阅读说明：本技术 一种ipos直流变换器自适应变参数输出均压控制方法 (IPOS direct current converter self-adaptive variable parameter output voltage-sharing control method ) 是由 蔡久青 徐正喜 吴浩伟 蔡凯 吴钫 李锐 李鹏 金翔 汪文涛 邓磊 张鹏程 张 于 2019-11-08 设计创作，主要内容包括：本发明公开了一种IPOS直流变换器自适应变参数输出均压控制方法,输入并联输出串联组合(IPOS)直流变换器中各直流变换模块采用集中式控制架构,本发明的控制环路包括输出电压环和自适应变参数输出均压环。输出电压环用于控制直流变换器恒压输出,自适应变参数输出均压环用于控制各直流变换模块的输出电压均衡,均压环控制器根据输出电压误差动态变化趋势实时调节控制器参数,以优化控制的稳定裕度、动态误差和动态响应速度。(The invention discloses a self-adaptive variable parameter output voltage-sharing control method for an IPOS (input-parallel output) direct current converter. The output voltage ring is used for controlling the constant voltage output of the direct current converter, the self-adaptive variable parameter output grading ring is used for controlling the output voltage balance of each direct current conversion module, and the grading ring controller adjusts the parameters of the controller in real time according to the dynamic change trend of the output voltage error so as to optimize the stability margin, the dynamic error and the dynamic response speed of the control.)

1. An IPOS DC converter self-adaptive variable parameter output voltage-sharing control method is characterized in that the IPOS DC converter comprises a plurality of DC conversion modules with input connected in parallel and output connected in series, the IPOS DC converter is provided with a double-loop control loop, the double-loop control loop comprises an output voltage loop and a self-adaptive variable parameter output voltage-sharing loop, and the output voltage loop comprises a voltage closed loop regulator G₁The self-adaptive variable parameter output equalizing ring comprises a moving average filter, a first multiplier, a first amplitude limiter, a second amplitude limiter and an equalizing closed-loop regulator G₂And an adaptive closed-loop regulator G₃The output voltage-sharing control method comprises the following steps:

(1) receiving an output voltage command V of the IPOS DC converter_orefAcquiring the actual output voltage V of the IPOS DC converter_o；

(2) Actual output voltage V of the IPOS DC converter to be obtained_oAs output voltage feedback of the IPOS direct current converter, calculating a difference value between an output voltage command of the IPOS direct current converter and the output voltage feedback to be used as an output voltage error of the direct current converter;

(3) taking the output voltage error as a voltage closed-loop regulator G₁Control input of, voltage closed-loop regulator G₁The output of the first adder is used as one input of the first adder;

(4) the actual output voltage V of the IPOS DC converter_oDividing the calculation result by the number n of the direct current conversion modules to be used as an output voltage instruction of the corresponding direct current conversion module;

(5) actual output voltage V to each DC conversion module_onSampling, and obtaining the actual output voltage V of each DC conversion module_onAs the output voltage feedback of the DC conversion module, calculating the output voltage command and the voltage inverse of the DC conversion moduleThe fed difference value is used as an output voltage error of a corresponding direct current conversion module, and the output voltage error of the direct current conversion module is filtered and then output to a first multiplier of the direct current conversion module;

(6) calculating the difference value between the absolute value of the output voltage error of each direct current conversion module in the current control period and the absolute value of the output voltage error of the same direct current conversion module in the previous control period, and taking the difference value as the output voltage error variation of the direct current conversion module;

(7) the output voltage error variable quantity of the direct current conversion module is output through the amplitude limiting of a first amplitude limiter and is used as a self-adaptive closed-loop regulator G₃Control input of, adaptive closed-loop regulator G₃The calculated output is then subjected to amplitude limiting output by a second amplitude limiter and is used as the other input of the first multiplier;

(8) the output of the multiplier is used as a voltage-sharing closed-loop regulator G₂Control input of, voltage-sharing closed-loop regulator G₂As the other input of the first adder, and a voltage closed-loop regulator G₁The calculated outputs are superposed and are used for controlling the on and off of a switch device in the direct current conversion module after PWM modulation, so that the output voltage-sharing control of each direct current conversion module in the IPOS direct current converter is realized.

2. The IPOS DC converter adaptive variable parameter output voltage-sharing control method according to claim 1, wherein a plurality of DC conversion modules with parallel inputs and series outputs in the IPOS DC converter are controlled by the same hardware control unit in a centralized manner.

3. The IPOS DC converter adaptive variable parameter output voltage equalizing control method according to claim 1, wherein the moving average filter is used for filtering an output voltage error signal of the DC conversion module to stabilize a large-range fluctuation of the output voltage error value of the DC conversion module caused by a random disturbance of the output voltage feedback of the DC conversion module.

4. The IPOS DC converter adaptive variable parameter output voltage equalizing control method according to claim 3, wherein the first limiter performs the limiting in such a way that the output of the first limiter is zero when the error variation of the output voltage of the DC conversion module is equal to or less than a limiting threshold △ V (△ V >0), and the output of the first limiter is equal to the input when the error variation of the output voltage of the DC conversion module is greater than a limiting threshold △ V.

5. The IPOS DC converter adaptive variable parameter output voltage equalizing control method according to claim 4, wherein the second limiter is used for limiting in the following way: adaptive closed-loop regulator G₃Is less than or equal to the limit threshold value △ K_c1(△K_c1>0) Then, the output of the second limiter is 1; adaptive closed-loop regulator G₃Is greater than the limit threshold △ K_c1And is less than or equal to limit threshold △ K_c2(△K_c2>△K_c1) The output of the second slicer is equal to the input; adaptive closed-loop regulator G₃Is greater than the limit threshold △ K_c2The output of the second limiter is then equal to a fixed value K_m(K_m>1)。

6. The IPOS DC converter adaptive variable parameter output voltage-sharing control method according to claim 5, wherein the output of the second limiter is used as a voltage-sharing closed-loop regulator G₂The variable gain K adjusts the parameters of the controller in real time through the gain change so as to optimize the stability margin, the dynamic error and the dynamic response speed of the control.

Technical Field

The invention relates to the field of control of IPOS (Internet protocol operating System) direct-current converters, in particular to a self-adaptive variable parameter output voltage-sharing control method of an IPOS direct-current converter.

Background

An IPOS (Input Parallel Output Series) dc converter is formed by combining a plurality of dc conversion modules in Parallel at an Input side and in Series at an Output side. The combination mode of input parallel connection and output series connection reduces the requirements on current stress of a switching device at the input side of the DC converter and voltage stress of a switching device at the output side, and has remarkable advantages in low-voltage input and high-voltage output application occasions such as photovoltaic power generation and the like.

In order to realize the efficient and reliable operation of the IPOS direct current converter, each direct current conversion module needs to meet the requirement of power balance. Because the input of the direct current conversion module is connected in parallel and the output of the direct current conversion module is connected in series, the input voltage balancing and the output current balancing of each conversion unit are automatically realized, and the power balancing target can be realized by carrying out output voltage balancing or input current balancing control on each conversion unit.

The existing IPOS direct current converter output voltage-sharing control method also adopts a double-loop control mode based on an output voltage loop and a voltage-sharing loop, the control parameters of the control loops of all direct current conversion modules generally adopt the same fixed value, and the control mode has good steady-state performance. However, when the input voltage fluctuates in a large range and the output load is switched in a large range, the dynamic adjustment process of the output voltage of each direct current conversion module is inconsistent due to the difference of hardware parameters of each direct current conversion module and the like, the dynamic response speed of control is reduced due to the inconsistency of the adjustment process, and the difference of the output voltage of each direct current conversion module in the dynamic adjustment process is increased.

Disclosure of Invention

The invention aims to provide a self-adaptive variable parameter output voltage-sharing control method for an IPOS (internet protocol operating system) direct-current converter, which adopts a self-adaptive control idea, adjusts the control characteristic of an output voltage-sharing ring in real time by introducing a variable gain K based on the output voltage error variation of a direct-current conversion module, can effectively realize the voltage quick response of large dynamic disturbance processes such as input voltage fluctuation, output load switching and the like, and simultaneously reduces the output voltage difference of each direct-current conversion module in the dynamic adjustment process.

In order to achieve the above object, the present invention provides an IPOS dc converter adaptive variable parameter output voltage-sharing control method, wherein the IPOS dc converter comprises a plurality of dc conversion modules with parallel inputs and series outputs;

a plurality of direct current conversion modules with input connected in parallel and output connected in series in the IPOS direct current converter are controlled in a centralized manner by the same hardware control unit;

the control method consists of a plurality of control loops, and comprises an output voltage ring and a plurality of self-adaptive variable parameter output voltage-equalizing rings;

the output voltage loop comprises a voltage closed-loop regulator G₁The constant-voltage output control circuit is used for realizing the constant-voltage output control of the IPOS direct-current converter;

the self-adaptive variable parameter output equalizing ring comprises a moving average filter, a multiplier, a first amplitude limiter, a second amplitude limiter and an equalizing closed-loop regulator G₂And an adaptive closed-loop regulator G₃The voltage-sharing output control device is used for realizing the output voltage-sharing output control of each direct current conversion module in the IPOS direct current converter;

the implementation method of the self-adaptive variable parameter output voltage-sharing control comprises the following steps:

the error variation of the output voltage of the DC conversion module is used as a self-adaptive closed-loop regulator G through a first amplitude limiter₃After the output of the regulator is calculated, the regulator is used as the variable gain K of the adaptive variable parameter output voltage-sharing control loop through a second amplitude limiter and is connected to the input of the multiplier;

the working mode of the first amplitude limiter is that when the error variation of the output voltage of the direct current conversion module is smaller than or equal to a limit threshold △ V (△ V >0), the output of the first amplitude limiter is zero;

the second limiter operates as an adaptive closed-loop regulator G₃Is less than or equal to the limit threshold value △ K_c1(△K_c1>0) Then, the output of the second limiter is 1; adaptive closed-loop regulator G₃Is greater than the limit threshold △ K_c1And is less than or equal to limit threshold △ K_c2(△K_c2>△K_c1) The output of the second slicer is equal to the input; adaptive closed-loop regulator G₃Is greater than the limit threshold △ K_c2The output of the second limiter is then equal to K_m(K_m>1)；

The output voltage error value of the direct current conversion module is calculated and output by a moving average filter and then is used as the input of a multiplier, and the moving average filter is used for filtering an output voltage error signal of the direct current conversion module so as to stabilize the large-range fluctuation of the output voltage error value caused by random disturbance of output voltage sampling of the conversion unit;

the output of the moving average filter passes through a variable gain K and a voltage-sharing closed-loop regulator G₂And after calculation output, the output voltage is used as the adjustment calculation output of the self-adaptive variable parameter output grading ring, the adjustment calculation output of the self-adaptive variable parameter output grading ring is superposed with the adjustment calculation output of the output voltage ring through a first adder, and the superposed result is subjected to PWM modulation and then used for controlling the on and off of a switching device in the direct current conversion module, so that the output grading control of each direct current conversion module in the IPOS direct current converter is realized.

Further, the first amplitude limiter is used for avoiding frequently adjusting the variable gain K when the error variation of the output voltage of the direct current conversion module changes in a small range;

further, the second limiter is configured to define a maximum value and a minimum value of the variable gain K;

further, when the error variation of the output voltage of the direct current conversion module is changed in a small range, the variable gain is maintained as a fixed value to ensure the stability margin of control; when the output voltage error variation of the direct current conversion module exceeds the range, the variable gain is increased in a certain range to improve the dynamic response speed of control and reduce the dynamic error.

The invention has the beneficial effects that:

the IPOS direct current converter self-adaptive variable parameter output voltage-sharing control method adopts a self-adaptive variable parameter output voltage-sharing control ring, and adjusts the control characteristics of the output voltage-sharing ring of each conversion unit in real time by introducing a variable gain K based on the output voltage error variation of a direct current conversion module, thereby comprehensively optimizing the stability margin, the dynamic error and the dynamic response speed of a controller.

Meanwhile, a moving average filter is introduced to filter the output voltage error calculation result of the DC conversion module so as to stabilize the large-range fluctuation of the output voltage error value caused by random disturbance of the output voltage sampling of the conversion unit, and further improve the anti-interference capability of voltage-sharing control.

Drawings

FIG. 1 is a control block diagram of the adaptive variable parameter output voltage-sharing control method of the IPOS DC converter of the present invention;

fig. 2 is a schematic diagram of a main circuit of the IPOS dc converter.

Fig. 3 is a simulated waveform of voltage and current of an IPOS dc converter to which a conventional output voltage-sharing control method is applied.

Fig. 4 is a simulated waveform of voltage and current of an IPOS dc converter applying an adaptive variable parameter output voltage-sharing control method.

Detailed Description

The following describes embodiments of the present invention with reference to the drawings.