Cooling system of power converter for on-vehicle rotary electric machine
First Claim
1. A cooling system of a power converter for an on-vehicle rotary electric machine comprising:
- a cooling circuit which has a circulation pump to circulate a coolant containing antifreeze solution and cools down, by using the coolant, a power element mounted in a power converter for an on-vehicle rotary electric machine;
a heat quantity calculation unit which calculates heat quantity generated by the power element;
a first temperature acquisition unit which acquires temperature of the power element;
a second temperature acquisition unit which acquires temperature of the coolant;
a heat transfer rate calculation unit which calculates, on the basis of the heat quantity, the temperature of the power element, and the temperature of the coolant, a heat transfer rate that is an amount of heat transferred from the power element to the coolant per unit temperature difference; and
a pump control unit which decreases an amount of the coolant discharged by the circulation pump when the heat transfer rate calculated is greater than a predetermined heat transfer rate reference, whereinthe heat quantity calculation unit calculates the heat quantity on the basis of torque information and speed information of a rotary electric machine.
2 Assignments
0 Petitions
Accused Products
Abstract
A cooling system includes a cooling circuit that has a circulation pump circulating a coolant containing antifreeze solution and cools down, by means of the coolant, a power element mounted in a power converter for an on-vehicle rotary electric machine; a control signal calculation unit that calculates heat quantity generated by the power element; a power element temperature sensor that detects the temperature of the power element; and a coolant temperature sensor that detects the temperature of the coolant. The control signal calculation unit calculates, on the basis of the heat quantity, the temperature of the power element, and the coolant temperature, power element cooling performance that is the amount of heat transferred from the power element to the coolant per unit temperature difference, and lowers the driving power of the circulation pump when the calculated power element cooling performance is greater than a predetermined criterion.
10 Citations
17 Claims
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1. A cooling system of a power converter for an on-vehicle rotary electric machine comprising:
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a cooling circuit which has a circulation pump to circulate a coolant containing antifreeze solution and cools down, by using the coolant, a power element mounted in a power converter for an on-vehicle rotary electric machine; a heat quantity calculation unit which calculates heat quantity generated by the power element; a first temperature acquisition unit which acquires temperature of the power element; a second temperature acquisition unit which acquires temperature of the coolant; a heat transfer rate calculation unit which calculates, on the basis of the heat quantity, the temperature of the power element, and the temperature of the coolant, a heat transfer rate that is an amount of heat transferred from the power element to the coolant per unit temperature difference; and a pump control unit which decreases an amount of the coolant discharged by the circulation pump when the heat transfer rate calculated is greater than a predetermined heat transfer rate reference, wherein the heat quantity calculation unit calculates the heat quantity on the basis of torque information and speed information of a rotary electric machine. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A cooling system of a power converter for an on-vehicle rotary electric machine comprising:
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a cooling circuit which has a circulation pump to circulate a coolant containing antifreeze solution and cools down, by using the coolant, a power element mounted in a power converter for an on-vehicle rotary electric machine; a heat quantity calculation unit which calculates heat quantity generated by the power element; a first temperature acquisition unit which acquires temperature of the power element; a second temperature acquisition unit which acquires temperature of the coolant; a heat transfer rate calculation unit which calculates, on the basis of the heat quantity, the temperature of the power element, and the temperature of the coolant, a heat transfer rate that is an amount of heat transferred from the power element to the coolant per unit temperature difference; a pump control unit which decreases an amount of the coolant discharged by the circulation pump when the heat transfer rate calculated is greater than a predetermined heat transfer rate reference; and a reference setting unit which sets the heat transfer rate reference in accordance with a level of the temperature of the power element acquired by the first temperature acquisition unit, wherein the second temperature acquisition unit sets the temperature of the coolant equal to the temperature of the power element acquired by the first temperature acquisition unit when the power element does not produce heat and when a predetermined time period has passed during which the power element has produced no heat, and the second temperature acquisition unit calculates the temperature of the coolant on the basis of the heat quantity generated by the power element that is calculated by the heat quantity calculation unit and the temperature of the power element that is acquired by the first temperature acquisition unit. - View Dependent Claims (10, 11, 12, 13)
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14. A cooling system of a power converter for an on-vehicle rotary electric machine comprising:
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a cooling circuit which has a circulation pump to circulate a coolant containing antifreeze solution and cools down, by using the coolant, a power element mounted in a power converter for an on-vehicle rotary electric machine; a heat quantity calculation unit which calculates heat quantity generated by the power element; a first temperature acquisition unit which acquires temperature of the power element; a second temperature acquisition unit which acquires temperature of the coolant; a heat transfer rate calculation unit which calculates, on the basis of the heat quantity, the temperature of the power element, and the temperature of the coolant, a heat transfer rate that is an amount of heat transferred from the power element to the coolant per unit temperature difference; and a pump control unit which decreases an amount of the coolant discharged by the circulation pump when the heat transfer rate calculated is greater than a predetermined heat transfer rate reference, wherein the second temperature acquisition unit sets the temperature of the coolant equal to the temperature of the power element acquired by the first temperature acquisition unit when the power element does not produce heat and when a predetermined time period has passed during which the power element has produced no heat, the second temperature acquisition unit calculates the temperature of the coolant on the basis of the heat quantity generated by the power element that is calculated by the heat quantity calculation unit and the temperature of the power element that is acquired by the first temperature acquisition unit, and the pump control unit increases an amount of the coolant discharged by the circulation pump when the heat transfer rate calculated is less than the predetermined heat transfer rate reference. - View Dependent Claims (15, 16, 17)
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Specification