A kind of electric vehicle motor controller
Technical field
The present invention relates to a kind of electric vehicle motor controller.
Background technology
Be becoming tight along with Global Oil resource day and environmental pollution is on the rise, the electric automobile of various energy-conserving and environment-protective continues to bring out, and generally can be divided into 3 classes, that is: pure electric automobile, hybrid vehicle, fuel cell-powered vehicle.Along with the policy support that technology constantly improves and various countries continue of electric automobile, the sales volume of electric automobile presents the situation increased fast year by year.
In electric automobile, electric machine controller realizes drive and control of electric machine and regenerating braking energy reclaims control, not only realizing direct current to the inversion of alternating current can realize alternating current to galvanic rectification, that is it is the bridge of electric automobile power battery and alternating current machine energy transferring, again because the electric machine controller of electric automobile belongs to kernel component, and the personal driving safety of direct relation, so there is higher requirement to the reliability of electric machine controller.Conventional motors controller also has the diagnosis and protection measure of operating state, much more general adopt main control chip MCU to monitor analog signal and abnormal time protection work, these all need to realize by software.The reaction speed of software is comparatively slow, and under some abnormal conditions, often safeguard measure response causes the damage of electric machine controller internal component not in time, and according to statistics, damaging maximum in engineer applied is exactly power device.For electric vehicle motor controller, the damage of power device may cause vehicle losing power or accelerate suddenly, brings great danger to people's driving safety.In addition, after the protection of conventional motors controller failure, its fault message cannot be read, so bring very big inconvenience to the maintenance and repair of electric machine controller.
Summary of the invention
Goal of the invention of the present invention is to provide a kind of electric vehicle motor controller, effectively can improve the safety and reliability of electric vehicle motor controller work.
Realize the technical scheme of the object of the invention:
A kind of electric vehicle motor controller; there is entire car controller, electric machine controller main control chip MCU, power model; MCU is controlled motor by power model; it is characterized in that: also there is over current fault diagnostic circuit, power device temperature collecting cell, busbar voltage collecting unit; the signal output part of over current fault diagnostic circuit, power device temperature collecting cell connects and door (U4), connects and door (U5) with the output of door (U4), the signal output part of busbar voltage collecting unit; With output and the key state signal output part of door (U5), connect the first input end with door (U7), with output and the power bridge enable signal output of door (U7), connect upper and lower bridge arm pwm signal interlock circuit, the output of upper and lower bridge arm pwm signal interlock circuit and power model drive singal output, connect power model.
The signal output part of over current fault diagnostic circuit, power device temperature collecting cell, connects and door (U4) through latch (U1), the latch clear signal input termination MCU of latch (U1).
The output of termination and door (U6) is inputted with second of door (U7); The motor enable signal output of MCU and the signal output part of entire car controller connect the input with door (U6).
Also there is power-down retaining circuit, power-down retaining circuit structure is, switching tube (Q3), switching tube (Q4) compose in parallel switching circuit, the control end of the output termination switching tube (Q5) of switching circuit, and switching tube (Q5) is for controlling electric machine controller power supply; The output of the control termination entire car controller of switching tube (Q3), the control termination MCU of switching tube (Q4).
Power device temperature collecting cell has power device temperature collection circuit and comparator (U3), the output termination comparator (U3) of power device temperature collection circuit; Busbar voltage collecting unit has busbar voltage Acquisition Circuit and comparator (U2), the output termination comparator (U2) of busbar voltage Acquisition Circuit, the output termination of comparator (U2) and door (U5).
Upper and lower bridge arm pwm signal interlock circuit is made up of two and door (U8), (U10) and two NAND gate (U9), (U11), and upper brachium pontis pwm signal input, the lower brachium pontis pwm signal input of upper and lower bridge arm pwm signal interlock circuit are connected with MCU.
With the output of door (U5) and key state signal output part, be all connected with MCU with the output of door (U7) and power bridge enable signal output, the output of comparator (U2) and the output of latch (U1).
The beneficial effect that the present invention has:
The signal output part access of over current fault diagnostic circuit of the present invention, power device temperature collecting cell, busbar voltage collecting unit and door, by exporting key state signal with door, power output bridge enable signal, controls power model then.The present invention has done Redundancy Design to the Working Status Monitoring of electric vehicle motor controller and protection, except the monitoring adopting software, outside safeguard measure, also add the monitoring of hardware, safeguard measure, key job quantity of state (busbar voltage when electric machine controller runs is monitored with hardware circuit, three-phase current, the temperature of power device), so-called key job quantity of state is because directly may cause the core devices of electric machine controller when the value of these quantity of states exceeds normal range (NR)---power device (power model) damage of three phase full bridge or the damage of motor, feature because of hardware circuit responds rapidly and high reliability, power device work can be stopped during any key job abnormal state in time to protect power device, power model work is recovered rapidly again after abnormal elimination, therefore, safety and reliability of the present invention is high, reaction speed is fast, maintenance cost and failure rate is low.Meanwhile, whether each monitor state is normally concentrated by the present invention is that a power bridge enable signal exports, and this greatly simplifies protective circuit, reduces cost, further increase the reliability of electric machine controller.
The signal output part of over current fault diagnostic circuit of the present invention, power device temperature collecting cell, connects and door (U4) through latch (U1), the latch clear signal input termination MCU of latch (U1).Latch can keep power device to be in closed condition always, avoids abnormality percussion power module and/or motor continually, thus further increases the reliability of power drive system.The fault level latched in circuit can export pulse by the I/O of MCU and remove, when electric machine controller key state returns within the scope of normal safe, electric machine controller can recover normal work again, for repeatedly removing, rear malfunction exists always, MCU can record purge number of times, and in time thoroughly close power tube according to security strategy, such electric machine controller can be got rid of some accidental exceptions and ensure electric machine controller ground continuous firing, avoids the safety problem that electric automobile impact is fast or anticlimax speed belt is next to a certain extent.
The present invention also has power-down retaining circuit, power-down retaining circuit structure is, switching tube (Q3), switching tube (Q4) compose in parallel switching circuit, the control end of the output termination switching tube (Q5) of switching circuit, and switching tube (Q5) is for controlling electric machine controller power supply; The output of the control termination entire car controller of switching tube (Q3), the control termination MCU of switching tube (Q4).Power-down retaining circuit makes electric machine controller postpone a period of time power down, is used for doing the storage of fault message during this period of time, further facilitates the maintenance of electric machine controller, improves the safety and reliability of electric machine controller work.
The present invention has upper and lower bridge arm pwm signal interlock circuit, upper and lower bridge arm pwm signal interlock circuit is made up of two and door (U8), (U10) and two NAND gate (U9), (U11), upper brachium pontis pwm signal input, the lower brachium pontis pwm signal input of upper and lower bridge arm pwm signal interlock circuit are connected with MCU, pwm signal interlock circuit avoids from hardware the situation that upper and lower bridge arm drive singal is all high level, avoid upper and lower bridge pwm signal and be all that power device that height causes is straight-through to be damaged, improve the fail safe that the reliability of Electric Machine Control and car load travel.
The output of the present invention and door (U5) and key state signal output part, to be all connected with MCU with the output of door (U7) and power bridge enable signal output, the output of comparator (U2) and the output of latch (U1), main control chip MCU can carry out effective monitoring to state information, simplify circuit simultaneously, effectively reduce cost.
Accompanying drawing explanation
Fig. 1 is power-down retaining circuit partial schematic diagram of the present invention;
Fig. 2 is fault diagnosis circuit partial schematic diagram of the present invention;
Fig. 3 is PWM interlock circuit partial schematic diagram of the present invention.
Embodiment
As shown in Figure 1, electric machine controller comprises entire car controller VMS, electric machine controller main control chip MCU, power model, and MCU is controlled motor by power model, and this is prior art.
As shown in Figure 2, the signal output part of over current fault diagnostic circuit, power device temperature collecting cell, connects and door U4 through latch U1, and the latch clear signal input of latch U1 meets MCU through switching tube U12.Connect and door U5 with the output of door U4, the signal output part of busbar voltage collecting unit.Power device temperature collecting cell has power device temperature collection circuit and comparator U3, the output termination comparator U3 of power device temperature collection circuit; Busbar voltage collecting unit has busbar voltage Acquisition Circuit and comparator U2, the output termination comparator U2 of busbar voltage Acquisition Circuit.
With output and the key state signal output part of door U5, connect the first input end with door U7, as shown in Figure 2 and Figure 3, with output and the power bridge enable signal output of door U7, connect upper and lower bridge arm pwm signal interlock circuit, the output of upper and lower bridge arm pwm signal interlock circuit and power model drive singal output, connect power model.The output of termination and door U6 is inputted with second of door U7; The motor enable signal output M of MCU and the signal output part L of entire car controller connects the input with door U6.
With the output of door U5 and key state signal output part, be all connected with MCU with the output of door U7 and power bridge enable signal output, the output of comparator U2 and the output of latch U1.
As shown in Figure 1, power-down retaining circuit structure is, switching tube Q3, switching tube Q4 compose in parallel switching circuit, and the output of switching circuit connects the control end of switching tube Q5 through resistance R10, and switching tube Q5 is for controlling electric machine controller power supply, and switch on power converter; The output of the control termination entire car controller VMS of switching tube Q3, the control termination MCU of switching tube Q4.
As shown in Figure 3, upper and lower bridge arm pwm signal interlock circuit (being called for short pwm signal interlock circuit) is made up of two and door U8, U10 and two NAND gate U9, U11, and upper brachium pontis pwm signal input, the lower brachium pontis pwm signal input of upper and lower bridge arm pwm signal interlock circuit are connected with the I/O port of MCU.
With reference to figure 1, when entire car controller VMS sends ignition signal R(high level) to switching tube Q3 time, after switching tube Q3 conducting immediately, a negative voltage is produced between the GS of MSOFET switching tube Q5, according to the characteristic of P type MOSFET, at this moment switch Q5 conducting, electric automobile little storage battery amount 12V voltage just powers also to all low-voltage circuits in electric machine controller by switching tube Q5.When entire car controller VMS sends ignition signal R(low level) to switching tube Q3 time, also receive ignition signal becomes low level to the I/O port of MCU simultaneously, then the I/O port of MCU exports power down inhibit signal S(high level), while switching tube Q3 turns off, switching tube Q4 is open-minded because receiving power down inhibit signal S, and MCU stores last critical state information immediately afterwards.After storage, disconnect low-voltage power supply, MCU sends power down inhibit signal S(low level), switching tube Q4 becomes closed condition from conducting state after receiving low level control signal, completes electric machine controller power down and keeps.
Following table 1 lists the low-voltage power supply state table of electric machine controller inside:
The low-voltage power supply state table of table 1 electric machine controller inside
Note: H represents high level, L represents low level, X represents any level, R, S, T hold as shown in Figure 1.
With reference to figure 1-Fig. 3:
After the inner normal power supply of electric machine controller, entire car controller VMS sends enable signal L(high level) give and door U6, when three Key states (motor three-phase electricity flow valuve, temperature of power module value, electric machine controller bus voltage value) all normal time, over current fault diagnostic circuit, comparator U2 and comparator U3 all exports high level, the level that over current fault diagnostic circuit and comparator U3 export by latch U1 exports high level to door U4, now, high level is with the voltage of door U5 input, then export high level to the MCU of rear end with door U5, MCU gives tacit consent to Key state after this high level being detected all normal, MCU is by I/O port output motor enable signal M(high level afterwards) give and door U6, then U7 input end signal is high level, so U7 power output bridge enable signal P(high level) to MCU and the PWM interlock circuit of rear end.Therefore PWM interlock circuit output channel is opened, and continue output low level and become output level with the same change of input, thus the running achieving motor controls from power model drive singal H and L before.
When comparator U2 exports high level, when motor three-phase current and/or temperature of power module exception, over current fault diagnostic circuit and/or comparator U3 output low level are to latch U1, latch U1 then gives and door U4 in corresponding output pin output low level, latch output status signal E and H is to the I/O port of MCU simultaneously, so that MCU knows which road fault concrete.Because becoming low level with door U4 input, then with door U4 output low level to U5, so U5 output low level P is to after the I/O mouth of PWM interlock circuit and MCU, PWM interlock circuit immediately whole output low level cuts out power device, in order to avoid the abnormal damage causing power device, MCU has known this state simultaneously.Power model is closed after rear over current fault diagnostic circuit output signal C and/or comparator U3 outputs signal D a period of time can revert to high level, MCU is once the biphase current value that detects and temperature of power module value return in a certain safe range and send fault clearance signal B immediately, Q1 and/or Q2 of latch U1 holds output to revert to high level, pwm signal controls motor operation by PWM interlock circuit afterwards, once again failure volume be detected, latch will latch output low level again, if each quantity of state talks about the normal work of electric machine controller recovery all normally when motor runs.If remove the number of times that latch arrives regulation, malfunction still exists, MCU output motor enable signal M(low level) carry out thorough switch-off power module.
When the overvoltage of electric machine controller busbar voltage, comparator U2 output low level is given and door U5 and MCU, then output low level can carry out switch-off power module immediately with door U7, export high level according to bus voltage value MCU by the control U7 that output signal M is in good time, thus recover electric machine controller to the control of motor.
Following table 2 lists the signal relation table in fault diagnosis circuit:
Signal relation table in table 2 fault diagnosis circuit
Annotation: H represents high level, L represents low level, X represents any level, C D I E F G H L M K P holds, as shown in Figure 2.
With reference to figure 3, what electric machine controller adopted is three phase full bridge, so there is three-phase PWM interlock circuit, Fig. 3 is the PWM interlock circuit of a certain phase wherein.When enable signal P is high level, the pwm signal that MCU sends is directly by controlling the switch of power device after PWM interlock circuit.If the pwm signal of bridge up and down of PWM interlock circuit input side is high level, PWM interlock circuit exports X high level one road, a road Y low level immediately, thus avoids the generation that power device leads directly to hazard event.When enable signal P is low level, PWM interlock circuit exports and is low level, then three-phase six road power device is all closed, thus avoids the damage of abnormal failure state to power model and/or motor.
Following table lists the signal relation table in PWM interlock circuit:
Signal relation table in table 3 PWM interlock circuit
Annotation: H represents high level, L represents low level, X represents any level, P U W X Y holds, as shown in Figure 3.