CN113394751A - Circuit system and method for realizing vehicle motor driving and self-protection - Google Patents
Circuit system and method for realizing vehicle motor driving and self-protection Download PDFInfo
- Publication number
- CN113394751A CN113394751A CN202110665371.1A CN202110665371A CN113394751A CN 113394751 A CN113394751 A CN 113394751A CN 202110665371 A CN202110665371 A CN 202110665371A CN 113394751 A CN113394751 A CN 113394751A
- Authority
- CN
- China
- Prior art keywords
- motor
- relay
- resistor
- nmos tube
- current
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/08—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for dynamo-electric motors
- H02H7/085—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for dynamo-electric motors against excessive load
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
Abstract
The invention relates to a circuit system for realizing vehicle motor drive and self-protection, which comprises a micro control unit, a first relay, a second relay, an NMOS (N-channel metal oxide semiconductor) tube, a motor, a storage battery, a sampling resistor and a TVS (transient voltage suppressor), wherein the positive and negative rotation directions of the motor are controlled through the first relay and the second relay, the NMOS tube controls the on-off of the current of a loop grounding end of the motor, the micro control unit processes the related control logic of the motor and respectively controls the attraction or the disconnection of the first relay and the second relay through signals, the micro control unit controls the on-off of the NMOS tube through control signals, and the TVS tube performs transient voltage suppression on the drain electrode of the NMOS tube to clamp the voltage to a safe voltage range. The invention also relates to a method for realizing the motor drive and self-protection control for the vehicle. The circuit system and the method for realizing the motor drive and the self-protection for the vehicle can effectively reduce the design cost, greatly prolong the electrical service life of the motor drive circuit and prevent the abnormal connection of the motor interface from damaging the internal circuit.
Description
Technical Field
The invention relates to the field of automobile embedded development, in particular to the field of hardware diagnosis and protection of automobile motor driving circuits, and specifically relates to a circuit system and a method for realizing automobile motor driving and self-protection.
Background
The motor for vehicles, such as a direct current motor for windows, door locks, etc., usually works in a 12V system or a 24V system, and the existing driving circuit technology usually adopts two schemes: 1. the intelligent power device scheme is as follows: the integrated circuit chip is used for realizing the integrated functions of control, diagnosis and protection of the motor drive, has the advantages of high safety and reliability integration level, and has the defects of higher practical application cost and lower upper limit of current driving capability, and the chip voltage resistance limit is only common in a 12V system and has failure risk when being applied to a 24V truck system; 2. the relay scheme is as follows: the H-bridge driving circuit is built through 2 single-pole double-throw relays, and the H-bridge driving circuit has the advantages of simple software control logic, low cost of a 12V system relay and high cost of a 24V system relay; an effective diagnosis protection circuit is lacked, and the risk of adhesion of relay contacts or fuse of fuses exists after the motor interface is short-circuited; in addition, the working current of the motor is large, the reliable electrical service life of the relay is only about 10 ten thousand times, and the mechanical service life of the relay is shortened by more than 5 times.
Nowadays, in the field of automotive electronics, requirements for reliability and cost control of an electronic control unit are higher and higher, and in order to improve market competitiveness, quality three-pack claim mileage and age limit required by various automobile manufacturers for parts are continuously increased, so that if the electronic control unit is short in service life, poor in self-protection capability and high in cost, the electronic control unit is inevitably eliminated in the future competitive development trend.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a circuit system and a method for realizing vehicle motor driving and self-protection, which have the advantages of good reliability, low cost and strong self-protection capability.
In order to achieve the above object, the circuit system and method for realizing the driving and self-protection of the vehicle motor of the present invention are as follows:
the circuit system for realizing the driving and the self-protection of the vehicle motor is mainly characterized by comprising a micro control unit, a first relay, a second relay, an NMOS (N-channel metal oxide semiconductor) tube, a motor, a storage battery, a sampling resistor and a TVS (transient voltage suppressor), wherein the drain electrode of the NMOS tube and a first relay K1And a second relay K2The normally closed contact of (2) is connected, the grid electrode is connected with the micro control unit, the control signal Mos _ Ctrl is received, the source electrode is connected with one end of the sampling resistor, the second analog signal acquisition end of the micro control unit is connected, the other end of the sampling resistor is grounded, one end of the TVS tube is connected with the drain electrode of the NMOS tube, the other end of the TVS tube is grounded, the normally closed contact is connected with the two ends of the motor, and the first relay K is connected with the two ends of the motor1And a second relay K2The normally open contact of the battery is connected with the storage battery,
the micro control unit controls the positive and negative rotation direction of the motor through the first relay and the second relay, the NMOS tube is used for controlling the current on-off of a loop grounding end of the motor, the micro control unit is used for processing control logic related to the motor, the attracting or the disconnection of the first relay and the second relay are respectively controlled through an M + _ Ctrl signal and an M- _ Ctrl signal, the micro control unit controls the connection or the disconnection of the NMOS tube through a control signal Mos _ Ctrl, and the TVS tube carries out transient voltage suppression on a drain electrode of the NMOS tube and clamps the voltage to a safe voltage range.
Preferably, the circuit further comprises a second resistor, a third resistor and a fourth resistor, the drain of the NMOS transistor is connected with one end of the second resistor and one end of the third resistor, the other end of the second resistor is connected with the storage battery, the other end of the third resistor is connected with the first analog signal acquisition end of the micro control unit and is connected with one end of the fourth resistor, and the other end of the fourth resistor is grounded.
Preferably, the first relay and the second relay both include coils, one end of each coil is connected to the storage battery, and the other end of each coil is connected to the micro control unit, and receives control signals M + _ Ctrl and M- _ Ctrl from the micro control unit.
The method for realizing the motor drive and the self-protection control for the vehicle by utilizing the system is mainly characterized by comprising the following steps of:
the micro control unit judges the short circuit or open circuit of the motor interface according to the voltage state of the motor interface in each control time sequence;
the contact adhesion of the relay is prevented by controlling the time sequence of the NMOS tube;
and the micro control unit calculates the time point of the current of the NMOS tube to be disconnected by the system parameters, and carries out overcurrent and overheating protection on the NMOS tube.
Preferably, the step of determining the short circuit or the open circuit of the motor interface specifically includes the following processing steps:
(1-1) the micro control unit judges whether the motor interface is abnormal or not by detecting the voltage value of the first analog signal acquisition end, and if so, the step (1-2) is continued; otherwise, continuing the step (1-3);
(1-2) judging the motor interface voltage V according to a calculation formula of the voltage value of the first analog signal acquisition endMOTORRestoring the initial state to the power supply short circuit or the ground short circuit, and retrying the step (1-1) after timing a certain time;
and (1-3) adjusting the voltage division values of the second resistor, the third resistor and the fourth resistor according to a calculation formula of the voltage value of the first analog signal acquisition end, so that the conventional sampling range of the power supply voltage is within the sampling range of the first analog signal acquisition end.
Preferably, the steps further include the following processes:
(1-4) controlling the relay to be closed, judging whether the voltage value of the first analog signal acquisition end is greater than 4.5V or not, and if so, judging that the circuit state is normal; otherwise, the circuit state is abnormal, fault recording is carried out, the initial state is recovered, and the step (1-1) is retried after timing for a certain time.
Preferably, the step of preventing the relay contact from being stuck by controlling the timing sequence of the NMOS transistor specifically includes the following steps:
after the relay contacts are closed, delaying at least 1 relay contact switching period, and opening an NMOS (N-channel metal oxide semiconductor) tube to conduct the current of the motor loop;
when the motor loop current is closed, the NMOS tube is closed, the motor loop current is cut off, at least 1 relay contact switching period is delayed, and the relay is controlled to be switched off.
Preferably, the step of calculating the time point of the system parameter to turn off the NMOS transistor current specifically includes the following processing steps:
(3-1) acquiring the voltage value of the second analog signal acquisition end at intervals, and calculating the current value I passing through the NMOS tuben；
(3-2) judging the current value I of the NMOS tubenWhether the current is less than the safe working current I of the NMOS tubesIf yes, calculating the time t from starting to shutting off the NMOS tubec(ii) a Judging the current value I of the NMOS tubenWhether the safe working current I is more than or equal to that of the NMOS tubesAnd less than or equal to short circuit judgment threshold current ImaxIf yes, calculating the time t from starting to shutting off the NMOS tubec(ii) a Judging the current value I of the NMOS tubenWhether or not it is larger than the short-circuit judgment threshold current ImaxIf yes, the micro control unit immediately processes through bottom layer interruption, judges that short-circuit protection is achieved, and controls the cut-off current of the NMOS tube;
(3) if the circuit state is overcurrent or short circuit, the time is delayed for a period of time, and the NMOS is conducted again.
Preferably, the step (1-2) of calculating the voltage value of the first analog signal acquisition end when the motor interface is abnormal specifically includes:
calculating the voltage value of the first analog signal acquisition end when the motor interface is abnormal according to the following formula:
wherein, VAD1Is the voltage value, V, of the first analog signal acquisition terminalBATTFor the supply voltage, R2Is the resistance value of the second resistor, R3Is the resistance value of the third resistor, R4Is the resistance of the fourth resistor.
Preferably, the step (1-3) of calculating the voltage value of the first analog signal acquisition end when the motor interface is abnormal specifically includes:
calculating the voltage value of the first analog signal acquisition end when the motor interface is abnormal according to the following formula:
wherein, VAD1Is the voltage value, V, of the first analog signal acquisition terminalMOTORIs the motor interface voltage, R2Is the resistance value of the second resistor, R3Is the resistance value of the third resistor, R4Is the resistance of the fourth resistor.
Preferably, the current value I of the NMOS transistor is calculated in the step (3-2)nWhether the safe working current I is more than or equal to that of the NMOS tubesAnd less than or equal to short circuit judgment threshold current ImaxTime t from start-up to turn-off of NMOS tubecThe method specifically comprises the following steps:
calculating the time t from starting to shutting off of the NMOS tube according to the following formulac：
Wherein K is a heat dissipation dynamic adjustment coefficient, RDS(ON)Is DS on-resistance of MOS, TmaxTo maximum withstanding junction temperature, TroomIs ambient temperature, TRIs the thermal resistivity of MOS.
The circuit system and the method for realizing the motor drive and the self-protection for the vehicle can effectively reduce the design cost, greatly prolong the electrical service life of the motor drive circuit and prevent the abnormal connection of the motor interface from damaging the internal circuit. The invention has the advantage of cost, and simultaneously has the self-protection function of the driving circuit, thereby avoiding the damage of the driving circuit or the fuse fusing caused by the short circuit of the motor interface.
Drawings
Fig. 1 is a schematic circuit diagram of a circuit system for realizing the driving and self-protection of the vehicle motor according to the present invention.
Fig. 2 is a flowchart of a method for implementing the motor driving and self-protection control for the vehicle according to the present invention.
Detailed Description
In order to more clearly describe the technical contents of the present invention, the following further description is given in conjunction with specific embodiments.
Referring to fig. 1, the circuit system for implementing driving and self-protection of a vehicle motor according to the present invention includes a micro control unit, a first relay, a second relay, an NMOS transistor, a motor, a battery, a sampling resistor, and a TVS transistor, wherein a drain of the NMOS transistor and a first relay K are connected to a drain of the NMOS transistor1And a second relay K2The normally closed contact of (2) is connected, the grid electrode is connected with the micro control unit, the control signal Mos _ Ctrl is received, the source electrode is connected with one end of the sampling resistor, the second analog signal acquisition end of the micro control unit is connected, the other end of the sampling resistor is grounded, one end of the TVS tube is connected with the drain electrode of the NMOS tube, the other end of the TVS tube is grounded, the normally closed contact is connected with the two ends of the motor, and the first relay K is connected with the two ends of the motor1And a second relay K2The normally open contact of the battery is connected with the storage battery,
the micro control unit controls the positive and negative rotation direction of the motor through the first relay and the second relay, the NMOS tube is used for controlling the current on-off of a loop grounding end of the motor, the micro control unit is used for processing control logic related to the motor, the attracting or the disconnection of the first relay and the second relay are respectively controlled through an M + _ Ctrl signal and an M- _ Ctrl signal, the micro control unit controls the connection or the disconnection of the NMOS tube through a control signal Mos _ Ctrl, and the TVS tube carries out transient voltage suppression on a drain electrode of the NMOS tube and clamps the voltage to a safe voltage range.
As a preferred embodiment of the present invention, the circuit further includes a second resistor, a third resistor, and a fourth resistor, the drain of the NMOS transistor is connected to one end of the second resistor and one end of the third resistor, the other end of the second resistor is connected to the battery, the other end of the third resistor is connected to the first analog signal acquisition end of the micro control unit, and is also connected to one end of the fourth resistor, and the other end of the fourth resistor is grounded.
As a preferred embodiment of the present invention, the first relay and the second relay each include a coil, one end of the coil is connected to the battery, and the other end of the coil is connected to the micro control unit, and receives the control signals M + _ Ctrl and M- _ Ctrl from the micro control unit.
Referring to fig. 2, the method for implementing vehicle motor driving and self-protection control by using the above system of the present invention includes the following steps:
the micro control unit judges the short circuit or open circuit of the motor interface according to the voltage state of the motor interface in each control time sequence;
the contact adhesion of the relay is prevented by controlling the time sequence of the NMOS tube;
and the micro control unit calculates the time point of the current of the NMOS tube to be disconnected by the system parameters, and carries out overcurrent and overheating protection on the NMOS tube.
As a preferred embodiment of the present invention, the step of determining a short circuit or an open circuit of the motor interface specifically includes the following processing steps:
(1-1) the micro control unit judges whether the motor interface is abnormal or not by detecting the voltage value of the first analog signal acquisition end, and if so, the step (1-2) is continued; otherwise, continuing the step (1-3);
(1-2) judging the motor interface voltage V according to a calculation formula of the voltage value of the first analog signal acquisition endMOTORRestoring the initial state to the power supply short circuit or the ground short circuit, and retrying the step (1-1) after timing a certain time;
and (1-3) adjusting the voltage division values of the second resistor, the third resistor and the fourth resistor according to a calculation formula of the voltage value of the first analog signal acquisition end, so that the conventional sampling range of the power supply voltage is within the sampling range of the first analog signal acquisition end.
(1-4) controlling the relay to be closed, judging whether the voltage value of the first analog signal acquisition end is greater than 4.5V or not, and if so, judging that the circuit state is normal; otherwise, the circuit state is abnormal, fault recording is carried out, the initial state is recovered, and the step (1-1) is retried after timing for a certain time.
As a preferred embodiment of the present invention, the step of preventing the relay contact from being stuck by controlling the timing of the NMOS transistor specifically includes the following steps:
after the relay contacts are closed, delaying at least 1 relay contact switching period, and opening an NMOS (N-channel metal oxide semiconductor) tube to conduct the current of the motor loop;
when the motor loop current is closed, the NMOS tube is closed, the motor loop current is cut off, at least 1 relay contact switching period is delayed, and the relay is controlled to be switched off.
As a preferred embodiment of the present invention, the step of calculating the time point of the system parameter to turn off the NMOS transistor current specifically includes the following processing procedures:
(3-1) acquiring the voltage value of the second analog signal acquisition end at intervals, and calculating the current value I passing through the NMOS tuben；
(3-2) judging the current value I of the NMOS tubenWhether the current is less than the safe working current I of the NMOS tubesIf yes, calculating the time t from starting to shutting off the NMOS tubec(ii) a Judging the current value I of the NMOS tubenWhether the safe working current I is more than or equal to that of the NMOS tubesAnd less than or equal to short circuit judgment threshold current ImaxIf yes, calculating the time t from starting to shutting off the NMOS tubec(ii) a Judging the current value I of the NMOS tubenWhether or not it is larger than the short-circuit judgment threshold current ImaxIf yes, the micro control unit immediately processes through bottom layer interruption, judges that short-circuit protection is achieved, and controls the cut-off current of the NMOS tube; wherein, ImaxIf the current is the short circuit judgment threshold current, the current is cut off immediately if the current exceeds the short circuit judgment threshold current;
(3) if the circuit state is overcurrent or short circuit, the time is delayed for a period of time, and the NMOS is conducted again.
As a preferred embodiment of the present invention, when there is no abnormality in the motor interface in step (1-2), the step of calculating the voltage value of the first analog signal acquisition end specifically includes:
calculating the voltage value of the first analog signal acquisition end when the motor interface is abnormal according to the following formula:
wherein, VAD1Is the voltage value, V, of the first analog signal acquisition terminalBATTFor the supply voltage, R2Is the resistance value of the second resistor, R3Is the resistance value of the third resistor, R4Is the resistance of the fourth resistor.
As a preferred embodiment of the present invention, in the step (1-3), when the motor interface is abnormal, the voltage value of the first analog signal collecting terminal is calculated, specifically:
calculating the voltage value of the first analog signal acquisition end when the motor interface is abnormal according to the following formula:
wherein, VAD1Is the voltage value, V, of the first analog signal acquisition terminalMOTORIs the motor interface voltage, R2Is the resistance value of the second resistor, R3Is the resistance value of the third resistor, R4Is the resistance of the fourth resistor.
As a preferred embodiment of the present invention, in the step (3-2), the current value I of the NMOS transistor is calculatednWhether the safe working current I is more than or equal to that of the NMOS tubesAnd less than or equal to short circuit judgment threshold current ImaxTime t from start-up to turn-off of NMOS tubecThe method specifically comprises the following steps:
calculating the time t from starting to shutting off of the NMOS tube according to the following formulac：
Wherein K is a heat dissipation dynamic adjustment coefficient, RDS(ON)Is DS on-resistance of MOS, TmaxTo maximum withstanding junction temperature, TroomIs ambient temperature, TRIs the thermal resistivity of MOS.
In a specific embodiment of the present invention, the motor driving circuit includes a micro control unit MCU, a relay unit, and an N-channel MOSFET, and the self-protection system includes: MCU, current diagnostic circuit, motor interface voltage detection circuit, overvoltage crowbar. The method comprises the following steps:
method 1, a method for realizing short circuit and open circuit diagnosis through voltage states of a motor interface in each control time sequence;
method 2, a method for preventing relay contact adhesion by specific logic control time sequence of NMOS;
Fig. 1 shows a motor driving circuit and a corresponding self-protection circuit, and fig. 2 shows a driving circuit working logic, which includes 3 self-protection methods. In the description of the invention and the accompanying drawings, the MCU refers to a Micro Controller Unit, namely a Micro control Unit; BATT refers to Battery, i.e., a storage Battery; AD refers To Analog To Digital, i.e., the amount of Analog To Digital signals; the NMOS refers to an N-Channel MOSFET, namely an N-Channel MOSFET; t isRThermal Resistance, i.e., Thermal Resistance; rDS(ON)Refer to Drain-to-Source On Resistance, DS On Resistance.
The system circuit connection mode of the present invention is shown in fig. 1, and the related driving circuit passes through a first relay K1And a second relay K2Build an H-bridge circuit and control a motor M1The direction is rotated positively and negatively; NMOS tube Q1The current on-off control circuit is used for controlling the current on-off of the grounding end of the whole motor loop; MCU-U1Processing the control logic related to the motor, and respectively controlling the first relay K through M + _ Ctrl and M- _ Ctrl signals1And a second relay K2Closing or opening, and Mos _ Ctrl controls the NMOS tube Q1Conducting or disconnecting, and acquiring 0-5V analog signals through AD1 and AD2 to obtain key data of a protection algorithm; TVS tube D1For NMOS tube Q1The D terminal of (1) performs transient voltage suppression to clamp the voltage to a safe voltage range.
In the normal initial state (the motor interface has no short circuit or abnormal connection), the NMOS tube Q1End D and first relay K1And a second relay K2The normally closed contact is connected with an external Motor + and a Motor-simultaneously; first relay K1And a second relay K2The normally open contact of (3) is connected with BATT; one end of the relay coil is connected with BATT, and the other end is connected with MCU-U1The control signals M + _ Ctrl and M- _ Ctrl are connected; NMOS tube Q1The G end of the NMOS tube Q is connected with the MCU control signal Mos _ Ctrl1S terminal and sampling resistor R1One end is connected with the MCU-AD2 port; r1The other end is connected with the ground; TVS tube D1One end of the NMOS tube Q1The end D is connected with the ground, and the other end of the D is connected with the ground; r2One end is connected with BATT, and the other end is connected with NMOS tube Q1Is connected to the D terminal of R3Are connected at one end to R3Is connected with the MCU-AD1 and is simultaneously connected with R4Are connected at one end to R4The other end of which is connected to ground.
The self-protection method 1 is a software control strategy, the MCU judges whether a motor interface is abnormal or not by detecting the voltage value of the AD1, and V is detected because the NMOS is not openedAD1Not in a grounded state;
when the interface of the motor is not abnormal,
wherein VBATTFor supply voltage, if the selected MCU is paired with VAD1The sampling range of the port is 0-5V (the sampling range is related to the MCU power supply voltage, the conventional voltage is 3.3V or 5V), R2、R3、R4For dividing the resistance, V is limited by reasonable voltage dividing valueAD1Corresponds to VBATTIs located at VAD1The port is within a sampling range (a typical range is 1.5V to 3.5V) and there is enough voltage interval to distinguish the full bias.
When the motor interface is shorted to power or ground,
if V is detectedAD1If the voltage is more than 4.5V, the motor interface voltage V is judgedMOTORFor power supply short circuit, if V is detectedAD1Less than 0.5V, determining the voltage V of the motor interfaceMOTORAnd (4) short circuit to the ground, and the software system returns to the initial state after recording the short circuit event and counts a certain time to allow retry.
In the logic, if the motor interface judges that no abnormity exists and the relay is controlled to be closed, VMOTORIs close to VBATTThe software judges according to formula 2 when VAD1If the voltage is more than 4.5V, the voltage is a correct value, otherwise, the voltage is judged to be abnormal, fault records are made, the initial state is recovered, and retry is allowed after a certain time is timed.
The self-protection method 2 is a control sequence of the MCU, is used for preventing the relay contact from being adhered, and comprises the following two points: 1. the NMOS must be turned on to turn on the current of the motor loop by delaying at least 1 switching cycle (typically 10ms) after the relay contacts are closed. 2. When the motor loop current is closed, the NMOS is closed firstly, the motor loop current is cut off, and then the relay is controlled to be switched off after at least 1 relay contact switching period is delayed.
The self-protection method 3 is a software control algorithm and strategy, and the MCU calculates the time point of the system for disconnecting the NMOS current according to system parameters to prevent the NMOS from being damaged by overheating. The specific algorithm and strategy are as follows:
(1) the AD2 voltage V is collected once every a period of timeAD2Calculating the value of the current through the NMOS
(2) Assuming that the safe working current of NMOS in the full temperature range is IsWhen I isn<IsWhen the NMOS is turned on to be turned off for time tc＝tmax(typical value is 8 seconds after start-up).
(3) When I iss≤In≤ImaxTime, calculate
K is a heat dissipation dynamic adjustment coefficient and needs to be calibrated according to the number of layers of the PCB and the heat dissipation condition; tmax is the highest tolerated junction temperature (typically 175 ℃); troom is the environmental temperature (usually set according to the highest test requirement of the product requirement, and the typical value of the automobile part is 85 ℃); t isRIs the thermal resistivity of MOS; rDS(ON)Is the DS on-resistance of the MOS. When the detected current is continuously in the interval and the accumulated time exceeds tcAnd when the current is detected, the MCU judges that the current is overcurrent protection and controls the NMOS to cut off the current.
(4) When I isn＞ImaxAnd meanwhile, the MCU immediately processes the interruption of the bottom layer, judges the short-circuit protection is carried out, and controls the NMOS to cut off the current.
(5) Once it is judged that the current is over-current or short-circuit, it needs to be delayed for a period of time tint(typically 30 seconds) to allow the NMOS to turn on again.
In the invention, the relay contact is protected by the self-protection method 1, the self-protection method 2 and the switching characteristic of the NMOS, and the self-protection method 3 protects the NMOS from being damaged in overcurrent and short circuit. Therefore, the invention can effectively prolong the service life of the easily damaged relay contact in the motor driving circuit and also ensure that the NMOS can still recover to work normally after passing through extreme working conditions.
The invention can greatly prolong the electric service life of the motor driving circuit and prevent the abnormal connection of the motor interface from damaging the internal circuit while effectively reducing the design cost. Taking only one automobile part as an example, the annual output is 10 ten thousand, the selling price is 500 yuan, the three-pack claim rate is 3-fold selling price, and the claim rate caused by the motor control circuit fault before the technical improvement is 1%, so that the claim amount generated in one year is 100000 × 500 × 0.01 × 3-150 ten thousand. After the technology of the invention is improved, the claim rate caused by the motor fault is reduced by 0.01%, and the claim amount generated in one year is 100000 multiplied by 500.0001 multiplied by 3 which is 1.5 ten thousand, and the economic benefit is 148.5 ten thousand.
The circuit system and the method for realizing the motor drive and the self-protection for the vehicle can effectively reduce the design cost, greatly prolong the electrical service life of the motor drive circuit and prevent the abnormal connection of the motor interface from damaging the internal circuit. The invention has the advantage of cost, and simultaneously has the self-protection function of the driving circuit, thereby avoiding the damage of the driving circuit or the fuse fusing caused by the short circuit of the motor interface.
In this specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.
Claims (11)
1. The utility model provides a realize circuit system of automobile-used motor drive and self preservation protection which characterized in that, the system include little the control unit, first relay, second relay, NMOS pipe, motor, battery, sampling resistor, TVS pipe, the drain electrode of NMOS pipe and first relay K1And a second relay K2The normally closed contact of (2) is connected, the grid electrode is connected with the micro control unit, the control signal Mos _ Ctrl is received, the source electrode is connected with one end of the sampling resistor, the second analog signal acquisition end of the micro control unit is connected, the other end of the sampling resistor is grounded, one end of the TVS tube is connected with the drain electrode of the NMOS tube, the other end of the TVS tube is grounded, the normally closed contact is connected with the two ends of the motor, and the first relay K is connected with the two ends of the motor1And a second relay K2The normally open contact of the battery is connected with the storage battery,
the micro control unit controls the positive and negative rotation direction of the motor through the first relay and the second relay, the NMOS tube is used for controlling the current on-off of a loop grounding end of the motor, the micro control unit is used for processing control logic related to the motor, the attracting or the disconnection of the first relay and the second relay are respectively controlled through an M + _ Ctrl signal and an M- _ Ctrl signal, the micro control unit controls the connection or the disconnection of the NMOS tube through a control signal Mos _ Ctrl, and the TVS tube carries out transient voltage suppression on a drain electrode of the NMOS tube and clamps the voltage to a safe voltage range.
2. The circuit system for realizing motor drive and self-protection for the vehicle as claimed in claim 1, wherein the circuit further comprises a second resistor, a third resistor and a fourth resistor, the drain of the NMOS transistor is connected to one end of the second resistor and one end of the third resistor, the other end of the second resistor is connected to the battery, the other end of the third resistor is connected to the first analog signal acquisition end of the micro control unit and is connected to one end of the fourth resistor, and the other end of the fourth resistor is grounded.
3. The circuit system for realizing the driving and self-protection of the vehicle motor according to claim 1, wherein the first relay and the second relay each include a coil, one end of the coil is connected to the battery, the other end of the coil is connected to the micro control unit, and the coil receives the control signals M + Ctrl and M _ Ctrl from the micro control unit.
4. A method for implementing motor drive and self-protection control for a vehicle based on the circuit system of claim 1, wherein the method comprises the following steps:
the micro control unit judges the short circuit or open circuit of the motor interface according to the voltage state of the motor interface in each control time sequence;
the contact adhesion of the relay is prevented by controlling the time sequence of the NMOS tube;
and the micro control unit calculates the time point of the current of the NMOS tube to be disconnected by the system parameters, and carries out overcurrent and overheating protection on the NMOS tube.
5. The method as claimed in claim 4, wherein the step of determining whether the motor interface is short-circuited or open-circuited includes the following steps:
(1-1) the micro control unit judges whether the motor interface is abnormal or not by detecting the voltage value of the first analog signal acquisition end, and if so, the step (1-2) is continued; otherwise, continuing the step (1-3);
(1-2) judging the motor interface voltage V according to a calculation formula of the voltage value of the first analog signal acquisition endMOTORShort-circuiting the power supply or the ground to restore the originalRetrying the step (1-1) after timing a certain time;
and (1-3) adjusting the voltage division values of the second resistor, the third resistor and the fourth resistor according to a calculation formula of the voltage value of the first analog signal acquisition end, so that the conventional sampling range of the power supply voltage is within the sampling range of the first analog signal acquisition end.
6. The method for realizing motor drive and self-protection control for vehicle according to claim 5, wherein said steps further comprise the following processes:
(1-4) controlling the relay to be closed, judging whether the voltage value of the first analog signal acquisition end is greater than 4.5V or not, and if so, judging that the circuit state is normal; otherwise, the circuit state is abnormal, fault recording is carried out, the initial state is recovered, and the step (1-1) is retried after timing for a certain time.
7. The method as claimed in claim 4, wherein the step of preventing the relay contact from being stuck by controlling the timing of the NMOS transistor includes the following steps:
after the relay contacts are closed, delaying at least 1 relay contact switching period, and opening an NMOS (N-channel metal oxide semiconductor) tube to conduct the current of the motor loop;
when the motor loop current is closed, the NMOS tube is closed, the motor loop current is cut off, at least 1 relay contact switching period is delayed, and the relay is controlled to be switched off.
8. The method as claimed in claim 4, wherein the step of calculating the time point of the NMOS transistor current disconnection by calculating the system parameter includes the following steps:
(3-1) acquiring the voltage value of the second analog signal acquisition end at intervals, and calculating the current value I passing through the NMOS tuben；
(3-2) judging the current value I of the NMOS tubenWhether the current is less than the safe working current I of the NMOS tubesAnd if so, the mobile phone can be used for,calculating the time t from the start-up to the turn-off of the NMOS tubec(ii) a Judging the current value I of the NMOS tubenWhether the safe working current I is more than or equal to that of the NMOS tubesAnd less than or equal to short circuit judgment threshold current ImaxIf yes, calculating the time t from starting to shutting off the NMOS tubec(ii) a Judging the current value I of the NMOS tubenWhether or not it is larger than the short-circuit judgment threshold current ImaxIf yes, the micro control unit immediately processes through bottom layer interruption, judges that short-circuit protection is achieved, and controls the cut-off current of the NMOS tube;
(3) if the circuit state is overcurrent or short circuit, the time is delayed for a period of time, and the NMOS is conducted again.
9. The method for realizing motor drive and self-protection control for the vehicle according to claim 5, wherein the step (1-2) of calculating the voltage value of the first analog signal acquisition terminal when the motor interface is abnormal specifically comprises:
calculating the voltage value of the first analog signal acquisition end when the motor interface is abnormal according to the following formula:
wherein, VAD1Is the voltage value, V, of the first analog signal acquisition terminalBATTFor the supply voltage, R2Is the resistance value of the second resistor, R3Is the resistance value of the third resistor, R4Is the resistance of the fourth resistor.
10. The method for realizing vehicle motor drive and self-protection control according to claim 5, wherein the step (1-3) of calculating the voltage value of the first analog signal acquisition terminal when the motor interface is abnormal specifically comprises:
calculating the voltage value of the first analog signal acquisition end when the motor interface is abnormal according to the following formula:
wherein, VAD1Is the voltage value, V, of the first analog signal acquisition terminalMOTORIs the motor interface voltage, R2Is the resistance value of the second resistor, R3Is the resistance value of the third resistor, R4Is the resistance of the fourth resistor.
11. The method for implementing motoring and self-protection control of a vehicle as claimed in claim 8, wherein the current value I of the NMOS transistor is calculated in the step (3-2)nWhether the safe working current I is more than or equal to that of the NMOS tubesAnd less than or equal to short circuit judgment threshold current ImaxTime t from start-up to turn-off of NMOS tubecThe method specifically comprises the following steps:
calculating the time t from starting to shutting off of the NMOS tube according to the following formulac：
Wherein K is a heat dissipation dynamic adjustment coefficient, RDS(ON)Is DS on-resistance of MOS, TmaxTo maximum withstanding junction temperature, TroomIs ambient temperature, TRIs the thermal resistivity of MOS.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110665371.1A CN113394751B (en) | 2021-06-16 | 2021-06-16 | Circuit system and method for realizing vehicle motor driving and self-protection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110665371.1A CN113394751B (en) | 2021-06-16 | 2021-06-16 | Circuit system and method for realizing vehicle motor driving and self-protection |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113394751A true CN113394751A (en) | 2021-09-14 |
| CN113394751B CN113394751B (en) | 2022-10-25 |
Family
ID=77621426
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110665371.1A Active CN113394751B (en) | 2021-06-16 | 2021-06-16 | Circuit system and method for realizing vehicle motor driving and self-protection |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113394751B (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101087125A (en) * | 2007-06-25 | 2007-12-12 | 中国科学院电工研究所 | An electromotor drive system of electromotive motorcar with life prediction function |
| CN105655984A (en) * | 2016-03-28 | 2016-06-08 | 广州七喜智能设备有限公司 | Over-temperature protection method for IGBT in frequency converter |
| CN106443400A (en) * | 2016-09-14 | 2017-02-22 | 河北工业大学 | Electric-heat-aging junction temperature calculation model establishing method of IGBT module |
| CN106896755A (en) * | 2015-12-18 | 2017-06-27 | 联创汽车电子有限公司 | The load driving circuits of automobile-used single low side control |
| CN107025364A (en) * | 2017-05-12 | 2017-08-08 | 西安交通大学 | A kind of junction temperature Forecasting Methodology of IGBT module |
| CN107993891A (en) * | 2017-12-31 | 2018-05-04 | 昌辉汽车电气系统（安徽）有限公司 | The protection circuit and method of a kind of relay contact in electric machine control system |
| CN207426963U (en) * | 2017-10-09 | 2018-05-29 | 北京亿华通科技股份有限公司 | Separate parallel driver circuit |
| CN108695833A (en) * | 2018-06-30 | 2018-10-23 | 昌辉汽车电气系统（安徽）有限公司 | Vehicle-mounted relay protection control circuit in 24V bodywork systems and method |
-
2021
- 2021-06-16 CN CN202110665371.1A patent/CN113394751B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101087125A (en) * | 2007-06-25 | 2007-12-12 | 中国科学院电工研究所 | An electromotor drive system of electromotive motorcar with life prediction function |
| CN106896755A (en) * | 2015-12-18 | 2017-06-27 | 联创汽车电子有限公司 | The load driving circuits of automobile-used single low side control |
| CN105655984A (en) * | 2016-03-28 | 2016-06-08 | 广州七喜智能设备有限公司 | Over-temperature protection method for IGBT in frequency converter |
| CN106443400A (en) * | 2016-09-14 | 2017-02-22 | 河北工业大学 | Electric-heat-aging junction temperature calculation model establishing method of IGBT module |
| CN107025364A (en) * | 2017-05-12 | 2017-08-08 | 西安交通大学 | A kind of junction temperature Forecasting Methodology of IGBT module |
| CN207426963U (en) * | 2017-10-09 | 2018-05-29 | 北京亿华通科技股份有限公司 | Separate parallel driver circuit |
| CN107993891A (en) * | 2017-12-31 | 2018-05-04 | 昌辉汽车电气系统（安徽）有限公司 | The protection circuit and method of a kind of relay contact in electric machine control system |
| CN108695833A (en) * | 2018-06-30 | 2018-10-23 | 昌辉汽车电气系统（安徽）有限公司 | Vehicle-mounted relay protection control circuit in 24V bodywork systems and method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113394751B (en) | 2022-10-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2986553C (en) | Power supply control apparatus and method thereof | |
| US7586214B2 (en) | High voltage energy storage connection monitoring system and method | |
| US9762050B2 (en) | Motor drive device | |
| US6239515B1 (en) | Circuit for the protection of electrical devices | |
| CN107143985B (en) | pressure protection device for air conditioning system and air conditioning system | |
| US20190097561A1 (en) | Inverter driver | |
| CN108767808B (en) | EPS controller power supply diagnosis and protection system and method | |
| CN100481688C (en) | Inverter device | |
| CN110445102A (en) | A kind of electronic RELAY devices and guard method | |
| CN110962606A (en) | Control system and method for emergency cut-off of high-voltage power supply of new energy automobile and new energy automobile | |
| US20130147414A1 (en) | Pulse width modulation controller | |
| CN107370443B (en) | Motor control device | |
| CN111880088A (en) | Relay bilateral control and diagnosis circuit and method and battery management system | |
| WO2023004952A1 (en) | Vehicle-mounted power supply circuit, and vehicle | |
| CN113394751B (en) | Circuit system and method for realizing vehicle motor driving and self-protection | |
| CN105742119B (en) | Relay drive circuit | |
| US7514906B1 (en) | Automotive rotary electrical apparatus | |
| JP3079776B2 (en) | Fuel pump control device | |
| CN113644621A (en) | Automobile circuit protection device, system and method | |
| CN116660784A (en) | Low-side switch load short circuit detection and protection method | |
| CN114337470B (en) | Motor reversal protection device, protection method thereof and motor driving system | |
| CN115764790A (en) | Power supply circuit of heavy current load | |
| CN115395935A (en) | High-side switch circuit with self-diagnosis function | |
| CN112462301B (en) | Motor phase open circuit and short circuit detection system and method used on EPS | |
| CN112737299B (en) | Method, device and system for protecting high voltage on inverter of electric automobile |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |