JP5338160B2 - Voltage control device for power converter - Google Patents

Description

  The present invention relates to a voltage control device for a power converter.

  Converters and inverters are used as power converters. That is, the converter converts AC power into DC power. Further, the inverter converts DC power into AC power. Various devices, motors, etc. are driven by this electric power. And in the switching control system of a converter or an inverter, the short circuit prevention time (henceforth a dead time) is provided. This dead time prevents the positive and negative switching elements from conducting simultaneously. However, due to the influence of this dead time, an excess / deficiency voltage is generated between the voltage command value obtained by the control calculation and the voltage actually output from the converter or inverter. Due to this excess / deficiency voltage, the output voltage is distorted and at the same time, pulsation of the current waveform occurs.

  As a means to solve this problem, the polarity of dead time compensation is determined using the detection polarity of the output current of the inverter or the polarity of the current command, and further the amplitude of dead time compensation is determined according to the magnitude of the current. Those are known (for example, see Patent Document 1). As a result, even when the DC power is converted into AC power having a variable voltage and variable frequency and the motor is controlled at a variable speed, the pulsation of the current waveform can be suppressed. This means can also be applied to a converter.

JP-A-3-135389

  The inverter or converter having the above configuration is normally used in a range in which the corrected voltage command value including the excess / deficiency voltage due to dead time does not exceed the voltage limiter value. However, in recent years, there is a demand for an increase in power load and downsizing of devices. In response to this requirement, inverters in power running operation and converters in regenerative operation are often used in a saturation region where the corrected voltage command value exceeds the voltage limiter value. In this case, even in the device described in Patent Document 1, the final voltage command value for controlling the output voltage is limited to the voltage limiter value. Due to this limitation, there is a problem that the output voltage becomes discontinuous, pulsation of the current waveform occurs, and harmonics are generated.

  The present invention has been made to solve the above-described problems, and its purpose is to perform power conversion that can suppress pulsation of a current waveform even when a corrected voltage command value exceeds a voltage limiter value. It is to provide a voltage control device for the device.

A voltage control device for a power conversion device according to the present invention includes: a voltage command calculation unit that calculates a voltage command value that is a target value of an output voltage of the power conversion device; and positive and negative switching elements of the power conversion device. A dead time correction value calculation unit for calculating an excess / deficiency voltage value generated due to a dead time provided to prevent conduction at the same time, and adding the excess / deficiency voltage value to the voltage command value to obtain a corrected voltage command A dead time correction unit that calculates a value, a voltage saturation determination unit that determines whether or not the corrected voltage command value exceeds a voltage limiter value, and the corrected voltage command value does not exceed the voltage limiter value If the corrected voltage command value exceeds the voltage limiter value, the output voltage of the power converter is controlled based on the corrected voltage command value. The final voltage command value for controlling the output voltage of the power converter is added to the voltage limiter value and the voltage limiter value so that the average of the output voltages of the power supply device is close to the voltage command value. Voltage saturation command value level compensation unit selected from the values, and when the voltage saturation command value level compensation unit exceeds the voltage limiter value, the corrected voltage command value compensation unit When the voltage difference is calculated by subtracting the voltage limiter value from the value and the voltage difference is smaller than half of the over / undervoltage value, the voltage limiter value is selected as the final voltage command value, and If the voltage difference is maintained as a new voltage difference and the voltage difference is larger than half of the over / under voltage value, a value obtained by adding the over / under voltage value to the voltage limiter value is the maximum value. Selecting the voltage command value, subtracting the excess / deficiency voltage value from the voltage difference value to obtain a new voltage difference, comparing the new voltage difference with half of the excess / deficiency voltage value, and The selection of the voltage command value is repeated .

  According to this invention, even when the corrected voltage command value exceeds the voltage limiter value, the pulsation of the current waveform can be suppressed.

  The best mode for carrying out the present invention will be described with reference to the accompanying drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or it corresponds, The duplication description is simplified or abbreviate | omitted suitably.

Embodiment 1 FIG.
1 is a diagram showing an elevator system in which a voltage control device of a power conversion device according to Embodiment 1 of the present invention is used.

  In FIG. 1, 1 is a car. 2 is a counterweight. The car 1 and the counterweight 2 are suspended from the main rope 3. The main rope 3 is wound around the drive sheave 4. The drive sheave 4 is provided in the motor 5 of the hoisting machine. AC power is supplied to the motor 5 from the power converter 6. The motor 5 is rotationally driven by the supply of the AC power. By this rotational driving, a frictional force is generated between the drive sheave 4 and the main rope 3. The main rope 3 is driven by this frictional force. By this driving, the car 1 and the counterweight 2 are raised and lowered.

Here, the power converter 6 will be described in more detail.
The power conversion device 6 includes a converter 7 and an inverter 8. The converter 7 and the inverter 8 are composed of a power semiconductor device such as an IGBT. The converter 7 is supplied with AC power from a three-phase AC power source 9. The converter 7 rectifies AC power and converts it into DC power. Converter 7 then outputs DC power to DC bus 10. A capacitor 11 is connected between the positive electrode side and the negative electrode side of the DC bus 10. The capacitor 11 removes the influence of a constant pulsating current or the like.

  The inverter 8 is supplied with DC power from the DC bus 10. The inverter 8 converts DC power into AC power having a variable voltage and variable frequency. The inverter 8 supplies AC power to the motor 5. At this time, the car load detection device 12 detects the car load. Further, the speed detector 13 detects the rotational speed of the motor 5. Information regarding the car load and the rotation speed of the motor 5 is input to the voltage control device 14. The voltage control device 14 controls the inverter 8 based on these pieces of information. Thereby, the output torque and rotation speed of the motor 5 are adjusted, and the driving speed of the car 1 is controlled.

Next, the voltage control device 14 will be described in more detail.
The voltage control device 14 includes a converter voltage control device 15 and a speed control device 16. The converter voltage control device 15 includes a current command calculation unit 15a, a voltage command calculation unit 15b, a two-phase modulation error correction calculation unit 15c, a dead time correction value calculation unit 15d, and a dead time correction unit 15e.

  The bus command voltage value and the bus voltage command value of the DC bus 10 are input to the current command calculation unit 15a. Current command calculation unit 15a calculates a current command value between AC power supply 9 and converter 7 based on these values. A current command value is input to the voltage command calculation unit 15b. Further, a detected current value between the AC power supply 9 and the converter 7 is also input to the voltage command calculation unit 15b. And the voltage command calculating part 15b calculates the voltage command value used as the target value of the output voltage of the power converter device 6 based on these values. This voltage command value is in the ideal switching state.

  A voltage command value is input to the two-phase modulation difference correction calculation unit 15c. The two-phase modulation difference correction calculation unit 15c applies two-phase modulation to the voltage command value. The detected current value or the current command value is input to the dead time correction value calculation unit 15d. The dead time correction value calculation unit 15d calculates an excess / deficiency voltage value generated due to a dead time provided to prevent the positive and negative switching elements of the power conversion device 6 from being turned on simultaneously. Specifically, the over / under voltage value is calculated by “over / under voltage value Vtd = bus voltage value Ed × dead time Td × carrier frequency fc”. This calculation is generally used. Specifically, the polarity of the over / under voltage value is determined based on the detected current value or the current command value. In addition, the amplitude of the over / under voltage value changes according to the magnitude of the current detection value.

  The dead time correction unit 15e receives the voltage command value after the two-phase modulation and the over / under voltage value. Then, the dead time correction unit 15e adds the excess / deficiency voltage value to the voltage command value after the two-phase modulation, and calculates the corrected voltage command value. That is, the dead time correction unit 15e corrects the excess / deficiency voltage value by feedforward.

  The speed control device 16 includes a speed pattern generation unit 16a and a speed control unit 16b. The speed pattern generation unit 16 a generates a car speed pattern according to the operation mode, the car load, and the rotation speed of the motor 5. The speed controller 16b includes a speed controller and a current controller. Although not shown in detail, the speed control unit 16b includes a dead time correction value calculation unit and a dead time correction unit similar to those of the converter 7. The speed controller calculates a current command value based on the speed pattern, the rotation speed of the motor 5, and the car position information. The current controller calculates a voltage command value based on the current command value and the current detection value. Subsequent processing is the same as that of the converter voltage control device 15.

Next, the principle of two-phase modulation applied by the converter voltage control device 15 according to the present embodiment will be described with reference to FIG. The means for two-phase modulation is known. For this reason, only the main points are shown below.
FIG. 2 is a diagram for explaining the principle of two-phase modulation performed by the voltage control device of the power conversion device according to Embodiment 1 of the present invention.

  2A to 2C, the horizontal axis represents an electrical angle, and the vertical axis represents a voltage command value for each phase, a voltage command value after two-phase modulation, and a voltage command value after two-phase modulation. Represents the line voltage. FIG. 2 shows a case where the stationary phase is determined for each electrical angle 60 (deg) and sequentially moved.

  In FIG. 2A, 17a to 17c are voltage command values for the U phase, the V phase, and the W phase, respectively. As shown in FIG. 2A, the phase in which the absolute value of the voltage command value is maximum is switched every electrical angle 60 (deg). In FIG. 2B, thick lines 18a to 18c are voltage command values for each phase after two-phase modulation. As shown in FIG. 2B, in the two-phase modulation, each phase is switched at every electrical angle 60 (deg) to become a stationary phase. Specifically, the voltage command value of the fixed phase is fixed to the + side voltage limiter value or the − side voltage limiter value. On the other hand, the voltage command value of the phase other than the fixed phase is corrected for the difference between the voltage limiter value and the original voltage command value.

  In FIG.2 (c), 19a-19c is the line voltage between U phase and V phase, the line voltage between V phase and W phase, and the line space between W phase and U phase, respectively. Voltage. As shown in FIG. 2C, the line voltage is a sine wave. Therefore, in principle, the occurrence of pulsation of the current waveform is suppressed. That is, the voltage utilization rate is improved. The fixed phase voltage command value is fixed to the voltage limiter value. For this reason, the semiconductor element (switching element) of a stationary phase will be in a continuous ON state or a continuous OFF state. That is, no fixed-phase PWM switching is required. For this reason, an over / under voltage due to dead time does not occur in the stationary phase. That is, the switching loss of the stationary phase is reduced.

Next, consider the power running operation of the converter 7.
FIG. 3 is a diagram schematically showing the relationship between the voltage command value and the corrected voltage command value during powering operation of the converter.
In FIG. 3, the horizontal axis represents the voltage command value, and the vertical axis represents the corrected voltage command value.

  FIG. 3A shows a conceptual diagram of the corrected voltage command value. In FIG. 3A, 20 is a voltage command value. 21a is an output voltage when an overvoltage due to dead time is included with respect to the voltage command value. Reference numeral 22 denotes a corrected voltage command value. As shown in FIG. 3A, during the power running operation of the converter 7, the output voltage 21a includes an overvoltage component due to the influence of the dead time. The converter voltage control device 15 calculates this overvoltage value. Converter voltage control device 15 subtracts the overvoltage value from voltage command value 20 to calculate corrected voltage command value 22. Based on this corrected voltage command value 22, converter voltage control device 15 controls the switching elements of each phase in a feedforward manner.

  FIG. 3B shows a schematic diagram of the relationship between the corrected voltage command value and the output voltage in FIG. As shown in FIG. 3B, the output voltage 21 b controlled with the corrected voltage command value 22 is equivalent to the voltage command value 20. That is, no voltage discontinuity occurs even in the vicinity of the voltage limiter value surrounded by a round frame.

Next, consider the regenerative operation of the converter 7.
FIG. 4 is a diagram schematically showing the relationship between the voltage command value and the corrected voltage command value during the regenerative operation of the converter.

  FIG. 4 is a view corresponding to FIG. FIG. 4A shows a conceptual diagram of the corrected voltage command value. As shown in FIG. 4A, during the regenerative operation of the converter 7, the output voltage 21a includes an insufficient voltage due to the influence of the dead time. The converter voltage control device 15 calculates the undervoltage value. Then, converter voltage control device 15 adds the undervoltage value to voltage command value 20 and calculates corrected voltage command value 22. Based on this corrected voltage command value 22, converter voltage control device 15 controls the switching elements of each phase in a feedforward manner.

FIG. 4B shows a schematic diagram of the relationship between the corrected voltage command value and the output voltage in FIG.
As shown in FIG. 4B, when the corrected voltage command value 22 exceeds the voltage limiter value, the final voltage command value for controlling the output voltage of the power converter 6 is limited to the voltage limiter value. For this reason, the output voltage 21b is not equivalent to the voltage command value 20 in the vicinity of the voltage limiter value. That is, a voltage discontinuity point occurs in the vicinity of the voltage limiter value surrounded by a round frame.

FIG. 5 is a diagram illustrating a first example for explaining a case where the voltage command value during the regenerative operation of the converter is in the vicinity of the voltage limiter value.
FIG. 5 shows a case where the final voltage command value is limited to the voltage limiter value when the corrected voltage command value exceeds the voltage limiter value except for the fixed phase every electrical angle 60 (deg).
5A to 5D, the horizontal axis represents the electrical angle, and the vertical axis represents the corrected voltage command value, the final voltage command value, the actual output voltage, and the actual line after the two-phase modulation of each phase. Expresses the voltage between the two.

  FIG. 5A shows the corrected voltage command value. In FIG. 5A, reference numerals 23a to 23c denote corrected voltage command values for the U phase, the V phase, and the W phase, respectively. As shown in FIG. 5A, in the A part (U phase), B part (V phase), and C part (W phase), the corrected voltage command value 23a and the like exceed the voltage limiter value.

  FIG. 5B shows a case where the final voltage command value is limited to the voltage limiter value in the parts A to C and the like. In FIG. 5B, 24a to 24c are final voltage command values of the U phase, the V phase, and the W phase, respectively. At this time, for example, in the period of 240 to 300 (deg), the U-phase voltage is a fixed phase. However, the U phase is not a stationary phase in the period before and after 210 to 240 (deg) and 300 to 330 (deg). Therefore, in practice, the U-phase switching element performs switching.

  FIG. 5C shows actual output voltages 25a to 25c with respect to the voltage command value in FIG. As shown in FIG. 5C, in the D section, the output voltage 25a changes steeply between the level 1 and the level 2. This amount of change corresponds to an insufficient voltage due to dead time. FIG. 5D shows line voltages 26a to 26c obtained by converting the actual output voltage of FIG. 5C. As shown in FIG. 5D, in the E section, the line voltage 26a changes abruptly. This change occurs corresponding to the change in the D part in FIG. Then, a pulsation of the current waveform occurs at a phase corresponding to the E portion.

FIG. 6 is a diagram showing a second example for explaining the case where the voltage command value during the regenerative operation of the converter is in the vicinity of the voltage limiter value.
FIG. 6 corresponds to FIG. FIG. 6 shows a case in which switching is not performed when the corrected voltage command value exceeds the voltage limiter value except for the fixed phase every electrical angle 60 (deg), as in the fixed phase. It is. That is, in FIG. 6, unlike the case of FIG. 5, the portion where the voltage limiter value at both ends for each electrical angle 60 (deg) is exceeded can be considered as a stationary phase. That is, the modulation mode is changed from two-phase modulation to one-phase modulation.

  FIG. 6A shows the corrected voltage command value. As shown in FIG. 6A, in the A part (U phase), B part (V phase), and C part (W phase), the corrected voltage command value 23a and the like exceed the voltage limiter value. FIG. 6B shows a case where the corrected voltage command values of the A to C portions and the like are limited by the voltage limiter value. At this time, for example, in the period of 240 to 300 (deg), the U-phase voltage is a fixed phase. Also, the U phase is a stationary phase during the period of 210 to 240 (deg) and 300 to 330 (deg) before and after that. For this reason, the switching element of the U phase does not perform switching.

  FIG. 6C shows an actual output voltage with respect to the voltage command value shown in FIG. As shown in FIG. 6 (c), there is no steep change in the actual voltage at the phase corresponding to the D portion in FIG. 5 (c). For this reason, the undervoltage due to the dead time is eliminated. However, the output voltage 25a changes abruptly in the F portion having a phase shifted from the D portion in FIG.

  FIG. 6D shows line voltages 26a to 26c obtained by converting the actual output voltage of FIG. 6C. As shown in FIG. 6D, in the G section, the line voltage 26a changes sharply. This change occurs corresponding to the change in the F part in FIG. Then, the pulsation of the current waveform occurs at the phase corresponding to the G part.

  The converter voltage control device 15 of the present embodiment is characterized in that the output voltage of the converter 7 is controlled so as to suppress the occurrence of the current pulsation. Hereinafter, the converter voltage control device 15 of the present embodiment will be described in detail with reference to FIGS. 1 and 7 to 10.

  In FIG. 1, the converter voltage control unit 15 includes a command value level compensation unit 15f at the time of voltage saturation. The voltage saturation command value level compensation unit 15f includes a voltage saturation determination unit 15g and a voltage output level selection unit 15h. The voltage saturation determination unit 15g determines whether or not the corrected voltage command value exceeds the voltage limiter value. The voltage output level selection unit 15h appropriately selects a voltage level when the voltage is saturated, and determines a final voltage command value for controlling the output voltage of the power converter 6.

  That is, when the corrected voltage command value does not exceed the voltage limiter value, the voltage saturation time command value level compensation unit 15f controls the output voltage of the phase of the converter 7 based on the corrected voltage command value. On the other hand, when the corrected voltage command value exceeds the voltage limiter, the voltage saturation time command value level compensation unit 15f controls the output voltage of the phase of the converter 7 based on the final voltage command value.

Next, the operation of the converter voltage control device 15 will be described in more detail with reference to FIGS.
FIG. 7 is a view showing a state around the A portion where the U-phase voltage command value in FIG. 5 exceeds the voltage limiter value. For simplification, the U-phase voltage command value is assumed to be a straight line.
In FIG. 7, the horizontal axis represents time, and the vertical axis represents the voltage command value and the output voltage. FIG. 7A shows a case where voltage control peculiar to the present embodiment is not performed. On the other hand, FIG. 7B shows a case where voltage control peculiar to the present embodiment is performed.

  As shown in FIG. 7A, in the case where the voltage control peculiar to the present embodiment is not performed, the corrected voltage command value 27 does not exceed the voltage limiter value in the two-phase modulation fluctuation A section. In this case, the output voltage is controlled based on the corrected voltage command value 27. In the two-phase modulation fluctuation B section, the corrected voltage command value 27 exceeds the voltage limiter value. In this case, the final voltage command value 28 is limited to the voltage limiter value. For this reason, the output voltage becomes a constant value.

  That is, in the two-phase modulation fluctuation B section, the voltage corresponding to the hatched portion is insufficient. In the two-phase modulation fixed phase section, switching of the switching element of the corresponding phase stops. For this reason, an overvoltage due to dead time does not occur. That is, the voltage limiter value is output as it is. As a result, a voltage discontinuity occurs between the two-phase modulation fluctuation B section and the two-phase modulation fixed phase section.

  On the other hand, as shown in FIG. 7B, when performing voltage control peculiar to the present embodiment, the corrected voltage command value 27 does not exceed the voltage limiter value in the two-phase modulation fluctuation A section. In this case, the output voltage is controlled based on the corrected voltage command value 27. In the two-phase modulation fluctuation B section, the corrected voltage command value 27 exceeds the voltage limiter value. In this case, the final voltage command value (not shown in FIG. 7B) is obtained by adding the over / under voltage value to the voltage limiter value and the voltage limiter value so that the average of the output voltage is close to the voltage command value. Selected from the values.

FIG. 8 is a diagram for explaining in more detail the voltage control performed by the voltage control device of the power conversion device according to Embodiment 1 of the present invention.
In FIG. 8, the horizontal axis represents time, and the vertical axis represents the voltage command value and the output voltage. In FIG. 8, the two-phase modulation fluctuation B section is divided into a plurality of sections. Specifically, the B section is divided every control calculation cycle Ts.

  Then, a final voltage command value is selected every control calculation cycle Ts. Specifically, in the interval (c), the voltage limiter value is selected as the final voltage command value. On the other hand, in the section (d), the voltage command value obtained by adding the excess / deficiency voltage value to the voltage limiter value is selected as the final voltage command value. As a result, in the interval (c), the value of the output voltage 29 is level 1. On the other hand, in the interval (d), the value of the output voltage 29 is level 2. The average of the output voltage 29 is close to the voltage command value 30.

Various algorithms for selecting the final voltage command value can be considered. Below, the example is demonstrated.
FIG. 9 is a timing chart for illustrating a voltage selection algorithm of the voltage control device of the power conversion device according to Embodiment 1 of the present invention.
FIG. 10 is a block diagram for illustrating a voltage selection algorithm of the voltage control device of the power conversion device according to Embodiment 1 of the present invention.
Here, FIG. 10 is another representation of FIG. For this reason, only FIG. 9 will be described below.

  Switching between levels 1 and 2 at the time of voltage saturation is performed in the two-phase modulation fluctuation B section of FIG. For this reason, if the phase is a stationary phase in step S1, the process does not proceed to step S2, but starts again from step S1 at the next sampling. On the other hand, if the phase is not a stationary phase, the process proceeds to step S2. In step S2, it is determined whether or not “voltage command value> voltage limiter value” is true. If the determination is true, it is determined that the voltage is saturated, and the process proceeds to step S3.

  From step S3, the voltage selection level algorithm is started. First, “voltage difference = voltage command value−voltage limiter value” is calculated, and the process proceeds to step S4. In step S4, it is determined whether or not “voltage difference> ½ of excess / deficiency voltage value” is true. If the determination is true, the process proceeds to step S5. In step S5, level 2 is selected as the next voltage command value, the operation as a fixed phase of two-phase modulation is performed, and the process proceeds to step S6. In step S6, “new voltage difference integral value = old voltage difference integral value−excess / undervoltage value” is computed in order to determine the voltage difference in the next control computation cycle Ts, and the process returns to step S1.

  On the other hand, if the determination is not true in step S4, the process proceeds to step S7. In step S7, voltage level 1 is selected as the next voltage command value, and the process returns to step S1. In step S2, if the determination is not true, it is determined that the voltage is not saturated. Therefore, the voltage difference integral value is reset to 0, and the process returns to step S1. The above calculation is performed every control calculation cycle Ts. Also, these calculations are performed for each phase.

  According to the first embodiment described above, when the corrected voltage command value exceeds the voltage limiter value, the final voltage command value for controlling the output voltage of the power converter 6 is the voltage limiter value and the voltage limiter. The value is selected from the value obtained by adding the over / under voltage value to the value. Thereby, the output voltage average of the converter 7 is close to the voltage command value. For this reason, a steep change in the output voltage is suppressed. That is, the pulsation of the current waveform can be suppressed. Thereby, the small power converter 6 can be used. Furthermore, the power consumption of the power converter 6 is also reduced.

  The final voltage command value is selected using the algorithm shown in FIG. That is, the final voltage command value is selected based on the undervoltage value. For this reason, more reliable control of the output voltage becomes possible. In the first embodiment, the case where the output voltage of converter 7 is controlled has been described. However, the same effect can be obtained even when the output voltage of the inverter 8 is controlled. Moreover, if the voltage in which such control was performed is utilized, the motor 5 of an elevator will be driven smoothly.

  In the first embodiment, the case of the regenerative operation of converter 7 has been described. However, the same effect can be obtained even in the case of the power running operation of the inverter 8. In the first embodiment, the case where the stationary phase is determined for each electrical angle 60 (deg) has been described as the two-phase modulation method. However, the same effect can be obtained even when the stationary phase is determined for each electrical angle 120 (deg). The same effect can be obtained even in the case of the third harmonic superimposing method. Furthermore, the same effect can be obtained even with a normal sine wave modulation method that does not use the voltage utilization rate improvement method.

  In the first embodiment, the presence or absence of voltage saturation and the voltage level are set for the voltage command value using the algorithm shown in FIG. However, when voltage saturation is detected, a simple method for determining the voltage level using a table prepared in advance based on information such as determination of powering operation or regenerative operation, car load, speed command value, etc. Is also applicable. In particular, the converter 7 or the like having a constant frequency is easy to configure, and is effective when it is difficult to secure the calculation time for the sequence of voltage saturation determination and voltage level determination.

  Further, the use of the voltage control device 14 of the present invention is not limited to the voltage control of the power conversion device 6 that drives the motor 5. That is, if the corrected voltage command value exceeds the voltage limiter value, the voltage controller 14 of the present invention can be used.

It is a figure which shows the elevator system by which the voltage control apparatus of the power converter device in Embodiment 1 of this invention is utilized. It is a figure for demonstrating the principle of the two-phase modulation which the voltage control apparatus of the power converter device in Embodiment 1 of this invention performs. It is the figure which showed typically the relationship between the voltage command value at the time of the power running operation of a converter, and the voltage command value after correction | amendment. It is the figure which showed typically the relationship between the voltage command value at the time of the regenerative operation of a converter, and the voltage command value after correction | amendment. It is a figure which shows the 1st example for demonstrating the case where the voltage command value at the time of the regenerative operation of a converter exists in the voltage limiter value vicinity. It is a figure which shows the 2nd example for demonstrating the case where the voltage command value at the time of the regenerative operation of a converter exists in the voltage limiter value vicinity. It is the figure which showed the state of the A section periphery in which the voltage command value of the U phase of FIG. 5 exceeds a voltage limiter value. It is a figure for demonstrating in detail the voltage control which the voltage control apparatus of the power converter device in Embodiment 1 of this invention performs. It is a timing chart for demonstrating the voltage selection algorithm of the voltage control apparatus of the power converter device in Embodiment 1 of this invention. It is a block diagram for demonstrating the voltage selection algorithm of the voltage control apparatus of the power converter device in Embodiment 1 of this invention.

Explanation of symbols

1 car, 2 counterweight, 3 main rope, 4 drive sheave, 5 motor,
6 power converter, 7 converter, 8 inverter, 9 AC power supply,
10 DC bus, 11 capacitor, 12 car load detector,
13 speed detector, 14 voltage control device, 15 voltage control device for converter,
15a current command calculation unit, 15b voltage command calculation unit,
15c two-phase modulation difference correction calculation unit, 15d dead time correction value calculation unit,
15e dead time correction unit, 15f voltage saturation command value level compensation unit,
15 g voltage saturation determination unit, 15 h voltage output level selection unit, 16 speed control device, 16 a speed pattern generation unit, 16 b speed control unit, 17 a to 17 c voltage command value, 18 a to 18 c voltage command value, 19 a to 19 c line voltage, 20 Voltage command value,
21a, 21b output voltage, 22 corrected voltage command value,
23a-23c corrected voltage command value, 24a-24c final voltage command value,
25a to 25c output voltage, 26a to 26c line voltage, 27 corrected voltage command value, 28 final voltage command value, 29 output voltage, 30 voltage command value

Claims (4)

A voltage command calculation unit that calculates a voltage command value that is a target value of the output voltage of the power converter,
A dead time correction value calculation unit for calculating an excess / deficiency voltage value generated by a dead time provided to prevent the positive and negative switching elements of the power converter from being conducted simultaneously;
A dead time correction unit that adds the over / under voltage value to the voltage command value and calculates a corrected voltage command value;
A voltage saturation determination unit that determines whether or not the corrected voltage command value exceeds a voltage limiter value;
When the corrected voltage command value does not exceed the voltage limiter value, based on the corrected voltage command value, control the output voltage of the power converter,
When the corrected voltage command value exceeds the voltage limiter value, the final voltage for controlling the output voltage of the power converter so that the average of the output voltages of the power converter is close to the voltage command value A command value level compensation unit at the time of voltage saturation for selecting a command value from the voltage limiter value and a value obtained by adding the over / undervoltage value to the voltage limiter value;
Equipped with a,
The voltage saturation command value level compensation unit is
When the corrected voltage command value exceeds the voltage limiter value, the voltage difference value is calculated by subtracting the voltage limiter value from the corrected voltage command value,
When the voltage difference is smaller than half of the over / under voltage value, the voltage limiter value is selected as the final voltage command value, and the voltage difference value is maintained to be a new voltage difference,
When the voltage difference is larger than half of the over / undervoltage value, a value obtained by adding the over / under voltage value to the voltage limiter value is selected as the final voltage command value, and the overvoltage is calculated from the voltage difference value. Subtract the undervoltage value to make a new voltage difference,
A voltage control device for a power converter, wherein the new voltage difference is compared with half of the excess / deficiency voltage value and the selection of the final voltage command value is repeated . The power converter, voltage control apparatus of power converter according to claim 1, characterized in that it consists of the converter. The power converter, voltage control apparatus of power converter according to claim 1, characterized in that an inverter. The said power converter device drives a motor with output electric power, The voltage control apparatus of the power converter device in any one of Claims 1-3 characterized by the above-mentioned.

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