Summary of the invention
The disclosure provides a kind of motor-drive circuit and motor, is being turned off with the motor-drive circuit for solving in the related technologyThe problem of drain electrode peak voltage is formed when metal-oxide-semiconductor.
To achieve the goals above, disclosure first aspect provides a kind of motor-drive circuit, and the circuit includes N number of phaseDrive module, N are the positive integer for being less than or equal to M greater than 0, and M is the number of phases of the motor；
Wherein, the i-th phase drive module 100 includes flash driving unit 110, low side driving unit 120, peak voltage inhibitionUnit 130, i are the positive integer for being less than or equal to N greater than 0；
The flash driving unit 110 includes flash metal-oxide-semiconductor Qi1；
The grid of the flash metal-oxide-semiconductor Qi1 is for connecting control terminal Vi1, and the drain electrode of the flash metal-oxide-semiconductor Qi1 is for connectingPower source bus Vbus is met, the source electrode of the flash metal-oxide-semiconductor Qi1 is used to connect the i-th load winding of the motor；
The low metal-oxide-semiconductor Qi2 when driving unit 120 further includes low；
The grid of the low side metal-oxide-semiconductor Qi2 is for connecting control terminal Vi2, and the drain electrode of the low side metal-oxide-semiconductor Qi2 is for connecingI-th load winding of the motor, the source electrode of the low side metal-oxide-semiconductor Qi2 is for being grounded；
It includes capacitor Ci1, inductance Li1, diode Di1, diode Di2 that the peak voltage, which inhibits unit 130,；
The drain electrode of the first termination low side metal-oxide-semiconductor Qi2 of the capacitor Ci1, described in the second termination of the capacitor Ci1The anode of diode Di1；The source electrode of the first termination low side metal-oxide-semiconductor Qi2 of the inductance Li1, the second of the inductance Li1Terminate the anode of the diode Di2；The cathode of the diode Di2 connects the anode of the diode Di1；The diodeThe cathode of Di1 is for connecting the power source bus Vbus.
Optionally, the flash driving unit 110 further includes flash grid current vent unit 111, the flash gridElectric current vent unit 111 includes diode Di3, triode Ti1；
The base stage of the triode Ti1 connects described for connecting the control terminal Vi1, the emitter of the triode Ti1The grid of flash metal-oxide-semiconductor Qi1, the collector of the triode Ti1 connect the source electrode of the flash metal-oxide-semiconductor Qi1；
The anode of the diode Di3 connects the base stage of the triode Ti1, and the cathode of the diode Di3 connects described threeThe emitter of pole pipe Ti1.
Optionally, the flash driving unit 110 includes resistance Ri1, and the resistance Ri1 is series at the control terminal and instituteBetween the emitter for stating triode Ti1.
Optionally, the resistance value of the resistance Ri1 isWherein, Ls is the parasitic inductance of the flash metal-oxide-semiconductor Qi1,The parasitic inductance includes the source electrode parasitic inductance of the flash metal-oxide-semiconductor Qi1 and the parasitic inductance of gate lead；Ciss is describedThe grid source electrode input capacitance of flash metal-oxide-semiconductor Qi1.
Optionally, the flash driving unit 110 includes capacitor Ci2, the first termination flash of the capacitor Ci2The grid of metal-oxide-semiconductor Qi1, the second end ground connection of the capacitor Ci2.
Optionally, the capacitance of the capacitor Ci2 isWherein, Iq is the flash metal-oxide-semiconductor Qi1 gridMaximum current；Dmax is the maximum duty cycle of the control terminal Vi1 output signal, and f is the work of the control terminal Vi1 output signalWorking frequency, Q are the static electric charge of the grid capacitance of the flash metal-oxide-semiconductor Qi1, and Δ V is the grid source electrode of the flash metal-oxide-semiconductor Qi1Cut-in voltage.
Optionally, it when the circuit includes multiple phase drive modules, is connected in parallel between the multiple phase drive module.
Disclosure second aspect provides a kind of motor, and the motor includes any one of above-mentioned first aspect or first aspect canSelect motor-drive circuit described in implementation.
The disclosure third aspect provides a kind of control method of motor-drive circuit, and the method is for controlling above-mentioned firstMotor-drive circuit described in aspect, which comprises
Low side off-phases: the first control signal for controlling the control terminal Vi1 is in low potential, so that the flashMetal-oxide-semiconductor Qi1 is held off；The second control signal for controlling the control terminal Vi2 switches to low potential by high potential, so thatThe low side metal-oxide-semiconductor Qi2 switches to off state by open state, flow through the first drain current of i-th load winding toThe first end of the capacitor Ci1 charges；
Low side open stage: the first control signal for controlling the control terminal Vi1 is in low potential, so that the flashMetal-oxide-semiconductor Qi1 is held off；The second control signal for controlling the control terminal Vi2 switches to high potential by low potential, so thatThe low side metal-oxide-semiconductor Qi2 switches to open state, the capacitor Ci1, the inductance Li1 and the diode by off stateDi2 forms oscillating circuit, and the second drain current that the capacitor Ci1 electric discharge generates flows through the oscillating circuit and two polePipe Di1 releases to power source bus Vbus.
Optionally, flash driving unit 110 described in the motor-drive circuit further includes that flash grid current is released listMember 111, the flash grid current vent unit 111 include diode Di3, triode Ti1；
The base stage of the triode Ti1 is for connecting the control terminal Vi1, and the emitter of the triode Ti1 is for connectingThe grid of the flash metal-oxide-semiconductor Qi1 is connect, the collector of the triode Ti1 is used to connect the source electrode of the flash metal-oxide-semiconductor Qi1；
The anode of the diode Di3 connects the base stage of the triode Ti1, and the cathode of the diode Di3 connects described threeThe emitter of pole pipe Ti1；
The method also includes:
Flash open stage: the second control signal for controlling the control terminal Vi2 is in low potential, so that the low sideMetal-oxide-semiconductor Qi2 is held off；The first control signal for controlling the control terminal Vi1 switches to high potential by low potential, describedDiode Di3 is opened, and the first control signal flows through the diode Di3 and fills to the grid capacitance of the flash metal-oxide-semiconductor Qi1Electricity, so that the flash metal-oxide-semiconductor Qi1 switches to open state by off state；
Flash off-phases: the second control signal for controlling the control terminal Vi2 is in low potential, so that the low sideMetal-oxide-semiconductor Qi2 is held off；The first control signal for controlling the control terminal Vi1 switches to low potential by high potential, describedThe emitter and collector of triode Ti1 is connected, and the grid current that the grid capacitance electric discharge of the flash metal-oxide-semiconductor Qi1 generates is logicalThe triode Ti1 emitter and collector is crossed to release to i-th load winding.
Through the above technical solutions, the low side metal-oxide-semiconductor Qi2 drain electrode access peak voltage of the i-th phase in motor-drive circuitInhibit unit 130.In this way, the electric current for partially flowing through the load of the i-th phase inductive coils can be right when turning off the low side metal-oxide-semiconductor Qi2It is connected to the capacitor Ci1 charging of the low side metal-oxide-semiconductor Qi2 drain electrode；When opening the low side metal-oxide-semiconductor Qi2 next time, the spikeVoltage inhibits capacitor Ci1, inductance Li1 and diode Di2 in unit 130 to form oscillating circuit, the electricity that capacitor Ci1 electric discharge generatesIt flows through the oscillating circuit and passes through diode Di1 to power source bus Vbus.Thus, it is suppressed that turning off the low side metal-oxide-semiconductorThe drain electrode peak voltage generated when Qi2, to reduce the switching loss of the low side metal-oxide-semiconductor.
Specific embodiment
It is described in detail below in conjunction with specific embodiment of the attached drawing to the disclosure.It should be understood that this place is retouchedThe specific embodiment stated is only used for describing and explaining the disclosure, is not limited to the disclosure.
Fig. 1 is a kind of motor-drive circuit shown in one exemplary embodiment of the disclosure.The motor-drive circuit 10 canTo include N number of phase drive module, wherein N is the positive integer for being less than or equal to M greater than 0, and M is the number of phases of the motor.To includeFor the brush DC three-phase motor of the motor-drive circuit, the number of phases 3, the motor-drive circuit may include 3The phase drive module also may include 2 phase drive modules, and the disclosure is it is not limited here.
As shown in Figure 1, wherein the i-th phase drive module 100 includes flash driving unit 110, low side driving unit120, peak voltage inhibits unit 130.Wherein, i is the positive integer for being less than or equal to N greater than 0.
The flash driving unit 110 includes flash metal-oxide-semiconductor Qi1.The grid of the flash metal-oxide-semiconductor Qi1 is for connecting controlFor connecting power source bus Vbus, the source electrode of the flash metal-oxide-semiconductor Qi1 is used for for the drain electrode of end Vi1 processed, the flash metal-oxide-semiconductor Qi1Connect the i-th load winding of the motor.
Wherein, the control terminal Vi1 can be a part of PWM controller.The PWM controller can be according to the electricityThe load change of machine adjusts the duty ratio of each control terminal output signal, to pass through the grid for controlling flash metal-oxide-semiconductor Qi1 electricityThe voltage-controlled system flash metal-oxide-semiconductor Qi1 is on or off.In the specific implementation, there can also be similar above-mentioned function using otherThe controller of energy.
With reference to the connection type of above-mentioned flash driving unit 110, when the output signal of control terminal Vi1 is high level, instituteThe grid voltage for stating flash metal-oxide-semiconductor Qi1 reaches the cut-in voltage of the flash metal-oxide-semiconductor Qi1, the flash metal-oxide-semiconductor Qi1 hourglass source electrodeConducting, electric current flow to i-th load winding from the hourglass source electrode that power source bus Vbus flows through the flash metal-oxide-semiconductor Qi1.
The low metal-oxide-semiconductor Qi2 when driving unit 120 further includes low.The grid of the low side metal-oxide-semiconductor Qi2 is for connectingThe drain electrode of control terminal Vi2, the low side metal-oxide-semiconductor Qi2 are for meeting the i-th load winding of the motor, the low side metal-oxide-semiconductor Qi2Source electrode for being grounded.
Wherein, the control mode of the on or off low side metal-oxide-semiconductor Qi2 can be with reference to above with respect to the flashThe description of metal-oxide-semiconductor Qi1.
It includes capacitor Ci1, inductance Li1, diode Di1, diode Di2 that the peak voltage, which inhibits unit 130,.The electricityHold the drain electrode of the first termination low side metal-oxide-semiconductor Qi2 of Ci1, the second termination diode Di1 of the capacitor Ci1 is justPole；The source electrode of the first termination low side metal-oxide-semiconductor Qi2 of the inductance Li1, the second termination two pole of the inductance Li1The anode of pipe Di2；The cathode of the diode Di2 connects the anode of the diode Di1；The cathode of the diode Di1 meets instituteState power source bus Vbus.
To include for three-phase star connects the DC brushless motor of load winding, when motor works normally, the 1st phase of control is drivenMetal-oxide-semiconductor Q11 in the flash driving unit 110 of dynamic model block and the metal-oxide-semiconductor in the low side driving unit of the 2nd phase drive moduleQ22 is opened simultaneously, and the electric current in power source bus Vbus flows to the 1st phase load winding after flowing through the hourglass source electrode of the metal-oxide-semiconductor Q11,Ground wire is flowed to after passing through the hourglass source electrode for flowing through the metal-oxide-semiconductor Q22 after the 2nd phase load winding.Next stage controls the MOSPipe Q22 shutdown, and the metal-oxide-semiconductor Q32 in the low side driving unit of the 3rd phase drive module of control is opened, then electric current is flowing through the 1st phaseThe 3rd phase load winding is flowed to after load winding, then flows to ground wire after the hourglass source electrode by the metal-oxide-semiconductor Q32.It is possible thereby to controlElectric current on power source bus Vbus successively flows into every two load winding, thus control the rotor structure of motor according to certain revolving speed andTurn to rotation.
It is worth noting that in the related art, the i-th phase load winding has the perception for the variation for preventing electric current specialMatter will continue to the output capacitance and circuit to the low side metal-oxide-semiconductor in the moment for the metal-oxide-semiconductor for turning off the i-th mutually low side driving unitIn parasitic capacitance in charge, cause the drain electrode of low side metal-oxide-semiconductor and source voltage to increase rapidly, and in the low side metal-oxide-semiconductorDrain electrode forms the peak voltage that pressure value is more than busbar voltage.The peak voltage can be such that low side metal-oxide-semiconductor punctures, and lead to fault.In the shutdown of low side metal-oxide-semiconductor, ∫ I (t) V (t) dt can be approximately in switching loss.Moment is raised when turning off low side metal-oxide-semiconductorDrain voltage increases wherein V (t) item numerical value, increases the switching loss of low side metal-oxide-semiconductor.When motor works normally, motorThe switching frequency of each metal-oxide-semiconductor in driving circuit is usually within the scope of 10~500KHz.When turning off the low side metal-oxide-semiconductor every timeElectric energy loss caused by the peak voltage can be partially converted into heat, propose higher want to the heat dissipation of motor-drive circuitIt asks.
And the technical solution for using the embodiment of the present disclosure to provide, in the low side driving unit of the i-th phase of motor-drive circuitIn 120, the drain electrode access peak voltage of the low side metal-oxide-semiconductor Qi2 inhibits unit 130, in this way, turning off the low side metal-oxide-semiconductorWhen Qi2, partially flow through the load of the i-th phase inductive coils electric current butt up against the low side metal-oxide-semiconductor Qi2 drain electrode capacitor Ci1 theOne end charging.The second end of the capacitor Ci1 is clamped to busbar voltage by the diode Di1.
When opening the low side metal-oxide-semiconductor Qi2 next time, the peak voltage inhibits capacitor Ci1, electricity in unit 130Feel Li1 and diode Di2 and form oscillating circuit, oscillation frequency isWherein L1 is the inductance of the inductance Li1Value, C1 is the capacitance of the capacitor Ci1.It is worth noting that the concussion period of the oscillating circuit should be less than it is described lowThe minimum opening time of side metal-oxide-semiconductor Qi2, those skilled in the art can need to select above-mentioned component according to specifically usedType.
It is shaken the period in first half, the electric current that the capacitor Ci1 electric discharge generates will be stored in capacitor through the oscillating circuitElectric energy on Ci1 is transferred in the inductance Li1 and stores；On the later half concussion period, the voltage of the inductance Li1 second endIt rises, the diode Di1 and the diode Di2 are opened, and the electric energy being stored in inductance Li1 is released into the form of electric currentPower source bus Vbus.
In this way, the electric energy for causing drain electrode to generate peak voltage when turning off the low side metal-oxide-semiconductor Qi2 originally is stored in instituteCapacitor Ci1 is stated, inhibits the oscillation electricity in unit 130 through the peak voltage again when opening the low side metal-oxide-semiconductor Qi2 next timeIt releases to power source bus Vbus on road.It can inhibit the drain electrode peak voltage generated when turning off the low side metal-oxide-semiconductor Qi2 as a result, fromAnd reduce the switching loss of the low side metal-oxide-semiconductor Qi2.
For the understanding above-mentioned technical proposal for being more clear those skilled in the art, it is based on identical thinking, the disclosure is realIt applies example and a kind of control method of motor-drive circuit is also provided, the method is used to control motor-drive circuit as shown in Figure 1,The described method includes:
Low side off-phases: the first control signal for controlling the control terminal Vi1 is in low potential, so that the flashMetal-oxide-semiconductor Qi1 is held off；The second control signal for controlling the control terminal Vi2 switches to low potential by high potential, so thatThe low side metal-oxide-semiconductor Qi2 switches to off state by open state, flow through the first drain current of i-th load winding toThe first end of the capacitor Ci1 charges.
Low side open stage: the first control signal for controlling the control terminal Vi1 is in low potential, so that the flashMetal-oxide-semiconductor Qi1 is held off；The second control signal for controlling the control terminal Vi2 switches to high potential by low potential, so thatThe low side metal-oxide-semiconductor Qi2 switches to open state, the capacitor Ci1, the inductance Li1 and the diode by off stateDi2 forms oscillating circuit, and the second drain current that the capacitor Ci1 electric discharge generates flows through the oscillating circuit and two polePipe Di1 releases to power source bus Vbus.
Wherein, when the control terminal is the output end of PWM controller, can respectively by adjusting PWM control terminal Vi1 orThe duty ratio of the output signal of control terminal Vi2 is switched on and off duration adjust flash metal-oxide-semiconductor Qi1 or low side metal-oxide-semiconductor Qi2,And output voltage.It is above-mentioned for it is low in off-phases and it is low while open stage division mode be only described low clearly to illustrateThe on or off moment circuital current variation of side metal-oxide-semiconductor Qi2.During the real-world operation of motor, above-mentioned low frontier juncture faulted-stageSection and low side open stage are not the continuous period.The present invention is not limited by described each phase sequence.
On the basis of motor-drive circuit shown in Fig. 1, as shown in Fig. 2, the flash driving unit 110 further includes flashGrid current vent unit 111, the flash grid current vent unit 111 include diode Di3, triode Ti1.Described threeFor the base stage of pole pipe Ti1 for connecting the control terminal Vi1, the emitter of the triode Ti1 connects the flash metal-oxide-semiconductor Qi1'sGrid, the collector of the triode Ti1 connect the source electrode of the flash metal-oxide-semiconductor Qi1；The anode of the diode Di3 connects describedThe base stage of triode Ti1, the cathode of the diode Di3 connect the emitter of the triode Ti1.
The control method of another motor-drive circuit provided below with the embodiment of the present disclosure is to above-mentioned flash grid electricityThe effect of stream vent unit 111 is described in detail.The described method includes:
Flash open stage: the second control signal for controlling the control terminal Vi2 is in low potential, so that the low sideMetal-oxide-semiconductor Qi2 is held off；The first control signal for controlling the control terminal Vi1 switches to high potential by low potential, describedDiode Di3 is opened, and the first control signal flows through the diode Di3 and fills to the grid capacitance of the flash metal-oxide-semiconductor Qi1Electricity, so that the flash metal-oxide-semiconductor Qi1 switches to open state by off state；
Flash off-phases: the second control signal for controlling the control terminal Vi2 is in low potential, so that the low sideMetal-oxide-semiconductor Qi2 is held off；The first control signal for controlling the control terminal Vi1 switches to low potential by high potential, describedThe emitter and collector of triode Ti1 is connected, and the grid current that the grid capacitance electric discharge of the flash metal-oxide-semiconductor Qi1 generates is logicalThe triode Ti1 emitter and collector is crossed to release to i-th load winding.
It is worth noting that the triode Ti1 is PNP type triode, the emitter and collector of the triode Ti1Unlocking condition is that base emitter voltage is greater than predetermined voltage threshold, such as 0.7V.It is switched in the control terminal Vi1 by high potential lowWhen current potential, the grid capacitance voltage change of the flash metal-oxide-semiconductor Qi1 is lagged, and the base emitter voltage of the triode Ti1 is big at this timeThe electric energy stored in predetermined voltage threshold, the grid capacitance is released through triode Ti1 to described i-th negative in the form of electric currentCarry winding.Increase the flash grid current vent unit 111 by the grid in the flash metal-oxide-semiconductor Qi1, increases shutdownElectric current when the flash metal-oxide-semiconductor Qi1 is released path, and the turn-off speed of the flash metal-oxide-semiconductor Qi1 is accelerated.
Meanwhile there are also emitter and base stage that part of grid pole electric current passes through the triode Ti1, the diode is passed throughDi3.Diode Di3 plays the role of afterflow herein, by the part of grid pole current limit by transistor emitter, base stage and instituteIn the circuit for stating diode Di3 composition, reduce the electric current for flowing through the flash metal-oxide-semiconductor Qi1 input capacitance, accelerates flash MOSThe turn-off speed of pipe Qi1.In addition, the afterflow that diode Di3 plays the role of can protect the base-emitter of the triode, this is avoidedBase-emitter is reversed breakdown.
Optionally, the flash driving unit 110 includes resistance Ri1, and the resistance Ri1 is series at the control terminal and instituteBetween the emitter for stating triode Ti1.
There is parasitic inductance Ls since flash metal-oxide-semiconductor Qi1 is encapsulated in connecting part and circuit board line, in the control terminalWhen the control signal of Vi1 is switched to high level by low level, parasitic inductance Ls and the grid source electrode of the flash metal-oxide-semiconductor Qi1 are defeatedEnter capacitor Ciss and form LC resonance series effect, specifically please refers to equivalent circuit as shown in Figure 3.The LC resonance series effect meetingThe grid of the flash metal-oxide-semiconductor Qi1 is caused to form oscillation.By adjusting the resistance value of resistance Ri1, the LC can be inhibited to go here and thereJoin resonance effects, to accelerate the opening speed of the flash metal-oxide-semiconductor Qi1.
In an alternative embodiment, the resistance value of the resistance Ri1 isWherein, Ls is the flash metal-oxide-semiconductorThe parasitic inductance of Qi1, the parasitic inductance include the source electrode parasitic inductance of the flash metal-oxide-semiconductor Qi1 and the parasitism of gate leadInductance；Ciss is the grid source electrode input capacitance of the flash metal-oxide-semiconductor Qi1.
Optionally, the flash driving unit 110 includes capacitor Ci2, the first termination flash of the capacitor Ci2The grid of metal-oxide-semiconductor Qi1, the second end ground connection of the capacitor Ci2.
When opening the flash metal-oxide-semiconductor Qi1, the capacitor Ci2 can be the grid capacitance of the flash metal-oxide-semiconductor Qi1Charging charge is provided, the opening speed of flash metal-oxide-semiconductor Qi1 is accelerated.If the control terminal Vi1 is the output end of PWM controller,In a kind of alternative embodiment, the capacitance of the capacitor Ci2 isWherein, Iq is the flash metal-oxide-semiconductor Qi1 gridThe maximum current of pole, the first control signal that the value of Iq can be approximated to be the control terminal Vi1 are in voltage value when high potentialDivided by the quotient of the resistance value of the resistance Ri1.Dmax is the maximum duty cycle of the first control signal.F is the control terminal Vi1The working frequency of output signal.Q is the static electric charge of the grid capacitance of the flash metal-oxide-semiconductor Qi1, that is, the first control letterThe total electrical charge of grid capacitance when number being in low potential.Δ V is the grid source electrode cut-in voltage of the flash metal-oxide-semiconductor Qi1.
In the specific implementation, this field engineering staff according to the component parameters of actual use and can use needThe capacitance of the resistance Ri1 resistance value and the capacitor Ci2 is set.
Optionally, it when the circuit includes multiple phase drive modules, is connected in parallel between the multiple phase drive module.
For the understanding technical solution of the present invention for being more clear those skilled in the art, the embodiment of the present disclosure also provides one kindThe structural schematic diagram of three-phase direct-current brushless motor, as shown in figure 4, the motor 400 includes the motor-drive circuit 10, PWMController 20, power supply 30 and load winding module 40.Wherein, each phase load winding uses in the load winding module 40Star connects mode and connects.The PWM controller includes control terminal Vi1~Vi6.
By taking the specific structure of the i-th phase drive module 100 as an example, as shown in figure 4, with the flash in the i-th phase drive module 100Driving unit 110 is similar, the low side grid current of the low metal-oxide-semiconductor Qi2 grid when driving unit 120 includes being connected to described lowVent unit 121 and resistance Ri2, capacitor Ci3.The low side grid current vent unit 121 further include triode Ti2 andDiode Di4.Each component connection relationship and first device each in the flash driving unit 110 in above-mentioned low side driving unit 120Part connection relationship is similar, and the effect about these components is referred to the description to flash driving unit 110 above, herein notIt repeats again.
Wherein, the motor-drive circuit 10 includes 3 phase drive modules, is connected in parallel between 3 phase drive modules.OftenA phase drive module is connected with the corresponding phase load winding in the load winding module 40, and the flash of each phase drive module drivesMoving cell and low side driving unit connect with the corresponding control port of the PWM controller 20 respectively.Each phase driving unitSpecific connection structure is referred to the description to the i-th phase drive module 100 above, and details are not described herein again.
The preferred embodiment of the disclosure is described in detail in conjunction with attached drawing above, still, the disclosure is not limited to above-mentioned realityThe detail in mode is applied, in the range of the technology design of the disclosure, a variety of letters can be carried out to the technical solution of the disclosureMonotropic type, these simple variants belong to the protection scope of the disclosure.
It is further to note that specific technical features described in the above specific embodiments, in not lanceIn the case where shield, can be combined in any appropriate way, for example, it is only low in driving unit include it is low while gridElectric current vent unit, and flash driving unit does not include flash grid current vent unit.The disclosure is to various possible combinationsNo further explanation will be given for mode.
In addition, any combination can also be carried out between a variety of different embodiments of the disclosure, as long as it is without prejudice to originallyDisclosed thought equally should be considered as disclosure disclosure of that.