JP5633462B2 - Motor voltage conversion control device - Google Patents

Description

  The present invention relates to a voltage conversion control device for a motor that performs voltage conversion control for a voltage conversion circuit that converts a DC voltage of a power source into an input DC voltage necessary for driving the motor between a motor control circuit that controls the motor and the power source. About.

  In recent years, hybrid vehicles, electric vehicles, and the like have been developed as environmentally friendly vehicles, and these vehicles include a motor as a drive source. An AC motor is used as this motor, and DC power is converted into three-phase AC power by an inverter, and the motor is driven by the three-phase AC power. Furthermore, since high voltage is required to output high rotation and high torque with the motor, the DC voltage of the battery is boosted to DC high voltage by the boost converter, and the DC high voltage is supplied to the inverter. . Therefore, in the vehicle, in order to control the motor, inverter control for switching control of the switching element of the inverter and boost control for switching control of the switching element of the boost converter are performed. A smoothing capacitor is provided between the boost converter and the inverter, and a voltage across the smoothing capacitor (a DC high voltage after boosting by the boost converter) is detected by a voltage sensor. In step-up control, control is performed using the DC high voltage detected by the voltage sensor so as to obtain a target voltage necessary for driving the motor.

  In Patent Document 1, in a motor drive device of a vehicle including one motor as a drive source, based on the sensor value of the voltage of the DC power supply, the sensor value of the voltage across the smoothing capacitor, the motor torque command value, and the motor rotation speed. Generates a gate signal for controlling the switching element of the boost converter, and controls the inverter switching element based on the sensor value of the voltage across the smoothing capacitor, the motor torque command value, and the sensor value of the motor current Is described.

JP-A-2005-341698

  In vehicle development, cost reduction and downsizing are required, and therefore, a reduction in the capacity of the smoothing capacitor between the boost converter and the inverter is required. The smaller the capacity of the smoothing capacitor, the larger the ratio of charge to and from the smoothing capacitor according to the switching of the switching element of the inverter. Therefore, when the smoothing capacity of the smoothing capacitor is exceeded, the voltage across the smoothing capacitor fluctuates greatly. Pulsation occurs in the DC high voltage after boosting.

Specifically, when the carrier frequency of the inverter control (switching frequency for turning on / off the inverter switching element) is temporarily lowered due to restrictions on the driving state (for example, when the temperature of the switching element of the inverter is high), etc. The cycle of turning on / off the switching element becomes longer, and the switching noise of the inverter control is superimposed as a large fluctuation (pulsation component) on the voltage across the smoothing capacitor (DC high voltage after boosting). FIG. 9 shows a DC high voltage time change VH _2.5 when the carrier frequency is 2.5 kHz and a DC high voltage time change VH _1.25 when the carrier frequency is 1.25 kHz. The curve indicated by symbol VH _F is time variation _VH 2.5 high DC _voltage, the time change of the filter value obtained by filtering the _{VH 1.25} with a predetermined time constant. As can be seen from FIG. 9, the DC high voltage after boosting greatly fluctuates due to the superposition of large pulsation components when the carrier frequency is lower than when the carrier frequency is high. Incidentally, the higher the carrier frequency, the easier the motor rotates, but the system loss increases due to the heat generated by the switching element increasing.

  Further, the target voltage required for driving the motor varies depending on the rotation speed and torque of the motor. When this target voltage is high and the DC high voltage after boosting is higher than the motor induced voltage, a large pulsating component is superimposed on the DC high voltage according to the voltage difference.

For example, FIG. 10A shows the relationship between the voltage VH _H when the DC high voltage is high, the voltage VH _L when the DC high voltage is low, and the motor induced voltage Vemf. As the voltage difference _Vdef H1, Vdef _H2 of the DC high voltage VH _H and the motor induced voltage Vemf when high, is compared with the voltage difference _Vdef L1, Vdef _L2 of the DC high voltage VH _L and the motor induced voltage Vemf lower case The voltage difference Vdef is larger when the DC high voltage VH _H is higher. As the voltage difference Vdef increases, the amount of fluctuation superimposed on the motor current increases.

FIG. 10B shows a carrier signal SC and a duty signal SD in the inverter control, and a gate signal for turning on / off the switching element of the inverter according to the intersection of the carrier signal SC and the duty signal SD. Is generated. Further, in FIG. 10 (c) shows a target current MI _T of the motor, and the actual current MI _H of the motor in the case of large voltage differences Vdef _H, the actual current MI _L in the case of small voltage difference Vdef _L motor ing. Actual current _MI H of the motor, MI _L is varied with respect to the target current MI _T, pulsating component due to the influence of the switching of the switching elements of the inverter are superposed, FIG. 10 (b), the from (c) As can be seen, the increase / decrease in the pulsation component changes at the intersection of the carrier signal SC and the duty signal SD (gate signal ON / OFF switching timing). As can be seen from FIG. 10C, the larger the voltage difference Vdef, the larger the pulsating component superimposed on the motor current. Furthermore, there is illustrated a DC high boosted voltage VH when the actual current MI _H in the case of large voltage differences Vdef _H motor FIG 10 (d). The DC high voltage VH pulsates according to the pulsation of the actual current of the motor and fluctuates greatly.

  That is, the pulsation component superimposed on the motor current due to the influence of switching in the inverter control is determined by the voltage difference Vdef between the DC high voltage VH and the motor induced voltage Vemf and the carrier frequency of the inverter control. For this reason, if the inverter frequency decreases when the voltage difference Vdef is large, the pulsating component superimposed on the motor current increases. When the capacity of the smoothing capacitor is small, if the pulsating component superimposed on the motor current increases, the smoothing capacity of the smoothing capacitor is exceeded, the voltage across the smoothing capacitor fluctuates greatly, and pulsation occurs in the boosted DC high voltage.

FIG. 10D shows an expected value of DC high voltage together with actual DC high voltage VH (intermediate value between peaks and valleys of DC high voltage VH, which is a DC high voltage that does not include a pulsating component) VH. _E and DC high voltage sampling timing request signals DS ₁ , DS ₂ , DS ₃ in the step-up control are shown. Sampling timing request signals DS ₁ , DS ₂ , DS ₃ are output every sampling timing period PS. In the conventional boost control, when the sampling timing request signals DS ₁ , DS ₂ , DS ₃ are output, the voltage across the smoothing capacitor is detected by the voltage sensor, and the detected DC high voltages VH ₁ , VH ₂ , VH ₃ are used. Control to achieve the target voltage. However, for example, in the case of the DC high voltage VH ₁ detected by the sampling timing request signal DS ₁ , a large pulsation component is superimposed due to the influence of the pulsation component of the motor current due to the switching noise on the inverter control side. A large deviation from the value VH _E1 . When performing the step-up control by using such a DC high voltage VH _1, boost control becomes unstable.

  In the control described in Patent Document 1, the gate signal for controlling the switching element of the boost converter and the gate signal for controlling the switching element of the inverter are generated separately, and the boost control and the inverter control are linked. Absent. Therefore, when pulsation occurs in the DC high voltage after boosting by the boost converter, the sensor value of the voltage across the smoothing capacitor used for boost control includes the pulsation component, which makes the boost control unstable. Become.

  Therefore, an object of the present invention is to provide a voltage conversion control device for a motor that performs stable voltage conversion control even when the input DC voltage of the motor caused by the pulsation of the motor current is pulsated in the motor system.

  A voltage conversion control device for a motor according to the present invention is a voltage conversion control for a voltage conversion circuit that converts a DC voltage of a power supply into an input DC voltage required for driving the motor between a motor control circuit that controls the motor and the power supply. A voltage conversion control device for a motor that performs sampling, detecting a voltage across a capacitor provided between the motor control circuit and the voltage conversion circuit, and sampling the input DC voltage converted by the voltage conversion circuit; The sampling timing generating means for generating the sampling timing for sampling the input DC voltage converted by the voltage conversion circuit based on the motor control gate signal for the motor, and the sampling timing generating means for each sampling timing request of the voltage conversion control Depending on the sampling timing Characterized in that it comprises a control means for performing a voltage conversion control by using a sampling input DC voltage.

  This motor voltage conversion control device is a device that performs voltage conversion control on a voltage conversion circuit in a motor system including a motor, a motor control circuit, a voltage conversion circuit, a power source, and the like. A capacitor is provided between the motor control circuit and the voltage conversion circuit, and the input DC voltage converted by the voltage conversion circuit is sampled by detecting the voltage across the capacitor by the sampling means. In the motor voltage conversion control device, control is performed using the input DC voltage sampled by the sampling means so that the input DC voltage becomes a target voltage necessary for driving the motor. The motor includes not only a motor having a drive function but also a motor generator and a generator having a power generation function.

  The pulsation of the input DC voltage of the motor is caused by the pulsation of the motor current. The pulsating component superimposed on the motor current is an influence of switching of motor control, and is a gate signal for switching on the motor control side (a signal generated on the motor control side, which controls switching of the switching element of the motor control circuit) Gate signal). Therefore, the peak and valley of the motor current on which the pulsation component is superimposed are the ON / OFF switching timing of the gate signal. Therefore, an intermediate value between the peaks and valleys of the input DC voltage on which the pulsation component is superimposed (that is, the input DC voltage from which the pulsation component is removed, and the expected value of the input DC voltage for stably performing the voltage conversion control). Is obtained at an intermediate timing between successive switching timings of the gate signal.

  Therefore, in this motor voltage conversion control device, the sampling timing generation means generates a sampling timing for sampling the input DC voltage based on the motor control gate signal. In the motor voltage conversion control device, the control means requests the sampling timing for the input DC voltage in the voltage conversion control (the timing at which the input DC voltage is output at the required timing in the voltage conversion control, and the gate on the motor control side Control is performed so that the target voltage is obtained using the input DC voltage (actual voltage) sampled by the sampling means in accordance with the sampling timing generated by the sampling timing generating means every time (not synchronized with the signal). In this way, this motor voltage conversion control device samples the input DC voltage used for voltage conversion control in consideration of the motor control gate signal, so that even if there is a pulsation in the input DC voltage of the motor, the sampling timing Since the input DC voltage close to the expected value of the input DC voltage at the time of request can be sampled, the difference between the expected value of the input DC voltage and the sampling value actually used in voltage conversion control is reduced, and stable voltage conversion control is performed. be able to. As a result, the capacity of the capacitor can be reduced, and the cost and size of the motor system can be reduced.

  In the motor voltage conversion control device of the present invention, the sampling timing generating means generates a sampling timing in accordance with the switching timing of the gate signal ON and OFF, and the sampling means generates the sampling timing by the sampling timing generating means. Each time, the average value of the input DC voltage converted by the voltage conversion circuit according to the current sampling timing and the input DC voltage converted by the voltage conversion circuit according to the previous sampling timing is calculated. For each sampling timing request for voltage conversion control, it is preferable to perform voltage conversion control using the average value of the input DC voltage calculated by the sampling means immediately before the sampling timing request.

  In this motor voltage conversion control device, sampling timing is generated by sampling timing generation means in accordance with the ON / OFF switching timing of the gate signal. In the motor voltage conversion control device, the sampling means converts the input DC voltage converted by the voltage conversion circuit according to the current sampling timing and the voltage conversion circuit according to the previous sampling timing at each sampling timing. The average value of the input DC voltage is calculated, and the average value of the input DC voltage is sampled. The average value of the input DC voltage sampled at each successive switching timing (continuous rising timing and falling timing) of the gate signal is an intermediate value between the peaks and troughs of the input DC voltage. In the motor voltage conversion control device, the control unit performs control so that the target voltage is obtained by using the average value of the input DC voltages calculated by the sampling unit immediately before the sampling timing request for each sampling timing request. The average value of the input DC voltages sampled at successive switching timings of the gate signal immediately before the sampling timing request is a voltage close to the expected value of the input DC voltage at the time of the sampling timing request. In this way, this motor voltage conversion control device samples the average value of the input DC voltage sampled at successive switching timings of the motor control gate signal, thereby pulsating the input DC voltage of the motor. Even in some cases, voltage conversion control can be performed using an input DC voltage close to the expected value of the input DC voltage at the time of sampling timing request, and stable voltage conversion control can be performed.

  The voltage conversion control device for a motor according to the present invention includes AD conversion means for converting the input DC voltage converted by the voltage conversion circuit from an analog value to a digital value every time the sampling timing is generated by the sampling timing generation means, When the switching time between ON and OFF of the gate signal is shorter than the AD conversion time in the AD conversion means, the sampling timing generation means may stop the generation of the sampling timing and the AD conversion means may not perform AD conversion. .

  In this motor voltage conversion control device, every time a sampling timing is generated by the sampling timing generation means, the input DC voltage converted by the voltage conversion circuit by the AD conversion means is converted from an analog value to a digital value, and the sampling means Outputs digital input DC voltage. When the gate signal ON / OFF switching time is shorter than the time required for AD conversion by the AD conversion means, before the AD conversion is completed by the AD conversion means, the sampling timing is generated by the sampling timing generation means. Become. In this case, even if the sampling timing is generated, AD conversion cannot be performed by the AD conversion means, and processing by the sampling means cannot be performed. Therefore, in the motor voltage conversion control device, when the switching time between ON and OFF of the gate signal is shorter than the AD conversion time in the AD conversion means, the sampling timing generation means stops generating the sampling timing. In this case, the AD conversion means does not perform AD conversion according to the current switching timing of the gate signal. Therefore, the sampling means does not calculate the average value using the input DC voltage corresponding to the current switching timing of the gate signal. As a result, the latest sampling value in the sampling means is the average value (previous value) of the input DC voltage corresponding to the previous switching timing of the gate signal and the input DC voltage corresponding to the previous switching timing of the gate signal. Become. Since this average value (previous value) is also an intermediate value between the peak and valley of the input DC voltage, the voltage is close to the expected value of the input DC voltage, and stable voltage conversion control can be performed.

  The voltage conversion control device for a motor according to the present invention includes AD conversion means for converting the input DC voltage converted by the voltage conversion circuit from an analog value to a digital value every time the sampling timing is generated by the sampling timing generation means, When the switching time of the gate signal ON and OFF is shorter than the AD conversion time in the AD conversion means, the sampling timing generation means generates a sampling timing immediately after the AD conversion in the AD conversion means is completed, and the AD conversion means The AD conversion may be started immediately after the conversion is completed.

  In this motor voltage conversion control device, AD conversion means is provided in the same manner as the above-mentioned motor voltage conversion control device, and the ON / OFF switching time of the gate signal is shorter than the AD conversion time in the AD conversion means. A similar problem occurs. Therefore, in the voltage conversion control device for motor, when the switching time between ON and OFF of the gate signal is shorter than the AD conversion time in the AD conversion means, the sampling timing generating means performs sampling immediately after the AD conversion in the AD conversion means is completed. Generate timing. In this case, the AD conversion means starts AD conversion immediately after the end of AD conversion. Therefore, the sampling means calculates an average value of the input DC voltage corresponding to the timing slightly delayed from the current switching timing of the gate signal and the input DC voltage corresponding to the previous switching timing of the gate signal. The input DC voltage with a slight delay from the current switching timing of the gate signal is used, but the average value using the input DC voltage at the previous switching timing does not deviate significantly from the expected value of the input DC voltage. Stable voltage conversion control can be performed.

  According to the present invention, by sampling the input DC voltage used for voltage conversion control in consideration of the motor control gate signal, even if there is a pulsation in the input DC voltage of the motor, the input DC voltage when the sampling timing is requested Since the input DC voltage close to the expected value can be sampled, the difference between the expected value of the input DC voltage and the sampling value actually used in the voltage conversion control is reduced, and stable voltage conversion control can be performed.

It is a block diagram which shows the structure of 1 motor system which concerns on 1st Embodiment. It is explanatory drawing of the calculation method of a target voltage. It is explanatory drawing of the sampling timing of DC high voltage which concerns on 1st Embodiment, (a) is a relationship figure between the case where DC high voltage is high and low, and a motor induced voltage, (b) is inverter control (C) is an inverter control gate signal, (d) is a motor target current and motor actual current, and (e) is a DC high voltage and sampling timing request signal. . It is a block diagram which shows the structure of 1 motor system which concerns on 2nd Embodiment. It is a relationship diagram between AD conversion time and gate signal switching time. It is explanatory drawing of the sampling timing of DC high voltage which concerns on 2nd Embodiment, (a) is DC high voltage, (b) is a gate signal by inverter control, (c) is a gate signal (D) is an AD conversion start signal to the AD converter, (e) is an averaging inhibition signal, (f) is an AD conversion end signal from the AD converter, and (g) ) Is an AD conversion value by the AD converter, and (h) is a binary averaged value. It is a block diagram which shows the structure of 1 motor system which concerns on 3rd Embodiment. It is explanatory drawing of the sampling timing of DC high voltage which concerns on 3rd Embodiment, (a) is DC high voltage, (b) is a gate signal by inverter control, (c) is a gate signal (D) is an AD conversion start signal to the AD converter, (e) is an AD conversion end signal from the AD converter, and (f) is an AD conversion value by the AD converter. , (G) is a binary averaged value. It is a figure which shows the change of the direct-current high voltage when the carrier frequency is high and low. It is explanatory drawing of generation | occurrence | production of the pulsation of DC high voltage, (a) is a relationship figure between the case where DC high voltage is high and low, and a motor induced voltage, (b) is the carrier signal and duty signal in inverter control (C) is the motor target current and motor actual current, and (d) is the DC high voltage and sampling timing request signal.

  Embodiments of a voltage conversion control device for a motor according to the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected about the element which is the same or it corresponds in each figure, and the overlapping description is abbreviate | omitted.

  In the present embodiment, the motor voltage conversion control device for a motor according to the present invention includes a motor ECU [Electronic of a vehicle of one motor system (for example, a hybrid vehicle, an electric vehicle, a fuel cell vehicle) having one motor as a drive source. Applies to boost control function in Control Unit]. In the one motor system according to the present embodiment, the DC voltage of the battery is boosted by a boost converter and converted to a DC high voltage necessary for driving the motor, and the DC power is supplied by an inverter supplied with the DC high voltage. It converts into phase alternating current power, and drives a motor with three phase alternating current power. In this embodiment, there are three forms in which the method of setting the timing for sampling the DC high voltage after boosting is different. The first embodiment is a basic form, and the second and third embodiments are the same. The form is a form in which an additional function is added to the first embodiment.

  With reference to FIGS. 1-3, the 1-motor system 1 which concerns on 1st Embodiment is demonstrated. FIG. 1 is a block diagram showing a configuration of one motor system according to the first embodiment. FIG. 2 is an explanatory diagram of a method for calculating a target voltage. FIG. 3 is an explanatory diagram of the sampling timing of the DC high voltage according to the first embodiment. FIG. 3A is a relationship diagram between the case where the DC high voltage is high and low and the motor induced voltage. ) Is a carrier signal and duty signal in inverter control, (c) is a gate signal in inverter control, (d) is a motor target current and motor actual current, and (e) is a DC high voltage and sampling timing. This is a request signal.

  The one motor system 1 includes a battery 10, a filter capacitor 11, a boost converter 12, a smoothing capacitor 13, an inverter 14, a motor 15, and a motor ECU 16. In the present embodiment, the battery 10 corresponds to the power source described in the claims, the boost converter 12 corresponds to the voltage conversion circuit described in the claims, and the smoothing capacitor 13 corresponds to the claims. The inverter 14 corresponds to the motor control circuit described in the claims, and the motor 15 corresponds to the motor described in the claims.

  In the one-motor system 1, the DC power of the battery 10 is converted into three-phase AC power according to the motor torque command DT from the travel control ECU 17, and the three-phase AC power is supplied to the motor 15. For this purpose, the motor ECU 16 performs step-up control on the boost converter 12 to step up from the DC low voltage VL of the battery 10 to a target voltage (DC high voltage VH) required for driving the motor 15, and from the DC power to the motor. Inverter control is performed on the inverter 14 in order to convert the three-phase AC power necessary for generating the torque command DT. In particular, in the motor ECU 16, in order to perform stable boost control even when there is a pulsation of the DC high voltage VH caused by the pulsation of the motor current due to the influence of switching noise on the inverter control side, the continuous control of the gate signal GS for the inverter control is performed. The average value VHA of the DC high voltage (voltage across the smoothing capacitor 13) VH at the switching timing (continuous rise timing and fall timing) is calculated and sampled, and this request is made for each VH sensor sampling timing request signal DS. Boost control is performed using the average value VHA of the DC high voltage at the successive rising and falling timings of the gate signal GS immediately before the signal DS.

  The travel control ECU 17 is an ECU for controlling the travel of the vehicle. The travel control ECU 17 calculates the target motor torque required by the motor 15 based on the travel state of the vehicle at that time in response to an accelerator request or a brake request by the driver or automatic driving, and the target motor Torque is output to the motor ECU 16 as a motor torque command DT.

  The battery 10 is a direct current power source and a secondary battery. Filter capacitor 11 is provided between battery 10 and boost converter 12, and is connected to battery 10 in parallel. The filter capacitor 11 smoothes the DC voltage of the battery 10 and stores the electric charge of the DC voltage. The voltage across the filter capacitor 11 is a DC low voltage VL. The filter capacitor 11 is a capacitor for preventing a pulsating current due to switching from flowing to the battery 10 side.

  Boost converter 12 includes a reactor 12a, switching elements 12b and 12c, and freewheeling diodes 12d and 12e. The high voltage side of the filter capacitor 11 is connected to one end of the reactor 12a. A connection point between the switching element 12b and the switching element 12c is connected to the other end of the reactor 12a. The IL sensor 12f detects a current IL (analog value) flowing through the reactor 12a, and outputs the detected current IL to the motor ECU 16. The switching element 12b and the switching element 12c are connected in series, the high voltage side of the smoothing capacitor 13 is connected to the collector of the switching element 12b, and the low voltage side of the smoothing capacitor 13 is connected to the emitter of the switching element 12c. Free-wheeling diodes 12d and 12e are connected in antiparallel to the switching elements 12b and 12c, respectively. With such a circuit configuration, the boost converter 12 performs switching control of the switching elements 12b and 12c on the basis of the gate signals for the switching elements 12b and 12c output from the motor ECU 16, thereby reducing the DC low voltage VL of the filter capacitor 11. Convert to DC high voltage VH.

  Smoothing capacitor 13 is provided between boost converter 12 and inverter 14. Smoothing capacitor 13 smoothes the DC voltage boosted by boost converter 12 and stores the charge of the DC voltage. The voltage across the smoothing capacitor 13 is the DC high voltage VH. The VH sensor 13 a detects the voltage (analog value) VH across the smoothing capacitor 13 and outputs the detected voltage to the motor ECU 16.

  Since the inverter 14 is a conventional general inverter circuit that converts DC power into three-phase AC power corresponding to one motor in one motor system, the detailed circuit configuration will not be described. In the inverter 14, the DC high voltage VH of the smoothing capacitor 13 is supplied, and based on each gate signal GS for the switching element corresponding to each phase (U phase, V phase, W phase) of the motor 15 output from the motor ECU 16. The switching elements of each phase are respectively subjected to switching control to convert DC power into three-phase AC power and supply it to the motor 15.

  The motor 15 is an AC motor and is one of the drive sources of the vehicle. The motor 15 is driven to rotate by supplying the three-phase AC power from the inverter 14 to coils (not shown) of each phase.

  The motor ECU 16 is an electronic control unit including a microcomputer and various memories, and performs motor control. In particular, the motor ECU 16 has an inverter control function (motor control 16a, gate generation 16b) for controlling the inverter 14 and a boost control function (motor target voltage calculation 16c, voltage control 16d, current control 16e, control for controlling the boost converter 12). A gate generation 16f, a VH sensor sampling timing generator 16g, a VH sensor data update & binary averaging process 16h). The inverter control function and the boost control function may be configured by the same microcomputer or may be configured by separate microcomputers. In the first embodiment, the VH sensor sampling timing generator 16g corresponds to the sampling timing generation means described in the claims, and the voltage control 16d corresponds to the control means described in the claims. The VH sensor 13a, AD converter 16i, and VH sensor data update & binary averaging process 16h correspond to sampling means described in the claims.

  The inverter control function will be described. In the motor control 16a, a motor torque command DT is input from the travel control ECU 17, and a motor that is a target of the motor torque command DT is obtained using the motor angle detected by the angle sensor from the motor 15 and the motor current detected by the current sensor. A carrier signal SC and a duty signal SD for generating torque are generated and output to the gate generation 16b. In the motor control 16a, the motor rotation number MR and the motor torque command DT are output to the motor target voltage calculation 16c of the boost control function.

  In the gate generation 16b, the carrier signal SC and the duty signal SD are input from the motor control 16a, and the gate signal GS (for example, PWM signal) of the switching element of each phase of the inverter 14 based on the carrier signal SC and the duty signal SD, respectively. And output to the inverter 14. In the gate generation 16b, the gate signal GS is output to the VH sensor sampling timing generator 16g having a boost control function. FIG. 3B shows an example of the carrier signal SC and the duty signal SD, and the gate signal GS for turning on / off the switching element of the inverter 14 is generated at the timing of the intersection of the carrier signal SC and the duty signal SD. FIG. 3C shows the gate signal GS.

  The carrier signal SC is a carrier frequency and a switching frequency of the switching element of the inverter 14. As shown in FIG. 3B, the carrier signal SC is, for example, a triangular wave having peaks and valleys as apexes. In order to make the motor 15 have high rotation and high torque, it is necessary to increase the carrier frequency. However, if the system loss increases due to the switching element of the inverter 14 becoming high temperature or the like, it is necessary to lower the carrier frequency. The duty signal SD is a signal for determining the ON / OFF duty ratio of the switching element of the inverter 14. As shown in FIG. 3B, the duty signal SD is, for example, a sine wave. The gate signal GS is a signal for turning on / off the switching element of the inverter 14. As shown in FIG. 3C, the gate signal GS is, for example, a PWM signal.

The switching element of the inverter 14 is switched at the ON / OFF switching timing of the gate signal GS, and a pulsation component is superimposed on the motor current due to the influence of the switching. The FIG. 3 (d), the actual current MI of the motor 15 when the target current MI _T of the motor 15, and the actual current MI _H of the motor 15 when a large pulsating component is superimposed, a small pulsating component superimposed _L is shown. As can be seen from FIG. 3 (d), the the actual current MI _H, MI _L of the motor 15 becomes a peak and valley at the rising timing and falling timing of the gate signal GS, and a change point of increase or decrease of the pulsating component.

The boost control function will be described. In the motor target voltage calculation 16c, the motor speed MR and the motor torque command DT are input from the inverter control function, and as shown in FIG. 2, the motor speed MR and the motor torque command are calculated from a map M1 between the motor speed and the motor torque. The intersection point P1 with the motor torque of DT is extracted. This map M1 has a field weakening control area A1 (area shown by oblique lines) and a PWM control area A2, and the range of the control area changes depending on the level of the system voltage (DC high voltage VH) of one motor system 1. In the example shown in FIG. 2, since the intersection point P1 is in the field weakening control area A1, field weakening control is performed. Further, in the motor target voltage calculation 16c, as shown in FIG. 2, from the map M2 of the system voltage and the system loss that changes in accordance with the intersection P1, the system voltage at which the system loss becomes the minimum point (the target of the DC high voltage VH). Voltage VH _T ) is calculated and output to voltage control 16d. The system loss is a loss in a switching element or the like in one motor system 1. When the system voltage becomes high, the motor 15 easily rotates, but the system loss increases. As a method for obtaining the target voltage for boost control, the method using the map as described above has been described, but other methods may be used.

In the voltage control 16d, as shown in FIG. 3E, the VH sensor sampling timing request signal DS is output to the VH sensor data update & binary averaging process 16h every sampling timing period PS, and the VH sensor sampling timing request signal DS is output. Accordingly, the average value VHA of the DC high voltage VH (digital value) sampled for use in the step-up control is input from the VH sensor data update & binary averaging process 16h. The sampling timing period PS may be a predetermined fixed value or a variable value. Since the sampling timing period PS is set irrespective of inverter control, the VH sensor sampling timing request signal DS is not synchronized with the inverter control gate signal GS. In the voltage control 16d, the target voltage VH _T from motor target voltage calculation 16c is inputted, using the average value VHA of the DC high voltage VH (digital value) from the VH sensor data update & binary averaging processing 16h, a smoothing capacitor 13 voltage across (DC high voltage) performs control to become the target voltage VH _T. At this time, the voltage controlled 16d, calculates the target current IL _T required for the control, and outputs the current control 16e.

The current control 16e, the target current IL _T from the voltage controlled 16d is input, using a current flowing through the reactor 12a IL (digital value), the current flowing through the reactor 12a performs control to become a target current IL _T. The current IL (digital value) used for control is a current (digital value) obtained by AD-converting the current (analog value) detected by the IL sensor 12f by the AD converter 16j in the motor ECU 16.

The gate generation 16f, based on the control to become target current IL _T in the control and the current control 16e to become a target voltage VH _T of voltage control 16d, the switching element 12b of the boost converter 12, the gates of 12c Each signal (for example, PWM signal) is generated and output to the boost converter 12.

  In the VH sensor sampling timing generator 16g, the gate signal GS is input from the gate generation 16b of the inverter control function, and the timing of switching the gate signal GS from ON to OFF (falling timing) and the timing of switching from OFF to ON ( The rise timing) is output to the AD converter 16i as the VH sensor sampling timing TS (AD conversion start signal). In the AD converter 16i, every time the VH sensor sampling timing TS is input from the VH sensor sampling timing generator 16g, the DC high voltage (analog value) VH detected by the VH sensor 13a is AD converted, and after AD conversion The DC high voltage (digital value) VH is output to the VH sensor data update & binary averaging process 16h. Note that the gate signal from the gate generator 16b may be any of the three-phase U-phase, V-phase, and W-phase gate signals.

  In the VH sensor data update & binary averaging process 16h, each time the DC high voltage (digital value) VH is input from the AD converter 16i, the DC high voltage (digital value) VH is stored in time series. Further, in the VH sensor data update & binary averaging process 16h, the average value of the DC high voltage (digital value) VH input this time and the DC high voltage (digital value) VH previously input stored in time series. VHA is calculated, and the average value VHA of the current and previous DC high voltages is stored in time series. Here, only the latest average value VHA may be stored. In the VH sensor data update & binary averaging process 16h, every time the VH sensor sampling timing request signal DS is input from the voltage control 16d, the average of the DC high voltage calculated immediately before the VH sensor sampling timing request signal DS The value VHA is output to the voltage control 16d as a VH sensor value used for boost control.

Here, referring to FIG. 3, stable boosting is possible even when there is a pulsation of DC high voltage VH caused by the pulsation of the motor current due to the influence of switching on the inverter control side, by the processing in the boosting control function as described above. The reason why the control can be performed will be described. When the carrier frequency in the inverter control is lowered to suppress the system loss, the pulsation component is superimposed on the voltage across the smoothing capacitor (the DC high voltage after the boost) due to the switching noise of the inverter control. The target voltage required for driving the motor varies depending on the motor speed and torque. However, the higher the target voltage and the higher the DC high voltage VH with respect to the motor induced voltage Vemf, the greater the voltage difference Vdef. In addition, the pulsating component of the DC high voltage is also increased. FIG. 3A shows the relationship between the voltage VH _H when the DC high voltage VH is high and the voltage VH _L when the DC high voltage VH is low, and the motor induced voltage Vemf. Voltage difference _Vdef H1 with high DC high voltage VH _H and the motor induced voltage Vemf, and Vdef _H2, is compared with the voltage difference _Vdef L1, Vdef _L2 with low DC high voltage VH _L and the motor induced voltage Vemf, the voltage difference Vdef It becomes larger in the case of high DC high voltage VH _H. As the voltage difference Vdef increases, the pulsation component superimposed on the motor current increases. The FIG. 3 (d), the and the target current MI _T of the motor 15, and the actual current MI _H of the motor 15 in the case of large voltage differences Vdef _H, the actual current MI _L of the motor 15 in the case of small voltage difference Vdef _L Show. Actual current MI H of the motor _15, the MI _L, pulsating component according to the switching of the switching elements of the inverter 14 are superimposed, the fall timing (FIG rising timing of the gate signal GS shown in FIG. 3 (c) The increase / decrease of the pulsation component is switched at the intersection of the carrier signal SC and the duty signal SD shown in FIG. As can be seen from FIG. 3D, the larger the voltage difference Vdef, the larger the pulsating component superimposed on the motor current MI. Further, in FIG. 3 (e) shows a DC high voltage VH when the motor current MI _H in the case of large voltage differences Vdef _H. High DC voltage VH, pulsating components according to the pulsation component of the motor current MI _H is superimposed, increase or decrease of the pulsating component is switched at the rising timing and falling timing of the gate signal GS shown in Figure 3 (c). Thus, when pulsation occurs in the motor current due to the influence of switching on the inverter side, the pulsation component is also superimposed on the DC high voltage after boosting.

  That is, the pulsation component (variation) superimposed on the motor current MI by switching by the inverter control includes the voltage difference Vdef between the DC high voltage VH and the motor induced voltage Vemf and the carrier frequency of the inverter control (carrier signal SC (gate signal GS )). For this reason, when the inverter frequency decreases when the voltage difference Vdef is large, the pulsation component superimposed on the motor current MI increases. When the capacity of the smoothing capacitor 13 is small, if the pulsation component superimposed on the motor current MI increases, the smoothing capacity of the smoothing capacitor 13 is exceeded, and the pulsation component is also superimposed on the voltage across the smoothing capacitor 13 (DC high voltage) VH. The DC high voltage VH after boosting varies greatly. In addition, in order to reduce the cost and size of the single motor system 1, it is required to reduce the capacity of the smoothing capacitor 13 having a large capacity as much as possible. Therefore, if the capacity of the smoothing capacitor 13 is reduced in accordance with the demand, pulsation occurs in the DC high voltage VH as described above.

As described above, the pulsation component due to switching by inverter control is switched between increasing and decreasing at the rising timing and falling timing of the gate signal GS. Accordingly, as can be seen from FIGS. 3C and 3D, the rising timing and falling timing of the gate signal GS are the peaks and valleys of the motor current MI on which the pulsating component is superimposed. The intermediate value between the peak and the valley is obtained at the intermediate timing between the continuous rising timing and falling timing of the gate signal GS. Therefore, as can be seen from FIGS. 3C and 3E, an intermediate value between the peaks and valleys of the DC high voltage VH on which the pulsation component is superimposed (that is, the DC high voltage for stably performing the boost control). Expected value VH _E ) is also obtained at an intermediate timing between the rising timing and falling timing of the gate signal GS. As can be seen from the example shown in FIG. 3 (e), the average value of the DC high voltage VH at the successive rising and falling timings of the gate signal GS is substantially the same as the expected value VH _E of the DC high voltage. Yes. The expected value VH _E of the DC high voltage is an intermediate value between the peak and valley of the DC high voltage VH, and is a DC high voltage from which the pulsation component has been substantially removed.

  Therefore, in the step-up control function of the motor ECU 16, the VH sensor sampling timing generator 16g generates a VH sensor sampling timing TS for each ON / OFF switching timing of the gate signal GS, and an AD converter for each VH sensor sampling timing TS. In 16i, the DC high voltage (analog value) VH detected by the VH sensor 13a is AD converted to obtain the DC high voltage (digital value) VH.

Further, as can be seen from the example shown in FIG. 3 (e), expected values VH _E1 , VH _E2 , VH _E3 of DC high voltages at the timings of the VH sensor sampling timing request signals DS ₁ , DS ₂ , DS ₃ , the average value of the VH sensor sampling timing request signals _{DS 1, DS 2, DS 3} just before the DC high voltage _{VH C1} when the fall timing and the rise timing of the gate signal GS DC high voltage _{VH C2,} a high DC voltage _{VH C3} When the average value of the DC high voltage VH _{C4 and} the average value of the DC high voltage VH _C5 and the DC high voltage VH _C6 are compared, the difference is very small. Therefore, the VH sensor sampling timing request is obtained by obtaining the average value VHA of the DC high voltage VH (VH sensor value) at the rising timing and falling timing of the continuous gate signal GS immediately before the VH sensor sampling timing request signal DS. A value very close to the expected value VH _E of the DC high voltage at the timing of the signal DS can be obtained.

Therefore, in the boost control function of the motor ECU 16, every time the VH sensor sampling timing request signal DS is input from the voltage control 16d in the VH sensor data update & binary averaging process 16h, the AD is immediately before the VH sensor sampling timing request signal DS. Average of DC high voltage (digital value) VH at ON / OFF switching timing of gate signal GS input from converter 16i and DC high voltage (digital value) VH at ON / OFF switching timing of gate signal GS input last time The value VHA is calculated and output to the voltage control 16d. In the voltage control 16d, the voltage control is performed by using the average value VHA of the DC high voltage (digital value) VH at the continuous ON / OFF switching timing of the gate signal GS immediately before the VH sensor sampling timing request signal DS, thereby obtaining VH Control can be performed using the average value VHA of the DC high voltage close to the expected value VH _E of the DC high voltage at the time of the sensor sampling timing request signal DS.

According to this one-motor system 1 (particularly, step-up control by the motor ECU 16), by sampling the DC high voltage VH (average value VHA) used for step-up control based on the gate signal GS for inverter control (inverter control and Even when a pulsating component is superimposed on the DC high voltage VH, the DC high voltage VH (close to the expected value VH _E of the DC high voltage at the time of the VH sensor sampling timing request signal DS) The average value VHA) can be sampled, and the difference between the expected value VH _E of the DC high voltage at the time of the VH sensor sampling timing request signal DS and the VH sensor value actually used in the boost control is reduced, and stable boost control is performed. Can do. Thereby, the capacity | capacitance of the smoothing capacitor 13 can be reduced to a limit, and the low cost and size reduction of 1 motor system 1 can be achieved.

In particular, in the one-motor system 1 according to the first embodiment, the average value VHA of the DC high voltage VH is sampled at the successive rise timing and fall timing (ON / OFF switching timing) of the inverter-controlled gate signal GS. The VH sensor sampling timing is obtained by using the average value VHA of the DC high voltage VH at the successive rising timing and falling timing of the gate signal GS sampled immediately before the VH sensor sampling timing request signal DS for boost control. Boost control can be performed using the sensor value of the DC high voltage VH close to the expected value VH _E of the DC high voltage at the time of the request signal DS, and stable boost control can be performed.

  Next, with reference to FIGS. 4-6, the 1-motor system 2 which concerns on 2nd Embodiment is demonstrated. FIG. 4 is a block diagram showing a configuration of one motor system according to the second embodiment. FIG. 5 is a relationship diagram between AD conversion time and gate signal switching time. FIG. 6 is an explanatory diagram of the sampling timing of the DC high voltage according to the second embodiment, (a) is the DC high voltage, (b) is the gate signal in the inverter control, (c) Is a gate signal switching timing, (d) is an AD conversion start signal to the AD converter, (e) is an averaging inhibition signal, and (f) is an AD conversion end signal from the AD converter. Yes, (g) is an AD converted value by the AD converter, and (h) is a binary averaged value.

  The one motor system 2 includes a battery 10, a filter capacitor 11, a boost converter 12, a smoothing capacitor 13, an inverter 14, a motor 15, and a motor ECU 26. The one motor system 2 differs from the one motor system 1 according to the first embodiment only in control by the motor ECU 26. In particular, when the AD conversion time is shorter than the ON / OFF switching time of the gate signal GS, the motor ECU 26 stops the AD conversion and uses the previous value as the average value VHA of the DC high voltage in the boost control. Here, only the motor ECU 26 will be described in detail.

Here, the relationship between the AD conversion time and the ON / OFF switching time (ON time, OFF time) of the gate signal GS will be described with reference to FIG. FIG. 5 shows an example of the gate signal GS, the AD conversion start signal SS (VH sensor sampling timing TS) to the AD converter, and the AD conversion end signal ES from the AD converter. The AD conversion time CH is determined by the AD converter and is a fixed time. When the switching times SH ₁ and SH ₂ of the gate signal GS are long to some extent, even if the AD conversion activation signals SS ₁ and SS ₂ are output at the ON / OFF switching timing of the gate signal GS, they are within the switching times SH ₁ and SH ₂ . The AD conversion end signals ES ₁ and ES ₂ are output from the AD converter until the AD conversion ends and the next ON / OFF switching timing of the gate signal GS is reached. However, if the switching time SH ₃ of the gate signal GS is shortened, with ON / OFF switching timing of the gate signal GS be output AD conversion start signal SS _3, until the next ON / OFF switching timing of the gate signal GS In this case, the AD conversion is not completed, and the AD conversion start signal SS ₄ is output before the AD conversion end signal ES ₃ is output from the AD converter. In this case, the AD converter can not AD conversion for AD conversion start signal SS _4. Therefore, the motor ECU 26 has an additional function that can cope with such a case.

  The motor ECU 26 is an electronic control unit including a microcomputer and various memories, and performs motor control. In particular, the motor ECU 26 has an inverter control function (motor control 26a, gate generation 26b) for controlling the inverter 14 and a boost control function (motor target voltage calculation 26c, voltage control 26d, current control 26e, control for controlling the boost converter 12). A gate generation unit 26f, a VH sensor sampling timing generator & switching time determination unit 26g, and a VH sensor data update & binary averaging process 26h). The inverter control function and the boost control function may be configured by the same microcomputer or may be configured by separate microcomputers. In the second embodiment, the VH sensor sampling timing generator & switching determination unit 26g corresponds to the sampling timing generating means described in the claims, and the voltage control 26d is the control described in the claims. The VH sensor 13a, the AD converter 26i, and the VH sensor data update & binary averaging process 26h correspond to the sampling means described in the claims, and the AD converter 26i is described in the claims. It corresponds to AD conversion means.

  The motor control 26a, the gate generation 26b, the motor target voltage calculation 26c, the voltage control 26d, the current control 26e, the gate generation 26f, and the AD converter 26j are the motor control 16a and the gate generation 16b according to the first embodiment. Since the same processing as the motor target voltage calculation 16c, voltage control 16d, current control 16e, gate generation 16f, and AD converter 16j is performed, description thereof is omitted.

  The gate signal GS is input from the gate generation 26b of the inverter control function and the AD conversion end signal ES is input from the AD converter 26i to the VH sensor sampling timing generator & switching time determination unit 26g. Each time the VH sensor sampling timing TS (AD conversion start signal) is output, the VH sensor sampling timing generator & switching determination unit 26g outputs an AD conversion end signal ES for the VH sensor sampling timing TS (AD conversion start signal). When the next ON / OFF switching timing of the gate signal GS comes after the AD conversion end signal ES based on the next ON / OFF switching timing of the gate signal GS, the next ON / OFF switching is performed. When the VH sensor sampling timing TS (AD conversion start signal) is output to the AD converter 26i according to the timing and the next ON / OFF switching timing of the gate signal GS is reached before the AD conversion end signal ES. VH set for the next ON / OFF switching timing Outputs no output sampling timing TS and (AD conversion start signal) to the AD converter 26i with (AD conversion stop) averaging inhibition signal RS to VH sensor data update & binary averaging process 26h. The ON timing of the averaging inhibition signal RS is the next switching timing of the gate signal GS after the stop of AD conversion, and the OFF timing of the averaging inhibition signal RS is the next switching timing of the gate signal GS. Each time the VH sensor sampling timing TS is input from the VH sensor sampling timing generator & switching time determination unit 26g, the AD converter 26i AD converts the DC high voltage (analog value) VH detected by the VH sensor 13a. Then, the DC high voltage (digital value) VH after AD conversion is output to the VH sensor data update & binary averaging process 26h. When the AD conversion is completed, the AD converter 26i outputs an AD conversion end signal ES to the VH sensor sampling timing generator & switching time determination unit 26g. In particular, when the next ON / OFF switching timing of the gate signal GS comes before the AD conversion end signal ES (when the switching time of the gate signal GS is shorter than the AD conversion time), the AD converter 26g performs AD conversion. Cancel.

  In the VH sensor data update & binary averaging process 26h, each time the DC high voltage (digital value) VH is input from the AD converter 26i, the DC high voltage (digital value) VH is stored in time series. Further, in the VH sensor data update & binary averaging process 26h, the average value of the DC high voltage (digital value) VH input this time and the DC high voltage (digital value) VH previously input stored in time series. VHA is calculated, and the average value VHA of the current and previous DC high voltages is stored in time series. In particular, when the averaging prohibition signal RS is input from the VH sensor sampling timing generator & switching determination unit 26g, the calculation of the average value VHA of the DC high voltage is prohibited in the VH sensor data update & binary averaging process 26h. To do. In this case, the average value VHA of the DC high voltage calculated last time is held as the latest value. Then, in the VH sensor data update & binary averaging process 26h, every time the VH sensor sampling timing request signal DS is input from the voltage control 26d, the average of the DC high voltage calculated immediately before the VH sensor sampling timing request signal DS The value VHA (the latest average value VHA held) is output to the voltage control 26d as a VH sensor value used for boost control. Therefore, when the averaging prohibition signal RS is input, the average value VHA of the DC high voltage calculated last time is output.

Here, referring to FIG. 6, in the boost control function as described above, the gate signal GS when the switching time of the gate signal GS is longer than the AD conversion time and when the switching time of the gate signal GS is shorter than the AD conversion time. The process of calculating the average value VHA of the DC high voltage VH at successive ON / OFF switching timings will be described. 6A shows the DC high voltage VH, FIG. 6B shows the gate signal GS, and FIG. 6C shows the ON / OFF switching timing ST of the gate signal GS. FIG. 6 (a) shows B values, C values, D values,... (Peaks and valleys) as DC high voltage values at switching timings ST ₁ , ST ₂ , ST ₃ ,. Each value). FIG. 6D shows an AD conversion start signal SS ₁ , output from the VH sensor sampling timing generator & switching time determination unit 26 g in accordance with the switching timings ST ₁ , ST ₂ , ST ₃ ,. SS ₂ , SS ₃ ,... (Corresponding to VH sensor sampling timing TS) are shown. Further, FIG. 6F shows an AD conversion end signal output from the AD converter 26i when the AD conversion performed in response to the AD conversion start signals SS ₁ , SS ₂ , SS ₃ ,. ES ₁ , ES ₂ , ES ₃ ,... FIG. 6G shows the A value, the B value, and the C value that are the DC voltage values ADC after AD conversion that are output from the AD converter 26i and held in the VH sensor data update & binary averaging process 26h. , D value,... (Each peak and valley value of the DC high voltage VA). Further, FIG. 6 (h) shows (A + B) / 2, (B + C) / 2,... As the average value VHA of the DC high voltage value calculated and held by the VH sensor data update & binary averaging process 26h. Indicates.

The case where the switching time of the gate signal GS is longer than the AD conversion time will be described, for example, at the switching timings ST ₁ and ST ₂ of the gate signal GS. VH sensor sampling timing generator & in accordance with the switching time determiner switching timing ST ₁ In 26g outputs an AD conversion start signal SS _1, start the AD converter 26i in AD conversion, the DC high voltage AD conversion is completed ( and it outputs the B value as a digital value) the AD conversion end signal ES ₁ and outputs the VH sensor data update & binary averaging 26h to VH sensor sampling timing generator & changeover determiner 26 g. In this case, in the VH sensor data update & binary averaging process 26h, the B value is held, and the average value (A + B) / 2 is calculated using the A value and the current B value held last time. Holds the value (A + B) / 2. Then, because it was the switching timing ST ₂ brat after VH sensor sampling timing generator & changeover determiner in 26 g AD conversion end signal ES _1, and outputs the AD conversion start signal SS ₂ in response to the switching timing ST _2, start the AD converter 26i in AD conversion, VH sensor AD conversion end signal ES ₂ with AD conversion and outputs the C value as a DC high voltage (digital value) and ending VH sensor data update & binary averaging 26h Output to the sampling timing generator & switching determination unit 26g. In this case, in the VH sensor data update & binary averaging process 26h, the C value is held, and the average value (B + C) / 2 is calculated using the previously held B value and the current C value. Holds the value (B + C) / 2. Thereafter, when the VH sensor sampling timing request signal DS is input from the voltage control 26d, the VH sensor data update & binary averaging process 26h outputs an average value (B + C) / 2 to the voltage control 26d.

The case where the switching time of the gate signal GS is shorter than the AD conversion time will be described, for example, at the switching timings ST ₅ and ST ₆ of the gate signal GS. VH sensor sampling timing generator & in accordance with the switching time determiner switching timing ST ₅ In 26g outputs the AD conversion start signal SS _5, starts AD converter 26i in AD conversion, the DC high voltage AD conversion is completed ( the F value and outputs an AD conversion end signal ES ₅ and outputs the VH sensor data update & binary averaging 26h to VH sensor sampling timing generator & changeover determination unit 26g as a digital value). In this case, in the VH sensor data update & binary averaging process 26h, the F value is held, and the average value (E + F) / 2 is calculated using the previously held E value and the current F value. Holds the value (E + F) / 2. Next, the VH sensor sampling timing generator & changeover determiner 26 g, because it was the switching timing ST ₆ brat before AD conversion end signal ES _5, does not output the AD conversion start signal in response to the switching timing ST _6. Therefore, the AD converter 26i, the AD conversion in accordance with the switching timing ST ₆ not performed. In the VH sensor data update & binary averaging process 26h, the F value is kept as the latest DC high voltage and (E + F) / 2 is kept as the latest average value. Thereafter, when the VH sensor sampling timing request signal DS is input from the voltage control 26d, the VH sensor data update & binary averaging process 26h outputs an average value (E + F) / 2 to the voltage control 26d. Then, when the next switching timing ST ₇ comes, the VH sensor sampling timing generator & changeover determiner 26 g, averaging inhibition signal RS to output during that until the next switching timing ST _8. In the VH sensor data update & binary averaging process 26h, the calculation of the average value is prohibited in accordance with the averaging prohibition signal RS, and the previous average value (E + F) / 2 is continuously held. Moreover, the VH sensor sampling timing generator & changeover determiner 26 g, and outputs the AD conversion start signal SS ₇ in accordance with the switching timing ST _7, starts AD converter 26i in AD conversion, the AD conversion is completed DC and outputs the H value as high voltage (digital value) AD conversion end signal ES ₇ and outputs the VH sensor data update & binary averaging 26h to VH sensor sampling timing generator & changeover determiner 26 g. In this case, in the VH sensor data update & binary averaging process 26h, the H value is held, but the calculation of the average value is prohibited. Thereafter, when the VH sensor sampling timing request signal DS is input from the voltage control 26d, the VH sensor data update & binary averaging process 26h outputs an average value (E + F) / 2 to the voltage control 26d. Although this average value (E + F) / 2 is the previous value, it is an intermediate value between the peaks and valleys of the DC high voltage VH, and is close to the expected value VH _E of the DC high voltage.

According to this one-motor system 2 (particularly, the boost control by the motor ECU 26), the same effect as that of the one-motor system 1 according to the first embodiment is obtained. In particular, in the one-motor system 2 according to the second embodiment, even when the AD conversion time is shorter than the switching time of the gate signal GS, the AD conversion is stopped and the calculation of the average value VHA of the DC high voltage VH is also prohibited. For the boost control, the previous value of the average value VHA of the DC high voltage VH is used. Since the previous value of the average value VHA is also a voltage close to the expected value VH _E of the DC high voltage, stable voltage conversion control can be performed.

  Next, with reference to FIG.7 and FIG.8, the 1 motor system 3 which concerns on 3rd Embodiment is demonstrated. FIG. 7 is a block diagram showing a configuration of one motor system according to the third embodiment. FIG. 8 is an explanatory diagram of a DC high voltage sampling timing according to the third embodiment, where (a) is a DC high voltage, (b) is a gate signal in inverter control, and (c). Is a gate signal switching timing, (d) is an AD conversion start signal to the AD converter, (e) is an AD conversion end signal from the AD converter, and (f) is an AD converter AD signal. It is a converted value, and (g) is a binary averaged value.

  The 1-motor system 3 includes a battery 10, a filter capacitor 11, a boost converter 12, a smoothing capacitor 13, an inverter 14, a motor 15, and a motor ECU 36. The one motor system 3 differs from the one motor system according to the first embodiment only in control by the motor ECU 36. When the AD conversion time is shorter than the ON / OFF switching time of the gate signal GS, the motor ECU 36 immediately starts AD conversion immediately after the end of AD conversion. Here, only the motor ECU 36 will be described in detail.

  The motor ECU 36 is an electronic control unit including a microcomputer, various memories, and the like, and performs motor control. In particular, the motor ECU 36 includes an inverter control function (motor control 36a, gate generation 36b) for controlling the inverter 14 and a boost control function (motor target voltage calculation 36c, voltage control 36d, current control 36e, A gate generation 36f, a VH sensor sampling timing generator & switching time determination unit 36g, and a VH sensor data update & binary averaging process 36h). The inverter control function and the boost control function may be configured by the same microcomputer or may be configured by separate microcomputers. In the third embodiment, the VH sensor sampling timing generator & switching determination unit 36g corresponds to the sampling timing generating means described in the claims, and the voltage control 36d is the control described in the claims. The VH sensor 13a, the AD converter 36i, and the VH sensor data update & binary averaging process 36h correspond to the sampling means described in the claims, and the AD converter 36i is described in the claims. It corresponds to AD conversion means.

  The motor control 36a, gate generation 36b, motor target voltage calculation 36c, voltage control 36d, current control 36e, gate generation 36f, VH sensor data update & binary averaging process 36h, and AD converter 36j are the first implementations. The motor control 16a, the gate generation 16b, the motor target voltage calculation 16c, the voltage control 16d, the current control 16e, the gate generation 16f, the VH sensor data update & binary averaging process 16h, and the AD converter 16j according to the embodiment are performed. Since this is done, the description is omitted.

  The gate signal GS is input from the gate generation 36b of the inverter control function and the AD conversion end signal ES is input from the AD converter 36i to the VH sensor sampling timing generator & switching time determination unit 36g. Each time the VH sensor sampling timing TS (AD conversion start signal) is output, the VH sensor sampling timing generator & switching time determination unit 36g outputs an AD conversion end signal ES for the VH sensor sampling timing TS (AD conversion start signal). When the next ON / OFF switching timing of the gate signal GS comes after the AD conversion end signal ES based on the next ON / OFF switching timing of the gate signal GS, the next ON / OFF switching is performed. When the VH sensor sampling timing TS (AD conversion start signal) is output to the AD converter 36i according to the timing and the next ON / OFF switching timing of the gate signal GS is reached before the AD conversion end signal ES. VH sensor sampling type according to AD conversion end signal ES Ing a TS (AD conversion start signal) to the AD converter 36i. In the AD converter 36i, every time the VH sensor sampling timing TS is input from the VH sensor sampling timing generator & switching determination unit 36g, the DC high voltage (analog value) VH detected by the VH sensor 13a is AD converted. Then, the DC high voltage (digital value) VH after AD conversion is output to the VH sensor data update & binary averaging process 36h. When the AD conversion is completed, the AD converter 36i outputs an AD conversion end signal ES to the VH sensor sampling timing generator & switching time determination unit 36g. In particular, when the next ON / OFF switching timing of the gate signal GS comes before the AD conversion end signal ES (when the switching time of the gate signal GS is shorter than the AD conversion time), the AD converter 36i performs AD conversion. A / D conversion starts immediately after the end.

Here, referring to FIG. 8, in the boost control function as described above, the gate signal GS when the switching time of the gate signal GS is longer than the AD conversion time and when the switching time of the gate signal GS is shorter than the AD conversion time. The process of calculating the average value VHA of the DC high voltage VH at successive ON / OFF switching timings will be described. 8A shows the DC high voltage VH, FIG. 8B shows the gate signal GS, and FIG. 8C shows the ON / OFF switching timing ST of the gate signal GS. FIG. 8A shows B value, C value, D value,... As DC high voltage values at the switching timings ST ₁ , ST ₂ , ST ₃ ,. 8D shows an AD conversion start signal SS ₁ , output from the VH sensor sampling timing generator & switching time determination unit 36g according to the switching timings ST ₁ , ST ₂ , ST ₃ ,. SS ₂ , SS ₃ ,... Are shown. Further, FIG. 8E shows an AD conversion end signal output from the AD converter 36i when the AD conversion performed in response to the AD conversion start signals SS ₁ , SS ₂ , SS ₃ ,. ES ₁ , ES ₂ , ES ₃ ,... FIG. 8F shows the A value, the B value, and the C value that are the DC voltage values ADC after AD conversion that are output from the AD converter 36i and held in the VH sensor data update & binary averaging process 36h. , D value,... Further, FIG. 8G shows (A + B) / 2, (B + C) / 2,... As the average value VHA of the DC high voltage value calculated and held in the VH sensor data update & binary averaging process 36h. Indicates. Note that the case where the switching time of the gate signal GS is longer than the AD conversion time is the same as that described in the second embodiment, and thus description thereof is omitted.

The case where the switching time of the gate signal GS is shorter than the AD conversion time will be described, for example, at the switching timings ST ₅ and ST ₆ of the gate signal GS. VH sensor sampling timing generator & in accordance with the switching time determiner switching timing ST ₅ In 36g outputs the AD conversion start signal SS _5, starts AD converter 36i in AD conversion, the DC high voltage AD conversion is completed ( the F value and outputs an AD conversion end signal ES ₅ and outputs the VH sensor data update & binary averaging 36h to VH sensor sampling timing generator & changeover determination unit 36g as a digital value). In this case, in the VH sensor data update & binary averaging process 36h, the F value is held, and the average value (E + F) / 2 is calculated using the previously held E value and the current F value. Holds the value (E + F) / 2. Next, the VH sensor sampling timing generator & changeover determiner 36 g, because it was the switching timing ST ₆ brat before AD conversion end signal ES _5, temporarily output of the AD conversion start signal in response to the switching timing ST ₆ I waited, when the AD conversion end signal ES ₅ is input and outputs the AD conversion start signal SS _6. In AD converter 36i, starting AD conversion in accordance with the AD conversion start signal SS ₆ (therefore, will initiate the AD conversion immediately after the AD conversion end), a DC high voltage AD conversion is completed (digital value) G 'value and outputs an AD conversion end signal ES ₆ VH sensor sampling timing generator & the changeover determination unit 36g outputs the VH sensor data update & binary averaging 36h as. The G 'value is a value close slightly smaller from G value when the switching timing ST ₆ of the gate signal GS in the DC high voltage VH. In this case, in the VH sensor data update & binary averaging process 36h, the G ′ value is held, and an average value (F + G ′) / 2 is calculated using the previously held F value and the current G ′ value. The average value (F + G ′) / 2 is held. After this, when the VH sensor sampling timing request signal DS is input from the voltage control 36d, the VH sensor data update & binary averaging process 36h outputs an average value (F + G ′) / 2 to the voltage control 36d. This average value (F + G ′) / 2 is a little smaller than the G value when the G ′ value is a peak of the DC high voltage VH, but is an average value with the F value when the DC high voltage is a valley. The value is close to the expected value of the high voltage value.

  According to this 1-motor system 3 (particularly, boost control by the motor ECU 36), the same effect as that of the 1-motor system 1 according to the first embodiment is obtained. In particular, in the one-motor system 3 according to the third embodiment, even when the AD conversion time is shorter than the switching time of the gate signal GS, the AD conversion is performed immediately after the AD conversion is completed, and the DC high current by the AD conversion immediately after that is converted. An average value VHA is calculated using the voltage VH, and the average value VHA is used for boost control. Since the average value VHA using the DC high voltage VH by AD conversion immediately after the AD conversion is also a voltage close to the expected value of the DC high voltage, stable voltage conversion control can be performed.

  As mentioned above, although embodiment which concerns on this invention was described, this invention is implemented in various forms, without being limited to the said embodiment.

  For example, in the present embodiment, the present invention is applied to a vehicle having a single motor system, but the present invention can be applied to various devices such as an apparatus and a moving body of a single motor system. Moreover, although it was set as the motor, it is applicable also to a motor generator and a generator.

  Further, although the present embodiment is applied to the boost control for the boost converter, it can also be applied to the buck control for the buck converter and the buck-boost control for the buck-boost converter.

  In this embodiment, three methods using the inverter-controlled gate signal are shown for the sampling timing of the DC high voltage used for the boost control, but other methods using the inverter-controlled gate signal may be used.

  1, 2, 3 ... 1 motor system, 10 ... battery, 11 ... filter capacitor, 12 ... boost converter, 12a ... reactor, 12b, 12c ... switching element, 12d, 12e ... freewheeling diode, 12f ... IL sensor, 13 ... smoothing Capacitor, 13a ... VH sensor, 14 ... Inverter, 15 ... Motor, 16, 26,36 ... Motor ECU, 16a, 26a, 36a ... Motor control, 16b, 26b, 36b ... Gate generation, 16c, 26c, 36c ... Motor target Voltage calculation, 16d, 26d, 36d ... voltage control, 16e, 26e, 36e ... current control, 16f, 26f, 36f ... gate generation, 16g ... VH sensor sampling timing generator, 26g, 36g ... VH sensor sampling timing generator & Switching time determination device, 16h, 26h, 36h VH sensor data update & binary averaging processing, 16i, 16j, 26i, 26j, 36i, 36j ... AD converter, 17 ... running control ECU.

Claims (3)

A motor voltage conversion control device that performs voltage conversion control on a voltage conversion circuit that converts a DC voltage of the power source into an input DC voltage required for driving the motor between a motor control circuit that controls the motor and a power source. And
Sampling means for detecting a voltage across a capacitor provided between the motor control circuit and the voltage conversion circuit, and sampling an input DC voltage converted by the voltage conversion circuit;
Sampling timing generating means for generating a sampling timing for sampling the input DC voltage converted by the voltage conversion circuit based on a motor control gate signal for the motor;
Control means for performing voltage conversion control using the input DC voltage sampled by the sampling means according to the sampling timing generated by the sampling timing generating means for each sampling timing request of voltage conversion control;
Equipped with a,
The sampling timing generating means generates a sampling timing according to the switching timing of ON and OFF of the gate signal,
The sampling means generates an input DC voltage converted by the voltage conversion circuit according to the current sampling timing and a voltage conversion circuit according to the previous sampling timing every time the sampling timing generation means generates the sampling timing. Calculate the average value with the converted input DC voltage,
The control means performs voltage conversion control using an average value of the input DC voltage calculated by the sampling means immediately before the sampling timing request for each sampling timing request of voltage conversion control . Voltage conversion control device. AD conversion means for converting the input DC voltage converted by the voltage conversion circuit from an analog value to a digital value every time the sampling timing generation means generates a sampling timing,
When the switching time of ON / OFF of the gate signal is shorter than the AD conversion time in the AD conversion means, the sampling timing generation means stops generating the sampling timing, and the AD conversion means does not perform AD conversion. The motor voltage conversion control device according to claim 1 . AD conversion means for converting the input DC voltage converted by the voltage conversion circuit from an analog value to a digital value every time the sampling timing generation means generates a sampling timing,
When the switching time between ON and OFF of the gate signal is shorter than the AD conversion time in the AD conversion means, the sampling timing generation means generates a sampling timing immediately after the AD conversion in the AD conversion means ends, 2. The motor voltage conversion control device according to claim 1 , wherein the AD conversion means starts AD conversion immediately after completion of AD conversion.

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