Power supply system and grid connection control method

Patent metadata

Field	Value
Publication number	US-12438371-B2
Application number	US-202418625478-A
Country	US
Kind code	B2
Filing date	Apr 3, 2024
Priority date	Jul 26, 2022
Publication date	Oct 7, 2025
Grant date	Oct 7, 2025

Abstract

A power supply system and a grid connection control method. The power supply system includes a power supply, an inverter, a transformer, a power station collection module, and an inverter collection control circuit. The inverter collection control circuit is configured to obtain an amplitude value and a frequency of an output voltage of the inverter, obtain an inverter power adjustment signal based on the amplitude value and the frequency of the output voltage, and control, based on the power station power adjustment signal and the inverter power adjustment signal, the inverter to output a target output power. Additionally, an output power of the inverter may be adjusted by using the power station collection module and the inverter collection control circuit. A structure is simple, and a control method is simple. This improves control precision and adjustment efficiency, reduces control time, and reduces control costs.

First claim

What is claimed is:

1. A power supply system, comprising:
a power supply,
an inverter,
a transformer,
a power station collection module, and
an inverter collection control circuit;
the power supply is connected to the transformer through the inverter, the transformer is connected to a power grid at a grid connection point, one end of the power station collection module is connected to the grid connection point, the other end of the power station collection module is connected to a first end of the inverter collection control circuit, a second end of the inverter collection control circuit is connected between the inverter and the transformer, and a third end of the inverter collection control circuit is connected to the inverter;
the power station collection module is configured to obtain an amplitude value and a frequency of a grid connection voltage at the grid connection point, and obtain a power station power adjustment signal based on the amplitude value and the frequency of the grid connection voltage; and
the inverter collection control circuit is configured to obtain an amplitude value and a frequency of an output voltage of the inverter, obtain an inverter power adjustment signal based on the amplitude value and the frequency of the output voltage, and control, based on the power station power adjustment signal and the inverter power adjustment signal, the inverter to output a target output power.

2. The power supply system according to claim 1 , wherein the inverter collection control circuit comprises an inverter collection module and a power adjustment module, a first end of the power adjustment module is used as the first end of the inverter collection control circuit and is connected to the power station collection module, one end of the inverter collection module is used as the second end of the inverter collection control circuit and is connected between the inverter and the transformer, the other end of the inverter collection module is connected to a second end of the power adjustment module, and a third end of the power adjustment module is used as the third end of the inverter collection control circuit and is connected to the inverter;
the inverter collection module is configured to obtain the amplitude value and the frequency of the output voltage of the inverter, obtain an inverter reactive power adjustment amount based on the amplitude value of the output voltage, obtain an inverter active power adjustment amount based on the frequency of the output voltage, and obtain the inverter power adjustment signal based on the inverter reactive power adjustment amount and the inverter active power adjustment amount; and
the power adjustment module is configured to generate an output power adjustment signal based on the power station power adjustment signal and the inverter power adjustment signal, and control, by using the output power adjustment signal, the inverter to output the target output power.

3. The power supply system according to claim 2 , wherein the power station power adjustment signal comprises a power station reactive power adjustment amount and a power station active power adjustment amount; and
the power station collection module is further configured to obtain the power station reactive power adjustment amount based on the amplitude value of the grid connection voltage, obtain the power station active power adjustment amount based on the frequency of the grid connection voltage, and output the power station reactive power adjustment amount and the power station active power adjustment amount to the inverter collection control circuit.

4. The power supply system according to claim 3 , wherein the power adjustment module further comprises an adjustment amount determining unit and a power control unit, the power control unit is connected to the inverter and one end of the adjustment amount determining unit, and the other end of the adjustment amount determining unit is connected to the inverter collection module
the adjustment amount determining unit is configured to obtain an output reactive power adjustment amount based on the power station reactive power adjustment amount and the inverter reactive power adjustment amount, obtain an output active power adjustment amount based on the power station active power adjustment amount and the inverter active power adjustment amount, and generate the output power adjustment signal based on the output reactive power adjustment amount and the output active power adjustment amount; and
the power control unit is configured to control, by using the output power adjustment signal, the inverter to output the target output power.

5. The power supply system according to claim 4 , wherein the inverter reactive power adjustment amount and the inverter active power adjustment amount satisfy:

d
2

⁢
Q
⁢
1
⁢

(
u
)

/

du
2

<
0

d
2

⁢
P
⁢
1
⁢

(
f
)

/

df
2

<
0

,

wherein Q1(u) is a function of the inverter reactive power adjustment amount about the amplitude value of the output voltage, d 2 Q1(u)/du 2 is a second derivative of the inverter reactive power adjustment amount about the amplitude value of the output voltage, P1(f) is a function of the inverter active power adjustment amount about the frequency of the output voltage, and d 2 P1(f)/df 2 is a second derivative of the inverter active power adjustment amount about the frequency of the output voltage.

6. The power supply system according to claim 5 , wherein the power station reactive power adjustment amount and the inverter active power adjustment amount satisfy:

d
2

⁢
Q
⁢
2
⁢

(
u
)

/

du
2

<
0

d
2

⁢
P
⁢
2
⁢

(
f
)

/

df
2

<
0

,

wherein

Assignees

• Huawei Digital Power Tech Co Ltd

Inventors

• Xu Fei
• Yu Xinyu
• Xin Kai
• Wang Shuchao

Classifications

• H02J2101/24

  Photovoltaics · CPC title

• H02J3/46

  Controlling the sharing of generated power between the generators, sources or networks · CPC title

• H02M7/44

  by static converters · CPC title

• H02J3/48

  Controlling the sharing of active power · CPC title

• H02J3/50

  Controlling the sharing of reactive power · CPC title