Electric power conversion device and refrigeration cycle applying device

Abstract

An electric power conversion device (1) comprises: an electric power supply unit (100) that converts AC electric power into DC electric power by using semiconductor elements (131–136); a smoothing unit (200) that smooths the DC electric power; an electric current and voltage detection unit (400) that detects an electric current and a voltage that indicate the operating states of the electric power supply unit (100) and the smoothing unit (200); and a control unit (800) that generates a gate voltage command value (600) for controlling the operation of the semiconductor elements (131–136) by using detected values of the electric current and the voltage detected by the electric current and voltage detection unit (400), wherein the control unit (800) comprises a high power factor control unit (500) that generates a modulated wave based on an output voltage command value by using the detection values and generates the gate voltage command value (600) on the basis of the result of comparing the modulated wave and the carrier signal; and an output voltage command value correction unit (700) that generates a correction term by using the detection values and a parameter that is used when generating the modulated wave, the modulated wave being corrected using the correction term.

Description

Power conversion equipment and refrigeration cycle application equipment

[0001] The present disclosure relates to a power conversion device that converts AC power into DC power and a refrigeration cycle device.

[0002] Conventionally, there is a power conversion device equipped with a converter that converts AC power to DC power. In such a power conversion device, a control unit performs PWM (Pulse Width Modulation) control for current control on semiconductor elements that perform switching in the converter. The semiconductor elements equipped in the converter are generally two semiconductor elements connected in series. To prevent a short circuit between the two semiconductor elements connected in series, the control unit sets a dead time for applying a voltage to the gates of the semiconductor elements during which both semiconductor elements are turned off.

[0003] However, due to the influence of dead time, an error occurs between the ideally calculated output voltage command value and the output voltage. As a result, in the converter, the influence of dead time distorts the current waveform and increases power supply current harmonics. To address this problem, Patent Document 1 discloses a technology for compensating for dead time and reducing power supply current harmonics.

[0004] International Publication No. 2020 / 117169

[0005] In addition to the aforementioned Patent Document 1, many other patent documents, papers, and other publications have proposed dead time compensation for PWM control. However, in most cases, dead time compensation involves adding a fixed value across the board. This has led to the problem that the effect is insufficient when the load condition changes or when a disturbance occurs in the detected current or voltage, resulting in deviations from the ideal condition.

[0006] The present disclosure has been made in view of the above, and has an object to provide a power conversion device that can reduce power supply current harmonics caused by dead time.

[0007] In order to solve the above-mentioned problems and achieve the object, the power conversion device of the present disclosure includes a power supply unit that converts AC power into DC power using semiconductor elements, a smoothing unit that smooths the DC power, a current / voltage detection unit that detects current and voltage that indicate the operating state of the power supply unit and the smoothing unit, and a control unit that generates a gate voltage command value that controls the operation of the semiconductor elements using the detected values ​​of the current and voltage detected by the current / voltage detection unit, and the control unit includes a high power factor control unit that generates a modulated wave based on the output voltage command value using the detected value and generates the gate voltage command value based on the result of comparing the modulated wave with a carrier signal, and an output voltage command value correction unit that generates a correction term using the detected value and parameters used when generating the modulated wave, and corrects the modulated wave using the correction term.

[0008] The power conversion device according to the present disclosure has an effect of being able to reduce power supply current harmonics caused by dead time.

[0009] FIG. 1 shows an example of the configuration of a power conversion device according to embodiment 1. FIG. 1 shows an example of the configuration of a high power factor control unit among the control units provided in the power conversion device according to embodiment 1. FIG. 2 shows an example of dead time set in a semiconductor element provided in the power conversion device according to embodiment 1. FIG. 3 shows, as a comparative example, an example of power supply current harmonics due to the influence of dead time when appropriate control is not performed in the power conversion device. FIG. 4 shows an example of the configuration of an output voltage command value correction unit among the control units provided in the power conversion device according to embodiment 1. FIG. 5 shows the relationship between α calculated by the correction timing generation unit of the control unit provided in the power conversion device according to embodiment 1 and the R-phase voltage of a three-phase AC voltage or the output voltage command value. FIG. 6 shows a calculation table and conditions used by a variable k calculator in an output voltage command value correction calculation unit of a control unit provided in the power conversion device according to embodiment 1. FIG. 7 shows an example of calculation table 1 used by a variable k calculator in an output voltage command value correction calculation unit of a control unit provided in the power conversion device according to embodiment 1. Simulation analysis of the effect obtained by introducing a correction term using calculation table 1 in the power conversion device according to embodiment 1. FIG. 1 shows an example of calculation table 2 used by a variable k calculator in an output voltage command value correction calculation unit of a control unit provided in the power conversion apparatus according to embodiment 1. FIG. 2 shows an example of calculation table 3 used by a variable k calculator in an output voltage command value correction calculation unit of a control unit provided in the power conversion apparatus according to embodiment 1. FIG. 3 shows a simulation analysis result of an effect obtained by introducing a correction term using calculation table 3 in the power conversion apparatus according to embodiment 1. FIG. 4 shows an example of calculation table 4 used by a variable k calculator in an output voltage command value correction calculation unit of a control unit provided in the power conversion apparatus according to embodiment 1. FIG. 5 shows a second diagram showing an example configuration of a high power factor control unit among the control units provided in the power conversion apparatus according to embodiment 1. FIG. 6 shows a simulation analysis result of an effect obtained by introducing a correction term using calculation table 4 in the power conversion apparatus according to embodiment 1.

[0010] Hereinafter, a power conversion device and a refrigeration cycle application device according to an embodiment of the present disclosure will be described in detail with reference to the drawings.

[0011] First Embodiment. Fig. 1 is a diagram showing an example of the configuration of a power conversion device 1 according to a first embodiment. The power conversion device 1 shown in Fig. 1 is a three-phase PWM converter as an example, but the configuration of the power conversion device 1 is not limited to the example shown in Fig. 1. In the following, a specific description will be given using the power conversion device 1 shown in Fig. 1 as an example. The power conversion device 1 includes a power supply unit 100, a smoothing unit 200, a load unit 300, a current / voltage detection unit 400, and a control unit 800. The power supply unit 100 includes an AC power supply 110, a reactor 120, and a semiconductor module 130. The control unit 800 includes a high power factor control unit 500 and an output voltage command value correction unit 700.

[0012] The AC power supply 110 supplies AC power to the semiconductor module 130 via the reactor 120. The AC power supply 110 is, for example, a commercial power supply. The AC power supply 110 may be external to the power conversion device 1. In other words, the power conversion device 1 may be configured to be connected to the AC power supply 110.

[0013] The reactor 120 is disposed between the AC power supply 110 and the semiconductor module 130. The position of the reactor 120 may vary depending on the configuration of the power conversion device 1, etc.

[0014] The semiconductor module 130 is composed of a plurality of semiconductor elements 131 to 136, and converts AC power into DC power using the semiconductor elements 131 to 136. The semiconductor module 130 may be implemented using discrete components. The semiconductor elements 131 to 136 are, for example, insulated gate bipolar transistors (IGBTs) or metal-oxide-semiconductor field-effect transistors (MOSFETs). The semiconductor elements 131 to 136 are switching elements that are turned on and off in accordance with a gate voltage command value 600 generated by a high power factor control unit 500 of the control unit 800, as will be described later. The gate voltage command value 600 is, for example, a gate voltage command value G1 for semiconductor element 131, a gate voltage command value G2 for semiconductor element 132, a gate voltage command value G3 for semiconductor element 133, a gate voltage command value G4 for semiconductor element 134, a gate voltage command value G5 for semiconductor element 135, and a gate voltage command value G6 for semiconductor element 136.

[0015] The smoothing unit 200 is composed of a smoothing element such as an electrolytic capacitor 210 and smoothes the DC power converted by the semiconductor module 130 .

[0016] The load unit 300 is connected downstream of the smoothing unit 200 and is assumed to be a constant current load. The load unit 300 is composed of a motor load, an inverter that drives the motor load, and the like. The voltage supplied to the load unit 300 can be made a substantially constant DC voltage by setting the capacitance of the electrolytic capacitor 210 of the smoothing unit 200 to a relatively large value. The motor load may be external to the power conversion device 1. In other words, the power conversion device 1 may be configured to be connected to the motor load.

[0017] The current / voltage detection unit 400 detects currents and voltages that indicate the operating states of the power supply unit 100 and the smoothing unit 200. Specifically, the current / voltage detection unit 400 senses the currents and voltages of each part of the main circuit using voltage sensors 410 to 412 and current sensors 420 to 422. In the example of FIG. 1 , the current / voltage detection unit 400 detects the R-phase voltage VR of the three-phase AC voltage using the voltage sensor 410, detects the T-phase voltage VT of the three-phase AC voltage using the voltage sensor 411, and detects the DC bus voltage V using the voltage sensor 412. ｄｃ The current sensor 420 detects the R-phase current IR of the three-phase AC current, the current sensor 421 detects the T-phase current IT of the three-phase AC current, and the current sensor 422 detects the DC bus current I ｄｃ The current / voltage detection unit 400 may detect currents and voltages that indicate the operating states of the inverter, motor load, and the like included in the load unit 300.

[0018] The control unit 800 generates a gate voltage command value 600 for controlling the operation of the semiconductor elements 131 to 136 using the current and voltage detected by the current / voltage detection unit 400 .

[0019] 2 is a first diagram showing a configuration example of a high power factor control unit 500 of the control unit 800 included in the power conversion device 1 according to embodiment 1. The high power factor control unit 500 includes a three-phase AC current / voltage calculator 510, a three-phase dq converter 520, a phase locked loop (PLL) circuit 530, a current controller 540, a voltage controller 550, a dq-three-phase converter 560, a modulated wave generator 570, and a gate voltage command value generator 580.

[0020] The three-phase AC current / voltage calculator 510 uses the R-phase current I R and T-phase current I T of the three-phase AC current detected by the current / voltage detection unit 400, and the R-phase voltage VR and T-phase voltage VT of the three-phase AC voltage detected by the current / voltage detection unit 400, to calculate the S-phase current I S of the three-phase AC current and the S-phase voltage VS of the three-phase AC voltage that are not detected by the current / voltage detection unit 400, based on Kirchhoff's law.

[0021] The three-phase dq converter 520 converts the R-phase current IR, the S-phase current IS, and the T-phase current IT of the three-phase AC current into a d-axis current I ｄ and q-axis current I ｑ and converts the R-phase voltage VR, S-phase voltage VS, and T-phase voltage VT of the three-phase AC voltage into the d-axis voltage V ｄ and the q-axis voltage V ｑ Convert to.

[0022] The phase locked loop PLL 530 calculates a phase angle θ1 used for three-phase dq conversion by the three-phase-dq converter 520 based on the R-phase voltage VR and the T-phase voltage VT of the three-phase AC voltage. The phase locked loop PLL 530 also adds a control operation period delay Δθ to the phase angle θ1 to calculate a phase angle θ2 used for dq-three-phase conversion by the dq-three-phase converter 560.

[0023] The current controller 540 controls the d-axis current I ｄ , the d-axis current command value I ｄｒｅｆ and the q-axis current I ｑ , the q-axis current command value I ｑｒｅｆ Specifically, the current controller 540 controls the d-axis current command value I ｄｒｅｆ and d-axis current I ｄ The d-axis voltage command value V is calculated using a PI (Proportional Integral) controller or the like so that the difference between ｄｒｅｆ The current controller 540 generates the q-axis current command value I ｑｒｅｆ and q-axis current I ｑ The q-axis voltage command value V is calculated using a PI controller or the like so that the difference between ｑｒｅｆ Generate.

[0024] The voltage controller 550 controls the DC bus voltage V ｄｃ DC bus voltage command value V ｄｃｒｅｆ Specifically, the voltage controller 550 controls the DC bus voltage command value V ｄｃｒｅｆ and DC bus voltage V ｄｃ The q-axis current command value I is calculated using a PI controller so that the difference between ｑｒｅｆ Generate.

[0025] The dq-three-phase converter 560 calculates the d-axis current command value I ｄｒｅｆ and the q-axis current command value I ｑｒｅｆ is the three-phase AC output current command value I ｒｒｅｆ , I ｓｒｅｆ , I ｔｒｅｆ and the d-axis voltage command value V ｄｒｅｆ and the q-axis voltage command value V ｑｒｅｆ The three-phase AC output voltage command value V ｒｒｅｆ , V ｓｒｅｆ , V ｔｒｅｆ Convert to.

[0026] The modulated wave generator 570 generates a three-phase AC output voltage command value V ｒｒｅｆ , V ｓｒｅｆ , V ｔｒｅｆ V ｄｃ Output current command value A normalized by dividing by 2 ｒｒｅｆ , A ｓｒｅｆ , A ｔｒｅｆ In order to improve the voltage utilization rate, a modulated wave is generated by adding a value m such as the intermediate voltage or zero-phase voltage calculated by the m-value calculator 571. The parameter value m is set to a value that satisfies equations (1) to (3) or equation (4).

[0027]

[0028]

[0029]

[0030]

[0031] In equation (4), maxmin1 is 1 or 0, and maxmin2 is 1 or 0. In equation (4), max is the output current command value A ｒｒｅｆ , A ｓｒｅｆ , A ｔｒｅｆ and min is the maximum value of the output current command value A ｒｒｅｆ , A ｓｒｅｆ , A ｔｒｅｆ is the minimum value of

[0032] In this embodiment, the modulated wave generator 570 further adds a correction term γ generated by the output voltage command value corrector 700 to the generated modulated wave and outputs the result to the gate voltage command value generator 580. That is, the modulated wave output from the modulated wave generator 570 to the gate voltage command value generator 580 includes the correction term γ. The correction term γ is expressed as in equation (5).

[0033]

[0034] In equation (5), k is a defined real variable, and f ｓｗ is the switching frequency of the semiconductor elements 131 to 136 of the semiconductor module 130 included in the power conversion device 1, and T ｄ is the dead time. Thus, the correction term γ includes the variable k.

[0035] The gate voltage command value generator 580 includes a carrier comparator 581 and a dead time generator 582. The carrier comparator 581 is configured to compare the modulated wave generated by the modulated wave generator 570 with the specified switching frequency f ｓｗ The dead time generator 582 compares the gate voltage command value 600 with a carrier signal, for example, a triangular wave carrier, which is repeated at 100 Hz, and generates and outputs a gate voltage command value 600 to be applied to the semiconductor elements 131 to 136. The dead time generator 582 adds a dead time T ｄ Set.

[0036] 1, PWM control is performed for current control. As shown in FIG. 1, in the semiconductor module 130, the semiconductor elements 131 and 132 are connected in series, the semiconductor elements 133 and 134 are connected in series, and the semiconductor elements 135 and 136 are connected in series. In order to prevent a short circuit between the semiconductor elements 131 and 132, the high power factor control unit 500 adjusts the dead time T as shown in FIG. 3 with respect to the gate voltage command value 600 applied to the gates of the semiconductor elements 131 and 132. ｄ 3 is a diagram showing the dead time T ｄ10 is a diagram showing an example of a semiconductor device according to the present invention. Note that the same applies to the combination of semiconductor devices 133 and 134 and the combination of semiconductor devices 135 and 136, and therefore the semiconductor devices 131 and 132 will be used as an example for explanation.

[0037] The semiconductor elements 131 and 132 are provided with a dead time T ｄ When the dead time T ｄ Due to the influence of the ideally calculated output voltage command value V ｒｒｅｆ , V ｓｒｅｆ , V ｔｒｅｆ If appropriate control is not performed, an error occurs between the dead time T ｄ 4 shows a comparative example of the dead time T ｄ 1 is a diagram showing an example of power supply current harmonics due to the influence of dead time T ｄ When the dead time T ｄ This distorts the current waveform compared to when there is no current, leading to an increase in power supply current harmonics.

[0038] Therefore, in this embodiment, the power conversion device 1 uses the output voltage command value correction unit 700 of the control unit 800 to correct the dead time T ｄ This improves current distortion based on an output voltage error caused by the above, i.e., power supply current harmonics. When the high power factor control unit 500 generates the gate voltage command value 600 for the semiconductor elements 131 to 136, the control unit 800 uses the correction term γ generated by the output voltage command value correction unit 700 to correct the gate voltage command value 600, thereby suppressing the output voltage error and reducing the power supply current harmonics. The detailed configuration and operation of the output voltage command value correction unit 700 included in the control unit 800 will be described below.

[0039] 5 is a diagram showing an example of the configuration of the output voltage command value corrector 700 of the control unit 800 included in the power conversion device 1 according to the first embodiment. The output voltage command value corrector 700 includes a case-by-case calculation unit 710 and an output voltage command value correction calculator 720. The case-by-case calculation unit 710 includes a load power calculation unit 711, a current information calculation unit 712, a correction timing generation unit 713, and a modulation scheme estimation unit 714. The output voltage command value corrector 700 generates a correction term γ by performing a preset calculation in the output voltage command value correction calculator 720 based on the information obtained by the case-by-case calculation unit 710, and outputs the correction term γ to the modulated wave generator 570 of the high power factor control unit 500.

[0040] The load power calculation unit 711 calculates the DC bus voltage V detected by the current / voltage detection unit 400. ｄｃ and DC bus current I ｄｃ Multiplying by this, the load power P ｄｃ The load power calculation unit 711 calculates the load power P ｄｃ Using this, the load power P ｄｃ The maximum output power P of the power conversion device 1 is calculated based on the change in ｄｃ１ The load power calculation unit 711 calculates the load power P ｄｃ (a) 0 or more P ｄｃ１ × (1 / 4) or less, (b) P ｄｃ１ × (1 / 4) or more P ｄｃ１ × (1 / 2) or less, (c) P ｄｃ１ × (1 / 2) or more P ｄｃ１ × (3 / 4) and (d) P ｄｃ１ × (3 / 4) or more P ｄｃ１ In this way, the load power calculation unit 711 determines in which of the four ranges the load power P ｄｃ Regarding the case of the maximum output power P of the power conversion device 1, ｄｃ１ Divide by 4 to divide the power band into four ranges, and calculate the current load power P ｄｃ corresponds to a power band, generates load information including the determination result, and outputs it to the output voltage command value correction calculation unit 720. The load information is the current load power P ｄｃThe output voltage command value correction calculation unit 720 selects an appropriate calculation formula for the variable k of the correction term γ using the load information acquired from the load power calculation unit 711, thereby correcting the output voltage command value V ｒｒｅｆ , V ｓｒｅｆ , V ｔｒｅｆ The correction effect can be improved.

[0041] Here, the load power P ｄｃ In determining the range in which the maximum output power P ｄｃ１ The range is divided into four equal parts, but is not limited to this. ｄｃ The range in which the maximum output power P of the power conversion device 1 is located is determined by ｄｃ１ The range obtained by dividing the range into three equal parts, the maximum output power P ｄｃ１ Alternatively, the ranges may be different in size rather than being equally divided. ｄｃ１ The area based on the load power P ｄｃ load information indicating the range in which the

[0042] The current information calculation unit 712 calculates the effective value I of the R-phase current IR from the R-phase current IR, which is the power supply current detected by the current / voltage detection unit 400. ｒｍｓ , and the maximum phase current effective value I of the power conversion device 1 ｒｍｓ１ The current information calculation unit 712 calculates the effective value I ｒｍｓ (A) 0 or more I ｒｍｓ１ × (1 / 4) or less, (B) I ｒｍｓ１ × (1 / 4) or more I ｒｍｓ１ × (1 / 2) less than (C) I ｒｍｓ１ × (1 / 2) or more I ｒｍｓ１ × (3 / 4) or less, and (D) I ｒｍｓ１ × (3 / 4) or more I ｒｍｓ１ The current information calculation unit 712 also determines in which of the four ranges the R-phase current IR is in. ｒｍｓThe current information calculation unit 712 calculates the current distortion rate THD (Total Harmonic Distortion) [%] based on the effective value I ｒｍｓ Regarding the case distinction, the maximum phase current effective value I ｒｍｓ１ Divide by 4 to divide the current band into four ranges, and calculate the current effective value I ｒｍｓ corresponds to a current band, generates input current information including the determination result and information on the magnitude relationship indicating whether the current distortion factor THD is larger or smaller than the threshold value, and outputs this to the output voltage command value correction calculation unit 720. The input current information indicates the state of the effective value of the current of the power conversion device 1. The output voltage command value correction calculation unit 720 calculates the output voltage command value V by selecting an appropriate calculation formula for the variable k of the correction term γ using the input current information obtained from the current information calculation unit 712. ｒｒｅｆ , V ｓｒｅｆ , V ｔｒｅｆ The correction effect can be improved.

[0043] Here, the effective value I ｒｍｓ In determining the range in which the maximum phase current effective value I of the power conversion device 1 is present, ｒｍｓ１ The effective value I is divided into four equal parts, but the range is not limited to this. ｒｍｓ The range in which the maximum phase current effective value I of the power conversion device 1 exists can be determined by ｒｍｓ１ The range obtained by dividing the range into three equal parts, the maximum phase current effective value I ｒｍｓ１ Alternatively, the ranges may be different in size rather than being equally divided. ｒｍｓ１ The area based on the RMS value I is divided into specified ranges. ｒｍｓ The input current information indicating the range in which the

[0044] The correction timing generation unit 713 calculates the DC bus voltage command value V ｄｃｒｅｆ and the R-phase voltage VR of the three-phase AC voltage or the output voltage command value V ｒｒｅｆ Using this, VR / V ｄｃｒｅｆ or V ｒｒｅｆ / V ｄｃｒｅｆThe correction timing generation unit 713 calculates α. １ is a specified positive value whose absolute value is less than 1, and α is (i) 0 or more α １ (ii) in the range of less than α １ The above range, (iii) -α １ or more and less than 0, and (iv) -α １ In this way, the correction timing generation unit 713 determines in which range α is located, generates correction timing information including the determination result, and outputs it to the output voltage command value correction calculation unit 720. That is, the correction timing generation unit 713 determines in which range α is located, generates correction timing information including the determination result, and outputs it to the output voltage command value correction calculation unit 720. ｄｃｒｅｆ the R-phase voltage VR of the three-phase AC voltage, which is the voltage relative to the output voltage command value V ｒｒｅｆ The correction timing information indicates in which range of the divided range the ratio of the DC bus voltage command value V ｄｃｒｅｆ the R-phase voltage VR of the three-phase AC voltage, which is the voltage relative to the output voltage command value V ｒｒｅｆ The output voltage command value correction calculation unit 720 selects an appropriate calculation formula for the variable k of the correction term γ using the correction timing information acquired from the correction timing generation unit 713, thereby calculating the output voltage command value V ｒｒｅｆ , V ｓｒｅｆ , V ｔｒｅｆ The correction timing generation unit 713 can improve the correction effect of α １ By appropriately setting, the output voltage command value correction calculation unit 720 can calculate the output voltage command value V ｒｒｅｆ , V ｓｒｅｆ , V ｔｒｅｆ It is possible to select an appropriate formula for calculating the variable k at the timing when the distortion of the variable k becomes large.

[0045] FIG. 6 shows the relationship between α calculated by the correction timing generation unit 713 of the control unit 800 included in the power conversion device 1 according to the first embodiment and the R-phase voltage VR of the three-phase AC voltage or the output voltage command value V ｒｒｅｆ In FIG. 6, the upper graph shows the relationship between the DC bus voltage command value V ｄｃｒｅｆ and the R-phase voltage VR of the three-phase AC voltage or the output voltage command value Vｒｒｅｆ The figure below shows an example of VR / V ｄｃｒｅｆ In the upper and lower diagrams of FIG. 6, the horizontal axis indicates time. １ , and the relationship between the ranges (i) to (iv) is as shown in the lower diagram of FIG.

[0046] The modulation method estimation unit 714 estimates the output current command value A ｒｒｅｆ , A ｓｒｅｆ , A ｔｒｅｆ The modulation scheme estimation unit 714 determines whether the value m, which is a parameter to be added to γ, is calculated using equations (1) to (3) or (4), and estimates the modulation scheme of the power conversion device 1. When the parameter value m is calculated using equations (1) to (3), the modulation scheme estimation unit 714 estimates that the modulation scheme of the power conversion device 1 is three-phase modulation, and when the parameter value m is calculated using equation (4), the modulation scheme estimation unit 714 estimates that the modulation scheme of the power conversion device 1 is two-phase modulation. In this way, the modulation scheme estimation unit 714 estimates the modulation scheme of the power conversion device 1, generates modulation scheme information including the estimated result, and outputs it to the output voltage command value correction calculation unit 720. Since the magnitude of the output voltage error and the value of α at which the output voltage error becomes noticeable differ depending on the modulation scheme, the output voltage command value correction calculation unit 720 selects an appropriate calculation formula for the variable k of the correction term γ according to the modulation scheme using the modulation scheme information acquired from the modulation scheme estimation unit 714, thereby correcting the output voltage command value V ｒｒｅｆ , V ｓｒｅｆ , V ｔｒｅｆ The correction effect can be improved.

[0047] The output voltage command value correction calculation unit 720 selects an appropriate formula for calculating the variable k to calculate the correction term γ using the load information acquired from the load power calculation unit 711, the input current information acquired from the current information calculation unit 712, the correction timing information acquired from the correction timing generation unit 713, and the modulation method information acquired from the modulation method estimation unit 714. The variable k of the correction term γ changes depending on the load information, the input current information, the correction timing information, and the modulation method information. In the output voltage command value correction calculation unit 720, a variable k calculator 721 selects a calculation table to use and calculates the variable k based on the current distortion factor THD included in the input current information acquired from the current information calculation unit 712 and the modulation method of the power conversion device 1 indicated by the modulation method information acquired from the modulation method estimation unit 714, as shown in FIG. 7 .

[0048] 7 is a diagram showing calculation tables and conditions used by the variable k calculator 721 in the output voltage command value correction calculation unit 720 of the control unit 800 included in the power conversion device 1 according to the first embodiment. As shown in FIG. 7 , when the current distortion factor THD is less than a threshold and the modulation method of the power conversion device 1 is three-phase modulation, the variable k calculator 721 calculates the variable k using calculation table 1. Furthermore, when the current distortion factor THD is less than a threshold and the modulation method of the power conversion device 1 is two-phase modulation, the variable k calculator 721 calculates the variable k using calculation table 2. Furthermore, when the current distortion factor THD is equal to or greater than a threshold and the modulation method of the power conversion device 1 is three-phase modulation, the variable k calculator 721 calculates the variable k using calculation table 3. Furthermore, when the current distortion factor THD is equal to or greater than a threshold and the modulation method of the power conversion device 1 is two-phase modulation, the variable k calculator 721 calculates the variable k using calculation table 4. Hereinafter, a specific calculation method using each calculation table will be described.

[0049] First, a case will be described in which the variable k calculator 721 uses calculation table 1. When the current distortion factor THD is less than the threshold value and the modulation method of the power conversion device 1 is three-phase modulation, the variable k calculator 721 calculates the variable k using calculation table 1. Fig. 8 is a diagram showing an example of calculation table 1 used by the variable k calculator 721 in the output voltage command value correction calculation unit 720 of the control unit 800 provided in the power conversion device 1 according to the first embodiment. Fig. 8(a) shows the load power P ｄｃ Calculation Table 1 shows the calculation of the effective value I ｒｍｓ 8( a) or 8(b) is used for case distinction. The variable k calculator 721 can calculate the variable k using either the calculation table 1 in FIG. 8( a) or 8(b), but here, the case where the calculation table 1 in FIG. 8( a) is used will be described as an example.

[0050] The variable k calculator 721 calculates the load power P based on the load information acquired from the load power calculation unit 711. ｄｃ is in the range of (a) or (b), based on the correction timing information acquired from the correction timing generation unit 713, α is (i) 0 or more and α １ If k is in the range less than k, the variable k is set to 1, and α is (ii) α １ The above range or (iv)-α １ If the variable k is in the range less than (iii)-α, the variable k is set to 0, and α is set to (iii)-α １ Similarly, when the load power Pdc based on the load information acquired from the load power calculation unit 711 is in the range of (c) or (d), the variable k calculator 721 calculates whether α is (i) 0 or more and α １ or (ii) α １ If it is within the above range, the variable k is set to 1, and α is (iii)-α １ or (iv) -α １If the current distortion factor THD is less than the threshold value and the modulation method of the power conversion device 1 is three-phase modulation, the variable k calculator 721 sets the variable k of the correction term γ to −1, 0, or 1, thereby improving the distortion of the power supply current and reducing power supply current harmonics.

[0051] As shown in FIG. 5, the output voltage command value correction calculation unit 720 calculates the variable k calculated by the variable k calculator 721 by multiplying the switching frequency f of the semiconductor elements 131 to 136 of the semiconductor module 130 included in the power conversion device 1. ｓｗ and then multiplying by the dead time T ｄ The output voltage command value correction calculation unit 720 outputs the calculated correction term γ to the modulated wave generator 570. As described above, the modulated wave generator 570 adds the correction term γ generated by the output voltage command value correction unit 700 to the modulated wave and outputs the result to the gate voltage command value generator 580. As a result, the control unit 800 calculates the output voltage command value V ｒｒｅｆ , V ｓｒｅｆ , V ｔｒｅｆ Since the modulation wave based on the above is corrected and the output voltage error is reduced, distortion of the power supply current is suppressed and power supply current harmonics can be reduced.

[0052] When using calculation table 1 in FIG. 8( b), the variable k calculator 721 can perform a similar calculation by using the range of (A) to (D) based on the input current information obtained from the current information calculator 712 instead of the range of (a) to (d) based on the load information obtained from the load power calculator 711.

[0053] Here, the effect obtained by introducing the correction term γ will be explained using simulation analysis results. FIG. 9 shows the results of a simulation analysis of the effect obtained by introducing the correction term γ into the power conversion device 1 according to the first embodiment using calculation table 1. FIG. 9( a) shows the state of the R-phase current IR when the output voltage command value correction calculation unit 720 is not present as a comparative example, and FIG. 9( b) shows the state of the R-phase current IR when the output voltage command value correction calculation unit 720 is present. As shown in FIG. 9, it can be seen that distortion near the current peak of the power supply current waveform is improved. Furthermore, when examining the harmonic current of the power supply current, it can be seen that the 11th, 17th, and 19th harmonic currents are significantly suppressed. When the output voltage error is large and the power supply current is distorted, the current value fluctuates rapidly near the peak value, as shown in FIG. 9( a). This can worsen the power supply current harmonics and potentially have adverse effects on connected electrical equipment.

[0054] In this embodiment, the power conversion device 1 appropriately sets the output voltage command value V under various conditions, such as when the load condition changes, when a disturbance occurs in the detected current or voltage, in addition to an ideal condition. ｒｒｅｆ , V ｓｒｅｆ , V ｔｒｅｆ Since the modulated wave based on the above can be corrected, it is possible to improve the power supply current harmonics. Note that the power conversion device 1 may be configured such that the AC power supply 110 is replaced with a motor load.

[0055] Next, a case where the variable k calculator 721 uses calculation table 2 will be described. When the current distortion factor THD is less than the threshold value and the modulation method of the power conversion device 1 is two-phase modulation, the variable k calculator 721 calculates the variable k using calculation table 2. Fig. 10 is a diagram showing an example of calculation table 2 used by the variable k calculator 721 in the output voltage command value correction calculation unit 720 of the control unit 800 provided in the power conversion device 1 according to the first embodiment. Fig. 10(a) shows the load power P ｄｃ Calculation Table 2 shows the calculation of the effective value I ｒｍｓ10(a) or 10(b) is used for case distinction. The variable k calculator 721 can calculate the variable k using either the calculation table 2 in FIG. 10(a) or 10(b), but here, the case where the calculation table 2 in FIG. 10(a) is used will be described as an example.

[0056] The variable k calculator 721 calculates the load power P based on the load information acquired from the load power calculation unit 711. ｄｃ is in the range of (a) or (b), based on the correction timing information acquired from the correction timing generation unit 713, α is (i) 0 or more and α １ or (ii) α １ If it is within the above range, the variable k is set to 1, and α is (iii)-α １ or (iv) -α １ If the load information is less than the load information, the variable k is set to -1. ｄｃ is in the range of (c) or (d), based on the correction timing information acquired from the correction timing generation unit 713, α is (i) 0 or more and α １ If k is in the range less than k, the variable k is set to 1, and α is (ii) α １ The above range or (iv)-α １ If the variable k is in the range less than (iii)-α, the variable k is set to 0, and α is set to (iii)-α １ If the current distortion factor THD is in the range of 0 or more, the variable k is set to -1. If the current distortion factor THD is less than the threshold value and the modulation method of the power conversion device 1 is two-phase modulation, the variable k calculator 721 sets the variable k of the correction term γ to -1, 0, or 1, thereby improving the distortion of the power supply current and reducing power supply current harmonics.

[0057] As shown in FIG. 5, the output voltage command value correction calculation unit 720 calculates the variable k calculated by the variable k calculator 721 by multiplying the switching frequency f of the semiconductor elements 131 to 136 of the semiconductor module 130 included in the power conversion device 1. ｓｗ and then multiplying by the dead time T ｄThe output voltage command value correction calculation unit 720 outputs the calculated correction term γ to the modulated wave generator 570. As described above, the modulated wave generator 570 adds the correction term γ generated by the output voltage command value correction unit 700 to the modulated wave and outputs the result to the gate voltage command value generator 580. As a result, the control unit 800 calculates the output voltage command value V ｒｒｅｆ , V ｓｒｅｆ , V ｔｒｅｆ Since the modulation wave based on the above is corrected and the output voltage error is reduced, distortion of the power supply current is suppressed and power supply current harmonics can be reduced.

[0058] When using calculation table 2 in FIG. 10( b), the variable k calculator 721 can perform a similar calculation by using the range of (A) to (D) based on the input current information obtained from the current information calculator 712 instead of the range of (a) to (d) based on the load information obtained from the load power calculator 711.

[0059] In this embodiment, the power conversion device 1 appropriately sets the output voltage command value V under various conditions, such as when the load condition changes, when a disturbance occurs in the detected current or voltage, in addition to an ideal condition. ｒｒｅｆ , V ｓｒｅｆ , V ｔｒｅｆ Since the modulated wave based on the above can be corrected, it is possible to improve the power supply current harmonics. Note that the power conversion device 1 may be configured such that the AC power supply 110 is replaced with a motor load.

[0060] Next, a case where the variable k calculator 721 uses the calculation table 3 will be described. When the current distortion factor THD is equal to or greater than the threshold value and the modulation method of the power conversion device 1 is three-phase modulation, the variable k calculator 721 calculates the variable k using the calculation table 3. Fig. 11 is a diagram showing an example of the calculation table 3 used by the variable k calculator 721 in the output voltage command value correction calculation unit 720 of the control unit 800 provided in the power conversion device 1 according to the first embodiment. Fig. 11(a) shows the load power P ｄｃ Calculation Table 3 shows the calculation of the effective value I ｒｍｓ11(a) or 11(b) is used for case distinction. The variable k calculator 721 can calculate the variable k using either the calculation table 3 in FIG. 11(a) or 11(b), but here, the case where the calculation table 3 in FIG. 11(a) is used will be described as an example.

[0061] The variable k calculator 721 calculates the load power P based on the load information acquired from the load power calculation unit 711. ｄｃ is in the range (a), based on the correction timing information acquired from the correction timing generation unit 713, α is (i) 0 or more, １ If the variable k is in the range less than α, the variable k is set to 1, and α is (ii) α １ The above range or (iv)-α １ If the variable k is in the range less than (iii)-α, the variable k is set to 0, and α is set to (iii)-α １ If the variable k is in the range of 0 or more and less than 0, the variable k is set to -1. Similarly, the variable k calculator 721 calculates the load power P ｄｃ is in the range of (b), (c), or (d), based on the correction timing information acquired from the correction timing generation unit 713, α is (i) 0 or more and α １ If the variable k is in the range less than α, the variable k is set to 1, and α is (ii) α １ If the variable k is within the above range, the variable k is expressed by the formula (6). １ and α is (iii)-α １ If the variable k is in the range of (iv) to (0), the variable k is set to -1, and α is set to (iv) - α １ If the variable k is in the range less than ２ Let's say.

[0062]

[0063]

[0064] In formulas (6) and (7), P ｄｃ is the load power, and V ｄｃｒｅｆ is the DC bus voltage command value, and P ｄｃｒａｔｅis the rated output power of the power conversion device 1. When the current distortion factor THD is equal to or greater than the threshold value and the modulation method of the power conversion device 1 is three-phase modulation, the variable k calculator 721 sets the variable k of the correction term γ to −1, 0, 1, or k １ or k ２ By doing so, it is possible to improve the distortion of the power supply current and reduce the power supply current harmonics.

[0065] As shown in FIG. 5, the output voltage command value correction calculation unit 720 calculates the variable k calculated by the variable k calculator 721 by multiplying the switching frequency f of the semiconductor elements 131 to 136 of the semiconductor module 130 included in the power conversion device 1. ｓｗ and then multiplying by the dead time T ｄ The output voltage command value correction calculation unit 720 outputs the calculated correction term γ to the modulated wave generator 570. As described above, the modulated wave generator 570 adds the correction term γ generated by the output voltage command value correction unit 700 to the modulated wave and outputs the result to the gate voltage command value generator 580. As a result, the control unit 800 calculates the output voltage command value V ｒｒｅｆ , V ｓｒｅｆ , V ｔｒｅｆ Since the modulation wave based on the above is corrected and the output voltage error is reduced, distortion of the power supply current is suppressed and power supply current harmonics can be reduced.

[0066] When using calculation table 3 in FIG. 11( b), the variable k calculator 721 can perform a similar calculation by using the range of (A) to (D) based on the input current information obtained from the current information calculator 712 instead of the range of (a) to (d) based on the load information obtained from the load power calculator 711.

[0067] Here, the effect obtained by introducing the correction term γ will be explained using the results of simulation analysis. Fig. 12 is a diagram showing the results of simulation analysis of the effect obtained by introducing the correction term γ into the power conversion device 1 according to the first embodiment using the calculation table 3. Fig. 12(a) shows the distribution of harmonic currents in a comparative example in the case where the output voltage command value correction calculation unit 720 is not provided, and Fig. 12(b) shows the distribution of harmonic currents in the case where the output voltage command value correction calculation unit 720 is provided. Note that Fig. 12(b) shows the distribution of harmonic currents in the case where the load power Pｄｃ This shows the effect obtained by the calculation formula for variable k when the variable k is in the region (c). １ satisfies equation (6), and the variable k ２ satisfies equation (7), and the variable k １ = 3, and variable k ２ = -3. As shown in Fig. 12, it can be confirmed that the harmonic current of the power supply current is reduced overall.

[0068] In this embodiment, the power conversion device 1 appropriately sets the output voltage command value V under various conditions, such as when the load condition changes, when a disturbance occurs in the detected current or voltage, in addition to an ideal condition. ｒｒｅｆ , V ｓｒｅｆ , V ｔｒｅｆ Since the modulated wave based on the above can be corrected, it is possible to improve the power supply current harmonics. Note that the power conversion device 1 may be configured such that the AC power supply 110 is replaced with a motor load.

[0069] Next, a case where the variable k calculator 721 uses calculation table 4 will be described. When the current distortion factor THD is equal to or greater than a threshold value and the modulation method of the power conversion device 1 is two-phase modulation, the variable k calculator 721 calculates the variable k using calculation table 4. Fig. 13 is a diagram showing an example of calculation table 4 used by the variable k calculator 721 in the output voltage command value correction calculation unit 720 of the control unit 800 provided in the power conversion device 1 according to the first embodiment. Fig. 13(a) shows the load power P ｄｃ Calculation Table 4 shows the calculation of the effective value I ｒｍｓ 13(a) or 13(b) is used for case distinction. The variable k calculator 721 can calculate the variable k using either the calculation table 4 in FIG. 13(a) or 13(b), but here, the case where the calculation table 4 in FIG. 13(a) is used will be described as an example.

[0070] The variable k calculator 721 calculates the load power P based on the load information acquired from the load power calculation unit 711. ｄｃ is in the range (a), based on the correction timing information acquired from the correction timing generation unit 713, α is (i) 0 or more, １ If the variable k is in the range less than α, the variable k is set to 1, and α is (ii) α１ The above range or (iv)-α １ If the variable k is in the range less than (iii)-α, the variable k is set to 0, and α is set to (iii)-α １ If the variable k is in the range of 0 or more and less than 0, the variable k is set to -1. Similarly, the variable k calculator 721 calculates the load power P ｄｃ is in the range of (b), (c), or (d), based on the correction timing information acquired from the correction timing generation unit 713, α is (i) 0 or more and α １ If k is in the range less than k, the variable k is set to 1, and α is (ii) α １ If the variable k is a specified real number a, and α is (iii)-α １ If the variable k is in the range of (iv) to (0), the variable k is set to -1, and α is set to (iv) - α １ If the variable k is in the range less than b, the variable k is set to the specified real number b.

[0071] Furthermore, the load power P ｄｃ In each case, regardless of the value of , the current controller 540 of the high power factor control unit 500 includes a current deviation superimposing unit 541, as shown in Fig. 14. Fig. 14 is a second diagram showing a configuration example of the high power factor control unit 500 in the control unit 800 included in the power conversion device 1 according to the first embodiment. The high power factor control unit 500 shown in Fig. 14 is different from the high power factor control unit 500 shown in Fig. 2 in that a current deviation superimposing unit 541 is added to the current controller 540. The current deviation superimposing unit 541 superimposes a d-axis current command value I ｄｒｅｆ From d-axis current I ｄ d-axis current deviation I ｄ＿ｄｉｆｆ , a real number A defined as shown in equation (8) ｍ The current controller 540 multiplies the value obtained by the multiplication of equation (8) by the d-axis voltage command value V ｄｒｅｆ and outputs the result to the dq-three-phase converter 560. Similarly, the current deviation superimposing unit 541 adds the q-axis current command value I ｑｒｅｆ From the q-axis current I ｑ The q-axis current deviation I ｑ＿ｄｉｆｆ , a real number A defined as shown in equation (9) ｍ The current controller 540 multiplies the value obtained by the multiplication of equation (9) by the q-axis voltage command value V ｑｒｅｆand output to the dq-three-phase converter 560.

[0072]

[0073]

[0074] 14, the current controller 540 is configured so that the path of the current deviation superimposing unit 541 is always established, but this is not limiting. The current controller 540 may include, for example, a switch on the three-phase-dq converter 520 side or the dq-three-phase converter 560 side of the current deviation superimposing unit 541, and control the switch according to a calculation table used in the output voltage command value corrector 700 to enable or disable the path of the current deviation superimposing unit 541. Specifically, when calculation table 1, calculation table 2, or calculation table 3 is used in the output voltage command value corrector 700, the current controller 540 controls the switch to disable the path of the current deviation superimposing unit 541, and ｍ ×I ｄ＿ｄｉｆｆ and A ｍ ×I ｑ＿ｄｉｆｆ When the calculation table 4 is used in the output voltage command value correction unit 700, the current controller 540 controls the switch to enable the path of the current deviation superimposing unit 541, and prevents A ｍ ×I ｄ＿ｄｉｆｆ and A ｍ ×I ｑ＿ｄｉｆｆ to be utilized.

[0075] In the control unit 800, when the current distortion factor THD is equal to or greater than the threshold value and the modulation method of the power conversion device 1 is two-phase modulation, the variable k calculator 721 sets the variable k of the correction term γ to −1, 0, 1, real number a, or real number b. Furthermore, the current controller 540 of the high power factor control unit 500 calculates the d-axis voltage command value V ｄｒｅｆ A ｍ ×I ｄ＿ｄｉｆｆ and the q-axis voltage command value V ｑｒｅｆ A ｍ ×I ｑ＿ｄｉｆｆ By adding the above, the distortion of the power supply current can be improved and the power supply current harmonics can be reduced.

[0076] As shown in FIG. 5, the output voltage command value correction calculation unit 720 calculates the variable k calculated by the variable k calculator 721 by multiplying the switching frequency f of the semiconductor elements 131 to 136 of the semiconductor module 130 included in the power conversion device 1. ｓｗ and then multiplying by the dead time T ｄ The output voltage command value correction calculation unit 720 outputs the calculated correction term γ to the modulated wave generator 570. As described above, the modulated wave generator 570 adds the correction term γ generated by the output voltage command value correction unit 700 to the modulated wave and outputs the result to the gate voltage command value generator 580. As a result, the control unit 800 calculates the output voltage command value V ｒｒｅｆ , V ｓｒｅｆ , V ｔｒｅｆ Since the modulation wave based on the above is corrected and the output voltage error is reduced, distortion of the power supply current is suppressed and power supply current harmonics can be reduced.

[0077] When using calculation table 4 in FIG. 13(b), the variable k calculator 721 can perform a similar calculation by using the range of (A) to (D) based on the input current information obtained from the current information calculator 712 instead of the range of (a) to (d) based on the load information obtained from the load power calculator 711.

[0078] Here, the effect obtained by introducing the correction term γ will be explained using the results of simulation analysis. Fig. 15 is a diagram showing the results of simulation analysis of the effect obtained by introducing the correction term γ into the power conversion device 1 according to the first embodiment using the calculation table 4. Fig. 15(a) shows the distribution of harmonic currents in a comparative example in the case where the output voltage command value correction calculation unit 720 is not provided, and Fig. 15(b) shows the distribution of harmonic currents in the case where the output voltage command value correction calculation unit 720 is provided. Note that Fig. 15(b) shows the distribution of harmonic currents in the case where the load power P ｄｃ This shows the effect obtained by the calculation formula for the variable k when the area is (c). ｍ satisfies the formula (8) and the formula (9), and A ｍ = 10. Also, real number a = 2 and real number b = -2. As shown in Fig. 15, it can be confirmed that the harmonic current of the power supply current has been reduced overall, with the distortion around the current peak being improved.

[0079] In this embodiment, the power conversion device 1 appropriately sets the output voltage command value V ｒｒｅｆ , V ｓｒｅｆ , V ｔｒｅｆ Since the modulated wave based on the above can be corrected, it is possible to improve the power supply current harmonics. Note that the power conversion device 1 may be configured such that the AC power supply 110 is replaced with a motor load.

[0080] In this way, the output voltage command value correction calculation unit 720 selects a calculation table to be used for calculating the variable k using the load information, input current information, correction timing information, and modulation method information, calculates the variable k, and calculates the switching frequency f of the semiconductor elements 131 to 136. ｓｗ and a dead time T set for the operation of the semiconductor elements 131 to 136. ｄ The output voltage command value correction calculation unit 720 selects a calculation table depending on the combination of whether the current distortion factor THD included in the input current information is less than or equal to a specified threshold value, and whether the modulation method indicated by the modulation method information is three-phase modulation or two-phase modulation. In addition, the output voltage command value correction calculation unit 720 selects calculation table 4 corresponding to the combination of the current distortion factor THD being equal to or greater than a threshold value and the modulation method being two-phase modulation. In this case, the high power factor control unit 500 calculates the d-axis voltage command value V ｄｒｅｆ d-axis current deviation I ｄ＿ｄｉｆｆ A real number A is a coefficient defined in ｍ The q-axis voltage command value V of the current control system is calculated by adding the multiplied value V ｑｒｅｆ q-axis current deviation I ｑ＿ｄｉｆｆ A real number A is a coefficient defined in ｍ The output voltage command value V ｒｒｅｆ , V ｓｒｅｆ , V ｔｒｅｆ Generate.

[0081] 16 is a flowchart showing the operation of the power conversion device 1 according to the first embodiment. In the power conversion device 1, the current / voltage detection unit 400 detects the current and voltage that indicate the operating states of the power supply unit 100 and the smoothing unit 200 (step S1). The high power factor control unit 500 calculates the output voltage command value V ｒｒｅｆ , V ｓｒｅｆ , V ｔｒｅｆ (Step S2). The high power factor control unit 500 generates the output voltage command value V ｒｒｅｆ , V ｓｒｅｆ , V ｔｒｅｆ (Step S3). The output voltage command value corrector 700 generates a correction term γ using the current and voltage detected by the current / voltage detector 400 and the parameter m used by the high power factor controller 500 when generating the modulated wave (Step S4). The high power factor controller 500 uses the correction term γ to correct the output voltage command value V ｒｒｅｆ , V ｓｒｅｆ , V ｔｒｅｆ The high power factor control unit 500 compares the modulated wave with a triangular wave carrier, which is a carrier signal, and generates a gate voltage command value 600 to be applied to the semiconductor elements 131 to 136 (step S6).

[0082] Next, a description will be given of the hardware configuration of the control unit 800 included in the power conversion device 1. Fig. 17 is a diagram showing an example of a hardware configuration that realizes the control unit 800 included in the power conversion device 1 according to embodiment 1. The control unit 800 is realized by a processor 801 and a memory 802.

[0083] The processor 801 is a CPU (Central Processing Unit, also called a central processing unit, processing unit, arithmetic unit, microprocessor, microcomputer, processor, or DSP (Digital Signal Processor)) or a system LSI (Large Scale Integration). Examples of memory 802 include non-volatile or volatile semiconductor memories such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), and EEPROM (Electrically Erasable Programmable Read Only Memory). Memory 802 is not limited to these, and may also be a magnetic disk, optical disk, compact disk, minidisc, or DVD (Digital Versatile Disc).

[0084] As described above, according to this embodiment, in the power conversion device 1, the control unit 800 calculates the output voltage command value V ｒｒｅｆ , V ｓｒｅｆ , V ｔｒｅｆ and generates a gate voltage command value 600 based on the result of comparing the modulated wave with a triangular wave carrier, which is a carrier signal, and an output voltage command value corrector 700 that generates a correction term γ using the value detected by the current / voltage detector 400 and a value m that is a parameter used by the high power factor controller 500 when generating the modulated wave. ｒｒｅｆ , V ｓｒｅｆ , V ｔｒｅｆ As a result, the power conversion device 1 corrects the modulated wave based on the dead time T ｄ The output voltage error can be suppressed when the dead time T ｄ It is possible to reduce power supply current harmonics caused by

[0085] Second Embodiment. Fig. 18 is a diagram showing a configuration example of a refrigeration cycle-applied device 900 according to a second embodiment. The refrigeration cycle-applied device 900 according to the second embodiment includes the power conversion device 1 described in the first embodiment. The refrigeration cycle-applied device 900 according to the second embodiment can be applied to products equipped with a refrigeration cycle, such as air conditioners, refrigerators, freezers, and heat pump water heaters. In Fig. 18, components having the same functions as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment. In Fig. 1 and other figures, the load unit 300 included in the power conversion device 1 is considered to include a motor load. However, in Fig. 18, the motor 916, which is the motor load, is located outside the power conversion device 1 due to the configuration in which the compressor 914 includes the motor 916.

[0086] The refrigeration cycle applied device 900 includes a compressor 914 , a four-way valve 902 , an indoor heat exchanger 906 , an expansion valve 908 , and an outdoor heat exchanger 910 attached via refrigerant piping 912 .

[0087] Inside the compressor 914, a compression mechanism 904 that compresses the refrigerant and a motor 916 that operates the compression mechanism 904 are provided.

[0088] The refrigeration cycle device 900 can perform heating or cooling operation by switching the four-way valve 902. The compression mechanism 904 is driven by a motor 916 that is variably controlled in speed.

[0089] During heating operation, as shown by the solid arrow, the refrigerant is pressurized by the compression mechanism 904 and sent out, passes through the four-way valve 902, the indoor heat exchanger 906, the expansion valve 908, the outdoor heat exchanger 910 and the four-way valve 902 and returns to the compression mechanism 904.

[0090] During cooling operation, as shown by the dashed arrow, the refrigerant is pressurized by the compression mechanism 904 and sent out, and returns to the compression mechanism 904 through the four-way valve 902, the outdoor heat exchanger 910, the expansion valve 908, the indoor heat exchanger 906 and the four-way valve 902.

[0091] During heating operation, the indoor heat exchanger 906 acts as a condenser to release heat, and the outdoor heat exchanger 910 acts as an evaporator to absorb heat. During cooling operation, the outdoor heat exchanger 910 acts as a condenser to release heat, and the indoor heat exchanger 906 acts as an evaporator to absorb heat. The expansion valve 908 reduces the pressure of the refrigerant to expand it.

[0092] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or different embodiments may be combined with each other. It is also possible to omit or modify parts of the configurations as long as they do not deviate from the gist of the invention.

[0093] 1 Power conversion device, 100 Power supply unit, 110 AC power supply, 120 Reactor, 130 Semiconductor module, 131 to 136 Semiconductor elements, 200 Smoothing unit, 210 Electrolytic capacitor, 300 Load unit, 400 Current voltage detection unit, 410 to 412 Voltage sensors, 420 to 422 Current sensors, 500 High power factor control unit, 510 Three-phase AC current voltage calculator, 520 Three-phase-dq converter, 530 Phase locked loop PLL, 540 Current controller, 541 Current deviation superposition unit, 550 Voltage controller, 560 dq-three-phase converter, 570 Modulated wave generator, 571 m-value calculator, 580 Gate voltage command value generator, 581 Carrier comparator, 582 Dead time generator, 600 Gate voltage command value, 700 Output voltage command value correction unit, 710 Case classification calculation unit, 711 load power calculation unit, 712 current information calculation unit, 713 correction timing generation unit, 714 modulation method estimation unit, 720 output voltage command value correction calculation unit, 721 variable k calculator, 800 control unit, 801 processor, 802 memory, 900 refrigeration cycle applied equipment, 902 four-way valve, 904 compression mechanism, 906 indoor heat exchanger, 908 expansion valve, 910 outdoor heat exchanger, 912 refrigerant piping, 914 compressor, 916 motor.

Claims

1. a power supply unit that converts AC power into DC power using a semiconductor element; a smoothing unit that smoothes the DC power; a current / voltage detection unit that detects a current and a voltage that indicate the operating state of the power supply unit and the smoothing unit; a control unit that generates a gate voltage command value for controlling an operation of the semiconductor element using the current and voltage detection values ​​detected by the current / voltage detection unit; Equipped with the control unit generates a modulated wave based on an output voltage command value using the detection value, and generates the gate voltage command value based on a result of comparing the modulated wave with a carrier signal; and an output voltage command value correction unit generates a correction term using the detection value and parameters used when generating the modulated wave, and the power conversion device corrects the modulated wave using the correction term, The output voltage command value correction unit a case-by-case calculation unit that generates load information indicating a current load power state of the power conversion device, input current information indicating a current effective current state of the power conversion device, correction timing information based on a ratio of the voltage or output voltage command value to a DC bus voltage command value, and modulation method information including a result of estimating a modulation method of the power conversion device; an output voltage command value correction calculation unit that uses the load information, the input current information, the correction timing information, and the modulation method information to select a calculation table to be used for calculating variables, calculates the variables, and multiplies the variables by a switching frequency of the semiconductor element and a dead time set for operation of the semiconductor element to generate the correction term; A power conversion device comprising:

2. the output voltage command value correction calculation unit selects the calculation table depending on a combination of whether a current distortion rate included in the input current information is less than a specified threshold value or greater than or equal to the threshold value, and whether the modulation method indicated by the modulation method information is three-phase modulation or two-phase modulation. The power conversion device according to claim 1 .

3. the output voltage command value correction calculation unit selects the calculation table corresponding to a combination in which the current distortion rate is equal to or greater than the threshold value and the modulation method is the two-phase modulation, the high power factor control unit adds a value obtained by multiplying a d-axis current deviation by a coefficient specified for the d-axis voltage command value of a current control system, and adds a value obtained by multiplying a q-axis current deviation by a coefficient specified for the q-axis voltage command value of a current control system, to generate the output voltage command value. The power conversion device according to claim 2 .

4. The case classification calculation unit a load power calculation unit that calculates the load power by multiplying the DC bus voltage and DC bus current detected by the current / voltage detection unit, calculates a maximum output power from the load power, and divides a region based on the maximum output power into specified ranges to generate the load information indicating in which range the load power exists; The power conversion device according to claim 1 .

5. The case classification calculation unit a current information calculation unit that calculates an effective value of the power supply current from the power supply current detected by the current / voltage detection unit, calculates a current distortion rate based on the effective value of the power supply current, and generates the input current information including magnitude relation information indicating whether the current distortion rate is larger or smaller than a specified threshold value; The power conversion device according to claim 1 .

6. The case classification calculation unit a correction timing generation unit that generates the correction timing information indicating in which range, divided into specified ranges, the ratio of the voltage or output voltage command value to a DC bus voltage command value exists; The power conversion device according to claim 1 .

7. The parameter is m, values ​​obtained in the process of generating the gate voltage command value by the high power factor control unit are output current command values ​​A rref , A sref , A tref , maxmin1 is 1 or 0, maxmin2 is 1 or 0, max is the maximum value of the output current command values ​​A rref , A sref , A tref , and min is the minimum value of the output current command values ​​A rref , A sref , A tref , The case classification calculation unit a modulation scheme estimation unit that estimates that the modulation scheme of the power conversion device is three-phase modulation when the parameters are calculated using the following equations (1) to (3), and estimates that the modulation scheme of the power conversion device is two-phase modulation when the parameters are calculated using the following equation (4), and generates the modulation scheme information indicating the estimation result; The power conversion device according to claim 1 . [Equation 1] [Equation 2] [Equation 3] [Equation 4]

8. A refrigeration cycle device comprising the power conversion device according to any one of claims 1 to 7.

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