Converter over-temperature control method, converter and power supply system

Abstract

The present application relates to a converter over-temperature control method, a converter and a power supply system. The converter over-temperature control method includes: obtaining the temperature of a sensitive element in the converter; judging whether the temperature of the sensitive element is greater than or equal to a first threshold; when the temperature of the sensitive element is greater than or equal to the first threshold, increasing the input voltage of the conversion circuit and reducing the input current of the conversion circuit. The converter includes a conversion circuit, the sensitive element is arranged in the conversion circuit, and the heat generation of the sensitive element is positively correlated with the current passing through the sensitive element. In the above-mentioned converter over-temperature control method, the control chip reduces the input current of the conversion circuit and increases the input voltage of the conversion circuit, thereby reducing the fluctuation of the input power of the conversion circuit while performing over-temperature protection, which is conducive to maintaining the stability of the output power and output power of the converter.

Description

Technical Field

[0001] The present application relates to the field of converter over-temperature protection, and in particular to a converter over-temperature control method, a converter, and a power supply system. Background Art

[0002] A converter is a device that converts one signal into another. Based on the characteristics of the electrical signal before and after the conversion, converters include DC-DC converters, rectifiers, and inverters.

[0003] Traditional converters detect the temperature of the converter by setting a temperature detection device. When the temperature is higher than the preset threshold, the input power is reduced to reduce the heat generated by the components in the converter to prevent the temperature from being too high. However, after reducing the input power, the output power of the converter will also be reduced, resulting in a decrease in system performance. Therefore, traditional converters with over-temperature control function have the disadvantages of large output power fluctuations and unstable output power. Summary of the invention

[0004] Based on this, it is necessary to provide a converter over-temperature control method, converter and power supply system to address the problems of large output power fluctuations and unstable output power when traditional converters are over-temperature controlled, so as to minimize the impact on the converter output power while performing over-temperature protection.

[0005] In a first aspect of the present application, a converter over-temperature control method is provided, comprising:

[0006] Acquiring the temperature of a sensitive element in a converter; the converter comprising a conversion circuit, the sensitive element being arranged in the conversion circuit, the conversion circuit being used to connect to a power supply, converting and outputting the electric energy output by the power supply; the heat generated by the sensitive element is positively correlated with the current passing through the sensitive element;

[0007] Determining whether the temperature of the sensitive element is greater than or equal to a first threshold;

[0008] When the temperature of the sensitive element is greater than or equal to a first threshold, the input voltage of the conversion circuit is increased and the input current of the conversion circuit is reduced.

[0009] In one embodiment, after determining whether the temperature of the sensitive element is greater than or equal to the first threshold, the method further includes:

[0010] When the temperature of the sensitive element is less than a first threshold, operating parameters of the power supply and the conversion circuit are adjusted based on a preset algorithm.

[0011] In one embodiment, the power supply is photovoltaic, and the adjusting the operating parameters of the power supply and the conversion circuit based on a preset algorithm includes:

[0012] The operating voltages of the power supply and the conversion circuit are adjusted based on an MPPT (Maximum Power Point Tracking) algorithm.

[0013] In one embodiment, when the temperature of the sensitive element is greater than or equal to the first threshold, before increasing the input voltage of the conversion circuit and reducing the input current of the conversion circuit, the method further includes:

[0014] Determine whether the temperature of the sensitive element is greater than or equal to a second threshold; the second threshold is greater than the first threshold;

[0015] If so, switching the converter to a standby mode;

[0016] If not, the steps of increasing the input voltage of the conversion circuit and reducing the input current of the conversion circuit are performed.

[0017] In a second aspect of the present application, a converter is provided, comprising a conversion circuit, a temperature acquisition device and a control chip, wherein the conversion circuit is used to connect to a power supply, and the control chip is connected to the temperature acquisition device and the conversion circuit;

[0018] The conversion circuit is used to convert the electric energy output by the power supply and then output it;

[0019] The temperature acquisition device is used to acquire the temperature of the sensitive element in the conversion circuit; the heat generated by the sensitive element is positively correlated with the current passing through the sensitive element;

[0020] The control chip is used to obtain the temperature of the sensitive element, determine whether the temperature of the sensitive element is greater than or equal to a first threshold, and when the temperature of the sensitive element is greater than or equal to the first threshold, increase the input voltage of the conversion circuit and reduce the input current of the conversion circuit.

[0021] In one of the embodiments, the temperature acquisition device is a temperature sensing package, the sensitive element is an IGBT (Insulated Gate Bipolar Transistor), and the temperature sensing package is arranged on a substrate of the IGBT.

[0022] In one embodiment, the conversion circuit is a boost circuit.

[0023] In one of the embodiments, the boost circuit is a Boost circuit (a switching DC boost circuit).

[0024] In one embodiment, the control chip is a DSP (Digital Signal Process) chip.

[0025] In a third aspect of the present application, a power supply system is provided, comprising a power supply and the converter in the above embodiment.

[0026] In the above-mentioned converter over-temperature control method, the control chip first obtains the temperature of the sensitive element in the conversion circuit; then determines whether the obtained temperature of the sensitive element is greater than or equal to the first threshold, and when the temperature of the sensitive element is greater than or equal to the first threshold, increases the input voltage of the conversion circuit and reduces the input current of the conversion circuit. Since the heat generation of the sensitive element is positively correlated with the current passing through the sensitive element, the purpose of reducing heat generation and avoiding excessive temperature can be achieved by reducing the input current of the conversion circuit. At the same time, by increasing the input voltage of the conversion circuit, the influence of the reduction of the input current on the input power of the conversion circuit can be offset, and the fluctuation of the input power of the conversion circuit can be reduced, which is conducive to maintaining the stability of the output power and output power of the converter when over-temperature control is performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic flow chart of a converter over-temperature control method in one embodiment;

[0028] Figure 2 A schematic flow chart of a converter over-temperature control method in another embodiment;

[0029] Figure 3 A schematic flow chart of a converter over-temperature control method in yet another embodiment;

[0030] Figure 4 is a structural block diagram of a converter in one embodiment;

[0031] Figure 5 FIG. 1 is a schematic diagram of the composition of a Boost circuit in an embodiment. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0034] It is understood that the terms "first", "second", etc. used in this application can be used to describe various elements in this article, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first capacitor can be referred to as a second capacitor, and similarly, a second capacitor can be referred to as a first capacitor. Both the first capacitor and the second capacitor are capacitors, but they are not the same capacitor.

[0035] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0036] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" etc. specify the presence of stated features, wholes, steps, operations, units, parts or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, units, parts or combinations thereof.

[0037] For the first aspect of this application, please refer to Figure 1 , a converter over-temperature control method is provided, comprising steps S200 to S600.

[0038] Step S200: obtaining the temperature of a sensitive element in the converter.

[0039] Wherein, the converter includes a conversion circuit, and the conversion circuit is used to connect to a power supply and convert the electric energy output by the power supply and then output it. The converter may be a DC-DC converter, a rectifier or an inverter. When the converter is a DC-DC converter, the conversion circuit may be a boost circuit or a buck circuit. In short, the embodiments of the present application do not limit the specific types and device configurations of the converter and the conversion circuit.

[0040] The sensitive element is a component device in the conversion circuit, and the heat generated by the sensitive element is positively correlated with the current passing through the sensitive element. Among them, the sensitive element can be the element in the conversion circuit that is most sensitive to temperature and most prone to overheating damage. Over-temperature control based on the temperature of the sensitive element can effectively avoid converter failure caused by damage to the sensitive element. The sensitive element can also be a valuable component in the conversion circuit. Since over-current damage also manifests as over-heating damage, over-current or over-heating damage to the sensitive element can be avoided by over-temperature control of the sensitive element, saving costs. Furthermore, the sensitive element can be a switching tube or a heating resistor. In short, the embodiments of the present application do not limit the specific device type of the sensitive element.

[0041] Specifically, the temperature of the sensitive element in the converter can be collected by a temperature collection device. The temperature collection device can be a contact temperature collection device or a non-contact temperature collection device. The control chip can obtain the temperature of the sensitive element in the converter by actively reading the temperature information collected by the temperature collection device, or by collecting the temperature information of the sensitive element by the temperature collection device and then sending the temperature information to the control chip. In short, this embodiment does not limit the method for obtaining the temperature of the sensitive element in the converter.

[0042] Step S400: determining whether the temperature of the sensitive element is greater than or equal to a first threshold.

[0043] Specifically, after the control chip obtains the temperature of the sensitive element in the converter, it compares the temperature with a preset first threshold to determine whether it is greater than or equal to the first threshold. When the temperature of the sensitive element is greater than or equal to the first threshold, it is in an overtemperature state and there is a risk of overheating damage. It can be understood that different first thresholds can be set accordingly according to the characteristics of the sensitive element in the conversion circuit.

[0044] Step S700: when the temperature of the sensitive element is greater than or equal to a first threshold, increasing the input voltage of the conversion circuit and reducing the input current of the conversion circuit.

[0045] As described above, the heat generated by the sensitive element is positively correlated with the current passing through the sensitive element. When the temperature of the sensitive element is greater than or equal to the first threshold, the control chip reduces the operating current of the sensitive element by reducing the input current of the conversion circuit to reduce heat generation and achieve the purpose of over-temperature control. At the same time, the control chip also reduces the fluctuation of the input power of the conversion circuit by increasing the input voltage of the conversion circuit, thereby maintaining the stability of the output power of the converter while performing over-temperature control. Furthermore, the difference between the reduction amplitude of the input current and the increase amplitude of the input voltage can be made less than the preset threshold to further maintain the stability of the input power of the conversion circuit.

[0046] It should be noted that by reducing the input current of the conversion circuit and increasing the input voltage of the conversion circuit, the heating of the sensitive element can be reduced while maintaining the power. On the one hand, considering the inherent characteristics of the sensitive element, that is, when the change amplitude of the current flowing through the sensitive element is the same as the change amplitude of the voltage across the sensitive element, the effect of the current change on the heating is greater than the voltage change. On the other hand, when the input voltage and input current of the conversion circuit are changed, due to the device composition and connection mode of the conversion circuit, the change degree of the current flowing through the sensitive element is greater than the change degree of the voltage across the sensitive element, which shows that the heating of the sensitive element is reduced.

[0047] Specifically, the conversion circuit is connected to the power supply, and the electric energy output by the power supply is converted and outputted, so the input voltage and input current of the conversion circuit are related to the output voltage and output current of the power supply. The control chip can directly control the input end of the conversion circuit to increase the input voltage of the conversion circuit and reduce the input current of the conversion circuit; the control chip can also control the power supply to reduce the input current of the conversion circuit by reducing the output current of the power supply, and raise the input voltage of the conversion circuit by increasing the output voltage of the power supply. Furthermore, the increase amplitude of the input voltage and the decrease amplitude of the input current can be adjusted step by step according to the preset adjustment amplitude respectively; it can also be adjusted according to the difference between the current temperature and the first threshold value. When the difference is large, the adjustment amplitude is increased, and when the difference is small, the adjustment amplitude is reduced. In short, the embodiment of the present application does not limit the specific way in which the control chip increases the input voltage of the conversion circuit and reduces the input current of the conversion circuit.

[0048] Furthermore, after the control chip adjusts the input current and input voltage of the conversion circuit, it re-acquires the temperature of the sensitive element in the converter, and performs over-temperature control based on the newly acquired temperature of the sensitive element.

[0049] In the above-mentioned converter over-temperature control method, the control chip first obtains the temperature of the sensitive element in the conversion circuit; then determines whether the obtained temperature of the sensitive element is greater than or equal to the first threshold, and when the temperature of the sensitive element is greater than or equal to the first threshold, increases the input voltage of the conversion circuit and reduces the input current of the conversion circuit. Since the heat generation of the sensitive element is positively correlated with the current passing through the sensitive element, the purpose of reducing heat generation and avoiding excessive temperature can be achieved by reducing the input current of the conversion circuit. At the same time, by increasing the input voltage of the conversion circuit, the influence of the reduction of the input current on the input power of the conversion circuit can be offset, and the fluctuation of the input power of the conversion circuit can be reduced, which is conducive to maintaining the stability of the output power and output power of the converter when over-temperature control is performed.

[0050] In one embodiment, please refer to Figure 2 After step S400, the method further includes step S500: when the temperature of the sensitive element is less than the first threshold, adjusting the operating parameters of the power supply and the conversion circuit based on a preset algorithm.

[0051] Among them, the working parameters of the power supply and the conversion circuit include working current, working voltage and other electrical parameter characteristics. Specifically, when the temperature of the sensitive element is less than the first threshold, it means that the sensitive element is not at risk of overheating damage. At this time, the control chip adjusts their working parameters based on the preset algorithm according to the working conditions of the power supply and the conversion circuit to improve the power supply efficiency of the power supply system. Furthermore, after the control chip adjusts the working parameters of the power supply and the conversion circuit based on the preset algorithm, it re-acquires the temperature of the sensitive element in the converter, and performs over-temperature control based on the newly acquired temperature of the sensitive element.

[0052] In one embodiment, the power supply is photovoltaic, and step S500 includes: when the temperature of the sensitive element is less than a first threshold, adjusting the operating voltage of the photovoltaic and conversion circuits based on the MPPT algorithm.

[0053] Among them, photovoltaic is the abbreviation of solar photovoltaic power generation system, which is a new type of power generation system that uses the photovoltaic effect of solar cell semiconductor materials to directly convert solar radiation energy into electrical energy. It has two modes of independent operation and grid-connected operation. The specific operation mode of photovoltaic is not limited in the embodiment of the present application. The converter connected to photovoltaic can be a DC-DC converter or an inverter. The DC-DC converter can step up or step down the DC voltage generated by the solar cell panels in photovoltaics and output it to the load. The inverter can convert the DC voltage generated by the solar panel into AC power at the mains frequency, and feed it back to the commercial power supply system, or for use in off-grid power grids. The converter used in conjunction with photovoltaics can have the function of maximum power point tracking while having the function of over-temperature control.

[0054] Specifically, the optimal operating point of a solar panel is called the maximum power point, which mainly depends on the operating temperature of the solar panel and the intensity of sunlight at that time. The maximum power point of a solar panel is different under different temperatures and sunlight intensities. To make the solar panel work at the maximum power point as much as possible, it is necessary to effectively track the maximum power point under rapidly changing weather conditions based on the MPPT algorithm, and control the solar panel to work at the maximum power point as much as possible by adjusting the operating parameters of the photovoltaic electrical module.

[0055] When the temperature of the sensitive element is less than the first threshold, the control chip can realize the maximum power point tracking by constant voltage tracking. Under the premise of certain weather conditions, according to the relationship between the output power and the working voltage of the solar panel, the optimal working voltage of the photovoltaic can be obtained, and the working voltage of the photovoltaic and conversion circuit can be adjusted to the optimal working voltage. When the photovoltaic power supply system works at this fixed voltage, the power can be maximized. The control signal can also be output by comparing the conductance increment and the instantaneous conductance of the solar panel to realize the maximum power point tracking. Specifically, when the sum of the conductance increment and the instantaneous conductance is zero, the solar panel works at the maximum power point. Based on this, when the sum of the conductance increment and the instantaneous conductance of the solar panel is greater than zero, the working voltage of the photovoltaic power supply system is increased; when the sum of the conductance increment and the instantaneous conductance of the solar panel is less than zero, the working voltage of the photovoltaic power supply system is reduced, and the sum of the conductance increment and the instantaneous conductance of the solar panel is close to zero through multiple adjustments, so that the maximum power point can be reached. In addition, the current output power can be compared with the output power collected last time, and then the working voltage of the photovoltaic power supply system can be adjusted according to the change of the output power so that it works at the maximum power point. In summary, the embodiments of the present application do not limit the specific manner in which the control chip adjusts the operating voltage of the photovoltaic and conversion circuits based on the MPPT algorithm.

[0056] Furthermore, after the control chip adjusts the operating voltage of the photovoltaic and conversion circuits based on the MPPT algorithm, it re-acquires the temperature of the sensitive element in the converter and performs over-temperature control based on the newly acquired temperature of the sensitive element.

[0057] In the above embodiment, when the temperature of the sensitive element is lower than the first threshold, the operating voltages of the photovoltaic and conversion circuits are adjusted based on the MPPT algorithm so that the power supply system operates at the maximum power point, thereby improving the photovoltaic power generation efficiency and the conversion efficiency of the conversion circuit.

[0058] In one embodiment, please refer to Figure 3 When the temperature of the sensitive element is greater than or equal to the first threshold, before step S700, step S600 is further included: determining whether the temperature of the sensitive element is greater than or equal to the second threshold. If not, step S700 is executed; if so, step S800 is executed.

[0059] Step S800: Switch the converter to the standby mode.

[0060] Among them, the second threshold is greater than the first threshold. When the temperature of the sensitive element is greater than or equal to the second threshold, it is in a high temperature state. If it is not controlled in time, there is a risk of overheating and damage. It can be understood that different second thresholds can be set accordingly according to the characteristics of the sensitive element in the conversion circuit. Specifically, when the temperature of the sensitive element is greater than or equal to the first threshold, it is determined whether the temperature of the sensitive element is greater than or equal to the second threshold. If not, the input voltage of the conversion circuit is increased and the input current of the conversion circuit is reduced; if so, the converter is switched to standby mode. At this time, the converter runs at low power consumption, the heat generation is significantly reduced, and the control chip continues to re-acquire the temperature of the sensitive element in the converter based on a certain period.

[0061] Furthermore, after step S800, the process can return to step S200 to reacquire the temperature of the sensitive element in the converter, and perform over-temperature control based on the newly acquired temperature of the sensitive element. When the temperature of the sensitive element in the converter is greater than or equal to the second threshold, the standby mode of the converter is maintained to allow the temperature of the sensitive element to continue to decrease; when the temperature of the sensitive element in the converter is less than the second threshold, the converter is exited from the standby mode and switched to the normal mode. When the temperature of the sensitive element is greater than or equal to the first threshold and less than the second threshold, the input voltage of the conversion circuit is increased, the input current of the conversion circuit is reduced, and the temperature of the sensitive element continues to decrease; when the temperature of the sensitive element in the converter is less than the first threshold, the operating parameters of the power supply and the conversion circuit are adjusted based on the preset algorithm to improve the power supply efficiency of the power supply system.

[0062] In the above embodiment, when the temperature of the sensitive element is greater than or equal to the second threshold, the converter is set to standby mode, which can effectively prevent the converter from being damaged due to excessive temperature. At the same time, the control chip continuously obtains the temperature of the sensitive element, and adjusts the working state of the converter according to the real-time temperature, which can maximize the conversion efficiency.

[0063] It should be understood that, although each step in each flow chart involved in the above-described embodiment is shown in sequence according to the indication of the arrow, these steps are not necessarily performed in sequence according to the order indicated by the arrow. Unless there is a clear explanation in this article, the execution of these steps does not have strict order restrictions, and these steps can be performed in other orders. Moreover, at least a portion of the steps in each flow chart involved in the above-described embodiment may include a plurality of sub-steps or a plurality of stages, and these sub-steps or stages are not necessarily performed at the same time, but can be performed at different times, and the execution order of these sub-steps or stages is not necessarily performed in sequence, but can be performed in turn or alternately with at least a portion of other steps or sub-steps or stages of other steps.

[0064] For the second aspect of this application, please refer to Figure 4, a converter is provided, including a conversion circuit 100, a temperature acquisition device 200 and a control chip 300. The control chip 300 is connected to the temperature acquisition device 200 and the conversion circuit 100, and the conversion circuit 100 is used to connect to a power supply to convert and output the electric energy output by the power supply. The temperature acquisition device 200 is used to acquire the temperature of a sensitive element in the conversion circuit 100, and the heat generation of the sensitive element is positively correlated with the current passing through the sensitive element. The control chip 300 is used to obtain the temperature of the sensitive element, determine whether the temperature of the sensitive element is greater than or equal to a first threshold, and when the temperature of the sensitive element is greater than or equal to the first threshold, increase the input voltage of the conversion circuit 100 and reduce the input current of the conversion circuit 100.

[0065] Among them, the conversion circuit 100 can be a rectifier circuit, an inverter circuit, a boost circuit or a buck circuit. The temperature acquisition device 200 refers to a device that can sense temperature and convert it into a usable output signal. The temperature acquisition device 200 can be a contact temperature acquisition device or a non-contact temperature acquisition device. For example, the temperature acquisition device 200 can be a temperature sensing package, a thermocouple sensor or an infrared sensor. The control chip 300 can be a programmable logic device such as an MCU (Single Chip Microcomputer) chip, a DSP chip, etc. In short, the embodiments of the present application do not limit the specific types of the conversion circuit 100, the temperature acquisition device 200 and the control chip 300.

[0066] Specifically, the conversion circuit 100 is used to connect to the power supply, convert the electric energy output by the power supply and output it. The sensitive element is a component of the conversion circuit 100, and the heat generation of the sensitive element is positively correlated with the current passing through the sensitive element. After the control chip 300 obtains the temperature of the sensitive element collected by the temperature acquisition device 200, it compares the temperature with the preset first threshold to determine whether it is greater than or equal to the first threshold. Among them, when the temperature of the sensitive element is greater than or equal to the first threshold, it is in an overtemperature state and there is a risk of overheating damage. When the temperature of the sensitive element is greater than or equal to the first threshold, the control chip 300 reduces the input current of the conversion circuit 100 to reduce the working current of the sensitive element to reduce heat generation and achieve the purpose of overtemperature control. At the same time, the control chip 300 also reduces the fluctuation of the input power of the conversion circuit 100 by increasing the input voltage of the conversion circuit 100, thereby maintaining the stability of the output power of the conversion circuit 100 while performing overtemperature control. Further, the reduction amplitude of the input current and the increase amplitude of the input voltage can be made the same to keep the input power of the conversion circuit unchanged. As described above, the conversion circuit 100 is connected to the power supply, and converts the electric energy output by the power supply and then outputs it. Therefore, the input voltage and input current of the conversion circuit 100 are related to the output voltage and output current of the power supply. The control chip 300 can directly control the input end of the conversion circuit 100 to increase the input voltage of the conversion circuit 100 and reduce the input current of the conversion circuit 100; the control chip 300 can also control the output end of the power supply, reduce the input current of the conversion circuit 100 by reducing the output current of the power supply, and increase the input voltage of the conversion circuit 100 by increasing the output voltage of the power supply.

[0067] Furthermore, when the temperature of the sensitive element is greater than or equal to the first threshold, the control chip 300 is also used to determine whether the temperature of the sensitive element is greater than or equal to the second threshold. The second threshold is greater than the first threshold. When the temperature of the sensitive element is greater than or equal to the second threshold, it is in a high temperature state. If it is not controlled in time, there is a risk of overheating and damage. If the temperature of the sensitive element is less than the second threshold, the control chip 300 increases the input voltage of the conversion circuit 100 and reduces the input current of the conversion circuit 100; if the temperature of the sensitive element is greater than or equal to the second threshold, the converter is switched to standby mode.

[0068] Furthermore, when the temperature of the sensitive element is lower than the first threshold, the control chip 300 adjusts the operating parameters of the power supply and the conversion circuit 100 based on a preset algorithm to improve the power supply efficiency of the power supply system.

[0069] In addition, after adjusting the working parameters of the conversion circuit 100 based on the current temperature of the sensitive element, the control chip 300 will re-acquire the temperature of the sensitive element in the conversion circuit 100 and perform over-temperature control based on the newly acquired temperature of the sensitive element.

[0070] The above-mentioned converter includes a conversion circuit 100, a temperature acquisition device 200 and a control chip 300. During the operation of the converter, the control chip 300 first obtains the temperature of the sensitive element in the conversion circuit 100; then determines whether the obtained temperature of the sensitive element is greater than or equal to the first threshold, and when the temperature of the sensitive element is greater than or equal to the first threshold, increases the input voltage of the conversion circuit 100 and reduces the input current of the conversion circuit 100. Since the heat generation of the sensitive element is positively correlated with the current passing through the sensitive element, the purpose of reducing heat generation and avoiding excessive temperature can be achieved by reducing the input current of the conversion circuit 100. At the same time, by increasing the input voltage of the conversion circuit 100, the influence of the reduction of the input current on the input power of the conversion circuit 100 can be offset, and the fluctuation of the input power of the conversion circuit 100 can be reduced, which is conducive to maintaining the stability of the output power and output power of the converter when over-temperature control is performed.

[0071] In one embodiment, the temperature collection device 200 is a temperature sensing package, the sensitive element is an IGBT, and the temperature sensing package is disposed on a substrate of the IGBT.

[0072] Among them, the temperature sensing package is a sensor that monitors the temperature by the change of the inert liquid in the package with the temperature. The inert liquid is usually a refrigerant. IGBT is a composite fully controlled voltage-driven power semiconductor device composed of a bipolar transistor and a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). Its input pole is a MOSFET and its output pole is a bipolar transistor. It has the advantages of low driving power and fast switching speed of MOSFET devices, as well as low saturation voltage drop and large capacity of bipolar devices. If a positive driving voltage is applied between the gate and emitter of the IGBT, the MOSFET is turned on, so that the collector and base of the bipolar transistor are in a low resistance state, making the transistor turned on; if the voltage between the gate and emitter of the IGBT is 0V, the MOSFET is turned off, cutting off the supply of the base current of the bipolar transistor, making the transistor turned off. IGBT works in an environment of high voltage and high current, and the price of the IGBT component itself is relatively expensive. Therefore, the IGBT is set as a sensitive component, and the temperature is detected and the temperature is controlled based on the detection result to avoid overheating and damage of the device.

[0073] Specifically, the IGBT is used as a switch of the conversion circuit 100, and the control chip 300 is also used to control the working state of the conversion circuit 100 by controlling the IGBT. The temperature sensing package is installed on the insulating substrate of the IGBT, and the temperature of the IGBT insulating substrate can be detected in real time, and then the temperature of the IGBT can be obtained. The control chip 300 then performs over-temperature control according to the obtained temperature of the IGBT.

[0074] In the above embodiment, the use of a temperature sensing package as the temperature acquisition device 200 is conducive to improving the accuracy of the collected data. The use of an IGBT as a switch of the conversion circuit 100 is conducive to improving the electrical performance of the conversion circuit 100. At the same time, the temperature sensing package is installed on the insulating substrate of the IGBT to detect the temperature of the IGBT in real time, and then the control chip 300 performs over-temperature control according to the acquired temperature of the IGBT, which is conducive to improving the control effect of over-temperature control.

[0075] In one embodiment, the conversion circuit 100 is a boost circuit. A boost circuit is also called a bootstrap circuit, which refers to a circuit whose output voltage is greater than the input voltage. A boost circuit generally includes electronic components such as a bootstrap boost diode and a bootstrap boost capacitor, and controls the discharge voltage of the bootstrap boost capacitor to be superimposed on the output voltage of the power supply, thereby achieving an effect of increasing the output voltage.

[0076] In the above embodiment, the boost circuit serves as a conversion circuit in the converter. Due to the boost function of the boost circuit, the output voltage of the boost circuit is greater than the output voltage of the power supply. Even when the output voltage of the power supply is insufficient, the normal operation of the load can be maintained, which can reduce the performance requirements of the load on the power supply, which is conducive to reducing costs and expanding the application scenarios of the converter.

[0077] In one embodiment, the boost circuit is a Boost boost circuit. The Boost boost circuit is a switching DC boost circuit with a simple circuit. Figure 5 The Boost boost circuit includes a first capacitor C1, an inductor L, a diode D1, a second capacitor C2 and a switch tube IGBT. The first capacitor C1 is used to connect to a power supply, one end of the inductor L is connected to the first end of the first capacitor C1, and the other end is connected to the anode of the diode D1, and the cathode of the diode D1 is connected to the output end. The second capacitor C2 is connected to the output end. The collector of the switch tube IGBT is connected to the anode of the diode D1, the emitter of the switch tube IGBT is connected to the second end of the first capacitor, and the gate of the switch tube IGBT is connected to the control chip 300.

[0078] Specifically, the control chip 300 is connected to the switch tube IGBT, and controls the working state of the Boost boost circuit by controlling the on and off of the switch tube IGBT. When the switch tube IGBT is turned on, the input voltage Ui flows through the inductor L and the switch tube IGBT to form a loop to charge the first capacitor C1. As the charging continues, the current in the inductor L increases linearly, and the current is converted into magnetic energy storage in the inductor L. In this process, the diode D1 is cut off, and the second capacitor C2 supplies power to the load to maintain the load operation. When the switch tube IGBT is turned off, the inductor L slowly discharges through the loop formed by the diode D1, the first capacitor C1 and the second capacitor C2 to charge the second capacitor C2. The electric energy at both ends of the second capacitor C2 is superimposed on the power supply to supply power to the load. By controlling the on and off time of the switch tube IGBT based on a preset duty cycle by the control chip 300, the output voltage U of the circuit can be maintained. 0 Furthermore, in one embodiment, the first capacitor C1 and the second capacitor C2 are both polar capacitors, wherein the positive electrode of the first capacitor C1 is connected to the positive output electrode of the power supply and the inductor L, and the positive electrode of the second capacitor C2 is connected to the cathode of the diode D1.

[0079] In the above embodiment, the Boost circuit is used as the conversion circuit 100 in the converter. Since the Boost circuit has fewer components and a simple circuit, it is beneficial to reduce the circuit cost.

[0080] In one embodiment, the control chip is a DSP chip. A DSP chip refers to a chip that can implement digital signal processing technology. It uses a Harvard structure that separates program and data, has a dedicated hardware multiplier, widely uses pipeline operations, and provides special DSP instructions, which can be used to quickly implement various digital signal processing algorithms. Classified by working clock and instruction type, DSP chips include static DSP chips and consistent DSP chips; classified by working data format, DSP chips include fixed-point DSP chips that work in fixed-point format and floating-point DSP chips that work in floating-point format; classified by purpose, DSP chips include general-purpose DSP chips and special-purpose DSP chips. In short, the embodiments of the present application do not limit the specific type of DSP chips.

[0081] Furthermore, in one embodiment, the model of the DSP chip is TMS320F28335.

[0082] TMS320F28335 is a 32-bit floating-point DSP chip of the TMS320C28x series, with 150MHz high-speed processing capability, 32-bit floating-point processing unit, 6 DMA (Direct Memory Access) channels, support for multiple interfaces, 18 PWM outputs, 6 of which are unique higher-precision PWM outputs. Thanks to its floating-point unit, users can quickly write control algorithms without spending too much time and energy on processing decimal operations. Compared with the previous generation of DSP, the average performance of TMS320F28335 is improved by 50%, and it is compatible with fixed-point C28x controller software, which is conducive to simplifying software development, shortening development cycles, and reducing development costs.

[0083] In the above embodiment, a DSP chip is used as the control chip. Since the DSP chip has many advantages such as good stability, fast operation speed, programmability and embeddability, it is beneficial to improve the performance of the converter.

[0084] In a third aspect of the present application, a power supply system is provided, comprising a power supply and the converter in the above embodiment.

[0085] The specific definition of the converter can be found above and will not be repeated here. Specifically, the power supply can be a DC power supply or an AC power supply. Correspondingly, the converter can be a DC-DC converter, a rectifier or an inverter. When the converter is a DC-DC converter, the power supply can be a photovoltaic or wind turbine. By working in conjunction with the converter, the power generation and energy conversion efficiency of the photovoltaic or wind turbine can be improved.

[0086] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0087] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A converter over-temperature control method, characterized in that: include: Acquiring the temperature of a sensitive element in a converter; the converter comprising a conversion circuit, the sensitive element being arranged in the conversion circuit, the conversion circuit being used to connect to a power supply, converting and outputting the electric energy output by the power supply; the heat generated by the sensitive element is positively correlated with the current passing through the sensitive element; The sensitive element is an IGBT; Determining whether the temperature of the sensitive element is greater than or equal to a first threshold; When the temperature of the sensitive element is greater than or equal to a first threshold, the input voltage of the conversion circuit is increased and the input current of the conversion circuit is reduced; the difference between the reduction amplitude of the input current and the increase amplitude of the input voltage is less than a preset threshold to maintain the stability of the input power of the conversion circuit.

2. The converter over-temperature control method according to claim 1, characterized in that: After determining whether the temperature of the sensitive element is greater than or equal to the first threshold, the method further includes: When the temperature of the sensitive element is less than a first threshold, operating parameters of the power supply and the conversion circuit are adjusted based on a preset algorithm.

3. The converter over-temperature control method according to claim 2, characterized in that: The power supply is photovoltaic, and the adjusting the operating parameters of the power supply and the conversion circuit based on a preset algorithm includes: The operating voltages of the power supply and the conversion circuit are adjusted based on the MPPT algorithm.

4. The converter over-temperature control method according to claim 1, characterized in that: When the temperature of the sensitive element is greater than or equal to the first threshold, before increasing the input voltage of the conversion circuit and reducing the input current of the conversion circuit, the method further includes: Determine whether the temperature of the sensitive element is greater than or equal to a second threshold; the second threshold is greater than the first threshold; If so, switching the converter to a standby mode; If not, the steps of increasing the input voltage of the conversion circuit and reducing the input current of the conversion circuit are performed.

5. A converter, characterized in that: It includes a conversion circuit, a temperature acquisition device and a control chip, wherein the conversion circuit is used to connect to a power supply, and the control chip is connected to the temperature acquisition device and the conversion circuit; The conversion circuit is used to convert the electric energy output by the power supply and then output it; The temperature acquisition device is used to acquire the temperature of the sensitive element in the conversion circuit; the heat generated by the sensitive element is positively correlated with the current passing through the sensitive element; The sensitive element is an IGBT; The control chip is used to obtain the temperature of the sensitive element, determine whether the temperature of the sensitive element is greater than or equal to a first threshold, and when the temperature of the sensitive element is greater than or equal to the first threshold, increase the input voltage of the conversion circuit and reduce the input current of the conversion circuit; the difference between the decrease in the input current and the increase in the input voltage is less than a preset threshold to maintain the stability of the input power of the conversion circuit.

6. The converter according to claim 5, characterized in that The temperature acquisition device is a temperature sensing package, and the temperature sensing package is arranged on the substrate of the IGBT.

7. The converter according to claim 5, characterized in that The conversion circuit is a boost circuit.

8. The converter according to claim 7, characterized in that The voltage boost circuit is a Boost voltage boost circuit.

9. The converter according to any one of claims 5 to 8, characterized in that: The control chip is a DSP chip.

10. A power supply system, characterized in that: It comprises a power supply and a converter as claimed in any one of claims 4 to 9.

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