Energy feedback converter voltage stabilization and current stabilization test system and method

Abstract

The invention belongs to the technical field of energy feedback, and provides an energy feedback converter voltage stabilization and current stabilization test system and method. The system comprises a DC power supply, an improved three-phase inversion module, two ADC sampling modules, two air switches, a three-phase load module, two SPWM modules, an STM32F407 module, a screen display module, a matrix key module, a three-phase common mode inductor and an improved three-phase rectification module. The three-phase inversion topology and the three-phase bridgeless APFC rectification topology are cascaded, a BOOST circuit is omitted in the bridgeless APFC rectification, the power factor is higher, the power consumption is reduced, and compared with a bridge rectification scheme, the energy utilization rate is improved; and meanwhile, a DC-AC-AC-DC energy circulation system is constructed, most of energy is subjected to closed-loop backflow, only system loss is supplemented, the output power of a direct-current power supply is as low as 13.13 W to 14.93 W, and the energy consumption of the system is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy feedback, in particular to an energy feedback converter voltage and current stabilizing test system and method. BACKGROUND

[0002] With the rapid development of industrial automation and new energy industry, energy feedback converters, as the core equipment for realizing the recycling of electric energy and reducing energy consumption, are increasingly widely used in various application scenarios. The technology development of energy feedback converters has experienced the evolution from mechanical speed regulation to electronic, modularization and intelligentization, and the core device has gradually transitioned from the early thyristor to IGBT module. In recent years, the application of new semiconductor materials such as SiC has further promoted the development of devices towards high frequency and high efficiency. The current core requirements of the industry are focused on improving energy utilization efficiency, reducing device size, reducing cost, enhancing operation stability, and optimizing control accuracy to adapt to diversified load scenarios.

[0003] However, 1) traditional rectification topology has high loss and large electromagnetic interference: the existing technology mostly adopts Boost APFC topology with a rectification bridge, the power loss is significant, and the reverse recovery process of the switching tube and the diode is easy to produce serious electromagnetic noise. 2) Traditional main circuit structure is complex: the traditional three-phase inverter scheme needs multiple auxiliary circuits to cooperate, the number of components is large, which leads to large system size, and the complex structure increases the risk of failure and maintenance cost; it is easy to cause local overcurrent or thermal runaway. 3) Poor adaptability and stability of the driving chip: the driving chip used in some existing schemes lacks perfect protection function, has long propagation delay, and is easy to cause misopening or overvoltage damage risk. 4) Low control accuracy and poor output characteristics: the traditional control scheme mostly uses single modulation or control algorithm, which has the problems of insufficient output voltage / frequency stability, high load adjustment rate, and excessive total harmonic distortion rate, and is difficult to meet the high-precision load test demand. 5) Low energy recovery efficiency and serious energy waste: the existing energy feedback system is mostly open-loop designed, the regenerated electric energy cannot be effectively recycled, and depends on external high-power DC power supply to supplement energy consumption, which has high operation cost. SUMMARY

[0004] In order to overcome the deficiencies of the prior art, the purpose of the present application is to provide an energy feedback converter voltage and current stabilizing test system and method, which solves the problems of significant power loss, easy to cause local overcurrent or thermal runaway, easy to cause misopening or overvoltage damage risk, difficult to meet the high-precision load test demand, and regenerated electric energy cannot be effectively recycled.

[0005] To achieve the above purpose, the present application provides the following solutions:

[0006] A converter voltage and current stabilization test system with energy feedback includes: a DC power supply, an improved three-phase inverter module, two ADC sampling modules, two air switches, a three-phase load module, two SPWM modules, an STM32F407 module, a screen display module, a matrix keypad module, a three-phase common-mode inductor, and an improved three-phase rectifier module; the improved three-phase inverter module and the improved three-phase rectifier module have the same circuit structure.

[0007] The DC power supply, the improved three-phase inverter module, the first ADC sampling module, the first air switch, and the three-phase load module are connected in sequence; the three-phase common-mode inductor, the second air switch, the second ADC sampling module, and the improved three-phase rectifier module are connected in sequence; the improved three-phase rectifier module is connected to the improved three-phase inverter module; the first ADC sampling module is connected to the three-phase common-mode inductor; the STM32F407 module is connected to the first SPWM module, the second SPWM module, the screen display module, the matrix keypad module, the first ADC sampling module, and the second ADC sampling module respectively; the first SPWM module is connected to the improved three-phase inverter module; and the second SPWM module is connected to the improved three-phase rectifier module.

[0008] Preferably, the improved three-phase inverter module includes: capacitors C1, C2, C3, HO1, HO2, HO3, LO1, LO2, LO3, resistors R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, NMOS1, NMOS4, NMOS2, NMOS5, NMOS3, NMOS6, VS1, VS2, VS3, phase A, phase B, and phase C;

[0009] HO1 is connected to the first terminal of NMOS1 through resistor R1; the first and third terminals of NMOS1 are connected through resistor R2; HO2 is connected to the first terminal of NMOS2 through resistor R3; the first and third terminals of NMOS2 are connected through resistor R4; HO3 is connected to the first terminal of NMOS3 through resistor R5; the first and third terminals of NMOS3 are connected through resistor R6; LO1 is connected to the first terminal of NMOS4 through resistor R7; the first and third terminals of NMOS4 are connected through resistor R5. The third terminal is connected via resistor R8; LO2 is connected to the first terminal of NMOS5 via resistor R9; the first and third terminals of NMOS5 are connected via resistor R10; LO3 is connected to the first terminal of NMOS6 via resistor R11; the first and third terminals of NMOS6 are connected via resistor R12; the second terminal of NMOS4 is connected to the third terminal of NMOS1; the second terminal of NMOS5 is connected to the third terminal of NMOS2; and the second terminal of NMOS6 is connected to the third terminal of NMOS3.

[0010] Preferably, a test method for voltage and current regulation of an energy feedback converter includes:

[0011] Read voltage and current sampling data;

[0012] When the three-phase inverter starts, it generates an SPWM wave according to the set frequency and collects voltage feedback.

[0013] Once the voltage loop is started, the SPWM modulation is adjusted using a preset circuit structure based on the voltage feedback.

[0014] After rectification starts, the phase-locked loop is triggered to generate a transient current;

[0015] The instantaneous current is input to the PR controller for instantaneous value tracking, and the process returns to the step "When the three-phase inverter starts, an SPWM wave is generated according to the set frequency, and voltage feedback is collected";

[0016] When the three-phase inverter or the voltage loop is not started, proceed to step "After rectification starts, trigger the phase-locked loop to generate instantaneous current";

[0017] When the rectifier is not started, proceed to step "input the instantaneous current to the PR controller for instantaneous value tracking, and return to step 'when the three-phase inverter starts, generate an SPWM wave according to the set frequency and collect voltage feedback'".

[0018] The present invention discloses the following technical effects:

[0019] This invention provides a voltage and current stabilization test system and method for energy feedback converters. By using a bridgeless APFC rectifier topology, it solves the problems of significant power loss in existing devices and severe electromagnetic noise generated during the reverse recovery process of switches and diodes, thereby reducing the number of conducting devices and lowering conduction losses and electromagnetic interference. By directly achieving three-phase inversion through a three-bridge arm, it overcomes the shortcomings of traditional three-phase inverter schemes that require multiple auxiliary circuits, optimizing the main circuit structure. By integrating SPWM waves, phase-locked loops, and PR controllers, it overcomes the shortcomings of traditional control schemes that often use single modulation or control algorithms, improving control accuracy and output waveform quality. By constructing a DC-AC-AC-DC energy recycling system, it overcomes the shortcomings of existing energy feedback systems, which are mostly open-loop designs, achieving effective recycling of regenerated electrical energy. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A structural diagram of an energy feedback converter voltage and current stabilization test system provided in an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of a three-phase inverter / three-phase rectifier provided in an embodiment of the present invention;

[0023] Figure 3 A flowchart provided for an embodiment of the present invention;

[0024] Figure 4 A schematic diagram of the driving circuit provided in an embodiment of the present invention;

[0025] Figure 5 The schematic diagram of the sampling circuit provided in the embodiment of the present invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] The purpose of this invention is to provide a voltage and current stabilization test system and method for energy feedback converters, which solves the problems of existing devices, such as significant power loss, easy to cause local overcurrent or thermal runaway, easy to cause accidental turn-on or overvoltage damage, difficulty in meeting the requirements of high-precision load testing, and inability to effectively recycle regenerated energy.

[0028] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] Figure 1 The structural diagram of the energy feedback converter voltage and current stabilization test system provided in the embodiment of the present invention is as follows: Figure 1 As shown, this invention provides an energy feedback converter voltage and current stabilization test system, comprising: a DC power supply, an improved three-phase inverter module, two ADC sampling modules, two air switches, a three-phase load module, two SPWM modules, an STM32F407 module, a screen display module, a matrix keypad module, a three-phase common-mode inductor, and an improved three-phase rectifier module; the improved three-phase inverter module and the improved three-phase rectifier module have the same circuit structure;

[0030] The DC power supply, the improved three-phase inverter module, the first ADC sampling module, the first air switch, and the three-phase load module are connected in sequence; the three-phase common-mode inductor, the second air switch, the second ADC sampling module, and the improved three-phase rectifier module are connected in sequence; the improved three-phase rectifier module is connected to the improved three-phase inverter module; the first ADC sampling module is connected to the three-phase common-mode inductor; the STM32F407 module is connected to the first SPWM module, the second SPWM module, the screen display module, the matrix keypad module, the first ADC sampling module, and the second ADC sampling module respectively; the first SPWM module is connected to the improved three-phase inverter module; and the second SPWM module is connected to the improved three-phase rectifier module.

[0031] refer to Figure 2 The improved three-phase inverter module includes: capacitors C1, C2, C3, HO1, HO2, HO3, LO1, LO2, LO3, resistors R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, NMOS1, NMOS4, NMOS2, NMOS5, NMOS3, NMOS6, VS1, VS2, VS3, phase A, phase B, and phase C;

[0032] HO1 is connected to the first terminal of NMOS1 through resistor R1; the first and third terminals of NMOS1 are connected through resistor R2; HO2 is connected to the first terminal of NMOS2 through resistor R3; the first and third terminals of NMOS2 are connected through resistor R4; HO3 is connected to the first terminal of NMOS3 through resistor R5; the first and third terminals of NMOS3 are connected through resistor R6; LO1 is connected to the first terminal of NMOS4 through resistor R7; the first and third terminals of NMOS4 are connected through resistor R5. The third terminal is connected via resistor R8; LO2 is connected to the first terminal of NMOS5 via resistor R9; the first and third terminals of NMOS5 are connected via resistor R10; LO3 is connected to the first terminal of NMOS6 via resistor R11; the first and third terminals of NMOS6 are connected via resistor R12; the second terminal of NMOS4 is connected to the third terminal of NMOS1; the second terminal of NMOS5 is connected to the third terminal of NMOS2; and the second terminal of NMOS6 is connected to the third terminal of NMOS3.

[0033] refer to Figure 3 A test method for voltage and current regulation of an energy feedback converter, comprising:

[0034] Read voltage and current sampling data;

[0035] When the three-phase inverter starts, it generates an SPWM wave according to the set frequency and collects voltage feedback.

[0036] Once the voltage loop is started, the SPWM modulation is adjusted using a preset circuit structure based on the voltage feedback.

[0037] After rectification starts, the phase-locked loop is triggered to generate a transient current;

[0038] The instantaneous current is input to the PR controller for instantaneous value tracking, and the process returns to the step "When the three-phase inverter starts, an SPWM wave is generated according to the set frequency, and voltage feedback is collected";

[0039] When the three-phase inverter or the voltage loop is not started, proceed to step "After rectification starts, trigger the phase-locked loop to generate instantaneous current";

[0040] When the rectifier is not started, proceed to step "input the instantaneous current to the PR controller for instantaneous value tracking, and return to step 'when the three-phase inverter starts, generate an SPWM wave according to the set frequency and collect voltage feedback'".

[0041] Specifically, this system mainly consists of a microcontroller module, a driver module, a signal acquisition module, a main circuit topology, an auxiliary power supply module, a button module, and a display module. The selection of the rectifier topology scheme, the three-phase inverter circuit module, and the driver module system scheme will be discussed below.

[0042] 1) Demonstration and selection of rectifier topology:

[0043] Option 1: Bridged diode rectification + Boost converter: Because it uses bridged rectification, it eliminates the need for a bridgeless PFC circuit, making operation simpler. An external boost converter ensures energy feedback. However, due to the direct use of bridged rectification, the power factor is relatively low. Option 2: Bridgeless APFC circuit: This directly uses SPWM waves to drive the three bridge arms, improving the power factor while saving the power consumption of a boost converter circuit, and ensuring energy feedback. Option 2 is chosen after comparison.

[0044] 2) Demonstration and selection of three-phase inverter circuit:

[0045] Option 1: Employing three single-phase inverter circuits. From a working principle perspective, each single-phase inverter circuit can use a full-bridge or half-bridge topology, achieving DC-to-single-phase AC conversion through its own control circuit. Synchronous control ensures the phase difference between the three phases meets the 120° electrical angle requirement. This method has a complex circuit structure, requiring three independent inverter and control circuits, leading to an increased number of components, increasing system size and weight, and raising costs. Furthermore, the high synchronization requirement between the three phases means that improper control can cause phase deviations, affecting the balance of the three-phase output and negatively impacting the load. Additionally, the overall efficiency is relatively low. Option 2: Direct three-phase inversion using three bridge arms. Six power switching devices form three bridge arms, each corresponding to one phase. Through orderly control of the power switching devices, DC power is directly converted to three-phase AC output. This method requires only one main circuit and control circuit, reducing the number of components, system size, weight, and cost, while also improving system reliability. Option 2 was chosen after comparing the characteristics of the two topologies.

[0046] 3) Demonstration and selection of the driving circuit:

[0047] Option 1: IR2109: A dual-channel gate driver chip designed specifically for driving high-voltage power MOSFETs and IGBTs. It has a wide operating voltage range, supports high-voltage side floating drive, but the maximum operating voltage on the high-voltage side is limited; it lacks isolation and requires additional circuitry for isolation; its performance degrades significantly at high temperatures. Option 2: IR2110S: A highly integrated half-bridge driver chip suitable for driving power MOSFETs and IGBTs. It employs proprietary HVIC and anti-latch-up CMOS technology for a robust construction. It supports high- and low-side drive and can directly drive N-channel MOSFETs or IGBTs; it has a built-in bootstrap diode for easy bootstrap circuit construction; it has low propagation delay, fast switching response, and reduces losses; it features undervoltage lockout and short-circuit protection. After comparing the performance of the two driver chips, Option 2 is selected.

[0048] Further theoretical analysis and calculations of the system. Analysis of the energy feedback principle: The core design concept of this energy feedback converter voltage and current stabilization test device lies in constructing an energy closed-loop circulation system to achieve energy saving during converter load testing. Its overall structure consists of a DC power supply, converter 1 (DC-AC), a connection unit, and converter 2 (AC-DC), with each part forming an organic whole through specific energy conversion and transmission relationships. The energy feedback mechanism is key to the system's energy saving. The AC power output from converter 1 is transmitted to converter 2 (AC-DC) through the connection unit, which converts the AC power back to DC power and feeds this energy back to the input of converter 1. At this time, the fed-back DC power and the original DC power supply jointly power converter 1, forming a cycle of energy utilization: most of the energy output from converter 1 is converted back through converter 2, achieving closed-loop return, only needing to supplement the energy losses during system operation (such as converter switching losses, line transmission losses, etc.), thereby significantly reducing the actual output power of the DC power supply. The formula is as follows:

[0049]

[0050] Where U1 is the power supply input voltage and I is the power supply input current. Let U1 be the angle between U1 and I, and THD be the total harmonic distortion rate.

[0051] Furthermore, the system's relevant parameters are calculated. In the energy feedback converter voltage and current stabilization test device, the DC bus voltage (i.e., the DC power supply output voltage U) is... d The selection of converter 1 (DC-AC) and converter 2 (AC-DC) needs to comprehensively consider their output characteristics and conversion efficiency to ensure stable closed-loop operation of the system energy. Converter 1 needs to output a three-phase symmetrical sinusoidal AC current (RMS value) with a line voltage U1 = 32V. For a three-phase bridge inverter circuit, its DC bus voltage Ud The relationship between the AC output line voltage RMS value U1 and the voltage is as follows:

[0052]

[0053] Where M is the modulation ratio, taken as 0.9. Substituting this into U1 = 32V, we can obtain U d ≥45.6V, meaning the minimum DC bus voltage required to meet the output requirements of converter 1 is no less than 45.6V; converter 2 needs to convert the AC output of converter 1 into DC and feed it back to the DC bus, and its DC output voltage U d2 The relationship between (feedback voltage) and AC input line voltage is as follows:

[0054]

[0055] in, Substituting U1 = 32V, we get U d2 ≈74.3V, considering the line voltage drop ΔU (2~3V), then U d The voltage should not exceed 76V to 77V; overall, the DC bus voltage U d The requirement is 45.6V ≤ U d For voltages ≤77V, a midpoint between 50V and 60V is recommended. This ensures the output accuracy of converter 1 while reserving sufficient voltage differential for energy feedback from converter 2, and simultaneously reduces the withstand voltage requirements of the switching devices. This calculation, based on the power conversion relationship of the converters and the output voltage specifications given in the problem, forms the core parameter foundation for the closed-loop energy efficiency of the system. Therefore, this embodiment selects a 60V bus voltage.

[0056] Preferably, the parameters of the three-phase rectifier PR controller are selected. The core parameters of the PR controller include the proportional coefficient KP, the resonant coefficient KR, and the resonant angular frequency ω0. The resonant angular frequency ω0 needs to match the fundamental angular frequency of the three-phase inverter. The proportional coefficient KP mainly affects the dynamic response speed and stability of the system, helping to improve the dynamic performance of the converter during load adjustment, but it affects the total harmonic distortion (THD) of the output AC voltage, which needs to be controlled within a range not exceeding 2%. Therefore, through final parameter adjustment, Kp is set to 7 and Kr to 25 in this embodiment. The PR control system function is:

[0057]

[0058] Specifically, circuit and programming design, and the overall system block diagram. The overall system block diagram is as follows: Figure 1As shown, the system mainly consists of a microcontroller module, a display module, a main circuit topology, a driver module, a sampling module, and an auxiliary power supply module. The main circuit consists of three parts: a three-phase inverter circuit, a connection module, and a three-phase rectifier circuit. These three circuits are controlled by a single F407 main control chip. According to the working process, during inversion, SPWM waves are used to generate three-phase AC power from DC power; during rectification, SPWM waves are also used to control the rectification of the three-phase inverter voltage. The circuit schematic is shown below. Figure 2 .

[0059] refer to Figure 4 The circuit consists of power supply VCC and VDD, capacitors C4, C5, C6, and C7, resistor R13, diode D1, and LED1. VDD is connected to the positive terminal of C4, VSS is connected to the negative terminal of C4, VCC is connected to C5, C6, D1, and one end of LED1, LED1 is then connected to one end of R13, the negative terminal of D1 is connected to the positive terminal of C7, and the negative terminal of C7 is connected to VS. The driving circuit schematic is shown. A floating power supply is dynamically generated using capacitor energy storage and the unidirectional conductivity of the diode: When the low-side MOSFET is turned on, the potential at the midpoint of the half-bridge (VS pin) is pulled low, and VCC charges the bootstrap capacitor through the bootstrap diode, making the capacitor voltage close to VCC and storing energy; when the low-side is turned off and the high-side is turned on, the VS pin jumps to the bus high voltage. Because the capacitor voltage cannot change abruptly, its positive terminal voltage rises synchronously with VS, forming a floating power supply to power the high-side gate and maintain conduction. (IR2110S circuit schematic reference) Figure 4 .

[0060] refer to Figure 5 The system includes a 3.3V and 1.65V power supply, capacitors C8, C9, C10, C11, and C12, resistors R14, R15, R16, R17, and R18, and current transformers ZMPT107 and ZMCT103C. The 3.3V power supply is connected to C8, C9, C11, C12, and one end of R14. The other end of R14 is connected to one end of R15 and C10. One end of R16 is connected to one end of ZMPT107, the other end of ZMPT107 is connected to R17, and one end of R18 is connected to one end of ZMCT103C. This is the signal acquisition module. Voltage transformers and current transformers respectively collect voltage and current signals from the AC system. After signal conditioning, they are sent to the operational amplifier circuit for processing: the voltage signal output from the power supply voltage divider is connected to the voltage follower formed by the first operational amplifier. Utilizing its high input impedance and low output impedance characteristics, signal isolation and buffering are achieved to avoid the load affecting the accuracy of the transformer; the second operational amplifier forms an adder circuit.

[0061] refer to Figure 3Program Function Description: The microcontroller reads voltage and current samples, generates an SPWM wave through the inverter voltage regulator loop and rectifier current regulator loop, and controls the three-phase inverter and three-phase rectifier respectively to stabilize U1 at 32V and I1 at 2A, maintaining stable feedback. Program Design Ideas: After the program starts, it initializes the ADC, PWM, interrupts, display, etc. The screen dynamically refreshes and displays key parameters: voltage, current, frequency, modulation, etc., providing real-time operation status monitoring. The ADC reads the voltage / current sample values ​​in real time, calculates the effective values ​​of voltage and current in the DMA interrupt, and uses them as inputs to the dual loops. The interrupt at the set frequency of 20KHz is integrated to generate phase, and a sine transform is performed to generate a controllable frequency SPWM wave. Then, the SPWM modulation is dynamically adjusted through voltage feedback to achieve stable control of the output voltage. After rectification starts, the phase-locked loop (PLL) of the upstream inverter voltage is triggered to generate the target value of the instantaneous current, which is sent to the PR controller to track the instantaneous value of the current and control the current waveform to stabilize it at 2A.

[0062] Preferably, the test plan and test results are as follows: Test Plan and Instruments: The test instruments used in the experiment include a digital multimeter, oscilloscope, clamp meter, current gun, differential probe, etc. The test method is as follows: 1) Change the current by changing the load, test the output voltage, and record the test results in Table 1. 2) Measure the three-phase voltage frequency using a three-phase power analyzer and oscilloscope, adjustable in 1Hz steps, and record the test results in Table 2. 3) Perform feedback control, measure the DC power supply input voltage and input current, and record the calculated power in Table 3.

[0063] Table 1

[0064] First Second Third Fourth Fifth Output voltage (0A current) 32.12 32.05 32.13 32.17 32.08 Output voltage (2A current) 32.06 32.01 32.17 32.23 32.05 Load regulation 0.18% 0.12% 0.12% 0.18% 0.09%

[0065] For calculating the load regulation rate, this embodiment uses a multimeter to directly display the output voltage U and current I, and then calculates the load regulation rate.

[0066] Table 2

[0067] Set voltage frequency (Hz) Actual voltage frequency (Hz) First 50 Hz 50.00 Hz Second 20 Hz 20.00 Hz Third 100 Hz 100.00 Hz

[0068] The results of the frequency conversion show that the frequency of three-phase electricity can be controlled by changing the integral angular frequency through button control.

[0069] Table 3

[0070] First Second Third Fourth Fifth DC power supply output voltage (V) 59.72 59.71 59.69 59.69 59.69 DC power supply output current (A) 0.25 0.25 0.25 0.24 0.22 DC power supply output power (W) 14.93 14.92 14.92 14.32 13.13

[0071] As shown in the table, the system achieves stable adjustment of output current through the coordinated control of SPWM waveform, dead time, and operating frequency by the microcontroller, and ultimately achieves controllable reduction of power output, thus precisely realizing flexible power adjustment.

[0072] The beneficial effects of this invention are as follows:

[0073] (1) This design adopts a bridgeless APFC rectifier topology, which eliminates the traditional rectifier bridge, reduces the number of conducting devices, significantly reduces conduction loss and electromagnetic interference, and improves the power factor.

[0074] (2) This design directly realizes three-phase inverter through three bridge arms, requiring only one main circuit and control circuit, which simplifies the structure, reduces the amount of components used, lowers the cost, and optimizes the main circuit structure.

[0075] (3) The design uses the IR2110S driver chip, which has built-in functions such as bootstrap diode, undervoltage lockout, and short circuit protection. It has low propagation delay and fast switching response, ensuring stable operation of the equipment.

[0076] (4) This design integrates SPWM wave, phase-locked loop and PR controller to achieve stable output of 32V line voltage (load regulation rate of only 0.12%), adjustable frequency step from 20Hz to 100Hz, THD≤2%, and current stable at 2A, which greatly improves control accuracy and output waveform quality.

[0077] (5) This design constructs a DC-AC-AC-DC energy cycle system, allowing most of the energy to flow back in a closed loop. Only the system loss needs to be replenished. The DC power output power is as low as 13.13W to 14.93W, achieving significant energy saving and solving the core pain point of high energy consumption in traditional solutions.

[0078] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0079] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A voltage and current stabilization test system for an energy feedback converter, characterized in that, include: The system includes a DC power supply, an improved three-phase inverter module, two ADC sampling modules, two air switches, a three-phase load module, two SPWM modules, an STM32F407 module, a screen display module, a matrix keypad module, a three-phase common-mode inductor, and an improved three-phase rectifier module; the improved three-phase inverter module and the improved three-phase rectifier module have the same circuit structure. The DC power supply, the improved three-phase inverter module, the first ADC sampling module, the first air switch, and the three-phase load module are connected in sequence; the three-phase common-mode inductor, the second air switch, the second ADC sampling module, and the improved three-phase rectifier module are connected in sequence; the improved three-phase rectifier module is connected to the improved three-phase inverter module; the first ADC sampling module is connected to the three-phase common-mode inductor; the STM32F407 module is connected to the first SPWM module, the second SPWM module, the screen display module, the matrix keypad module, the first ADC sampling module, and the second ADC sampling module respectively; the first SPWM module is connected to the improved three-phase inverter module; and the second SPWM module is connected to the improved three-phase rectifier module.

2. The energy feedback converter voltage and current stabilization test system according to claim 1, characterized in that, The improved three-phase inverter module includes: capacitors C1, C2, C3, HO1, HO2, HO3, LO1, LO2, LO3, resistors R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, NMOS1, NMOS4, NMOS2, NMOS5, NMOS3, and NMOS6; HO1 is connected to the first terminal of NMOS1 through resistor R1; the first and third terminals of NMOS1 are connected through resistor R2; HO2 is connected to the first terminal of NMOS2 through resistor R3; the first and third terminals of NMOS2 are connected through resistor R4; HO3 is connected to the first terminal of NMOS3 through resistor R5; the first and third terminals of NMOS3 are connected through resistor R6; LO1 is connected to the first terminal of NMOS4 through resistor R7; the first and third terminals of NMOS4 are connected through resistor R5. The third terminal is connected via resistor R8; LO2 is connected to the first terminal of NMOS5 via resistor R9; the first and third terminals of NMOS5 are connected via resistor R10; LO3 is connected to the first terminal of NMOS6 via resistor R11; the first and third terminals of NMOS6 are connected via resistor R12; the second terminal of NMOS4 is connected to the third terminal of NMOS1; the second terminal of NMOS5 is connected to the third terminal of NMOS2; and the second terminal of NMOS6 is connected to the third terminal of NMOS3.

3. A test method for voltage and current regulation of an energy feedback converter, characterized in that, The method applied to the energy feedback converter voltage and current stabilization test system according to claim 1 includes: Read voltage and current sampling data; When the three-phase inverter starts, it generates an SPWM wave according to the set frequency and collects voltage feedback. Once the voltage loop is started, the SPWM modulation is adjusted using a preset circuit structure based on the voltage feedback. After rectification starts, the phase-locked loop is triggered to generate a transient current; The instantaneous current is input to the PR controller for instantaneous value tracking, and the process returns to the step "When the three-phase inverter starts, an SPWM wave is generated according to the set frequency, and voltage feedback is collected"; When the three-phase inverter or the voltage loop is not started, proceed to step "After rectification starts, trigger the phase-locked loop to generate instantaneous current"; When the rectifier is not started, proceed to step "input the instantaneous current to the PR controller for instantaneous value tracking, and return to step "when the three-phase inverter starts, generate an SPWM wave according to the set frequency and collect voltage feedback".

Images