阅读说明：本技术 一种静止变频器脉冲换相阶段转速控制方法 (A kind of static frequency changer pulse phase change stage method for controlling number of revolution ) 是由 刘文戈 王熙 黄河清 漫自强 阚朝晖 李子龙 李玲 于 2019-09-25 设计创作，主要内容包括：本发明涉及一种静止变频器脉冲换相阶段转速控制方法,静止变频器含有整流桥、逆变桥和晶闸管,本方法是在现有的转速外环与电流内环之间增加一自适应速度滑模控制器。当需要将同步电机稳定在极低转速时,由于静止变频器的直流电流指令值存在一个最小值,当电流维持在最小值时,若对于某些机组由于在脉冲换相阶段负载损耗极小,输出电磁转矩仍大于负载转矩,转速无法稳定,此时通过滑模控制器在转速达到设定值时闭锁脉冲输出,当转速因负载而下降到设定值时,预估换相时刻,若预计换相时刻大于定值,则再次导通晶闸管,若预计换相时刻小于定值,则等待换相时刻出现以后,重新导通晶闸管。该定值的设定,根据系统设计及电流上升与闭锁的时间确定。(The present invention relates to a kind of static frequency changer pulse phase change stage method for controlling number of revolution, static frequency changer contains rectifier bridge, inverter bridge and thyristor, and this method is to increase by an adaptive speed sliding mode controller between existing revolving speed outer ring and current inner loop.It is when needing that synchronous motor is stable in extremely low revolving speed, since there are a minimum values for the DC current instruction value of static frequency changer, when electric current maintains minimum value, if for certain units due to minimum in pulse phase change stage load loss, output electromagnetic torque is still greater than load torque, revolving speed can not be stablized, it is latched pulse output when revolving speed reaches setting value by sliding mode controller at this time, when revolving speed drops to setting value because of load, estimate the commutation moment, if it is expected that the commutation moment is greater than definite value, then conducting thyristor again, if it is expected that the commutation moment is less than definite value, after then waiting the commutation moment to occur, again conducting thyristor.The setting of the definite value rises according to system design and electric current and determines with the time of locking.)

1. a kind of static frequency changer pulse phase change stage method for controlling number of revolution, static frequency changer includes rectifier bridge and inverter bridge, It is controlled by the conducting to each thyristor, to adjust output frequency；It is characterized by: rate-determining steps are as follows:

(1), between existing revolving speed outer ring and current inner loop, an adaptive speed sliding mode controller is increased, when needs will be same Motor stabilizing is walked in the case where extremely low revolving speed, controls the target of current inner loop by sliding mode controller by revolving speed outer ring first Continuous current reference value is adjusted to the new current setting value switched between 0 value and former revolving speed outer ring calculated value by value；

(2) rotor real time position angle θ, is detected by position sensor or position-sensor-free technology, and is obtained according to rotor position angle To current rotor angular rate ω, i.e. rotary speed measure value；According to the rotor angular rate target value ω of setting_setTurn with current Sub- angular rate measured value ω is controlled by the PI of revolving speed outer ring, obtains current instruction value I_dcal, and current instruction value is carried out Current instruction value is set in stably and controllable range by clipping；

(3), by the current instruction value I_dcalWith the rotor angular rate target value of current rotor angular rate ω and setting ω_setInput sliding mode controller；When the sliding mode controller includes a hysteresis loop comparator containing prediction of speed function and one Between limiter, sliding mode controller realizes the switching of mode by hysteresis loop comparator and time restriction device；

(4), the hysteresis loop comparator in sliding mode controller is according under the upper limit value calculation formula and hysteresis loop comparator of hysteresis loop comparator The calculation formula of limit value calculates selection current target value and exports to current inner loop, and current inner loop is according to the current target value tune Whole rectifier bridge Trigger Angle；If the current target value is 0, current inner loop adjusts rectifier bridge Trigger Angle to the inversion angle of setting After be latched pulse, enable loop current be down to 0；

The upper limit value of hysteresis loop comparator+Δ n calculation formula are as follows:

+ Δ n=Δ n_set-0.5(α_up+α_down)Δt₁

In formula+Δ n be hysteresis loop comparator upper limit value；Δn_setFor the speed error value of permission, it is set as definite value；α_upFor circuit Electric current is I_dcalWhen unit electric angle acceleration, α_downUnit electric angle acceleration when for loop current being 0 value is sampling meter It obtains；Δt₁Decay to for 0 time for loop current；

The lower limit value of the hysteresis loop comparator-Δ n calculation formula are as follows:

Δ n=- Δ n_set+0.5(α_up+α_down)Δt₃

In formula-Δ n be hysteresis loop comparator lower limit value；Δn_setFor the speed error value of permission, it is set as definite value；Same α_upFor Loop current is I_dcalWhen unit electric angle acceleration, α_downUnit electric angle acceleration when for loop current being 0 value, is to adopt Sample is calculated；Δt₃The time is re-established for loop current；

(5), when the output of the hysteresis loop comparator is 0 value, the output time, there are a lower limit Δ t₂, Δ t₂To guarantee brilliant lock The minimum time that electric current required for pipe reliable turn-off is 0；

(6) it, is latched pulse output when revolving speed reaches setting value, when revolving speed drops to setting value due to load-reason, estimates and changes The phase moment, if it is expected that the commutation moment be greater than definite value, conducting thyristor again, if it is expected that the commutation moment be less than definite value, After waiting the commutation moment to occur, conducting thyristor again.

2. static frequency changer pulse phase change stage method for controlling number of revolution according to claim 1, it is characterised in that: step is (3) Described in the hysteresis loop comparator containing prediction of speed function input be current rotating speed measured value and revolving speed target value difference with The output valve of revolving speed outer ring.

3. static frequency changer pulse phase change stage method for controlling number of revolution according to claim 1, it is characterised in that: step is (4) Described in sliding mode controller in hysteresis loop comparator the upper limit and lower limit in real time by setting definite value and current acceleration It is calculated:

Assuming that Δ t₁And Δ t₃In time range, acceleration linear change, then current target value selection is regular are as follows:

When rotating speed difference is greater than upper limit value, the output of the hysteresis loop comparator is 0 value, i.e.,

ω-ω_set>+Δ n=Δ n_set-0.5(α_up+α_down)Δt₁, then the current target value exported is 0 value；

When rotating speed difference is less than lower limit value, the output of the hysteresis loop comparator is the output valve of revolving speed outer ring, i.e.,

ω-ω_set<-Δ n=- Δ n_set+0.5(α_up+α_down)Δt₃, then the current target value exported is the electric current of revolving speed outer ring Instruction value is I_dcal；

To realize the current target value of output in 0 value and current instruction value I_dcalIt is toggled between two mode.

4. static frequency changer pulse phase change stage method for controlling number of revolution according to claim 1, it is characterised in that: described Rotor angular rate target value ω_set, current setting value, permission speed error Δ n_setSetting be according to system design and electricity Stream rises to be determined with the time of locking.

Technical field

The present invention relates to a kind of static frequency changer pulse phase change stage stabilization of speed control methods, belong to Electrical Motor and electric power Electronic technology field.

Background technique

Static frequency changer is at starting synchronous motor initial stage, and since set end voltage is lower, inverter bridge thyristor is unable to complete certainly Right commutation needs by way of forcing commutation, and cutoff thyristor electric current is to realize commutation.In the pulse phase change stage, due to Revolving speed is extremely low, and the load torque of motor is also very low, therefore to realize the stability contorting of pulse phase change stage revolving speed, needs to realize The output of extremely low torque.

Output torque T_MCalculation formula it is as follows:

T_M=C_m*ψ_r*i_ssinα

In formula, C_m-- torque coefficient；ψ_r-- rotor flux；i_s-- stator resultant current；α -- stator magnetic linkage and rotor flux Angle.

In the pulse phase change stage, the too small set end voltage that will cause of rotor flux is too low, turns so as to cause can not accurately detect Speed and rotor-position；Stator resultant current is too small to will lead to current fluctuation, can not generate stably and controllable output torque；Stator The angle of magnetic linkage and rotor flux is adjustable to be limited in scope for thyristor, and angle is too small to will lead to current fluctuation, from And the problems such as stably and controllable output torque can not be generated.

It has just been installed for needing the stable occasion in the pulse phase change stage of motor speed, such as in capital generating unit It needs man, pull-over gear group cooperation main engine plants to be tested Deng, static frequency changer, host is stablized in different rotating speeds to facilitate host Producer tests unit runout parameter etc., and static frequency changer is needed in the pulse phase change stage, to stablize set steady at this time Speed error need to meet requirement of invitation for bid.

It is difficult for pulse phase change stage long-standing direct torque, it is difficult to by stabilization of speed asking at very low frequencies end Topic, for many years, those skilled in the art are being endeavoured to solve low-speed stage starting of static frequency conversion starting of pumped storage power station always The problem of control, such as " low-speed stage starting of static frequency conversion starting of pumped storage power station control method " patent disclosed in 2009 Application No. is 200910184027.X, a kind of method for controlling number of revolution of low-speed stage is proposed, on implementation, mainly basis Output torque prejudges revolving speed and rotor-position, it is therefore an objective to unit are dragged to 5Hz from 0Hz as soon as possible, the final target of the algorithm Be the rotor-position obtained under permanent torque, make entire start-up course constant torque, increase revolving speed to the maximum extent, but this method without Method realizes the stabilization of speed control between 0Hz-5Hz.

Disclosed in 2011 " working condition excitation system of static frequency converter of pumped-storage aggregate set starting control method ", patent Number be CN201110000002.7, disclosed in 2013 " a kind of variable frequency starting control method of heavy duty gas turbine group ", specially Benefit number is CN201310347417.0, disclosed in 2014 " method for running the electric unit of hydroenergy storage station ", specially Application No. is CN201380013136.X for benefit, " control method for coordinating, frequency converter, energizing apparatus and static disclosed in 2018 Variable frequency starting system ", number of patent application CN201810359800.0, this four technologies all describe hydroenergy storage station with Combustion engine power station is using in static frequency changer start-up course, and the process of required experience, only disclosure starts grid-connected to 50Hz from 0Hz In the process, how each equipment cooperates, and when switches, but to the control mode of static frequency changer in start-up course, does not have It refers to.For this purpose, it is difficult to pulse phase change stage long-standing direct torque, it is necessary to provide a kind of static frequency changer pulse Commutation stage method for controlling number of revolution.

Summary of the invention

It is of the existing technology the invention aims to solve the problems, such as, and a kind of static frequency changer pulse phase change rank is provided Section method for controlling number of revolution, can enable the output power of static frequency changer switch between 0 mode and minimum output modalities, thus sharp There are the characteristics that inertia with rotor, enables motor speed stablize the tachometer value in needs, speed error is enabled to maintain needs In range.

In order to achieve the above objectives, the technical solution adopted by the present invention is that: a kind of static frequency changer pulse phase change stage is provided Method for controlling number of revolution, static frequency changer include rectifier bridge and inverter bridge, are controlled by the conducting to each thyristor, thus Adjust output frequency；Rate-determining steps are as follows:

(1), between existing revolving speed outer ring and current inner loop, increase an adaptive speed sliding mode controller, work as needs Synchronous motor is stablized in the case where extremely low revolving speed, controls the mesh of current inner loop by sliding mode controller by revolving speed outer ring first Continuous current reference value is adjusted to the new current setting value switched between 0 value and former revolving speed outer ring calculated value by scale value；

(2) rotor real time position angle θ, is detected by position sensor or position-sensor-free technology, and according to rotor-position Angle obtains current rotor angular rate ω, i.e. rotary speed measure value；According to the rotor angular rate target value ω of setting_setWith it is current Rotor angular rate measured value ω, controlled by the PI of revolving speed outer ring, obtain current instruction value I_dcal, and to current instruction value Clipping is carried out, current instruction value is set in stably and controllable range；

(3), by the current instruction value I_dcalWith the rotor angular rate target of current rotor angular rate ω and setting Value ω_setInput sliding mode controller；The sliding mode controller includes a hysteresis loop comparator containing prediction of speed function and one Time restriction device, sliding mode controller realize the switching of mode by hysteresis loop comparator and time restriction device；

(4), the hysteresis loop comparator in sliding mode controller is according to the upper limit value calculation formula and hysteresis loop comparator of hysteresis loop comparator Lower limit value calculation formula, calculate selection current target value export to current inner loop, current inner loop is according to the current target Value adjustment rectifier bridge Trigger Angle；If the current target value is 0, current inner loop adjusts rectifier bridge Trigger Angle to the inversion of setting It is latched pulse after angle, loop current is enabled to be down to 0；

The upper limit value of hysteresis loop comparator+Δ n calculation formula are as follows:

+ Δ n=Δ n_set-0.5(α_up+α_down)Δt₁

In formula+Δ n be hysteresis loop comparator upper limit value；Δn_setFor the speed error value of permission, it is set as definite value；α_upFor Loop current is I_dcalWhen unit electric angle acceleration, α_downUnit electric angle acceleration when for loop current being 0 value, is to adopt Sample is calculated；Δt₁Decay to for 0 time for loop current；

The lower limit value of the hysteresis loop comparator-Δ n calculation formula are as follows:

Δ n=- Δ n_set+0.5(α_up+α_down)Δt₃

In formula-Δ n be hysteresis loop comparator lower limit value；Δn_setFor the speed error value of permission, it is set as definite value；Equally α_upIt is I for loop current_dcalWhen unit electric angle acceleration, α_downUnit electric angle acceleration when for loop current being 0 value, It is calculated for sampling；Δt₃The time is re-established for loop current；

(5), when the output of the hysteresis loop comparator is 0 value, the output time, there are a lower limit Δ t₂, Δ t₂To guarantee The minimum time that electric current required for thyristor reliable turn-off is 0；

(6), pulse output is latched when revolving speed reaches setting value, when revolving speed drops to setting value due to load-reason, in advance Estimate the commutation moment, if it is expected that the commutation moment be greater than definite value, conducting thyristor again, if it is expected that the commutation moment be less than it is fixed Value, then after waiting the commutation moment to occur, conducting thyristor again.

Further say, step (3) described in the input of the hysteresis loop comparator containing prediction of speed function be that current rotating speed is real The output valve of the difference and revolving speed outer ring of measured value and revolving speed target value.

Further say, step (4) described in sliding mode controller in the upper limit of hysteresis loop comparator lead in real time with lower limit The definite value for crossing setting is calculated with current acceleration:

Assuming that Δ t₁And Δ t₃In time range, acceleration linear change, then current target value selection is regular are as follows:

When rotating speed difference is greater than upper limit value, the output of the hysteresis loop comparator is 0 value, i.e.,

ω-ω_set>+Δ n=Δ n_set-0.5(α_up+α_down)Δt₁, then the current target value exported is 0 value；

When rotating speed difference is less than lower limit value, the output of the hysteresis loop comparator is the output valve of revolving speed outer ring, i.e.,

ω-ω_set<-Δ n=- Δ n_set+0.5(α_up+α_down)Δt₃, then the current target value exported is revolving speed outer ring Current instruction value I_dcal；

To realize the current target value of output in 0 value and current instruction value I_dcalIt is toggled between two mode.

It further says, the rotor angular rate target value ω_set, current setting value, permission speed error Δ n_setSetting be according to system design and electric current rise with locking time determine.

The beneficial effect of static frequency changer pulse phase change stage method for controlling number of revolution of the present invention compared with prior art is:

1., control method of the invention proposes is a kind of synovial membrane control algolithm, control is torque between 0Hz-5Hz, Stabilization of speed, obtained result not instead of revolving speed, torque are realized by control torque, and torque is achieved effective control.

2., in static frequency changer pulse phase change stage method for controlling number of revolution of the invention, only existing in system Between revolving speed outer ring and current inner loop, increase an adaptive speed sliding mode controller, does not increase the difficulty of system equipment transformation. Sliding mode controller includes that a hysteresis loop comparator containing prediction of speed function and a time restriction device, sliding mode controller pass through Hysteresis loop comparator and time restriction device realize the switching of mode.

3., using control method of the invention by real-time detection synchronous motor rotor position, calculate rotor current rotating speed, By switching between the current instruction value that revolving speed outer ring calculates and 0 value output electric current, realization torque is being stably controlled Switch between minimum torque and zero-turn square, using unit set inertia, generating unit speed is allowed to be stably held in the error upper limit of demand revolving speed Between error floor, unit is accurately controlled in pulse phase change stage revolving speed to realize.

4., for conventional PI control, it is minimum in slow-speed of revolution section torque, current target value to be restrained by PI parameter To accurate result, time-consuming, while high to PI parameter request, PI parameter slightly error, i.e., can not converge to correctly as a result, And low speed segment PI parameter is different from PI parameter stability range when total power output, needs to set more set parameters to adapt to different need It asks, using method for controlling torque of the invention, using synovial membrane controller, does not need the demand for having excessive to PI parameter, directly adopt The PI parameter being calculated with existing total power output method, reduces the difficulty of parameter tuning.

Detailed description of the invention

Fig. 1 is the structural schematic diagram of existing static frequency changer.

Fig. 2 is the structural schematic diagram of newly-increased sliding mode controller of the invention.

Fig. 3 is the schematic diagram that the present invention stablizes the stator current under demand revolving speed and rotation speed change.

Specific embodiment

The present invention will be further explained below with reference to the attached drawings and specific examples, but implementation of the invention is without being limited thereto.