CN111913026A - Current detection circuit, current detection method and parameter calibration system of power switch - Google Patents
Current detection circuit, current detection method and parameter calibration system of power switch Download PDFInfo
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- G01R19/0092—Arrangements for measuring currents or voltages or for indicating presence or sign thereof measuring current only
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Abstract
The invention discloses a current detection circuit, a current detection method and a parameter system of a power switch. The current detection circuit includes: the device comprises a power input end, a power output end, a power switch, a voltage detection module, a first temperature detection module and a control module; the first end of the power switch is electrically connected with the power input end, the second end of the power switch is electrically connected with the power output end, and the control end of the power switch is electrically connected with the control module; the voltage detection module is electrically connected with the control module; the first temperature detection module is electrically connected with the control module; the control module is used for calculating the current value flowing through the power switch according to the voltage value detected by the voltage detection module and the temperature value detected by the first temperature detection module. The invention can accurately measure the current value flowing through the power switch under the condition of not increasing extra loss, improves the measured current precision by a corresponding calibration method, and can judge whether the power switch is abnormal or not and implement corresponding protection by adding a circuit and a corresponding diagnosis strategy.
Description
Technical Field
The embodiment of the invention relates to a current detection technology, in particular to a current detection circuit, a current detection method and a parameter calibration system of a power switch.
Background
The circuit has wide application in various industries, the current is used as an important parameter in the circuit, the influence on the stable operation of the circuit is very large, and the sampling of the current in the circuit is more and more important.
In the prior art, when a sampling current is obtained, a sampling resistor or a hall sensor is generally connected in series in a loop. However, the sampling resistor connected in series in the loop will additionally increase the loss of the loop, especially when the current in the loop is large, if the resistance value of the sampling resistor connected in series is large, the loop loss is large, and if the resistance value of the sampling resistor connected in series is small, the measurement accuracy is low; the method of serially connecting the hall sensor in the loop also increases the loss, and if the current induction of the hall sensor is performed by means of the copper bar/wire of the circuit, the sampling speed is slower due to the coupling principle.
Disclosure of Invention
The invention provides a current detection circuit, a current detection method and a parameter calibration system of a power switch, which can accurately measure a current value under the condition of not increasing extra loss.
In a first aspect, an embodiment of the present invention provides a current detection circuit, where the current detection circuit includes: the device comprises a power input end, a power output end, a power switch, a voltage detection module, a first temperature detection module and a control module; the first end of the power switch is electrically connected with the power input end, the second end of the power switch is electrically connected with the power output end, and the control end of the power switch is electrically connected with the control module; the voltage detection module is electrically connected with the control module and is used for detecting a voltage difference value between a first end of the power switch and a second end of the power switch; the first temperature detection module is electrically connected with the control module and is used for detecting the temperature value of the power switch; the control module is used for obtaining a current value flowing through the power switch according to the voltage value detected by the voltage detection module and the temperature value detected by the first temperature detection module.
Optionally, the control module is configured to obtain a current value flowing through the power switch according to the potential of the control end of the power switch, the voltage value detected by the voltage detection module, and the temperature value detected by the first temperature detection module.
Optionally, the current detection circuit further includes a second temperature detection module, and the second temperature detection module is electrically connected to the control module and is configured to detect an ambient temperature;
the control module is used for closing the power switch when the temperature value detected by the first temperature detection module and/or the environment temperature detected by the second temperature detection module is abnormal.
Optionally, the current detection circuit further comprises: the control module is electrically connected with the control end of the power switch through the driving module, and the driving module is used for controlling the state of the power switch according to the signal of the control module.
Optionally, the method further comprises: the protection module is electrically connected with the voltage detection module, the driving module and the control module and is used for outputting a turn-off signal according to a signal of the voltage detection module; the driving module is used for turning off the power switch according to the turn-off signal of the protection module and sending the turn-off signal to the control module.
In a second aspect, an embodiment of the present invention further provides a parameter calibration system for a power switch, configured to calibrate a conduction current of the power switch, where the system includes the current detection circuit, the power supply, the calibration resistor, the load, and the detection device in the first aspect; the power supply is electrically connected with the power input end, the first end of the calibration resistor is electrically connected with the power output end, and the second end of the calibration resistor is electrically connected with the load; the detection device is electrically connected with two ends of the calibration resistor respectively and is used for detecting the value of the current flowing through the calibration resistor.
Optionally, the current detection circuit further includes a second temperature detection module and a storage module, and the second temperature detection module is electrically connected to the control module; the control module is used for obtaining the conduction current of the power switch according to the current value detected by the detection equipment; and correspondingly storing the conduction current of the power switch, the voltage value detected by the voltage detection module, the temperature value detected by the first temperature detection module, the environment temperature and the electric potential of the control end of the power switch.
In a third aspect, an embodiment of the present invention further provides a current detection method, which is performed by the current detection circuit described in the first aspect, and the method includes: the control module controls the power switch to be conducted; the control module obtains a current value flowing through the power switch according to the temperature value detected by the first temperature detection module and the voltage value detected by the voltage detection module.
Optionally, the current detection circuit further comprises: the second temperature detection module is electrically connected with the control module and used for detecting the ambient temperature; the step of obtaining, by the control module, a current flowing through the power switch according to the temperature value detected by the first temperature detection module and the voltage value detected by the voltage detection module includes: the control module obtains a current value flowing through the power switch according to the environment temperature, the temperature value detected by the first temperature detection module and the voltage value detected by the voltage detection module.
Optionally, the method further comprises: calibrating the conducting current of the power switch; the power input end is electrically connected with a power supply, the power output end is electrically connected with a first end of the calibration resistor, and a second end of the calibration resistor is electrically connected with a load; the calibration resistor is electrically connected with detection equipment, and the detection equipment is used for detecting current values at two ends of the calibration resistor; the calibrating the conduction current of the power switch comprises: the control module obtains the conduction current of the power switch according to the current value detected by the detection equipment; and storing the conduction current, the temperature value detected by the first temperature detection module, the environment temperature and the potential of the power switch control end.
According to the technical scheme of the embodiment of the invention, the adopted current detection circuit comprises: the device comprises a power input end, a power output end, a power switch, a voltage detection module, a first temperature detection module and a control module; the first end of the power switch is electrically connected with the power input end, the second end of the power switch is electrically connected with the power output end, and the control end of the power switch is electrically connected with the control module; the voltage detection module is electrically connected with the control module and the power switch and is used for detecting a voltage value between the first end of the power switch and the second end of the power switch; the first temperature detection module is electrically connected with the control module and used for detecting the temperature value of the power switch; the control module is used for obtaining the current value flowing through the power switch according to the voltage value detected by the voltage detection module and the temperature value detected by the first temperature detection module. Because the temperature of the power switch has strong correlation with the conduction internal resistance, the more accurate conduction internal resistance value is obtained through the strategy temperature, and therefore the current value of the loop to be measured can be accurately obtained; especially in the heavy current power return circuit, reduced the degree of difficulty of thermal design, compare the very big reduction extra loss of traditional detection mode.
Drawings
Fig. 1 is a schematic circuit structure diagram of a current detection circuit according to an embodiment of the present invention;
fig. 2 is a schematic circuit diagram of another current detection circuit according to an embodiment of the present invention;
fig. 3 is a schematic circuit diagram of another current detection circuit according to an embodiment of the present invention;
fig. 4 is a schematic circuit diagram of another current detection circuit according to an embodiment of the present invention;
fig. 5 is a schematic circuit diagram of another current detection circuit according to an embodiment of the present invention;
fig. 6 is a schematic circuit diagram of a parameter calibration system according to an embodiment of the present invention;
fig. 7 is a flowchart of a current detection method according to an embodiment of the present invention;
fig. 8 is a flowchart of an operating process of a current 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 not restrictive thereof; 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 circuit structure diagram of a current detection circuit according to an embodiment of the present invention, and referring to fig. 1, the current detection circuit includes: the power control circuit comprises a power input end IN, a power output end OUT, a power switch 101, a voltage detection module 102, a first temperature detection module 103 and a control module 104; a first end of the power switch 101 is electrically connected with a power input end IN, a second end of the power switch 101 is electrically connected with a power output end OUT, and a control end of the power switch 101 is electrically connected with the control module 104; the voltage output by the control module 104 may not meet the turn-on voltage of the power switch 101, and at this time, the control module 104 may output a control signal to the power switch 101 to control the power switch 101 to be turned on; the voltage detection module 102 is electrically connected with the control module 104 and the power switch 101, and is configured to detect a voltage difference between a first end of the power switch 101 and a second end of the power switch 102; the first temperature detection module 103 is electrically connected with the control module 104 and is used for detecting the temperature value of the power switch 101; the control module 104 obtains a current value flowing through the power switch 101 according to the voltage value detected by the voltage detection module 102 and the temperature value detected by the first temperature detection module 103.
Specifically, the current detection circuit can be connected IN series to the loop through the power input terminal IN and the power output terminal OUT, for example, the power input terminal IN can be electrically connected to a power supply, the power output terminal OUT can be electrically connected to a load, the power supply can be, for example, a dc power supply or a battery, and the load can be, for example, a motor or a controller, so that the current detection circuit is used to detect a current value IN the loop, and the state of the loop to be detected can be controlled, for example: an electronic relay is used. The power switch 101 may be a silicon field effect transistor, a silicon carbide field effect transistor, a gallium nitride field effect transistor, or the like. The on-resistance of the power switch 101 is related to the temperature of the power switch 101, and in this embodimentThe temperature value of the power switch 101 can be detected by the first temperature detecting module 103, for example, the first temperature detecting module 103 can be a temperature measuring device such as an NTC/PTC device, which detects the temperature of the power switch 101; a memory may be integrated in the control module 104, and the memory stores a corresponding relationship between the conduction internal resistance of the power switch 101 at the current temperature and the current temperature value; the voltage detection module 102 may be, for example, a voltmeter, and detects a voltage value between the first terminal and the second terminal of the power switch 101, and transmits the voltage value to the control module 104, in some other embodiments, the voltage detection module 102 may further integrate a signal conditioning function, for example, the detected voltage value is amplified, reduced, or impedance-matched and then sent to the control module 104, and the voltage value of the analog quantity is converted into a digital quantity by an analog-to-digital converter inside the control module 104 or an external analog-to-digital converter, and is filtered by N2 times and then stored; the control module 104 receives the temperature value detected by the first temperature detection module 103, so as to obtain the current on-resistance of the power switch 101 according to the corresponding relationship between the on-resistance and the current temperature value, and then according to the condition that I is V/RdsonThe value of the current flowing through the power switch 101 is obtained. Wherein, I is the current flowing through the power switch 101 and the current value of the loop to be detected, V is the voltage value detected by the voltage detection module 102, and R is the voltage valuedsonThe current on internal resistance of the power switch 101.
In the technical solution of this embodiment, the current detection circuit includes: the device comprises a power input end, a power output end, a power switch, a voltage detection module, a first temperature detection module and a control module; the first end of the power switch is electrically connected with the power input end, the second end of the power switch is electrically connected with the power output end, and the control end of the power switch is electrically connected with the control module; the voltage detection module is electrically connected with the control module and the power switch and is used for detecting a voltage value between the first end of the power switch and the second end of the power switch; the first temperature detection module is electrically connected with the control module and used for detecting the temperature value of the power switch; the control module is used for obtaining the current value flowing through the power switch according to the voltage value detected by the voltage detection module and the temperature value detected by the first temperature detection module. The temperature of the power switch has strong correlation with the conduction internal resistance, and the conduction internal resistance obtained through the temperature is more accurate, so that the current value in the loop to be detected can be accurately obtained; especially under heavy current, the difficulty of thermal design has been reduced, compares and to reduce extra loss that traditional detection mode can be very big.
Optionally, fig. 2 is a schematic circuit structure diagram of another current detection circuit provided in an embodiment of the present invention, and referring to fig. 2, the current detection circuit further includes: the second temperature detection module 105, the second temperature detection module 105 is electrically connected with the control module 104, and is used for detecting the ambient temperature; the control module 104 is configured to turn off the power switch when the ambient temperature, the temperature value detected by the first temperature detection module 103, and/or the ambient temperature detected by the second temperature detection module are abnormal.
The risk that power switch all has the damage when ambient temperature is unusual and/or power switch's temperature value is unusual, and in this embodiment, accessible second temperature detection module detects ambient temperature, when control module judges power switch's temperature and ambient temperature in any one unusual, all turn-offs power switch to avoid power switch to damage.
It should be noted that the on-state internal resistance of the power switch 101 has a certain relationship with the ambient temperature of the power switch 101 (e.g., when the current detection circuit is indoors, the ambient temperature is room temperature), in this embodiment, the second temperature detection module 105 may be used to detect the ambient temperature, and the second temperature detection module 105 may be, for example, a temperature measurement device such as NTC/PTC; the memory of the control module 104 stores the corresponding ambient temperature, the temperature value of the power switch and the conduction internal resistance, and the control module obtains the ambient temperature or the temperature value of the power switch to obtain the conduction internal resistance of the power switch; the memory may further store a corresponding relationship between the on-resistance and the temperature of the power switch 101 at the current ambient temperature, for example, the corresponding relationship at the current ambient temperature is RdsonK × T + B, where T is a temperature value of the power switch 101, and values of K and B may be different at different ambient temperatures, and R may be conveniently calculated according to the corresponding relationshipdsonFurther, the value of the current flowing through the power switch 101 is obtained. In this embodiment, the current ambient temperature and the temperature of the power switch 101 can be determinedThe value of the current is used to obtain the on-resistance of the power switch 101, so that the current value can be measured more accurately.
Optionally, the control module 104 is configured to obtain a current value flowing through the power switch 101 according to the potential of the control terminal of the power switch 101, the voltage value detected by the voltage detection module 102, and the temperature value detected by the first temperature detection module 103.
Specifically, the control module 104 can directly detect the potential of the control terminal of the power switch 101, and the on-state internal resistance of the power switch 101 has a certain relationship with the potential of the control terminal of the power switch 101; the memory of the control module 104 may store the corresponding potential of the control terminal of the power switch, the temperature value of the power switch, and the on-resistance in a lookup table manner, and the control module may directly look up the table to obtain the on-resistance of the power switch after obtaining the ambient temperature or the temperature value of the power switch; the memory may further store a corresponding relationship between the on-resistance of the power switch 101 and the temperature value of the power switch 101 at the current potential of the control terminal of the power switch 101, where the corresponding relationship is R at the current ambient temperaturedsonWhen the control terminal of the power switch 101 is different in potential, the values of K and B may be different, and R may be conveniently calculated according to the corresponding relationshipdsonFurther, a current value flowing through the power switch 101 is obtained; thereby making the current value measurement more accurate.
Optionally, fig. 3 is a schematic circuit structure diagram of another current detection circuit according to an embodiment of the present invention, and referring to fig. 3, the current detection circuit further includes a driving module 106, the control module 104 is electrically connected to the power switch 101 through the driving module 106, and the driving module 106 is configured to control a state of the power switch 101 according to a signal of the control module 104.
Specifically, the voltage output by the control module 104 may not satisfy the turn-on voltage of the power switch 101, and at this time, the control module 104 may output a control signal to the driving module 106, and then control the driving module 106 to output the turn-on voltage of the power switch 101, so as to control the turn-on of the power switch 101.
Optionally, fig. 4 is a schematic circuit structure diagram of another current detection circuit according to an embodiment of the present invention, referring to fig. 4, the current detection circuit further includes a protection module 107, where the protection module 107 is electrically connected to the voltage detection module 102, the driving module 106, and the control module, and is configured to output a shutdown signal according to a signal of the voltage detection module 102; the driving module 106 is configured to output a shutdown signal according to the signal of the protection module 107, and send the shutdown signal to the control module.
Specifically, when the current detection circuit works normally, energy output by the power supply is connected to the current detection circuit through the power input end IN, is output to the power output end OUT through the power switch 101, and is finally output to the load; if a load short circuit or overload exists in the circuit to be detected, the power switch 101 is easily damaged if a current exceeding the bearing capacity of the power switch 101 occurs at the moment of starting or in the normal working process. When an abnormal large current exists in the power switch 101, the voltage value detected by the voltage detection module 102 will be abnormally high, if the voltage value is higher than the set value, the protection module 107 will output a turn-off signal to the driving module 106, and at this time, no matter what kind of signal the control module 104 outputs to the driving module 106, the driving module 106 outputs a signal for turning off the power switch 101, thereby ensuring that the power switch is not damaged. When the loop to be detected is normal, the voltage value detected by the voltage detection module 102 is less than or equal to the set value, the protection module 107 does not output the turn-off signal, and the driving module 106 can turn on or turn off the power switch 101 under the control of the control module 104. The protection module 107 may include, for example, a comparator and logic devices that can trigger quickly when a state is abnormal.
The protection module 107 may also be electrically connected to the control module 104 for outputting fault information to the control module 104.
Optionally, fig. 5 is a schematic circuit structure diagram of another current detection circuit provided in an embodiment of the present invention, and referring to fig. 5, the current detection circuit further includes: the control conditioning and communication module 108, the power supply module 109, the control communication connection end a1 and the programming and debugging end a2 are electrically connected to the structure shown in fig. 5, the control communication connection end a1 can be used for receiving an external control signal, control is started when a control signal is input, control is not started when no control signal is input, and control is not started if the time difference between two times of control signal input is too short; meanwhile, the control conditioning and communication module 108 may be configured to communicate with an upper computer to display status information. For example, the working state of the current detection circuit CAN be transmitted to an interface for display through a system bus (CAN, LIN and the like), so that the man-machine interaction is improved, and the state control and the abnormal investigation are facilitated. A program may be written to control module 104 by programming debug port a2 to perform a firmware upgrade on the control module. The power module 109 may be used to provide the power required for operation of the control module 104.
An embodiment of the present invention further provides a parameter calibration system for a power switch, and referring to fig. 6, fig. 6 is a schematic circuit structure diagram of the parameter calibration system provided in the embodiment of the present invention. The parameter calibration system comprises a current sampling circuit, a power supply 201, a calibration resistor 202, a load 203 and a detection device 204, which are provided by any embodiment of the invention; the power supply 201 is electrically connected with the power input end IN, the first end of the calibration resistor 202 is electrically connected with the power output end OUT, and the second end of the calibration resistor 202 is electrically connected with the load 203; the detection device 204 is electrically connected to the calibration resistor 202, and the detection device 204 is used for detecting the value of the current flowing through the calibration resistor 202.
Specifically, the calibration resistor 202 is a precise sampling source, and the detection device 204 may be, for example, an ammeter that connects the ammeter and the calibration resistor 202 in series, so as to obtain an actual current value of the parameter calibration system; the detection device 204 may also be a voltmeter connected in parallel with the calibration resistor 202, and obtains a current value of the parameter calibration system by detecting voltages at two ends of the calibration resistor 202, so as to obtain a current value flowing through the power switch, and correspondingly stores (for example, in the control module or an additionally arranged storage module) a temperature value detected by the first temperature detection module 103, a current value flowing through the power switch, and a voltage value detected by the voltage detection module to complete parameter calibration; in other embodiments, the on-resistance of the power switch 101 at the temperature detected by the first temperature detection module 103 may be obtained by detecting the voltage values of the first end and the second end of the power switch 101 by the voltage detection module 102 and dividing the voltage values by the current value of the parameter calibration system, and the temperature value detected by the first temperature detection module 103, the voltage value detected by the voltage detection module 102, and the on-resistance are stored correspondingly to complete parameter calibration.
Optionally, with continued reference to fig. 6, the current detection circuit further includes a second temperature detection module 105 and a storage module, the second temperature detection module 105 is electrically connected with the control module 104 for detecting the ambient temperature; the control module 104 is configured to calculate an on-current of the power switch 101 according to a resistance value of the calibration resistor 202, a current value detected by the detection device 204, and a voltage value detected by the voltage detection module 102; and correspondingly stores the conduction current, the temperature value detected by the first temperature detection module 103, the ambient temperature and the potential of the control end of the power switch 101.
Specifically, the equivalent resistance of the power switch 101 after being turned on is related to many factors, such as: control terminal potential, ambient temperature, die temperature, etc. In order to accurately reflect the real current value, the external calibration resistor 202 and the detection device 204 measure the accurate current value flowing through the power switch 101, so that the current value flowing through the power switch can be obtained, in addition, the conduction internal resistance of the power switch 101 under different conditions can be obtained through calculation, the conduction internal resistance data table of the power switch 101 is stored in the control module 104 after being corrected, and the calibration process enables the result to be more reliable. It should be noted that multiple calibration can be performed under the same condition, such as by the power supply 201, the calibration resistor 202 and the detection device 204 measuring X sets of voltage values V (the number of the sets is related to the current detection accuracy) under the same environment respectively1X, Current value I1X and synchronously records the voltage value V transmitted by the control module 1042X, Current value I2X; the control communication connection end A1 transmits the related grouping measured data to the control module 104 for storage; the control module 104 calculates an error value between the calibration data and the measured data and couples out compensation parameters in different segments.
Fig. 7 is a flowchart of a current detection method according to an embodiment of the present invention, and referring to fig. 7, the current detection method includes:
step S301, a control module controls a power switch to be conducted;
specifically, the control module may control the power switch to be turned on by outputting a control signal, such as a high-level control signal.
Step S302, the control module obtains a current value flowing through the power switch according to the temperature value detected by the first temperature detection module and the voltage value detected by the voltage detection module.
Specifically, the temperature value of the power switch 101 may be detected by the first temperature detection module 103; a memory may be integrated in the control module 104, and the memory stores the conduction internal resistance of the power switch 101 at the current temperature; the voltage detection module 102 detects a voltage between the first end and the second end of the power switch 101, and transmits the voltage value to the control module 104; the control module 104 receives the temperature value detected by the first temperature detection module 103, so as to obtain the current on-resistance of the power switch 101, and then obtains the current flowing through the power switch 101 according to the condition that I is V/R, where I is also the current value in the loop to be detected. Because the temperature of the power switch 101 has strong correlation with the conduction internal resistance, the conduction internal resistance obtained through the temperature is more accurate, and therefore, the current value in the loop to be detected can be accurately obtained.
Optionally, the current detection circuit further comprises: the second temperature detection module is electrically connected with the control module and is used for detecting the ambient temperature;
the control module obtains the current flowing through the power switch according to the temperature value detected by the first temperature detection module and the voltage value detected by the voltage detection module, and the control module comprises:
the control module obtains current flowing through the power switch according to the environment temperature, the temperature value detected by the first temperature detection module, the potential of the control end of the power switch and the voltage value detected by the voltage detection module.
Specifically, the on-resistance of the power switch 101 has a certain relationship with the ambient temperature of the power switch 101 and the potential of the control terminal of the power switch, and in this embodiment, the second temperature detection module 105 may be used to detect the ambient temperature and the control module 104 may be used to detect the potential of the control terminal of the power switch 101; the control module 104 may obtain a current value flowing through the power switch according to the ambient temperature, the potential of the control terminal of the power switch, the voltage value detected by the voltage detection module, and the temperature value detected by the first temperature detection module. If the memory stores the current environment temperature, the current potential of the power switch control end, the temperature value of the power switch and the conduction internal resistance of the power switch; or the corresponding relation between the current environment temperature, the conduction internal resistance of the power switch 101 at the current potential of the power switch control end and the temperature value is stored, so that more accurate conduction internal resistance can be obtained, and the accuracy of current detection is further improved.
Optionally, the current detection method further comprises: calibrating the conducting current of the power switch;
the power input end is electrically connected with a power supply, the power output end is electrically connected with the first end of the calibration resistor, and the second end of the calibration resistor is electrically connected with a load; the calibration resistor is electrically connected with the detection equipment, and the detection equipment is used for detecting voltage values at two ends of the calibration resistor;
calibrating the conduction current of the power switch comprises:
the control module obtains the conduction current of the power switch according to the current value detected by the detection equipment; and correspondingly storing the conduction current, the temperature value detected by the first temperature detection module, the ambient temperature and the electric potential of the power switch control end.
Specifically, the equivalent resistance of the power switch 101 after being turned on is related to many factors, such as: control terminal potential, ambient temperature, die temperature, etc. In order to accurately reflect the real current value, the external calibration resistor 202 and the detection device 204 measure the accurate current value, the tube core temperature value, the control end potential and the two-end voltage value of the power switch 101, the conduction current of the power switch 101 under different conditions can be obtained through calculation, and the conduction current data table of the power switch 101 is stored in the control module 104 after being corrected, so that the obtained conduction current is more accurate.
Optionally, fig. 8 is a flowchart of an operation process of a current detection circuit according to an embodiment of the present invention, and the operation process with reference to fig. 8 includes: step S401, electrifying the system; the system in this embodiment is a current detection circuit. Step S402, initializing work and starting a timer; the control module 104 starts initialization, such as hardware initialization, configuration parameter initialization, and working state initialization, and starts a timer; then step S425 and step S403 are executed simultaneously; step S425 of determining whether the timer has reached the count time T1, if so, performing step S426, and if not, performing step S425; step S426, automatically uploading system state information; step S403, detecting whether the system voltage, temperature, and storage state are abnormal, if so, executing step S404, otherwise, executing step S419; step S419, uploading real-time state information; storing data required to be stored when power failure occurs; step S404, judging whether an upper computer instruction is received; if yes, executing step S405, if no, executing step S427, determining whether the timer reaches the counting time T2, if yes, executing step S411, if no, executing step S404, that is, determining whether a control command of the upper computer is received within a time period T2; if the command is received, judging that the control communication terminal A1 receives the control signal; and after receiving the judgment signal, sequentially analyzing whether the instruction is a firmware upgrading instruction, whether the instruction is a calibration data instruction, and whether the instruction is a work starting instruction.
Step S405, whether a firmware upgrading instruction is received or not is judged, if yes, step S406 is executed, and if not, step S408 is executed; step S406, analyzing the instruction and upgrading the firmware; step 407, detecting whether the system firmware is updated, if yes, executing step 419;
step S408, whether an instruction of calibrating data is received, if yes, step S409 is executed, and if no, step S411 is executed; step S409, analyzing and prompting to perform calibration work; step S410, detecting whether the updating of the calibration data is finished, if so, executing step S419;
step S411, whether to start a working instruction; if yes, go to step S413; step S413, determining whether the control signal starts to operate, if yes, performing step S414, and if no, performing step S422; step S414, starting the work, and turning on the power switch; then, step S421, step S423 and step S415 are executed simultaneously; step S415, sampling the voltage value and the temperature value in real time; step S416, determining whether the sampled voltage value and temperature value are within a safe range, if yes, performing step S417, and if no, performing step S419; step S417, calculating the current value of the power switch; step S418, determining whether the current exceeds the limit, if not, performing step S413, and if so, performing step S419;
step S423, the timer accumulates working time T3, step S424, determines whether the on-time of the power switch is over-limit, if yes, step S419 is executed, and this embodiment can store state information of the system when the system is abnormally working, i.e. a "black box" function, which is beneficial to obtaining a failure model of the system, analyzing failure causes, and the like; if not, go to step S423; step S422, adopting voltage and temperature signals in real time; step S420, the output is stopped.
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 invention is not limited to the specific embodiments described herein and that various obvious changes, modifications and substitutions are possible, 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 current sense circuit, comprising:
the device comprises a power input end, a power output end, a power switch, a voltage detection module, a first temperature detection module and a control module;
a first end of the power switch is electrically connected with the power input end, and a second end of the power switch is electrically connected with the power output end; the control end of the power switch is electrically connected with the control module;
the voltage detection module is electrically connected with the control module and is used for detecting a voltage difference value between a first end of the power switch and a second end of the power switch;
the first temperature detection module is electrically connected with the control module and is used for detecting the temperature value of the power switch;
the control module obtains a current value flowing through the power switch according to the voltage value detected by the voltage detection module and the temperature value detected by the first temperature detection module.
2. The current sensing circuit of claim 1, further comprising:
the second temperature detection module is electrically connected with the control module and used for detecting the ambient temperature;
the control module is used for closing the power switch when the temperature value detected by the first temperature detection module and/or the environment temperature detected by the second temperature detection module is abnormal.
3. The current detection circuit of claim 1,
the control module is used for obtaining a current value flowing through the power switch according to the electric potential of the control end of the power switch, the voltage value detected by the voltage detection module and the temperature value detected by the first temperature detection module.
4. The current sensing circuit of claim 1, further comprising:
the control module is electrically connected with the control end of the power switch through the driving module, and the driving module is used for controlling the state of the power switch according to the signal of the control module.
5. The current sensing circuit of claim 4, further comprising:
the protection module is electrically connected with the voltage detection module, the driving module and the control module and is used for outputting a turn-off signal according to a signal of the voltage detection module;
the driving module is used for turning off the power switch according to the turn-off signal of the protection module and sending the turn-off signal to the control module.
6. A parameter calibration system for a power switch, for calibrating a conduction current of the power switch, wherein the system comprises the current detection circuit, the power supply, the calibration resistor, the load and the detection device of any one of claims 1 to 5;
the power supply is electrically connected with the power input end, the first end of the calibration resistor is electrically connected with the power output end, and the second end of the calibration resistor is electrically connected with the load;
the detection device is electrically connected with two ends of the calibration resistor respectively and is used for detecting the value of the current flowing through the calibration resistor.
7. The system of claim 6, wherein the current detection circuit further comprises a second temperature detection module and a storage module, the second temperature detection module being electrically connected to the control module for detecting an ambient temperature; the control module is used for obtaining the conduction current of the power switch according to the current value detected by the detection equipment; and correspondingly storing the conduction current of the power switch, the voltage value detected by the voltage detection module, the temperature value detected by the first temperature detection module, the environment temperature and the electric potential of the control end of the power switch.
8. A current sensing method performed by the current sensing circuit of any one of claims 1-5, the method comprising:
the control module controls the power switch to be conducted;
the control module obtains a current value flowing through the power switch according to the temperature value detected by the first temperature detection module and the voltage value detected by the voltage detection module.
9. The current detection method according to claim 8, wherein the current detection circuit further comprises: the second temperature detection module is electrically connected with the control module and used for detecting the ambient temperature;
the step of obtaining, by the control module, a current flowing through the power switch according to the temperature value detected by the first temperature detection module and the voltage value detected by the voltage detection module includes:
the control module obtains current flowing through the power switch according to the environment temperature, the temperature value detected by the first temperature detection module and the voltage value detected by the voltage detection module.
10. The current detection method according to claim 9, further comprising:
calibrating the conducting current of the power switch;
the power input end is electrically connected with a power supply, the power output end is electrically connected with a first end of the calibration resistor, and a second end of the calibration resistor is electrically connected with a load; the calibration resistor is electrically connected with detection equipment, and the detection equipment is used for detecting current values at two ends of the calibration resistor;
the calibrating the conduction current of the power switch comprises:
the control module obtains the conduction current of the power switch according to the current value detected by the detection equipment; and storing the conduction current, the temperature value detected by the first temperature detection module, the environment temperature and the potential of the power switch control end.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN202010768590.8A CN111913026A (en) | 2020-08-03 | 2020-08-03 | Current detection circuit, current detection method and parameter calibration system of power switch |
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| CN202010768590.8A CN111913026A (en) | 2020-08-03 | 2020-08-03 | Current detection circuit, current detection method and parameter calibration system of power switch |
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| CN202010768590.8A Pending CN111913026A (en) | 2020-08-03 | 2020-08-03 | Current detection circuit, current detection method and parameter calibration system of power switch |
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Application publication date: 20201110 |