System and method for diagnosing state of cooling water

A system for diagnosing a cooling water state, comprising:

• an inverter configured to provide power to a cooling water pump;
• a speed controller configured to generate an output current instruction value of the inverter based on a difference between a speed instruction value of the cooling water pump and an actual speed measurement value of the cooling water pump;
• a speed controller model unit configured to generate a current instruction estimation value to predict an output current of the inverter based on a difference between the speed instruction value and a speed estimation value to predict a speed of the cooling water pump;
• a pump speed prediction model unit configured to generate the speed estimation value based on the current instruction estimation value;
• and
• a pump state diagnosing unit configured to compare the current instruction estimation value and the output current instruction value to diagnose a circulation state of the cooling water.

A method for diagnosing a cooling water state applied to a cooling water pump control system having an inverter configured to provide power to a cooling water pump and a speed controller configured to generate an output current instruction value of the inverter based on a difference between a speed instruction value of the cooling water pump and an actual speed measurement value of the cooling water pump, the method comprising:

• generating, by a pump speed prediction model unit, a speed estimation value to predict a speed of the cooling water pump based on the output current instruction value;
• calculating, by a pump state diagnosing unit, a ratio of the speed estimation value over an actual speed measurement value of the cooling water pump multiple times;
• calculating, by the pump state diagnosing unit, a mean value of the calculated plurality of ratios;
• and
• determining, by the pump state diagnosing unit, a circulation state of the cooling water as abnormal when a state, in which the mean value is less than a preset reference value for normal circulation determination, continues in excess of a preset period of time.

A method for diagnosing a cooling water state applied to a cooling water pump control system having an inverter configured to provide power to a cooling water pump and a speed controller configured to generate an output current instruction value of the inverter based on a difference between a speed instruction value of the cooling water pump and an actual speed measurement value of the cooling water pump, the method comprising:

• generating, by a speed controller model unit modeling the speed controller, a current instruction estimation value to predict an output current of the inverter based on a difference between the speed instruction value and a speed estimation value to predict a speed of the cooling pump;
• generating, by a pump speed prediction model unit, the speed estimation value based on the current instruction estimation value;
• calculating, by a pump state diagnosing unit, a ratio of the output current instruction value over the current instruction estimation value multiple times for a preset period of time;
• calculating, by the pump state diagnosing unit, a mean value of the calculated plurality of ratios;
• and
• determining, by the pump state diagnosing unit, a circulation state of the cooling water as abnormal, when a state, in which the mean value is less than a preset reference value for normal circulation determination, is continued in excess of a preset period of time.