阅读说明：本技术 电力机车辅助变流器直流电压震荡抑制方法 (Method for inhibiting DC voltage oscillation of auxiliary converter of electric locomotive ) 是由 张宇龙 葸代其 邹会杰 张瑞峰 詹哲军 贺志学 于 2020-05-22 设计创作，主要内容包括：本发明涉及变流器直流电压震荡抑制方法,具体为电力机车辅助变流器直流电压震荡抑制方法。解决现有技术存在的缺陷和问题,提供一种电力机车辅助变流器直流电压震荡抑制方法,其抑制控制方法简单、效果好,同时灵活性、适用性强。该抑制方法如下步骤实现：步骤一：从不同功率等级下的逆变侧直流电压U<Sub>dc</Sub>与电流I<Sub>dc</Sub>的震荡频率f中选取最大值f<Sub>max</Sub>及对应的相位差Δ<Sub>θmax</Sub>；步骤二：实时采集逆变侧直流电压U<Sub>dc</Sub>；步骤三：计算逆变侧直流电压U<Sub>dc</Sub>的震荡量Δ<Sub>U</Sub>；步骤四：选取相应参数A、B并计算调制比补偿量Δ<Sub>M</Sub>；步骤五：计算补偿量Δ<Sub>Mn</Sub>；步骤六：对Δ<Sub>M</Sub>或Δ<Sub>Mn</Sub>进行限幅运算；步骤七：将调制比M与补偿量Δ<Sub>M</Sub>或Δ<Sub>Mn</Sub>相加,并对相加的结果进行限幅处理,然后将结果用于逆变调制算法。(The invention relates to a method for inhibiting direct current voltage oscillation of a converter, in particular to a method for inhibiting direct current voltage oscillation of an auxiliary converter of an electric locomotive. The method for restraining the direct-current voltage oscillation of the auxiliary converter of the electric locomotive is simple, good in effect, flexible and high in applicability. The inhibition method is realized by the following steps: the method comprises the following steps: DC voltage U of inversion side under different power levels dc And current I dc Selecting the maximum value f from the oscillation frequencies f max And corresponding phase difference delta θmax (ii) a Step two: real-time acquisition of DC voltage U at inversion side dc (ii) a Step three: calculating DC voltage U of inversion side dc Amount of oscillation Δ U (ii) a Step four: selecting corresponding parameters A, B and calculating the compensation quantity delta of modulation ratio M (ii) a Step five: calculating the compensation amount delta Mn (ii) a Step six: for a M Or Δ Mn Carrying out amplitude limiting operation; step seven: the modulation ratio M is compared with the compensation quantity delta M Or Δ Mn Add and doThe result of the addition is clipped and then used in the inverse modulation algorithm.)

1. The method for suppressing the direct-current voltage oscillation of the auxiliary converter of the electric locomotive is characterized in that the suppression method is realized by the following steps:

the method comprises the following steps: through test measurement, the test waveforms of the selected auxiliary converter under different power levels are obtained to obtain the inversion side direct current voltage U corresponding to the different power levels_dcAnd current I_dcAnd the corresponding inverter-side DC voltage U_dcAnd current I_dcPhase difference Δ of_θWherein, is_θ＝θ_U-θ_I，θ_UFor inverting the phase of the side DC voltage, theta_IThe phase is the direct current phase of the inversion side; DC voltage U of inversion side under different power levels_dcAnd current I_dcSelecting the maximum value f from the oscillation frequencies f_maxAnd corresponding phase difference delta_θmax；

Step two: real-time acquisition of DC voltage U at inversion side_dc；

Step three: calculating DC voltage U of inversion side_dcAmount of oscillation Δ_U，Δ_U＝U_dc-U_ref，U_refThe target value of the direct current voltage at the inversion side is obtained;

step four: let Delta be_{Theta supplement}＝180o-Δ_θmaxWhen Δ is_{Theta supplement}Not more than 45 degrees according to the angle_{Theta supplement}The corresponding parameter A, B is selected as follows:

0°＜Δ_{theta supplement}When the temperature is less than or equal to 5 degrees, A is 1, B is 1/0.08412132;

5°＜Δ_{theta supplement}When the temperature is less than or equal to 10 degrees, A is 0.984835645397554, B is 1/0.17616129;

10°＜Δ_{theta supplement}When the angle is less than or equal to 15 degrees, A is 0.966092383592143, B is 1/0.26725875;

15°＜Δ_{theta supplement}When the temperature is less than or equal to 20 degrees, A is 0.939916925046859, B is 1/0.36322704;

20°＜Δ_{theta supplement}When the temperature is less than or equal to 25 ℃, A is 0.906435415347077, B is 1/0.46593993;

25°＜Δ_{theta supplement}When the temperature is less than or equal to 30 degrees, A is 0.866354444531846, B is 1/0.57647266;

30°＜Δ_{theta supplement}When the temperature is less than or equal to 35 degrees, A is 0.819387258924401, B is 1/0.69959639;

35°＜Δ_{theta supplement}When the temperature is less than or equal to 40 ℃, A is 0.766130961732220, B is 1/0.83887027;

40°＜Δ_{theta supplement}When the angle is less than or equal to 45 degrees, A is 0.707106781186548, B is 1;

according to the formulaCalculating the modulation ratio compensation quantity delta for inhibiting voltage oscillation_M(ii) a Function F (F)_cut,Δ_U) Is a first-order low-pass digital filter, F_cutA cut-off frequency of a first-order low-pass digital filter, the magnitude of which is in accordance with F_cut＝B·2π·f_maxCalculating;

step five: if Δ_{Theta supplement}Greater than 45 deg., into n values less than or equal to 45 deg., i.e. delta_{Theta supplement}＝Δ_{Theta is complemented by 1}+Δ_{Theta plus 2}+...+Δ_{Theta is compensated for n}In which Δ_{Theta is complemented by 1}、Δ_{Theta plus 2}、...、Δ_{Theta is compensated for n}N is less than or equal to 45 degrees, and according to the decomposition clearance angle value, according to the step four respectively selecting corresponding A, B values, compensating quantity delta_MnThe method comprises the following steps:wherein A is_nTo correspond to Δ_{Theta is compensated for n}A value of (A), F_cut(n)＝B_n·2π·f_max，B_nTo correspond to Δ_{Theta is compensated for n}B value of (2);

step six: for a_MOr Δ_MnPerforming a clipping operation, Δ_MOr Δ_MnThe value range is-M_max·25％＜Δ_M＜M_max·25％，-M_max·25％＜Δ_Mn＜M_max25% of where M_maxDesigning a maximum value for the three-phase inversion modulation ratio;

step seven: modulating ratio M and compensation quantity delta calculated by inverter control_MOr Δ_MnAdding the two components, and performing amplitude limiting processing on the addition result, i.e. 0 < M + delta_M＜M_max,0＜M+Δ_Mn＜M_maxAnd then the result is used in the inverse modulation algorithm.

2. The method according to claim 1, wherein the phase difference Δ in the first step is_θmaxIt can also be used to determine the location of the dc voltage oscillation: when delta_θmaxWhen the angle is 180 degrees, judging that the direct-current voltage oscillation occurs on the inversion side; when 0 < delta_θmaxAnd when the angle is less than 180 degrees, judging that the direct current voltage oscillation occurs on the input side.

Technical Field

The invention relates to a method for inhibiting direct current voltage oscillation of a converter, in particular to a method for inhibiting direct current voltage oscillation of an auxiliary converter of an electric locomotive.

Background

In the application of a typical high-power electric locomotive auxiliary converter, because the input voltage level is high, a main circuit often connects a Buck chopper Buck circuit and an inverter together in a cascade mode (as shown in fig. 1), after the direct-current voltage input by the auxiliary converter is reduced by the Buck chopper Buck circuit, the direct-current voltage is inverted by a three-phase inverter to output auxiliary three-phase alternating current required by the electric locomotive, wherein two input and output sides of the Buck chopper Buck circuit are respectively called an input side and an inversion side. When the parasitic parameters or the output power of the auxiliary system change, the direct-current voltage on the input side or the direct-current voltage on the inversion side easily vibrates due to the negative impedance characteristic, so that the output voltage of the auxiliary converter fluctuates greatly, and the use requirement cannot be met.

In the engineering, for the problem of direct-current voltage oscillation, the direct-current voltage oscillation is often suppressed by serially adding a resistor or adding an intermediate support capacitor to the intermediate direct-current bus side of the auxiliary converter. However, energy loss is increased through series connection of resistors, system efficiency is reduced, and the size and cost of the auxiliary converter are increased by increasing the supporting capacitor; the flexibility is not enough by changing the mode of the support capacitor or the series resistor of the converter, and the converter is not applicable any more after the working condition is changed; meanwhile, the existing method cannot determine the initial specific position of the direct-current voltage oscillation, and is inconvenient for subsequent optimization of the system.

Disclosure of Invention

The invention solves the defects and problems of the existing method for inhibiting the direct-current voltage oscillation of the auxiliary converter of the electric locomotive, and provides the method for inhibiting the direct-current voltage oscillation of the auxiliary converter of the electric locomotive, which has the advantages of simple control method, good effect, high flexibility and high applicability.

The invention is realized by adopting the following technical scheme: the method for suppressing the direct-current voltage oscillation of the auxiliary converter of the electric locomotive is characterized in that the auxiliary converter is formed by cascade connection of a Buck chopper Buck circuit and an inverter, and the suppression method is realized by the following steps:

the method comprises the following steps: through test measurement, the test waveforms of the selected auxiliary converter under different power levels (from no load to full load) are obtained, and the inversion side direct current voltage U corresponding to the different power levels is obtained_dcAnd current I_dcAnd the corresponding inverter-side DC voltage U_dcAnd current I_dcPhase difference Δ of_θWherein, is_θ＝θ_U-θ_I，θ_UFor inverting the phase of the side DC voltage, theta_IThe phase is the direct current phase of the inversion side; DC voltage U of inversion side under different power levels_dcAnd current I_dcSelecting the maximum value f from the oscillation frequencies f_maxAnd corresponding phase difference delta_θmax；

Step two: real-time acquisition of DC voltage U at inversion side_dc；

Step three: calculating DC voltage U of inversion side_dcAmount of oscillation Δ_U，Δ_U＝U_dc-U_ref，U_refThe target value of the direct current voltage at the inversion side is obtained;

step four: let Delta be_{Theta supplement}＝180°-Δ_θmaxWhen Δ is_{Theta supplement}Not more than 45 degrees according to the angle_{Theta supplement}The corresponding parameter A, B is selected as follows:

0°＜Δ_{theta supplement}When the temperature is less than or equal to 5 degrees, A is 1, B is 1/0.08412132;

5°＜Δ_{theta supplement}When the temperature is less than or equal to 10 degrees, A is 0.984835645397554, B is 1/0.17616129;

10°＜Δ_{theta supplement}When the angle is less than or equal to 15 degrees, A is 0.966092383592143, B is 1/0.26725875;

15°＜Δ_{theta supplement}When the temperature is less than or equal to 20 degrees, A is 0.939916925046859, B is 1/0.36322704;

20°＜Δ_{theta supplement}When the temperature is less than or equal to 25 ℃, A is 0.906435415347077, B is 1/0.46593993;

25°＜Δ_{theta supplement}When the temperature is less than or equal to 30 degrees, A is 0.866354444531846, B is 1/0.57647266;

30°＜Δ_{theta supplement}When the temperature is less than or equal to 35 degrees, A is 0.819387258924401, B is 1/0.69959639;

35°＜Δ_{theta supplement}When the temperature is less than or equal to 40 ℃, A is 0.766130961732220, B is 1/0.83887027;

40°＜Δ_{theta supplement}When the angle is less than or equal to 45 degrees, A is 0.707106781186548, B is 1;

according to the formulaCalculating the modulation ratio compensation quantity delta for inhibiting voltage oscillation_M(ii) a Function F (F)_cut,Δ_U) Is a first-order low-pass digital filter, F_cutA cut-off frequency of a first-order low-pass digital filter, the magnitude of which is in accordance with F_cut＝B·2π·f_maxCalculating;

step five: if Δ_{Theta supplement}Greater than 45 deg., into n values less than or equal to 45 deg., i.e. delta_{Theta supplement}＝Δ_{Theta is complemented by 1}+Δ_{Theta plus 2}+...+Δ_{Theta is compensated for n}In which Δ_{Theta is complemented by 1}、Δ_{Theta plus 2}、...、Δ_{Theta is compensated for n}N is less than or equal to 45 degrees, and according to the decomposition clearance angle value, according to the step four respectively selecting corresponding A, B values, compensating quantity delta_MnThe method comprises the following steps:wherein A is_nTo correspond to Δ_{Theta is compensated for n}A value of (A), F_cut(n)＝B_n·2π·f_max，B_nTo correspond to Δ_{Theta is compensated for n}B value of (2);

step six: for a_MOr Δ_MnPerforming a clipping operation, Δ_MOr Δ_MnThe value range is as follows:

-M_max·25％＜Δ_M＜M_max·25％，-M_max·25％＜Δ_Mn＜M_max25% (i.e., Δ)_MOr Δ_MnGreater than M_maxWhen 25%, take equal to M_max·25％；Δ_MOr Δ_MnLess than-M_maxWhen 25%, take to be equal to-M_max25%; at M_max25% and-M_maxBetween 25%, get the real value), where M_maxDesigning a maximum value for the three-phase inversion modulation ratio;

step seven: modulating ratio M and compensation quantity delta calculated by inverter control_MOr Δ_MnAdding the two components, and performing amplitude limiting processing on the addition result, i.e. 0 < M + delta_M＜M_max,0＜M+Δ_Mn＜M_maxAnd then the result is used in the inverse modulation algorithm.

Compared with the prior art, the control method for inhibiting the direct-current voltage oscillation is simple, good in effect, flexible and high in applicability.

Drawings

FIG. 1 is a main circuit structure diagram of an auxiliary converter of an electric locomotive;

FIG. 2 is a schematic waveform diagram of voltage and current of the inverter side DC voltage;

fig. 3 is a schematic waveform diagram of voltage and current when the input side dc voltage oscillates.

Detailed Description

The method for suppressing the direct-current voltage oscillation of the auxiliary converter of the electric locomotive is characterized in that the auxiliary converter is formed by cascade connection of a Buck chopper Buck circuit and an inverter, and the suppression method is realized by the following steps:

the method comprises the following steps: through test measurement, the test waveforms of the selected auxiliary converter under different power levels (from no load to full load) are obtained, and the inversion side direct current voltage U corresponding to the different power levels is obtained_dcAnd current I_dcAnd the corresponding inverter-side DC voltage U_dcAnd current I_dcPhase difference Δ of_θWherein, is_θ＝θ_U-θ_I，θ_UFor inverting the phase of the side DC voltage, theta_IThe phase is the direct current phase of the inversion side; DC voltage U of inversion side under different power levels_dcAnd current I_dcSelecting the maximum value f from the oscillation frequencies f_maxAnd corresponding phase difference delta_θmax；

Step two: real-time acquisition of DC voltage U at inversion side_dc；

Step three: calculating DC voltage U of inversion side_dcAmount of oscillation Δ_U，Δ_U＝U_dc-U_ref，U_refThe target value of the direct current voltage at the inversion side is obtained;

step four: let Delta be_{Theta supplement}＝180°-Δ_θmaxWhen Δ is_{Theta supplement}Not more than 45 degrees according to the angle_{Theta supplement}The corresponding parameter A, B is selected as follows:

0°＜Δ_{theta supplement}When the temperature is less than or equal to 5 degrees, A is 1, B is 1/0.08412132;

5°＜Δ_{theta supplement}When the temperature is less than or equal to 10 degrees, A is 0.984835645397554, B is 1/0.17616129;

10°＜Δ_{theta supplement}When the angle is less than or equal to 15 degrees, A is 0.966092383592143, B is 1/0.26725875;

15°＜Δ_{theta supplement}When the temperature is less than or equal to 20 degrees, A is 0.939916925046859, B is 1/0.36322704;

20°＜Δ_{theta supplement}When the temperature is less than or equal to 25 ℃, A is 0.906435415347077, B is 1/0.46593993;

25°＜Δ_{theta supplement}When the temperature is less than or equal to 30 degrees, A is 0.866354444531846, B is 1/0.57647266;

30°＜Δ_{theta supplement}When the temperature is less than or equal to 35 degrees, A is 0.819387258924401, B is 1/0.69959639;

35°＜Δ_{theta supplement}When the temperature is less than or equal to 40 ℃, A is 0.766130961732220, B is 1/0.83887027;

40°＜Δ_{theta supplement}When the angle is less than or equal to 45 degrees, A is 0.707106781186548, B is 1;

according to the formulaCalculating the modulation ratio compensation quantity delta for inhibiting voltage oscillation_M(ii) a Function F (F)_cut,Δ_U) Is a first-order low-pass digital filter, F_cutA cut-off frequency of a first-order low-pass digital filter, the magnitude of which is in accordance with F_cut＝B·2π·f_maxCalculating;

step five: if Δ_{Theta supplement}Greater than 45 deg., into n values less than or equal to 45 deg., i.e. delta_{Theta supplement}＝Δ_{Theta is complemented by 1}+Δ_{Theta supplement2}+...+Δ_{Theta is compensated for n}In which Δ_{Theta is complemented by 1}、Δ_{Theta plus 2}、...、Δ_{Theta is compensated for n}N is less than or equal to 45 deg. (e.g. 60 deg. is decomposed into 45 deg. and 15 deg., or six 10 deg., or three 20 deg., … …), and according to the decomposition angle value, according to step four, respectively selecting corresponding A, B values, compensating quantity delta is respectively_MnThe method comprises the following steps:

wherein A is_nTo correspond to Δ_{Theta is compensated for n}A value of (A), F_cut(n)＝B_n·2π·f_max，B_nTo correspond to Δ_{Theta is compensated for n}B value of (2);

step six: for a_MOr Δ_MnPerforming a clipping operation, Δ_MOr Δ_MnThe value range is as follows:

-M_max·25％＜Δ_M＜M_max·25％，-M_max·25％＜Δ_Mn＜M_max25% (i.e., Δ)_MOr Δ_MnGreater than M_maxWhen 25%, take equal to M_max·25％；Δ_MOr Δ_MnLess than-M_maxWhen 25%, take to be equal to-M_max25%; at M_max25% and-M_maxBetween 25%, get the real value), where M_maxDesigning a maximum value for the three-phase inversion modulation ratio;

step seven: modulating ratio M and compensation quantity delta calculated by inverter control_MOr Δ_MnAdding the two components, and performing amplitude limiting processing on the addition result, i.e. 0 < M + delta_M＜M_max,0＜M+Δ_Mn＜M_maxAnd then the result is used in the inverse modulation algorithm.