JP2013048499A - Control device for rotating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for a rotating machine capable of suitably avoiding reduction in reliability of a switching element caused by excessive increase in the temperature of the switching element.SOLUTION: A control device for a rotating machine makes command torque Trq* of a motor generator be lower as a switching element temperature Tth is higher when it is determined that the switching element temperature Tth is higher than a threshold temperature T1, inputs the reduced command torque Trq* to a primary delay filter where a time constant Ts of the primary delay filter is set small when it is determined that the switching element temperature Tth is higher than the threshold temperature T1, and performs current feedback control of the motor generator on the basis of command torque Trqc output from the primary delay filter.

Description

  The present invention relates to a control device for a rotating machine including control means for controlling a control amount of the rotating machine by operating a switching element of a power conversion circuit interposed between a DC power source and the rotating machine.

  2. Description of the Related Art Conventionally, a technique for operating a switching element of an inverter interposed between a direct current power source and a rotating machine is known so that the generated torque of the rotating machine is used as a command torque. Here, when the current flowing through the switching element is increased, the temperature of the switching element is excessively increased, and the reliability of the switching element may be reduced.

  In order to solve such a problem, as seen in Patent Document 1 below, a switching element that detects a temperature abnormality in which the temperature of the switching element excessively rises and limits a current flowing through the switching element when a temperature abnormality is detected Protection devices are known. Specifically, in this device, when it is determined that the switching element temperature exceeds a predetermined value, the higher the switching element temperature, the lower the command torque of the rotating machine and the lower the current flowing through the rotating machine. As a result, the current flowing through the switching element is reduced to suppress an increase in switching element temperature.

Japanese Patent Laid-Open No. 7-194094

  By the way, in the technique described in Patent Document 1, although the command torque of the rotating machine can be reduced so as to reduce the current flowing through the switching element, the time until the actual generated torque of the rotating machine becomes the command torque. Can be long. In this case, an increase in the switching element temperature cannot be appropriately suppressed, and the reliability of the switching element may be reduced.

  As a countermeasure against such a problem, for example, it is conceivable to set the predetermined value as a threshold value for reducing the command torque low. However, in this case, there is a concern that inconvenience such as restriction of the generated torque of the rotating machine occurs.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a rotating machine that can suitably avoid a decrease in reliability of a switching element due to an excessive increase in switching element temperature. It is to provide a control device.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

  The invention according to claim 1 is a control device for a rotating machine comprising control means for controlling a control amount of the rotating machine by operating a switching element of a power conversion circuit interposed between a DC power source and the rotating machine. When the temperature of the switching element exceeds a specified temperature, a change unit that performs a process of changing the command value of the control amount to a side where the current flowing through the rotating machine decreases, and the command value is changed by the change unit And a time reduction means for performing a process for shortening the time until the control amount reaches the command value changed by the changing means.

  In the above invention, when the temperature of the switching element exceeds the specified temperature, the command value of the control amount of the rotating machine is changed to the side where the current flowing through the rotating machine becomes small, and the control amount reaches the changed command value. To shorten the time. That is, when the temperature of the switching element exceeds the specified temperature, the current flowing through the rotating machine is reduced as quickly as possible. Thereby, it can avoid that the temperature of a switching element rises too much, and can avoid suitably that the reliability of a switching element falls by extension.

  According to a second aspect of the present invention, in the first aspect of the invention, the control unit further includes a delay unit that delays a change in the command torque of the rotating machine, and the control unit changes a current flowing through the rotating machine by the delay unit. The switching element is operated to control to a command current corresponding to the delayed command torque, the changing means performs a process of reducing the command torque as the changing process, and the time shortening means is the shortening means. As the processing, the processing for reducing the degree of delay of the change in the command torque by the delay means is performed.

  In the above invention, the delay means is provided for the purpose of avoiding a sudden change in the command torque. Here, if the change of the command torque is delayed by the delay means, there is a possibility that the temperature rise of the switching element cannot be appropriately suppressed. In this regard, in the above invention, in view of the fact that when the command torque of the rotating machine is reduced, the current flowing through the rotating machine as the control amount tends to decrease, the command torque is reduced to obtain the command value of the control amount. Reduce the command current. And the delay degree of the change of the command torque by a delay means is made small. Thereby, when the temperature of a switching element is high, the electric current which flows through a rotary machine can be rapidly reduced to command current, and it can avoid suitably that the temperature of a switching element rises excessively by extension.

  The invention according to claim 3 is the invention according to claim 2, wherein the delay means is a first-order lag filter, and the time-shortening means reduces the time constant of the first-order lag filter as the shortening process. It is characterized by performing processing.

  In the said invention, the structure which makes the delay degree of the change of command torque small can be implement | achieved simply and appropriately by reducing the time constant of a primary delay filter.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the control means operates the switching element so as to feedback-control a current flowing through the rotating machine to a command current, The changing means performs a process of reducing the command current as the changing process, and the time shortening means performs a process of increasing a feedback gain used for the feedback control as the shortening process. .

  In the above invention, the command current as the control value command value is reduced, and the feedback gain used for the current feedback control is further increased. As a result, the time until the current flowing through the rotating machine as the control amount reaches the reduced command current can be shortened, and the current flowing through the rotating machine can be quickly reduced when the temperature of the switching element is high. be able to. Therefore, it is possible to suitably avoid an excessive increase in the temperature of the switching element.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to third aspects, the control means converts the power conversion so as to feedback-control a generated torque of the rotating machine to a command torque of the rotating machine. A phase setting unit for setting a phase of an output voltage vector of the circuit; and operating the switching element based on the set phase, wherein the changing unit includes a process of reducing the command torque as the changing process. And the time shortening means performs a process of increasing a feedback gain used for setting the phase in the feedback control as the shortening process.

  In the above invention, when the command torque of the rotating machine as the control amount is reduced, the command torque as the command value of the control quantity is reduced in view of the fact that the current flowing through the rotating machine tends to decrease. Then, the feedback gain used for setting the phase in the torque feedback control is increased. For this reason, the time until the generated torque of the rotating machine reaches the reduced command torque can be shortened. That is, the current flowing through the rotating machine can be quickly reduced. Thereby, it can avoid suitably that the temperature of a switching element rises too much.

  According to a sixth aspect of the present invention, in the invention according to any one of the first to fifth aspects, when it is determined that the temperature of the switching element is lowered, the execution of the shortening process by the time shortening unit is stopped. It further comprises a canceling means.

  In the above invention, priority is given to the stability of the control of the rotating machine in a situation where the possibility of the temperature of the switching element rising excessively is reduced by providing the stopping means.

1 is a system configuration diagram according to a first embodiment. FIG. The block diagram which shows the response time shortening process etc. concerning the embodiment. 6 is a flowchart showing a procedure of response time reduction processing according to the embodiment. The figure which shows the response time shortening process aspect concerning the embodiment. The figure which shows the response time shortening process aspect concerning the embodiment. The block diagram which shows the response time shortening process etc. concerning 2nd Embodiment. 6 is a flowchart showing a procedure of response time reduction processing according to the embodiment. The block diagram which shows the response time shortening process etc. concerning 3rd Embodiment. The block diagram which shows the response time shortening process etc. concerning 4th Embodiment. 6 is a flowchart showing a procedure of response time reduction processing according to the embodiment. The flowchart which shows the procedure of the response time shortening process concerning 5th Embodiment. The figure which shows the response time shortening process aspect concerning the embodiment.

(First embodiment)
Hereinafter, a first embodiment in which a control device according to the present invention is applied to a vehicle (for example, a hybrid vehicle) including a rotating machine as an in-vehicle main machine will be described with reference to the drawings.

  FIG. 1 shows a system configuration according to the present embodiment.

  The illustrated motor generator 10 is an in-vehicle main machine, and is mechanically coupled to drive wheels (not shown). The motor generator 10 is connected to a high voltage battery 16 via an inverter IV, a boost converter 12 and a relay 14. In the present embodiment, a permanent magnet synchronous motor (for example, an embedded magnet synchronous motor) is used as the motor generator 10.

  The high voltage battery 16 is a storage battery whose terminal voltage is a high voltage of, for example, 100 V or more. As the high voltage battery 16, for example, a lithium ion storage battery or a nickel hydride storage battery can be employed.

  Boost converter 12 has a function of boosting the voltage of high-voltage battery 16 with a predetermined voltage (for example, “650 V”) as an upper limit. The voltage boosted by boost converter 12 is applied to inverter IV.

  The inverter IV is configured by connecting three series connection bodies of a high potential side switching element Sjp (j = u, v, w) as a power element and a low potential side switching element Sjn in parallel. Connection points of the high-potential side switching element Sjp and the low-potential side switching element Sjn are connected to the respective phases of the motor generator 10. In the present embodiment, each of the switching elements Sjp and Sjn is an insulated gate bipolar transistor (IGBT) which is a voltage control type switching element. Free wheel diodes FDp and FDn are connected between the input / output terminals (between the collector and the emitter) of the switching element Sjp on the high potential side and the switching element Sjn on the low potential side.

  In the vicinity of the switching element Sjk (k = p, n), a temperature sensitive diode SDjk for detecting the temperature of the switching element Sjk is provided. Specifically, the temperature sensitive diode SDjk outputs an output voltage corresponding to the temperature of the switching element Sjk. Note that the output voltage of the temperature sensitive diode SDjk and the temperature of the switching element Sjk have a negative correlation.

  The hybrid control device (HVECU 18) is an electronic control device that is higher than the motor generator control device (MGECU 20) to be described later (upstream when a user request input from a user interface such as an accelerator pedal is the most upstream). . The HVECU 18 has a function of outputting a command torque of the motor generator 10 to the MGECU 20.

  On the other hand, MGECU 20 is an electronic control unit for controlling a control amount (for example, torque) of motor generator 10 as desired by operating switching element Sjk of inverter IV. Specifically, the MGECU 20 includes a rotation angle sensor 22 (for example, a resolver) that detects the rotation angle (electrical angle) of the rotor of the motor generator 10, and a current sensor 24 that detects a current flowing through the V and W phases of the motor generator 10. 26, an operation signal for operating the switching element Sjp for each of the U-phase, V-phase, and W-phase of the inverter IV based on the voltage sensor 28 that detects the input voltage of the inverter IV, and further the detected value of the temperature-sensitive diode SDjk. gjp and an operation signal gjn for operating the switching element Sjn are generated and output. Thus, the switching elements Sjp and Sjn are operated by the MGECU 20 via the drive unit DU connected to their conduction control terminals (gates). The operation signal gjp and the operation signal gjn are complementary signals that are alternately turned on.

  Incidentally, the in-vehicle high voltage system including the inverter IV and the in-vehicle low voltage system including the HVECU 18 and the MGECU 20 are insulated by an interface 30 including a photocoupler (not shown), and the operation signal gjk (j = u, v, w, k = p, n) is output to the high pressure system via the interface 30. Further, the temperature Tjk of the switching element Sjk detected by the temperature-sensitive diode SDjk, the rotation angle θ detected by the rotation angle sensor 22, the current values iv and iw detected by the current sensors 24 and 26, and the voltage sensor 28 The input voltage VINV of the inverter IV detected by is output to the low-voltage system via the interface 30.

  Next, processing related to control of the control amount of the motor generator 10 (current feedback control) executed by the MGECU 20 will be described with reference to FIG.

The command current setting unit B1 is a command current on the d-axis that is a command value of the current in the rotating two-phase coordinate system for setting the generated torque of the motor generator 10 to the command torque Trqc output from the annealing processing unit B12 described later. (D-axis command current id *) and q-axis command current (q-axis command current iq *) are set. Here, when the generated torque T of the motor generator 10 uses a d-axis inductance Ld, a q-axis inductance Lq, a d-axis current id, a q-axis current iq, an armature flux linkage constant φ, and the number of pole pairs P, The expression (e1) is used.
T = P {φ · iq + (Ld−Lq) id · iq} (e1)
Incidentally, the d-axis command current id * and the q-axis command current iq * are specifically a map (current command map) in which these command currents id * and iq * related to the command torque Trqc are defined. It may be calculated using.

  Two-phase converter B2 flows through each phase of motor generator 10 based on rotation angle θ detected by rotation angle sensor 22 and V-phase current iv and W-phase current iw detected by current sensors 24 and 26. The currents iu, iv, iw are converted into an actual current on the d-axis (d-axis actual current idr) and an actual current on the q-axis (q-axis actual current iqr), which are actual currents in the rotating two-phase coordinate system. . Note that the current iu flowing through the U phase of the motor generator 10 used in the conversion of these actual currents is calculated based on the V phase current iv and the W phase current iw.

  The speed calculation unit B3 calculates the rotational speed ω (electrical angular speed) of the rotor of the motor generator 10 based on the rotational angle θ detected by the rotational angle sensor 22.

  The d-axis current comparison unit B4 calculates a deviation Δid between the d-axis command current id * and the d-axis actual current idr. Here, the deviation Δid is a value obtained by subtracting the d-axis actual current idr from the d-axis command current id *. On the other hand, the q-axis current comparison unit B5 calculates a deviation Δiq between the q-axis command current iq * and the q-axis actual current iqr. Here, the deviation Δiq is a value obtained by subtracting the q-axis actual current iqr from the q-axis command current iq *.

  The d-axis command voltage setting unit B6 adds a non-interference term for performing known non-interference control as a feedforward operation amount to the feedback operation amount based on the proportional-integral control (PI control) using the deviation Δid. Then, the d-axis command voltage Vd * is set. The feedback manipulated variable is specifically calculated as an addition value of a product of the deviation Δid and the proportional gain Kp and an integral operation value of the product of the deviation Δid and the integral gain Ki. Further, the non-interference term is calculated by inputting the rotational speed ω output from the speed calculation unit B3 and the d-axis command current id * and the q-axis command current iq * output from the command current setting unit B1. Calculated by the part B8.

  The q-axis command voltage setting unit B7 adds a non-interference term for performing non-interacting control as a feedforward operation amount to the feedback operation amount based on proportional integral control (PI control) using the deviation Δiq, Set q-axis command voltage Vq *. The feedback manipulated variable is specifically calculated as an addition value of a multiplication value of the deviation Δiq and the proportional gain Kp and an integral calculation value of the multiplication value of the deviation Δiq and the integral gain Ki.

  Based on the rotation angle θ detected by the rotation angle sensor 22, the three-phase conversion unit B9 converts the command voltages Vd * and Vq * to U-phase command voltages Vu and V-phase which are command voltages in a three-phase fixed coordinate system. The command voltage Vv is converted into a W-phase command voltage Vw.

  The PWM modulation unit B10 uses the operation signal gjk (j = u, v, w; k = p, n) for setting the three-phase output voltage of the inverter IV as a voltage simulating the command voltages Vu, Vv, Vw. Generate. Here, for example, the operation signal gjk is obtained by comparing the magnitude of the command voltage Vu, Vv, Vw standardized by the input voltage VINV of the inverter IV detected by the voltage sensor 28 with the triangular wave carrier. That's fine. Then, the generated operation signal gjk is output to the inverter IV.

  By the way, if the temperature of the switching element Sjk rises excessively, the reliability of the switching element Sjk may be reduced. In order to avoid the occurrence of such a situation, the present embodiment includes a command torque limiter B11 that reduces the command torque Trq * output from the HVECU 18 using the switching element temperature as an input.

  Specifically, when it is determined that the switching element temperature Tth exceeds the threshold temperature T1, the command torque limiting unit B11 performs a torque limiting process that decreases the command torque Trq * as the switching element temperature Tth increases. This process will be described. First, a torque limit coefficient Ktrq is set. The torque limit coefficient Ktrq is set to 1 when the switching element temperature Tth is equal to or lower than the threshold temperature T1, and switching is performed when the switching element temperature Tth exceeds the threshold temperature T1 and is lower than the upper limit temperature T2 higher than the threshold temperature T1. The lower the element temperature Tth is, the smaller the element temperature Tth is set. Then, the command torque Trq * is reduced by multiplying the command torque Trq * by the set torque limit coefficient Ktrq.

  Note that the switching element temperature Tth used for setting the torque limiting coefficient Ktrq may be, for example, the maximum value among the temperatures Tjk of all (six) switching elements Sjk included in the inverter IV. The upper limit temperature T2 may be set as an upper limit value that can maintain the reliability of the switching element Sjk, for example.

  The annealing processing unit B12 is configured by a first-order lag filter, and performs a process of delaying a change in the command torque output from the command torque limiting unit B11. This is for avoiding a sudden change in the command torque output from the command torque limiting unit B11 (smooth changes in the command torque), and for avoiding a decrease in drivability.

  Here, according to the annealing processing unit B12, although the change in the command torque Trqc input to the command current setting unit B1 can be smoothed, the actual generated torque of the motor generator 10 is changed by the command torque limiting unit B11. There is a concern that the time until the reduced command torque is reached becomes longer. In this case, the temperature rise of the switching element Sjk cannot be appropriately suppressed, and the reliability of the switching element Sjk may be reduced.

  In order to solve such a problem, in the present embodiment, the time constant of the first-order lag filter of the smoothing processing unit B12 is determined in a situation where the switching element temperature Tth is determined to exceed the threshold temperature T1 and the command torque Trq * is reduced. Response time shortening processing for reducing Ts is performed.

  FIG. 3 shows a control processing procedure of the motor generator 10 including the response time reduction processing according to the present embodiment. This process is repeatedly executed by the MGECU 20 at a predetermined cycle, for example.

  In this series of processing, it is determined whether or not the switching element temperature Tth exceeds the threshold temperature T1 in step S10.

  If it is determined in step S10 that the switching element temperature Tth is equal to or lower than the threshold temperature T1, the process proceeds to step S12, and the torque limit coefficient Ktrq is set to 1.

  In the subsequent step S14, the time constant Ts of the first-order lag filter is set to the first time constant Ta.

  On the other hand, when a negative determination is made in step S10, it is determined that the current flowing through the switching element needs to be suppressed, and the process proceeds to step S16. In step S16, as described above, torque limit processing is performed in which the torque limit coefficient Ktrq is set smaller as the switching element temperature Tth is higher (see FIG. 2 above).

  In the subsequent step S18, a response time shortening process for setting the time constant Ts of the primary filter to a second time constant Tb smaller than the first time constant Ta is performed. The second time constant Tb may be set to 0, for example, when it is desired to increase the degree of decrease in the current flowing through the motor generator 10.

  After the processes of steps S14 and S18 are completed, in step S20, the command torque Trqc is calculated based on the command torque Trq * output from the HVECU 18 and the torque limiting coefficient Ktrq and the first order lag filter in the annealing process unit B12.

  In addition, when the process of step S20 is completed, this series of processes is once complete | finished.

  FIG. 4 shows an example of response time reduction processing according to the present embodiment. Specifically, FIG. 4A shows the transition of the switching element temperature Tth, and FIG. 4B shows the transition of the generated torque of the motor generator 10.

  As indicated by the solid line in the figure, when the switching element temperature Tth exceeds the threshold temperature T1 at time t1, a response time shortening process in which the time constant Ts of the first-order lag filter is set small is started together with the torque limiting process. . For this reason, the generated torque of motor generator 10 can be quickly reduced to command torque Trqc. That is, the current flowing through motor generator 10 can be quickly reduced, and the switching element temperature Tth can be prevented from rising excessively.

  On the other hand, as shown by a broken line in the figure, when the response time shortening process is not performed, the generated torque of the motor generator 10 cannot be quickly reduced to the command torque Trqc and flows to the motor generator 10. The current cannot be reduced quickly. For this reason, the switching element temperature Tth greatly increases.

  Next, the advantage of using the response time shortening process will be further described with reference to FIG. Specifically, FIG. 5A and FIG. 5B correspond to FIG. 4A and FIG. 4B, respectively. The waveform shown by the broken line in FIG. 5 is the same as the waveform shown by the broken line in FIG.

  As described above, according to the response time shortening process, it is possible to avoid the switching element temperature Tth from rising excessively. For this reason, the threshold temperature can be increased from T1 to T1 '. As a result, as shown by a solid line in the figure, the restriction on the generated torque of the motor generator 10 can be suppressed, for example, the timing for starting the torque limiting process can be delayed from the time t1 to the time t2.

  As described above, in this embodiment, when it is determined that the switching element temperature Tth exceeds the threshold temperature T1, the response time shortening process for setting the time constant Ts of the first-order lag filter to be small is performed together with the torque limiting process. Therefore, it is possible to avoid an excessive increase in the switching element temperature Tth.

  According to the embodiment described in detail above, the following effects can be obtained.

  (1) When it is determined that the switching element temperature Tth exceeds the threshold temperature T1, a torque limiting process is performed to decrease the command torque Trq * as the switching element temperature Tth is higher, and the time constant Ts of the primary delay filter is decreased. Response time reduction processing to be set was performed. Thereby, the current flowing through motor generator 10 can be quickly reduced, and the switching element temperature can be prevented from rising excessively. Therefore, it is possible to avoid a decrease in the reliability of the switching element Sjk.

  (2) The change in the command torque output from the command torque limiter B11 is delayed using a first-order lag filter. Thereby, the delay degree of the change of the command torque can be easily and appropriately adjusted by changing the time constant Ts.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 6 shows a block diagram of processing related to current feedback control according to the present embodiment. In FIG. 6, the same processing as shown in FIG. 2 is given the same reference numeral for convenience.

  In the present embodiment, in addition to the process of setting the time constant Ts of the first-order lag filter to be small as the response time shortening process, when it is determined that the switching element temperature Tth exceeds the threshold temperature T1, the d-axis command voltage setting unit In B6 and the q-axis command voltage setting unit B7, a gain increasing process for increasing the proportional gain Kp and the integral gain Ki is performed.

  FIG. 7 shows a procedure of control processing of the motor generator 10 including response time reduction processing according to the present embodiment. This process is repeatedly executed by the MGECU 20 at a predetermined cycle, for example. In FIG. 7, the same steps as those shown in FIG. 3 are given the same step numbers for the sake of convenience.

  In this series of processes, when the process of step S14 is completed, the proportional gain Kp is set to the first proportional gain Kpa and the integral gain Ki is set to the first integral gain Kia in step S22.

  On the other hand, when the process of step S18 is completed, the proportional gain Kp is set to the second proportional gain Kpb larger than the first proportional gain Kpa in step S24, and the integral gain Ki is set to the first integral gain. A second integral gain Kib that is larger than Kia is set. In order to avoid a decrease in controllability of the d-axis actual current idr and the q-axis actual current iqr, for example, the ratio of the second integral gain Kib to the second proportional gain Kpb is set to the first proportional gain Kpa. The ratio of the integral gain Kia of 1 may be substantially the same.

  When the processes of steps S22 and S24 are completed, the process proceeds to step S20.

  In addition, when the process of step S20 is completed, this series of processes is once complete | finished.

  As described above, in the present embodiment, the current flowing through the motor generator 10 can be quickly reduced by further performing the gain increasing process as the response time shortening process. Thereby, it can avoid more suitably that the temperature of a switching element rises too much.

(Third embodiment)
Hereinafter, the third embodiment will be described with reference to the drawings with a focus on differences from the second embodiment.

  In the present embodiment, torque feedback control is performed as control of the control amount of the motor generator 10.

  FIG. 8 shows a block diagram of processing relating to torque feedback control according to the present embodiment. In FIG. 8, the same processing as shown in FIG. 6 is given the same reference numeral for convenience.

  Torque estimation unit B13 calculates estimated torque Te of motor generator 10 based on d-axis actual current idr and q-axis actual current iqr output from two-phase conversion unit B2. Here, specifically, the estimated torque Te may be calculated using, for example, a map or a mathematical formula in which the actual currents idr, iqr and the estimated torque Te are related.

  The deviation calculating unit B14 calculates a deviation ΔTr between the command torque Trqc output from the annealing processing unit B12 and the estimated torque Te. Here, the deviation ΔTr is a value obtained by subtracting the estimated torque Te from the command torque Trqc.

  The phase setting unit B15 sets the phase δ as an operation amount for performing feedback control of the estimated torque Te to the command torque Trqc based on the deviation ΔTr. Specifically, the phase δ is set by proportional-integral control (PI control) using the deviation ΔTr. More specifically, the phase δ is set as an addition value of the multiplication value of the deviation ΔTr and the proportional gain Kp and the integral calculation value of the multiplication value of the deviation ΔTr and the integral gain Ki.

  Here, in this embodiment, when it is determined that the switching element temperature Tth exceeds the threshold temperature T1, a gain increasing process for increasing the proportional gain Kp and the integral gain Ki is performed as a response time shortening process.

  The norm setting unit B16 receives the command torque Trqc output from the annealing processing unit B12 and the electrical angular velocity ω, and sets the norm Vn of the output voltage vector of the inverter IV. Here, the norm of the vector is defined by the square root of the sum of the squares of the components of the vector. Incidentally, the norm Vn is specifically a means for uniquely calculating the norm Vn from the command torque Trqc and the electrical angular velocity ω, such as a map in which the command torque Trqc and the electrical angular velocity ω are related to the norm Vn. It can set by having.

  The operation signal generator B17 generates and outputs an operation signal gjk based on the phase δ, the norm Vn, the input voltage VINV of the inverter IV, and the electrical angle θ. Specifically, the operation signal generation unit B17 stores an operation signal waveform for one rotation period of the electrical angle as map data for each modulation rate. The operation signal generation unit B17 calculates a modulation rate based on the input voltage VINV and norm Vn of the inverter IV, and selects a corresponding operation signal waveform according to this. When the operation signal waveform is selected, the operation signal generation unit B17 generates the operation signal gjk by setting the output timing of this waveform based on the phase δ.

  The procedure of the control process of the motor generator 10 including the response time shortening process according to the present embodiment is in accordance with the procedure shown in FIG.

  Further, the torque feedback control according to the present embodiment and the current feedback control according to the second embodiment are actually selected and executed according to the operating state of the motor generator 10. Specifically, for example, when it is determined that the modulation rate is less than a predetermined value greater than 1, current feedback control is performed, and when it is determined that the modulation rate is equal to or greater than the predetermined value, torque feedback control is performed. The

  Thus, in this embodiment, it is possible to suitably avoid an excessive increase in the temperature of the switching element by performing the response time shortening process in the configuration that performs the torque feedback control.

(Fourth embodiment)
Hereinafter, the fourth embodiment will be described with reference to the drawings with a focus on differences from the second embodiment.

  FIG. 9 shows a block diagram of processing related to current feedback control according to the present embodiment. In FIG. 9, the same processing as shown in FIG. 6 is given the same reference numeral for convenience.

  In the present embodiment, when it is determined that the switching element temperature Tth exceeds the threshold temperature T1, the command current setting unit B1 performs a process of reducing the d-axis command current id * and the q-axis command current iq *. Specifically, first, the command torque Trq * output from the HVECU 18 is input, and the d-axis command current idm and the q-axis command current iqm are calculated using the current command map.

  When it is determined that the switching element temperature Tth exceeds the threshold temperature T1, the d-axis command current idm and the q-axis command current iqm are decreased as the switching element temperature Tth is higher. That is, the norm of the command current vector for motor generator 10 is reduced. Here, a method for reducing the command current will be described. Specifically, for example, first, the current limiting coefficient a is set. The current limiting coefficient a is set to 1 when the switching element temperature Tth is equal to or lower than the threshold temperature T1, and is switched when the switching element temperature Tth exceeds the threshold temperature T1 and is lower than the upper limit temperature T2 higher than the threshold temperature T1. The lower the element temperature Tth is, the smaller the element temperature Tth is set. Then, the command current idm and iqm are reduced by multiplying the d-axis command current idm and the q-axis command current iqm by the current limiting coefficient a.

  FIG. 10 shows a procedure of control processing of the motor generator 10 including response time reduction processing according to the present embodiment. This process is repeatedly executed by the MGECU 20 at a predetermined cycle, for example. In FIG. 10, the same steps as those shown in FIG. 7 are given the same step numbers for the sake of convenience.

  In this series of processes, if a negative determination is made in step S10, the process proceeds to step S26, and the current limiting coefficient a is set to 1. When the process of step S26 is completed, the process proceeds to step S22.

  On the other hand, if an affirmative determination is made in step S10, the process proceeds to step S28, and as described above, the current limiting coefficient a is set smaller as the switching element temperature Tth is higher (see FIG. 9 above). When the process of step S28 is completed, the process proceeds to step S24.

  In addition, when the process of step S22, S24 is completed, this series of processes is once complete | finished.

  Thus, in the present embodiment, when the command current setting unit B1 determines that the switching element temperature Tth exceeds the threshold temperature T1, the d-axis command current idm and the q-axis command current calculated based on the current command map By reducing iqm, it is possible to suitably avoid an excessive increase in the temperature of the switching element.

(Fifth embodiment)
Hereinafter, a fifth embodiment will be described with reference to the drawings, focusing on differences from the first embodiment.

  FIG. 11 shows a control processing procedure of the motor generator 10 including the response time reduction processing according to the present embodiment. This process is repeatedly executed by the MGECU 20 at a predetermined cycle, for example. In FIG. 11, the same steps as those shown in FIG. 3 are given the same step numbers for the sake of convenience.

  In the series of processes, when the process of step S16 is completed, a change amount (temperature change amount ΔTth) of the switching element temperature Tth is calculated in step S30. In the present embodiment, the temperature change amount ΔTth is calculated as a value obtained by subtracting the switching element temperature Tth (n−1) at the previous sampling timing from the switching element temperature Tth (n) at the current sampling timing.

  In a succeeding step S32, it is determined whether or not the temperature change amount ΔTth is larger than zero. This process is a process for determining whether or not the switching element temperature Tth is decreasing.

  If an affirmative determination is made in step S32, it is determined that the switching element temperature Tth is still on the rise, and the process proceeds to step S18. That is, the time constant Ts of the first-order lag filter in the annealing process unit B12 is maintained at the second time constant Tb, and the response time shortening process is continued.

  On the other hand, if a negative determination is made in step S32, it is determined that the switching element temperature Tth is decreasing, and the process proceeds to step S14. That is, the time constant Ts of the first-order lag filter is returned to the first time constant Ta, and the response time shortening process is stopped.

  In addition, when the process of step S20 is completed, this series of processes is once complete | finished.

  FIG. 12 shows an example of the response time shortening process according to this embodiment. Specifically, FIG. 12A corresponds to the previous FIG. FIG. 12B shows the transition of whether or not the torque limiting process is executed, and FIG. 12C shows the transition of the time constant Ts of the first-order lag filter.

  In the illustrated example, when it is determined that the switching element temperature Tth exceeds the threshold temperature T1 at time t1, the torque limiting process is started and the time constant Ts is changed from the first time constant Ta to the second time. It is switched to the constant Tb.

  Thereafter, at time t2, when it is determined that the temperature change amount ΔTth becomes 0 or less, the time constant Ts of the first-order lag filter is switched from the second time constant Tb to the first time constant Ta, thereby shortening the response time. Processing is aborted. At time t3, when it is determined that the switching element temperature Tth is equal to or lower than the threshold temperature T1, the torque limiting process is terminated.

  Thus, in the present embodiment, the time constant Ts of the first-order lag filter is switched based on the temperature change amount ΔTth. According to such a configuration, the current flowing through the motor generator 10 is rapidly reduced in a situation where the increase degree of the switching element temperature Tth is large, and then the d-axis actual current idr and the q-axis actual current iqr in the situation where the switching element temperature Tth decreases. It is possible to avoid a decrease in control stability.

(Other embodiments)
Each of the above embodiments may be modified as follows.

  In the first embodiment, the HVECU 18 may perform processing in the command torque limiting unit B11 and the annealing processing unit B12.

  In each of the above embodiments, the temperature sensitive diode SDjk is provided so that each temperature of the switching element Sjk can be detected separately. However, the present invention is not limited to this. For example, a temperature sensitive diode may be arranged only in the vicinity of those switching elements Sjk that are relatively likely to rise in temperature.

  In the second and third embodiments, the annealing processing unit B12 may not be provided. Even in this case, since the gain increasing process is performed, it is possible to prevent the switching element temperature Tth from rising excessively.

  The mode of setting the time constant Ts of the first-order lag filter is not limited to that exemplified in the first embodiment. For example, when it is determined that the switching element temperature Tth exceeds the threshold temperature T1, the time constant Ts may be set to be smaller stepwise as the switching element temperature Tth is higher.

  The delay means is not limited to the first-order lag filter, but may be a second-order lag filter, for example. In this case, for example, when it is determined that the switching element temperature Tth exceeds the threshold temperature T1 while the attenuation coefficient of the second-order lag filter is larger than 1, the natural frequency of the second-order lag filter may be set higher.

  The feedback gain increasing method is not limited to those exemplified in the second to fourth embodiments. For example, either the proportional gain Kp or the integral gain Ki may be increased.

  The feedback control is not limited to proportional integral control, and may be proportional integral derivative control, for example. In this case, when it is determined that the switching element temperature Tth exceeds the threshold temperature T1, the differential gain may be increased.

  In the fourth embodiment, a process of reducing either the d-axis command current idm or the q-axis command current iqm may be performed.

  In the fifth embodiment, if the temperature change amount ΔTth is positive and the absolute value of the temperature change amount ΔTth is very small even if the temperature change amount ΔTth is not less than or equal to 0, the first-order lag filter The time constant Ts may be switched to the first time constant Ta.

  In the fifth embodiment, in addition to the process of reducing the time constant Ts of the first-order lag filter, the gain increasing process shown in the second embodiment may be performed. In this case, once it is determined that the switching element temperature Tth exceeds the threshold temperature T1, if the temperature change amount ΔTth is determined to be 0 or less, the gain increasing process is stopped in addition to the process of decreasing the time constant Ts. That's fine.

  In the fifth embodiment, as the response time shortening process, a gain increasing process may be performed instead of the process of reducing the time constant Ts.

  The detection method of the switching element temperature Tth is not limited to those exemplified in the above embodiments. For example, a thermistor may be provided near the switching element Sjk, and the temperature Tjk of the switching element Sjk may be detected by the thermistor.

  Further, the method is not limited to the method of directly detecting the switching element temperature, and a method of estimating the switching element temperature may be employed. By adopting this method, the number of sensors for detecting the switching element temperature can be reduced. Here, a method for estimating the switching element temperature will be described. Specifically, for example, first, only the temperature of a part of the switching elements Sjk is detected by the temperature sensitive diode. Then, the detected switching element temperature, and the amount of current flowing through each of the specific switching element other than the switching element to be detected by the temperature-sensitive diode and the switching element to be detected (hereinafter referred to as a pair of switching elements). The temperature of the specific switching element is estimated based on the correlation between the relative magnitude relationship between the temperatures of the pair of switching elements and the amount of current flowing through the pair of switching elements. This technique is based on the fact that there is a correlation between the relative magnitude relationship between the amounts of current flowing through the pair of switching elements and the relative magnitude relationship between the temperatures of these switching elements.

  The rotary machine to which the present invention is applied is not limited to a machine mechanically connected to the drive wheels, for example, a rotary machine built in a compressor of an air conditioner using the high voltage battery 16 as a direct power source. Also good.

  -As a rotating machine, not only a brushless DC motor but a DC motor with a brush may be sufficient. In this case, the power conversion circuit applied to the rotating machine is not limited to the DC / AC conversion circuit (inverter) that converts the power of the DC power source into AC power, and may be, for example, an H-bridge circuit.

  DESCRIPTION OF SYMBOLS 10 ... Motor generator, 16 ... High voltage battery, 20 ... MGECU (one Embodiment of the control apparatus of a rotary machine), IV ... Inverter, Sjk ... Switching element, SDjk ... Temperature-sensitive diode.

Claims (6)

In a control device for a rotating machine comprising control means for controlling a control amount of the rotating machine by operating a switching element of a power conversion circuit interposed between a DC power source and the rotating machine,
When the temperature of the switching element exceeds a specified temperature, changing means for performing a process of changing the command value of the control amount to the side where the current flowing through the rotating machine is reduced,
A rotating machine comprising: a time-shortening unit that performs a process of shortening a time until the control amount reaches the command value changed by the changing unit when the command value is changed by the changing unit; Control device. A delay means for delaying a change in the command torque of the rotating machine;
The control means operates the switching element to control a current flowing through the rotating machine to a command current corresponding to a command torque whose change is delayed by the delay means,
The changing means performs a process of reducing the command torque as the changing process,
The control device for a rotating machine according to claim 1, wherein the time shortening means performs a process of reducing a degree of delay of the change in the command torque by the delay means as the shortening process. The delay means is a first order lag filter;
The control device for a rotating machine according to claim 2, wherein the time shortening means performs a process of reducing a time constant of the first-order lag filter as the shortening process. The control means operates the switching element to feedback control the current flowing through the rotating machine to a command current,
The changing means performs a process of reducing the command current as the changing process,
The said time shortening means performs the process which increases the feedback gain used for the said feedback control as the said process to shorten, The control apparatus of the rotary machine of any one of Claims 1-3 characterized by the above-mentioned. The control means further comprises phase setting means for setting the phase of the output voltage vector of the power conversion circuit so as to feedback control the generated torque of the rotating machine to the command torque of the rotating machine, and based on the set phase Operating the switching element;
The changing means performs a process of reducing the command torque as the changing process,
The said time shortening means performs the process which increases the feedback gain used for the setting of the said phase in the said feedback control as the said shortening process, The rotary machine of any one of Claims 1-3 characterized by the above-mentioned. Control device.   The rotation according to any one of claims 1 to 5, further comprising stop means for stopping execution of the shortening process by the time shortening means when it is determined that the temperature of the switching element is lowered. Machine control device.

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