Method and device for identifying pre-charge resistance of high-power rectifier

Abstract

The present invention discloses a method and device for identifying the pre-charging resistance of a high-power rectifier. The method comprises: collecting two-phase incoming line voltages during the pre-charging process of the high-power rectifier; obtaining a phase difference between the two-phase incoming line voltages; determining a successful phase lock moment based on the phase difference, and obtaining the voltage phase at the successful phase lock moment; based on the voltage phase at the successful phase lock moment, inferring the voltage amplitude and phase angle of the two-phase incoming line voltages before the successful phase lock moment, and determining the incoming line three-phase AC voltage signal before the successful phase lock moment; and identifying the pre-charging resistance based on the incoming line three-phase AC voltage signal before the successful phase lock moment. The present invention can accurately identify the pre-charging resistance of a high-power rectifier.

Description

Technical Field

[0001] The present invention relates to the field of circuit technology, and in particular to a method and device for identifying a pre-charging resistance of a high-power rectifier. Background Art

[0002] This section is intended to provide a background or context to the embodiments of the invention that are recited in the claims. No statement herein is admitted to be prior art by virtue of its inclusion in this section.

[0003] A high-power rectifier is a type of rectifier used to handle high currents. High-power rectifier power supplies require rectifiers with high current capacity, high breakdown voltage, and good heat dissipation. However, these devices have large junction areas and high junction capacitance, resulting in very low operating frequencies, typically below tens of kilohertz.

[0004] In two basic types of rectifiers, based on high-power diodes or thyristors, the high-voltage AC power from the grid is converted into DC power. Other future rectifier types include choppers based on leading-edge uncontrolled diodes, chopper DC / DC converters, or current-source inverter-type active rectifiers. While these latest rectifiers clearly involve significant technical development, they offer advantages, such as minimal harmonic interference and a power factor of unity when applied to the grid.

[0005] Currently, existing technologies use an offline method to measure resistance with the help of external instruments. The data measured by this technology is only the resistance value of a single component, which cannot formally characterize the pre-charge resistance characteristics of the rectifier, nor can it be quantified and calculated. Summary of the Invention

[0006] An embodiment of the present invention provides a method for identifying a pre-charging resistor of a high-power rectifier, for accurately identifying the pre-charging resistor of the high-power rectifier. The method includes:

[0007] During the pre-charging process of the high-power rectifier, the two-phase incoming line voltage is collected;

[0008] Obtain the phase difference between the two-phase incoming line voltages;

[0009] Determining a phase-locked success moment according to the phase difference, and obtaining a voltage phase at the phase-locked success moment;

[0010] According to the voltage phase at the moment of successful phase locking, the voltage amplitude and phase angle of the two-phase incoming line voltage before the moment of successful phase locking are reversed, and the incoming line three-phase AC voltage signal before the moment of successful phase locking is determined;

[0011] The pre-charging resistor is identified based on the incoming three-phase AC voltage signal before the phase locking is successful.

[0012] An embodiment of the present invention provides a device for identifying a pre-charging resistance of a high-power rectifier, for accurately identifying the pre-charging resistance of the high-power rectifier. The device includes:

[0013] Two-phase incoming line voltage acquisition module, used to collect the two-phase incoming line voltage during the pre-charging process of the high-power rectifier;

[0014] Phase difference acquisition module, used to obtain the phase difference between the two-phase incoming line voltages;

[0015] A phase locking module, configured to determine a phase locking success moment according to the phase difference, and obtain the voltage phase at the phase locking success moment;

[0016] The two-phase incoming line voltage reverse calculation module is used to reversely calculate the voltage amplitude and phase angle of the two-phase incoming line voltage before the phase lock is successful based on the voltage phase at the phase lock is successful, and determine the incoming line three-phase AC voltage signal before the phase lock is successful;

[0017] The pre-charging resistance identification module is used to identify the pre-charging resistance according to the incoming three-phase AC voltage signal before the phase locking is successful.

[0018] An embodiment of the present invention further provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned method for identifying the pre-charging resistance of the high-power rectifier when executing the computer program.

[0019] An embodiment of the present invention further provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the method for identifying the pre-charging resistance of the high-power rectifier is implemented.

[0020] An embodiment of the present invention further provides a computer program product, which includes a computer program. When the computer program is executed by a processor, the computer program implements the above-mentioned method for identifying the pre-charging resistance of the high-power rectifier.

[0021] In an embodiment of the present invention, during the pre-charging process of a high-power rectifier, the two-phase incoming line voltage is collected; the phase difference of the two-phase incoming line voltage is obtained; based on the phase difference, the phase-locking success moment is determined, and the voltage phase at the phase-locking success moment is obtained; based on the voltage phase at the phase-locking success moment, the voltage amplitude and phase angle of the two-phase incoming line voltage before the phase-locking success moment are reversed, and the incoming line three-phase AC voltage signal before the phase-locking success moment is determined; based on the incoming line three-phase AC voltage signal before the phase-locking success moment, the pre-charging resistor is identified. Through the above method, the phase-locking success moment can be accurately determined, and then based on the voltage phase at the phase-locking success moment, the voltage amplitude and phase angle of the two-phase incoming line voltage before the phase-locking success moment can be accurately reversed, and finally the pre-charging resistor can be accurately identified based on the incoming line three-phase AC voltage signal before the phase-locking success moment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0023] Figure 1 Flowchart of a method for identifying a pre-charge resistor of a high-power rectifier according to an embodiment of the present invention;

[0024] Figure 2 The present invention is a circuit diagram of the pre-charging process of an existing high-power rectifier;

[0025] Figure 3 The two-phase incoming line voltage collected in the embodiment of the present invention;

[0026] Figure 4 is the phase difference of the two-phase incoming line voltage after filtering in the embodiment of the present invention;

[0027] Figure 5 The fitting result obtained by fitting the phase difference using the least squares method in an embodiment of the present invention;

[0028] Figure 6 The voltage amplitude and phase angle of the two-phase incoming line voltage before the successful phase locking in the embodiment of the present invention are reversely calculated;

[0029] Figure 7 are the DC bus voltage and incoming line current in the embodiment of the present invention;

[0030] Figure 8 Schematic diagram of a pre-charging resistance identification device for a high-power rectifier according to an embodiment of the present invention;

[0031] Figure 9 Schematic diagram of the computer device structure according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] To make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the embodiments of the present invention are further described in detail below with reference to the accompanying drawings. Here, the exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0033] The inventors believe that the existing technology does not take into account factors such as the internal cable resistance of the rectifier and the internal resistance of the reactor. Therefore, the measured data is only the resistance value of a single component, which cannot formally characterize the characteristics of the rectifier, nor can it be quantified and calculated. In addition, the existing technology does not have a virtual voltage neutral point, which may cause AC voltage signal offset.

[0034] The embodiment of the present invention provides a method for identifying a pre-charging resistor of a high-power rectifier to overcome the above-mentioned problem.

[0035] Figure 1 Flowchart of a method for identifying a pre-charge resistance of a high-power rectifier according to an embodiment of the present invention, including:

[0036] Step 101, during the pre-charging process of the high-power rectifier, collecting the two-phase incoming line voltage;

[0037] Step 102, obtaining a phase difference between two-phase incoming line voltages;

[0038] Step 103, determining a phase-locked success moment based on the phase difference, and obtaining a voltage phase at the phase-locked success moment;

[0039] Step 104, based on the voltage phase at the time of successful phase locking, reversely calculate the voltage amplitude and phase angle of the two-phase incoming line voltage before the successful phase locking moment, and determine the incoming line three-phase AC voltage signal before the successful phase locking moment;

[0040] Step 105 , identifying the pre-charging resistor based on the incoming three-phase AC voltage signal before the phase locking is successful.

[0041] In the above process, the moment of successful phase locking can be accurately determined, and then based on the voltage phase at the moment of successful phase locking, the voltage amplitude and phase angle of the two-phase incoming line voltage before the moment of successful phase locking can be accurately reversed, and finally the pre-charging resistance can be accurately identified based on the incoming three-phase AC voltage signal before the moment of successful phase locking.

[0042] Figure 2This is a circuit diagram of the pre-charging process for an existing high-power rectifier. After the pre-charging three-phase contactor Sw receives a close command, it closes, and the three-phase moving contact gradually approaches the three-phase stationary contact. When the moving and stationary contacts are fully in contact, the contactor closing is complete. Because the moving contacts of the three-phase contactor Sw do not move in perfect unison during the closing process, some moving contacts may contact the stationary contacts first. When the first two moving and stationary contacts close, a single-phase full-bridge rectifier circuit is formed, charging the DC capacitor. When all three moving and stationary contacts are closed, a three-phase full-bridge rectifier circuit is formed, charging the DC capacitor simultaneously. Assume that the U and V phase moving and static contacts touch first, forming a single-phase full-bridge rectifier circuit. After the charging current I passes through the moving contact 1 and static contact 2 of the three-phase contactor Sw, it passes through the pre-charging resistor Ru, the incoming line reactor L11, and the diode D1 of the insulated gate bipolar transistor IGBT to flow to the positive DC bus, charging the DC capacitors C1 to C3. Then, after passing through the diode D4 of the insulated gate bipolar transistor IGBT, the incoming line reactor L12, and the pre-charging resistor Rv, it passes through the static contact 4 and moving contact 3 of the three-phase contactor Sw, forming a complete current closed loop between the U phase and the V phase.

[0043] Since the amplitude of the three-phase AC voltage is different at each moment, the three-phase contactor Sw is closed at different moments, which will cause the DC capacitor charging current to be different, the DC bus voltage charging process to be different, and the power consumed by the pre-charging resistors Ru, Rv, and Rw to be different.

[0044] The following is a message introduction to each step.

[0045] In step 101, during the pre-charging process of the high-power rectifier, the two-phase incoming line voltage is collected;

[0046] In one embodiment, during the pre-charging process of the high-power rectifier, collecting the line voltages of two-phase incoming lines includes:

[0047] During the pre-charging process of the high-power rectifier, the two-phase incoming line voltage is collected with reference to the virtual neutral point, wherein the virtual neutral point is generated by the high-power rectifier's incoming line three-phase AC voltage signal after resistor voltage division.

[0048] In one embodiment, before obtaining the phase difference between the line voltages of the two-phase incoming lines, the method further includes:

[0049] performing low-pass filtering on the two-phase incoming line voltage to obtain filtered two-phase incoming line voltage;

[0050] Calculate the phase difference between the two-phase incoming line voltages after filtering.

[0051] The step of performing low-pass filtering on the two-phase incoming line voltage to obtain filtered two-phase incoming line voltage includes:

[0052] The two-phase incoming line voltage is subjected to low-pass filtering and digital band-pass filtering in sequence to obtain filtered two-phase incoming line voltage.

[0053] Specifically, it can be low-pass filtered through a low-pass filter with a cutoff frequency of 33kHz, and then input into the analog sampling channel of the smart chip. The analog voltage signal acquisition cycle and execution cycle of the smart chip are both 3kHz. It can be digitally band-pass filtered through a 50Hz band-pass digital filter G, which can eliminate the DC bias of the two-phase AC line voltage signal and filter out external low-frequency interference and high-frequency interference signals, providing a basis for subsequent phase sequence judgment.

[0054] In step 102, the phase difference between the line voltages of the two-phase incoming lines is obtained;

[0055] In one embodiment, obtaining the phase difference between the line voltages of two-phase incoming lines includes:

[0056] Calculate the phase angle of each single-phase incoming line voltage in the filtered two-phase incoming line voltage;

[0057] The phase angle of the single-phase incoming line voltage Uvw is subtracted from the phase angle of the single-phase incoming line voltage Uuv to obtain the phase difference of the two-phase incoming line voltages after filtering.

[0058] In one embodiment, calculating the phase angle of each single-phase incoming line voltage in the filtered two-phase incoming line voltage includes:

[0059] Calculate the real and imaginary parts of each single-phase incoming line voltage based on the standard sine wave reference signal and the standard cosine wave reference signal;

[0060] The inverse tangent of the calculated real and imaginary parts is calculated to obtain the phase angle of the line voltage of each single-phase incoming line.

[0061] Among them, the smart chip has a built-in standard sine wave reference signal U_sin and a standard cosine wave reference signal U_cos. If the storage space of the smart chip is sufficient, only the standard sine wave reference signal U_14th of 0-90° can be saved, and the reference signals of other phases can be derived from the 0-90° reference signal.

[0062] U_14th(t)=sin(2*PI*t),t=[0,0.005]

[0063] U_sin(t)=U_14th(t),t=[0,0.005]

[0064] U_sin(t)=U_14th(0.01-t),t=[0.005,0.01]

[0065] U_sin(t)=-1*U_14th(t-0.01),t=[0.01,0.015]

[0066] U_sin(t)=-1*U_14th(0.02-t),t=[0.015,0.02]

[0067] U_cos(t)=U_14th(0.005-t),t=[0,0.005]

[0068] U_cos(t)=-1*U_14th(t-0.005),t=[0.005,0.01]

[0069] U_cos(t)=-1*U_14th(0.015-t),t=[0.01,0.015]

[0070] U_cos(t)=U_14th(t–0.015),t=[0.015,0.02]

[0071] Use the following formula to calculate the real and imaginary parts of each single-phase incoming line voltage:

[0072]

[0073]

[0074] Among them, Re u is the real part of the line voltage of each single-phase incoming line, Im u is the imaginary part of each single-phase incoming line voltage, u(t) is the single-phase incoming line voltage, U_sin(t) is the standard sine wave reference signal, and U_cos(t) is the standard cosine wave reference signal;

[0075] The phase angle of each single-phase incoming line voltage is obtained using the following formula:

[0076] Phy=arctan2(Re u ,Im u )

[0077] Wherein, Phy is the phase angle of the line voltage of each single-phase incoming line.

[0078] Similarly, the amplitude of each single-phase incoming line voltage can also be obtained:

[0079]

[0080] In step 103, the phase-locking success moment is determined based on the phase difference, and the voltage phase at the phase-locking success moment is obtained;

[0081] In one embodiment, determining the phase-lock success moment according to the phase difference includes:

[0082] Fitting the phase difference using a least squares method to obtain a fitting result;

[0083] According to the fitting results, the phase-locking success moment is determined, and the voltage phase at the phase-locking success moment is obtained.

[0084] In one embodiment, determining the phase-lock success moment includes:

[0085] The moment when the root mean square value of the deviation of the fitting result first enters a value less than a preset threshold (eg, 5%) is determined as the moment when the phase locking is successful.

[0086] In one embodiment, when the fluctuation range of the phase difference between the two-phase incoming line voltages is within a first preset range (a range of approximately 120°), and the RMS value of the phase difference deviation is less than a preset threshold (e.g., 5%), it indicates that the phase difference is constant, and the phase sequence of the two-phase incoming line voltages is determined to be positive sequence. The formula for the two-phase incoming line voltages before the phase lock is successful is as follows:

[0087]

[0088]

[0089] When the fluctuation range of the phase difference between the two-phase incoming line voltages is within the second preset range (a range of approximately -120 degrees), and the RMS value of the phase difference deviation is less than a preset threshold (e.g., 5%), it indicates that the phase difference is constant, and the phase sequence of the two-phase incoming line voltages is determined to be negative sequence. The formula for the two-phase incoming line voltages before the phase lock is successful is as follows:

[0090]

[0091]

[0092] Where Uuv2(t) and Uvw2(t) are the two-phase incoming line voltages that change with time t and frequency f before the phase-locking success moment, T0 is the moment of successful phase-locking, Mag0 is the constant value of the incoming line voltage amplitude, and Phy0 is the voltage phase at the moment of successful phase-locking.

[0093] That is, whether it is positive sequence or negative sequence, as long as the RMS value of the fitting result deviation is less than 5%, it means that the phase lock is successful and the phase lock result at that moment can be used.

[0094] In step 104, based on the voltage phase at the time of successful phase locking, the voltage amplitude and phase angle of the two-phase incoming line voltage before the successful phase locking are reversed, and the incoming line three-phase AC voltage signal before the successful phase locking is determined;

[0095] In one embodiment, based on the voltage phase at the moment of successful phase locking, the voltage amplitude and phase angle of the two-phase incoming line voltage before the moment of successful phase locking are reversed, including:

[0096] Obtain the constant value Mag0 of the incoming line voltage amplitude after pre-charging is completed;

[0097] According to a preset sampling period (eg, 1 kHz), the voltage amplitude and phase angle of the two-phase incoming line voltage before the phase locking is successful are reversed based on the incoming line voltage constant value Mag0 and the voltage phase Phy0 at the phase locking success time T0.

[0098] Since the amplitude of the line voltage is the phase voltage times, the line voltage phase angle leads the phase voltage by 30°. Therefore, based on the two-phase incoming line voltage before the phase lock is successful, the formula for determining the incoming three-phase AC voltage signal before the phase lock is successful is as follows:

[0099]

[0100]

[0101]

[0102] Where Uu(t), Uv(t), and Uw(t) are the three-phase AC voltage signals before phase locking is successful. The above formula is derived using the positive sequence as an example, but the derivation process and expression method for the negative sequence are the same.

[0103] In step 105, the pre-charging resistor is identified based on the incoming three-phase AC voltage signal before the phase locking is successful.

[0104] In one embodiment, identifying the pre-charge resistor based on the incoming three-phase AC voltage signal before the phase lock is successful includes:

[0105] Determine the three-phase pre-charging resistance of the incoming line according to the three-phase AC voltage signal of the incoming line before the phase locking is successful and the three-phase AC current signal whose absolute value of the instantaneous value is greater than a preset ratio (for example, 0.2%);

[0106] The least square method is used to perform linear fitting on the three-phase pre-charging resistance of the incoming line, and the fitting result is determined as the pre-charging resistance identification result.

[0107] According to Ohm's law U=IR, the formula corresponding to the three-phase pre-charging resistors Ru, Rv, and Rw can be derived as follows:

[0108] Uu(t)-Udc(t)=Ru(t)·Iu(t)

[0109] Uv(t)-Udc(t)=Rv(t)·Iv(t)

[0110] Uw(t)-Udc(t)=Rw(t)·Iw(t)

[0111] Finally, the formula for the incoming three-phase pre-charging resistance can be determined:

[0112]

[0113]

[0114]

[0115] Among them, Ru(t), Rv(t), and Rw(t) are the three-phase pre-charging resistors of the incoming line, Uu(t), Uv(t), and Uw(t) are the three-phase AC voltage signals before the phase locking is successful, Iu(t), Iv(t), and Iw(t) are the three-phase AC current signals, and Udc(t) is the DC bus voltage.

[0116] Due to errors in the analog sampling and identification algorithm process, the results of the pre-charge resistance calculation will fluctuate. Therefore, for the pre-charge resistance calculated above, the least squares method is used for linear fitting, and the fitting results are the pre-charge resistance identification results Ru(t), Rv(t), and Rw(t).

[0117] The specific application of the method proposed in the embodiment of the present invention is illustrated by taking the pre-charging process of an on-site rectifier device of a certain steel enterprise as an example.

[0118] Figure 3 is the two-phase incoming line voltage collected in the embodiment of the present invention, Figure 4 is the phase difference between the two-phase incoming line voltages after filtering in the embodiment of the present invention. The determined phase-locked success time is 0.1s. Table 1 shows the values ​​of the phase difference.

[0119] Table 1

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131] The least square method was used to fit the above phase difference, and the root mean square error was 1.75. Figure 5 This is the fitting result obtained by fitting the phase difference using the least squares method in an embodiment of the present invention. It can be seen that the phase identification result is very good, the signal coincidence is very high, the voltage phase Phy0 at the moment of successful phase locking is 100°, and the constant value of the incoming voltage amplitude Mag0 is 104.8158. Figure 6 is the voltage amplitude and phase angle of the two-phase incoming line voltage before the successful phase locking in the embodiment of the present invention, Figure 7 are the DC bus voltage and the incoming line current in the embodiment of the present invention, and the final pre-charging resistance identification results are Ru=2.03, Rv=1.99, and Rw=2.15.

[0132] In summary, in the method proposed in the embodiment of the present invention, during the pre-charging process of the high-power rectifier, the two-phase incoming line voltage is collected; the phase difference of the two-phase incoming line voltage is obtained; based on the phase difference, the moment of successful phase locking is determined, and the voltage phase at the moment of successful phase locking is obtained; based on the voltage phase at the moment of successful phase locking, the voltage amplitude and phase angle of the two-phase incoming line voltage before the moment of successful phase locking are reversed, and the incoming line three-phase AC voltage signal before the moment of successful phase locking is determined; based on the incoming line three-phase AC voltage signal before the moment of successful phase locking, the pre-charging resistor is identified. Through the above method, the moment of successful phase locking can be accurately determined, and then based on the voltage phase at the moment of successful phase locking, the voltage amplitude and phase angle of the two-phase incoming line voltage before the moment of successful phase locking can be accurately reversed, and finally the pre-charging resistor is accurately identified based on the incoming line three-phase AC voltage signal before the moment of successful phase locking.

[0133] The embodiment of the present invention further provides a pre-charging resistance identification device for a high-power rectifier, the principle of which is similar to the pre-charging resistance identification method for a high-power rectifier, and will not be described in detail here.

[0134] Figure 8 Schematic diagram of a pre-charge resistance identification device for a high-power rectifier according to an embodiment of the present invention, comprising:

[0135] The two-phase incoming line voltage acquisition module 801 is used to acquire the two-phase incoming line voltage during the pre-charging process of the high-power rectifier;

[0136] Phase difference obtaining module 802, used to obtain the phase difference between the line voltages of the two-phase incoming lines;

[0137] The phase locking module 803 is used to determine the phase locking success moment according to the phase difference and obtain the voltage phase at the phase locking success moment;

[0138] The two-phase incoming line voltage reverse calculation module 804 is used to reversely calculate the voltage amplitude and phase angle of the two-phase incoming line voltage before the phase lock is successful based on the voltage phase at the phase lock is successful, and determine the incoming line three-phase AC voltage signal before the phase lock is successful;

[0139] The pre-charging resistance identification module 805 is used to identify the pre-charging resistance according to the incoming three-phase AC voltage signal before the phase locking is successful.

[0140] In one embodiment, during the pre-charging process of the high-power rectifier, collecting the line voltages of two-phase incoming lines includes:

[0141] During the pre-charging process of the high-power rectifier, the two-phase incoming line voltage is collected with reference to the virtual neutral point, wherein the virtual neutral point is generated by the high-power rectifier's incoming line three-phase AC voltage signal after resistor voltage division.

[0142] In one embodiment, the apparatus further includes a filtering module 806 configured to:

[0143] Before obtaining the phase difference between the two-phase incoming line voltages, low-pass filtering is performed on the two-phase incoming line voltages to obtain filtered two-phase incoming line voltages;

[0144] Calculate the phase difference between the two-phase incoming line voltages after filtering.

[0145] In one embodiment, the filtering module 806 is specifically configured to:

[0146] The two-phase incoming line voltage is subjected to low-pass filtering and digital band-pass filtering in sequence to obtain filtered two-phase incoming line voltage.

[0147] In one embodiment, the phase difference obtaining module is specifically configured to:

[0148] Calculate the phase angle of each single-phase incoming line voltage in the filtered two-phase incoming line voltage;

[0149] The phase angle of the single-phase incoming line voltage Uvw is subtracted from the phase angle of the single-phase incoming line voltage Uuv to obtain the phase difference of the two-phase incoming line voltages after filtering.

[0150] In one embodiment, the phase difference obtaining module is specifically configured to:

[0151] Calculate the real and imaginary parts of each single-phase incoming line voltage based on the standard sine wave reference signal and the standard cosine wave reference signal;

[0152] The inverse tangent of the calculated real and imaginary parts is calculated to obtain the phase angle of the line voltage of each single-phase incoming line.

[0153] In one embodiment, the phase-locking module is specifically configured to:

[0154] Fitting the phase difference using a least squares method to obtain a fitting result;

[0155] According to the fitting results, the phase-locking success moment is determined, and the voltage phase at the phase-locking success moment is obtained.

[0156] In one embodiment, the phase locking module is specifically configured to:

[0157] The moment when the root mean square value of the deviation of the fitting result first falls below a preset threshold is determined as the moment when the phase locking is successful.

[0158] In one embodiment, the two-phase incoming line voltage reverse calculation module is specifically used to:

[0159] Obtaining a constant value of the incoming line voltage amplitude after pre-charging is completed;

[0160] According to the preset sampling period, based on the constant value of the incoming line voltage amplitude and the voltage phase at the time of successful phase locking, the voltage amplitude and phase angle of the two-phase incoming line voltage before the successful phase locking are reversed.

[0161] In one embodiment, the two-phase incoming line voltage reverse calculation module is specifically used to:

[0162] When the fluctuation range of the phase difference between the two-phase incoming line voltages is within a first preset range and the root mean square value of the phase difference deviation is less than a preset threshold, it is determined that the phase sequence of the two-phase incoming line voltages is positive sequence. The formula for the two-phase incoming line voltages before the phase lock is successful is as follows:

[0163]

[0164]

[0165] When the fluctuation range of the phase difference between the two-phase incoming line voltages is within the second preset range and the root mean square value of the phase difference deviation is less than the preset threshold, it is determined that the phase sequence of the two-phase incoming line voltages is negative sequence. The formula for the two-phase incoming line voltages before the phase lock is successful is as follows:

[0166]

[0167]

[0168] Where Uuv2(t) and Uvw2(t) are the two-phase incoming line voltages that change with time t and frequency f before the phase-locking success moment, T0 is the moment of successful phase-locking, Mag0 is the constant value of the incoming line voltage amplitude, and Phy0 is the voltage phase at the moment of successful phase-locking;

[0169] Based on the two-phase incoming line voltage before the phase lock is successful, the formula for determining the incoming three-phase AC voltage signal before the phase lock is successful is as follows:

[0170]

[0171]

[0172]

[0173] Among them, Uu(t), Uv(t), and Uw(t) are the three-phase AC voltage signals before the phase locking is successful.

[0174] In one embodiment, the pre-charge resistance identification module is specifically configured to:

[0175] Determine the three-phase pre-charging resistance of the incoming line according to the three-phase AC voltage signal of the incoming line before the phase locking is successful and the three-phase AC current signal whose absolute value of the instantaneous value is greater than the preset ratio;

[0176] The least square method is used to perform linear fitting on the three-phase pre-charging resistance of the incoming line, and the fitting result is determined as the pre-charging resistance identification result.

[0177] In one embodiment, the pre-charge resistance identification module is specifically configured to:

[0178] Use the following formula to determine the three-phase pre-charging resistance of the incoming line:

[0179]

[0180]

[0181]

[0182] Among them, Ru(t), Rv(t), and Rw(t) are the three-phase pre-charging resistors of the incoming line, Uu(t), Uv(t), and Uw(t) are the three-phase AC voltage signals before the phase locking is successful, Iu(t), Iv(t), and Iw(t) are the three-phase AC current signals, and Udc(t) is the DC bus voltage.

[0183] In summary, in the device proposed in the embodiment of the present invention, the two-phase incoming line voltage acquisition module is used to collect the two-phase incoming line voltage during the pre-charging process of the high-power rectifier; the phase difference acquisition module is used to obtain the phase difference of the two-phase incoming line voltage; the phase locking module is used to determine the phase locking success moment according to the phase difference and obtain the voltage phase at the phase locking success moment; the two-phase incoming line voltage reverse calculation module is used to reverse the voltage amplitude and phase angle of the two-phase incoming line voltage before the phase locking success moment according to the voltage phase at the phase locking success moment, and determine the incoming line three-phase AC voltage signal before the phase locking success moment; the pre-charging resistance identification module is used to identify the pre-charging resistance according to the incoming line three-phase AC voltage signal before the phase locking success moment. Through the above method, the phase locking success moment can be accurately determined, and then the voltage amplitude and phase angle of the two-phase incoming line voltage before the phase locking success moment can be accurately reversed according to the voltage phase at the phase locking success moment, and finally the pre-charging resistance can be accurately identified according to the incoming line three-phase AC voltage signal before the phase locking success moment.

[0184] Based on the above invention concept, Figure 9 As shown, an embodiment of the present invention further provides a computer device 900, including a memory 910, a processor 920, and a computer program 930 stored in the memory 910 and executable on the processor 920. When the processor 920 executes the computer program 930, the above-mentioned method for identifying the pre-charging resistance of the high-power rectifier is implemented.

[0185] Based on the aforementioned inventive concept, an embodiment of the present invention further provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the method for identifying the pre-charging resistance of the high-power rectifier is implemented.

[0186] An embodiment of the present invention further provides a computer program product, which includes a computer program. When the computer program is executed by a processor, the computer program implements the above-mentioned method for identifying the pre-charging resistance of the high-power rectifier.

[0187] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0188] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0189] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0190] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0191] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for identifying the pre-charge resistance of a high-power rectifier, characterized in that: include: During the pre-charging process of the high-power rectifier, the two-phase incoming line voltage is collected; Obtain the phase difference between the two-phase incoming line voltages; Determining a phase-locked success moment according to the phase difference, and obtaining a voltage phase at the phase-locked success moment; According to the voltage phase at the moment of successful phase locking, the voltage amplitude and phase angle of the two-phase incoming line voltage before the moment of successful phase locking are reversed, and the incoming line three-phase AC voltage signal before the moment of successful phase locking is determined; Identify the pre-charging resistance based on the incoming three-phase AC voltage signal before the phase lock is successful; Reversely calculating the voltage amplitude and phase angle of the two-phase incoming line voltage before the phase lock is successful based on the voltage phase at the time of successful phase lock, including: obtaining a constant value of the incoming line voltage amplitude after precharging is completed; and reversely calculating the voltage amplitude and phase angle of the two-phase incoming line voltage before the phase lock is successful based on the constant value of the incoming line voltage amplitude and the voltage phase at the time of successful phase lock according to a preset sampling period; When the fluctuation range of the phase difference between the two-phase incoming line voltages is within a first preset range and the root mean square value of the phase difference deviation is less than a preset threshold, it is determined that the phase sequence of the two-phase incoming line voltages is positive sequence. The formula for the two-phase incoming line voltages before the phase lock is successful is as follows: When the fluctuation range of the phase difference between the two-phase incoming line voltages is within the second preset range and the root mean square value of the phase difference deviation is less than the preset threshold, it is determined that the phase sequence of the two-phase incoming line voltages is negative sequence. The formula for the two-phase incoming line voltages before the phase lock is successful is as follows: Where Uuv2(t) and Uvw2(t) are the two-phase incoming line voltages that change with time t and frequency f before the phase-locking success moment, T0 is the moment of successful phase-locking, Mag0 is the constant value of the incoming line voltage amplitude, and Phy0 is the voltage phase at the moment of successful phase-locking; Based on the constant value of the incoming line voltage amplitude and the voltage phase at the time of successful phase locking, the voltage amplitude and phase angle of the two-phase incoming line voltage before the successful phase locking are reversed, and the incoming line three-phase AC voltage signal before the successful phase locking is determined, including: Based on the two-phase incoming line voltage before the phase lock is successful, the formula for determining the incoming three-phase AC voltage signal before the phase lock is successful is as follows: Among them, Uu(t), Uv(t), and Uw(t) are the three-phase AC voltage signals before the phase locking is successful.

2. The method according to claim 1, wherein During the pre-charging process of the high-power rectifier, the two-phase incoming line voltage is collected, including: During the pre-charging process of the high-power rectifier, the two-phase incoming line voltage is collected with reference to the virtual neutral point, wherein the virtual neutral point is generated by the high-power rectifier's incoming line three-phase AC voltage signal after resistor voltage division.

3. The method according to claim 1, wherein Before obtaining the phase difference between the two-phase incoming line voltages, the following steps are also included: performing low-pass filtering on the two-phase incoming line voltage to obtain filtered two-phase incoming line voltage; Calculate the phase difference between the two-phase incoming line voltages after filtering.

4. The method according to claim 3, wherein Performing low-pass filtering on the two-phase incoming line voltage to obtain filtered two-phase incoming line voltage includes: The two-phase incoming line voltage is subjected to low-pass filtering and digital band-pass filtering in sequence to obtain filtered two-phase incoming line voltage.

5. The method according to claim 3, wherein Obtain the phase difference between the two-phase incoming line voltages, including: Calculate the phase angle of each single-phase incoming line voltage in the filtered two-phase incoming line voltage; The phase angle of the single-phase incoming line voltage Uvw is subtracted from the phase angle of the single-phase incoming line voltage Uuv to obtain the phase difference of the two-phase incoming line voltages after filtering.

6. The method according to claim 5, wherein Calculate the phase angle of each single-phase incoming line voltage in the filtered two-phase incoming line voltage, including: Calculate the real and imaginary parts of each single-phase incoming line voltage based on the standard sine wave reference signal and the standard cosine wave reference signal; The inverse tangent of the calculated real and imaginary parts is calculated to obtain the phase angle of the line voltage of each single-phase incoming line.

7. The method according to claim 1, wherein Determining a phase-lock success moment according to the phase difference includes: Fitting the phase difference using a least squares method to obtain a fitting result; According to the fitting results, the phase-locking success moment is determined, and the voltage phase at the phase-locking success moment is obtained.

8. The method according to claim 7, wherein According to the fitting results, determine the phase-locking success moment, including: The moment when the root mean square value of the deviation of the fitting result first falls below a preset threshold is determined as the moment when the phase locking is successful.

9. The method according to claim 1, wherein Identify the pre-charge resistance based on the incoming three-phase AC voltage signal before the phase lock is successful, including: Determine the three-phase pre-charging resistance of the incoming line according to the three-phase AC voltage signal of the incoming line before the phase locking is successful and the three-phase AC current signal whose absolute value of the instantaneous value is greater than the preset ratio; The least square method is used to perform linear fitting on the three-phase pre-charging resistance of the incoming line, and the fitting result is determined as the pre-charging resistance identification result.

10. The method according to claim 9, wherein Use the following formula to determine the three-phase pre-charging resistance of the incoming line: Among them, Ru(t), Rv(t), and Rw(t) are the three-phase pre-charging resistors of the incoming line, Uu(t), Uv(t), and Uw(t) are the three-phase AC voltage signals before the phase locking is successful, Iu(t), Iv(t), and Iw(t) are the three-phase AC current signals, and Udc(t) is the DC bus voltage.

11. A pre-charge resistance identification device for a high-power rectifier, characterized in that: include: Two-phase incoming line voltage acquisition module, used to collect the two-phase incoming line voltage during the pre-charging process of the high-power rectifier; Phase difference acquisition module, used to obtain the phase difference between the two-phase incoming line voltages; A phase locking module, configured to determine a phase locking success moment according to the phase difference, and obtain the voltage phase at the phase locking success moment; The two-phase incoming line voltage reverse calculation module is used to reversely calculate the voltage amplitude and phase angle of the two-phase incoming line voltage before the phase lock is successful based on the voltage phase at the phase lock is successful, and determine the incoming line three-phase AC voltage signal before the phase lock is successful; A pre-charging resistance identification module is used to identify the pre-charging resistance based on the incoming three-phase AC voltage signal before the phase locking is successful; Reversely calculating the voltage amplitude and phase angle of the two-phase incoming line voltage before the phase lock is successful based on the voltage phase at the time of successful phase lock, including: obtaining a constant value of the incoming line voltage amplitude after precharging is completed; and reversely calculating the voltage amplitude and phase angle of the two-phase incoming line voltage before the phase lock is successful based on the constant value of the incoming line voltage amplitude and the voltage phase at the time of successful phase lock according to a preset sampling period; When the fluctuation range of the phase difference between the two-phase incoming line voltages is within a first preset range and the root mean square value of the phase difference deviation is less than a preset threshold, it is determined that the phase sequence of the two-phase incoming line voltages is positive sequence. The formula for the two-phase incoming line voltages before the phase lock is successful is as follows: When the fluctuation range of the phase difference between the two-phase incoming line voltages is within the second preset range and the root mean square value of the phase difference deviation is less than the preset threshold, it is determined that the phase sequence of the two-phase incoming line voltages is negative sequence. The formula for the two-phase incoming line voltages before the phase lock is successful is as follows: Where Uuv2(t) and Uvw2(t) are the two-phase incoming line voltages that change with time t and frequency f before the phase-locking success moment, T0 is the moment of successful phase-locking, Mag0 is the constant value of the incoming line voltage amplitude, and Phy0 is the voltage phase at the moment of successful phase-locking; Based on the constant value of the incoming line voltage amplitude and the voltage phase at the time of successful phase locking, the voltage amplitude and phase angle of the two-phase incoming line voltage before the successful phase locking are reversed, and the incoming line three-phase AC voltage signal before the successful phase locking is determined, including: Based on the two-phase incoming line voltage before the phase lock is successful, the formula for determining the incoming three-phase AC voltage signal before the phase lock is successful is as follows: Among them, Uu(t), Uv(t), and Uw(t) are the three-phase AC voltage signals before the phase locking is successful.

12. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the method according to any one of claims 1 to 10 is implemented.

13. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 10 is implemented.

14. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 10 is implemented.

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