the k-1 th sampling period(k-1)mObtaining the measurement precision estimated value e of the mth current sensor in the kth sampling periodkmAnd M is from 1 to M.
2. The method of claim 1, wherein obtaining a sampling error value for each current sensor prior to the power cell outputting current to the load comprises:
obtaining current sampling values of an mth current sensor at different sampling moments before the power battery outputs current to a load, wherein M is from 1 to M;
respectively obtaining sampling error values of the mth current sensor according to current sampling values of the mth current sensor at different sampling moments to serve as initial measurement precision estimated values e0m。
3. The method as claimed in claim 1, wherein said obtaining of current estimate IR of said power cell for the kth sampling periodkThe method comprises the following steps:
obtaining the current estimated value IR of the power battery in the kth sampling period by adopting a fusion algorithmk。
4. The method of claim 3, wherein the fusion algorithm is a mean algorithm, a least squares algorithm, or a minimum mean square error algorithm.
5. Method according to claim 1, characterized in that said passing of said current estimation value IRkThe current sampling value IkmAnd an estimate e of the measurement accuracy of the k-1 th sampling period(k-1)mObtaining the measurement precision estimated value e of the mth current sensor in the kth sampling periodkmThe method comprises the following steps:
by the current sampling value IkmAnd said current estimate IRkObtaining the sampling error value E of the m current sensor in the k sampling periodkm；
Obtaining the sampling error value EkmAnd said measurement accuracy estimate e(k-1)mIs taken as the measurement accuracy estimation e of the kth sampling periodkm。
6. The utility model provides a current detection device of power battery, characterized in that, be provided with M current sensor in the return circuit of power battery place, each current sensor is used for gathering the output current of power battery, its characterized in that, the device includes:
an initial measurement accuracy estimation unit for obtaining a sampling error value E of the mth current sensor before the power battery outputs current to the load0mAs an initial measurement accuracy estimate e0mM is from 1 to M, M is more than or equal to 2;
the current estimation unit is used for sequentially obtaining the current estimation value IR of the power battery in the kth sampling period after the power battery outputs current to a loadkK starting from 1, the current estimation unit comprising:
a current sampling value acquisition unit for respectively acquiring current sampling values I of the m current sensor in the k sampling periodkmM is from 1 to M;
a current estimated value acquisition unit for acquiring a current sampled value I according to the m-th current sensorkmAnd an estimate e of the measurement accuracy in the k-1 th sampling period(k-1)mObtaining the current estimated value IR of the power battery in the kth sampling periodkWhen k is 1, the measurement accuracy estimate of the 0 th sampling period is the initial measurement accuracy estimate e0m；
A measurement accuracy obtaining unit for passing the current estimation value IRkThe current sampling value IkmAnd an estimate e of the measurement accuracy of the k-1 th sampling period(k-1)mObtaining the measurement precision estimated value e of the mth current sensor in the kth sampling periodkmAnd M is from 1 to M.
7. The apparatus of claim 6, wherein the obtaining of the sampling error value of each current sensor before the power battery outputs the current to the load in the initial measurement accuracy estimation unit comprises:
obtaining current sampling values of an mth current sensor at different sampling moments before the power battery outputs current to a load, wherein M is from 1 to M;
respectively obtaining sampling error values of the mth current sensor according to current sampling values of the mth current sensor at different sampling moments to serve as initial measurement precision estimated values e0m。
8. The device as claimed in claim 6, wherein in the current estimation value obtaining unit, the current estimation value IR of the power battery in the k sampling period is obtainedkThe method comprises the following steps:
obtaining the current estimated value IR of the power battery in the kth sampling period by adopting a fusion algorithmk。
9. The apparatus of claim 8, wherein the fusion algorithm is a mean algorithm, a least squares algorithm, or a minimum mean square error algorithm.
10. The apparatus according to claim 6, wherein in the measurement accuracy obtaining unit, the current passing through the current estimation value IR is obtainedkThe current sampling value IkmAnd an estimate e of the measurement accuracy of the k-1 th sampling period(k-1)mObtaining the m current senseThe estimated value e of the measurement precision of the device in the k sampling periodkmThe method comprises the following steps:
by the current sampling value IkmAnd said current estimate IRkObtaining the sampling error value E of the m current sensor in the k sampling periodkm；
Obtaining the sampling error value EkmAnd said measurement accuracy estimate e(k-1)mIs taken as the measurement accuracy estimation e of the kth sampling periodkm。
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