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CN111190056B - Online estimation method for inductance parameter of LC alternating current filter of power converter - Google Patents

Online estimation method for inductance parameter of LC alternating current filter of power converter Download PDF

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CN111190056B
CN111190056B CN202010017759.6A CN202010017759A CN111190056B CN 111190056 B CN111190056 B CN 111190056B CN 202010017759 A CN202010017759 A CN 202010017759A CN 111190056 B CN111190056 B CN 111190056B
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孙向东
刘江
郝卓
任碧莹
张琦
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Xian University of Technology
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Abstract

本发明公开了功率变换器LC交流滤波器电感参数的在线估计方法，具体为：采样三相电网电压、三相滤波电感电流以及通过直流侧电压以及三相占空比进行重构得到三相变换器端口电压，然后将采样的电压及电流变为同步旋转坐标下对应的d、q轴分量，建立参考模型、可调模型，选取合适的自适应率来实时调节可调模型中的电感参数，保证可调模型的两相电感电流，即可调电流模型，与参考模型的实际两相电感电流，即参考电流模型一致，从而得到在线估计的电感参数。本发明功率变换器LC交流滤波器电感参数的在线估计方法，解决了现实工况下实际的滤波电感值与控制方法中采用的电感标称值误差比较大时并网电流控制精度下降的问题。

Figure 202010017759

The invention discloses an on-line estimation method for the inductance parameters of the LC AC filter of a power converter. Then, the sampled voltage and current are changed into the corresponding d and q axis components under the synchronous rotation coordinates, the reference model and the adjustable model are established, and the appropriate adaptive rate is selected to adjust the inductance parameters in the adjustable model in real time. It is ensured that the two-phase inductor current of the adjustable model, that is, the adjustable current model, is consistent with the actual two-phase inductor current of the reference model, that is, the reference current model, so as to obtain the online estimated inductor parameters. The online estimation method of the inductance parameter of the LC AC filter of the power converter of the present invention solves the problem that the control accuracy of the grid-connected current decreases when the error between the actual filter inductance value and the nominal value of the inductance used in the control method is relatively large under actual working conditions.

Figure 202010017759

Description

功率变换器LC交流滤波器电感参数的在线估计方法On-Line Estimation Method for Inductor Parameters of LC AC Filters in Power Converters

技术领域technical field

本发明属于电力电子技术领域，涉及一种功率变换器LC交流滤波器电感参数的在线估计方法。The invention belongs to the technical field of power electronics, and relates to an on-line estimation method for inductance parameters of an LC AC filter of a power converter.

背景技术Background technique

功率变换器对电能进行变换来满足相关负载供电要求，不论功率变换器是整流功能还是逆变功能，在交流电网侧通常会使用LC滤波器对工频交流电进行滤波，使得交流侧的电流谐波含量满足国家标准，减小对电网的谐波污染。在功率变换器的控制之中，三相滤波电感电流常常被当作控制对象，而电流控制的效果好坏与电感大小密切相关。实际电路中的电感值常常会因为加工工艺、工作温度、频率等因素而偏移标称值。当实际控制中所采用的控制方法含有电感值时，一旦实际电感值偏离控制方法中所用的电感标称值误差较大时，会直接影响电流的控制精度，甚至影响系统的稳定性，对电网电流质量造成一定的影响。The power converter converts electrical energy to meet the power supply requirements of the relevant loads. Regardless of whether the power converter has a rectification function or an inverter function, an LC filter is usually used on the AC grid side to filter the power frequency AC power, so that the current harmonics on the AC side are filtered. The content meets the national standard and reduces the harmonic pollution to the power grid. In the control of the power converter, the three-phase filter inductor current is often used as the control object, and the effect of current control is closely related to the size of the inductor. The inductance value in the actual circuit often deviates from the nominal value due to factors such as processing technology, operating temperature, and frequency. When the control method used in the actual control contains an inductance value, once the actual inductance value deviates from the nominal value of the inductance used in the control method, the error will directly affect the control accuracy of the current, and even affect the stability of the system. The current quality has a certain impact.

发明内容SUMMARY OF THE INVENTION

本发明的目的是提供一种功率变换器LC交流滤波器电感参数的在线估计方法，解决了现实工况下实际的滤波电感值与控制方法中采用的电感标称值误差比较大时并网电流控制精度下降的问题。The purpose of the present invention is to provide an online estimation method for the inductance parameters of the LC AC filter of the power converter, which solves the problem of the grid-connected current when the error between the actual filter inductance value and the nominal value of the inductance used in the control method is relatively large under actual working conditions. The problem of decreased control accuracy.

本发明所采用的技术方案是，功率变换器LC交流滤波器电感参数的在线估计方法，所述功率变换器为包括带有LC滤波器的直流-交流并网逆变电路或交流-直流整流电路，所述功率变换器的直流侧连接具有直流电压源性质的直流电，所述功率变换器的交流侧连接交流电网，所述功率变换器的主电路是三相变换电路，电感参数的在线估计方法为：采样三相电网电压ea、eb、ec、三相滤波电感电流ia、ib、ic以及通过直流侧电压以及三相占空比进行重构得到三相变换器端口电压ua、ub、uc，然后将三相电网电压ea、eb、ec、三相滤波电感电流ia、ib、ic以及重构的三相变换器端口电压ua、ub、uc经过坐标变换变为同步旋转坐标下对应的d、q轴分量，设定d、q轴上的实际两相电感电流为参考模型，以d、q轴上的两相电网电压和两相重构端口电压建立电感电流的可调模型，以可调模型的d、q两相电感电流去逼近参考模型的实际d、q两相电感电流，参考模型的实际d、q两相电感电流与对应的可调模型的d、q两相电感电流分别做差，选取合适的自适应率来实时调节可调模型中的电感参数，保证可调模型的两相电感电流，即可调电流模型，与参考模型的实际两相电感电流，即参考电流模型一致，从而得到在线估计的电感参数。The technical solution adopted by the present invention is an online estimation method for the inductance parameters of the LC AC filter of a power converter, wherein the power converter includes a DC-AC grid-connected inverter circuit or an AC-DC rectifier circuit with an LC filter. , the DC side of the power converter is connected to a direct current with the nature of a DC voltage source, the AC side of the power converter is connected to the AC power grid, the main circuit of the power converter is a three-phase conversion circuit, an online estimation method of inductance parameters is: sampling three-phase grid voltages e a , e b , e c , three-phase filter inductor currents i a , ib , ic , and reconstructing the three-phase converter port voltage through DC side voltage and three-phase duty cycle u a , ub , uc , then the three-phase grid voltages ea , eb , ec , the three-phase filter inductor currents ia , ib , ic and the reconstructed three-phase converter port voltage ua , u b and u c are transformed into corresponding d and q axis components under synchronous rotation coordinates through coordinate transformation, and the actual two-phase inductor currents on the d and q axes are set as the reference model, and the two-phase grid voltage on the d and q axes is and the two-phase reconstructed port voltage to establish an adjustable model of the inductor current, and use the d and q two-phase inductor currents of the adjustable model to approximate the actual d and q two-phase inductor currents of the reference model, and the actual d and q two-phase inductor currents of the reference model. The difference between the inductor current and the d and q two-phase inductor currents of the corresponding adjustable model is made respectively, and the appropriate adaptive rate is selected to adjust the inductor parameters in the adjustable model in real time to ensure that the two-phase inductor current of the adjustable model can be adjusted. The current model is consistent with the actual two-phase inductor current of the reference model, that is, the reference current model, so as to obtain the online estimated inductor parameters.

本发明的特征还在于，The present invention is also characterized in that,

主电路是三相两电平变换电路或三相T型或I型三电平变换电路。The main circuit is a three-phase two-level conversion circuit or a three-phase T-type or I-type three-level conversion circuit.

重构三相变换器端口电压具体为：The reconstructed three-phase converter port voltage is specifically:

通过采样的直流侧电压Udc和利用控制器上一拍计算的三相调制波的占空比da、db、dc，根据式(1)进行重构得到三相变换器端口电压ua、ub和uc：Through the sampled DC side voltage U dc and the duty ratios da , db , and dc of the three-phase modulated wave calculated by the controller in the last beat, the three-phase converter port voltage u is obtained by reconstruction according to formula (1 ) . a , ub and uc :

Figure BDA0002359553890000021
Figure BDA0002359553890000021

将三相电网电压ea、eb、ec、三相滤波电感电流ia、ib、ic以及重构的三相变换器端口电压ua、ub、uc经过坐标变换变为同步旋转坐标下对应的d、q轴分量具体按照公式(2)-(4)变换：The three-phase grid voltages ea , eb , ec , the three-phase filter inductor currents ia , ib , ic and the reconstructed three-phase converter port voltages ua , ub , uc are transformed into The corresponding d and q axis components under the synchronous rotation coordinates are specifically transformed according to formulas (2)-(4):

Figure BDA0002359553890000031
Figure BDA0002359553890000031

式中，ud、uq为变换器三相端口电压在d、q坐标轴的电压分量，id、iq为三相电感电流在d、q坐标轴的电流分量，ed、eq为三相电网电压在d、q坐标轴的电压分量，ω为电网角频率。In the formula, ud and u q are the voltage components of the three-phase port voltage of the converter on the d and q coordinate axes, id and i q are the current components of the three-phase inductor current on the d and q coordinate axes, and ed and e q is the voltage component of the three-phase grid voltage on the d and q coordinate axes, and ω is the grid angular frequency.

参考模型的电感电流表达式具体为：The inductor current expression of the reference model is specifically:

参考模型的电感电流为实际采样的三相电感电流在d、q坐标轴的电流分量id、iq，其表达式为公式(3)。The inductor current of the reference model is the current components id and i q of the actually sampled three-phase inductor current on the d and q coordinate axes, and its expression is formula (3).

可调模型的电感电流表达式为：The inductor current expression for the adjustable model is:

Figure BDA0002359553890000032
Figure BDA0002359553890000032

其中，

Figure BDA0002359553890000033
表示估计的电感值，
Figure BDA0002359553890000034
分别表示在d、q坐标系下的估计的电流分量在当前时刻的值，
Figure BDA0002359553890000035
分别表示在d、q坐标系下的估计的电流分量在上一时刻的值，Ts表示开关周期。in,
Figure BDA0002359553890000033
represents the estimated inductance value,
Figure BDA0002359553890000034
respectively represent the estimated value of the current component at the current moment in the d and q coordinate systems,
Figure BDA0002359553890000035
respectively represent the value of the estimated current component at the last moment in the d and q coordinate systems, and T s represents the switching period.

自适应率的表达式为：The expression for the adaptation rate is:

Figure BDA0002359553890000041
Figure BDA0002359553890000041

式中，L为滤波电感标称值，

Figure BDA0002359553890000042
为积分结构，R2(t)为比例结构，Ki和Kp分别为积分系数和比例系数，即R1(t)＝Ki[εd(ud-ed)+εq(uq-eq)]，R2(t)＝Kp[εd(ud-ed)+εq(uq-eq)]，εd和εq分别为参考模型的电感电流与可调模型的电感电流在d、q坐标系下的误差分量，即
Figure BDA0002359553890000043
In the formula, L is the nominal value of the filter inductor,
Figure BDA0002359553890000042
is the integral structure, R 2 (t) is the proportional structure, and K i and K p are the integral coefficient and proportional coefficient respectively, that is, R 1 (t)=K i [ε d (u d -e d )+ε q (u q -e q )], R 2 (t)=K p [ε d (u d -e d )+ε q (u q -e q )], ε d and ε q are the reference model inductor current and The error components of the inductor current of the adjustable model in the d and q coordinate systems, namely
Figure BDA0002359553890000043

选取合适的自适应率来实时调节可调模型中的电感参数，保证可调模型的两相电感电流，即可调电流模型，与参考模型的实际两相电感电流，即参考电流模型一致，从而得到在线估计的电感参数具体为：Select an appropriate adaptive rate to adjust the inductance parameters in the adjustable model in real time, to ensure that the two-phase inductor current of the adjustable model, that is, the adjustable current model, is consistent with the actual two-phase inductor current of the reference model, that is, the reference current model, so that The inductance parameters estimated online are as follows:

当满足条件

Figure BDA0002359553890000044
时，得到在线估计的电感参数的表达式(9)：when the conditions are met
Figure BDA0002359553890000044
When , the expression (9) of the online estimated inductance parameter is obtained:

Figure BDA0002359553890000045
Figure BDA0002359553890000045

若不满足上述条件，则根据自适应率公式(8)调节

Figure BDA0002359553890000046
作用到公式(7)中，重新建立电感电流的可调模型，重新进行电感参数的在线估计。If the above conditions are not met, adjust according to the adaptive rate formula (8).
Figure BDA0002359553890000046
Acting on the formula (7), the adjustable model of the inductor current is re-established, and the on-line estimation of the inductor parameters is performed again.

本发明的有益效果是The beneficial effects of the present invention are

本发明提供的功率变换器LC交流滤波器电感参数的在线估计方法，原理简单、思路清晰、易于实现，解决了现实工况下实际的滤波电感值与控制方法中采用的电感标称值误差比较大时并网电流控制精度下降、电流可能发生畸变甚至出现不稳定的问题，通过本发明的在线估计算法的准确预估，在不增加系统硬件成本的基础上，能够有效提高功率变换器交流侧三相电流的控制精度，减小对大电网的电流谐波污染。The on-line estimation method for the inductance parameters of the LC AC filter of the power converter provided by the present invention has the advantages of simple principle, clear thinking and easy implementation, and solves the comparison between the actual filter inductance value under actual working conditions and the inductance nominal value used in the control method. When the grid-connected current control accuracy is reduced, the current may be distorted or even unstable, the accurate estimation of the online estimation algorithm of the present invention can effectively improve the AC side of the power converter without increasing the cost of system hardware. The control accuracy of the three-phase current reduces the current harmonic pollution to the large power grid.

附图说明Description of drawings

图1是本发明功率变换器LC交流滤波器电感参数的在线估计方法中具有LC交流滤波器的功率变换器示意图；1 is a schematic diagram of a power converter having an LC AC filter in the online estimation method of the LC AC filter inductance parameter of a power converter of the present invention;

图2是本发明功率变换器LC交流滤波器电感参数的在线估计方法的流程图。FIG. 2 is a flow chart of the on-line estimation method of the inductance parameter of the LC AC filter of the power converter according to the present invention.

具体实施方式Detailed ways

下面结合附图和具体实施方式对本发明进行详细说明。The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

本发明功率变换器LC交流滤波器电感参数的在线估计方法，其结构如图1所示，所述功率变换器为包括带有LC滤波器的直流-交流并网逆变电路或交流-直流整流电路，所述功率变换器的直流侧连接具有直流电压源性质的直流电，所述功率变换器的交流侧连接交流电网，所述功率变换器的主电路是三相变换电路，电感参数的在线估计方法为：其流程如图2所示，采样三相电网电压ea、eb、ec、三相滤波电感电流ia、ib、ic以及通过直流侧电压以及三相占空比进行重构得到三相变换器端口电压ua、ub、uc，然后将三相电网电压ea、eb、ec、三相滤波电感电流ia、ib、ic以及重构的三相变换器端口电压ua、ub、uc经过坐标变换变为同步旋转坐标下对应的d、q轴分量，设定d、q轴上的实际两相电感电流为参考模型，以d、q轴上的两相电网电压和两相重构端口电压建立电感电流的可调模型，以可调模型的d、q两相电感电流去逼近参考模型的实际d、q两相电感电流，参考模型的实际d、q两相电感电流与对应的可调模型的d、q两相电感电流分别做差，选取合适的自适应率来实时调节可调模型中的电感参数，保证可调模型的两相电感电流，即可调电流模型，与参考模型的实际两相电感电流，即参考电流模型一致，从而得到在线估计的电感参数。The on-line estimation method of the inductance parameter of the LC AC filter of the power converter of the present invention, its structure is shown in Figure 1, the power converter includes a DC-AC grid-connected inverter circuit with an LC filter or an AC-DC rectifier circuit, the DC side of the power converter is connected to the DC power with the nature of the DC voltage source, the AC side of the power converter is connected to the AC power grid, the main circuit of the power converter is a three-phase conversion circuit, and the online estimation of the inductance parameter The method is as follows: the process is shown in Figure 2, sampling the three-phase grid voltages ea , eb , ec , the three-phase filter inductor currents ia , ib , ic , and conducts the process through the DC side voltage and the three-phase duty cycle. The three-phase converter port voltages ua , ub , uc are obtained by reconstruction, and then the three-phase grid voltages ea , eb , ec , the three-phase filter inductor currents ia , ib , ic and the reconstructed The three-phase converter port voltages u a , u b , and u c are transformed into the corresponding d and q-axis components in synchronous rotation coordinates through coordinate transformation, and the actual two-phase inductor currents on the d and q axes are set as the reference model. , the two-phase grid voltage on the q-axis and the two-phase reconstructed port voltage to establish an adjustable model of the inductor current, and the d and q two-phase inductor currents of the adjustable model are used to approximate the actual d and q two-phase inductor currents of the reference model, The difference between the actual d and q two-phase inductor currents of the reference model and the d and q two-phase inductor currents of the corresponding adjustable model is made respectively, and an appropriate adaptive rate is selected to adjust the inductance parameters in the adjustable model in real time to ensure the adjustable model. The two-phase inductor current of , the adjustable current model, is consistent with the actual two-phase inductor current of the reference model, that is, the reference current model, so as to obtain the online estimated inductor parameters.

优选地，主电路是三相两电平变换电路或三相T型或I型三电平变换电路。Preferably, the main circuit is a three-phase two-level conversion circuit or a three-phase T-type or I-type three-level conversion circuit.

优选地，重构三相变换器端口电压具体为：Preferably, the reconstructed three-phase converter port voltage is specifically:

通过采样的直流侧电压Udc和利用控制器上一拍计算的三相调制波的占空比da、db、dc，根据式(1)进行重构得到三相变换器端口电压ua、ub和uc：Through the sampled DC side voltage U dc and the duty ratios da , db , and dc of the three-phase modulated wave calculated by the controller in the last beat, the three-phase converter port voltage u is obtained by reconstruction according to formula (1 ) . a , ub and uc :

Figure BDA0002359553890000061
Figure BDA0002359553890000061

优选地，将三相电网电压ea、eb、ec、三相滤波电感电流ia、ib、ic以及重构的三相变换器端口电压ua、ub、uc经过坐标变换变为同步旋转坐标下对应的d、q轴分量具体按照公式(2)-(4)变换：Preferably, the three-phase grid voltages ea , eb , ec , the three-phase filter inductor currents ia , ib , ic and the reconstructed three-phase converter port voltages ua , ub , uc are passed through the coordinates The transformation becomes the corresponding d and q-axis components under the synchronous rotation coordinates, which are specifically transformed according to formulas (2)-(4):

Figure BDA0002359553890000062
Figure BDA0002359553890000062

式中，ud、uq为变换器三相端口电压在d、q坐标轴的电压分量，id、iq为三相电感电流在d、q坐标轴的电流分量，ed、eq为三相电网电压在d、q坐标轴的电压分量，ω为电网角频率。In the formula, ud and u q are the voltage components of the three-phase port voltage of the converter on the d and q coordinate axes, id and i q are the current components of the three-phase inductor current on the d and q coordinate axes, and ed and e q is the voltage component of the three-phase grid voltage on the d and q coordinate axes, and ω is the grid angular frequency.

优选地，参考模型的电感电流表达式具体为：Preferably, the inductor current expression of the reference model is specifically:

参考模型的电感电流为实际采样的三相电感电流在d、q坐标轴的电流分量id、iq，其表达式为公式(3)。The inductor current of the reference model is the current components id and i q of the actually sampled three-phase inductor current on the d and q coordinate axes, and its expression is formula (3).

可调模型的电感电流表达式为：The inductor current expression for the adjustable model is:

Figure BDA0002359553890000071
Figure BDA0002359553890000071

其中，

Figure BDA0002359553890000072
表示估计的电感值，
Figure BDA0002359553890000073
分别表示在d、q坐标系下的估计的电流分量在当前时刻的值，
Figure BDA0002359553890000074
分别表示在d、q坐标系下的估计的电流分量在上一时刻的值，Ts表示开关周期。in,
Figure BDA0002359553890000072
represents the estimated inductance value,
Figure BDA0002359553890000073
respectively represent the estimated value of the current component at the current moment in the d and q coordinate systems,
Figure BDA0002359553890000074
respectively represent the value of the estimated current component at the last moment in the d and q coordinate systems, and T s represents the switching period.

优选地，自适应率的表达式为：Preferably, the expression of the adaptation rate is:

Figure BDA0002359553890000075
Figure BDA0002359553890000075

式中，L为滤波电感标称值，

Figure BDA0002359553890000076
为积分结构，R2(t)为比例结构，Ki和Kp分别为积分系数和比例系数，即R1(t)＝Ki[εd(ud-ed)+εq(uq-eq)]，R2(t)＝Kp[εd(ud-ed)+εq(uq-eq)]，εd和εq分别为参考模型的电感电流与可调模型的电感电流在d、q坐标系下的误差分量，即
Figure BDA0002359553890000077
In the formula, L is the nominal value of the filter inductor,
Figure BDA0002359553890000076
is the integral structure, R 2 (t) is the proportional structure, and K i and K p are the integral coefficient and proportional coefficient respectively, that is, R 1 (t)=K i [ε d (u d -e d )+ε q (u q -e q )], R 2 (t)=K p [ε d (u d -e d )+ε q (u q -e q )], ε d and ε q are the reference model inductor current and The error components of the inductor current of the adjustable model in the d and q coordinate systems, namely
Figure BDA0002359553890000077

优选地，选取合适的自适应率来实时调节可调模型中的电感参数，保证可调模型的两相电感电流，即可调电流模型，与参考模型的实际两相电感电流，即参考电流模型一致，从而得到在线估计的电感参数具体为：Preferably, an appropriate adaptive rate is selected to adjust the inductance parameters in the adjustable model in real time, so as to ensure that the two-phase inductor current of the adjustable model, that is, the adjustable current model, and the actual two-phase inductor current of the reference model, that is, the reference current model The inductance parameters estimated online are as follows:

当满足条件

Figure BDA0002359553890000078
时，得到在线估计的电感参数的表达式(9)：when the conditions are met
Figure BDA0002359553890000078
When , the expression (9) of the online estimated inductance parameter is obtained:

Figure BDA0002359553890000081
Figure BDA0002359553890000081

若不满足上述条件，则根据自适应率公式(8)调节

Figure BDA0002359553890000082
作用到公式(7)中，重新建立电感电流的可调模型，重新进行电感参数的在线估计。If the above conditions are not met, adjust according to the adaptive rate formula (8).
Figure BDA0002359553890000082
Acting on the formula (7), the adjustable model of the inductor current is re-established, and the on-line estimation of the inductor parameters is performed again.

图1是本发明所采用的LC交流滤波器的功率变换器事宜图，包括直流电源、功率变换器、LC滤波器、电网等。图中，Udc为直流侧稳压电源；L为滤波电感；Cf为滤波电容；ea、eb、ec为三相电网电压；ua、ub、uc为功率变换器三相端口电压；ia、ib、ic为三相交流电流。FIG. 1 is a diagram of the power converter of the LC AC filter adopted in the present invention, including a DC power supply, a power converter, an LC filter, a power grid, and the like. In the figure, U dc is the DC side regulated power supply; L is the filter inductance; C f is the filter capacitor; e a , e b , and e c are the three-phase grid voltage ; Phase port voltage; ia , ib , ic are three-phase alternating current.

图2是本发明电感参数估计算法框图。将实际采样获得的三相电感电流ia、ib、ic，根据参考电流模型的公式(3)，计算出参考模型的电感电流id、iq。根据公式(1)利用直流侧电压Udc和控制器上一拍计算的三相调制波的占空比da、db、dc，进行重构得到三相变换器端口电压ua、ub、uc，根据公式(4)得到d、q坐标轴的电压分量ud、uq。将实际采样获得的三相电网电压ea、eb、ec，根据公式(2)计算出d、q坐标轴的电压分量ed、eq。根据可调电流模型公式(7)计算出估计的电流分量

Figure BDA0002359553890000083
若满足条件
Figure BDA0002359553890000084
则利用公式(9)计算得出电感估计值，估计过程结束；否则，根据自适应率公式(8)调节
Figure BDA0002359553890000085
作用到公式(7)中，继续进行上述估计过程。Fig. 2 is a block diagram of an inductance parameter estimation algorithm of the present invention. According to the formula ( 3 ) of the reference current model, the three-phase inductor currents i a , ib , and ic obtained by actual sampling are used to calculate the inductor currents id and i q of the reference model. According to formula (1), using the DC side voltage U dc and the duty ratios da , db , and dc of the three-phase modulated wave calculated in the last beat of the controller, reconstruct the three-phase converter port voltages u a , u b and uc , according to formula (4), the voltage components ud and u q of the d and q coordinate axes are obtained. According to formula (2), the voltage components ed and eq of the d and q coordinate axes are calculated from the three-phase grid voltages ea , eb , and ec obtained by actual sampling. The estimated current component is calculated according to the adjustable current model formula (7)
Figure BDA0002359553890000083
If the conditions are met
Figure BDA0002359553890000084
Then use the formula (9) to calculate the estimated value of the inductance, and the estimation process ends; otherwise, adjust according to the adaptive rate formula (8).
Figure BDA0002359553890000085
Acting on formula (7), the above estimation process is continued.

本发明在建立可调模型的电感电流表达式时，对于三相LC型滤波器，将功率变换器看成一个黑匣子，只从其输出端口电压向电网方向看，得到等效电路，依据基尔霍夫电压定律，列写等效电路在d、q坐标系下的状态方程表达式为：When establishing the inductance current expression of the adjustable model, the present invention regards the power converter as a black box for the three-phase LC filter, and only looks at the voltage of its output port towards the power grid to obtain the equivalent circuit. Hough's voltage law, the state equation expression of the equivalent circuit in the d, q coordinate system is listed as:

Figure BDA0002359553890000091
Figure BDA0002359553890000091

式中，L为滤波电感标称值。In the formula, L is the nominal value of the filter inductor.

由于实际采样的电感电流存在噪声，以及滤波电感会因为加工工艺、工作温度、频率等因素而偏移标称值，所以将式(5)改写为式(6)的形式。Since the actual sampled inductor current has noise, and the filter inductance will deviate from the nominal value due to factors such as processing technology, operating temperature, and frequency, equation (5) is rewritten into the form of equation (6).

Figure BDA0002359553890000092
Figure BDA0002359553890000092

式中，

Figure BDA0002359553890000093
表示估计的电感值，
Figure BDA0002359553890000094
分别表示在dq坐标系下的估计的电流分量。In the formula,
Figure BDA0002359553890000093
represents the estimated inductance value,
Figure BDA0002359553890000094
represent the estimated current components in the dq coordinate system, respectively.

对式(6)进行后向差分离散化，可以得到当前拍dq坐标系下电流估计分量的表达式，如式(7)所示。By discretizing the backward difference of equation (6), the expression of the current estimation component in the dq coordinate system of the current beat can be obtained, as shown in equation (7).

Figure BDA0002359553890000095
Figure BDA0002359553890000095

式(7)是本发明的可调模型的电感电流表达式。Equation (7) is the inductor current expression of the adjustable model of the present invention.

本发明公开了一种功率变换器LC交流滤波器的电感参数在线估计方法，将采集到三相电感电流、三相电网电压以及重构的三相端口电压经过三相到两相的坐标变换，得到系统的参考电流模型，然后根据状态方程以估计值的形式列写出系统的可调电流模型，将系统的参考电流模型与可调电流模型作差得出系统的电流误差，并根据电流误差构建出系统的自适应率，最终使电流误差收敛到较小的定值，从而得到估计的电感值，反馈至电流控制之中，从而提高电流控制精度。The invention discloses an on-line estimation method for inductance parameters of an LC AC filter of a power converter. The collected three-phase inductance current, the three-phase grid voltage and the reconstructed three-phase port voltage are subjected to three-phase to two-phase coordinate transformation. The reference current model of the system is obtained, and then the adjustable current model of the system is written in the form of estimated value according to the state equation, and the current error of the system is obtained by the difference between the reference current model of the system and the adjustable current model. The adaptive rate of the system is constructed, and the current error is finally converged to a small fixed value, so as to obtain the estimated inductance value, which is fed back to the current control, thereby improving the current control accuracy.

Claims (3)

1. The method for estimating inductance parameters of the LC alternating current filter of the power converter on line is characterized in that the power converter comprises a direct current-alternating current grid-connected inverter circuit or an alternating current-direct current rectifying circuit with the LC filter, the direct current side of the power converter is connected with direct current with the property of a direct current voltage source, the alternating current side of the power converter is connected with an alternating current power grid, a main circuit of the power converter is a three-phase converting circuit,the online estimation method of the inductance parameter comprises the following steps: sampling three-phase grid voltage ea、eb、ecThree-phase filter inductor current ia、ib、icReconstructing the direct-current side voltage and the three-phase duty ratio to obtain the three-phase converter port voltage ua、ub、ucThen the three-phase network voltage ea、eb、ecThree-phase filter inductor current ia、ib、icAnd reconstructed three-phase converter port voltage ua、ub、ucThe method comprises the steps of converting the current into corresponding d-axis and q-axis components under synchronous rotation coordinates through coordinate transformation, setting actual two-phase inductive currents on the d-axis and the q-axis as a reference model, establishing an adjustable model of the inductive currents by using two-phase grid voltages on the d-axis and the q-axis and two-phase reconstruction port voltages, approximating the actual d-phase and q-phase inductive currents of the reference model by using the d-phase and q-phase inductive currents of the adjustable model, respectively subtracting the actual d-phase and q-phase inductive currents of the reference model from the d-phase and q-phase inductive currents of the corresponding adjustable model, selecting a proper self-adaption rate to adjust inductive parameters in the adjustable model in real time, ensuring that the two-phase inductive currents of the adjustable model are consistent with the actual two-phase inductive currents of the reference model, namely the reference current model, and obtaining online estimated inductive parameters;
the three-phase network voltage ea、eb、ecThree-phase filter inductor current ia、ib、icAnd reconstructed three-phase converter port voltage ua、ub、ucThe components of the d and q axes which are transformed into the corresponding components of the synchronous rotation coordinate by the coordinate transformation are transformed according to the formulas (2) to (4):
Figure FDA0003276204810000011
Figure FDA0003276204810000021
Figure FDA0003276204810000022
in the formula ud、uqIs the voltage component of the three-phase port voltage of the converter on d and q coordinate axes, id、iqThe current components of three-phase inductive current on d and q coordinate axes, ed、eqVoltage components of three-phase grid voltage in d and q coordinate axes are shown, and omega is grid angular frequency;
the inductance current expression of the reference model is specifically as follows:
the inductive current of the reference model is the current component i of the actually sampled three-phase inductive current on the d and q coordinate axesd、iqThe expression is formula (3);
the inductance and current expression of the adjustable model is as follows:
Figure FDA0003276204810000023
wherein,
Figure FDA0003276204810000024
which represents the estimated inductance value of the inductor,
Figure FDA0003276204810000025
respectively representing the values of the estimated current components in the d and q coordinate systems at the current moment,
Figure FDA0003276204810000026
respectively representing the values of the estimated current components in the d, q coordinate systems at the previous instant, TsRepresents a switching cycle;
the expression of the adaptive rate is as follows:
Figure FDA0003276204810000027
wherein L is the nominal value of the filter inductance,
Figure FDA0003276204810000028
for integral structure, R2(t) is a proportional structure, KiAnd KpRespectively, integral coefficient and proportionality coefficient, i.e. R1(t)＝Ki[εd(ud-ed)+εq(uq-eq)]，R2(t)＝Kp[εd(ud-ed)+εq(uq-eq)]，εdAnd εqThe error components of the inductive current of the reference model and the inductive current of the adjustable model in d and q coordinate systems, i.e.
Figure FDA0003276204810000031
The selection of the proper self-adaptive rate to adjust the inductance parameter in the adjustable model in real time ensures that the two-phase inductance current of the adjustable model, namely the adjustable current model, is consistent with the actual two-phase inductance current of the reference model, namely the reference current model, so that the inductance parameter obtained by online estimation specifically comprises the following steps:
when the condition is satisfied
Figure FDA0003276204810000032
And is
Figure FDA0003276204810000033
And then, obtaining an expression (9) of the inductance parameter estimated on line:
Figure FDA0003276204810000034
if the above condition is not satisfied, then the adjustment is made according to the adaptive rate formula (8)
Figure FDA0003276204810000035
Act uponIn the formula (7), the adjustable model of the inductive current is reestablished, and the inductive parameter is reestablished.
2. The method of on-line estimation of inductance parameters of a power converter LC ac filter according to claim 1, characterized in that said main circuit is a three-phase two-level conversion circuit or a three-phase T-type or I-type three-level conversion circuit.
3. The method for online estimation of inductance parameters of an LC/ac filter of a power converter according to claim 1 or 2, wherein the reconstruction of the three-phase converter port voltages is specifically:
DC side voltage U by samplingdcAnd the duty ratio d of the three-phase modulated wave calculated by one beat on the controllera、db、dcReconstructing according to the formula (1) to obtain the port voltage u of the three-phase convertera、ubAnd uc：
Figure FDA0003276204810000036
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Publication number Priority date Publication date Assignee Title
CN110417320B (en) * 2019-07-04 2021-06-01 东南大学 Up-down no-position control method for vertical operation magnetic flux switching permanent magnet linear motor
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Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101650390A (en) * 2009-08-31 2010-02-17 苏州经贸职业技术学院 Method of measuring inductance parameters of stator of surface AC permanent magnet synchronous motor on line
CN102611380A (en) * 2012-03-09 2012-07-25 哈尔滨工业大学 Online identification method for parameters of double-fed motor
CN102914740A (en) * 2012-08-31 2013-02-06 常州联力自动化科技有限公司 Method for rapidly identifying parameters of asynchronous motor
CN103532465A (en) * 2013-09-30 2014-01-22 清华大学 Permanent magnet synchronous motor inductance identification algorithm based on incremental model reference adaptive system
CN104360171A (en) * 2014-11-17 2015-02-18 长春工程学院 Method for measuring inductance parameter of permanent magnet synchronous motor
CN106452261A (en) * 2016-10-19 2017-02-22 南京理工大学 BCPWM based phase current reconstruction method and device
CN107861061A (en) * 2017-10-27 2018-03-30 安徽大学 Data-driven induction motor parameter online identification method
CN108390602A (en) * 2018-02-24 2018-08-10 西安理工大学 A kind of direct prediction power control method of hybrid exciting synchronous motor
CN110137975A (en) * 2019-05-24 2019-08-16 河北德瑞特电器有限公司 New electric energy quality controller and its control method based on current source inverter
CN110649851A (en) * 2019-09-18 2020-01-03 重庆中涪科瑞工业技术研究院有限公司 Multi-parameter decoupling online identification method for asynchronous motor

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2942865A1 (en) * 2014-05-06 2015-11-11 ABB Technology Oy Frequency converter parameter optimization
US10309330B2 (en) * 2016-10-27 2019-06-04 Rolls-Royce Corporation Model reference adaptive controller

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101650390A (en) * 2009-08-31 2010-02-17 苏州经贸职业技术学院 Method of measuring inductance parameters of stator of surface AC permanent magnet synchronous motor on line
CN102611380A (en) * 2012-03-09 2012-07-25 哈尔滨工业大学 Online identification method for parameters of double-fed motor
CN102914740A (en) * 2012-08-31 2013-02-06 常州联力自动化科技有限公司 Method for rapidly identifying parameters of asynchronous motor
CN103532465A (en) * 2013-09-30 2014-01-22 清华大学 Permanent magnet synchronous motor inductance identification algorithm based on incremental model reference adaptive system
CN104360171A (en) * 2014-11-17 2015-02-18 长春工程学院 Method for measuring inductance parameter of permanent magnet synchronous motor
CN106452261A (en) * 2016-10-19 2017-02-22 南京理工大学 BCPWM based phase current reconstruction method and device
CN107861061A (en) * 2017-10-27 2018-03-30 安徽大学 Data-driven induction motor parameter online identification method
CN108390602A (en) * 2018-02-24 2018-08-10 西安理工大学 A kind of direct prediction power control method of hybrid exciting synchronous motor
CN110137975A (en) * 2019-05-24 2019-08-16 河北德瑞特电器有限公司 New electric energy quality controller and its control method based on current source inverter
CN110649851A (en) * 2019-09-18 2020-01-03 重庆中涪科瑞工业技术研究院有限公司 Multi-parameter decoupling online identification method for asynchronous motor

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
On-line Identification Methods of Parameters for Permanent Magnet Synchronous Motors Based on Cascade MRAS;Yanqing Zhang et.al;《9th International Conference on Power Electronics-ECCE Asia》;20150730(第2期);第345-350页 *
基于模型参考自适应的永磁同步电机在线参数辨识方法研究;张瑞峰;《机车电传动》;20150310(第2期);第71-76页 *

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