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EP-3936967-B1 - POWER GENERATION DEVICE AND SYSTEM CAPABLE OF MAXIMUM POWER TRACKING

EP3936967B1EP 3936967 B1EP3936967 B1EP 3936967B1EP-3936967-B1

Inventors

  • WU, GUOMING

Dates

Publication Date
20260506
Application Date
20190428

Claims (8)

  1. A power generation device capable of maximum power tracking, comprising a power generation assembly (1) and at least one optimizer (2), the optimizer (2) comprises a maximum power tracking circuit (201), a drive control circuit (202), a first switch (203) and a second switch (204) arranged in a chip, wherein a first end of the first switch (203) is connected to a positive output end of the power generation assembly (1), a second end of the first switch (203) is connected to a first end of the second switch (204), and a second end of the second switch (204) is connected to a negative output end of the power generation assembly (1); the second end of the first switch (203) and the first end of the second switch (204) are further connected to an intermediate port (205), and a power may be further output to a peripheral circuit of the chip through the intermediate port (205); the intermediate port (205) is connected to the power generation device of a former stage; the maximum power tracking circuit (201) comprises a voltage and current detection unit (2011), a multiplier (2012), and a maximum power tracking processing unit (2013); the voltage and current detection unit (2011) is configured to collect a voltage of the positive output end, a voltage of the negative output end and a voltage of the intermediate port (205); determine an assembly output voltage of the power generation assembly (1) according to the voltage of the positive output end and the voltage of the negative output end; and determine a current of the first switch (203) according to the voltage of the positive output end and the voltage of the intermediate port (205) as an assembly output current; the multiplier (2012) is configured to multiply the assembly output voltage of the power generation assembly (1) by the assembly output current of the power generation assembly (1) to obtain an assembly output power of the power generation assembly (1); the maximum power tracking processing unit (2013) is configured to track and determine a current maximum power of the power generation assembly (1) according to the assembly output power, determine a duty ratio signal according to the current maximum power, and send the duty ratio signal to the drive control circuit (202); and the drive control circuit (202) is connected to a control end of the first switch (203) and a control end of the second switch (204) respectively for controlling on-off of the first switch (203) and the second switch (204) according to the duty ratio signal, characterised in that the maximum power tracking processing unit (2013), when determining the duty ratio signal according to the current maximum power, is specifically configured to: determine a current reference voltage according to the current maximum power; compare the current reference voltage with a current voltage of a voltage reference signal, and generate the duty ratio signal of a corresponding duty ratio according to a comparison result, wherein the voltage reference signal is a voltage signal of a sine waveform or a voltage signal of a triangular waveform, and in that the maximum power tracking processing unit (2013) is further connected to the voltage and current detection unit (2011); the voltage and current detection unit (2011) is further configured to: determine a current of the second switch (204) according to the voltage of the negative output end and the voltage of the intermediate port (205), and add the current of the first switch (203) to the current of the second switch (204) to obtain an output current of the intermediate port (205); the maximum power tracking processing unit (2013) is further configured to: perform a safety regulation on the duty ratio signal if an output voltage of the intermediate port (205) is not matched with a safety voltage interval corresponding thereto so that the voltage of the intermediate port (205) is matched with the safety voltage interval corresponding thereto; perform a safety regulation on the duty ratio signal if the output current of the intermediate port (205) is not matched with a first safety current interval corresponding thereto or the current of the first switch (203) is not matched with a second safety current interval corresponding thereto so that the output current of the intermediate port (205) is matched with the first safety current interval corresponding thereto and the current of the first switch (203) is matched with the second safety current interval corresponding thereto; and give priority to the safety regulation if the safety regulation conflicts with the duty ratio signal determined according to the current maximum power.
  2. The device according to claim 1, wherein the drive control circuit (202) comprises a logic control unit (2023), a first drive unit (2021) and a second drive unit (2022), wherein an input end of the logic control unit (2023) is connected to the maximum power tracking circuit (201) for receiving the duty ratio signal, generating a first drive signal and a second drive signal according to the duty ratio signal, and sending the first drive signal to the first drive unit (2021) and sending the second drive signal to the second drive unit (2022); the logic control unit (2023) is connected to the first drive unit (2021) and the second drive unit (2022) respectively, an output end of the first drive unit (2021) is connected to the control end of the first switch (203), and an output end of the second drive unit (2022) is connected to the control end of the second switch (204); and the first drive unit (2021) is configured to control the on-off of the first switch (203) according to the first drive signal, and the second drive unit (2022) is configured to control on-off of the second switch (204) according to the second drive signal.
  3. The device according to claim 2, wherein a power supply end of the first drive unit (2021) is connected to an internal power supply circuit (208) through a power supply control switch (K), the power supply end of the first drive unit (2021) is further connected to one end of a boot-strap capacitor (C2), and the other end of the boot-strap capacitor is connected to the intermediate port (205).
  4. The device according to any one of claims 1 to 3, wherein the optimizer (2) further comprises the internal power supply circuit (208), the internal power supply circuit (208) is directly or indirectly connected to the positive output end, and the internal power supply circuit (208) is connected to the drive control circuit (202) for powering the drive control circuit (202) by using an output electric energy of the power generation assembly (1).
  5. The device according to claim 4, further comprising a reference voltage generation circuit (209), wherein the reference voltage generation circuit (209) is connected to the internal power supply circuit (208) and the maximum power tracking circuit (201) respectively for providing the maximum power tracking circuit (201) with a reference voltage for determining the duty ratio signal by using the power supply of the internal power supply circuit (208).
  6. The device according to any preceding claim, wherein the optimizer (2) further comprises an over-temperature protection circuit (210) and an enable control circuit (211); the over-temperature protection circuit (210) is configured to detect temperature information of the optimizer (2), and send a specific enable signal to the enable control circuit (211) when the temperature information is higher than a pre-set temperature threshold value; the enable control circuit (211) is connected to the drive control circuit(202) for controlling the first switch (203) to be turned off by using the drive control circuit (202) when receiving the specific enable signal, so as to disconnect the intermediate port (205) from the power generation assembly (1) and turn on the second switch (204).
  7. The device according to any preceding claim, further comprising a communication circuit (214) and a communication interface assembly (215), wherein the communication circuit (214) interacts and communicates externally through the communication interface assembly (215), and is capable to perform analog-digital conversion on temperature information, assembly output information and device output information of the optimizer (2) and send externally the temperature information, assembly output information and device output information of the optimizer (2) through the communication interface assembly (215) after the analog-digital conversion, as well as receive external information transmitted externally through the communication interface assembly (215) and performing the analog-digital conversion on the external information so that threshold value information may be determined according to the external information; the assembly output information comprises at least one of the assembly output voltage of the power generation assembly (1), the assembly output current of the power generation assembly (1) and the assembly output power of the power generation assembly (1); the device output information comprises at least one of a device output voltage of the power generation device, a device output current of the power generation device and a device output power of the power generation device; and the threshold value information comprises at least one of a temperature threshold value, a voltage threshold value corresponding to the safety voltage interval and a current threshold value corresponding to the safety current interval.
  8. A power generation system capable of maximum power tracking, comprising at least two power generation devices capable of maximum power tracking connected in sequence according to any one of claims 1 to 7.

Description

TECHNICAL FIELD The present invention relates to the technical field of power generation, in particular, to a power generation device and system capable of maximum power tracking. BACKGROUND Each power generation assembly has its own output power characteristics, and the maximum power output of the assembly can only be exerted at a specific voltage and current. However, the output of a single power generation assembly is usually insufficient to provide actual power requirements, so a power generation assembly array is often formed in series connection and in parallel connection to meet design requirements. In the prior art, the conversion from a direct current to an alternating current is required for the power generation assembly array (since the power generation assembly is usually in the direct current and needs to be converted to be in the alternating current before being connected in parallel to the actual civil or industrial electricity grid, resulting in a process called inversion, i.e., a process from the direct current to the alternating current) after the power generation. In the prior art, before the conversion (i.e., before the direct current is converted into the alternating current), the same maximum power point tracking (MPPT) can be used to realize the maximum power point tracking of the assembly array. When the assembly is applied in series connection, the current passing though each assembly is equal, which can result in a mismatch of the power characteristics of the assembly. For example, when an assembly A operates at a maximum power point, the maximum power point may not be the current of a maximum power point of an assembly B, which may cause the assembly B to be unable to operate on its own maximum power point as the current of the series connection is the same, thereby resulting in a power loss of the assembly B. Therefore, in the existing solution, a power optimizer with an independent maximum power point tracking MPPT function can be equipped for each power generation assembly; and the output of each power generation assembly is connected to an input end of the power optimizer. Each power generation assembly is connected to the power optimizer, and each assembly is a separate whole relative to the array while the output power may not be affected by other assemblies, so as to further enable the assembly to operate at the maximum power value under the current environmental conditions. Therefore, the condition that each assembly cannot work at its own maximum power point due to the above mismatch of the assembly can be avoided. In the existing related art, the maximum power optimizer is usually implemented with a microprocessor MCU chip that is used for digital signal processing; in order to be adapted to information processing of the MCU chip, the MCU chip is required to be equipped with a sampling circuit to sample voltage and current information of the assembly, so as to calculate the power of the assembly. Meanwhile, since the sampling circuit collects analog signals and the MCU chip can only process digital signals, the optimizer is required to be equipped with an analog signal amplifier, an analog-digital signal converter and the like again, and the MCU outputs signals to pass through a pre-drive circuit to drive the corresponding out-built power transistor after calculating the maximum power point so as to reach a condition that the assembly array operates at the maximum power point. As such, the current solution is complex, has a lower degree of integration and has a higher cost. The higher cost causes the solution where the optimizer is equipped in this way not to be easy to popularize, thereby affecting the efficiency of the power generation assembly. WO 2012/024537 A2 discloses at least one related art example of a power generation device capable of optimal maximum power point tracking. SUMMARY The present invention provides a power generation device according to independent claim 1 and a system according to dependent claim 8 capable of maximum power tracking to solve the problems of complex solution, low degree of integration and high cost. According to a first aspect of the present invention, a power generation device capable of maximum power tracking is provided, including a power generation assembly and at least one optimizer; the optimizer includes a maximum power tracking circuit, a drive control circuit, a first switch and a second switch arranged in a chip, wherein a first end of the first switch is connected to a positive output end of the power generation assembly, a second end of the first switch is connected to a first end of the second switch, and a second end of the second switch is connected to a negative output end of the power generation assembly; the second end of the first switch and the first end of the second switch are further connected to an intermediate port, and a power may be further output to a peripheral circuit of the chip through the intermedia