US-12620810-B2 - Power converter analog chip and power converter

US12620810B2US 12620810 B2US12620810 B2US 12620810B2US-12620810-B2

Abstract

A power converter analog chip includes a sampling circuit configured to collect electrical parameters of the power converter; a maximum power point tracking circuit configured to perform maximum power point tracking based on the input power or the output power obtained by the electrical parameters, and to obtain an adjustment signal; a rapid shutdown circuit configured to, when receiving a rapid shutdown instruction sent from the outside of the analog chip, generate a rapid shutdown signal; a protection circuit, configured to, when an electrical parameter of the power converter exceeds a first preset threshold, generate a protection signal and send the protection signal to the multiplexer; and a multiplexer configured to select one of the rapid shutdown signal, the protection signal, or the adjustment signal as a control signal, to control a power component in the power converter.

Inventors

Dong Chen
Zhen Cao
Xiaofeng Yao
Jiebin CHENG
Guilei GU

Assignees

Huawei Digital Power Technologies Co., Ltd.

Dates

Publication Date: 20260505
Application Date: 20221012
Priority Date: 20211013

Claims (20)

1 . A power converter analog chip, comprising: a sampling circuit configured to receive electrical parameters from a power converter; a maximum power point tracking circuit coupled to the sampling circuit, wherein the maximum power point tracking circuit is configured to: obtain at least one of input power of the power converter or output power of the power converter based on the electrical parameters; perform maximum power point tracking based on the input power of the power converter or the output power of the power converter to obtain an adjustment signal; and send the adjustment signal; a protection circuit coupled to the sampling circuit, wherein the protection circuit is configured to: generate a protection signal when an electrical parameter of the power converter exceeds a first preset threshold; and send the protection signal; a rapid shutdown circuit configured to: receive a rapid shutdown instruction; generate a rapid shutdown signal based on the rapid shutdown instruction; and send the rapid shutdown signal; and a multiplexer coupled to the maximum power point tracking circuit, the protection circuit, and the rapid shutdown circuit, wherein the multiplexer is configured to: receive the rapid shutdown signal from the rapid shutdown circuit; receive the protection signal from the protection circuit; receive the adjustment signal from the maximum power point tracking circuit; select from one of the rapid shutdown signal, the protection signal, or the adjustment signal as a control signal; and control a power component in the power converter using the control signal.
2 . The power converter analog chip of claim 1 , wherein the multiplexer is further configured to further select the control signal from one of the rapid shutdown signal, the protection signal, or the adjustment signal according to a descending order of their priorities.
3 . The power converter analog chip of claim 1 , further comprising a communication circuit coupled to the rapid shutdown circuit and to the sampling circuit, wherein the communication circuit is configured to: forward, to the rapid shutdown circuit, the rapid shutdown instruction; and send the electrical parameters to a multiplexer; and wherein the multiplexer is configured to monitor operation of the power converter based on the electrical parameters.
4 . The power converter analog chip of claim 3 , wherein the communication circuit is further configured to: send, to the controller, at least one of the control signal or a control signal selection result of the multiplexer; or send, to the multiplexer, a mandatory selection instruction from the controller, and wherein the multiplexer is further configured to select the control signal from at least one of the rapid shutdown signal, the protection signal, or the adjustment signal based on the mandatory selection instruction.
5 . The power converter analog chip of claim 3 , wherein the maximum power point tracking circuit comprises: a multiplier configured to obtain at least one of the input power or the output power based on voltages and currents in the electrical parameters; a maximum power point tracker coupled to the multiplier, wherein the maximum power point tracker is configured to perform maximum power point tracking based on the input power or the output power to obtain a voltage reference value; and a voltage processor coupled to the maximum power point tracker, wherein the voltage processor is configured to obtain the adjustment signal based on the voltage reference value and an input voltage or an output voltage in the electrical parameters.
6 . The power converter analog chip of claim 5 , wherein the maximum power point tracking circuit further comprises a voltage simulator coupled to the voltage processor, wherein the voltage simulator is configured to obtain a voltage preset value based on a preset coefficient and the input voltage or the output voltage, and wherein the voltage processor is further configured to: compare the voltage reference value with the voltage preset value to obtain a comparison result; and obtain the adjustment signal based on the comparison result and either the input voltage or the output voltage.
7 . The power converter analog chip of claim 5 , wherein the maximum power point tracker is further configured to: store the input power or the output power from the multiplier as memory power; and compare real-time power of a photovoltaic module with the memory power to obtain the voltage reference value.
8 . The power converter analog chip of claim 5 , wherein the voltage processor is further configured to control, using the control signal, the power converter to work in a pass-through mode when a parameter represented by the adjustment signal exceeds a second preset threshold.
9 . The power converter analog chip of claim 5 , wherein the communication circuit is coupled to the maximum power point tracking circuit, wherein the communication circuit is further configured to perform at least one of: send, to the controller, the power of the power converter or the adjustment signal, wherein the power of the power converter is at least one of the input power or the output power; or send a power adjustment instruction of the controller to the maximum power point tracking circuit, wherein the power adjustment instruction enables the controller to adjust the power of the power converter or the adjustment signal.
10 . The power converter analog chip of claim 5 , wherein the communication circuit is coupled to the maximum power point tracking circuit, wherein the communication circuit is further configured to perform at least one of sending the voltage reference value to the controller or forwarding, to the voltage processor, an instruction for adjusting the voltage reference value, and wherein the instruction is received from the controller.
11 . The power converter analog chip of claim 6 , wherein the communication circuit is coupled to the maximum power point tracking circuit, wherein the communication circuit is further configured to perform at least one of sending at least one of the preset coefficient, the voltage preset value, or the voltage reference value to the controller or forwarding, to the voltage processor, an instruction for adjusting at least one of the preset coefficient, the voltage preset value, or the voltage reference value, and wherein the instruction is received from the controller.
12 . The power converter analog chip of claim 3 , wherein the communication circuit is connected to the protection circuit, and wherein the communication circuit is further configured to: send the first preset threshold and the protection signal to a controller; receive, from the controller, a protection adjustment instruction; and send the protection adjustment instruction to the protection circuit, wherein the protection adjustment instruction enables the protection circuit to adjust the first preset threshold or the protection signal.
13 . The power converter analog chip of claim 1 , wherein the control signal enables the power converter analog chip to be configured to control the power converter to perform a pulse-by-pulse current limit or control the power converter to be disabled.
14 . The power converter analog chip of claim 1 , wherein when communication between the rapid shutdown module and the controller is abnormal, the rapid shutdown circuit is configured to: generate the rapid shutdown signal; and send the rapid shutdown signal to the multiplexer.
15 . The power converter analog chip of claim 1 , wherein when the control signal is the rapid shutdown signal, the control signal enables the power converter analog chip be configured to control the power converter to rapidly discharge or to be disabled.
16 . The power converter analog chip of claim 3 , further comprising a curve scanning circuit, wherein the curve scanning circuit is configured to: generate a curve scanning start signal based on a scanning instruction; and send the curve scanning start signal to the multiplexer, wherein the multiplexer is further configured to: select the control signal from one of the rapid shutdown signal, the protection signal, the curve scanning start signal, or the adjustment signal in descending order of priority; and control the power converter to perform curve scanning on the input voltage and an input current when the curve scanning start signal is used as the control signal or perform curve scanning on the output voltage and an output current when the curve scanning start signal is used as the control signal.
17 . The power converter analog chip of claim 16 , wherein the communication circuit is coupled to the curve scanning circuit, and wherein the communication circuit is configured to: send the curve scanning start signal and a curve scanning mode of the curve scanning circuit to the controller; and send, to the curve scanning circuit, a scanning adjustment instruction from the controller, wherein the scanning adjustment instruction enables the curve scanning circuit to adjust the curve scanning mode and the curve scanning start signal.
18 . A power converter, comprising: a power conversion circuit comprising: an input end configured to couple to a photovoltaic module; and an output end configured to couple to a combiner box or an inverter; and an analog chip coupled to the power conversion circuit, wherein the analog chip is configured to output a control signal to the power converter, and wherein the analog chip comprises: a sampling circuit configured to receive electrical parameters from a power converter; a maximum power point tracking circuit coupled to the sampling circuit, wherein the maximum power point tracking circuit is configured to: obtain at least one of input power of the power converter or output power of the power converter based on the electrical parameters; perform maximum power point tracking based on the input power of the power converter or the output power to obtain an adjustment signal; and send the adjustment signal; a protection circuit coupled to the sampling circuit, wherein the protection circuit is configured to: generate a protection signal when an electrical parameter of the power converter exceeds a first preset threshold; and send the protection signal; a rapid shutdown circuit configured to: receive a rapid shutdown instruction; generate a rapid shutdown signal based on the rapid shutdown instruction; and send the rapid shutdown signal; and a multiplexer coupled to the maximum power point tracking circuit, the protection circuit, and the rapid shutdown circuit, wherein the multiplexer is configured to: receive the rapid shutdown signal from the rapid shutdown circuit; receive the protection signal from the protection circuit; receive the adjustment signal from the maximum power point tracking circuit; select from one of the rapid shutdown signal, the protection signal, or the adjustment signal as a control signal; and control a power component in the power converter using the control signal.
19 . The power converter to claim 18 , wherein the multiplexer is further configured to: further select the control signal from one of the rapid shutdown signal, the protection signal, or the adjustment signal according to a descending order of their priorities; and control the power component using the control signal.
20 . The power converter of claim 18 , further comprising a communication circuit coupled to the rapid shutdown circuit and to the sampling circuit, wherein the communication circuit is configured to: forward, to the rapid shutdown circuit, the rapid shutdown instruction; and send the electrical parameters to a multiplexer, and wherein the multiplexer is configured to monitor operation of the power converter based on the electrical parameters.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to Chinese Patent Application No. 202111194553.1, filed on Oct. 13, 2021, which is hereby incorporated by reference in its entirety. TECHNICAL FIELD This application relates to the field of photovoltaic power generation technologies, and in particular, to a power converter analog chip and a power converter. BACKGROUND The photovoltaic power generation system usually includes a photovoltaic module and a power converter. The photovoltaic module can convert solar energy into electric energy. Currently, the photovoltaic module includes a plurality of photovoltaic substrings, and each photovoltaic substring includes a plurality of photovoltaic cells. A plurality of photovoltaic modules may be connected in series or in parallel to form a photovoltaic array. A diode is connected between two ends of each photovoltaic substring of the photovoltaic module in parallel. When the photovoltaic sub string cannot output enough currents due to shadow shielding, the diode may bypass the photovoltaic substring, and currents of the other photovoltaic substrings can flow through the diode, to ensure that the other photovoltaic substrings can continue generating power. However, in this manner, the diode completely bypasses the shielded photovoltaic substring. Consequently, the shielded photovoltaic sub string completely cannot generate power, causing a waste of a power generation capability of the photovoltaic substring. In order that a photovoltaic substring can continue generating power when being shielded, a power converter may be connected between two ends of the photovoltaic substring or two ends of the photovoltaic module, to replace the parallel diode with the power converter. When the photovoltaic substring is shielded by a shadow, an output current of the photovoltaic substring decreases but can still output power. The power converter may convert the output power of the photovoltaic substring, and adjust an output current of the power converter to a current equal to those of the other photovoltaic substrings or power converters connected to the photovoltaic substrings, to improve power generation efficiency of the entire photovoltaic power generation system. Currently, the power converter is controlled by a digital chip. However, if there is a relatively large quantity of photovoltaic substrings in the photovoltaic power generation system, a relatively large quantity of power converters is also required. If each power converter requires one digital chip, a relatively large quantity of digital chips is required. Consequently, costs of the entire photovoltaic power generation system are relatively high. SUMMARY To resolve the foregoing technical problem, this application provides a power converter analog chip and a power converter, to control working of the power converter, thereby reducing costs of a photovoltaic power generation system. This application provides a power converter analog chip, configured to control working of a power converter. In an example, the analog chip may control a switching status of a power component in the power converter. This application provides an example in which the power converter is applied to a photovoltaic system. The analog chip includes a sampling circuit, a maximum power point tracking circuit, a protection circuit, a rapid shutdown circuit, and a multiplexer. The sampling circuit collects electrical parameters of the power converter, where an input end of the power converter is configured to be connected to a photovoltaic module. The maximum power point tracking circuit obtains input power and/or output power of the power converter based on the electrical parameters, and performs maximum power point tracking based on the input power or the output power, to obtain an adjustment signal and send the adjustment signal to the multiplexer. When receiving a rapid shutdown instruction sent from the outside of the analog chip, the rapid shutdown circuit generates a rapid shutdown signal and sends the rapid shutdown signal to the multiplexer. When an electrical parameter of the power converter exceeds a first preset threshold, the protection circuit generates a protection signal and sends the protection signal to the multiplexer. The multiplexer selects one of the rapid shutdown signal, the protection signal, or the adjustment signal as a control signal, to control the power component in the power converter. The electrical parameters may include an input voltage, an input current, an output voltage, an output current, and a temperature of the power converter. The electrical parameters collected by the sampling circuit are sent to both the maximum power point tracking circuit and the protection circuit. The circuits in the analog chip provided in this application are all built by using analog circuits, that is, the analog chip is implemented by using an analog integrated circuit, and processes an analog signal. The analo