JP2013048506A - Reactor temperature estimation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately estimate a reactor temperature in consideration of thermal interference between a core and a coil constituting the reactor.SOLUTION: A control device 100 estimates a temperature of a reactor included in a converter which converts a voltage inputted from a power storage device to output. The control device comprises a first estimation unit 110, a second estimation unit 120, and a third estimation unit 130. The first estimation unit uses current Ib flowing in the power storage device as a parameter, and separately estimates a coil temperature variation amount ΔTi1 caused by heat generation and heat radiation of a coil, and a core temperature variation amount ΔTr1 caused by heat generation and heat radiation of a core. The second estimation unit uses an estimation result of the first estimation unit, and separately estimates a core temperature variation amount ΔTr2 and a coil temperature variation amount ΔTi2 caused by thermal interference between the coil and the core. The third estimation unit uses the estimation result of the first estimation unit and an estimation result of the second estimation unit, and separately estimates a coil temperature Ti and a core temperature Tr.

Description

  The present invention relates to a technique for estimating the temperature of a reactor.

  In JP 2009-303329 A (Patent Document 1), the temperature of a reactor provided in a converter that boosts and outputs a voltage input from a battery, the charge / discharge current of the battery, and the battery is input to the converter. A technique for estimating from a voltage, a voltage output from the converter, and a temperature of cooling water for cooling the converter is disclosed.

JP 2009-303329 A Republished patent WO2002 / 065622 JP 2008-99518 A JP 2000-312484 A JP 2004-77245 A JP 2004-135465 A

  Normally, a reactor is composed of a core and a coil, but the core and the coil generate heat by different mechanisms, and there is mutual heat interference (heat transfer) between the core and the coil. However, since the technique of Patent Document 1 does not consider such thermal interference, there is a problem that the temperature estimation accuracy of the reactor is low.

  The present invention has been made in order to solve the above-described problem, and an object of the present invention is to provide a core that constitutes the reactor with the temperature of the reactor included in the converter that converts and outputs the voltage input from the power storage device. It is to estimate accurately based on the thermal interference between the coil and the coil.

  A control device according to the present invention is a reactor temperature estimation device included in a converter that converts and outputs a voltage input from a power storage device. The reactor is composed of a core and a coil wound around the outer periphery of the core. The temperature estimation device uses at least a reactor current to separately estimate a first core temperature change amount due to heat generation and heat dissipation of the core and a first coil temperature change amount due to heat generation and heat dissipation of the coil. And a second estimation unit that estimates a second core temperature change amount and a second coil temperature change amount due to mutual thermal interference between the coil and the core using the estimation result of the first estimation unit, A third estimating unit for separately estimating the core temperature and the coil temperature using the estimation results of the first estimating unit and the second estimating unit;

  Preferably, when the first core temperature change amount is larger than the first coil temperature change amount, the second estimation unit sets the second core temperature change amount to substantially zero and the first core temperature change amount. When the first coil temperature change amount is larger than the first core temperature change amount, the second coil temperature change amount is estimated from the difference between the first coil temperature change amount and the first coil temperature change amount. Is substantially zero, and the second core temperature change amount is estimated from the difference between the first core temperature change amount and the first coil temperature change amount.

  Preferably, when the first core temperature change amount is larger than the first coil temperature change amount, the second estimation unit is obtained from a difference between the first core temperature change amount and the first coil temperature change amount. A value obtained by subjecting the temporary second coil temperature change amount to the filter processing corresponding to the thermal interference time constant of the coil due to heat transfer from the core is defined as the final second coil temperature change amount. When the first coil temperature change amount is larger than the first core temperature change amount, the second estimation unit temporarily determines the difference between the first core temperature change amount and the first coil temperature change amount. A value obtained by subjecting the second core temperature change amount to the filter processing corresponding to the thermal interference time constant of the core due to heat transfer from the coil is defined as the final second core temperature change amount.

  Preferably, the thermal time constant of the core and the thermal time constant of the coil are different from each other. The converter performs voltage conversion according to a control signal generated using the carrier signal. The reactor is cooled by the refrigerant flowing inside the cooler arranged adjacent to the reactor. The first estimator performs a filtering process in accordance with the thermal time constant of the core to the temporary first core temperature variation obtained from the reactor current, the converter input voltage and output voltage, the refrigerant temperature, and the carrier signal frequency. The value subjected to is the final first core temperature change amount. The first estimator performs filtering processing according to the thermal time constant of the coil to the temporary first coil temperature variation obtained from the reactor current, the converter input voltage and output voltage, the refrigerant temperature, and the carrier signal frequency. The value subjected to is used as the final first coil temperature change amount.

  Preferably, the third estimation unit sets a value obtained by adding the first core temperature change amount and the second core temperature change amount to the refrigerant temperature as the core temperature, and sets the first coil temperature change amount and the first coil temperature as the refrigerant temperature. The value obtained by adding the coil temperature change amount of 2 is defined as the coil temperature.

  Preferably, the temperature estimation device further includes a limiting unit that limits charging / discharging of the power storage device when the core temperature exceeds the allowable temperature of the core and / or when the coil temperature exceeds the allowable temperature of the coil.

  ADVANTAGE OF THE INVENTION According to this invention, the temperature of the reactor contained in the converter which converts and outputs the voltage input from an electrical storage apparatus can be estimated accurately based on the thermal interference with the core and coil which comprise a reactor.

1 is an overall configuration diagram of a motor drive control system. It is a figure which shows the cross section of a reactor typically. It is a figure which shows the AA cross section of the reactor in FIG. It is a figure which shows typically the mode of a change of real core temperature and real coil temperature. It is a functional block diagram of a control device. It is a flowchart (the 1) which shows the process sequence of a control apparatus. It is a flowchart (the 2) which shows the process sequence of a control apparatus. It is the figure which compared the core temperature Tr and the coil temperature Ti which the control apparatus estimated, and the actual core temperature and the actual coil temperature.

  Embodiments of the present invention will be described below in detail with reference to the drawings. In the following, the same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated in principle.

  FIG. 1 is an overall configuration diagram of a motor drive control system 1 to which a reactor temperature estimation device according to an embodiment of the present invention is applied. The motor drive control system 1 includes a power storage device B, a system main relay SMR, smoothing capacitors C0 and C1, a converter 10, an inverter 20, a motor M1, and a control device 100.

  The motor M1 is an AC motor for generating torque for driving drive wheels of an electric vehicle (referred to as a vehicle that generates vehicle driving force by electric energy such as a hybrid vehicle, an electric vehicle, and a fuel cell vehicle). It is. Typically, the motor M1 is a permanent magnet type synchronous motor provided with three coils of three phases (U, V, W phase). The motor M1 may be configured to have a generator function.

  The power storage device B is typically configured by a power storage device such as a secondary battery such as nickel metal hydride or lithium ion, or an electric double layer capacitor.

  System main relay SMR is controlled by a control signal from control device 100, and switches between connection and disconnection between power storage device B and converter 10.

  Converter 10 is connected to power storage device B via positive line 6 and negative line 5. Converter 10 includes a reactor L, switching elements Q1, Q2, and diodes D1, D2. Switching elements Q 1 and Q 2 are connected in series between positive line 7 and negative line 5. Reactor L is connected between a connection node of switching elements Q 1 and Q 2 and positive electrode line 6. Further, the smoothing capacitor C 0 is connected between the positive electrode line 7 and the negative electrode line 5. Smoothing capacitor C <b> 1 is connected between positive electrode line 6 and negative electrode line 5.

  Voltage conversion of the converter 10 (ON / OFF of the switching elements Q1 and Q2) is controlled by a PWM control signal generated by the control device 100 by pulse width modulation (hereinafter referred to as “PWM”) control. . This PWM control signal is generated so that the switching elements Q1 and Q2 are turned on and off in a complementary manner based on a voltage comparison between a carrier signal (carrier signal) and a voltage command. During the boosting operation, converter 10 boosts the voltage across smoothing capacitor C1 and outputs the boosted voltage to smoothing capacitor C0. Further, converter 10 steps down the voltage across smoothing capacitor C0 and outputs it to smoothing capacitor C1 during the step-down operation. In the following description, for convenience of explanation, the voltage across the smoothing capacitor C1 (the voltage input from the power storage device B to the converter 10) is “converter input voltage VL”, and the voltage across the smoothing capacitor C0 (output from the converter 10 to the inverter 20). Voltage) is also referred to as “converter output voltage VH”.

  Inverter 20 includes a U-phase upper and lower arm, a V-phase upper and lower arm, and a W-phase upper and lower arm provided in parallel between positive electrode line 7 and negative electrode line 5. Each phase upper and lower arm is constituted by a switching element connected in series between the positive electrode line 7 and the negative electrode line 5. For example, the U-phase upper and lower arms are composed of switching elements Q3 and Q4, the V-phase upper and lower arms are composed of switching elements Q5 and Q6, and the W-phase upper and lower arms are composed of switching elements Q7 and Q8. Further, diodes D3 to D8 are connected in antiparallel to switching elements Q3 to Q8, respectively. The other end of each phase coil of the motor M1 is connected to an intermediate point of the switching elements of the upper and lower arms of each phase.

  The power conversion of the inverter 20 (on / off of the switching elements Q3 to Q8) is also controlled by the PWM control signal generated by the control device 100 by the PWM control described above. The inverter 20 converts the DC voltage from the converter 10 into an AC voltage and supplies it to the motor M1. Further, the inverter 20 can also convert the AC voltage generated by the motor M1 into a DC voltage and supply it to the converter 10.

  Further, the motor drive control system 1 includes voltage sensors 12, 13 and 17, current sensors 11 and 14, a resolver 15, and a temperature sensor 16. Voltage sensor 12 detects converter input voltage VL. Voltage sensor 13 detects converter output voltage VH. Voltage sensor 17 detects a voltage Vb across power storage device B. Current sensor 11 detects current Ib flowing through power storage device B. In the present embodiment, the current Ib is treated as a reactor current (current flowing through the reactor L) to estimate the reactor temperature. However, when a current sensor that directly detects the reactor current is provided, the current sensor The detection result may be used. The current sensor 14 detects a current flowing through the motor M1. Since the sum of instantaneous values of the three-phase currents iu, iv, and iw is zero, the current sensor 14 has two phases of motor current (for example, V-phase current iv and W-phase current iw) as shown in FIG. It is sufficient to arrange it so as to detect. The resolver 15 detects the rotor rotation angle θ of the motor M1. Temperature sensor 16 detects a coolant temperature THw flowing through cooler 40 (see FIG. 3 described later) of converter 10. Each of these sensors outputs a detection result to the control device 100.

  The control device 100 includes a CPU (Central Processing Unit) (not shown) and an electronic control unit (ECU: Electronic Control Unit) with a built-in memory, and executes predetermined arithmetic processing based on information and programs stored in the memory. By doing so, the operation of the motor drive control system 1 is controlled. In the present embodiment, this control device 100 functions as a temperature estimation device for reactor L.

  FIG. 2 is a diagram schematically showing a cross section of the reactor L. As shown in FIG. FIG. 3 is a view showing a cross section AA of reactor L in FIG. The structure of the reactor L will be described in detail with reference to FIGS.

  The reactor L includes an annular core and a coil wound around the outer periphery of the core. The core is made of iron. The coil is mainly made of copper. Note that the current flowing through the coil is a reactor current, which is substantially the same value as the current Ib.

  The reactor L is fixed inside the case 30 with a resinous potting material. The cooler 40 is arranged to contact the bottom surface of the case 30. The reactor L is cooled by the cooling water flowing through the cooler 40.

  FIG. 4 is a diagram schematically showing how the actual core temperature and the actual coil temperature of the reactor L change. In FIG. 4, the actual coil temperature is indicated by a two-dot chain line, and the actual core temperature is indicated by a one-dot chain line. As a reference, the estimated reactor temperature calculated by the conventional method is shown by a solid line.

  When energization of reactor L is performed until time t1 is reached, both the actual core temperature and the actual coil temperature gradually increase. When the energization of the reactor L is stopped at time t1, both the actual core temperature and the actual coil temperature gradually decrease. However, the core and the coil generate heat by a different mechanism. That is, the coil generates heat when the current from the power storage device B flows directly to itself, whereas the core generates heat when a dielectric current flows to itself due to the electromagnetic induction action of the coil. Further, the thermal time constant τr of the core and the thermal time constant τi of the coil are different from each other due to the difference in the main material and the positional relationship with the cooler 40. For these reasons, as shown in FIG. 4, the actual core temperature and the actual coil temperature change at different rates of change. The “thermal time constant” is an index indicating the rate of change of temperature, and usually means the time required to change from a certain temperature to a target temperature (more specifically, 63.2% of the target temperature). To do. In the present embodiment, the core is mainly made of iron while the coil is mainly made of copper having a specific heat smaller than that of iron, and the coil is arranged on the outer peripheral side of the core and closer to the cooler 40. The coil thermal time constant τi (for example, about 400 sec) is shorter than the core thermal time constant τr (for example, about 1000 sec). Therefore, the actual coil temperature increases or decreases more rapidly than the actual core temperature. Therefore, in particular, after the energization is stopped at time t1, the actual coil temperature decreases more rapidly than the actual core temperature in the case of a coil alone, but in reality, thermal interference (heat transfer) from the core to the coil occurs. Therefore, the actual coil temperature gradually decreases.

  Although the estimated reactor temperature calculated by the conventional method was calculated according to the actual coil temperature, the thermal interference between the coil and the core was not taken into consideration. Therefore, as shown in FIG. 4, the estimated reactor temperature deviates from the actual core temperature or the actual coil temperature after the energization is stopped at the time t <b> 1 (the state where the actual core temperature is higher than the actual coil temperature). There was a problem.

  In order to solve such a problem, in the present embodiment, the temperature estimation accuracy of the reactor is drastically improved by separately estimating the core temperature and the coil temperature in consideration of the thermal interference between the core and the coil. Improve. This is the most characteristic point of the present embodiment.

  FIG. 5 is a functional block diagram of the control device 100. Each functional block shown in FIG. 5 may be realized by hardware or software.

  Control device 100 includes a first estimation unit 110, a second estimation unit 120, a third estimation unit 130, and a restriction unit 140.

  The first estimation unit 110 estimates separately the coil temperature change amount ΔTi1 due to heat generation and heat dissipation of the coil itself and the core temperature change amount ΔTr1 due to heat generation and heat dissipation of the core itself. In the present embodiment, the “temperature change amount” is a positive value when the temperature is increased, and is a negative value when the temperature is decreased.

  The first estimation unit 110 includes a coil temperature change amount calculation unit 111 that calculates the coil temperature change amount ΔTi1, and a core temperature change amount calculation unit 112 that calculates the core temperature change amount ΔTr1.

  First, the function of the coil temperature change amount calculation unit 111 will be described. The coil temperature change amount calculation unit 111 includes a current Ib (reactor current), a converter input voltage VL, a converter output voltage VH, a cooling water temperature THw, and a frequency of a carrier signal used for PWM control of the converter 10 (hereinafter, “carrier frequency f”). Is used as a parameter to determine a temporary coil temperature change amount ΔTi1temp. Then, the coil temperature change amount calculation unit 111 sets a value obtained by subjecting the temporary coil temperature change amount ΔTi1temp to filter processing according to the thermal time constant τi of the coil as the final coil temperature change amount ΔTi1.

  More specifically, the coil temperature change amount calculation unit 111 first calculates the basic coil temperature change amount ΔTi1base using a one-dimensional map using the current Ib as a parameter. The coil temperature change amount calculation unit 111 sets the basic coil temperature change amount ΔTi1base to a high value in consideration of the fact that the amount of heat generated by the coil increases as the current Ib increases.

  Then, the coil temperature change amount calculation unit 111 calculates the correction coefficient K1 using a two-dimensional map using the converter input voltage VL and the converter output voltage VH as parameters. As the step-up ratio of converter 10 (= converter output voltage VH / converter input voltage VL) increases, the magnitude of the ripple component superimposed on current Ib (hereinafter referred to as “ripple width”) increases, and the amount of heat generated by the coil increases. There is a tendency. Considering this point, the coil temperature change amount calculation unit 111 sets the correction coefficient K1 to a larger value as the step-up ratio (= VH / VL) is larger.

  Furthermore, the coil temperature change amount calculation unit 111 calculates the correction coefficient K2 using a one-dimensional map using the carrier frequency f as a parameter. As the carrier frequency f is smaller, the ripple width is larger and the amount of heat generated by the coil tends to be larger. Considering this point, the coil temperature change amount calculation unit 111 sets the correction coefficient K2 to a larger value as the carrier frequency f is smaller.

  Furthermore, the coil temperature change amount calculation unit 111 calculates the correction coefficient K3 using a one-dimensional map using the cooling water temperature THw as a parameter. As the coolant temperature THw is higher, the coil temperature tends to increase. Considering this point, the coil temperature change amount calculation unit 111 sets the correction coefficient K3 to a larger value as the coolant temperature THw is higher.

  Then, the coil temperature change amount calculation unit 111 calculates a temporary coil temperature change amount ΔTi1temp by the following equation (1).

ΔTi1temp = ΔTi1base × K1 × K2 × K3 (1)
Further, the coil temperature change amount calculation unit 111 calculates a value obtained by subjecting the temporary coil temperature change amount ΔTi1temp to the filtering process according to the coil thermal time constant τi as the final coil temperature change amount ΔTi1. . As the “filter process”, for example, a first-order lag process, a second-order lag process, a moving average process, and the like can be used. For example, when the first-order lag processing is performed, assuming that the value (= τi / T) obtained by dividing the thermal time constant τi of the coil by the sampling period T of each parameter is “A” and A + 1 is “B”, the coil temperature change amount is calculated. The unit 111 can calculate the final coil temperature change amount ΔTi1 by the following equation (2).

ΔTi1n = (A / B) × (ΔTi1n−1) + (1 / B) × ΔTi1temp (2)
“ΔTi1n” is the current value of the final coil temperature change amount ΔTi1, and “ΔTi1n-1” is the previous value of the final coil temperature change amount ΔTi1.

  Next, the function of the core temperature change amount calculation unit 112 will be described. Similarly to the coil temperature change amount calculation unit 111, the core temperature change amount calculation unit 112 uses the current Ib, the converter input voltage VL, the converter output voltage VH, the cooling water temperature THw, and the carrier frequency f as parameters to set the temporary core temperature. A change amount ΔTr1temp is obtained. Then, the core temperature change amount calculation unit 112 sets a value obtained by subjecting the temporary core temperature change amount ΔTr1temp to filter processing according to the core thermal time constant τr as the final core temperature change amount ΔTr1.

  More specifically, the core temperature change amount calculation unit 112 first calculates the basic core temperature change amount ΔTr1base using a two-dimensional map using the converter input voltage VL and the converter output voltage VH as parameters.

  Then, similarly to the coil temperature change calculation unit 111, the core temperature change calculation unit 112 calculates the correction coefficient K4 using a one-dimensional map using the current Ib as a parameter, and uses the carrier frequency f as a parameter. The correction coefficient K5 is calculated using the map, and the correction coefficient K6 is calculated using a one-dimensional map using the cooling water temperature THw as a parameter. Then, the core temperature change amount calculation unit 112 calculates a temporary core temperature change amount ΔTr1temp by the following equation (3).

ΔTr1temp = ΔTr1base × K4 × K5 × K6 (3)
Furthermore, the core temperature change amount calculation unit 112 calculates a value obtained by performing filtering processing on the temporary core temperature change amount ΔTr1temp according to the thermal time constant τr of the core as the final core temperature change amount ΔTr1. . As described above, as the “filter process”, for example, a first-order lag process, a second-order lag process, a moving average process, and the like can be used. For example, when first-order lag processing is performed, if the value obtained by dividing the thermal time constant τr of the core by the sampling period T of each parameter (= τr / T) is “C” and C + 1 is “D”, the calculation of the core temperature change amount is performed. The unit 112 can calculate the final core temperature change amount ΔTr1 by the following equation (4).

ΔTr1n = (C / D) × (ΔTr1n−1) + (1 / D) × ΔTr1temp (4)
“ΔTr1n” is the current value of the final core temperature change amount ΔTr1, and “ΔTr1n-1” is the previous value of the final core temperature change amount ΔTr1.

  The second estimation unit 120 estimates separately the core temperature change amount ΔTr2 and the coil temperature change amount ΔTi2 due to mutual thermal interference between the coil and the core, using the estimation result of the first estimation unit 110.

  More specifically, when the core temperature change amount ΔTr1 is larger than the coil temperature change amount ΔTi1, the second estimation unit 120 sets the core temperature change amount ΔTr2 to be substantially zero and sets the coil temperature change amount ΔTi2 to the following method. Estimated by The second estimation unit 120 estimates the temporary coil temperature change amount ΔTi2temp using the absolute value (= | ΔTr1-ΔTi1 |) of the difference between the core temperature change amount ΔTr1 and the coil temperature change amount ΔTi1 as a parameter. The second estimation unit 120 increases the temporary coil temperature change amount ΔTi2temp as the value of | ΔTr1−ΔTi1 | increases. Then, the second estimation unit 120 sets a value obtained by subjecting the temporary coil temperature change amount ΔTi2temp to the filter processing according to the thermal interference time constant τir of the coil as the final coil temperature change amount ΔTi2. Here, the “coil thermal interference time constant τri” is an index indicating a rate of change in temperature of the coil due to heat transfer from the core to the coil. Note that, as described above, for example, a first-order lag process, a second-order lag process, and a moving average process may be used as the filter process.

  On the other hand, when the coil temperature change amount ΔTi1 is larger than the core temperature change amount ΔTr1, the second estimation unit 120 sets the coil temperature change amount ΔTi2 to be substantially zero and estimates the core temperature change amount ΔTr2 by the following method. The second estimation unit 120 estimates a temporary core temperature change amount ΔTr2temp using | ΔTr1-ΔTi1 | as a parameter. The second estimation unit 120 sets the temporary core temperature change amount ΔTr2temp to a larger value as | ΔTr1−ΔTi1 | increases. Then, the second estimation unit 120 sets a value obtained by subjecting the temporary core temperature change amount ΔTr2temp to the filtering process according to the core thermal interference time constant τri as the final coil temperature change amount ΔTi2. Here, the “core thermal interference time constant τri” is an index indicating the rate of change in temperature of the core due to thermal interference from the coil. Note that, as described above, for example, a first-order lag process, a second-order lag process, and a moving average process may be used as the filter process.

  The third estimation unit 130 estimates the coil temperature Ti and the core temperature Tr separately using the estimation results of the first estimation unit 110 and the second estimation unit 120.

  The third estimation unit 130 includes a coil temperature calculation unit 131 that calculates the coil temperature Ti and a core temperature calculation unit 132 that calculates the core temperature Tr.

  The coil temperature calculation unit 131 calculates the coil temperature Ti by taking the cooling water temperature THw as the base temperature of the coil and taking into account the base temperature and the coil temperature changes ΔTi1 and ΔTi2. That is, the coil temperature calculation unit 131 calculates the coil temperature Ti by the following equation (5).

Ti = THw + ΔTi1 + ΔTi2 (5)
As described above, when the coil temperature change amount ΔTi1 is larger than the core temperature change amount ΔTr1, the coil temperature change amount ΔTi2 is substantially zero.

  Similarly to the coil temperature calculation unit 131, the core temperature calculation unit 132 uses the cooling water temperature THw as the base temperature of the core, and calculates the core temperature Tr taking into account the base temperature and the core temperature change amounts ΔTr1, ΔTr2. That is, the core temperature calculation unit 132 calculates the core temperature Tr by the following equation (6).

Tr = THw + ΔTr1 + ΔTr2 (6)
As described above, when the core temperature change amount ΔTr1 is larger than the coil temperature change amount ΔTi1, the core temperature change amount ΔTr2 is substantially zero.

  Limiting unit 140 limits at least one of charging and discharging of power storage device B when coil temperature Ti exceeds coil allowable temperature Tilimit and / or when core temperature Tr exceeds core allowable temperature Trlimit. For example, when remaining capacity SOC of power storage device B exceeds a reference value (for example, 60%), limiting unit 140 decreases charge power allowable value Win of power storage device B. Otherwise, power storage device B The allowable discharge power value Wout is reduced.

  FIG. 6 is a flowchart illustrating a processing procedure of the control device 100 for realizing the functions of the first estimation unit 110, the second estimation unit 120, and the third estimation unit 130 described above. This flowchart is repeatedly executed at a predetermined cycle.

  In step (hereinafter, step is abbreviated as “S”) 10, control device 100 calculates basic coil temperature change amount ΔTi1base using current Ib as a parameter. In S11, control device 100 calculates correction coefficient K1 using converter input voltage VL and converter output voltage VH as parameters, calculates correction coefficient K2 using carrier frequency f as a parameter, and correction coefficient K3 using cooling water temperature THw as a parameter. Is calculated. In S12, control device 100 calculates temporary coil temperature change amount ΔTi1temp (see the above-described equation (1)). In S13, control device 100 calculates, as final coil temperature change amount ΔTi1, a value obtained by subjecting temporary coil temperature change amount ΔTi1temp to filter processing in accordance with the coil thermal time constant τi (described above). (See equation (2)).

  Further, at S20, control device 100 calculates basic core temperature change amount ΔTr1base using converter input voltage VL and converter output voltage VH as parameters. In S21, control device 100 calculates correction coefficient K4 using current Ib as a parameter, calculates correction coefficient K5 using carrier frequency f as a parameter, and calculates correction coefficient K6 using cooling water temperature THw as a parameter. In S22, control device 100 calculates temporary core temperature change amount ΔTr1temp (see equation (3) above). In S23, control device 100 calculates, as final core temperature change amount ΔTr1, a value obtained by subjecting temporary core temperature change amount ΔTr1temp to filter processing in accordance with the core thermal time constant τr (described above). (See equation (4)).

  In S30, control device 100 determines whether or not coil temperature change amount ΔTi1 is larger than core temperature change amount ΔTr1.

  When ΔTi1> ΔTr1 (YES in S30), control device 100 calculates temporary core temperature change amount ΔTr2temp using | ΔTr1-ΔTi1 | as a parameter in S31, and temporary core temperature change amount in S32. A value obtained by subjecting ΔTr2temp to a filtering process according to the thermal interference time constant τri of the core is defined as a final coil temperature change amount ΔTi2. In S33, control device 100 calculates coil temperature Ti as THw + ΔTi1 (ΔTi2 = 0 in the above equation (5)), and in S34, calculates core temperature Tr as THw + ΔTr1 + ΔTr2 (described above). (Refer Formula (6)).

  On the other hand, if ΔTi1 <ΔTr1 (NO in S30), control device 100 calculates temporary coil temperature change amount ΔTi2temp using | ΔTr1-ΔTi1 | as a parameter in S35, and temporarily coil temperature in S36. A value obtained by subjecting the change amount ΔTi2temp to the filter processing corresponding to the thermal interference time constant τir of the coil is defined as a final coil temperature change amount ΔTi2. In S37, control device 100 calculates coil temperature Ti as THw + ΔTi1 + ΔTi2 (see the above equation (5)), and in S38, calculates core temperature Tr as THw + ΔTr1 (in the above equation (6)). ΔTr2 = 0).

  FIG. 7 is a flowchart showing a processing procedure of the control device 100 for realizing the function of the restriction unit 140 described above. This flowchart is repeatedly executed at a predetermined cycle.

  In S40, control device 100 determines whether or not core temperature Tr exceeds core allowable temperature Trlimit. In S41, control device 100 determines whether or not coil temperature Ti exceeds coil allowable temperature Tilimit.

  When coil temperature Ti exceeds coil allowable temperature Tilimit (YES in S40) and / or core temperature Tr exceeds core allowable temperature Trlimit (YES in S41), control device 100 performs S42. At least one of charging and discharging of the power storage device B is limited. On the other hand, when coil temperature Ti does not exceed coil allowable temperature Tilimit (NO in S40) and core temperature Tr does not exceed core allowable temperature Trlimit (NO in S41), control device 100 stores power The process is terminated without limiting the charging / discharging of the apparatus B.

  FIG. 8 is a diagram comparing the core temperature Tr and the coil temperature Ti estimated in the present embodiment with the actual core temperature and the actual coil temperature. As shown in FIG. 8, the core temperature Tr and the coil temperature Ti estimated in the present embodiment substantially follow the actual temperatures corresponding to the core temperature Tr and the coil temperature Ti even when the power storage device B is repeatedly charged and discharged frequently. It can be seen that high estimation accuracy is ensured.

  As described above, the control device 100 according to the present embodiment estimates the core temperature and the coil temperature separately in consideration of the thermal interference between the core and the coil and the difference in the thermal time constant between the core and the coil. To do. Therefore, the estimation accuracy of the reactor temperature can be dramatically improved.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Motor drive control system, 5 Negative electrode wire, 6, 7 Positive electrode wire, 10 Converter, 11, 14 Current sensor, 12, 13, 17 Voltage sensor, 15 Resolver, 16 Temperature sensor, 20 Inverter, 30 Case, 40 Cooler, DESCRIPTION OF SYMBOLS 100 Control apparatus, 110 1st estimation part, 111 Coil temperature change calculation part, 112 Core temperature change calculation part, 120 2nd estimation part, 130 3rd estimation part, 131 Coil temperature calculation part, 132 Core temperature calculation part, 140 Limiting unit, B power storage device, C0, C1 smoothing capacitor, D1-D8 diode, L reactor, M1 motor, Q1-Q8 switching element, SMR system main relay.

Claims (6)

A reactor temperature estimation device included in a converter that converts and outputs a voltage input from a power storage device, wherein the reactor includes a core and a coil wound around an outer periphery of the core,
The temperature estimation device includes:
A first estimation unit that separately estimates a first core temperature change amount due to heat generation and heat dissipation of the core and a first coil temperature change amount due to heat generation and heat dissipation of the coil, using at least the current of the reactor;
A second estimation unit that estimates a second core temperature change amount and a second coil temperature change amount due to mutual thermal interference between the coil and the core, using the estimation result of the first estimation unit;
A reactor temperature estimation device, comprising: a third estimation unit that separately estimates a core temperature and a coil temperature using estimation results of the first estimation unit and the second estimation unit. The second estimation unit includes
When the first core temperature change amount is larger than the first coil temperature change amount, the second core temperature change amount is set to substantially zero, and the first core temperature change amount and the first core temperature change amount are set to be substantially zero. The second coil temperature change amount is estimated from the difference from the coil temperature change amount,
When the first coil temperature change amount is larger than the first core temperature change amount, the second coil temperature change amount is set to substantially zero, and the first core temperature change amount and the first core temperature change amount are set to be substantially zero. The reactor temperature estimation device according to claim 1, wherein the second core temperature change amount is estimated from a difference from a coil temperature change amount. The second estimation unit includes
When the first core temperature change amount is larger than the first coil temperature change amount, the temporary first temperature obtained from the difference between the first core temperature change amount and the first coil temperature change amount is obtained. A value obtained by performing a filtering process in accordance with the thermal interference time constant of the coil by heat transfer from the core to the coil temperature change amount of 2 as a final second coil temperature change amount,
When the first coil temperature change amount is larger than the first core temperature change amount, the temporary first time obtained from the difference between the first core temperature change amount and the first coil temperature change amount is obtained. The final value of the second core temperature change is a value obtained by performing a filtering process according to a thermal interference time constant of the core by heat transfer from the coil to the core temperature change amount of 2 in claim 2. The reactor temperature estimation apparatus described. The thermal time constant of the core and the thermal time constant of the coil are different from each other,
The converter performs the voltage conversion according to a control signal generated using a carrier signal,
The reactor is cooled by a refrigerant flowing inside a cooler disposed adjacent to the reactor,
The first estimation unit includes
Filter processing according to the thermal time constant of the core to the temporary first core temperature change obtained from the current of the reactor, the input voltage and output voltage of the converter, the temperature of the refrigerant, and the frequency of the carrier signal Is the final first core temperature change amount,
Filter processing according to the time constant of the first coil temperature obtained from the current of the reactor, the input voltage and output voltage of the converter, the temperature of the refrigerant, and the frequency of the carrier signal, according to the thermal time constant of the coil The reactor temperature estimation device according to any one of claims 1 to 3, wherein a value obtained by applying the value is used as a final change amount of the first coil temperature. The third estimation unit includes
A value obtained by adding the first core temperature change amount and the second core temperature change amount to the temperature of the refrigerant is the core temperature,
The reactor temperature estimation device according to claim 4, wherein a value obtained by adding the first coil temperature change amount and the second coil temperature change amount to the temperature of the refrigerant is used as the coil temperature.   The temperature estimation device includes a limiting unit that limits charge / discharge of the power storage device when the core temperature exceeds an allowable temperature of the core and / or when the coil temperature exceeds an allowable temperature of the coil. The reactor temperature estimation device according to claim 1, further comprising:

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