CN115902670A - Insulation detection method, system and equipment based on frequency conversion small signal injection - Google Patents
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Abstract
The invention discloses an insulation detection method, system and equipment based on frequency conversion small signal injection, wherein the method comprises the steps of generating a first sine alternating current voltage signal according to a first frequency, and generating a second sine alternating current voltage signal according to a second frequency; presetting a circuit model in the power battery system, and obtaining a first voltage, a first current and a first phase from the circuit model according to a first sinusoidal alternating-current voltage signal; calculating a first impedance real part; obtaining a second voltage, a second current and a second phase from the circuit model according to the second sinusoidal alternating voltage signal; calculating a second impedance real part; calculating a first equivalent of the real part of the first impedance and a second equivalent of the real part of the second impedance based on the circuit model; and calculating the insulation resistance value of the circuit model according to the first real impedance part, the second real impedance part, the first equivalent value and the second equivalent value. The invention improves the insulation detection speed and can realize insulation detection before high voltage is applied to a power system.
Description
Technical Field
The invention relates to the technical field of insulation detection, in particular to an insulation detection method, system and device based on frequency conversion small signal injection.
Background
The external resistance method is adopted for measuring the insulation resistance of the power battery system, and an unbalanced bridge is often adopted for detection, so that the detection method of the external resistance method has the problems of low detection speed, high cost, incapability of realizing insulation detection before high voltage is applied to a power system and the like, and is influenced by a Y capacitor.
Disclosure of Invention
The present invention is directed to solving at least one of the problems of the prior art. Therefore, the invention provides an insulation detection method, system and equipment based on frequency conversion small signal injection, which can improve the insulation detection speed and realize insulation detection before high voltage is applied to a power system.
In a first aspect, an embodiment of the present invention provides an insulation detection method based on variable frequency small signal injection, where the insulation detection method based on variable frequency small signal injection includes:
generating a first sinusoidal alternating voltage signal according to a first frequency, and generating a second sinusoidal alternating voltage signal according to a second frequency;
presetting a circuit model in a power battery system, and obtaining a first voltage, a first current and a first phase from the circuit model according to the first sinusoidal alternating-current voltage signal;
calculating a first real impedance part according to the first voltage, the first current and the first phase;
obtaining a second voltage, a second current and a second phase from the circuit model according to the second sinusoidal alternating voltage signal;
calculating a second real impedance part according to the second voltage, the second current and the second phase;
calculating a first equivalent of the first real part of impedance and a second equivalent of the second real part of impedance based on the circuit model;
and calculating the insulation resistance value of the circuit model according to the first real impedance part, the second real impedance part, the first equivalent value and the second equivalent value.
Compared with the prior art, the first aspect of the invention has the following beneficial effects:
in order to improve the insulation detection speed, the method comprises the steps of generating a first sinusoidal alternating-current voltage signal according to a first frequency and generating a second sinusoidal alternating-current voltage signal according to a second frequency; presetting a circuit model in the power battery system, and obtaining a first voltage, a first current and a first phase from the circuit model according to a first sinusoidal alternating-current voltage signal; calculating a first real impedance part according to the first voltage, the first current and the first phase; obtaining a second voltage, a second current and a second phase from the circuit model according to the second sinusoidal alternating voltage signal; and calculating a second real impedance part according to the second voltage, the second current and the second phase. In order to enable insulation detection before high voltage on the power system, calculating a first equivalent value of the first real part of impedance and a second equivalent value of the second real part of impedance based on a circuit model; and calculating to obtain the insulation resistance value of the circuit model according to the first impedance real part, the second impedance real part, the first equivalent value and the second equivalent value. The method can improve the insulation detection speed by obtaining the insulation resistance value under the sinusoidal alternating-current voltage signals of the first frequency and the second frequency. According to the method, an external resistor is not needed, the insulation resistance value is obtained only through presetting a circuit model in the power battery system and sine alternating current voltage signals of the first frequency and the second frequency, and insulation detection can be achieved before high voltage is applied to the power battery system. The method does not need to arrange a high-voltage switch, can reduce the cost, adopts an alternating current signal and is not influenced by a Y capacitor.
According to some embodiments of the invention, the obtaining a first voltage, a first current and a first phase from the circuit model from the first sinusoidal alternating voltage signal comprises:
according to the first sinusoidal alternating voltage signal, a first voltage is obtained from the circuit model through a voltage detection module, a first current is obtained from the circuit model through a current detection module, and a first phase is obtained from the circuit model through a phase detection module.
According to some embodiments of the invention, the calculating a first real impedance component from the first voltage, the first current, and the first phase comprises:
calculating a first input impedance from the first voltage and the first current:
wherein Z is 0 Representing said first input impedance, V 0 Representing said first voltage, I 0 Representing the first current;
calculating the first real impedance part according to the first input impedance and the first phase:
Re 0 ＝|Z 0 |×cos(θ 0 )
wherein, re 0 Representing the real part of the first impedance, θ 0 Representing the first phase.
According to some embodiments of the invention, the obtaining a second voltage, a second current and a second phase from the circuit model according to the second sinusoidal alternating voltage signal comprises:
and obtaining a second voltage from the circuit model through a voltage detection module, obtaining a second current from the circuit model through a current detection module and obtaining a second phase from the circuit model through a phase detection module according to the second sinusoidal alternating voltage signal.
According to some embodiments of the invention, the calculating a second real impedance component from the second voltage, the second current, and the second phase comprises:
calculating a second input impedance from the second voltage and the second current:
wherein Z is n Representing said second input impedance, V n Represents the second voltage, I n Represents the second current;
calculating the second real impedance part according to the second input impedance and the second phase:
Re n ＝|Z n |×cos(θ n )
wherein, re n Representing the real part of the second impedance, θ n Representing the second phase.
According to some embodiments of the invention, the calculating a first equivalent of the real part of the first impedance based on the circuit model comprises:
calculating an equivalent value of the first input impedance based on the circuit model by:
wherein the content of the first and second substances,
ω 0 representing angular frequency, ω, at said first frequency 0 ＝2×π×f 0 ω represents angular frequency, C represents capacitance value of capacitor in the circuit model y Representing capacitance value of Y capacitor in the circuit model, R representing insulation resistance value in the circuit model, j representing imaginary part of impedance expression, f 0 Representing the first frequency;
obtaining a first equivalent of the real part of the first impedance from the equivalent of the first input impedance:
according to some embodiments of the invention, the calculating a second equivalent of the real part of the second impedance based on the circuit model comprises:
calculating an equivalent value of the second input impedance based on the circuit model by:
wherein, the first and the second end of the pipe are connected with each other,
ω 0 representing an angular frequency, ω, at said second frequency 0 ＝2×π×f 0 ω represents angular frequency, C represents capacitance value of capacitor in the circuit model y Represents the capacitance value of the capacitor Y in the circuit model, R represents the insulation resistance value in the circuit model, j represents the imaginary part of the impedance expression, and/or>
f n Representing said second frequency, f 0 Representing the second frequency;
obtaining a second equivalent of the real part of the second impedance from the equivalent of the second input impedance:
in a second aspect, an embodiment of the present invention further provides an insulation detection system based on variable frequency small signal injection, where the insulation detection system based on variable frequency small signal injection includes:
the voltage signal generating unit is used for generating a first sine alternating-current voltage signal according to a first frequency and generating a second sine alternating-current voltage signal according to a second frequency;
the first data acquisition unit is used for presetting a circuit model in the power battery system, and acquiring a first voltage, a first current and a first phase from the circuit model according to the first sinusoidal alternating-current voltage signal;
a first real part of impedance calculation unit for calculating a first real part of impedance from the first voltage, the first current, and the first phase;
a second data obtaining unit, configured to obtain a second voltage, a second current, and a second phase from the circuit model according to the second sinusoidal ac voltage signal;
a second real impedance part calculating unit, configured to calculate a second real impedance part according to the second voltage, the second current, and the second phase;
an equivalent value calculation unit for calculating a first equivalent value of the real part of the first impedance and a second equivalent value of the real part of the second impedance based on the circuit model;
and the insulation resistance value acquisition unit is used for calculating the insulation resistance value of the circuit model according to the first impedance real part, the second impedance real part, the first equivalent value and the second equivalent value.
In a third aspect, an embodiment of the present invention further provides an insulation detection device based on variable frequency small signal injection, including at least one control processor and a memory, where the memory is used for being in communication connection with the at least one control processor; the memory stores instructions executable by the at least one control processor to enable the at least one control processor to perform a variable frequency small signal injection based insulation detection method as described above.
In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, where the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are configured to enable a computer to execute the insulation detection method based on variable-frequency small-signal injection as described above.
It is to be understood that the advantageous effects of the second aspect to the fourth aspect compared to the related art are the same as the advantageous effects of the first aspect compared to the related art, and reference may be made to the related description of the first aspect, which is not repeated herein.
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The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
fig. 1 is a flowchart of an insulation detection method based on frequency-conversion small-signal injection according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a circuit model in a power battery system in accordance with an embodiment of the present invention;
fig. 3 is a structural diagram of an insulation detection system based on frequency-conversion small-signal injection according to an embodiment of the present invention.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention and are not to be construed as limiting the present invention.
In the description of the present invention, if there are first, second, etc. described, it is only for the purpose of distinguishing technical features, and it is not understood that relative importance is indicated or implied or the number of indicated technical features is implicitly indicated or the precedence of the indicated technical features is implicitly indicated.
In the description of the present invention, it should be understood that the orientation or positional relationship referred to, for example, the upper, lower, etc., is indicated based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, but does not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention.
In the description of the present invention, it should be noted that unless otherwise explicitly defined, terms such as setup, installation, connection, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention by combining the detailed contents of the technical solutions.
The external resistance method is adopted for measuring the insulation resistance of the power battery system, and an unbalanced bridge is often adopted for detection, so that the detection method of the external resistance method has the problems of low detection speed, high cost, incapability of realizing insulation detection before high voltage is applied to a power system and the like, and is influenced by a Y capacitor.
In order to solve the above problems, the present invention is to improve the insulation detection speed by generating a first sinusoidal ac voltage signal according to a first frequency and generating a second sinusoidal ac voltage signal according to a second frequency; presetting a circuit model in the power battery system, and obtaining a first voltage, a first current and a first phase from the circuit model according to a first sinusoidal alternating-current voltage signal; calculating a first real impedance part according to the first voltage, the first current and the first phase; obtaining a second voltage, a second current and a second phase from the circuit model according to the second sinusoidal alternating voltage signal; and calculating a second real impedance part according to the second voltage, the second current and the second phase. In order to enable insulation detection before high voltage on the power system, calculating a first equivalent value of the first real part of impedance and a second equivalent value of the second real part of impedance based on a circuit model; and calculating to obtain the insulation resistance value of the circuit model according to the first impedance real part, the second impedance real part, the first equivalent value and the second equivalent value. The invention can improve the insulation detection speed by obtaining the insulation resistance value under the sinusoidal alternating-current voltage signals of the first frequency and the second frequency. According to the invention, an external resistor is not needed, and insulation detection can be realized before high voltage is applied to the power battery system by only presetting a circuit model in the power battery system and obtaining the insulation resistance value under the sinusoidal alternating-current voltage signals of the first frequency and the second frequency. The invention does not need to arrange a high-voltage switch, can reduce the cost, and adopts an alternating current signal which is not influenced by a Y capacitor.
Referring to fig. 1, an embodiment of the present invention provides an insulation detection method based on frequency conversion small signal injection, where the insulation detection method based on frequency conversion small signal injection includes, but is not limited to, step S100 to step S700:
step S100, generating a first sinusoidal alternating-current voltage signal according to a first frequency, and generating a second sinusoidal alternating-current voltage signal according to a second frequency;
step S200, presetting a circuit model in the power battery system, and obtaining a first voltage, a first current and a first phase from the circuit model according to a first sinusoidal alternating-current voltage signal;
step S300, calculating a first impedance real part according to the first voltage, the first current and the first phase;
step S400, obtaining a second voltage, a second current and a second phase from a circuit model according to a second sinusoidal alternating current voltage signal;
step S500, calculating a second impedance real part according to the second voltage, the second current and the second phase;
step S600, calculating a first equivalent value of a first impedance real part and a second equivalent value of a second impedance real part based on a circuit model;
step S700, calculating the insulation resistance value of the circuit model according to the first impedance real part, the second impedance real part, the first equivalent value and the second equivalent value.
In steps S100 to S700 of some embodiments, the present embodiment, in order to increase the insulation detection speed, generates a first sinusoidal ac voltage signal according to a first frequency, and generates a second sinusoidal ac voltage signal according to a second frequency; presetting a circuit model in the power battery system, and obtaining a first voltage, a first current and a first phase from the circuit model according to the first sinusoidal alternating-current voltage signal; calculating a first real impedance part according to the first voltage, the first current and the first phase; obtaining a second voltage, a second current and a second phase from the circuit model according to the second sinusoidal alternating voltage signal; and calculating a second real impedance part according to the second voltage, the second current and the second phase. In order to enable insulation detection before high voltage on the power system, calculating a first equivalent value of the first real part of impedance and a second equivalent value of the second real part of impedance based on a circuit model; and calculating to obtain the insulation resistance value of the circuit model according to the first impedance real part, the second impedance real part, the first equivalent value and the second equivalent value. The present embodiment can improve the insulation detection speed by obtaining the insulation resistance value under the sinusoidal alternating-current voltage signals of the first frequency and the second frequency. According to the embodiment, an external resistor is not needed, and insulation detection can be realized before high voltage is applied to the power battery system only by presetting a circuit model in the power battery system and obtaining the insulation resistance value under the sinusoidal alternating voltage signals of the first frequency and the second frequency. This embodiment need not to set up high voltage switch, can reduce cost to what this embodiment adopted is alternating signal, does not receive the Y electric capacity influence.
In some embodiments, obtaining the first voltage, the first current, and the first phase from the circuit model from the first sinusoidal alternating voltage signal comprises:
according to the first sinusoidal alternating voltage signal, a first voltage is obtained from the circuit model through the voltage detection module, a first current is obtained from the circuit model through the current detection module, and a first phase is obtained from the circuit model through the phase detection module.
It should be noted that, the voltage detection module and the current detection module in this embodiment use an ADC (analog-to-digital converter), the first phase may be obtained by the phase detection module, or may be obtained by a phase difference between the first voltage phase and the first current phase, and this embodiment is not limited in particular.
In some embodiments, calculating a first real part of impedance from the first voltage, the first current, and the first phase comprises:
calculating a first input impedance based on the first voltage and the first current:
wherein Z is 0 Representing a first input impedance, V 0 Denotes a first voltage, I 0 Representing a first current;
calculating a first real part of impedance according to the first input impedance and the first phase:
Re 0 ＝|Z 0 |×cos(θ 0 )
wherein, re 0 Representing the real part of the first impedance, θ 0 Representing a first phase.
In some embodiments, obtaining the second voltage, the second current, and the second phase from the circuit model from the second sinusoidal ac voltage signal comprises:
and obtaining a second voltage from the circuit model through the voltage detection module, obtaining a second current from the circuit model through the current detection module and obtaining a second phase from the circuit model through the phase detection module according to the second sinusoidal alternating voltage signal.
It should be noted that, in this embodiment, the second phase may be obtained by the phase detection module, or may be obtained by a phase difference between the second voltage phase and the second current phase, and this embodiment is not limited in particular.
In some embodiments, calculating a second real impedance component from the second voltage, the second current, and the second phase comprises:
calculating a second input impedance based on the second voltage and the second current:
wherein Z is n Representing a second input impedance, V n Denotes a second voltage, I n Representing a second current;
calculating a second real impedance part according to the second input impedance and the second phase:
Re n ＝|Z n |×cos(θ n )
wherein, re n Representing the real part of the second impedance, θ n Representing the second phase.
In some embodiments, calculating a first equivalent of the real part of the first impedance based on the circuit model comprises:
calculating an equivalent value of the first input impedance based on the circuit model by:
wherein, the first and the second end of the pipe are connected with each other,
ω 0 representing angular frequency, ω, at a first frequency 0 ＝2×π×f 0 ω represents angular frequency, C represents capacitance in the circuit model, C y Representing the capacitance value of the Y capacitor, C, in the circuit model y ＝(C′ p +C″ p )//(C′ n +C″ n ) Where Cp denotes a parasitic capacitance between the positive electrode of the battery pack and the ground,// denotes a parallel connection,// denotes an insulation resistance value in the circuit model, j denotes an imaginary part of an impedance expression, and f denotes a parasitic capacitance between the negative electrode of the battery pack and the ground 0 Representing a first frequency;
obtaining a first equivalent value of the real part of the first impedance according to the equivalent value of the first input impedance:
in some embodiments, calculating a second equivalent of the real part of the second impedance based on the circuit model comprises:
calculating an equivalent value of the second input impedance based on the circuit model by:
wherein the content of the first and second substances,
ω 0 representing angular frequency, ω, at a second frequency 0 ＝2×π×f 0 ω represents angular frequency, C represents capacitance in the circuit model, C y Represents the capacitance value of Y capacitor in the circuit model, R represents the insulation resistance value in the circuit model, j represents the imaginary part of the impedance expression, and>
f n representing a second frequency, f 0 Representing a second frequency;
obtaining a second equivalent value of the real part of the second impedance according to the equivalent value of the second input impedance:
to facilitate understanding by those skilled in the art, the following provides a set of preferred embodiments:
referring to fig. 2, a first frequency f is generated in a variable frequency sinusoidal signal generator 0 The first voltage V is obtained from the circuit model by the voltage detection module based on the first sinusoidal ac voltage signal by presetting the circuit model in the power battery system (refer to fig. 2) 0 It can be seen from fig. 2 that one end of the voltage detection module is connected to the left end of the capacitor C in the circuit model, the other end is grounded, and the first current I is obtained from the circuit model through the current detection module 0 As shown in fig. 2, two ends of the current detection module are respectively connected to two ends of the resistor, and the first phase θ is obtained from the circuit model by the phase detection module 0 。
Calculating a first input impedance based on the first voltage and the first current:
wherein Z is 0 Representing a first input impedance, V 0 Denotes a first voltage, I 0 Representing a first current;
calculating a first real impedance part according to the first input impedance and the first phase:
Re 0 ＝|Z 0 |×cos(θ 0 )
wherein, re 0 Representing the real part of the first impedance, θ 0 Representing a first phase.
Switching the first frequency to f 0 Generating a second frequency f in a variable frequency sinusoidal signal generator n Is obtained from the circuit model by the voltage detection module according to the second sinusoidal AC voltage signalA second voltage V n Obtaining a second current I from the circuit model by a current detection module n Obtaining a second phase θ from the circuit model by a phase detection module n 。
Calculating a second input impedance based on the second voltage and the second current:
wherein Z is n Representing a second input impedance, V n Represents a second voltage, I n Represents a second current;
calculating a second real impedance part according to the second input impedance and the second phase:
Re n ＝|Z n |×cos(θ n )
wherein, re n Representing the real part of the second impedance, θ n Representing the second phase.
Based on the circuit model, when at the first frequency f 0 When next, the equivalent value of the first input impedance is calculated by:
wherein the content of the first and second substances,
ω 0 representing angular frequency, ω, at a first frequency 0 ＝2×π×f 0 ω represents angular frequency, C represents capacitance in the circuit model, C y Representing the capacitance value of Y capacitor in the circuit model, R representing the insulation resistance value in the circuit model, j representing the imaginary part of the impedance expression, f 0 Representing a first frequency; />
Obtaining a first equivalent value of the real part of the first impedance according to the equivalent value of the first input impedance:
based on the circuit model, when at the second frequency f n When next, the equivalent value of the second input impedance is calculated by:
wherein the content of the first and second substances,
ω 0 representing angular frequency, ω, at a second frequency 0 ＝2×π×f 0 ω denotes angular frequency, C denotes capacitance in the circuit model, C y Represents the capacitance value of Y capacitor in the circuit model, R represents the insulation resistance value in the circuit model, j represents the imaginary part of the impedance expression, and/or>
f n Representing a second frequency, f 0 Representing a second frequency;
obtaining a second equivalent value of the real part of the second impedance according to the equivalent value of the second input impedance:
combining the calculation equation of the first impedance real part, the second impedance real part, the first equivalent value of the first impedance real part and the second equivalent value of the second impedance real part, and calculating to obtain the insulation resistance value of the circuit model as follows:
it should be noted that, the variable frequency sinusoidal signal generator in this embodiment may adopt PWM modulation or PDM modulation, and this embodiment is not particularly limited. And the circuit model in the preset power battery system can be changed according to actual needs, and the embodiment is not particularly limited.
The insulation resistance value R is calculated by the formula R = (R' p +R″ p )//(R′ n +R″ n ) Wherein Rp represents the insulation resistance between the positive electrode of the battery pack and the ground, rn represents the insulation resistance between the negative electrode of the battery pack and the ground, and there is only one insulation resistance R in the embodiment, so that the circuit model is simplified in the embodiment. In the embodiment, the insulation resistance value can be obtained by switching two sinusoidal alternating-current voltage signals with different frequencies, and the insulation detection speed can be improved. In addition, according to the embodiment, an external resistor is not needed, the insulation resistance value is obtained by presetting a circuit model in the power battery system and switching the sinusoidal alternating-current voltage signals of the first frequency and the second frequency, and insulation detection can be realized before high voltage is applied to the power battery system. This embodiment need not to set up high voltage switch, can reduce cost to what this embodiment adopted is alternating signal, can not receive the Y electric capacity influence.
Referring to fig. 3, an embodiment of the present invention further provides an insulation detection system based on variable frequency small signal injection, and the insulation detection system based on variable frequency small signal injection includes a voltage signal generating unit 100, a first data acquiring unit 200, a first impedance real part calculating unit 300, a second data acquiring unit 400, a second impedance real part calculating unit 500, an equivalent value calculating unit 600, and an insulation resistance value acquiring unit 700, where:
a voltage signal generating unit 100 for generating a first sinusoidal alternating voltage signal according to a first frequency and a second sinusoidal alternating voltage signal according to a second frequency;
a first data obtaining unit 200, configured to preset a circuit model in the power battery system, and obtain a first voltage, a first current, and a first phase from the circuit model according to the first sinusoidal alternating-current voltage signal;
a first real part of impedance calculation unit 300 for calculating a first real part of impedance from the first voltage, the first current, and the first phase;
a second data obtaining unit 400, configured to obtain a second voltage, a second current, and a second phase from the circuit model according to a second sinusoidal ac voltage signal;
a second real impedance part calculation unit 500 for calculating a second real impedance part from the second voltage, the second current, and the second phase;
an equivalent value calculation unit 600 for calculating a first equivalent value of the first real impedance part and a second equivalent value of the second real impedance part based on the circuit model;
the insulation resistance value obtaining unit 700 is configured to calculate an insulation resistance value of the circuit model according to the first real impedance part, the second real impedance part, the first equivalent value, and the second equivalent value.
It should be noted that, since the insulation detection system based on the injection of the frequency conversion small signal in the embodiment is based on the same inventive concept as the insulation detection method based on the injection of the frequency conversion small signal, the corresponding contents in the method embodiment are also applicable to the embodiment of the system, and are not described in detail herein.
The embodiment of the invention also provides insulation detection equipment based on frequency conversion small signal injection, which comprises: at least one control processor and a memory for communicative connection with the at least one control processor.
The memory, which is a non-transitory computer readable storage medium, may be used to store non-transitory software programs as well as non-transitory computer executable programs. Further, the memory may include high speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid state storage device. In some embodiments, the memory optionally includes memory located remotely from the processor, and these remote memories may be connected to the processor through a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.
The non-transitory software program and instructions required to implement a variable frequency small signal injection-based insulation detection method of the above-described embodiments are stored in a memory, and when executed by a processor, perform the variable frequency small signal injection-based insulation detection method of the above-described embodiments, for example, perform the above-described method steps S100 to S700 in fig. 1.
The above described system embodiments are merely illustrative, wherein the units illustrated as separate components may or may not be physically separate, i.e. may be located in one place, or may also be distributed over a plurality of network elements. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
Embodiments of the present invention further provide a computer-readable storage medium, where the computer-readable storage medium stores computer-executable instructions, which, when executed by one or more control processors, may cause the one or more control processors to perform one of the insulation detection methods based on variable frequency small signal injection in the foregoing method embodiments, for example, to perform the functions of the method steps S100 to S700 in fig. 1 described above.
It will be understood by those of ordinary skill in the art that all or some of the steps, systems, and methods disclosed above may be implemented as software, firmware, hardware, or suitable combinations thereof. Some or all of the physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on computer readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). The term computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data, as is well known to those of ordinary skill in the art. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can accessed by a computer. In addition, communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media as known to those skilled in the art.
While the preferred embodiments of the present invention have been described in detail, it will be understood, however, that the invention is not limited to those precise embodiments, and that various other modifications and substitutions may be affected therein by one skilled in the art without departing from the scope of the invention.
Claims (10)
1. An insulation detection method based on frequency conversion small signal injection is characterized in that the insulation detection method based on frequency conversion small signal injection comprises the following steps:
generating a first sinusoidal alternating voltage signal according to a first frequency, and generating a second sinusoidal alternating voltage signal according to a second frequency;
presetting a circuit model in a power battery system, and obtaining a first voltage, a first current and a first phase from the circuit model according to the first sinusoidal alternating-current voltage signal;
calculating a first real impedance part according to the first voltage, the first current and the first phase;
obtaining a second voltage, a second current and a second phase from the circuit model according to the second sinusoidal alternating voltage signal;
calculating a second real impedance part according to the second voltage, the second current and the second phase;
calculating a first equivalent of the first real part of impedance and a second equivalent of the second real part of impedance based on the circuit model;
and calculating the insulation resistance value of the circuit model according to the first real impedance part, the second real impedance part, the first equivalent value and the second equivalent value.
2. The method for insulation detection based on variable frequency small signal injection according to claim 1, wherein the obtaining a first voltage, a first current and a first phase from the circuit model according to the first sinusoidal ac voltage signal comprises:
according to the first sinusoidal alternating voltage signal, a first voltage is obtained from the circuit model through a voltage detection module, a first current is obtained from the circuit model through a current detection module, and a first phase is obtained from the circuit model through a phase detection module.
3. The insulation detection method based on variable-frequency small signal injection according to claim 1, wherein the calculating a first real impedance part according to the first voltage, the first current and the first phase comprises:
calculating a first input impedance from the first voltage and the first current:
wherein, Z 0 Representing said first input impedance, V 0 Representing said first voltage, I 0 Representing the first current;
calculating the first real impedance part according to the first input impedance and the first phase:
Re 0 ＝|Z 0 |×cos(θ 0 )
wherein, re 0 Representing the real part of the first impedance, θ 0 Representing the first phase.
4. The method for insulation detection based on variable-frequency small-signal injection according to claim 1, wherein the obtaining a second voltage, a second current and a second phase from the circuit model according to the second sinusoidal alternating voltage signal comprises:
and obtaining a second voltage from the circuit model through a voltage detection module, obtaining a second current from the circuit model through a current detection module and obtaining a second phase from the circuit model through a phase detection module according to the second sinusoidal alternating voltage signal.
5. The method for detecting insulation based on injection of small variable frequency signals according to claim 1, wherein the calculating a second real impedance part according to the second voltage, the second current and the second phase comprises:
calculating a second input impedance from the second voltage and the second current:
wherein Z is n Representing said second input impedance, V n Represents the second voltage, I n Represents the second current;
calculating the second real impedance part according to the second input impedance and the second phase:
Re n ＝|Z n |×cos(θ n )
wherein, re n Representing the real part of the second impedance, θ n Representing the second phase.
6. The insulation detection method based on variable-frequency small signal injection as claimed in claim 3, wherein the calculating a first equivalent value of the first real impedance part based on the circuit model comprises:
calculating an equivalent value of the first input impedance based on the circuit model by:
wherein, the first and the second end of the pipe are connected with each other,
ω 0 representing angular frequency, ω, at said first frequency 0 ＝2×π×f 0 ω represents angular frequency, C represents capacitance value of capacitance in the circuit model, C y Representing the capacitance value of Y capacitor in the circuit model, R representing the insulation resistance value in the circuit model, j representing the imaginary part of the impedance expression, f 0 Representing the first frequency;
obtaining a first equivalent value of the real part of the first impedance from the equivalent value of the first input impedance:
7. the insulation detection method based on injection of small signals with variable frequency according to claim 5, wherein the calculating the second equivalent value of the second real impedance part based on the circuit model comprises:
calculating an equivalent value of the second input impedance based on the circuit model by:
wherein the content of the first and second substances,
ω 0 representing angular frequency, ω, at said second frequency 0 ＝2×π×f 0 ω represents angular frequency, C represents capacitance value of capacitor in the circuit model y Represents the capacitance value of the capacitor Y in the circuit model, R represents the insulation resistance value in the circuit model, j represents the imaginary part of the impedance expression, and/or>
f n Presentation instrumentThe second frequency, f 0 Representing the second frequency;
obtaining a second equivalent of the real part of the second impedance from the equivalent of the second input impedance:
8. an insulation detection system based on frequency conversion small signal injection, characterized in that the insulation detection system based on frequency conversion small signal injection comprises:
the voltage signal generating unit is used for generating a first sine alternating-current voltage signal according to a first frequency and generating a second sine alternating-current voltage signal according to a second frequency;
the first data acquisition unit is used for presetting a circuit model in a power battery system, and acquiring a first voltage, a first current and a first phase from the circuit model according to the first sinusoidal alternating-current voltage signal;
a first real part of impedance calculation unit for calculating a first real part of impedance from the first voltage, the first current, and the first phase;
a second data obtaining unit, configured to obtain a second voltage, a second current, and a second phase from the circuit model according to the second sinusoidal ac voltage signal;
a second real impedance part calculating unit, configured to calculate a second real impedance part according to the second voltage, the second current, and the second phase;
the equivalent value calculating unit is used for calculating a first equivalent value of the first impedance real part and a second equivalent value of the second impedance real part based on the circuit model;
and the insulation resistance value acquisition unit is used for calculating the insulation resistance value of the circuit model according to the first impedance real part, the second impedance real part, the first equivalent value and the second equivalent value.
9. An insulation detection device based on frequency conversion small signal injection is characterized by comprising at least one control processor and a memory which is in communication connection with the at least one control processor; the memory stores instructions executable by the at least one control processor to enable the at least one control processor to perform the variable frequency small signal injection based insulation detection method of any of claims 1 to 7.
10. A computer-readable storage medium storing computer-executable instructions for causing a computer to perform the method for insulation detection based on variable frequency small signal injection of any one of claims 1 to 7.
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| CN202211245025.9A CN115902670A (en) | 2022-10-12 | 2022-10-12 | Insulation detection method, system and equipment based on frequency conversion small signal injection |
| PCT/CN2023/115800 WO2024078174A1 (en) | 2022-10-12 | 2023-08-30 | Insulation detection method, system and device based on variable-frequency small signal injection |
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| WO2024078174A1 (en) * | 2022-10-12 | 2024-04-18 | 欣旺达动力科技股份有限公司 | Insulation detection method, system and device based on variable-frequency small signal injection |
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| KR101406546B1 (en) * | 2013-05-30 | 2014-06-11 | 공주대학교 산학협력단 | Sinusoidal insulation monitoring apparatus having operation frequency setting function |
| CN206161785U (en) * | 2016-08-31 | 2017-05-10 | 天津市捷威动力工业有限公司 | Insulating detection circuitry of power battery based on small -signal pours into method into |
| CN108802494B (en) * | 2017-05-03 | 2020-03-20 | 华为技术有限公司 | Detection circuit, detection method and device of insulation resistance |
| CN110108940B (en) * | 2018-02-01 | 2021-03-02 | 宁德时代新能源科技股份有限公司 | Battery pack insulation impedance detection method and device |
| CN108445397B (en) * | 2018-02-01 | 2020-08-18 | 宁德时代新能源科技股份有限公司 | Parameter selection method and device for insulation detection circuit and storage medium |
| CN113252980A (en) * | 2021-03-31 | 2021-08-13 | 华为技术有限公司 | Optical storage system and ground insulation impedance detection method |
| CN115902670A (en) * | 2022-10-12 | 2023-04-04 | 欣旺达电动汽车电池有限公司 | Insulation detection method, system and equipment based on frequency conversion small signal injection |
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| WO2024078174A1 (en) * | 2022-10-12 | 2024-04-18 | 欣旺达动力科技股份有限公司 | Insulation detection method, system and device based on variable-frequency small signal injection |
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