CN112114250B - Relay state detection circuit and method - Google Patents
Relay state detection circuit and method Download PDFInfo
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- CN112114250B CN112114250B CN202011074788.2A CN202011074788A CN112114250B CN 112114250 B CN112114250 B CN 112114250B CN 202011074788 A CN202011074788 A CN 202011074788A CN 112114250 B CN112114250 B CN 112114250B
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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
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- G01R31/327—Testing of circuit interrupters, switches or circuit-breakers
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Abstract
The embodiment of the invention discloses a relay state detection circuit and a relay state detection method. The relay state detection circuit includes: the circuit comprises a first voltage division module, a second voltage division module, an impedance module, a switch module and a sampling circuit; the input end of the sampling circuit is connected with an electric connection node between the first voltage division module and the second voltage division module, the sampling circuit is used for respectively measuring the voltage on the electric connection node between the first voltage division module and the second voltage division module after the switch module is switched on and switched off, so that the state of the relay is judged according to the voltage on the electric connection node between the first voltage division module and the second voltage division module when the switch module is switched on and the voltage on the electric connection node between the first voltage division module and the second voltage division module when the switch module is switched off; by the technical scheme of the embodiment, the relay state is detected simply and conveniently at low cost.
Description
Technical Field
The embodiment of the invention relates to the technical field of relays, in particular to a relay state detection circuit and a relay state detection method.
Background
Hybrid electric vehicles and energy storage systems typically each include a high voltage battery pack, a relay is connected between the high voltage battery pack and a load to protect the high voltage battery pack, and relay status diagnostics become particularly important as the relay is driven together with the high voltage battery pack.
At present, two methods for detecting the state of a relay are mainly used, one method is to sample the voltages of the front end and the rear end of the relay by two paths of ADCs (Analog-to-Digital converters, sampling circuits), and then compare the voltages of the front end and the rear end of the relay to judge the state of the relay, but the two paths of ADCs are adopted, so that the circuit cost is high, and the occupied resources are more; the other method is to inject voltage from one end of the relay, further detect the loop voltage and realize the state diagnosis of the relay, but the power supply needs to be added when injecting the voltage, which causes high circuit cost and complex circuit.
Disclosure of Invention
The embodiment of the invention provides a relay state detection circuit and a relay state detection method, which are used for realizing simple and low-cost detection of a relay state.
In a first aspect, an embodiment of the present invention provides a relay state detection circuit, where the relay state detection circuit includes: the circuit comprises a first voltage division module, a second voltage division module, an impedance module, a switch module and a sampling circuit;
the first end of the switch module is connected with the first pole of the battery cell and the first end of the relay, the second end of the switch module is connected with the second pole of the battery cell sequentially through the first voltage division module and the second voltage division module, and the second end of the relay is connected with the second pole of the battery cell sequentially through the impedance module, the first voltage division module and the second voltage division module;
the input end of the sampling circuit is connected with an electric connection node between the first voltage division module and the second voltage division module, the sampling circuit is used for measuring the voltage on the electric connection node between the first voltage division module and the second voltage division module after the switch module is switched on and off respectively, and therefore the state of the relay is judged according to the voltage on the electric connection node between the first voltage division module and the second voltage division module when the switch module is switched on and the voltage on the electric connection node between the first voltage division module and the second voltage division module when the switch module is switched off.
Optionally, the sampling circuit is specifically configured to measure voltages at an electrical connection node between the first voltage division module and the second voltage division module after the switch module is turned on and off, and determine a resistance value of the relay according to the voltage at the electrical connection node between the first voltage division module and the second voltage division module when the switch module is turned on and the voltage at the electrical connection node between the first voltage division module and the second voltage division module when the switch module is turned off, so as to determine the state of the relay according to the resistance value of the relay.
Optionally, the impedance module comprises a first resistor, the first voltage division module comprises a second resistor, and the second voltage division module comprises a third resistor;
the first end of the first resistor is connected with the second end of the relay, and the second end of the first resistor is connected with the first end of the second resistor;
and the second end of the second resistor is connected with the first end of the third resistor, and the second end of the third resistor is connected with the second pole of the battery cell.
Optionally, a third voltage dividing module is further included; and the second end of the switch module is connected with the second pole of the battery cell sequentially through the third voltage division module, the first voltage division module and the second voltage division module.
Optionally, the third voltage division module comprises a fourth resistor; the first end of the fourth resistor is connected with the second end of the switch module, and the second end of the fourth resistor is connected with the first voltage division module.
Optionally, the sampling circuit is specifically configured to measure voltages at electrical connection nodes between the first voltage division module and the second voltage division module after the switch module is turned on and off, respectively, so as to determine the state of the relay by determining a ratio of the voltages at the electrical connection nodes between the first voltage division module and the second voltage division module after the switch module is turned on to the voltages at the electrical connection nodes between the first voltage division module and the second voltage division module after the switch module is turned off.
In a second aspect, an embodiment of the present invention further provides a relay state detection method, where the method is performed by any relay state detection circuit in the embodiment of the present invention, and the method includes:
the relay state detection circuit controls the switch module to be switched on or switched off;
the sampling circuit respectively measures the voltage on the electric connection node between the first voltage division module and the second voltage division module after the switch module is switched on and switched off, so that the state of the relay is judged according to the voltage on the electric connection node between the first voltage division module and the second voltage division module when the switch module is switched on and the voltage on the electric connection node between the first voltage division module and the second voltage division module when the switch module is switched off.
Optionally, the determining the state of the relay according to the voltage at the electrical connection node between the first voltage dividing module and the second voltage dividing module when the switch module is turned on and the voltage at the electrical connection node between the first voltage dividing module and the second voltage dividing module when the switch module is turned off includes:
and determining the resistance value of the relay according to the voltage on the electric connection node between the first voltage division module and the second voltage division module when the switch module is switched on and the voltage on the electric connection node between the first voltage division module and the second voltage division module when the switch module is switched off, and judging the state of the relay according to the resistance value of the relay.
Optionally, the resistance value of the relay is R; the R is obtained according to the following formula:
wherein R1 is a resistance value of the first resistor, R2 is a resistance value of the second resistor, R3 is a resistance value of the third resistor, V1 is a voltage at an electrical connection node between the second resistor and the third resistor when the switch module is turned on, and V2 is a voltage at an electrical connection node between the second resistor and the third resistor when the switch module is turned off.
Optionally, the determining the state of the relay according to the voltage includes:
judging the state of the relay by judging the ratio of the voltage on the electric connection node between the first voltage division module and the second voltage division module after the switch module is switched off to the voltage on the electric connection node between the first voltage division module and the second voltage division module after the switch module is switched on;
judging the state of the relay by judging the ratio of the voltage on the electric connection node between the first voltage division module and the second voltage division module after the switch module is turned off to the voltage on the electric connection node between the first voltage division module and the second voltage division module after the switch module is turned on comprises:
if the ratio is equal to zero, judging that the relay is disconnected;
and if the ratio is not equal to zero, judging that the relay is closed or sintered.
The relay state detection circuit provided by the embodiment of the invention can judge the state of the relay according to the voltage on the electric connection node between the first voltage division module and the second voltage division module when the switch module is switched on and the voltage on the electric connection node between the first voltage division module and the second voltage division module when the switch module is switched off only by sampling the voltage on the electric connection node between the first voltage division module and the second voltage division module after the switch module is switched on and switched off by using one sampling circuit, so that the simple detection of the state of the relay is realized.
Drawings
Fig. 1 is a schematic structural diagram of a relay state detection circuit according to an embodiment of the present invention;
FIG. 2 is a specific circuit diagram of a relay status detection circuit according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of another relay status detection circuit according to an embodiment of the present invention;
fig. 4 is a specific circuit diagram of another relay status detection circuit according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.
Fig. 1 is a schematic structural diagram of a relay state detection circuit according to an embodiment of the present invention, and referring to fig. 1, the relay state detection circuit includes: the circuit comprises a first voltage division module 4, a second voltage division module 5, an impedance module 3, a switch module 2 and a sampling circuit 1;
the first end of the switch module 2 is connected with the first pole of the battery cell E and the first end of the relay S, the second end of the switch module 2 is connected with the second pole of the battery cell E sequentially through the first voltage division module 4 and the second voltage division module 5, and the second end of the relay S is connected with the second pole of the battery cell E sequentially through the impedance module 3, the first voltage division module 4 and the second voltage division module 5;
the input end M of the sampling circuit 1 is connected with an electric connection node N between the first voltage division module 4 and the second voltage division module 5, the sampling circuit 1 is used for measuring the voltage on the electric connection node N between the first voltage division module 4 and the second voltage division module 5 after the switch module 2 is switched on and switched off respectively, and the state of the relay S is judged according to the voltage on the electric connection node N between the first voltage division module 4 and the second voltage division module 5 when the switch module 2 is switched on and the voltage on the electric connection node N between the first voltage division module 4 and the second voltage division module 5 when the switch module 2 is switched off.
In this embodiment, the battery cell E may be a battery cell of a high voltage battery pack, for example, the battery pack is a battery pack with a voltage of 0 to 800 v, the first pole of the battery cell E may be a positive pole of the battery cell E, the second pole of the battery cell E is a negative pole of the battery cell E, or the first pole of the battery cell E is a negative pole of the battery cell E, and the second pole of the battery cell E is a positive pole of the battery cell E, where the first pole of the battery cell E is a positive pole of the battery cell E, and the second pole of the battery cell E is a positive pole of the battery cell E in fig. 1. The first voltage division module 4 and the second voltage division module 5 play a role in voltage division when the switch module 2 is switched on or switched off; the first voltage dividing module 4, the second voltage dividing module 5 and the impedance module 3 may be respectively composed of at least one impedance based on a certain electrical connection relationship, and the impedance may include a resistor. The sampling circuit 1 is capable of obtaining a voltage of an electrical connection node N between the first voltage division module 4 and the second voltage division module 5 from an input terminal M thereof, for example, the sampling circuit 1 is an analog/digital converter or an analog-to-digital converter. The switch module 2 may comprise a mechanical switch or an electronic switch.
Referring to fig. 1, when the switch module 2 is turned on, the first voltage division module 4 and the second voltage division module 5 divide voltage, and the sampling circuit 1 obtains a voltage V1 of a node N from an input terminal M thereof, where the voltage V1 of the node N may be regarded as a front end voltage of the relay S; when the switch module 2 is turned off, the impedance module 3, the first voltage division module 4 and the second voltage division module 5 divide voltage, the sampling circuit 1 obtains the voltage V2 of the node N from the input end M of the sampling circuit, and the voltage V2 of the node N can be regarded as the rear end voltage of the relay S; therefore, in the embodiment, only one sampling circuit 1 is sampled, that is, only one sampling channel and one switch module 2 are adopted, and the front end voltage and the rear end voltage of the relay S can be obtained through the on and off of the switch module 2; further, the state of the relay S is judged based on the front end voltage and the rear end voltage of the relay S.
For example, the state of the relay S is judged by comparing the difference between the front end voltage and the rear end voltage of the relay S, and if the difference between the front end voltage and the rear end voltage is large, the relay S is in an off state, and if the difference between the front end voltage and the rear end voltage is small, the relay S is in a closed or sintered state. That is, for example, in the actual working process of the relay S, after the controller issues an instruction to turn off the relay S (or when the operation program of the relay S runs to the turn-off state of the relay S), if the relay S state detection circuit of this embodiment detects that the difference between the front end voltage and the rear end voltage of the relay S is still small, it indicates that the relay S is still in the closed or sintered state rather than turning off following the instruction of the controller (or running to the turn-off state following the program), and at this time, it can be determined that the relay S has a fault and should be overhauled in time to ensure the safety of the high-voltage battery pack. In addition, the state of the relay S can be judged according to the ratio of the front end voltage and the rear end voltage of the relay S; or under the condition that the first voltage division module 4, the second voltage division module 5 and the impedance module 3 are known, the resistance value of the relay S can be determined according to the front end voltage and the rear end voltage of the relay S, and the state of the relay S is judged according to the resistance value of the relay S, so that the relay S can be overhauled in time when in fault, and the safety of the high-voltage battery pack is guaranteed.
In summary, compared with the prior art, the relay state detection circuit provided in the embodiment of the present invention does not need to set at least two sampling circuits 1 and add a power supply, but only uses one sampling channel and only one switch module 2, and simply obtains the front end voltage and the rear end voltage of the relay S through the sampling channel when the switch module 2 is turned on and off, and further determines the state of the relay S according to the front end voltage and the rear end voltage of the relay S.
Optionally, with reference to fig. 1 continuously, the sampling circuit 1 is specifically configured to measure voltages at an electrical connection node N between the first voltage dividing module 4 and the second voltage dividing module 5 after the switch module 2 is turned on and off, and determine a resistance value of the relay S according to the voltage at the electrical connection node N between the first voltage dividing module 4 and the second voltage dividing module 5 when the switch module 2 is turned on and the voltage at the electrical connection node N between the first voltage dividing module 4 and the second voltage dividing module 5 when the switch module 2 is turned off, so as to determine the state of the relay S according to the resistance value of the relay S.
Specifically, in consideration of more accurately judging the state of the relay S, when the front end voltage and the rear end voltage of the relay S are obtained, the resistance value of the relay S can be accurately calculated by using the impedance values or the resistance values of the first voltage division module 4, the second voltage division module 5 and the impedance module 3, that is, the resistance values of the relay S corresponding to a group of the front end voltage and the rear end voltage of the relay S are calculated, so that the state of the relay S can be more accurately judged according to the resistance value of the relay S, and the structure of the relay S state detection circuit is simple based on the embodiment, so that the calculation of the resistance value of the relay S according to the front end voltage and the rear end voltage of the relay S is relatively simple; in this embodiment, the number of impedances or the number of resistors included in the first voltage dividing module 4, the second voltage dividing module 5, and the impedance module 3 is not particularly limited.
Optionally, fig. 2 is a specific circuit diagram of a relay state detection circuit according to an embodiment of the present invention, and referring to fig. 2, the impedance module 3 includes a first resistor r1, the first voltage division module 4 includes a second resistor r2, and the second voltage division module 5 includes a third resistor r3; the first end of the first resistor r1 is connected with the second end of the relay S, and the second end of the first resistor r1 is connected with the first end of the second resistor r 2; the second end of the second resistor r2 is connected to the first end of the third resistor r3, and the second end of the third resistor r3 is connected to the second pole of the battery cell E.
Specifically, in order to further simplify the structure of the relay S state detection circuit, in this embodiment, the impedance module 3 only includes one first resistor r1, the first voltage division module 4 only includes one second resistor r2, and the second voltage division module 5 only includes one third resistor r3, so that an electrical connection point between the second resistor r2 and the third resistor r3 is an electrical connection node N between the first voltage division module 4 and the second voltage division module 5, and a voltage of an electrical connection point between the second resistor r2 and the third resistor r3, which is obtained by the sampling circuit 1 from the input end M thereof, is a voltage of an electrical connection node N between the first voltage division module 4 and the second voltage division module 5.
Referring to fig. 2, when the switch module 2 is turned on, the second resistor r2 and the third resistor r3 divide voltage, and the sampling circuit 1 obtains the voltage V1 of the node N from the input end M thereof, where the voltage V1 of the node N may be regarded as the front end voltage of the relay S; when the switch module 2 is turned off, the first resistor r1, the second resistor r2 and the third resistor r3 divide voltage, the sampling circuit 1 obtains the voltage V2 of the node N from the input end M of the sampling circuit, and the voltage V2 of the node N can be regarded as the rear end voltage of the relay S; therefore, in the embodiment, only one sampling circuit 1 is adopted on the basis of setting the first resistor r1, the second resistor r2 and the third resistor r3, that is, only one sampling channel and one switch module 2 are adopted, and the front end voltage and the rear end voltage of the relay S are simply and conveniently obtained before and after the switch module 2 is turned on and off; furthermore, the state of the relay S is judged according to the front end voltage and the rear end voltage of the relay S, the circuit structure is simpler, and the cost is lower.
The resistance values of the first resistor R1, the second resistor R2, and the third resistor R3 may be in a range of several hundred ohms, and under the condition that the resistance values of the first resistor R1, the second resistor R2, and the third resistor R3 are known, for example, when the resistance value of the first resistor R1 is R1, the resistance value of the second resistor R2 is R2, and the resistance value of the third resistor R3 is R3, and assuming that the voltage of the battery cell E is VB, when the sampling circuit 1 obtains the front end voltage V1 and the rear end voltage V2 of the relay S when the switch module 2 is turned on and off, a mathematical formula for calculating the resistance value R of the relay S may be obtained as follows:
therefore, the state of the relay S can be accurately judged according to the calculated resistance value of the relay S, for example, if R is very large or even close to infinity, the relay S is in a turn-off state, and if R is very small, for example, within a range of several ohms or even close to zero, the relay S is in a closed or sintered state;
wherein, the first and the second end of the pipe are connected with each other,
the relay detection circuit provided by the embodiment of the invention not only adopts one adopting channel and one switch module 2, so that the circuit structure is simple, the cost is low, but also can determine the resistance value of the relay S, so that the state of the relay S is accurately judged according to the resistance value of the relay S, and the method for determining the resistance value of the relay S, namely the calculation formula is simple, and the calculation is convenient and simple.
On the basis of the above scheme, the state detection circuit of the relay provided in this embodiment may include a plurality of voltage division modules and a plurality of impedance modules, and it is ensured that the sampling circuit can acquire the front-end voltage and the rear-end voltage of the relay when the switch module is turned on and off. Optionally, fig. 3 is a schematic structural diagram of another relay state detection circuit provided in the embodiment of the present invention, and referring to fig. 3, the relay state detection circuit further includes a third voltage division module 6; the second end of the switch module 2 is connected with the second pole of the battery cell E sequentially through the third voltage division module 6, the first voltage division module 4 and the second voltage division module 5.
Specifically, referring to fig. 3, when the switch module 2 is turned on, the third voltage division module 6 and the first voltage division module 4 divide the voltage with the second voltage division module 5, and the sampling circuit 1 obtains the voltage V1 of the node N from the input terminal M thereof, where the voltage V1 of the node N may be regarded as the front end voltage of the relay S; when the switch module 2 is turned off, the impedance module 3, the first voltage division module 4 and the second voltage division module 5 divide voltage, the sampling circuit 1 obtains the voltage V2 of the node N from the input end M of the sampling circuit, and the voltage V2 of the node N can be regarded as the rear end voltage of the relay S; therefore, in the embodiment, only one sampling circuit 1 is sampled, that is, only one sampling channel and one switch module 2 are adopted, and the front end voltage and the rear end voltage of the relay S can be obtained through the on and off of the switch module 2; further, the state of the relay S is judged based on the front end voltage and the rear end voltage of the relay S.
Optionally, with reference to fig. 3, the sampling circuit 1 is specifically configured to measure voltages at an electrical connection node N between the first voltage dividing module 4 and the second voltage dividing module 5 after the switch module 2 is turned on and off, respectively, so as to determine the state of the relay S by determining a ratio between the voltages at the electrical connection node N between the first voltage dividing module 4 and the second voltage dividing module 5 after the switch module 2 is turned on and the voltages at the electrical connection node N between the first voltage dividing module 4 and the second voltage dividing module 5 after the switch module 2 is turned off. Specifically, in view of determining the state of the relay S more quickly, the state of the relay S may be determined only by the ratio of the front end voltage and the rear end voltage of the relay S when the front end voltage and the rear end voltage of the relay S are acquired.
Optionally, fig. 4 is a specific circuit diagram of another relay state detection circuit provided in the embodiment of the present invention, and referring to fig. 4, the third voltage dividing module 6 includes a fourth resistor r4; the first end of the fourth resistor r4 is connected with the second end of the switch module 2, and the second end of the fourth resistor r4 is connected with the first voltage division module 4.
For example, under the condition that the resistance values of the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 are known, for example, the resistance value of the first resistor R1 is R1, the resistance value of the second resistor R2 is R2, the resistance value of the third resistor R3 is R3, and the resistance value of the fourth resistor R4 is R4, and assuming that the voltage of the battery cell E is VB and the resistance value of the relay S is R, when the sampling circuit 1 acquires the front end voltage V1 and the rear end voltage V2 of the relay S when the switch module 2 is turned on and off, mathematical formulas for calculating the front end voltage V1 and the rear end voltage V2 can be obtained as follows:
if the relay S is turned off, the resistance value R of the relay S is close to infinity, and the mathematical formulas of the front end voltage V1 and the rear end voltage V2 are further as follows:
V2＝0
if the relay S is closed or sintered, the resistance value R of the relay S is close to zero, and the mathematical formulas of the front end voltage V1 and the rear end voltage V2 are further:
therefore, when the sampling circuit 1 acquires the front end voltage V1 and the rear end voltage V2 of the relay S when the switch module 2 is turned on and off, if the ratio of the rear end voltage V2 to the front end voltage V1 of the relay S is equal to zero, that is, the sampling circuit 1 is capable of obtaining the voltage difference between the front end voltage V1 and the rear end voltage V2 of the relay S when the switch module 2 is turned on and turned off
The relay S is in a turn-off state, if the ratio of the rear end voltage V2 to the front end voltage V1 of the relay S is not equal to zero, namely
The relay S is in a closed or sintered state. The relay S detection circuit provided by the embodiment of the invention not only adopts one adoption channel and one switch module 2, so that the circuit structure is simple, the cost is low, but also the state of the relay S can be rapidly judged according to the ratio of the front end voltage and the rear end voltage of the relay S, and the relay S detection circuit is simple, rapid and convenient to use.
The embodiment of the invention also provides a relay state detection method, which is executed by any relay state detection circuit in the embodiment of the invention and comprises the following steps:
the relay state detection circuit controls the switch module 2 to be switched on or switched off;
the sampling circuit 1 measures the voltage of the electrical connection node N between the first voltage dividing module 4 and the second voltage dividing module 5 after the switch module 2 is turned on and off, so as to judge the state of the relay S according to the voltage of the electrical connection node N between the first voltage dividing module 4 and the second voltage dividing module 5 when the switch module 2 is turned on and the voltage of the electrical connection node N between the first voltage dividing module 4 and the second voltage dividing module 5 when the switch module 2 is turned off.
Specifically, referring to fig. 1, after the relay state detection circuit provided in the foregoing technical solution of this embodiment is connected to the front end and the rear end of the relay S, the switch module 2 is controlled to be turned on, the sampling circuit 1 measures a voltage V1 at an electrical connection node N between the first voltage division module 4 and the second voltage division module 5, that is, a front end voltage of the relay S, and then the switch module 2 is controlled to be turned off, and the sampling circuit 1 measures a voltage V2 at an electrical connection node N between the first voltage division module 4 and the second voltage division module 5, that is, a rear end voltage of the relay S, so that the state of the relay S is determined simply and inexpensively according to the front end voltage and the rear end voltage of the relay S. In addition, in this embodiment, whether the switch module 2 is turned on or off first is not limited, but only that it is ensured that the front end voltage and the rear end voltage of the relay S can be acquired by controlling the switch module 2 to be turned on or off.
Alternatively, referring to fig. 1, determining the state of the relay S according to the voltage at the electrical connection node N between the first voltage dividing module 4 and the second voltage dividing module 5 when the switch module 2 is turned on and the voltage at the electrical connection node N between the first voltage dividing module 4 and the second voltage dividing module 5 when the switch module 2 is turned off includes: the resistance value of the relay S is determined according to the voltage on the electric connection node N between the first voltage division module 4 and the second voltage division module 5 when the switch module 2 is switched on and the voltage on the electric connection node N between the first voltage division module 4 and the second voltage division module 5 when the switch module 2 is switched off, and the state of the relay S is judged according to the resistance value of the relay S.
Alternatively, referring to fig. 2, the resistance of the relay S is R; r is given according to the following formula:
wherein, R1 is a resistance value of the first resistor R1, R2 is a resistance value of the second resistor R2, R3 is a resistance value of the third resistor R3, V1 is a voltage at an electrical connection node N between the second resistor R2 and the third resistor R3 when the switch module 2 is turned on, and V2 is a voltage at an electrical connection node N between the second resistor R2 and the third resistor R3 when the switch module 2 is turned off.
Alternatively, referring to fig. 3 or 4, the judging the state of the relay S according to the voltage includes: judging the state of the relay S by judging the ratio of the voltage on the electric connection node N between the first voltage division module 4 and the second voltage division module 5 after the switch module 2 is switched off to the voltage on the electric connection node N between the first voltage division module 4 and the second voltage division module 5 after the switch module 2 is switched on; through judging electric connection node N voltage on the switch module 2 switches off between first pressure division module 4 and the second pressure division module 5, the ratio of electric connection node N voltage on the switch module 2 switches on between first pressure division module 4 and the second pressure division module 5 and judges that relay S' S state includes: if the ratio is equal to zero, the relay S is judged to be disconnected; and if the ratio is not equal to zero, judging that the relay S is closed or sintered.
The relay state detection method provided by the embodiment of the invention and the relay state detection circuit provided by the embodiment belong to the same inventive concept, can realize the technical effect which is the same as the technical effect realized by the relay state detection circuit, and repeated contents are not repeated.
In the above-mentioned detection of the state of the relay S, the relay S is connected to the positive electrode of the battery cell E, that is, the detection of the state of the relay S in the above-mentioned description of the present embodiment is the detection of the state of the positive electrode relay. The relay state detection circuit provided by the embodiment of the invention can also be used for detecting the state of the negative relay, namely, the state of the relay connected to the negative electrode of the battery cell E can be detected, at the moment, only two ends of the negative relay are required to be connected into any relay state detection circuit provided by the embodiment of the invention, and the relay state detection circuit executes any relay state detection method provided by the embodiment of the invention, so that the technical effect which is the same as the technical effect of detecting the state of the positive relay in the embodiment can be achieved, and repeated contents are not repeated.
It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will appreciate that the present invention is not limited to the particular embodiments described herein, and that various obvious changes, rearrangements and substitutions will now be apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.
Claims (10)
1. A relay state detection circuit, comprising: the circuit comprises a first voltage division module, a second voltage division module, an impedance module, a switch module and a sampling circuit;
a first end of the switch module is connected with a first pole of the battery cell and a first end of the relay, a second end of the switch module is connected with a second pole of the battery cell sequentially through the first voltage division module and the second voltage division module, and a second end of the relay is connected with the second pole of the battery cell sequentially through the impedance module, the first voltage division module and the second voltage division module;
the input end of the sampling circuit is connected with an electric connection node between the first voltage division module and the second voltage division module, the sampling circuit is used for respectively measuring the voltage on the electric connection node between the first voltage division module and the second voltage division module after the switch module is switched on and switched off, so that the state of the relay is judged according to the voltage on the electric connection node between the first voltage division module and the second voltage division module when the switch module is switched on and the voltage on the electric connection node between the first voltage division module and the second voltage division module when the switch module is switched off.
2. The relay state detection circuit according to claim 1,
the sampling circuit is specifically configured to measure voltages at an electrical connection node between the first voltage division module and the second voltage division module after the switch module is turned on and off, and determine a resistance value of the relay according to the voltage at the electrical connection node between the first voltage division module and the second voltage division module when the switch module is turned on and the voltage at the electrical connection node between the first voltage division module and the second voltage division module when the switch module is turned off, so as to determine a state of the relay according to the resistance value of the relay.
3. The relay state detection circuit according to claim 2,
the impedance module comprises a first resistor, the first voltage division module comprises a second resistor, and the second voltage division module comprises a third resistor;
the first end of the first resistor is connected with the second end of the relay, and the second end of the first resistor is connected with the first end of the second resistor;
and the second end of the second resistor is connected with the first end of the third resistor, and the second end of the third resistor is connected with the second pole of the battery cell.
4. The relay state detection circuit according to claim 1, further comprising a third voltage division module;
and the second end of the switch module is connected with the second pole of the battery cell sequentially through the third voltage division module, the first voltage division module and the second voltage division module.
5. The relay state detection circuit according to claim 4, wherein the third voltage division module includes a fourth resistor;
the first end of the fourth resistor is connected with the second end of the switch module, and the second end of the fourth resistor is connected with the first voltage division module.
6. The relay status detection circuit according to claim 4,
the sampling circuit is specifically configured to measure voltages at an electrical connection node between the first voltage division module and the second voltage division module after the switch module is turned on and off, respectively, so as to determine the state of the relay by determining a ratio of the voltages at the electrical connection node between the first voltage division module and the second voltage division module after the switch module is turned on to the voltages at the electrical connection node between the first voltage division module and the second voltage division module after the switch module is turned off.
7. A relay status detection method, performed by the relay status detection circuit of any one of claims 1-6, the method comprising:
the relay state detection circuit controls the switch module to be switched on or switched off;
the sampling circuit respectively measures the voltage on the electric connection node between the first voltage division module and the second voltage division module after the switch module is switched on and switched off, so that the state of the relay is judged according to the voltage on the electric connection node between the first voltage division module and the second voltage division module when the switch module is switched on and the voltage on the electric connection node between the first voltage division module and the second voltage division module when the switch module is switched off.
8. The relay state detection method according to claim 7, wherein determining the state of the relay based on the voltage at the electrical connection node between the first voltage division module and the second voltage division module when the switch module is on and the voltage at the electrical connection node between the first voltage division module and the second voltage division module when the switch module is off comprises:
and determining the resistance value of the relay according to the voltage on the electric connection node between the first voltage division module and the second voltage division module when the switch module is switched on and the voltage on the electric connection node between the first voltage division module and the second voltage division module when the switch module is switched off, and judging the state of the relay according to the resistance value of the relay.
9. The relay state detection method according to claim 8,
the resistance value of the relay is R; the R is obtained according to the following formula:
wherein R1 is a resistance value of a first resistor, R2 is a resistance value of a second resistor, R3 is a resistance value of a third resistor, V1 is a voltage at an electrical connection node between the second resistor and the third resistor when the switch module is turned on, V2 is a voltage at an electrical connection node between the second resistor and the third resistor when the switch module is turned off, and the first resistor is located in the impedance module, the second resistor is located in the first voltage division module, the third resistor is located in the second voltage division module, the first end of the first resistor is connected with the second end of the relay, the second end of the first resistor is connected with the first end of the second resistor, the second end of the second resistor is connected with the first end of the third resistor, and the second end of the third resistor is connected with the second pole of the battery core.
10. The relay state detection method according to claim 8, wherein determining the state of the relay according to the voltage includes:
judging the state of the relay by judging the ratio of the voltage on the electric connection node between the first voltage division module and the second voltage division module after the switch module is switched off to the voltage on the electric connection node between the first voltage division module and the second voltage division module after the switch module is switched on;
judging the state of the relay by judging the ratio of the voltage on the electric connection node between the first voltage division module and the second voltage division module after the switch module is turned off to the voltage on the electric connection node between the first voltage division module and the second voltage division module after the switch module is turned on comprises:
if the ratio is equal to zero, judging that the relay is disconnected;
and if the ratio is not equal to zero, judging that the relay is closed or sintered.
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