JP7235531B2 - Converter device, processing method and program - Google Patents

Description

The present invention relates to a converter device, processing method and program.

Converter devices are used in various fields. Patent Literature 1 describes a technique for applying a converter device to an air conditioner to achieve downsizing and simplification of the device.

JP 2014-150622 A

By the way, if an abnormality such as a sudden change in phase occurs in the power supplied to the converter device, an overcurrent may flow and the converter device may malfunction.

Therefore, there is a demand for a technique that allows the converter device to continue operating even when an abnormality occurs in the power supplied to the converter device.

An object of the present invention is to provide a converter device, a processing method, and a program that can solve the above problems.

According to the first aspect of the present invention, a converter device uses a waveform detection section that detects a voltage waveform of a power supply voltage to be supplied, and a peak value of the power supply voltage in a period equal to or longer than a predetermined cycle of the power supply voltage. A voltage for calculating a voltage command using a normalization processing unit that normalizes the power supply voltage and a correction value based on a difference between the voltage normalized by the normalization processing unit and an ideal voltage of the power supply voltage and a command calculator .

According to a second aspect of the present invention, the converter device according to the first aspect includes: a component specifying unit that specifies an in-phase component and a quadrature component of the voltage waveform; and based on the in-phase component and the quadrature component, the A phase difference calculator for calculating a phase difference between the estimated phase of the power supply voltage and the actual phase of the power supply voltage.

According to a third aspect of the present invention, the converter device according to the second aspect may include a phase control section that controls the estimated phase of the power supply voltage based on the phase difference.

According to a fourth aspect of the present invention, in the converter device according to any one of the first aspect to the third aspect, when the normalization processing unit passes the peak value through a low-pass filter, The power supply voltage may be normalized by the value output by the low-pass filter .

According to a fifth aspect of the present invention, in the converter device according to any one of the first aspect to the fourth aspect, the voltage command calculator may calculate the power supply voltage normalized by the normalization processor. The range that the voltage command can take may be restricted by the reciprocal of the upper limit of the boost ratio based on .

According to a sixth aspect of the present invention, a processing method by a converter device includes detecting a voltage waveform of a supplied power supply voltage, and using a peak value of the power supply voltage in a period equal to or longer than a predetermined cycle of the power supply voltage. and calculating a voltage command using a correction value based on the difference between the normalized voltage and the ideal voltage of the power supply voltage.

According to a seventh aspect of the present invention, the program causes the computer of the converter device to:
detecting a voltage waveform of a supplied power supply voltage; normalizing the power supply voltage using a peak value of the power supply voltage in a period equal to or longer than a predetermined period of the power supply voltage; and voltage after normalization. and calculating a voltage command using a correction value based on the difference between the power supply voltage and the ideal voltage.

According to the converter device, the processing method, and the program according to the embodiments of the present invention, the operation of the converter device can be continued even when an abnormality occurs in the power supplied to the converter device.

1 is a diagram showing the configuration of a motor drive device according to a first embodiment of the present invention; FIG. It is a figure which shows the structure of the converter control part by 1st Embodiment of this invention. It is a figure which shows the processing flow of the converter apparatus by 1st Embodiment of this invention. It is a figure which shows the simulation result in 1st Embodiment of this invention. It is a figure which shows the structure of the motor drive device by 2nd Embodiment of this invention. It is a figure which shows the structure of the converter control part by 2nd Embodiment of this invention. FIG. 9 is a diagram for explaining generation of control signals in the second embodiment of the present invention; It is a figure which shows the processing flow of the converter apparatus by 2nd Embodiment of this invention. FIG. 11 is a first diagram showing simulation results in the second embodiment of the present invention; FIG. 11 is a second diagram showing simulation results in the second embodiment of the present invention; 1 is a schematic block diagram showing a configuration of a computer according to at least one embodiment; FIG.

<First embodiment>
Hereinafter, embodiments will be described in detail with reference to the drawings.
A motor drive device according to a first embodiment of the present invention will be described.
FIG. 1 is a diagram showing the configuration of a motor drive device 1 according to a first embodiment of the present invention. The motor drive device 1 is a device that converts AC power from an AC power supply 4 into DC power, converts the DC power into three-phase AC power, and outputs the three-phase AC power to a compressor motor 20 . The motor drive device 1 includes a converter device 2 and an inverter device 3, as shown in FIG.

The converter device 2 is a device that converts AC power from the AC power supply 4 into DC power and outputs the DC power to the inverter device 3 . Converter device 2 includes rectifier circuit 5 , switching circuit 10 a , switching circuit 10 b , smoothing capacitor 12 , converter control section 15 , and voltage detection section 17 .
The rectifier circuit 5 includes an input terminal, an input-side reference terminal, an output terminal, and an output-side reference terminal. The potential of the reference terminal on the input side is a potential that serves as a reference for the potential of the input terminal. The potential of the reference terminal on the output side is a potential that serves as a reference for the potential of the output terminal. The rectifier circuit 5 converts the AC power input from the AC power supply 4 into DC power, and outputs the DC power to the switching circuits 10a and 10b.

The switching circuit 10 a causes current to flow through the smoothing capacitor 12 and generates a voltage to be input to the inverter device 3 . The switching circuit 10a includes a reactor 6a, a diode 7a, and a switching element 8a.

The reactor 6a includes a first terminal and a second terminal.
The diode 7a has an anode terminal and a cathode terminal.
The switching element 8a has a first terminal, a second terminal, and a third terminal. The switching element 8a switches between an on-state period and an off-state period according to a signal received by the first terminal, thereby controlling the current flowing from the second terminal to the third terminal. Change the value of the current that flows. Examples of the switching element 8a include a field effect transistor (FET), an IGBT (Insulated Gate Bipolar Transistor), and the like. When the switching element 8a is, for example, an nMOS transistor, the first terminal of the switching element 8a is the gate terminal, the second terminal is the source terminal, and the third terminal is the drain terminal.

Similar to the switching circuit 10a, the switching circuit 10b causes current to flow through the smoothing capacitor 12 and generates a voltage to be input to the inverter device 3. FIG. The switching circuit 10b includes a reactor 6b, a diode 7b, and a switching element 8b.

The reactor 6b has a first terminal and a second terminal.
The diode 7b has an anode terminal and a cathode terminal.
The switching element 8b, like the switching element 8a, has a first terminal, a second terminal, and a third terminal. The switching element 8b switches between an on-state period and an off-state period in accordance with a signal received by the first terminal, thereby controlling the current flowing from the second terminal to the third terminal. Change the value of the current that flows. A field effect transistor, an IGBT, or the like can be used as the switching element 8b. When the switching element 8b is, for example, an nMOS transistor, the first terminal of the switching element 8b is the gate terminal, the second terminal is the source terminal, and the third terminal is the drain terminal.

The smoothing capacitor 12 has a first terminal and a second terminal. Smoothing capacitor 12 receives current from both switching circuit 10a and switching circuit 10b. That is, the voltage input to the inverter device 3 is determined by the sum of current values flowing through the smoothing capacitor 12 from both the switching circuits 10a and 10b.

The voltage detector 17 has a first input terminal, a second input terminal, and an output terminal. The voltage detection unit 17 detects an input voltage that the AC power supply 4 inputs to the rectifier circuit 5 . Voltage detection unit 17 provides information on the detected input voltage to converter control unit 15 .

Converter control unit 15 includes a first input terminal, a first output terminal, and a second output terminal. Converter control unit 15 receives input voltage information from voltage detection unit 17 via the first input terminal and observes the input voltage waveform. The converter control section 15 controls the switching circuit 10a via the first output terminal. Also, the converter control unit 15 controls 10b through the second output terminal.

The AC power supply 4 has an output terminal and a reference terminal. AC power supply 4 supplies AC power to converter device 2 .

The inverter device 3 is a device that converts the DC power output from the converter device 2 into three-phase AC power and outputs the three-phase AC power to the compressor motor 20 . The inverter device 3 includes a bridge circuit 18 and an inverter control section 19 .

The bridge circuit 18, as shown in FIG. 1, has an input terminal, a first output terminal, a second output terminal, a third output terminal, and a reference terminal. The potential of the reference terminal is a potential that serves as a reference for the potentials of the input terminal, the first output terminal, the second output terminal, and the third output terminal. The bridge circuit 18 includes switching elements 181 , 182 , 183 , 184 , 185 and 186 . The bridge circuit 18 is configured by pairs of switching elements 181 and 182, switching elements 183 and 184, and switching elements 185 and 186, respectively. Each of the switching elements 181-186 has a first terminal, a second terminal and a third terminal. Each of the switching elements 181 to 186 controls the current flowing from the second terminal to the third terminal by switching between the ON state period and the OFF state period according to the signal received by the first terminal, Three-phase AC power for driving the compressor motor 20 is generated, and the generated three-phase AC power is output to the compressor motor 20 . Examples of the switching elements 181, 182, 183, 184, 185, 186 include power field effect transistors, IGBTs, and the like.

The inverter control unit 19 has a first output terminal, a second output terminal, a third output terminal, a fourth output terminal, a fifth output terminal, and a sixth output terminal. A first output terminal of the inverter control unit 19 is a terminal for outputting to the first terminal of the switching element 181 a gate drive signal for switching between the ON state period and the OFF state period of the switching element 181 . The second output terminal of the inverter control unit 19 is a terminal for outputting to the first terminal of the switching element 182 a gate drive signal for switching between the ON state period and the OFF state period of the switching element 182 . A third output terminal of the inverter control unit 19 is a terminal for outputting to a first terminal of the switching element 183 a gate drive signal for switching between the ON state period and the OFF state period of the switching element 183 . A fourth output terminal of the inverter control unit 19 is a terminal for outputting to the first terminal of the switching element 184 a gate drive signal for switching between the ON state period and the OFF state period of the switching element 184 . A fifth output terminal of the inverter control unit 19 is a terminal for outputting to a first terminal of the switching element 185 a gate driving signal for switching between the ON state period and the OFF state period of the switching element 185 . A sixth output terminal of the inverter control unit 19 is a terminal for outputting to a first terminal of the switching element 186 a gate drive signal for switching between the ON state period and the OFF state period of the switching element 186 . 1, the first to sixth output terminals of the inverter control section 19 are omitted. In FIG. 1, the gate drive signals output from the first to sixth output terminals of the inverter control section 19 to the bridge circuit 18 are collectively indicated as the gate drive signal Spwm. The inverter control unit 19 controls opening and closing of switching elements in the bridge circuit 18 . The inverter control unit 19 generates a gate drive signal Spwm for the switching elements 181 to 186 based on, for example, a required rotational speed command input from a host device (not shown). The inverter control section 19 supplies the gate drive signal Spwm to the bridge circuit 18 through the first to sixth output terminals. Examples of specific methods of inverter control include vector control, sensorless vector control, V/F (Variable Frequency) control, overmodulation control, and one-pulse control.

An input terminal of the rectifier circuit 5 is connected to an output terminal of the AC power supply 4 and a first input terminal of the voltage detector 17 . A reference terminal on the input side of the rectifier circuit 5 is connected to the reference terminal of the AC power supply 4 and the second input terminal of the voltage detector 17 . An output terminal of the rectifier circuit 5 is connected to a first terminal of the reactor 6a and a first terminal of the reactor 6b. Reference terminals on the output side of the rectifier circuit 5 are the third terminal of the switching element 8a, the third terminal of the switching element 8b, the second terminal of the smoothing capacitor 12, and the reference terminals of the inverter device 3 (switching elements 182 and 184). , 186).

A second terminal of the reactor 6a is connected to the anode terminal of the diode 7a and the second terminal of the switching element 8a. A second terminal of reactor 6b is connected to an anode terminal of diode 7b and a second terminal of switching element 8b.
The cathode terminal of diode 7a is connected to the cathode terminal of diode 7b, the first terminal of smoothing capacitor 12, and the input terminal of inverter device 3 (the second terminals of switching elements 181, 183, and 185).
A first terminal of switching element 8 a is connected to a first output terminal of converter control section 15 . A first terminal of switching element 8 b is connected to a second output terminal of converter control section 15 .

A first terminal of converter control unit 15 is connected to an output terminal of voltage detection unit 17 .
A first terminal of the switching element 181 is connected to a first output terminal of the inverter control section 19 . A first terminal of the switching element 182 is connected to a second output terminal of the inverter control section 19 . A first terminal of the switching element 183 is connected to a third output terminal of the inverter control section 19 . A first terminal of the switching element 184 is connected to a fourth output terminal of the inverter control section 19 . A first terminal of the switching element 185 is connected to a fifth output terminal of the inverter control section 19 . A first terminal of the switching element 186 is connected to a sixth output terminal of the inverter control section 19 .

The third terminal of switching element 181 is connected to the second terminal of switching element 182 and the first terminal of compressor motor 20 . The third terminal of switching element 183 is connected to the second terminal of switching element 184 and the second terminal of compressor motor 20 . The third terminal of switching element 185 is connected to the second terminal of switching element 186 and the first terminal of compressor motor 20 .

When the inverter control unit 19 controls opening and closing of the switching elements in the bridge circuit 18 as described above, a DC voltage detection unit and a motor current detection unit are provided as described in Patent Document 1. may be
The DC voltage detector is a detector that detects the input DC voltage Vdc of the bridge circuit 18 .
The motor current detector is a detector that detects phase currents iu, iv, and iw flowing through the compressor motor 20 . The motor current detector inputs these detected values Vdc, iu, iv, and iw to the inverter controller 19 . The motor current detector may detect the current flowing in the negative power line between the bridge circuit 18 and the smoothing capacitor 12 and obtain the phase currents iu, iv, and iw from this detection signal.

FIG. 2 is a functional block diagram of converter control section 15. As shown in FIG.
The converter control unit 15 includes a waveform detection unit 21, a component identification unit 22, a phase difference calculation unit 23, a control signal generation unit 24 (an example of a phase control unit), and a storage unit 25, as shown in FIG.

Waveform detector 21 detects a voltage waveform of AC power supply 4 (an example of power supply voltage). Waveform detection section 21 outputs the detected voltage waveform to component identification section 22 .

The component identification unit 22 identifies the in-phase component and the quadrature component of the voltage waveform of the AC power supply 4 .
For example, let the actual voltage waveform of the AC power supply 4 be vin, and let it be represented by Equation (1).

Here, in equation (1), Va is the amplitude of the power supply voltage. Also, θreal is the phase of the power supply voltage.
The component identifying unit 22 identifies the in-phase component vq and the quadrature component vd of the fundamental wave component in the voltage waveform of the AC power supply 4 by, for example, performing a primary Fourier transform on the voltage waveform vin. Specifically, the component identifying unit 22 determines the in-phase component vq and the quadrature component vd of the voltage waveform of the AC power supply 4 at predetermined timings (for example, every phase π, every phase 2π, all the time, etc.) using formula (2) Identify using

where θ is the current phase being estimated. The formula (2) shown here is a formula for calculating the in-phase component vq and the quadrature component vd within the past 2π range. If the quadrature component vd calculated using equation (2) is zero, the quadrature component vd does not exist. That is, if the quadrature component vd calculated using the equation (2) is zero, the voltage waveform of the AC power supply 4 calculated using the equation (2) is only the in-phase component vq, and the in-phase component vq is the alternating current The phase matches the actual voltage waveform of the power supply 4 .
The component identifying section 22 outputs the in-phase component vq and the quadrature component vd to the phase difference calculating section 23 .

The phase difference calculator 23 calculates the phase difference Δθbar between the estimated phase θ and the actual phase θreal using, for example, Equation (3) based on the specified in-phase component vq and quadrature component vd.

The phase difference calculator 23 outputs the calculated phase difference Δθbar to the control signal generator 24 .

For example, the control signal generator 24 controls the phase difference Δθbar to converge to zero using Equation (4) including the phase difference Δθbar (for example, PI (Proportional-Integral) control), thereby reducing the phase θ can be adjusted.

In equation (4), K _θp is the proportional gain. Also, K _θi is the integral gain.
As a result, even if the frequency of the AC power supply 4 suddenly changes, the phase difference can be quickly achieved compared to the case where the phase is adjusted using a zero-cross signal that requires a predetermined observation period in order to avoid false detection due to noise. Δθbar can be zero. That is, the responsiveness of the phase correction in the converter device 2 can be improved.

Storage unit 25 stores various information necessary for processing performed by converter control unit 15 .
For example, the storage unit 25 stores the above equations (1) to (4).

Next, processing of the motor drive device 1 according to the first embodiment of the present invention will be described.
Here, the processing flow of the converter device 2 shown in FIG. 3 will be described.
Note that the processing of the converter device 2 shown in FIG. 3 is processing performed when an input current is flowing.

The waveform detector 21 detects the voltage waveform of the AC power supply 4 (step S1). Waveform detection section 21 outputs the detected voltage waveform to component identification section 22 .

Component identifying section 22 receives the voltage waveform from waveform detecting section 21 . The component identifying unit 22 identifies the in-phase component vq and the quadrature component vd of the fundamental wave component of the received voltage waveform at predetermined timings (step S2). The component specifying unit 22 outputs the specified in-phase component vq and quadrature component vd to the phase difference calculating unit 23 .

The phase difference calculator 23 receives the in-phase component vq and the quadrature component vd from the component identifier 22 . The phase difference calculator 23 calculates the phase difference Δθbar between the estimated phase θ and the actual phase θreal based on the received in-phase component vq and quadrature component vd (step S3). The phase difference calculator 23 outputs the calculated phase difference Δθbar to the control signal generator 24 .

The control signal generator 24 receives the phase difference Δθbar from the phase difference calculator 23 . The control signal generation unit 24 can adjust the phase θ by performing control (for example, PI control) to converge the phase difference Δθbar to zero, for example, using Equation (4).

(Comparison of simulation results)
Next, in order to show the effect of the processing of the converter device 2 according to the first embodiment of the present invention, the simulation results of the motor driving device 1 according to the first embodiment of the present invention and the simulation results of the conventional motor driving device are shown. compare.
In the simulation of the motor driving device 1 according to the first embodiment of the present invention, control is performed so that the phase difference Δθbar converges to zero. is not controlled to converge to

FIG. 4 is a diagram showing simulation results of the motor driving device 1 according to the first embodiment of the present invention and simulation results of a conventional motor driving device.
In the simulation, the frequency of the power supply voltage is changed 10% faster than the rated frequency at 3 seconds.
Parts (A) and (B) of FIG. 4 are simulation results of the motor drive device 1 according to the first embodiment of the present invention. Parts (C) and (D) of FIG. 4 are simulation results of a conventional motor driving device.
In addition, parts (A) and (C) of FIG. 4 are for a long time (part (A) is 2.5 seconds to 5 seconds, part (C) is 2.5 seconds to 6 seconds). Voltage waveforms and current waveforms are shown. Parts (B) and (D) of FIG. 4 show voltage waveforms and current waveforms before and after the frequency of the power supply voltage changes.
The vertical axes other than the power supply phase are normalized by steady-state values. The steady-state crest value is 1 for the power supply voltage and the input current. The steady state DC bus voltage is unity for the DC bus voltage. The duty is 1 when the signal is always off, and 0 when the signal is always on (representing the duty ratio of the off state). The steady state frequency is 1 for the line frequency estimate. The steady state period is 1 for the power supply period estimate. The unit of the power supply phase is [deg], the solid line is the estimated value of the power supply phase, and the dashed line is the true value of the power supply phase.

Voltage and current waveforms of particular note are the DC bus voltage and input current shown in portions (A) and (C) of FIG. Note that the DC bus voltage is the output voltage of the converter device 2 .
As can be seen from part (A) of FIG. 4, when the frequency of the power supply voltage is changed 10% faster than the rated frequency at 3 seconds, the motor driving device 1 according to the first embodiment of the present invention can The DC bus voltage waveform is only disturbed for about 0.2 seconds of 3.2 seconds. Also, no large disturbance is seen in the input current waveform. That is, in the motor drive device 1 according to the first embodiment of the present invention, since the phase difference Δθbar is calculated, it is possible to control the phase difference Δθbar to converge to zero. As a result, in the motor driving device 1 according to the first embodiment of the present invention, even if the frequency of the power supply voltage changes, the DC bus voltage waveform and the input current waveform immediately respond (follow up) the frequency change. ) becomes possible.
On the other hand, as can be seen from part (C) of FIG. 4, when the frequency of the power supply voltage is changed 10% faster than the rated frequency at 3 seconds, in the conventional motor drive device, the DC bus voltage waveform and the input current waveform are is irregularly disturbed in amplitude, phase, and period.

The motor drive device 1 according to the first embodiment of the present invention has been described above.
In the converter device 2 of the motor drive device 1 according to the first embodiment of the present invention, the waveform detection section 21 detects the voltage waveform of the supplied power supply voltage. The component identifying section 22 identifies the in-phase component and the quadrature component of the voltage waveform. The phase difference calculator 23 calculates the phase difference based on the in-phase component and the quadrature component.
Input current distortion is caused by distortion of the input voltage waveform. Therefore, the phase difference calculator 23 calculates the phase difference between the estimated phase and the actual phase based on the in-phase component and the quadrature component, thereby controlling the phase difference to converge to zero (for example, PI control). As a result, for example, compared to the case of phase adjustment using a zero-cross signal that requires a predetermined observation period to avoid erroneous detection due to noise, even if the frequency of the AC power supply 4 changes suddenly, The phase difference Δθbar can be zero. Therefore, the responsiveness of the phase correction in the converter device 2 can be improved, and even if an abnormality such as a sudden change in phase occurs, the phase can be adjusted appropriately. In other words, even if an abnormality occurs in the power supply, it is possible to suppress the occurrence of an abnormality such as an overcurrent in the input current, and to continue the operation.

<Second embodiment>
A motor drive device according to a second embodiment of the present invention will be described.
FIG. 5 is a diagram showing the configuration of a motor driving device 1 according to a second embodiment of the invention. Like the motor drive device 1 according to the first embodiment of the present invention, the motor drive device 1 converts the AC power from the AC power supply 4 into DC power, converts the DC power into three-phase AC power, and operates the compressor. It is a device that outputs to the motor 20 . The motor drive device 1 includes a converter device 2 and an inverter device 3, as shown in FIG.

The converter device 2 is a device that converts AC power from the AC power supply 4 into DC power and outputs the DC power to the inverter device 3 . Converter device 2 includes rectifier circuit 5 , switching circuit 10 a , switching circuit 10 b , smoothing capacitor 12 , converter control section 15 , voltage detection section 17 , and input current detection section 30 .

Converter control unit 15 further includes a second input terminal in addition to the first input terminal, first output terminal, and second output terminal. The input current detector 30 has an input terminal and an output terminal. The input terminal of the input current detector 30 is connected to the reference terminal. The output terminal of input current detection section 30 is connected to the second input terminal of converter control section 15 .

The input current detector 30 detects a return current to the AC power supply 4 (hereinafter referred to as "input current"). Input current detection unit 30 outputs information on the detected input current to converter control unit 15 .

Control signal generator 24 of converter controller 15 receives input current information from input current detector 30, as shown in FIG. The control signal generator 24 uses the received input current information and the phase difference Δθbar between the estimated phase θ and the actual phase θreal to perform converter control by referring to a data table and performing predetermined calculations. A phase (phase difference with the power supply voltage) φ is derived, and a duty can be derived as shown below based on the derived converter control phase φ and a preset predetermined voltage amplitude value.

First, the control signal generation unit 24 (an example of a normalization processing unit) normalizes the power supply voltage vin based on the peak value of the power supply voltage vin during a period equal to or longer than a predetermined cycle of the power supply voltage vin.
For example, the control signal generator 24 calculates the peak value vp of the voltage waveform vin at a predetermined phase (eg, from phase (θ−π) to θ) as shown in Equation (5).

The control signal generation unit 24 (an example of a normalization processing unit) normalizes the power supply voltage vin with the value output by the LPF (Low Pass Filter) when the peak value vp is passed through the LPF.
For example, the control signal generator 24 normalizes the voltage waveform vin based on the value obtained by passing the peak value vp through the LPF, thereby calculating the first voltage command duty _vin as shown in Equation (6). .

Here, based on the positive/negative of the first voltage command duty _vin and the relationship between the first voltage command duty _vin and the value obtained by multiplying α by the absolute value of sin θ, the second voltage command Calculate duty' _vin .

Here, α is the reciprocal of the upper limit of the boost ratio and has a value of 0 to 1. By calculating the second voltage command duty' _vin as in Equation (7), overcurrent in the input current can be suppressed. That is, the control signal generation unit 24 (an example of the normalization processing unit) limits the possible range of the voltage command by the reciprocal α of the upper limit of the step-up ratio based on the normalized power supply voltage vin.
Then, the control signal generation unit 24 uses the information of the input current and the phase difference Δθbar between the estimated phase θ and the actual phase θreal to refer to the data table and perform predetermined calculations to generate the converter. Derive the control phase φ.
The control signal generator 24 (an example of a voltage command calculator) calculates a voltage command using a correction value based on the difference between the normalized voltage and the ideal voltage of the power supply voltage vin.
For example, the control signal generation unit 24 uses the derived converter control phase φ and the second voltage command duty' _vin (eg, formula (7)) to obtain the final voltage command duty Calculate

When the power supply voltage vin has a constant amplitude and a constant frequency, when the control signal generator 24 controls the phase θ so that the phase difference Δθbar becomes zero, the estimated phase θ and the actual phase θreal matches. Therefore, in equation (8), the second voltage command duty' _vin and sin θ match. As a result, equation (8) becomes sin(θ−φ). That is, equation (8) is an equation representing only the adjustment amount φ of the phase of the input current for making the phase of the input current the same as the input voltage vin.

The control signal generator 24 compares the calculated voltage command duty with a reference waveform represented by a triangular wave, as shown in parts (A) and (C) of FIG.
The control signal generator 24 generates a control signal Sg1 for controlling the switching element 8a and a control signal Sg2 for controlling the switching element 8b based on the comparison result.
Specifically, the control signal generator 24 outputs a High level voltage during a period when the reference waveform is greater than the voltage command duty, and outputs a Low level voltage during a period when the reference waveform is equal to or less than the voltage command duty. 7B and 7D, the control signal generator 24 generates the control signal Sg1 for controlling the switching element 8a and the control signal Sg2 for controlling the switching element 8b. to generate

Next, processing of the motor drive device 1 according to the second embodiment of the present invention will be described.
Here, the processing flow of the converter device 2 shown in FIG. 8 will be described.
Note that the processing of the converter device 2 shown in FIG. 8 is processing performed when an input current is flowing.

The converter device 2 performs steps S1 to S3 in the same manner as the converter device 2 according to the first embodiment of the present invention. The phase difference calculator 23 of the converter device 2 outputs the calculated phase difference Δθbar to the control signal generator 24 .

The control signal generator 24 receives the phase difference Δθbar from the phase difference calculator 23 . Further, the control signal generator 24 receives input current information from the input current detector 30 .

The control signal generator 24 calculates the peak value vp of the voltage waveform vin at a predetermined phase (step S4).
The control signal generator 24 calculates the first voltage command duty _vin by normalizing the voltage waveform vin based on the value obtained by passing the peak value vp through the LPF (step S5).

The control signal generation unit 24 generates the second voltage command duty' _vin based on the positive/negative of the first voltage command duty vin and the relationship between the value obtained by multiplying α by the absolute value of sin θ _and the first voltage command duty _vin . is calculated (step S6).
By calculating the second voltage command _duty'vin , overcurrent in the input current can be suppressed.

The control signal generation unit 24 uses the information of the input current and the phase difference Δθbar between the estimated phase θ and the actual phase θreal to refer to a data table and perform predetermined calculations to obtain the converter control phase φ is derived (step S7). The control signal generator 24 uses the derived converter control phase φ and the second voltage command duty' _vin to calculate the final voltage command duty (step S8).

The control signal generator 24 adjusts the phase θ by performing control (for example, PI control) to converge the phase difference Δθbar to zero (step S9).
The control signal generator 24 compares the final voltage command duty with the reference waveform (step S10). The control signal generator 24 generates a control signal Sg1 for controlling the switching element 8a and a control signal Sg2 for controlling the switching element 8b based on the comparison result (step S11).

(Comparison of simulation results)
Next, in order to show the effect of the processing of the converter device 2 according to the second embodiment of the present invention, the simulation results of the motor driving device 1 according to the second embodiment of the present invention and the simulation results of the conventional motor driving device are shown. compare.
In the simulation of the motor driving device 1 according to the second embodiment of the present invention, a case where the amplitude of the power supply voltage vin changes abruptly and a case where the phase of the power supply voltage vin abruptly changes are illustrated. 8 shows the effect of the processing of the converter device 2 according to the second embodiment.

First, simulation results when the amplitude of the power supply voltage vin changes abruptly will be described.
FIG. 9 is a diagram showing simulation results when the amplitude of the power supply voltage vin changes abruptly. Part (A) of FIG. 9 shows the power supply voltage vin. A portion (B) in FIG. 9 indicates the voltage command duty.
Here, as shown in part (A) of FIG. 9, the amplitude of the power supply voltage vin suddenly decreases at a phase of 90 degrees, the amplitude continues up to a phase of 450 degrees, and then the power supply voltage vin suddenly returns to its normal state at a phase of 450 degrees. is returned to the amplitude of

In the case of a conventional converter device, even if the amplitude of the power supply voltage vin suddenly decreases at a phase of 90 degrees, the converter device cannot follow the change. Therefore, as indicated by the dashed line in part (B) of FIG. 9, the conventional converter device continues to output the voltage command duty with an amplitude of 1 for a sufficiently long period of time relative to one cycle of the signal. As a result, the DC bus voltage Vdc decreases as the amplitude of the power supply voltage vin increases.

On the other hand, in the case of the converter device 2 according to the second embodiment of the present invention, when the amplitude of the power supply voltage vin suddenly decreases at a phase of 90 degrees, the converter device 2 follows the change and shifts from a phase of 90 degrees to a phase of 450 degrees. becomes smaller. Therefore, the DC bus voltage Vdc increases as the amplitude of the power supply voltage vin decreases. As a result, it is possible to prevent an inrush current when the power is restored. Further, in the case of the converter device 2 according to the second embodiment of the present invention, by introducing the reciprocal α of the upper limit of the step-up ratio, the lower limit of the voltage command duty can be restricted, preventing the step-up ratio from becoming too large. be able to. As a result, overcurrent due to boosting can be prevented.

Next, simulation results when the phase of the power supply voltage vin changes abruptly will be described.
FIG. 10 is a diagram showing simulation results when the phase of the power supply voltage vin abruptly changes. Part (A) of FIG. 10 shows the power supply voltage vin. A portion (B) in FIG. 10 indicates the voltage command duty.
Here, it is assumed that the phase of the power supply voltage vin suddenly advances by 90 degrees at the phase of 360 degrees, as shown in part (A) of FIG.

In the case of the conventional converter device, if the phase of the power supply voltage vin suddenly advances by 90 degrees at the phase of 360 degrees, the converter device cannot follow the change. Therefore, as indicated by the dashed line in part (B) of FIG. 10, the conventional converter device continues to output the voltage command duty with an amplitude of 1 for a sufficiently long period of time relative to one cycle of the signal. As a result, the DC bus voltage Vdc decreases as the amplitude of the power supply voltage vin increases. Then, for example, at the square phase shown in FIG. 10B, the voltage command duty originally takes a large value, but becomes a small value. As a result, at the square phase shown in FIG. 10(B), a control signal with a long ON state is generated instead of a control signal with a short ON state.

On the other hand, in the case of the converter device 2 according to the second embodiment of the present invention, when the phase of the power supply voltage vin suddenly advances by 90 degrees at the phase of 360 degrees, the converter device 2 follows the change and changes the phase at the phase of 360 degrees. is advanced by 90 degrees, and the amplitude suddenly increases. In this case, the voltage command duty cannot follow the voltage command that should be due to the change in the input voltage vin near the phase of 450 degrees. can be limited and the step-up ratio can be prevented from becoming too large. As a result, overcurrent due to boosting can be prevented.
Then, the control signal generator 24 can correct the phase θ in a short time by performing control (for example, PI control) so that the phase difference Δθbar converges to zero. As a result, the voltage command duty follows the voltage command that should be in accordance with the change in the input voltage vin in that short period of time.

The motor drive device 1 according to the second embodiment of the present invention has been described above.
In the motor drive device 1 according to the second embodiment of the present invention, the waveform detector 21 detects the voltage waveform of the supplied power supply voltage. The component identifying section 22 identifies the in-phase component and the quadrature component of the voltage waveform. The phase difference calculator 23 calculates the phase difference based on the in-phase component and the quadrature component. In addition, the control signal generation unit 24 (an example of a normalization processing unit) normalizes the power supply voltage vin based on the peak value of the power supply voltage vin during a period equal to or longer than a predetermined cycle of the power supply voltage vin. The control signal generation unit 24 (an example of a normalization processing unit) normalizes the power supply voltage vin with the value output by the LPF when the LPF is passed through the peak value vp. The control signal generation unit 24 (an example of the normalization processing unit) limits the possible range of the voltage command by the reciprocal α of the upper limit of the step-up ratio based on the normalized power supply voltage vin. The control signal generation unit 24 uses the information of the input current and the phase difference Δθbar between the estimated phase θ and the actual phase θreal to refer to a data table and perform predetermined calculations to obtain the converter control phase Derive φ. The control signal generator 24 (an example of a voltage command calculator) calculates a voltage command using a correction value based on the difference between the normalized voltage and the ideal voltage of the power supply voltage vin.
By doing so, the motor drive device 1 according to the second embodiment of the present invention can follow rapid changes in the amplitude and phase of the power supply voltage vin, and furthermore, the range of the voltage command is suppressed by the reciprocal α of the upper limit of the step-up ratio. By doing so, overcurrent in the input current can be suppressed.

It should be noted that the order of the processes in the embodiment of the present invention may be changed as long as appropriate processes are performed.

Each of the storage unit 25 and the storage device (including registers and latches) in the embodiment of the present invention may be provided anywhere as long as appropriate information transmission/reception is performed. Further, each of the storage unit 25 and the storage device may have a plurality of storage units and store data in a distributed manner within a range where appropriate information transmission/reception is performed.

Although the embodiments of the present invention have been described, the converter control section 15, the inverter control section 19, and other control devices described above may have a computer system therein. The process of the above-described processing is stored in a computer-readable recording medium in the form of a program, and the above-described processing is performed by reading and executing this program by a computer. Specific examples of computers are shown below.
FIG. 11 is a schematic block diagram showing the configuration of a computer according to at least one embodiment;
The computer 50 includes a CPU 60, a main memory 70, a storage 80, and an interface 90, as shown in FIG.
For example, each of the above-described converter control unit 15 , inverter control unit 19 , and other control devices is implemented in computer 50 . The operation of each processing unit described above is stored in the storage 80 in the form of a program. The CPU 60 reads out a program from the storage 80, develops it in the main memory 70, and executes the above processes according to the program. In addition, the CPU 60 secures storage areas corresponding to the storage units described above in the main memory 70 according to the program.

Examples of the storage 80 include HDD (Hard Disk Drive), SSD (Solid State Drive), magnetic disk, magneto-optical disk, CD-ROM (Compact Disc Read Only Memory), DVD-ROM (Digital Versatile Disc Read Only Memory). , semiconductor memory, and the like. The storage 80 may be an internal medium directly connected to the bus of the computer 50, or an external medium connected to the computer 50 via the interface 90 or communication line. Further, when this program is distributed to the computer 50 via a communication line, the computer 50 receiving the distribution may develop the program in the main memory 70 and execute the above process. In at least one embodiment, storage 80 is a non-transitory, tangible storage medium.

Further, the program may implement part of the functions described above. Furthermore, the program may be a file capable of realizing the above functions in combination with a program already recorded in the computer system, that is, a so-called difference file (difference program).

While several embodiments of the invention have been described, these embodiments are examples and do not limit the scope of the invention. Various additions, omissions, replacements, and modifications may be made to these embodiments without departing from the scope of the invention.

Reference Signs List 1 Motor drive device 2 Converter device 3 Inverter device 4 AC power supply 5 Rectifier circuits 6a, 6b Reactors 7a, 7b Diodes 8a, 8b Switching elements 10a, 10b Switching circuit 12 Smoothing capacitor 15 Converter control unit 17 Voltage detection unit 19 Inverter control unit 21 Waveform detection unit 22 Components Identification unit 23 Phase difference calculation unit 24 Control signal generation unit 25 Storage unit 30 Input current detection unit 50 Computer 60 CPU
70 Main memory 80 Storage 90 Interface Lp Positive electrode bus

Claims (7)

a waveform detection unit that detects a voltage waveform of the supplied power supply voltage;
a normalization processing unit that normalizes the power supply voltage using a peak value of the power supply voltage in a period equal to or longer than a predetermined cycle of the power supply voltage;
a voltage command calculation unit that calculates a voltage command using a correction value based on a difference between the voltage normalized by the normalization processing unit and the ideal voltage of the power supply voltage;
A converter device comprising : a component identifying unit that identifies an in-phase component and a quadrature component of the voltage waveform;
a phase difference calculator that calculates a phase difference, which is the difference between the estimated phase of the power supply voltage and the actual phase of the power supply voltage, based on the in-phase component and the quadrature component;
The converter device of claim 1, comprising: a phase control unit that controls the estimated phase of the power supply voltage based on the phase difference;
3. The converter device of claim 2, comprising: The normalization processing unit
normalizing the power supply voltage with the value output by the low-pass filter when the peak value is passed through the low-pass filter;
The converter device according to any one of claims 1 to 3. The voltage command calculator,
limiting the possible range of the voltage command by the reciprocal of the upper limit of the step-up ratio based on the power supply voltage normalized by the normalization processing unit;
The converter device according to any one of claims 1 to 4. detecting a voltage waveform of the supplied power supply voltage;
normalizing the power supply voltage using a peak value of the power supply voltage in a period equal to or longer than a predetermined cycle of the power supply voltage;
calculating a voltage command using a correction value based on the difference between the normalized voltage and the ideal voltage of the power supply voltage;
A processing method by a converter device comprising: on the computer of the converter device,
detecting a voltage waveform of the supplied power supply voltage;
normalizing the power supply voltage using a peak value of the power supply voltage in a period equal to or longer than a predetermined cycle of the power supply voltage;
calculating a voltage command using a correction value based on the difference between the normalized voltage and the ideal voltage of the power supply voltage;
program to run.

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