阅读说明：本技术 一种航空交流发电机电压数字综合控制方法 (Digital comprehensive control method for voltage of aviation alternating-current generator ) 是由 向子琦 秦昌立 魏佳丹 张卓然 杨善水 于 2020-06-04 设计创作，主要内容包括：本发明公开一种航空交流发电机电压数字综合控制方法,其特征在于：在发电机初始建压过程中,发电机电压给定为从0上升的斜坡电压,直接采用开环控制,检测并判断励磁电流输出能力和发电机发电能力是否正常,正常则继续工作,故障则停止工作；当发电机给定电压值达到恒定给定值后,进入双电压闭环控制,结合负载电流前馈控制、负载电流负反馈控制、励磁电流限制控制和励磁电源电压前馈控制,实现发电机输出电压的数字综合控制。本发明能够提高发电设备可靠性,提高发电系统输出电压的动态响应速度以及稳态控制精度及抗干扰能力。(The invention discloses a voltage digital comprehensive control method of an aviation alternating-current generator, which is characterized by comprising the following steps of: in the initial voltage building process of the generator, the voltage of the generator is given as a slope voltage rising from 0, open loop control is directly adopted, whether the output capacity of the exciting current and the generating capacity of the generator are normal or not is detected and judged, if the output capacity of the exciting current and the generating capacity of the generator are normal, the generator continues to work, and if the output capacity of the generator fails, the generator stops working; when the given voltage value of the generator reaches a constant given value, double-voltage closed-loop control is performed, and digital comprehensive control of the output voltage of the generator is realized by combining load current feedforward control, load current negative feedback control, exciting current limit control and exciting power supply voltage feedforward control. The invention can improve the reliability of the power generation equipment, and improve the dynamic response speed of the output voltage of the power generation system, the steady-state control precision and the anti-interference capability.)

1. A voltage digital comprehensive control method of an aviation alternating-current generator is characterized by comprising the following steps:

in the initial voltage building process of the generator, the voltage of the generator is given as a slope voltage rising from 0, open loop control is directly adopted, whether the output capacity of the exciting current and the generating capacity of the generator are normal or not is detected and judged, if the output capacity of the exciting current and the generating capacity of the generator are normal, the generator continues to work, and if the output capacity of the generator fails, the generator stops working; when the given voltage value of the generator reaches a constant given value, double-voltage closed-loop control is performed, and digital comprehensive control of the output voltage of the generator is realized by combining load current feedforward control, load current negative feedback control, exciting current limit control and exciting power supply voltage feedforward control.

2. The aero-alternator voltage digital integrated control method as claimed in claim 1 wherein dual voltage closed loop control: when the initial voltage build-up of the generator is completed, and the voltage of the generator reaches a constant given value, the given voltage and the effective value of the output voltage of the alternator are fed back to be subjected to difference comparison and then are used as slow voltage closed-loop regulation through a PI regulator, the given voltage and the instantaneous value of the output voltage of the alternator are fed back to be subjected to difference comparison and then are used as fast voltage closed-loop regulation through the PI regulator, and the output of the slow voltage closed-loop regulation is superposed to the fast voltage closed-loop regulation, so that the double-voltage-loop PI regulation is realized.

3. The aero-alternator voltage digital integrated control method as claimed in claim 2 wherein the slow voltage closed loop control: and taking a true effective value obtained by calculating the output voltage of the alternating-current generator through a sliding window algorithm as a feedback voltage, carrying out external slow-speed voltage closed-loop PI regulation after the true effective value is different from a given voltage, and outputting the true effective value as a correction compensation quantity of an internal fast-speed voltage closed-loop PI regulator.

4. The aero-alternator voltage digital integrated control method as claimed in claim 2 wherein the fast voltage closed loop control: sampling the maximum value of the three-phase voltage of the output voltage of the alternating-current generator, obtaining the effective value of the three-phase voltage after conversion, carrying out internal fast voltage closed-loop PI regulation after the difference is made with the given voltage, and jointly realizing the regulation of the output voltage of the generator by combining the correction compensation quantity output by slow voltage closed-loop regulation.

5. The aero-alternator voltage digital integrated control method as claimed in claim 1 wherein the load current feed forward control: and when the load current is less than or equal to the set threshold, the load current is used as feedforward to control the constant voltage output of the generator.

6. The aero alternator voltage digital integrated control method as claimed in claim 1 wherein the load current negative feedback control: and when the load current is greater than a set threshold value, carrying out droop control, and controlling the constant power output of the generator by using the load current as negative feedback.

7. The aircraft alternator voltage digital integrated control method of claim 1, wherein the excitation supply voltage feed forward control: and (3) obtaining the control quantity of the excitation voltage required in no-load through an open-loop experiment, and taking the control quantity as given voltage compensation in the initial voltage building process and as feedforward compensation after the initial voltage building is finished.

8. The aero alternator voltage digital integrated control method as claimed in claim 1 wherein the field current limit control: detecting the exciting current in real time, and when the exciting current is greater than a set maximum threshold, outputting the exciting current in a current-limiting manner, so that the reliability of the system is improved; and when the exciting current is smaller than the set minimum threshold, judging whether the system works normally by combining the output voltage of the generator, and if so, entering a fault mode and stopping generating power.

Technical Field

The invention relates to optimization of a voltage regulation control method of an aviation three-level permanent magnet synchronous motor power generation system, and belongs to the technical field of aviation power generation.

Background

The voltage regulator product of the current installed and mass-produced aero-generator still mainly regulates the voltage of an analog circuit. The analog circuit voltage regulator mainly comprises an analog circuit, and has inherent defects of the analog circuit, such as difficult parameter adjustment, difficult acquisition of circuit parameters suitable for various states, difficult realization of complex control rules and the like.

With the development of new technology, the rotating speed range of the aero-generator is increased, the load power change range is increased, the harmonic content is increased due to the increase of electronic loads, the response speed of the analog voltage regulator is slow, the steady-state and dynamic performances are poor, and the development requirement of an aero power supply system is difficult to meet.

The invention provides a digital voltage regulator of a generator, which is formed by applying a digital control technology to an airplane generator control system. A comprehensive control strategy of multiple feedback variables and multiple control rules is adopted in the digital voltage regulator, so that the response speed of the system is improved, and the dynamic and steady-state performance of the aircraft power generation system is improved.

Disclosure of Invention

The purpose of the invention is as follows:

the invention aims to improve the reliability of power generation equipment, and improve the dynamic response speed, the steady-state control precision and the anti-interference capability of the output voltage of a power generation system.

In order to achieve the purpose, the invention adopts the following technical scheme:

a voltage digital comprehensive control method of an aviation alternating-current generator is characterized by comprising the following steps:

in the initial voltage building process of the generator, the voltage of the generator is given as a slope voltage rising from 0, open loop control is directly adopted, whether the output capacity of the exciting current and the generating capacity of the generator are normal or not is detected and judged, if the output capacity of the exciting current and the generating capacity of the generator are normal, the generator continues to work, and if the output capacity of the generator fails, the generator stops working;

when the given voltage value of the generator reaches a constant given value, double-voltage closed-loop control is performed, and digital comprehensive control of the output voltage of the generator is realized by combining load current feedforward control, load current negative feedback control, exciting current limit control and exciting power supply voltage feedforward control.

The method of the invention is a digital comprehensive voltage regulation and control method of generator voltage, which integrates generator voltage staged control, double-voltage closed-loop control, load current feed-forward, load current negative feedback, excitation power supply voltage feed-forward and excitation current limitation.

When the given value of the voltage of the generator is smaller than the given constant voltage, open-loop control is introduced in the voltage building process without voltage loop PI control, the given voltage feedforward quantity is directly used for output control, meanwhile, the given voltage ramp is increased progressively to obtain the given constant value, whether the output capacity of the exciting current and the generating capacity of the generator are normal or not is judged in the open-loop control process, if the generating capacity is abnormal in the process, the generating is stopped, and the system enters a fault mode; if the system is normal, open-loop voltage building is completed, the system executes normal power generation control, and the influence of a voltage closed-loop PI regulation algorithm on system voltage building and state detection is avoided;

when the voltage of the generator reaches a constant given value, a double-voltage-ring closed-loop control algorithm is adopted, the voltage regulation of the alternating-current generator consists of a slow voltage closed loop and a fast voltage closed loop, the given voltage and the output voltage effective value of the alternating-current generator are fed back to be subjected to difference comparison and then are used as slow voltage closed-loop regulation through a PI regulator, the given voltage and the output voltage instantaneous value of the alternating-current generator are fed back to be subjected to difference comparison and then are used as fast voltage closed-loop regulation through the PI regulator, the slow voltage closed-loop regulation output is superposed on the fast voltage closed-loop regulation, the double-voltage-ring PI regulation is realized, the correction given compensation of the fast voltage ring is realized, the regulation depth of the PI regulation is improved by combining the compensation mode of the load current and the feedforward of the given voltage, the PI control algorithm is optimized.

Slow voltage closed-loop control: the real effective value of the output voltage of the alternating current generator calculated through a sliding window algorithm is used as feedback voltage, the difference between the feedback voltage and given voltage is carried out, external slow voltage closed-loop PI regulation is carried out, the output of the feedback voltage is used as correction compensation quantity of an internal fast voltage loop PI regulator, the output voltage of the generator can be closer to the real voltage effective value due to the fact that the real effective value closed-loop control can be carried out, and the stable accuracy of the regulated output voltage of the generator of the fast voltage loop is improved.

Fast voltage closed-loop control: the output voltage of the alternating current generator samples the maximum value of the three-phase voltage of the alternating current generator, the three-phase voltage effective value is obtained after conversion, internal rapid voltage closed-loop PI regulation is carried out after the difference between the three-phase voltage effective value and the given voltage, and the change of the output voltage of the generator can be rapidly tracked due to the fact that the equivalent instantaneous voltage value is used as a feedback signal, and therefore the rapid response of the system is improved.

Control of load current: when the load current is less than or equal to two times of overload current, the constant voltage output of the generator is controlled, the load current is used as feedforward, the generation voltage change caused by the change of the load can be controlled in advance, the effect of quickly removing saturation from load sudden change is achieved, the saturation depth of the voltage loop PI regulator is reduced, and the response speed of the system is improved; the anti-interference capability of the system is improved, and the influence of the disturbance quantity on the output of the system is weakened. When the load current is more than twice of the overload current, droop control is carried out, load current negative feedback is carried out, and the constant power output of the generator is controlled, so that the normal work of the system is ensured, and the reliability of the system is improved.

Excitation power supply voltage feedforward control: in the initial voltage building process, the voltage feedforward of the excitation power supply is adopted to control the power generation output to be the slope voltage from 0 to a constant given value, the response speed of the system can be improved, and the action depth of the double-loop voltage ring PI when the voltage building is finished is reduced. After the voltage build-up is finished, the digital voltage regulation comprehensive control is carried out, and the excitation power supply voltage feedforward is adopted, so that the influence of the excitation power supply voltage fluctuation after the rectification of the permanent magnet machine can be eliminated to a certain extent, and the steady-state precision of the system voltage regulation is improved.

Excitation current limiting control: detecting the exciting current in real time, and if the exciting current is greater than the maximum threshold value, outputting the exciting current in a current-limiting manner, so that the reliability of the system is improved; and if the exciting current is smaller than the minimum threshold value, judging whether the system works normally by combining the output voltage of the generator, if so, entering a fault mode to stop generating power, further ensuring the normal work of the system and improving the reliability of the system. Compared with the prior art, the technical scheme of the invention can achieve the following beneficial effects:

1. the comprehensive strategy voltage regulating technology provided by the invention uses a small exciting current output by open-loop control to carry out a voltage building process, then modulates the voltage in a closed loop manner, detects and judges whether the system can normally generate power in real time in the open-loop voltage building process, and stops generating power if the system works abnormally in the process. The damage caused by the abnormal closed-loop modulation output of the power generation system by large exciting current can be avoided.

2. According to the comprehensive strategy voltage regulating technology provided by the invention, a double-voltage-ring PI algorithm is used, and the rapid voltage ring can rapidly track the change of the output voltage of the generator, so that the rapid response of the system is improved. The slow voltage loop realizes the correction given compensation of the fast voltage loop, ensures the authenticity of the sampling data, reduces the steady static difference of the control loop and improves the steady precision of the system voltage regulation.

3. According to the comprehensive strategy voltage regulation technology provided by the invention, the load current control quantity is introduced, and when the load current is less than or equal to twice of the overload current, the constant voltage output of the generator is controlled to be used as the load current feedforward, so that the regulation depth of a PI link is reduced, and the acceleration of desaturation is facilitated. When the load current is more than twice of the overload current, the load current is used as negative feedback to control the constant power output of the generator, so that the normal work of the system is ensured, and the reliability of the system is improved.

4. The comprehensive strategy voltage regulating technology provided by the invention introduces the excitation power supply voltage feedforward control quantity, controls the power generation output to be the slope voltage from 0 to a constant given value in the initial voltage building process, can improve the system response speed, and reduces the action depth of the double-loop voltage ring PI when the voltage building is finished. After the voltage build-up is finished, the digital voltage regulation is comprehensively controlled, the influence of the voltage fluctuation of the excitation power supply rectified by the permanent magnet machine can be eliminated to a certain extent, and the steady-state precision of the system voltage regulation is improved.

5. According to the comprehensive strategy voltage regulating technology provided by the invention, an exciting current control algorithm is introduced, exciting current is detected in real time, and if the exciting current is overlarge, the exciting current is limited and output, so that the reliability of the system is improved; if the exciting current is too small, the output voltage of the generator is combined to judge whether the system works normally, if the system works abnormally, the system enters a fault mode to stop generating electricity, the normal work of the system is further ensured, and the reliability of the system is improved.

Drawings

Fig. 1 is a block diagram of a power generation system according to the present invention.

Fig. 2 is a control structure scheme of the power generation voltage regulating system of the invention.

FIG. 3 is a block diagram of a generator voltage digital integrated control strategy of the present invention.

Fig. 4 is a block diagram of load current control according to the present invention.

FIG. 5 is a flow chart of the operation of the generator voltage digital integrated control strategy of the present invention.

Detailed Description

The technical solution of the present invention will be described in detail below with reference to the accompanying drawings, taking a three-stage synchronous generator system as an example.

As shown in fig. 1, the control object of the generator controller is a three-stage synchronous generator, and the control system is rectified by an emergency power supply and a permanent magnet machine of a three-stage motor and then supplies power to the controller through a power module. DSP28335 real-time detection electricity generation enable/reset signal, generator voltage, generator current, excitation power supply voltage, excitation current and other data, when detecting that electricity generation enable is effective, control GCR relay to close, the generator voltage is given as the slope voltage from 0 to 115V (the constant given value can be set according to the actual situation, the voltage regulation point of the generator on the airplane is 115V) initially, open loop control is carried out, whether the excitation current output capacity and the generator generating capacity are normal is judged, if electricity generation is abnormal in the process, electricity generation is stopped, and the system enters the fault mode; if the system is normal, the system executes normal power generation control, when the given value of the voltage of the generator is equal to a stable value 115V, open-loop voltage building is completed, fast voltage closed-loop PI control is performed, algorithms such as load current feedforward, load current limitation, exciting power supply voltage feedforward and the like are added, the digital comprehensive control of the voltage of the generator is formed, and the main contactor GCB is controlled, so that the power generation system can be safely connected to and disconnected from a power supply network.

As shown in fig. 2, the system detects data such as generator voltage, generator current, excitation power supply voltage, excitation current and the like in real time, the ratio of the obtained excitation power supply voltage control quantity to the excitation power supply voltage value, namely the PWM on ratio, is obtained by algorithms such as generator voltage staged control, dual-voltage closed-loop control, load current feed-forward, load current negative feedback, excitation power supply voltage feed-forward, excitation current limitation and the like through a given voltage 115V, and the excitation voltage regulator on the excitation winding is realized through a chopper control power circuit, so that the functions of quick magnetizing and demagnetizing of the exciter are realized, and the function of regulating the output voltage of the generator is further realized.

As shown in fig. 3, the generator voltage digital integrated control method mainly adopts integrated control strategies such as generator voltage segment control, dual-voltage closed-loop control, load current feed-forward, load current negative feedback, excitation power supply voltage feed-forward, and excitation current limitation.

(1) Generator voltage phased control

When the given voltage value of the generator is smaller than the given constant voltage value, open-loop control is introduced in the voltage building process without voltage loop PI control, given voltage feedforward quantity output control is directly used, the given voltage ramp is increased progressively to obtain the given constant value, whether the exciting current output capacity and the generating capacity of the generator are normal or not is judged in the open-loop control process, if the generating capacity is abnormal in the process, the generation is stopped, and the system enters a fault mode; if the system is normal, open-loop voltage building is completed, the system executes normal power generation control, and the influence of a voltage closed-loop PI regulation algorithm on system voltage building and state detection is avoided;

(2) dual voltage closed loop control

When the given voltage is constant at 115V, the double-voltage PID algorithm is used, the quick response of the system can be improved by the quick voltage loop PI algorithm, and the authenticity of the sampled data can be ensured by the slow voltage loop PI algorithm, so that the steady static error of a control loop of the system is reduced, and the steady precision of the system voltage regulation is improved.

The quick voltage loop PI algorithm is carried out on the given voltage and an equivalent instantaneous voltage value of the maximum value in the three-phase voltage of the generator read by an external A/D, and the equivalent instantaneous voltage value is used as a feedback signal, so that the change of the voltage value of the generator can be reflected more quickly, and the quick response of the system is improved. Since the driving frequency is 5kHz, the fast voltage loop algorithm period is 2 ms.

According to the low-speed voltage loop PI algorithm, the given voltage and the real effective value obtained through calculation of the sliding window algorithm are used as feedback voltages to carry out the outer loop PI algorithm, the outer loop PI algorithm is closer to the real voltage value, correction given compensation of the high-speed voltage loop PI can be achieved, and therefore the steady-state control precision is improved. The time for calculating and acquiring the true effective value by the sliding window algorithm needs 160ms at least, so the period of the slow voltage loop PI algorithm is 200 ms.

The two sets of voltage ring PI parameters adopt an integral amplitude limiting method to realize rapid anti-saturation, and the two sets of PI parameters are respectively used: when the error between the given value and the actual value is large, the proportion link is strengthened, the integral link is weakened, the error is responded quickly, the adjustment can be accelerated, and the error is reduced. When the error between the given value and the actual value is small, the integral link is strengthened, the proportional link is weakened, the rapid desaturation is realized, and the large overshoot and oscillation are avoided.

(3) Load current control

Because the change of the load current can cause the change of the voltage of the generator, when the load current is less than or equal to twice of the overload current, the system introduces the feedforward of the load current to control the constant voltage output of the generator, the load current is used as the feedforward to control the change of the generating voltage caused by the change of the load in advance, the predictive control is realized, the saturation depth of the voltage loop PI regulator can be reduced, the anti-interference capability of the system is improved, and the influence of the disturbance quantity on the output of the system is weakened. As shown in fig. 3, Kl is a compensation factor for the load current, and can be set by an open loop experiment.

As shown in fig. 4, when the load current is greater than twice the overload current, droop control is performed, and the load current is used as negative feedback to control the constant power output of the generator, so as to ensure the normal operation of the system and improve the reliability of the system.

(4) Excitation supply voltage feed forward

As shown in fig. 3, Kf is a compensation factor of a given voltage, a value of Kf is obtained through an open loop experiment, a given feedforward compensation control amount is equivalent to an excitation voltage control amount required during no-load, an open loop voltage building process is used as excitation power supply voltage feedforward compensation, a ramp voltage of 0 to 115V of power generation output is controlled, a system response speed can be improved, and an action depth of a double loop voltage loop PI when voltage building is completed is reduced. After the voltage build-up is finished, the digital voltage regulation comprehensive control is carried out, the influence of the voltage fluctuation of the excitation power supply rectified by the permanent magnet machine can be eliminated to a certain extent, and the steady-state precision of the system voltage regulation is improved.

(5) Limiting the current of the exciting current

As shown in fig. 3, the current Ie on the exciting winding is detected in real time, and if the exciting current is greater than 5A, the current is limited and output to the exciting current, so that the system reliability is improved; and if the exciting current is less than 0.1A, judging whether the system works normally by combining the output voltage of the generator, and if so, entering a fault mode to stop generating power, so that the normal work of the system is ensured, and the reliability of the system is improved.

As shown in fig. 5, a generator voltage digital integrated control strategy work flow chart mainly detects a power generation enabling switch to perform power generation control, and when the power generation enabling switch is reset, the power generation control is not performed; when the power generation enable switch is to enable power generation, the generator voltage is controlled in stages. The voltage of the generator is given as a slope voltage rising from 0 in the initial voltage building process, the control strategy is to directly adopt open-loop control, the given value of the open-loop voltage building control is the control quantity of the voltage of the excitation power supply required when the no-load voltage is given, whether the output capacity of the excitation current and the generating capacity of the generator are normal or not is detected and judged, the generator continues to work when the output capacity of the excitation current and the generating capacity of the generator are normal, and the. When the given value of the generating voltage is equal to a constant 115V, the digital comprehensive control of the generator voltage is carried out by executing algorithms such as double-voltage closed-loop control, load current feed-forward, load current negative feedback, excitation power supply voltage feed-forward, excitation current limitation and the like, and the modulation of the generator voltage is realized, namely, the voltage regulator regulates the excitation current of the generator by changing the conduction ratio of power MOS tubes T1 and T2 connected in series in an excitation winding, so that the voltage of the generator of the system is stabilized at 115V, and the purposes of improving the reliability of a generating system, the dynamic response speed of output voltage, the steady-state control precision and the anti-.