CN105850031B - Motor driver - Google Patents

Abstract

An object of the present invention is to provide a motor drive device having a small and low-cost overvoltage protection unit that protects equipment from transient overvoltage. In the motor drive device (10), when an excessive voltage is generated, the transistors (Q3a to Q5b) of both the upper and lower arms are turned off, so that the excessive voltage is divided by the two ends of the two transistors connected in series, and applied to Since the excessive voltage of one transistor is reduced to half of that when either one is operating, it is possible to protect the transistor from damage. In addition, there is a high possibility that the switching elements (diodes D3a to D5b) are turned on due to the energy of the inductance component of the motor (51) and the induced voltage of the motor 51. However, after the transistors of both the upper and lower arms are turned off, By electrically braking the motor (51) to quickly stop the motor (51), the conduction time of the switching element (diode) can be shortened.

Description

Motor driver

Technical field

The present invention relates to motor drivers.

Background technique

Alternating voltage is rectified and obtain DC voltage equipment in, DC voltage is become according to alternating voltage It is dynamic.In particular, supply voltage be easy to produce equipment used in the region of variation no matter voltage rise when countermeasure how, all It is likely to result in the failure of equipment.Therefore, it is equipped with as disclosed in patent document 1 (Japanese Unexamined Patent Publication 2007-166815 bulletin) Overvoltage protective unit.Using input transformer as subsidiary load ratio bridging switch, (タ ッ プ is cut the overvoltage protective unit when load Parallel operation) transformer, when the voltage more than threshold value is input to inverter and exceeds schedule time, by subsidiary load ratio bridging switch Transformer tap (tap) conversion to low-pressure side.

Summary of the invention

Subject to be solved by the invention

But although the transformer of subsidiary load ratio bridging switch as described above is as towards large-scale electrical equipment Transformer is suitable, but the driving device for the motor by inverter control for being dfficult to apply to household appliances etc..

In addition, supply voltage becomes, the excessive required time is extremely short, and tap conversion as described above excessively spends the time, because This, it is difficult to reliably protect such motor driver.Furthermore, for as semiconductor element, overvoltage can be born Time shorter element, can not be protected by the cutting based on relay.Though in this way, but excessive just to moment Voltage and the pressure resistance for improving semiconductor element etc. will lead to high cost and enlargement.

Therefore, the issue of the present invention is to provide have protection equipment be not subjected to moment excessive voltage it is small-sized and low at The motor driver of this overvoltage protective unit.

The means used to solve the problem

The motor driver of 1st viewpoint of the invention is following motor driver: by dividing with multiple phases of motor Not corresponding multiple upper lower arms are connected in series with 2 switch elements respectively and are constituted, from the tie point being consequently formed respectively to right The phase output voltage answered, wherein there is power suppling part, voltage detection department and control unit.The upward lower arm of power suppling part DC voltage Vdc is provided.Voltage detection department is connected in parallel with upper lower arm.Control unit makes switch element carry out turn-on deadline movement. In addition, control unit when the detected value of voltage detection department has been more than defined threshold value ends, the switch element of lower arm both sides.

In the motor driver, during the switch element movement of any one arm in upper lower arm, DC voltage Vdc can be applied to the switch element ended in lower arm, and therefore, when becoming excessive voltage, which is applied to cut-off 1 switch element and a possibility that destroying the switch element it is big.

Therefore, when generating excessive voltage, by ending the switch element of upper lower arm both sides, so that excessive voltage is gone here and there Join the respective both ends partial pressure of 2 switch elements of connection, the excessive voltage for being applied to 1 switch element is reduced to either side Half when being acted, therefore being capable of protective switch element damage.

The motor driver of 2nd viewpoint of the invention also has electricity on the basis of the motor driver of the 1st viewpoint The braking circuit of machine.Control unit brakes motor after the switch element cut-off for making upper lower arm both sides.

In the motor driver, when generating excessive voltage, by ending the switch element of upper lower arm both sides, make The respective both ends partial pressure of 2 switch elements that voltage too much is connected in series, is applied to the excessive voltage quilt of 1 switch element Half when either side being reduced to be acted, therefore being capable of protective switch element damage.

Although in addition, the energy due to possessed by the inductance ingredient of motor and the induced electricity due to caused by the rotation of motor A possibility that pressing and leading to switching elements conductive is big, still, after the switch element cut-off for making upper lower arm both sides, by motor Electric braking is carried out soon to make its stopping, the energy of inductance ingredient can be soon consumed, further, it is possible to soon make electricity The rotating energy of machine is decayed, and the time of switching elements conductive is shortened.

The basis of motor driver of the motor driver of 3rd viewpoint of the invention in the 1st viewpoint or the 2nd viewpoint On, also there is ohmic load and ohmic load connection unit.Ohmic load connection unit by the tie point of two switch elements with It is attached between ohmic load or cuts off the connection between the tie point and ohmic load of two switch elements.Control unit After the switch element cut-off for making upper lower arm both sides, which is connect with ohmic load.

In the motor driver, when generating excessive voltage, by ending the switch element of upper lower arm both sides, make The respective both ends partial pressure of 2 switch elements that voltage too much is connected in series, is applied to the excessive voltage quilt of 1 switch element Half when either side being reduced to be acted, therefore being capable of protective switch element damage.

Although in addition, the energy due to possessed by the inductance ingredient of motor and the induced electricity due to caused by the rotation of motor A possibility that pressing and leading to switching elements conductive is big, still, after the switch element cut-off for making upper lower arm both sides, by making resistance Load is respectively connected with motor, consumes energy possessed by the inductance ingredient of motor, energy in a short time using ohmic load Enough shorten the time of switching elements conductive.

The motor of any one viewpoint of the motor driver of 4th viewpoint of the invention in the 1st viewpoint to the 3rd viewpoint drives On the basis of dynamic device, the mechanical brake that is also dismounted with respect to the rotary shaft of motor.Control unit is on making After the switch element cut-off of lower arm both sides, mechanical braking is carried out to motor.

In the motor driver, when generating excessive voltage, by ending the switch element of upper lower arm both sides, make The respective both ends for 2 switch elements that voltage too much is connected in series divide, and are applied to the excessive voltage of 1 switch element It is reduced to half when either side is acted, therefore being capable of protective switch element damage.

Although in addition, the energy as possessed by the inductance ingredient of motor and the induced voltage of the rotation based on motor and A possibility that leading to switching elements conductive, is big, still, after the switch element cut-off for making upper lower arm both sides, by carrying out to motor Mechanical braking soon makes its stopping, the rotating energy of motor can be made to decay, shortens the time of switching elements conductive.

The motor of any one viewpoint of the motor driver of 5th viewpoint of the invention in the 1st viewpoint to the 4th viewpoint drives On the basis of dynamic device, wherein control unit makes all upper lower arms when the detected value of voltage detection department has been more than threshold value After the switch element of any one arm in 2 switch elements all turns on, end all switch elements.

In the motor driver, any one arm in 2 switch elements by making all upper lower arms is opened It closes element to all turn on, the current reflux from motor can be made, cause preventing the regeneration due to the rotating energy of motor Dc voltage boost while, make current attenuation 0 using the internal driving of motor.Then, make opening for all upper lower arms Element cut-off is closed, even if assuming the induced voltage of the energy as possessed by the inductance ingredient of motor and the rotation based on motor And lead to switching elements conductive, it can also shorten the time of its conducting.

The motor of any one viewpoint of the motor driver of 6th viewpoint of the invention in the 2nd viewpoint to the 5th viewpoint drives On the basis of dynamic device, wherein other than when the detected value of voltage detection department is more than threshold value, control unit not to the motor into The row braking.

It, need not to inhibit by the way that the operating of braking to be limited to only in overvoltage in the motor driver The motor wanted stops.

The motor of any one viewpoint of the motor driver of 7th viewpoint of the invention in the 1st viewpoint to the 6th viewpoint drives On the basis of dynamic device, also there is boostrap circuit.Boostrap circuit in order to the upper arm side switch element of upper lower arm driving power and Generate the current potential for being higher than the low potential side of the switch element.

In the motor driver, when generating excessive voltage, by ending the switch element of upper lower arm both sides, make The respective both ends partial pressure of 2 switch elements that voltage too much is connected in series, is applied to the excessive voltage quilt of 1 switch element Half when either side being reduced to be acted, therefore being capable of protective switch element damage.In other words, as direct current The voltage in voltage portion (hereinafter, saving the slightly portion DC), one times of the voltage that can bear to reach a component pressure, so that series connection connects 2 switch elements connect are able to bear component pressure (sub-prime pressure resistance).

At this point, the midpoint potential of upper lower arm be up to component pressure or so (element can destroy if on this, Because without regard to), therefore, for boostrap circuit, on its circuit structure, can bear the portion DC common voltage rating (that is, One component pressure) design with regard to enough.

The motor of any one viewpoint of the motor driver of 8th viewpoint of the invention in the 1st viewpoint to the 6th viewpoint drives On the basis of dynamic device, also there are insulated power supplies.Insulated power supplies be used to drive the upper arm side switch element of lower arm.

In the motor driver, when generating excessive voltage, by ending the switch element of upper lower arm both sides, make The respective both ends partial pressure of 2 switch elements that voltage too much is connected in series, is applied to the excessive voltage quilt of 1 switch element Half when either side being reduced to be acted, therefore being capable of protective switch element damage.

At this point, when generating excessive voltage, by ending the switch element of upper lower arm both sides, so that the midpoint of upper lower arm (element will be destroyed on this) until current potential maximum a to component pressure or so, therefore, for insulated power supplies, can bear The design of the common voltage rating (that is, a component pressure) in the portion DC is with regard to enough.

The motor driver of 9th viewpoint of the invention also has flat on the basis of the motor driver of the 1st viewpoint Weigh circuit.Balanced circuit configurations are between connection power suppling part and a pair of of the DC bus and above-mentioned tie point of upper lower arm.Control Portion makes switch element carry out turn-on deadline movement.In addition, when the detected value of voltage detection department has been more than defined threshold value, control Portion ends the switch element of lower arm both sides.

During the switch element of any one movement in upper lower arm, DC voltage Vdc can be applied in lower arm The switch element of cut-off, therefore, when becoming excessive voltage, which is applied to 1 switch element of cut-off and destroys A possibility that switch element, is big.

In the motor driver, when generating excessive voltage, by ending the switch element of upper lower arm both sides, make The respective both ends partial pressure of 2 switch elements that voltage too much is connected in series, is applied to the excessive voltage quilt of 1 switch element Half when either side being reduced to be acted, therefore being capable of protective switch element damage.

But DC voltage Vdc is since the difference of the impedance of 2 switch elements is without equably being divided, lead to Connection balancing circuitry is crossed, so that DC voltage Vdc is substantially uniformly divided by the both ends of 2 switch elements.

The motor driver of 10th viewpoint of the invention is on the basis of the motor driver of the 9th viewpoint, wherein flat Weighing apparatus circuit is configured to respectively correspond with the switch element of multiple upper lower arms.

In the motor driver, such as in the case where inverter circuit, 3 pairs of upper lower arms are connected in parallel, therefore, By the way that balancing circuitry to be connect with each upper lower arm, so that DC voltage Vdc is by 2 switches of each upper lower arm in overvoltage The both ends of element substantially uniformly divide, therefore being capable of protective switch element damage.

The base of motor driver of the excess voltage protection of 11st viewpoint of the invention in the 9th viewpoint or the 10th viewpoint On plinth, there is switch.The tie point of two switch elements of the switch for that will be connected in series and with described two switch elements pair Be attached between the intermediate point for a pair of of the balancing circuitry answered or by the tie point of two switch elements and with described two switches Connection cutting between the intermediate point of corresponding a pair of of the balancing circuitry of element.Control unit is more than in the detected value of voltage detection department When defined threshold value, balancing circuitry is connected.

In the motor driver, by tie point NU, NV, NW and with described tie point NU, NV, NW corresponding one To configuration switch between the intermediate point of balancing circuitry and balancing circuitry only is connected when inverter ends, is able to suppress balancing circuitry Power consumption.

The motor of any one viewpoint of the motor driver of 12nd viewpoint of the invention in the 9th viewpoint to the 11st viewpoint On the basis of driving device, wherein balancing circuitry is made of resistive element.

In the motor driver, since resistive element is less expensive, it is able to suppress since balancing circuitry is arranged Caused by increased costs.

The present invention provides a kind of motor driver, is distinguished by multiple mutually corresponding multiple upper lower arms with motor It is connected in series and constitutes with 2 switch elements, from the tie point being consequently formed respectively to the corresponding phase output voltage, In,

The motor driver includes

Power suppling part rectifies the alternating voltage exported from source power supply and generates DC power supply, to described Upper lower arm provides DC voltage；

Voltage detection department is connected in parallel with the upper lower arm；And

Control unit makes the switch element carry out turn-on deadline movement,

The control unit when the detected value of the voltage detection department has been more than defined threshold value, make it is all it is described on After the switch element of any one arm in 2 switch elements of lower arm all turns on, make it is all it is described up and down The switch element of arm both sides ends.

The present invention provides a kind of motor driver, is distinguished by multiple mutually corresponding multiple upper lower arms with motor It is connected in series and constitutes with 2 switch elements, from the tie point being consequently formed respectively to the corresponding phase output voltage, In,

The motor driver includes

Power suppling part rectifies the alternating voltage exported from source power supply and generates DC power supply, to described Upper lower arm provides DC voltage；

Voltage detection department is connected in parallel with the upper lower arm；

Boostrap circuit, in order to the upper arm side switch element of the upper lower arm driving power and generate higher than the switch The current potential of the low potential side of element；And

Control unit makes the switch element carry out turn-on deadline movement,

The control unit makes the upper lower arm both sides when the detected value of the voltage detection department has been more than defined threshold value The switch element cut-off.

The present invention provides a kind of motor driver, is distinguished by multiple mutually corresponding multiple upper lower arms with motor It is connected in series and constitutes with 2 switch elements, from the tie point being consequently formed respectively to the corresponding phase output voltage, In,

The motor driver includes

Power suppling part rectifies the alternating voltage exported from source power supply and generates DC power supply, to described Upper lower arm provides DC voltage；

Voltage detection department is connected in parallel with the upper lower arm；

Balancing circuitry is configured in a pair of of the DC bus and the connection for connecting the power suppling part and the upper lower arm Between point；And

Control unit makes the switch element carry out turn-on deadline movement,

The control unit makes the upper lower arm both sides when the detected value of the voltage detection department has been more than defined threshold value The switch element cut-off.

The effect of invention

In the motor driver of the 1st viewpoint of the invention, when generating excessive voltage, by making upper lower arm both sides' Switch element cut-off, so that the respective both ends partial pressure of 2 switch elements that excessive voltage is connected in series, is applied to 1 switch The excessive voltage of element is reduced to half when either side is acted, therefore being capable of protective switch element damage.

In the motor driver of the 2nd viewpoint of the invention, when ending the switch element of upper lower arm both sides, although The energy due to possessed by the inductance ingredient of motor and the induced voltage due to caused by the rotation of motor and lead to switch element A possibility that conducting, is big, still, after the switch element cut-off for making upper lower arm both sides, by carrying out electric braking to motor come very Make its stopping fastly, the time of switching elements conductive can be shortened.

In the motor driver of the 3rd viewpoint of the invention, when ending the switch element of upper lower arm both sides, although The energy due to possessed by the inductance ingredient of motor and the induced voltage due to caused by the rotation of motor and lead to switch element A possibility that conducting, is big, still, after the switch element cut-off for making upper lower arm both sides, by making each phase of the ohmic load with motor Connection, is consumed energy possessed by the inductance ingredient of motor in a short time using ohmic load, can shorten switch element and lead The logical time.

In the motor driver of the 4th viewpoint of the invention, when ending the switch element of upper lower arm both sides, although The energy due to possessed by the inductance ingredient of motor and the induced voltage due to caused by the rotation of motor and lead to switch element A possibility that conducting, is big, still, after the switch element cut-off for making upper lower arm both sides, by carrying out mechanical braking to motor come very Make its stopping fastly, the time of switching elements conductive can be shortened.

In the motor driver of the 5th viewpoint of the invention, in 2 switch elements by making all upper lower arms The switch element of any one arm all turns on, and can make the current reflux from motor, is preventing the rotational energy due to motor Caused by the regeneration of amount while dc voltage boost, make current attenuation 0 using the internal driving of motor.Then, make institute The switch element for the upper lower arm having ends, even if assuming the energy as possessed by the inductance ingredient of motor and induced voltage Lead to switching elements conductive, can also shorten the time of its conducting.

In the motor driver of the 6th viewpoint of the invention, by the way that the operating of braking is limited to only in overvoltage, To inhibit unnecessary motor to stop.

In the motor driver of the 7th viewpoint of the invention, when generating excessive voltage, by making upper lower arm both sides' Switch element cut-off, so that the midpoint potential of upper lower arm is up to the degree of a component pressure, therefore, for bootstrapping electricity Road can bear the design of common voltage rating (that is, a component pressure) in the portion DC with regard to enough.

In the motor driver of the 8th viewpoint of the invention, when generating excessive voltage, by making upper lower arm both sides' Switch element cut-off, so that the midpoint potential of upper lower arm is up to the degree of a component pressure, therefore, for insulated electro Source can bear the design of common voltage rating (that is, a component pressure) in the portion DC with regard to enough.

In the motor driver of the 9th viewpoint of the invention, the switch element of any one in upper lower arm is carried out During movement, DC voltage Vdc can be applied to the switch element of the cut-off of lower arm, therefore, should when becoming excessive voltage A possibility that excessive voltage is applied to 1 switch element of cut-off and destroys the switch element is big.

Therefore, when generating excessive voltage, by ending the switch element of upper lower arm both sides, so that excessive voltage is gone here and there Join the respective both ends partial pressure of 2 switch elements of connection, the excessive voltage for being applied to 1 switch element is reduced to either side Half when being acted or so, therefore being capable of protective switch element damage.

But DC voltage Vdc is since the difference of the impedance of 2 switch elements is without equably being divided, lead to Connection balancing circuitry is crossed, so that DC voltage Vdc is substantially uniformly divided by the both ends of 2 switch elements.

In the motor driver of the 10th viewpoint of the invention, in the case where inverter circuit, 3 pairs of upper lower arms are by simultaneously Connection connection, therefore, by the way that balancing circuitry to be connect with each upper lower arm, so that DC voltage Vdc is by each in overvoltage The both ends of 2 switch elements of lower arm substantially uniformly divide, therefore being capable of protective switch element damage.

In the motor driver of the 11st viewpoint of the invention, by tie point NU, NV, NW and with the tie point Configuration switchs and only connects balancing circuitry when inverter ends between the intermediate point of corresponding a pair of of the balancing circuitry of NU, NV, NW, It is able to suppress the power consumption of balancing circuitry.

In the motor driver of the 12nd viewpoint of the invention, since resistive element is less expensive, it is able to suppress Due to increased costs caused by balancing circuitry is arranged.

Detailed description of the invention

Fig. 1 is the overall structure and electricity for showing the system of the motor driver using the 1st embodiment of the invention The block diagram of the circuit structure of machine actuating device.

Fig. 2A is the figure for showing the mode for applying voltage when motor driver operating to upper lower arm.

Fig. 2 B is the figure for showing the mode for applying voltage when motor driver stops to upper lower arm.

Fig. 3 is the overall structure and electricity for showing the system of the motor driver using the 2nd embodiment of the invention The block diagram of the circuit structure of machine actuating device.

Fig. 4 is the overall structure and electricity for showing the system of the motor driver using the 3rd embodiment of the invention The block diagram of the circuit structure of machine actuating device.

Fig. 5 is the overall structure and electricity for the system for showing the motor driver using other embodiments of the present invention The block diagram of the internal structure of machine actuating device.

Fig. 6 be show be applied to the voltage at electrolytic capacitor both ends and flow through electrolytic capacitor electric current between relationship The curve graph of voltage/current characteristic.

Fig. 7 A is the curve graph for showing the control of the variation for DC voltage Vdc.

Fig. 7 B is to be loaded into have avalanche region in the curve graph of the control for indicating the variation for DC voltage Vdc of Fig. 7 A The curve graph of the variation of the voltage Vds at the both ends of the semiconductor element in domain.

Fig. 8 is the circuit diagram with the major part of motor driver of boostrap circuit.

Fig. 9 is the circuit diagram with the major part of motor driver of insulated power supplies.

Figure 10 is the circuit diagram with the major part of motor driver of charge pump circuit.

Figure 11 is the block diagram for showing the circuit structure of motor driver of the 4th embodiment of the invention.

Figure 12 A is the figure for showing the mode for applying voltage when motor driver operating to upper lower arm.

Figure 12 B is the figure for showing the mode for applying voltage when motor driver stops to upper lower arm.

Figure 12 C is the mode for applying voltage after showing motor driver stopping, when being connected to balancing circuitry to upper lower arm Figure.

Figure 13 is the block diagram for showing the circuit structure of motor driver of the 5th embodiment of the invention.

Figure 14 is to apply after showing the motor driver stopping of other embodiment, when being connected to balancing circuitry to upper lower arm The figure of alive mode.

Specific embodiment

Hereinafter, the embodiments of the present invention will be described with reference to the drawings.In addition, following implementation is tool of the invention Body example does not limit technical scope of the invention.

(the 1st embodiment)

(1) summary

Fig. 1 is the overall structure for showing the system 100 of the motor driver 10 using the 1st embodiment of the invention With the block diagram of the internal structure of motor driver 10.In Fig. 1, device 10 is driven by motor in system 100 and motor 51 is constituted.

(1-1) motor 51

Motor 51 is three-phase brushless DC motor, has stator 52 and rotor 53.Stator 52 includes the U phase of star-star connection, V Driving coil Lu, Lv, Lw of phase, W phase.One end of each driving coil Lu, Lv, Lw respectively with extend from inverter 25 U phase, V Phase, the respective wiring of W phase coil terminals TU, TV, TW connection.The other end of each driving coil Lu, Lv, Lw are as terminal TN is connected with each other.Driving coil Lu, Lv, Lw of this three-phase, which are rotated by rotor 53 so that generating, rotates speed and rotor The corresponding induced voltage in 53 position.

Rotor 53 includes the permanent magnet for the multiple poles being made of the pole N and the pole S, relative to stator 52 centered on rotary shaft It is rotated.

In addition, motor 51 is, for example, compressor electric motor, the fan motor of heat pump type air conditioner.

(1-2) motor driver 10

As shown in Figure 1, motor driver 10 includes rectification part 21；Smoothing capacity device 22；Voltage detection department 23；Electric current Test section 24；Inverter 25；Gate driving circuit 26；And control unit 40.Above-mentioned part can also for example be mounted at 1 print On brush substrate.

(2) detailed construction of motor driver 10

(2-1) rectification part 21

Rectification part 21 is configured to bridge like by 4 diodes D1a, D1b, D2a, D2b.Specifically, diode D1a and D1b, D2a and D2b connection in series with each other.The respective cathode terminal of diode D1a, D2a all with the positive side of smoothing capacity device 22 Son connection, the positive side output terminal as rectification part 21 play a role.The respective anode terminal of diode D1b, D2b is all and smoothly The negative side terminal of capacitor 22 connects, and the negative side output terminal as rectification part 21 plays a role.

The tie point of diode D1a and diode D1b are connect with a pole of source power supply 91.Diode D2a and two poles The tie point of pipe D2b is connect with another pole of source power supply 91.Rectification part 21 is to the alternating voltage exported from source power supply 91 It is rectified and generates DC power supply, and DC power supply is supplied to smoothing capacity device 22.

(2-2) smoothing capacity device 22

One end of smoothing capacity device 22 is connect with the positive side output terminal of rectification part 21, the negative side of the other end and rectification part 21 Output terminal connection.Smoothing capacity device 22 is smoothed the voltage after being rectified by rectification part 21.Hereinafter, for the ease of saying It is bright, the smoothed out voltage of capacitor 22 will be smoothed and be referred to as DC voltage Vdc.

DC voltage Vdc is applied to the inverter 25 connecting with the outlet side of smoothing capacity device 22.That is, 21 He of rectification part Smoothing capacity device 22 constitutes the power suppling part 20 for inverter 25.

In addition, the type as capacitor, can enumerate electrolytic capacitor and thin film capacitor, Tantal condenser etc., In present embodiment, using thin film capacitor as smoothing capacity device 22.

(2-3) voltage detection department 23

Voltage detection department 23 is connect with the outlet side of smoothing capacity device 22, for detecting the both end voltage of smoothing capacity device 22 That is the value of DC voltage Vdc.Voltage detection department 23 is for example configured to will be connected in series with each other two resistance and smoothing capacities Device 22 is connected in parallel, and is divided to DC voltage Vdc.The voltage value of tie point between the two resistance is entered control Portion 40 processed.

(2-4) current detecting part 24

Current detecting part 24 is connected between smoothing capacity device 22 and inverter 25, and is negative with smoothing capacity device 22 The connection of side output terminal side.Current detecting part 24 will flow through the current of electric Im of motor 51 as three-phase after the starting of motor 51 The aggregate value of electric current detects.

Current detecting part 24 can also for example by having used shunt resistance and having amplified the both end voltage of the resistance operation The amplifying circuit of amplifier is constituted.Control unit 40 is entered by the current of electric that current detecting part 24 detects.

(2-5) inverter 25

Inverter 25 and respectively 3 corresponding with driving coil Lu, Lv, Lw of the U phase of motor 51, V phase and W phase upper lower arms It is parallel with one another, and connect with the outlet side of smoothing capacity device 22.

In Fig. 1, inverter 25 include multiple IGBT (insulated gate bipolar transistor, hereinafter simply referred to as transistor) Q3a, Q3b, Q4a, Q4b, Q5a, Q5b and multiple reflux diode D3a, D3b, D4a, D4b, D5a, D5b.

Transistor Q3a and Q3b, Q4a and Q4b, Q5a and Q5b constitute each upper lower arm and being connected in series with each other respectively, Also, driving coil Lu, Lv, Lw that output line is respectively facing corresponding phase from tie point NU, NV, the NW being consequently formed prolong It stretches.

Each diode D3a~D5b is connected in parallel with each transistor Q3a~Q5b as follows: the current collection of transistor Extreme son is connected with the cathode terminal of diode, and the emitter terminal of transistor is connected with the anode terminal of diode.By this point The transistor and diode not being connected in parallel constitute switch element.

Inverter 25 is applied to the DC voltage Vdc from smoothing capacity device 22 via DC bus (power supply line 801,802), And each transistor Q3a~Q5b is connected and is ended in the timing indicated by gate driving circuit 26, is thus generated and is used for Driving voltage SU, SV, SW of driving motor 51.Driving voltage SU, SV, SW from each transistor Q3a and Q3b, Q4a and Q4b, Each tie point NU, NV, NW of Q5a and Q5b is exported to driving coil Lu, Lv, Lw of motor 51.

Although but not limited to this, is also possible to electricity in addition, the inverter 25 of present embodiment is voltage source inverter Flow pattern inverter.

(2-6) gate driving circuit 26

Gate driving circuit 26 makes each transistor of inverter 25 according to the command voltage Vpwm from control unit 40 The state change of the on and off of Q3a~Q5b.Specifically, gate driving circuit 26 generate to each transistor Q3a~ Grid-control voltage Gu, Gx, Gv, Gy, Gw, Gz that the grid of Q5b applies so that from inverter 25 to motor 51 output have by Driving voltage SU, SV, SW of the pulse type for the duty ratio that control unit 40 determines.Grid-control voltage Gu, Gx generated, Gv, Gy, Gw, Gz are applied to the gate terminal of each transistor Q3a~Q5b.

(2-7) control unit 40

Control unit 40 is connect with voltage detection department 23, current detecting part 24 and gate driving circuit 26.In present embodiment In, control unit 40 is the part of the driving motor 51 in a manner of no-rotor position sensor.In addition, being not limited to no-rotor position Approach sensor, therefore can also be carried out with approach sensor.

No-rotor position sensor mode refers to such as under type: using the various parameters for the characteristic for indicating motor 51, motor 51 start after the testing result of the voltage detection department 23, testing result of current detecting part 24, relevant to the control of motor 51 Defined mathematical model etc., the estimation, the PI control for revolving speed, the PI for current of electric for carrying out rotor-position and revolving speed are controlled System etc. is come the mode that is driven.As the various parameters for the characteristic for indicating motor 51, used motor 51 can be enumerated Winding resistance, inductance ingredient, induced voltage, number of poles etc..In addition, about no-rotor position sensor control, there are many patent texts It offers, therefore, details please refers to these patent documents (for example, Japanese Unexamined Patent Publication 2013-17289 bulletin).

In addition, control unit 40 monitors the detected value of voltage detection department 23, when the detected value of voltage detection department 23 is more than regulation Threshold value when, also carry out protection control, make transistor Q3a~Q5b end.

(2-8) braking circuit 61

In Fig. 1, braking circuit 61 is made of 3 transistors 61u, 61v, 61w.Transistor 61u is connected to the driving of U phase The midway of coil Lu and the shared tie point N wiring connecting.Transistor 61v is connected to the driving coil Lv of V phase and the company of sharing The midway of the wiring of contact N connection.Transistor 61w is connected to the wiring for connecting the driving coil Lw of W phase with shared tie point N Midway.In addition, transistor 61u~61w is connect with reflux with diode respectively.

3 respective base stages of transistor 61u, 61v, 61w are connect via signal wire with control unit 40.

During motor 51 normally rotates, control unit 40 does not export 3 respective base stages of transistor 61u, 61v, 61w Therefore driving signal is nonconducting state between the respective collector-emitter of 3 transistors 61u, 61v, 61w.

But when control unit 40 is to the respective base stage output drive signal of 3 transistors 61u, 61v, 61w, Ge Geji Become on state between electrode-transmitter pole, driving coil Lu, Lv, Lw are connected, to brake to motor 51.

(3) movement of motor driver 10

Hereinafter, being illustrated to the movement of motor driver 10.In Fig. 1, control unit 40 to gate driving circuit 26 into The output of traveling wave shape, also, the state of waveform output is controlled, driving motor 51 is come with egulation rotating speed.

Fig. 2A is the figure for showing the mode for applying voltage when motor driver 10 operates to upper lower arm, and Fig. 2 B is to show electricity Apply the figure of the mode of voltage when machine actuating device 10 stops to upper lower arm.

As shown in Figure 2 A, in operating, in the transistor Q3a of upper arm corresponding with driving coil Lu and Lv couples of driving coil During the transistor Q5b of the transistor Q4b for the lower arm answered and lower arm corresponding with driving coil Lw carries out turn-on action, DC voltage Vdc be applied to the cut-off of each upper lower arm switch element (transistor Q3b, Q4a, Q5a, diode D3b, D4a, D5a)。

At this point, the excessive voltage can be applied to the switch member of cut-off in the case where DC voltage Vdc becomes excessive voltage The transistor and diode of part.If the element of a switch element (transistor Q3a~Q5b and diode D3a~D5b) is resistance to Pressure is set as Vr, then as DC voltage Vdc > component pressure Vr, the transistor Q3a~Q5b or diode D3a of switch element A possibility that~D5b is destroyed is big.

Therefore, when control unit 40 is judged as that the detected value of voltage detection department 23 has been more than defined threshold value, make lower arm Transistor Q3a, Q3b, Q4a, Q4b, Q5a, Q5b of both sides ends.

As a result, as shown in Figure 2 B, 2 switch elements that excessive voltage is connected in series (transistor Q3a, Q3b, Q4a, Q4b, Q5a, Q5b, diode D3a, D3b, D4a, D4b, D5a, D5b) respective both ends partial pressure.For example, partial pressure value V1 is applied to The both ends of the switch element (transistor Q3a, Q4a, Q5a, diode D3a, D4a, D5a) of upper arm, partial pressure value V2 are applied to lower arm Switch element (transistor Q3b, Q4b, Q5b, diode D3b, D4b, D5b) both ends.In the ideal case, if each switch The impedance of element is equal, then V1=V2, and therefore, the excessive voltage for being applied to 1 switch element is reduced to either side progress Half when movement, so as to protect each switch element damage.

In turn, control unit 40 make transistor Q3a~Q5b end after, to braking circuit 61 3 transistor 61u, 61v, The respective base stage output drive signal of 61w makes to become on state between each collector-emitter.As a result, motor 51 It is braked.

The purpose braked to motor 51 is because the energy as possessed by the inductance ingredient of motor 51 and being based on The induced voltage of the rotation of motor 51 and cause switch element diode D3a~D5b be connected a possibility that it is big.Even if assuming two Pole pipe D3a~D5b conducting soon makes its stopping by carrying out electric braking to motor 51, can also shorten diode D3a The time of~D5b conducting.

In addition, in the present embodiment, other than when the detected value of voltage detection department 23 is more than threshold value, control unit 40 is not Motor 51 is braked.That is, by the way that the operating of braking is limited to only in overvoltage, to inhibit unnecessary motor Stop.

The feature of (4) the 1st embodiments

(4-1)

In motor driver 10, when generating excessive voltage, by the transistor Q3a~Q5b for making upper lower arm both sides It is (brilliant to be applied to 1 switch element so that the respective both ends for 2 switch elements that excessive voltage is connected in series divide for cut-off Body pipe Q3a~Q5b, diode D3a~D5b) excessive voltage be reduced to half when either side is acted, therefore energy Enough protective switch element damages.

(4-2)

In motor driver 10, although the energy as possessed by the inductance ingredient of motor 51 and due to motor 51 Rotation caused by induced voltage and cause diode D3a~D5b be connected a possibility that it is big, still, make upper lower arm both sides' After transistor Q3a~Q5b cut-off, soon makes its stopping by carrying out electric braking to motor 51, diode can be shortened The time of D3a~D5b conducting.

(the 2nd embodiment)

(1) summary

Fig. 3 is the overall structure for showing the system 100 of the motor driver 10 using the 2nd embodiment of the invention With the block diagram of the internal structure of motor driver 10.

Ohmic load 71 and relay circuit 73 are equipped in Fig. 3, in the motor driver 10 of the 2nd embodiment to replace Braking circuit 61 in 1st embodiment shown in FIG. 1.Therefore, herein, ohmic load 71 and relay circuit 73 are said It is bright, element in addition to this due to identical as the 1st embodiment (structure in addition to braking circuit 61), mark it is identical Title and label, and omit detail explanation.

(2) detailed construction of motor driver 10

(2-1) ohmic load 71

In Fig. 3, ohmic load 71 is made of 3 resistive elements 71u, 71v, 71w.Resistive element 71u is connected to U phase The midway of driving coil Lu and the shared tie point N route connecting.Resistive element 71v be connected to by the driving coil Lv of V phase with Share the midway of the route of tie point N connection.Resistive element 71w, which is connected to, connects the driving coil Lw of W phase and shared tie point N The midway of the route connect.In general, above-mentioned each route is cut off by relay circuit 73.

(2-2) relay circuit 73

Relay circuit 73 includes driving coil Lu, Lv of each phase of motor 51, Lw, keeps connection corresponding with them each Relay tip 73a that the route of resistive element 71u, 71v, 71w are electrically disconnected and are closed, carry out relay tip 73a The relay coil 73b of movement and to relay coil 73b carry out be powered and cold transistor 73c.Relay coil One end of 73b is connect with the anode of driving power Vb, and the other end is connect with the collector side of transistor 73c.Control unit 40 is cut The presence or absence of the base current for changing transistor 73c makes to be connected and end between collector and emitter, carry out to relay coil The energization of 73b and no power.

(3) movement of motor driver 10

Hereinafter, being illustrated to the movement of motor driver 10.In addition, being judged as voltage detection department to when control unit 40 Until making at transistor Q3a~Q5b cut-off of lower arm both sides when 23 detected value has been more than defined threshold value with the 1st embodiment party Formula is identical, and and the description is omitted.

After control unit 40 ends transistor Q3a~Q5b, exports and drive to the base stage of the transistor 73c of relay circuit 73 Dynamic signal makes to become on state between each collector-emitter.At this point, relay coil 73b is motivated, relay is connect Point 73a closure connects the driving coil Lu of the resistive element 71u and U phase or driving coil Lv of resistive element 71v and V phase, into And the driving coil Lw of resistive element 71w and W phase is connected, motor is consumed in a short time using resistive element 71u, 71v, 71w Energy possessed by 51 inductance ingredient, to carry out electric braking.

Although the energy as possessed by the inductance ingredient of motor 51 and induced voltage and lead to diode D3a~D5b A possibility that conducting, is big, still, even if assuming diode D3a~D5b conducting, by being existed using resistive element 71u, 71v, 71w Energy possessed by the inductance ingredient of consumption motor 51, can also shorten the time of diode D3a~D5b conducting in short time.

The feature of (4) the 2nd embodiments

(4-1)

In motor driver 10, when generating excessive voltage, by the transistor Q3a~Q5b for making upper lower arm both sides Cut-off, so that 2 switch elements (transistor Q3a~Q5b, diode D3a~D5b) that excessive voltage is connected in series are respective Both ends partial pressure, the excessive voltage for being applied to 1 switch element (transistor Q3a~Q5b, diode D3a~D5b) are reduced to appoint The half when side that anticipates acts, therefore the transistor Q3a~Q5b and diode D3a~D5b of being capable of protective switch element exempt from It is damaged.

(4-2)

In motor driver 10, although the energy as possessed by the inductance ingredient of motor 51 and due to motor A possibility that rotating caused induced voltage and diode D3a~D5b is caused to be connected is big, still, in the crystalline substance for making upper lower arm both sides After the cut-off of body pipe, by being consumed in a short time using resistive element 71u, 71v, 71w possessed by the inductance ingredient of motor 51 Energy can shorten the time of diode D3a~D5b conducting.

(the 3rd embodiment)

(1) summary

Fig. 4 is the overall structure for showing the system 100 of the motor driver 10 using the 3rd embodiment of the invention With the block diagram of the internal structure of motor driver 10.

In Fig. 4, in the motor driver 10 of the 3rd embodiment, by the electricity in the 1st embodiment shown in Fig. 1 Braking circuit 61 unload after structure in, it is new to be provided with the mechanical brake that dismounted relative to the output shaft of motor 51 81.Therefore, herein, brake 81 is illustrated, element in addition to this is due to (removing braking circuit 61 with the 1st embodiment Outer structure) it is identical, therefore, identical title and label are marked, and omit detail explanation.

(2) structure of motor driver 10

Brake 81 is mechanical brake, 85 is made of electromagnetic clutch 83 and load, wherein load 85 via electromagnetism from The rotation axis connection of clutch 83 and motor 51.Electromagnetic clutch 83 is according to the driving signal from control unit 40, by motor 51 Rotary shaft and load 85 link up or release the rotary shaft of motor 51 and the connection of load 85.

Since load 85 will make the rotary force of rotor 53 decay, had by the rotor 53 compared to motor 51 sufficiently large The rotating disk or rotary damper of rotary inertia are constituted.Certainly, it is not limited to rotating disk and rotary damper, as long as load 85 The rotary force of rotor 53 can be made to decay.

(3) movement of motor driver 10

Hereinafter, being illustrated to the movement of motor driver 10.In addition, until when control unit 40 is judged as voltage detecting The detected value in portion 23 is implemented until making at transistor Q3a~Q5b cut-off of lower arm both sides when being more than defined threshold value with the 1st Mode is identical, and and the description is omitted.

Control unit 40 acts electromagnetic clutch 83, by the rotation of motor 51 after ending transistor Q3a~Q5b Shaft and load 85 connect.

At this point, the conduct of the rotating energy of energy possessed by the inductance ingredient of motor 51 and motor 51 will make 85 rotation of load Energy and be consumed in a short time.

Although the energy due to possessed by the inductance ingredient of motor 51 and due to rotation caused by induced voltage and cause A possibility that diode D3a~D5b is connected is big, still, even if diode D3a~D5b conducting is assumed, by the electricity for making motor 51 The rotating energy of energy possessed by sense ingredient and motor 51 is disappeared in a short time as the energy that make 85 rotation of load Consumption can also shorten the time of diode D3a~D5b conducting.

The feature of (4) the 3rd embodiments

(4-1)

In motor driver 10, when generating excessive voltage, by the transistor Q3a~Q5b for making upper lower arm both sides Cut-off, so that 2 switch elements (transistor Q3a~Q5b, diode D3a~D5b) that excessive voltage is connected in series are respective Both ends partial pressure, the excessive voltage for being applied to 1 switch element (transistor Q3a~Q5b, diode D3a~D5b) are reduced to appoint The half when side that anticipates acts, therefore the transistor Q3a~Q5b and diode D3a~D5b of being capable of protective switch element exempt from It is damaged.

(4-2)

In motor driver 10, although the energy as possessed by the inductance ingredient of motor 51 and due to rotation draw Rise induced voltage and cause diode D3a~D5b be connected a possibility that it is big, still, in the transistor for the both sides for making upper lower arm After Q3a~Q5b cut-off, by consuming energy possessed by the inductance ingredient of motor 51 in a short time using mechanical brake 81 And the rotating energy of motor 51, the time of diode D3a~D5b conducting can be shortened.

The other > of <

(A)

It is following such structures: setting electric braking in the 1st embodiment, the 2nd embodiment and the 3rd embodiment Device or mechanical brake consume energy possessed by the inductance ingredient of motor 51 and braking to motor 51 in a short time The rotating energy of amount and motor 51, to shorten the time of switch element (diode D3a~D5b) conducting.

But from the viewpoint of in cost and structure, there is also the feelings that braking circuit or mechanical brake can not be arranged Condition.Under such circumstances, it is effective for carrying out following such control.

For example, when control unit 40 is judged as that the detected value of voltage detection department 23 has been more than threshold value, make it is all up and down After the transistor of any one arm in 2 transistors Q3a, Q3b, Q4a, Q4b, Q5a, Q5b of arm all turns on, make all Transistor Q3a~Q5b cut-off.

Any one arm in 2 transistors Q3a, Q3b, Q4a, Q4b, Q5a, Q5b by making all upper lower arms Transistor all turns on, and can make the current reflux from motor 51, preventing the regeneration due to the rotating energy of motor 51 and While caused dc voltage boost, make current attenuation 0 using the internal driving of motor 51.

Then, end transistor Q3a~Q5b of all upper lower arms, even if assuming the inductance ingredient due to motor 51 The induced voltage of possessed energy and motor 51 and cause diode D3a~D5b be connected, can also shorten its conducting when Between.

(B)

(B-1) summary

Fig. 5 is the whole knot for showing the system 100 of the motor driver 10 using other embodiments of the present invention The block diagram of the internal structure of structure and motor driver 10.

In Fig. 5, in the motor driver 10 of present embodiment, it will braked from the 1st embodiment shown in Fig. 1 Circuit 61 unload after structure in, the new relay circuit 75 being provided with for line of cutting off the power.In addition, smoothing capacity device is made For electrolytic capacitor 77.Therefore, herein, relay circuit 75 and electrolytic capacitor 77 are illustrated, element in addition to this Due to identical as the 1st embodiment (structure in addition to braking circuit 61), identical title and label are marked, and omit Detail explanation.

(B-2) structure of motor driver 10

(B-2-1) relay circuit 75

In Fig. 5, relay circuit 75 makes power supply line 801 disconnect and be closed.Herein, so that power supply line 801 is disconnected and is closed is Refer to, power supply line 801 is connected or is cut off become it is non-conduction.

As shown in figure 5, relay circuit 75 includes the relay tip 75a for making power supply line 801 disconnect and be closed, makes relay The relay coil 75b and energization and cold transistor are carried out to relay coil 75b that device contact 75a is acted 75c。

One end of relay coil 75b is connect with the anode of driving power Vb, the collector of the other end and transistor 75c Side connection.The presence or absence of the base current of 40 switching transistor 75c of control unit makes to be connected and end between collector and emitter, Carry out the energization and no power to relay coil 75b.

In general, relay circuit 75 is closed power supply line 801, on state is become.On the other hand, in overvoltage, Relay circuit 75 receives the signal output from control unit 40 to line 801 of cutting off the power.

(B-2-2) electrolytic capacitor 77

Electrolytic capacitor 77 is the electrolytic capacitor being connected in parallel with inverter 25.Herein, in relay circuit 75 from control During portion 40 processed receives 10msec after signal exports until line 801 of cutting off the power or so, electrolytic capacitor 77 is applied The state of overvoltage is added to continue.I.e., it is assumed that a possibility that such: to relay electricity after voltage detection department 23 detects overvoltage During road 75 is cut off the power until line 801, overvoltage value is more than the pressure resistance of electrolytic capacitor 77.

Fig. 6 is applied to the voltage at the both ends of electrolytic capacitor 77 and flows through the relationship between the electric current of electrolytic capacitor 77 Voltage/current characteristic curve graph.

In Fig. 6, in the case where electrolytic capacitor 77, when applying the voltage for being higher than the pressure resistance of oxidation overlay film, implement to be formed The chemical conversion treatment (voltage at this time is referred to as formation voltage (formation voltage)) for aoxidizing overlay film, flows through the electricity in electrolytic capacitor 77 Stream increases.

Wherein, electrolytic capacitor 77 will not be destroyed in 10msec or so, and both end voltage is clamped at formation voltage.

(B-3) movement of motor driver 10

Fig. 7 A is the curve graph for showing the control of the variation for DC voltage Vdc.In Fig. 5 and Fig. 7 A, work as DC voltage When Vdc rises, the detected value of voltage detection department 23 is more than overvoltage threshold, control unit 40 is via relay circuit 75 by power supply line 801 cuttings.

Although the phase of the 10msec until the relay tip 75a to relay circuit 75 cuts off the power line 801 or so Between DC voltage Vdc can be more than capacitor pressure resistance, but DC voltage Vdc be clamped at formation voltage (generally capacitor pressure resistance 1.3~1.5 times or so).Herein, if the component pressure of thyristor (transistor, diode) preset For the value of the formation voltage higher than capacitor, then during the voltage clamping, relay tip 75a can cut power supply line 801 Disconnected, therefore, DC voltage Vdc is not up to semiconductor element pressure resistance.

It therefore, can will be to inverter 25 during the both end voltage of electrolytic capacitor 77 is clamped at formation voltage The Overvoltage suppressing of application is in the formation voltage of electrolytic capacitor 77, and within this period, relay circuit 75 cuts power supply line 801 It is disconnected, thereby, it is possible to prevent electrolytic capacitor 77 from wrecking, and can reduce such to the transistor (IGBT) of inverter 25 The semiconductor element without avalanche region stress.

In addition, the area for the phenomenon that avalanche region refers to, semiconductor is more than a certain pressure resistance and flows carrier sharply Domain.

Next, Fig. 7 B is to be loaded into tool in the curve graph of the control for the variation for DC voltage Vdc for indicating Fig. 7 A There is the curve graph of the variation of the voltage Vds at the semiconductor element both ends of avalanche region.In Fig. 7 B, for example, by inverter 25 Transistor is replaced by IGBT and using in the case where MOSFET, and the voltage Vds at the both ends MOSFET is due to the production based on wiring inductance It gives birth to impact or boost action etc. and can generally become to be above DC voltage Vdc.Also, voltage Vds is with along with supply voltage Rising DC voltage Vdc rising and rise.

In this case, even if assuming to be lower than the feelings of the formation voltage of electrolytic capacitor in the semiconductor element pressure resistance of MOSFET Under condition, voltage Vds has just been more than that semiconductor element is resistance to before the both end voltage of electrolytic capacitor 77 is clamped at formation voltage When pressure, since voltage Vds can be clamped at avalanche voltage, during this period, the both end voltage of electrolytic capacitor 77 also can be by Clamper is in formation voltage, and then, relay tip 75a cuts off power supply line 801.

As described above, being born during the 10msec or so until power supply line 801 is cut off using snowslide movement Overvoltage, it is therefore not necessary to make MOSFET high voltage component.

In addition, being able to suppress the snow of MOSFET by making the both end voltage of electrolytic capacitor 77 be clamped at formation voltage Collapse energy.

(C)

In the 3rd embodiment, although only used mechanical brake, the 1st embodiment, can also be used together Brake as 2 embodiments (electric brake).

(D)

(D-1) project when charge pump circuit 46 is used

In the embodiment of the above-mentioned 1st, the 2nd and the 3rd, the overvoltage protection of the switch element of the above lower arm is emphasis progress Explanation.But in actual use, overvoltage is not limited to switch element, further relates to the output circuit of gate driving circuit 26.

In particular, using charge pump mode as production upper arm side switch element driving power (with changed Upper lower arm tie point current potential accordingly improves grid potential) mode in the case where, constitute switch of charge pump circuit etc. Pressure resistance is typically designed to the pressure-resistant degree (that is, degree of DC voltage Vdc when usual) an of switch element, therefore, most Whole resistance to compaction force is limited in the resistance to compaction force of switch for constituting charge pump circuit (referring to Fig.1 0) etc..

In Figure 10, in charge pump circuit 46, make the conducting of the 1st switch element 465, the cut-off of the 2nd switch element 466, thus It charges to the 1st capacitor 461.Then, make the cut-off of the 1st switch element 465, the conducting of the 2nd switch element 466, thus by the 1st The electric charge transfer accumulated in capacitor 461 is to the 2nd capacitor 462.By repeating the movement, upper arm driving power can be made (the 2nd capacitor 462 after charging).The charging that 1st capacitor 461 and the 2nd capacitor 462 are carried out by oscillating circuit 464 It carries out.

Although the 2nd capacitor 462 is charged to Vb, since the low potential side of the 2nd capacitor 462 is connect with Vdc, because This, the hot side of the 2nd capacitor 462 is Vb+Vdc.

Therefore, in charge pump circuit 46, the 1st switch element 465 and the 2nd switch element 466 require Vb+Vdc or more Pressure resistance, be typically designed as degree corresponding with an element of switch element pressure resistance (that is, usually when DC voltage The degree of Vdc).Accordingly, there exist pressure resistances when overvoltage to be limited in the resistance to of the 1st switch element 465 and the 2nd switch element 466 Press such problems.

(D-2) boostrap circuit 31 is used

It is preferred, therefore, that using bootstrap approach as production upper arm side switch element driving power (with become Dynamic upper lower arm tie point current potential accordingly improves grid potential) mode.

Fig. 8 is the circuit diagram with the major part of motor driver 10 of boostrap circuit 31.In Fig. 8, it is equipped with bootstrapping Circuit 31 is to improve the grid potential of upper arm side switch element.Herein, gate driving circuit 26 and boostrap circuit 31 are said It is bright.

(D-2-1) structure of gate driving circuit 26

Gate driving circuit 26 internal there is the upper arm side for driving transistor Q3a, Q4a, Q5a of upper arm side to drive Circuit 26a and lower arm side drive circuit 26b for driving transistor Q3b, Q4b, Q5b of lower arm side, outside have Vcc, This 10 terminals of Vdd, Hin, Lin, Vss, Vbo, Ho, Vs, Lo and COM.

In gate driving circuit 26, for driving the anode of driving power Vb of transistor to connect with terminal Vcc, patrol It collects and is connect with the anode of power supply Vc with terminal Vdd.Signal wire from control unit 40 is connect with terminal Hin, terminal Lin, driving It is connect with the cathode of power supply Vb and logic power supply Vc with terminal Vss, and the cathode with motor source (DC voltage Vdc) Connection.

In addition, connect from the route of the one pole branch of hot side of the capacitor 311 of boostrap circuit 31 with terminal Vbo, it is brilliant The respective emitter of body pipe Q3a, Q4a, Q5a is connect with terminal Vs, the respective emitter of transistor Q3b, Q4b, Q5b and terminal COM connection.In addition, the grid of transistor Q3a, Q4a, Q5a are connect with terminal Ho, the grid of transistor Q3b, Q4b, Q5b and end Sub- Lo connection.

The conduction and cut-off of transistor Q3a, Q4a, Q5a, Q3b, Q4b, Q5b by gate driving circuit 26 via terminal Ho, Terminal Lo controls grid potential to carry out.By control unit 40 according to the duty cycle control signal for being input to terminal Hin, terminal Lin Carry out the movement of control gate drive circuit 26.

(D-2-2) structure of boostrap circuit 31

In gate driving circuit 26, the driving power Vb being connect with terminal Vcc anode with transistor Q3a, Q4a, Boostrap circuit 31 is equipped between the respective emitter of Q5a, suitably to input transistor from grid to upper arm side Q3a, Q4a, Q5a Current potential.

In Fig. 8, only describes gate driving circuit 26 corresponding with transistor Q3a, Q3b of upper lower arm and driven with grid The dynamic corresponding boostrap circuit 31 of circuit 26, but in fact, respectively with 3 groups on each arm of lower arm be accordingly equipped with gate driving electricity Road and boostrap circuit.

Boostrap circuit 31 is made of capacitor 311, resistance 312 and diode 313.One end and upper arm side of capacitor 311 The emitter of transistor Q3a connected with the tie point NU of the collector of the transistor Q3b of lower arm side.Capacitor 311 it is another End is connect via resistance 312, diode 313 with the anode of driving power Vb.

Resistance 312 is the charging current for limiting capacitance device 311 and is arranged that the positive of diode 313 is used from driving The side of the positive electrode of power supply Vb makes capacitor 311 not discharge towards 311 side of capacitor, will pass through resistance 312, and makes in Vs electricity Electric current will not flow through Vb when position is changed.

Upper arm side drive circuit 26a inside gate driving circuit 26 takes high potential from capacitor 311, to control crystal The turn-on deadline of pipe Q3a.In addition, although the lower arm side drive circuit 26b inside gate driving circuit 26 controls transistor Q3b's Turn-on deadline, but since the emitter side of transistor Q3b is grounded, the only driving power Vb by being connect with terminal Vcc Anode current potential be just able to carry out control.

By being connected the transistor Q3b of lower arm side using lower arm side drive circuit 26b, so that electric current is used in driving Power supply Vb (anode)-diode 313- resistance 312- capacitor 311- lower arm side transistor Q3b- driving power Vb (cathode) It is flowed in path.At this point, since capacitor 311 is electrically charged, it can be used as upper arm side driving power.Although using upper The switch of the transistor of lower arm flow electric current will not due to diode 313 change Vs current potential between Vdc~0 To the side Vb.Herein, the pressure resistance of diode 313 is generally designed to bear the common voltage rating in the portion DC (that is, an element Pressure resistance) value.

(D-3) effect when boostrap circuit 31 is used

In motor driver 10, when generating excessive voltage, by the transistor Q3a~Q5b for making upper lower arm both sides Cut-off, so that the respective both ends partial pressure of 2 switch elements that excessive voltage is connected in series, is applied to 1 switch element (crystal Pipe Q3a~Q5b, diode D3a~D5b) excessive voltage be reduced to half when either side is acted, therefore can Protective switch element damage.In other words, the voltage as the portion DC wants one times that can bear to reach a component pressure Voltage, so that each switch element for 2 switch elements being connected in series is able to bear component pressure.

At this point, the midpoint potential of upper lower arm is up to the degree of a component pressure, (element can be broken if on this Bad, there is no need to consider), therefore, for boostrap circuit 31, on its circuit structure, the common specified electricity in the portion DC can be born Press the design of (that is, a component pressure) with regard to enough.

(E)

In above-mentioned (D), as the mode for the grid potential for improving upper arm side switch element, recommend (the ginseng of boostrap circuit 31 According to Fig. 8) replace charge pump mode, but not limited to this.

Fig. 9 is the circuit diagram with the major part of motor driver 10 of insulated power supplies 36.In Fig. 9, each upper arm Grid be equipped with an insulated power supplies 36.In Fig. 9, gate driving corresponding with transistor Q3a, Q3b of upper lower arm is only described Circuit 26 and insulated power supplies 36 corresponding with gate driving circuit 26, but in fact, with 3 groups on lower arm each arm it is right respectively It is equipped with gate driving circuit and insulated power supplies with answering.

With it is above-mentioned be illustrated in boostrap circuit it is identical, in motor driver 10, when generate excessive voltage When, by ending transistor Q3a~Q5b of upper lower arm both sides, and the midpoint potential of lower arm is made to be up to a member Therefore the degree (element can be then destroyed on this) of part pressure resistance for insulated power supplies 36, can bear the common specified of the portion DC The design of voltage (that is, a component pressure) is with regard to enough.

(the 4th embodiment)

(1) summary

Figure 11 is the block diagram for showing the circuit structure of motor driver 10 of the 4th embodiment of the invention.In Figure 11, System 100 is whole to be driven by motor device 10 and the composition of motor 51.

In Figure 11, in the motor driver 10 of the 4th embodiment, be formed as the 1st embodiment shown in Fig. 1 On the basis of the structure that braking circuit 61 is unloaded, it is also newly provided with balancing circuitry 33a, 33b, 34a, 34b, 35a, 35b, this Outside, using electrolytic capacitor as smoothing capacity device 22.

In the present embodiment, will by voltage detection department 23, current detecting part 24 and balancing circuitry 33a, 33b, 34a, The part that 34b, 35a, 35b are constituted is referred to as excess voltage protection 50.

To being illustrated, element in addition to this due to identical as the 1st embodiment (structure in addition to braking circuit 61), Therefore, identical title and label are marked, and omits detail explanation.

(2) balancing circuitry 33a, 33b, 34a, 34b, 35a, 35b

Balancing circuitry 33a~35b is made of resistive element.A pair of of balancing circuitry 33a, 33b and a pair for constituting upper lower arm Switch element (transistor Q3a, Q3b and diode D3a, D3b) is corresponding.Similarly, a pair of of balancing circuitry 34a, 34b and one split It closes element (transistor Q4a, Q4b and diode D4a, D4b) to correspond to, a pair of of balancing circuitry 35a, 35b and a pair of switches element are (brilliant Body pipe Q5a, Q5b and diode D5a, D5b) it is corresponding.

Balancing circuitry 33a and 33b, 34a and 34b, 35a and 35b are connected in series with each other respectively, the tie point formed therefrom MU, MV, MW with the tie point to be formed is connected in series with each other by transistor Q3a and Q3b, Q4a and Q4b, Q5a and Q5b respectively NU, NV, NW connection.

For ease of description, the wiring for connecting tie point MU and tie point NU is set as route 47u, tie point MV will be connected Wiring with tie point NV is set as route 47v, and the wiring for connecting tie point MW and tie point NW is set as route 47w.

(3) movement of motor driver 10

Hereinafter, being illustrated to the movement of motor driver 10.In Figure 11, control unit 40 to gate driving circuit 26 into The output of traveling wave shape, also, the state of waveform output is controlled, to carry out driving motor 51 with egulation rotating speed.

Figure 12 A is the figure for showing the mode for applying voltage when motor driver 10 operates to upper lower arm, and Figure 12 B is to show Apply the figure of the mode of voltage when motor driver 10 stops to upper lower arm.

As illustrated in fig. 12, in operating, in the transistor Q3a of upper arm corresponding with driving coil Lu and Lv couples of driving coil During the transistor Q5b of the transistor Q4b for the lower arm answered and lower arm corresponding with driving coil Lw carries out turn-on action, DC voltage Vdc is applied to the transistor of the cut-off of each upper lower arm.

At this point, the excessive voltage can be applied to the switch member of cut-off in the case where DC voltage Vdc becomes excessive voltage Transistor Q3b, Q4a, Q5a and diode D3b, D4a, D5a of part.If by a switch element (transistor Q3a~Q5b and Diode D3a~D5b) component pressure be set as Vr, then as DC voltage Vdc > component pressure Vr, the crystalline substance of switch element A possibility that body pipe Q3a~Q5b or diode D3a~D5b are destroyed is big.

Therefore, when control unit 40 is judged as that the detected value of voltage detection department 23 has been more than defined threshold value, make lower arm Transistor Q3a, Q3b, Q4a, Q4b, Q5a, Q5b of both sides ends.

As a result, as shown in Figure 2 B, 2 switch elements that excessive voltage is connected in series (transistor Q3a, Q3b, Q4a, Q4b, Q5a, Q5b, diode D3a, D3b, D4a, D4b, D5a, D5b) respective both ends partial pressure.For example, partial pressure value V1 is applied to The both ends of the switch element (transistor Q3a, Q4a, Q5a, diode D3a, D4a, D5a) of upper arm, partial pressure value V2 are applied to lower arm Switch element (transistor Q3b, Q4b, Q5b, diode D3b, D4b, D5b) both ends.In the ideal case, if each switch The impedance of element is equal, then V1=V2, and therefore, the excessive voltage for being applied to 1 switch element is reduced to either side progress Half when movement, so as to protect each switch element (transistor Q3a~Q5b, diode D3a~D5b) damage.

But in fact, switch element (transistor Q3a, Q3b, Q4a, Q4b, Q5a, Q5b, two poles with upper lower arm both sides Pipe D3a, D3b, D4a, D4b, D5a, D5b) internal resistance (leakage current) and the voxel of element correspondingly divided, Therefore it will not become impartial partial pressure.

Therefore, as shown in Figure 1, so that balancing circuitry 33a, 33b and switch element (transistor Q3a, Q3b, diode D3a, D3b) corresponding, balancing circuitry 34a, 34b and switch element (transistor Q4a, Q4b, diode D4a, D4b) corresponding, balancing circuitry 35a, 35b mode corresponding with switch element (transistor Q5a, Q5b, diode D5a, D5b) are attached.

The switch element (transistor Q3a, Q4a, Q5a, diode D3a, D4a, D5a) that thereby, it is possible to make to be applied to upper arm The partial pressure value V1 at both ends and the both ends switch element (transistor Q3b, Q4b, Q5b, diode D3b, D4b, D5b) for being applied to lower arm Partial pressure value V2 it is impartial.

The feature of (4) the 1st embodiments

(4-1)

In motor driver 10, when generating excessive voltage, control unit 40 is by making the transistor of upper lower arm both sides Q3a, Q3b, Q4a, Q4b, Q5a, Q5b cut-off, so that 2 respective both ends of switch element point that excessive voltage is connected in series Pressure, the excessive voltage for being applied to 1 switch element (transistor Q3a~Q5b, diode D3a~D5b) are reduced to either side Half when being acted, therefore being capable of protective switch element (transistor Q3a~Q5b, diode D3a~D5b) damage.

(4-2)

So that balancing circuitry 33a, 33b are corresponding with transistor Q3a, Q3b and diode D3a, D3b, balancing circuitry 34a, 34b , balancing circuitry 35a, 35b corresponding with transistor Q4a, Q4b and diode D4a, D4b and transistor Q5a, Q5b and diode D5a, The corresponding mode of D5b is attached, and therefore, can make the switch element (transistor Q3a, Q4a, Q5a, two poles that are applied to upper arm Pipe D3a, D4a, D5a) both ends partial pressure value V1 be applied to switch element (transistor Q3b, Q4b, Q5b, the diode of lower arm D3b, D4b, D5b) both ends partial pressure value V2 it is impartial, the switch element (transistor caused by capable of preventing because of unequal partial pressure Q3a~Q5b and diode D3a~D5b) it destroys.

(the 5th embodiment)

(1) summary

Figure 13 is the block diagram for showing the circuit structure of motor driver 10 of the 2nd embodiment of the invention.In Figure 13, System 100 is whole to be driven by motor device 10 and the composition of motor 51.

In Figure 13, in the motor driver 10 of the 2nd embodiment, other than the 4th embodiment shown in Figure 11, also Equipped with relay circuit 43,44,45.Therefore, herein, relay circuit 43,44,45 is illustrated, element in addition to this Due to identical as the 1st embodiment, identical title and label are marked, and omit detail explanation.

(2) detailed construction of motor driver 10

(2-1) relay circuit 43,44,45

Relay circuit 43,44,45 is for making route 47u, 47v, 47w disconnect and be closed.Herein, make route 47u, 47v, 47w disconnect and closure refers to, by between tie point MU and tie point NU, between tie point MV and tie point NV, tie point MW with Be attached between tie point NW or by between tie point MU and tie point NU, between tie point MV and tie point NV, connection Connection cutting between point MW and tie point NW.

Relay circuit 43,44,45 include relay tip 43a, 44a, 45a, relay coil 43b, 44b, 45b and Transistor 43c, 44c, 45c.

Relay tip 43a, 44a, 45a make route 47u, 47v, 47w disconnect and be closed.Relay coil 43b, 44b, 45b acts relay tip 43a, 44a, 45a.

Transistor 43c, 44c, 45c carry out energization and no power to relay coil 43b, 44b, 45b.

One end of relay coil 43b, 44b, 45b are connect with the anode of driving power Vb, the other end and transistor The collector side of 43c, 44c, 45c connect.

The presence or absence of the base current of control unit 40 switching transistor 43c, 44c, 45c, make to lead between collector and emitter Logical and cut-off, carries out the energization and no power to relay coil 43b, 44b, 45b.

When usual, route 47u, 47v, 47w are maintained nonconducting state by relay circuit 43,44,45.Also, when from When control unit 40 is to transistor 43c, 44c, 45c of each relay circuit 43,44,45 respective base stage output drive signal, respectively A relay coil 43b, 44b, 45b are motivated, and make relay tip 43a, 44a, 45a to making route 47u, 47v, 47w The direction of conducting is acted.

(3) movement of motor driver 10

Hereinafter, being illustrated to the movement of motor driver 10.In addition, being judged as voltage detection department to when control unit 40 Until making at transistor Q3a~Q5b cut-off of lower arm both sides when 23 detected value has been more than defined threshold value with the 1st embodiment party Formula is identical, and and the description is omitted.

Control unit 40 is when ending transistor Q3a, Q3b, Q4a, Q4b, Q5a, Q5b of upper lower arm both sides, via relay Device circuit 43,44,45, so that balancing circuitry 33a, 33b are corresponding with transistor Q3a, Q3b and diode D3a, D3b, balancing circuitry 34a, 34b be corresponding with transistor Q4a, Q4b and diode D4a, D4b, balancing circuitry 35a, 35b and transistor Q5a, Q5b and two The corresponding mode of pole pipe D5a, D5b is attached.

The switch element (transistor Q3a, Q4a, Q5a, diode D3a, D4a, D5a) that thereby, it is possible to make to be applied to upper arm The partial pressure value V1 at both ends and the both ends switch element (transistor Q3b, Q4b, Q5b, diode D3b, D4b, D5b) for being applied to lower arm Partial pressure value V2 it is impartial.

The feature of (4) the 5th embodiments

(4-1)

In motor driver 10, when generating excessive voltage, by the transistor Q3a~Q5b for making upper lower arm both sides Cut-off, so that 2 switch elements (transistor Q3a~Q5b, diode D3a~D5b) that excessive voltage is connected in series are respective Both ends partial pressure, the excessive voltage for being applied to 1 switch element (transistor Q3a~Q5b, diode D3a~D5b) are reduced to appoint The half when side that anticipates acts, therefore the transistor Q3a~Q5b and diode D3a~D5b of being capable of protective switch element exempt from It is damaged.

(4-2)

Control unit 40 is when ending transistor Q3a, Q3b, Q4a, Q4b, Q5a, Q5b of upper lower arm both sides, via relay Device circuit 43,44,45, so that balancing circuitry 33a, 33b are corresponding with transistor Q3a, Q3b and diode D3a, D3b, balancing circuitry 34a, 34b be corresponding with transistor Q4a, Q4b and diode D4a, D4b, balancing circuitry 35a, 35b and transistor Q5a, Q5b and two The corresponding mode of pole pipe D5a, D5b is attached, therefore, can make to be applied to upper arm switch element (transistor Q3a, Q4a, Q5a, diode D3a, D4a, D5a) both ends partial pressure value V1 be applied to lower arm switch element (transistor Q3b, Q4b, Q5b, Diode D3b, D4b, D5b) both ends partial pressure value V2 it is impartial, the switch element caused by capable of preventing because of unequal partial pressure (transistor Q3a~Q5b and diode D3a~D5b) is destroyed.

(4-3)

Pass through the intermediate point in tie point NU, NV, NW and a pair of of balancing circuitry corresponding with described tie point NU, NV, NW Between configuration switch and only inverter cut-off when connect balancing circuitry, be able to suppress the power consumption of balancing circuitry.

That is, do not having switch and balancing circuitry is always in connected situation, when the switching elements conductive of inverter, Since the balancing circuitry to an arm side applies DC voltage Vdc, if for example the resistance value of balancing circuitry is set as If R, then the power consumption of balancing circuitry is (Vdc) 2/R, still, in the state of not connected balancing circuitry, balancing circuitry Power consumption is (Vdc) 2/2R, therefore can inhibit power consumption 1/2.

< other embodiments >

(A)

Switch may not be relay, and use the semiconductor switch such as MOSFET.In this case, can connect to higher speed Balancing circuitry is connect, therefore, the even state of unbalanced-voltage-division can be got rid of quickly.

(B)

In order to be further reduced power consumption than the 2nd embodiment, connection/disconnection balancing circuitry may be provided for certainly 2nd switch of body.

Figure 14 is after showing the stopping of motor driver 10 of other embodiment, when being connected to balancing circuitry 33a, 33b Apply the figure of one side of voltage to upper lower arm.In Figure 14, contact 47a is generally set as disconnecting (opening) by the 2nd switch 47 in advance, and makes The relay tip 43a of relay circuit 43 is connected, meanwhile, the 2nd switch 47 makes contact 47a connect (closing), thus it enables that The power consumption of balancing circuitry under usual state is zero.

Industrial availability

The present application can protect the respective transistor of lower arm to be not subjected to overvoltage, therefore, be not limited in motor Driving device is also useful to other driving devices for having used inverter.

Label declaration

10: motor driver；

20: power suppling part；

23: voltage detection department；

31: boostrap circuit；

33a: balancing circuitry；

33b: balancing circuitry；

34a: balancing circuitry；

34b: balancing circuitry；

35a: balancing circuitry；

35b: balancing circuitry；

36: insulated power supplies；

40: control unit；

43: relay circuit (switch)；

44: relay circuit (switch)；

45: relay circuit (switch)；

50: excess voltage protection；

51: motor；

61: braking circuit；

71: ohmic load；

73: relay circuit (ohmic load connection unit)；

81: brake (mechanical brake)；

Q3a: transistor (switch element)；

Q3b: transistor (switch element)；

Q4a: transistor (switch element)；

Q4b: transistor (switch element)；

Q5a: transistor (switch element)；

Q5b: transistor (switch element)；

D3a: diode (switch element)；

D3b: diode (switch element)；

D4a: diode (switch element)；

D4b: diode (switch element)；

D5a: diode (switch element)；

D5b: diode (switch element)；

NU: tie point；

NV: tie point；

NW: tie point；

Vdc: DC voltage.

Existing technical literature

Patent document

Patent document 1: Japanese Unexamined Patent Publication 2007-166815 bulletin

Claims (11)

1. a kind of motor driver (10) is opened with 2 respectively by multiple mutually corresponding multiple upper lower arms with motor It closes element (Q3a, Q3b, Q4a, Q4b, Q5a, Q5b, D3a, D3b, D4a, D4b, D5a, D5b) to be connected in series and constitute, from thus The tie point (NU, NV, NW) of formation is respectively to the corresponding phase output voltage, wherein

The motor driver (10) includes

Power suppling part (20) rectifies the alternating voltage exported from source power supply (91) and generates DC power supply, to The upper lower arm provides DC voltage (Vdc)；

Voltage detection department (23) is connected in parallel with the upper lower arm；And

Control unit (40) makes the switch element (Q3a, Q3b, Q4a, Q4b, Q5a, Q5b) to carry out turn-on deadline movement,

The control unit (40) makes all institutes when the detected value of the voltage detection department (23) has been more than defined threshold value State the switch member of any one arm in 2 switch elements (Q3a, Q3b, Q4a, Q4b, Q5a, Q5b) of lower arm After part all turns on, cut the switch element (Q3a, Q3b, Q4a, Q4b, Q5a, Q5b) of all upper lower arm both sides Only.

2. motor driver (10) according to claim 1, wherein

The motor driver (10) also has insulated power supplies (36), which is used for the upper of the upper lower arm The driving of arm side switch element (Q3a, Q4a, Q5a).

3. a kind of motor driver (10) is opened with 2 respectively by multiple mutually corresponding multiple upper lower arms with motor It closes element (Q3a, Q3b, Q4a, Q4b, Q5a, Q5b, D3a, D3b, D4a, D4b, D5a, D5b) to be connected in series and constitute, from thus The tie point (NU, NV, NW) of formation is respectively to the corresponding phase output voltage, wherein

The motor driver (10) includes

Power suppling part (20) rectifies the alternating voltage exported from source power supply (91) and generates DC power supply, to The upper lower arm provides DC voltage (Vdc)；

Voltage detection department (23) is connected in parallel with the upper lower arm；

Boostrap circuit (31), in order to the upper arm side switch element (Q3a, Q4a, Q5a) of the upper lower arm driving power and give birth to At the current potential of the low potential side higher than the switch element (Q3a, Q4a, Q5a)；And

Control unit (40) makes the switch element (Q3a, Q3b, Q4a, Q4b, Q5a, Q5b) to carry out turn-on deadline movement,

The control unit (40) makes the upper lower arm when the detected value of the voltage detection department (23) has been more than defined threshold value The switch element (Q3a, Q3b, Q4a, Q4b, Q5a, Q5b) of both sides ends.

4. motor driver (10) according to claim 3, wherein

The motor driver (10) also has the braking circuit (61) of the motor,

The control unit (40) is cut in the switch element (Q3a, Q3b, Q4a, Q4b, Q5a, Q5b) for making the upper lower arm both sides After only, the motor is braked.

5. motor driver (10) according to claim 3, wherein the motor driver (10) also includes

Ohmic load (71)；With

Ohmic load connection unit (73) will connect between the tie point (NU, NV, NW) and the ohmic load (71) It connects or cuts off the connection between the tie point (NU, NV, NW) and the ohmic load (71),

The control unit (40) is cut in the switch element (Q3a, Q3b, Q4a, Q4b, Q5a, Q5b) for making the upper lower arm both sides After only, the tie point (NU, NV, NW) is connect with the ohmic load (71), the motor is braked.

6. motor driver (10) according to claim 3, wherein

The motor driver (10) also has mechanical brake (81), can carry out relative to the rotary shaft of the motor Dismounting,

The control unit (40) is cut in the switch element (Q3a, Q3b, Q4a, Q4b, Q5a, Q5b) for making the upper lower arm both sides After only, mechanical braking is carried out to the motor.

7. according to motor driver described in any one in claim 4 to 6 (10), wherein

Other than when the detected value of the voltage detection department (23) is more than the threshold value, the control unit (40) is not to the electricity Machine carries out the braking.

8. a kind of motor driver (10) is opened with 2 respectively by multiple mutually corresponding multiple upper lower arms with motor It closes element (Q3a, Q3b, Q4a, Q4b, Q5a, Q5b, D3a, D3b, D4a, D4b, D5a, D5b) to be connected in series and constitute, from thus The tie point (NU, NV, NW) of formation is respectively to the corresponding phase output voltage, wherein

The motor driver (10) includes

Power suppling part (20) rectifies the alternating voltage exported from source power supply (91) and generates DC power supply, to The upper lower arm provides DC voltage (Vdc)；

Voltage detection department (23) is connected in parallel with the upper lower arm；

Balancing circuitry (33a, 33b, 34a, 34b, 35a, 35b), configuration connect the power suppling part (20) and it is described on Between a pair of of the DC bus and the tie point (NU, NV, NW) of lower arm；And

Control unit (40) makes the switch element (Q3a, Q3b, Q4a, Q4b, Q5a, Q5b) to carry out turn-on deadline movement,

The control unit (40) makes the upper lower arm when the detected value of the voltage detection department (23) has been more than defined threshold value The switch element (Q3a, Q3b, Q4a, Q4b, Q5a, Q5b) of both sides ends.

9. motor driver (10) according to claim 8, wherein

The balancing circuitry (33a, 33b, 34a, 34b, 35a, 35b) is configured to each switch element with multiple upper lower arms (Q3a, Q3b, Q4a, Q4b, Q5a, Q5b) is respectively corresponded.

10. motor driver (10) according to claim 8 or claim 9, wherein

The motor driver (10) also has switch (43,44,45), and the switch (43,44,45) is by the tie point (NU, NV, NW) and a pair balancing circuitry corresponding with the tie point (NU, NV, NW) (33a, 33b, 34a, 34b, 35a, Be attached between intermediate point 35b) or by the tie point (NU, NV, NW) and with the tie point (NU, NV, NW) it is right Connection cutting between the intermediate point for a pair balancing circuitry (33a, 33b, 34a, 34b, 35a, 35b) answered,

The control unit (40) connects the balance when the detected value of the voltage detection department (23) has been more than defined threshold value Circuit (33a, 33b, 34a, 34b, 35a, 35b).

11. motor driver (10) according to claim 10, wherein

The balancing circuitry (33a, 33b, 34a, 34b, 35a, 35b) is made of resistive element.