CN103236372B - A kind of based on PWM monostable vacuum circuit breaker permanent-magnet operating mechanism control method and device thereof - Google Patents

Abstract

The present invention relates to a kind of monostable vacuum circuit breaker permanent-magnet operating mechanism control method based on PWM, by contact position, contact speed, actuator coil electric current three closed-loop adjustment, contact position ring regulates exciting current according to contact position, contact speed ring regulates PWM duty ratio according to the feedback signal of contact position ring, actuator coil electric current loop is according to the breaking-closing operating of exciting current and PWM duty ratio real time control machine structure, wherein contact position ring and contact speed ring adopt fuzzy controller, and actuator coil electric current loop adopts PI to control.Its beneficial effect is: the simultaneous operation ability and the reliability that improve mechanism, master is detected as with coil current, be detected as auxiliary with contact travel, the two cooperatively interacts, in breaker operator process, adopting pulse modulation technology, by changing coil current, realizing that circuit breaker divides, the closed-loop control of contacts movement features in closing operation process, the stability of safety action time, improves the accuracy of divide-shut brake phase place.

Description

A kind of based on PWM monostable vacuum circuit breaker permanent-magnet operating mechanism control method and device thereof

Technical field

The present invention relates to electrical automation control field, particularly relate to a kind of based on PWM monostable vacuum circuit breaker permanent-magnet operating mechanism control method and device thereof.

Background technology

The action phase place of traditional switch is random, easily produces very large surge current and very high induction overvoltage when connection and disjunction electric power system, causes the useful life of switchgear and the power supply quality of electric power system to reduce.Therefore, the intelligent control technology of research circuit breaker can either ensure power supply reliability, stability and the raising quality of power supply, and to conscientiously improving the production efficiency of enterprise and the important in inhibiting in useful life of equipment.

What Synchronous Closing control technology produced when effectively can weaken circuit-breaker switching on-off principle shoves and overvoltage, its essence is the dynamic and static contact of circuit breaker under control of the control system, close at the appointment phase angle place of power system voltage waveform, make the power equipments such as no-load transformer, capacitor and nonloaded line when to self and system shock is minimum drop into a kind of intelligent control technology of electric power system.This technology is better than the method for traditional suppression transient process such as switching-on resistance, series reactor.But the mechanical system that traditional operating mechanism is normally made up of the transmission mechanism of complexity, run duration is dispersed large, and motion poor controllability, response speed are slow, are thus difficult to the accurate control realizing mechanical movement.

The machine driving of vacuum circuit breaker permanent-magnet operating mechanism is simple, parts only have about 40% of spring operating mechanism, the magnetic field Direct driver that coil magnetization electric current produces moves iron core, on/off switch motion done by the main shaft that dynamic iron core directly promotes vacuum circuit-breaker, without the need to traditional mechanical trip and locker, this simple, the direct kind of drive makes the branch wire time of permanent-magnet manipulating mechanism stable and run duration dispersiveness is little.Therefore vacuum circuit breaker permanent-magnet operating mechanism can meet the requirement of Synchronous Closing control technology in the accuracy of branch wire time.But, because environmental condition difference will cause have dispersiveness the operate time of vacuum circuit-breaker, such as, when normal temperature, the coercive force of permanent magnetic material is 850kA/m, and when temperature is 80 DEG C, coercive force drops to 750kA/m, the direct result of generation is that the confining force of permanent-magnet manipulating mechanism diminishes, resultant magnetic field density reduces, and then causes the closing time of circuit breaker to change.And Synchronous Closing suppression is shoved and superpotential effect depends primarily on the accuracy that circuit breaker closes phase place, so control system need compensate the dispersiveness of operate time.Compensation method operate time traditional is at present control system by carrying out on-line checkingi to various influencing factor and calculating the numerical value changed operate time of being caused by them, to determine the moment sending actuating signal, this kind of method only can by branch wire time control errors at ± 2ms, divide-shut brake phase error reaches ± and 36 °, but, the prerequisite practical in intelligent grid of Synchronous Closing control technology be close the error of time must within ± 0.5ms, just control switching-on phase so likely more accurately, so lower with superpotential rejection ability to shoving in current control system actual motion.

Summary of the invention

The object of the invention is to overcome the deficiencies in the prior art, a kind of monostable vacuum circuit breaker permanent-magnet operating mechanism control method based on PWM and device thereof be provided, specifically have following technical scheme to realize:

The described monostable vacuum circuit breaker permanent-magnet operating mechanism control method based on PWM, by contact position, contact speed, actuator coil electric current three closed-loop adjustment, contact position ring regulates exciting current according to contact position, contact speed ring regulates PWM duty ratio according to the feedback signal of contact position ring, actuator coil electric current loop is according to the breaking-closing operating of exciting current and PWM duty ratio real time control machine structure, wherein contact position ring and contact speed ring adopt fuzzy controller, and actuator coil electric current loop adopts PI to control.

The further design of described method is, described fuzzy controller selects two dimension fuzzy PID controller, the input variable of contact position ring is error v and the error change △ v of location feedback value and given position value, contact movement velocity adjuster input variable is error e and the error change △ e of speed feedback value and given rotating speed value, carry out after obfuscation through fuzzy controller, obtain fuzzy quantity E and △ E and R and △ R, then the output variable obtained by fuzzy reasoning, fuzzy decision and anti fuzzy method process is as the set-point of electric current loop.

The further design of described method is, the design procedure of described fuzzy controller is as follows:

(1) 7 linguistic variables are got: negative large, in negative, negative little, zero, just little, center, honest, the fuzzy subset of setting input/output variable is: { NB, NM, MS, ZO, PS, PM, PB}, the domain of described linguistic variable is: {-6 ,-5 ,-4 ,-3,-2 ,-1,0,1,2,3,4,5,6};

(2) setting membership function is Normal Type membership function;

(3) carry out fuzzy decision by Mamdani type reasoning algorithm, fuzzy control rule is as shown in table 1, carries out defuzzification process finally by the center method of average.

Table 1

The further design of described method is, described permanent-magnet manipulating mechanism adopts the mode of capacitor discharge excitation, dynamical equation is built by the behavioral characteristics of contact, described contact position ring solves coil current i according to dynamical equation, upgrade PWM output order, the control capacitance velocity of discharge, described dynamical equation becomes large at magnet exciting coil electric current gradually by zero, when the electromagnetic force F that namely dynamic iron core is subject to is less than mechanism counter-force f is:

$\left\{\begin{array}{c}\frac{\mathrm{dt}}{\mathrm{dt}}=1\\ \frac{\mathrm{d\ψ}}{\mathrm{dt}}=U_c-\mathrm{iR}\\ \frac{\mathrm{dv}}{\mathrm{dt}}=\frac{F-f}{m}\\ \frac{\mathrm{dx}}{\mathrm{dt}}=\mathrm{\ν}\\ \frac{{\mathrm{dU}}_c}{\mathrm{dt}}=-\frac{i}{C}\\ U_c{|}_{t=0}=U_{c0},\mathrm{\ψ}{|}_{t=0}={\mathrm{\ψ}}_0,{\mathrm{\ν}|}_{t=0}=v_0=0,x{|}_{t=0}{x}_0=0\end{array}\right.---\left(1\right)$

In formula, t is time variable, U_cfor electric capacity both end voltage, ψ is the magnetic linkage by coil, and i is the electric current by coil, and R is coil resistance; ν is the speed of iron core movement; X is displacement unshakable in one's determination; C is capacitance; F is making a concerted effort of the electromagnetic attraction that iron core is subject to and permanent magnetic attraction; M is the quality of mechanism kinematic parts reduction to iron core place; F is the counter-force that iron core is subject to, and is the function of displacement x;ψ₀represent when magnetizing coil electric current is zero by the magnetic linkage of coil;

When the continuing current flow in magnet exciting coil increases, the electromagnetic force of generation has exceeded the time marquis of mechanism's counter-force, dynamic unshakable in one's determination depart from inactive state and setting in motion time, when namely F is greater than f be:

$\left\{\begin{array}{c}\frac{\mathrm{dt}}{\mathrm{dt}}=1\\ \frac{\mathrm{di}}{\mathrm{dt}}=\frac{U_C-\mathrm{iR}-\frac{{\mathrm{d\ψ}}_0}{\mathrm{dt}}-i\frac{\mathrm{dG}}{\mathrm{dt}}}{G}\\ \frac{\mathrm{d\ν}}{\mathrm{dt}}=\frac{F-f}{m}\\ \frac{\mathrm{dx}}{\mathrm{dt}}=\mathrm{\ν}\\ \frac{{\mathrm{dU}}_c}{\mathrm{dt}}=-\frac{i}{C}\\ U_c{|}_{t=t1}=U_{c1},i{|}_{t=t1}{i}_1,\mathrm{\ν}{|}_{t=t1}=0,x{|}_{t=1}=x_1\end{array}\right.---\left(2\right)$

According to the control method of the monostable vacuum circuit breaker permanent-magnet operating mechanism based on PWM that described method provides, communicate to connect with breaker permanent magnet control mechanism, comprise microprocessor, storage capacitor, drive circuit, current signal sample circuit, contact position testing circuit, discharge control loop and phase detecting circuit, described storage capacitor,

Drive circuit is connected with permanent-magnet manipulating mechanism by a rectification circuit, described current signal sample circuit and permanent-magnet manipulating mechanism communicate to connect, the contact of described contact position testing circuit and permanent-magnet manipulating mechanism circuit breaker communicates to connect, described drive circuit, current signal sample circuit, contact position testing circuit and phase detecting circuit are connected with microprocessor communication respectively, described phase detecting circuit connects power supply, and described discharge control loop is connected with storage capacitor and microprocessor communication respectively.

The further design of described control device is, described phase detecting circuit is connected to form by voltage transformer, operational amplifier, resistance and electric capacity.

The further design of described control device is, described current signal sample circuit, connected to form by Hall element, two operational amplifiers and resistance, described Hall element connects the in-phase input end of an operational amplifier, then is connected with the in-phase input end of another operational amplifier.

The further design of described control device is, described storage capacitor, drive circuit are connected with permanent-magnet manipulating mechanism by a rectification circuit.

The further design of described control device is, described contact position testing circuit comprises a transducer and bus transceiver, and described transducer is connected with microprocessor communication by bus transceiver.

The further design of described control device is, described discharge control loop is connected with storage capacitor by magnetic bead and capacitance-resistance, comprise capacitance voltage testing circuit and divide-shut brake control circuit, described capacitance voltage testing circuit comprises operational amplifier and linear optical coupling, described linear optical coupling is connected to the in-phase end of operational amplifier, described divide-shut brake control circuit comprises insulated gate bipolar transistor and linear optical coupling, and described linear optical coupling is connected with storage capacitor and insulated gate bipolar transistor respectively.

Advantage of the present invention is as follows:

The described monostable vacuum circuit breaker permanent-magnet operating mechanism control method based on PWM improves simultaneous operation ability and the reliability of vacuum circuit breaker permanent-magnet operating mechanism, the present invention is detected as master with coil current, be detected as auxiliary with contact travel, the two cooperatively interacts, pulse modulation technology is adopted in breaker operator process, by changing coil current, realize circuit breaker to divide, the closed-loop control of contacts movement features in closing operation process, the stability of safety action time, improve the accuracy of divide-shut brake phase place, final for realizing Synchronous Closing control technology, effectively suppress shove and overvoltage lay the foundation, apparatus module based on the described method division of labor provided by the invention is clear and definite simultaneously, and circuit is simple.

Accompanying drawing explanation

Fig. 1 is the structural representation of the monostable vacuum circuit breaker permanent-magnet operating mechanism control device based on PWM.

Fig. 2 is the schematic diagram of described two dimension fuzzy PID controller.

Fig. 3 is described Normal Type membership function schematic diagram.

Fig. 4 is the circuit diagram of described phase detecting circuit.

Fig. 5 is the circuit diagram of described drive circuit.

Fig. 6 is the circuit diagram of described current signal sample circuit.

Fig. 7 is the Three-loop control schematic diagram of described method and device thereof.

Fig. 8 is the circuit diagram of described contact position testing circuit.

Fig. 9 is the circuit diagram of described discharge control loop.

Embodiment

Below in conjunction with accompanying drawing, the present invention program is described in detail.

Monostable vacuum circuit breaker permanent-magnet operating mechanism control method based on PWM provided by the invention, by contact position, contact speed, actuator coil electric current three closed-loop adjustment, contact position ring regulates exciting current according to contact position, contact speed ring regulates PWM duty ratio according to the feedback signal of contact position ring, and actuator coil electric current loop is according to the breaking-closing operating of exciting current and PWM duty ratio real time control machine structure.Wherein contact position ring and contact speed ring adopt fuzzy controller, and actuator coil electric current loop adopts PI to control.So both can have the high stable state accuracy of fuzzy control, and can obtain again controlling dynamic response faster than PID, improve the control performance of system.The present embodiment fuzzy controller selects two dimension fuzzy PID controller, and the block diagram of two dimension fuzzy PID controller is as Fig. 1.In figure, Kp is proportionality coefficient, and Ki is integral coefficient, and Kd is differential coefficient, and e is error, and △ e is error change, and output variable is Systematical control value.

The input variable of contact position ring is error v and the error change △ v of location feedback value and given position value, contact movement velocity adjuster input variable is error e and the error change △ e of speed feedback value and given rotating speed value, carry out after obfuscation through fuzzy controller, obtain fuzzy quantity E and △ E and R and △ R, then the output variable obtained by fuzzy reasoning, fuzzy decision and anti fuzzy method process is as the set-point of electric current loop.

The design procedure of fuzzy controller is as follows:

(1) 7 linguistic variables are got: negative large, in negative, negative little, zero, just little, center, honest, the fuzzy subset of setting input/output variable is: { NB, NM, MS, ZO, PS, PM, PB}, the domain of linguistic variable is: {-6 ,-5 ,-4 ,-3,-2 ,-1,0,1,2,3,4,5,6};

(2) setting membership function is Normal Type membership function;

(3) carry out fuzzy decision by Mamdani type reasoning algorithm, fuzzy control rule is as shown in table 1, carries out defuzzification process finally by the center method of average.

Table 1

Permanent-magnet manipulating mechanism adopts the mode of capacitor discharge excitation, and build dynamical equation by the behavioral characteristics of contact, contact position ring solves coil current i according to dynamical equation, upgrades PWM output order, the control capacitance velocity of discharge.

For the permanent-magnet manipulating mechanism under charging capacitor electric discharge excitation, dynamic characteristic differential equation group can be expressed as:

$\left\{\begin{array}{c}\frac{\mathrm{dt}}{\mathrm{dt}}=1\\ \frac{\mathrm{d\ψ}}{\mathrm{dt}}=U_c-\mathrm{iR}\\ \frac{\mathrm{d\ν}}{\mathrm{dt}}=\frac{F-f}{m}\\ \frac{\mathrm{dx}}{\mathrm{dt}}=\mathrm{\ν}\\ \frac{{\mathrm{dU}}_c}{\mathrm{dt}}=-\frac{i}{C}\\ U_c{|}_{t=0}=U_{c0},\mathrm{\ψ}{|}_{t=0}={\mathrm{\ψ}}_0,\mathrm{\ν}{|}_{t=0}={\mathrm{\ν}}_0=0,x{|}_{t=0}{x}_0=0\end{array}\right.---(2-1)$

In formula, t is time variable, U_cfor electric capacity both end voltage, ψ is the magnetic linkage by coil, i is the electric current by coil, and R is coil resistance, and ν is the speed of iron core movement, x is displacement unshakable in one's determination, C is capacitance, and F is making a concerted effort of the electromagnetic attraction that iron core is subject to and permanent magnetic attraction, and m is the quality of mechanism kinematic parts reduction to iron core place, f is the counter-force that iron core is subject to, and is the function of displacement x.

(key of 2-1} is to solve the magnetic linkage ψ by coil, and variable i in formula, F are at U to solve formula_c, R, C, m and f be the function of ψ, x under given condition.Therefore, the key of above-mentioned solving equations is exactly under the prerequisite of magnetic linkage ψ knowing magnetic system in given armature displacement x and oneself, tries to achieve current i, electromagnetic attraction and permanent magnetic attraction.Because do not have clear and definite mathematical between ψ and i, so for such electromagnetic field reverse problem, we can not solve by the method for resolving, and can only adopt numerical solution.Therefore solve this formula and must utilize a series of iteration, solved the approximation of electric current by approximatioss.But because this algorithm needs successive ignition, the very large operand of needs, thus when at this, we adopt a kind of novel calculating permanent magnetism and electromagnetism acting in conjunction dynamic characteristic ask method.

First variable G is introduced:

ψ in formula₀represent when magnetizing coil electric current is zero by the magnetic linkage of coil.Namely dynamic unshakable in one's determination in current location, the magnetic linkage through coil produced by permanent magnet when coil current is zero.Above formula can be rewritten as:

ψ＝ψ₀+iG

According to total differential theorem, can obtain:

dψ＝dψ₀+idG+Gdi

By formula$\frac{\mathrm{d\ψ}}{\mathrm{dt}}=U_C-\mathrm{iR}$Can obtain:

$\frac{\mathrm{d\ψ}}{\mathrm{dt}}=\frac{{\mathrm{d\ψ}}_0}{\mathrm{dt}}+i\frac{\mathrm{dG}}{\mathrm{dt}}+G\frac{\mathrm{di}}{\mathrm{dt}}=U_C-\mathrm{iR}$

Further derivation can obtain:

$\frac{\mathrm{di}}{\mathrm{dt}}=\frac{U_C-\mathrm{iR}-\frac{{\mathrm{d\ψ}}_0}{\mathrm{dt}}-i\frac{\mathrm{dG}}{\mathrm{dt}}}{G}$

In formula: G, for after magnetizing coil electric current becomes currency from zero, by the magnetic linkage changing value of coil and the ratio of electric current, also can be regarded as the equivalent inductance value of coil simultaneously.Unit is H; ψ₀for dynamic iron core is when current location, the magnetic linkage through coil produced by permanent magnet when coil current is zero.

Circuit breaker is carrying out in breaking-closing operating process, and the whole dynamic process of permanent-magnet manipulating mechanism can be divided into two stages.Because the stressing conditions in two stages is different, so their dynamical equation is also different.First stage is, magnetizing coil electric current becomes large gradually by zero, and when the electromagnetic force that dynamic iron core is subject to also is less than mechanism's counter-force, dynamic iron core is subject to making a concerted effort being zero, and now dynamic iron core remains static, and dynamical equation is now:

$\left\{\begin{array}{c}\frac{\mathrm{dt}}{\mathrm{dt}}=1\\ \frac{\mathrm{di}}{\mathrm{dt}}=\frac{U_C-\mathrm{iR}-\frac{{\mathrm{d\ψ}}_0}{\mathrm{dt}}-i\frac{\mathrm{dG}}{\mathrm{dt}}}{G}\\ \frac{\mathrm{d\ν}}{\mathrm{dt}}=\frac{F-f}{m}\\ \frac{\mathrm{dx}}{\mathrm{dt}}=\mathrm{\ν}\\ \frac{{\mathrm{dU}}_c}{\mathrm{dt}}=-\frac{i}{C}\\ U_c{|}_{t=0}=U_{c0},i{|}_{t=0}=0,\mathrm{\ν}{|}_{t=0}{\mathrm{\ν}}_0=0,x{|}_{t=0}=x_0=0\end{array}\right.$

Second stage is: when the continuing current flow in magnetizing coil increases, the electromagnetic force of generation has exceeded the time marquis of mechanism's counter-force, and dynamic iron core departs from inactive state and setting in motion, until final position.We supposed when electromagnetic force and mechanism's reaction force are zero time: t=t₁, i=i₁, U_c=U_c1, then at the dynamical equation of this stage permanent-magnet manipulating mechanism be:

$\left\{\begin{array}{c}\frac{\mathrm{dt}}{\mathrm{dt}}=1\\ \frac{\mathrm{di}}{\mathrm{dt}}=\frac{U_C-\mathrm{iR}-\frac{{\mathrm{d\ψ}}_0}{\mathrm{dt}}-i\frac{\mathrm{dG}}{\mathrm{dt}}}{G}\\ \frac{\mathrm{d\ν}}{\mathrm{dt}}=\frac{F-f}{m}\\ \frac{\mathrm{dx}}{\mathrm{dt}}=\mathrm{\ν}\\ \frac{{\mathrm{dU}}_c}{\mathrm{dt}}=-\frac{1}{C}\\ U_c{|}_{t=t1}{U}_{c1},i{|}_{t=t1}=i_1,\mathrm{\ν}{|}_{t=t1}=0,x{|}_{t=1}=x_1\end{array}\right.$

According to the control device of the monostable vacuum circuit breaker permanent-magnet operating mechanism based on PWM that method provides, communicate to connect with breaker permanent magnet control mechanism, comprise microprocessor, storage capacitor, drive circuit, current signal sample circuit, contact position testing circuit, discharge control loop and phase detecting circuit, storage capacitor, drive circuit is connected with permanent-magnet manipulating mechanism by a rectification circuit, current signal sample circuit and permanent-magnet manipulating mechanism communicate to connect, the contact of contact position testing circuit and permanent-magnet manipulating mechanism circuit breaker communicates to connect, drive circuit, current signal sample circuit, contact position testing circuit and phase detecting circuit are connected with microprocessor communication respectively, phase detecting circuit connects power supply, discharge control loop is connected with storage capacitor and microprocessor communication respectively.In the present embodiment, microprocessor adopts TMS320F28335DPS chip.

Phase detecting circuit is connected to form by voltage transformer, operational amplifier, resistance and electric capacity.In phase detecting circuit in the present embodiment, voltage transformer adopts TV1013-1M.Operational amplifier adopts LM385.This circuit carries out Real-time Collection to system voltage and ensures that voltage magnitude is in DSP and receives in amplitude range by arranging sampling resistor R4.The voltage signal gathered sends into the AD analog channel mouth of DSP, processing, realizing accurately detecting the phase place of system voltage at the inner signal to gathering of DSP.Phase detecting circuit as shown in Figure 4.Current signal sample circuit is connected to form by Hall element, two operational amplifiers and resistance, and Hall element connects the in-phase input end of an operational amplifier, then is connected with the in-phase input end of another operational amplifier.Traditional current signal sample circuit, utilizes the mode of divider resistance more.This kind of method is simple, but resistance can change because of temperature drift.The precision measured cannot be ensured.There is no electrical isolation between external circuit and control circuit simultaneously, very easily cause the high voltage in major loop to the counterattack of control loop, the safety of control system is constituted a threat to.Therefore, in the current sampling circuit of the present embodiment, adopt the Hall type current sensor CHF-400B that can realize electrical isolation, sensor output voltage becomes ratio with input current, and ratio is 1/100.Permanent-magnet manipulating mechanism is carrying out in breaking-closing operating process, and coil current can change direction, but in DSP, the input voltage range of A/D module is 0 ~ 3.3V, so devise the current signal sample circuit shown in Fig. 6.

Select insulated gate bipolar transistor to do the switching device of circuit, when performing combined floodgate order, DSP sends signal and drives T1 and T4 conducting; When performing separating brake order, DSP sends signal and drives T2 and T3 conducting, in divide-shut brake moment, very high back-pressure can be produced in coil, therefore need continuous current circuit, the fault offset in divide-shut brake coil is fallen, therefore devise continuous current circuit in drive circuit, after combined floodgate puts in place, the electric current in closing coil passes through D2, D3 afterflow, energy in release coil, after separating brake puts in place, the electric current in coil is by D1 and D4 afterflow, energy in release switching winding, drive circuit as shown in Figure 5.

Discharge control loop is connected with storage capacitor by magnetic bead and capacitance-resistance, to eliminate high-frequency noise and spike interference, adopts ferrite bean in the present embodiment.Discharge control loop comprises capacitance voltage testing circuit and divide-shut brake control circuit.Capacitance voltage testing circuit comprises operational amplifier and linear optical coupling, and linear optical coupling is connected to the in-phase end of operational amplifier.The present embodiment neutral line optocoupler is HCNR200, after controller powers on, first Capacitor banks is charged, DSP gathers the signal of capacitance voltage and to go forward side by side row relax, when magnitude of voltage reaches systems operational requirement, DSP sends stopping charging instruction, cut off under extraneous power supply HCNR200 is operated in photovoltage pattern, first divider resistance is passed through, condenser voltage is carried out voltage division processing, intercept out a part of voltage, and after follower driving is carried out to this voltage, give the primary side of linear optical coupling, again voltage signal is exported out by the secondary side of optocoupler after Phototube Coupling, the A/D pin finally voltage signal being transported to DSP carries out analog-to-digital conversion thus obtains the magnitude of voltage on capacitor.Divide-shut brake control circuit comprises insulated gate bipolar transistor and linear optical coupling, and linear optical coupling is connected with storage capacitor and insulated gate bipolar transistor respectively.Send divide-shut brake instruction by TMS320F28335, by PWM waveform, control the switch of insulated gate bipolar transistor in power tube drive circuit, and then control the speed of movable contact of vacuum circuit breaker, realize point closing operation to vacuum circuit-breaker.Discharge control loop, according to the above-mentioned dynamical equation based on the setting of contact behavioral characteristics, upgrades PWM and exports sequential logic regulation and control storage capacitor, discharge, then this electric current is supplied to actuator coil.Meanwhile, the signal that contact speed ring feeds back according to contact position ring adjusts PWM duty ratio in real time, and actuator coil electric current is changed as requested, carry out the regulation and control of contact speed and to complete point, closing operation.

Contact position testing circuit comprises a transducer and bus transceiver, and transducer is connected with microprocessor communication by bus transceiver.The present embodiment selects SGC6T200 type grating sensor, and this type grating sensor output signal is Transistor-Transistor Logic level, effective range 200mm, every 50mm zero reference point.The grating sensor scope of testing the speed be 0 ~ 4.8m/s, resolution 0.005mm (grating space }, can record more exactly vacuum circuit-breaker point, the dynamic speed of contact in making process and position characteristic.In the sheet of TMS320F28335DSP, peripheral hardware receives the voltage signal of 3.3V.But what grating scale transducer exported is the Transistor-Transistor Logic level signal of 5V.Because control system requires higher to the speed/frequency of conversion, require that again converted power consumption can not be too large simultaneously, consider the requirement of sensitivity, final decision adopts bus transceiver SN74LVCH245A as level conversion device, realizes the conversion of the 3.3V level that 5V input signal can receive to DSP.

In the method and device thereof of monostable control mechanism of vacuum circuit breaker speed regulating control, differ distance between the effect minimizing three-phase contact of contact position ring, reduce asynchrony as far as possible.The effect of contact movement velocity ring suppresses the fluctuation of speed, and ensureing the synchronism of three-phase Contact Breaking/Making Operations lock, is the major control link of system.In order to improve the dynamic and static state characteristic of system, contact movement velocity adjuster and contact position adjuster adopt fuzzy-adaptation PID control.Electric current loop makes electric current tightly follow the output of speed regulator, plays Anti-Jamming to the fluctuation of line voltage.

Claims (10)

1. the monostable vacuum circuit breaker permanent-magnet operating mechanism control method based on PWM, by contact position, contact speed, actuator coil electric current three closed-loop adjustment, it is characterized in that, contact position ring regulates exciting current according to contact position, contact speed ring regulates PWM duty ratio according to the feedback signal of contact position ring, actuator coil electric current loop is according to the breaking-closing operating of exciting current and PWM duty ratio real time control machine structure, wherein contact position ring and contact speed ring adopt fuzzy controller, and actuator coil electric current loop adopts PI to control.

2. method according to claim 1, it is characterized in that, described fuzzy controller selects two dimension fuzzy PID controller, the input variable of contact position ring is error v and the error change △ v of location feedback value and given position value, contact movement velocity adjuster input variable is error e and the error change △ e of speed feedback value and given rotating speed value, carry out after obfuscation through fuzzy controller, obtain fuzzy quantity E and △ E and R and △ R, then the output variable obtained by fuzzy reasoning, fuzzy decision and defuzzification process is as the set-point of electric current loop.

3. method according to claim 2, is characterized in that, the design procedure of described fuzzy controller is as follows:

(1) 7 linguistic variables are got: negative large, in negative, negative little, zero, just little, center, honest, the fuzzy subset of setting input/output variable is: { NB, NM, MS, ZO, PS, PM, PB}, the domain of described linguistic variable is: {-6 ,-5 ,-4 ,-3,-2 ,-1,0,1,2,3,4,5,6};

(2) setting membership function is Normal Type membership function;

(3) carry out fuzzy decision by Mamdani type reasoning algorithm, fuzzy control rule is as shown in table 1, carries out defuzzification process finally by the center method of average.

Table 1

4. method according to claim 1, it is characterized in that, described permanent-magnet manipulating mechanism adopts the mode of capacitor discharge excitation, dynamical equation is built by the behavioral characteristics of contact, described contact position ring solves coil current i according to dynamical equation, upgrades PWM output order, the control capacitance velocity of discharge, described dynamical equation becomes large at magnet exciting coil electric current gradually by zero, when the electromagnetic force F that namely dynamic iron core is subject to is less than mechanism counter-force f is:

$\{\begin{array}{c}\frac{dt}{dt}=1\\ \frac{di}{dt}=\frac{U_C-iR-\frac{{\mathrm{d\ψ}}_0}{dt}-i\frac{dG}{dt}}{G}\\ \frac{\mathrm{dv}}{dt}=\frac{F-f}{m}\\ \frac{dx}{dt}=v\\ \frac{{\mathrm{dU}}_c}{dt}=-\frac{i}{C}\\ U_c{|}_{t=0}=U_{c0},i{|}_{t=0}=0,v{|}_{t=0}=v_0=0,x{|}_{t=0}=x_0=0\end{array}---\left(1\right)$

In formula, t is time variable, U_cfor electric capacity both end voltage, ψ is the magnetic linkage by coil, and i is the electric current by coil, and R is coil resistance; ν is the speed of iron core movement; X is displacement unshakable in one's determination; C is capacitance; F is making a concerted effort of the electromagnetic attraction that iron core is subject to and permanent magnetic attraction; M is the quality of mechanism kinematic parts reduction to iron core place; F---the counter-force that dynamic iron core is subject to is the function of displacement x;ψ₀represent when magnetizing coil electric current is zero by the magnetic linkage of coil;

When the continuing current flow in magnet exciting coil increases, the electromagnetic force of generation has exceeded the time marquis of mechanism's counter-force, dynamic unshakable in one's determination depart from inactive state and setting in motion time, when namely F is greater than f be:

$\{\begin{array}{c}\frac{dt}{dt}=1\\ \frac{di}{dt}=\frac{U_C-iR-\frac{{\mathrm{d\ψ}}_0}{dt}-i\frac{dG}{dt}}{G}\\ \frac{\mathrm{dv}}{dt}=\frac{F-f}{m}\\ \frac{dx}{dt}=v\\ \frac{{\mathrm{dU}}_c}{dt}=-\frac{i}{C}\\ U_c{|}_{t=0}=U_{c0},i{|}_{t=0}=0,v{|}_{t=0}=v_0=0,x{|}_{t=0}=x_0=0\end{array}---\left(2\right).$

5. as described in any one of claim 1-4 based on the monostable vacuum circuit breaker permanent-magnet operating mechanism control device of PWM, communicate to connect with breaker permanent magnet control mechanism, it is characterized in that, comprise microprocessor, storage capacitor, drive circuit, current signal sample circuit, contact position testing circuit, discharge control loop and phase detecting circuit, described storage capacitor, drive circuit is connected with permanent-magnet manipulating mechanism by a rectification circuit, described current signal sample circuit and permanent-magnet manipulating mechanism communicate to connect, the contact of described contact position testing circuit and permanent-magnet manipulating mechanism circuit breaker communicates to connect, described drive circuit, current signal sample circuit, contact position testing circuit and phase detecting circuit are connected with microprocessor communication respectively, described phase detecting circuit connects power supply, described discharge control loop is connected with storage capacitor and microprocessor communication respectively.

6. control device according to claim 5, is characterized in that, described phase detecting circuit is connected to form by voltage transformer, operational amplifier, resistance and electric capacity.

7. control device according to claim 5, it is characterized in that, described current signal sample circuit, connected to form by Hall element, two operational amplifiers and resistance, described Hall element connects the in-phase input end of an operational amplifier, then is connected with the in-phase input end of another operational amplifier.

8. control device according to claim 5, is characterized in that, described storage capacitor, drive circuit are connected with permanent-magnet manipulating mechanism by a rectification circuit.

9. control device according to claim 5, is characterized in that, described contact position testing circuit comprises a transducer and bus transceiver, and described transducer is connected with microprocessor communication by bus transceiver.

10. control device according to claim 5, it is characterized in that, described discharge control loop is connected with storage capacitor by magnetic bead and capacitance-resistance, comprise capacitance voltage testing circuit and divide-shut brake control circuit, described capacitance voltage testing circuit comprises operational amplifier and linear optical coupling, described linear optical coupling is connected to the in-phase end of operational amplifier, described divide-shut brake control circuit comprises insulated gate bipolar transistor and linear optical coupling, and described linear optical coupling is connected with storage capacitor and insulated gate bipolar transistor respectively.