JP4964637B2 - Inverter cooling system - Google Patents

Description

  The present invention relates to an inverter cooling device that circulates a coolant supplied from the outside to generate heat from an inverter unit of an inverter device and cools it by heat exchange.

  As a conventional inverter cooling apparatus, there exists a thing of a structure as shown in FIG.

  In FIG. 7, reference numeral 1 denotes an inverter device. This inverter device 1 includes a main circuit element (switching element IGBT) 3a in a case 2, a cooling fin 3b for cooling heat generated from the main circuit element 3a, and a capacitor 3c. An inverter unit 3 and an inverter control device 4 for controlling the main circuit element 3a in the inverter unit 3 are installed.

  In this case, the main circuit element 3a is connected to an input / output terminal 3d attached to one side surface of the case 2 by an electric wire 3e, and input / output is performed between an external power source and a load (not shown).

  On the other hand, as a cooling system of the inverter device 1 having such a configuration, the secondary side cooling pump 5 causes the secondary side cooling liquid (secondary side cooling water in this example) to enter the case 2 through the cooling water inflow side piping 6a. The secondary side cooling water that is introduced into the cooling fin 3b that exchanges heat with the main circuit element 3a of the installed inverter unit 3 and flows out of the inverter device 1 from the cooling fin 3b is passed through the cooling water outflow side pipe 6b. A secondary side cooling water circulation system returning to the secondary side cooling pump 5 through the secondary side of the external heat exchanger 7 is configured.

  In this case, the cooling water outflow side pipe 6b in front of the heat exchanger 7 is branched, the cooling water bypass pipe 6c is connected to the inflow side pipe of the secondary side cooling water pump 5, and the cooling water outflow side pipe 6b is connected. An electric three-way valve 8 is provided at the branch point.

  An inverter inlet cooling water temperature detector 9 for detecting the cooling water temperature on the inlet side of the case 2 is provided on the cooling water discharge port side of the secondary side cooling pump 5, and this inverter inlet cooling water temperature detector 9 is provided. The cooling water temperature detection signal detected in (2) is input to the secondary cooling water temperature control device 10.

  As shown in FIG. 8, the secondary-side cooling water temperature control device 10 compares the inverter input cooling water temperature detection signal 9a with the cooling water temperature set value 10a and adjusts the PID controller 10b so that the deviation value becomes zero. Thus, the opening degree of the electric three-way valve 7 is obtained, and the electric three-way valve 8 is controlled by this opening degree signal.

  Further, on the primary side of the heat exchanger 7, the primary side cooling water circulation system in which the primary side cooling water that exchanges heat with the secondary side cooling water by the primary side cooling pump 11 circulates through the primary side cooling water pipe 12. Is configured.

  The above is the configuration of the cooling water circulation system that flows in the cooling fin 3b that exchanges heat with the main circuit element 3a of the inverter unit 3. However, as the heating element of the inverter device 1, in addition to the above, the control device 4, the capacitor 3c, the electric wire 3e, etc. For these heating elements, there are an intake port 13 for taking outside air into the front surface of the case 2, and an exhaust gas for discharging the air sucked from the intake port 13 to the rear surface of the case 2 to the outside of the case 2. The air cooling system which comprises the opening | mouth 14 and radiates the heat which generate | occur | produced with the heat generating body with the ventilation fan which is not shown in figure is comprised.

  In the inverter system cooling system having such a configuration, if the secondary cooling pump 5 is operated at a constant speed by a commercial power source or the like, the secondary cooling water passes through the cooling water inflow side pipe 6a. It is introduced into the cooling fin 3b that exchanges heat with the main circuit element 3a of the inverter unit 3 installed in the case 2, and passes through the cooling water outflow side pipe 6b from the cooling fin 3b via the secondary side of the heat exchanger 7. Then, the secondary side cooling water circulation system returning to the secondary side cooling pump 5 is circulated.

  In this case, the secondary side cooling water temperature control device 10 has a zero deviation value between the secondary side cooling water temperature on the inlet side of the case 2 detected by the inverter inlet cooling water temperature detector 9 and the cooling water temperature set value. By controlling the opening degree of the electric three-way valve 8 so that a part of the secondary side cooling water flowing to the secondary side of the heat exchanger 7 is diverted through the cooling water bypass pipe 6c, the inverter inlet cooling water is The temperature is controlled.

  Therefore, the cooling fin 3b cools the heat generated by the switching of the main circuit element 3a by making physical contact with the main circuit element 3a, and the cooling fin 3b circulates in the secondary side cooling water circulation system. Heat exchange with cooling water.

  Further, when the cooling water whose temperature has been increased by cooling the cooling fins 3 b flows into the secondary side of the heat exchanger 7, heat exchange is performed with the cooling water circulating in the primary cooling water circulation system by the primary cooling water pump 11. Is exhausted to the outside.

  On the other hand, the heat generated in the inverter control device 4 other than the cooling fins in the inverter device 1, the capacitor 3c, the electric wire 3e, etc., takes outside air into the case 2 from the intake port 13 of the case 2, and cools these heating elements. Thereafter, the air is exhausted from the exhaust port 14 to the outside.

  Such a conventional inverter cooling apparatus has the following problems.

  If the cooling system of the inverter device as described above is used, the heat generation of the main circuit element (IGBT) 3a can be cooled by the cooling fin 3b. However, in the large-capacity inverter device, the inverter control device 4 other than the cooling fins. The heat generated in the condenser 3c, the electric wire 3e, etc. cannot be ignored, and the temperature in the case 2 rises only by the air cooling system in which the intake port 13 and the exhaust port 10 are simply provided in the case 2. . In particular, for capacitors and electronic components used in the inverter device 1, the failure rate increases at an accelerated rate when the temperature in the case 2 generally increases according to Arrhenius' law.

  Further, when high humidity air is taken into the case 2 from the air inlet 13 in a state where the temperature in the case 2 is high and the temperature of the cooling fin 3b is low, condensation occurs in the cooling fin 3b.

  For this reason, the temperature setting value of the secondary side cooling water flowing through the cooling fins 3b can be set to a value higher than the temperature in the case 2, and the secondary side cooling pump 5 can be cooled against heat generated during the rated operation of the inverter device 1. Thus, the rated operation is always performed, and the secondary side cooling water is supplied to the cooling fins 3b.

  However, since the secondary cooling pump 5 must be operated at the rated value even when the inverter device 1 is not rated, the power consumption required for the operation of the secondary cooling pump 5 increases, which is economically disadvantageous. It is.

  In addition, if the installation location of the inverter device is in a temperature environment that affects the inverter device 1, there is a difference between the internal temperature of the case 2 and the set temperature of the secondary cooling water, and the internal temperature of the case 2 is low However, there is a problem that condensation occurs on the cooling fin 2 and the device is damaged due to poor insulation.

  The present invention has been made to solve the above-described problems. The rotational speed of the secondary cooling pump is controlled in accordance with the output of the inverter device to reduce power consumption. It is an object of the present invention to provide an inverter cooling device capable of preventing condensation of cooling fins generated due to a temperature difference with air taken into a case.

  In order to achieve the above object, the present invention constitutes an inverter cooling device by the following means.

  The invention corresponding to claim 1 includes an inverter unit including a main circuit element and a cooling fin for cooling heat generated from the main circuit element in a case having an intake port and an exhaust port for ventilating outside air. As a cooling system of an inverter device provided with an inverter control device for controlling a main circuit element in the inverter unit, a cooling liquid is introduced into a cooling fin of the inverter unit in the case by the cooling pump, and the inverter is supplied from the cooling fin. The cooling liquid flowing out of the apparatus is heat-exchanged by a heat exchanger and returned to the cooling pump, and the flow path of the cooling liquid flowing into the heat exchanger is branched, and an electric motor provided at this branching point A coolant circulation system is constituted by a coolant bypass system that divides the coolant according to the opening of the three-way valve and returns it to the cooling pump, and the inverter unit In the inverter cooling device for cooling the heat generated from the inverter, a room temperature detector provided in the vicinity of the air inlet in the case, and an inverter for detecting the temperature of the coolant flowing into the inverter device from the cooling pump Obtain the dew point temperature from which the dew point is not dewed from the temperature detected by the inlet coolant temperature detector and the room temperature detector, and set the coolant temperature setter with this dew point temperature as the coolant set temperature, and this coolant temperature setter. A coolant that controls the temperature of the inverter inlet coolant by controlling the opening of the electric three-way valve based on the deviation between the set coolant temperature and the coolant temperature detected by the inverter inlet coolant temperature detector A temperature control device, and a function for calculating inverter loss based on inverter unit control and inverter unit drive conditions in the inverter control device. The pump speed setting device that obtains the pump speed based on the inverter loss calculated by this function and the coolant setting temperature obtained by the coolant temperature setting device, and the pump speed obtained by the pump speed setting device. And a pump driving inverter device for driving and controlling the cooling pump.

  The invention corresponding to claim 2 is the inverter cooling device of the invention corresponding to claim 1, wherein an inverter outlet coolant temperature detector for detecting the temperature of the coolant flowing out from the inverter device is provided, and this inverter outlet cooling water is provided. An actual coolant temperature rise value of the inverter device is obtained from the difference between the inverter outlet temperature of the coolant detected by the temperature detector and the inverter inlet temperature detected by the inverter inlet coolant room temperature detector, and the pump speed From the difference between the calculated value of the coolant temperature rise value of the inverter device and the actual temperature rise value from the pump speed and inverter loss determined by the setting device, the heat exchange rate or inverter loss in the inverter device is at a normal value. A liquid cooling protection device that detects and protects whether an inverter loss abnormality or cooling efficiency abnormality is detected.

  The invention corresponding to claim 3 is the inverter cooling device of the invention corresponding to claim 2, wherein the speed setting value output from the pump speed setting device when the abnormality detection signal is taken in by the liquid cooling protection device is There is provided a cooling efficiency correction device which is corrected by a value proportional to the absolute value of the deviation between the calculated value of the coolant temperature rise of the inverter device and the actual coolant temperature rise value and which is given to the pump drive inverter device.

  According to a fourth aspect of the present invention, there is provided an inverter unit including a main circuit element and a cooling fin for cooling heat generated from the main circuit element in a case having an intake port and an exhaust port for ventilating outside air. As a cooling system of an inverter device provided with an inverter control device for controlling a main circuit element in the inverter unit, a cooling liquid is introduced into a cooling fin of the inverter unit in the case by the cooling pump, and the inverter is supplied from the cooling fin. The cooling liquid flowing out of the apparatus is heat-exchanged by a heat exchanger and returned to the cooling pump, and the flow path of the cooling liquid flowing into the heat exchanger is branched, and an electric motor provided at this branching point A coolant circulation system is constituted by a coolant bypass system that divides the coolant according to the opening of the three-way valve and returns it to the cooling pump, and the inverter unit In the inverter cooling device for cooling the heat generated from the inverter, a room temperature detector provided in the vicinity of the air inlet in the case, and an inverter for detecting the temperature of the coolant flowing into the inverter device from the cooling pump The inlet coolant temperature detector and the inverter control device have a function of calculating inverter loss based on the control of the inverter unit and the drive condition of the inverter unit, and the inverter loss obtained by this function is input. An inverter input coolant temperature setter that obtains the coolant temperature of the inverter device from the inverter loss and outputs this as a coolant temperature correction value; and the inverter input coolant temperature is detected by the room temperature detector. The coolant set temperature value obtained by adding the coolant temperature correction value output from the setter is input, An inverter input coolant temperature control device for controlling the opening degree of the electric three-way valve based on a deviation between the coolant temperature value detected by the inverter inlet coolant temperature detector 9 and a cooling set temperature value; The temperature rise value at the outlet of the inverter unit obtained from the difference between the coolant temperature setting value obtained by adding the coolant temperature correction value to the inverter unit temperature rise value determined from the maximum operating temperature of the main circuit element of the inverter unit. A pump speed setting device that divides an inverter loss input from the inverter control device and obtains a pump speed proportional to the value from a pump speed function, and the cooling pump according to the pump speed obtained by the pump speed setting device And an inverter device for driving the pump for controlling the drive.

  According to the present invention, the rotational speed of the secondary cooling pump is controlled according to the output of the inverter device to reduce power consumption, and the temperature in the case of the inverter device and the air taken into the case are reduced. Condensation of the cooling fins caused by the temperature difference can be prevented.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a system configuration diagram showing a first embodiment of an inverter cooling apparatus according to the present invention. The same parts as those in FIG. State.

  In the first embodiment, as shown in FIG. 1, a room temperature detector 15 is provided near the inlet 13 having the lowest temperature in the case 2 of the inverter device 1, and an inverter unit is provided for the inverter control device 4. The function of calculating the loss generated in the inverter unit by inputting the output current, the output voltage, and the input voltage to the characteristic curve of the main circuit element 3a and determining the switching loss of the main circuit element 3a and the on-loss of the main circuit element 3a. Furthermore, a pump drive inverter device 16 corresponding to the secondary side cooling pump 5, a temperature detection signal detected by the room temperature detector 15, an inverter loss required by the inverter control device 4 and an inverter inlet cooling water temperature detector 9, the opening degree of the electric three-way valve 8 is determined by obtaining the valve opening degree and the pump speed based on the secondary side cooling water temperature on the inlet side of the case 2 detected in 9. With Gosuru, it is an arrangement to provide a water cooling control unit 17 to provide a speed reference for driving and controlling the secondary-side cooling pump 5 to the pump drive inverter 16.

  The water cooling control device 17 includes an inverter input cooling water temperature setting device 18, an inverter input cooling water temperature control device 19, and a pump speed setting device 20.

  Here, when the temperature detection signal detected by the room temperature detector 15 is input to the inverter input cooling water temperature setting device 18 and the upper limit of humidity is known in the inverter installation conditions, this is shown in FIG. The dew point temperature that does not condense from the humidity is determined and set as the cooling water set temperature. If the upper limit of humidity is not known in the inverter installation conditions, the temperature in the case 2 detected by the room temperature detector 15 is used as the dew point temperature as it is. It has a function.

  Further, the inverter input cooling water temperature control device 19, as shown in FIG. 2A, detects the secondary side cooling water temperature on the inlet side of the case 2 detected by the inverter inlet cooling water temperature detector 9 and the inverter input cooling water. The cooling water set temperature deviation input from the temperature setter 18 is input to the PID controller 19a, and the opening degree of the electric three-way valve 8 is controlled so that the deviation becomes zero.

  Further, as shown in FIG. 2 (b), the pump speed setting device 20 has an inverter outlet temperature that is determined from the cooling water set temperature input from the inverter input cooling water temperature setter 18 and the maximum operating temperature of the main circuit element of the inverter unit. Take the difference from the setting (upper limit) to find the temperature rise value at the inverter unit outlet, divide the inverter loss input from the inverter controller 4 by the temperature rise value at the inverter unit outlet, and set the pump speed proportional to this value. It has a function of obtaining it from the pump speed function and giving it to the pump drive inverter device 16.

  In the inverter cooling device having such a configuration, it is assumed that the secondary side cooling pump 5 is driven and operated by the pump drive inverter device 16.

  The secondary side cooling water is introduced into the cooling fin 3b that exchanges heat with the main circuit element 3a of the inverter unit 3 installed in the case 2 through the cooling water inflow side pipe 6a, and the cooling water flows out from the cooling fin 3b. The three-way valve 8 controlled by the opening signal output from the inverter input cooling water temperature control device 19 of the water cooling control device 17 through the side piping 6b passes through the secondary side of the heat exchanger 7 and the cooling water bypass piping 6c. It is assumed that the secondary side cooling water circulation system returning to the secondary side cooling pump 5 is circulating.

  In such a state, the temperature of the cooling water flowing through the cooling fins 3b and the secondary side cooling pump 5 are controlled by the water cooling control device 17 as follows.

  In the water cooling control device 17, the inverter input cooling water temperature setter 18 does not condense from the temperature detected by the room temperature detector 15 provided near the air inlet 13 of the case 2 having the lowest temperature in the inverter device 1. The dew point temperature is obtained, and this dew point temperature is given to the inverter input cooling water temperature controller 19 as the cooling water set temperature.

  In this inverter input cooling water temperature control device 19, when the difference between the secondary side cooling water temperature on the inlet side of the case 2 detected by the inverter inlet cooling water temperature detector 9 and the cooling water set temperature is given to the PID controller 19a. The PID controller 19a obtains an opening at which this deviation becomes zero, and controls the electric three-way valve 8 by the opening signal.

  As a result, the temperature of the secondary side cooling water flowing in the cooling fins 3b in physical contact with the main circuit element 3a in the inverter unit 3 is controlled, so the temperature in the case 2 and the secondary side cooling water are controlled. Condensation generated on the cooling fins 3b due to the temperature difference between them can be prevented.

  On the other hand, when the dew point temperature calculated by the inverter input cooling water temperature setting device 18 and the inverter loss calculated by the inverter control device 4 are input to the pump speed setting device 20, the pump speed setting device 20 sets the cooling water. The temperature rise value at the inverter unit outlet is obtained from the difference between the temperature and the inverter outlet temperature setting value (upper limit) determined from the maximum operating temperature of the main circuit element of the inverter unit. The input inverter loss is divided, and a pump speed proportional to this value is obtained from the pump speed function and supplied to the pump drive inverter device 16.

  In general, the temperature rise of the cooling water flowing in the cooling system of the inverter device 1 is proportional to the inverter loss and inversely proportional to the pump speed (cooling water flow rate). Therefore, the inverter loss is divided by the temperature rise value of the inverter device. By setting the pump speed proportional to this value, the pump speed corresponding to the inverter loss and room temperature can be obtained.

  By giving this pump speed to the pump drive inverter device 16 as a speed reference, the secondary cooling pump 5 is driven and controlled.

  By these operations, it is possible to prevent dew condensation that occurs in the cooling fins 3b that cool the main circuit elements in the inverter device 1, and the rotational speed of the secondary cooling pump 5 is controlled according to the output of the inverter device 1. Therefore, power consumption can be reduced.

  In the above embodiment, the case where one inverter device is cooled by one cooling system has been described. However, when a plurality of inverter devices are cooled by one cooling system, the temperature and room temperature detector 15 of each inverter device is described. For the temperatures detected in (1), a low value among them is used, and a high value is used for the humidity, and the pump speed setting device 20 can be adapted by adding each inverter loss to obtain the pump speed.

  Further, when the humidity in the inverter device 1 can be detected, the dew point temperature can be accurately obtained from the characteristic curve of the saturated water vapor shown in FIG. 2A. Therefore, when the humidity is low, the temperature of the cooling water is further increased. Even if the temperature is set to a low temperature, the cooling fin can be operated without causing condensation, and the output of the inverter device 1 can be increased.

  FIG. 3 is a system configuration diagram showing a second embodiment of the inverter cooling apparatus according to the present invention. The same parts as those in FIG. 1 are denoted by the same reference numerals and the description thereof is omitted, and different parts are described here.

  In the second embodiment, as shown in FIG. 3, in addition to the water cooling control device 17 and the pump drive inverter device 16, a water cooling protection device 21 is provided, and the water cooling protection device 21 is detected by the room temperature detector 15. The detected temperature detection signal, the secondary cooling water temperature detection signal detected by the inverter inlet cooling water temperature detector 9, and the inverter outlet cooling water room temperature detection provided in the cooling water outflow side piping 6b before the electric three-way valve 8 The temperature detection signal of the secondary side cooling water detected by the vessel 22 and the pump speed determined by the pump speed setting device 20 of the water cooling control device 17 are respectively input.

  This water cooling protection device 21 is based on the difference between the temperature of the secondary side cooling water detected by the inverter outlet cooling water temperature detector 22 and the inverter inlet temperature detected by the inverter inlet cooling water room temperature detector 9. The actual cooling water temperature rise value is obtained, and the inverter is obtained from the difference between the calculated value of the cooling water temperature rise value of the inverter device 1 and the actual temperature rise value from the pump speed obtained by the pump speed setting device 20 and the inverter loss. It is confirmed whether the heat exchange rate and inverter loss in the apparatus 1 are normal values. In this case, when the actual temperature rise value is high, the inverter loss is abnormal, and when it is low, it is determined that the heat exchange rate of the cooling system is abnormal.

  According to the second embodiment, the actual cooling water temperature rise value obtained from the difference between the inverter inlet temperature and the inverter outlet temperature of the secondary side cooling water, the pump speed obtained by the pump speed setting device 20, and the inverter loss. By detecting the difference from the calculated value of the cooling water temperature rise value of the inverter device 1 from the above, it is possible to detect a decrease in the heat exchange rate in the cooling system of the inverter device 1 or an abnormality in the inverter loss. It can be performed.

  FIG. 4 is a system configuration diagram showing a third embodiment of the inverter cooling apparatus according to the present invention. The same parts as those in FIG. 1 are denoted by the same reference numerals and the description thereof is omitted, and different parts are described here.

  In the third embodiment, a water cooling protection device 21 and a cooling efficiency correction device 23 are provided in addition to the water cooling control device 17 and the pump drive inverter device 16 as shown in FIG. The temperature detection signal detected by the room temperature detector 15, the cooling water temperature detection signal detected by the inverter inlet cooling water room temperature detector 9 on the inverter inlet side, and the cooling water outflow side pipe 6 b in front of the electric three-way valve 8 are provided. The cooling water temperature detection signal detected by the secondary cooling water room temperature detector 22 on the inverter exit side and the pump speed obtained by the pump speed setting device 20 of the water cooling control device 17 are input, and the cooling efficiency is corrected. An abnormal detection signal is input to the device 23 from the water cooling protection device 21.

  The water cooling protection device 21 includes the temperature of the secondary cooling water detected by the secondary cooling water room temperature detector 22 on the inverter outlet side and the temperature detected by the inverter inlet cooling water room temperature detector 9 on the inverter inlet side. The actual cooling water temperature rise value of the inverter device 1 is obtained from the difference between the pump speed and the pump speed obtained by the pump speed setting device 20, and the cooling water temperature rise of the inverter device 1 is calculated from the inverter loss. From the difference between the calculated increase value and the actual cooling water temperature increase value, it is determined whether the heat exchange rate and the inverter loss in the inverter device are normal values. In this case, when the actual detected temperature is high, the inverter loss is abnormal, and conversely, when it is low, it is determined that the heat exchange rate of the cooling system is abnormal.

  Further, the cooling efficiency correction device 23 takes the speed setting value output from the pump speed setting device 20 of the water cooling control device 17 when the abnormality detection signal is taken in from the water cooling protection device 21, and the cooling water temperature of the inverter device 1. A value proportional to the absolute value of the deviation between the calculated rise value and the actual cooling water temperature rise value is obtained, and this value is given as a correction value to the pump drive inverter device 16 to determine the rotational speed of the secondary side cooling pump 5. increase. Further, when the speed of the secondary cooling pump 5 exceeds the rated speed due to the correction of the speed setting value, a current limit command is given to the inverter control device 4 to limit the output of the inverter device 1.

  As described above, according to the third embodiment, when an abnormality detection signal is taken in from the water cooling protection device 21, the speed of the secondary cooling pump 5 that circulates the secondary cooling water is increased to increase the heat exchange rate. Since the decrease can be corrected, it is possible to correct the deterioration due to the secular change of the heat exchange rate in the inverter device 1.

  FIG. 5 is a system configuration diagram showing a fourth embodiment of the inverter cooling apparatus according to the present invention. The same parts as those in FIG. 1 are denoted by the same reference numerals and the description thereof is omitted, and different parts are described here.

  In the fourth embodiment, as the water cooling control device 17, the inverter loss obtained by the calculation function of the inverter control device 4 as shown in FIG. 5 is input, and the secondary side cooling water of the inverter device 1 is input from this inverter loss. The cooling water temperature output from the inverter input cooling water temperature setting device 24 to the temperature detection value detected by the inverter input cooling water temperature setting device 24 and the room temperature detector 15 that obtains the temperature and outputs this as a cooling water temperature correction value. The cooling water set temperature value to which the correction value is added is input, and the deviation between the secondary side cooling water temperature value on the inlet side of the case 2 detected by the inverter inlet cooling water room temperature detector 9 and the cooling set temperature value is PID. The temperature detection value detected by the inverter input cooling water temperature control device 19 and the room temperature detector 15 for controlling the opening degree of the electric three-way valve 8 to be zero by the controller. The temperature rise value at the outlet of the inverter unit is obtained from the difference between the cooling water set temperature value obtained by adding the cooling water temperature correction value and the temperature rise value at the inverter unit outlet determined from the maximum operating temperature of the main circuit element of the inverter unit. The difference between the water set temperature and the inverter outlet temperature setting (upper limit) determined from the maximum operating temperature of the main circuit element of the inverter unit is taken to obtain the temperature rise value at the inverter unit outlet, and the inverter loss input from the inverter controller 4 is calculated. A pump speed setting device 20 is provided that divides by the temperature rise value at the outlet of the inverter unit and obtains a pump speed proportional to this value from the pump speed function and gives it to the pump drive inverter device 16.

  If such a water cooling control device is used, when the inverter device is operating at a light load with respect to the room temperature where the inverter unit 3 is installed, the setting of the cooling temperature at the inverter inlet should be corrected to a high value. Can do.

  In general, if the temperature of the cooling water at the inlet of the inverter device 1 is controlled near the room temperature, when the inverter device 1 is operated at a high load, the room temperature rises due to the exhaust heat of the inverter device, so that the humidity decreases. Further, since the temperature of the cooling fin 3b in contact with the inverter unit 3 also becomes higher than the room temperature due to the increase of the inverter loss and there is a margin until the dew point temperature is reached, dew condensation is less likely to be a problem.

  However, when the inverter device 1 is operated at a light load, the temperature of the cooling fin 3b is almost the same as the temperature of the secondary side cooling water at the inverter inlet, and there is little margin until the dew point temperature is reached. If this is not detected correctly, there is a problem that causes condensation.

  The inverter input cooling water temperature setting unit 24 obtains the secondary side cooling water temperature of the inverter device 1 from the inverter loss of the inverter device 1, and uses this as the temperature detection value detected by the room temperature detector 15 as the cooling water temperature correction value. Since the value is added, the temperature correction value of the secondary cooling water is increased for light loads, and the temperature correction value is output low for high loads, thereby increasing the margin for reaching the dew point temperature at light loads. Make corrections to take.

  Therefore, condensation can be prevented when the inverter device 1 is cooled.

  In the above embodiment, the case where one inverter device is cooled by one cooling system has been described. However, when a plurality of inverter devices 1a and 1b are cooled by one cooling system as shown in FIG. Although it is difficult to accurately detect the ambient temperature inside the inverter device due to the difference depending on the installation location, as described above, the inverter input cooling water temperature setting device 24 and the pump speed setting device 20 of the water cooling control device 17 are connected to each inverter device 1a. 1b, the inverter loss is input from the inverter control device 4 and the cooling water temperature correction value and the pump speed are obtained based on the average value, thereby cooling a plurality of inverter devices with one cooling system. Condensation can be prevented.

The line | wire system block diagram which shows 1st Embodiment of the inverter cooling device by this invention. The figure which shows the detail of the water cooling control apparatus in the embodiment. The line | wire system block diagram which shows 2nd Embodiment of the inverter cooling device by this invention. The system block diagram which shows 3rd Embodiment of the inverter cooling device by this invention. The system block diagram which shows 4th Embodiment of the inverter cooling device by this invention. The system block diagram which applied the same embodiment to the case where several inverter apparatuses are cooled. The system block diagram which shows the conventional inverter cooling device. The figure which shows the water cooling device shown in FIG. 7 in detail.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Inverter device, 2 ... Case, 3 ... Inverter unit, 3a ... Main circuit element, 3b ... Cooling fin, 3c ... Capacitor, 3d ... Input / output terminal, 3e ... Electric wire, 4 ... Inverter control device, 5 ... Secondary side Cooling pump, 6a ... cooling water inflow side pump, 6b ... cooling water outflow side piping, 6c ... cooling water bypass piping, 7 ... heat exchanger, 8 ... electric three-way valve, 9 ... inverter inlet cooling water room temperature detector, 11 ... Primary side cooling pump, 12 ... Primary side cooling water piping, 13 ... Intake port, 14 ... Exhaust port, 15 ... Room temperature detector, 16 ... Pump drive inverter device, 17 ... Water cooling control device, 18 ... Inverter input cooling Water temperature setting device, 19 ... Inverter input cooling water temperature control device, 20 ... Pump speed setting device, 21 ... Water cooling protection device, 22 ... Inverter outlet cooling water room temperature detector, 23 ... Cooling efficiency correction device, 2 ... inverter input cooling water temperature setting device

Claims (4)

Controls the inverter unit having a main circuit element and a cooling fin for cooling heat generated from the main circuit element in a case having an intake port and an exhaust port for ventilating outside air, and the main circuit element in the inverter unit As an inverter device cooling system provided with an inverter control device
A cooling system that introduces the cooling liquid into the cooling fins of the inverter unit in the case by the cooling pump, and returns the cooling liquid that flows out of the inverter device from the cooling fins to the cooling pump by heat exchange. Cooling is performed by a coolant bypass system that branches the flow path of the coolant flowing into the heat exchanger and diverts the coolant according to the opening degree of the electric three-way valve provided at the branch point and returns the coolant to the cooling pump. In the inverter cooling device configured to cool the heat generated from the inverter unit by configuring a liquid circulation system,
A room temperature detector provided near the air inlet in the case;
An inverter inlet coolant temperature detector for detecting the temperature of the coolant flowing into the inverter device from the cooling pump;
A dew point temperature at which no dew condensation is obtained from the temperature detected by the room temperature detector, and a coolant temperature setter having the dew point temperature as a coolant set temperature,
Based on the deviation between the coolant set temperature set by the coolant temperature setter and the coolant temperature detected by the inverter inlet coolant temperature detector, the opening of the electric three-way valve is controlled to cool the inverter inlet. A coolant temperature control device for controlling the temperature of the liquid;
The inverter control device has a function of calculating inverter loss based on inverter unit control and inverter unit driving conditions, and the inverter loss calculated by this function and the coolant obtained by the coolant temperature setting device A pump speed setting device for determining the pump speed based on the set temperature;
An inverter cooling device comprising: a pump driving inverter device that drives and controls the cooling pump according to a pump speed determined by the pump speed setting device. The inverter cooling device according to claim 1,
An inverter outlet coolant temperature detector for detecting the temperature of coolant flowing out of the inverter device is provided,
From the difference between the inverter outlet temperature of the coolant detected by the inverter outlet coolant temperature detector and the inverter inlet temperature detected by the inverter inlet coolant temperature detector, the actual coolant temperature rise value of the inverter device is obtained. The heat exchange rate or inverter in the inverter device is calculated from the difference between the calculated coolant temperature rise value of the inverter device and the actual coolant temperature rise value from the pump speed and inverter loss obtained by the pump speed setting device. An inverter cooling device comprising a liquid cooling protection device for determining whether or not the loss is a normal value and detecting and protecting an abnormality in the inverter loss or an abnormality in the cooling efficiency. The inverter cooling device according to claim 2,
When an abnormality detection signal is taken in from the liquid cooling protection device, the speed set value output from the pump speed setting device is calculated as the deviation between the calculated value of the coolant temperature rise of the inverter device and the actual coolant temperature rise value. An inverter cooling device comprising a cooling efficiency correction device that corrects a value proportional to an absolute value and applies the correction to the pump drive inverter device. Controls the inverter unit having a main circuit element and a cooling fin for cooling heat generated from the main circuit element in a case having an intake port and an exhaust port for ventilating outside air, and the main circuit element in the inverter unit As an inverter device cooling system provided with an inverter control device
A cooling system that introduces the cooling liquid into the cooling fins of the inverter unit in the case by the cooling pump, and returns the cooling liquid that flows out of the inverter device from the cooling fins to the cooling pump by heat exchange. Cooling is performed by a coolant bypass system that branches the flow path of the coolant flowing into the heat exchanger and diverts the coolant according to the opening degree of the electric three-way valve provided at the branch point and returns the coolant to the cooling pump. In the inverter cooling apparatus configured to cool the heat generated from the inverter unit by configuring a water circulation system,
A room temperature detector provided near the air inlet in the case;
An inverter inlet coolant temperature detector for detecting the temperature of the coolant flowing into the inverter device from the cooling pump;
The inverter control device has a function of calculating an inverter loss based on the control of the inverter unit and the drive condition of the inverter unit, and the inverter loss obtained by this function is input, and the inverter device is cooled from the inverter loss. An inverter input coolant temperature setter that calculates the liquid temperature and outputs it as a coolant temperature correction value;
A coolant setting temperature value obtained by adding a coolant temperature correction value output from the inverter input coolant temperature setting device to the temperature detection value detected by the room temperature detector is input, and the inverter inlet coolant temperature detector 9 is input. An inverter input coolant temperature control device for controlling the opening degree of the electric three-way valve based on the deviation between the coolant temperature value detected in step S3 and the cooling set temperature value;
The temperature of the inverter unit outlet obtained from the difference between the coolant set temperature value obtained by adding the coolant temperature correction value to the temperature detection value and the temperature rise value of the inverter unit outlet determined from the maximum operating temperature of the main circuit element of the inverter unit. A pump speed setting device that divides an inverter loss input from the inverter control device by a temperature rise value and obtains a pump speed proportional to the value from a pump speed function;
An inverter cooling device comprising: a pump driving inverter device that drives and controls the cooling pump according to a pump speed determined by the pump speed setting device.

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