JP5757225B2 - Electric vehicle power equipment cooling device - Google Patents

Description

  The present invention relates to a cooling device corresponding to the enhancement of cooling capacity of electric power equipment accompanying improvement in performance of an electric vehicle.

  Conventionally, cooling of transistors and the like of power conversion means in electric vehicles has been widely adopted by air cooling with a simple configuration. In such a case, there is a tendency to increase the output of the power conversion means in order to improve the performance of the electric vehicle, and it is necessary to enlarge the heat sink or fan of the air cooling means as a measure for enhancing the cooling capacity. However, the increase in size of the heat sink and the fan has caused the problem that the size of the power conversion means and the noise increase.

  There exists patent document 1 as what solves the said problem. The technology disclosed in Patent Document 1 relates to a water-cooled cooling device having a unified system that can cool each power conversion means provided in an electric vehicle more efficiently than air-cooled cooling.

  In the air-cooling type cooling device, each of the individual power conversion means is provided with an independent air-cooling device having a simple configuration. On the other hand, according to the technique disclosed in Patent Document 1, the cooling system of all the power conversion means is provided. Since the water-cooled cooling system with the unified circulating cooling water is used, it can be constituted by a pair of circulating devices and a heat exchanger, and the water-cooling device can be downsized.

JP-A-4-275492

  By the way, the output required for a general vehicle in various driving situations is a running resistance of less than 15 kW at a constant speed of 60 km / h, and is about 30 w or less even at 100 km / h. The most necessary output in the 10, 15 mode, which is the standard driving pattern, is when accelerating to 50 km / h of No. 2 in the 15 mode (18 seconds), but even in that case it is about 20 kW. . Even a conventional EV vehicle having a maximum output by air cooling of less than 30 kw can run in the 10, 15 mode, and can run at a speed of 100 km / h.

  Thus, in reality, an output of about 100 kW is not continuously required in general driving of a car. A scene where the accelerator pedal is kept fully open to output about 100 kW is limited to an extremely short time (several seconds) such as overtaking on an expressway. Since the technology disclosed in Patent Document 1 is a cooling device that can continuously cope with such a maximum load that has only an extremely short time in practice, it has sufficient remaining power in consideration of the case where all the cooling systems are circulated. Requires a high power pump. For this reason, the cooling device disclosed in Patent Document 1 is over-spec, is wasteful, increases cost and size, and adds a lot of piping and valves, which complicates the device. Moreover, since valve control becomes complicated, a new development of the control system is required. Furthermore, the radiator that cools the cooling water requires a fan having more powerful and sufficient wind power in preparation for a low vehicle speed or a stop when the traveling wind cannot be obtained.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a low-cost, small and simple cooling device that is necessary and sufficient according to the load of the power equipment. .

In order to achieve the above object, the invention according to claim 1 is a cooling device for water-cooling a power device of an electric vehicle by heat of vaporization, the air-cooling mechanism of the power device being disposed in the vicinity of the power device. Whether to respond to the heat generation state of the electric power device, a water benefit portion that provides cooling water, a tank that stores the cooling water, a pumping portion that pressurizes the cooling water in the tank and pumps it to the water benefit portion Or a controller that predicts heat generation and controls the opening and closing of the water benefit unit, and a cooling fan that blows air to the power device and cools it, and the controller determines the necessity of cooling the power device. And determining that the necessity for cooling is the first degree, the control is performed to drive the cooling fan, and the necessity for cooling is less than the first degree. Determined to be a high second degree If, and performs control to benefit the cooling water from the water benefit unit to air cooling mechanism of the power equipment.

According to this configuration, the cooling water stored in the tank is pressurized and pumped to the water benefit unit, and the controller responds to the heat generation state of the power equipment or predicts the heat generation state to control the opening and closing of the water benefit unit. When the controller determines that the necessity for cooling is the first level, control is performed to drive a cooling fan that blows air to the power equipment and performs cooling. When it is determined that the second degree is higher than the first degree, the water benefit unit performs control to provide cooling water to the air cooling mechanism of the electric power device. As a result, it has an excellent effect that it can be locally cooled by providing cooling water from the water benefit section only to electric power equipment that is practically high load only for an extremely short time and is insufficiently cooled by air cooling with a cooling fan. Play. Moreover, the electric device cooling device for an electric vehicle has an excellent effect that it can be obtained by adding a simple and small water cooling mechanism to an existing air cooling mechanism at low cost.

  The invention described in claim 2 is characterized in that the controller determines and controls the necessity of cooling based on temperature information transmitted from the power device.

  According to this configuration, an unnecessary cooling action can be prevented, and the cooling device can be used efficiently.

  The invention according to claim 3 is characterized in that the controller selectively controls air cooling or water cooling based on temperature information transmitted from the power device.

  According to this configuration, necessary and sufficient cooling can be performed in accordance with the load of the power equipment.

The invention according to claim 4 is characterized in that the controller determines whether or not cooling of the power device can be handled by water cooling based on temperature information transmitted from the power device. To do.

  According to this configuration, overheating of the power device can be prevented, and the safety of the electric vehicle can be ensured.

  The invention according to claim 5 is characterized in that the water benefit section is opened and closed based on the operation amount of the driving controller.

  According to this configuration, since excessive heat generation is predicted and water-cooled in advance by an operation requiring an excessive load, effective cooling can be performed.

The invention according to claim 6, wherein the tank, characterized in that the window pretensions over or a tank which is used in a headlight washer

  According to this configuration, the tank can be made in the right place for the right material, and the cooling device can be reduced in size, simplified, and reduced in cost.

It is a schematic block diagram which shows the structure of the electric power equipment cooling device which concerns on an Example with the main structure part of an electric vehicle. It is a flowchart figure which shows operation | movement of the cooling device of an Example.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, since the power equipment cooling apparatus 1 is shown together with main components of the electric vehicle, first, an outline of the main components of the known electric vehicle will be described.

  The AC power source 2 is a power source provided outside, and is connected to the electric vehicle by the connector 3. The electric vehicle is provided with a charger 4 that receives power from the AC power source 2, and the charger 4 rectifies the power from the AC power source 2 to charge the main battery 5. The electric power of the main battery 5 is converted into a three-phase alternating current by the inverter 6 and supplied to a three-phase motor that is a drive motor to drive the electric vehicle.

  The main battery 5 is also connected to the auxiliary battery 8 via the DC-DC converter 7, and the electric power of the main battery 5 is dropped to a predetermined voltage by the DC-DC converter 7. Charging is performed, and power is supplied from the DC-DC converter 7 to the auxiliary load.

  The charger 4, the inverter 6 and the DC-DC converter 7 as power devices are provided with fans 15, 16 and 17 for cooling them. Each of these cooling fans 15, 16, and 17 is attached to the component of each electric power apparatus, and is performing the cooling effect | action by each ventilation. The wind introduction structures 18 to 21 are for effectively introducing traveling wind into the electric power equipment. Note that these power devices have a waterproof structure equivalent to that of water and can sufficiently withstand the injection of cooling water.

  The electric power equipment cooling device 1 is provided in the vicinity of the inverter 6 that is the electric power equipment and is provided in the motor 9 that is provided in the vicinity of the heat sink that is the air cooling mechanism provided in the inverter 6 and the motor 9 that is the electric power equipment. Water injection nozzles 12 and 13 that are water benefit units that provide cooling water to the fins that are air cooling devices, a tank 10 that stores cooling water, and pressurizing the cooling water in the tank 10 to the water injection nozzles 12 and 13. It comprises a pump 11 which is a pumping unit for pumping, and a controller 14 which controls the opening and closing of the water benefit unit according to the heat generation state of the inverter 6 and the motor 9 or predicting the heat generation state.

  The tank 10 may be of any shape and material as long as it can store cooling water. For example, a tank for a window washer may be shared. In that case, it is also possible to use a washer liquid as cooling water. Further, a long life coolant may be used instead of the washer liquid. Further, a sensor is provided in the tank 10 and its signal is input to the controller 14, and the controller 14 judges whether or not the cooling water is insufficient and gives an alarm, or transmits a signal to the engine control unit 23 to limit the output. It may be.

  As the pump 11, a window washer pump or a headlight washer pump can be suitably employed. Note that the pressure feeding unit is not an electric one such as a window washer pump or a headlight washer pump, but may be a pressure accumulating mechanism in which a person steps on the pedal to increase the output of the electric motor in conjunction with the simple pump mechanism. . Moreover, you may utilize the water head difference of a tank and a water benefit part. In that case, the water benefit section is not a water injection nozzle 12 but a simple pipe end, and includes only an opening / closing valve for dropping cooling water instead of jetting and supplying or blocking the cooling water. Further, the inverter device has a basic hermetic structure, and internal elements and the like generate heat due to a change in output, and the temperature rises and falls. At this time, since the pressure also changes at the same time, it is possible to use this action to operate the one-way pump and simply generate the accumulated pressure so that no new electric power or power is required.

  The water injection nozzles 12 and 13 have a function of receiving or transmitting the cooling water by receiving a signal transmitted from the controller 14, and when the signal is ON, the cooling water is diffused from a tip thereof to a relatively wide range. Are to be injected. However, as described above, when the pressure of the pumping unit is not sufficient, the water injection nozzle may have a simple pipe terminal shape so that the cooling water can be dropped without being injected.

  The controller 14 performs calculations and determinations as shown in the flowchart of FIG. 2 to control the water injection nozzles 12 and 13. The controller 14 may be provided independently independently, or may be shared with a control unit of another device such as an auxiliary machine.

  The operation of the power equipment cooling device 1 will be described with reference to FIG.

  Respective temperature information is received from the inverter 6 and the motor 9 (S1). The subsequent steps are executed for each power device of the inverter 6 and the motor 9. The required cooling capacity is calculated based on the temperature information (S2). The cooling required capacity is expressed by a torque value or a current value, and is obtained from a map of the correlation between the temperature and output of the power device corrected by the ambient temperature. The necessity of cooling is determined based on the calculated cooling required capacity (S3), and when it is determined that cooling is unnecessary or small, nothing is done and natural air cooling or running wind cooling is performed (S4). That is, in general, when the vehicle is traveling, the output is about 10 kw when traveling at a constant speed of about 50 km / h. When it is determined in S3 that cooling is necessary, the necessity for cooling is further determined based on a higher level of required cooling capacity (S5), and when it is determined that cooling is moderately required, the controller 14 corresponds to the power equipment. The cooled cooling fan is driven (S6). That is, if the vehicle is generally accelerated from a stationary state or cruising on a highway at a constant speed, the cooling capacity by the fan is increased to assist cooling. When it is determined in S5 that cooling is very necessary, it is determined whether or not it is possible to cope with water injection (S7), and when it is determined that it is possible to cope with water injection, water injection is started (S8). That is, when more than 100 kW or the like is required during high-speed traveling, cooling water is jetted according to the heat generation status of the electric power equipment to cope with high-speed cooling for a short time. When it is determined in S7 that water injection is not possible, the controller 14 transmits a signal to the engine control unit 23 to start output restriction (S9).

  Here, the cooling performance in water injection, which is the basis for the above determination, will be described.

  The heat of vaporization of water is 2454 KJ / kg (586.2 kcal / kg) at 20 ° C. Based on this, the ability of water jet cooling at an output of 100 kW is simulated assuming overtaking during high speed driving.

  From the above constant, if 1 g of water is efficiently sprayed onto a heat sink such as an inverter, evaporated and used for cooling, cooling of 2.45 KJ = 2.45 kw × 1 second is possible. Since the efficiency of the average output 100 kw class inverter is about 95% or more, if the output is 100 kw, the loss is 5 kw, and cooling is possible with the water injection of about 2 g / sec. If an output state of about 100 kW for about 5 seconds is required for overtaking, 10 g of water is required for one overtaking. Assuming that the capacity of the water tank is about 2 L corresponding to the window washer liquid capacity, it is possible to cope with cooling equivalent to 200 overtakings. Therefore, it is considered that it is not necessary to replenish the cooling water frequently in practice. A water injection device of about 2 g per second is at a level that can be adequately handled by a pump system of a headlight washer that has a smaller injection amount than a window washer.

  As described above, the controller 14 controls the opening and closing of the water benefit unit according to the heat generation state of the power device. However, the controller 14 can also control the opening and closing of the water benefit section by predicting the heat generation state of the power device. That is, when the operating device 22 such as an accelerator or a brake is suddenly operated to give an operation amount equal to or greater than a predetermined value, the controller 14 determines that and determines the amount of time corresponding to the excess amount exceeding the predetermined value. It is controlled to open the water benefit department. The inverter 6 generates heat when accelerating by operating the accelerator, and generates heat by current due to regenerative braking when stopping by operating the brake.

  As is clear from the above detailed description, the power equipment cooling apparatus 1 of the present embodiment is a heat sink that is an air cooling mechanism provided in the inverter 6 and is provided in the vicinity of the inverter 6 that is the power equipment, and the power equipment. Water jet nozzles 12 and 13 that are water benefit portions that provide cooling water to fins that are air-cooling devices provided in the motor 9 and are disposed in the vicinity of a motor 9, a tank 10 that stores cooling water, and a tank The pump 11 serving as a pumping unit that pressurizes 10 cooling water and pumps it to the water injection nozzles 12 and 13 and the heat generating state of the inverter 6 and the motor 9 according to the heat generation state or predicting the heat generation state, the water benefit unit is controlled to open and close And a controller 14 for Since it comprised in this way, the electric power equipment cooling device 1 of this embodiment can locally cool only the inverter 6 etc. which are actually high-load only for an extremely short time and are insufficiently cooled by air cooling, This provides an excellent effect of realizing necessary and sufficient cooling in accordance with the load of the power equipment in a compact, simple and low cost.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention. For example, although the inverter 6 and the motor 9 are cited as the power equipment, it goes without saying that the present invention can be applied to the DC-DC converter 7 and the like.

DESCRIPTION OF SYMBOLS 1 Electric power equipment cooling device 5 Main battery 6 Inverter 9 Motor 10 Tank 11 Pump (pressure feed part)
12,13 Water jet nozzle (Water Benefit Department)
14 Controller 15-17 Fan 22 Operation Controller 23 Engine Control Unit

Claims (6)

A cooling device that cools electric vehicle power equipment by heat of vaporization,
A water benefit unit that is disposed in the vicinity of the power device and that provides cooling water to an air cooling mechanism of the power device; and
A tank for storing the cooling water;
A pumping unit that pressurizes the cooling water of the tank and pumps it to the water benefit unit;
A controller for controlling opening and closing of the water benefits unit predicts Ozuru or heat generation state in the heat generation state of the power device,
A cooling fan that blows and cools the power equipment;
With
The controller includes a determination unit that determines the necessity of cooling of the electric power device, and controls the driving of the cooling fan when the determination unit determines that the necessity of cooling is the first degree. And when the necessity for cooling is determined to be a second degree higher than the first degree, the water benefit unit performs control to provide cooling water to the air cooling mechanism of the power device. A power equipment cooling device for an electric vehicle.   The power device cooling apparatus for an electric vehicle according to claim 1, wherein the controller determines and controls whether cooling is necessary based on temperature information transmitted from the power device.   The electric device cooling of the electric vehicle according to claim 1, wherein the controller selectively controls air cooling or water cooling based on temperature information transmitted from the electric power device. apparatus. 4. The control device according to claim 1 , wherein the controller determines whether or not cooling of the power device can be supported by water cooling based on temperature information transmitted from the power device. 5. The electric device cooling apparatus for an electric vehicle according to Item 1.   The electric device cooling apparatus for an electric vehicle according to claim 1, wherein the controller opens and closes the water benefit unit based on an operation amount of a driving operation device. The tank, window pretensions over or power device cooling apparatus for an electric vehicle according to any one of claims 1 to 5, characterized in that a tank is used in headlights washer.

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