TWI644192B - A simplest circuit drive magneto-rheological fluid - Google Patents

Abstract

A simplified circuit for driving a magnetorheological fluid, suitable for controlling the fluidity of a magnetorheological fluid, comprising a power source side unit, a load side unit, and a fluidity control unit. The fluidity control unit detects the fluidity of the magnetorheological fluid, and controls the power source side unit with a pulse width modulation control to control the magnetic field strength generated by the load side unit from the magnetorheological fluid, further controlling the The fluidity of the magnetorheological fluid.

Description

The simplest circuit for driving magnetorheological fluid

The present invention relates to a transformer circuit, and more particularly to a simple circuit for driving a magnetorheological fluid.

Magnetorheological fluid is an emerging intelligent material, which is mainly composed of carrier liquid, magnetic particles and surfactant. When a magnetic field is applied, obvious magnetization effect occurs, and it is widely used in the mechanical, chemical and optoelectronic industries.

The magnetorheological fluid is mainly composed of carrier liquid, magnetic particles and surfactant. When a magnetic field is applied, the magnetorheological fluid produces a significant magnetorheological effect, which is continuous, rapid, reversible, and easy to control. .

Among them, magnetorheological fluid can replace the shock absorber fluid in the damper. The magnetorheological fluid damper is an ideal semi-active control device. The control circuit can be used to change the fluidity of the magnetorheological fluid even when the damping force is If a fault occurs during the adjustment process, the magnetorheological fluid damper can still be used in a passive manner, allowing the damper to function normally.

However, the driving circuit for controlling the magnetorheological fluid is very complicated at present, and the number of electronic components used is large. Therefore, after the driving circuit is operated for a long time, it is easy to work due to damage of one of the electronic components. Therefore, how to simplify the driving circuit to improve the durability is an urgent need of the technicians.

In view of the above, it is an object of the present invention to provide a simplified circuit for driving a magnetorheological fluid suitable for controlling the fluidity of a magnetorheological fluid comprising a power supply side unit and a load side unit.

The power supply side unit includes a DC power supply, a first switch, a second switch, a power supply side transformer, an inductor, a first capacitor, a first diode, and a second diode.

The positive terminal of the DC power source is electrically connected to the positive terminal of the first switch, and the negative terminal of the DC power source is electrically connected to the negative terminal of the second switch, and the negative terminal of the first switch and the power transformer side transformer The positive terminal is electrically connected, and one end of the inductor is electrically connected to a negative terminal of the power transformer side transformer, and the other end of the inductor is electrically connected to a positive terminal of the second switch, and one end of the first capacitor and the first switch The positive end of the first capacitor is electrically connected to the negative terminal of the power transformer side transformer, and the positive terminal of the first diode is electrically connected to the positive terminal of the second switch. The negative terminal of the first diode is electrically connected to the positive terminal of the first switch, and the positive terminal of the second diode is electrically connected to the negative terminal of the second switch, and the negative terminal of the second diode It is electrically connected to the negative terminal of the first switch.

The load side unit includes a load side transformer coil and a load module.

The load side transformer coil is electromagnetically coupled to the power source side transformer coil, and the load module obtains power of the load side transformer coil to generate a magnetic field in the magnetorheological fluid and control the fluidity of the magnetorheological fluid .

Another technical means of the present invention lies in the above load The side unit further includes a third diode, and a second capacitor, wherein the positive terminal of the third diode is electrically connected to the negative terminal of the load side transformer, and the third terminal and the third capacitor The negative terminal of the diode is electrically connected, and the other end of the second capacitor is electrically connected to the positive terminal of the load side transformer, and the load module is connected in parallel with the second capacitor.

Another technical method of the present invention is that the simplified circuit for driving the magnetorheological fluid further comprises a fluidity control unit, comprising a fluidity detecting module, and a liquidity detecting module a fluidity control module for detecting the fluidity of the magnetorheological fluid, the fluidity control module analyzing the detection information of the fluidity detecting module to control the first switch and The opening and closing frequency of the second switch.

According to still another aspect of the present invention, the fluidity control unit further includes a current detecting module electrically connected to the fluidity control module, wherein the current detecting module is configured to detect the load side voltage change The output of the coil.

Another technical means of the present invention is that the fluidity control module has a first frequency modulation control circuit for controlling the first switch, and a second frequency modulation control circuit for controlling the second switch.

Another technical means of the present invention is that the fluidity control module controls the power supply side unit to change between a first state and a second state when the pulse width modulation is performed, and when the first state is Turning on the first switch, turning off the second switch, the DC power source stores power to the inductor, and outputs power to the power source side transformer coil through the inductor, so that the current of the power source side transformer coil gradually rises. In the second state, cut The first switch is turned on, and the second switch is turned on, and the power is outputted to the power supply side transformer coil only through the inductance, so that the current of the power source side transformer coil gradually decreases.

The utility model has the beneficial effects that the power source side unit is a combination of a conventional step-down circuit and a flyback type conversion circuit, and can control the output power of the load side transformer coil, and the fluidity control module detects the mode according to the fluidity. The detection information of the group and the current detecting module is used to modulate the pulse width, so that the fluidity of the magnetorheological fluid can be controlled more accurately. Moreover, the circuit does not require a very low duty cycle, and the transformer does not require a very high turns ratio to achieve a high buck gain. In addition, the circuit can recover the leakage inductance energy of the transformer.

A‧‧‧ Magnetorheological fluid

B‧‧ damper

3‧‧‧Power side unit

V _in ‧‧‧DC power supply

SW ₁ ‧‧‧first switch

SW ₂ ‧‧‧Second switch

L _m1 ‧‧‧Power side transformer

L‧‧‧Inductance

L _k ‧‧‧Transformation leakage inductance

C ₁ ‧‧‧first capacitor

D ₁ ‧‧‧First Diode

D ₂ ‧‧‧Secondary

4‧‧‧Load side unit

L _m2 ‧‧‧Load side transformer

R‧‧‧ load module

D _o ‧‧‧third diode

C _o ‧‧‧second capacitor

5‧‧‧Liquidity Control Unit

51‧‧‧liquidity detection module

52‧‧‧Liquidity Control Module

521‧‧‧First frequency modulation control circuit

522‧‧‧Second frequency modulation control circuit

53‧‧‧ Current detection module

i _Lm1 ‧‧‧Power side transformer coil current

i _Lk ‧‧‧Variable leakage current

i _L ‧‧‧Inductor current

i _D1 ‧‧‧first diode current

i _D2 ‧‧‧Second diode current

i _DO ‧‧‧third diode current

V _SW1 ‧‧‧first switching voltage

V _SW2 ‧‧‧second switching voltage

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a circuit diagram showing a preferred embodiment of a simplified circuit for driving a magnetorheological fluid; Figure 2 is a schematic view of a device for controlling the term rheological fluid; Figure 3 Is a timing diagram illustrating the circuit variations controlled by the preferred embodiment; FIG. 4 is a current diagram illustrating a first state of control of the preferred embodiment; and FIG. 5 is a current diagram illustrating the preferred embodiment Control one of the second states.

The related features and technical details of the present invention will be apparent from the following detailed description of the preferred embodiments.

1 and 2, a preferred embodiment of a simplified circuit for driving a magnetorheological fluid according to the present invention, the preferred embodiment is suitable for controlling the fluidity of a magnetorheological fluid A, which comprises a power source side unit 3. A load side unit 4 and a fluidity control unit 5.

Wherein, the present invention is used to control the shock absorbing effect of a damper B, the fluid used in the damper B is the magnetorheological fluid A, and the damper B can be controlled by controlling the fluidity of the magnetorheological fluid A. The shock absorbing effect of the damper B using the magnetorheological fluid A as the fluid has been used in commercially available products, and will not be described in detail herein. In actual practice, the present invention can be used to utilize the magnetorheological fluid. A's item control should not be limited to this.

The power source side unit 3 includes a DC power source V _in , a first switch SW ₁ , a second switch SW ₂ , a power source side transformer coil L _m1 , an inductor L, a first capacitor C ₁ , and a first two a polar body D ₁ and a second diode D ₂ .

The positive terminal of the DC power source V _in is electrically connected to the positive terminal of the first switch SW ₁ , and the negative terminal of the DC power source V _in is electrically connected to the negative terminal of the second switch SW ₂ , the first switch SW ₁ the negatively and positively charged terminal electrically L terminal of the power supply-side transformer coil _M1 is connected to one end of the inductor L is electrically connected to the negative terminal of the power supply side L _M1 transformer coil, the other end of the inductor L and the second switch SW ₂ the positively charged terminal electrically connected to a first end of the capacitor C ₁ is electrically connected to the positively charged end of the first switch SW _1, the first capacitor C ₁ and the other end of the power supply side of the transformer coil L _m1 negative electrical terminals Electrically connected, the positive terminal of the first diode D ₁ is electrically connected to the positive terminal of the second switch SW ₂ , and the negative terminal of the first diode D _{1 and} the positive terminal of the first switch SW ₁ The positive terminal of the second diode D ₂ is electrically connected to the negative terminal of the second switch SW _{2 , and} the negative terminal of the second diode D _{2 and} the negative terminal of the first switch SW ₁ . Electrical connection.

The load side unit 4 includes a load side transformer coil L _m2 , a third diode body D _o , a second capacitor C _o , and a load module R. The load side transformer coil L _m2 and the power source The side transformer coil L _{m1 is} electromagnetically coupled, and the load module R obtains electric power of the load side transformer coil L _m2 to generate a magnetic field in the magnetorheological fluid A and control the fluidity of the magnetorheological fluid A.

The positive terminal of the third diode D _o is electrically connected to the negative terminal of the load-side transformer coil L _m2 , and one end of the second capacitor C _o is electrically connected to the negative terminal of the third diode D _o . The other end of the second capacitor C _o is electrically connected to the positive terminal of the load side transformer coil L _m2 , and the load module R is connected in parallel with the second capacitor C _o . The voltage leakage inductance L _k of one of the power source side units 3 is the leakage inductance of the transformer, and forms a transformer with the power source side transformer coil L _m1 and the load side transformer coil L _m2 .

The fluidity control unit 5 includes a fluidity detecting module 51, a fluidity control module 52 electrically connected to the fluidity detecting module 51, and a current electrically connected to the fluidity control module 52. Detection module 53. The fluidity control module 52 is provided with an adjusting component for providing the user with the fluidity of the magnetorheological fluid A required for adjustment.

The fluidity detecting module 51 detects the fluidity of the magnetorheological fluid A. In the preferred embodiment, the fluidity detecting module 51 is a pressure detecting component for detecting the inside of the damper B. The fluidity detecting module 51 can be other detecting components, and should not be limited thereto. The flow of the control module 52 analyzes the information detected fluidity detection module 51 to control out switch SW ₁ of the first and the second opening and closing frequency of switch SW _2, the OFF state is turned on, is turned off state.

The current detecting module 53 is configured to detect an output of the load side transformer coil L _m2 . In the preferred embodiment, the current detecting module 53 is a current comparator, so that the fluidity control module 52 obtains the output current of the load side transformer coil L _m2 , that is, through the third diode. Current i _DO value.

The flow of the control module 52 has a switch SW for controlling the first frequency control circuit 521 of a first ₁ and a second switch SW for controlling the second frequency modulation of the _second control circuit 522. Preferably, the flow control module 52 analyzes the detection information of the fluidity detection module 51 and the current detection module 53 according to the parameters set by the user, and then the first frequency modulation control circuit 521 and the second frequency control circuit 522 to pulse width modulation (PWM) control of the first out switch SW ₁ and the second opening and closing state of the switch SW _2.

Referring to FIG. 3, it is a circuit timing diagram of the preferred embodiment, wherein the fluidity control module 52 controls the power source side unit 3 in a first state and a second state in a pulse width modulation. change. Among them, it is divided into five working modes in the timing chart. All the switches and diodes are assumed to be ideal components in the analysis process. The capacitance is assumed to be infinite, and the capacitance voltage does not change with time. The leakage inductance of the pressure coil L _m2 is not taken into consideration to facilitate analysis of the operation mode and calculation. When the first switch SW _{1 is} turned on, the first switching voltage V _SW1 is zero, and the second switch SW _{2 is} turned on. The second switching voltage V _{SW2 has a} value of zero.

Referring to FIG. 4, when in the first state, the first switch SW _{1 is} turned on, and the second switch SW ₂ is turned off, which is mode1 of t ₀ ~ t _{1 in} the timing chart, and the DC power source V _{in is the} inductance L The electric power is stored, and electric power is output to the power source side transformer coil L _m1 through the inductance L to gradually increase the power source side transformer coil current i _Lm1 . Among them, the solid line part is a circuit through which a current flows, and the broken line part is a circuit in which no current flows.

Referring to FIG. 5, when in the second state, the first switch is turned off SW _1, turns on the second switch SW _2, is a timing diagram of t ₂ ~ t ₄ mode3 ~ mode4, which transmits only the inductance L supply-side transformer winding L _m1 output power, so that the power supply-side transformer coil current i _Lm1 decreased. Among them, the solid line part is a circuit through which a current flows, and the broken line part is a circuit in which no current flows.

The mode ₂ of t ₁ to t _{2 and} the mode ₅ of t ₄ to t _{5 are} intervals between the first frequency modulation control circuit 521 and the second frequency modulation control circuit 522 for controlling the first switch SW ₁ and the second switch SW ₂ . the first out switch SW ₁ and the second switch SW ₂ are both off-state, to avoid the first out switch SW ₁ and the second switch SW ₂ is turned on at the same time. The mode ₃ of t ₂ to t ₃ stores the power of the voltage leakage leakage inductance L _k in the inductance L to release the power of the voltage leakage leakage inductance L _k , to avoid generating a surge in the circuit, and to Recycle.

In detail, in the mode ₁ of t ₀ ~ t ₁ , that is, the first state of the preferred embodiment, the first switch SW _{1 is} turned on at time t ₀ , and the inductance L is compliant via the first diode D ₁ The partial conduction is because the inductor current i _{L is} greater than the voltage leakage leakage current i _Lk , so the inductor current i _L is shunted, and the first container, the variable leakage inductance L _k and the power supply side transformer coil L _m1 are respectively performed. The energy storage, so the voltage leakage leakage current i _Lk and the power supply side transformer coil current i _Lm1 rise, and the load side voltage transformation coil L _{m2 is} not turned on because the third diode D _{o is} reverse biased, the second The capacitor C _o supplies energy to the output load module R. When the inductor current i _L is equal to the voltage leakage leakage current i _Lk , the inductor L continues to release energy because the inductor current i _{L is} smaller than the voltage leakage leakage current i _Lk Therefore, the inductor L and the first capacitor C ₁ provide energy to the variable leakage inductance L _k and the power supply side transformer coil L _m1 . At this time, the voltage leakage leakage current i _Lk and the power supply side voltage transformation The coil current i _Lm1 continues to rise. In addition, the third diode D _o impartial reverse conduction, the second capacitor C _o to provide energy to the load module R, when the first out switch SW ₁ is turned off, ending mode1.

At t ₁ ~ t ₂ of MODE2, the first switch SW _{1 2} of the second switch SW is turned off, the inductor L, the transformer leakage inductance L _k, and the power supply-side transformer winding L _m1 discharging, the first The diode D ₁ , the second diode D ₂ , and the third diode D _{0 are} turned on, and the inductor L stores the first capacitor C ₁ , and the voltage leakage inductance L _{k is} via The first diode D ₁ recovers energy to the DC power source V _in , and the power source side transformer coil L _m1 transmits energy to the load side transformer coil L _m2 , the third diode current i _{The DO stores} energy to the second capacitor C _o and supplies energy to the load module R. When the second switch SW _{2 is} turned on, mode 2 ends.

In mode _{2 of} t ₂ to t ₃ , that is, the second state of the preferred embodiment, the second switch SW ₂ starts to conduct, and the second diode D ₂ and the third diode D _{0 are} turned on. The DC power source V _in stores energy for the first capacitor C ₁ and the inductor L, so the inductor current i _L starts to rise, and the voltage leakage leakage inductance L _k recovers energy to the inductor L and flows through the second pole Body D ₂ . Wherein, the power supply side transformer coil L _m1 continues mode2 to transfer energy to the load side transformer coil L _m2 , and the third diode current i _DO stores energy to the second capacitor C _o and supplies energy to the load mode Group R, when the pressure leakage inductance L _k releases the energy, mode3 ends.

In a mode ₄ of t ₃ to t ₄ , that is, a second state of the preferred embodiment, the second switch SW _{2 is} continuously turned on, and the DC power source V _in continues mode3 to store energy of the first capacitor C ₁ and the inductor L. The inductor current i _L continues to rise, the power supply side transformer coil L _m1 continues to transfer energy to the load side transformer coil L _m2 , and the third diode current i _DO stores the second capacitor C _o , and Energy is supplied to the load module R, and the third diode current i _DO gradually decreases, and the mode ₄ ends when the second switch SW ₂ is turned off.

In the mode ₅ of t ₄ to t ₅ , the first switch SW ₁ and the second switch SW _{2 are} turned off, and the first diode D ₁ and the third diode D _{0 are} turned on, and the inductor L passes through the The first diode D ₁ stores energy to the first capacitor C ₁ , and the power supply side transformer coil L _m1 continues to transfer energy to the load side transformer coil L _m2 , the third diode current i _DO pair The second capacitor C _o stores energy and supplies energy to the load module R. The third diode current i _DO continues to decrease. When the first switch SW _{1 is} turned on, the mode 5 ends.

The calculation of the output voltage gain of the present invention can be regarded as a combination of a conventional power converter step-down circuit and a flyback conversion circuit. When the second switch SW _{2 is} turned on and the first switch SW ₁ is turned off, the DC power source V _in The inductor L and the first capacitor C _{1 are} stored by a step-down circuit, and the power-side transformer coil L _{m1 of the} flyback converter circuit transmits energy to the load-side transformer coil L _m2 . When the second switch SW _{2 is} turned off and the first switch SW _{1 is} turned on, it can be seen that the output of the step-down circuit is an input of the flyback conversion circuit, and at this time, the power supply side transformer coil L of the flyback conversion circuit _M1 is storing energy, so its gain is multiplied by the gain of the buck circuit and the gain of the flyback converter circuit, and is derived by the following equation.

The gain derivation of the buck circuit, where V _o — buck is the output gain of the buck circuit, and V _{o —} flyback is the output gain of the flyback converter circuit:

After formula (1) is finished:

Gain derivation of the flyback converter circuit:

After formula (3) is finished:

By multiplying equation (2) by equation (4), the gain ratio of the proposed high-voltage power converter can be obtained:

It can be seen from the above analysis that the voltage gain ratio of the architecture proposed by the present invention varies according to the gains of the buck circuit and the flyback converter circuit.

The inventor wants to emphasize that the general high-performance electric vehicle drive The dynamic voltage is very high, and is used to drive the electric vehicle to generate a strong torque. However, the present invention can directly use the high voltage power of the electric vehicle to adjust the control power suitable for the damper B suitable for using the magnetorheological fluid A. In addition, the fluidity control module 52 further analyzes the detection information of the fluidity detecting module 51 and the current detecting module 53 to control the fluidity of the magnetorheological fluid A, which can be used. Under the parameter set, the damper B is automatically adjusted to achieve the desired shock absorbing effect, wherein the magnetic field control of the fluidity of the magnetorheological fluid A is very fast, and therefore, the fluidity control module 52 can be Analyze the information of the damper B feedback, understand the current road conditions, and automatically adjust the required suspension parameters.

As can be seen from the above description, the simple circuit for driving a magnetorheological fluid of the present invention does have the following effects:

First, the circuit is simple:

When used in a high-voltage power supply, it is no longer necessary to set a step-down circuit, which effectively reduces the amount of electronic components used.

Second, the efficiency is higher:

The circuit used in the invention can reduce the turns ratio of the transformer and can achieve high-voltage step-down, wherein the leakage current of the transformer can be recovered, and the performance is better.

Third, the durability is higher:

Compared with the control circuit used in the early stage, the invention controls the fluidity of the magnetorheological fluid with fewer electronic parts, can reduce the damage rate of the electronic parts, and has higher durability.

In summary, the present invention can effectively control the power outputted by the load-side transformer coil L _m2 , and the fluidity control module 52 detects the flow detection module 51 and the current detection module 53 . Information is used to modulate the pulse width to achieve precise control of the fluidity of the magnetorheological fluid A. Moreover, the circuit does not require a very low duty cycle, and the transformer does not need a very high turns ratio to achieve a high step-down gain to control the flow of the magnetorheological fluid A, and further control the avoidance of the damper B. The effect of the earthquake is indeed achieved, and the object of the present invention can be achieved.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

Claims (6)

A simple circuit for driving a magnetorheological fluid, suitable for controlling the fluidity of a magnetorheological fluid, comprising: a power source side unit, comprising a DC power source, a first switch, a second switch, and a power supply side change a voltage coil, an inductor, a first capacitor, a first diode, and a second diode, wherein a positive terminal of the DC power source is electrically connected to a positive terminal of the first switch, and a negative power of the DC power source The terminal is electrically connected to the negative terminal of the second switch, and the negative terminal of the first switch is electrically connected to the positive terminal of the power transformer side voltage transformer coil, and one end of the inductor is electrically connected to the negative terminal of the power source side transformer coil. The other end of the inductor is electrically connected to the positive terminal of the second switch, and one end of the first capacitor is electrically connected to the positive terminal of the first switch, and the other end of the first capacitor and the negative terminal of the power transformer side transformer Electrically connected, the positive terminal of the first diode is electrically connected to the positive terminal of the second switch, and the negative terminal of the first diode is electrically connected to the positive terminal of the first switch, the second The positive terminal of the pole body is electrically connected to the negative terminal of the second switch, the second pole The negative side is electrically connected to the negative end of the first switch; and a load side unit includes a load side transformer coil, and a load module, the load side transformer coil is electromagnetically coupled to the power side transformer The load module obtains power of the load side transformer coil to generate a magnetic field in the magnetorheological fluid and control the fluidity of the magnetorheological fluid. The simplified circuit for driving a magnetorheological fluid according to claim 1, wherein the load side unit further comprises a third diode, and a second capacitor, and the positive terminal of the third diode And the load side transformer coil The negative terminal is electrically connected, one end of the second capacitor is electrically connected to the negative terminal of the third diode, and the other end of the second capacitor is electrically connected to the positive terminal of the load side transformer, the load module and The second capacitors are connected in parallel. The simplified circuit for driving a magnetorheological fluid according to claim 2, further comprising a fluidity control unit, comprising a fluidity detecting module, and an electrical connection with the fluidity detecting module The fluidity control module detects the fluidity of the magnetorheological fluid, and the fluidity control module analyzes the detection information of the fluidity detecting module to control the first switch and the first The opening and closing frequency of the two switches. The simplified circuit for driving a magnetorheological fluid according to claim 3, wherein the fluidity control unit further comprises a current detecting module electrically connected to the fluidity control module, the current detecting module The group is used to detect the output of the load side transformer coil. The simplified circuit for driving a magnetorheological fluid according to claim 4, wherein the fluidity control module has a first frequency modulation control circuit for controlling the first switch, and a control unit The second frequency modulation control circuit of the second switch. The simplified circuit for driving a magnetorheological fluid according to claim 4, wherein the fluidity control module controls the power source side unit in a first state and a second state by pulse width modulation. Changing, when in the first state, turning on the first switch, turning off the second switch, the DC power source stores power to the inductor, and outputs power to the power source side transformer coil through the inductor, so that the power source The current of the side transformer coil gradually rises. When in the second state, the first switch is turned off, and the first switch is turned on. The two switches output power to the power supply side transformer coil only through the inductance, so that the current of the power source side transformer coil gradually decreases.