Multi-pulse rectifier power supply device, control method and device thereof, and power supply system

Abstract

This application relates to a multi-pulse rectifier power supply device and its control method, apparatus, and power supply system. The method includes: determining a first reactive current reference value that needs to be injected into the point of common coupling (PCC) of an active power filter based on the actual output power value and a reference output power value of the multi-pulse rectifier; determining a control signal for the active power filter based on the first reactive current reference value; and controlling the active power filter according to the control signal to inject the target current into the PCC. This method enables regulation of the output power of the multi-pulse rectifier, thereby improving the reliability of the power supply device.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to a multi-pulse rectifier power supply device and its control method, apparatus and power supply system. Background Technology

[0002] In the field of power electronics, the twelve-pulse rectifier has significant advantages in terms of structure, reliability, overload capacity, and efficiency, making it a key interface converter between medium- and high-voltage DC power systems and AC power grids in aerospace, marine, and rail transportation industries. However, the output voltage and power of the twelve-pulse rectifier depend on the AC input and load conditions, and it lacks the ability to actively regulate its own output power, affecting the reliability of the power supply unit in which the twelve-pulse rectifier is located. Summary of the Invention

[0003] Therefore, it is necessary to provide a multi-pulse rectifier power supply device and its control method, device and power supply system that can regulate the output power of the multi-pulse rectifier in order to address the above-mentioned technical problems.

[0004] In a first aspect, this application provides a multi-pulse rectifier power supply device, comprising: a multi-pulse rectifier and an active power filter, wherein the AC input terminal of the multi-pulse rectifier and the AC output terminal of the active power filter are connected in parallel and then connected to a common connection point, the common connection point being connected to an AC power grid, and the DC output terminal of the multi-pulse rectifier and the DC input terminal of the active power filter are connected in parallel and then connected to a DC bus.

[0005] The active power filter is used to receive a control signal determined based on an output power reference value, and under the control of the control signal, injects a target current into the common coupling point based on the current input at the DC input terminal. The target current is used to adjust the output power of the multi-pulse rectifier.

[0006] Secondly, this application provides a control method for a multi-pulse rectifier power supply device, applied to the multi-pulse rectifier power supply device of the first aspect, the method comprising:

[0007] Based on the actual output power value of the multi-pulse rectifier and the output power reference value, the first reactive current reference value that the active power filter needs to inject into the point of common coupling is determined.

[0008] The control signal for the active power filter is determined based on the first reactive current reference value;

[0009] The active power filter is controlled according to the control signal to inject the target current into the point of common coupling.

[0010] In one embodiment, determining the first reactive current reference value that the active power filter needs to inject into the point of common coupling based on the actual output power value of the multi-pulse rectifier and the output power reference value includes: determining the required output voltage regulation of the multi-pulse rectifier based on the actual output power value and the output power reference value; determining the required voltage amplitude change of the point of common coupling based on the output voltage regulation; and determining the first reactive current reference value based on the voltage amplitude change.

[0011] In one embodiment, the method further includes: determining a second active current reference value and a second reactive current reference value corresponding to the harmonic compensation current of the instantaneous value of the input current of the multi-pulse rectifier; determining the control signal for the active power filter based on the first reactive current reference value includes: acquiring a first active current reference value that the active power filter needs to inject into the point of common coupling; determining a third active current reference value that the active power filter needs to inject into the point of common coupling based on the first active current reference value and the second active current reference value; determining a third reactive current reference value that the active power filter needs to inject into the point of common coupling based on the first reactive current reference value and the second reactive current reference value; and determining the control signal for the active power filter based on the third active current reference value and the third reactive current reference value.

[0012] In one embodiment, determining the control signal of the active power filter based on the third active current reference value and the third reactive current reference value includes: determining the target active output voltage and target reactive output voltage that the active power filter needs to output based on the third active current reference value and the third reactive current reference value; and determining the control signal of the active power filter based on the target active output voltage and the target reactive output voltage.

[0013] In one embodiment, determining the second active current reference value and the second reactive current reference value corresponding to the harmonic compensation current of the instantaneous input current of the multi-pulse rectifier includes: determining the grid voltage frequency based on the instantaneous voltage value of the point of common coupling; determining the harmonic current in the instantaneous input current value of the multi-pulse rectifier; and determining the second active current reference value and the second reactive current reference value based on the harmonic current and the grid voltage frequency.

[0014] Thirdly, this application also provides a power supply system, including: an AC power grid, a DC bus, a load, a controller, and a plurality of multi-pulse rectifier power supply devices according to the first aspect. The DC output terminals of each of the multi-pulse rectifier power supply devices are connected in parallel and then connected to the DC bus. The load is connected to the DC bus. The multi-pulse rectifier power supply devices are used to supply power to the load. The controller is used to implement the control method of the pulse rectifier power supply device provided in the second aspect embodiment.

[0015] Fourthly, this application also provides a control device for a multi-pulse rectifier power supply device, comprising:

[0016] The first determining module is used to determine the first reactive current reference value that the active power filter needs to inject into the point of common coupling based on the actual output power value of the multi-pulse rectifier and the output power reference value.

[0017] The second determining module is used to determine the control signal for the active power filter based on the first reactive current reference value;

[0018] The injection module is used to control the active power filter according to the control signal to inject the target current into the point of common coupling.

[0019] Fifthly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the control method of the multi-pulse rectifier power supply device provided in the first aspect of this application.

[0020] In a sixth aspect, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the control method of the multi-pulse rectifier power supply device provided in the first aspect of this application.

[0021] In a seventh aspect, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the control method of the multi-pulse rectifier power supply device provided in the first aspect of this application.

[0022] The aforementioned multi-pulse rectifier power supply device, power supply system, control method, apparatus, computer equipment, computer-readable storage medium, and computer program product regulate the voltage of the point of common coupling by injecting a target current into the point of common coupling through an active power filter. This regulates the AC voltage of the multi-pulse rectifier and actively controls the DC output voltage of the multi-pulse rectifier. As a result, the output power is controlled by outputting a controllable target current, solving the problem of uncontrollable output power and improving the reliability of the power supply device. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a structural block diagram of a multi-pulse rectifier power supply device in one embodiment;

[0025] Figure 2 This is a topology diagram of a 12-pulse rectifier power supply device in one embodiment;

[0026] Figure 3 This is a flowchart illustrating the control method of a multi-pulse rectifier power supply device in one embodiment;

[0027] Figure 4 This is a flowchart illustrating step 301 in one embodiment;

[0028] Figure 5 This is a flowchart illustrating step 302 in one embodiment;

[0029] Figure 6 Here is a control block diagram of a multi-pulse rectifier power supply device in a specific example;

[0030] Figure 7 A schematic diagram of a structure in which n power supply devices are powered by a common DC bus in one embodiment;

[0031] Figure 8 This is a vector diagram illustrating the increase in voltage magnitude at a common connection point in one embodiment;

[0032] Figure 9 This is a vector diagram illustrating the reduction in voltage amplitude at a common connection point in one embodiment;

[0033] Figure 10 This is a structural block diagram of the control device of a multi-pulse rectifier power supply device in one embodiment;

[0034] Figure 11 This is a structural block diagram of the power supply system in one embodiment;

[0035] Figure 12 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0037] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0038] Explanation of terms used in this application:

[0039] Twelve-pulse rectifier: A rectifier device that generates two sets of three-phase power supplies with a phase difference of 30 degrees through a transformer, which are then rectified by a three-phase bridge rectifier and connected in parallel for output, thereby making the DC side voltage pulsation frequency 12 times the grid frequency.

[0040] Active Power Filter (APF): A device that uses power electronic converter technology to dynamically generate compensation current to offset load harmonics and / or reactive current.

[0041] Point of Common Coupling (PCC): The connection point between the equipment and the public power grid.

[0042] Pulse Width Modulation (PWM): A technique that controls the output by adjusting the pulse width.

[0043] Reactive current: The component of current that is 90 degrees out of phase with the voltage. Its instantaneous power average is zero. It does not transmit active energy, but it will affect the voltage amplitude.

[0044] In related technologies, multi-pulse rectifiers, such as twelve-pulse rectifiers, are conventional twelve-pulse diode rectifiers. They achieve twelve-pulse rectification through a multi-winding transformer and a diode bridge, completing the AC-to-DC power conversion. Twelve-pulse rectifiers have two drawbacks:

[0045] Uncontrollable output power problem: Because it adopts uncontrolled rectification (diode) method, the output voltage and power are completely determined by AC input and load. It cannot actively regulate the output power, which affects the reliability of the power supply device where the twelve-pulse rectifier is located. For example, when multiple such rectifiers are connected in parallel on the same DC bus, there is no effective power distribution mechanism. They can only passively distribute the current based on the slight differences in equipment parameters and line impedance, which can easily lead to uneven power, single-unit overload, and poor system stability.

[0046] Harmonic pollution problem: The input current of the twelve-pulse rectifier contains a large number of low-order harmonics (such as the 11th, 13th, 23rd and 25th harmonics). When used alone, it still cannot meet the requirements of harmonic standards such as IEEE-519, which will cause harmonic pollution to the power grid.

[0047] Therefore, effectively reducing the input current harmonics of multi-pulse rectifiers and solving the problems of the inability to actively control the output power of multi-pulse rectifiers during operation and the difficulty in parallel operation have become key technical challenges in improving the performance and reliability of such systems.

[0048] Therefore, this application provides a multi-pulse rectifier power supply device and its control method to adjust the output power of the multi-pulse rectifier.

[0049] In one exemplary embodiment, such as Figure 1 As shown, a multi-pulse rectifier power supply device is provided, including a multi-pulse rectifier 101 and an active power filter 102. The AC input terminal of the multi-pulse rectifier 101 and the AC output terminal of the active power filter 102 are connected in parallel and then connected to a common coupling point PCC. The common coupling point PCC is connected to an AC power grid 103. The DC output terminal of the multi-pulse rectifier 101 and the DC input terminal of the active power filter 102 are connected in parallel and then connected to a DC bus 104.

[0050] The active power filter 102 is used to receive a control signal determined based on an output power reference value, and under the control of the control signal, injects a target current into the common coupling point PCC based on the current input at the DC input terminal. The target current is used to regulate the output power of the multi-pulse rectifier 101.

[0051] The multi-pulse rectifier 101 can be a multi-pulse rectifier with a six-, eighteen-, twelve-, or twelve-four-eighths structure. The multi-pulse rectifier can be connected in series or in parallel. It can use diode switching devices and requires no additional control, achieving AC-DC power conversion through uncontrolled rectification. The active power filter 102 can be a parallel active power filter.

[0052] For example, the DC output terminal of the multi-pulse rectifier 101 is first connected to the DC bus 104, and the AC input terminal is connected to the AC power grid 103. The multi-pulse rectifier 101 is used to perform AC-DC power conversion, realize power transmission, and provide output power to the DC bus 104 to supply power to loads, energy storage devices, etc. on the DC bus 104. Then, the active power filter 102 is connected in parallel with the multi-pulse rectifier 101. Through output current control technology, a controllable target current (such as reactive current) is injected into the AC power grid 103 to realize active regulation of the output power of the multi-pulse rectifier 101 during operation, which facilitates the parallel operation of multiple multi-pulse rectifiers 101. When multiple power supply devices are connected in parallel to the DC bus to supply power to the loads on the DC bus, each multi-pulse rectifier 101 realizes power conversion and power transmission from the AC power grid to the DC bus. In this connection method, the DC power supply of the active power filter 102 is entirely provided by the DC output of the multi-pulse rectifier 101, without the need for additional independent DC power supply or voltage control module. The voltage support is achieved by relying on the stable DC output of the rectifier, which greatly simplifies the topology and control logic.

[0053] During the operation of the multi-pulse rectifier 101, the controller (not shown in the figure) acquires the actual output power value of the multi-pulse rectifier 101 and obtains the output power reference value of the multi-pulse rectifier 101. Based on the actual output power value and the output power reference value, it determines the control signal for the active power filter 102 and sends it to the active power filter 102. Under the control of the received control signal, the active power filter 102 performs current control based on the current at its DC input terminal (i.e., the output current of the multi-pulse rectifier 101) to obtain the target current. The target current is input to the common coupling point PCC to change the voltage amplitude of the PCC, thereby regulating the DC output voltage of the multi-pulse rectifier 101. The difference between the DC output voltage and the DC bus voltage is used as the driving force to actively adjust the DC output power of the multi-pulse rectifier 101, thereby achieving the purpose of actively regulating the output power of the multi-pulse rectifier 101. When multiple power supply devices are connected in parallel, the output power of the multi-pulse rectifier 101 can be actively distributed, improving the stability of the parallel system.

[0054] In addition to the active power regulation function, the active power filter 102 is also used to suppress harmonics in the input current of the multi-pulse rectifier 101.

[0055] For example, such as Figure 2 As shown, the multi-pulse rectifier 101 can be a 12-pulse rectifier, powered by the grid voltage source e. s Provide electrical energy, with the grid-side input current being i. s The equivalent inductance of the power grid is Ls, and the twelve-pulse rectifier includes an AC input voltage u. r AC input current ir The transformer windings N1, N2, and N3, which implement 12-pulse rectification, and the diodes, also include the reactor L. dc and resistance R dc Its DC output voltage is U rec12 The DC bus voltage is U bus The active power filter 102 includes its output current i f Filter inductor L f Filter capacitor C f Power switching transistors S1 to S6 and capacitor C o The power supply unit achieves main power transmission through a twelve-pulse rectifier and injects the target current i through an active power filter. f The voltage amplitude at the PCC point is changed to adjust the rectifier output power. In addition, the active power filter 102 can suppress harmonics in the input current of the twelve-pulse rectifier.

[0056] In the aforementioned multi-pulse rectifier power supply device, the multi-pulse rectifier and the active power filter are connected in parallel. The AC input terminal of the multi-pulse rectifier and the AC output terminal of the active power filter are connected to a common coupling point (PCP), which is connected to the AC power grid. The DC output terminal of the multi-pulse rectifier and the DC input terminal of the active power filter are connected in parallel to the DC bus. The active power filter receives a control signal determined based on an output power reference value and, under the control of the control signal, injects a target current into the PCP based on the current input at the DC input terminal. This target current is used to regulate the output power of the multi-pulse rectifier. This embodiment of the application couples the active power filter and the multi-pulse rectifier in parallel on both the AC and DC sides, achieving integrated power supply and regulation. Specifically, the active power filter injects a target current into the AC power grid to regulate the AC voltage of the multi-pulse rectifier, thereby actively regulating the DC output voltage of the multi-pulse rectifier. This achieves the regulation of output power through a controllable target current, solving the problem of uncontrollable output power and improving the reliability of the power supply device. Furthermore, since the multi-pulse rectifier provides DC voltage for the active power filter, the active power filter eliminates the need for a welfare DC power supply or complex DC voltage control circuitry, simplifying the entire topology and control algorithm.

[0057] The active power filter in the aforementioned power supply device does not bear the main power; it only assists the multi-pulse rectifier in regulating output power and suppressing harmonic currents. These two functions can be implemented independently or coupled (jointly). To achieve control of the aforementioned power supply device, this application proposes a control method for a multi-pulse rectifier power supply device, applicable to the aforementioned power supply device, which can be executed by a controller.

[0058] In one exemplary embodiment, such as Figure 3As shown, a control method for a multi-pulse rectifier power supply device includes steps 301 to 303. Wherein:

[0059] Step 301: Based on the actual output power value and the reference output power value of the multi-pulse rectifier, determine the first reactive current reference value that the active power filter needs to inject into the point of common coupling.

[0060] The actual output power value is obtained by collecting the output power of each multi-pulse rectifier during operation, which can be achieved by collecting the DC voltage and DC current at the DC output terminal. The output power reference value is the required output power of each multi-pulse rectifier, preset according to the actual load demand or scheduling instructions. In a scenario where all multi-pulse rectifiers share a common DC bus, the output power reference values ​​of each multi-pulse rectifier can be the same or different, depending on the power allocation requirements of each multi-pulse rectifier; this application does not impose any restrictions on this.

[0061] For example, during the operation of each multi-pulse rectifier, the controller acquires the actual output power value of the multi-pulse rectifier and obtains the output power reference value of the multi-pulse rectifier. The difference between the output power reference value and the actual output power value is determined to obtain the output power deviation. Then, based on the output power deviation, the active power filter needs to inject the first reactive current reference value into the point of common coupling.

[0062] Step 302: Determine the control signal for the active power filter based on the first reactive current reference value.

[0063] For example, the controller first obtains the first active current reference value that the active power filter needs to output (needs to be injected into the point of common coupling), where the first active current reference value is an active current value set in advance according to actual needs. Then, based on the first reactive current reference value and the first active current reference value, the controller determines the control signal (i.e., the switching signal) for the active power filter. Optionally, when the active power filter has no active power transmission, the first active current reference value is set to 0 in advance.

[0064] Optionally, step 302 includes: obtaining the actual output current value of the active power filter, and extracting the actual reactive current value and the actual active current value therefrom; determining the first reactive current deviation based on the actual reactive current value and the first reactive current reference value; determining the first active current deviation based on the actual active current value and the first active current reference value; performing current control (e.g., proportional-integral control) based on the first reactive current deviation and the first active current deviation respectively to obtain the first initial reactive output voltage and the first initial active output voltage that the active power filter needs to output; decoupling the first initial reactive output voltage and the first initial active output voltage to obtain the first target active output voltage and the first target reactive output voltage that the active power filter needs to output; and performing pulse width modulation based on the first target active output voltage and the first target reactive output voltage to obtain a control signal for the active power filter.

[0065] Step 303: Control the active power filter according to the control signal to inject the target current into the point of common coupling.

[0066] For example, the controller controls the switching transistors in the active power filter according to the control signal. The active power filter then receives the control signal, and simultaneously, its DC input terminal receives the current output from the multi-pulse rectifier. Therefore, under the control of the control signal, the active power filter transforms the current input to the DC input terminal to obtain the target current (i.e., reactive current), and injects this target current into the point of common coupling (PCC). This adjusts the voltage amplitude at PCC, thereby regulating the output voltage of the multi-pulse rectifier. This allows for the regulation of the voltage difference between the output voltage and the DC bus voltage, ultimately achieving active control of the multi-pulse rectifier's output power.

[0067] In other words, the output power of the multi-pulse rectifier in this embodiment is driven by adjusting the voltage difference between its output voltage and the DC bus. The output voltage is adjusted by changing the voltage amplitude at the common coupling point, and the voltage amplitude at the common coupling point is achieved by outputting the target current (reactive current) through the active power filter.

[0068] In the control method of the aforementioned multi-pulse rectifier power supply device, based on the actual output power value and the reference output power value of the multi-pulse rectifier, a first reactive current reference value that the active power filter needs to inject into the point of common coupling is determined; a control signal for the active power filter is determined based on the first reactive current reference value; and the active power filter is controlled according to the control signal to inject the target current into the point of common coupling. In this embodiment, the voltage of the point of common coupling is regulated by injecting the target current into the point of common coupling through the active power filter, thereby adjusting the AC voltage of the multi-pulse rectifier and actively regulating the DC output voltage of the multi-pulse rectifier. This achieves the regulation of output power by outputting a controllable target current, solving the problem of uncontrollable output power and improving the reliability of the power supply device.

[0069] In one exemplary embodiment, such as Figure 4 As shown, step 301 includes steps 401 to 403. Wherein:

[0070] Step 401: Determine the required output voltage adjustment for the multi-pulse rectifier based on the actual output power value and the output power reference value.

[0071] The output voltage regulation amount is used to characterize the amount of regulation required for the output voltage of the multi-pulse rectifier to track the output power reference value.

[0072] In one possible implementation, the step includes: determining the output power deviation of the multi-pulse rectifier based on the actual output power value and the output power reference value; and determining the required output voltage regulation of the multi-pulse rectifier based on the output power deviation.

[0073] For example, the difference between the output power reference value and the actual output power value is calculated to obtain the output power deviation. The output power deviation is then subjected to proportional-integral control or proportional-integral-derivative control to obtain the output voltage regulation required by the multi-pulse rectifier.

[0074] Step 402: Determine the required voltage amplitude change at the point of common coupling based on the output voltage adjustment.

[0075] For example, after obtaining the output voltage regulation amount, based on the characteristics of the multi-pulse rectifier, the required voltage amplitude change at the point of common coupling is determined according to the output voltage regulation amount, so as to convert the voltage control requirement on the output side into the voltage amplitude regulation requirement on the input side. The characteristics of the multi-pulse rectifier include the relationship between its output voltage and the input voltage amplitude (i.e., the voltage amplitude at the point of common coupling), which can be specifically reflected by a proportionality coefficient.

[0076] For example, the output voltage of a multi-pulse rectifier is equal to the product of the input voltage amplitude and a preset proportional coefficient. Optionally, the ratio between the output voltage adjustment and the preset proportional coefficient is determined, and the required voltage amplitude change at the point of common coupling is determined based on this ratio.

[0077] Step 403: Determine the first reactive current reference value based on the voltage amplitude change.

[0078] For example, proportional-integral control or proportional-integral-derivative control can be performed on the voltage amplitude change to obtain the reactive current value that the active power filter needs to inject into the point of common coupling, which is the first reactive current reference value, so that the controller can determine the control signal of the active power filter.

[0079] Therefore, this embodiment converts the output power control requirements of the multi-pulse rectifier into a current command at the point of common coupling, realizing the active regulation of the output power of the multi-pulse rectifier using an active power filter. It does not require any changes to the structure of the multi-pulse rectifier; power regulation can be achieved simply by connecting an active power filter in parallel. It has the advantages of high control accuracy and low cost.

[0080] In addition to using active power filters to actively regulate output power, the harmonic compensation capability of active power filters can also be used to suppress input current harmonics generated by multi-pulse rectifiers. This will be explained in detail below.

[0081] In one exemplary embodiment, the method further includes: determining a second active current reference value and a second reactive current reference value for the harmonic compensation current corresponding to the instantaneous value of the input current of the multi-pulse rectifier.

[0082] For example, the controller first acquires the instantaneous voltage value at the point of common coupling and the instantaneous input current value of the multi-pulse rectifier and extracts the harmonic current. Then, based on the instantaneous voltage value and the harmonic current, it determines the second active current reference value and the second reactive current reference value of the harmonic compensation current corresponding to the instantaneous input current value of the multi-pulse rectifier, so as to determine the control signal.

[0083] Furthermore, such as Figure 5 As shown, step 302 includes steps 501 to 504, wherein:

[0084] Step 501: Obtain the first active current reference value that the active power filter needs to inject into the point of common coupling.

[0085] The first active current reference value is an active current value set in advance according to actual needs. When the active power filter has no active power transmission, the first active current reference value is 0.

[0086] Step 502: Based on the first active current reference value and the second active current reference value, determine the third active current reference value that the active power filter needs to inject into the point of common coupling.

[0087] For example, the controller determines the sum of the first active current reference value and the second active current reference value as the third active current reference value that the active power filter needs to output.

[0088] Step 503: Based on the first reactive current reference value and the second reactive current reference value, determine the third reactive current reference value that the active power filter needs to inject into the point of common coupling.

[0089] For example, the controller determines the sum of the first reactive current reference value and the second reactive current reference value as the third reactive current reference value that the active power filter needs to output.

[0090] Step 504: Determine the control signal for the active power filter based on the third active current reference value and the third reactive current reference value.

[0091] For example, the controller performs corresponding control based on the third active current reference value and the third reactive current reference value to obtain a control signal for the active power filter.

[0092] Therefore, this embodiment simultaneously achieves active regulation of the output power of the multi-pulse rectifier and harmonic suppression of the input current, which can improve both the reliability of the power supply device and the power quality of the power grid.

[0093] In an exemplary embodiment, step 504 includes: determining the target active power output voltage and target reactive power output voltage that the active power filter needs to output based on the third active current reference value and the third reactive current reference value; and determining the control signal of the active power filter based on the target active power output voltage and the target reactive power output voltage.

[0094] For example, firstly, the actual output current value of the active power filter is obtained, and the actual reactive current value and the actual active current value are extracted from it. A second reactive current deviation is determined based on the actual reactive current value and a third reactive current reference value. Then, the second active current deviation is determined based on the actual active current value and the third active current reference value. Current control (e.g., proportional-integral control) is performed based on the second reactive current deviation and the second active current deviation to obtain the second initial reactive output voltage and the second initial active output voltage required by the active power filter. The second initial reactive output voltage and the second initial active output voltage are decoupled to obtain the second target active output voltage and the second target reactive output voltage required by the active power filter. Finally, pulse width modulation is performed based on the second target active output voltage and the second target reactive output voltage to obtain a control signal for the active power filter.

[0095] Therefore, this embodiment determines the control signal based on the third active current reference value and the third reactive current reference value, which can ensure the reliability of the control signal.

[0096] In an exemplary embodiment, the determination of the second active current reference value and the second reactive current reference value corresponding to the harmonic compensation current of the instantaneous input current of the multi-pulse rectifier includes: determining the grid voltage frequency based on the instantaneous voltage value of the point of common coupling; determining the harmonic current in the instantaneous input current value of the multi-pulse rectifier; and determining the second active current reference value and the second reactive current reference value based on the harmonic current and the grid voltage frequency.

[0097] For example, the controller acquires the instantaneous value of the input current of the multi-pulse rectifier and the instantaneous value of the voltage at the point of common coupling. It then uses a digital phase-locked loop to transform the instantaneous voltage value to obtain the grid voltage frequency, and detects the harmonic current in the instantaneous input current value. Based on the grid voltage frequency, the harmonic current undergoes a preset transformation to obtain a second active current reference value and a second reactive current reference value.

[0098] Therefore, in this embodiment, the instantaneous value of the input current of the multi-pulse rectifier and the instantaneous value of the voltage at the common connection point are used to determine the second active current reference value and the second reactive current reference value for suppressing harmonics, thereby achieving harmonic suppression of the input current.

[0099] The following example uses a 12-pulse rectifier. Figure 6 The control block diagram illustrates the power supply device control method of the embodiments of this application.

[0100] In a specific example, the control method includes the following steps:

[0101] S1, Obtain the preset output power reference value of the 12-pulse rectifier. The first active current reference value required for the output of the active power filter When there is no active power transmission in the active power filter, Set to 0;

[0102] S2, collects the DC output power of the rectifier. and as Figure 6 As shown, the output power deviation of the rectifier is calculated using the following formula:

[0103] ;

[0104] S3, based on the output power deviation Perform voltage adjustment calculations to obtain the rectifier's output voltage adjustment amount. ;

[0105] S4, Adjustment based on output voltage Perform AC voltage calculations to obtain the voltage amplitude change of PCC. ;

[0106] S5, based on the voltage amplitude change of PCC Perform reactive current calculations to obtain the first reactive current reference value that the active power filter needs to inject into the grid. ;

[0107] S6, acquire the instantaneous three-phase voltage at the AC common connection point PCC of the 12-pulse rectifier and active filter. , and And the grid voltage frequency ω is obtained using a digital phase-locked loop;

[0108] S7, acquires the instantaneous value of the three-phase input current of the 12-pulse rectifier. , , The harmonic components in the three-phase input current are detected and processed. The transformation yields the second active current reference value corresponding to the harmonic compensation current reference value. Second reactive current reference value , The transformation formula is:

[0109] ;

[0110] S8, based on the second active current reference value and the first active current reference value The third active current reference value that needs to be injected into the PCC for calculating the active power filter. And based on the second reactive current reference value and the first reactive current reference value The third reactive current reference value that needs to be injected into the PCC for the active power filter is calculated. The calculation formula is:

[0111] ;

[0112] S9 will set the third active and reactive reference current values. , The active power output voltage of the active power filter is obtained by inputting the current into the current controller and performing decoupling control. and target reactive power output voltage ;

[0113] S10, will and use Transformation to obtain three-phase voltage command , and The signal is then fed into the pulse width modulation stage to obtain the control signal for the active power filter.

[0114] Active power filters in power supply systems regulate rectifier output power and suppress current harmonics. The power supplied by the AC grid is handled by multi-pulse rectifiers, and the active power filter assists in the active regulation of the 12-pulse rectifier's output power. For example... Figure 7 As shown, when n power supply devices share a DC bus, each device, based on its own set output power target, regulates the reactive current command of its active power filter to dynamically adjust the AC input voltage of the corresponding rectifier. This creates a controlled difference between the DC output voltage of each rectifier and the DC bus voltage. This voltage difference then drives the active allocation of DC power among the rectifiers, thereby adjusting the rectifier output power and achieving optimal output power distribution. This improves the stability of the parallel system and ensures stable and reliable parallel power supply. Simultaneously, the active power filter can extract the input current harmonics of each rectifier in real time, achieving harmonic suppression of the rectifier input current and improving the power quality of the AC grid.

[0115] Figure 8 and Figure 9 This is a vector diagram of the output current of an active power filter and the system voltage and current. It is the voltage at point PCC before the output current of the active power filter; For inductance voltage and with vertical; It is the voltage at point PCC after the output current of the active power filter; It is the input current of a 12-pulse rectifier; It is the current output by the active power filter; This refers to the AC mains current. Figure 8 Output current of active power filter Superimposed on the input current of the 12-pulse rectifier The above caused AC power grid current The change In the inductor Under the influence of this, the voltage at point PCC changes from... This transforms the voltage amplitude into an increase. Figure 9 Injected current in active power filter This causes the voltage at point PCC to change from become This reduces the voltage amplitude.

[0116] In summary, the controller directs the active power filter to inject reactive current into the AC grid according to the rectifier's output power setting. This alters the three-phase voltage amplitude on the AC side of the rectifier. By regulating the AC voltage, a preset controlled difference is generated in the DC output voltage of the twelve-pulse rectifier, actively adjusting its output power. This enables parallel operation of multiple power supply units, improving the stability of the parallel system. Simultaneously, the active power filter can extract harmonic currents, achieving harmonic suppression and improving the power quality of the AC grid.

[0117] In summary, the embodiments of this application have the following technical effects:

[0118] Active power regulation and stable parallel operation are achieved: By regulating the reactive current through the power APF to change the PCC voltage, the output power of the twelve-pulse rectifier is actively regulated. This enables the power to be actively and accurately distributed according to the settings when multiple power supply devices are connected in parallel, solving the system instability problem caused by uneven power distribution and improving the reliability of the parallel system.

[0119] Harmonic suppression is achieved: Through the harmonic compensation function of the APF, low-order harmonics in the input current of the twelve-pulse rectifier are effectively eliminated, enabling the system to meet relevant power quality standards and improving the power quality of the power grid.

[0120] Simplified topology: Since the rectifier provides DC voltage support for the APF, the APF eliminates the need for complex DC voltage control, simplifying the overall system topology and control algorithm, and improving reliability.

[0121] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0122] Based on the same inventive concept, this application also provides a control device for a multi-pulse rectifier power supply device for implementing the control method of the multi-pulse rectifier power supply device described above. The solution provided by this device is similar to the implementation described in the above method. Therefore, the specific limitations of one or more control device embodiments of the multi-pulse rectifier power supply device provided below can be found in the limitations of the control method of the multi-pulse rectifier power supply device described above, and will not be repeated here.

[0123] In one exemplary embodiment, such as Figure 10 As shown, a control device for a multi-pulse rectifier power supply is provided, including a first determining module 1001, a second determining module 1002, and an injection module 1003, wherein:

[0124] The first determining module 1001 is used to determine the first reactive current reference value that the active power filter needs to inject into the point of common coupling based on the actual output power value and the output power reference value of the multi-pulse rectifier.

[0125] The second determining module 1002 is used to determine the control signal for the active power filter based on the first reactive current reference value;

[0126] The injection module 1003 is used to control the active power filter according to the control signal to inject the target current into the point of common coupling.

[0127] In one embodiment, the first determining module 1001 is specifically used to: determine the required output voltage regulation amount of the multi-pulse rectifier based on the actual output power value and the output power reference value; determine the required voltage amplitude change amount of the common coupling point based on the output voltage regulation amount; and determine the first reactive current reference value based on the voltage amplitude change amount.

[0128] In one embodiment, the apparatus further includes: a third determining module, configured to determine a second active current reference value and a second reactive current reference value of the harmonic compensation current corresponding to the instantaneous value of the input current of the multi-pulse rectifier. The second determining module 1002 includes: an acquiring unit, configured to acquire a first active current reference value that the active power filter needs to inject into the point of common coupling; a first determining unit, configured to determine a third active current reference value that the active power filter needs to inject into the point of common coupling based on the first and second active current reference values; a second determining unit, configured to determine a third reactive current reference value that the active power filter needs to inject into the point of common coupling based on the first and second reactive current reference values; and a third determining unit, configured to determine a control signal for the active power filter based on the third active current reference value and the third reactive current reference value.

[0129] In one embodiment, the third determining unit is specifically used to: determine the target active power output voltage and target reactive power output voltage that the active power filter needs to output based on the third active current reference value and the third reactive current reference value; and determine the control signal of the active power filter based on the target active power output voltage and the target reactive power output voltage.

[0130] In one embodiment, the third determining module is specifically used to: determine the grid voltage frequency based on the instantaneous voltage value of the point of common coupling; determine the harmonic current in the instantaneous input current value of the multi-pulse rectifier; and determine the second active current reference value and the second reactive current reference value based on the harmonic current and the grid voltage frequency.

[0131] Each module in the control device of the aforementioned multi-pulse rectifier power supply device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0132] In one exemplary embodiment, such as Figure 11 As shown, a power supply system is provided, including: an AC power grid, a DC bus, a load, a controller, and multiple multi-pulse rectifier power supply devices according to the above embodiments. The DC output terminals of each multi-pulse rectifier power supply device are connected in parallel and then connected to the DC bus. The load is connected to the DC bus. The multi-pulse rectifier power supply device is used to supply power to the load. The controller is used to implement the control method of the above embodiments.

[0133] In one exemplary embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 12As shown, the computer device includes a processor, memory, input / output interfaces (I / O), and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores control data for the multi-pulse rectifier power supply device. The I / O interfaces are used for information exchange between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a control method for a multi-pulse rectifier power supply device.

[0134] Those skilled in the art will understand that Figure 12 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0135] In one exemplary embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement a control method for a multi-pulse rectifier power supply device.

[0136] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements a control method for a multi-pulse rectifier power supply device.

[0137] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements a control method for a multi-pulse rectifier power supply device.

[0138] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0139] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0140] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A multi-pulse rectifier power supply device, characterized in that, The device includes a multi-pulse rectifier and an active power filter. The AC input terminal of the multi-pulse rectifier and the AC output terminal of the active power filter are connected in parallel to a common connection point, which is connected to the AC power grid. The DC output terminal of the multi-pulse rectifier and the DC input terminal of the active power filter are connected in parallel to a DC bus. The active power filter is used to receive a control signal determined based on an output power reference value, and under the control of the control signal, injects a target current into the common coupling point based on the current input at the DC input terminal. The target current is used to adjust the output power of the multi-pulse rectifier.

2. A control method for a multi-pulse rectifier power supply device, characterized in that, The method is used to control the multi-pulse rectifier power supply device as described in claim 1, the method comprising: Based on the actual and reference values ​​of the output power of the multi-pulse rectifier, the reference value of the first reactive current that needs to be injected into the point of common coupling for the active power filter is determined. The control signal for the active power filter is determined based on the first reactive current reference value; The active power filter is controlled according to the control signal to inject the target current into the point of common coupling.

3. The method according to claim 2, characterized in that, The determination of the first reactive current reference value that the active power filter needs to inject into the point of common coupling based on the actual output power value of the multi-pulse rectifier and the reference output power value includes: The required output voltage regulation of the multi-pulse rectifier is determined based on the actual output power value and the output power reference value. The required voltage amplitude change at the common connection point is determined based on the output voltage adjustment amount. The first reactive current reference value is determined based on the voltage amplitude change.

4. The method according to claim 2 or 3, characterized in that, The method further includes: Determine the second active current reference value and the second reactive current reference value of the harmonic compensation current corresponding to the instantaneous value of the input current of the multi-pulse rectifier. The step of determining the control signal for the active power filter based on the first reactive current reference value includes: Obtain the first active current reference value that needs to be injected into the point of common coupling for the active power filter; Based on the first active current reference value and the second active current reference value, determine the third active current reference value that the active power filter needs to inject into the point of common coupling; Based on the first reactive current reference value and the second reactive current reference value, determine the third reactive current reference value that the active power filter needs to inject into the point of common coupling; The control signal for the active power filter is determined based on the third active current reference value and the third reactive current reference value.

5. The method according to claim 4, characterized in that, The step of determining the control signal for the active power filter based on the third active current reference value and the third reactive current reference value includes: Based on the third active current reference value and the third reactive current reference value, determine the target active output voltage and target reactive output voltage that the active power filter needs to output; The control signal for the active power filter is determined based on the target active power output voltage and the target reactive power output voltage.

6. The method according to claim 4, characterized in that, The determination of the second active current reference value and the second reactive current reference value corresponding to the harmonic compensation current of the instantaneous value of the input current of the multi-pulse rectifier includes: The grid voltage frequency is determined based on the instantaneous voltage value at the point of common coupling. Determine the harmonic current in the instantaneous value of the input current of the multi-pulse rectifier; The second active current reference value and the second reactive current reference value are determined based on the harmonic current and the grid voltage frequency.

7. A power supply system, characterized in that, include: An AC power grid, a DC bus, a load, a controller, and multiple multi-pulse rectifier power supply devices as described in claim 1 are provided. The DC output terminals of each multi-pulse rectifier power supply device are connected in parallel and then connected to the DC bus. The load is connected to the DC bus. The multi-pulse rectifier power supply device is used to supply power to the load; The controller is used to implement the control method of the multi-pulse rectifier power supply device as described in any one of claims 2 to 6.

8. A control device for a multi-pulse rectifier power supply device, characterized in that, The device includes: The first determining module is used to determine the first reactive current reference value that the active power filter needs to inject into the point of common coupling based on the actual output power value and the output power reference value of the multi-pulse rectifier. The second determining module is used to determine the control signal for the active power filter based on the first reactive current reference value; The injection module is used to control the active power filter according to the control signal to inject the target current into the point of common coupling.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 2 to 6.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 2 to 6.

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