Automatic oil level retention system for compressor and method for controlling same

An automatic oil level retention system for a compressor, comprising:

• a compressor body (1), a first gas-liquid separator (2) and a low-pressure gas-liquid separator (3), wherein an outlet of the first gas-liquid separator (2) is connected to the compressor body (1) through a gas inlet pipe (4), an oil return hole (31) of the low-pressure gas-liquid separator (3) is connected to an inlet of the first gas-liquid separator (2) through a gas return pipe (5), and an inlet of the low-pressure gas-liquid separator (3) is provided with an inlet pipe (32) for being connected by a preset refrigeration system;
• and further comprising:
• an oil return auxiliary loop (6) and a liquid level detection unit (7), wherein an inlet and an outlet of the oil return auxiliary loop (6) are connected to a bottom of the low-pressure gas-liquid separator (3) and the inlet of the first gas-liquid separator (2), respectively, and wherein the liquid level detection unit (7) is disposed in an inner cavity of the first gas-liquid separator (2) and is configured to monitor lubricating oil liquid level conditions within the first gas-liquid separator (2) in real time,
• wherein the oil return auxiliary loop (6) comprises an oil return pipe (61) and an oil return valve (62) disposed on the oil return pipe (61),
• wherein the oil return valve (62) is opened or closed is in response the lubricating oil liquid level conditions.