Wide-voltage high-reliability charging module and rectification control method thereof

Abstract

The invention provides a wide-voltage high-reliability charging module and a rectification control method thereof, and relates to the technical field of power electronics, and the system comprises a two-stage rectifier and a control framework. The two-stage rectifier comprises a pre-stage rectifier module and a post-stage converter module; the pre-stage rectifier module comprises an AC / DC rectifier and two groups of output capacitors; the rear-stage converter module comprises two groups of DC / DC converters and three groups of switches; the input ends of the two groups of DC / DC converters are respectively connected in parallel with two output capacitors of the preceding-stage rectifier module; the control framework comprises two groups of controllers, the two groups of controllers are respectively a first controller and a second controller, and 250V-1000V wide-range voltage output is realized by controlling the direct-current bus voltage and the connection mode of the output ends of the two LLC resonant converters at the rear stage. Meanwhile, the input voltage of the LLC resonant converter is only half of the voltage of the direct-current bus, so that the voltage stress and the like of a switching device are greatly reduced.

Description

Technical Field

[0001] The present invention provides a wide-voltage high-reliability charging module and a rectification control method thereof, and relates to the technical field of power electronics, and in particular to the technical field of wide-voltage high-reliability charging rectification control. Background Art

[0002] Electric vehicles have been rapidly developed in my country due to their advantages such as low pollution and low cost of use. As one of its core technologies, electric vehicle charging devices have received extensive attention and research. Since the battery voltages used by various electric vehicle manufacturers are different, higher requirements are placed on the output voltage range of electric vehicle charging devices. The power module of a DC charging pile can generally be composed 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 the output voltage regulation, current balancing and other issues are dealt with by the rear-stage DC / DC converter. Therefore, the development of the rear-stage DC / DC converter faces many difficulties such as high power density, high efficiency and wide output voltage range. Summary of the invention

[0003] The present invention provides a wide voltage and high reliability charging module and a rectification control method thereof to solve the above problems:

[0004] The present invention provides a wide voltage and high reliability charging module and a rectification control method thereof, wherein the charging module includes a two-stage rectifier and a control architecture;

[0005] The two-stage rectifier comprises 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 post-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, the two groups of controllers are respectively a first controller and a second controller;

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

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

[0012] The working state of the DC / DC converter is a direct current conversion state.

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

[0014] 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;

[0015] 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;

[0016] 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;

[0017] 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.

[0018] Further, the first switch and the third switch are turned on, and the second 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;

[0019] When the second switch is turned on and the first switch and the third 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.

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

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

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

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

[0024] 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.

[0025] Further, 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;

[0026] 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.

[0027] Furthermore, the AC / DC rectifier is controlled by the first controller to correct the power factor and adjust the DC bus voltage;

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

[0029] Furthermore, 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 a preset value;

[0031] 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.

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

[0033] 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;

[0034] 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 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;

[0035] 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 of the control architecture;

[0036] Each accuracy coefficient is compared with the corresponding preset threshold value to obtain a coefficient comparison result, and a warning is issued to the control module (front-stage rectifier module, rear-stage converter module and control architecture) corresponding to the corresponding accuracy coefficient according to the comparison result.

[0037] Beneficial effects of the present invention: the rear-stage converter module can automatically adjust the output voltage of the front-stage rectifier module according to the required output voltage, so that the rear-stage converter module can operate at the optimal efficiency point under most working conditions. The rear-stage converter module can obtain a wider voltage output range by adjusting the input voltage and the output connection mode of the internal DC / DC converter module. 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, which is conducive to reducing the voltage stress and current stress of the DC / DC converter switch tube. 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 groups of switches is adopted to improve 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 converter adopt a high-efficiency design, which reduces energy loss and improves the energy efficiency of the system. Through the filtering and smoothing effect of the output capacitor 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, which can monitor the working status of the system in real time, facilitate timely detection and handling of faults, and reduce maintenance costs and management difficulties. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic diagram of a rectification control method for a wide voltage and high reliability charging module;

[0039] Figure 2 It is a principle block diagram of a preferred embodiment of rectifier control of a wide voltage and high reliability charging module;

[0040] Figure 3 It is a topological circuit diagram of a preferred embodiment of rectifier control of a wide voltage and high reliability charging module;

[0041] Figure 4 It is a schematic diagram of the architecture of a preferred embodiment of rectifier control of a wide voltage and high reliability charging module;

[0042] Figure 5 It is a control block diagram of a preferred embodiment of rectifier control of a wide voltage and high reliability charging module. DETAILED DESCRIPTION

[0043] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0044] One embodiment of the present invention provides a wide voltage and high reliability charging module and a rectification control method thereof, wherein the charging module includes a two-stage rectifier and a control architecture;

[0045] The two-stage rectifier comprises a front-stage rectifier module and a rear-stage converter module;

[0046] The front-stage rectifier module includes an AC / DC rectifier and two groups of output capacitors;

[0047] The post-stage converter module includes two groups of DC / DC converters and three groups of switches;

[0048] 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;

[0049] The control architecture includes two groups of controllers, the two groups of controllers are respectively a first controller and a second controller;

[0050] 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;

[0051] The working state of the AC / DC rectifier is a rectification state;

[0052] The working state of the DC / DC converter is a direct current conversion state.

[0053] The working principle of the above technical solution is as follows: The present invention provides a wide voltage high reliability charging module and a rectifier control method thereof, comprising 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 have a wider range of voltage input. On this basis, the rear-stage converter module can enter different working modes by changing the output connection mode of the internal DC / DC converter to obtain a wider voltage output range.

[0054] The technical solution adopted by the present invention to solve its technical problems is: constructing a wide voltage high reliability charging module and a rectifier control method thereof, including 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 groups of 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, which effectively reduces the voltage stress of the DC / DC converter switch tube.

[0055] The AC / DC rectifier works in a rectifying state to pre-regulate the DC bus voltage; the DC / DC converter works in a DC conversion state to provide a stable power output for the load.

[0056] The control architecture includes two groups 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 groups of DC / DC converters to achieve output voltage regulation control and constant current control.

[0057] 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. Furthermore, the second controller controls the switching states of the first switch, the second switch and the third switch, thereby changing the connection mode of the output terminals of the two sets of DC / DC converters to achieve a wider range of voltage output.

[0058] In the wide voltage output range rectifier control system described in the present invention, the converter module includes two groups of DC / DC converters and three groups of switches, and both groups of DC / DC converters work in the DC converter state to provide 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 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, 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.

[0059] When the first switch and the third switch are turned on and the second switch is turned off, the output ends of the first DC / DC converter and the second DC / DC converter enter a low-voltage output state.

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

[0061] In the wide voltage output range rectifier control system described in 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; and the semiconductor switches include IGBTs and MOSFETs.

[0062] In the rectifier control of the wide voltage and high reliability charging module described in 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 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 consistent.

[0063] In the rectifier control of the wide voltage and high reliability charging module described in the present invention, 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 and 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, which effectively reduces the switching tube voltage stress of the DC / DC converter.

[0064] In the rectifier control of the wide voltage and high reliability charging module described in the present invention, the control architecture includes two groups 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 regulation control and constant current control.

[0065] In the rectifier control of the wide voltage high reliability charging module described in the present invention, for a given output voltage, the second controller calculates the corresponding DC / DC converter input voltage and modifies the DC bus voltage setting value. After receiving the DC bus voltage setting value, the first controller controls the AC / DC rectifier module to adjust its output voltage, i.e., the DC bus voltage, in real time.

[0066] like Figure 2 As shown, the rectifier control of the wide voltage and high reliability charging module of the present invention includes a two-stage rectifier and a control architecture.

[0067] The two-stage rectifier comprises a front-stage rectifier module and a rear-stage converter module. The rectifier module comprises an AC / DC rectifier and two groups of output capacitors C1 and C2; the converter module comprises two groups of DC / DC converters and three groups of switches.

[0068] The control architecture includes two groups 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 of the two groups of DC / DC converters.

[0069] like Figure 3 As shown, Ea, Eb, Ec are input voltages, Ia, Ib, Ic are input currents, UBUS is the DC bus voltage, and UO and IO are output voltage and output current, respectively.

[0070] In this embodiment, the AC / DC rectifier uses a Vienna rectifier, the DC / DC converter uses an LLC resonant converter, and the first switch, the second switch, and the third switch use relays SS, SP1, and SP2. The input ends of the two LLC resonant converters in this embodiment are respectively connected in parallel to 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, which effectively reduces the voltage stress of the LLC resonant converter switch tube.

[0071] When the parallel relays SP1 and SP2 are turned on and the series relay SS is turned off, the output ends of the two groups of LLC resonant converters are connected in parallel and enter a low-voltage output state.

[0072] When the series relay SS is turned on and the parallel relays SP1 and SP2 are turned off, the output ends of the two groups of LLC resonant converters are connected in series and enter a high-voltage output state.

[0073] 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.

[0074] like Figure 4 As shown, the Vienna rectifier works in the rectification state, and the first controller controls the switch tubes Sa1, Sa2, Sb1, Sb2, Sc1, and Sc2 of the Vienna rectifier to control the input currents Ia, Ib, and Ic and the DC bus voltage UBUS, further realizing power factor correction and pre-regulation of the DC bus voltage; the LLC resonant converter works in the DC conversion state, and the second controller controls the switch tubes Q1-Q8 of the two groups of 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.

[0075] like Figure 5 As shown, 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 transformed by clark and park.

[0076] The control process in this embodiment is described below.

[0077] After the output voltage setting value VO_Set is input into the second controller, the DC bus voltage setting value VBUS_Ref is first obtained after the bus voltage is calculated and VBUS_Ref is transmitted to the first controller. In addition, after VO_Set is judged by the output voltage range, the second controller outputs a switch 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 a 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 a high-voltage output state, the series relay SS is turned on, and the parallel relays SP1 and SP2 are turned off.

[0078] After the output voltage setting value VO_Set and the output current setting value IO_Set are input to the second controller, the voltage reference values ​​Vref_1 and Vref_2 of the voltage controlled oscillator are obtained after being calculated by the output voltage controller and the output current controller, and the maximum value Vref of Vref_1 and Vref_2 is input to the voltage controlled oscillator VCO to obtain the output of the subsequent stage drive signal with different frequencies, thereby controlling the output voltage and the output current to reach the set value. The output voltage controller and the output current controller in this embodiment both use a proportional integral (PI) regulator.

[0079] After the first controller receives the bus voltage setting value VBUS_Ref, it inputs VBUS_Ref to the bus voltage controller, and the bus voltage controller uses VBUS_Ref and VBUS_Act to calculate the input current reference value IAC_Ref. The input current controller uses IAC_Ref and IAC_Act to calculate the modulation wave, and then inputs the modulation wave to the SPWM module and compares it with the carrier to obtain the front-stage drive signal, thereby controlling the input current and the DC bus voltage to reach the set value, thereby realizing power factor correction and DC bus voltage regulation. The bus voltage controller in this embodiment adopts a proportional integral (PI) regulator, and the input current controller adopts a proportional integral (PI) regulator plus a proportional resonance (PR) controller.

[0080] The preferred embodiment of the wide voltage high reliability charging module and its rectifier control system of the present invention realizes a wide range voltage output of 250V-1000V by controlling the DC bus voltage and the output terminal connection mode of the two LLC resonant converters at the rear stage. 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 within the range of 600V-830V, the LLC resonant converter can operate at the optimal efficiency point in most of the voltage output range, effectively improving the efficiency of the rectifier system.

[0081] The two-stage rectifier is mainly composed 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), while the rear-stage converter module further converts the voltage of the DC output of the front stage to meet the needs 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 smoothes it through 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 sets of 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 realize voltage conversion of the DC output of the front stage. The three sets of switches are used to control different voltage outputs or realize functions such as redundant backup. The control architecture is controlled by two sets of controllers (the first controller and the second controller). These controllers are responsible for monitoring the working status of the rectifier module and the converter module, and adjusting the working parameters of each module according to the preset algorithm and logic to achieve stable voltage output and efficient energy conversion. The AC / DC rectifier is always in the rectification state, converting the input AC power into DC power. 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 needs of the load. The input AC power is first converted into DC power by the AC / DC rectifier and filtered and smoothed by the output capacitor. The stable DC power then enters the two sets of DC / DC converters for voltage conversion according to the instructions of the controller. The converted DC power is output to the load through the switch. The controller monitors the working status of the rectifier module and the converter module in real time, and makes adjustments as needed to ensure the stable operation of the system.

[0082] The control system includes a two-stage rectifier and a control architecture, wherein the two-stage rectifier is composed of a front-stage rectifier module and a rear-stage converter module. The rectifier module works in a rectifier state to pre-regulate the DC bus voltage; the converter module works in a DC conversion state to provide a stable power output for the load. The converter module includes two groups of DC / DC converters and three groups of switches. The inputs of the two groups of DC / DC converters are respectively connected to the two output capacitors of the front-stage rectifier module, which effectively reduces the voltage stress of the switch tube. The control architecture includes two groups 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 the DC / DC converter to achieve output voltage regulation 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. Furthermore, the second controller controls the switching state of the first switch, the second switch and the third switch, thereby changing the connection mode of the output ends of the two groups of DC / DC converters to achieve a wider range of voltage output.

[0083] The technical effects of the above technical solution are as follows: 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 groups of switches improves the reliability and stability of the system. Even if one of the converters or switches fails, the system can continue to operate to ensure the normal power supply of the load. Both the AC / DC rectifier and the DC / DC converter adopt a high-efficiency design, which reduces energy loss and improves the energy efficiency of the system. Through the filtering and smoothing effect of the output capacitor and the precise control of the controller, the system can provide a stable output voltage to meet the load's requirements for voltage stability. The controller has monitoring and fault diagnosis functions, and can monitor the working status of the system in real time, making it easy to find and handle faults in a timely manner, reducing maintenance costs and management difficulties.

[0084] In one embodiment of the present invention, the two groups of DC / DC converters include a first DC / DC converter and a second DC / DC converter;

[0085] 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;

[0086] 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;

[0087] 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;

[0088] 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.

[0089] The first switch and the third switch are turned on, and the second 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;

[0090] When the second switch is turned on and the first switch and the third 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.

[0091] The first switch, the second switch and the third switch include mechanical switches and semiconductor switches;

[0092] The mechanical switch includes a relay and a contactor;

[0093] The semiconductor switch includes an IGBT and a MOSFET.

[0094] The working principle of the above technical solution is: 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, and 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 a low voltage state. When the second switch is turned on and the first switch and the third switch are turned off, the high voltage end of the first DC / DC converter is connected in series with the high voltage end of the second DC / DC converter 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 high voltage output. For example, relays and contactors have the ability to withstand high voltage and high current, and are suitable for occasions that require frequent operation but require a long switch life. For example, IGBT (insulated gate bipolar transistor) and MOSFET (metal oxide semiconductor field effect transistor) have the characteristics of fast switching speed and good controllability, and are suitable for occasions that require high frequency switching and precise control.

[0095] The technical effect of the above technical solution is: through the different combination states of the three switches, the system can flexibly switch between low-voltage and high-voltage output states to meet the voltage requirements of different loads. The redundant design of two sets of DC / DC converters and three switches is adopted. Even if one of the converters or switches fails, the system can still maintain the output by adjusting the state of other switches, thereby improving the reliability and stability of the system. In the low-voltage output state, the two converters work in parallel, which can share the load current, reduce the heat loss of a single converter, and improve the overall energy efficiency. In the high-voltage output state, the two converters work in series, which can output a higher voltage to meet the needs of specific loads. Through the precise control of the switch state by the controller, the system can monitor and diagnose the working state of the switch in real time, facilitate timely detection and handling of faults, and reduce maintenance costs and management difficulties. The design is easy to expand, and more voltage levels can be output by adding more DC / DC converters and switches to meet a wider range of application needs.

[0096] In one embodiment of the present invention, the two groups of output capacitors include output capacitor C1 and output capacitor C2;

[0097] 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.

[0098] 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;

[0099] 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.

[0100] 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 smoothes the two output capacitors C1 and C2 connected in series and then in parallel at the output end. The parameters of the two output capacitors are consistent, 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 the two ends of the 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 by the output capacitors C1 and C2 connected in series and then in parallel. Since the parameters of the two capacitors are consistent, they can share the filtering task together, reduce voltage fluctuations and ripples, and provide a stable direct current output voltage. The filtered and smoothed direct current enters the input ends of the first DC / DC converter and the second DC / DC converter respectively. The two converters perform voltage conversion according to the instructions of the controller and convert the direct current into direct current outputs of different voltage levels. Through the precise control of the switch state by the controller, the system can monitor and diagnose the working state of each module in real time, and adjust the output voltage and current as needed to meet the needs of the load.

[0101] The technical effect of the above technical solution is: using two output capacitors with consistent parameters for series connection and then parallel 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 consistent in this case, there may be slight differences in actual applications), the corresponding resonant frequencies are also different, which can better filter out ripple noise of different frequencies. The parallel use of 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 works in a high efficiency range, reduce energy loss, and improve the energy efficiency of the system. The redundant design of two DC / DC converters is adopted, even if one of the converters fails, the other converter can continue to work, ensuring the normal power supply of 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, facilitate timely detection and handling of faults, and reduce maintenance costs and management difficulties. The system achieves efficient voltage conversion and stable DC output by using two output capacitors with consistent parameters for series connection and then parallel filtering, and the redundant design of two DC / DC converters, thereby improving the reliability and energy efficiency of the system.

[0102] In one embodiment of the present invention, the AC / DC rectifier is controlled by a first controller to correct the power factor and adjust the DC bus voltage;

[0103] The second controller controls two groups of DC / DC converters to perform output voltage stabilization control and constant current control.

[0104] The second controller calculates the corresponding DC bus voltage according to the preset output voltage;

[0105] The first controller controls the DC bus voltage according to the calculated value of the second controller to make it reach a preset value;

[0106] 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.

[0107] The working principle of the above technical solution is as follows: the first controller and the second controller respectively undertake 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 reactive power in the power grid and improve the utilization rate of electric energy; while the regulation of the DC bus voltage ensures the stability of the DC voltage output by the rectifier 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 regulation control and constant current control. First, the corresponding DC bus voltage value is calculated according to the preset output voltage value, and the calculated value is sent to the first controller. The first controller adjusts the output of the AC / DC rectifier according to the received calculated value so that the DC bus voltage reaches the preset value, thereby providing a suitable input voltage for the DC / DC converter. The second controller also converts the connection mode of the output terminals 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.

[0108] The technical effect of the above technical solution is: by correcting the power factor of the AC / DC rectifier through the first controller, the reactive power in the power grid can be reduced, the power grid loss can be reduced, and the utilization rate of electric energy can be improved. The first controller accurately adjusts the DC bus voltage to ensure that the DC voltage output by the rectifier is stable, and provides a stable input for the DC / DC converter, thereby improving the stability of the entire system. The second controller can flexibly adjust the output voltage of the two groups of DC / DC converters by controlling the switching state of the switch to meet the voltage requirements of different loads. This control method improves the adaptability and flexibility of the system. By accurately controlling the working state 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 the two controllers and the flexible control of the switch, even if one of the controllers or the switch fails, the system can still maintain the output by adjusting the working state of the other parts, thereby improving the reliability and stability of the system. The system achieves efficient voltage conversion and stable output by accurately controlling the working state of the AC / DC rectifier and the DC / DC converter, and flexible switch control, thereby improving the reliability and energy efficiency of the system.

[0109] In one embodiment of the present invention, the method includes pre-regulating the DC bus voltage by a two-stage rectifier controller;

[0110] 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;

[0111] 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 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;

[0112] 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 of the control architecture;

[0113] Each accuracy coefficient is compared with the corresponding preset threshold value to obtain a coefficient comparison result, and a warning is issued to the control module (front-stage rectifier module, rear-stage converter module and control architecture) corresponding to the corresponding accuracy coefficient according to the comparison result.

[0114] Acquire control data of a front-stage rectifier module, and calculate a front-stage control accuracy coefficient of the front-stage rectifier module according to the control data of the front-stage rectifier module;

[0115] The calculation formula of the front-stage control accuracy coefficient is:

[0116]

[0117] 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 It is the efficiency factor of power factor correction, which is the ratio of the actual power factor to the ideal power factor (usually 1);

[0118] Compare the front-stage control accuracy coefficient with the preset front-stage coefficient threshold to obtain the front-stage comparison result;

[0119] When the pre-stage control accuracy coefficient is less than the preset pre-stage coefficient threshold, a pre-stage control early warning of the pre-stage rectifier is performed, otherwise, no pre-stage control early warning of the pre-stage rectifier is performed.

[0120] Acquiring control data of a subsequent converter module, and calculating a subsequent control accuracy coefficient of the subsequent converter module according to the control data of the subsequent converter module;

[0121] The calculation formula of the post-stage control accuracy coefficient is:

[0122]

[0123] 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 (in constant current control mode);

[0124] Compare the post-stage control accuracy coefficient with a preset post-stage coefficient threshold to obtain a post-stage comparison result;

[0125] When the post-stage control accuracy coefficient is less than a preset post-stage coefficient threshold, a post-stage control early warning of the post-stage rectifier is performed, otherwise, no post-stage control early warning of the post-stage rectifier is performed.

[0126] Acquiring control architecture control data, and calculating an architecture control accuracy coefficient of the control architecture according to the control architecture control data;

[0127] The calculation formula of the architecture control accuracy coefficient is:

[0128]

[0129] Where JG is the architecture control accuracy coefficient, Δt s is the actual communication delay between controls, Δt y It is the preset communication delay time between controllers;

[0130] Comparing the architecture control accuracy coefficient with a preset architecture coefficient threshold to obtain an architecture comparison result;

[0131] When the architecture control accuracy coefficient is less than the preset architecture coefficient threshold, an architecture control warning of the architecture rectifier is performed, otherwise, no post-control warning of the architecture rectifier is performed, such as Figure 1 shown.

[0132] The working principle of the above technical solution is: pre-regulate the DC bus voltage through a two-stage rectifier controller. The two-stage rectifier controller usually includes an AC input terminal, a DC output terminal and a control circuit, which 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 so that the DC voltage output by the front-stage rectifier module reaches near the preset value. The rear-stage converter module further regulates the output voltage of the front-stage rectifier module according to the preset output voltage. The rear-stage converter module includes a DC / DC converter and other control circuits, which can realize the conversion of the input voltage and the stable control of the output voltage. In this step, the rear-stage converter module generates a control signal by sampling and comparing the difference between the preset output voltage and the actual output voltage, 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 rear-stage converter module will record relevant information in the regulation process, such as regulation time, 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 input voltage and the output connection mode of the DC / DC converter module (such as series, parallel or mixed connection) according to the preset output voltage range and load requirements 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 end of the post-stage converter module is 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 end can also achieve redundant backup and load balancing of the post-stage converter module, improving the reliability and energy efficiency of the system.

[0133] The technical effect of the above technical solution is: by pre-regulating the DC bus voltage and accurately regulating the post-stage converter module through the two-stage rectifier controller, the stability of the output voltage can be significantly improved. This regulation method can reduce voltage fluctuations and ripple noise, and provide a more stable power supply environment for the load. The post-stage converter module can flexibly expand the range of the output voltage by adjusting the input voltage and the output connection method of the DC / DC converter module. This design enables the system to adapt to application scenarios with different loads and voltage requirements. The parallel input terminal design and redundant backup mechanism can improve the energy efficiency and reliability of the system. By making full use of the filtering and energy storage effects of the two output capacitors and the redundant backup function of the post-stage converter module, the system can reduce energy consumption and improve fault tolerance while ensuring the stability of the output voltage. The method also provides a basis for optimizing 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 achieves accurate regulation of DC bus voltage and stable control of output voltage through the coordinated work between the two-stage rectifier controller, the front-stage rectifier module, the rear-stage converter module and the DC / DC converter module. This design method has significant advantages in improving voltage stability, expanding output range, improving energy efficiency and reliability, and optimizing system performance.

[0134] The front-stage rectifier module is responsible for converting AC power into DC power and adjusting the DC bus voltage to near the preset value, while realizing power factor correction (PFC). The rear-stage converter module further adjusts the DC bus voltage provided by the front-stage rectifier module according to the preset output voltage (or current) requirements, and realizes the target voltage (or current) output range through the regulation of the internal DC / DC converter module and the output connection mode. The rear-stage converter module generates control 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 control information are transmitted to the front-stage rectifier module through the control architecture to guide it to adjust the DC bus voltage to meet the needs of the rear-stage converter module. By obtaining the control data of the front-stage rectifier module, the rear-stage converter module and the control architecture, the front-stage control accuracy coefficient (QK), the rear-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 in actual operation, and provide a basis for the optimization and improvement of the system.

[0135] By accurately calculating the pre-stage control accuracy coefficient and the post-stage control accuracy 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 accuracy coefficient further considers the impact of communication delays between controllers on system performance, which helps to optimize the control strategy and improve the system response speed and stability. The post-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 requirements and working environments, improving the applicability and reliability of the system. By monitoring and evaluating the control accuracy and stability of the system in real time, potential problems can be discovered and solved in a timely manner to avoid system performance degradation or failure. Optimizing and improving the system based on the evaluation results can further improve the efficiency and performance of the system and reduce energy consumption and costs.

[0136] Obviously, those skilled in the art may 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 equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A wide voltage high reliability charging module, characterized in that: The charging module 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; 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 manner, the AC / DC rectifier is connected to the first controller in a bidirectional communication manner, and the two groups of DC / DC converters are connected to the second controller in a bidirectional communication manner.

2. According to claim 1, a wide voltage high reliability 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. A wide voltage high reliability charging module according to claim 1, 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. A wide voltage high reliability charging module according to claim 3, characterized in that: The first switch and the third switch are turned on, and the second 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 second switch is turned on and the first switch and the third 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. A wide voltage high reliability charging module according to claim 3, 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. A wide voltage high reliability charging module according to claim 1, 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. A wide voltage high reliability charging module according to claim 3, 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. A wide voltage high reliability charging module according to claim 1, characterized in that: 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 perform output voltage stabilization control and constant current control.

9. A wide voltage high reliability charging module according to claim 8, 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.

10. A rectification control method for a wide voltage and high reliability charging module, 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 of the control architecture; 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.

Images