Component controller, power conversion device, control method of component controller, and power electronic conversion system

Abstract

The invention discloses a component controller, a power conversion device, a control method of the component controller and a power electronic conversion system, relates to the technical field of new energy, and aims to reduce the duration of a high level in a PWM (Pulse Width Modulation) driving signal currently output to a direct current converter under the condition that the power supply voltage of the component controller is lower than a threshold value. The power supply voltage of the component controller is increased by reducing the duty ratio of the PWM driving signal, the power supply stability of the component controller is ensured, the problem that the component controller is frequently restarted in a weak light environment due to the fact that the component controller is shut down immediately when the power supply voltage of the component controller is lower than a threshold value is solved, the performance of the component controller is improved, and the service life of the component controller is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy, in particular to a component controller, a power conversion device, a control method of the component controller and a power electronic conversion system. BACKGROUND

[0002] In a weak light environment, the output power of a photovoltaic component is low. During the operation of the component controller, the input voltage of the component controller may be pulled down as the output voltage rises. When the input voltage of the component controller is lower than the minimum operating voltage of an auxiliary source, the component controller will shut down. After the component controller shuts down, the output power of the photovoltaic component returns to normal, and the component controller starts to restart. As the output voltage rises during the startup process, the input voltage of the component controller is pulled down again, thereby causing the component controller to shut down again. In a scenario where the light is weak and lasts for a long time, the component controller will frequently restart, affecting the performance and service life of the component controller. SUMMARY

[0003] In view of the above problems, the present application provides a component controller, a power conversion device, a control method of the component controller and a power electronic conversion system, which solves the problem that the component controller frequently restarts in a weak light environment when the input voltage of the component controller is immediately shut down below a threshold value, and improves the performance and service life of the component controller. The specific scheme is as follows:

[0004] The first aspect of the present application provides a component controller, comprising: a control unit, a voltage detection module and a direct current converter;

[0005] The voltage detection module detects a power supply voltage and sends the power supply voltage to the control unit.

[0006] The control unit receives the power supply voltage and, in the case where the power supply voltage is lower than a threshold value, reduces the duration of a high level in a PWM drive signal currently output to the direct current converter.

[0007] In a possible implementation, the voltage detection module is arranged inside the control unit and detects the power supply voltage of the control unit.

[0008] In a possible implementation, the component controller further comprises a circuit power supply module.

[0009] The voltage detection module detects the input voltage of the circuit power supply module, and the input voltage of the circuit power supply module is the power supply voltage of the component controller.

[0010] In a possible implementation, the control unit, after reducing the duration of the high level in the PWM drive signal currently output to the DC converter, controls the component controller to start the component-level maximum power point tracking function if the duration that the power supply voltage is not lower than the threshold value reaches a first preset time.

[0011] In a possible implementation, the control unit, after reducing the duration of the high level in the PWM drive signal currently output to the DC converter, reduces the duration of the high level in the PWM drive signal currently output to the DC converter again if the power supply voltage is detected to be lower than the threshold value again, where the magnitude of each reduction of the duration of the high level in the PWM drive signal is increased successively.

[0012] In a possible implementation, the control unit records the number of times of continuous burping of the component controller in a second preset time; and controls the component controller to not be chopped and not output if the number of times of continuous burping of the component controller in the second preset time reaches a preset value.

[0013] The control unit controls the component controller to be chopped again after the time that the component controller is not chopped and not output reaches a third preset time; and continues to record the number of times of continuous burping of the component controller in the second preset time if the number of times of continuous burping of the component controller in the second preset time is less than the preset value after the component controller is chopped again; and performs the chopping-off operation if the number of times of continuous burping of the component controller in the second preset time reaches the preset value after the component controller is chopped again.

[0014] The second aspect of the present application provides a power conversion device, the DC side of the power conversion device is connected with at least one component controller, and the power conversion device comprises a master control unit;

[0015] The master control unit acquires the power supply voltage of the component controller, and sends a first control instruction to the component controller if the power supply voltage is lower than a threshold value, so that the component controller reduces the duration of the high level in the PWM drive signal currently output to the DC converter in response to the first control instruction.

[0016] In a possible implementation, the master control unit sends a second control instruction to the component controller if the duration that the power supply voltage is not lower than the threshold value reaches a first preset time, so that the component controller starts the component-level maximum power point tracking function in response to the second control instruction.

[0017] In a possible implementation, after sending the first control instruction to the component controller, the master control unit sends a third control instruction to the component controller to make the component controller, in response to the third control instruction, reduce the duration of the high level in the PWM drive signal currently output to the DC converter again, and the component controller increases the amplitude of the duration of the high level in the PWM drive signal each time it is reduced.

[0018] In a possible implementation, the master control unit acquires and records the number of times of continuous burping of the component controller in a second preset time; if the number of times of continuous burping of the component controller in the second preset time reaches a preset value, the master control unit sends a fourth control instruction to the component controller to make the component controller, in response to the fourth control instruction, not to be bucked and not to output.

[0019] After the time during which the component controller is not bucked and not output reaches a third preset time, the master control unit controls the component controller to be bucked again; after the component controller is bucked again, if the number of times of continuous burping of the component controller in the second preset time is less than the preset value, the master control unit continues to acquire and record the number of times of continuous burping of the component controller in the second preset time; after the component controller is bucked again, if the number of times of continuous burping of the component controller in the second preset time reaches the preset value, the master control unit sends a fifth control instruction to the component controller to make the component controller, in response to the fifth control instruction, perform a bucking operation.

[0020] The third aspect of the present application provides a control method of a component controller, comprising:

[0021] detecting a supply voltage;

[0022] if the supply voltage is lower than a threshold, reducing the duration of the high level in the PWM drive signal currently output by the control unit of the component controller to the DC converter.

[0023] In a possible implementation, after reducing the duration of the high level in the PWM drive signal currently output by the control unit of the component controller to the DC converter, the control method of the component controller further comprises:

[0024] if the duration during which the supply voltage is not lower than the threshold reaches a first preset time, controlling the component controller to start a component-level maximum power point tracking function.

[0025] In a possible implementation, after reducing the duration of the high level in the PWM drive signal currently output by the control unit of the component controller to the DC converter, the control method of the component controller further comprises:

[0026] If the power supply voltage is detected to be less than the threshold value again, the duration of the high level in the PWM drive signal currently output to the DC converter is reduced again, wherein the magnitude of each reduction in the duration of the high level in the PWM drive signal is sequentially increased.

[0027] In a possible implementation, the control method of the component controller further includes:

[0028] Recording the number of continuous burps of the component controller in a second preset time;

[0029] If the number of continuous burps of the component controller in the second preset time reaches a preset value, the component controller is controlled to be unchopped and unoutput;

[0030] After the time during which the component controller is unchopped and unoutput reaches a third preset time, the component controller is controlled to be chopped again;

[0031] After the component controller is chopped again, if the number of continuous burps of the component controller in the second preset time is less than the preset value, the operation of recording the number of continuous burps of the component controller in the second preset time is returned to be performed;

[0032] After the component controller is chopped again, if the number of continuous burps of the component controller in the second preset time reaches the preset value, a chopping operation is performed.

[0033] The fourth aspect of the present application provides an electric power electronic conversion system, comprising: a power conversion device and the component controller of the first aspect or any implementation manner of the first aspect;

[0034] The DC side of the power conversion device is connected with at least one component controller;

[0035] The component controller is connected with at least one DC source.

[0036] The fifth aspect of the present application provides an electric power electronic conversion system, comprising: a component controller and the power conversion device of the second aspect or any implementation manner of the second aspect;

[0037] The DC side of the power conversion device is connected with at least one component controller;

[0038] The component controller is connected with at least one DC source.

[0039] The component controller, the power conversion device and the control method of the component controller provided by the embodiments of the present application can raise the supply voltage of the component controller by reducing the duration of the high level in the PWM drive signal output by the direct current converter, i.e. reducing the duty cycle of the PWM drive signal, when the supply voltage of the component controller is lower than the threshold value, thereby ensuring the stability of the supply of the component controller, solving the problem of frequent restart of the component controller in a weak light environment caused by immediate shutdown when the supply voltage of the component controller is lower than the threshold value, and improving the performance and service life of the component controller. BRIEF DESCRIPTION OF DRAWINGS

[0040] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent as various embodiments of the present disclosure are described in detail with reference to the drawings, in which like reference numerals refer to like elements throughout the various figures. It is to be understood that the drawings are schematic and elements and features do not necessarily appear in proportion to one another.

[0041] Figure 1 A schematic diagram of a photovoltaic system is provided for the embodiments of the present application;

[0042] Figure 2 A schematic diagram of a component controller is provided for the embodiments of the present application;

[0043] Figure 3 An LVD threshold waveform diagram is provided for the embodiments of the present application;

[0044] Figure 4 Another schematic diagram of a component controller is provided for the embodiments of the present application;

[0045] Figure 5 A schematic diagram of a power conversion device is provided for the embodiments of the present application;

[0046] Figure 6 A flowchart of a control method of a component controller is provided for the embodiments of the present application. DETAILED DESCRIPTION

[0047] The embodiments of the present application are described below in conjunction with the accompanying drawings. The terms used in the embodiment part of the present application are only used to explain the specific embodiments of the present application, and are not intended to limit the present application.

[0048] The embodiments of the present application are described below in conjunction with the accompanying drawings. Those skilled in the art can know that the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems as the technology develops and new scenarios appear.

[0049] The terms "first", "second", and the like in the description and in the claims of the present application and above-described drawings are used to distinguish similar objects and are not necessarily used to describe a specific sequential or chronological order. It should be understood that the terms so used are interchangeable under appropriate circumstances and are merely employed to distinguish one embodiment of the application from another embodiment of the application in the description. Furthermore, the terms "comprise", "have", and any variations thereof are intended to cover a non-exclusive inclusion, such that processes, methods, systems, products, or apparatuses that comprise a list of elements are not necessarily limited to those elements, but can include other elements not expressly listed or inherent to such processes, methods, systems, products, or apparatuses.

[0050] The present application provides an assembly controller, a power conversion device, a control method of the assembly controller, and a power electronic conversion system. Before introducing embodiments of the present application, a possible application scenario of the embodiments of the present application is described.

[0051] The power electronic conversion system includes a power conversion device, an assembly controller, and the like. The assembly controller is connected to at least one DC source. The DC side of the power conversion device is connected to at least one assembly controller. If the power electronic conversion system includes multiple assembly controllers, the output ends of the multiple assembly controllers are connected in series to the DC side of the power conversion device.

[0052] The assembly controller can realize assembly-level maximum power point tracking, and the assembly controllers do not affect each other.

[0053] The power electronic conversion system can be a photovoltaic system. Exemplarily, Figure 1 Fig. 1 is a schematic diagram of a photovoltaic system structure. The photovoltaic system includes an inverter, Figure 1 a power conversion device, an assembly controller, a photovoltaic assembly, a battery, a load, and a meter, Figure 1 In the embodiment, three assembly controllers and three photovoltaic assemblies are taken as examples. The inverter is in communication connection with the assembly controllers. The assembly controllers are connected to the photovoltaic assemblies.

[0054] The assembly controller can be an optimizer, a shutdown device, or the like. The inverter and the assembly controller communicate through power line carrier communication (PLC). The PLC central coordination officer (CCO) included in the inverter is a master controller. The assembly controller is a station (STA) of the PLC. The photovoltaic system does not need to be rewired. The photovoltaic system uses power lines, is convenient to deploy, has a short construction period, low cost, and high reliability. The communication rate can meet the system requirements, and provides a cheap data communication platform for the intelligent monitoring system of the photovoltaic power station system.

[0055] The following will be described in detail the component controller and the power conversion device in the power electronic conversion system provided by the embodiments of the present application with reference to the accompanying drawings.

[0056] The component controller is connected with at least one direct current source, which can be a photovoltaic module. The component controller continuously detects the current voltage output by the direct current source, and adjusts the duration of high level in the PWM drive signal output to the direct current converter (DC / DC) according to the current voltage output by the direct current source, that is, adjusts the duty cycle of the PWM drive signal output to the direct current converter, so as to realize the maximum output of the direct current source, that is, to realize the maximum power point tracking (MPPT) at the module level. However, taking the photovoltaic module as the direct current source as an example, in the weak light environment such as early morning and evening, the output power of the photovoltaic module is low. During the operation of the component controller, the input voltage of the component controller may be lowered with the rise of the output voltage, resulting in that the power supply voltage of the component controller is too low to shut down. After the component controller is shut down, the output power of the photovoltaic module returns to normal, and the component controller starts to restart. With the rise of the output voltage during the start-up process, the input voltage of the component controller is lowered again, resulting in that the component controller is shut down again. In the scenario where the light is weak and lasts for a long time, the component controller will frequently restart, affecting the performance and service life of the component controller.

[0057] In order to solve the above technical problems, the embodiments of the present application provide a component controller, which comprises a control unit, a voltage detection module and a direct current converter.

[0058] The voltage detection module detects the power supply voltage.

[0059] The control unit receives the power supply voltage, and in the case that the power supply voltage is lower than a threshold value, the duration of high level in the PWM drive signal currently output to the direct current converter is reduced.

[0060] It should be understood that the control unit reduces the duty cycle of the PWM drive signal currently output to the direct current converter.

[0061] When the power supply voltage is lower than the threshold value, the control unit turns off the maximum power point tracking function at the module level. By reducing the duration of high level in the PWM drive signal currently output to the direct current converter, the output voltage of the component controller is reduced, so as to raise the input voltage of the component controller, thereby raising the power supply voltage of the component controller and ensuring the power supply stability of the component controller. The problem that the component controller is frequently restarted in the weak light environment due to the immediate shutdown when the input voltage of the component controller is lower than the threshold value is solved, and the performance and service life of the component controller are improved.

[0062] The voltage detection module can be implemented in various ways.

[0063] In one possible implementation, the voltage detection module is arranged inside the control unit and detects the supply voltage of the control unit. Since the control unit is the core module of the component controller, detecting the supply voltage of the control unit can more accurately determine whether the core function of the component controller can normally operate, so as to accurately determine whether the duty cycle of the PWM drive signal currently output by the DC converter needs to be reduced according to the supply voltage of the control unit. In this implementation, the threshold corresponding to the supply voltage is the first threshold, and the first threshold represents the minimum voltage value for the normal operation of the MCU.

[0064] Taking the control unit as an MCU (Microcontroller Unit), the voltage detection function of the LVD (Low Voltage Detect) in the MCU can be reused, and the LVD is used as the voltage detection module. Please refer to FIG. 1, which shows a structural schematic diagram of a component controller, the component controller comprising an MCU 201 and a DC converter 202, the MCU comprising an internal power supply module 2011 of the MCU and an LVD 2012. The internal power supply module 2011 of the MCU provides a stable power supply for the MCU, and the LVD 2012 is connected to the internal power supply module 2011 of the MCU and detects the supply voltage of the MCU. Figure 2

[0065] The LVD detects the supply voltage of the MCU, the supply voltage of the MCU is VDD (positive power supply voltage) or VDDA (analog power supply voltage), and the LVD sends the supply voltage of the MCU to the MCU. When the supply voltage is lower than the first threshold, the MCU reduces the duration of the high level in the PWM drive signal currently output by the DC converter.

[0066] ​The voltage detection function of the LVD can also be reused. The LVD detects the MCU's supply voltage and determines whether the MCU's supply voltage is lower than a first threshold. The MCU's supply voltage is either VDD (positive power supply voltage) or VDDA (analog power supply voltage). The first threshold is configured by the LVDT[2:0] bits (Low Voltage DetectionThreshold) in the power control register (not shown) of the MCU. Specifically, the LVD is enabled by setting LVDEN (Low Voltage Detection Enable). When the MCU's supply voltage is lower than the first threshold, the LVDF (Low Voltage Detect Flag) bit in the power control and status register (not shown) is set to 1, indicating that a low voltage event has occurred. This triggers line 16 of the EXTI (External Interrupt / Event Controller) to send an interrupt signal to the MCU. After receiving the interrupt signal, the MCU reduces the duration of the high level in the PWM drive signal currently output to the DC-DC converter.

[0067] like Figure 3 As shown, the LVD threshold waveform diagram illustrates the relationship between the VDD / VDDA supply voltage and the LVD output signal. Whether the LVD sends an interrupt signal depends on the rising or falling edge configuration of line 16 of EXTI. When VDD / VDDA is below the first threshold ( Figure 3 When VDD / VDDA is lower than the first threshold (represented by the LVD threshold), the LVD sends an interrupt signal to the MCU. It should be noted that a hysteresis voltage Vhyst is set during the VDD / VDDA decrease process. When VDD / VDDA is lower than the first threshold, the LVD sends an interrupt signal to the MCU. When VDD / VDDA decreases again, it needs to drop below the hysteresis voltage range before sending an interrupt signal to the MCU again. This avoids the problem of frequent interrupt signal sending due to small fluctuations in VDD / VDDA. For example, the hysteresis voltage Vhyst can be set to 100mV.

[0068] In some embodiments, a voltage sampling component for the MCU can be added to the component controller to detect the MCU's power supply voltage and send it to the MCU. This embodiment does not impose specific limitations.

[0069] The embodiment detects the supply voltage of the MCU, accurately determines whether the core function of the component controller can normally operate, and then accurately determines whether the supply voltage of the MCU needs to be raised by reducing the duty cycle of the PWM drive signal output by the MCU to the DC converter, reducing the output voltage of the component controller, and raising the input voltage of the component controller, so as to raise the supply voltage of the component controller and ensure the stability of the supply of the component controller.

[0070] In another possible implementation, the component controller further includes a circuit power supply module, please refer to Figure 4 The component controller includes an MCU 401, a circuit power supply module 402, a voltage detection module 403, and a DC converter 404. The DC source is connected to the circuit power supply module 402 of the component controller, the input voltage of the circuit power supply module 402 is the supply voltage of the whole component controller, the voltage detection module 403 detects the input voltage of the circuit power supply module 402, that is, the supply voltage of the whole component controller, and sends the supply voltage to the MCU 401. When the supply voltage is lower than the second threshold value (in this implementation, the threshold value corresponding to the supply voltage is the second threshold value), the MCU 401 reduces the duration of the high level in the PWM drive signal currently output to the DC converter. It can be understood that when the input voltage of the circuit power supply module 402 detected by the voltage detection module 403 is lower than the second threshold value, the supply voltage of the component controller is too low, and the second threshold value represents the minimum voltage value for the normal operation of the component controller.

[0071] The above two detection methods of the supply voltage are only examples, and the application is not limited thereto. In the following embodiments, the supply voltage can be obtained by any of the above methods, which will not be described again.

[0072] In a possible implementation, the control unit in the component controller records the duration when the supply voltage is not lower than the threshold value, and if the duration when the supply voltage is not lower than the threshold value is less than a first preset time, the duration of the high level in the PWM drive signal currently output to the DC converter is reduced again, that is, the duty cycle of the PWM drive signal is reduced again.

[0073] The duration when the supply voltage is not lower than the threshold value is less than the first preset time, which indicates that the supply of the component controller is still unstable. Taking the DC source as a photovoltaic component, for example, in the evening, the light will become weaker and weaker, and the output power of the photovoltaic component will continue to decrease, so the component controller needs to continue to reduce the duty cycle of the PWM drive signal currently output to the DC converter to raise the supply voltage of the component controller. The first preset time is preset, for example, it can be set to 10 seconds.

[0074] In a possible implementation, the control unit in the component controller controls the component controller to start the component-level maximum power point tracking function when the duration for which the supply voltage is not lower than the threshold value reaches a first preset time.

[0075] If the duration for which the supply voltage is not lower than the threshold value reaches the first preset time, it indicates that the supply of the component controller is stable. In addition, taking the photovoltaic module as an example, in the early morning, the light will be stronger and stronger, and as the light increases, the output power of the photovoltaic module increases. Even if the output voltage of the component controller rises, the supply voltage of the component controller will not be pulled down to the threshold value. The component controller can be controlled to start the component-level maximum power point tracking function, gradually increase the duty cycle of the PWM drive signal output to the DC converter, realize the maximum output of the DC source, and realize the component-level maximum power point tracking.

[0076] It should be noted that after the control unit controls the component controller to start the component-level maximum power point tracking function, the supply voltage detected by the voltage detection module is continuously acquired to realize timely discovery when the supply voltage is too low, and the supply voltage of the component controller is pulled up by reducing the duty cycle of the PWM drive signal currently output to the DC converter, to ensure stable operation of the component controller.

[0077] When the control unit reduces the duty cycle of the PWM drive signal currently output to the DC converter, the amplitude of the reduction of the duty cycle of the PWM drive signal can be gradually increased, or the amplitude of the reduction of the duty cycle of the PWM drive signal can be gradually decreased, or the amplitude of the reduction of the duty cycle of the PWM drive signal can be the same each time.

[0078] In a possible implementation, when the duration for which the supply voltage is not lower than the threshold value is less than the first preset time, the amplitude of the reduction of the duty cycle of the PWM drive signal can be gradually increased to quickly pull up the supply voltage of the component controller. For ease of description, after the control unit determines that the supply voltage is lower than the threshold value and controls the component controller to turn off the component-level maximum power point tracking function, the component controller is defined to enter an under-voltage protection mode. After the duty cycle of the PWM drive signal is reduced for the first time in the under-voltage protection mode, the amplitude of the reduction of the duty cycle of the PWM drive signal each time is not less than the amplitude of the reduction of the duty cycle of the PWM drive signal last time. For example, in the under-voltage protection mode, the duty cycle of the PWM drive signal is adjusted to 80% of the current duty cycle of the PWM drive signal for the first time, and the duty cycle of the PWM drive signal is adjusted to 70% of the current duty cycle of the PWM drive signal for the second time.

[0079] It can be understood that if the duration of the supply voltage being not lower than the threshold value is less than the first preset time, for example, in the evening, the light will become weaker and weaker, and the output power of the photovoltaic module will continue to decrease, and the control unit cannot finally pull up the supply voltage of the module controller to the threshold value by reducing the duty cycle of the PWM drive signal output to the DC converter, for example, if the duty cycle of the PWM drive signal output to the DC converter is reduced to a set value close to 0, the control unit performs the blocking operation.

[0080] There are various implementations of the present embodiment regarding the conditions under which the control unit controls the module controller to perform the blocking operation.

[0081] In one possible implementation, after the control unit reduces the duty cycle of the PWM drive signal output to the DC converter, if the duration of the supply voltage being not lower than the threshold value is less than the first preset time, the control unit continues to reduce the duty cycle until it is detected that the duty cycle is reduced to a set value, and then the control unit performs the blocking operation, wherein the set value is a value close to 0.

[0082] In another possible implementation, the control unit records the number of consecutive burps of the module controller within a second preset time, wherein the supply voltage being lower than the threshold value is a burp. Specifically, the voltage detection module detects the supply voltage and sends the supply voltage to the control unit, and the control unit receives the supply voltage and records a burp when the supply voltage is lower than the threshold value.

[0083] For example, the number of burps is recorded in a memory, and the controller reads the number of burps in the memory, and if the number of consecutive burps of the module controller within the second preset time reaches a preset value, the control unit controls the module controller to not be chopped and not output.

[0084] If the number of consecutive burps of the module controller within the second preset time reaches the preset value, the supply voltage is unstable, for example, in the evening, the light will become weaker and weaker, and the output power of the photovoltaic module will continue to decrease, and the supply voltage of the module controller cannot be stably pulled up to the threshold value by reducing the duty cycle, at this time, the control unit controls the module controller to not be chopped and not output, i.e., not to output the duty cycle and the power.

[0085] The preset value is a preset value, and the preset value is greater than 2, for example, it can be set to 3.

[0086] In order to avoid the loss caused by not chopping for a long time in the scene where the light intensity fluctuates, after the time of not chopping and not outputting of the module controller reaches a third preset time, the control unit controls the module controller to chop again and output the duty cycle.

[0087] The second preset time and the third preset time are both preset according to actual application scenarios, and the second preset time and the third preset time can be equal or not equal.

[0088] If the number of continuous burps of the component controller is less than the preset value within the second preset time after the component controller is chopped again, it indicates that the supply voltage of the component controller tends to be stable, and the control unit continues to record the number of continuous burps of the component controller within the second preset time for cyclic monitoring and judgment.

[0089] If the number of continuous burps of the component controller reaches the preset value within the second preset time, the control unit performs the chopping operation. If the number of continuous burps of the component controller reaches the preset value within the second preset time, it indicates that the supply voltage of the component controller is still unstable. For example, in the evening scenario, the supply voltage of the component controller cannot be finally pulled up to the threshold value by continuously reducing the duty cycle, and the control unit performs the chopping operation.

[0090] The embodiment of the present application also provides a power conversion device, which refers to a structure schematic diagram of the power conversion device shown in the figure. Figure 5 The direct current side of an inverter circuit 502 of the power conversion device is connected with at least one component controller, and a master control unit 501 in the power conversion device is in communication connection with the component controller.

[0091] The master control unit 502 acquires the supply voltage of the component controller, and if the supply voltage is lower than a threshold value, sends a first control instruction to the component controller, so that the component controller reduces the duration of the high level in the PWM driving signal currently output to the direct current converter in response to the first control instruction.

[0092] The master control unit acquires the supply voltage of the component controller in multiple ways, for example, the component controller can actively and periodically send the supply voltage to the master control unit, the master control unit can also periodically request the supply voltage of the component controller from the component controller, and then the component controller sends the supply voltage of the component controller to the master control unit in response to the request.

[0093] The supply voltage can be the supply voltage of the control unit in the component controller, or the supply voltage of the whole component controller, which is detected by a voltage detection module of the component controller.

[0094] The power conversion device disclosed in the embodiment can pull up the supply voltage of the component controller by sending a first control instruction to the component controller when the supply voltage of the component controller is lower than a threshold value, so that the component controller reduces the duration of the high level in the PWM driving signal currently output to the direct current converter in response to the first control instruction, that is, reduces the duty cycle of the PWM driving signal, thereby ensuring the power supply stability of the component controller, solving the problem that the component controller is frequently restarted in a weak light environment due to immediate shutdown when the supply voltage of the component controller is lower than the threshold value, and improving the performance and service life of the component controller.

[0095] In a possible implementation, the master control unit records a duration during which the supply voltage is not lower than the threshold value, and sends a second control instruction to the component controller in a case where the duration during which the supply voltage is not lower than the threshold value reaches a first preset time, so that the component controller starts the component-level maximum power point tracking function in response to the second control instruction.

[0096] In the method, the power conversion device continues to acquire the supply voltage of the component controller after sending the second control instruction to the component controller, and performs the cyclic judgment on the supply voltage.

[0097] In a possible implementation, after sending the first control instruction to the component controller, the master control unit sends a third control instruction to the component controller in a case where the supply voltage is detected to be lower than the threshold value again, so that the component controller reduces the duration of the high level in the PWM driving signal output to the direct-current converter again in response to the third control instruction, and the amplitude of the reduction of the duration of the high level in the PWM driving signal is increased successively each time.

[0098] For example, the first control instruction and the third control instruction respectively carry the amplitude of the reduction of the duration of the high level in the PWM driving signal, and the amplitude of the reduction of the duration of the high level in the PWM driving signal carried by the third control instruction is greater than the amplitude of the reduction of the duration of the high level in the PWM driving signal carried by the first control instruction, so that the component controller rapidly pulls up the supply voltage thereof, and the stable operation of the component controller is ensured.

[0099] In a possible implementation, the master control unit acquires and records the number of continuous burps of the component controller within a second preset time, where the supply voltage being lower than the threshold value is regarded as one burp. Specifically, the master control unit acquires the supply voltage, and records one burp in a case where the supply voltage is lower than the threshold value. If the number of continuous burps of the component controller within the second preset time reaches a preset value, the master control unit sends a fourth control instruction to the component controller, so that the component controller does not perform the chopper operation and does not output in response to the fourth control instruction.

[0100] After the time during which the component controller does not perform the chopper operation and does not output reaches a third preset time, the master control unit controls the component controller to perform the chopper operation again. After the component controller performs the chopper operation again, if the number of continuous burps of the component controller within the second preset time is less than the preset value, the master control unit continues to acquire and record the number of continuous burps of the component controller within the second preset time. After the component controller performs the chopper operation again, if the number of continuous burps of the component controller within the second preset time reaches the preset value, the master control unit sends a fifth control instruction to the component controller, so that the component controller performs the blocking operation in response to the fifth control instruction.

[0101] The power conversion device in the embodiment determines the operation trend of the component controller by recording the number of continuous burps of the second preset component controller, and determines whether the supply voltage of the component controller can be stably pulled up to the threshold value by reducing the duty cycle of the PWM drive signal output to the DC converter. If not, the component controller is controlled to perform the blocking wave.

[0102] The embodiment of the application further provides a component controller control method, which can be applied to any component controller provided by the embodiment of the application or any power conversion device provided by the embodiment of the application.

[0103] Please refer to Figure 6 The component controller control method provided by the embodiment of the application comprises the following steps 601-602.

[0104] 601: obtaining the supply voltage of the component controller;

[0105] The supply voltage can be the supply voltage of the control unit in the component controller, or the supply voltage of the whole component controller, which is detected by the voltage detection module of the component controller.

[0106] If the component controller control method is applied to the component controller, the control unit in the component controller receives the supply voltage detected by the voltage detection module.

[0107] If the component controller control method is applied to the power conversion device, the main control unit of the power conversion device receives the supply voltage of the component controller sent by the component controller.

[0108] 602: if the supply voltage is lower than the threshold value, reducing the duration of the high level in the PWM drive signal output by the control unit of the current component controller to the DC converter.

[0109] For example, if the supply voltage is the supply voltage of the control unit in the component controller, it is necessary to determine whether the supply voltage of the control unit is lower than the first threshold value, which represents the minimum voltage value for the normal operation of the control unit.

[0110] For example, if the supply voltage is the supply voltage of the whole component controller, it is necessary to determine whether the supply voltage of the whole component controller is lower than the second threshold value, which represents the minimum voltage value for the normal operation of the component controller.

[0111] The threshold value is stored in the control unit of the component controller if the component controller control method is applied to the component controller, or stored in the main control unit of the power conversion device if the component controller control method is applied to the power conversion device.

[0112] If the control method of the component controller is applied to the component controller, the control unit of the component controller reduces the duration of high level in the PWM drive signal currently output to the direct current converter.

[0113] If the control method of the component controller is applied to the power conversion device, the main control unit of the power conversion device sends a first control instruction to the component controller, so that the component controller reduces the duration of high level in the PWM drive signal currently output to the direct current converter in response to the first control instruction.

[0114] If the power supply voltage is not lower than the threshold value, the power supply voltage of the component controller is continuously acquired, and the cyclic judgment of the power supply voltage is continuously performed.

[0115] In a possible implementation, after the duration of high level in the PWM drive signal currently output to the direct current converter by the control unit of the component controller is reduced, the control method of the component controller further includes:

[0116] If the duration of the power supply voltage being not lower than the threshold value reaches a first preset time, the component controller is controlled to start the component-level maximum power point tracking function.

[0117] In a possible implementation, after the duration of high level in the PWM drive signal currently output to the direct current converter by the control unit of the component controller is reduced, the control method of the component controller further includes:

[0118] If the power supply voltage is detected to be less than the threshold value again, the duration of high level in the PWM drive signal currently output to the direct current converter is reduced again, and the amplitude of reducing the duration of high level in the PWM drive signal each time is increased successively.

[0119] In a possible implementation, the control method of the component controller further includes:

[0120] The number of continuous burps of the component controller in a second preset time is recorded;

[0121] If the number of continuous burps of the component controller in the second preset time reaches a preset value, the component controller is controlled to be unclipped and unoutput;

[0122] After the time of the component controller being unclipped and unoutput reaches a third preset time, the component controller is controlled to be clipped again;

[0123] After the component controller is clipped again, if the number of continuous burps of the component controller in the second preset time is less than the preset value, the operation of recording the number of continuous burps of the component controller in the second preset time is returned to be performed;

[0124] After the component controller chops again, if the number of continuous burps of the component controller reaches the preset value within the second preset time, a chopping-off operation is performed.

[0125] The controller control method disclosed in the embodiment raises the power supply voltage of the component controller by reducing the duration of the high level in the PWM drive signal output by the control unit of the current component controller to the DC converter, i.e., reducing the duty cycle of the PWM drive signal, when the power supply voltage of the component controller is lower than a threshold value, ensures the power supply stability of the component controller, solves the problem of frequent restart of the component controller in a weak light environment caused by immediate shutdown when the power supply voltage of the component controller is lower than the threshold value, and improves the performance and service life of the component controller.

[0126] The embodiment of the application further provides an electric power electronic conversion system, comprising: a power conversion device and any one of the component controllers provided by the embodiment of the application.

[0127] The DC side of the power conversion device is connected with at least one of the component controllers.

[0128] The component controller is connected with at least one DC source.

[0129] The embodiment of the application further provides an electric power electronic conversion system, comprising: a component controller and any one of the power conversion devices provided by the embodiment of the application.

[0130] The DC side of the power conversion device is connected with at least one of the component controllers.

[0131] The component controller is connected with at least one DC source.

[0132] Through the description of the above embodiments, those skilled in the art can clearly understand that the application can be realized by means of software and necessary general hardware, and of course, it can also be realized by special hardware including special integrated circuits, special CPUs, special memories, special components and the like. Generally, functions completed by computer programs can be easily realized by corresponding hardware, and specific hardware structures for realizing the same function can be various, such as analog circuits, digital circuits or special circuits. However, for the application, software program implementation is a better embodiment. Based on such understanding, the technical solutions of the application can be embodied in the form of a software product, which is stored in a readable storage medium, such as a computer floppy disk, U disk, mobile hard disk, ROM, RAM, magnetic disk or optical disk, and includes a plurality of instructions for causing a computer device (which can be a personal computer, a training device or a network device) to execute the methods described in the embodiments of the application.

[0133] In the above-described embodiments, all or some of the embodiments can be implemented by software, hardware, firmware, or any combination thereof. When implemented by software, all or some of the embodiments can be implemented in the form of a computer program product.

[0134] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions can be transmitted from one website, computer, training device or data center to another website, computer, training device or data center through wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that a computer can store or a data storage device such as a training device, a data center, etc. integrated with one or more available media sets. The available media can be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a DVD), or a semiconductor medium (for example, a solid state disk (SSD)), etc.

Claims

1. A component controller, characterized in that, include: Control unit, voltage detection module, and DC-DC converter; The voltage detection module detects the supply voltage and sends the supply voltage to the control unit; The control unit receives the supply voltage and, if the supply voltage is lower than a threshold, reduces the duration of the high level in the PWM drive signal currently output to the DC-DC converter.

2. The component controller according to claim 1, characterized in that, The voltage detection module is located inside the control unit and detects the power supply voltage of the control unit.

3. The component controller according to claim 1, characterized in that, The component controller also includes a circuit power supply module; The voltage detection module detects the input voltage of the circuit power supply module, and the input voltage of the circuit power supply module is the power supply voltage of the component controller.

4. The component controller according to claim 1, characterized in that, After reducing the duration of the high level in the PWM drive signal currently output to the DC-DC converter, if the duration of the power supply voltage not being lower than the threshold reaches a first preset time, the control unit controls the component controller to start the component-level maximum power point tracking function.

5. The component controller according to claim 1 or 4, characterized in that, After the control unit reduces the duration of the high level in the PWM drive signal currently output to the DC-DC converter, if it detects again that the supply voltage is less than the threshold, it further reduces the duration of the high level in the PWM drive signal currently output to the DC-DC converter, wherein the magnitude of each reduction in the duration of the high level in the PWM drive signal increases sequentially.

6. The component controller according to claim 1 or 4, characterized in that, The control unit records the number of consecutive hiccups of the component controller within a second preset time period; if the number of consecutive hiccups of the component controller within the second preset time period reaches a preset value, the control unit controls the component controller not to chop or output. After the component controller has not chopped or output for a third preset time, the control unit controls the component controller to chop again. After the component controller chops again, if the number of consecutive hiccups of the component controller within the second preset time is less than the preset value, the control unit continues to record the number of consecutive hiccups of the component controller within the second preset time. After the component controller chops again, if the number of consecutive hiccups of the component controller within the second preset time reaches the preset value, the control unit performs a wave blocking operation.

7. A power conversion device, wherein at least one component controller is connected to the DC side of the power conversion device, characterized in that, The power conversion device includes a main control unit; The main control unit obtains the power supply voltage of the component controller. If the power supply voltage is lower than the threshold, it sends a first control command to the component controller, causing the component controller to reduce the duration of the high level in the PWM drive signal currently output to the DC-DC converter in response to the first control command.

8. The power conversion device according to claim 7, characterized in that, When the duration of the power supply voltage not being lower than the threshold reaches a first preset time, the main control unit sends a second control command to the component controller, causing the component controller to activate the component-level maximum power point tracking function in response to the second control command.

9. The power conversion device according to claim 7 or 8, characterized in that, After sending a first control command to the component controller, if the main control unit detects that the supply voltage is less than the threshold again, it sends a third control command to the component controller, causing the component controller to respond to the third control command by reducing the duration of the high level in the PWM drive signal currently output to the DC-DC converter. The component controller reduces the duration of the high level in the PWM drive signal by an increasing amount each time.

10. The power conversion device according to claim 7 or 8, characterized in that, The main control unit acquires and records the number of consecutive hiccups of the component controller within a second preset time period; if the number of consecutive hiccups of the component controller within the second preset time period reaches a preset value, a fourth control command is sent to the component controller, causing the component controller to respond to the fourth control command by not chopping and not outputting. After the component controller has not chopped or output for a third preset time, the main control unit controls the component controller to chop again. After the component controller chops again, if the number of consecutive hiccups of the component controller within the second preset time is less than the preset value, the main control unit continues to acquire and record the number of consecutive hiccups of the component controller within the second preset time. After the component controller chops again, if the number of consecutive hiccups of the component controller within the second preset time reaches the preset value, the main control unit sends a fifth control command to the component controller, causing the component controller to perform a wave blocking operation in response to the fifth control command.

11. A control method for a component controller, characterized in that, include: Obtain the power supply voltage of the component controller; If the supply voltage is lower than the threshold, reduce the duration of the high level in the PWM drive signal output by the control unit of the current component controller to the DC-DC converter.

12. The control method for the component controller according to claim 11, characterized in that, After reducing the duration of the high level in the PWM drive signal output by the control unit of the current component controller to the DC-DC converter, the control method of the component controller further includes: If the duration for which the supply voltage is not lower than the threshold reaches a first preset time, the component controller is controlled to start the component-level maximum power point tracking function.

13. The control method for the component controller according to claim 11 or 12, characterized in that, After reducing the duration of the high level in the PWM drive signal output by the control unit of the current component controller to the DC-DC converter, the control method of the component controller further includes: If the supply voltage is detected to be less than the threshold again, the duration of the high level in the PWM drive signal currently output to the DC-DC converter is reduced again, wherein the magnitude of the reduction in the duration of the high level in the PWM drive signal increases sequentially each time.

14. The control method for the component controller according to claim 11 or 12, characterized in that, The control method of the component controller also includes: Record the number of consecutive hiccups of the component controller within a second preset time period; If the number of consecutive hiccups of the component controller within the second preset time reaches a preset value, then the component controller is controlled to not chop or output. After the component controller has not chopped or output for a third preset time, the component controller is controlled to chop again. After the component controller chops again, if the number of consecutive hiccups of the component controller within the second preset time is less than the preset value, then return to the operation of recording the number of consecutive hiccups of the component controller within the second preset time. If the number of consecutive hiccups of the component controller reaches the preset value within the second preset time after the component controller chops again, then a wave blocking operation is performed.

15. A power electronic conversion system, characterized in that, include: The power conversion device and the component controller according to any one of claims 1-6; At least one of the component controllers is connected to the DC side of the power conversion device; The component controller is connected to at least one DC source.

16. A power electronic conversion system, characterized in that, include: The component controller and the power conversion device according to any one of claims 7-10; At least one of the component controllers is connected to the DC side of the power conversion device; The component controller is connected to at least one DC source.

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