JP5521768B2 - Semiconductor power converter cooling device - Google Patents

Description

  The present invention relates to a cooling device for a power device in a semiconductor power conversion device such as a pulse power supply device for an excimer laser, and particularly protects the power device from thermal damage by flowing cooling water through cooling fins in contact with the power device. The present invention relates to a cooling device.

  FIG. 21 shows a configuration example of a pulse power supply device for excimer laser, and FIG. 22 shows a charge / discharge operation timing chart of a capacitor that generates a pulse current by discharging. The capacitor 1 stores DC power using a three-phase power source, a rectifier circuit, or the like. In the period T1 of FIG. 22, by turning on the switch S1 of the single-phase inverter 2, current flows through the circuits A and B in the circuit of the transformer 3 and the rectifier 4, and the capacitor 6 is charged while accumulating energy in the reactor 5. To do. Next, in the period T2 in FIG. 22, by turning off the switch S1 of the inverter 2, a current flows through the circuit through the path C, the energy stored in the reactor 5 is transferred to the capacitor 6, and the capacitor 6 is set to the target. The battery is charged to a high voltage slightly exceeding the voltage (hereinafter referred to as coarse adjustment operation). After the rough adjustment operation, in the period T3 in FIG. 22, the power device MC1 is turned on to lower the capacitor 6 to a predetermined target voltage, and to match the charging voltage of the capacitor 6 with the target voltage (hereinafter referred to as a fine adjustment operation). Called). After that, in the period T4 in FIG. 22, the power device MC2 is turned on to supply the energy accumulated in the capacitor 6 to the pulse compression circuit / magnetic compression circuit (Pulse Power Module) 7 as a discharge current and load (laser tube). ) 8 is supplied with a pulse current that is boosted and narrowly compressed.

  In the pulse power supply device as described above, rapid charge control and rapid discharge control of the capacitor 6 are performed by controlling the inverter 2 and the power device MC2. As a semiconductor switching element used in the inverter 2 and the power device MC2, a device capable of controlling a voltage / current of several thousand volts and several hundred to several thousand amperes and having a switching speed of several μs is required. As these switches, in addition, considering a lifetime, cost, maintainability, etc., for example, a power device such as an IGBT is adopted. However, when using a power device, power loss occurs mainly during switching (turn-on, turn-off) and steady ON, and the device itself generates heat.

  On the other hand, a pulse power supply device for excimer lasers is required to be downsized, used environment (used in a clean room), and high repetitive operation (frequency: several kiloHz). When the operation is repeated repeatedly, the power loss increases almost in proportion to the frequency, and the heat generation amount also increases in proportion to the loss. Cooling means must be provided to prevent device damage due to heat generation. In consideration of downsizing and use in a clean room, this cooling means must have a more compact outer shape of a heat exchanger such as a cooling fin, and it is not desired to release heat as much as possible into the atmosphere. Accordingly, a water cooling method is generally used as a cooling method for a semiconductor power conversion device equipped with a power device that performs switching operation with high current, high voltage, and high repetition, such as an excimer laser pulse power supply device.

  As a device for cooling (water cooling) a power device, a method of fixing the power device to a cooling fin as a heat exchanger by surface contact and cooling is generally used. An example of the structure of the cooling fin is shown in FIG. The cooling fin 11 has a structure in which a cooling water pipe 12 is embedded or a groove is cut in order to form a cooling water flow path therein. The heat generated in the power device 13 is released to the outside through the cooling water passing through the flow path in the cooling fin 11.

  As a cooling device for this type of water-cooled power device, the loss of the semiconductor device is calculated from the energization current of the semiconductor device, and the rise in the outside water temperature is calculated based on this loss. There has been proposed a method in which detection values by a detector are compared, and the result of this comparison is used to determine and notify the lack of flow rate of outside water (see, for example, Patent Document 1).

JP-A-8-340067

  In a conventional cooling device for water-cooling a power device, the size of the contact area, the thermal conductivity of the material, etc., at the joint between the cooling fin and the power device case and the joint between the power device case and the semiconductor chip inside the power device case, etc. There is a thermal resistance that depends on the temperature of the semiconductor chip, and in fact, a temperature difference is created between the junction temperature of the semiconductor chip and the cooling water temperature. The relationship between the junction temperature and the temperature of each part and the thermal resistance is shown in Equation (1) (provided that one element is mounted on one fin).

Tj = a * f * ([theta] j-c + [theta] c-f + [theta] f-w) + Tw (1)
Here, Tj is the junction temperature of the power device, a is the loss per switch operation of the power device (Joule / 1 pulse), f is the operating frequency (Hz), θj-c is the junction-to-case thermal resistance, θc-f is the case-fin thermal resistance, θf-w is the fin-cooling water thermal resistance, and Tw is the maximum cooling water temperature.

Here, the thermal resistance θ _jc is determined by the internal structure of the power device and the like. The thermal resistance θ _cf is determined by the shape of the power device case, the grease used, the fin used, and the like. However, the thermal resistance θ _jc and the thermal resistance θ _cf are fixed constants if the power device, the grease used, and the cooling fin are determined. The thermal resistance θ _fw varies depending on the shape and material of the cooling fin, but varies greatly depending on the flow rate.

FIG. 24 shows the relationship between the cooling water flow rate of a certain cooling fin and the thermal resistance θ _fw . In general, the smaller the flow rate, the greater the thermal resistance (thermal resistance and flow rate are inversely related). The relationship that the thermal resistance increases as the flow rate decreases can also be obtained from the Fourier equation. The Fourier equation is shown in Equation (2), and the relational expression of thermal resistance is shown in Equation (3). In general, the relationship between the amount of heat in the cooling fin, the flow rate, and the temperature difference between the input and output is expressed by equation (4). Equation (5) can be derived from Equations (2), (3), and (4), and it can be seen that the flow rate and thermal resistance are in an inversely proportional relationship.

Q = kA × ΔT / d (2)
R = d / k (3)
Q = 0.07 × L × ΔT (4)
R × L = A / 0.07 (5)
Here, Q is the amount of heat (W), k is the thermal conductivity [W / mK], A is the contact area (m ² ), ΔT is the fin input / output temperature difference (K), d is the contact distance (m), R Is the thermal resistance (K / W), and L is the flow rate (L / min).

From the above, as the flow rate L decreases, the thermal resistance θ _fw increases. Therefore, the junction temperature T _j becomes larger than the expression (1), and if this temperature T _j exceeds the rating of the power device, there is a fear of breakage.

However, in the above-mentioned patent document 1, from the relationship of the following formula (6), the thermal resistance θ _fw increases as the flow rate L decreases, and the temperature of the fin rises. By monitoring the fin temperature, the device was protected against a decrease in flow rate or a stoppage.

Tf = a * f * thetaf-w + Tw ... (6)
Here, Tf is the cooling fin temperature, a is the loss per switch operation of the power device (Joule / one pulse), f is the operating frequency (Hz), θf-w is the fin-cooling water thermal resistance, Tw Is the cooling water temperature.

  For this reason, in the conventional protection system, the reaction time (about 30 seconds) of the temperature sensor is slow, and there is a problem that the power device is damaged before the temperature sensor detects a temperature rise particularly when the flow rate is reduced or stopped.

In addition, when the flow rate is increased, the thermal resistance θ _fw is reduced, so there is no risk of damage to the power device due to heat generation, but a cooling water flow path such as a radiator, cooling fins, cooling water piping for flowing cooling water into the device, etc. There was a problem that the system was damaged by erosion.

  An object of the present invention is to provide a cooling device for a semiconductor power conversion device that can determine overheating of a power device at high speed and reliably protect against thermal damage, and can also prevent damage due to erosion of a cooling water flow path system. There is to do.

In order to solve the above problems, the present invention basically defines the temperature difference between the junction temperature of the power device and the cooling water temperature as a relational expression between the temperature of each part of the cooling device and the thermal resistance. The cooling water flow that is monitored by the flow sensor is reduced to the cooling water flow rate at which the junction temperature T _j determined by the equation becomes equal to or greater than the maximum value T _j (max), so that the overheating of the power device is determined and further monitoring is performed. The erosion of the cooling water flow path system is determined by an abnormal increase in the flow rate, and has the following configuration.

(1) A cooling device for bringing a power device of a main circuit of a semiconductor power converter into contact with a cooling fin and flowing cooling water into the cooling fin to protect the power device from thermal damage,
A flow rate sensor for detecting a flow rate of cooling water flowing in the cooling fin;
The temperature difference between the junction temperature of the power device and the cooling water temperature is determined as a relational expression between the temperature of each part of the cooling device and the thermal resistance, and the junction temperature T _j determined by this relational expression is equal to or greater than the maximum value T _j (max). A cooling water flow rate setting device for setting the cooling water flow rate, and
It is provided with a temperature suppression control circuit that suppresses an increase in the junction temperature of the power device when the cooling water flow detected by the flow sensor is reduced to a cooling water flow set below the cooling water flow setting device. And

(2) A cooling device for bringing a power device of a main circuit of a semiconductor power converter into contact with a cooling fin and flowing cooling water through the cooling fin to protect the power device from thermal damage,
A flow rate sensor for detecting a flow rate of cooling water flowing in the cooling fin;
The temperature difference between the junction temperature of the power device and the cooling water temperature is determined as a relational expression between the temperature of each part of the cooling device and the thermal resistance, and the junction temperature T _j determined by this relational expression is equal to or greater than the maximum value T _j (max). A cooling water flow rate setting device for setting the cooling water flow rate, and
A frequency-loss conversion circuit for obtaining a current loss per unit time from a current operating frequency of the power device, and obtaining a change coefficient of the cooling water flow rate set in the cooling water flow rate setting device based on the loss;
When the cooling water flow detected by the flow sensor falls below the cooling water flow set by the cooling water flow setter and the change coefficient of the frequency-loss conversion circuit, the junction temperature of the power device is increased. A temperature suppression control circuit is provided.

(3) A cooling device for bringing a power device of a main circuit of a semiconductor power converter into contact with a cooling fin and flowing cooling water through the cooling fin to protect the power device from thermal damage,
A flow rate sensor for detecting a flow rate of cooling water flowing in the cooling fin;
The temperature difference between the junction temperature of the power device and the cooling water temperature is determined as a relational expression between the temperature of each part of the cooling device and the thermal resistance, and the junction temperature T _j determined by this relational expression is equal to or greater than the maximum value T _j (max). A cooling water flow rate setting device for setting the cooling water flow rate, and
A main circuit voltage-loss conversion circuit for obtaining a current loss per unit time from a current main circuit voltage of the power device, and obtaining a change coefficient of the cooling water flow rate set in the cooling water flow rate setting device based on the loss;
When the cooling water flow detected by the flow sensor falls below the cooling water flow set by the cooling water flow setting device and the change coefficient of the main circuit voltage-loss conversion circuit, the junction temperature of the power device is reduced. A temperature suppression control circuit that suppresses the rise is provided.

(4) A cooling device for bringing a power device of a main circuit of a semiconductor power converter into contact with a cooling fin and flowing cooling water into the cooling fin to protect the power device from thermal damage,
A flow rate sensor for detecting a flow rate of cooling water flowing in the cooling fin;
The temperature difference between the junction temperature of the power device and the cooling water temperature is determined as a relational expression between the temperature of each part of the cooling device and the thermal resistance, and the junction temperature T _j determined by this relational expression is equal to or greater than the maximum value T _j (max). A cooling water flow rate setting device for setting the cooling water flow rate, and
A frequency-loss conversion circuit for obtaining a current loss per unit time from a current operating frequency of the power device, and obtaining a change coefficient of the cooling water flow rate set in the cooling water flow rate setting device based on the loss;
A main circuit voltage-loss conversion circuit for obtaining a current loss per unit time from a current main circuit voltage of the power device, and obtaining a change coefficient of the cooling water flow rate set in the cooling water flow rate setting device based on the loss;
When the cooling water flow rate detected by the flow rate sensor falls below the cooling water flow rate set by the cooling water flow rate setting device and changed by the change coefficient of the frequency-loss conversion circuit and the main circuit voltage-loss conversion circuit A temperature suppression control circuit that suppresses an increase in the junction temperature of the power device is provided.

  (5) The temperature suppression control circuit includes a storage circuit that stores the first switching operation of the power device and allows the increase in the junction temperature of the power device after the first switching operation. And

  (6) The temperature suppression control circuit includes a timer circuit that masks detection of a decrease in the cooling water flow rate for a predetermined time from a reset signal that is input when the semiconductor power converter apparatus is reset.

  (7) The temperature suppression control circuit includes a storage circuit that starts suppression of increase in the junction temperature of the power device after the first switching operation of the power device, and a reset signal that is input upon canceling the device error of the semiconductor power converter. A timer circuit that masks detection of a decrease in the coolant flow rate for a certain period of time is provided.

  (8) The temperature suppression control circuit issues a warning (danger notice) when the cooling water flow rate exceeds the flow rate that causes erosion of the cooling water flow path system, and the flow rate leading to this erosion has exceeded a certain time. In some cases, an anti-corrosion circuit for the cooling water passage system that stops the operation of the power device and stops the apparatus is provided.

As described above, according to the present invention, the temperature difference between the junction temperature of the power device and the cooling water temperature is determined as a relational expression between the temperature of each part of the cooling device and the thermal resistance, and the junction temperature T _j determined by this relational expression is determined. Since the cooling water flow rate monitored by the flow sensor has decreased until the cooling water flow rate reaches a maximum value T _j (max), the overheating of the power device is detected by the conventional temperature sensor in order to determine overheating of the power device. As compared with the above, it is possible to detect the overheating of the power device by the flow rate sensor at high speed and to reliably protect the power device from thermal damage.

  Furthermore, since the erosion of the cooling water flow path system is determined based on the abnormal increase in the cooling water flow rate to be monitored, damage due to the erosion of the cooling water flow path system can be prevented.

FIG. 3 is a cooling control circuit diagram of the cooling device according to the first embodiment. FIG. 6 is a cooling control circuit diagram of the cooling device according to the second embodiment. FIG. 6 is a cooling control circuit diagram of a cooling device according to a third embodiment. FIG. 6 is a cooling control circuit diagram of a cooling device according to a fourth embodiment. FIG. 10 is a cooling control circuit diagram of a cooling device according to a fifth embodiment. FIG. 9 is a cooling control circuit diagram of a cooling device according to a sixth embodiment. FIG. 10 is a cooling control circuit diagram of a cooling device according to a seventh embodiment. FIG. 10 is a cooling control circuit diagram of a cooling device according to an eighth embodiment. The cooling control circuit diagram of the cooling device which concerns on Embodiment 9. FIG. FIG. 12 is a cooling control circuit diagram of the cooling device according to the tenth embodiment. FIG. 14 is a cooling control circuit diagram of a cooling device according to an eleventh embodiment. The cooling control circuit diagram of the cooling device which concerns on Embodiment 12. FIG. The cooling control circuit diagram of the cooling device which concerns on Embodiment 13. FIG. FIG. 16 is a cooling control circuit diagram of a cooling device according to a fourteenth embodiment. FIG. 18 is a cooling control circuit diagram of the cooling device according to the fifteenth embodiment. FIG. 18 is a cooling control circuit diagram of the cooling device according to the sixteenth embodiment. FIG. 18 is a cooling control circuit diagram of a cooling device according to a seventeenth embodiment. FIG. 19 is a cooling control circuit diagram of a cooling device according to an eighteenth embodiment. FIG. 20 is a cooling control circuit diagram of a cooling device according to a nineteenth embodiment. FIG. 22 is a cooling control circuit diagram of a cooling device according to a twentieth embodiment. 1 is a configuration example of a pulse power supply device for excimer laser. Capacitor charge / discharge timing chart. The structural example of a cooling fin. The relationship diagram of the cooling water flow rate of the cooling fin and the thermal resistance θ _fw .

(Embodiment 1)
FIG. 1 is a cooling control circuit diagram of the cooling device showing the present embodiment. The power device 21 to be cooled has its device case attached to the cooling fin 22 in surface contact, and cooling water is forcedly circulated through the cooling fin 22. A flow rate sensor 23 is provided in the cooling water flow path of the cooling fin 22 to continuously detect the cooling water flow rate. The flow sensor 23 is, for example, a turbine flow meter in which an impeller is inserted in the cooling water flow path, and the rotation detection signal of the impeller is converted into an analog voltage signal by the analog voltage converter 24.

The comparator 25 includes a coolant flow rate setting value (analog voltage value) at which the junction temperature T _j set in the coolant flow rate setting device 26 is equal to or higher than the maximum value T _j (max), and the coolant flow rate detected by the flow sensor 23. A comparison is made with (analog voltage value), and it is determined whether or not the power device 21 has fallen below the cooling water flow rate at which it is thermally damaged. The cooling water flow rate setting value set in the cooling water flow rate setting device 26 is, from the relationship of the above formula (1), the cooling fin-cooling water thermal resistance θ _fw (see FIG. 24) that varies greatly depending on the cooling water flow rate, It is calculated in advance based on the relationship of the following equation (7) with the junction temperature maximum value T _j (max).

(Tj (max) −Tw (max)) / a × f− θj −c−θc−f <θf−w (7)
When it is determined that the cooling water flow rate has decreased until the power device 21 is thermally damaged, the comparator 25 activates the temperature suppression control circuit to suppress an increase in the junction temperature of the power device. Specifically, as the temperature suppression control circuit, the output of the gate drive circuit 29 of the power device 21 is suppressed by suppressing the output of the IGBT_ON signal generator 28 that is input to the AND gate 27 by the output of the comparator 25. The switching operation is stopped before the power device 21 is thermally damaged due to insufficient cooling water flow. In parallel with this, the output of the comparator 25 is notified to the user of the semiconductor power conversion device through error signal transmission, LED display, or the like.

  In addition, as a temperature suppression control circuit, although the case where the switching operation of a power device is stopped immediately is shown, the frequency | count of switching operation (operation frequency) may be reduced rapidly by the abnormal fall of a cooling water flow rate.

  Therefore, according to this embodiment, since the overheating of the junction temperature of the power device is monitored by the decrease in the flow rate of the cooling water, the overheating of the power device can be determined at a high speed and reliable protection from the thermal damage can be achieved. Furthermore, the change of the driving | running state of a semiconductor power converter device can be alert | reported by notifying a user using abnormality so that a power device may not be damaged.

(Embodiment 2)
In the configuration of FIG. 1, the determination of an abnormal flow rate is started immediately after the control power supply of the cooling control circuit is turned on. However, the heat generation of the power device starts only after the on / off control of the power device 21 is started, that is, during the main circuit operation in which the output of the IGBT_ON signal is started. For this reason, if the cooling water flow rate control has not reached the predetermined value between the time when the control power is turned on and the start of the main circuit operation, the comparator 25 detects a shortage of the flow rate, and the control of the power device 21 cannot be started. Further, although there is no possibility of thermal damage of the power device, the flow rate abnormality is reported to the user.

  The present embodiment solves the above inconvenience, and its configuration is shown in FIG. The basic configuration is almost the same as the configuration of FIG. 1, but a memory circuit 30 such as an SR type flip-flop is provided as a temperature suppression control circuit, and the first IGBT_ON signal output from the IGBT_ON signal generator 28 is output. Is stored in the memory circuit 30 and this retained output is used as the third input of the AND gate 27, thereby permitting the control of the increase in the junction temperature of the power device after the first switching operation of the power device. Further, an AND gate 31 is provided, and the output of the comparator 25 is masked by the retained output of the storage circuit 30 to suppress notification of abnormality to the user.

  With this configuration, the flow rate abnormality determination is performed from the first turn of the IGBT_ON signal after the control power is turned on, so that the monitoring timing of the flow rate abnormality can be narrowed down after the first main circuit control start time after the control power is turned on, After that, if the abnormal flow is resolved, the control can be started. Also, even if there is a flow rate fluctuation after the control power is turned on, an abnormal flow rate is not reported erroneously.

(Embodiment 3)
As described above, in the configuration of FIG. 1, the determination of the flow rate abnormality is started immediately when the control power of the cooling control circuit is turned on, and the coolant flow control reaches a predetermined value between the time when the control power is turned on and the start of the main circuit operation. If not, the comparator 25 detects a shortage of the flow rate, and the control of the power device 21 cannot be started, and a flow rate abnormality is reported to the user.

  The present embodiment solves the above inconvenience, and its configuration is shown in FIG. The basic configuration is almost the same as the configuration of FIG. 1, but the temperature suppression control circuit uses a reset signal that is input to the device when a device error release signal is issued by the user or the like. A timer circuit 32 is provided for masking the flow rate abnormality detection for a certain time (for example, several seconds) from the reset signal. The output of the timer circuit 32 is the third input of the AND gate 27, and is the inhibition input of the AND gate 27 for a certain period from the time when the reset signal is applied. Further, the output of the timer circuit 32 masks the input of the AND gate 31 and prevents the user from being erroneously notified by the output of the comparator 25 for a certain period of time.

  With this configuration, when the cooling water flow rate changes instantaneously after the control power is turned on, there is no possibility of thermal damage to the power device. When the device error release signal is issued, a reset signal is input to the timer circuit 32 at that timing so that the control can be started after the timer time limit that the cooling water flow rate is assumed to be in the original stable state, and the flow rate is abnormal. Can prevent false alarms.

(Embodiment 4)
The configuration of the present embodiment is shown in FIG. The basic configuration of the present embodiment is a combination of the first, second, and third embodiments. As a temperature suppression control circuit, the power is reduced when the cooling water flow rate setting device 26 sets the cooling water flow rate or lower. The device junction temperature rise suppression control, the power device junction temperature rise suppression start after the first switching operation by the memory circuit 30, and the reset signal input when the semiconductor power converter apparatus error is released for a certain period of time A mask for detecting a decrease in the coolant flow rate by the timer circuit 32 is made possible.

  With this configuration, the protection operation by detecting the flow rate abnormality starts after the first IGBT_ON signal after the control power is turned on and after a certain time (several seconds) from the reset signal input.

  For example, when applied to a cooling device for a pulse power supply device for excimer laser, the supply of pulse current to the laser is started at the same time when the control power is turned on, so the cooling water flow rate fluctuates rapidly. Since the circuit operates, when monitoring is started from the first 1GBT_ON signal, the flow rate is not yet stable, and an abnormal flow rate may be reported.

  Therefore, in this embodiment, if there is a possibility that the flow rate may vary within the range where the device is not damaged even during the operation of the main circuit, a reset signal is input and masked at that timing, so that an erroneous flow rate is not detected. Information can be prevented.

(Embodiment 5)
The configuration of the present embodiment is shown in FIG. The basic configuration is substantially the same as the configuration of FIG. 1, but the temperature suppression control circuit is configured to prevent cooling water flow path system damage caused by erosion when the cooling water flow rate is abnormally increased. A circuit to monitor the upper limit of flow rate is added. However, a rise in the cooling water flow rate does not immediately cause damage due to erosion, so a filter is provided to protect the power supply in two stages. First, when the flow rate leading to the erosion of the cooling water flow path system is exceeded, a warning (risk notice) is first given, and neither the main circuit operation stop nor the device stop is performed. When the flow rate leading to this erosion exceeds a certain time, an abnormality is notified and the power device operation is stopped and the apparatus is stopped.

  In FIG. 5, the cooling water flow rate setting unit 33 sets an upper limit value (analog voltage value) of the cooling water flow rate at which the cooling water flow path system becomes eroded, and the comparator 34 cools the cooling water flow rate detected by the flow rate sensor 23. It is determined that the cooling water flow rate upper limit value set by the water flow rate setting unit 33 has been exceeded, the filter 35 confirms that the determination result of the comparator 34 continues for a predetermined time or longer, and the OR gate 36 determines whether the comparator 25 or 34 has determined. As a result, the input of the AND gate 27 is suppressed. The output of the comparator 34 is a warning notification signal to the user.

  With this configuration, in addition to monitoring when the cooling water flow rate is abnormally decreased, monitoring is also performed when the cooling water flow rate exceeds the upper limit setting value. Damage due to erosion can also be prevented. Further, since the erosion does not occur immediately when the cooling water flow rate rises, the filter 35 is provided to provide protection in two stages, so that it is not necessary to stop the power supply unnecessarily. For example, a semiconductor using an excimer laser It will also reduce downtime and increase the operating rate of the production line.

  In addition, the protection function of the cooling water system and the power device due to the abnormal increase in the cooling water flow rate according to this embodiment can be applied to the second to fourth embodiments to obtain the same effects.

(Embodiment 6)
FIG. 6 is a cooling control circuit diagram of the cooling device showing the present embodiment. 1 is different from FIG. 1 in that the cooling water flow rate setting value, which is a comparison criterion of the detected cooling water flow rate, is changed with the current operating frequency f of the power device per switching operation of the power device. It is the point which provided the flow volume -loss conversion circuit changed according to the present loss per unit time of the power device which changes with loss .

Specifically, this flow rate -loss conversion circuit counts the current operating frequency f of the power device 21 and the loss per switch operation of the power device by counting the output of the IGBT_ON signal generator 28 by the counter 41. A current loss per unit time of the power device 21 as a variable is obtained, and a change coefficient of the cooling water flow rate set in the cooling water flow rate setting device is obtained based on this loss. The cooling water flow rate setting device 42 changes the cooling water flow rate setting value at which the junction temperature rises to its maximum value Tj (max) with a change coefficient corresponding to the current loss magnitude obtained by the counter 41. This change coefficient may be set in advance as table data with the flow rate and the operating frequency as variables.

  Therefore, according to the present embodiment, in addition to the temperature suppression control of the power device by detecting the coolant flow rate by the flow sensor, the frequency-loss conversion circuit that changes the coolant flow rate setting value based on the operating frequency is provided. The cooling water flow rate setting value for determining that the flow rate has decreased until the power device 21 is damaged is changed according to the current loss of the power device 21, and the cooling water flow rate setting value is changed when the operating frequency f is high. By changing the height higher, the power device can be detected and reliably protected before thermal damage, and damage to the power device case and wire bonding due to sudden temperature changes can be reduced.

  Conversely, when the cooling water flow rate is lowered by changing the cooling water flow rate setting value at a low operating frequency f, the power device will not be thermally damaged, and the device will not be shut down. The operation can be continued, and the operable area of the apparatus can be further expanded. By expanding the operable region, for example, the downtime and the operating rate of a semiconductor manufacturing line using an excimer laser can be reduced.

(Embodiment 7)
FIG. 7 is a cooling control circuit diagram of the cooling device showing the present embodiment. 6 is different from FIG. 6 in that a storage circuit 43 such as an SR type flip-flop is provided as a temperature suppression control circuit, and the storage circuit 43 stores the first IGBT_ON signal output from the IGBT_ON signal generator 28. Then, by using this held output as the third input of the AND gate 27, the control for increasing the junction temperature of the power device is allowed after the first switching operation of the power device. Further, an AND gate 44 is provided, and the output of the comparator 25 is masked by the retained output of the storage circuit 43 to suppress the abnormality notification to the user.

  With this configuration, by detecting the flow rate abnormality after the control power is turned on and starting from the first IGBT_ON signal, the monitoring timing of the flow rate abnormality can be narrowed down after the first main circuit control start time after the control power is turned on, After that, if the abnormal flow is resolved, the control can be started. Also, even if there is a flow rate fluctuation after the control power is turned on, an abnormal flow rate is not reported erroneously.

(Embodiment 8)
FIG. 8 is a cooling control circuit diagram of the cooling device showing the present embodiment. The basic configuration is almost the same as the configuration of FIG. 6, but the temperature suppression control circuit uses a reset signal input to the device when a device error release signal is issued by the user or the like. A timer circuit 45 is provided for masking the flow rate abnormality detection for a certain time (for example, several seconds) from the reset signal. The output of the timer circuit 45 is the third input of the AND gate 27, and is the inhibition input of the AND gate 27 for a fixed time from the time when the reset signal is applied. Further, the output of the timer circuit 45 masks the input of the AND gate 44, and the output of the comparator 25 is prevented from being erroneously reported to the user for a certain period of time.

  With this configuration, if the cooling water flow rate changes instantaneously after the control power is turned on, the control device or the device will stop due to a flow rate abnormality, even though there is no possibility of thermal damage to the power device. When the device error release signal is issued, a reset signal is input to the timer circuit 45 at that timing, so that the control can be started after the timer period when the cooling water flow rate is assumed to be in the original stable state, and the flow rate is abnormal. Can prevent false alarms.

(Embodiment 9)
The configuration of the present embodiment is shown in FIG. The basic configuration of the present embodiment is a combination of the sixth, seventh, and eighth embodiments. As a temperature suppression control circuit, power is reduced when the cooling water flow rate set by the cooling water flow rate setting device 26 falls below the level. Device junction temperature rise suppression control, counter 41 changes the coolant flow rate setting value according to the operating frequency change, storage circuit 43 starts the first switching operation after power device junction temperature rise suppression, It is possible to mask the detection of a decrease in the coolant flow rate by the timer circuit 45 for a certain period of time from a reset signal that is input upon canceling the device error of the semiconductor power conversion device.

  With this configuration, the protection operation by detecting the flow rate abnormality starts after the first IGBT_ON signal after the control power is turned on and after a certain time (several seconds) from the reset signal input.

  For example, when applied to a cooling device for a pulse power supply device for excimer laser, the supply of pulse current to the laser is started at the same time when the control power is turned on, so the cooling water flow rate fluctuates rapidly. Since the circuit operates, when monitoring is started from the first 1GBT_ON signal, the flow rate is not yet stable, and an abnormal flow rate may be reported.

  Therefore, in this embodiment, if there is a possibility that the flow rate may vary within the range where the device is not damaged even during the operation of the main circuit, a reset signal is input and masked at that timing, so that an erroneous flow rate is not detected. Information can be prevented.

(Embodiment 10)
The configuration of the present embodiment is shown in FIG. The basic configuration is substantially the same as the configuration of FIG. 6, but the temperature suppression control circuit is configured to prevent cooling water flow path system from being damaged due to erosion when the cooling water flow rate is abnormally increased. A circuit to monitor the upper limit of flow rate is added. However, because the cooling water flow rate does not cause immediate damage, a filter is provided to protect the power supply in two stages. First, when the flow rate leading to the erosion of the cooling water flow path system is exceeded, a warning (risk notice) is first given, and neither the main circuit operation stop nor the device stop is performed. When the flow rate leading to this erosion exceeds a certain time, an abnormality is notified, and the main circuit operation is stopped and the apparatus is stopped.

  In FIG. 10, the cooling water flow rate setting unit 46 sets the cooling water flow rate upper limit value (analog voltage value) at which the cooling water flow path system is eroded, and the comparator 47 cools the cooling water flow rate detected by the flow sensor 23. It is determined that the cooling water flow rate upper limit set by the water flow rate setting unit 46 has been exceeded, the filter 48 confirms that the determination result of the comparator 47 continues for a certain period of time, and the OR gate 49 determines whether the comparator 25 or 47 is determined. As a result, the input of the AND gate 27 is suppressed. The output of the comparator 47 is a warning notification signal to the user.

  With this configuration, in addition to monitoring when the cooling water flow rate is abnormally decreased, monitoring is also performed when the cooling water flow rate exceeds the upper limit setting value. Damage due to erosion can also be prevented. In addition, since erosion does not occur immediately when the cooling water flow rate rises, it is not necessary to stop the power supply unnecessarily by providing a filter 48 and providing protection in two stages. For example, a semiconductor using an excimer laser It will also reduce downtime and increase the operating rate of the production line.

  In addition, the protection function of the cooling water system and the power device due to the abnormal increase in the cooling water flow rate according to this embodiment can be applied to the seventh to ninth embodiments to obtain the same effects.

(Embodiment 11)
FIG. 11 is a cooling control circuit diagram of the cooling device showing the present embodiment. 1 differs from FIG. 1 in that the cooling water flow rate setting value, which is a reference for comparing the detected cooling water flow rate, is changed according to the current loss per unit time of the power device, which varies with the main circuit voltage. The main circuit voltage-loss conversion circuit is provided.

The main circuit voltage-loss conversion circuit 51 obtains the current loss per unit time of the power device 21 from the main circuit voltage set value or the detected value. The relationship between the main circuit voltage and the power device loss is obtained in advance by design, experiment, or the like. The cooling water flow rate setting device 52 is a change coefficient corresponding to the current loss obtained by the main circuit voltage-loss conversion circuit 51, and the cooling water flow rate setting value at which the junction temperature rises to its maximum value T _j (max). To change. This change coefficient may be set in advance as table data using the main circuit voltage as a variable.

  Therefore, according to the present embodiment, in addition to the temperature suppression control of the power device by detecting the cooling water flow rate by the flow sensor, the main circuit voltage-loss conversion circuit that changes the cooling water flow rate setting value based on the main circuit voltage is provided. By providing, the cooling water flow rate setting value for determining that the flow rate has decreased until the power device 21 is damaged is changed according to the current loss of the power device 21, and when the main circuit voltage is high, the cooling water flow rate By changing the setting value to a higher value, the power device can be detected at an early stage before it is thermally damaged and reliably protected, and the damage to the power device case and wire bonding due to sudden temperature changes is also reduced. it can.

  Conversely, when the main circuit voltage is low, changing the cooling water flow rate setting value to a low value prevents the power device from being thermally damaged even when the cooling water flow rate is reduced, without shutting down the device. The operation can be continued, and the operable area of the apparatus can be further expanded. By expanding the operable region, for example, the downtime and the operating rate of a semiconductor manufacturing line using an excimer laser can be reduced.

Embodiment 12
FIG. 12 is a cooling control circuit diagram of the cooling device showing the present embodiment. 11 differs from FIG. 11 in that a storage circuit 53 such as an SR type flip-flop is provided as a temperature suppression control circuit, and the storage circuit 53 stores the first IGBT_ON signal output from the IGBT_ON signal generator 28. Then, by using this held output as the third input of the AND gate 27, the control for increasing the junction temperature of the power device is allowed after the first switching operation of the power device. Further, an AND gate 54 is provided, and the output of the comparator 25 is masked by the retained output of the storage circuit 53 to suppress the notification of abnormality to the user.

  With this configuration, by detecting the flow rate abnormality after the control power is turned on and starting from the first IGBT_ON signal, the monitoring timing of the flow rate abnormality can be narrowed down after the first main circuit control start time after the control power is turned on, After that, if the abnormal flow is resolved, the control can be started. Also, even if there is a flow rate fluctuation after the control power is turned on, an abnormal flow rate is not reported erroneously.

(Embodiment 13)
FIG. 13 is a cooling control circuit diagram of the cooling device showing the present embodiment. The basic configuration is almost the same as the configuration shown in FIG. 11, but as a temperature suppression control circuit, when a device error release signal is issued by a user or the like, a certain time (for example, several seconds) from the reset signal is issued. Provides a timer circuit 55 for masking the flow rate abnormality detection. The output of the timer circuit 55 is the third input of the AND gate 27, and is the inhibition input of the AND gate 27 for a certain period from the time when the reset signal is applied. Further, the output of the timer circuit 55 masks the input of the AND gate 54, and the erroneous output to the user by the output of the comparator 25 is suppressed for a certain period of time.

  With this configuration, if the cooling water flow rate changes instantaneously after the control power is turned on, the control device or the operation stop due to a flow rate abnormality may occur depending on the user, etc., even though there is no possibility of thermal damage to the power device. When a device error release signal is issued, a reset signal is input to the timer circuit 55 at that timing, so that control can be started after a timer period when the cooling water flow rate is assumed to be in the original stable state, and the flow rate abnormality Can prevent false alarms.

(Embodiment 14)
The configuration of the present embodiment is shown in FIG. The basic configuration of the present embodiment is a combination of the eleventh, twelfth, and thirteenth embodiments, and the temperature suppression control circuit is powered when the cooling water flow rate is set below the cooling water flow rate set by the cooling water flow rate setting device 26. The device junction temperature rise suppression control, the main circuit voltage-loss conversion circuit 51 changes the cooling water flow rate setting value according to the main circuit voltage change, and the memory circuit 53 performs the first switching operation and then the power device junction. It is possible to mask the detection of a decrease in the coolant flow rate by the timer circuit 55 for a certain period of time from the start of temperature rise suppression and the reset signal that is input when the semiconductor power converter apparatus error is released.

  With this configuration, the protection operation by detecting the flow rate abnormality starts after the first IGBT_ON signal after the control power is turned on and after a certain time (several seconds) from the reset signal input.

  For example, when applied to a cooling device for a pulse power supply device for excimer laser, the supply of pulse current to the laser is started at the same time when the control power is turned on, so the cooling water flow rate fluctuates rapidly. Since the circuit operates, when monitoring is started from the first 1GBT_ON signal, the flow rate is not yet stable, and an abnormal flow rate may be reported.

  Therefore, in this embodiment, if there is a possibility that the flow rate may vary within the range where the device is not damaged even during the operation of the main circuit, a reset signal is input and masked at that timing, so that an erroneous flow rate is not detected. Information can be prevented.

(Embodiment 15)
The configuration of the present embodiment is shown in FIG. The basic configuration is almost the same as the configuration shown in FIG. 11, but the temperature suppression control circuit uses cooling water in order to prevent damage caused by erosion of the cooling water flow path system when the cooling water flow rate rises abnormally. A circuit to monitor the upper limit of flow rate is added. However, because the cooling water flow rate does not cause immediate damage, a filter is provided to protect the power supply in two stages. First, when the flow rate leading to the erosion of the cooling water flow path system is exceeded, a warning (risk notice) is first given, and neither the main circuit operation stop nor the device stop is performed. When the flow rate leading to this erosion exceeds a certain time, an abnormality is notified, and the main circuit operation is stopped and the apparatus is stopped.

  In FIG. 15, the cooling water flow rate setting device 56 sets an upper limit value (analog voltage value) of the cooling water flow rate at which the cooling water flow path system becomes eroded, and the comparator 57 cools the cooling water flow rate detected by the flow sensor 23. It is determined that the cooling water flow rate upper limit value set by the water flow rate setting device 56 has been exceeded, the filter 58 confirms that the determination result of the comparator 57 continues for a certain period of time, and the OR gate 59 determines the determination of the comparator 25 or 57. As a result, the input of the AND gate 27 is suppressed. The output of the comparator 57 is a warning notification signal to the user.

  With this configuration, in addition to monitoring when the cooling water flow rate is abnormally decreased, monitoring is also performed when the cooling water flow rate exceeds the upper limit setting value. Damage due to erosion can also be prevented. In addition, since erosion does not occur immediately when the cooling water flow rate rises, the filter 58 is provided to provide protection in two stages, so that it is not necessary to stop the power supply unnecessarily. For example, a semiconductor using an excimer laser It will also reduce downtime and increase the operating rate of the production line.

  In addition, the protection function of the cooling water system and the power device due to the abnormal increase in the cooling water flow rate according to the present embodiment can be applied to the twelfth to fourteenth embodiments to obtain the same effects.

(Embodiment 16)
FIG. 16 is a cooling control circuit diagram of the cooling device showing the present embodiment. 1 is different from FIG. 1 in that the cooling water flow rate setting value, which is a comparison criterion of the detected cooling water flow rate, is changed by the current operating frequency f of the power device and the main circuit voltage per unit time of the power device. The frequency-loss conversion circuit and the main circuit voltage-loss conversion circuit which are changed according to the current loss are provided.

  Of these, the frequency-loss conversion circuit specifically counts the output of the IGBT_ON signal generator 28 with the counter 61, so that the current operating frequency f of the power device 21 is a variable per unit time of the power device 21. The current loss is calculated, and the change coefficient of the cooling water flow rate set in the cooling water flow rate setting device is obtained based on this loss. The main circuit voltage-loss conversion circuit 62 obtains the current loss per unit time of the power device 21 from the main circuit voltage setting value or the detected value thereof, and sets the cooling water flow rate set in the cooling water flow rate setting device based on this loss. Find the change factor of. The relationship between the main circuit voltage and the power device loss can be obtained in advance by design, experiment, or the like.

The cooling water flow rate setting unit 63 is responsive to a change coefficient corresponding to the current loss magnitude obtained by the counter 61 and a change coefficient corresponding to the current loss magnitude obtained from the main circuit voltage-loss conversion circuit 62. The cooling water flow rate set value at which the junction temperature rises to its maximum value T _j (max) is changed. This change coefficient may be set in advance as table data using the operating frequency and the main circuit voltage as variables.

  Therefore, according to the present embodiment, in addition to the temperature suppression control of the power device by detecting the cooling water flow rate by the flow sensor, the frequency-loss conversion circuit based on the operating frequency and the main circuit voltage based on the main circuit voltage -By providing the loss conversion circuit, the cooling water flow rate setting value for determining that the flow rate has decreased until the power device 21 is damaged is changed according to the current loss of the power device 21, and the high operating frequency f or When the main circuit voltage is high, the cooling water flow rate setting value is changed to a high value so that the power device can be detected at an early stage before thermal damage and reliable protection can be achieved. Damage to the case and wire bonding can also be reduced.

  Conversely, when the operating frequency f is low or the main circuit voltage is low, the power device will not be thermally damaged even when the cooling water flow rate is lowered by changing the cooling water flow rate setting value to a low level. The operation can be continued without stopping the operation, and the operable range of the apparatus can be further expanded. By expanding the operable region, for example, the downtime and the operating rate of a semiconductor manufacturing line using an excimer laser can be reduced.

(Embodiment 17)
FIG. 17 is a cooling control circuit diagram of the cooling device showing the present embodiment. 16 is different from FIG. 16 in that a storage circuit 64 such as an SR type flip-flop is provided as a temperature suppression control circuit, and the storage circuit 64 stores and holds the first IGBT_ON signal output from the IGBT_ON signal generator 28. Then, by using this held output as the third input of the AND gate 27, the control for increasing the junction temperature of the power device is allowed after the first switching operation of the power device. Further, an AND gate 65 is provided, and the output of the comparator 25 is masked by the retained output of the storage circuit 64 to suppress the abnormality notification to the user.

  With this configuration, by detecting the flow rate abnormality after the control power is turned on and starting from the first IGBT_ON signal, the monitoring timing of the flow rate abnormality can be narrowed down after the first main circuit control start time after the control power is turned on, After that, if the abnormal flow is resolved, the control can be started. Also, even if there is a flow rate fluctuation after the control power is turned on, an abnormal flow rate is not reported erroneously.

(Embodiment 18)
FIG. 18 is a cooling control circuit diagram of the cooling device showing the present embodiment. The basic configuration is substantially the same as the configuration of FIG. 16, but the temperature suppression control circuit uses a reset signal input to the device when the device error is canceled by the user, and the reset signal A timer circuit 66 is provided for masking the flow rate abnormality detection for a certain period of time (for example, several seconds). The output of the timer circuit 66 is the third input of the AND gate 27, and is the inhibition input of the AND gate 27 for a certain period from the time when the reset signal is applied. Further, the output of the timer circuit 66 masks the input of the AND gate 65, and the output of the comparator 25 is prevented from being erroneously reported to the user for a certain period of time.

  With this configuration, if the cooling water flow rate changes instantaneously after the control power is turned on, the control device or the operation stop due to a flow rate abnormality may occur depending on the user, etc., even though there is no possibility of thermal damage to the power device. When a device error release signal is issued, a reset signal is input to the timer circuit 66 at that timing, so that control can be started after a timer period in which the cooling water flow rate is assumed to be in the original stable state, and the flow rate is abnormal. Can prevent false alarms.

(Embodiment 19)
The configuration of the present embodiment is shown in FIG. The basic configuration of the present embodiment is a combination of the sixteenth, seventeenth, and eighteenth embodiments. As the temperature suppression control circuit, the coolant flow rate setting according to the main circuit voltage change by the main circuit voltage-loss conversion circuit 62 is used. It is possible to mask a predetermined time from the change of the value, the storage and holding of the first IGBT_ON signal output by the storage circuit 64, and the reset signal input by the timer circuit 66.

  With this configuration, the protection operation by detecting the flow rate abnormality starts after the first IGBT_ON signal after the control power is turned on and after a certain time (several seconds) from the reset signal input.

  For example, when applied to a cooling device for a pulse power supply device for excimer laser, the supply of pulse current to the laser is started at the same time when the control power is turned on, so the cooling water flow rate fluctuates rapidly. Since the circuit operates, when monitoring is started from the first 1GBT_ON signal, the flow rate is not yet stable, and an abnormal flow rate may be reported.

  Therefore, in this embodiment, if there is a possibility that the flow rate may vary within the range where the device is not damaged even during the operation of the main circuit, a reset signal is input and masked at that timing, so that an erroneous flow rate is not detected. Information can be prevented.

(Embodiment 20)
The configuration of this embodiment is shown in FIG. The basic configuration is substantially the same as the configuration of FIG. 16, but the temperature suppression control circuit is configured to prevent cooling water flow path system from being damaged due to erosion when the cooling water flow rate is abnormally increased. A circuit to monitor the upper limit of flow rate is added. However, because the cooling water flow rate does not cause immediate damage, a filter is provided to protect the power supply in two stages. First, when the flow rate leading to the erosion of the cooling water flow path system is exceeded, a warning (risk notice) is first given, and neither the main circuit operation stop nor the device stop is performed. When the flow rate leading to this erosion exceeds a certain time, an abnormality is notified, and the main circuit operation is stopped and the apparatus is stopped.

  In FIG. 20, a cooling water flow rate setting unit 67 sets a cooling water flow rate upper limit value (analog voltage value) at which the cooling water flow path system is eroded, and the comparator 68 cools the cooling water flow rate detected by the flow sensor 23. It is determined that the cooling water flow rate upper limit set by the water flow rate setting unit 67 has been exceeded, the filter 69 confirms that the determination result of the comparator 68 continues for a certain time or longer, and the OR gate 70 determines whether the comparator 25 or 68 is determined. As a result, the input of the AND gate 27 is suppressed. The output of the comparator 68 is a warning notification signal to the user.

  With this configuration, in addition to monitoring when the cooling water flow rate is abnormally decreased, monitoring is also performed when the cooling water flow rate exceeds the upper limit setting value. Damage due to erosion can also be prevented. In addition, since erosion does not occur immediately when the cooling water flow rate rises, the filter 69 is provided to provide protection in two stages, so that it is not necessary to stop the power supply unnecessarily. For example, a semiconductor using an excimer laser It will also reduce downtime and increase the operating rate of the production line.

  In addition, the protection function of the cooling water system and the power device due to the abnormal increase in the cooling water flow rate according to the present embodiment can be applied to the seventeenth to nineteenth embodiments to obtain the same effects.

21 Power device 22 Cooling fin 23 Flow rate sensor 24 Analog voltage converter 25, 34, 57, 68 Comparator 26, 33, 42, 46, 52, 56, 63, 67 Cooling water flow rate setting device 28 IGBT_ON signal generator 29 Gate drive Circuit 30, 43, 53, 64 Memory circuit 32, 45, 55, 66 Timer circuit 35, 58 Filter 41, 61 Counter (frequency-loss conversion circuit)
51, 62 Main circuit voltage-loss conversion circuit

Claims (8)

A cooling device for bringing a power device of a main circuit of a semiconductor power converter into contact with a cooling fin and flowing cooling water through the cooling fin to protect the power device from thermal damage,
A flow rate sensor for detecting a flow rate of cooling water flowing in the cooling fin;
The temperature difference between the junction temperature of the power device and the cooling water temperature is determined as a relational expression between the temperature of each part of the cooling device and the thermal resistance, and the junction temperature T _j determined by this relational expression is equal to or greater than the maximum value T _j (max). A cooling water flow rate setting device for setting the cooling water flow rate, and
It is provided with a temperature suppression control circuit that suppresses an increase in the junction temperature of the power device when the cooling water flow detected by the flow sensor is reduced to a cooling water flow set below the cooling water flow setting device. A cooling device for a semiconductor power converter. A cooling device for bringing a power device of a main circuit of a semiconductor power converter into contact with a cooling fin and flowing cooling water through the cooling fin to protect the power device from thermal damage,
A flow rate sensor for detecting a flow rate of cooling water flowing in the cooling fin;
The temperature difference between the junction temperature of the power device and the cooling water temperature is determined as a relational expression between the temperature of each part of the cooling device and the thermal resistance, and the junction temperature T _j determined by this relational expression is equal to or greater than the maximum value T _j (max). A cooling water flow rate setting device for setting the cooling water flow rate, and
A frequency-loss conversion circuit for obtaining a current loss per unit time from a current operating frequency of the power device, and obtaining a change coefficient of the cooling water flow rate set in the cooling water flow rate setting device based on the loss;
When the cooling water flow detected by the flow sensor falls below the cooling water flow set by the cooling water flow setter and the change coefficient of the frequency-loss conversion circuit, the junction temperature of the power device is increased. A cooling device for a semiconductor power conversion device, comprising a temperature suppression control circuit for suppressing the semiconductor power conversion device. A cooling device for bringing a power device of a main circuit of a semiconductor power converter into contact with a cooling fin and flowing cooling water through the cooling fin to protect the power device from thermal damage,
A flow rate sensor for detecting a flow rate of cooling water flowing in the cooling fin;
The temperature difference between the junction temperature of the power device and the cooling water temperature is determined as a relational expression between the temperature of each part of the cooling device and the thermal resistance, and the junction temperature T _j determined by this relational expression is equal to or greater than the maximum value T _j (max). A cooling water flow rate setting device for setting the cooling water flow rate, and
A main circuit voltage-loss conversion circuit for obtaining a current loss per unit time from a current main circuit voltage of the power device, and obtaining a change coefficient of the cooling water flow rate set in the cooling water flow rate setting device based on the loss;
When the cooling water flow detected by the flow sensor falls below the cooling water flow set by the cooling water flow setting device and the change coefficient of the main circuit voltage-loss conversion circuit, the junction temperature of the power device is reduced. A cooling device for a semiconductor power conversion device, comprising a temperature suppression control circuit for suppressing an increase. A cooling device for bringing a power device of a main circuit of a semiconductor power converter into contact with a cooling fin and flowing cooling water through the cooling fin to protect the power device from thermal damage,
A flow rate sensor for detecting a flow rate of cooling water flowing in the cooling fin;
The temperature difference between the junction temperature of the power device and the cooling water temperature is determined as a relational expression between the temperature of each part of the cooling device and the thermal resistance, and the junction temperature T _j determined by this relational expression is equal to or greater than the maximum value T _j (max). A cooling water flow rate setting device for setting the cooling water flow rate, and
A frequency-loss conversion circuit for obtaining a current loss per unit time from a current operating frequency of the power device, and obtaining a change coefficient of the cooling water flow rate set in the cooling water flow rate setting device based on the loss;
A main circuit voltage-loss conversion circuit for obtaining a current loss per unit time from a current main circuit voltage of the power device, and obtaining a change coefficient of the cooling water flow rate set in the cooling water flow rate setting device based on the loss;
When the cooling water flow rate detected by the flow rate sensor falls below the cooling water flow rate set by the cooling water flow rate setting device and changed by the change coefficient of the frequency-loss conversion circuit and the main circuit voltage-loss conversion circuit A cooling device for a semiconductor power converter, comprising a temperature suppression control circuit for suppressing an increase in junction temperature of a power device.   The temperature suppression control circuit includes a storage circuit that stores a first switching operation of a power device, and that allows an increase suppression of a junction temperature of the power device after the first switching operation. Item 5. The cooling device for a semiconductor power conversion device according to any one of Items 1 to 4.   5. The temperature suppression control circuit includes a timer circuit that masks detection of a decrease in the coolant flow rate for a predetermined time from a reset signal that is input when a device error of the semiconductor power converter is released. The cooling apparatus of the semiconductor power converter device of any one of these.   The temperature suppression control circuit includes a storage circuit that starts suppression of increase in the junction temperature of the power device after the first switching operation of the power device, and a reset signal that is input upon canceling the device error of the semiconductor power conversion device for a certain period of time. The cooling device for a semiconductor power conversion device according to any one of claims 1 to 4, further comprising a timer circuit for masking detection of a decrease in the cooling water flow rate.   The temperature suppression control circuit gives a warning (danger notice) when the cooling water flow rate exceeds the flow rate leading to erosion of the cooling water flow path system, and the power supply when the flow rate leading to this erosion exceeds a certain time. The cooling device for a semiconductor power conversion device according to any one of claims 1 to 7, further comprising an anti-corrosion circuit for a cooling water flow path system for stopping operation of the device and stopping the device.

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