JPH08331856A - Power converting apparatus - Google Patents

Abstract

PURPOSE: To prevent fluctuation of output current of an inverter during changeover in number of the pulses of the PWM signal. CONSTITUTION: A pulse mode instruction generating means 4 sets the number of pulses per half-period of an inverter output voltage. A changeover phase angle generating means 7 obtains and outputs a changeover phase angle which minimizes transient change of an inverter current generated during changeover between the five-pulse mode and 3-pulse mode. A pulse mode phase changeover instruction generating means 8 specifies the number of pulses set by the pulse mode instruction generating means 4 for each phase when the phase angle instructing value is within the range of the changeover phase angle. Depending on this number of pulses, the changeover means of each phase 9, 10, 11 generate and output the gate signal, based on the PWM signal of each phase outputted from the 5-pulse mode PWM signal generating means 5 or 3-pulse mode PWM signal generating means 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power converter for converting a DC voltage into an AC voltage by pulse width modulation (hereinafter referred to as PWM) control.

[0002]

2. Description of the Related Art A power converter (hereinafter referred to as an inverter) that converts DC power into AC power by PWM control.
Are controlled to operate with the number of n pulses (n is any positive integer, for example, n = 1, 3, 5 ...) Per half cycle in synchronization with the cycle of the output voltage.

In the operation mode with five pulses (hereinafter referred to as five-pulse mode), the phase voltage level of a two-level output inverter for converting a DC voltage into an AC voltage having two positive and negative phase voltages is the output voltage 1 Since it changes 10 times per cycle, the switching element forming the inverter performs ON / OFF switching operation (switching) 10 times per output voltage cycle. The phase voltage level of a three-level output inverter that converts a DC voltage into an AC voltage having three positive and negative phase voltages changes 20 times per output voltage cycle. Looking at each of the switching elements that make up the inverter, Switching is performed 10 times per output voltage cycle.

As described above, in the 5-pulse mode, the switching frequency of the switching element is 5 times the frequency of the output voltage of the inverter (hereinafter referred to as the output frequency), so that the output frequency of the inverter is 100 [H], for example.
z], the switching frequency of the switching element is 500 [Hz]. Similarly, in the operation mode of the pulse number 3 (hereinafter, referred to as 3 pulse mode), the switching frequency of the switching element is three times the output frequency of the inverter, and the operation mode of the pulse number n (hereinafter,
It is called n-pulse mode. ), The switching frequency of the switching element is n times the output frequency of the inverter.

Generally, for the output frequency of the same inverter, it is possible to suppress the ripple due to the harmonic component of the output current of the inverter by increasing the switching frequency. Further, when the electric motor is connected as the load of the inverter, the torque ripple of the electric motor can be reduced. Therefore, it is desirable that the inverters be controlled in an operation mode in which the switching frequency becomes higher than the output frequency of the same inverter, for example, a 3-pulse mode rather than the 1-pulse mode and a 5-pulse mode rather than the 3-pulse mode.

[0006]

However, since the upper limit of the switching frequency is set in the switching element which constitutes the inverter, for example, when the inverter is controlled in the 5-pulse mode and the output frequency of the inverter is in the rising process, Before the switching frequency of the switching element reaches its upper limit, the inverter must be controlled by switching to an operation mode in which the switching frequency is lowered, for example, a 3-pulse mode. In this way, the inverter switches the number of pulses in the operation mode according to the output frequency of the inverter, but at this time, switches all the phases (for example, u phase, v phase, w phase in the case of 3 phases) of the inverter at the same time. Was there. However, if the number of operating mode pulses is switched simultaneously in all phases of the inverter, due to the discontinuity of the high frequency components between the two operating modes being switched,
There has been a problem that the output current of the inverter changes transiently and affects the load of the inverter.

Therefore, the present invention has been made to solve the above-mentioned problems, and it is possible to prevent the output current of the inverter from fluctuating at the time of switching the number of pulses in the operation mode of the inverter and to suppress the influence on the load. To aim.

[0008]

In order to achieve the above-mentioned object, the invention described in claim 1 is constituted by a plurality of switching elements, and a DC voltage is multiphase based on a frequency command value and an amplitude command value. Conversion means for converting to an AC voltage, pulse mode command generation means for setting and outputting the number of pulses per half cycle in synchronization with the cycle of the AC voltage output by this conversion means, and phase angle command value determined from the frequency command value. And the amplitude command value, a plurality of pulse width modulation signal generating means for respectively outputting a pulse width modulation signal having an arbitrary number of pulses per half cycle synchronized with the cycle of the AC voltage, and these pulse width modulation signal generating means output. When each pulse width modulation signal is input and the number of pulses per half cycle synchronized with the cycle of the AC voltage is changed, the transient fluctuation of the output of the conversion means is small The switching phase angle generating means for obtaining and outputting the phase angle is compared with the phase angle command value and the switching phase angle, and the pulse mode switching command for switching to the number of pulses output from the pulse mode command generating means is output independently for each phase. Of the pulse mode phase-dependent switching command generating means and the pulse width modulation signal generating means, which corresponds to the pulse mode switching command, outputs the gate signals to the plurality of switching elements based on the pulse width modulation signal output by one. And a pulse mode switching means for outputting for each phase.

Further, the invention according to claim 2 is composed of a plurality of switching elements, and a conversion means for converting a DC voltage into a multi-phase AC voltage based on the frequency command value and the amplitude command value, and the conversion means. From the pulse mode command generation means that sets and outputs the number of pulses per half cycle synchronized with the cycle of the output AC voltage, and the phase angle command value and amplitude command value determined from the frequency command value, the half cycle synchronized with the cycle of the AC voltage A plurality of pulse width modulation signal generating means each outputting a pulse width modulation signal having an arbitrary number of pulses per cycle, and an amplitude command value are input, and the number of pulses per half cycle synchronized with the cycle of the AC voltage is changed. At this time, the switching phase angle generating means for obtaining and outputting the switching phase angle in which the transient fluctuation of the output of the converting means is small, and the phase angle command value and the switching phase angle are compared, and each phase is uniquely determined. The pulse mode switching command generating means for outputting a pulse mode switching command for switching to the number of pulses output from the pulse mode command generating means, and one of a plurality of pulse width modulation signal generating means corresponding to the pulse mode switching command And a pulse mode switching means for outputting a gate signal to a plurality of switching elements for each phase based on the pulse width modulation signal output by one.

According to a third aspect of the present invention, there is provided a converting means which is composed of a plurality of switching elements, and which converts a direct current voltage into a multi-phase alternating current voltage based on a frequency command value and an amplitude command value, and the converting means. From the pulse mode command generation means that sets and outputs the number of pulses per half cycle synchronized with the cycle of the output AC voltage, and the phase angle command value and amplitude command value determined from the frequency command value, the half cycle synchronized with the cycle of the AC voltage A plurality of pulse width modulation signal generating means for respectively outputting a pulse width modulation signal having an arbitrary number of pulses per cycle, and the output of the converting means when the number of pulses per half cycle synchronized with the cycle of the AC voltage is changed. The switching phase angle generating means for storing the switching phase angle with a small transient variation of the output and outputting the switching phase angle according to the amplitude command value, and the phase angle command value and the switching phase angle are compared. The pulse mode switching command generating means for outputting a pulse mode switching command for switching to the number of pulses output from the pulse mode command generating means for each phase, and the pulse mode switching among the plurality of pulse width modulation signal generating means It has pulse mode switching means for outputting a gate signal to each of the plurality of switching elements for each phase based on the pulse width modulation signal output by one corresponding to the command.

According to a fourth aspect of the present invention, there is provided a converting means which is composed of a plurality of switching elements, and which converts a direct current voltage into a multi-phase alternating current voltage based on a frequency command value and an amplitude command value, and the converting means. From the pulse mode command generation means that sets and outputs the number of pulses per half cycle synchronized with the cycle of the output AC voltage, and the phase angle command value and amplitude command value determined from the frequency command value, the half cycle synchronized with the cycle of the AC voltage A plurality of pulse width modulation signal generating means for respectively outputting a pulse width modulation signal having an arbitrary number of pulses per cycle, and the output of the converting means when the number of pulses per half cycle synchronized with the cycle of the AC voltage is changed. The transitional phase is small and the phase angle command value is compared, and each phase is individually switched to the number of pulses output from the pulse mode command generation means. Based on the pulse width modulation signal output by one of the pulse mode phase switching command generating means for outputting a command and the pulse width modulation signal generating means, which corresponds to the pulse mode switching command, a plurality of switching elements are output. And a pulse mode switching means for outputting a gate signal for each phase.

According to a fifth aspect of the present invention, there is provided a conversion means which is composed of a plurality of switching elements, and which converts a DC voltage into a multi-phase AC voltage based on the frequency command value and the amplitude command value, and the conversion means. The number of pulses per half cycle synchronized with the cycle of the AC voltage is changed by inputting the pulse mode command generation means that sets and outputs the number of pulses per half cycle synchronized with the cycle of the output AC voltage, and the amplitude command value. At this time, the switching phase angle generating means for obtaining and outputting the switching phase angle in which the transient fluctuation of the output of the converting means is small, the phase angle command value determined from the frequency command value and the switching phase angle are compared, and each phase is uniquely Pulse mode switching command generation means for outputting a pulse mode switching command for switching to the number of pulses output from the pulse mode command generation means, phase angle command value and amplitude command , And outputs a gate signal to a plurality of switching elements for each phase based on a pulse width modulation signal having a number of pulses corresponding to a pulse mode switching command per half cycle synchronized with the cycle of the AC voltage. And a pulse width modulation signal generating means.

According to a sixth aspect of the present invention, there is provided a converting means which is composed of a plurality of switching elements, and which converts the direct current voltage into a multi-phase alternating current voltage based on the frequency command value and the amplitude command value, and the converting means. Pulse mode command generation means that sets and outputs the number of pulses per half cycle synchronized with the cycle of the output AC voltage, and output of the conversion means when the number of pulses per half cycle synchronized with the cycle of the AC voltage is changed Of the switching phase angle with a small transient variation of, and the switching phase angle generating means for outputting the switching phase angle according to the amplitude command value, the phase angle command value determined from the frequency command value and the switching phase angle are compared. A pulse mode switching command generating means for outputting a pulse mode switching command for switching to the number of pulses output from the pulse mode command generating means independently for each phase; Command value and an amplitude command value, based on a pulse width modulation signal having a number of pulses corresponding to a pulse mode switching command per half cycle synchronized with the cycle of the AC voltage, gate signals to a plurality of switching elements And pulse width modulation signal generating means for outputting for each phase.

According to a seventh aspect of the present invention, there is provided a converting means which is composed of a plurality of switching elements, and which converts a direct current voltage into a multi-phase alternating current voltage based on a frequency command value and an amplitude command value, and the converting means. Pulse mode command generation means that sets and outputs the number of pulses per half cycle synchronized with the cycle of the output AC voltage, and output of the conversion means when the number of pulses per half cycle synchronized with the cycle of the AC voltage is changed , Which has a small transient fluctuation, compares the switching phase angle with the phase angle command value determined from the frequency command value, and outputs the pulse mode switching command to switch to the number of pulses output from the pulse mode command generating means independently for each phase. Input another switching command generation means, phase angle command value and amplitude command value,
Pulse width modulation signal generation that outputs the gate signal to multiple switching elements for each phase based on the pulse width modulation signal that has the number of pulses corresponding to the pulse mode switching command per half cycle synchronized with the cycle of the AC voltage And means.

[0015]

With the above structure, in the invention according to any one of claims 1 to 7, when the number of pulses is changed,
A switching phase angle with a small transient fluctuation of the output of the converting means is obtained, and when the phase angle command value is within the range of the switching phase angle by the pulse mode phase-by-phase switching command generating means, the pulse mode command generating means for each phase is obtained. Switch to the number of pulses output from. Then, a gate signal to the switching element is output based on the pulse width modulation signal corresponding to the number of pulses switched by the pulse mode phase-specific switching command generating means. Therefore, since the pulse mode is switched independently for each phase, it is possible to suppress the transient fluctuation of the output of the conversion means.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the drawings. 1 and 2 are diagrams showing a first embodiment of the invention described in claim 1, FIG. 1 is a configuration diagram of an inverter, and FIG. 2 is a configuration diagram of a control device.

The main circuit of the inverter is a DC power source E, a switching element having a conduction control terminal, for example, gate turn-off thyristors SU1, SU2, SV1, SV2, SW1, SW.
2, diode DU connected in parallel to each switching element
1, DU2, DV1, DV2, DW1, DW2, which converts the DC voltage VDC into a three-phase AC voltage with a phase voltage of two levels, positive and negative, and supplies the AC motor M of the load with three phases of U-phase, V-phase, and W-phase. Supply phase alternating voltage.

The U phase voltage is generated by the switching element SU1 being O.
When the switching element SU2 is N, the voltage is + VDC / 2, and when the switching element SU1 is OFF and the switching element SU2 is ON, the voltage is -VDC / 2. Similarly, as the V-phase voltage and the W-phase voltage, two levels of voltage of + VDC / 2 and -VDC / 2 are output.

The control device 100 includes an inverter output voltage amplitude command value generating means 1, an inverter output voltage frequency command value generating means 2, an inverter output voltage phase angle command value generating means 3, a pulse mode command generating means 4 and a pulse mode PW.
M signal generating means 5, 3 pulse mode PWM signal generating means 6, switching phase angle generating means 7, pulse mode phase-specific switching command generating means 8, U phase switching means 9, V phase switching means 10, W phase switching means 11 It is configured.

Inverter output voltage amplitude command generation means 1
Outputs the inverter output voltage amplitude command value VmRef.
The inverter output voltage frequency command value generation means 2 outputs the inverter output voltage frequency command value FoRef. The inverter output voltage phase angle command value generation means 3 receives the inverter output voltage frequency command value FoRef output from the inverter output voltage frequency command value generation means 2 and outputs an inverter output voltage phase angle command value θRef. The inverter output voltage phase angle command value generation means 3 has, for example, the configuration shown in FIG. 3 and integrates the inverter output voltage frequency command value FoRef to obtain the inverter output voltage phase angle θRef.
(0 to 2π) is obtained and output. The pulse mode command generating means 4 is the inverter output voltage frequency command value generating means 2
Inverter output voltage output from the frequency command value FoRef
Input to set the number of pulses per half cycle of the inverter output voltage. 5 pulse mode PWM signal generating means 5
Is the input of the inverter output voltage amplitude command value VmRef output from the inverter output voltage amplitude command value generation means 1 and the inverter output voltage phase angle command value θRef output from the inverter output voltage phase angle command value generation means 3,
For example, a U-phase, a V-phase in a 5-pulse mode in which there are five pulses per half cycle of the inverter output voltage shown in FIG.
The W-phase PWM signal is output. The 3-pulse mode PWM signal generating means 6 outputs the inverter output voltage amplitude command value VmRe output from the inverter output voltage amplitude command value generating means 1.
f and the inverter output voltage phase angle command value generation means 3 outputs the inverter output voltage phase angle command value θRef as an input, for example, three pulses having three pulses per half cycle of the inverter output voltage shown in FIG. 4A. It outputs PWM signals of U-phase, V-phase, and W-phase of the mode.

The three-pulse mode PWM waveform is a waveform in which one phase voltage has three pulses per half cycle in synchronization with the inverter output voltage cycle, as shown in FIG. 4 (a). In the waveform of (a), the inverter output voltage fundamental wave Vs is

[0022]

[Equation 1] The amplitude of the inverter output voltage fundamental wave is controlled by performing the PWM control by changing the switching phase angle θα. Further, from the equation (1), the switching phase angle θα with respect to the inverter output voltage amplitude command value VmRef is

[0023]

[Equation 2] It is represented by.

The 5-pulse mode PWM waveform is a waveform in which one phase voltage has five pulses in synchronization with a half cycle of the inverter output voltage, as shown in FIG. 4 (b). In the waveform shown in FIG. 4B as an example, the inverter output voltage fundamental wave Vs is

[0025]

(Equation 3) PW by changing the switching phase angles θβ and θγ
By performing M control, the amplitude of the fundamental wave of the inverter output voltage is controlled.

Here, for example, the switching phase angle θγ is set to θ
If γ = 2 × θβ is set, from the equation (3), the switching phase angle θβ with respect to the inverter output voltage amplitude command value VmRef is

[0027]

[Equation 4] It is represented by.

Since the example here is a three-phase output inverter, the inverter output voltage waveform is as shown in FIG.
The waveform of (b) is U phase, V phase, W phase, and the phase angles are 2π with respect to each other.
The output is shifted by / 3.

Further, a 5-pulse mode PWM signal generating means 5
Outputs the switching phase angle θβ as a value representing the waveform pattern of the 5-pulse mode PWM waveform to the switching phase angle generating means 7, and the 3-pulse mode PWM signal generating means 6 outputs to the switching phase angle generating means 7. The switching phase angle θα is output as a value representing the waveform pattern of the 3-pulse mode PWM waveform. The switching phase angle generating means 7 receives the switching phase angles θα and θβ, which are values representing the waveform patterns of the two pulse modes (in this case, the 5 pulse mode and the 3 pulse mode) to be switched, and inputs the switching phase angles θα and θβ. The switching phase angle θCHG (the upper limit and lower limit of the switchable phase angle θ) that can minimize the transient fluctuation of the output current is obtained and output.

The switching phase angle θCHG is obtained as shown in FIG. 5, for example. From the PWM waveforms of the 5 pulse mode and the 3 pulse mode corresponding to the current inverter output voltage amplitude command value VmRef, in the case of FIG. 5, the switching phase angle θCHG is between θ1L and θ1H, and between θ2L and θ2H,
That is, there is no extra switching at the time of switching, and the inverter output voltage fundamental wave Vs does not change even if the PWM waveform is switched.

Pulse mode phase-by-phase switching command generation means 8
Is configured as shown in FIG. 6, for example. The pulse mode phase-by-phase switching command generating means 8 is a U-phase phase angle converting means 81, a V-phase phase angle converting means 82, a W-phase phase angle converting means 83, a U-phase switching phase angle condition determining means 84, a V-phase switching phase angle condition. It comprises a judging means 85, a W phase switching phase angle condition judging means 86, a U phase pulse mode switching command generating means 87, a V phase pulse mode switching command generating means 88, and a W phase pulse mode switching command generating means 89.

The U-phase phase angle conversion means 81, the V-phase phase angle conversion means 82, and the W-phase phase angle conversion means 83 each receive the inverter output voltage phase angle command value θRef as an input, and the phase angles for the U-phase, V-phase, and W-phase. Outputs θU, θV, and θW. The U-phase switching phase angle condition judging means 84 compares the U-phase phase angle θU with the switching phase angle θCHG, and when the U-phase phase angle θU is within the range of the switching phase angle θCHG (for example, θ1H ≧ θU ≧ θ1L), U Outputs the phase switching permission signal. V-phase switching phase angle condition determining means 85, W-phase switching phase angle condition determining means 86
V phase angle θV and switching phase angles θCHG, W
The same operation is performed for the phase phase angle θW and the switching phase angle θCHG. U-phase pulse mode switching command generation means 87
Inputs the pulse mode command and the U-phase switching permission signal, and the pulse mode command is, for example, from 5 pulse modes to 3
When changing to the pulse mode, if there is no U-phase switching permission signal, the 5-pulse mode command up to that point is output, and the 3-pulse mode command is output only after receiving the U-phase switching permission signal. Similarly, the V-phase pulse mode switching command generating means 88 and the W-phase pulse mode switching command generating means 89 respectively output the V-phase pulse mode switching command and the W-phase pulse mode switching command independently for each phase.

The U-phase switching means 9 is constructed, for example, as shown in FIG. 7, and the input U-phase 5-pulse mode PWM signal,
Of the U-phase 3-pulse mode PWM signals, any PWM signal corresponding to the U-phase pulse mode switching command is output as a U-phase gate signal. Similarly, the V-phase switching means 10 and the W-phase switching means 11 are respectively V-phase gate signals,
Output the W-phase gate signal.

FIG. 8 shows an example of the inverter output voltage waveform when the pulse mode is switched by the above-mentioned configuration. When the pulse mode command output from the pulse mode command generation unit 4 changes from the 5-pulse mode to the 3-pulse mode at time T1, the pulse mode phase-specific switching command generation unit 8 outputs each phase pulse mode switching command as follows. To do.

The U-phase phase angle conversion means 81 receives the inverter output voltage phase angle command value θRef output from the inverter output voltage phase angle command value generation means 3, and determines the phase angle θU with respect to the U phase. Then, the U-phase switching phase angle condition determining means 84 compares the switching phase angle θCHG output from the switching phase angle generating means 7 with the phase angle θU. In this example, as shown in FIG. 8A, at time T1, the phase angle θU is in the range of the switching phase angle θCHG, so U
The phase switching phase angle condition determining means 84 outputs a U phase switching permission signal to the U phase pulse mode switching command generating means 87. The U-phase pulse mode switching command generating means 87
Is the U-phase pulse mode switching command at time T1 (= time T
Output at U). Similarly, V phase angle converting means 8
2. In the W phase phase angle conversion means 83, the phase angle θV with respect to the V phase
, The phase angle θW for the W phase is determined accordingly. Then, the V-phase switching phase angle condition determining means 85 and the W-phase switching phase angle condition determining means 86 compare the switching phase angle θCHG with the phase angle θV and the phase angle θW, respectively, but in this example, FIG. 8B and FIG. As shown in 8 (c), since the phase angles θV and θW are not within the range of the switching phase angle θCHG at time T1, the V-phase switching permission signal and the W-phase switching permission signal are not output. When the phase angles θV and θW fall within the range of the switching phase angle θCHG as shown in FIGS. 8B and 8C, the V-phase switching phase angle condition diagnosing means 85 and the W-phase switching phase angle condition diagnosing means 86. Is a V-phase switching permission signal, W
A phase switching permission signal is output, the V-phase pulse mode switching command generation means 88 issues a V-phase pulse mode switching command at time TV, and the W-phase pulse mode switching command generation means 89 outputs a W-phase pulse mode switching command at time TW. Is output.

As described above, in the pulse mode switching, the PWM signals of the inverter output voltages U phase, V phase, and W phase are independent of each other at the switching phase angle at which the transient fluctuation of the inverter output current at the time of switching is minimized. Since it is switched to, it is possible to eliminate the torque shock of the electric motor at the time of switching.

In the present embodiment, an example of switching between two types of pulse modes, that is, a 5-pulse mode and a 3-pulse mode, is shown. However, even when other pulse modes are provided and when three or more pulse modes are provided, The pulse mode switching operation can be performed in the same manner as in this embodiment.

FIG. 9 is a configuration diagram of an inverter showing a second embodiment of the invention described in claim 1. The main circuit of the inverter is a DC power supply E, DC voltage dividing capacitors C1 and C2,
A switching element having a conduction control terminal, for example, gate turn-off thyristors SU1, SU2, SU3, SU4, SV1,
SV2, SV3, SV4, SW1, SW2, SW3, SW4, diodes DU1, DU2, D connected in parallel to each switching element
U3, DU4, DV1, DV2, DV3, DV4, DW1, DW2, DW
3, DW4, and DC voltage neutral point clamp diode DC
It consists of U1, DCU2, DCV1, DCV2, DCW1 and DCW2.

U phase The phase voltage becomes + V DC / 2 when SU1 and SU2 are ON and SU3 and SU4 are OFF, and SU2 and SU3 are O.
It becomes 0 when N, SU1 and SU4 are OFF, or −VDC / 2 when SU1 and SU2 are OFF and SU3 and SU4 are ON. Similarly, V phase phase voltage and W phase phase voltage are + VDC / 2, 0, -VDC
Three-level voltage of / 2 is output.

The control device has the configuration shown in FIG. 2 as in the first embodiment, and includes inverter output voltage amplitude command generation means 1, inverter output frequency command value generation means 2, and inverter output voltage phase angle generation means 3. , Pulse mode command generating means 4, 5 pulse mode PWM signal generating means 5, 3 pulse mode PWM signal generating means 6, switching phase angle generating means 7, pulse mode phase-specific switching command generating means 8, U
It is composed of a phase switching means 9, a V phase switching means 10, and a W phase switching means 11.

The 5-pulse mode PWM signal generating means 5 is
With the inverter output voltage amplitude command value VmRef output from the inverter output voltage amplitude command value generation means 1 and the inverter output voltage phase angle command value θRef output from the inverter output voltage phase angle command value generation means 3 as inputs, for example, FIG. The PWM signals of the U-phase, V-phase, and W-phase in the 5-pulse mode having five pulses per half cycle of the inverter output voltage shown in (b) are output.

The 3-pulse mode PWM signal generating means 6 is
With the inverter output voltage amplitude command value VmRef output from the inverter output voltage amplitude command value generation means 1 and the inverter output voltage phase angle command value θRef output from the inverter output voltage phase angle command value generation means 3 as inputs, for example, FIG. The PWM signals of the U-phase, V-phase, and W-phase in the 3-pulse mode having three pulses per half cycle of the inverter output voltage shown in (a) are output.

As shown in FIG. 10A for one phase voltage, the three-level output three-pulse mode PWM waveform has three pulses in a half cycle of the inverter output voltage. In the waveform of (a), the inverter output voltage fundamental wave Vs is

[0044]

(Equation 5) PW by changing the switching phase angle θa to θc
By performing M control, the amplitude of the fundamental wave of the inverter output voltage is controlled.

Also, three-level output five-pulse mode PWM
As shown in FIG. 10B, the waveform has five pulses in a half cycle of the inverter output voltage at one phase voltage. In the waveform shown in FIG. 10B as an example, the inverter output voltage fundamental wave Vs is

[0046]

(Equation 6) PW by changing the switching phase angle θd to θh
By performing M control, the amplitude of the fundamental wave of the inverter output voltage is controlled.

Since this example is a three-phase output inverter, the inverter output voltage waveform is as shown in FIG.
The waveform of (b) is U phase, V phase, W phase, and the phase angles are 2π with respect to each other
The output is shifted by / 3.

Further, 5-pulse mode PWM signal generating means 5
Is, for example, the switching phase angle θh as a value representing the waveform pattern of the 5-pulse mode PWM waveform to the switching phase angle generating means 7, and the 3-pulse mode PWM is output.
The signal generating means 6 is different from the switching phase angle generating means 7 in that
For example, the switching phase angle θc is output as a value representing the 3-pulse mode PWM waveform pattern.

The switching phase angle generating means 7 inputs switching phase angles θc and θh, which are values representing waveform patterns of two pulse modes (in this case, 5 pulse mode and 3 pulse mode) to be switched, and switches The switching phase angle θCHG (upper and lower limit values of switchable θ) that can minimize the transient fluctuation of the inverter output current at the time is calculated and output.

The switching phase angle θCHG is obtained as shown in FIG. 11, for example. From the PWM waveforms of the 5 pulse mode and the 3 pulse mode corresponding to the current inverter output voltage amplitude command value VmRef, in FIG. 11, the switching phase angle θCHG is between θ1L to θ1H and θ2L to θ2H,
That is, there is no extra switching at the time of switching, and the inverter output voltage fundamental wave Vs does not change even if the PWM waveform is switched.

Other configurations and operations are the same as those in the first embodiment. FIG. 12 shows an example of the inverter output voltage waveform when switching the pulse mode according to the configuration of the second embodiment described above. When the pulse mode command changes from 5 pulse mode to 3 pulse mode at time T1, U phase, V
Phase and W phase when the respective phase angles θU, θV, θW are the switching phase angle θCHG (time TU, time TV, time TW).
) Is switching the inverter output voltage waveform.

With this configuration, in the pulse mode switching, the PWM signals for the U phase, V phase, and W phase of the inverter output voltage are independent of each other at the switching phase angle at which the transient fluctuation of the inverter output current at the time of switching is minimized. Since it is switched to, it is possible to eliminate the torque shock of the electric motor at the time of switching.

In the present embodiment, an example of switching between two types of pulse modes, that is, a 5-pulse mode and a 3-pulse mode, is shown. However, as in the first embodiment, when there are other pulse modes, and Even when there are three or more pulse modes, the switching operation of the pulse modes can be performed in the same manner as in the present embodiment.

13 and 14 are views showing an embodiment of the invention described in claim 2, FIG. 13 is a block diagram of the controller of the main circuit shown in FIG. 1, and FIG. 14 is a switching phase angle generating means. It is a block diagram of 71.

The difference from the configuration of the first embodiment shown in FIG. 2 of the present embodiment is that the inverter output amplitude command value VmRef output from the inverter output voltage amplitude command value generating means 1 to the switching phase angle generating means 71. Is input directly.

The switching phase angle generating means 71 is a pulse mode PWM waveform switching phase angle calculating means 711, a 3-pulse mode PWM waveform switching phase angle calculating means 712,
It is composed of a pulse mode switchable phase angle calculation means 713. The 5-pulse mode PWM waveform switching phase angle calculating means 711 receives the inverter output voltage amplitude command value VmRef as an input and calculates and outputs the switching phase angle θβ determined by the equation (4). 3-pulse mode PWM switching phase angle calculation means 712 is an inverter output voltage amplitude command value.
VmRef is input and the switching phase angle θα determined by equation (2) is calculated and output. The pulse mode switchable phase angle calculation means 713 uses switching phase angles θα and θβ.
, The switching phase angle θCHG that can minimize the transient fluctuation when switching two PWM waveforms (in this case, 5 pulse mode and 3 pulse mode)
It calculates (the upper and lower limit values of switchable θ) and outputs it. When the relationship between the PWM waveform of each pulse mode and the inverter output voltage amplitude command value VmRef is clear, the switching phase angle θCHG can be obtained by this configuration.

Other configurations and operations are similar to those of the first embodiment. With this configuration, as in the first embodiment, when the pulse mode is switched, the inverter output voltage U
Since the PWM signals of each phase, V phase, and W phase can be switched independently for each phase at the switching phase angle at which the transient fluctuation of the inverter output current at the time of switching is minimized, torque shock of the electric motor at switching can be eliminated. .

In this embodiment, 5 pulse mode and 3 pulse mode are used.
Although an example of switching between two types of pulse modes has been shown, the switching of pulse modes is performed in the same manner as in the first embodiment, even when other pulse modes are provided and when three or more pulse modes are provided. Can be done similarly.

FIG. 15 is a diagram showing an embodiment of the invention described in claim 3, and is a configuration diagram of the switching phase angle generating means 71 of FIG. The switching phase angle storage unit 714 stores the switching phase angle θCHG previously obtained from the relationship between the inverter output voltage amplitude command value VmRef and the PWM waveform of each pulse mode for the two pulse modes to be switched and stores the inverter output voltage. The amplitude command value VmRef is input and the corresponding switching phase angle θCHG is output.

With this configuration, in the pulse mode switching, the PWM signals for the U phase, V phase, and W phase of the inverter output voltage are independent of each other at the switching phase angle at which the transient fluctuation of the inverter output current during switching is minimized. Since it is switched to, it is possible to eliminate the torque shock of the electric motor at the time of switching.

In the present embodiment, an example of switching between the two pulse modes of the 5-pulse mode and the 3-pulse mode has been shown. However, even in the case of having another pulse mode and in the case of having three or more pulse modes. The pulse mode can be switched in the same manner.

FIG. 16 is a diagram showing an embodiment of the invention described in claim 4, and is a block diagram of the controller of the main circuit shown in FIG. In this embodiment, the switching phase angle θCHG uses a constant value obtained in advance from the PWM waveform of each pulse mode. For example, in FIG. 5, the switching phase angle θ CHG is θ = π
With constant values of / 2 and 3π / 2, the inverter output voltage waveform when switching the pulse mode according to this configuration is the same as that of the first embodiment.

Other configurations and operations are similar to those of the first embodiment. With this configuration, when the pulse mode is switched, the inverter output voltage U is changed as in the first embodiment.
Since the PWM signals of each phase, V phase, and W phase can be switched independently for each phase at the switching phase angle at which the transient fluctuation of the inverter output current at the time of switching is minimized, torque shock of the electric motor at switching can be eliminated. .

In this embodiment, an example of switching between two types of pulse modes, that is, a 5-pulse mode and a 3-pulse mode, is shown. However, as in the case of the first embodiment, when there is another pulse mode, and Even when there are three or more types of pulse modes, the switching of pulse modes can be performed similarly.

FIG. 17 is a diagram showing an embodiment of the invention described in claim 5, and is a block diagram of the controller of the main circuit shown in FIG. The U-phase PWM signal generating means 12 is composed of, for example, a U-phase 5 pulse mode PWM signal generating means 121, a U-phase 3 pulse mode PWM signal generating means 122 and a U-phase switching means 123 as shown in FIG.

U-phase 3-pulse mode PWM signal generating means 12
2 inputs the inverter output voltage amplitude command value VmRef and the inverter output voltage phase angle command value θRef, and outputs the corresponding U-phase P waveform of the 3-pulse mode PWM waveform as shown in FIG. 4 (a).
It outputs a WM signal. U phase 5 pulse mode P
The WM signal generating means 121 receives the inverter output voltage amplitude command value VmRef and the inverter output voltage phase angle command value θRef, and outputs the corresponding U-phase PWM signal of the 5-pulse mode PWM waveform as shown in FIG. 4 (b). It is what is output.
Further, the U-phase switching unit 123 receives the inverter output voltage amplitude command value Vm according to the U-phase pulse mode switching command output from the pulse mode phase-specific switching command generating unit 8.
The Ref and the inverter output voltage phase angle command value θRef are switched so as to be input to only one of the U phase 5 pulse mode PWM signal generating means 121 and the U phase 3 pulse mode PWM signal generating means 122. This makes U
The U-phase PWM signal in either the 5-pulse mode or the 3-pulse mode is output from the phase PWM signal generating means 12.

Similarly, V-phase PWM signal generating means and W-phase PW
M signal generating means is also configured, and V phase P of either one of the pulse modes corresponding to the pulse mode switching command of each phase
The WM signal and the W-phase PWM signal are output.

With this configuration, in the pulse mode switching, the PWM signals of the U phase, V phase, and W phase of the inverter output voltage are independent of each other at the switching phase angle at which the transient fluctuation of the inverter output current at the time of switching is minimized. Since it is switched to, it is possible to eliminate the torque shock of the electric motor at the time of switching.

In the present embodiment, an example of switching between the two pulse modes of the 5-pulse mode and the 3-pulse mode has been shown. However, even in the case of having another pulse mode and in the case of having three or more pulse modes. The pulse mode switching operation can be performed in the same manner as in this embodiment.

Further, in the embodiment corresponding to claim 6, the inside of the switching phase angle generating means 7 may be constituted only by the switching phase angle storage section 74 as shown in FIG. The switching phase angle storage unit 74 stores and inputs the switching phase angle θCHG previously obtained from the relationship between the inverter output voltage amplitude command value VmRef and the PWM waveform of each pulse mode for the two pulse modes to be switched. Outputs the switching phase angle θCHG corresponding to the inverter output voltage amplitude command value VmRef.

With this configuration, in the pulse mode switching, the PWM signals of the U phase, V phase, and W phase of the inverter output voltage are independently output at the switching phase angle at which the transient fluctuation of the inverter output voltage at the time of switching is minimized. Since switching is performed, torque shock of the electric motor at the time of switching can be eliminated.

In this embodiment, 5 pulse mode and 3 pulse mode are used.
Although an example of switching between two types of pulse modes, which is a pulse mode, has been described, the switching between pulse modes can be performed in the same manner even when other pulse modes are included and when three or more pulse modes are included.

FIG. 19 is a diagram showing an embodiment of the invention described in claim 7, and is a block diagram of the controller for the main circuit shown in FIG. In this embodiment, the switching phase angle θCHG uses a constant value obtained in advance from the PWM waveform of each pulse mode.

With this configuration, in the pulse mode switching, the PWM signals for the U phase, V phase, and W phase of the inverter output voltage are independent of each other at the switching phase angle at which the transient fluctuation of the inverter output current at the time of switching is minimized. Since it is switched to, it is possible to eliminate the torque shock of the electric motor at the time of switching.

In the present embodiment, an example of switching between two types of pulse modes, that is, a 5-pulse mode and a 3-pulse mode, is shown. However, even when other pulse modes are provided and when three or more pulse modes are provided, The pulse mode can be switched in the same manner.

Further, in the embodiment shown in FIGS. 13 to 19 described above, when the main circuit configuration is replaced with the three-level output inverter main circuit shown in FIG. The pulse mode can be switched in the same manner as in the embodiment of FIG.

Therefore, even when the configuration of the main circuit is replaced with the three-level output inverter main circuit shown in FIG. 9, the inverter output voltage inverter signals at the time of switching the U-phase, V-phase, and W-phase PWM signals are switched. Since each phase can be switched independently at the switching phase angle that can minimize the transient fluctuation of the output current, torque shock of the electric motor at the time of switching can be eliminated.

[0078]

According to the first to seventh aspects of the present invention, the transient mode of the inverter output current and the torque shock of the motor do not occur, and the pulse mode (per half cycle synchronized with the inverter output voltage cycle) is obtained. It is possible to provide a power conversion device that can switch the number of pulses).

[Brief description of drawings]

FIG. 1 is a main circuit configuration diagram of an inverter showing a first embodiment of the invention described in claim 1.

FIG. 2 is a diagram showing a configuration of a control device of FIG.

FIG. 3 is a diagram showing a configuration of inverter output voltage phase angle command value generation means in FIG.

FIG. 4 is a diagram showing a PWM waveform.

FIG. 5 is a diagram illustrating how to determine a pulse mode switching phase angle.

FIG. 6 is a diagram showing a configuration of pulse mode phase-by-phase switching instruction generating means in FIG. 2;

FIG. 7 is a diagram showing a configuration of a switching unit of FIG.

FIG. 8 is a diagram showing an example of an inverter output voltage waveform when switching from a 5-pulse mode to a 3-pulse mode.

FIG. 9 is a main circuit configuration diagram of an inverter showing a second embodiment of the invention described in claim 1.

FIG. 10 is a diagram showing a PWM waveform.

FIG. 11 is a diagram illustrating how to determine a pulse mode switching phase angle.

FIG. 12 is a diagram showing an example of an inverter output voltage waveform when switching from a 5-pulse mode to a 3-pulse mode.

FIG. 13 is a diagram showing a configuration of a control device according to a second aspect of the invention.

14 is a diagram showing a configuration of a switching phase angle generating means of FIG.

FIG. 15 is a diagram showing a configuration of a switching phase angle generating means according to the third aspect of the invention.

FIG. 16 is a diagram showing a configuration of a control device according to a fourth aspect of the invention.

FIG. 17 is a diagram showing a configuration of a control device according to a fifth aspect of the invention.

FIG. 18 is a diagram showing a configuration of U-phase PWM signal generation means in FIG.

FIG. 19 is a diagram showing a configuration of a control device according to a seventh aspect of the invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Inverter output voltage amplitude command value generation means, 2 ... Inverter output voltage frequency command value generation means, 3 ... Inverter output voltage phase angle command value generation means, 4 ... Pulse mode command generation means, 5 ... 5 Pulse mode PWM signal generation Means, 6
... 3 pulse mode PWM signal generating means, 7, 71 ... switching phase angle generating means, 8 ... pulse mode phase-specific switching generating means, 9 ... U phase switching means, 10 ... V phase switching means,
11 ... W-phase switching means, 12 ... U-phase PWM signal generating means,
13 ... V-phase PWM signal generating means, 14 ... W-phase PWM signal generating means, 711 ... 5 pulse mode PWM waveform switching phase angle calculating means, 712 ... 3 pulse mode PWM waveform switching phase angle calculating means, 713 ... Pulse mode switchable Phase angle calculation means, 714 ... Switching phase angle storage means, 81
... U-phase phase angle conversion means, 82 ... V-phase phase angle conversion means, 83 ...
W phase phase angle converting means, 84 ... U phase switching phase angle condition determining means, 85 ... V phase switching phase angle condition determining means, 86 ... W phase switching phase angle condition determining means, 87 ... U phase pulse mode switching command generating means , 88 ... V phase pulse mode switching command generating means, 89 ... W phase pulse mode switching command generating means, 121 ... U phase 5 pulse mode PWM signal generating means, 1
22 ... U-phase 3-pulse mode PWM signal generating means, 123 ... U
Phase switching means

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[Procedure amendment]

[Submission date] January 8, 1996

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

A power conversion device (hereinafter referred to as an inverter) for converting DC power into AC power by PWM control is
N pieces per cycle in synchronization with the period of the output voltage (n is any positive integer, for example, n = 1, 3, 5 ...) is controlled to operate at a number of pulses.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

In the operation mode with five pulses (hereinafter referred to as five-pulse mode), the phase voltage level of a two-level output inverter for converting a DC voltage into an AC voltage having two positive and negative phase voltages is the output voltage 1 Since it changes 10 times per cycle, the switching element forming the inverter performs ON / OFF switching operation (switching) 10 times per output voltage cycle. In addition, the phase voltage level of a three-level output inverter that converts a DC voltage into an AC voltage with a phase voltage of three levels is 5 positive pulses and 5 negative pulses, and the output voltage changes 20 times per cycle. Looking at each of the switching elements that make up the inverter, per output voltage cycle
Switching is performed 10 times.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

[0008]

In order to achieve the above-mentioned object, the invention described in claim 1 is constituted by a plurality of switching elements, and a DC voltage is multiphase based on a frequency command value and an amplitude command value. conversion means for converting the AC voltage, and a pulse mode command generating means for outputting to set the number of pulses per period synchronized with the period of the AC voltage output from the converting means, the phase angle command value determined from the frequency command value from the amplitude command value, and a plurality of pulse width modulation signal generating means for outputting respectively a pulse width modulated signal having a number of pulses any per period synchronized with the period of the AC voltage, these pulse-width-modulated signal generating means outputs switching enter each pulse width modulated signal, when changing the number of pulses per period synchronized with the period of the AC voltage, transient fluctuations in the output of the conversion means small for The switching phase angle generating means for obtaining and outputting the phase angle is compared with the phase angle command value and the switching phase angle, and the pulse mode switching command for switching to the number of pulses output from the pulse mode command generating means is output independently for each phase. Of the pulse mode phase-dependent switching command generating means and the pulse width modulation signal generating means, which corresponds to the pulse mode switching command, outputs the gate signals to the plurality of switching elements based on the pulse width modulation signal output by one. And a pulse mode switching means for outputting for each phase.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

Further, the invention according to claim 2 is composed of a plurality of switching elements, and a conversion means for converting a DC voltage into a multi-phase AC voltage based on the frequency command value and the amplitude command value, and the conversion means. Synchronized with the cycle of the output AC voltage
Has a pulse mode command generating means for outputting to set the number of pulses per cycle, from the phase angle command value and the amplitude command value determined from the frequency command value, the number of pulses any per period synchronized with the period of the AC voltage a plurality of pulse width modulation signal generating means for outputting respectively a pulse width modulated signal, when entered the amplitude command value, changing the number of pulses per period synchronized with the period of the AC voltage, the transient of the output of the conversion means A pulse for switching to the number of pulses output from the pulse mode command generating means by comparing the phase angle command value and the switching phase angle with the switching phase angle generating means that obtains and outputs the switching phase angle with a small fluctuation. The pulse mode switching command generator that outputs the mode switching command and the pulse mode switching command among the plurality of pulse width modulation signal generators Based on one of the pulse width modulation signal to be output to respond, comprising a pulse mode switching means for outputting a gate signal to the plurality of switching elements for each phase.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

According to a third aspect of the present invention, there is provided a converting means which is composed of a plurality of switching elements, and which converts a direct current voltage into a multi-phase alternating current voltage based on a frequency command value and an amplitude command value, and the converting means. Synchronized with the cycle of the output AC voltage
Has a pulse mode command generating means for outputting to set the number of pulses per cycle, from the phase angle command value and the amplitude command value determined from the frequency command value, the number of pulses any per period synchronized with the period of the AC voltage a plurality of pulse width modulation signal generating means for outputting respectively a pulse width modulated signal, when changing the number of pulses per period synchronized with the period of the AC voltage, the transient is small switching phase angle of the output of the conversion means The number of pulses output from the pulse mode command generating means by comparing the phase angle command value and the switching phase angle with the switching phase angle generating means that stores and outputs the switching phase angle according to the amplitude command value. Pulse mode switching command generating means for outputting a pulse mode switching command for switching to the One corresponding to place command based on the pulse width modulation signal is to be output, comprising a pulse mode switching means for outputting a gate signal to the plurality of switching elements for each phase.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

According to a fourth aspect of the present invention, there is provided a converting means which is composed of a plurality of switching elements, and which converts a direct current voltage into a multi-phase alternating current voltage based on a frequency command value and an amplitude command value, and the converting means. Synchronized with the cycle of the output AC voltage
Has a pulse mode command generating means for outputting to set the number of pulses per cycle, from the phase angle command value and the amplitude command value determined from the frequency command value, the number of pulses any per period synchronized with the period of the AC voltage a plurality of pulse width modulation signal generating means for outputting respectively a pulse width modulated signal, when changing the number of pulses per period synchronized with the period of the AC voltage, and transients are small switching phase angle of the output of the conversion means A pulse mode phase switching command generator that outputs a pulse mode switching command that compares the phase angle command value with the number of pulses output from the pulse mode command generator independently for each phase, and multiple pulse width modulation signal generation Based on the pulse width modulation signal output by one of the means, which corresponds to the pulse mode switching command, a gate to a plurality of switching elements is provided. Comprising a pulse mode switching means for outputting a signal for each phase.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

According to a fifth aspect of the present invention, there is provided a conversion means which is composed of a plurality of switching elements, and which converts a DC voltage into a multi-phase AC voltage based on the frequency command value and the amplitude command value, and the conversion means. Synchronized with the cycle of the output AC voltage
A pulse mode command generating means for outputting to set the number of pulses per period, type the amplitude command value, when changing the number of pulses per period synchronized with the period of the AC voltage, the transient of the output of the conversion means A switching phase angle generating means for obtaining and outputting a switching phase angle with a small variation is compared with a phase angle command value determined from a frequency command value and the switching phase angle, and each phase is independently output from the pulse mode command generating means. a pulse mode phase-specific switching command generating means for outputting a pulse mode switching command for switching the number of pulses, and inputs the phase angle command value and the amplitude command value, corresponding to the synchronized per cycle pulse mode switching command to the period of the AC voltage Pulse width modulation signal that outputs the gate signal to multiple switching elements for each phase based on the pulse width modulation signal that has a certain number of pulses. Made and a generator.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

According to a sixth aspect of the present invention, there is provided a converting means which is composed of a plurality of switching elements, and which converts the direct current voltage into a multi-phase alternating current voltage based on the frequency command value and the amplitude command value, and the converting means. Synchronized with the cycle of the output AC voltage
A pulse mode command generating means for outputting to set the number of pulses per period, when changing the number of pulses per period synchronized with the period of the AC voltage, the transient is small switching phase angle of the output of the conversion means A switching phase angle generating means for storing and outputting a switching phase angle according to an amplitude command value is compared with a phase angle command value determined from a frequency command value and a switching phase angle, and the pulse mode command generating means is unique to each phase. a pulse mode phase-specific switching command generating means for outputting a pulse mode switching command for switching the number of pulses output from the inputs the phase angle command value and the amplitude command value, one cycle per pulse mode synchronized with the cycle of the AC voltage Outputs gate signals to multiple switching elements for each phase based on a pulse width modulation signal that has a number of pulses corresponding to the switching command. Comprising a pulse width modulation signal generating means.

[Procedure Amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

According to a seventh aspect of the present invention, there is provided a converting means which is composed of a plurality of switching elements, and which converts a direct current voltage into a multi-phase alternating current voltage based on a frequency command value and an amplitude command value, and the converting means. Synchronized with the cycle of the output AC voltage
A pulse mode command generating means for outputting to set the number of pulses per period, when changing the number of pulses per period synchronized with the period of the AC voltage, and transients are small switching phase angle of the output of the conversion means The phase angle command value, which compares the phase angle command value determined from the frequency command value, and outputs the pulse mode switching command that switches to the number of pulses output from the pulse mode command generating means independently for each phase, and the phase angle Enter the command value and the amplitude command value,
Based on the pulse width modulation signal having a number of pulses corresponding to synchronized one cycle per pulse mode switching command to the period of the AC voltage, a pulse width modulation signal generator for outputting a gate signal to the plurality of switching elements for each phase And means.

[Procedure Amendment 11]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

Inverter output voltage amplitude command generation means 1
Outputs the inverter output voltage amplitude command value VmRef.
The inverter output voltage frequency command value generation means 2 outputs the inverter output voltage frequency command value FoRef. The inverter output voltage phase angle command value generation means 3 receives the inverter output voltage frequency command value FoRef output from the inverter output voltage frequency command value generation means 2 and outputs an inverter output voltage phase angle command value θRef. The inverter output voltage phase angle command value generation means 3 has, for example, the configuration shown in FIG. 3 and integrates the inverter output voltage frequency command value FoRef to obtain the inverter output voltage phase angle θRef.
(0 to 2π) is obtained and output. The pulse mode command generating means 4 is the inverter output voltage frequency command value generating means 2
Inverter output voltage output from the frequency command value FoRef
The as input, it sets the number of pulses per cycle of the inverter output voltage. 5 pulse mode PWM signal generating means 5
Is the input of the inverter output voltage amplitude command value VmRef output from the inverter output voltage amplitude command value generation means 1 and the inverter output voltage phase angle command value θRef output from the inverter output voltage phase angle command value generation means 3,
For example, FIG. 4 (b) there are five pulses per cycle of the inverter output voltage shown in 5 pulse mode of U-phase, V-phase,
The W-phase PWM signal is output. The 3-pulse mode PWM signal generating means 6 outputs the inverter output voltage amplitude command value VmRe output from the inverter output voltage amplitude command value generating means 1.
The inverter output voltage phase angle command value θRef output from f and the inverter output voltage phase angle command value generating means 3 as an input, for example, there are three pulses per cycle of the inverter output voltage shown in FIG. 4 (a) 3 pulse It outputs PWM signals of U-phase, V-phase, and W-phase of the mode.

[Procedure Amendment 12]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

[0021] 3-pulse mode PWM waveform in the one phase voltage as shown in FIG. 4 (a), in synchronization with the inverter output voltage cycle there are three pulses per cycle waveform, Figure 4 shows as an example In the waveform of (a), the inverter output voltage fundamental wave Vs is

[Procedure Amendment 13]

[Document name to be amended] Statement

[Name of item to be corrected] 0024

[Correction method] Change

[Correction content]

The 5-pulse mode PWM waveform is a waveform in which one phase voltage has five pulses in synchronization with one cycle of the inverter output voltage, as shown in FIG. 4 (b). In the waveform shown in FIG. 4B as an example, the inverter output voltage fundamental wave Vs is

[Procedure Amendment 14]

[Document name to be amended] Statement

[Correction target item name] 0041

[Correction method] Change

[Correction content]

The 5-pulse mode PWM signal generating means 5 is
With the inverter output voltage amplitude command value VmRef output from the inverter output voltage amplitude command value generation means 1 and the inverter output voltage phase angle command value θRef output from the inverter output voltage phase angle command value generation means 3 as inputs, for example, FIG. per cycle of the inverter output voltage shown in (b)
Positive pulse five negative pulses U-phase five is 5 pulse mode, V-phase, and outputs a PWM signal of the W phase.

[Procedure Amendment 15]

[Document name to be amended] Statement

[Correction target item name] 0042

[Correction method] Change

[Correction content]

The 3-pulse mode PWM signal generating means 6 is
With the inverter output voltage amplitude command value VmRef output from the inverter output voltage amplitude command value generation means 1 and the inverter output voltage phase angle command value θRef output from the inverter output voltage phase angle command value generation means 3 as inputs, for example, FIG. per cycle of the inverter output voltage shown in (a)
Positive pulse three negative pulses U-phase three are three-pulse mode, V-phase, and outputs a PWM signal of the W phase.

[Procedure Amendment 16]

[Document name to be amended] Statement

[Correction target item name] 0043

[Correction method] Change

[Correction content]

The 3-pulse mode PWM waveform of 3-level output has three positive pulses and one negative pulse in one cycle of the inverter output voltage, as shown in FIG.
In the waveform shown in FIG. 10A as an example, the inverter output voltage fundamental wave Vs is

[Procedure Amendment 17]

[Document name to be amended] Statement

[Name of item to be corrected] 0045

[Correction method] Change

[Correction content]

Also, three-level output five-pulse mode PWM
The waveform has five positive pulses in one cycle of the inverter output voltage for one phase voltage, as shown in FIG.
This is a waveform with five negative pulses . Figure 10 as an example
In the waveform of (b), the inverter output voltage fundamental wave Vs
Is

[Procedure 18]

[Document name to be amended] Statement

[Correction target item name] 0078

[Correction method] Change

[Correction content]

[0078]

Effects of the Invention According to the invention described in claims 1 to 7, without occur transient fluctuations and motor torque shock of the inverter output current, the pulse mode (per period synchronized to the inverter output voltage cycle It is possible to provide a power conversion device that can switch the number of pulses).

Claims (7)

[Claims] 1. A conversion means which is composed of a plurality of switching elements and which converts a DC voltage into a multi-phase AC voltage based on a frequency command value and an amplitude command value, and a synchronization of the cycle of the AC voltage output by the conversion means. Pulse mode command generating means for setting and outputting the number of pulses per half cycle, and from the phase angle command value and the amplitude command value determined from the frequency command value, any number per half cycle synchronized with the cycle of the AC voltage A plurality of pulse width modulation signal generating means for outputting pulse width modulation signals each having a pulse and the respective pulse width modulation signals output by these pulse width modulation signal generating means, and are synchronized with the cycle of the AC voltage. Switching phase angle generating means for obtaining and outputting a switching phase angle with a small transient fluctuation of the output of the converting means when the number of pulses per half cycle is changed A pulse mode switching command generating means for comparing the phase angle command value with the switching phase angle and outputting a pulse mode switching command for switching to the number of pulses output from the pulse mode command generating means for each phase independently. And outputting a gate signal to each of the plurality of switching elements for each phase based on a pulse width modulation signal output by one of the plurality of pulse width modulation signal generating means corresponding to the pulse mode switching command. A power converter having pulse mode switching means. 2. A conversion means which is composed of a plurality of switching elements and which converts a direct current voltage into a multi-phase alternating current voltage based on a frequency command value and an amplitude command value, and a synchronization of the cycle of the alternating voltage output by this conversion means. Pulse mode command generating means for setting and outputting the number of pulses per half cycle, and from the phase angle command value and the amplitude command value determined from the frequency command value, any number per half cycle synchronized with the cycle of the AC voltage A plurality of pulse width modulation signal generating means for respectively outputting a pulse width modulation signal having a pulse, when inputting the amplitude command value, when changing the number of pulses per half cycle synchronized with the cycle of the AC voltage, Switching phase angle generating means for obtaining and outputting a switching phase angle with a small transient fluctuation of the output of the converting means, and comparing the phase angle command value and the switching phase angle, A pulse mode switching command generating means for outputting a pulse mode switching command that independently switches the number of pulses output from the pulse mode command generating means, and for each phase, among the plurality of pulse width modulation signal generating means, A power conversion device having pulse mode switching means for outputting a gate signal to the plurality of switching elements based on a pulse width modulation signal output by one corresponding to the pulse mode switching command. 3. A conversion means which is composed of a plurality of switching elements and which converts a DC voltage into a multi-phase AC voltage based on a frequency command value and an amplitude command value, and a synchronization of the cycle of the AC voltage output by this conversion means. Pulse mode command generating means for setting and outputting the number of pulses per half cycle, and from the phase angle command value and the amplitude command value determined from the frequency command value, any number per half cycle synchronized with the cycle of the AC voltage A plurality of pulse width modulation signal generating means each outputting a pulse width modulation signal having a pulse of, and a transient fluctuation of the output of the converting means when the number of pulses per half cycle synchronized with the cycle of the AC voltage is changed. , A switching phase angle generating means for storing the switching phase angle and outputting the switching phase angle according to the amplitude command value; the phase angle command value and the switching A pulse mode switching command generating means for comparing the phase angle and outputting a pulse mode switching command for switching to the number of pulses output from the pulse mode command generating means independently for each phase; and a plurality of pulse width modulation signal generations. Of the means, a pulse mode switching means for outputting a gate signal to each of the plurality of switching elements for each phase based on a pulse width modulation signal output by one corresponding to the pulse mode switching command. . 4. A conversion means which is composed of a plurality of switching elements, and which converts a DC voltage into a multi-phase AC voltage based on a frequency command value and an amplitude command value, and a synchronization of the cycle of the AC voltage output by the conversion means. Pulse mode command generating means for setting and outputting the number of pulses per half cycle, and from the phase angle command value and the amplitude command value determined from the frequency command value, any number per half cycle synchronized with the cycle of the AC voltage A plurality of pulse width modulation signal generating means each outputting a pulse width modulation signal having a pulse of, and a transient fluctuation of the output of the converting means when the number of pulses per half cycle synchronized with the cycle of the AC voltage is changed. Is small, the phase angle command value is compared with the switching phase angle, and the pulse mode switching is switched to the number of pulses output from the pulse mode command generating means independently for each phase. And a plurality of pulse width modulation signal generating means for outputting a change command, and one of the plurality of pulse width modulation signal generating means, which corresponds to the pulse mode switching command, outputs the plurality of pulse width modulation signals based on the pulse width modulation signal. A power converter having pulse mode switching means for outputting a gate signal to a switching element for each phase. 5. A conversion means which is composed of a plurality of switching elements, and which converts a direct current voltage into a multi-phase alternating current voltage based on a frequency command value and an amplitude command value, and a synchronization of the cycle of the alternating voltage output by this conversion means. Pulse mode command generating means for setting and outputting the number of pulses per half cycle, and inputting the amplitude command value, and changing the number of pulses per half cycle in synchronization with the cycle of the AC voltage, the converting means Switching phase angle generating means for obtaining and outputting a switching phase angle with a small transient fluctuation of the output, and comparing the phase angle command value and the switching phase angle determined from the frequency command value, and the pulse mode command independently for each phase. Pulse mode switching command generating means for outputting a pulse mode switching command for switching to the number of pulses output from the generating means, the phase angle command value and the amplitude And a gate width to each of the plurality of switching elements based on a pulse width modulation signal having a number of pulses corresponding to the pulse mode switching command per half cycle synchronized with the cycle of the AC voltage. A power conversion device having a pulse width modulation signal generating means for outputting for each phase. 6. A conversion means which is composed of a plurality of switching elements and which converts a direct current voltage into a multi-phase alternating current voltage based on a frequency command value and an amplitude command value, and a synchronization of the cycle of the alternating voltage output by this conversion means. And a pulse mode command generating means for setting and outputting the number of pulses per half cycle, and switching when the number of pulses per half cycle synchronized with the cycle of the AC voltage is changed to have a small transient fluctuation of the output of the converting means. A switching phase angle generating unit that stores the phase angle and outputs the switching phase angle according to the amplitude command value, compares the phase angle command value determined from the frequency command value with the switching phase angle, and uniquely for each phase. A pulse mode switching command generating means for outputting a pulse mode switching command for switching to the number of pulses output from the pulse mode command generating means, The plurality of switching elements are input based on a pulse width modulation signal having a number of pulses corresponding to the pulse mode switching command per half cycle in synchronization with the cycle of the AC voltage, the angle command value and the amplitude command value being input. Power converter having pulse width modulation signal generating means for outputting a gate signal to each phase. 7. A conversion means which is composed of a plurality of switching elements and which converts a DC voltage into a multi-phase AC voltage based on a frequency command value and an amplitude command value, and a synchronization of the cycle of the AC voltage output by the conversion means. And a pulse mode command generating means for setting and outputting the number of pulses per half cycle, and switching when the number of pulses per half cycle synchronized with the cycle of the AC voltage is changed to have a small transient fluctuation of the output of the converting means. A pulse mode switching command generation that outputs a pulse mode switching command that compares the phase angle and the phase angle command value determined from the frequency command value, and switches to the number of pulses output from the pulse mode command generating means independently for each phase Means for inputting the phase angle command value and the amplitude command value, and the pulse mode switching command per half cycle synchronized with the cycle of the AC voltage A pulse width modulation signal generating means for outputting a gate signal to each of the plurality of switching elements for each phase based on a pulse width modulation signal having a number of pulses corresponding to.