A rectification control system and method for a wide-voltage-output charging module

Abstract

The present invention provides a rectification control system and method for a wide-voltage-output charging module, which relates to the field of power electronics technology. The system includes a two-stage rectifier and a control architecture. The two-stage rectifier includes a front-stage rectifier module and a rear-stage converter module. The front-stage rectifier module includes an AC / DC rectifier and two groups of output capacitors. The rear-stage converter module includes two groups of DC / DC converters and three switches. The input ends of the two groups of DC / DC converters are respectively connected in parallel with the two output capacitors of the front-stage rectifier module. The control architecture includes two groups of controllers, namely a first controller and a second controller. The present invention realizes a wide-range voltage output of 250V - 1000V by controlling the DC bus voltage and the connection mode of the output ends of the two rear-stage LLC resonant converters. At the same time, since the input voltage of the LLC resonant converter is only half of the DC bus voltage, the voltage stress of the switching devices is greatly reduced, etc.

Description

Technical Field

[0001] The present invention provides a rectification control system and method for a wide-voltage-output charging module, which relates to the field of power electronics technology, specifically to the field of wide-voltage and high-reliability charging rectification control technology. Background Art

[0002] Electric vehicles have developed rapidly in China due to their advantages such as low pollution and low usage cost. As one of its core technologies, the electric vehicle charging device has received extensive attention and research. Since the battery voltages used by various electric vehicle manufacturers are not the same, higher requirements are put forward for the output voltage range of the electric vehicle charging device. The power module of a DC charging pile generally consists of a front-stage AC / DC rectifier and a rear-stage DC / DC converter. In the traditional AC / DC+DC / DC two-stage power topology architecture, the intermediate bus voltage is usually fixed at a specific value, and problems such as output voltage regulation and current sharing are handled by the rear-stage DC / DC converter. Therefore, the development of the rear-stage DC / DC converter faces many problems such as high power density, high efficiency, and wide output voltage range. Summary of the Invention

[0003] The present invention provides a rectification control system and method for a wide-voltage-output charging module to solve the above problems:

[0004] A rectification control system and method for a wide-voltage-output charging module proposed by the present invention, the system includes a two-stage rectifier and a control architecture;

[0005] The two-stage rectifier includes a front-stage rectifier module and a rear-stage converter module;

[0006] The front-stage rectifier module includes an AC / DC rectifier and two groups of output capacitors;

[0007] The rear-stage converter module includes two groups of DC / DC converters and three groups of switches;

[0008] The input ends of the two groups of DC / DC converters are respectively connected in parallel with the two output capacitors of the front-stage rectifier module;

[0009] The control architecture includes two groups of controllers, which are the first controller and the second controller respectively;

[0010] The two-stage rectifier is connected to the control architecture for bidirectional communication, the AC / DC rectifier is connected to the first controller for bidirectional communication, and the two groups of DC / DC converters are connected to the second controller for bidirectional communication.

[0011] Furthermore, the working state of the AC / DC rectifier is the rectification state;

[0012] The operating state of the DC / DC converter is the DC conversion state.

[0013] Further, the two sets of DC / DC converters include a first DC / DC converter and a second DC / DC converter;

[0014] The connection mode of the output ends of the first DC / DC converter and the second DC / DC converter is controlled by the switching states of a first switch, a second switch, and a third switch;

[0015] The first switch is connected to the high-voltage end of the output ends of the first DC / DC converter and the second DC / DC converter;

[0016] The second switch is connected to the low-voltage end of the output ends of the first DC / DC converter and the second DC / DC converter;

[0017] The third switch is connected to the low-voltage end of the output end of the first DC / DC converter and the high-voltage end of the output end of the second DC / DC converter.

[0018] Further, when the first switch and the second switch are turned on and the third switch is turned off, the output ends of the first DC / DC converter and the second DC / DC converter are in the low-voltage output state;

[0019] When the third switch is turned on and the first switch and the second switch are turned off, the output ends of the first DC / DC converter and the second DC / DC converter are in the high-voltage output state.

[0020] Further, the first switch, the second switch, and the third switch include a mechanical switch and a semiconductor switch;

[0021] The mechanical switch includes a relay and a contactor;

[0022] The semiconductor switch includes an IGBT and a MOSFET.

[0023] Further, the two sets of output capacitors include an output capacitor C1 and an output capacitor C2;

[0024] The output capacitor C1 and the output capacitor C2 are connected in series, and after being connected in series, they are connected in parallel to the output end of the AC / DC rectifier, and the parameters of the output capacitor C1 and the output capacitor C2 are the same.

[0025] Further, the input end of the first DC / DC converter is connected in parallel to both ends of the output capacitor C1 of the AC / DC rectifier;

[0026] The input end of the second DC / DC converter is connected in parallel to both ends of the output capacitor C2 of the AC / DC rectifier.

[0027] Further, the first controller controls the AC / DC rectifier to perform power factor correction and regulate the DC bus voltage;

[0028] The second controller controls the two groups of DC / DC converters to perform output voltage regulation control and constant current control.

[0029] Further, the second controller calculates the corresponding DC bus voltage according to the preset output voltage;

[0030] The first controller controls the DC bus voltage according to the calculated value of the second controller to make it reach the preset data;

[0031] The second controller converts the connection mode of the output ends of the two groups of DC / DC converters by controlling the switching states of the first switch, the second switch, and the third switch to obtain the target voltage output range.

[0032] Further, the method includes pre-regulating the DC bus voltage through a two-stage rectifier controller;

[0033] The post-stage converter module regulates the output voltage of the pre-stage rectifier module according to the preset output voltage to obtain regulation information;

[0034] The post-stage converter module regulates the input voltage and the output connection mode of the internal DC / DC converter module to obtain the target voltage output range;

[0035] The input ends of the post-stage converter module are respectively connected in parallel to the two output capacitors of the pre-stage rectifier module;

[0036] Obtain the control data of the control system, and calculate the pre-stage control accuracy coefficient of the pre-stage rectifier module, the post-stage control accuracy coefficient of the post-stage converter module, and the architecture control accuracy of the control architecture respectively;

[0037] Compare each accuracy coefficient with the corresponding preset threshold to obtain the coefficient comparison result, and give a warning to the control module (pre-stage rectifier module, post-stage converter module, and control architecture) corresponding to the corresponding accuracy coefficient according to the comparison result.

[0038] Advantages of the present invention: The post-stage converter module can independently regulate the output voltage of the pre-stage rectifier module according to the required output voltage, enabling the post-stage converter module to operate at the optimal efficiency point under most operating conditions. The post-stage converter module can obtain a wider voltage output range by regulating the input voltage and the output connection mode of the internal DC / DC converter module. The input terminals of the post-stage converter module are respectively connected in parallel to the two output capacitors of the pre-stage rectifier module, which is beneficial to reducing the voltage stress and current stress of the switching tubes of the DC / DC converter. Through the two-stage rectifier design, the system can adapt to a wider input voltage range, improving the adaptability and flexibility of the system. The redundant design of two groups of DC / DC converters and three switches improves the reliability and stability of the system. Even if one of the converters or switches fails, the system can still continue to operate to ensure the normal power supply of the load. The AC / DC rectifier and DC / DC converter both adopt high-efficiency designs, reducing energy losses and improving the energy efficiency of the system. Through the filtering and smoothing effects of the output capacitors and the precise control of the controller, the system can provide a stable output voltage to meet the requirements of the load for voltage stability. The controller has monitoring and fault diagnosis functions, can monitor the working state of the system in real time, is convenient for timely detecting and handling faults, and reduces the maintenance cost and management difficulty. Description of the Drawings

[0039] Figure 1 It is a schematic diagram of the rectification control method of a rectification control system for a wide-voltage output charging module;

[0040] Figure 2 It is a principle block diagram of a preferred embodiment of a rectification control system for a wide-voltage output charging module;

[0041] Figure 3 It is a schematic diagram of the topological circuit of a preferred embodiment of a rectification control system for a wide-voltage output charging module;

[0042] Figure 4 It is a schematic diagram of the architecture of a preferred embodiment of a rectification control system for a wide-voltage output charging module;

[0043] Figure 5 It is a control block diagram of a preferred embodiment of a rectification control system for a wide-voltage output charging module. Detailed Embodiments

[0044] The following describes the preferred embodiments of the present invention with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only for the purpose of illustrating and explaining the present invention, and are not used to limit the present invention.

[0045] In an embodiment of the present invention, a rectification control system and method for a wide-voltage output charging module are proposed. The system includes a two-stage rectifier and a control architecture;

[0046] The two-stage rectifier includes a front-stage rectifier module and a rear-stage converter module;

[0047] The front-stage rectifier module includes an AC / DC rectifier and two groups of output capacitors;

[0048] The rear-stage converter module includes two groups of DC / DC converters and three switches;

[0049] The inputs of the two groups of DC / DC converters are respectively connected in parallel with the two output capacitors of the front-stage rectifier module;

[0050] The control architecture includes two groups of controllers, namely the first controller and the second controller;

[0051] The two-stage rectifier is bidirectionally communicatively connected to the control architecture, the AC / DC rectifier is bidirectionally communicatively connected to the first controller, and the two groups of DC / DC converters are bidirectionally communicatively connected to the second controller;

[0052] The working state of the AC / DC rectifier is the rectification state;

[0053] The working state of the DC / DC converter is the DC conversion state.

[0054] The working principle of the above technical solution is as follows: The present invention provides a rectification control system for a wide-voltage-output charging module, which includes a two-stage rectifier and a control architecture. The front-stage AC / DC rectifier can adjust the output voltage within a certain range, so that the rear-stage DC / DC conversion module can input voltages within a relatively wide range. On this basis, the rear-stage converter module can enter different working modes by changing the output connection mode of the internal DC / DC converters to obtain a wider voltage output range.

[0055] The technical solution adopted by the present invention to solve its technical problems is to construct a rectification control system for a wide-voltage-output charging module, which includes a two-stage rectifier and a control architecture. The two-stage rectifier includes a front-stage rectifier module and a rear-stage converter module. The rectifier module includes an AC / DC rectifier and two groups of output capacitors; the converter module includes two groups of DC / DC converters and three switches, and the inputs of the two groups of DC / DC converters are respectively connected in parallel to the two output capacitors of the front-stage rectifier module, effectively reducing the voltage stress of the switching tubes of the DC / DC converters.

[0056] The AC / DC rectifier works in the rectification state to pre-regulate the DC bus voltage; the DC / DC converter works in the DC conversion state to provide a stable power output for the load.

[0057] The control architecture includes two sets of controllers. The first controller controls the AC / DC rectifier to achieve power factor correction and DC bus voltage regulation, and the second controller controls two sets of DC / DC converters to achieve output voltage stabilization control and constant current control.

[0058] The second controller calculates the corresponding DC bus voltage according to the required output voltage, and the first controller controls the DC bus voltage to reach the set value according to the calculated value of the second controller. Further, the second controller changes the connection mode of the output ends of the two sets of DC / DC converters by controlling the switching states of the first switch, the second switch, and the third switch, so as to achieve a wider range of voltage output.

[0059] In the rectification control system of the wide-voltage-output charging module of the present invention, the converter module includes two sets of DC / DC converters and three switches. Both sets of DC / DC converters operate in the DC converter state to provide a stable power output for the load. The connection mode of the output ends of the first DC / DC converter and the second DC / DC converter is determined by the switching states of the first switch, the second switch, and the third switch. The first switch is connected to the high-voltage end of the output ends of the first DC / DC converter and the second DC / DC converter, the second switch is connected to the low-voltage end of the output ends of the first DC / DC converter and the second DC / DC converter, and the third switch is connected to the low-voltage end of the output end of the first DC / DC converter and the high-voltage end of the output end of the second DC / DC converter.

[0060] When the first switch and the second switch are turned on and the third switch is turned off, the output ends of the first DC / DC converter and the second DC / DC converter enter the low-voltage output state.

[0061] When the third switch is turned on and the first switch and the second switch are turned off, the output ends of the first DC / DC converter and the second DC / DC converter enter the high-voltage output state.

[0062] In the rectification control system of the wide-voltage-output charging module of the present invention, the first switch, the second switch, and the third switch include mechanical switches and semiconductor switches; the mechanical switches include relays and contactors; the semiconductor switches include IGBTs and MOSFETs.

[0063] In the rectification control system of the wide-voltage-output charging module of the present invention, the rectifier module includes an AC / DC rectifier and two output capacitors. The output capacitor C1 and the output capacitor C2 are connected in series and then connected in parallel to the output end of the AC / DC rectifier, and the parameters of the output capacitor C1 and the output capacitor C2 are the same.

[0064] In the rectification control system of the wide-voltage-output charging module according to the present invention, the input end of the first DC / DC converter is connected in parallel across both ends of the output capacitor C1 of the AC / DC rectifier, and the input end of the second DC / DC converter is connected in parallel across both ends of the output capacitor C2 of the AC / DC rectifier, effectively reducing the switching tube voltage stress of the DC / DC converter.

[0065] In the rectification control system of the wide-voltage-output charging module according to the present invention, the control architecture includes two sets of controllers. The first controller controls the AC / DC rectifier module to achieve power factor correction and DC bus voltage regulation, and the second controller controls the DC / DC converter module to achieve output voltage stabilization control and constant current control.

[0066] In the rectification control system of the wide-voltage-output charging module according to the present invention, for a given output voltage, the second controller calculates the corresponding input voltage of the DC / DC converter and modifies the DC bus voltage set value. After receiving the DC bus voltage set value, the first controller controls the AC / DC rectifier module to adjust its output voltage in real time, that is, the DC bus voltage.

[0067] As Figure 2 shown, the rectification control system of the wide-voltage-output charging module of the present invention includes a two-stage rectifier and a control architecture.

[0068] The two-stage rectifier includes a front-stage rectifier module and a rear-stage converter module. The rectifier module includes an AC / DC rectifier and two output capacitors C1 and C2; the converter module includes two DC / DC converters and three switches.

[0069] The control architecture includes two sets of controllers. The first controller controls the voltage output of the rectifier module, and the second controller controls the voltage output, current output, and series-parallel switching at the output end of the two DC / DC converters.

[0070] As Figure 3 shown, where Ea, Eb, and Ec are input voltages, Ia, Ib, and Ic are input currents, UBUS is the DC bus voltage, and UO and IO are the output voltage and output current respectively.

[0071] In this embodiment, the AC / DC rectifier adopts a Vienna rectifier, the DC / DC converter adopts an LLC resonant converter, and the first switch, the second switch, and the third switch adopt relays SS, SP1, and SP2. The input ends of the two LLC resonant converters in this embodiment are respectively connected in parallel across the output capacitors C1 and C2 of the Vienna rectifier, and the input voltage of the LLC resonant converter is only half of the DC bus voltage, effectively reducing the switching tube voltage stress of the LLC resonant converter.

[0072] When the parallel relays SP1 and SP2 are turned on and the series relay SS is turned off, the output terminals of the two LLC resonant converters are in parallel, entering the low-voltage output state.

[0073] When the series relay SS is turned on and the parallel relays SP1 and SP2 are turned off, the output terminals of the two LLC resonant converters are in series, entering the high-voltage output state.

[0074] In a preferred embodiment of the present invention, the DC bus voltage can be adjusted between 600V - 830V; the wide voltage output range generally refers to 250V - 1000V, the low-voltage output state is 250V - 500V, and the high-voltage output state is 500V - 1000V.

[0075] As Figure 4 shown, the Vienna rectifier operates in the rectification state, and the first controller controls the switching tubes Sa1, Sa2, Sb1, Sb2, Sc1, Sc2 of the Vienna rectifier to control the input currents Ia, Ib, Ic and the DC bus voltage UBUS, further realizing power factor correction and pre-regulation of the DC bus voltage; the LLC resonant converter operates in the DC conversion state, and the second controller controls the switching tubes Q1 - Q8 of the two LLC resonant converters to control the output voltage UO and the output current IO, providing a stable power output for the load. In addition, the second controller can control the relays SS, SP1 and SP2 to switch different output states.

[0076] As Figure 5 shown, where VO_Act, IO_Act and VBUS_Act are the sampled values of the output voltage, output current and DC bus voltage respectively, and IAC_Act is the dq-axis component obtained after the input currents Ia, Ib and Ic are subjected to Clark transformation and Park transformation.

[0077] The control process in this embodiment will be described below.

[0078] After the output voltage set value VO_Set is input into the second controller, first, the DC bus voltage set value VBUS_Ref is obtained through bus voltage calculation and VBUS_Ref is transmitted to the first controller. In addition, after VO_Set passes through the output voltage range judgment, the second controller outputs a switching signal through the series-parallel switching module to control the series-parallel relays SS, SP1 and SP2 to switch different output states. When VO_Set is between 250V - 500V, the converter module is in the low-voltage output state, the parallel relays SP1 and SP2 are turned on, and the series relay SS is turned off. When VO_Set is between 500V - 1000V, the converter module is in the high-voltage output state, the series relay SS is turned on, and the parallel relays SP1 and SP2 are turned off.

[0079] After the output voltage set value VO_Set and the output current set value IO_Set are input into the second controller, they are respectively operated by the output voltage controller and the output current controller to obtain the voltage controlled oscillator voltage reference values Vref_1 and Vref_2. The maximum value Vref of Vref_1 and Vref_2 is input into the voltage controlled oscillator VCO to obtain a subsequent drive signal with different frequencies, thereby controlling the output voltage and output current to reach the set values. In this embodiment, both the output voltage controller and the output current controller adopt a proportional integral (PI) regulator.

[0080] After the first controller receives the bus voltage set value VBUS_Ref, it inputs VBUS_Ref into the bus voltage controller. The bus voltage controller calculates the input current reference value IAC_Ref using VBUS_Ref and VBUS_Act. The input current controller calculates a modulation wave using IAC_Ref and IAC_Act, inputs the modulation wave into the SPWM module, compares it with the carrier wave to obtain a pre-stage drive signal, thereby controlling the input current and the DC bus voltage to reach the set values, and realizing power factor correction and DC bus voltage regulation. In this embodiment, the bus voltage controller adopts a proportional integral (PI) regulator, and the input current controller adopts a proportional integral (PI) regulator plus a proportional resonance (PR) controller.

[0081] The preferred embodiment of the rectification control system of the wide-voltage-output charging module of the present invention realizes a wide-range voltage output of 250V - 1000V by controlling the DC bus voltage and the connection mode of the output ends of the two subsequent LLC resonant converters. At the same time, since the input voltage of the LLC resonant converter is only half of the DC bus voltage, the voltage stress of the switching device is greatly reduced. Since the DC bus voltage can be adjusted in the range of 600V - 830V, the LLC resonant converter can operate at the optimal efficiency point in most of the voltage output ranges, effectively improving the efficiency of the rectifier system.

[0082] The two-stage rectifier mainly consists of a front-stage rectifier module and a rear-stage converter module. The front-stage rectifier module is responsible for converting the input alternating current (AC) into direct current (DC), and the rear-stage converter module further performs voltage conversion on the DC output by the front stage to meet the requirements of different loads. The front-stage rectifier module includes an AC / DC rectifier and two sets of output capacitors. The AC / DC rectifier converts the input AC into DC and filters and smooths it through the two sets of output capacitors to reduce voltage fluctuations and ripples and provide a stable DC output voltage. The rear-stage converter module consists of two sets of DC / DC converters and three switches. The input ends of the two sets of DC / DC converters are respectively connected in parallel with the two output capacitors of the front-stage rectifier module to achieve voltage conversion on the DC output by the front stage. The three switches are used to control different voltage outputs or achieve functions such as redundant backup. The control architecture uses two controllers (the first controller and the second controller) for control. These controllers are responsible for monitoring the working states of the rectifier module and the converter module and adjusting the working parameters of each module according to preset algorithms and logics to achieve stable voltage output and efficient energy conversion. The AC / DC rectifier is always in the rectification state, converting the input AC into DC. The DC / DC converter is in the DC conversion state, adjusting the output voltage and current according to the instructions of the controller to meet the requirements of the load. The input AC first passes through the AC / DC rectifier to be converted into DC and is filtered and smoothed through the output capacitors. The stable DC then enters the two sets of DC / DC converters and undergoes voltage conversion according to the instructions of the controller. The converted DC is output to the load through the switches. The controller monitors the working states of the rectifier module and the converter module in real time and makes adjustments as needed to ensure the stable operation of the system.

[0083] The described control system includes a two-stage rectifier and a control architecture. The two-stage rectifier consists of a front-stage rectifier module and a rear-stage converter module. The rectifier module operates in the rectification state to pre-regulate the DC bus voltage. The converter module operates in the DC conversion state to provide a stable power output to the load. The converter module includes two sets of DC / DC converters and three switches. The inputs of the two sets of DC / DC converters are respectively connected to two output capacitors of the front-stage rectifier module, effectively reducing the voltage stress on the switching tubes. The control architecture includes two sets of controllers. The first controller controls the AC / DC rectifier to achieve power factor correction and DC bus voltage regulation. The second controller controls the DC / DC converters to achieve output voltage stabilization control and constant current control. The second controller calculates the corresponding DC bus voltage according to the required output voltage, and the first controller controls the DC bus voltage to reach the set value according to the calculated value of the second controller. Further, the second controller changes the connection mode of the output ends of the two sets of DC / DC converters by controlling the switching states of the first switch, the second switch, and the third switch, to achieve a wider range of voltage output.

[0084] The technical effects of the above technical solution are as follows: Through the two-stage rectifier design, the system can adapt to a wide input voltage range, improving the adaptability and flexibility of the system. The redundant design of two sets of DC / DC converters and three switches improves the reliability and stability of the system. Even if one of the converters or switches fails, the system can still continue to operate to ensure the normal power supply of the load. Both the AC / DC rectifier and the DC / DC converters adopt high-efficiency designs, reducing energy losses and improving the energy efficiency of the system. Through the filtering and smoothing effects of the output capacitors and the precise control of the controller, the system can provide a stable output voltage to meet the requirements of the load for voltage stability. The controller has monitoring and fault diagnosis functions, can monitor the working state of the system in real time, is convenient for timely detecting and handling faults, and reduces the maintenance cost and management difficulty.

[0085] In an embodiment of the present invention, the two sets of DC / DC converters include a first DC / DC converter and a second DC / DC converter;

[0086] Control the connection mode of the output ends of the first DC / DC converter and the second DC / DC converter through the switching states of the first switch, the second switch, and the third switch;

[0087] The first switch is connected to the high-voltage end of the output ends of the first DC / DC converter and the second DC / DC converter;

[0088] The second switch is connected to the low-voltage end of the output ends of the first DC / DC converter and the second DC / DC converter;

[0089] The third switch is connected to the low-voltage end of the output terminal of the first DC / DC converter and the high-voltage end of the output terminal of the second DC / DC converter.

[0090] When the first switch and the second switch are turned on and the third switch is turned off, the output terminals of the first DC / DC converter and the second DC / DC converter are in the low-voltage output state;

[0091] When the third switch is turned on and the first switch and the second switch are turned off, the output terminals of the first DC / DC converter and the second DC / DC converter are in the high-voltage output state.

[0092] The first switch, the second switch and the third switch include mechanical switches and semiconductor switches;

[0093] The mechanical switches include relays and contactors;

[0094] The semiconductor switches include IGBTs and MOSFETs.

[0095] The working principle of the above technical solution is as follows: When the first switch and the third switch are turned on and the second switch is turned off, the low-voltage end of the first DC / DC converter is connected to the high-voltage end of the second DC / DC converter through the third switch. At the same time, the high-voltage end of the first DC / DC converter is directly output through the first switch. Since the low-voltage ends of the two converters are connected through the third switch, a parallel low-voltage output path is formed, so the output of the system is in the low-voltage state. When the second switch is turned on and the first switch and the third switch are turned off, the high-voltage ends of the first DC / DC converter and the second DC / DC converter are connected in series through the second switch to form a higher output voltage. At this time, the low-voltage ends of the two converters are independent of each other and do not participate in the formation of the high-voltage output. Such as relays and contactors, they have the ability to withstand high voltage and high current, and are suitable for occasions that require frequent operation but have a long switch life. Such as IGBTs (Insulated Gate Bipolar Transistors) and MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), they have the characteristics of fast switching speed and good controllability, and are suitable for occasions that require high-frequency switching and precise control.

[0096] The technical effects of the above technical solution are as follows: Through different combination states of three switches, the system can flexibly switch between low-voltage and high-voltage output states to meet the voltage requirements of different loads. With the redundant design of two groups of DC / DC converters and three switches, even if one of the converters or switches fails, the system can still maintain the output by adjusting the states of other switches, improving the reliability and stability of the system. In the low-voltage output state, the two converters work in parallel to share the load current, reduce the thermal loss of a single converter, and improve the overall energy efficiency. In the high-voltage output state, the two converters work in series to output a higher voltage to meet the requirements of specific loads. Through the precise control of the switch states by the controller, the system can monitor and diagnose the working states of the switches in real time, facilitating the timely discovery and handling of faults, reducing the maintenance cost and management difficulty. This design is easy to expand and can achieve outputs of more voltage levels by adding more DC / DC converters and switches to meet a wider range of application requirements.

[0097] In one embodiment of the present invention, the two groups of output capacitors include output capacitor C1 and output capacitor C2;

[0098] The output capacitor C1 and the output capacitor C2 are connected in series and then connected in parallel at the output end of the AC / DC rectifier, and the parameters of the output capacitor C1 and the output capacitor C2 are the same.

[0099] The input end of the first DC / DC converter is connected in parallel with both ends of the output capacitor C1 of the AC / DC rectifier;

[0100] The input end of the second DC / DC converter is connected in parallel with both ends of the output capacitor C2 of the AC / DC rectifier.

[0101] The working principle of the above technical solution is as follows: The AC / DC rectifier converts the input alternating current into direct current, and filters and smooths it through two output capacitors C1 and C2 connected in series and then in parallel at the output end. The parameters of these two output capacitors are the same, ensuring the stability and consistency of the filtering effect. Subsequently, the input ends of the first DC / DC converter and the second DC / DC converter are respectively connected in parallel with both ends of these two output capacitors, so as to obtain a stable DC power supply for voltage conversion. The input alternating current is rectified by the AC / DC rectifier and converted into direct current. The rectified direct current is filtered and smoothed through the output capacitors C1 and C2 connected in series and then in parallel. Since the parameters of the two capacitors are the same, they can jointly share the filtering task, reduce voltage fluctuations and ripples, and provide a stable DC output voltage. The filtered and smoothed direct current respectively enters the input ends of the first DC / DC converter and the second DC / DC converter. These two converters perform voltage conversion according to the instructions of the controller, converting the direct current into DC outputs with different voltage levels. Through the precise control of the switch state by the controller, the system can monitor and diagnose the working status of each module in real time, and adjust the output voltage and current as needed to meet the requirements of the load.

[0102] The technical effects of the above technical solution are as follows: Using two output capacitors with the same parameters connected in series and then in parallel for filtering can expand the filtering frequency band and improve the filtering effect. Since the capacitance values of the two capacitors are not exactly the same (although the parameters are the same in this case, there may be slight differences in actual applications), their corresponding resonance frequencies are also different, which can better filter out ripple noises of different frequencies. The parallel use of the two output capacitors can provide a more stable DC output voltage, reduce the impact of voltage fluctuations on the DC / DC converter, and thus improve the stability of the entire system. The stable DC output voltage can ensure that the DC / DC converter operates in the high-efficiency range, reduce energy loss, and improve the energy efficiency of the system. The redundant design of using two DC / DC converters enables the other converter to continue working even if one converter fails, ensuring the normal power supply to the load and improving the reliability of the system. The controller has monitoring and fault diagnosis functions, can monitor the working status of the system in real time, is convenient for timely detecting and handling faults, and reduces the maintenance cost and management difficulty. The system realizes efficient voltage conversion and stable DC output through the series-parallel filtering of two output capacitors with the same parameters and the redundant design of two DC / DC converters, improving the reliability and energy efficiency of the system.

[0103] In one embodiment of the present invention, the AC / DC rectifier is controlled by the first controller to perform power factor correction and regulation of the DC bus voltage;

[0104] The two sets of DC / DC converters are controlled by the second controller to perform output voltage stabilization control and constant current control.

[0105] The second controller calculates the corresponding DC bus voltage according to the preset output voltage;

[0106] The first controller controls the DC bus voltage according to the calculated value of the second controller to make it reach the preset data;

[0107] The second controller converts the connection mode of the output ends of the two groups of DC / DC converters by controlling the switching states of the first switch, the second switch and the third switch to obtain the target voltage output range.

[0108] The working principle of the above technical solution is as follows: The first controller and the second controller are respectively responsible for the control tasks of the AC / DC rectifier and the two groups of DC / DC converters, and work together to achieve efficient voltage conversion and stable output. The first controller is responsible for controlling the AC / DC rectifier, mainly for power factor correction and DC bus voltage regulation. Power factor correction can reduce the reactive power in the power grid and improve the utilization rate of electric energy; while the regulation of the DC bus voltage ensures that the DC voltage output by the rectifier is stable and provides a stable input for the DC / DC converter. The second controller is responsible for controlling the two groups of DC / DC converters, mainly for output voltage stabilization control and constant current control. First, it calculates the corresponding DC bus voltage value according to the preset output voltage value and sends this calculated value to the first controller. The first controller adjusts the output of the AC / DC rectifier according to the received calculated value to make the DC bus voltage reach the preset value, so as to provide a suitable input voltage for the DC / DC converter. The second controller also converts the connection mode of the output ends of the two groups of DC / DC converters by controlling the switching states of the first switch, the second switch and the third switch to obtain the required target voltage output range. This control method can flexibly adjust the output voltage to meet the needs of different loads.

[0109] The technical effects of the above technical solution are as follows: By performing power factor correction on the AC / DC rectifier through the first controller, the reactive power in the power grid can be reduced, the power grid loss can be decreased, and the utilization rate of electric energy can be improved. The first controller precisely adjusts the DC bus voltage to ensure the stability of the DC voltage output by the rectifier, providing a stable input for the DC / DC converter, thereby enhancing the stability of the entire system. The second controller can flexibly adjust the output voltages of the two groups of DC / DC converters by controlling the switching states of the switches to meet the voltage requirements of different loads. This control method improves the adaptability and flexibility of the system. By precisely controlling the operating states of the AC / DC rectifier and the DC / DC converter, the system can achieve efficient energy conversion, reduce energy loss, and improve the energy efficiency of the system. With the redundant design of two controllers and the flexible control of the switches, even if one of the controllers or switches fails, the system can still maintain the output by adjusting the operating states of other parts, improving the reliability and stability of the system. The system realizes efficient voltage conversion and stable output through precise control of the operating states of the AC / DC rectifier and the DC / DC converter, as well as flexible switch control, improving the reliability and energy efficiency of the system.

[0110] In an embodiment of the present invention, the method includes pre-adjusting the DC bus voltage through a two-stage rectification controller;

[0111] The output voltage of the front-stage rectifier module is regulated by the rear-stage converter module according to a preset output voltage to obtain regulation information;

[0112] The input voltage and the output connection mode of the internal DC / DC converter module are regulated by the rear-stage converter module to obtain a target voltage output range;

[0113] The input terminals of the rear-stage converter module are respectively connected in parallel to two output capacitors of the front-stage rectifier module;

[0114] The control data of the control system is obtained, and the front-stage control accuracy coefficient of the front-stage rectifier module, the rear-stage control accuracy coefficient of the rear-stage converter module, and the architecture control accuracy of the control architecture are respectively calculated;

[0115] Each accuracy coefficient is compared with a corresponding preset threshold to obtain a coefficient comparison result, and early warnings are given to the control modules (front-stage rectifier module, rear-stage converter module, and control architecture) corresponding to the corresponding accuracy coefficients according to the comparison result.

[0116] The control data of the front-stage rectifier module is obtained, and the front-stage control accuracy coefficient of the front-stage rectifier module is calculated according to the control data of the front-stage rectifier module;

[0117] The calculation formula of the front-stage control accuracy coefficient is:

[0118]

[0119] Among them, QK is the front-stage control precision coefficient, V p is the average value of the actual DC bus voltage, V f is the ripple amplitude of the DC bus voltage, V y is the preset value of the DC bus voltage, PFC yz is the efficiency factor of power factor correction, which is the ratio of the actual power factor to the ideal power factor (usually 1);

[0120] Compare the front-stage control precision coefficient with the preset front-stage coefficient threshold to obtain the front-stage comparison result;

[0121] When the front-stage control precision coefficient is less than the preset front-stage coefficient threshold, a front-stage control warning for the front-stage rectifier is given; otherwise, no front-stage control warning for the front-stage rectifier is given.

[0122] Obtain the control data of the post-stage converter module, and calculate the post-stage control precision coefficient of the post-stage converter module according to the control data of the post-stage converter module;

[0123] The calculation formula for the post-stage control precision coefficient is:

[0124]

[0125] Among them, HK is the post-stage control precision coefficient, U a is the actual output voltage, U s is the preset value of the output voltage, I a is the actual output current, I s is the preset value of the output current (in the constant current control mode);

[0126] Compare the post-stage control precision coefficient with the preset post-stage coefficient threshold to obtain the post-stage comparison result;

[0127] When the post-stage control precision coefficient is less than the preset post-stage coefficient threshold, a post-stage control warning for the post-stage rectifier is given; otherwise, no post-stage control warning for the post-stage rectifier is given.

[0128] Obtain the control data of the control architecture, and calculate the architecture control precision coefficient of the control architecture according to the control data of the control architecture;

[0129] The calculation formula for the architecture control precision coefficient is:

[0130]

[0131] Among them, JG is the architecture control precision coefficient, Δt s is the actual communication delay duration between controllers, Δty is the preset communication delay duration between controllers;

[0132] Compare the architecture control precision coefficient with the preset architecture coefficient threshold to obtain an architecture comparison result;

[0133] When the architecture control precision coefficient is less than the preset architecture coefficient threshold, give an architecture control warning for the architecture rectifier. Otherwise, do not give a post-stage control warning for the architecture rectifier, as Figure 1 shown.

[0134] The working principle of the above technical solution is as follows: The DC bus voltage is pre-regulated by a two-stage rectifier controller. The two-stage rectifier controller usually includes an AC input terminal, a DC output terminal, and a control circuit, and can realize the rectification of the AC power supply voltage and the regulation of the DC output voltage. In this step, the rectifier controller adjusts its internal control circuit according to the preset DC bus voltage value to make the DC voltage output by the front-stage rectifier module reach near the preset value. The post-stage converter module further regulates the output voltage of the front-stage rectifier module according to the preset output voltage. The post-stage converter module includes a DC / DC converter and other control circuits, and can realize the conversion of the input voltage and the stable control of the output voltage. In this step, the post-stage converter module samples and compares the difference between the preset output voltage and the actual output voltage, generates a regulation signal, and adjusts the output voltage of the front-stage rectifier module through the control circuit until the actual output voltage is consistent with the preset value. At the same time, the post-stage converter module will record relevant information during the regulation process, such as the regulation time, the regulation amplitude, etc. The post-stage converter module also regulates the input voltage and the output connection mode of the internal DC / DC converter module to obtain the target voltage output range. In this step, the post-stage converter module adjusts the magnitude of the input voltage and the output connection mode of the DC / DC converter module (such as series connection, parallel connection, or hybrid connection) according to the preset output voltage range and the load demand to achieve precise regulation of the output voltage and expand the output range. This regulation method can ensure that the system can provide a stable output voltage under different load conditions. The input terminals of the post-stage converter module are respectively connected in parallel to the two output capacitors of the front-stage rectifier module. This design can make full use of the filtering and energy storage functions of the two output capacitors to improve the stability and reliability of the DC bus voltage. At the same time, the parallel input terminals can also realize the redundant backup and load balancing of the post-stage converter module, improving the reliability and energy efficiency of the system.

[0135] The technical effects of the above technical solution are as follows: By pre-regulating the DC bus voltage through a two-stage rectifier controller and precisely controlling the post-stage converter module, the stability of the output voltage can be significantly improved. This regulation method can reduce voltage fluctuations and ripple noise, providing a more stable power supply environment for the load. The post-stage converter module can flexibly expand the output voltage range by adjusting the input voltage and the output connection mode of the DC / DC converter module. This design enables the system to adapt to application scenarios with different load and voltage requirements. The parallel input terminal design and the redundant backup mechanism can improve the energy efficiency and reliability of the system. By making full use of the filtering and energy storage functions of the two output capacitors and the redundant backup function of the post-stage converter module, the system can reduce energy consumption and improve the fault tolerance ability while ensuring the stability of the output voltage. The method also provides a basis for optimizing the system performance by recording and analyzing relevant information (such as regulation time, regulation amplitude, etc.) during the regulation process. By continuously analyzing and optimizing the regulation strategy, the energy efficiency, stability, and reliability of the system can be further improved. The method realizes the precise regulation of the DC bus voltage and the stable control of the output voltage through the collaborative work of the two-stage rectifier controller, the pre-stage rectifier module, the post-stage converter module, and the DC / DC converter module. This design method has significant advantages in improving voltage stability, expanding the output range, improving energy efficiency and reliability, and optimizing system performance.

[0136] The pre-stage rectifier module is responsible for converting alternating current into direct current, regulating the DC bus voltage to near the preset value, and simultaneously achieving power factor correction (PFC). The post-stage converter module further regulates the DC bus voltage provided by the pre-stage rectifier module according to the preset output voltage (or current) requirement. Through the regulation of the internal DC / DC converter module and the output connection mode, the target voltage (or current) output range is achieved. The post-stage converter module generates regulation information based on the difference between the preset output voltage (or current) and the actual output voltage (or current), as well as the working state of the internal DC / DC converter module. These regulation information are transmitted to the pre-stage rectifier module through the control architecture to guide it to adjust the DC bus voltage to meet the requirements of the post-stage converter module. By obtaining the control data of the pre-stage rectifier module, the post-stage converter module, and the control architecture, the pre-stage control accuracy coefficient (QK), the post-stage control accuracy coefficient (HK), and the architecture control accuracy coefficient (JG) are calculated respectively. These coefficients reflect the control accuracy and stability of the system during actual operation, providing a basis for the optimization and improvement of the system.

[0137] By precisely calculating the front-stage control precision coefficient and the rear-stage control precision coefficient, the control performance of the system can be monitored and evaluated in real time to ensure the stability and accuracy of the output voltage (or current). The introduction of the architecture control precision coefficient further considers the impact of communication delay between controllers on system performance, which helps to optimize the control strategy and improve the system response speed and stability. The rear-stage converter module can flexibly adjust the output connection mode and input voltage of the internal DC / DC converter module according to the requirements of the preset output voltage (or current) to achieve a wide range of voltage (or current) output. This flexibility enables the system to adapt to different load demands and working environments, improving the applicability and reliability of the system. By monitoring and evaluating the control precision and stability of the system in real time, potential problems can be discovered and solved in a timely manner to avoid a decline in system performance or the occurrence of faults. Optimizing and improving the system based on the evaluation results can further improve the efficiency and performance of the system, reducing energy consumption and costs.

[0138] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these changes and modifications.

Claims

1. A rectifier control system for a wide voltage output charging module, characterized in that: The system includes a two-stage rectifier and a control architecture; The two-stage rectifier comprises a front-stage rectifier module and a rear-stage converter module; The front-stage rectifier module includes an AC / DC rectifier and two groups of output capacitors; The post-stage converter module includes two groups of DC / DC converters and three groups of switches; Connect the three sets of switches to the two sets of DC / DC converters respectively; The input ends of the two groups of DC / DC converters are respectively connected in parallel with the two output capacitors of the front-stage rectifier module; The control architecture includes two groups of controllers, the two groups of controllers are respectively a first controller and a second controller; The two-stage rectifier is connected to the control architecture in a bidirectional communication, the AC / DC rectifier is connected to the first controller in a bidirectional communication, and the two groups of DC / DC converters are connected to the second controller in a bidirectional communication; The AC / DC rectifier is controlled by the first controller to correct the power factor and adjust the DC bus voltage; The second controller controls two groups of DC / DC converters to control output voltage stabilization and constant current; Calculate the front-stage control accuracy coefficient through DC bus voltage data and power factor correction data; The calculation formula of the front-stage control accuracy coefficient is: Among them, QK is the previous stage control accuracy coefficient, V p is the average value of the actual DC bus voltage, V f is the ripple amplitude of the DC bus voltage, V y is the preset value of the DC bus voltage, PFC yz is the efficiency factor of power factor correction, which is the ratio of the actual power factor to the ideal power factor; Compare the front-stage control accuracy coefficient with the preset front-stage coefficient threshold to obtain the front-stage comparison result; Whether to perform a pre-stage control warning of the pre-stage rectifier is determined according to the pre-stage comparison result.

2. According to claim 1, a rectifier control system for a wide voltage output charging module is characterized in that: The working state of the AC / DC rectifier is a rectification state; The working state of the DC / DC converter is a direct current conversion state.

3. According to the rectifier control system of the wide voltage output charging module of claim 1, it is characterized in that: The two groups of DC / DC converters include a first DC / DC converter and a second DC / DC converter; Controlling the connection mode of the output ends of the first DC / DC converter and the second DC / DC converter by the switch states of the first switch, the second switch and the third switch; The first switch is connected to the high voltage end of the output end of the first DC / DC converter and the second DC / DC converter; The second switch is connected to the low voltage end of the output end of the first DC / DC converter and the second DC / DC converter; The third switch is connected to a low voltage end of the output end of the first DC / DC converter and a high voltage end of the output end of the second DC / DC converter.

4. According to claim 3, a rectifier control system for a wide voltage output charging module is characterized in that: The first switch and the second switch are turned on, and the third switch is turned off, so that the output ends of the first DC / DC converter and the second DC / DC converter are in a low-voltage output state; When the third switch is turned on and the first switch and the second switch are turned off, the output ends of the first DC / DC converter and the second DC / DC converter are in a high-voltage output state.

5. According to claim 3, a rectifier control system for a wide voltage output charging module is characterized in that: The first switch, the second switch and the third switch include mechanical switches and semiconductor switches; The mechanical switch includes a relay and a contactor; The semiconductor switch includes an IGBT and a MOSFET.

6. According to claim 1, a rectifier control system for a wide voltage output charging module is characterized in that: The two groups of output capacitors include output capacitor C1 and output capacitor C2; The output capacitor C1 and the output capacitor C2 are connected in series and then connected in parallel at the output end of the AC / DC rectifier. The parameters of the output capacitor C1 and the output capacitor C2 are consistent.

7. According to claim 3, a rectifier control system for a wide voltage output charging module is characterized in that: Said The input end of the first DC / DC converter is connected in parallel with both ends of the output capacitor C1 of the AC / DC rectifier; The input terminal of the second DC / DC converter is connected in parallel to both ends of the output capacitor C2 of the AC / DC rectifier.

8. According to claim 1, a rectifier control system for a wide voltage output charging module is characterized in that: The second controller calculates the corresponding DC bus voltage according to the preset output voltage; The first controller controls the DC bus voltage according to the calculated value of the second controller to make it reach a preset value; The second controller switches the connection mode of the two groups of DC / DC converter output terminals by controlling the switch states of the first switch, the second switch and the third switch to obtain the target voltage output range.

9. A control method for a rectifier control system of a wide voltage output charging module as claimed in claim 1, characterized in that: The method includes pre-regulating the DC bus voltage by a two-stage rectifier controller; The output voltage of the front-stage rectifier module is regulated by the rear-stage converter module according to the preset output voltage to obtain regulation information; The input voltage and the output connection mode of the internal DC / DC converter module are regulated by the post-stage converter module to obtain the target voltage output range; The input end of the rear-stage converter module is respectively connected in parallel to the two output capacitors of the front-stage rectifier module; Acquire control data of the control system, and respectively calculate a front-stage control accuracy coefficient of a front-stage rectifier module, a rear-stage control accuracy coefficient of a rear-stage converter module, and an architecture control accuracy coefficient of a control architecture; The calculation formula of the front-stage control accuracy coefficient is: Among them, QK is the previous stage control accuracy coefficient, V p is the average value of the actual DC bus voltage, V f is the ripple amplitude of the DC bus voltage, V y is the preset value of the DC bus voltage, PFC yz is the efficiency factor of power factor correction, which is the ratio of the actual power factor to the ideal power factor; The calculation formula of the post-stage control accuracy coefficient is: Among them, HK is the post-stage control accuracy coefficient, U a is the actual output voltage, U s is the preset value of the output voltage, I a is the actual output current, I s is the preset value of the output current; The calculation formula of the architecture control accuracy coefficient is: Where JG is the architecture control accuracy coefficient, Δt s is the actual communication delay between controllers, Δt y It is the preset communication delay time between controllers; Each accuracy coefficient is compared with a corresponding preset threshold value to obtain a coefficient comparison result, and a warning is issued to a control module corresponding to the corresponding accuracy coefficient according to the comparison result.

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