Fault-tolerant control system of input-parallel output-series Boost converter

Abstract

The utility model belongs to the technical field of power supply circuits, and discloses a fault-tolerant control system for input-parallel output-series Boost converters, which comprises an input source, an output load, two paths of input-series output-parallel Boost converters, two topological conversion switch tubes, a voltage / current acquisition module, and a fault-tolerant PWM control and isolation driving module. According to the utility model, the modularized design is adopted, the control precision is high, the fault detection and fault-tolerant control response time is short, the reliability is high, the installation is convenient, the wiring is simple, the debugging and maintenance are easy, the cost is low, and the use is safe. The device has the capability of rapid diagnosis and recovery, can accurately position a specific fault switch tube, gives an alarm on a response fault alarm lamp, and completes topology reconstruction in the shortest time, no extra hardware equipment is needed, and the stability of the output bus voltage is ensured. The circuit is simple in structure, solves the problem of high cost, and has high system reliability.

Description

Technical Field

[0001] The utility model belongs to the technical field of power supply circuits, and in particular relates to a fault-tolerant control system of an input parallel-connected and output series-connected Boost converter. Background Art

[0002] With the gradual depletion of fossil fuels, clean energy power generation systems such as wind power generation systems, photovoltaic power generation systems, and fuel cell power generation systems have received extensive research attention. In these renewable energy systems, DC-DC converters have always played an important role in energy conversion. Since the input parallel output series converter can effectively reduce the input current ripple and does not increase the voltage / current stress of the switch tube, it has been widely used in new energy systems and other fields. However, it should be noted that when the DC-DC converter works under harsh conditions, the failure of one component will cause the collapse of the entire system. In the document "M. Shahbazi, E. Jamshidpour, P. Poure, S. Saadate and MR Zolghadri,"Open-and Short-Circuit Switch Fault Diagnosis for Nonisolated DC–DC Converters Using Field Programmable Gate Array," IEEE Transactions on Industrial Electronics, vol. 60, no. 9, pp. 4136-4146, Sept. 2013", M. Shahbazi pointed out that the failure of the power switch tube accounts for more than 30% of the converter failures and is the most prone to failure. Therefore, its reliability needs to be considered. The failure types of power switch tubes are generally divided into short-circuit failures and open-circuit failures. For short-circuit failures, the overcurrent protection circuit can usually be directly integrated into the drive circuit to obtain a safe and reliable protection effect. However, for open-circuit failures, similar hardware protection circuits are difficult to integrate into the drive circuit to achieve effective protection against open-circuit failures. Therefore, it is necessary to conduct in-depth research on the open-circuit failure of the power switch tube in the converter.

[0003] The open-circuit fault detection methods of power switch tubes can be mainly divided into two categories: signal-based and model-based. Signal-based detection methods generally select parameters such as inductor voltage / current, switch voltage / diode voltage, and magnetic field signals as monitoring variables. In practical applications, these signal patterns are measured in real time, and fault diagnosis is performed by checking their consistency with known healthy signal patterns. However, this method requires a higher sampling frequency, which limits its application in practice. The model-based method can avoid the system's requirement for high sampling frequency. Its mechanism is to compare the system residual with a predefined threshold. If the residual value is greater than the threshold, a corresponding fault signal is generated. However, in order to achieve better results for the model-based fault detection method, a more accurate mathematical model of the DC-DC converter needs to be constructed. However, in actual industrial applications, it is difficult to consider all the details of a complex system and construct an accurate mathematical model for it. In order to solve this problem, the observer can be integrated into the model-based fault detection method. The feedback characteristics of the observer can enable the model-based method to get rid of the dependence on the accuracy of the system model, and directly use a rough mathematical model for fault diagnosis, but this method has less application research in the input series output parallel type Boost converter.

[0004] Through the above analysis, the problems and defects of the prior art are as follows:

[0005] Existing fault detection methods for series-input and parallel-output Boost converters usually require the construction of an accurate mathematical model. However, a converter in actual application usually has strong nonlinearity, making modeling difficult. Utility Model Content

[0006] In view of the problems existing in the prior art, the utility model provides a fault-tolerant control system of a parallel-input and series-output Boost converter.

[0007] The purpose of the utility model is to solve the problems existing in the existing input series output parallel type Boost converter fault detection and processing system, such as the difficulty in accurate modeling, the difficulty in implementation and application due to the complexity of the system, and provide a fault-tolerant control system for the input parallel output series type Boost converter.

[0008] The utility model is implemented as follows: a fault-tolerant control system of an input parallel-output series-type Boost converter, comprising an input source and an output load, a two-way input series-output parallel-type Boost converter, two topology conversion switch tubes, a voltage / current acquisition module, a fault-tolerant PWM control and an isolation drive module.

[0009] Each of the input parallel output series type Boost converters comprises an inductor, a power switch tube, a filter capacitor and a diode;

[0010] The input sides of the first converter and the second converter are connected in parallel through the air switch interface of the input source, the first filter capacitor and the second filter capacitor on the output side are connected in series, and the load is connected in parallel to the two filter capacitors in series;

[0011] The first diode is connected between the first filter capacitor and the first inductor, with the anode close to the first inductor, and the second diode is connected between the second filter capacitor and the negative end of the input source, with the anode close to the second filter capacitor.

[0012] Furthermore, the power switch tube is divided into a first power switch tube and a second power switch tube, the source and drain of the first power switch tube are respectively connected to one end of the first inductor and the negative electrode of the input source; the source and drain of the second power switch tube are respectively connected to one end of the second inductor and one end of the air switch.

[0013] Furthermore, the topology conversion switch tube is divided into a first topology conversion switch tube and a second topology conversion switch tube, one end of the first topology conversion switch tube is arranged at the connection between the second inductor and the second power switch tube, and the other end is arranged at the connection between the first filter capacitor and the second filter capacitor; one end of the second topology conversion switch tube is arranged at the connection between the first inductor and the first diode, and the other end is arranged at the connection between the second inductor and the first topology conversion switch tube.

[0014] Further, the control terminals of the first power switch tube, the second power switch tube, the first topology conversion switch tube and the second topology conversion switch tube are connected to the DSP28335 controller after passing through the isolation drive module, and the DSP28335 controller is connected to the first fault alarm light and the second fault alarm light and the fault mark clearing switch;

[0015] The first inductor current, the second inductor current, the first filter capacitor voltage, the second filter capacitor voltage and the output load voltage are all connected to the DSP28335 controller after passing through the voltage / current acquisition module.

[0016] First, the utility model adopts modular design, with high control accuracy, short fault detection and fault-tolerant control response time, high reliability, convenient installation, simple wiring, easy debugging and maintenance, low cost, and safe use. The output is stable and all DC output is within the safe voltage range. The control end and the power end are isolated and protected, and there is no risk of electric shock.

[0017] The controller adopted by the utility model is DSP28335, the clock frequency can reach 150MHz, it has high-speed calculation, high-precision calculation and rich peripheral interfaces, strong anti-interference ability and convenient adjustment of control parameters.

[0018] The first power switch tube, the second power switch tube, the first topology conversion switch tube and the second topology conversion switch tube of the utility model all adopt N-channel MOSFET semiconductor power electronic devices, which have fast switching speed and strong overcurrent capacity.

[0019] Second, the utility model has the ability of rapid diagnosis and recovery, and can accurately locate the specific fault switch tube, warn on the corresponding fault alarm light, and then complete the topology reconstruction in the shortest time without adding additional hardware equipment to ensure the stability of the output bus voltage. The circuit structure is simple, which solves the problem of high cost and has high system reliability.

[0020] Third, the technical solution of this utility model fills the technical gap in the industry at home and abroad:

[0021] The utility model adopts modular design, with high control accuracy, short fault detection and fault-tolerant control response time, high reliability, convenient installation, simple wiring, easy debugging and maintenance, low cost and safe use. The output is stable, all DC output is adopted, within the safe voltage range. The control end and the power end are isolated and protected, without the risk of electric shock. The controller adopted by the utility model is DSP28335, the clock frequency can reach 150MHz, with high-speed calculation, high-precision calculation and rich peripheral interfaces, strong anti-interference ability, and convenient adjustment of control parameters. The first power switch tube, the second power switch tube, the first topology conversion switch tube and the second topology conversion switch tube of the utility model all adopt N-channel MOSFET semiconductor power electronic devices, with fast switching speed and strong overcurrent capacity. The utility model has the ability of rapid diagnosis and recovery, and can accurately locate the specific fault switch tube, warn on the corresponding fault alarm light, and then complete the topology reconstruction in the shortest time, without adding additional hardware equipment, to ensure the stability of the output bus voltage. The circuit structure is simple, which solves the problem of high cost and has high system reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a circuit diagram of a fault-tolerant control system of an input parallel-output series-type Boost converter provided by an embodiment of the utility model;

[0023] Figure 2 These are two topological structures before and after fault-tolerant control of a fault-tolerant control system of a parallel-input and series-output Boost converter provided by an embodiment of the utility model;

[0024] Figure 3 It is a control logic diagram of a fault-tolerant control system of an input parallel-output series-type Boost converter provided by an embodiment of the utility model;

[0025] In the figure: S1, air switch; RL1, first inductor impedance; L1, first inductor reactance; RL2, second inductor impedance; L2, second inductor reactance; Q1, first power switch tube; Q2, second power switch tube; Q3, first topology conversion switch tube; Q4, second topology conversion switch tube; C1, first filter capacitor; C2, second filter capacitor; D1, first diode; D2, second diode; VD1, first fault alarm light; VD2, second fault alarm light; S2, fault mark clear switch. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail in combination with the embodiments below. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not used to limit the utility model.

[0027] As attached Figure 1 , 2 As shown, a fault-tolerant control system of a parallel-input and series-output Boost converter includes an input source and an output load, a two-way series-input and parallel-output Boost converter, two topology conversion switches, a voltage / current acquisition module, a fault-tolerant PWM control and an isolation drive module.

[0028] Based on the components and symbols provided, the following is a detailed description of the component connection relationship of the fault-tolerant control system of the input parallel output series Boost converter:

[0029] 1. Input source and air switch:

[0030] The input source is connected to the input terminal of the system through air switch S1.

[0031] 2. The first Boost converter:

[0032] The source of the first power switch tube Q1 is connected to the negative electrode of the input source.

[0033] The drain of the first power switch tube Q1 is connected to one end of the first inductor L1.

[0034] The other end of the first inductive reactance L1 is connected to the first inductive impedance RL1 and then connected to the cathode of the first diode D1.

[0035] The anode of the first diode D1 is connected to the positive electrode of the first filtering capacitor C1.

[0036] The cathode of the first filter capacitor C1 is connected to the output load and the cathode of the second filter capacitor C2.

[0037] 3. Second Boost Converter:

[0038] The source of the second power switch tube Q2 is connected to the negative electrode of the input source (or through the other end of the air switch S1).

[0039] The drain of the second power switch tube Q2 is connected to one end of the second inductor L2.

[0040] The other end of the second inductive reactance L2 is connected to the second inductive impedance RL2 and then connected to the cathode of the second diode D2.

[0041] The anode of the second diode D2 is connected to the positive electrode of the second filtering capacitor C2.

[0042] The cathode of the second filter capacitor C2 and the cathode of the first filter capacitor C1 are commonly connected to the output load.

[0043] 4. Topology conversion switch:

[0044] One end of the first topology conversion switch tube Q3 is connected to the connection point between the second inductor L2 and the second power switch tube Q2.

[0045] The other end of the first topology conversion switch tube Q3 is connected to the connection point of the first filter capacitor C1 and the second filter capacitor C2 (ie, the negative electrode of the output load).

[0046] One end of the second topology conversion switch tube Q4 is connected to the connection point of the first inductor L1 and the first diode D1.

[0047] The other end of the second topology conversion switch tube Q4 is connected to the connection point between the second inductor L2 and the first topology conversion switch tube Q3.

[0048] 5. Fault alarm and clearing:

[0049] The DSP28335 controller is connected to the first fault warning lamp VD1 and the second fault warning lamp VD2, and is used to light up the corresponding warning lamp when a fault is detected.

[0050] The fault flag clearing switch S2 is connected to the DSP28335 controller and is used to clear the fault flag so that the system can resume normal operation.

[0051] 6. Voltage / current acquisition module and DSP28335 controller:

[0052] The voltage / current acquisition module is connected to the measurement points of the first inductor current, the second inductor current, the first filter capacitor voltage, the second filter capacitor voltage and the output load voltage.

[0053] The collected data is transmitted to the DSP28335 controller for processing through the isolation driver module.

[0054] 7. Isolation drive module, power switch tube and topology conversion switch tube:

[0055] The isolation driving module is connected to the DSP28335 controller and is used to generate and isolate driving signals to drive the first power switch tube Q1, the second power switch tube Q2, the first topology conversion switch tube Q3 and the second topology conversion switch tube Q4.

[0056] Through these connection relationships, the system can realize the Boost conversion function of parallel input and series output, and realize fault-tolerant control through topology transformation of switch tubes when a fault occurs, ensuring the stability and reliability of the system.

[0057] Each input parallel output series type Boost converter includes an inductor, a power switch tube, a filter capacitor and a diode; the input sides of the first converter and the second converter are connected in parallel through the air switch interface of the input source, the first filter capacitor and the second filter capacitor on the output side are connected in series, and the load is connected in parallel to the two filter capacitors in series; the first diode is connected between the first filter capacitor and the first inductor, and the anode is close to the first inductor, and the second diode is connected between the second filter capacitor and the negative end of the input source, and the anode is close to the second filter capacitor.

[0058] The power switch tube is divided into a first power switch tube and a second power switch tube, the source and drain of the first power switch tube are respectively connected to one end of the first inductor and the negative electrode of the input source; the source and drain of the second power switch tube are respectively connected to one end of the second inductor and one end of the air switch.

[0059] The topology conversion switch tube is divided into a first topology conversion switch tube and a second topology conversion switch tube. One end of the first topology conversion switch tube is arranged at the connection between the second inductor and the second power switch tube, and the other end is arranged at the connection between the first filter capacitor and the second filter capacitor; one end of the second topology conversion switch tube is arranged at the connection between the first inductor and the first diode, and the other end is arranged at the connection between the second inductor and the first topology conversion switch tube.

[0060] The control terminals of the first power switch tube, the second power switch tube, the first topology conversion switch tube and the second topology conversion switch tube are connected to the DSP28335 controller after passing through the isolation drive module. The DSP28335 controller is connected to the first fault alarm light, the second fault alarm light and the fault mark clearing switch; the first inductor current, the second inductor current, the first filter capacitor voltage, the second filter capacitor voltage and the output load voltage are connected to the DSP28335 controller after passing through the voltage / current acquisition module.

[0061] The specific embodiment of the utility model is as follows: adding additional topology conversion switches Q3 and Q4 on the basis of the original topology structure of the input parallel output series Boost converter; collecting the voltage across the first filter capacitor and the second filter capacitor and , the first inductor and the second inductor current and and output load voltage ; When no fault occurs, Q3 is turned on, Q4 is turned off, and the Fault value is 0. At this time, the system working topology is Figure 2 The upper half shows an input parallel output series Boost converter. The controller controls the output voltage through the input parallel output series Boost converter algorithm to stabilize the output voltage at the set value. When a fault occurs, the inductor current of the faulty circuit will quickly decrease to zero, and the corresponding current signal will be detected by the controller. Regardless of whether Q1 or Q2 fails, Q3 changes from the original on state to the off state, and Q4 changes from the original off state to the on state. At this time, the system working topology changes from the original input parallel output series Boost converter to the traditional Boost converter, and the Fault value is 1, as shown in Figure 1. Figure 2 The controller switches to the traditional Boost converter algorithm to control the output voltage to ensure that the converter can still work normally after the fault and maintain the bus voltage at the target value. At the same time, the fault alarm light corresponding to the faulty switch tube lights up to prompt the maintenance personnel to the specific fault location, so that the maintenance personnel can detect and repair it; when the fault location is repaired, the fault mark clear switch can be pressed to restore the original input parallel output series type Boost converter working state.

[0062] This application embodiment provides a fault-tolerant control system of a Boost converter with parallel input and series output, which belongs to the field of power supply circuit technology. This control system includes an input source and an output load, a Boost converter with two series inputs and parallel outputs, two topology conversion switches, a voltage / current acquisition module, a fault-tolerant PWM control and an isolation drive module. The utility model adopts a modular design, has high control accuracy, short fault detection and fault-tolerant control response time, high reliability, convenient installation, simple wiring, easy debugging and maintenance, low cost, and safe use. The utility model has the ability to quickly diagnose and recover, and can accurately locate a specific fault switch tube, warn on the corresponding fault alarm light, and then complete the topology reconstruction in the shortest time, without adding additional hardware equipment, to ensure the stability of the output bus voltage. The circuit structure is simple, which solves the problem of high cost and has high system reliability.

[0063] In the description of the present invention, unless otherwise specified, "multiple" means two or more; the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third" and the like are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0064] The above description is only a specific implementation method of the present invention, but the protection scope of the present invention is not limited thereto. Any modification, equivalent substitution and improvement made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention shall be covered by the protection scope of the present invention.

Claims

1. A fault-tolerant control system for a parallel-input and series-output Boost converter, characterized in that: The fault-tolerant control system includes an input source and an output load, a Boost converter with two inputs in series and outputs in parallel, two topology conversion switches, a voltage / current acquisition module, a fault-tolerant PWM control and an isolation drive module; Each input parallel output series boost converter includes an inductor, a power switch tube, a filter capacitor and a diode; The input sides of the first converter and the second converter are connected in parallel through the air switch interface of the input source, the first filter capacitor and the second filter capacitor on the output side are connected in series, and the load is connected in parallel to the two filter capacitors connected in series; The first diode is connected between the first filter capacitor and the first inductor, with the anode close to the first inductor, and the second diode is connected between the second filter capacitor and the negative end of the input source, with the anode close to the second filter capacitor.

2. The fault-tolerant control system of the input parallel output series Boost converter according to claim 1, characterized in that: The power switch tube is divided into a first power switch tube and a second power switch tube, the source and drain of the first power switch tube are respectively connected to one end of the first inductor and the negative electrode of the input source; the source and drain of the second power switch tube are respectively connected to one end of the second inductor and one end of the air switch.

3. The fault-tolerant control system of the input parallel output series Boost converter according to claim 1, characterized in that: The topology conversion switch tube is divided into a first topology conversion switch tube and a second topology conversion switch tube, one end of the first topology conversion switch tube is arranged at the connection between the second inductor and the second power switch tube, and the other end is arranged at the connection between the first filter capacitor and the second filter capacitor; One end of the second topology conversion switch tube is arranged at the connection between the first inductor and the first diode, and the other end is arranged at the connection between the second inductor and the first topology conversion switch tube.

4. The fault-tolerant control system of the input parallel output series Boost converter according to any one of claims 1 to 3, characterized in that: The control terminals of the first power switch tube, the second power switch tube, the first topology conversion switch tube and the second topology conversion switch tube are connected to the DSP28335 controller after passing through the isolation drive module, and the DSP28335 controller is connected to the first fault alarm light and the second fault alarm light and the fault mark clearing switch; The first inductor current, the second inductor current, the first filter capacitor voltage, the second filter capacitor voltage and the output load voltage are all connected to the DSP28335 controller after passing through the voltage / current acquisition module.

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