Gate drive device, power converter, and inverter

Abstract

The present invention provides a gate drive device, a power converter, and an inverter that allow the estimation results to be used on the controller side. [Solution] According to one embodiment, the gate drive device includes a loss calculation circuit that estimates the loss value of a power device using the voltage values ​​of the power device at multiple points in time. The loss calculation circuit also includes an integration circuit that performs time integration based on the voltage values ​​at multiple points in time. The loss calculation circuit also includes an estimation circuit that estimates the loss value of the power device based on the result of the time integration.

Description

[Technical Field]

[0001] Embodiments of the present invention relate to a gate drive device, a power converter, and an inverter. [Background technology]

[0002] Power devices experience losses and short circuits due to degradation and other factors. Traditionally, power device losses have been estimated. If a power device is estimated to have significant losses, a fault signal is sent to the controller, which then protects the power device based on this signal. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] U.S. Patent No. 10601415 [Overview of the project] [Problems that the invention aims to solve]

[0004] In the circuit described above, the time during which the collector voltage of the power device exceeds a specified value, that is, the time during which a large current is flowing, is counted. If this time exceeds the specified value, it is determined that the power device is overheating and that a short circuit has occurred somewhere in the circuit, and a fault signal is sent to the controller.

[0005] There is a request to use the estimated loss value for control at the controller. However, the circuit described above does not consider transmitting the estimated loss value to the controller for use. Furthermore, transmitting waveform data such as current and voltage to the controller side, which is an isolated transmission section, is not practical due to the low communication speed.

[0006] Therefore, this embodiment of the present invention provides a gate drive device, a power converter, and an inverter that make the estimation results available on the controller side. [Means for solving the problem]

[0007] According to one embodiment, the power device includes a loss calculation circuit that estimates the loss value of the power device using the voltage values ​​of the power device at multiple points in time. The loss calculation circuit also includes an integration circuit that performs time integration based on the voltage values ​​at multiple points in time. The loss calculation circuit also includes an estimation circuit that multiplies the result of the time integration by a predetermined proportionality constant. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram of the power conversion device in the first embodiment. [Figure 2] This is an example of a circuit diagram of the inverter in the first embodiment. [Figure 3] This figure shows the configuration of the loss calculation circuit and power device in the first embodiment. [Figure 4] This diagram shows the relationship between the drain-source voltage VCE of a power device and the drain current flowing at that time. [Figure 5] This figure shows a comparison of the estimated loss in the first embodiment and the estimated loss in the comparative example. [Figure 6] This diagram illustrates another operation of the power device in the first embodiment. [Figure 7] This figure shows the configuration of the loss calculation circuit and power device in the second embodiment. [Figure 8] This figure shows the configuration of the loss calculation circuit and power device in the first modified example of the second embodiment. [Figure 9] This figure shows the configuration of the loss calculation circuit and power device in a second modified example of the second embodiment. [Figure 10] This figure shows the configuration of the loss calculation circuit and power device in a third modified example of the second embodiment. [Figure 11] This figure shows the configuration of the loss calculation circuit and power device in a fourth modified example of the second embodiment. [Figure 12] This figure shows the configuration of the current estimation circuit in a fifth modified example of the second embodiment. [Figure 13] This figure shows the configuration of the short-circuit detection circuit in the sixth modified example of the second embodiment. [Figure 14] This figure shows the configuration of the short-circuit detection circuit in the seventh modified example of the second embodiment. [Figure 15] This figure shows the configuration of the short-circuit detection circuit in the eighth modified example of the second embodiment. [Figure 16] This figure shows the configuration of the loss calculation circuit and power device in the ninth modified example of the second embodiment. [Figure 17] This figure shows the configuration of the loss calculation circuit and power device in the third embodiment. [Figure 18] This figure shows the configuration of the loss calculation circuit and power device in a modified example of the third embodiment. [Figure 19] This figure shows the configuration of the loss calculation circuit and power device in the fourth embodiment. [Figure 20] This figure shows the configuration of the loss calculation circuit and power device in a modified example of the fourth embodiment. [Modes for carrying out the invention]

[0009] (First Embodiment) Embodiments of this disclosure will be described below with reference to the drawings. These embodiments are not intended to limit the present invention. The drawings are schematic or conceptual, and the proportions of each part may not necessarily be the same as those of actual objects. In the specification and drawings, elements similar to those described above with respect to previously shown drawings are denoted by the same reference numerals, and detailed descriptions are omitted as appropriate.

[0010] Furthermore, in this disclosure, the terms "greater than or equal to" and "less than or equal to" may be interpreted as "greater than" and "less than," respectively.

[0011] Figure 1 is a schematic diagram of the power converter 1 in the first embodiment.

[0012] The power converter 1 comprises a gate drive unit 10, a power device 20, and a controller 30. The power converter 1 outputs various signals under the control of the controller 30, and operates the power device 20 based on these signals. In addition, the power converter 1 of this embodiment estimates the loss value from the on-voltage of the power device 20. If it is determined that the loss value occurring in the power device 20 is large, the device is shut down or otherwise controlled to protect the power device 20.

[0013] The gate drive unit 10 includes a driver circuit 11 and a loss calculation circuit 12. The driver circuit 11 operates in response to a PWN signal supplied from the controller 30 and drives the gate of the power device 20 by supplying a control voltage Dr. In this way, the gate drive unit 10 controls the operation of the power device 20. The loss calculation circuit 12 performs a short-circuit detection of the power device 20 and estimates the losses occurring in the circuit based on the ON voltage of the power device 20. The detailed configuration of the loss calculation circuit 12 will be described later. The short-circuit detection results and the loss estimation results are transmitted to the controller 30.

[0014] The power device 20 comprises a switching element 201 and a freewheeling diode 202. In this example, the power device 20 also includes a sensor 23 on the input side of the gate drive unit 10. The power device 20 supplies a power supply voltage as a sinusoidal signal to a connected load (not shown) based on a control voltage Dr input from the gate drive unit 10 to the gate of the switching element 201. The load (not shown) is, for example, a three-phase motor. In this embodiment, sensor data measured by the sensor 23 installed on the power device 20 is supplied to the loss calculation circuit 12. In this example, the sensor 23 controls the voltage V of the loss calculation circuit 12. DESAT This is measured.

[0015] The controller 30 controls the gate drive unit 10. The controller 30 controls the operation by supplying a PWN signal to the driver circuit 11, and also supplies calculation parameters used by the loss calculation circuit 12 when performing loss estimation, adjusting the parameters in the loss calculation. The controller 30 also receives the short-circuit detection result and the loss estimation result as estimation results from the loss calculation circuit 12. The short-circuit detection result is received, for example, as a short-circuit detection signal, and the loss estimation result is received, for example, as an overheat detection signal or as loss data (hereinafter also referred to as Loss data) with the estimated loss value. The controller 30 may also receive the short-circuit detection signal and the overheat detection signal together as a Fault signal. The controller 30 may also use this feedbacked Loss data and Fault signal to, for example, control the duty cycle of the PWN signal for the next cycle. The controller 30 may also display these values ​​on a display device (not shown).

[0016] Furthermore, the signal transmission section between the gate drive unit 10 and the controller 30 is also called the isolated transmission section.

[0017] Figure 2 shows an example of a circuit diagram of the inverter 100 in the first embodiment.

[0018] In this diagram, the controller 30 and gate drive unit 10 are omitted from the description. As shown in the diagram, multiple power devices 20 are used, for example, in a three-phase AC inverter 100. Each of these power devices 20 is connected to the gate drive unit 10 and operates based on the PWM signal from the controller 30 as described above. For the sake of explanation, a power device 20 provided on the opposite side of a power device 20 of a certain phase will be referred to as power device 20', and the switching element 201 and freewheeling diode 202 included in power device 20' will be referred to as switching element 201' and freewheeling diode 202', respectively.

[0019] Figure 3 shows the configuration of the loss calculation circuit 12 and the power device 20 in the first embodiment.

[0020] The loss calculation circuit 12 in this embodiment includes a short-circuit determination circuit 14, an estimation circuit 101, a blanking circuit 102, a first integration circuit 103, a first D / A conversion circuit 104, a comparison circuit 105, a failure determination circuit 106, an A / D conversion circuit 107, and a switch 130. In this embodiment, for the purpose of mainly explaining the operation of the loss calculation circuit 12, the description of the connection relationship of the driver circuit 11 is omitted.

[0021] The loss calculation circuit 12 of this embodiment receives, as sensor data, the input of the voltage V, which is the input voltage, and based on this voltage, calculates the drain-source voltage V of the switching element 201, and then estimates the loss value generated in the switching element 201. Also, in this embodiment, when the drain-source voltage of the power device 20 is V with reference to GND, the total voltage drop of elements such as the diode 203 and the resistor 204 included in the power device 20 is V (hereinafter, simply referred to as the voltage drop V) for explanation. In the power conversion device 1, since the voltage that can be measured as the data of the sensor 23 by the loss calculation circuit 12 is V, when the loss calculation circuit 12 uses V instead of V for loss calculation, according to Equation (1), it may be calculated using the voltage V and the voltage drop V. Also, a voltage calculation circuit may be provided in the loss calculation circuit 12 for the calculation of V. DESAT The loss calculation circuit 12 of this embodiment receives, as sensor data, the input of the voltage V, which is the input voltage, and based on this voltage, calculates the drain-source voltage V of the switching element 201, and then estimates the loss value generated in the switching element 201. Also, in this embodiment, when the drain-source voltage of the power device 20 is V with reference to GND, the total voltage drop of elements such as the diode 203 and the resistor 204 included in the power device 20 is V (hereinafter, simply referred to as the voltage drop V) for explanation. In the power conversion device 1, since the voltage that can be measured as the data of the sensor 23 by the loss calculation circuit 12 is V, when the loss calculation circuit 12 uses V instead of V for loss calculation, according to Equation (1), it may be calculated using the voltage V and the voltage drop V. Also, a voltage calculation circuit may be provided in the loss calculation circuit 12 for the calculation of V. CE を算出した後、スイッチング素子201で発生する損失値を推定する。また、本実施形態では、GNDを基準として、パワーデバイス20のドレイン-ソース間電圧をV CE とした場合、パワーデバイスに含まれるダイオード203分及び抵抗204分といった素子の合計の電圧降下をV p (以下、単に電圧降下V p とも表記する)として説明する。電力変換装置1において、損失計算回路12で、センサ23のデータとして計測可能な電圧はV DESAT であるため、損失計算回路12は、損失計算を行うにあたり、電圧V DESAT の代わりにV CE を用いる場合、式(1)により、電圧V DESAT 及び電圧降下V p を用いて算出してもよい。また、V CE の計算にあたり、損失計算回路12に電圧算出回路が設けられてもよい。<000\\0277>V CE =V<000001\\4>-V p (1) [[ID=\\7]]

[0022] The short-circuit determination circuit 14 performs the short-circuit determination of the loss calculation circuit 12. The short-circuit determination circuit 14, for example, V\\0]] CEA short circuit is detected based on the time integral of the value over time t. For example, the short circuit detection circuit 14 compares the integrated value with the detection threshold to determine if a short circuit has occurred. For example, if the integrated value is greater than the detection threshold, the short circuit detection circuit 14 determines that a short circuit has occurred in the power device 20. If the integrated value is equal to the detection threshold or if the integrated value is less than the detection threshold, the short circuit detection circuit 14 determines that no short circuit has occurred in the power device 20. For example, in the former case, the short circuit detection circuit 14 outputs a Low signal as the short circuit detection signal, and in the latter case, it outputs a High signal.

[0023] The blanking circuit 102 receives the input V CE Blanking of the value of is performed. For example, when the power device 20 is turned on, a high voltage may be generated in the switching element 201. To prevent incorrect judgment, V CE While the calculated value is unstable, this period is set as a predetermined blanking time, and the blanking circuit 102 is used to V CE The circuit is blanked. During the blanking time, the loss calculation function is disabled. The blanking time is determined, for example, based on the capacitance value of the blanking capacitance included in the blanking circuit 102. During the blanking time, the loss calculation circuit 12 may output 0V to disable loss calculations for this value.

[0024] The first integrating circuit 103 is V CE The value of is integrated with respect to time t. The integral value calculated by the first integrating circuit 103 is expressed by equation (2).

number

[0025] Furthermore, the loss generated in the power device 20 is V CE The time integral value is roughly proportional to the time integral value. Therefore, the loss calculation circuit 12 calculates this integral value and estimates it as the loss value by multiplying it by a predetermined proportionality constant. When this loss is taken as Loss, the relationship in equation (3) holds. The loss calculation circuit 12 takes the loss threshold Lth If the estimated loss value is greater than the calculated loss, a fault signal is output to the controller 30. The loss calculation circuit 12 may, for example, obtain a proportionality constant from the LUT signal as a calculation parameter. The estimation circuit 101 calculates the loss value by multiplying the proportionality constant obtained as a calculation parameter by the right-hand side of equation (3), i.e., the integral result.

number

[0026] The first D / A conversion circuit 104 receives input from the controller 30 of a LUT (Look Up Table) write signal which will be a calculation parameter, and the loss threshold L included in this signal th The first D / A conversion circuit 104 converts from a digital value to an analog value. The loss threshold L th After digital-to-analog conversion, the signal is input to the comparator circuit 105.

[0027] The comparison circuit 105 compares the value of the loss and the loss threshold L th The values ​​are compared. The comparison circuit 105 compares the loss value Loss to the loss threshold L. th If it is greater than the loss threshold L, the power device 20 is determined to be in an overheating state. The comparison circuit 105 determines that the loss value Loss is greater than the loss threshold L th If the loss value Loss is equal to or equal to the loss threshold L th If the value is smaller than the given value, it is determined that the power device 20 is not overheating. The comparison circuit 105 outputs a Low signal as an overheat detection signal in the former case, and a High signal in the latter case.

[0028] The fault detection circuit 106 receives the output result from the short-circuit detection circuit 14 and the output result from the comparison circuit 105 as input, performs fault detection, and outputs a Fault signal to the controller 30 if it determines that a fault has occurred. In this embodiment, the fault detection circuit 106 is configured as a NOR circuit. The NOR circuit outputs a High signal when both the output result from the short-circuit detection circuit 14 and the output result from the comparison circuit 105 are Low. Also, if either the output result from the short-circuit detection circuit 14 or the output result from the comparison circuit 105 is High, the NOR circuit outputs a Low signal. In this case, the Low signal corresponds to the Fault signal, and the controller 30, upon receiving the Fault signal, can determine that a fault has occurred in the power device 20. In this embodiment, a NOR circuit is used as the fault detection circuit 106, but it may also be configured as an OR circuit, for example. In this case, if either the output result from the short-circuit detection circuit 14 or the output result from the comparison circuit 105 is High, the OR circuit outputs a High signal. In this case, the High signal is the Fault signal. Furthermore, the fault detection circuit 106 may be constructed using various logic circuits, not limited to these examples.

[0029] The A / D conversion circuit 107 converts the Loss value from an analog value to a digital value and transmits it to the controller 30 as Loss data. Upon receiving the Loss data, the controller 30 performs various controls, such as PWN control for the next cycle, based on the Loss value occurring in the power device 20.

[0030] Switch 130 connects the loss calculation circuit 12 to GND when opened or closed.

[0031] Figure 4 shows the drain-source voltage V of the power device 20. CE This diagram shows the relationship between the drain current flowing at that time.

[0032] In this figure, the horizontal axis represents the drain-source voltage V of the power device 20. CEThis figure shows the drain-source voltage V for five different control voltages Dr (1st control voltage < 2nd control voltage < 3rd control voltage < 4th control voltage < 5th control voltage), respectively. CE This shows the relationship between the drain current and the drain current.

[0033] As shown in the figure, at each control voltage, the drain-source voltage V CE The relationship between the current and the drain current is roughly proportional. Also, since the current value and the loss are correlated, in this embodiment, the drain-source voltage V CE The loss value is estimated by multiplying the time integral of by a proportionality constant. Below, the drain-source voltage V CE This is simply referred to as voltage V CE It can also be written as follows:

[0034] Figure 5 shows a comparison image of the estimated loss in the first embodiment and the estimated loss in the comparative example.

[0035] Figure 5(A) shows the estimated loss value of the gate drive device 10 in this embodiment, and Figure 5(B) shows the estimated loss value of the gate drive device 10 in the comparative example. For explanatory purposes, the gate drive device 10 and power device 20 in this embodiment will be referred to as gate drive device 10 and power device 20, and the gate drive device 10 and power device 20 in the comparative example will be referred to as gate drive device 10' and power device 20'.

[0036] In the comparative example gate drive device 10', the collector voltage V of the power device 20' is const The loss value is estimated by multiplying this value by time t.

[0037] In Figure 5(A), the gate drive device 10 controls the voltage V, which is a variable value. CETo estimate the loss value based on the time integral of , the sum of the areas of the strips in each interval of dt becomes the estimated loss value. On the other hand, in Figure 5(B), the collector voltage V is a constant value. const The rectangular area obtained by multiplying by time t becomes the estimated loss value. The gate drive device 10 of this embodiment uses a variable voltage V CE By using this method to estimate the loss value, the accuracy is improved compared to the comparative example.

[0038] Figure 6 illustrates another operation of the power device 20 in the first embodiment.

[0039] This diagram explains the switching element 201 and the freewheeling diode 202, which are components of the power device 20. The loss estimation described above is the calculation method when the control voltage Dr is supplied to the switching element 201 and it becomes the ON voltage. During the ON period, current flows in the positive direction as shown in the diagram. On the other hand, while the switching element 201 is at the OFF voltage, current flows in the reverse direction through the freewheeling diode 202, resulting in a reverse conduction state. Even during the OFF period, the gate drive device 10 controls the voltage V of the switching element 201. CE Loss estimation can be performed by calculating the time integral value and multiplying it by the proportionality constant.

[0040] According to this embodiment, the gate drive device 10 controls the voltage V of the power device 20, which is a variable value. CE The loss value is estimated based on the time integral value. The estimated loss value is also transmitted to the controller 30 as Loss data, so that the controller 30 can use these values ​​to control the power device 20. Furthermore, since the gate drive unit 10 estimates the loss value by the method described above, the accuracy of the loss estimation can be improved.

[0041] Furthermore, according to this embodiment, the gate drive unit 10 performs short-circuit detection in addition to overheat detection by loss estimation. This allows for the safe use of the power device 20.

[0042] Furthermore, according to this embodiment, the gate drive device 10 monitors the voltage V in the reverse conduction state of the power device 20 not only during the ON period but also during the OFF period. CE Loss can be estimated by measuring [this value].

[0043] (Second Embodiment) Figure 7 shows the configuration of the loss calculation circuit 12 and the power device 20 in the second embodiment.

[0044] The loss calculation circuit 12 in this embodiment includes a short-circuit detection circuit 14, an estimation circuit 101, a blanking circuit 102, a first integration circuit 103, a first D / A conversion circuit 104, a comparison circuit 105, a fault detection circuit 106, an A / D conversion circuit 107, a second D / A conversion circuit 108, a first subtraction circuit 109, an n-th power circuit 110, a first multiplication circuit 112, and a switch 130. In this embodiment, the operation of the loss calculation circuit 12 is mainly described, so the connection relationship of the driver circuit 11 is omitted from the description. Also in this embodiment, the circuit comprising the second D / A conversion circuit 108, the first subtraction circuit 109, the n-th power circuit 110, and the first multiplication circuit 112 is also called the current estimation circuit 13. In the following embodiments, the circuit is configured using a subtraction circuit, but an addition circuit may be used instead of a subtraction circuit depending on the input value.

[0045] In this embodiment, the loss calculation circuit 12 uses the n-th power circuit 110 to calculate the current value I flowing through the power device 20. C The current is estimated, and the loss is estimated based on the estimated current. In this embodiment, the loss calculation circuit 12 estimates the voltage drop V of the work function that occurs when the diode included in the power device 20 conducts. f (Hereafter, simply voltage drop V f (Also written as) with voltage V CE Corrected current value I C In this embodiment, the voltage drop V is estimated and the loss is estimated. f This will be explained using a value (a constant value in this example) that the controller 30 holds as a calculation parameter.

[0046] Also, as described above, the relationship between the voltage V CE and the drain current is generally a proportional relationship. Therefore, in this embodiment, the loss calculation circuit 12 uses the value obtained by raising to the nth power (n is a real number where 0 <= n <= 2) the value obtained by subtracting the voltage drop V CE from the voltage V f as the estimated value of the current. Since the value of n changes depending on the value of the control voltage Dr, it is a design matter as a calculation parameter. For example, values such as 0.9 or 1 may be used as the value of n.

[0047] The second D / A conversion circuit 108 receives the input of the LUT write signal serving as a calculation parameter from the controller 30, and converts the value of the voltage drop V f included in this signal from a digital value to an analog value. The first D / A conversion circuit 104 digitally - analog - converts the loss threshold L th and inputs it to the first subtraction circuit 109.

[0048] The first subtraction circuit 109 performs an operation of subtracting the voltage drop V CE from the voltage V f . The operation result is expressed by Equation (4). Also, the first subtraction circuit 109 inputs the operation result to the n - th power circuit 110. Also, in this embodiment, correction is performed using a subtraction circuit, but correction may also be realized by an addition circuit. V CE - V f (4)

[0049] The n - th power circuit 110 receives the input of the LUT write signal serving as a calculation parameter from the controller 30, raises the operation result of the first subtraction circuit 109 to the power of the value of n included in this signal, and estimates this value as the current value I C . The operation result is expressed by Equation (5). Also, the n - th power circuit 110 inputs the operation result to the first multiplication circuit 112. When estimating the loss, a proportionality constant may be provided in Equation (5). In this case, the loss calculation circuit 12 may, for example, obtain the proportionality constant as a calculation parameter from the LUT signal.

Equation

[0050] The first multiplier circuit 112 calculates the estimated current value I C The value and voltage V CE Multiplication is performed. Since the instantaneous value of the loss is proportional to the multiplication result, the first multiplication circuit 112 may multiply this multiplication result by a proportionality constant to calculate the instantaneous value of the loss. The first multiplication circuit 112 inputs the calculation result to the blanking circuit 102.

[0051] The blanking circuit 102 performs blanking of the input value. For example, when the power device 20 is turned on, the current value may be estimated as a high value for the reasons mentioned above. Thus, while the operation of the power device 20 is unstable, the accuracy of the value estimated as the loss value is low, so the blanking circuit 102 blanks the calculation result of the first multiplication circuit 112.

[0052] The first integrating circuit 103 integrates the output of the blanking circuit with respect to time t. The integral value calculated by the first integrating circuit 103 is expressed by equation (6). The estimation circuit 101, as described above, estimates the loss value by multiplying the integration result by a proportionality constant.

number

[0053] Figure 8 shows the configuration of the loss calculation circuit 12 and the power device 20 in the first modified example of the second embodiment.

[0054] In this modified example, from the standpoint of the device's voltage withstand capability, the voltage V input to the loss calculation circuit 12 is DESAT To input a lower value, the voltage V of the switching element 201 CE The voltage is divided by capacitance and input. In this modified example, the first capacitance 205 and the second capacitance 206 that perform the capacitance division are connected in series, and these capacitances are further connected in parallel between the drain and source terminals of the switching element 201. The voltage V becomes the input voltage of the loss calculation circuit 12. DESATThe value of is obtained from the terminal between the first capacitor 205 and the second capacitor 206. The capacitance values ​​of the first capacitor 205 and the second capacitor 206 are design items determined by the withstand voltage of the loss calculation circuit 12, etc. In this modified example as well, the current estimation circuit 13 uses the voltage V CE Based on the proportional relationship between the drain current and the current value I C Calculate.

[0055] Furthermore, in this modified example, the short-circuit detection circuit 14 receives the current value I estimated by the current estimation circuit 13. C The value that indicates (for the sake of simplicity in the explanation below, simply the current value I C The input is (also written as ). The short-circuit detection circuit 14 detects the current value I C For example, a short circuit can be detected by comparing threshold values. In this circuit, the voltage drop V p No correction is needed.

[0056] Figure 9 shows the configuration of the loss calculation circuit 12 and the power device 20 in a second modified example of the second embodiment.

[0057] In this modified example, the voltage V input to the loss calculation circuit 12 is DESAT To input a lower value, the voltage V of the switching element 201 CE The voltage is divided by resistors and input. In this modified example, the first resistor 207 and the second resistor 208 that perform the resistive voltage division are connected in series, and these resistors are further connected in parallel between the drain and source terminals of the switching element 201. The voltage V becomes the input voltage of the loss calculation circuit 12. DESAT The value of is obtained from between the first resistor 207 and the second resistor 208. The capacitance values ​​of the first resistor 207 and the second resistor 208 are design items determined by the voltage rating of the loss calculation circuit 12, etc. Similar to the embodiment described above, the current estimation circuit 13 uses the voltage V CE Based on the proportional relationship between the drain current and the current value I C Calculate the voltage drop V in this circuit. p No correction is needed.

[0058] Figure 10 shows the configuration of the loss calculation circuit 12 and the power device 20 in a third modified example of the second embodiment.

[0059] In this modified version, the calculation parameters for estimating the current value are changed according to the temperature of the power device 20. In addition to the configuration shown in Figure 7, the loss calculation circuit 12 includes a temperature estimation circuit 140. Furthermore, the power device 20 is equipped with a thermistor 141.

[0060] In this modified example, the loss calculation circuit 12 includes a temperature estimation circuit 140 that estimates the temperature of the power device 20. In this example, a thermistor 141 that measures temperature is provided on the source side of the switching element 201 for temperature estimation, and the temperature estimation circuit 140 estimates the temperature T of the power device 20 based on the resistance value of the thermistor 141. The temperature estimation circuit 140 inputs the estimated temperature T to the current estimation circuit 13.

[0061] The current estimation circuit 13 calculates the current value I C In estimating this, for example, the value of n used in the n-th power circuit 110 and the voltage drop V used in the second D / A conversion circuit 108 are considered. f The value is corrected by the temperature T. This correction value may be input as a calculation parameter for the LUT write signal, for example, or a correction circuit may be provided in the current estimation circuit 13 to calculate the correction value.

[0062] Figure 11 shows the configuration of the loss calculation circuit 12 and the power device 20 in a fourth modified example of the second embodiment.

[0063] In this modified example, the loss calculation circuit 12 adds the switching loss value generated by the elements in the power device 20 to the loss value (mainly conduction loss) calculated by the estimation circuit 101, and uses the sum of these values ​​as the estimated loss value. In addition to the configuration shown in Figure 7, the loss calculation circuit 12 includes a switching loss input circuit 150 and an addition circuit 151.

[0064] The switching loss input circuit 150 inputs the loss value generated by the switching of elements included in the power device 20 to the summing circuit 151. This loss value may be a constant value determined by the design as a calculation parameter. The switching loss value may be, for example, the loss value generated by a single switching of elements included in the power device 20, or it may be the loss value generated during the integration time output from the first integrating circuit 103.

[0065] Furthermore, in this modified example, the switching loss input circuit 150 also inputs this switching loss value to the short-circuit detection circuit 14. CE The value of is integrated over time t, multiplied by a proportionality constant, and the value of the switching loss is added to this value. A short circuit is detected by comparing this sum with a threshold value.

[0066] Figure 12 shows the configuration of the current estimation circuit 13 in a fifth modified example of the second embodiment.

[0067] This figure shows an excerpt of the configuration of the current estimation circuit 13 in this modified example; other configurations can be, for example, those shown in Figures 7 to 11.

[0068] Depending on the type of power device 20 used, the voltage V CE The order of the drain current, the offset of the work function, and the temperature dependence coefficient differ for each. In this modified example, the current estimation circuit 13 generates a temperature coefficient C according to the temperature of the power device 20 and corrects the current value.

[0069] In this modified example, the current estimation circuit 13 includes a second D / A conversion circuit 108, a first subtraction circuit 109, an n-th power circuit 110, a temperature coefficient generation circuit 152, and a second multiplication circuit 153.

[0070] In this modified example, the loss calculation circuit 12 uses the voltage V CE Voltage drop V f The value obtained by subtracting [a certain factor] is raised to the power of n (where n is a real number between 0 and 2), and then multiplied by the temperature coefficient C to obtain the estimated current.

[0071] The temperature coefficient generation circuit 152 receives a temperature T as input and calculates a temperature coefficient C corresponding to this value. The value of temperature T may be a value measured by a sensor not shown, such as a thermistor 141. If the controller 30 knows the value of temperature T, the value of temperature T may be included in the LUT write signal and this signal may be input to the temperature coefficient generation circuit 152. Alternatively, the temperature coefficient C may be directly included in the LUT write signal and input to the current estimation circuit 13. The input may also be received from the temperature estimation circuit 140. The temperature coefficient generation circuit 152 inputs the calculated temperature coefficient C to the second multiplication circuit 153.

[0072] The second multiplication circuit 153 multiplies the result of the n-th power circuit 110 by the temperature coefficient C. This multiplication result becomes the estimated value of the current. The estimated value of the current is expressed by equation (7).

number

[0073] Current value I estimated by current estimation circuit 13 C This is used for loss estimation and short-circuit detection, similar to the above.

[0074] Figure 13 shows the configuration of the short-circuit detection circuit 14 in the sixth modified example of the second embodiment.

[0075] In this modified example, the short-circuit detection circuit 14 includes a detection threshold generation circuit 121, a comparison circuit 122, a blanking circuit 123, and a noise reduction filter 124. The short-circuit detection circuit 14 receives a current value I from the current estimation circuit 13. C Based on this, a short-circuit detection is performed. For example, if a large current flows through the power device 20, the short-circuit detection circuit 14 determines that a short circuit has occurred. The short-circuit detection circuit 14 can employ, for example, the loss calculation circuit 12 shown in Figures 8-10.

[0076] The detection threshold generation circuit 121 receives a temperature T value as input and generates a current threshold for short-circuit detection. The temperature T value may be a value measured by a sensor (not shown), such as a thermistor 141. If the controller 30 knows the temperature, the temperature value may be included in the LUT write signal and this signal may be input to the detection threshold generation circuit 121. The current threshold may also be included in the LUT write signal and input to the short-circuit determination circuit 14.

[0077] The comparison circuit 122 reads the current value I estimated by the current estimation circuit 13. C The detection threshold generation circuit 121 accepts the threshold generated as input and performs a short-circuit determination. For example, current value I C If the value is above a threshold, the comparison circuit 122 determines that a short circuit has occurred. As a result of the short circuit determination, the comparison circuit 122 outputs a High signal if a short circuit has occurred, and a Low signal if no short circuit has occurred.

[0078] The blanking circuit 123 receives a PWM signal input from the controller 30 and the short-circuit detection result from the short-circuit detection circuit 14 as input, and performs blanking based on the short-circuit detection result according to the PWM signal. For example, during periods of unstable operation, such as when the power device 20 is turned on, the short-circuit detection result is unstable, so blanking may be performed by the blanking circuit 123.

[0079] The noise reduction filter 124 removes noise from the value output from the blanking circuit 123. For example, the current value I input to the short-circuit detection circuit 14 C Since this is an instantaneous value, if an outlier is entered, this value should be removed.

[0080] In this modified example, the short-circuit detection circuit 14 configuration is such that the value of n in equation (5) is set to n=1, and the voltage drop V f The value of V f When set to =0, it can be used as the short-circuit detection circuit 14 explained in Figure 7.

[0081] Figure 14 shows the configuration of the short-circuit detection circuit 14 in the seventh modified example of the second embodiment.

[0082] In this modified example, the short-circuit detection circuit 14 includes a detection threshold generation circuit 121, a comparison circuit 122, and a noise reduction filter 124. The short-circuit detection circuit 14 performs a short-circuit detection based on the estimated loss value received as input from the estimation circuit 101. For example, the short-circuit detection circuit 14 determines that a short circuit has occurred if a large loss occurs in the power device. The short-circuit detection circuit 14 can be used in any of the above-described loss calculation circuit 12 configurations, as long as it accepts input branched from the estimation circuit 101.

[0083] The detection threshold generation circuit 121 receives a temperature T input and generates a threshold value for the estimated loss required for short-circuit detection. The temperature T value may be a value measured by a sensor (not shown), such as a thermistor 141. If the controller 30 knows the temperature, the temperature T value may be included in the LUT write signal and this signal may be input to the temperature coefficient generation circuit 152. The temperature coefficient generation circuit 152 may convert the threshold value determined based on the temperature T from a digital value to an analog value.

[0084] The comparison circuit 122 receives the loss value estimated by the estimation circuit 101 and the threshold generated by the detection threshold generation circuit 121 as inputs and performs a short circuit detection. For example, if the estimated loss value is greater than or equal to the threshold, the comparison circuit 122 determines that a short circuit has occurred. As a result of the short circuit detection, the comparison circuit 122 outputs a High signal if a short circuit has occurred, and a Low signal if a short circuit has not occurred.

[0085] The noise reduction filter 124 removes noise from the value output from the comparator circuit 122.

[0086] Figure 15 shows the configuration of the short-circuit detection circuit 14 in the eighth modified example of the second embodiment.

[0087] In this modification example, the short-circuit determination circuit 14 includes a loss threshold generation circuit 125, a first integration circuit 103, a detection threshold generation circuit 121, a comparison circuit 122, and a noise removal filter 124. The short-circuit determination circuit 14 performs a short-circuit determination based on the value of the current I C received from the first multiplication circuit 112 and the multiplication result of the voltage V CE . When the loss is large, the amount of heat generation also becomes large. Therefore, the short-circuit determination circuit 14 compares the time integration value with the detection threshold generated based on the temperature T to perform a short-circuit determination. For example, when the amount of heat generation of the power device 20 is large, that is, when the temperature is high, the short-circuit determination circuit 14 determines that a short circuit has occurred. As long as the short-circuit determination circuit 14 is configured to receive the multiplication result from the first multiplication circuit 112 as an input, it can be adopted in any of the above-described loss calculation circuits 12.

[0088] The loss threshold generation circuit 125 generates a loss threshold L th for performing loss detection. When generating the loss threshold L th , for example, the loss threshold generation circuit 125 receives an input of a LUT write signal serving as a calculation parameter from the controller 30 and converts the value of the loss threshold L th included in this signal from a digital value to an analog value.

[0089] The first integration circuit 103 performs time integration of the multiplication result of the value of the current I C and the voltage V CE . When the multiplication result of the value of the current I C and the voltage V CE is smaller than the loss threshold L th , this multiplication result may not be used for integration.

[0090] The detection threshold generation circuit 121 receives an input of the value of the temperature T and generates a threshold of the integration value for performing short-circuit detection. The value of the temperature T may be a value measured by a sensor (not shown) such as a thermistor 141. When the controller 30 grasps the temperature, the temperature value may be included in the LUT write signal and this signal may be input to the detection threshold generation circuit 121.

[0091] The comparison circuit 122 receives the integral value calculated by the first integrating circuit 103 and the threshold value of the integral value as input and performs a short circuit detection. For example, if the integral value is greater than or equal to the threshold value, the comparison circuit 122 determines that a short circuit has occurred. As a result of the short circuit detection, the comparison circuit 122 outputs a High signal if a short circuit has occurred, and a Low signal if no short circuit has occurred.

[0092] The noise reduction filter 124 removes noise from the value output from the comparator circuit 122.

[0093] Figure 16 shows the configuration of the loss calculation circuit 12 and the power device 20 in the ninth modified example of the second embodiment.

[0094] In this modified example, the loss calculation circuit 12 inputs the voltage V to the current estimation circuit 13 as the input voltage. DESAT From there, voltage drop V p It includes a front-end section 160 for correcting the minutes. The front-end section 160 includes a third D / A conversion circuit 126 and a second subtraction circuit 127.

[0095] The third D / A conversion circuit 126 receives an input of a LUT write signal, which will be a calculation parameter, from the controller 30, and the voltage drop V included in this signal p The value is converted from a digital value to an analog value. The third D / A conversion circuit 126 measures the voltage drop V p The value is converted from digital to analog and then input to the second subtraction circuit 127.

[0096] The second subtraction circuit 127 uses the voltage V CE Voltage drop V p The first subtraction circuit 109 inputs the calculation result to the current estimation circuit 13. The current estimation circuit 13 then calculates the voltage drop V from this voltage value. f You can use this to estimate the current value, or you can use this value without subtracting it to estimate the current value I CAn estimation of the current may also be performed. The current is estimated using the method described above. In this modified example, a subtraction circuit is used for correction, but the correction may also be achieved using an addition circuit.

[0097] According to this embodiment and its various modifications, the loss calculation circuit 12 calculates the voltage V CE Based on this, the current value I of the drain current flowing through the power device 20 C This allows for the estimation of losses without the use of current sensors, thereby reducing the area of ​​the power device 20 and lowering manufacturing costs. Furthermore, the estimated loss values ​​are transmitted to the controller 30 as Loss data, allowing the controller 30 to use these values ​​to control the power device 20.

[0098] Furthermore, according to a third modification of this embodiment, the loss calculation circuit 12 estimates the temperature T of the power device 20 and the current value I C In estimating this, the voltage drop V f The value is corrected by the temperature T. This allows the loss calculation circuit 12 to perform loss estimation and short-circuit detection with high accuracy even with respect to temperature fluctuations of the power device 20.

[0099] Furthermore, according to a fourth modification of this embodiment, the loss calculation circuit 12 adds the switching loss value generated by the elements in the power device 20 to the loss value (mainly conduction loss) calculated by the estimation circuit 101, and estimates the total value of these as the loss. The loss calculation circuit 12 can improve the accuracy of loss estimation and short-circuit detection by correcting the integral value for the switching loss.

[0100] Furthermore, according to a fifth modification of this embodiment, the loss calculation circuit 12 uses the temperature coefficient C generated by the temperature coefficient generation circuit 152 to calculate the current value I C The loss calculation circuit 12 corrects the current value I based on the temperature coefficient. C By correcting this, the accuracy of loss estimation and short-circuit detection can be improved.

[0101] Furthermore, according to the sixth modification of this embodiment, the loss calculation circuit 12 calculates the current value I C A short-circuit determination is made based on the temperature T value. As a result, the loss calculation circuit 12 uses the current value I instead of the voltage value. C Furthermore, it becomes possible to protect the power device 20 based on the temperature T value.

[0102] Furthermore, according to the seventh modification of this embodiment, the loss calculation circuit 12 performs a short-circuit determination based on the estimated loss value received as input from the first integrating circuit 103. This makes it possible for the loss calculation circuit 12 to protect the power device 20 based on the estimated loss value rather than the current value.

[0103] Furthermore, according to the eighth modification of this embodiment, the loss calculation circuit 12 performs a short-circuit determination by comparing the amount of heat generated with a detection threshold generated based on the temperature T. As a result, the loss calculation circuit 12 can estimate the temperature of the power device 20 with higher accuracy than in the seventh modification, and the accuracy of loss estimation and short-circuit detection can be further improved.

[0104] Furthermore, according to the ninth modification of this embodiment, the loss calculation circuit 12 uses the voltage V CE From there, voltage drop V p It includes a front-end section 160 that reduces the voltage drop V. The loss calculation circuit 12 calculates the voltage drop V. p By correcting this, the accuracy of the calculation can be improved.

[0105] (Third embodiment) Figure 17 shows the configuration of the loss calculation circuit 12 and the power device 20 in the third embodiment.

[0106] In this embodiment, the power device 20 is equipped with an inductance 209. The loss calculation circuit 12 receives the terminal voltage value of this inductance 209 as sensor data, performs time integration, and calculates the current value I from this value. C We estimate it as follows. For explanation purposes, the value of the inductance 209 is L sLet's assume that the inductance 209 is either a parasitic inductance or an element inductance.

[0107] The loss calculation circuit 12 includes a first multiplication circuit 112, a first integrating circuit 103, a short-circuit detection circuit 14, and a second integrating circuit 128.

[0108] The second integrating circuit 128 controls the value of the terminal voltage of the inductance 209 in the power device 20. s dI c The input is accepted as / dt. The second integrating circuit 128 accepts the terminal voltage L that is the input. s dI C Integrating / dt over time gives the current value I C The second integrating circuit 128 then inputs the result of the calculation to the short-circuit detection circuit 14 and the first multiplier circuit 112.

[0109] The first integrating circuit 103 integrates the multiplication result from the first multiplier circuit 112 with respect to time t. The estimation circuit 101 calculates an estimated loss value by multiplying the integration result by a proportionality constant. The short-circuit detection circuit 14 calculates the current value I using the same method as described above. C For example, a short circuit can be detected by comparing threshold values.

[0110] Figure 18 shows the configuration of the loss calculation circuit 12 and the power device 20 in a modified example of the third embodiment.

[0111] In this modified example, the loss calculation circuit 12 inputs the voltage V to the current estimation circuit 13 as the input voltage. CE From there, voltage drop V p It includes a front-end section 160 for correction. The front-end section 160 includes a third D / A conversion circuit 126 and a second subtraction circuit 127.

[0112] The first multiplier circuit 112 has a current value I C The value and voltage V CE Perform multiplication.

[0113] The third D / A conversion circuit 126 receives an input of a LUT write signal, which will be a calculation parameter, from the controller 30, and the voltage drop V included in this signal p The value is converted from a digital value to an analog value. The third D / A conversion circuit 126 measures the voltage drop V p The value is converted from digital to analog and then input to the second subtraction circuit 127.

[0114] The second subtraction circuit 127 uses the voltage V CE Voltage drop V p The first subtraction circuit 109 inputs the calculation result to the current estimation circuit 13. The current estimation circuit 13 then calculates the voltage drop V from this voltage value. f You can use this to estimate the current value, or you can use this value without subtracting it to estimate the current value I C An estimation of the current may also be performed. The current is estimated using the method described above. In this modified example, a subtraction circuit is used for correction, but the correction may also be achieved using an addition circuit.

[0115] The first multiplication circuit 112 receives the results of the calculations performed by the second subtraction circuit 127 and the second integration circuit 128 and performs multiplication. The multiplication result is then input to the first integration circuit 103, where it is integrated over time, and then multiplied by a proportionality constant by the estimation circuit 101 to calculate an estimated loss.

[0116] According to this embodiment and its modifications, the loss calculation circuit 12 can estimate loss values ​​with a simple structure without requiring a current sensor on the power device 20, thereby reducing the area of ​​the power device 20 and lowering manufacturing costs.

[0117] Furthermore, according to a modified version of this embodiment, the loss calculation circuit 12 uses the voltage V CE From there, voltage drop V p It includes a front-end section 160 that reduces the voltage drop V. The loss calculation circuit 12 multiplies the voltage drop V. p By correcting this, the accuracy of the calculation can be improved.

[0118] (Fourth Embodiment) Figure 19 shows the configuration of the loss calculation circuit 12 and the power device 20 in the fourth embodiment.

[0119] In this embodiment, the power device 20 is equipped with a current sensor 210. Furthermore, the loss calculation circuit 12 uses the current value I measured by the current sensor 210. C Accept input.

[0120] The first multiplication circuit 112 receives the current value I from the power device 20 as sensor data. C And, voltage V CE The multiplication is performed. The first integrating circuit 103 integrates the multiplication result with respect to time t. The estimation circuit 101 calculates an estimated loss value using the same method as described above. The short-circuit detection circuit 14 uses the current value I measured by the current sensor. C The system accepts the input and, in the same manner as described above, calculates the current value I C For example, a short circuit can be detected by comparing threshold values.

[0121] Figure 20 shows the configuration of the loss calculation circuit 12 and the power device 20 in a modified example of the fourth embodiment.

[0122] In this modified example, the loss calculation circuit 12 inputs the voltage V to the current estimation circuit 13 as the input voltage. CE From there, voltage drop V p It includes a front-end section 160 for correction. The front-end section 160 includes a third D / A conversion circuit 126 and a second subtraction circuit 127.

[0123] The second subtraction circuit 127 uses the voltage V CE Voltage drop V p The first subtraction circuit 109 inputs the calculation result to the current estimation circuit 13. The current estimation circuit 13 then calculates the voltage drop V from this voltage value. f You can use this to estimate the current value, or you can use this value without subtracting it to estimate the current value I CAn estimation of the current may also be performed. The current is estimated using the method described above. In this modified example, a subtraction circuit is used for correction, but the correction may also be achieved using an addition circuit.

[0124] The first multiplication circuit 112 combines the calculation result of the second subtraction circuit 127 with the current value I from the current sensor 210. C It accepts the input and calculates an estimated value of the loss.

[0125] According to this embodiment and its modifications, the loss calculation circuit 12 estimates the loss value using sensor data from the current sensor 210 provided on the power device 20. This allows the loss calculation circuit 12 to further improve the accuracy of loss estimation and short-circuit detection.

[0126] Furthermore, according to this embodiment and its modifications, the loss calculation circuit 12 can estimate losses with high accuracy by measuring the current at each measurement point, even when multiple switching elements 201 are provided in the circuit, such as in an inverter 100, and multiple states such as turn-on, on, and off coexist among the multiple switching elements 201.

[0127] Furthermore, according to a modified version of this embodiment, the loss calculation circuit 12 uses the voltage V CE From there, voltage drop V p It includes a front-end section 160 that reduces the voltage drop V generated by the diode 203 and resistor 204. The loss calculation circuit 12 calculates the voltage drop V p By correcting this, the accuracy of the calculation can be improved.

[0128] Although several embodiments have been described above, these embodiments are presented only as examples and are not intended to limit the scope of the invention. The novel gate drive device 10 described herein can be implemented in a variety of other forms. Furthermore, various omissions, substitutions, and modifications can be made to the forms of the gate drive device 10 described herein without departing from the spirit of the invention. The appended claims and equivalents are intended to include such forms and modifications included in the scope and spirit of the invention.

[0129] (Note) Furthermore, for example, this embodiment and its variations can have the following configurations.

[0130] (1) The system includes a loss calculation circuit that estimates the loss value of a power device using the voltage values ​​of the power device at multiple points in time, The loss calculation circuit is, An integrating circuit that performs time integration based on the voltage values ​​at multiple points in time, Includes an estimation circuit that estimates the power device loss value based on the results of the time integration, Gate drive device.

[0131] (2) The gate drive device according to (1), further comprising a driver circuit that operates in response to an input control signal and drives the power device.

[0132] (3) The loss calculation circuit further includes a blanking circuit that blanks the voltage value of the power device at a predetermined blanking time among a plurality of time points, The integrating circuit performs time integration using the voltage value after the blanking time has elapsed. The gate drive device described in (1) to (2).

[0133] (4) The loss calculation circuit further receives, as an input, at least any one of a voltage drop value of an element included in the power device, a switching loss value, a temperature of the power device, a temperature coefficient for correcting a current value according to the temperature of the power device, and a detection threshold value of the loss value, and estimates the loss value. The gate drive device according to (1) to (3).

[0134] (5) The loss calculation circuit further includes a current estimation circuit that estimates a current value flowing through the power device. The current estimation circuit raises to the power of n (n is a real number satisfying 0 =< n =< 2) a value obtained by correcting a voltage corresponding to a voltage drop due to a work function of an element included in the power device from the voltage value, and estimates the current value. The gate drive device according to (1) to (4).

[0135] (6) The loss calculation circuit further includes a power circuit that raises the input value to the power of n (n is a real number of 0 =< n =< 2) and outputs it. The power circuit raises to the power of n a value obtained by correcting a voltage corresponding to a voltage drop due to a work function of an element included in the power device from the voltage value, and outputs the result. The integration circuit performs time integration using the voltage value and the output value of the power circuit at a plurality of time points. The gate drive device according to (1) to (4).

[0136] (7) The loss calculation circuit further includes a temperature estimation circuit that estimates the temperature of the power device. The loss calculation circuit changes either one of the calculation parameters of the value of n and the voltage corresponding to the voltage drop due to the work function of the element included in the power device according to the estimated temperature. The gate drive device according to (1) to (5).

[0137] (8) The loss calculation circuit further includes a switching loss input circuit that inputs the value of the switching loss generated by the elements included in the power device, The loss calculation circuit further adds the switching loss value to the output value from the estimation circuit to estimate the loss value. The gate drive device described in (1) to (7).

[0138] (9) The current estimation circuit further includes a temperature coefficient generation circuit that calculates a temperature coefficient corresponding to the temperature of the power device, The current estimation circuit calculates the current value by taking the value obtained by subtracting a predetermined voltage from the drain-source voltage of the switching element of the power device, which is calculated based on the voltage value, raising the value to the power of n, and then multiplying this value by the temperature coefficient. The gate drive device described in (5) to (8).

[0139] (10) The loss calculation circuit further includes a short-circuit detection circuit that performs short-circuit detection, The gate drive device according to (5) to (9), wherein the short-circuit detection circuit performs a short-circuit detection using the current value and the temperature of the power device.

[0140] (11) The loss calculation circuit further includes a short-circuit detection circuit that performs short-circuit detection, The gate drive device according to (1) to (10), wherein the short-circuit detection circuit performs short-circuit detection using the loss value and the temperature of the power device.

[0141] (12) The loss calculation circuit further includes a short-circuit detection circuit that performs short-circuit detection, The gate drive device according to (5) to (10), wherein the short-circuit detection circuit performs a short-circuit detection using the result of multiplying the voltage value and the current value and the temperature of the power device.

[0142] (13) The loss calculation circuit is, A current estimation circuit for estimating the current value flowing through the power device, The system further includes a front-end unit that corrects the voltage corresponding to the voltage drop of the elements included in the power device from the aforementioned voltage value, The loss calculation circuit estimates the loss value using the voltage value corrected for the voltage drop of the elements included in the power device, and the current value. The gate drive device described in (1) to (4).

[0143] (14) The loss calculation circuit further includes an integration circuit that estimates the current value flowing through the power device using the terminal voltage of the inductance within the power device. The integrating circuit integrates the terminal voltage over time to estimate the current value. The gate drive device described in (1) to (4).

[0144] (15) The loss calculation circuit further includes a front-end section that corrects the voltage value for a voltage corresponding to the voltage drop of the elements included in the power device, The loss calculation circuit estimates the loss value using the voltage value corrected for the voltage drop of the elements included in the power device, and the current value. (14) The gate drive device described above.

[0145] (16) The gate drive device according to (1) to (4), wherein the loss calculation circuit receives the current value flowing through the power device as input and estimates the loss value based on the current value and the voltage value.

[0146] (17) The loss calculation circuit further includes a front-end section that corrects the voltage value for a voltage corresponding to the voltage drop of the elements included in the power device, The loss calculation circuit estimates the loss value using the voltage value corrected for the voltage drop of the elements included in the power device, and the current value. (16) The gate drive device described above.

[0147] (18) The loss calculation circuit transmits the value of the loss to the controller, as described in (1) to (4).

[0148] (19) A power converter equipped with a gate drive device, The gate drive device is, Includes a loss calculation circuit that estimates the loss value of a power device using the voltage values ​​of the power device at multiple points in time, The loss calculation circuit is, An integrating circuit that performs time integration based on the voltage values ​​at multiple points in time, Includes an estimation circuit that estimates the power device loss value based on the results of the time integration, Power converter.

[0149] (20) An inverter equipped with multiple gate drive devices, Multiple gate drive devices, Includes a loss calculation circuit that estimates the loss value of a power device using the voltage values ​​of the power device at multiple points in time, The loss calculation circuit is, An integrating circuit that performs time integration based on the voltage values ​​at multiple points in time, Includes an estimation circuit that estimates the power device loss value based on the results of the time integration, Inverter. [Explanation of Symbols]

[0150] 1: Power converter, 10: Gate drive unit, 11: Driver circuit, 12: Loss calculation circuit, 13: Current estimation circuit, 14: Short circuit detection circuit, 20: Power device, 23: Sensor, 20': Power device, 30: Controller, 100: Inverter, 101: Estimation circuit, 102: Blanking circuit, 103: First integrating circuit, 104: First D / A conversion circuit, 105: Comparison circuit, 106: Fault detection circuit, 107: A / D conversion circuit 107, 108: Second D / A conversion circuit, 109: First subtraction circuit, 110: nth power circuit, 112: First multiplication circuit, 121: Detection threshold generation circuit, 122: Comparison circuit, 123: Blanking circuit, 124: Noise reduction filter, 125: Loss threshold generation circuit, 126: Third D / A conversion circuit, 127: Second subtraction circuit, 128: Second integration circuit, 150: Switching loss input circuit, 130: Switch, 140: Temperature estimation circuit, 151: Adding circuit, 152: Temperature coefficient generation circuit, 153: Second multiplication circuit, 160: Front end section, 201: Switching element, 201': Switching element, 202: Freewheeling diode, 202': Freewheeling diode, 203: Diode, 204: Resistor, 205: First capacitor, 206: Second capacitor, 207: First resistor, 208: Second resistor, 209: Inductance, 210: Current sensor

Claims

1. The system includes a loss calculation circuit that estimates the loss value of a power device using the voltage values ​​of the power device at multiple points in time, The loss calculation circuit is, An integrating circuit that performs time integration based on the voltage values ​​at multiple points in time, Includes an estimation circuit that estimates the power device loss value based on the results of the time integration, Gate drive device.

2. The gate drive device according to claim 1, further comprising a driver circuit that operates in response to an input control signal and drives the power device.

3. The loss calculation circuit further includes a blanking circuit that blanks the voltage value of the power device at a predetermined blanking time among a plurality of time points, The integrating circuit performs time integration using the voltage value after the blanking time has elapsed. The gate drive device according to claim 1.

4. The gate drive device according to claim 1, wherein the loss calculation circuit further accepts at least one of the following as input: the voltage drop value of the elements included in the power device, the switching loss value, the temperature of the power device, a temperature coefficient for correcting the current value according to the temperature of the power device, and a detection threshold for the loss value, and estimates the loss value.

5. The loss calculation circuit further includes a current estimation circuit that estimates the current value flowing through the power device, The current estimation circuit estimates the current value by raising the value obtained by correcting the voltage value for the voltage drop corresponding to the work function of the elements included in the power device to the power of n (where n is a real number satisfying 0 ≠ < n ≠ 2). The gate drive device according to claim 1.

6. The loss calculation circuit further includes an n-th power circuit that raises the input value to the power of n (where n is a real number between 0 and 2) and outputs the result. The n-th power circuit outputs a value obtained by raising the voltage value to the power of n, correcting the voltage corresponding to the voltage drop due to the work function of the elements included in the power device, from the voltage value. The integrating circuit performs time integration using the voltage values ​​and the output values ​​of the n-th power circuit at multiple time points. The gate drive device according to claim 1.

7. The loss calculation circuit further includes a temperature estimation circuit for estimating the temperature of the power device, The loss calculation circuit modifies at least one of the values ​​of n and the voltage corresponding to the voltage drop due to the work function of the element included in the power device, based on the estimated temperature. The gate drive device according to claim 5.

8. The loss calculation circuit further includes a switching loss input circuit that inputs the value of the switching loss generated by the elements included in the power device, The loss calculation circuit further adds the switching loss value to the output value from the estimation circuit to estimate the loss value. The gate drive device according to claim 5.

9. The current estimation circuit further includes a temperature coefficient generation circuit that calculates a temperature coefficient corresponding to the temperature of the power device, The current estimation circuit calculates the current value by taking the value obtained by subtracting a predetermined voltage from the drain-source voltage of the switching element of the power device, which is calculated based on the voltage value, raising the value to the power of n, and then multiplying this value by the temperature coefficient. The gate drive device according to claim 5.

10. The loss calculation circuit further includes a short-circuit detection circuit that performs short-circuit detection, The gate drive device according to claim 5, wherein the short-circuit detection circuit performs a short-circuit detection using the current value and the temperature of the power device.

11. The loss calculation circuit further includes a short-circuit detection circuit that performs short-circuit detection, The gate drive device according to claim 1, wherein the short-circuit detection circuit performs a short-circuit detection using the loss value and the temperature of the power device.

12. The loss calculation circuit further includes a short-circuit detection circuit that performs short-circuit detection, The gate drive device according to claim 5, wherein the short-circuit detection circuit performs a short-circuit detection using the result of multiplying the voltage value and the current value and the temperature of the power device.

13. The loss calculation circuit is, A current estimation circuit for estimating the current value flowing through the power device, The system further includes a front-end unit that corrects the voltage corresponding to the voltage drop of the elements included in the power device from the aforementioned voltage value, The loss calculation circuit estimates the loss value using the voltage value corrected for the voltage drop of the elements included in the power device, and the current value. The gate drive device according to claim 1.

14. The loss calculation circuit further includes an integration circuit that estimates the current value flowing through the power device using the terminal voltage of the inductance within the power device. The integrating circuit integrates the terminal voltage over time to estimate the current value. The gate drive device according to claim 1.

15. The loss calculation circuit further includes a front-end section that corrects the voltage value for a voltage corresponding to the voltage drop of the elements included in the power device, The loss calculation circuit estimates the loss value using the voltage value corrected for the voltage drop of the elements included in the power device, and the current value. The gate drive device according to claim 14.

16. The gate drive device according to claim 1, wherein the loss calculation circuit estimates the loss value based on the current value flowing through the power device and the voltage value.

17. The loss calculation circuit further includes a front-end section that corrects the voltage value for a voltage corresponding to the voltage drop of the elements included in the power device, The loss calculation circuit estimates the loss value using the voltage value corrected for the voltage drop of the elements included in the power device, and the current value. The gate drive device according to claim 16.

18. The gate drive device according to claim 1, wherein the loss calculation circuit transmits the value of the loss to the controller.

19. A power converter equipped with a gate drive device, The gate drive device, Includes a loss calculation circuit that estimates the loss value of a power device using the voltage values ​​of the power device at multiple points in time, The loss calculation circuit is, An integrating circuit that performs time integration based on the voltage values ​​at multiple points in time, Includes an estimation circuit that estimates the power device loss value based on the results of the time integration, Power converter.

20. An inverter equipped with multiple gate drive devices, Multiple gate drive devices, Includes a loss calculation circuit that estimates the loss value of a power device using the voltage values ​​of the power device at multiple points in time, The loss calculation circuit is, An integrating circuit that performs time integration based on the voltage values ​​at multiple points in time, Includes an estimation circuit that estimates the power device loss value based on the results of the time integration, Inverter.

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