A three-phase full-rectification system, a control method and device thereof and a storage medium

Abstract

This invention discloses a control method, device, system, and storage medium for a three-phase fully controlled rectifier system. The method includes: sampling the line voltage between any two phase voltages of the three-phase AC output from the power grid to obtain a single-line voltage, denoted as the single-line voltage of the power grid; sampling the three-phase current at the input of the three-phase fully controlled rectifier bridge and sampling the bus voltage at the output of the bridge; determining the phase of the grid voltage based on the single-line voltage; and controlling the operation of the three-phase fully controlled rectifier bridge based on the phase of the grid voltage, the three-phase current, and the bus voltage. This scheme, by acquiring a single-line voltage signal from the three-phase power grid and obtaining the grid voltage phase based on this signal, avoids the failure of the three-phase fully controlled rectifier system to operate due to sampling failure of the single-line voltage or phase voltage, thus improving the fault tolerance of the system.

Description

Technical Field

[0001] This invention belongs to the technical field of three-phase fully controlled rectifier systems, specifically relating to a control method, device, three-phase fully controlled rectifier system, and storage medium for a three-phase fully controlled rectifier system, and particularly to a method, device, three-phase fully controlled rectifier system, and storage medium for obtaining the grid voltage phase of a single-voltage sampling three-phase fully controlled rectifier system. Background Technology

[0002] Three-phase fully controlled rectifier systems not only enable adjustable bus voltage but also correct the power factor at the input, making them widely used in grid-connected inverters and applications with high requirements for input current harmonics. One key aspect of fully controlled rectification in a three-phase fully controlled rectifier system is obtaining the phase of the grid voltage; among related solutions, one method for obtaining the phase of the grid voltage is the phase voltage locked loop (PLL) method based on dq transformation.

[0003] However, when using the phase-locked loop (PLL) method based on dq transformation to obtain the phase of the grid voltage, at least two line voltages or phase voltages need to be collected. If the sampling of one of the line voltages or phase voltages fails, the three-phase fully controlled rectifier system will not be able to operate, resulting in poor fault tolerance of the three-phase fully controlled rectifier system.

[0004] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The purpose of this invention is to provide a control method, device, system, and storage medium for a three-phase fully controlled rectifier system. This addresses the problem that when using a phase-locked loop (PLL) method based on dq transformation to obtain the phase of the grid voltage, at least two line voltages or phase voltages need to be sampled. Furthermore, if the sampling of one of these line voltages or phase voltages fails, the three-phase fully controlled rectifier system will be unable to operate, resulting in poor fault tolerance. The invention achieves this by sampling one line voltage signal from the three-phase grid and obtaining the grid voltage phase based on that signal. This avoids the system failing to operate due to the sampling failure of one line voltage or phase voltage, thus improving the fault tolerance of the three-phase fully controlled rectifier system.

[0006] This invention provides a control method for a three-phase fully controlled rectifier system. The three-phase fully controlled rectifier system includes: a three-phase fully controlled rectifier bridge; three-phase AC power supplied by the power grid; the input terminal of the three-phase fully controlled rectifier bridge being connected to the output terminal of the three-phase AC power supplied by the power grid; the output terminal of the three-phase fully controlled rectifier bridge being connected to the bus voltage output terminal of the three-phase fully controlled rectifier system; and the control method for the three-phase fully controlled rectifier system including: sampling the line voltage between any two phase voltages of the three-phase phase voltages output by the three-phase AC power supplied by the power grid. The single-line voltage of the power grid is obtained by sampling the input current of the three-phase fully controlled rectifier bridge and the output bus voltage of the three-phase fully controlled rectifier bridge. The phase of the power grid voltage is determined based on the single-line voltage of the power grid. The operation of the three-phase fully controlled rectifier bridge is controlled based on the phase of the power grid voltage, the three-phase current at the input of the three-phase fully controlled rectifier bridge, and the output bus voltage of the three-phase fully controlled rectifier bridge, so as to realize the control of the three-phase fully controlled rectifier system.

[0007] In some implementations, determining the phase of the grid voltage based on the single-line voltage of the grid includes: separating two orthogonal signals with the same amplitude and containing only the fundamental component from the single-line voltage of the grid; performing phase-locked loop processing on the two orthogonal signals to obtain the phase of the grid voltage.

[0008] In some implementations, separating two orthogonal signals with the same amplitude and containing only the fundamental component from a single line voltage of the power grid includes: processing the single line voltage of the power grid using the following formula (1) to separate two orthogonal signals with the same amplitude and containing only the fundamental component:

[0009]

[0010] Where k is the gain coefficient, ω0 is the fundamental angular frequency, u is the single-line voltage of the power grid, u0 is one of two orthogonal signals with the same amplitude and containing only the fundamental component, and qu0 is the other orthogonal signal with the same amplitude and containing only the fundamental component.

[0011] In some embodiments, phase-locked loop processing is performed on the two orthogonal signals to obtain the phase of the grid voltage, including: processing the two orthogonal signals using the following formulas (2) and (3) to obtain the angular frequency of the grid voltage; and processing the angular frequency of the grid voltage using the following formula (4) to obtain the phase of the grid voltage; wherein,

[0012]

[0013]

[0014]

[0015] Where U represents the magnitude of the grid phase voltage, (θ represents the actual phase of the grid phase voltage, This indicates the estimated phase of the grid phase voltage, where Δ represents the deviation. The angular frequency of the grid phase voltage meter, k p It is the proportionality coefficient, k i It is the integral coefficient.

[0016] In some implementations, the operation of the three-phase fully controlled rectifier bridge is controlled based on the phase of the grid voltage, the three-phase current at the input of the three-phase fully controlled rectifier bridge, and the bus voltage at the output of the three-phase fully controlled rectifier bridge to achieve control of the three-phase fully controlled rectifier system. This includes: determining a PWM wave signal based on the phase of the grid voltage, the three-phase current at the input of the three-phase fully controlled rectifier bridge, and the bus voltage at the output of the three-phase fully controlled rectifier bridge; and controlling the switching transistors in the three-phase fully controlled rectifier bridge based on the PWM wave signal to control the operation of the three-phase fully controlled rectifier bridge and achieve control of the three-phase fully controlled rectifier system.

[0017] In conjunction with the above method, another aspect of the present invention provides a control device for a three-phase fully controlled rectifier system, the three-phase fully controlled rectifier system comprising: a three-phase fully controlled rectifier bridge; three-phase AC power supplied by the power grid, the input terminal of the three-phase fully controlled rectifier bridge being connected to the output terminal of the three-phase AC power supplied by the power grid; the output terminal of the three-phase fully controlled rectifier bridge being connected to the bus voltage output terminal of the three-phase fully controlled rectifier system; the control device for the three-phase fully controlled rectifier system comprising: a sampling unit configured to sample the line voltage between any two phase voltages of the three-phase phase voltages output by the three-phase AC power supplied by the power grid. The voltage is obtained by sampling a single-line voltage, which is denoted as the single-line voltage of the power grid. The three-phase current at the input terminal of the three-phase fully controlled rectifier bridge is sampled, and the bus voltage at the output terminal of the three-phase fully controlled rectifier bridge is sampled. The control unit is configured to determine the phase of the power grid voltage based on the single-line voltage of the power grid. The control unit is also configured to control the operation of the three-phase fully controlled rectifier bridge based on the phase of the power grid voltage, the three-phase current at the input terminal of the three-phase fully controlled rectifier bridge, and the bus voltage at the output terminal of the three-phase fully controlled rectifier bridge, so as to realize the control of the three-phase fully controlled rectifier system.

[0018] In some embodiments, the control unit determines the phase of the grid voltage based on the single-line voltage of the grid by: separating two orthogonal signals with the same amplitude and containing only the fundamental component from the single-line voltage of the grid; and performing phase-locked loop processing on the two orthogonal signals to obtain the phase of the grid voltage.

[0019] In some embodiments, the control unit separates two orthogonal signals with the same amplitude and containing only the fundamental component from a single line voltage of the power grid, including: processing the single line voltage of the power grid using the following formula (1) to separate two orthogonal signals with the same amplitude and containing only the fundamental component:

[0020]

[0021] Where k is the gain coefficient, ω0 is the fundamental angular frequency, u is the single-line voltage of the power grid, u0 is one of two orthogonal signals with the same amplitude and containing only the fundamental component, and qu0 is the other orthogonal signal with the same amplitude and containing only the fundamental component.

[0022] In some embodiments, the control unit performs phase-locked loop processing on the two orthogonal signals to obtain the phase of the grid voltage, including: processing the two orthogonal signals using the following formulas (2) and (3) to obtain the angular frequency of the grid voltage; and processing the angular frequency of the grid voltage using the following formula (4) to obtain the phase of the grid voltage; wherein,

[0023]

[0024]

[0025]

[0026] Where U represents the magnitude of the grid phase voltage, (θ represents the actual phase of the grid phase voltage, This indicates the estimated phase of the grid phase voltage, where Δ represents the deviation. The angular frequency of the grid phase voltage meter, k p It is the proportionality coefficient, k i It is the integral coefficient.

[0027] In some embodiments, the control unit controls the operation of the three-phase fully controlled rectifier bridge based on the phase of the grid voltage, the three-phase current at the input of the three-phase fully controlled rectifier bridge, and the bus voltage at the output of the three-phase fully controlled rectifier bridge, to achieve control of the three-phase fully controlled rectifier system. This includes: determining a PWM wave signal based on the phase of the grid voltage, the three-phase current at the input of the three-phase fully controlled rectifier bridge, and the bus voltage at the output of the three-phase fully controlled rectifier bridge; and controlling the switching transistors in the three-phase fully controlled rectifier bridge based on the PWM wave signal to control the operation of the three-phase fully controlled rectifier bridge and achieve control of the three-phase fully controlled rectifier system.

[0028] In conjunction with the above-mentioned device, the present invention further provides a three-phase fully controlled rectifier system, comprising: the control device for the three-phase fully controlled rectifier system described above.

[0029] In conjunction with the above method, the present invention further provides a storage medium comprising a stored program, wherein, when the program is executed, the device containing the storage medium is controlled to perform the control method of the three-phase fully controlled rectifier system described above.

[0030] Therefore, the solution of this invention acquires the bus voltage signal, three-phase current signal, and a line voltage signal. The line voltage signal is then processed by an orthogonal signal generator composed of a second-order generalized integrator to separate two orthogonal signals with the same amplitude and containing only the fundamental component. These two orthogonal signals are then processed by a PLL to obtain the accurate grid voltage phase. Furthermore, a PWM wave signal is determined based on the bus voltage signal, three-phase current signal, and grid voltage phase. This PWM wave signal is used to control the switching transistors of the three-phase full-bridge rectifier bridge, achieving high-performance three-phase fully controlled rectification control. Thus, by acquiring the line voltage signal of the three-phase grid and obtaining the grid voltage phase based on this line voltage signal, the failure of sampling the line voltage or phase voltage can be avoided, preventing the three-phase fully controlled rectifier system from failing to operate and improving the fault tolerance of the three-phase fully controlled rectifier system.

[0031] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention.

[0032] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0033] Figure 1 This is a flowchart illustrating an embodiment of the control method for the three-phase fully controlled rectifier system of the present invention;

[0034] Figure 2This is a schematic flowchart of an embodiment of the method of the present invention for determining the phase of the power grid voltage based on the single-line voltage of the power grid;

[0035] Figure 3 This is a schematic flowchart of an embodiment of the method of the present invention, which involves phase-locked loop processing of the two orthogonal signals to obtain the phase of the grid voltage.

[0036] Figure 4 This is a schematic flowchart of an embodiment of the method of the present invention, which controls the operation of the three-phase fully controlled rectifier bridge according to the phase of the grid voltage, the three-phase current and the bus voltage.

[0037] Figure 5 This is a schematic diagram of the structure of a control device for a three-phase fully controlled rectifier system according to an embodiment of the present invention;

[0038] Figure 6 A schematic diagram of an embodiment of a three-phase fully controlled rectifier system;

[0039] Figure 7 A schematic diagram of one embodiment of a line voltage sampling circuit;

[0040] Figure 8 This is a schematic diagram of one embodiment of the voltage phase calculation module;

[0041] Figure 9 A schematic diagram illustrating the workflow of an embodiment of a second-order generalized integral quadrature signal generator;

[0042] Figure 10 This is a schematic diagram of the workflow of one embodiment of a phase-locked loop (PLL).

[0043] Referring to the accompanying drawings, the reference numerals in the embodiments of the present invention are as follows:

[0044] 102 - Sampling unit; 104 - Control unit. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0046] Considering that obtaining the phase of the grid voltage using the phase-locked loop (PLL) method based on dq transformation requires sampling at least two line voltages or phase voltages, the three-phase fully controlled rectifier system will fail to operate if the sampling of one of these line voltages or phase voltages fails, resulting in poor fault tolerance. Furthermore, when harmonics are present in the grid voltage, the dq transformation-based PLL method will be unable to obtain an accurate phase of the grid voltage, ultimately affecting the performance of the three-phase fully controlled rectifier system.

[0047] Therefore, the present invention proposes a control method for a three-phase fully controlled rectifier system, specifically a method for obtaining the grid voltage phase of a three-phase fully controlled rectifier system using single-voltage sampling. This method involves acquiring the bus voltage signal, three-phase current signal, and a line voltage signal. The line voltage signal is then processed by an orthogonal signal generator composed of a second-order generalized integrator to separate two orthogonal signals with the same amplitude and containing only the fundamental component. These two orthogonal signals are then processed by a PLL to obtain the accurate grid voltage phase. Furthermore, a PWM wave signal is determined based on the bus voltage signal, three-phase current signal, and grid voltage phase. This PWM wave signal is then used to control the switching transistors of the three-phase full-bridge rectifier bridge, achieving three-phase fully controlled rectification. Since the line voltage signal... When acquiring the signal, only one line voltage signal needs to be collected. If the acquisition of one line voltage signal fails, other line voltage signals can be collected. This avoids the three-phase fully controlled rectifier system failing to operate due to the sampling failure of one line voltage or phase voltage. It can realize three-phase fully controlled rectifier control under single voltage (i.e., single line voltage) sampling. For the fully controlled rectifier system based on multi-phase voltage sampling in related schemes, it can still ensure the effective operation of the three-phase fully controlled rectifier system even if some voltage sampling fails, which is beneficial to improving the fault tolerance of the three-phase fully controlled rectifier system. At the same time, it can solve the problem of accurate voltage phase acquisition when there are harmonics in the grid voltage, which is beneficial to improving the performance and reliability of the three-phase fully controlled rectifier system.

[0048] According to an embodiment of the present invention, a control method for a three-phase fully controlled rectifier system is provided, such as... Figure 1 The diagram shows a flowchart of an embodiment of the method of the present invention. The three-phase fully controlled rectifier system includes: a three-phase fully controlled rectifier bridge; three-phase AC power is provided by the power grid, the input terminal of the three-phase fully controlled rectifier bridge is connected to the output terminal of the three-phase AC power provided by the power grid; the output terminal of the three-phase fully controlled rectifier bridge is connected to the bus voltage output terminal of the three-phase fully controlled rectifier system.

[0049] Specifically, Figure 6 This is a schematic diagram of an embodiment of a three-phase fully controlled rectifier system. Figure 6As shown, the output terminal of the three-phase AC power supplied by the power grid can output three-phase voltages a, b, and c, with phase a voltage being u. sa The voltage of phase b is u sb The voltage of phase c is u sc Phase a voltage u sa Through resistor R a and inductor L a The voltage of phase b is then input to the first input terminal of the three-phase fully controlled rectifier bridge. sb Through resistor R b and inductor L b The voltage is then input to the second input terminal of the three-phase fully controlled rectifier bridge, and the voltage of phase c is u. sc Through resistor R c and inductor L c The voltage is then input to the third input terminal of the three-phase fully controlled rectifier bridge. The output of the three-phase fully controlled rectifier bridge outputs the bus voltage after passing through the bus capacitor. Phase a voltage u sa Phase b voltage u sb The voltage of phase c is u sc Any two phase voltages are connected to the input of a single-line voltage sampling module, and the inductor L... a Inductor L b and inductor L c The output terminal of the bus capacitor is connected to the input terminal of the three-phase current sampling module, the output terminal of the bus capacitor is connected to the input terminal of the bus voltage sampling module, and the output terminals of the voltage phase calculation module, the three-phase current sampling module, and the bus voltage sampling module are respectively connected to the full-control rectifier control module in the main control system.

[0050] like Figure 1 As shown, the control method of the three-phase fully controlled rectifier system includes steps S110 to S130.

[0051] In step S110, when it is necessary to control the three-phase fully controlled rectifier bridge, the line voltage between any two phase voltages of the three-phase phase voltages output by the three-phase AC power supplied by the power grid is sampled to obtain the single-line voltage, which is recorded as the single-line voltage of the power grid; the three-phase current at the input terminal of the three-phase fully controlled rectifier bridge is sampled, and the bus voltage at the output terminal of the three-phase fully controlled rectifier bridge is sampled.

[0052] Specifically, Figure 7 This is a schematic diagram of one embodiment of a line voltage sampling circuit. Figure 8 This is a schematic diagram of one embodiment of the voltage phase calculation module. The voltage phase calculation of this invention only requires single-channel voltage sampling, typically line voltage. In actual line voltage sampling, the line voltage between any two of the three phases (a, b, and c) can be sampled. Taking the line voltage of phase BC as an example, the sampling circuit for single-channel voltage sampling is as follows: Figure 7As shown, the collected single-line voltage is input to... Figure 8 In the voltage phase calculation module shown.

[0053] like Figure 7 As shown, the line voltage sampling circuit includes: resistors R1, R2, R3, R4, and R5; capacitors C1, C2, C3, C4, and C5; and a comparator. Phase b of the grid voltage, after passing through resistor R2, is grounded to phase A via capacitor C2. GND On the other hand, it is connected to the non-inverting input of the comparator; the non-inverting input of the comparator is also connected in parallel with resistor R4 and capacitor C4, which is then connected to the reference voltage V. ref The c-phase voltage from the mains, after passing through resistor R1, is grounded via capacitor C1. GND On the other hand, it is connected to the inverting input of the comparator; the inverting input of the comparator is also connected to the output of the comparator via a parallel capacitor C5 and a resistor R5. The output of the comparator is then connected to the line voltage u via a resistor R3. ac Line voltage u ac The output terminal is also grounded after passing through capacitor C3. GND .

[0054] In step S120, the phase of the grid voltage is determined based on the single-line voltage of the grid.

[0055] Specifically, such as Figure 8 As shown, the voltage phase calculation module includes a second-order generalized integrator quadrature signal generator and a phase-locked loop (PLL). The input to this voltage phase calculation module is the acquired single-channel grid line voltage, and the output is the phase of the grid voltage. Specifically, the single-channel line voltage output from the line voltage sampling circuit is input to the second-order generalized integrator quadrature signal generator. In the second-order generalized integrator quadrature signal generator, two quadrature signals with the same amplitude and containing only the fundamental component are separated by the quadrature signal generator composed of a second-order generalized integrator. These two quadrature signals are then input to the PLL, and the PLL processes the two quadrature signals to obtain the accurate grid voltage phase.

[0056] In the relevant scheme, calculating the grid voltage phase requires acquiring at least two grid voltage signals (such as line voltage or phase voltage) for phase-locked loop (PLL) operation. This involves acquiring two voltage signals, then using Clark coordinate transformation to obtain two voltage signals with a 90° phase difference. Finally, PLL processing is performed on these two voltage signals with a 90° phase difference to obtain the accurate grid voltage phase. However, the hardware cost for obtaining two voltage signals with a 90° phase difference through Clark coordinate transformation is relatively high. Furthermore, if the sampling of either the line voltage or the phase voltage fails, the three-phase fully controlled rectifier system will be unable to operate.

[0057] In the present invention, only one line voltage signal is collected, and then two voltage signals with a 90° phase difference are separated by a second-order generalized integrator quadrature signal generator. The accurate grid voltage phase is then obtained by PLL processing of the two voltage signals with a 90° phase difference. Since only one line voltage signal needs to be separated into two voltage signals with a 90° phase difference by the second-order generalized integrator quadrature signal generator, compared with the fully controlled rectifier system based on multi-phase voltage sampling in related schemes, hardware sampling circuits can be saved, resulting in lower hardware costs. In addition, the present invention can still ensure the effective operation of the three-phase fully controlled control system even if some voltage sampling fails, improving the fault tolerance of the three-phase fully controlled control system and avoiding the failure of the three-phase fully controlled rectifier system due to the sampling failure of one line voltage or phase voltage.

[0058] In some implementations, the specific process of determining the phase of the grid voltage based on the single-line voltage of the grid in step S120 is described in the following exemplary description.

[0059] The following is combined with Figure 2 The schematic diagram shown is a flowchart of an embodiment of the method of the present invention for determining the phase of the grid voltage based on the single-line voltage of the grid. The specific process of determining the phase of the grid voltage based on the single-line voltage of the grid in step S120 is further explained, including steps S210 to S220.

[0060] Step S210: Separate two orthogonal signals with the same amplitude and containing only the fundamental component from the single-line voltage of the power grid. Specifically, a second-order generalized integral orthogonal signal generator is used to separate two orthogonal signals with the same amplitude and containing only the fundamental component from the single-line voltage of the power grid.

[0061] In some implementations, separating two orthogonal signals with the same amplitude and containing only the fundamental component from the single-line voltage of the power grid in step S210 includes: processing the single-line voltage of the power grid using the following formula (1) to separate two orthogonal signals with the same amplitude and containing only the fundamental component:

[0062]

[0063] Where k is the gain coefficient, ω0 is the fundamental angular frequency, u is the single-line voltage of the power grid, u0 is one of two orthogonal signals with the same amplitude and containing only the fundamental component, and qu0 is the other orthogonal signal with the same amplitude and containing only the fundamental component.

[0064] Specifically, Figure 9This is a schematic diagram illustrating the workflow of one embodiment of a second-order generalized integral quadrature signal generator. Figure 9 As shown, the second-order generalized integrator orthogonal signal generator separates two orthogonal signals with the same amplitude and containing only the fundamental component through the action of the orthogonal signal generator composed of the second-order generalized integrator. The transfer function used is shown in Equation (1). Its function is to separate the acquired single-line voltage u into two orthogonal signals with the same amplitude and containing only the fundamental component, namely an orthogonal signal u0 and another orthogonal signal qu0. The amplitude and phase of the fundamental component of the orthogonal signal u0 are the same as those of the original signal u, and the amplitude of the fundamental component of the other orthogonal signal qu0 is the same as those of the original signal u, but the phase lags by 90°.

[0065]

[0066] Where k is the gain coefficient, typically taken as 0.707. ω0 is the fundamental angular frequency.

[0067] Step S220: Phase-locked loop (PLL) processing is performed on the two orthogonal signals to obtain the phase of the grid voltage. Specifically, the phase of the grid voltage is obtained by performing PLL processing on the two orthogonal signals.

[0068] In some implementations, the specific process of performing phase-locked loop processing on the two orthogonal signals in step S220 to obtain the phase of the grid voltage is described in the following exemplary description.

[0069] The following is combined with Figure 3 The diagram shows a schematic flowchart of an embodiment of the method of the present invention in which the phase-locked loop is performed on the two orthogonal signals to obtain the phase of the grid voltage. The specific process of obtaining the phase of the grid voltage by performing phase-locked loop on the two orthogonal signals in step S220 is further explained, including steps S310 to S320.

[0070] In step S310, the two orthogonal signals are processed using the following formulas (2) and (3) to obtain the angular frequency of the grid voltage.

[0071] Step S320: The angular frequency of the grid voltage is processed using the following formula (4) to obtain the phase of the grid voltage.

[0072] in,

[0073]

[0074]

[0075]

[0076] Where U represents the magnitude of the grid phase voltage, (θ represents the actual phase of the grid phase voltage, This indicates the estimated phase of the grid phase voltage, where Δ represents the deviation. The angular frequency of the grid phase voltage meter, k p It is the proportionality coefficient, k i It is the integral coefficient.

[0077] Specifically, Figure 10 This is a schematic diagram illustrating the workflow of one embodiment of a phase-locked loop (PLL). Figure 10 As shown, the phase-locked loop (PLL) processes the two input quadrature signals u0 and qu0 to obtain the accurate grid voltage phase. Specifically, since the bc line voltage is at the zero-crossing point of the rising edge when the grid voltage phase is 0, the two quadrature signals u0 and qu0 output by the second-order generalized integrator quadrature signal generator are first calculated according to equation (2), and then the calculation result is adjusted by PI according to equation (3) to obtain the grid voltage angular frequency. Finally, the grid voltage phase is obtained by integrating the grid voltage angular frequency according to equation (4).

[0078]

[0079]

[0080]

[0081] Where U represents the magnitude of the grid phase voltage, (θ represents the actual phase of the grid phase voltage, This indicates the estimated phase of the grid phase voltage, where Δ represents the deviation. This represents the angular frequency of the grid phase voltage meter. k p It is the proportionality coefficient, k i It is the integral coefficient.

[0082] Of course, see Figures 6 to 10 In the example shown, if the collected line voltage is the line voltage of phase ab or phase ca, the grid voltage phase can also be calculated using the method described above, except that... Figure 10 The angle obtained from the phase-locked loop needs to be compensated for the phase difference. For example, the compensated phase difference when acquiring the voltage of line ab is -120°, and the compensated phase difference when acquiring the voltage of line ca is 120°. In addition, for a three-phase five-wire system with a neutral point, the phase of the grid voltage can also be obtained by acquiring the input voltage relative to the neutral point and calculating the grid voltage phase according to the scheme of this invention.

[0083] The present invention provides a solution that obtains the grid voltage phase by sampling only one line voltage. After orthogonal separation of the sampled line voltage, phase-locking is performed directly without requiring coordinate transformation. Thus, the present invention only needs to acquire one voltage signal to obtain the grid voltage phase, saving hardware costs. Furthermore, for three-phase fully controlled rectifier systems that acquire multiple voltages in related solutions, the present invention avoids the system failing to operate due to sampling failure of a single line voltage or phase voltage, improving the fault tolerance of the three-phase fully controlled rectifier system. In addition, the present invention directly phase-locks the voltage after orthogonal separation of the line voltage, eliminating the need for positive and negative sequence voltage extraction and coordinate transformation compared to related solutions, while still achieving accurate acquisition of the grid voltage frequency and phase, and simplifying the control program.

[0084] In step S130, the operation of the three-phase fully controlled rectifier system is controlled in conjunction with the phase of the grid voltage. Specifically, the operation of the three-phase fully controlled rectifier bridge is controlled based on the phase of the grid voltage, the three-phase current at the input terminal of the three-phase fully controlled rectifier bridge, and the bus voltage at the output terminal of the three-phase fully controlled rectifier bridge, thereby achieving control of the three-phase fully controlled rectifier system.

[0085] The present invention proposes a method for obtaining the grid voltage phase of a three-phase fully controlled rectifier system using single-voltage sampling. This method involves acquiring the bus voltage signal, three-phase current signal, and a line voltage signal. The line voltage signal is then processed by an orthogonal signal generator composed of a second-order generalized integrator to separate two orthogonal signals with the same amplitude and containing only the fundamental component. These two orthogonal signals are then processed by a PLL to obtain the accurate grid voltage phase. Furthermore, a PWM wave signal is determined based on the bus voltage signal, three-phase current signal, and grid voltage phase. This PWM wave signal is used to control the switching transistors of the three-phase full-bridge rectifier bridge, achieving high-performance three-phase fully controlled rectifier control. Since only one line voltage signal needs to be acquired during line voltage signal acquisition, if the acquisition of one line voltage signal fails, other line voltage signals can be acquired, preventing the three-phase fully controlled rectifier system from failing to operate due to the sampling failure of one line voltage or phase voltage. Thus, three-phase fully controlled rectification control under single-voltage (i.e., single-line voltage) sampling is realized. For fully controlled rectification systems based on multi-phase voltage sampling in related schemes, the effective operation of the three-phase fully controlled rectification system can still be ensured even when some voltage sampling fails, thus improving the fault tolerance of the three-phase fully controlled rectification system. At the same time, it solves the problem of accurately obtaining voltage phase when there are harmonics in the grid voltage, thus improving the performance and reliability of the three-phase fully controlled rectification system.

[0086] In some implementations, the operation of the three-phase fully controlled rectifier bridge in step S130 is controlled according to the phase of the grid voltage, the three-phase current at the input terminal of the three-phase fully controlled rectifier bridge, and the bus voltage at the output terminal of the three-phase fully controlled rectifier bridge, so as to realize the specific process of controlling the three-phase fully controlled rectifier system. See the following exemplary description.

[0087] The following is combined with Figure 4 The schematic diagram shown is an embodiment of the method of the present invention, which controls the operation of the three-phase fully controlled rectifier bridge according to the phase of the grid voltage, the three-phase current and the bus voltage. It further illustrates the specific process of controlling the operation of the three-phase fully controlled rectifier bridge according to the phase of the grid voltage, the three-phase current and the bus voltage in step S130, including steps S410 to S420.

[0088] Step S410: Determine the PWM wave signal based on the phase of the grid voltage, the three-phase current at the input terminal of the three-phase fully controlled rectifier bridge, and the bus voltage at the output terminal of the three-phase fully controlled rectifier bridge.

[0089] Step S420: Based on the PWM wave signal, control the switching transistors in the three-phase fully controlled rectifier bridge to control the operation of the three-phase fully controlled rectifier bridge and realize the control of the three-phase fully controlled rectifier system.

[0090] like Figure 6The fully controlled rectifier system shown acquires bus voltage signals through a bus voltage sampling module, three-phase current signals through a three-phase current sampling module, and single-line voltage signals through a single-line voltage sampling module. A voltage phase calculation module calculates the grid voltage phase based on the acquired single-line voltage signals. The bus voltage signals acquired by the bus voltage sampling module, the three-phase current signals acquired by the three-phase current sampling module, and the grid voltage phase calculated by the voltage phase calculation module are transmitted to the main control system of the three-phase fully controlled rectifier system. The fully controlled rectifier control module in the main control system performs digital calculations according to a preset control strategy, outputs a PWM wave signal, and controls the switching transistors of the three-phase fully controlled rectifier bridge, thereby achieving three-phase fully controlled rectification. The preset control strategy, also known as the fully controlled rectifier control strategy, is calculated in the DSP to obtain the PWM switching signal (i.e., the PWM wave signal) controlling the switching transistors. One of the key aspects of the preset control strategy is the calculation of the grid voltage phase. In this way, the phase of the grid voltage can be obtained by sampling only one voltage line (i.e., a single line voltage), thereby achieving three-phase fully controlled rectification control and reducing the hardware cost of the three-phase fully controlled rectification system. For related solutions based on multi-phase voltage sampling, the three-phase fully controlled rectification system will fail to operate when the sampling of one line voltage or phase voltage fails. However, the solution of this invention can still ensure the effective operation of the three-phase fully controlled rectification system even when some voltage sampling fails, improving the fault tolerance of the three-phase fully controlled rectification system. At the same time, it solves the problem of inaccurate voltage phase acquisition in related solutions based on multi-phase voltage sampling when harmonics exist in the grid voltage, improving the performance and reliability of the three-phase fully controlled rectification system.

[0091] The technical solution of this embodiment acquires the bus voltage signal, three-phase current signal, and a line voltage signal. The line voltage signal is then processed by an orthogonal signal generator composed of a second-order generalized integrator to separate two orthogonal signals with the same amplitude and containing only the fundamental component. These two orthogonal signals are then processed by a PLL to obtain the accurate grid voltage phase. Furthermore, a PWM wave signal is determined based on the bus voltage signal, three-phase current signal, and grid voltage phase. This PWM wave signal is used to control the switching transistors of the three-phase full-bridge rectifier bridge, achieving high-performance three-phase fully controlled rectification control. Therefore, by acquiring the line voltage signal of the three-phase grid and obtaining the grid voltage phase based on this line voltage signal, the failure of sampling the line voltage or phase voltage can be avoided, thus improving the fault tolerance of the three-phase fully controlled rectifier system.

[0092] According to embodiments of the present invention, a control device for a three-phase fully controlled rectifier system, corresponding to a control method for a three-phase fully controlled rectifier system, is also provided. See also Figure 5The diagram shows a structural schematic of an embodiment of the device of the present invention. The three-phase fully controlled rectifier system includes: a three-phase fully controlled rectifier bridge; three-phase AC power is provided by the power grid, the input terminal of the three-phase fully controlled rectifier bridge is connected to the output terminal of the three-phase AC power provided by the power grid; the output terminal of the three-phase fully controlled rectifier bridge is connected to the bus voltage output terminal of the three-phase fully controlled rectifier system.

[0093] Specifically, Figure 6 This is a schematic diagram of an embodiment of a three-phase fully controlled rectifier system. Figure 6 As shown, the output terminal of the three-phase AC power supplied by the power grid can output three-phase voltages a, b, and c, with phase a voltage being u. sa The voltage of phase b is u sb The voltage of phase c is u sc Phase a voltage u sa Through resistor R a and inductor L a The voltage of phase b is then input to the first input terminal of the three-phase fully controlled rectifier bridge. sb Through resistor R b and inductor L b The voltage is then input to the second input terminal of the three-phase fully controlled rectifier bridge, and the voltage of phase c is u. sc Through resistor R c and inductor L c The voltage is then input to the third input terminal of the three-phase fully controlled rectifier bridge. The output of the three-phase fully controlled rectifier bridge outputs the bus voltage after passing through the bus capacitor. Phase a voltage u sa Phase b voltage u sb The voltage of phase c is u sc Any two phase voltages are connected to the input of a single-line voltage sampling module, and the inductor L... a Inductor L b and inductor L c The output terminal of the bus capacitor is connected to the input terminal of the three-phase current sampling module, the output terminal of the bus capacitor is connected to the input terminal of the bus voltage sampling module, and the output terminals of the voltage phase calculation module, the three-phase current sampling module, and the bus voltage sampling module are respectively connected to the full-control rectifier control module in the main control system.

[0094] like Figure 5 As shown, the control device of the three-phase fully controlled rectifier system includes: a sampling unit 102 and a control unit 104.

[0095] The sampling unit 102 is configured to, when control of the three-phase fully controlled rectifier bridge is required, sample the line voltage between any two phase voltages of the three-phase AC output from the power grid to obtain a single-line voltage, denoted as the single-line voltage of the power grid; sample the three-phase current at the input terminal of the three-phase fully controlled rectifier bridge; and sample the bus voltage at the output terminal of the three-phase fully controlled rectifier bridge. The specific functions and processing of this sampling unit 102 are described in step S110.

[0096] Specifically, Figure 7 This is a schematic diagram of one embodiment of a line voltage sampling circuit. Figure 8 This is a schematic diagram of one embodiment of the voltage phase calculation module. The voltage phase calculation of this invention only requires single-channel voltage sampling, typically line voltage. In actual line voltage sampling, the line voltage between any two of the three phases (a, b, and c) can be sampled. Taking the line voltage of phase BC as an example, the sampling circuit for single-channel voltage sampling is as follows: Figure 7 As shown, the collected single-line voltage is input to... Figure 8 In the voltage phase calculation module shown.

[0097] like Figure 7 As shown, the line voltage sampling circuit includes: resistors R1, R2, R3, R4, and R5; capacitors C1, C2, C3, C4, and C5; and a comparator. Phase b of the grid voltage, after passing through resistor R2, is grounded to phase A via capacitor C2. GND On the other hand, it is connected to the non-inverting input of the comparator; the non-inverting input of the comparator is also connected in parallel with resistor R4 and capacitor C4, which is then connected to the reference voltage V. ref The c-phase voltage from the mains, after passing through resistor R1, is grounded via capacitor C1. GND On the other hand, it is connected to the inverting input of the comparator; the inverting input of the comparator is also connected to the output of the comparator via a parallel capacitor C5 and a resistor R5. The output of the comparator is then connected to the line voltage u via a resistor R3. ac Line voltage u ac The output terminal is also grounded after passing through capacitor C3. GND .

[0098] The control unit 104 is configured to determine the phase of the grid voltage based on the single-line voltage of the grid. The specific functions and processing of the control unit 104 are described in step S120.

[0099] Specifically, such as Figure 8As shown, the voltage phase calculation module includes a second-order generalized integrator quadrature signal generator and a phase-locked loop (PLL). The input to this voltage phase calculation module is the acquired single-channel grid line voltage, and the output is the phase of the grid voltage. Specifically, the single-channel line voltage output from the line voltage sampling circuit is input to the second-order generalized integrator quadrature signal generator. In the second-order generalized integrator quadrature signal generator, two quadrature signals with the same amplitude and containing only the fundamental component are separated by the quadrature signal generator composed of a second-order generalized integrator. These two quadrature signals are then input to the PLL, and the PLL processes the two quadrature signals to obtain the accurate grid voltage phase.

[0100] In the relevant scheme, calculating the grid voltage phase requires acquiring at least two grid voltage signals (such as line voltage or phase voltage) for phase-locked loop (PLL) operation. This involves acquiring two voltage signals, then using Clark coordinate transformation to obtain two voltage signals with a 90° phase difference. Finally, PLL processing is performed on these two voltage signals with a 90° phase difference to obtain the accurate grid voltage phase. However, the hardware cost for obtaining two voltage signals with a 90° phase difference through Clark coordinate transformation is relatively high. Furthermore, if the sampling of either the line voltage or the phase voltage fails, the three-phase fully controlled rectifier system will be unable to operate.

[0101] In the present invention, only one line voltage signal is collected, and then two voltage signals with a 90° phase difference are separated by a second-order generalized integrator quadrature signal generator. The accurate grid voltage phase is then obtained by PLL processing of the two voltage signals with a 90° phase difference. Since only one line voltage signal needs to be separated into two voltage signals with a 90° phase difference by the second-order generalized integrator quadrature signal generator, compared with the fully controlled rectifier system based on multi-phase voltage sampling in related schemes, hardware sampling circuits can be saved, resulting in lower hardware costs. In addition, the present invention can still ensure the effective operation of the three-phase fully controlled control system even if some voltage sampling fails, improving the fault tolerance of the three-phase fully controlled control system and avoiding the failure of the three-phase fully controlled rectifier system due to the sampling failure of one line voltage or phase voltage.

[0102] In some embodiments, the control unit 104 determines the phase of the grid voltage based on the single-line voltage of the grid, including:

[0103] The control unit 104 is further configured to separate two orthogonal signals with the same amplitude and containing only the fundamental component from a single line voltage of the power grid. Specifically, the control unit 104 is further configured to separate two orthogonal signals with the same amplitude and containing only the fundamental component from a single line voltage of the power grid using a second-order generalized integral orthogonal signal generator. The specific functions and processing of the control unit 104 are further described in step S210.

[0104] In some embodiments, the control unit 104 separates two orthogonal signals with the same amplitude and containing only the fundamental component from a single line voltage of the power grid. Specifically, the control unit 104 is further configured to process the single line voltage of the power grid using the following formula (1) to separate two orthogonal signals with the same amplitude and containing only the fundamental component:

[0105]

[0106] Where k is the gain coefficient, ω0 is the fundamental angular frequency, u is the single-line voltage of the power grid, u0 is one of two orthogonal signals with the same amplitude and containing only the fundamental component, and qu0 is the other orthogonal signal with the same amplitude and containing only the fundamental component.

[0107] Specifically, Figure 9 This is a schematic diagram illustrating the workflow of one embodiment of a second-order generalized integral quadrature signal generator. Figure 9 As shown, the second-order generalized integrator orthogonal signal generator separates two orthogonal signals with the same amplitude and containing only the fundamental component through the action of the orthogonal signal generator composed of the second-order generalized integrator. The transfer function used is shown in Equation (1). Its function is to separate the acquired single-line voltage u into two orthogonal signals with the same amplitude and containing only the fundamental component, namely an orthogonal signal u0 and another orthogonal signal qu0. The amplitude and phase of the fundamental component of the orthogonal signal u0 are the same as those of the original signal u, and the amplitude of the fundamental component of the other orthogonal signal qu0 is the same as those of the original signal u, but the phase lags by 90°.

[0108]

[0109] Where k is the gain coefficient, typically taken as 0.707. ω0 is the fundamental angular frequency.

[0110] The control unit 104 is further configured to perform phase-locked loop (PLL) processing on the two orthogonal signals to obtain the phase of the grid voltage. Specifically, the control unit 104 is further configured to perform PLL processing on the two orthogonal signals through a PLL to obtain the phase of the grid voltage. The specific functions and processing of the control unit 104 are further described in step S220.

[0111] In some embodiments, the control unit 104 performs phase-locked loop processing on the two orthogonal signals to obtain the phase of the grid voltage, including:

[0112] The control unit 104 is further configured to process the two orthogonal signals using the following formulas (2) and (3) to obtain the angular frequency of the grid voltage. The specific functions and processing of the control unit 104 are further described in step S310.

[0113] The control unit 104 is further configured to process the angular frequency of the grid voltage using the following formula (4) to obtain the phase of the grid voltage. The specific functions and processing of the control unit 104 are further described in step S320.

[0114] in,

[0115]

[0116]

[0117]

[0118] Where U represents the magnitude of the grid phase voltage, (θ represents the actual phase of the grid phase voltage, This indicates the estimated phase of the grid phase voltage, where Δ represents the deviation. The angular frequency of the grid phase voltage meter, k p It is the proportionality coefficient, k i It is the integral coefficient.

[0119] Specifically, Figure 10 This is a schematic diagram illustrating the workflow of one embodiment of a phase-locked loop (PLL). Figure 10 As shown, the phase-locked loop (PLL) processes the two input quadrature signals u0 and qu0 to obtain the accurate grid voltage phase. Specifically, since the bc line voltage is at the zero-crossing point of the rising edge when the grid voltage phase is 0, the two quadrature signals u0 and qu0 output by the second-order generalized integrator quadrature signal generator are first calculated according to equation (2), and then the calculation result is adjusted by PI according to equation (3) to obtain the grid voltage angular frequency. Finally, the grid voltage phase is obtained by integrating the grid voltage angular frequency according to equation (4).

[0120]

[0121]

[0122]

[0123] Where U represents the magnitude of the grid phase voltage, (θ represents the actual phase of the grid phase voltage, This indicates the estimated phase of the grid phase voltage, where Δ represents the deviation. This represents the angular frequency of the grid phase voltage meter. k p It is the proportionality coefficient, k i It is the integral coefficient.

[0124] Of course, see Figures 6 to 10 In the example shown, if the collected line voltage is the line voltage of phase ab or phase ca, the grid voltage phase can also be calculated using the above-described device, except that... Figure 10 The angle obtained from the phase-locked loop needs to be compensated for the phase difference. For example, the compensated phase difference when acquiring the voltage of line ab is -120°, and the compensated phase difference when acquiring the voltage of line ca is 120°. In addition, for a three-phase five-wire system with a neutral point, the phase of the grid voltage can also be obtained by acquiring the input voltage relative to the neutral point and calculating the grid voltage phase according to the scheme of this invention.

[0125] The present invention provides a solution that obtains the grid voltage phase by sampling only one line voltage. After orthogonal separation of the sampled line voltage, phase-locking is performed directly without requiring coordinate transformation. Thus, the present invention only needs to acquire one voltage signal to obtain the grid voltage phase, saving hardware costs. Furthermore, for three-phase fully controlled rectifier systems that acquire multiple voltages in related solutions, the present invention avoids the system failing to operate due to sampling failure of a single line voltage or phase voltage, improving the fault tolerance of the three-phase fully controlled rectifier system. In addition, the present invention directly phase-locks the voltage after orthogonal separation of the line voltage, eliminating the need for positive and negative sequence voltage extraction and coordinate transformation compared to related solutions, while still achieving accurate acquisition of the grid voltage frequency and phase, and simplifying the control program.

[0126] The control unit 104 is further configured to control the operation of the three-phase fully controlled rectifier system in conjunction with the phase of the grid voltage. Specifically, it controls the operation of the three-phase fully controlled rectifier bridge based on the phase of the grid voltage, the three-phase current at the input terminal of the three-phase fully controlled rectifier bridge, and the bus voltage at the output terminal of the three-phase fully controlled rectifier bridge, thereby achieving control of the three-phase fully controlled rectifier system. The specific functions and processing of this control unit 104 are further described in step S130.

[0127] The present invention proposes a grid voltage phase acquisition device for a three-phase fully controlled rectifier system with single-voltage sampling. This device acquires the bus voltage signal, three-phase current signal, and a line voltage signal. The line voltage signal is then processed by an orthogonal signal generator composed of a second-order generalized integrator to separate two orthogonal signals with the same amplitude and containing only the fundamental component. These two orthogonal signals are then processed by a PLL to obtain the accurate grid voltage phase. Furthermore, a PWM wave signal is determined based on the bus voltage signal, three-phase current signal, and grid voltage phase. This PWM wave signal is used to control the switching transistors of the three-phase full-bridge rectifier bridge, achieving high-performance three-phase fully controlled rectifier control. Since only one line voltage signal needs to be acquired during line voltage signal acquisition, if the acquisition of one line voltage signal fails, other line voltage signals can be acquired, preventing the three-phase fully controlled rectifier system from failing to operate due to the sampling failure of one line voltage or phase voltage. Thus, three-phase fully controlled rectification control under single-voltage (i.e., single-line voltage) sampling is realized. For fully controlled rectification systems based on multi-phase voltage sampling in related schemes, the effective operation of the three-phase fully controlled rectification system can still be ensured even when some voltage sampling fails, thus improving the fault tolerance of the three-phase fully controlled rectification system. At the same time, it solves the problem of accurately obtaining voltage phase when there are harmonics in the grid voltage, thus improving the performance and reliability of the three-phase fully controlled rectification system.

[0128] In some embodiments, the control unit 104 controls the operation of the three-phase fully controlled rectifier bridge based on the phase of the grid voltage, the three-phase current at the input terminal of the three-phase fully controlled rectifier bridge, and the bus voltage at the output terminal of the three-phase fully controlled rectifier bridge, thereby achieving control of the three-phase fully controlled rectifier system, including:

[0129] The control unit 104 is further configured to determine the PWM wave signal based on the phase of the grid voltage, the three-phase current at the input terminal of the three-phase fully controlled rectifier bridge, and the bus voltage at the output terminal of the three-phase fully controlled rectifier bridge. The specific functions and processing of the control unit 104 are further described in step S410.

[0130] The control unit 104 is further configured to control the switching transistors in the three-phase fully controlled rectifier bridge according to the PWM wave signal, thereby controlling the operation of the three-phase fully controlled rectifier bridge and realizing the control of the three-phase fully controlled rectifier system. The specific functions and processing of the control unit 104 are further described in step S420.

[0131] like Figures 6 to 10The fully controlled rectifier system shown acquires bus voltage signals through a bus voltage sampling module, three-phase current signals through a three-phase current sampling module, and single-line voltage signals through a single-line voltage sampling module. A voltage phase calculation module calculates the grid voltage phase based on the acquired single-line voltage signals. The bus voltage signals acquired by the bus voltage sampling module, the three-phase current signals acquired by the three-phase current sampling module, and the grid voltage phase calculated by the voltage phase calculation module are transmitted to the main control system of the three-phase fully controlled rectifier system. The fully controlled rectifier control module in the main control system performs digital calculations according to a preset control strategy, outputs a PWM wave signal, and controls the switching transistors of the three-phase fully controlled rectifier bridge, thereby achieving three-phase fully controlled rectification. The preset control strategy, also known as the fully controlled rectifier control strategy, is calculated in the DSP to obtain the PWM switching signal (i.e., the PWM wave signal) controlling the switching transistors. One of the key aspects of the preset control strategy is the calculation of the grid voltage phase. In this way, the phase of the grid voltage can be obtained by sampling only one voltage line (i.e., a single line voltage), thereby achieving three-phase fully controlled rectification control and reducing the hardware cost of the three-phase fully controlled rectification system. For related solutions based on multi-phase voltage sampling, the three-phase fully controlled rectification system will fail to operate when the sampling of one line voltage or phase voltage fails. However, the solution of this invention can still ensure the effective operation of the three-phase fully controlled rectification system even when some voltage sampling fails, improving the fault tolerance of the three-phase fully controlled rectification system. At the same time, it solves the problem of inaccurate voltage phase acquisition in related solutions based on multi-phase voltage sampling when harmonics exist in the grid voltage, improving the performance and reliability of the three-phase fully controlled rectification system.

[0132] Since the processing and functions implemented by the device in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0133] The technical solution of this invention involves acquiring bus voltage signals, three-phase current signals, and a line voltage signal. The line voltage signal is then processed by an orthogonal signal generator composed of a second-order generalized integrator to separate two orthogonal signals with the same amplitude and containing only the fundamental component. These two orthogonal signals are then processed by a PLL to obtain the accurate grid voltage phase. Furthermore, a PWM wave signal is determined based on the bus voltage signal, three-phase current signals, and grid voltage phase. This PWM wave signal is used to control the switching transistors of the three-phase full-bridge rectifier bridge, achieving high-performance three-phase fully controlled rectification control. This addresses the problem of inaccurate voltage phase acquisition when grid voltage harmonics are present, improving the performance and reliability of the three-phase fully controlled rectifier system.

[0134] According to an embodiment of the present invention, a three-phase fully controlled rectifier system corresponding to a control device for a three-phase fully controlled rectifier system is also provided. This three-phase fully controlled rectifier system may include: the control device for the three-phase fully controlled rectifier system described above.

[0135] Since the processing and functions implemented by the three-phase fully controlled rectifier system in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned devices, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0136] The technical solution of this invention involves acquiring bus voltage signals, three-phase current signals, and a single-line voltage signal. This single-line voltage signal is then processed by an orthogonal signal generator composed of a second-order generalized integrator to separate two orthogonal signals with the same amplitude and containing only the fundamental component. These two orthogonal signals are then processed by a PLL to obtain the accurate grid voltage phase. Furthermore, a PWM wave signal is determined based on the bus voltage signal, three-phase current signals, and grid voltage phase. This PWM wave signal is used to control the switching transistors of the three-phase full-bridge rectifier bridge, achieving high-performance three-phase fully controlled rectification control. The grid voltage phase can be obtained by acquiring only one voltage line (i.e., single-line voltage), thus realizing three-phase fully controlled rectification control and reducing the hardware cost of the three-phase fully controlled rectification system.

[0137] According to an embodiment of the present invention, a storage medium corresponding to a control method for a three-phase fully controlled rectifier system is also provided. The storage medium includes a stored program, wherein, when the program is executed, the device where the storage medium is located executes the control method for the three-phase fully controlled rectifier system described above.

[0138] Since the processing and functions implemented by the storage medium in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0139] The technical solution of this invention involves acquiring bus voltage signals, three-phase current signals, and a line voltage signal. The line voltage signal is then processed by an orthogonal signal generator composed of a second-order generalized integrator to separate two orthogonal signals with the same amplitude and containing only the fundamental component. These two orthogonal signals are then processed by a PLL to obtain the accurate grid voltage phase. Furthermore, a PWM wave signal is determined based on the bus voltage signal, three-phase current signals, and grid voltage phase. This PWM wave signal is used to control the switching transistors of the three-phase full-bridge rectifier bridge, achieving high-performance three-phase fully controlled rectification control. Even in the event of partial voltage sampling failure, the three-phase fully controlled rectifier system can still operate effectively, improving its fault tolerance.

[0140] In summary, it is readily understood by those skilled in the art that, without conflict, the aforementioned advantageous methods can be freely combined and superimposed.

[0141] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A control method of a three-phase fully controlled rectification system, characterized by, The three-phase fully controlled rectifier system includes: a three-phase fully controlled rectifier bridge; three-phase AC power is provided by the power grid, and the input terminal of the three-phase fully controlled rectifier bridge is connected to the output terminal of the three-phase AC power provided by the power grid; the output terminal of the three-phase fully controlled rectifier bridge is connected to the bus voltage output terminal of the three-phase fully controlled rectifier system; the control method of the three-phase fully controlled rectifier system includes: The line voltage between any two phase voltages of the three-phase AC power output from the power grid is sampled to obtain the single-line voltage, which is denoted as the single-line voltage of the power grid; the three-phase current at the input terminal of the three-phase fully controlled rectifier bridge is sampled, and the bus voltage at the output terminal of the three-phase fully controlled rectifier bridge is sampled. Based on the single-line voltage of the power grid, determine the phase of the single-line voltage of the power grid; pass the single-line voltage signal through an orthogonal signal generator composed of a second-order generalized integrator to separate two orthogonal signals with the same amplitude and containing only the fundamental component; then, obtain the accurate power grid voltage phase by performing PLL processing on the two orthogonal signals. The operation of the three-phase fully controlled rectifier bridge is controlled based on the phase of the grid voltage, the three-phase current at the input terminal of the three-phase fully controlled rectifier bridge, and the bus voltage at the output terminal of the three-phase fully controlled rectifier bridge, so as to realize the control of the three-phase fully controlled rectifier system; a PWM wave signal is determined based on the bus voltage signal, the three-phase current signal, and the phase of the grid voltage, so as to control the switching transistors of the three-phase full-bridge rectifier bridge according to the PWM wave signal, thereby realizing high-performance three-phase fully controlled rectification control.

2. The control method of a three-phase controlled rectifier system according to claim 1, characterized by, Determining the phase of the grid voltage based on the single-line voltage of the grid includes: Two orthogonal signals with the same amplitude and containing only the fundamental component are separated from the single-line voltage of the power grid. The phase of the grid voltage is obtained by performing phase-locked loop processing on the two orthogonal signals.

3. The control method for the three-phase fully controlled rectifier system according to claim 2, characterized in that, From the single-line voltage of the power grid, two orthogonal signals with the same amplitude and containing only the fundamental component are separated, including: Using the following formula (1), the single-line voltage of the power grid is processed to separate two orthogonal signals with the same amplitude and containing only the fundamental component: （1）； Where k is the gain coefficient. ω 0 The fundamental angular frequency, u The voltage of a single line in the power grid. u 0 It is one of two orthogonal signals with the same amplitude that contains only the fundamental component. qu 0 It is the other orthogonal signal among two orthogonal signals with the same amplitude and containing only the fundamental component.

4. The control method of a three-phase controlled rectifier system according to claim 2 or 3, characterized by, Phase-locked loop processing is performed on the two orthogonal signals to obtain the phase of the grid voltage, including: The two orthogonal signals are processed using the following formulas (2) and (3) to obtain the angular frequency of the grid voltage; The angular frequency of the grid voltage is processed using the following formula (4) to obtain the phase of the grid voltage; in, （2）； （3）； （4）； Where U represents the phase voltage amplitude of the power grid. Indicates the actual phase of the grid phase voltage. This indicates the estimated phase of the grid phase voltage, where Δ represents the deviation. Indicates the angular frequency of the grid phase voltage meter. k p It is a proportionality coefficient. k i It is the integral coefficient.

5. The control method of a three-phase controlled rectifier system according to any one of claims 1 to 4, characterized by, The operation of the three-phase fully controlled rectifier bridge is controlled based on the phase of the grid voltage, the three-phase current at the input terminal of the three-phase fully controlled rectifier bridge, and the bus voltage at the output terminal of the three-phase fully controlled rectifier bridge, so as to achieve control of the three-phase fully controlled rectifier system, including: The PWM wave signal is determined based on the phase of the grid voltage, the three-phase current at the input of the three-phase fully controlled rectifier bridge, and the bus voltage at the output of the three-phase fully controlled rectifier bridge. Based on the PWM wave signal, the switching transistors in the three-phase fully controlled rectifier bridge are controlled to control the operation of the three-phase fully controlled rectifier bridge and realize the control of the three-phase fully controlled rectifier system.

6. A control device for a three-phase fully controlled rectifier system, employing the control method of any one of claims 1 to 5 to achieve control of the three-phase fully controlled rectifier system, characterized in that, The three-phase fully controlled rectifier system includes: a three-phase fully controlled rectifier bridge; three-phase AC power is provided by the power grid, and the input terminal of the three-phase fully controlled rectifier bridge is connected to the output terminal of the three-phase AC power provided by the power grid; the output terminal of the three-phase fully controlled rectifier bridge is connected to the bus voltage output terminal of the three-phase fully controlled rectifier system; the control device of the three-phase fully controlled rectifier system includes: The sampling unit is configured to sample the line voltage between any two phase voltages of the three-phase phase voltages output by the three-phase AC power supplied by the power grid, to obtain the single-line voltage, which is denoted as the single-line voltage of the power grid; sample the three-phase current at the input terminal of the three-phase fully controlled rectifier bridge; and sample the bus voltage at the output terminal of the three-phase fully controlled rectifier bridge. The control unit is configured to determine the phase of a single-line voltage of the power grid based on the single-line voltage of the power grid. The control unit is further configured to control the operation of the three-phase fully controlled rectifier bridge based on the phase of the grid voltage, the three-phase current at the input terminal of the three-phase fully controlled rectifier bridge, and the bus voltage at the output terminal of the three-phase fully controlled rectifier bridge, so as to realize the control of the three-phase fully controlled rectifier system.

7. The control device of a three-phase controlled rectifier system according to claim 6, characterized by The control unit determines the phase of the grid voltage based on the single-line voltage of the grid, including: Two orthogonal signals with the same amplitude and containing only the fundamental component are separated from the single-line voltage of the power grid. The phase of the grid voltage is obtained by performing phase-locked loop processing on the two orthogonal signals.

8. The control device of a three-phase controlled rectifier system according to claim 7, characterized by The control unit separates two orthogonal signals with the same amplitude and containing only the fundamental component from the single-line voltage of the power grid, including: Using the following formula (1), the single-line voltage of the power grid is processed to separate two orthogonal signals with the same amplitude and containing only the fundamental component: （1）； Where k is the gain coefficient. ω 0 The fundamental angular frequency, u The voltage of a single line in the power grid. u 0 It is one of two orthogonal signals with the same amplitude that contains only the fundamental component. qu 0 It is the other orthogonal signal among two orthogonal signals with the same amplitude and containing only the fundamental component.

9. The control device of a three-phase controlled rectifier system according to claim 7 or 8, characterized in that, The control unit performs phase-locked loop processing on the two orthogonal signals to obtain the phase of the grid voltage, including: The two orthogonal signals are processed using the following formulas (2) and (3) to obtain the angular frequency of the grid voltage; The angular frequency of the grid voltage is processed using the following formula (4) to obtain the phase of the grid voltage; in, （2）； （3）； （4）； Where U represents the phase voltage amplitude of the power grid. Indicates the actual phase of the grid phase voltage. This indicates the estimated phase of the grid phase voltage, where Δ represents the deviation. Indicates the angular frequency of the grid phase voltage meter. k p It is a proportionality coefficient. k i It is the integral coefficient.

10. The control device of a three-phase controlled rectifier system according to any one of claims 6 to 9, characterized in that, The control unit controls the operation of the three-phase fully controlled rectifier bridge based on the phase of the grid voltage, the three-phase current at the input terminal of the three-phase fully controlled rectifier bridge, and the bus voltage at the output terminal of the three-phase fully controlled rectifier bridge, thereby achieving control of the three-phase fully controlled rectifier system, including: The PWM wave signal is determined based on the phase of the grid voltage, the three-phase current at the input of the three-phase fully controlled rectifier bridge, and the bus voltage at the output of the three-phase fully controlled rectifier bridge. Based on the PWM wave signal, the switching transistors in the three-phase fully controlled rectifier bridge are controlled to control the operation of the three-phase fully controlled rectifier bridge and realize the control of the three-phase fully controlled rectifier system.

11. A three-phase, fully controlled rectification system, characterized by, include: The control device of the three-phase full-rectifier system according to any one of claims 6 to 10.

12. A storage medium, characterized by The storage medium includes a stored program, wherein the device where the storage medium is located executes the control method of the three-phase full-rectifier system according to any one of claims 1 to 5 when the program is run.

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