Electric vehicle control unit

Abstract

To provide an electric-vehicle control unit that increases the operation efficiency of an entire system combining the electric vehicle control unit and a rotary motor.SOLUTION: An electric vehicle control unit includes an inverter main circuit 21 that converts direct-current power supplied from a direct-current power source into alternating-current power and outputs it to a rotary motor. The electric vehicle control unit controls the inverter main circuit 21 in a manner that an output voltage of the inverter main circuit 21 is increased as the revolution speed of the rotary motor increases from zero, and when the vehicle speed of a vehicle equipped with a rotary motor 3 has exceeded a predetermined value that is set according to a torque command pattern of a rotary motor 2, the output voltage of the inverter main circuit 21 is brought to a constant value.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] An embodiment of the present invention relates to an electric vehicle control device. [Background technology]

[0002] In general, an electric vehicle control device that drives an AC rotating motor increases an output voltage in proportion to the rotation speed from a low speed range to a medium speed range, and when the output voltage rises to the maximum output voltage that the electric vehicle control device can output, the output voltage is controlled to be a constant maximum output voltage in the subsequent high speed range. In this case, in a range where the rotation speed is high and the output torque is low, such as an intermediate powering notch, the entire system including the AC rotating motor and the electric vehicle control device is not necessarily operated at maximum efficiency. For this reason, the efficiency of the entire system may deteriorate in an operation mode that requires a small output torque to maintain speed, such as constant speed control in a high speed range.

[0003] 2. Description of the Related Art Conventionally, in order to improve the operating efficiency of the entire system combining the AC rotary motor and the electric vehicle control device, it has been proposed to change the voltage and current applied to the AC rotary motor.

[0004] For example, it has been proposed in the past that an electric vehicle control device increases the output voltage as the rotation speed of an AC rotating motor increases, and then, after the output voltage has reached its maximum value, the output voltage is controlled to decrease as the rotation speed increases so as to minimize the total copper loss and iron loss of the AC rotating motor.

[0005] In addition, it has been proposed to define a first magnetic flux command value that minimizes losses in the AC rotating motor, and a second magnetic flux command value that is a magnetic flux command value when the electric vehicle control device controls the AC rotating motor in one-pulse mode, and to perform control to select and switch between the magnetic flux command value that results in the smaller sum of losses in the AC rotating motor and losses in the electric vehicle control device.

[0006] In addition, it has been proposed to define the excitation current command that provides the minimum effective current value for the torque current command and excitation current command of an AC rotating motor controlled by an electric vehicle control device as a first excitation current command, calculate a compensation amount that reduces the total copper loss and iron loss of the AC rotating motor compared to when the first excitation current command is used, and perform control using a second excitation current command obtained by subtracting the compensation amount from the first excitation current command. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 6751683 [Patent Document 2] Patent No. 4956611 [Patent Document 3] Patent No. 5586798 Summary of the Invention [Problem to be solved by the invention]

[0008] The combination of electric vehicle control equipment and AC rotating motors for electric vehicles is often designed so that the total loss (main circuit loss) of both is minimized at the maximum notch of powering and at rated speed. For this reason, at intermediate notches of powering and at high speeds above the rated speed, the main circuit loss is not minimized, and the efficiency of the equipment may deteriorate during constant speed control operation to maintain train speed at high speeds.

[0009] An embodiment of the present invention has been made in consideration of the above circumstances, and aims to provide an electric vehicle control device that improves the operating efficiency of the entire system combining a rotating motor and an electric vehicle control device. [Means for solving the problem]

[0010] An electric vehicle control device according to an embodiment includes an inverter main circuit that converts DC power supplied from a DC power source into AC power and outputs it to a rotating motor, and controls the inverter main circuit so that the output voltage of the inverter main circuit is kept at a constant value when the vehicle speed of a vehicle in which the rotating motor is mounted exceeds a predetermined value set in accordance with the torque command pattern of the rotating motor after increasing the output voltage of the inverter main circuit as the rotational speed of the rotating motor increases from zero. [Brief description of the drawings]

[0011] [Figure 1A] FIG. 1A is a diagram showing an example of a vector relationship diagram of an induction motor under a first condition (rated speed / rated torque 100%) and a second condition (rated speed / rated torque 25%). [Figure 1B] FIG. 1B is a diagram showing another example of a vector relationship diagram of an induction motor under a first condition (rated speed / rated torque 100%) and a second condition (rated speed / rated torque 25%). [Diagram 2] FIG. 2 is a block diagram that shows a schematic configuration example of an electric car equipped with the electric car control device of the first embodiment. [Diagram 3] FIG. 3 is a diagram illustrating an example of train speed-traction force characteristics of an electric car controlled by an electric car control device. [Figure 4] FIG. 4 is a diagram illustrating an example of a relationship between the train speed of an electric car controlled by an electric car control device and an excitation current command value. [Diagram 5] FIG. 5 is a diagram for explaining an example of an excitation current command pattern in an electric vehicle control device according to an embodiment. [Figure 6] FIG. 6 is a block diagram that illustrates an example of the configuration of a current command generating unit of the electric vehicle control device illustrated in FIG. [Figure 7] FIG. 7 is a diagram for explaining another example of the excitation current command pattern in the electric vehicle control device according to an embodiment. [Figure 8] FIG. 8 is a diagram for explaining an example of the effect of the electric vehicle control device of the first embodiment. [Figure 9] FIG. 9 is a diagram illustrating a schematic configuration example of an electric car equipped with an electric car control device according to the second embodiment. [Figure 10] FIG. 10 is a block diagram illustrating an example of the configuration of the CNV / INV device logic operation unit illustrated in FIG. [Figure 11] FIG. 11 is a diagram illustrating an example of a relationship between a train speed and a DC link voltage command in an electric vehicle control device. [Figure 12] FIG. 12 is a diagram for explaining an example of the effect of the electric vehicle control device according to the second embodiment. [Figure 13] FIG. 13 is a diagram showing an example of the modulation rate and the PWM pulse mode of the inverter. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an electric vehicle control device according to an embodiment will be described with reference to the drawings. In this embodiment, a configuration of an electric vehicle control device using excitation current command to increase the equipment efficiency of one electric vehicle control device and one or more AC rotary motors as much as possible will be described.

[0013] First, an example of vector control of an AC induction motor will be described using equations. The state equations based on the secondary flux linkage of an AC induction motor in a dq-axis coordinate system rotating at an angular velocity ω are expressed by the following equations (1) to (3). The angular velocity ω in this case corresponds to the rotational angular velocity of the inverter.

[0014]

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[0015] In general indirect vector control, the objects of control are the instantaneous output torque and the magnitude of the secondary flux linkage vector, and these controls are replaced with current control. In equation (1), if the d-axis is aligned with the direction of the secondary flux linkage vector, then Ψ 2d =φ 2 , Ψ 2q =0. Here, φ 2 represents the magnitude of the secondary interlinkage magnetic flux vector. The torque is expressed by the following equation (4) from equation (3).

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[0016] According to equation (4), the q-axis primary current i 1q Therefore, the torque τ can be controlled by the q-axis primary current i 1q is the torque current. Also, from the third line of equation (1), φ 2 is expressed as the following equation (5).

number

[0017] According to equation (5), the d-axis primary current i 1d The magnitude of the secondary flux linkage vector φ 2 Therefore, the d-axis primary current i 1d is the excitation current. Here, T 2 =L2 / R 2 and is called the second order time constant.

[0018] Secondary flux linkage φ 2 From equation (5), the steady state of φ 2 =Mi 1d From equation (4), the torque τ is expressed as equation (6) below.

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[0019] In formula (6), M 2 / L 2 is a constant, so for the torque command τ, the d-axis primary current i 1d and the q-axis primary current i 1q If the product of is the same, the d-axis primary current i 1d and the q-axis primary current i 1q Here, the primary current i flowing through the motor can be freely selected. 1 is √(i 1d 2 +i 1q 2 The primary copper loss of the motor is R 1 i 1 2 Since it can be obtained by i 1d =i 1q The primary copper loss is minimized when the rotor angular speed ω m As the frequency increases, the effect of iron loss on motor loss becomes more dominant. Therefore, Patent Document 3 proposes generating compensation based on the inverter frequency ω to reduce loss due to iron loss and subtracting the compensation from the excitation current command.

[0020] d-axis primary voltage V 1d and the q-axis primary voltage V 1q From equation (1) and the above-mentioned preconditions for vector control, the following equation (7) is obtained.

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[0021] In a steady state, the above equation (7) becomes the following equation (8).

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[0022] Primary voltage V 1 and the primary current i 1 The magnitude of is calculated using the following equations (9) and (10).

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[0023] From the fourth line of the above equation (1) and equation (5), the slip angular velocity ω S is calculated using the following formula (11).

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[0024] FIG. 1A is a diagram showing an example of a vector relationship diagram of an induction motor under a first condition (rated speed / rated torque 100%=solid line) and a second condition (rated speed / rated torque 25%=dashed line). FIG. 1B is a diagram showing another example of a vector relationship diagram of an induction motor under a first condition (rated speed / rated torque 100%=solid line) and a second condition (rated speed / rated torque 25%=dashed line).

[0025] In addition, in FIG. 1A and FIG. 1B, the subscript "'" indicates each parameter in the second condition. FIG. 1A shows that the excitation current command (i 1d ,i 1d This is a vector relationship diagram when the magnetic flux is fixed at the upper limit value, and the torque current relationship is i 1q '=0.25×i 1q FIG. 1B shows the excitation current command i 1d ' is the excitation current command i 1d This is a vector relationship diagram when the magnetic flux upper limit value is set to 70%.

[0026] In FIG. 1A, the voltage command V 1 and voltage command V under the second condition 1 In contrast, in FIG. 1B, the voltage command V 1 '<< Voltage command V under the first condition 1 Therefore, when the rotation speed and the output torque are the same, it is understood that the magnitude of the output voltage of the inverter can be reduced by making the excitation current command smaller than the magnetic flux upper limit value.

[0027] Regarding the loss characteristics of AC motors, when the rotation speed is constant, there exists a maximum efficiency operating point magnetic flux (= excitation current command) at which motor loss is smallest for each motor torque. At rated torque, motor loss is smallest near the upper magnetic flux limit, and below the rated torque, this maximum efficiency operating point becomes smaller as the torque decreases, and so does the magnetic flux.

[0028] On the other hand, as shown in FIG. 1A, in a typical electric vehicle control device, when outputting a torque below the rated torque, the excitation current command is fixed at the magnetic flux upper limit value, and only the torque current command is reduced.

[0029] FIG. 2 is a block diagram that shows a schematic configuration example of an electric car equipped with the electric car control device of the first embodiment. The electric car shown in FIG. 2 includes an electric car control device 100, a cab control device 61, and an AC rotary motor 3, and is, for example, a railway vehicle on which the AC rotary motor 3 is mounted and driven by the AC rotary motor 3.

[0030] The electric vehicle control device 100 of this embodiment drives the AC rotating motor 3 in accordance with a notch command from the cab control device 61. The AC rotating motor 3 is, for example, an AC induction motor. Although there is one AC rotating motor 3 in Fig. 2, when an AC induction motor is used, the AC rotating motor 3 may be configured by connecting a plurality of AC induction motors in parallel.

[0031] The cab controller 61 controls the operation of the components included in the electric vehicle based on the operation of the cab of the electric vehicle. For example, the cab controller 61 supplies a notch command based on the operation of the cab to the electric vehicle controller 100. The notch command is a torque command indicating a notch step number corresponding to the operation of accelerating or decelerating the electric vehicle, and includes a plurality of torque command patterns.

[0032] The electric vehicle control device 100 drives the AC rotating motor 3 by the above-mentioned indirect vector control. The rotation speed of the AC rotating motor 3 is detected by a speed sensor 511 attached to the AC rotating motor 3, and the detected value is supplied to the electric vehicle control device 100. Note that the electric vehicle control device 100 may perform speed sensorless vector control that drives the AC rotating motor 3 without using a value detected by the speed sensor, and in that case the speed sensor 511 may be omitted.

[0033] The electric vehicle control device 100 includes a calculation device having at least one processor, such as a CPU or MPU, and a memory in which a program executed by the processor is recorded. The electric vehicle control device 100 can realize various functions described below by software or a combination of software and hardware.

[0034] The electric vehicle control device 100 includes a current command generating unit 11, a voltage command calculating unit 12, a DQ three-phase conversion unit (vector conversion unit) 13, a PWM (Pulse Width Modulation) unit 14, a three-phase DQ conversion unit (vector conversion unit) 15, an integrating circuit 16, an adding unit 17, an inverter main circuit 21, and current sensors 411, 412.

[0035] The current command generation unit 11 generates a d-axis current command (excitation current command) I based on the notch command supplied from the cab control device 61 and the detection value of the speed sensor 511. d REF and q-axis current command (torque current command) I q The current command generating unit 11 generates and outputs the reference current REF. The configuration of the current command generating unit 11 will be described in detail later.

[0036] The current sensors 411 and 412 detect the three-phase AC current I U , I W The current detection values ​​of the current sensors 411 and 412 are input to the coordinate three-phase DQ conversion unit 15.

[0037] The adder 17 outputs the rotational angular velocity W of the inverter which is the sum of the slip angular velocity WS output from the voltage command calculation unit 12 and the rotor rotational angular velocity WR of the AC rotary motor 3 detected by the speed sensor 511.

[0038] The integration circuit 16 integrates the rotational angular velocity W of the inverter supplied from the addition unit 17 to calculate a rotational angle Q, and supplies the rotational angle Q to the DQ three-phase conversion unit 13 and the three-phase DQ conversion unit 15 .

[0039] The three-phase DQ conversion unit 15 performs vector conversion on the values ​​in the three-phase fixed coordinate system to values ​​in a dq rotating coordinate system synchronized with the rotational angular velocity W (rotational angle Q) of the inverter, and outputs the converted values. The d-axis is a vector axis rotated by the rotational angle Q from the α-axis (U-phase) in the αβ fixed coordinate system, and the q-axis is a vector axis orthogonal to the d-axis in terms of electrical angle. In this embodiment, the three-phase DQ conversion unit 15 converts the current detection value I in the three-phase fixed coordinate system detected by the current sensors 411 and 412 into U , I W The current detection value I 1d , I 1q Convert it to and output it.

[0040] The voltage command calculation unit 12 calculates the d-axis current command I d REF and q-axis current command I q REF and the d-axis current I supplied from the three-phase DQ conversion unit 15 1d and the q-axis current I 1q From the values ​​of and, the d-axis current command I d REF and q-axis current command I q d-axis current command V that realizes REF 1d and the q-axis voltage command V 1q The voltage command calculation unit 12 generates and outputs the d-axis current I 1dand the q-axis current I 1q The value of this is the d-axis current command I d REF and q-axis current command I q The d-axis current command V is controlled by proportional-integral control, for example, so that it follows REF (so that the difference becomes zero). 1d and the q-axis voltage command V 1q can be generated. In addition, the voltage command calculation unit 12 calculates the d-axis current command I 1d REF and q-axis current command I 1q Based on REF, the slip angular velocity WS of the AC rotary motor 3 is calculated using equation (11) and output.

[0041] The DQ three-phase conversion unit 13 performs vector conversion on the values ​​in the dq rotating coordinate system synchronized with the rotational angular velocity W (rotation angle Q) of the inverter to values ​​in the three-phase fixed coordinate system, and outputs the converted values. In this embodiment, the DQ three-phase conversion unit 13 converts the d-axis current command V 1d and the q-axis voltage command V 1q is the three-phase voltage command value V U , V V , V W Convert it to and output it.

[0042] The PWM unit 14 outputs a three-phase voltage command value V U , V V , V W into a gate command for the inverter main circuit 21. In this embodiment, the PWM unit 14 converts a triangular wave carrier and a three-phase voltage command value V U , V V , V W A gate command for each phase can be generated by PWM modulation (Pulse Width Modulation) that compares the above and can be output to the inverter main circuit 21. A gate command for each phase can also be generated in a one-pulse mode and output to the inverter main circuit 21.

[0043] The inverter main circuit 21 converts DC power into three-phase AC power and outputs it to the AC rotary motor 3. The inverter main circuit 21 includes upper arm switching elements and lower arm switching elements in each phase. The inverter main circuit 21 receives control signals (gate commands) for the switching elements of the upper arms (U, V, W) and lower arms (X, Y, Z) from the PWM unit 14. The inverter main circuit 21 can convert between AC power and DC power by switching the switching elements on / off.

[0044] Although the electric vehicle control device 100 of this embodiment shown in FIG. 2 is assumed to be an inverter device that receives a DC voltage as an input, it may also be applied to an inverter section in an inverter-converter device that receives an AC voltage as an input.

[0045] FIG. 3 is a diagram illustrating an example of train speed-traction force characteristics of an electric car controlled by an electric car control device. In the electric vehicle control device 100 of this embodiment, four patterns of characteristics (train speed-tractional force characteristics) from powering notch 1 to powering notch 4 as shown in FIG. 1 ) increases in proportion to the train speed (vehicle speed) (constant V / F characteristic) as shown in Fig. 3, and the train speed (first vehicle speed) VT 1 When the maximum possible output voltage is reached, the voltage is controlled to be kept constant thereafter. Note that the vertical axis of Fig. 3 shows the maximum value of the output voltage in four powering notches as 100% output voltage.

[0046] FIG. 4 is a diagram illustrating an example of a relationship between the train speed of an electric car controlled by an electric car control device and an excitation current command value. When the output voltage of the inverter main circuit 21 is controlled as shown in FIG. 3, the excitation current command I d REF(i 1d ) pattern, as shown in Fig. 4, the train speed is the first train speed VT 1 The following is a constant value, and the first train speed VT 1In the above cases, the train speed is often decreased inversely proportional to the train speed. 1 The following excitation current command values ​​are set to the maximum values ​​(=100%).

[0047] There are also examples where the excitation current command is controlled based on the output torque command, but the secondary magnetic flux Φ 2 From the above equation (5), the second-order time constant T 2 Since the motor follows the command value with a delay, it is difficult to control sudden changes in the output torque command. For this reason, the excitation current command is often fixed at a constant value up to a certain speed, as shown in Figure 3.

[0048] In the example shown in Fig. 3, the characteristic at power running 4 notches is set as the rated torque, and the excitation current command (i 1d ) is set as the upper limit of the magnetic flux, in the intermediate notches between powering 1 notch and powering 3 notch, the AC rotating motor 3 often operates outside the maximum efficiency operating point, especially in the high speed region (e.g., within the dashed line A in FIG. 3). For this reason, the excitation current command I d By appropriately lowering the REF, it is expected that the energy utilization efficiency of the AC rotary motor 3 will be improved.

[0049] On the other hand, the excitation current command I d When REF is pulled down, the output voltage (V 1 ) decreases, the switching loss of the inverter main circuit 21 increases, and the improvement in the efficiency of the AC rotary motor 3 may be offset.

[0050] For example, when the output voltage is lowered from the operating point in the one-pulse mode to the multi-pulse mode, the number of switching operations in the inverter main circuit 21 increases, resulting in a large increase in switching loss. Also, for example, when the output voltage is lowered while remaining in the one-pulse mode, the output voltage (V 1 ) increases, which may result in a decrease in efficiency of the AC rotary motor 3.

[0051] For the above reasons, it is difficult to determine the switching pattern of the inverter main circuit 21 and the excitation current command pattern that will provide the optimal efficiency points for both the electric car control device 100 and the rotating motor at each intermediate powering notch and each train speed only through desk studies, and ultimately it becomes necessary to adjust and determine the optimal patterns for both while measuring the main circuit loss in a combination test that combines an actual electric car control device 100 and an AC rotating motor 3. In this case, it was necessary to make the excitation current command pattern as simple as possible in configuration and to reduce the number of parameters for adjusting the pattern as much as possible. In addition, as described above, the response of the secondary magnetic flux of the controlled object is poor, so it was difficult to operate the excitation current command too frequently.

[0052] FIG. 5 is a diagram for explaining an excitation current command pattern in the electric vehicle control device of one embodiment. Based on the above considerations, the inventors of the present application propose an excitation current command pattern for the electric vehicle control device 100 that improves the energy utilization efficiency of the entire system including the electric vehicle control device 100 and the AC rotary motor 3.

[0053] The excitation current command pattern shown in Fig. 5 is 1 The upper limit of the magnetic flux is constant up to the train speed VT 1 4 in that the excitation current command pattern is a pattern that decreases inversely proportional to the train speed in the region exceeding the train speed V T in FIG. 1 is variable.

[0054] That is, in the electric vehicle control device 100 of this embodiment, the upper limit of the train speed at which the excitation current command is a constant value is set to the train speed VT 1 Train speed (second vehicle speed) VT 2 That is, in this embodiment, the excitation current command pattern is 2 The train speed is constant up to VT 2 This pattern decreases inversely proportional to the speed when the speed exceeds this value.

[0055] In other words, as the rotation speed of the AC rotating motor 3 increases from zero, the output voltage of the inverter main circuit 21 is increased, and then the predetermined train speed VT corresponding to the torque command (notch command) of the AC rotating motor 3 is increased. 2 In the region exceeding the target value (train speed VT 2 The inverter main circuit 21 is controlled so as to fix the output voltage at the output terminal 11 at the output terminal 12.

[0056] In the electric vehicle control device 100 of this embodiment, for example, when the notch command (torque command) is at a maximum value and the train speed is equal to or faster than the first vehicle speed VT 1 When the train speed is equal to or faster than the first vehicle speed VT 1 When the train speed exceeds the first vehicle speed VT, the excitation current command is reduced in inverse proportion to the train speed so that the output voltage of the inverter main circuit 21 becomes a constant maximum voltage. In addition, in the electric vehicle control device 100 of this embodiment, when the notch command (torque command) is a value smaller than the maximum value, for example, the train speed is reduced when the train speed exceeds the first vehicle speed VT 1 A second vehicle speed VT smaller than 2 When the output voltage of the inverter main circuit 21 exceeds the second vehicle speed VT 2 The excitation current command is decreased inversely proportional to the train speed so that the value at

[0057] In this case, the inverter output voltage V 1 is the train speed VT 2 In the range exceeding train speed VT 2 Since the output voltage is fixed at a constant value in the inverter main circuit 21, the switching pattern of the inverter main circuit 21 can be easily adjusted.

[0058] In addition, the excitation current command pattern also changes with the train speed VT 2 The value of can be adjusted as an adjustment parameter, and the excitation current command calculation function shown in FIG. 4 can be used.

[0059] FIG. 6 is a block diagram that illustrates an example of the configuration of a current command generating unit of the electric vehicle control device illustrated in FIG. The current command generator 11 is a VT 2 The control circuit 110 includes a generating logic circuit 111, a first excitation current command calculation circuit 112, a second excitation current command calculation circuit 113, a torque current command calculation circuit 114, a division unit 115, and a multiplication unit .

[0060] VT 2 The generation logic circuit 111 calculates the train speed VT corresponding to the notch command supplied from the cab control device 61. 2 In this embodiment, VT 2 In the generation logic circuit 111, the train speed VT corresponding to the number of notches (torque command pattern) is calculated. 2 is preset.

[0061] The first excitation current command calculation circuit 112 calculates the excitation current command maximum value I1d_Ref_MAX and the train speed VT 2 From the train speed WR, the excitation current command I 1d The excitation current command maximum value I1d_Ref_MAX is a value preset in the current command generating unit 11. That is, the first excitation current command calculation circuit 112 generates and outputs a train speed WR detected by the speed sensor 511 in accordance with the train speed (a predetermined value set corresponding to the torque command pattern) VT 2 In the following cases, the excitation current command I 1d The first excitation current command calculation circuit 112 calculates the train speed WR detected by the speed sensor 511 in accordance with the train speed VT 2 When it exceeds the excitation current command I 1d REF is a value calculated using a predetermined function inversely proportional to the train speed WR. The first excitation current command calculation circuit 112 calculates the excitation current command I 1d REF is supplied to the voltage command calculation unit 12 and the division unit 115 .

[0062] The second excitation current command calculation circuit 113 determines the upper limit of the train speed at which the excitation current command is a constant value as the train speed VT 1The second excitation current command calculation circuit 113 calculates and outputs a second excitation current command I1d_REF_C based on the excitation current command pattern fixed by the current command generation unit 11. The excitation current command maximum value I1d_Ref_MAX is a value preset in the current command generation unit 11, and is the same as the value used by the first excitation current command calculation circuit 113. That is, the second excitation current command calculation circuit 113 calculates and outputs a second excitation current command I1d_REF_C based on the excitation current command pattern fixed by the current command generation unit 11. The excitation current command maximum value I1d_Ref_MAX is a value preset in the current command generation unit 11, and is the same as the value used by the first excitation current command calculation circuit 113. 1 In the following cases, the second excitation current command I1d_REF_C is set to a constant value (100%). 1 When the second excitation current command I1d_REF_C exceeds the train speed WR, the second excitation current command I1d_REF_C is set to a value calculated using a predetermined function inversely proportional to the train speed WR. The second excitation current command calculation circuit 113 supplies the second excitation current command I1d_REF_C to the division unit 115.

[0063] The torque current command calculation circuit 114 calculates and outputs a second torque current command I1q_REF_C corresponding to the second excitation current command I1d_REF_C. The torque current command calculation circuit 114 calculates and outputs the torque (τ) and the second excitation current command I1d_REF_C(i d ) corresponding to the torque current command (i q ) and outputs it as the second torque current command I1q_REF_C. For example, the torque current command calculation circuit 114 may be preset with a function for calculating the second torque current command I1q_REF_C corresponding to the train speed WR for each notch command.

[0064] The dividing unit 115 converts the second excitation current command I1d_REF_C into an excitation current command I 1d The quotient obtained by dividing by REF is calculated, and the calculated value is supplied to the multiplication unit 116. The multiplier 116 multiplies the value supplied from the divider 115 by the value of the second torque current command I1d_REF_C to calculate the product, and calculates the excitation current command I 1d Torque current command I corresponding to REF 1qThe multiplier 116 outputs the torque current command I 1q REF is supplied to the voltage command calculation unit 12.

[0065] That is, from the above equation (6), when the output torque is the same, the excitation current command I 1d REF and torque current command I 1q As long as the product with REF is the same, the excitation current command I 1d The ratio of REF to the second excitation current command I1d_REF_C (second excitation current command I1d_REF_C / excitation current command I 1d REF) is multiplied by the second torque current command I1d_REF to obtain the excitation current command I 1d Torque current command I corresponding to REF 1q REF is required.

[0066] In other words, according to the configuration shown in FIG. 6, the upper limit of the train speed at which the excitation current command is a constant value is set to the train speed VT 1 The current command generating unit 11 adopts the excitation current command pattern and the torque current command pattern when the excitation current command pattern is fixed to VT 2 The electric vehicle control device 100 of this embodiment can be realized by adding a generating logic circuit 111, an excitation current command calculation circuit 112, a division unit 115, and a multiplication unit 116. The function of the excitation current command pattern used in the first excitation current command calculation circuit 112 and the function of the excitation current command pattern used in the second excitation current command calculation circuit 113 may be the same. The function of the torque current command pattern used in the torque current command calculation circuit 114 may also be the same as the function of the train speed VT 1 It is possible to use a function of a torque current command corresponding to the excitation current command (second excitation current command I1d_REF_C) when the excitation current command is fixed to . Therefore, in the electric vehicle control device 100 of this embodiment, it is not necessary to define a new function in the current command generating unit 11.

[0067] In addition, with the excitation current command pattern employed in the electric vehicle control device 100 of this embodiment, the energy utilization efficiency (main circuit efficiency) of the inverter main circuit 21 and the AC rotary motor 3 may deviate from the maximum efficiency point depending on the train speed. However, in general, intermediate notches in the high speed range of train speed are often used to maintain the train speed (constant speed operation), and this speed is often almost fixed depending on the line on which the train runs and the type of operation. Therefore, if frequently used speeds and powering notches are known in advance, it is possible to set the VT so that the main circuit efficiency is maximized according to the speed and powering notch. 2 The second train speed VT generated by the generating logic circuit 111 2 You just need to adjust the value of .

[0068] FIG. 7 is a diagram for explaining another example of the excitation current command pattern in the electric vehicle control device according to an embodiment. The basic pattern of the excitation current command pattern shown in FIG. 7 is the same as the excitation current command pattern shown in FIG. 5. In the example shown in FIG. 7, the train speed (third vehicle speed) VT 3 The excitation current command pattern is reduced in inverse proportion to the square of the train speed.

[0069] In this case, the inverter output voltage is proportional to the train speed VT 2 The train speed becomes constant at VT 3 This makes it possible to set a pattern that reduces the inverter output voltage more in the high train speed range.

[0070] As described above, the sum of the energy loss in the inverter main circuit 21 and the energy loss in the AC rotary motor 3 (main circuit loss) is a trade-off between an increase in the switching loss of the inverter main circuit 21 and a decrease in the loss of the AC rotary motor 3. That is, in order to improve the operating efficiency of the entire system, for example, if the output voltage of the inverter main circuit 21 is lowered in accordance with an increase in the train speed so that the total loss of the AC rotary motor is minimized at the intermediate notch after the output voltage of the inverter main circuit 21 reaches a maximum value, the switching loss of the inverter main circuit 21 increases, so that the main circuit loss is in a trade-off relationship between the AC rotary motor 3 and the loss improvement amount described above. In particular, when the inverter output voltage is lowered and the pulse mode of the inverter main circuit 21 is switched from the one-pulse mode to the non-one-pulse mode, the switching loss of the inverter increases rapidly. For this reason, it is desirable to keep the output voltage of the inverter main circuit 21 constant at a voltage that minimizes the main circuit loss and to set it relatively freely so that it can be easily adjusted.

[0071] Fig. 8 is a diagram for explaining an example of the effect of the electric vehicle control device of the first embodiment. Here, an example of a simulation result of the main circuit loss (PT3) when the excitation current command pattern shown in Fig. 4 is adopted in the powering 2 notch of the powering characteristic shown in Fig. 3, and the main circuit loss with the excitation current command pattern (Fig. 5 (PT1) and Fig. 7 (PT2)) in the electric vehicle control device of this embodiment is shown.

[0072] According to the simulation results shown in Fig. 8, when the excitation current command pattern in Fig. 5 is used (PT1) and when the excitation current command pattern in Fig. 7 is used (PT2), the main circuit loss is reduced more than when the excitation current command pattern in Fig. 4 is used (PT3). On the other hand, when the excitation current command pattern shown in Fig. 7 is used, the main circuit loss is reduced more than when the excitation current command pattern in Fig. 4 is used (PT3). P As a result, the main circuit loss is higher than when the excitation current command pattern shown in Fig. 5 is used. This is because 3 As a result, the output voltage command of the inverter main circuit 21 decreases in proportion to the speed, and the train speed VTP This is because the pulse mode has been switched as described above. In this way, the increase in inverter switching loss is greater than the decrease in loss in the AC rotary motor 3, and there is a possibility that the main circuit loss will worsen. Therefore, by selecting an appropriate excitation current command pattern in consideration of the pulse mode of the inverter main circuit 21, the main circuit loss can be effectively reduced.

[0073] As described above, according to the electric vehicle control device of this embodiment, by arbitrarily switching the parameters of the function while following the generation function of the existing excitation current command pattern, it is possible to realize a voltage command output in which the main circuit loss is close to a minimum at each notch. That is, according to this embodiment, it is possible to provide an electric vehicle control device that improves the operating efficiency of the entire system combining the rotary motor and the electric vehicle control device.

[0074] Next, an electric vehicle control device according to a second embodiment will be described in detail with reference to the drawings. 9 is a diagram showing a schematic configuration example of an electric car equipped with an electric car control device of the second embodiment. In the following description, the same components as those in the first embodiment described above are given the same reference numerals and the description thereof will be omitted.

[0075] In the above-described first embodiment, an inverter device that drives an AC rotating motor 3 with a DC power source has been described as the electric vehicle control device 100. However, in the electric vehicle control device 101 of this embodiment, the DC power source is supplied by a converter device that converts the AC power source into a DC voltage (converter-inverter device).

[0076] The electric vehicle control device 101 of this embodiment is supplied with AC power from an AC power source such as an overhead line via a current collector 24 and a main transformer (primary winding and secondary winding) 23. The electric vehicle control device 101 converts the supplied AC power into a predetermined AC power and supplies it to the AC rotary motor 3 to drive the AC rotary motor 3.

[0077] The electric vehicle control device 101 includes a main transformer 23 , a converter main circuit 22 , an inverter main circuit 21 , a CNV / INV device logic operation unit 200 , current sensors 411 , 412 , 413 , and voltage sensors 71 , 72 .

[0078] The converter main circuit 22 is electrically connected to the secondary winding of the main transformer 23 and is also electrically connected to the inverter main circuit 21 via a DC link.

[0079] The converter main circuit 22 includes a plurality of switching elements (not shown), and converts secondary output power (AC power) output from the main transformer 23 into DC power and outputs it to the DC link. The converter main circuit 22 may be configured to convert DC power supplied from the DC link into AC power and supply it to the main transformer 23. In the electric vehicle control device 101 of this embodiment, the converter main circuit 22 is a so-called PWM converter.

[0080] The voltage sensor 71 detects the voltage (DC link voltage) Vdc of the DC link connecting the converter main circuit 22 and the inverter main circuit 21 , and supplies the detected value to the CNV / INV device logic operation unit 200 . The voltage sensor 72 detects the AC voltage Vs of the AC power supplied from the AC power source to the auxiliary circuit via the auxiliary circuit tertiary winding of the main transformer 23 , and supplies the detected value to the CNV / INV device logic operation unit 200 .

[0081] The current sensor 413 detects the AC current Is supplied from the main transformer (secondary winding) 23 to the converter main circuit 22 , and supplies the detected value to the CNV / INV device logic operation unit 200 . The current sensors 411 and 412 detect the three-phase AC current I U , I W The current detection values ​​of the current sensors 411 and 412 are supplied to the CNV / INV device logic operation unit 200. The speed sensor 511 detects the rotor rotation angular speed WR of the AC rotary motor 3 , and supplies the detected value to the CNV / INV device logic operation unit 200 .

[0082] The CNV / INV device logic operation unit 200 controls the operations of the converter main circuit 22 and the inverter main circuit 21 based on the detection values ​​of various sensors in accordance with the notch command and vehicle state information supplied from the cab control device 61 . FIG. 10 is a block diagram illustrating an example of the configuration of the CNV / INV device logic operation unit illustrated in FIG. The CNV / INV device logic operation unit 200 includes a converter control unit 210 and an inverter control unit 220 .

[0083] The current command generating unit 221, voltage command calculating unit 222, DQ three-phase conversion unit 223, PWM unit 224, three-phase DQ conversion unit 225, adder unit, and integrator unit 226 of the inverter control unit 220 have the same configuration as those of the electric vehicle control device 100 of the first embodiment described above, so their explanation will be omitted here. The converter control unit 210 includes a DC voltage command generating unit 211 , a voltage control unit 212 , a current control unit 213 , a phase detection unit 215 , and a PWM unit 214 .

[0084] The DC voltage command generating unit 211 generates a DC voltage command VdcREF which is a command value for the DC link voltage. The lower limit value of the DC link voltage Vdc supplied from the converter main circuit 22 to the DC link is determined by the maximum voltage of the AC power supplied to the primary side of the converter main circuit 22. For this reason, the DC voltage command generating unit 211 cannot set the DC voltage command VdcREF to a value equal to or lower than the lower limit value of the DC voltage Vdc.

[0085] For example, when the DC voltage command VdcREF is set to a value equal to or higher than the lower limit of the DC voltage Vdc, the DC voltage command VdcREF is lowered in the range from the DC voltage value at the maximum voltage of the output of the inverter main circuit 21 to the lower limit of the DC voltage Vdc, so that, for example, the inverter control unit 220 can reduce the train speed VT 2 =VT 1It is also possible to reduce the output voltage of the inverter main circuit 21 while keeping the above-mentioned voltage Vdc. In this case, since the DC link voltage Vdc (the voltage on the primary side of the inverter main circuit 21) is reduced, it is possible to reduce the switching loss of the inverter main circuit 21 and extend the life of the switching elements.

[0086] FIG. 11 is a diagram illustrating an example of a relationship between a train speed and a DC link voltage command in an electric vehicle control device. Here, the lower limit of the DC link voltage is V dcA , the given DC link voltage is V dcB (>V dcA ) Train speed VT A Train speed VT B The DC link voltage at the maximum powering notch of the electric vehicle is DC link voltage V dcA to DC link voltage V dcB In the case where the characteristic changes to Vdc (dotted line), the DC link voltage Vdc at the electric car's powering intermediate notch is set to the lower limit V dcA By keeping it constant (solid line), it is possible to reduce the output voltage of the inverter main circuit 21 without changing the modulation factor of the inverter main circuit 21 in the high speed range.

[0087] The voltage control unit 212 controls the AC current command I by, for example, proportional-integral control so that the value of the DC voltage Vdc detected by the voltage sensor 71 follows the DC voltage command VdcREF supplied from the DC voltage command generation unit 211 (so that the difference becomes zero). s A REF can be generated.

[0088] The phase detection unit 215 detects the phase of the AC voltage Vs from the value of the AC voltage Vs detected by the voltage sensor 72, and converts the detected value into a phase reference value Q 1 Output as REF.

[0089] The current control unit 213 detects the phase reference value Q 1 With reference to REF, the value of the AC current Is detected by the current sensor 413 is compared with the AC current command Is The DC voltage command V is controlled by proportional-integral control, for example, so that it follows REF (so that the difference becomes zero). C A REF can be generated.

[0090] The PWM unit 214 outputs a DC voltage command V C REF into a gate command for the converter main circuit 22. In this embodiment, the PWM unit 214 converts, for example, a triangular wave carrier and a DC voltage command V C A gate command for each phase can be generated by PWM modulation (Pulse Width Modulation) that compares with REF, and can be output to the converter main circuit 22.

[0091] FIG. 12 is a diagram for explaining an example of the effect of the electric vehicle control device according to the second embodiment. Here, an example of a comparison result of loss calculation for only the inverter main circuit 21 of the electric car control device 101 (converter / inverter device) of this embodiment at a powering intermediate notch of the electric car is shown.

[0092] If the output voltage of the inverter main circuit 21 at which the AC rotating motor 3 driven by the electric vehicle control device 101 is at maximum efficiency is V1, and the inverter output voltage in the comparative example is V1' (=0.79 x V1), the conditions are as follows.

[0093] Where, DC link voltage: V D , inverter modulation factor: AL. DC link voltage V D corresponds to the DC link voltage Vdc in FIGS. Comparative example: V D =V dcA →V dcB , inverter output voltage = V1, AL = 100% Condition 1: V D =V dcA →V dcB , Inverter output voltage = V1', AL = 79% Condition 2: V D =V dcA , Inverter output voltage = V1', AL = 88% In addition, under condition 2, the DC link voltage V D The reduction in the lower limit V dcA Since it was not possible to obtain a desired output voltage of the inverter main circuit 21 by simply fixing the modulation factor to V', the modulation factor of the inverter main circuit 21 is adjusted to realize the inverter output voltage V'.

[0094] In FIG. 12, the loss in only the inverter main circuit 21 under the condition of the comparative example is shown as PT3', the loss in only the inverter main circuit 21 under condition 1 is shown as PT1', and the loss in only the inverter main circuit 21 under condition 2 is shown as PT2'.

[0095] According to FIG. 12, the loss in the inverter main circuit 21 is smaller in the case of condition 2 than in the case of condition 1. This is because the DC link voltage V D The amount by which the lower limit V dcA Since the switching loss of the inverter main circuit 21 is reduced by the amount of the change in the primary side voltage of the inverter main circuit 21, and the inverter modulation factor is relatively higher under condition 2 than under condition 1, the PWM pulse mode is changed to a pulse mode one step lower (for example, the 9-pulse mode (synchronous) shown in FIG. 13). 9P ) to 3-pulse mode (synchronous 3P )).

[0096] FIG. 13 is a diagram showing an example of the relationship between the modulation rate of an inverter and a PWM pulse mode. In this example, the inverter's PWM pulse mode is asynchronous mode and 9-pulse mode (synchronous 9P ) and 3-pulse mode (synchronous 3P ) and 1-pulse mode (synchronous 1P ) is included. The inverter modulation rate is 0 or more. P9 When the PWM pulse mode is asynchronous, the modulation rate of the inverter is less than AL P9 More AL P3 (>AL P9 ) the PWM pulse mode is 9-pulse mode, and the modulation rate of the inverter is V P3 More than 100(>ALP3 ), the PWM pulse mode is 3-pulse mode, and when the modulation rate of the inverter is 100[%], the PWM mode is 1-pulse mode. As mentioned above, the PWM pulse mode of the inverter is determined by the modulation rate of the inverter, so if the modulation rate is lowered, the pulse mode becomes higher and the switching loss increases. That is, the DC link voltage V D Under conditions where the DC link voltage V can be reduced, the inverter modulation rate is reduced before the DC link voltage V D By lowering the input voltage Vcc, the energy loss in the entire system including the inverter main circuit 21 and the AC rotary motor 3 can be reduced.

[0097] In this way, in the electric vehicle control device 101 (converter / inverter device) of this embodiment, the PWM mode (pulse mode) can be changed arbitrarily in accordance with the modulation rate of the inverter, and the switching loss of the inverter main circuit 21 can be minimized even under the same conditions of the output voltage of the inverter main circuit 21 by combining the DC link voltage Vdc and the pulse mode of the inverter main circuit 21. Also, even in the case of a single electric vehicle control device 100 (inverter device) driven by a DC power source as in the above-mentioned first embodiment, the switching loss of the inverter main circuit 21 can be minimized by arbitrarily switching the PWM mode (pulse mode). That is, according to this embodiment, it is possible to provide an electric vehicle control device that improves the operating efficiency of the entire system combining the rotary motor and the electric vehicle control device.

[0098] In the electric vehicle control device 101 (converter / inverter device) in FIG. 9, the CNV / INV device logic operation unit 200 can calculate the power consumption of the main circuit from the input voltage and input current Is of the converter main circuit 22.

[0099] The input current Is of the converter main circuit 22 can use the detection value of the current sensor 413. Since the capacity of the sensor would be large if the secondary winding of the main transformer 23 was to be detected directly, the input voltage of the converter main circuit 22 can be obtained by detecting the voltage of the tertiary winding (winding for auxiliary circuit) of the main transformer 23 with a voltage sensor 72 and correcting it by multiplying it by the turn ratio of the secondary winding and the tertiary winding. The difference between the power consumption of the main circuit thus obtained and the mechanical output of the AC rotating motor 3 is obtained as the main circuit loss. The electric vehicle control device 101 adjusts the aforementioned train speed VT so as to minimize this main circuit loss (loss of the entire system). 2 or DC voltage command V dc The REF parameter values ​​may be automatically calculated, which can significantly reduce the time required to adjust these parameters and facilitate device updates.

[0100] As described above, the power consumption of the main circuit can be calculated relatively easily by the CNV / INV device logic operation unit 200. The mechanical output of the AC rotating motor 3 can be calculated by attaching a torque meter to the output shaft of the AC rotating motor 3 and inputting the detected value of the torque meter into the CNV / INV device logic operation unit 200.

[0101] On the other hand, when the device is installed in an actual vehicle due to equipment update or the like, it is difficult to attach a torque meter to the AC rotary motor 3, and therefore it is difficult to calculate the mechanical output from the detection value of the torque meter. In this case, for example, the CNV / INV device logic operation unit 200 may obtain the mechanical output of the AC rotary motor 3 from the mass and acceleration of the vehicle. The mass of the vehicle may be a design value as is, or if a load compensation signal can be referenced from the vehicle status information from the cab control device 61, the design value may be corrected and used. The acceleration of the vehicle can be obtained from the detection value of the speed sensor 511. In addition, if the running position (kilometers) of the vehicle can be referenced from the vehicle status information, multiple parameters are tried under the conditions of the same kilometer, the same speed, and the same notch, and the parameter with the smallest main circuit loss is automatically selected and updated, so that the parameter with the smallest main circuit loss can be automatically converged to the parameter with the smallest main circuit loss while running.

[0102] The program according to the present embodiment may be transferred in a state where it is stored in an electronic device, or in a state where it is not stored in an electronic device. In the latter case, the program may be transferred via a network, or in a state where it is stored in a storage medium. The storage medium is a non-transitory tangible medium. The storage medium is a computer-readable medium. The storage medium may be in any form, such as a CD-ROM or a memory card, as long as it is capable of storing a program and is computer-readable.

[0103] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0104] 3...AC rotating motor, 11...current command generation unit, 12...voltage command calculation unit, 13...phase conversion unit, 14...PWM unit, 15...three-phase DQ conversion unit, 16...integration circuit, 17...addition unit, 21...inverter main circuit, 22...converter main circuit, 23...main transformer, 24...current collector, 61...cab control device, 71, 72...voltage sensor, 100, 101...electric vehicle control device, 111...VT 2 Generation logic circuit, 112...first excitation current command calculation circuit, 113...second excitation current command calculation circuit, 114...torque current command calculation circuit, 115...division unit, 116...multiplication unit, 200...CNV / INV device logic calculation unit, 210...converter control unit, 211...DC voltage command generation unit, 212...voltage control unit, 213...current control unit, 214...PWM unit, 215...phase detection unit, 220...inverter control unit, 221...current command generation unit, 222...voltage command calculation unit, 223...phase conversion unit, 224...PWM unit, 225...three-phase DQ conversion unit, 226...integration unit, 411, 412, 413...current sensor, 511...speed sensor, VT 1 …First train speed (first vehicle speed), VT 2 …Second train speed (second vehicle speed), VT 3 …Third train speed (third vehicle speed)

Claims

1. An inverter main circuit converts DC power supplied from a DC power source into AC power and outputs the AC power to a rotary motor, An electric vehicle control device that controls the inverter main circuit so that the output voltage of the inverter main circuit is increased as the rotational speed of the rotating motor increases from zero, and then the output voltage of the inverter main circuit is made to be a constant value when the vehicle speed of a vehicle in which the rotating motor is mounted exceeds a predetermined value set in accordance with a torque command pattern of the rotating motor.

2. an electric vehicle control device that divides a current to the rotary electric motor into a torque current and an excitation current, and controls each of the torque current and the excitation current based on a torque current command and an excitation current command obtained from the torque command pattern, The output voltage of the inverter main circuit increases in proportion to the vehicle speed, and the vehicle speed at which the output voltage of the inverter main circuit becomes a maximum voltage that can be output by the inverter main circuit is a first vehicle speed, When the torque command pattern is at a maximum value and the vehicle speed is equal to or lower than the first vehicle speed, the excitation current command is kept constant, and when the vehicle speed exceeds the first vehicle speed, the excitation current command is reduced inversely proportional to the vehicle speed so that an output voltage of the inverter main circuit becomes a constant maximum voltage; 2. The electric vehicle control device according to claim 1, wherein, when the torque command pattern is a value smaller than the maximum value and the vehicle speed exceeds a second vehicle speed that is smaller than the first vehicle speed, the excitation current command is reduced in inverse proportion to the vehicle speed so that the output voltage of the inverter main circuit becomes a value at the second vehicle speed.

3. 3. The electric vehicle control device according to claim 2, wherein a plurality of said torque command patterns are supplied, and said second vehicle speed is switched in response to each of said plurality of said torque command patterns.

4. A converter main circuit converts AC power supplied from an AC power source into DC power and supplies the DC power to the inverter main circuit, 3. An electric vehicle control device according to claim 2, wherein, when a target value of an output voltage of the inverter main circuit becomes less than a maximum voltage of the inverter main circuit, the DC voltage output from the converter main circuit can be arbitrarily reduced within a range from the DC voltage at the maximum voltage of the output of the inverter main circuit to a lower limit value.

5. 2. The electric vehicle control device according to claim 1, wherein, when a target value of the output voltage of the inverter main circuit based on the torque command pattern becomes less than a maximum output voltage of the inverter main circuit, a PWM mode for driving the inverter main circuit can be arbitrarily changed so as to reduce energy loss in an entire system including the inverter main circuit and the rotating electric motor.

Images