ACDC bidirectional single-stage energy storage converter and modulation method thereof, and storage medium

Abstract

The invention relates to the technical field of power electronic control, and discloses an ACDC bidirectional single-stage energy storage converter and a modulation method thereof, and a storage medium, through configuring a power control unit, an energy conversion unit, a filtering unit and a bus capacitor into a whole, dual functions of boost inversion and rectification voltage reduction are realized, the integration level of a system is significantly improved, and the system reliability is improved. Particularly, bidirectional unobstructed flow of power is realized based on the energy conversion unit, the energy storage converter can be ensured to stably work in a bidirectional mode of discharging and charging, and a first SPWM modulation signal and a second SPWM modulation signal are generated through a plurality of pre-configured signals. Therefore, the turn-off states of the third switch tube and the fourth switch tube are controlled based on the first SPWM modulation signal, and the turn-off states of the first switch tube and the second switch tube are controlled based on the second SPWM modulation signal, so that the complementary turn-off control of the switch tubes is realized, and the high efficiency of the energy storage converter in different application occasions is maintained. The device is especially suitable for application occasions with low power and high portability requirements.

Description

Technical Field

[0001] This invention relates to the field of power electronic control technology, and in particular to an AC-CDC bidirectional single-stage energy storage converter and its modulation method, electronic equipment, and computer-readable storage medium. Background Technology

[0002] Portable energy storage power supplies refer to miniaturized energy storage systems with built-in energy storage batteries. They have AC and DC power supply capabilities and are lightweight, safe, portable, easy to operate, noiseless, and environmentally friendly. They can widely replace small fuel generators and are also known as "outdoor power supplies." They are suitable for various scenarios such as outdoor travel, emergency rescue, medical relief, and outdoor operations.

[0003] Currently, most mainstream energy storage converters on the market adopt a two-stage design. The front stage uses a DC / DC buck-boost converter and PWM modulation strategy to flexibly adjust the DC voltage, while the rear stage is cascaded with the front stage using a full-bridge structure and uses SPWM modulation strategy to achieve voltage rectification and inversion. Although this structure allows the front and rear stages to work independently and provides a flexible control method for cascaded voltage, the instability of front and rear cascading means that the intermediate connection needs to rely on large electrolytic capacitors, and the front and rear stages may not necessarily have high conversion efficiency, which cannot ensure the high efficiency of the overall system application. At the same time, this design also faces the challenges of large size and low integration. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, this invention proposes an AC-CDC bidirectional single-stage energy storage converter, its modulation method, and a storage medium, which can significantly improve the system integration of the energy storage converter and maintain its high efficiency in different applications.

[0005] In a first aspect, embodiments of the present invention provide an ACDC bidirectional single-stage energy storage converter, comprising: The power control unit is used to output a DC-DC converter voltage during discharge or a rectified voltage during charging. An energy conversion unit is used to realize unobstructed bidirectional power flow. The energy conversion unit includes a first conversion element and a second conversion element, both of which are connected to the power control unit. The filtering unit includes a first filtering circuit for filtering out high-frequency noise from voltage fluctuations and a second filtering circuit for filtering out high-order harmonics from the output AC. One end of the first filtering circuit is connected to the first conversion element and the second conversion element, respectively, and the other end is connected to a DC source. One end of the second filtering circuit is connected to the power control unit, and the other end is connected to an AC source. The bus capacitor is connected in parallel across the power control unit to stabilize the DC-DC converter voltage or the rectified voltage.

[0006] Optionally, in one embodiment of the present invention, the power control unit includes a first switch, a second switch, a third switch, and a fourth switch. The first switch and the second switch are connected in series to form a first branch, and the third switch and the fourth switch are connected in series to form a second branch. The first branch and the second branch are connected in parallel. The source of the first switch is connected to the drain of the second switch and the source of the third switch, respectively. The drain of the second switch and the source of the third switch are also connected to the drain of the fourth switch. The drain of the first switch is connected to the drain of the third switch, and the source of the second switch is connected to the source of the fourth switch.

[0007] Optionally, in one embodiment of the present invention, the first end of the first conversion element and the first end of the second conversion element are both connected to the midpoint between the source of the first switching transistor and the drain of the second switching transistor, and the second end of the first conversion element is connected to the second end of the second conversion element.

[0008] Optionally, in one embodiment of the present invention, the first filter circuit includes a first inductor and a first capacitor, the first capacitor being connected in parallel to a DC source, one end of the first inductor being connected to the DC source and the first capacitor respectively, and the other end being connected to the second terminal of the first conversion element and the second terminal of the second conversion element respectively; the second filter circuit includes a second inductor and a second capacitor, the second capacitor being connected in parallel to an AC source, one end of the second inductor being connected to the AC source and the second capacitor respectively, and the other end being connected to the midpoint between the source of the third switch and the drain of the fourth switch.

[0009] Optionally, in one embodiment of the present invention, one end of the bus capacitor is connected to the drain of the first switching transistor, and the other end is connected to the source of the second switching transistor.

[0010] In a second aspect, embodiments of the present invention also provide a modulation method for an ACDC bidirectional single-stage energy storage converter as described in the first aspect, comprising the following steps: Step S1: Generate the corresponding upper sine half-wave and lower sine half-wave according to the pre-configured initial sine wave, wherein the amplitude of the upper sine half-wave is greater than 0 and the amplitude of the lower sine half-wave is less than 0. Step S2: Superimpose the acquired DC bias signal with the lower sine half-wave and the upper sine half-wave to obtain the first half-wave modulation signal and the second half-wave modulation signal respectively. Step S3: Compare the first half-wave modulation signal and the second half-wave modulation signal with the pre-configured carrier signal respectively, and generate the first SPWM modulation signal and the second SPWM modulation signal accordingly. Step S4: Control the turn-off state of the third switch and the fourth switch based on the first SPWM modulation signal, and control the turn-off state of the first switch and the second switch based on the second SPWM modulation signal, so as to perform complementary turn-off control on the first switch, the second switch, the third switch and the fourth switch.

[0011] Optionally, in one embodiment of the present invention, step S4 includes the following steps: Step S41: When the energy storage converter is in a discharge state, if the voltage of the first half-wave modulation signal at a certain moment exceeds the voltage of the carrier signal at the same moment, control the fourth switch to turn on and the third switch to turn off; otherwise, control the third switch to turn on and the fourth switch to turn off. Also, if the voltage of the second half-wave modulation signal at a certain moment exceeds the voltage of the carrier signal at the same moment, control the second switch to turn on and the first switch to turn off; otherwise, control the first switch to turn on and the second switch to turn off. or, Step S42: When the energy storage converter is in a charging state, if the voltage of the first half-wave modulation signal at a certain moment exceeds the voltage of the carrier signal at the same moment, control the third switch to turn on and the fourth switch to turn off; otherwise, control the fourth switch to turn on and the third switch to turn off. Also, if the voltage of the second half-wave modulation signal at a certain moment exceeds the voltage of the carrier signal at the same moment, control the first switch to turn on and the second switch to turn off; otherwise, control the second switch to turn on and the first switch to turn off.

[0012] Optionally, in one embodiment of the present invention, when the energy storage converter is in a discharge state, the amplitude of the first half-wave modulation signal and the amplitude of the second half-wave modulation signal are both greater than 0. When the energy storage converter is in a charging state, the amplitude of both the first half-wave modulation signal and the amplitude of the second half-wave modulation signal are less than 1.

[0013] Thirdly, embodiments of the present invention also provide an electronic device, comprising: At least one processor; At least one memory for storing at least one program; When at least one of the programs is executed by at least one of the processors, the modulation method of the ACDC bidirectional single-stage energy storage converter as described in the second aspect is implemented.

[0014] Fourthly, embodiments of the present invention also provide a computer-readable storage medium storing a processor-executable program, which, when executed by a processor, is used to implement the modulation method of the ACDC bidirectional single-stage energy storage converter as described in the second aspect.

[0015] This invention proposes an AC-DC bidirectional single-stage energy storage converter, its modulation method, and storage medium. By integrating a power control unit, energy conversion unit, filter unit, and bus capacitor into one unit, it achieves dual functions of boost inverter and rectification buck converter, significantly improving the system's integration. In particular, the energy conversion unit enables unimpeded bidirectional power flow, ensuring the energy storage converter operates stably in both discharging and charging modes. Furthermore, by generating a first SPWM modulation signal and a second SPWM modulation signal using a pre-configured sinusoidal initial wave, DC bias signal, and carrier signal, the first and second SPWM modulation signals are controlled based on the first SPWM modulation signal to control the turn-off states of the third and fourth switches, and based on the second SPWM modulation signal to control the turn-off states of the first and second switches. This achieves complementary turn-off control of each switch, maintaining the energy storage converter's high efficiency in various applications, especially those requiring low power and high portability. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of an ACDC bidirectional single-stage energy storage converter provided in an embodiment of the present invention; Figure 2 This is a circuit topology diagram of an ACDC bidirectional single-stage energy storage converter provided in an embodiment of the present invention; Figure 3 This is a flowchart of a modulation method for an ACDC bidirectional single-stage energy storage converter provided in an embodiment of the present invention; Figure 4 This is a modulation schematic diagram of an ACDC bidirectional single-stage energy storage converter in a discharge state according to an embodiment of the present invention; Figure 5 This is a control waveform diagram of each switch of an ACDC bidirectional single-stage energy storage converter in the discharge state, provided by an embodiment of the present invention. Figure 6(a) shows the overall equivalent circuit diagram of the energy storage converter in the discharge state during the T0 time period; Figure 6(b) shows the equivalent circuit diagram of the energy storage converter in the discharge state during the T0 time period of the Boost converter; Figure 6(c) is the equivalent circuit diagram of the full-bridge circuit of the energy storage converter in the discharge state during the T0 time period; Figure 7(a) shows the overall equivalent circuit diagram of the energy storage converter in the discharge state during time period T1; Figure 7(b) shows the equivalent circuit diagram of the Boost converter of the energy storage converter in the discharge state during the T1 time period; Figure 7(c) is the equivalent circuit diagram of the full-bridge circuit of the energy storage converter in the discharge state during the T1 time period. Figure 8(a) shows the overall equivalent circuit diagram of the energy storage converter in the discharge state during time period T3; Figure 8(b) shows the equivalent circuit diagram of the energy storage converter in the discharge state during the T3 time period of the Boost converter; Figure 8(c) is the equivalent circuit diagram of the full-bridge circuit of the energy storage converter in the discharge state during the T3 time period; Figure 9 This is a modulation diagram of an ACDC bidirectional single-stage energy storage converter in a charging state according to an embodiment of the present invention; Figure 10 This is a control waveform diagram of each switching transistor of an ACDC bidirectional single-stage energy storage converter in the charging state, provided by an embodiment of the present invention. Figure 11(a) is the overall equivalent circuit diagram of the energy storage converter in the charging state during the T0 period; Figure 11(b) is the equivalent circuit diagram of the rectifier circuit of the energy storage converter in the charging state during the T0 period. Figure 11(c) is the equivalent circuit diagram of the energy storage converter in the charging state during the T0 time period of the Buck converter; Figure 12(a) shows the overall equivalent circuit diagram of the energy storage converter in the charging state during time period T1; Figure 12(b) is the equivalent circuit diagram of the rectifier circuit of the energy storage converter in the charging state during the T1 time period; Figure 12(c) is the equivalent circuit diagram of the energy storage converter in the charging state during the T1 time period of the Buck converter; Figure 13(a) shows the overall equivalent circuit diagram of the energy storage converter in the charging state during time period T2; Figure 13(b) is the equivalent circuit diagram of the rectifier circuit of the energy storage converter in the charging state during the T2 period; Figure 13(c) is the equivalent circuit diagram of the energy storage converter in the charging state during the T2 time period of the Buck converter; Figure 14 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0018] It should be noted that although functional modules are divided in the device schematic diagram and the logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart.

[0019] Figure 1 This is a schematic diagram of the structure of an ACDC bidirectional single-stage energy storage converter provided in an embodiment of the present invention, as shown below. Figure 1 As shown, the ACDC bidirectional single-stage energy storage converter may include, but is not limited to, the following: The power control unit 100 is used to output a DC-DC converter voltage during discharge or a rectified voltage during charging. The energy conversion unit 200 is used to realize the bidirectional unobstructed flow of power. The energy conversion unit 200 includes a first conversion element SLa and a second conversion element SLb, both of which are connected to the power control unit 100. The filtering unit includes a first filtering circuit 300 for filtering out high-frequency noise from voltage fluctuations and a second filtering circuit 400 for filtering out high-order harmonics from the output AC. One end of the first filtering circuit 300 is connected to the first conversion element SLa and the second conversion element SLb, respectively, and the other end is connected to a DC source. One end of the second filtering circuit 400 is connected to the power control unit 100, and the other end is connected to an AC source. The DC source or the AC source needs to be determined according to the actual situation. For example, the voltage of the DC source can be set by the user, and the AC source can use mains power or other AC power sources. There are no restrictions here. The bus capacitor C2 is connected in parallel across the power control unit 100 to stabilize the DC conversion voltage or rectified voltage.

[0020] As can be seen, the AC / DC bidirectional single-stage energy storage converter provided in this embodiment is essentially a power conversion device that does not require separate front and rear stages (DC / DC or DC / AC), but instead achieves bidirectional conversion of AC and DC power (i.e., AC→DC charging, DC→AC discharging) through a single bridge circuit topology. It features a compact structure and high integration. By integrating the power control unit 100, energy conversion unit 200, filter unit, and bus capacitor C2 into one unit, it achieves the dual functions of boost inverter and rectification buck, significantly improving the system integration. In particular, the unobstructed bidirectional power flow based on the energy conversion unit 200 ensures that the energy storage converter operates stably in the bidirectional modes of discharging and charging.

[0021] In one embodiment, the power control unit 100 may be implemented using, but is not limited to, multiple switching elements, that is, the voltage output control for the discharge or charging state is achieved by combining and switching multiple switching elements; the first conversion element SLa and the second conversion element SLb may be, but are not limited to, MOSFETs, which can be used to realize bidirectional energy conversion, that is, to realize bidirectional energy flow between the energy storage battery and the external circuit (grid / load), supporting both charging (grid → battery) and discharging (battery → load).

[0022] In one embodiment, such as Figure 2 As shown, the power control unit may include, but is not limited to, a first switch Sa, a second switch Sb, a third switch Sc, and a fourth switch Sd. The first switch Sa and the second switch Sb are connected in series to form a first branch, and the third switch Sc and the fourth switch Sd are connected in series to form a second branch. The first branch and the second branch are connected in parallel. The source of the first switch Sa is connected to the drain of the second switch Sb and the source of the third switch Sc. The drain of the second switch Sb and the source of the third switch Sc are also connected to the drain of the fourth switch Sd. The drain of the first switch Sa is connected to the drain of the third switch Sc, and the source of the second switch Sb is connected to the source of the fourth switch Sd. It can be seen that by adopting the core topology of bridge switches, the functions of energy rectification, inversion, boost, and buck can be integrated through the complementary conduction of the switches to maintain the high efficiency of the energy storage converter in different applications. The switches may be, but are not limited to, MOSFETs.

[0023] In one embodiment, such as Figure 2 As shown, the first end of the first switching element SLa and the first end of the second switching element SLb are both connected to the midpoint between the source of the first switching transistor Sa and the drain of the second switching transistor Sb, and the second end of the first switching element SLa is connected to the second end of the second switching element SLb.

[0024] In one embodiment, such as Figure 2As shown, the first filter circuit may include, but is not limited to, a first inductor L1 and a first capacitor C1. The first capacitor C1 is connected in parallel to the DC source DC. One end of the first inductor L1 is connected to both the DC source DC and the first capacitor C1, and the other end is connected to the second terminal of the first conversion element SLa and the second terminal of the second conversion element SLb. The second filter circuit includes a second inductor L2 and a second capacitor C3. The second capacitor C3 is connected in parallel to the AC source AC. One end of the second inductor L2 is connected to both the AC source AC and the second capacitor C3, and the other end is connected to the third switching transistor S. The midpoint between the source of capacitor C and the drain of the fourth switching transistor Sd is used. The first inductor L1 serves as a step-up / step-down inductor, combining both boost and buck functions. This is equivalent to integrating the independent boost and buck inductors found in a traditional two-stage converter, simplifying the circuit structure. The first capacitor C1 can be used to filter out high-frequency noise on the DC side. The second capacitor C3 and the second inductor L2 form a filter circuit on the AC side, filtering out high-order harmonics in the AC output, improving the output voltage waveform quality, meeting the load's requirements for the power supply waveform, and ensuring stable output voltage.

[0025] In one embodiment, such as Figure 2 As shown, one end of the bus capacitor C2 is connected to the drain of the first switching transistor Sa, and the other end is connected to the source of the second switching transistor Sb. Using the bus capacitor C2 as an intermediate cascaded capacitor, it can replace the large electrolytic capacitor in the traditional two-stage converter to stabilize the bus voltage after rectification or inversion, reduce voltage ripple, and improve system stability.

[0026] Figure 3 This is a flowchart of a modulation method provided in an embodiment of the present invention. This modulation method can be applied to, but is not limited to, [various applications]. Figure 1 or Figure 2 The ACDC bidirectional single-stage energy storage converter shown in the figure; such as Figure 3 As shown, the modulation method of the ACDC bidirectional single-stage energy storage converter may include, but is not limited to, steps S1 to S4.

[0027] Step S1: Generate the corresponding upper sine half-wave and lower sine half-wave according to the pre-configured initial sine wave, wherein the amplitude of the upper sine half-wave is greater than 0 and the amplitude of the lower sine half-wave is less than 0. Step S2: Superimpose the obtained DC bias signal with the lower sine half-wave and the upper sine half-wave to obtain the first half-wave modulation signal and the second half-wave modulation signal. That is, the first half-wave modulation signal and the second half-wave modulation signal are both sine half-wave reference signals with DC bias, which can directly determine the conduction logic of the switching transistor. Step S3: Compare the first half-wave modulation signal and the second half-wave modulation signal with the pre-configured carrier signal respectively, and generate the first SPWM modulation signal and the second SPWM modulation signal accordingly. The carrier signal refers to the high-frequency reference signal compared with the corresponding modulation wave signal during the modulation process. It can be, but is not limited to, an isosceles triangular wave or a leading / trailing sawtooth wave, etc. Its frequency determines the switching period length. The higher the frequency, the fewer the output harmonics, but the greater the switching loss. Step S4: Control the turn-off state of the third switch Sc and the fourth switch Sd based on the first SPWM modulation signal, and control the turn-off state of the first switch Sa and the second switch Sb based on the second SPWM modulation signal, so as to perform complementary turn-off control on the first switch Sa, the second switch Sb, the third switch Sc and the fourth switch Sd. The complementary turn-off control means that when one of the switches is turned on, the other is turned off (e.g., when the third switch Sc is turned on, the fourth switch Sd is turned off), to avoid short circuit risk and ensure the safety and efficiency of high-frequency switching operation.

[0028] As can be seen, by generating the first SPWM modulation signal and the second SPWM modulation signal through the pre-configured sinusoidal initial wave, DC bias signal and carrier signal, the first switch Sc and the fourth switch Sd are controlled based on the first SPWM modulation signal, and the first switch Sa and the second switch Sb are controlled based on the second SPWM modulation signal, so as to achieve complementary turn-off control of each switch, thereby maintaining the high efficiency of the energy storage converter in different applications, especially in applications with low power and high portability requirements. The whole process adopts hybrid SPWM (sinusoidal pulse width modulation) modulation technology, which is a hybrid modulation strategy that integrates SPWM and fixed duty cycle PWM. The rectification stage uses SPWM to stabilize the bus voltage, and the step-down stage uses fixed duty cycle PWM to adjust the voltage level, taking into account both stability and adjustment flexibility. By precisely controlling the conduction and turn-off of the switches, the efficient and stable conversion of DC and AC in the same stage circuit is achieved, thereby improving the overall performance and stability of the power electronic system. In hybrid SPWM modulation, the system dynamically adjusts the modulation strategy according to actual needs to optimize the output waveform, reduce harmonic distortion, improve the power factor, and reduce switching losses.

[0029] In one embodiment, step S4 may include, but is not limited to, the following steps: Step S41: When the energy storage converter is in the discharge state, if the voltage of the first half-wave modulation signal at a certain moment exceeds the voltage of the carrier signal at the same moment, control the fourth switch Sd to turn on and the third switch Sc to turn off; otherwise, control the third switch Sc to turn on and the fourth switch Sd to turn off. Also, if the voltage of the second half-wave modulation signal at a certain moment exceeds the voltage of the carrier signal at the same moment, control the second switch Sb to turn on and the first switch Sa to turn off; otherwise, control the first switch Sa to turn on and the second switch Sb to turn off. Here, the discharge state refers to the converter being in DC→AC working mode, where the battery DC voltage is boosted by the Boost converter and then inverted into power frequency AC power by the full-bridge unit to supply power to the external AC load.

[0030] In this step, when the energy storage converter is discharging, one pair of full-bridge arms operates in PWM mode with a fixed duty cycle. This pair of arms acts as a boost circuit, ensuring that the input voltage is raised to the preset voltage level. Simultaneously, the other pair of arms operates in SPWM mode, serving as the core of the inverter circuit and responsible for converting DC power to the required AC power. It is worth noting that as the output voltage changes within different positive and negative half-cycles, the operating modes of these two pairs of arms switch accordingly to ensure the symmetry of the discharge process, thereby outputting stable and reliable AC power. This hybrid SPWM modulation strategy combines the advantages of PWM and SPWM modes, maintaining a constant charging and discharging time for the first inductor L1, helping to maintain the continuity of the inductor current, providing a stable voltage for the bus capacitor C2, and facilitating the design and optimization of the system inductors, thus improving the overall system performance.

[0031] The following combination Figure 4 The given modulation diagram under the discharge state provides a detailed explanation of the working principle of step S41.

[0032] The core of this modulation strategy lies in using a sine wave to generate two sets of sinusoidal half-waves with a 180° phase difference, thereby simultaneously satisfying the requirements of both PWM and SPWM modulation modes. This strategy involves three key signals: urdc (i.e., DC bias signal), urac (i.e., initial sine wave), and uc (i.e., carrier signal). In PWM mode, urdc is responsible for regulating the bus voltage UC2 to ensure that the voltage gain of the bus capacitor C2 remains stable during discharge. In SPWM mode, urac is responsible for controlling the output AC voltage and current to achieve precise power conversion. uc, as the carrier signal to be compared, requires consideration of multiple factors in practical applications to select an appropriate carrier frequency for optimal performance.

[0033] Specifically, refer to Figure 4In the modulation stage, the urac signal is first mathematically transformed to obtain the desired sinusoidal half-wave signal. Then, these two sinusoidal half-wave signals are superimposed on the urdc signal to generate a first half-wave modulation signal urac1 and a second half-wave modulation signal urac2 with DC bias. These two modulation signals are then compared with uc, resulting in two SPWM signals (the first SPWM modulation signal and the second SPWM modulation signal) output by a comparator to directly control the state of the switching transistors. Specifically, when the voltage of urac1 is higher than uc, the fourth switch Sd is turned on while the third switch Sc is turned off; conversely, when urac1 is lower than uc, the third switch Sc is turned on while the fourth switch Sd is turned off. The same logic applies to the control of the first switch Sa and the second switch Sb by urac2, which will not be elaborated further. It can be seen that this complementary switching transistor control strategy ensures the precise execution of high-frequency switching operations.

[0034] In particular, the amplitudes of urac1 and urac2 should both remain non-negative in this case, meaning the boost duty cycle of the Boost circuit must be greater than or equal to the modulation ratio of the inverter to avoid output voltage waveform distortion caused by overmodulation. Analysis reveals that a key operating mode of this energy storage converter during the discharge phase is: the first inductor L1 will only release energy to charge the bus capacitor C2 when the first switch Sa and the third switch Sc are simultaneously turned on. If the bipolar modulation strategy in existing technologies is used, the first inductor L1 will not be able to effectively release its stored energy because the output level at the midpoint of the full-bridge arm does not include a zero-level state. If a unipolar SPWM modulation method is used, the input inductor current will be unstable, resulting in discontinuity, accompanied by higher peak current and ripple. The application effect is not as good as the hybrid SPWM modulation technology used in this embodiment. The following analysis combines specific timing data to examine the steady-state characteristics of the inverter modulation during the discharge state.

[0035] It should be noted that, in order to simplify the analysis, the following reasonable assumptions are made, but they are not the only limitations: (1) Each MOSFET switch is idealized, that is, the influence of its internal parasitic parameters is ignored; (2) The second inductor L2 is large enough, which means that the current flowing through the second inductor L2 changes very little during a switching cycle, and can be regarded as constant. This assumption greatly simplifies the analysis of current and makes the voltage change clearer. (3) The bus capacitor C2 has sufficient capacity, so its voltage ripple is very small. The bus voltage can be approximated as constant. That is, the bus capacitor C2 can be regarded as a stable voltage source, which further simplifies the circuit analysis. (4) Under normal operating conditions, the current flowing through the first inductor L1 is continuous.

[0036] Based on the above assumptions, the circuit is divided into two independent parts for in-depth analysis using the superposition principle. The first part is the Boost converter, which is mainly responsible for boosting the input voltage to a higher level, providing sufficient voltage margin for the subsequent inverter process. During the operation of the Boost converter, the switching state of each MOSFET directly affects the charging and discharging process of the first inductor L1, thereby controlling the output voltage. The second part is the full-bridge inverter, where the four MOSFET switches generate the desired sinusoidal output voltage, operating based on PWM modulation and SPWM modulation. Therefore, by superimposing the analysis results of the two parts, the discharge process within the entire switching cycle can be determined. Specifically, this process can be broken down into the following four specific operating states: First, refer to Figure 5 The control waveforms of each switch under discharge conditions are shown. T0-T3 is the positive half-cycle, and T4-T7 is the negative half-cycle. The table below shows the timing of the switches under this condition. "1" indicates conduction and "0" indicates disconnection.

[0037] Table 1 - Timing table of hybrid SPWM modulation switching transistors under discharge conditions (1) T0 stage: Before the T0 period, the first switch Sa and the third switch Sc are in the on state. The first inductor L1 is in the linear discharge state due to the reverse voltage, that is, the difference between UC2 and UC1 (UC2 is the voltage across the second inductor L2 and UC1 is the voltage across the first inductor L1). At the beginning of the T0 period, the first switch Sa remains on, the third switch Sc is turned off, and then the fourth switch Sd is turned on until the end of the T0 period. The circuit state during the T0 period is shown in Figure 6(a), Figure 6(b) and Figure 6(c). Among them, Figure 6(a) is the overall equivalent circuit diagram of the energy storage converter, Figure 6(b) is the equivalent circuit diagram of the Boost converter, and Figure 6(c) is the equivalent circuit diagram of the full bridge circuit. During time period T0, the second switch Sb in the Boost converter remains on, allowing current to flow. At this time, a positive voltage is applied to the first inductor L1, and it begins to draw energy from the DC source for energy storage. Simultaneously, the current flowing through the first inductor L1... It increases gradually in a linear manner, that is , The current flowing through the second conversion element SLb, This refers to the current between the fourth switch Sd and the DC source DC. The following parameters are named accordingly, and will not be elaborated further. During the T0 period, for the full-bridge inverter section, the current of the second inductor L2... A specific current path is formed through the first switch Sa and the second switch Sb. Therefore, we can obtain: .

[0038] (2) T1 stage: During time period T1, the previously conducting first switch Sa is turned off, while the second switch Sb becomes on. The third and fourth switches Sc and Sd remain unchanged. The circuit states during time period T1 are shown in Figures 7(a), 7(b), and 7(c). Figure 7(a) is the overall equivalent circuit diagram of the energy storage converter, Figure 7(b) is the equivalent circuit diagram of the Boost converter, and Figure 7(c) is the equivalent circuit diagram of the full-bridge circuit. It can be seen that during time period T1, the second switch Sb of the Boost converter is in the off state, and its voltage is 0. The first switch Sa is on, and the first inductor L1 bears a positive voltage UC1. The current flowing through the first inductor L1... It increases gradually in a linear manner, that is The full-bridge inverter uses the second switch Sb and the fourth switch Sd as freewheeling paths; therefore, we can obtain: .

[0039] (3) T2 phase: The T2 period is the same as the T0 period. Please refer to the above description of the working state of the T0 period and its equivalent circuit diagram. It will not be repeated here.

[0040] (4) T3 stage: Entering time period T3, the previously conducting fourth switch Sd is turned off, the third switch Sc turns on, and the states of the first switch Sa and the second switch Sb remain unchanged. During this time period, the first inductor L1 begins to release its stored energy and uses this energy to charge the bus capacitor C2. The circuit states during time period T1 are shown in Figures 8(a), 8(b), and 8(c). Figure 8(a) is the overall equivalent circuit diagram of the energy storage converter, Figure 8(b) is the equivalent circuit diagram of the Boost converter, and Figure 8(c) is the equivalent circuit diagram of the full-bridge circuit. In the current Boost circuit section, the second switch Sb enters the off state, and the voltage drop across it is zero. At the same time, the first switch Sa turns on, causing the current in the first inductor L1 to... The current is freewheeled through the first switching element SLa. During this process, a reverse voltage difference, UC2 minus UC1, is experienced across the first inductor L1. This voltage difference causes the current in the first inductor L1 to... Decrease gradually in a linear manner, that is In the full-bridge circuit section, the current in the second inductor L2... Freewheeling is achieved by controlling the conduction states of the first switch Sa and the third switch Sc to ensure a continuous flow of energy in the circuit. Based on this, the following conclusion can be drawn: .

[0041] In one embodiment, step S4 may include, but is not limited to, the following steps: Step S42: When the energy storage converter is in the charging state, if the voltage of the first half-wave modulation signal at a certain moment exceeds the voltage of the carrier signal at the same moment, control the third switch Sc to turn on and the fourth switch Sd to turn off; otherwise, control the fourth switch Sd to turn on and the third switch Sc to turn off. Also, if the voltage of the second half-wave modulation signal at a certain moment exceeds the voltage of the carrier signal at the same moment, control the first switch Sa to turn on and the second switch Sb to turn off; otherwise, control the second switch Sb to turn on and the first switch Sa to turn off. Here, the discharging state refers to the converter being in AC→DC working mode, where the external power frequency AC is rectified into DC by the full-bridge rectifier, and then stepped down to the battery adaptation voltage by the Buck converter to realize the charging of the energy storage battery.

[0042] In this step, when the energy storage converter is charging, a hybrid SPWM technology is employed. When it receives an input sinusoidal AC power supply, its rectifier bridge section uses SPWM modulation to stably raise the voltage of the bus capacitor C2 to a preset level. Simultaneously, the Buck converter operates in a fixed duty cycle PWM mode through a pair of bridge arms, aiming to reduce the voltage of the bus capacitor C2 to the required voltage level. To maintain the symmetry of the charging process, the two pairs of bridge arms alternately switch their operating modes within a set time period. This hybrid SPWM modulation strategy combines the advantages of both SPWM and PWM modes, ensuring that the charging and discharging time of the first inductor L1 remains constant, while also maintaining continuous current and reducing current ripple, thereby significantly improving the overall system performance.

[0043] The following combination Figure 9 The given modulation diagram in the charging state provides a detailed explanation of the working principle of step S42.

[0044] The core of this modulation strategy lies in using a sine wave to generate two sets of sinusoidal half-waves with a 180° phase difference, thereby simultaneously satisfying the requirements of both PWM and SPWM modulation modes. This strategy involves three key signals: urdc (i.e., DC bias signal), urac (i.e., initial sine wave), and uc (i.e., carrier signal). In PWM mode, urdc is used to ensure that the voltage value of the first capacitor C1 in the buck converter remains stable, while in SPWM mode, urac is used to precisely control the DC voltage delivered by the rectifier to the bus capacitor C2; uc, as the carrier signal to be compared, requires consideration of multiple factors in practical applications to select an appropriate carrier frequency to achieve optimal performance.

[0045] Specifically, refer to Figure 9 In the modulation stage, the urac signal is first mathematically transformed to obtain the desired sinusoidal half-wave signal. Then, these two sinusoidal half-wave signals are superimposed on the urdc signal to generate a first half-wave modulation signal urac1 and a second half-wave modulation signal urac2 with DC bias. These two modulation signals are then compared with uc, resulting in two SPWM signals (the first SPWM modulation signal and the second SPWM modulation signal) output by a comparator to directly control the state of the switching transistors. Specifically, when the voltage of urac1 is higher than uc, the first switching transistor Sa is turned on while the second switching transistor Sb is turned off; conversely, when urac1 is lower than uc, the second switching transistor Sb is turned on while the first switching transistor Sa is turned off. The same logic applies to the control of the third switching transistor Sc and the fourth switching transistor Sd by urac2, which will not be elaborated further. It can be seen that this complementary switching transistor control strategy ensures the precise execution of high-frequency switching operations.

[0046] In particular, the amplitudes of urac1 and urac2 in this case should both be controlled below 1, meaning the sum of the duty cycle of the DC step-down converter and the modulation ratio of the rectifier should be less than or equal to 1. Exceeding this limit will trigger overmodulation, causing distortion of the voltage waveform output by the energy storage converter, thus affecting the system's performance and stability. Analysis shows that a specific energy flow path exists during the charging process of the energy storage converter. Specifically, during the positive half-cycle, when the second switch Sb is turned on, only the third switch Sc is turned on, allowing the bus capacitor C2 to charge the first inductor L1. Similarly, during the negative half-cycle, when the first conversion element SLa is turned on, only the first switch Sa is turned on, allowing the bus capacitor C2 to charge the first inductor L1. If a bipolar modulation strategy from existing technologies is used, since the output level at the midpoint of the full-bridge arm does not include a zero-level state, the first inductor L1 will not receive the necessary energy. However, if a unipolar SPWM is used… Although the modulation method can ensure that the converter outputs a sinusoidal voltage, since a certain switch in the lower bridge arm is always on for half a cycle, the first inductor L1 will continue to discharge and cannot be replenished with energy. In this state, the inductor current is prone to discontinuity, the peak current and ripple increase, and the change in the inductor charging time will also make it difficult to determine the inductor parameters. The application effect is not as good as the hybrid SPWM modulation technology used in this embodiment. The following analysis combines specific timing to determine the steady-state characteristics of inverter modulation under the discharge state.

[0047] It should be noted that, in order to simplify the analysis, the following reasonable assumptions are made, but they are not the only limitations: (1) Each MOSFET switch is idealized, that is, the influence of its internal parasitic parameters is ignored; (2) The second inductor L2 is large enough, which means that the current flowing through the second inductor L2 changes very little during a switching cycle, and can be regarded as constant. This assumption greatly simplifies the analysis of current and makes the voltage change clearer. (3) The bus capacitor C2 has sufficient capacity, so its voltage ripple is very small. The bus voltage can be approximated as constant. That is, the bus capacitor C2 can be regarded as a stable voltage source, which further simplifies the circuit analysis. (4) Under normal operating conditions, the current flowing through the first inductor L1 is continuous.

[0048] Based on the above assumptions, the circuit is divided into two independent parts for in-depth analysis using the superposition principle. The first part is the full-bridge inverter section, where four MOSFET switches are precisely controlled to generate the desired sinusoidal output voltage. This section operates based on PWM technology, achieving precise control of the output voltage waveform and amplitude by flexibly adjusting the switching cycle and phase. The second part is the Buck converter section, where the switching status of each MOSFET directly affects the charging and discharging of the relevant inductors, thus influencing the strength of the output voltage. Integrating the analyses of these two parts provides a comprehensive picture of the charging dynamics throughout the entire operating cycle. Specifically, this process can be broken down into the following four specific operating states: First, refer to Figure 10 The control waveform diagram of each switch in the charging state is shown. T0-T3 is the positive half-cycle, and T4-T7 is the negative half-cycle. The table below shows the timing of the switches in this case. "1" indicates that the switch is turned on and "0" indicates that the switch is turned off.

[0049] Table 2 - Timing table of switching transistors under hybrid SPWM modulation in charging state (1) T0 stage: Before time period T0, the first switch Sa and the fourth switch Sd are in the on state; just entering time period T0, the fourth switch Sd is turned off, the third switch Sc is turned on, and the first switch Sa and the second switch Sb remain unchanged until the end of time period T0. The circuit state during time period T0 is shown in Figures 11(a), 11(b), and 11(c). Figure 11(a) is the overall equivalent circuit diagram of the energy storage converter, Figure 11(b) is the equivalent circuit diagram of the rectifier circuit, and Figure 11(c) is the equivalent circuit diagram of the Buck converter. During time period T0, in the Boost converter section, the first conversion element SLa is cut off, and its voltage is 0. The second switch Sb is turned on, and the bus capacitor C2 charges the first inductor L1 through the third switch Sc. The voltage across the first inductor L1 is UC2-UC1, i.e. In the rectifier circuit section, the current of the second inductor L2 By using the first switch Sa and the third switch Sc for freewheeling, the stable operation of the circuit is ensured. Therefore, we can obtain: .

[0050] (2) T1 stage: During time period T1, the third switch Sc is turned off, while the fourth switch Sd is turned on. Simultaneously, the states of the first switch Sa and the second switch Sb remain unchanged. During this time period, the second inductor L2 begins to release its stored energy, charging the bus capacitor C2. The circuit states during time period T1 are shown in Figures 12(a), 12(b), and 12(c). Figure 12(a) is the overall equivalent circuit diagram of the energy storage converter, Figure 12(b) is the equivalent circuit diagram of the rectifier circuit, and Figure 12(c) is the equivalent circuit diagram of the Buck converter. It can be seen that during time period T1, the first switch Sa of the Boost converter is in the off state, with a voltage of 0 across it, while the second switch Sb is turned on, and the current in the first inductor L1... Freewheeling is achieved through the fourth switch Sd. Linear descent, i.e. In the full-bridge inverter section, the current in the second inductor L2... The bus capacitor C2 is charged through the first switch Sa and the fourth switch Sd. Therefore, we can obtain: .

[0051] (3) T2 phase: Entering time period T2, the first switch Sa is turned off, the second switch Sb is turned on, and the states of the third switch Sc and the fourth switch Sd remain unchanged. The circuit states during time period T2 are shown in Figures 13(a), 13(b), and 13(c). Figure 13(a) is the overall equivalent circuit diagram of the energy storage converter, Figure 13(b) is the equivalent circuit diagram of the rectifier circuit, and Figure 13(c) is the equivalent circuit diagram of the Buck converter. It can be seen that during time period T2, the first switch Sa of the Boost converter is in the off state, and its voltage is 0, while the second switch Sb is turned on, and the current of the first inductor L1 is... Freewheeling is achieved through the fourth switch Sd. Linear descent, i.e. In the full-bridge inverter section, the current in the second inductor L2... With freewheeling via the first switch Sa and the fourth switch Sd, based on this state, we can obtain: .

[0052] (4) T3 stage: The equivalent circuit diagram for time period T3 is exactly the same as that for time period T1, as shown in Figures 12(a), 12(b), and 12(c).

[0053] Entering time T3, the previously conducting second switch Sb turns off, and the first switch Sa turns on, while the states of the third and fourth switches Sc and Sd remain unchanged. In the Buck converter section, the first switching element SLa is in the off state, with a voltage of 0 across it, and the second switch Sb is in the conducting state, causing the inductor current to... Freewheeling is achieved through the fourth switch Sd; during this process, the inductor current... It exhibits a linear downward trend, that is... In the full-bridge inverter section, the current in the second inductor L2... The bus capacitor C2 is charged through the first switch Sa and the fourth switch Sd. Based on this state, we can obtain: .

[0054] Based on the above in-depth analysis and precise theoretical calculations, a charging and discharging simulation model of the energy storage converter was successfully built in the Simulink environment of MATLAB. The example simulation parameters of this model are listed in detail in Table 3 to ensure the accuracy and reliability of the simulation results.

[0055] Table 3 - Simulation Parameters of Energy Storage Converter Specifically, when the input DC voltage is 48V, it is effectively boosted to 400V by the Boost converter. Subsequently, in the inverter circuit, this 400V DC voltage is converted into an effective value of 220V AC output, ensuring that the current on both the input and output sides maintains a good sinusoidal waveform.

[0056] Figure 14 This is a schematic diagram of the structure of an electronic device 1000 provided in an embodiment of the present invention. For example... Figure 14 As shown, the electronic device 1000 includes a memory 1100 and a processor 1200. The number of memories 1100 and processors 1200 can be one or more. Figure 14 Taking a memory 1100 and a processor 1200 as an example; the memory 1100 and the processor 1200 in the device can be connected via a bus or other means. Figure 14 Taking the example of a connection between China and Israel via a bus.

[0057] The memory 1100, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as the program instructions / modules corresponding to the modulation method of the ACDC bidirectional single-stage energy storage converter provided in any embodiment of the present invention. The processor 1200 implements the above-described modulation method of the ACDC bidirectional single-stage energy storage converter by running the software programs, instructions, and modules stored in the memory 1100.

[0058] The memory 1100 may primarily include a program storage area and a data storage area, wherein the program storage area may store the operating system and application programs required for at least one function. Furthermore, the memory 1100 may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some instances, the memory 1100 may further include memory remotely located relative to the processor 1200, which can be connected to the device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0059] One embodiment of the present invention also provides a computer-readable storage medium storing computer-executable instructions for performing a modulation method for an ACDC bidirectional single-stage energy storage converter as provided in any embodiment of the present invention.

[0060] An embodiment of the present invention also provides a computer program product, including a computer program or computer instructions, which are stored in a computer-readable storage medium. A processor of a computer device reads the computer program or computer instructions from the computer-readable storage medium and executes the computer program or computer instructions, causing the computer device to perform the modulation method of the ACDC bidirectional single-stage energy storage converter as provided in any embodiment of the present invention.

[0061] The electronic devices and application scenarios described in the embodiments of this invention are for the purpose of more clearly illustrating the technical solutions of the embodiments of this invention, and do not constitute a limitation on the technical solutions provided by the embodiments of this invention. As those skilled in the art will know, with the evolution of electronic devices and the emergence of new application scenarios, the technical solutions provided by the embodiments of this invention are also applicable to similar technical problems.

[0062] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0063] In hardware implementations, the division between functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed collaboratively by several physical components. Some or all physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0064] The terms “component,” “module,” “system,” etc., used in this specification are used to refer to computer-related entities, hardware, firmware, combinations of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, or a computer. As illustrated, applications running on computing devices and computing devices can both be components. One or more components may reside in a process or execution thread, and components may be located on a single computer or distributed among two or more computers. Furthermore, these components can be executed from various computer-readable media on which various data structures are stored. Components can communicate, for example, via local or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system, or a network, such as the Internet interacting with other systems via signals).

Claims

1. An ACDC bidirectional single-stage energy storage converter, characterized in that, include: The power control unit is used to output a DC-DC converter voltage during discharge or a rectified voltage during charging. An energy conversion unit is used to realize unobstructed bidirectional power flow. The energy conversion unit includes a first conversion element and a second conversion element, both of which are connected to the power control unit. The filtering unit includes a first filtering circuit for filtering out high-frequency noise from voltage fluctuations and a second filtering circuit for filtering out high-order harmonics from the output AC. One end of the first filtering circuit is connected to the first conversion element and the second conversion element, respectively, and the other end is connected to a DC source. One end of the second filtering circuit is connected to the power control unit, and the other end is connected to an AC source. The bus capacitor is connected in parallel across the power control unit to stabilize the DC-DC converter voltage or the rectified voltage.

2. The ACDC bidirectional single-stage energy storage converter according to claim 1, characterized in that, The power control unit includes a first switch, a second switch, a third switch, and a fourth switch. The first switch and the second switch are connected in series to form a first branch, and the third switch and the fourth switch are connected in series to form a second branch. The first branch and the second branch are connected in parallel. The source of the first switch is connected to the drain of the second switch and the source of the third switch. The drain of the second switch and the source of the third switch are also connected to the drain of the fourth switch. The drain of the first switch is connected to the drain of the third switch, and the source of the second switch is connected to the source of the fourth switch.

3. The ACDC bidirectional single-stage energy storage converter according to claim 2, characterized in that, The first end of the first conversion element and the first end of the second conversion element are both connected to the midpoint between the source of the first switching transistor and the drain of the second switching transistor, and the second end of the first conversion element is connected to the second end of the second conversion element.

4. The ACDC bidirectional single-stage energy storage converter according to claim 2, characterized in that, The first filter circuit includes a first inductor and a first capacitor. The first capacitor is connected in parallel to a DC source. One end of the first inductor is connected to both the DC source and the first capacitor, and the other end is connected to the second terminal of the first conversion element and the second terminal of the second conversion element. The second filter circuit includes a second inductor and a second capacitor. The second capacitor is connected in parallel to an AC source. One end of the second inductor is connected to both the AC source and the second capacitor, and the other end is connected to the midpoint between the source of the third switching transistor and the drain of the fourth switching transistor.

5. The ACDC bidirectional single-stage energy storage converter according to claim 2, characterized in that, One end of the bus capacitor is connected to the drain of the first switching transistor, and the other end is connected to the source of the second switching transistor.

6. A modulation method for an ACDC bidirectional single-stage energy storage converter as described in any one of claims 2 to 5, characterized in that, Includes the following steps: Step S1: Generate the corresponding upper sine half-wave and lower sine half-wave according to the pre-configured initial sine wave, wherein the amplitude of the upper sine half-wave is greater than 0 and the amplitude of the lower sine half-wave is less than 0. Step S2: Superimpose the acquired DC bias signal with the lower sine half-wave and the upper sine half-wave to obtain the first half-wave modulation signal and the second half-wave modulation signal respectively. Step S3: Compare the first half-wave modulation signal and the second half-wave modulation signal with the pre-configured carrier signal respectively, and generate the first SPWM modulation signal and the second SPWM modulation signal accordingly. Step S4: Control the turn-off state of the third switch and the fourth switch based on the first SPWM modulation signal, and control the turn-off state of the first switch and the second switch based on the second SPWM modulation signal, so as to perform complementary turn-off control on the first switch, the second switch, the third switch and the fourth switch.

7. The modulation method for the ACDC bidirectional single-stage energy storage converter according to claim 6, characterized in that, Step S4 includes the following steps: Step S41: When the energy storage converter is in a discharge state, if the voltage of the first half-wave modulation signal at a certain moment exceeds the voltage of the carrier signal at the same moment, control the fourth switch to turn on and the third switch to turn off; otherwise, control the third switch to turn on and the fourth switch to turn off. Also, if the voltage of the second half-wave modulation signal at a certain moment exceeds the voltage of the carrier signal at the same moment, control the second switch to turn on and the first switch to turn off; otherwise, control the first switch to turn on and the second switch to turn off. or, Step S42: When the energy storage converter is in a charging state, if the voltage of the first half-wave modulation signal at a certain moment exceeds the voltage of the carrier signal at the same moment, control the third switch to turn on and the fourth switch to turn off; otherwise, control the fourth switch to turn on and the third switch to turn off. Also, if the voltage of the second half-wave modulation signal at a certain moment exceeds the voltage of the carrier signal at the same moment, control the first switch to turn on and the second switch to turn off; otherwise, control the second switch to turn on and the first switch to turn off.

8. The modulation method for the ACDC bidirectional single-stage energy storage converter according to claim 6, characterized in that: When the energy storage converter is in a discharge state, the amplitude of the first half-wave modulation signal and the amplitude of the second half-wave modulation signal are both greater than 0. When the energy storage converter is in a charging state, the amplitude of both the first half-wave modulation signal and the amplitude of the second half-wave modulation signal are less than 1.

9. An electronic device, characterized in that, include: At least one processor; At least one memory for storing at least one program; When at least one of the programs is executed by at least one of the processors, the modulation method of the ACDC bidirectional single-stage energy storage converter as described in any one of claims 6 to 8 is implemented.

10. A computer-readable storage medium, characterized in that, It stores a processor-executable program, which, when executed by the processor, is used to implement the modulation method of the ACDC bidirectional single-stage energy storage converter as described in any one of claims 6 to 8.

Images