Temperature control system for fuel cell electric vehicle cooling circuit

A fuel cell powered vehicle comprising:

• a fuel cell system serving as a power source;
• an electric drive train powered by the fuel cell system;
• a plurality of electronic components;
• and
• a temperature control system for the fuel cell system and plurality of electronic components, the fuel cell system and the electronic components each having optimal temperature operating limits, the control system including
• sensors to determine temperature of the fuel cell system,
• sensors to determine temperature of each of the electronic components,
• a high temperature cooling circuit to cool the fuel cell system,
• a low temperature cooling circuit to cool the electronic components,
• a variable speed fan for cooling coolant flowing in the high and low temperature cooling circuits,
• a variable position radiator bypass valve for controlling the flow of coolant in the high temperature cooling circuit, and
• a controller for simultaneously and separately controlling the high and low temperature cooling circuits to maintain optimal operating temperature limits of both the fuel cell system and the electronic components, the controller including overshoot and undershoot compensation based on controller preset action and a logic circuit for coordinating the operation of the fan with the bypass valve such that the speed of the fan is dependent on the operating position of the bypass valve.

A method of controlling temperature of a fuel cell system and a plurality of electronic components in a fuel cell vehicle, the fuel cell system and the electronic components each having optimal temperature operating limits, comprising the steps of:

• determining temperature of the fuel cell system;
• determining temperature of each of the electronic components;
• and
• controlling simultaneously and separately a high temperature cooling circuit to cool the fuel cell system and
• a low temperature cooling circuit to cool the electronic components to maintain optimal operating temperature limits of both the fuel cell system and the electronic components, including overshoot and undershoot compensation based on controller preset actions and
• controlling the operating position of a variable position bypass valve used to control the flow of coolant in the high temperature cooling circuit, and
• controlling the speed of a fan used to cool coolant flowing in the high and low temperature cooling circuits based on the operating position of the bypass valve.

A temperature control system for a fuel cell vehicle having a fuel cell system and a plurality of electronic components, the fuel cell system and the electronic components each having optimal temperature operating limits, comprising:

• sensors to determine temperature of the fuel cell system;
• sensors to determine temperature of each of the electronic components;
• and
• a controller to simultaneously and separately control a high temperature cooling circuit to cool the fuel cell system and a low temperature cooling circuit to cool the electronic components, the controller maintaining optimal operating temperature limits of both the fuel cell system and the electronic components, the controller including
• (a) a first fast response controller to maintain a coolant at a high temperature coolant circuit fuel cell system inlet to a first predetermined coolant temperature,
• (b) a second fast response controller to maintain the coolant temperature difference between a high temperature coolant circuit fuel cell system outlet and the high temperature coolant circuit fuel cell system inlet to a second predetermined coolant value, and
• (c) a third fast response controller to maintain the coolant temperature within a low temperature coolant circuit to a third predetermined coolant temperature when coolant temperature exceeds the third predetermined temperature,
• wherein the fast response controllers are proportional integral controllers.

A temperature control system for a fuel cell vehicle having a fuel cell system and a plurality of electronic components, the fuel cell system and the electronic components each having optimal temperature operating limits, comprising:

• sensors to determine temperature of the fuel cell system;
• sensors to determine temperature of each of the electronic components;
• and
• a controller to simultaneously and separately control a high temperature cooling circuit to cool the fuel cell system and a low temperature cooling circuit to cool the electronic components, the controller maintaining optimal operating temperature limits of both the fuel cell system and the electronic components, the controller using feed-forward disturbance compensation to reduce coolant temperature spikes comprising measured signals for fuel cell output power and vehicle speed, and control strategies to reduce coolant temperature dynamic control errors, and control errors caused by a bypass valve dead-zone effect, the control strategies including overshoot compensation and undershoot compensation based on controller preset actions.

A temperature control system for a fuel cell vehicle having a fuel cell system and a plurality of electronic components, the fuel cell system and the electronic components each having optimal temperature operating limits, comprising:

• sensors to determine temperature of the fuel cell system;
• sensors to determine temperature of each of the electronic components;
• and
• a controller to simultaneously and separately control a high temperature cooling circuit to cool the fuel cell system and a low temperature cooling circuit to cool the electronic components, the controller maintaining optimal operating temperature limits of both the fuel cell system and the electronic components, the controller including
• (a) a first fast response controller to maintain a coolant at a high temperature coolant circuit fuel cell system inlet to a first predetermined coolant temperature, and to control bypass valve position and fan speed, the first fast response controller controlling, in sequence, the bypass valve position until fully opened to deliver coolant to a first radiator, then flip-flops to fan speed control, then flip flops back to bypass valve position control if the commanded fan speed reaches a lower limit or if the third fast response controller is activated when a second radiator inlet temperature exceeds an upper limit,
• (b) a second fast response controller to maintain the coolant temperature difference between a high temperature coolant circuit fuel cell system outlet and the high temperature coolant circuit fuel cell system inlet to a second predetermined coolant value, and to control pump speed, and
• (c) a third fast response controller to control fan speed and to maintain the coolant temperature within a low temperature coolant circuit to a third predetermined coolant temperature when coolant temperature exceeds the third predetermined temperature.

A method of controlling temperature of a fuel cell system and a plurality of electronic components in a fuel cell vehicle, the fuel cell system and the electronic components each having optimal temperature operating limits, comprising the steps of:

• determining temperature of the fuel cell system;
• determining temperature of each of the electronic components;
• and
• controlling simultaneously and separately a high temperature cooling circuit to cool the fuel cell system and a low temperature cooling circuit to cool the electronic components to maintain optimal operating temperature limits of both the fuel cell system and the electronic components, the step of controlling the cooling circuits being performed by
• (a) controlling a first fast response proportional integral controller to maintain a coolant at a high temperature coolant circuit fuel cell system inlet to a first predetermined coolant temperature,
• (b) controlling a second fast response proportional integral controller to maintain the coolant temperature difference between a high temperature coolant circuit fuel cell system outlet and the high temperature coolant circuit fuel cell fuel cell system inlet to a second predetermined coolant value, and
• (c) controlling a third fast response proportional integral controller to maintain the coolant temperature within the low temperature coolant circuit to a third predetermined coolant temperature when coolant temperature exceeds the third predetermined temperature.

A method of controlling temperature of a fuel cell system and a plurality of electronic components in a fuel cell vehicle, the fuel cell system and the electronic components each having optimal temperature operating limits, comprising the steps of:

• determining temperature of the fuel cell system;
• determining temperature of each of the electronic components;
• and
• controlling simultaneously and separately a high temperature cooling circuit to cool the fuel cell system and a low temperature cooling circuit to cool the electronic components to maintain optimal operating temperature limits of both the fuel cell system and the electronic components, the step of controlling the cooling circuits being performed by
• (a) compensating feed-forward disturbance to reduce coolant temperature spikes comprising measuring signals for fuel cell output power and vehicle speed,
• (b) reducing coolant temperature dynamic control errors by overshooting compensation and undershooting compensation based on controller preset actions, and
• (c) controlling errors caused by a bypass valve dead-zone effect.

A method of controlling temperature of a fuel cell system and a plurality of electronic components in a fuel cell vehicle, the fuel cell system and the electronic components each having optimal temperature operating limits, comprising the steps of:

• determining temperature of the fuel cell system;
• determining temperature of each of the electronic components;
• and
• controlling simultaneously and separately a high temperature cooling circuit to cool the fuel cell system and a low temperature cooling circuit to cool the electronic components to maintain optimal operating temperature limits of both the fuel cell system and the electronic components, the step of controlling the cooling circuits being performed by
• (a) controlling a first fast response controller to maintain a coolant at a high temperature coolant circuit fuel cell system inlet to a first predetermined coolant temperature,
• (b) controlling a second fast response controller to maintain the coolant temperature difference between a high temperature coolant circuit fuel cell system outlet and the high temperature coolant circuit fuel cell fuel cell system inlet to a second predetermined coolant value, and
• (c) controlling a third fast response controller to maintain the coolant temperature within the low temperature coolant circuit to a third predetermined coolant temperature when coolant temperature exceeds the third predetermined temperature,
• wherein the first fast response controller controls bypass valve position and fan speed, the second fast response controller controls pump speed, and the third fast response controller controls fan speed.

A temperature control system for a fuel cell vehicle having a fuel cell system and a plurality of electronic components, the fuel cell system and the electronic components each having optimal temperature operating limits, comprising:

• sensors to determine temperature of the fuel cell system;
• sensors to determine temperature of each of the electronic components;
• and
• a controller to simultaneously and separately control a high temperature cooling circuit to cool the fuel cell system and a low temperature cooling circuit to cool the electronic components, the controller maintaining optimal operating temperature limits of both the fuel cell system and the electronic components, the controller including overshoot and undershoot compensation based on controller preset actions for reducing coolant temperature control errors.

A method of controlling temperature of a fuel cell system and a plurality of electronic components in a fuel cell vehicle, the fuel cell system and the electronic components each having optimal temperature operating limits, comprising the steps of:

• determining temperature of the fuel cell system;
• determining temperature of each of the electronic components;
• and
• controlling simultaneously and separately a high temperature cooling circuit to cool the fuel cell system and a low temperature cooling circuit to cool the electronic components to maintain optimal operating temperature limits of both the fuel cell system and the electronic components, the step of controlling the cooling circuits including reducing coolant temperature dynamic control errors by overshooting compensation and undershooting compensation based on present controller actions.