Three-phase three-port converter control method, device and equipment and storage medium

Abstract

The invention relates to the technical field of power electronics, in particular to a three-phase three-port converter control method, device and equipment and a storage medium, and the method comprises the following steps: connecting a direct-current power supply VDC1, a direct-current power supply VDC2 and an alternating-current port to a power grid through a filter inductor Lf; a control parameter ctr is generated on the direct current side through power control of the direct current ports VDC1 and VDC2; a VSG is adopted to control an alternating current side, an output voltage V * is obtained through active loop and reactive loop control, and a reference voltage Vm is obtained through voltage and current double-closed-loop control; and inputting the control parameter ctr, the reference voltage Vm and the direct current side voltage ratio VDC1 / VDC2 as input quantities into a three-level carrier pulse width modulation wave generator to generate a modulation wave, and generating a driving pulse signal of the hybrid device. According to the method, direct current end power port control, VSG alternating current side control and three-level PWM modulation are combined, an efficient and stable energy conversion strategy can be provided in a multi-port converter system, frequency and voltage fluctuation is effectively suppressed under the condition of power grid load fluctuation or new energy fluctuation, and the stability of power grid operation is improved.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and in particular to a three-phase three-port converter control method, device, equipment and storage medium. Background Art

[0002] With the acceleration of industrialization and urbanization, energy shortage and environmental pollution are becoming more and more serious. Renewable energy represented by wind and solar energy accounts for an increasing proportion of the entire power system. However, the randomness and volatility of renewable energy generation have brought severe challenges to the power grid. In order to achieve stable power supply and efficient energy utilization, renewable energy generation technology is usually used in conjunction with energy storage units. Therefore, a three-port converter that can simultaneously connect renewable energy, energy storage and the power grid is required, as well as maintaining the stability of the grid frequency and voltage through network control.

[0003] Among the existing converter designs, the simplest is the single-stage two-level structure, where the DC / AC converter is directly connected to the energy storage medium and the power grid. This topology is simple, but the capacity is low and the IGBT withstand voltage is limited, resulting in a narrow DC input voltage problem. To solve the above problem, a two-stage topology has emerged. The energy generated by the new energy passes through the DC / DC converter and then the DC / AC converter, making the energy storage capacity configuration more flexible and not limited to the type of energy storage medium. However, the operating efficiency of the device is reduced, the volume is larger, and the power density is lower. However, although the three-port converter can ensure the coordinated operation of each port, the control strategy is relatively complex. At the same time, the generation of new energy reduces the proportion of synchronous generators in the power grid and lacks sufficient inertial support. Especially when facing complex energy flows and dynamic power regulation requirements, it is necessary to adopt a network control strategy to improve system stability and thus suppress load fluctuations.

[0004] Therefore, there is an urgent need for a three-phase three-port converter control method, device, equipment and storage medium that can provide an efficient and stable energy conversion strategy in a multi-port converter system, thereby improving the stability of power grid operation. Summary of the invention

[0005] In view of at least one of the above technical problems, the present invention provides a three-phase three-port converter control method, device, equipment and storage medium, and adopts the improvement of the method to improve the stability of power grid operation.

[0006] According to a first aspect of the present invention, there is provided a three-phase three-port converter control method, comprising the following steps:

[0007] The DC power supply V DC1 , DC power supply V DC2 , AC port through the filter inductor L f Access to the power grid;

[0008] Through the DC port VDC1 and V DC2 The power control generates control parameters ctr on the DC side;

[0009] VSG is used to control the AC side, and the output voltage V* is obtained through active loop and reactive loop control, and the reference voltage V is obtained through voltage and current double closed loop control. m ;

[0010] Set the control parameter ctr, reference voltage V m And DC side voltage ratio V DC1 / V DC2 The three-level carrier wave pulse width modulation wave generator is input as an input quantity to generate a modulation wave and a driving pulse signal for the hybrid device.

[0011] In some embodiments of the present invention, the three-phase three-port converter adopts an active midpoint clamp structure converter, each phase uses four silicon carbide MOSFETs and two silicon-based IGBTs as switch units, and the DC power supply V DC2 Directly connected to the midpoint of the bridge arm.

[0012] In some embodiments of the present invention, the reference voltage V of the initial modulation wave of the upper and lower bridge arms of the converter m On the contrary, the carrier wave is composed of a set of triangular waves, and the modulating wave needs to be corrected. The correction offset is α, which is defined as:

[0013] α=2V DC2 / V DC1 -1

[0014] When α>0, the modulation wave shifts upward, the amplitude of the positive half cycle becomes 1-α, and the amplitude of the negative half cycle becomes 1+α; when α<0, the change rule is opposite.

[0015] In some embodiments of the present invention, obtaining the output voltage V* comprises the following steps:

[0016] The inertia and primary frequency modulation characteristics of the synchronous generator are simulated through the active loop;

[0017] The phase θ of the output reference voltage;

[0018] The primary voltage regulation characteristics of synchronous generators are simulated through reactive loops;

[0019] The amplitude of the output reference voltage V;

[0020] V* is obtained by voltage synthesis.

[0021] In some embodiments of the present invention, the calculated output voltage V* is subjected to voltage and current double closed-loop control to obtain a new reference voltage V m * As the input quantity of the modulation wave generator of three-level carrier pulse width modulation.

[0022] In some embodiments of the present invention, the size and offset direction of the injected modulation wave zero-sequence component are adjusted according to the control parameter ctr, the initial sinusoidal modulation wave is converted into a saddle wave, and the duty cycle of the output PWM signal and the on-off time of the switch tube are changed.

[0023] In some embodiments of the present invention, the control parameter ctr ranges from -1 to 1.

[0024] According to a second aspect of the present invention, there is also provided a three-phase three-port converter control device, comprising:

[0025] DC port, used to provide DC power V DC1 and V DC2 ;

[0026] AC port, through the filter inductor L f Intervention into the power grid to achieve the transmission of AC power;

[0027] The power control module is used to connect the DC power supply V DC1 and V DC2 The power control generates the DC side control parameter ctr;

[0028] The VSG control module is used to control the AC side, generate the output voltage V* through active loop and reactive loop control, and obtain the reference voltage V through voltage and current double closed loop control. m ;

[0029] Three-level carrier pulse width modulation wave generator, used to receive control parameters ctr, reference voltage V m And DC side voltage ratio V DC1 / V DC2 As input, a modulation wave is generated and a driving pulse signal for the hybrid device is produced.

[0030] According to a third aspect of the present invention, there is also provided a three-phase three-port converter control device, comprising a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method described above is implemented.

[0031] According to a fourth aspect of the present invention, there is also provided a three-phase three-port converter control storage medium, comprising a storage medium on which a computer program is stored, and the computer program implements the above method when executed by a processor.

[0032] The beneficial effects of the present invention are as follows: by combining DC power port control, VSG AC side control and three-level PWM modulation, the present invention can provide an efficient and stable energy conversion strategy in a multi-port converter system, effectively suppress frequency and voltage fluctuations in the case of grid load fluctuations or new energy fluctuations, and improve the stability of grid operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 A flowchart of the steps of a three-phase three-port converter control method according to an embodiment of the present invention;

[0035] Figure 2 A flowchart of the steps of obtaining the output voltage V* in an embodiment of the present invention;

[0036] Figure 3 This is a waveform diagram of a high-frequency industrial frequency driving signal generated by carrier pulse width modulation in an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0039] like Figures 1 to 3 The three-phase three-port converter control method shown comprises the following steps:

[0040] S10: The DC power supply V DC1 , DC power supply V DC2 , AC port through the filter inductor L f Access to the power grid;

[0041] S20: Through the DC port V DC1 and V DC2 The power control generates control parameters ctr on the DC side;

[0042] S30: Use VSG to control the AC side, obtain the output voltage V* through active loop and reactive loop control, and obtain the reference voltage V through voltage and current double closed loop control. m ;

[0043] S40: Set the control parameter ctr and reference voltage V m And DC side voltage ratio V DC1 / V DC2 The three-level carrier wave pulse width modulation wave generator is input as an input quantity to generate a modulation wave and a driving pulse signal for the hybrid device.

[0044] like Figure 1 As shown, this embodiment is to realize the energy flow control between two DC ports and one AC port to adapt to different application scenarios, such as new energy grid connection, energy storage system or multi-port power electronic conversion system. The DC port can be connected to different DC power sources, such as photovoltaic cells, energy storage batteries, etc., and the AC port is connected to the power supply through the filter inductor L f Connect to the power grid to achieve efficient energy conversion and transmission. In step S10, the DC power supply V DC1 and V DC2 They are connected to the DC port of the converter to provide input energy; the AC port is connected to the DC port through the filter inductor L f Connect to the power grid, reduce high-frequency harmonics and smooth the current waveform. Multi-port energy management supports flexible power scheduling of two DC ports to improve the energy utilization of the system. In step S20, by detecting the DC power supply V DC1 and V DC2 , combined with the system power demand, calculate the power control parameter ctr on the DC side, which is used to balance the power flow between DC ports, ensure reasonable energy distribution, and improve the stability of the DC side. In step S30, VSG is a virtual synchronous generator. The VSG control strategy is adopted to make the converter have the characteristics of a synchronous generator and improve the interactive stability with the power grid. The system power balance is maintained through the active power control loop, and the AC voltage amplitude is maintained stable through the reactive power control loop to obtain the output voltage V*. Combined with the voltage and current double closed-loop control, the reference voltage V is further calculated. m To ensure the dynamic response capability of the converter to the external power grid. VSG control can improve the dynamic response capability of the AC side, enhance the adaptability of the power grid and the stability of the grid connection. In step S40, PWM, i.e., three-level carrier pulse width modulation, calculates the control parameter ctr, the reference voltage V m And the AC side voltage ratio V DC1 / V DC2As input, PWM modulation wave is generated to control the driving pulse signal of hybrid power device to realize accurate switching control of converter. The three-level modulation method can effectively reduce the harmonic content of output voltage, improve system conversion efficiency and reduce the difficulty of filter design.

[0045] In the above embodiments, by combining DC power port control, VSG AC side control and three-level PWM modulation, an efficient and stable energy conversion strategy can be provided in a multi-port converter system, which can effectively suppress frequency and voltage fluctuations in the case of grid load fluctuations or new energy fluctuations, thereby improving the stability of grid operation.

[0046] In the embodiment of the present invention, the three-phase three-port converter adopts an active midpoint clamp structure converter, each phase uses four silicon carbide MOSFETs and two silicon-based IGBTs as switch units, and the DC power supply V DC2 Directly connected to the midpoint of the bridge arm. Here, we need to explain the system topology. This topology uses four high-frequency silicon carbide MOSFET wide-bandgap power switch tubes and two industrial-frequency silicon-based IGBTs as the switching devices of the converter per phase. The input uses two asymmetric DC ports, which are high-level V DC1 and low level V DC2 Port. It should also be understood that the active midpoint clamping structure used by the three-phase three-port converter in this embodiment belongs to one of the three-level topologies. The traditional two-level inverter has only two states, high voltage and low voltage, on the DC side. The active midpoint clamping structure three-level topology can provide an additional intermediate voltage level on the output voltage through the midpoint clamping method, thereby reducing switching losses and harmonic content. In this structure, the DC power supply V DC2 Directly connected to the midpoint of the bridge arm, the DC side voltage can be divided into two sub-levels to optimize power management and device utilization. In addition, silicon carbide MOSFET has low on-resistance characteristics, and the switching loss is much lower than that of traditional silicon-based devices. It is suitable for high-frequency switching positions and is usually placed in the upper and lower bridge arm main switch positions where high-speed switching is required; silicon-based IGBT has excellent low-frequency conduction characteristics and is suitable for occasions with large currents but low switching frequencies. It is used in mid-point clamping and low-frequency conduction positions to increase the service life of the overall system. DC power supply V DC2 As the midpoint potential, the output voltage of the three-level transformer can also be +V DC1 , 0, and -V DC1 Compared with the traditional two-level structure, the voltage borne by each switching device is only half of the single DC bus voltage, which reduces the voltage resistance requirement of the device and improves the power density of the converter.

[0047] In an embodiment of the present invention, Figure 3As shown, the reference voltage V of the initial modulation wave of the upper and lower bridge arms of the converter m On the contrary, the carrier wave is composed of a set of triangular waves, and the modulating wave needs to be corrected. The correction offset is α, which is defined as:

[0048] α=2V DC2 / V DC1 -1

[0049] When α>0, the modulation wave shifts upward, the amplitude of the positive half cycle becomes 1-α, and the amplitude of the negative half cycle becomes 1+α; when α<0, the change rule is opposite. In the control process of the converter, the modulation wave and the signal used to generate the PWM control signal are composed of a triangular wave and a reference signal (such as a sine wave). The modulation wave needs to be based on the DC power supply voltage V DC1 and V DC2 The actual situation is corrected to adapt to different voltage inputs and system requirements. When α>0, the modulation wave shifts upward. At this time, the amplitude of the positive half cycle of the modulation wave becomes smaller, the amplitude of the negative half cycle increases, the amplitude of the modulation wave loses symmetry, the positive half cycle amplitude becomes 1-α, that is, the positive half cycle amplitude of the modulation wave decreases; the negative half cycle amplitude becomes 1+α, that is, the negative half cycle amplitude of the modulation wave increases. When α<0, the symmetry of the modulation wave is reversed, and the change law is opposite. Through the above adjustment, the output voltage and current waveforms of the converter can be accurately controlled. By adjusting the amplitude offset of the modulation wave, the converter can balance the working state of the DC power supply at both ends according to the actual voltage conditions. Especially when the voltages of the two DC power supplies are asymmetric, the corrected modulation wave can prevent excessive voltage imbalance, reduce system load and heat accumulation, and extend the service life of the device. In addition, adjusting the amplitude asymmetry of the modulation wave helps to reduce high-order harmonics and improve the quality of the output voltage waveform. This correction method is particularly important in multi-port converters, which can improve energy transmission efficiency and reduce interference to the power grid.

[0050] In an embodiment of the present invention, Figure 2 As shown, obtaining the output voltage V* includes the following steps:

[0051] S31: Simulate the inertia and primary frequency modulation characteristics of the synchronous generator through the active loop;

[0052] S32: output reference voltage phase θ;

[0053] S33: simulate the primary voltage regulation characteristics of the synchronous generator through the reactive loop;

[0054] S34: output the amplitude V of the reference voltage;

[0055] S35: V* is obtained by voltage synthesis.

[0056] In step S31, the active loop control is responsible for achieving stable control of the output power, simulating the inertia characteristics and primary frequency modulation characteristics of the synchronous generator. In the converter control, this process simulates the response of the synchronous generator by adjusting the active power, so that the output power of the converter and the grid frequency can be dynamically matched to ensure power balance and frequency stability. In step S32, the calculation of the phase takes into account the frequency and load fluctuations of the grid, ensuring that the output of the converter is synchronized with the grid voltage, so that the power conversion and the grid interaction will not cause frequency and phase deviations. In step S33, the reactive loop control is responsible for the regulation of reactive power, simulating the voltage regulation characteristics of the synchronous generator. The synchronous generator adjusts the output reactive power by adjusting the excitation current, thereby maintaining the voltage stability of the grid. In step S34, the amplitude V of the reference voltage is the result of the reactive loop control, which indicates the output voltage amplitude required by the converter to maintain the grid voltage. In step S35, the final output voltage V* is synthesized by the amplitude and phase of the reference voltage. The reference voltage V* is the output voltage used by the converter control system to interact with the power grid. Through the control of this voltage, the converter can achieve smooth connection with the power grid, power exchange and stable operation. The method generates the reference voltage V* through the active loop and reactive loop control strategies, and simulates the inertia and frequency modulation characteristics of the synchronous generator, thereby achieving precise control of the converter output voltage.

[0057] In an embodiment of the present invention, the calculated output voltage V* is subjected to voltage and current double closed-loop control to obtain a new reference voltage V m * As the input of the modulation wave generator of three-level carrier pulse width modulation. Voltage and current dual closed-loop control is a commonly used converter control method, which mainly involves two loops: voltage loop and current loop. Voltage loop: controls the stability of the output voltage. Its main goal is to ensure that the voltage output by the converter remains near the reference voltage V* and can effectively respond to external load changes. Current loop: controls the accuracy of the output current. The current loop is responsible for adjusting the output current of the converter to ensure that the amplitude and phase of the current are consistent with the requirements of the power grid, avoiding overcurrent or current waveform distortion. After voltage and current dual closed-loop control, the output voltage V* is further optimized to obtain a new reference voltage It can better match the system load and the grid demand. At this stage, the new reference voltage generated The input of the three-level carrier pulse width modulation wave generator is used to generate the PWM wave according to the input The modulation waveform controls the switching of the converter, thereby accurately adjusting the output voltage and current to achieve stable grid connection and power exchange.

[0058] In an embodiment of the present invention, the size and offset direction of the injected zero-sequence component of the modulation wave are adjusted according to the control parameter ctr, the initial sinusoidal modulation wave is changed into a saddle wave, and the duty cycle of the output PWM signal and the on-off time of the switch tube are changed. The initial modulation wave is usually a sine wave, representing the ideal voltage waveform of the three-phase system. This waveform is used to generate a PWM signal, and the switch tube of the converter is controlled by comparison with the carrier to ensure that the output voltage matches the reference voltage. At this time, the three-phase voltage is usually symmetrical and has no obvious zero-sequence component. The zero-sequence component refers to the sum of all three-phase voltages in a three-phase AC system. Ideally, the zero-sequence component in a three-phase system is zero, that is, the three-phase voltage is symmetrical. However, the introduction of the zero-sequence component can be beneficial in some specific cases, especially in converter control to adjust the balance of current or voltage, improve harmonic performance, or introduce a certain imbalance in a three-phase system to achieve load regulation. The adjustment of the control parameter ctr is used to control the size and offset direction of the zero-sequence component. This means that by adjusting the ctr value, the symmetry of the modulation wave can be changed, thereby affecting the characteristics of the output voltage waveform. Specifically, by adjusting ctr, the amplitude of the zero-sequence component can be increased or decreased. When the zero-sequence component increases, the three-phase voltage waveform will be unbalanced, the output waveform will no longer be symmetrical, and the output of the converter will show a saddle waveform. A saddle wave is an asymmetric waveform that is shaped like a saddle. By adjusting ctr, the offset direction of the zero-sequence component can also be changed, causing the three-phase voltage to have different degrees of positive and negative offsets, affecting the upper and lower offsets of the final output waveform. This offset control makes the output waveform of the converter more in line with specific power requirements or grid conditions. This adjustment can be used to optimize the output waveform of the converter, improve the power quality, or meet special load regulation requirements.

[0059] On the basis of the above embodiment, the range of the control parameter ctr is between -1 and 1. When ctr=0, the zero-sequence component is zero, the modulation wave remains symmetrical, and the output voltage waveform is still a standard sinusoidal waveform. At this time, the amplitude and phase of the three-phase voltage are completely symmetrical, and the output waveform of the converter is idealized. When ctr=1, the zero-sequence component reaches the maximum value, and the imbalance of the modulation wave is the most serious. At this time, the three-phase voltage waveform becomes an extremely asymmetric state, such as a saddle wave. At this time, the output of the converter has a strong zero-sequence component, which is suitable for some specific loads or power adjustment requirements. When ctr=-1, the size and offset direction of the zero-sequence component will be opposite to the case of ctr=1. At this time, the asymmetry of the modulation wave and the distortion of the output waveform also reach the maximum, but the direction is opposite. By adjusting to a negative value, the control system can achieve different adaptation strategies for the power grid or load. The output waveform of the converter can be changed by adjusting ctr, the power quality can be optimized, the grid connection can be stabilized, the system response speed can be improved, and the stable control of voltage and current can be ensured under different working conditions.

[0060] Those skilled in the art should know that the embodiments of the present application can be provided as methods, devices, electronic devices or computer storage media products. Therefore, the embodiments of the present application can completely adopt hardware embodiments, embodiments combining hardware and software, or pure software embodiments. The test detection process data processing device in the embodiments of the present application is introduced below. The device embodiments below correspond to the method embodiments above. Those skilled in the art can understand the implementation process below based on the above description, and no detailed description is given here.

[0061] In an embodiment of the present invention, a three-phase three-port converter control device is also proposed, which is characterized by comprising:

[0062] DC port, used to provide DC power V DC1 and V DC2 ;

[0063] AC port, through the filter inductor L f Intervention into the power grid to achieve the transmission of AC power;

[0064] The power control module is used to connect the DC power supply V DC1 and V DC2 The power control generates the DC side control parameter ctr;

[0065] The VSG control module is used to control the AC side, generate the output voltage V* through active loop and reactive loop control, and obtain the reference voltage V through voltage and current double closed loop control. m ;

[0066] Three-level carrier pulse width modulation wave generator, used to receive control parameters ctr, reference voltage V m And DC side voltage ratio V DC1 / V DC2 As input, a modulation wave is generated and a driving pulse signal for the hybrid device is produced.

[0067] In the following part of the embodiments of the present invention, the electronic device and computer storage medium embodiments in the embodiments of the present invention are introduced. The electronic device and computer storage medium embodiments in the following correspond to the method embodiments in the above. Those skilled in the art can understand the following implementation process based on the above description, which will not be described in detail here.

[0068] In an embodiment of the present invention, a computer device is also proposed, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the above method is implemented.

[0069] An embodiment of the present application further provides a storage medium on which a computer program is stored, and the computer program implements the above method when executed by a processor.

[0070] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0071] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0072] Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A three-phase three-port converter control method, characterized in that: The following steps are involved: The DC power supply V DC1 , DC power supply V DC2 , AC port through the filter inductor L f Access to the power grid; Through the DC port V DC1 and V DC2 The power control generates control parameters ctr on the DC side; VSG is used to control the AC side, and the output voltage V* is obtained through active loop and reactive loop control, and the reference voltage V is obtained through voltage and current double closed loop control. m ; Set the control parameter ctr, reference voltage V m And DC side voltage ratio V DC1 / V DC2 The three-level carrier wave pulse width modulation wave generator is input as an input quantity to generate a modulation wave and a driving pulse signal for the hybrid device.

2. The three-phase three-port converter control method according to claim 1, characterized in that: The three-phase three-port converter adopts an active midpoint clamp structure. Each phase uses four silicon carbide MOSFETs and two silicon-based IGBTs as switch units. The DC power supply V DC2 Directly connected to the midpoint of the bridge arm.

3. The three-phase three-port converter control method according to claim 2, characterized in that: The reference voltage V of the initial modulation wave of the upper and lower bridge arms of the converter m On the contrary, the carrier wave is composed of a set of triangular waves, and the modulating wave needs to be corrected. The correction offset is α, which is defined as: α=2V DC2 / V DC1 -1 When α>0, the modulation wave shifts upward, the amplitude of the positive half cycle becomes 1-α, and the amplitude of the negative half cycle becomes 1+α; When α<0, the change rule is opposite.

4. The three-phase three-port converter control method according to claim 1, characterized in that: Obtaining the output voltage V* includes the following steps: The inertia and primary frequency modulation characteristics of the synchronous generator are simulated through the active loop; The phase θ of the output reference voltage; The primary voltage regulation characteristics of synchronous generators are simulated through reactive loops; The amplitude of the output reference voltage V; V* is obtained by voltage synthesis.

5. The three-phase three-port converter control method according to claim 4, characterized in that: The calculated output voltage V* is controlled by voltage and current double closed loop to obtain a new reference voltage V m * As the input quantity of the modulation wave generator of three-level carrier pulse width modulation.

6. The three-phase three-port converter control method according to claim 3, characterized in that: The size and offset direction of the injected zero-sequence component of the modulation wave are adjusted according to the control parameter ctr, the initial sinusoidal modulation wave is changed into a saddle wave, and the duty cycle of the output PWM signal and the on-off time of the switch tube are changed.

7. The three-phase three-port converter control method according to claim 6, characterized in that: The control parameter ctr ranges from -1 to 1.

8. A three-phase three-port converter control device, characterized in that: include: DC port, used to provide DC power V DC1 and V DC2 ; AC port, through the filter inductor L f Intervention into the power grid to achieve the transmission of AC power; The power control module is used to connect the DC power supply V DC1 and V DC2 The power control generates the DC side control parameter ctr; The VSG control module is used to control the AC side, generate the output voltage V* through active loop and reactive loop control, and obtain the reference voltage V through voltage and current double closed loop control. m ; Three-level carrier pulse width modulation wave generator, used to receive control parameters ctr, reference voltage V m And DC side voltage ratio V DC1 / V DC2 As input, a modulation wave is generated and a driving pulse signal for the hybrid device is produced.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

10. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

Images