CN109991475A - Bridge-type insulation detecting circuit and method based on KF observer - Google Patents
Bridge-type insulation detecting circuit and method based on KF observer Download PDFInfo
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- CN109991475A CN109991475A CN201910234209.7A CN201910234209A CN109991475A CN 109991475 A CN109991475 A CN 109991475A CN 201910234209 A CN201910234209 A CN 201910234209A CN 109991475 A CN109991475 A CN 109991475A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/025—Measuring very high resistances, e.g. isolation resistances, i.e. megohm-meters
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Abstract
The present invention provides a kind of bridge-type insulation detecting circuit and method based on KF observer, including switching gate circuit, divider resistance and microprocessor, by control switch gating device, the positive insulation resistance and negative insulation resistance of electrokinetic cell system are calculated according to sampled voltage.The present invention eliminates sampling disturbance using KF observer, realizes the accurate calculating of insulation resistance；Circuit simply and readily realizes there is very high universality.
Description
Technical Field
The invention relates to the technical field of energy management of a new energy automobile power battery system, in particular to a KF observer-based bridge type insulation detection circuit and a KF observer-based bridge type insulation detection method.
Background
With the continuous popularization and promotion of new energy automobiles, the use safety of the battery motor car is more and more concerned by people. The working voltage of the power battery system is mostly above 300V, so that the battery management system is required to accurately predict the insulation state of the battery, and can give an early warning in real time to prevent the occurrence of electric shock. At present, the mainstream insulation acquisition scheme mainly comprises a small signal injection method and a bridge voltage division method, and the detection precision is low.
Disclosure of Invention
In order to accurately estimate the insulation state of a power system, the invention provides a KF observer-based bridge insulation detection circuit and method, which adopt the following technical scheme:
a KF observer-based bridge insulation detection circuit comprising:
a voltage dividing circuit including a resistor R1, a resistor R2, a resistor R3, a resistor R4, and a resistor R5;
a switch gating circuit including a switch K1, a switch K2, and a switch K3;
the microprocessor is used for acquiring the total voltage of the system to be tested and the voltage on the resistor R5;
the first end of the resistor R1 is connected with the first end of the resistor R2 and the anode insulation resistor of the system to be tested, and the second end of the resistor R1 is connected with the second end of the resistor R2 and the first end of the resistor R4 through a switch K1;
the first end of the resistor R4 is connected with the first end of the resistor R4 through a switch K2, and the second end of the resistor is connected with the second end of the resistor R3 and the negative insulation resistor of the system to be tested through a resistor R5;
and the connecting point of the resistor R2 and the resistor R4 is connected with the outer shell of the system to be tested.
Preferably, the connection point of the resistor R4 and the resistor R5 is connected with the acquisition end of the microprocessor.
Preferably, the system to be tested is a power battery system.
A detection method adopting the bridge type insulation detection circuit comprises the following steps:
opening a switch K1 and a switch K2, closing a switch K3, and acquiring a potential difference U2 between a positive insulation resistor and a negative insulation resistor of a system to be tested and a voltage drop U1 on a resistor R5 through a microprocessor;
opening a switch K3, closing a switch K1 or a switch K2, and acquiring a potential difference U4 between a positive insulation resistor and a negative insulation resistor of a system to be tested and a voltage drop U3 on a resistor R5 through a microprocessor;
collecting the states of the voltages U1, U2, U3 and U4, and establishing a variance matrix equation, wherein the formula is as follows:
wherein,for a voltage observation matrix, P1,k＝0For the voltage covariance matrix, P1 is U1 variance, P2 is U2 variance, P3 is U3 variance, P4 is U4 variance, and K is the current observation time.
Collecting voltage state update and variance matrix update, wherein the formula is as follows:
wherein QkSystem observer noise;
and calculating Kalman gain and voltage state update, wherein the formula is as follows:
wherein R iskDenotes the measurement variance, y ═ U1U 2U 3U 4]；
The variance is updated, and the formula is as follows:
calculating the insulation resistance:
according to the technical scheme, the switch gating device is controlled, the anode insulation resistance and the cathode insulation resistance of the power battery system are calculated according to the sampling voltage, and in order to eliminate the interference of the disturbance in the voltage acquisition process on the insulation resistance calculation, a KF observer is adopted to eliminate the sampling disturbance, so that the insulation resistance is accurately calculated; the circuit is simple and easy to realize, and has high universality.
Drawings
FIG. 1 is a schematic diagram of a bridge insulation detection circuit according to the present invention.
Detailed Description
A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.
As shown in fig. 1, the bridge insulation detection circuit includes a switch gating circuit, a voltage dividing resistor and a microprocessor.
The voltage division circuit comprises a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a resistor R5, the switch gating circuit comprises a switch K1, a switch K2 and a switch K3, and the microprocessor is used for collecting the total voltage of the system to be tested and the voltage on the resistor R5.
In the embodiment, the system to be tested is a power battery system, and the positive insulation resistance and the negative insulation resistance of the power battery system are calculated according to the sampling voltage.
The power battery system comprises a resistor R1, a switch K1, a resistor R2, a resistor R3, a switch K2, a circuit R4 and a circuit R5, wherein the circuit R2 and the circuit R4 are connected in series and then connected in parallel, the circuit R2 and the circuit R4 are connected in series and then connected to the positive pole and the negative pole of the power battery system, the middle connection point of the R2 and the R4 is connected to the outer shell of the power battery system through a switch K3, and the total pressure of the power battery system and the voltage on the resistor R5 are acquired through an AD.
When the insulation state of the battery system needs to be acquired, the insulation resistance of the system can be obtained only by closing the corresponding switch. In order to avoid the voltage acquisition fluctuation of the MCU caused by the interference of the external environment in the operation process of the power battery system, a Kalman filtering observer (KF) observer is adopted to observe the sampling voltage, and the KF is a high-efficiency recursive filter (autoregressive filter) and can estimate the state of the dynamic system from a series of measurements which do not completely contain noise.
The invention also provides an insulation detection method of the bridge type insulation detection circuit, which comprises the following steps:
s1, opening a switch K1 and a switch K2, closing the switch K3, and acquiring a potential difference U2 between a positive insulation resistor R + and a negative insulation resistor R-of a system to be tested and a voltage drop U1 on a resistor R5 through a microprocessor;
s2, opening a switch K3, closing a switch K1 or a switch K2, and acquiring a potential difference U4 between a positive insulation resistor R + and a negative insulation resistor R-of a system to be tested and a voltage drop U3 on a resistor R5 through a microprocessor;
s3, collecting the states of the voltages U1, U2, U3 and U4, and establishing a variance matrix equation, wherein the formula is as follows:
wherein,for a voltage observation matrix, P1,k＝0For the voltage covariance matrix, P1 is U1 variance, P2 is U2 variance, P3 is U3 variance, P4 is U4 variance, and K is the current observation time.
S4, updating the state of the collected voltage and updating the variance matrix, wherein the formula is as follows:
wherein QkSystem observer noise;
s5, calculating Kalman gain and voltage state update, wherein the formula is as follows:
wherein R iskDenotes the measurement variance, y ═ U1U 2U 3U 4]；
S6, updating the variance, wherein the formula is as follows:
s7, calculating insulation resistance:
in S1, switch K3 is closed, so that the positive insulation resistance R + of the power battery system is connected in parallel with resistance R2, the negative insulation resistance is connected in parallel with the series circuit of R4 and R5, and the voltage difference U2 between the total positive and total negative of the power battery system and the voltage drop U1 across resistance R5 are collected by the MCU. And collecting U2 and U1 in the state, judging whether the circuit has insulation problems currently by judging the sizes of the U1 and U2 values, and using the insulation problems to calculate the insulation resistance subsequently.
And closing a switch K1 or K2 (taking the embodiment as an example of closing K2), and collecting the potential difference U4 between the total positive and total negative of the power battery system and the voltage drop U3 on a resistor R5 through the MCU. And collecting U3 and U4 in the state, and comparing U3 and U4 to determine the positions of the insulation of the positive electrode and the negative electrode and subsequently calculate the insulation resistance value.
The above-mentioned embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements made to the technical solution of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.
Claims (4)
1. A KF observer-based bridge insulation detection circuit, comprising:
a voltage dividing circuit including a resistor R1, a resistor R2, a resistor R3, a resistor R4, and a resistor R5;
a switch gating circuit including a switch K1, a switch K2, and a switch K3;
the microprocessor is used for acquiring the total voltage of the system to be tested and the voltage on the resistor R5;
the first end of the resistor R1 is connected with the first end of the resistor R2 and the anode insulation resistor of the system to be tested, and the second end of the resistor R1 is connected with the second end of the resistor R2 and the first end of the resistor R4 through a switch K1;
the first end of the resistor R4 is connected with the first end of the resistor R4 through a switch K2, and the second end of the resistor is connected with the second end of the resistor R3 and the negative insulation resistor of the system to be tested through a resistor R5;
and the connecting point of the resistor R2 and the resistor R4 is connected with the outer shell of the system to be tested.
2. The bridge insulation detection circuit of claim 1, wherein the connection point of the resistor R4 and the resistor R5 is connected to the acquisition end of the microprocessor.
3. The bridge insulation detection circuit according to claim 1 or 2, wherein the system under test is a power battery system.
4. A method of testing using the bridge insulation test circuit of any of claims 1 to 3, comprising:
opening a switch K1 and a switch K2, closing a switch K3, and acquiring a potential difference U2 between a positive insulation resistor and a negative insulation resistor of a system to be tested and a voltage drop U1 on a resistor R5 through a microprocessor;
opening a switch K3, closing a switch K1 or a switch K2, and acquiring a potential difference U4 between a positive insulation resistor and a negative insulation resistor of a system to be tested and a voltage drop U3 on a resistor R5 through a microprocessor;
collecting the states of the voltages U1, U2, U3 and U4, and establishing a variance matrix equation, wherein the formula is as follows:
wherein,for a voltage observation matrix, P1,k＝0For the voltage covariance matrix, P1 is U1 variance, P2 is U2 variance, P3 is U3 variance, P4 is U4 variance, and K is the current observation time.
Collecting voltage state update and variance matrix update, wherein the formula is as follows:
wherein QkSystem observer noise;
and calculating Kalman gain and voltage state update, wherein the formula is as follows:
wherein R iskDenotes the measurement variance, y ═ U1U 2U 3U 4]；
The variance is updated, and the formula is as follows:
calculating the insulation resistance:
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111722069A (en) * | 2020-06-30 | 2020-09-29 | 蜂巢能源科技有限公司 | Selection method, device, medium and equipment for sampling resistance of insulation detection circuit |
| CN112083299A (en) * | 2020-09-11 | 2020-12-15 | 国网重庆市电力公司北碚供电分公司 | Direct current system insulation fault prediction method based on Kalman filtering |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011021990A (en) * | 2009-07-15 | 2011-02-03 | Yazaki Corp | Insulation state detector |
| KR20130127828A (en) * | 2012-05-15 | 2013-11-25 | 주식회사 엘지화학 | Apparatus and method for measuring isolation resistance of battery using extended kalman filter |
| CN103576064A (en) * | 2013-10-28 | 2014-02-12 | 惠州市亿能电子有限公司 | Insulation detection circuit with calibration module and calibration method thereof |
| CN104635119A (en) * | 2013-11-14 | 2015-05-20 | 北汽福田汽车股份有限公司 | Power system insulation monitoring method and system |
| CN105759207A (en) * | 2016-05-06 | 2016-07-13 | 上海海事大学 | Ocean current generator insulation system failure detecting method based on M-EKF algorithm |
| CN105911353A (en) * | 2016-04-15 | 2016-08-31 | 广州汽车集团股份有限公司 | Automobile insulation resistance detection circuit and method |
| CN107329049A (en) * | 2017-08-21 | 2017-11-07 | 集美大学 | A kind of transmission line of electricity incipient fault detection method based on Kalman filter |
| CN208000342U (en) * | 2018-04-09 | 2018-10-23 | 骆驼集团武汉光谷研发中心有限公司 | A kind of Insulation Inspection Device for Direct-Current System based on nonequilibrium bridge |
-
2019
- 2019-03-26 CN CN201910234209.7A patent/CN109991475B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011021990A (en) * | 2009-07-15 | 2011-02-03 | Yazaki Corp | Insulation state detector |
| KR20130127828A (en) * | 2012-05-15 | 2013-11-25 | 주식회사 엘지화학 | Apparatus and method for measuring isolation resistance of battery using extended kalman filter |
| CN103576064A (en) * | 2013-10-28 | 2014-02-12 | 惠州市亿能电子有限公司 | Insulation detection circuit with calibration module and calibration method thereof |
| CN104635119A (en) * | 2013-11-14 | 2015-05-20 | 北汽福田汽车股份有限公司 | Power system insulation monitoring method and system |
| CN105911353A (en) * | 2016-04-15 | 2016-08-31 | 广州汽车集团股份有限公司 | Automobile insulation resistance detection circuit and method |
| CN105759207A (en) * | 2016-05-06 | 2016-07-13 | 上海海事大学 | Ocean current generator insulation system failure detecting method based on M-EKF algorithm |
| CN107329049A (en) * | 2017-08-21 | 2017-11-07 | 集美大学 | A kind of transmission line of electricity incipient fault detection method based on Kalman filter |
| CN208000342U (en) * | 2018-04-09 | 2018-10-23 | 骆驼集团武汉光谷研发中心有限公司 | A kind of Insulation Inspection Device for Direct-Current System based on nonequilibrium bridge |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111722069A (en) * | 2020-06-30 | 2020-09-29 | 蜂巢能源科技有限公司 | Selection method, device, medium and equipment for sampling resistance of insulation detection circuit |
| CN111722069B (en) * | 2020-06-30 | 2023-09-22 | 蜂巢能源科技股份有限公司 | Insulation detection circuit sampling resistor selection method, device, medium and equipment |
| CN112083299A (en) * | 2020-09-11 | 2020-12-15 | 国网重庆市电力公司北碚供电分公司 | Direct current system insulation fault prediction method based on Kalman filtering |
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