JP5069882B2 - Three-phase converter / inverter device and module - Google Patents

Description

  The present invention relates to a converter device that converts alternating current to direct current, and an inverter device and module that convert direct current to alternating current.

  A sine wave PWM converter device is widely used as a power converter capable of extremely reducing a harmonic current generated from a power converter for converting from alternating current to direct current.

  In the PWM converter device, a reactor is connected to an AC power supply on the input side, and a smoothing capacitor and a load are connected between DC terminals on the output side. Therefore, when power is supplied from the power supply side to the load side, the PWM converter is controlled so that a sinusoidal input current flows in the same phase as the power supply voltage. Further, when power is regenerated from the load side to the power source side, the PWM converter is controlled so that a sinusoidal input current flows in a phase opposite to the power source voltage.

  Specifically, an amplitude command of the input current is given so that the DC voltage of the smoothing capacitor becomes a predetermined value, and the PWM command is performed so that the input current detection value matches the command value as a current command value synchronized with the power supply voltage phase. Controls the AC input voltage of the converter.

  In order to control the PWM converter in this way, detection of the power supply voltage phase and the input current to the converter is indispensable.

  The sine wave PWM converter has been developed for a long time, and many methods have been proposed.

  Here, as a method of detecting the power supply voltage phase without using the power supply voltage sensor, “One Method of Power Supply Voltage Sensorless Three-Phase PWM Converter” described in the 1994 Journal of the Institute of Electrical Engineers, D Volume 114, No. 12 has been proposed. ing. In this method, it is possible to flow a sine wave current synchronized with the power supply voltage phase without detecting the power supply voltage phase.

On the other hand, in the motor drive inverter device, as a means for estimating the motor rotor position from the induced voltage generated while the motor is idling, JP 2006-25587A and 2005 IEEJ Industrial Application Division Conference Proceedings There is a “free-run start-up method of a sensorless PM motor drive system applicable to a phase current and DC bus current detection method”. JP 2006
Japanese Patent No. 25587 discloses means for estimating the position of the rotor based on the current flowing by short-circuiting the windings of some of the phases during the idling of the multiphase AC motor. “The free-run start-up method of the sensorless PM motor drive system applicable to the phase current and DC bus current detection method” described in the annual meeting of the Institute of Electrical Engineers of the Institute of Electrical Engineers of Japan is to turn on / off one switching element of the inverter circuit. At that time, a method is described in which the induced voltage phase is estimated from the flow state of one-phase current or bus DC current.

JP 2006-25587 A "One Method of Power Supply Voltage Sensorless Three-Phase PWM Converter" described in 1994, IEEJ Transaction D, Volume 114, No. 12 "Free-run start-up method of sensorless PM motor drive system applicable to phase current and DC bus current detection method" described in the annual meeting of the Institute of Electrical Engineers of Japan

As described above, various methods have been proposed in the background art, but “One Method of Power Supply Voltage Sensorless Three-Phase PWM Converter” described in the 1994 Journal of Electrical Engineering, D Department, Volume 114,
In order to detect the initial phase of the power supply voltage when starting the PWM converter, it is necessary to perform a switching operation of the PWM converter at an appropriate phase and to estimate the power supply voltage phase using the voltage and current information obtained there.

  For this reason, it is necessary to consider not to cause overcurrent during the switching operation, and the above method may not be applied depending on the application (product) used.

  In addition, in order to detect and process the current information, at least two high-performance current sensors and a high-performance digital controller are required, which increases the cost.

  Furthermore, when starting the PWM converter, if there is a load, it is necessary to switch from the diode rectification mode to the PWM control mode. However, since the diode rectification voltage can only be charged up to the peak value of the power supply voltage, When the voltage command is large, overmodulation occurs, and when the voltage command is small, the difference in the voltage applied to the AC reactor increases, resulting in an overcurrent phenomenon.

  As conventional measures, there are a method of initially charging to a boosted voltage with a separate power supply and a method of gradually increasing the DC voltage command at start-up from the diode rectified voltage to the boosted voltage, but if there is a load on the DC side, in principle a diode Since the rectified voltage is low, the voltage that can be output from the converter is small, so the effect of suppressing the inrush current is considered to be small.

  On the other hand, as means for estimating the rotor position during idling of the motor, Japanese Patent Laid-Open No. 2006-25587 discloses means for estimating the position of the idling rotor of the multiphase AC motor. There is no consideration for it.

  “The free-run start-up method of the sensorless PM motor drive system applicable to the phase current and DC bus current detection method” described in the 2005 Annual Meeting of the Institute of Electrical Engineers of Japan, can be applied to the bus DC current detection method. There is no consideration for the detection error being increased due to the influence of the motor constant or the rotational speed, the application to the regenerative operation mode and the converter device.

  The object of the present invention is to solve the above-mentioned problems, and without using a voltage phase sensor or a phase current sensor, the phase, frequency, and phase sequence of the induced voltage generated when the AC power supply voltage or the permanent magnet synchronous motor is idling are switched during the switching operation. An object of the present invention is to provide a converter device, an inverter device, and a module that can be estimated by a flowing busbar direct current and can be stably started.

  In order to achieve the above object, an on / off signal control signal is sequentially given to a plurality of switching elements of a switching element group constituting a converter circuit, and the relationship between the bus DC current flowing at that time and the on / off control signal is used. Detecting at least one of the voltage phase, frequency, and phase sequence of the AC power supply.

  By using the present invention, a voltage phase sensor and a phase current sensor become unnecessary, and the converter device, the inverter device, and the module can be reduced in size and cost.

  Embodiments will be described below with reference to the drawings.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a PWM converter device according to an embodiment of the present invention. An example of the final utilization form of the PWM converter apparatus of this invention is shown.

  As shown in FIG. 1, the PWM converter device includes a converter circuit 4 connected to a three-phase AC power source 1 via a ripple filter 2 and a reactor 3, and a smoothing capacitor 5 connected to a DC output terminal of the converter circuit 4. And a load 9, a converter control unit 6 for controlling the converter circuit 4, a current detection circuit 7 for detecting a bus direct current, and a DC voltage detection circuit 8. The converter control unit 6 uses a semiconductor arithmetic element such as a microcomputer or a DSP (digital signal processor).

  In the following description, the converter circuit 4 has a three-phase bridge connection, and the switching elements on the upper arm side are Qr, Qs, and Qt, and the switching elements on the lower arm side are Qx, Qy, and Qz. The parallel diode is represented by symbols Dr, Ds, Dt, Dx, Dy, and Dz.

  FIG. 2 shows a startup sequence of the converter device. The start-up sequence of the converter device of this embodiment is switched to sensorless control by performing (1) load estimation, (2) boosting operation, and (3) phase detection. The details of this activation sequence will be described below.

  (1) Load estimation: The bus current detection circuit 7 detects a DC side current during diode rectification operation, and a Low Pass filter or a predetermined time by arithmetic processing (not shown) in the converter control unit 6 The DC component is taken out by averaging. When this DC component is larger than the set value, the converter is started.

  (2) Boosting operation: The control signal 12 shown in FIG. 3 is given to each switching element to boost the DC voltage. For example, when the switching element Qx switches from the on state to the off state, the current flowing through Qx is charged to the smoothing capacitor 5 through Dr, and the DC voltage is boosted. By boosting the DC voltage, it is possible to suppress overcurrent when switching sensorless control.

In addition, the DC voltage can be adjusted by adjusting the conduction ratio (ON time ratio) applied to the switching element. In order to avoid overvoltage and overcurrent, the pulse width of each on / off control signal should be gradually increased from zero. These on / off control signals are obtained by comparing the triangular wave carrier 14 and the command value 13 as shown in FIG. Three-phase on / off control signals P _Qx , P _Qy , and P _Qz are obtained by shifting each phase command value by one carrier period. In order to ensure the accuracy of phase detection described below, the carrier frequency should be set to several tens to several hundreds times the power frequency.

  While increasing the pulse width of the control signal, the DC voltage is detected using the DC voltage detection circuit 8. When the detected DC voltage exceeds the set value, the pulse width of the control signal is fixed and the process goes to phase detection processing.

  (3) Phase detection: A current is detected by the bus current detection circuit 7 in a state where the pulse width of the control signal is maintained and the switching element is turned on, and phase detection described below is performed.

  FIG. 5 shows a three-phase voltage waveform for one cycle of the power source. The six regions I to VI are shown depending on the magnitude relationship of the phase voltages. The detected current signal differs depending on the magnitude relationship between the phase voltages.

  For example, when the switching element Qx is on and in the power supply phase regions I and II, the U-phase voltage is higher than the V-phase or W-phase, as shown in FIG. 6, so that the switching elements Qx and Dy or Dz flow. To do. At this time, the bus DC current is not detected.

  On the other hand, in the case of the power supply phase regions IV and V, as shown in FIG. 7, since the U-phase voltage is lower than the V-phase or W-phase, even if the switching element Qx is turned on, Dx and Ds or Dt Circulate. At this time, the bus DC current is detected.

Similarly, in the power supply phase regions III and VI, since the V-phase or W-phase voltage is the maximum value or the minimum value, even if Qx is turned on, as shown in FIGS. 8 and 9, Dy and Dt or Since Dz and Ds are energized, the bus DC current is detected.

  As described above, only the power supply phase regions I and II have a feature that the detection current becomes 0 when the switching element Qx is on. Similarly, when the switching element Qy is on, the detection current is 0 in the power supply phase regions III and IV, and when the switching element Qz is on, the detection current is 0 in the power supply phase regions V and VI. .

  As described above, when the detected bus DC current signal is disassembled according to the phase of the on state when the switching element is on. In other words, the current detected with Qx on is the U-phase current; the current detected with Qy on is the V-phase current; the current detected with Qz on is the W-phase current. .

  FIG. 10 shows a waveform obtained by decomposing the detected current as described above. As shown in FIG. 10, the power supply voltage phase can be estimated because the fixed value of the power supply voltage phase and the start point and end point of the section where the detected current is 0 substantially match. Further, the phase order of the power supply can be determined from the order of the start point and end point of the 0 section of each detected waveform. Further, the power supply frequency can be calculated from the time difference between the waveforms.

  For example, in the detected current waveform 16 corresponding to the U phase, when the time when the current changes from positive to 0 is t1, the power supply voltage phase corresponding to that time (starting point) is about 30 °, and the current is changed from 0 to positive. If the time at a certain time is t2, the power supply voltage phase corresponding to that time (end point) is about 150 °. With the above correspondence, the power supply voltage phase can be estimated from the detected current waveform shown in FIG. However, the starting point and the end point may be slightly shifted due to the influence of the power supply inductance and the load, so that the detection accuracy is improved by using the middle point of the starting point and the end point.

  Hereinafter, a specific calculation algorithm for phase estimation performed in the converter control unit 6 will be described with reference to FIG.

  FIG. 11 shows a counter value 19 that is cleared at the start of the phase detection operation (time t0) and then up-counted for each carrier period, and a detected current waveform 16 corresponding to the U phase shown in FIG. Here, only U phase will be described for explanation.

  After time t0, converter control unit 6 compares the previous value of the detected current value with the current value and 0 value, and periodically searches for points that satisfy the following conditions.

Condition 1: The current value is smaller than the previous value and the current value is 0. Condition 2: The current value is larger than the previous value and the previous value is 0. Here, the 0 value is a value where the detected current value is 0 (ideal value). However, in reality, the value does not become completely zero due to the conversion accuracy of the A / D converter and the influence of noise, and therefore it is necessary to set the value below a predetermined set value to zero.

In FIG. 11, the point A is a condition 1 and the point B is a condition 2 point, the counter value at the time of the condition 1 is stored as N _1u , and the counter value at the time of the condition 2 is stored as N _2u .

As described above, it is possible to detect the counter value (time t1) N _1u when the power supply voltage phase is about 30 ° and the counter value N _2u (time t2) when the power supply voltage phase is about 150 °.

From the above data, the power supply voltage phase θ _dc at the present time (time t3) is obtained using the following equation.

θ _dc = (N− (N _2U + N _1U ) / 2) × Δθ + 90 °
Here, N is a counter value at the present time (time t3), and Δθ is a phase increment of one carrier cycle (Δθ = 360 ° × power supply frequency / carrier frequency).

  As can be seen from the above equation, in this embodiment, the average phase (90 °) is obtained from two points of condition 1 and condition 2, and the current phase is calculated using this as the reference phase. After the condition 2 is detected, the current phase may be calculated using the phase as a reference phase.

  As described above, the current power supply voltage phase can be detected from the detected current value.

  In the above description, it is assumed that the phase order of the power supply voltage is the normal order (U, V, W order). If the phase order of the power supply voltage is unknown, it is necessary to determine the phase order of the power supply first.

  Next, a method for determining the power supply voltage phase order will be described.

In order to determine the phase order, it is necessary to perform the above detection in each phase. Although details are not described, the phase order can be determined from the magnitude relationship of the counter values (N _1u , N _1v , N _1w , N _2u , N _2v , N _2w ) corresponding to the conditions of each phase.

For example,
When _N1u < _N1v < _N1w or _N1w < _N1u < _N1v or _N1v < _N1w < _N1u , the power supply voltage corresponds to the order of U, V, and W (normal order).

For N _1u <N _1w <N _1v, or N _1w <N _1v <N _1u or _{N 1v <N 1u <N 1w} , the supply voltage corresponds to the U, W, the order of V (reverse order).

Next, a method for detecting the power supply frequency will be briefly described. Similarly to the above, this can be calculated using counter values (N _1u , N _1v , N _1w , N _2u , N _2v , N _2w ) corresponding to the conditions of each phase. As a simple method, a method of obtaining from a difference between a counter value (for example, N _1u ) of condition 1 of a phase and a counter value of condition 2 (for example, N _2u ), or a difference between counter values before and after one cycle of the same condition There is a way to ask.

  In this embodiment, a method of using the difference between the counter value of condition 1 and the counter value of condition 2 of adjacent phases is shown. However, this calculation method needs to be performed after the determination of the phase order.

As an example, the case of N _1u <N _1v <N _1w or N _1w <N _1u <N _1v will be described. In this example, the frequency calculation formula is as follows.

fs = 120 × fc / (360 × | N _1v −N _1u |)
= Fc / (3 × | N _1v −N _1u |)
Here, fs: power supply frequency, fc: carrier frequency, N _1u : counter value of U-phase current start point, N _1v : counter value of V-phase current end point.

  As described above, after detecting the phase, frequency, and phase order, switching to sensorless control is performed.

  FIG. 12 shows a control flow until the converter device is activated.

In the present embodiment, as described above, since the setting is made such that the converter device is not operated unless the load of the converter device exceeds a certain value, the bus DC current is detected and the load is estimated. For this reason, F2,
At F3, the bus DC current is detected and monitored for starting conditions. When the start condition is cleared, the DC voltage boosting process described above is performed in F4 and F5.

After DC voltage boosting, the pulse width of the switching element is fixed (F6), and the power supply voltage phase, phase order, and power supply frequency are detected by the above-described phase, phase order, and frequency detection method and set in the control system (F7 to F9). Then, the process proceeds to sensorless control (F10).

  A second embodiment of the present invention will be described with reference to FIGS.

  The present embodiment shows a countermeasure when there is a noise component in the detected current during the phase detection of the first embodiment. FIG. 1 shows a PWM converter device according to an embodiment of the present invention.

  The configuration shown in FIG. 1 has been described in the first embodiment.

  The on / off control signal and the startup sequence of each switching element of the present embodiment are the same as those described in the first embodiment.

  In the phase detection method of the first embodiment described above, the zero-crossing point of the detected current waveform (that is, the point of time when the detected current is switched to the zone where there is no detected current, or the zone where the detected current is present from the zone where there is no detected current) The power supply phase is estimated using the time point of switching to (1). However, if there is a noise component in the detected current, a positional deviation or a determination error occurs at the time of the zero crossing, and the error becomes large in the phase estimation result.

  Further, in order to detect the zero crossing time point, it is necessary to compare the detected current with zero. Actually, the predetermined comparison value needs to be set larger than 0 due to the conversion accuracy of the A / D converter and the influence of noise. If the noise component is large, this comparison value must also be set large.

  In order to reduce the influence of the noise, a moving average process of the detection current is performed. In particular, the current waveform shown in FIG. 10 has a feature that there is no detection current during the 1/3 cycle of the power supply. Therefore, the length of the average section of the moving average process is set to the power supply cycle with respect to the current waveform shown in FIG. If it is set to 1/3, a minimum value close to 0 is obtained periodically in the average processing output.

  FIG. 13 shows the U-phase detected current waveform 16 and the U-phase current waveform 20 after the moving average process. The time point corresponding to the minimum value of the U-phase current waveform after the moving average processing corresponds to the zero-crossing time point of the U-phase detection current (the time point when switching from the section without the detection current to the section with the detection current). That is, the power supply phase can be estimated in the same manner as in the conventional phase calculation method using the time point corresponding to the minimum value of the U-phase current waveform after the moving average process.

  Hereinafter, a specific algorithm for calculating the phase order, frequency, and power supply phase will be described with reference to FIGS. 14 and 15.

  FIG. 14 shows three-phase detection current waveforms 20a, 20b and 20c after moving average processing and a microcomputer internal counter value 19 which is cleared at the start of the phase detection operation (time t0) and then up-counted every carrier cycle. .

  During time t0 to t4, a point that satisfies the following condition is searched (a counter value corresponding to the minimum value of the detected current value of the same phase is searched).

  Counter value update condition: The current value after moving average processing is smaller than or equal to the minimum current value.

Operation: Change the current minimum value to the current detection value after this moving average processing, and change the counter value to N _x
(X = u, v, w).

In order to reliably detect the minimum value of the three-phase detection current after the moving average process during one power cycle, the search time T _det needs to be set to 1 to 4/3 times the power cycle. Since the power supply frequency is 50 Hz or 60 Hz, the search time should be set as follows.

  This value is an average value of 1 times the power cycle of 50 Hz and 4/3 times the power cycle of 60 Hz.

After the minimum value search is completed (time t4), the counter value N _u , corresponding to the minimum current value of each phase,
Using N _v and N _w , phase order determination, frequency calculation, and phase calculation processing are performed as follows.
(1) Phase order determination process Using the counter values N _u , N _v , and N _w corresponding to the minimum current value, the phase order and θ ₀ and ΔN are determined according to the magnitude relationship shown in FIG. 15 (Table 1). Here, Δθ _dc is a current phase delay of the input reactor and an A / D conversion value capturing delay.
(2) Calculation of power supply frequency Since the phase corresponding to ΔN in FIG. 15 is 240 °, the power supply frequency fs can be obtained by the following equation.

fs = 240 ° × fc / (360 ° × ΔN) [Hz]
Here, fs: power supply frequency, fc: carrier frequency.

Since the actual power supply frequency is only 50 Hz and 60 Hz, the power supply frequency can be determined directly from the magnitude of ΔN.
(3) Power supply phase calculation The power supply phase calculation is obtained by the following formula according to the phase order. In normal order:
θ _dc = θ ₀ + (N− (N _u + N _v + N _w ) / 3) × Δθ [°]
In reverse order:
θ _dc = θ ₀ − (N− (N _u + N _v + N _w ) / 3) × Δθ [°]
Here, N is the counter value at the present time (time t4), Δθ is the phase increment of one carrier cycle (Δθ = 360 ° × power supply frequency / carrier frequency).

  After the completion of the phase order determination, frequency calculation, and phase calculation processing, as in the first embodiment, it is set in the control system and shifts to sensorless control.

  A second embodiment of the present invention will be described with reference to FIGS.

  FIG. 16 shows the application of the present invention to a motor drive PWM inverter device.

The same reference numerals as those in FIG. 1 denote the same operations. The difference from FIG. 1 is that the converter control unit 6 is changed to the inverter control unit 22, the DC load 9 is changed to the DC power source 23, and the AC power source 1 is changed to the motor 21.

  When the motor 21 is idling and the position or speed sensor is not attached to the motor, it is possible to detect the induced voltage of the motor and estimate the rotor position from the phase of the detected voltage. In order to detect the induced voltage, a dedicated circuit is required.

  Thus, as in the first embodiment, an induced phase detection means that does not require a dedicated circuit will be described.

  As in the first embodiment, the on / off control signal shown in FIG. 3 is applied to each switching element. In addition, the induced voltage is divided into six regions I to VI depending on the magnitude relationship of the phase voltages as in the three-phase voltage waveform shown in FIG.

  Generally, when the DC power supply voltage is larger than the phase voltage amplitude value of the motor induced voltage, there is no diode rectified current. Therefore, when the bus DC current is detected with the switching element as in the first embodiment turned on, Current cannot be detected in all areas. This can be dealt with by changing the timing of detecting the bus DC current immediately after switching the switching element from the on state to the off state.

  FIG. 17 shows an equivalent circuit in the idling state of the motor. Since the U-phase voltage is higher than the V-phase or W-phase in the induced voltage phase regions I to III and VI while the switching element Qx is on, the switching elements Qx and Dy or Dz flow. Immediately after Qx switches from the on state to the off state, as shown in FIG. 18, the current flowing through Qx is charged to the capacitor through Dr. At this time, the charging current can be detected by the bus DC current detection circuit 7.

  On the contrary, in the power supply phase regions IV and V, as shown in FIG. 19, since the U-phase voltage is lower than the V-phase or W-phase, even if the switching element Qx is turned on, it does not flow through Qx. Accordingly, no bus DC current flows immediately after Qx is switched from on to off.

  As described above, in the induced voltage phase regions IV and V, the detection current of the bus DC current detection circuit 7 becomes 0 immediately after the switching element Qx is switched from on to off.

  Similarly, immediately after the switching element Qy is switched from on to off, the detected current is 0 in the induced voltage phase regions I and VI, and immediately after the switching element Qz is switched from on to off, in the induced voltage phase regions V and VI. The detection current becomes zero.

  As described above, when the bus DC current signal detected immediately after each switching element is switched from on to off is decomposed according to the phase of the on state, the waveform shown in FIG. 20 is obtained.

  From these waveforms, the phase, frequency and rotation direction of the motor induced voltage can be estimated using the same algorithm described in the first embodiment and the second embodiment.

  When the motor induced voltage is low, the bus direct current becomes excessively small and cannot be detected. This is addressed by the following two measures.

  <Countermeasure 1> Increase the width of the on / off control signal.

  <Countermeasure 2> If the detected current does not reach the predetermined value even when the width of the on / off control signal reaches the maximum value, the carrier frequency is gradually lowered from the maximum setting value, and the bus DC current value is set to the predetermined value. Adjust so that

  In the present embodiment, the rotor position estimating means has been described using the induced voltage in the idling state of the motor. However, the present invention can also be applied when the control target is not a motor but an AC power supply facility such as a power generator.

  A fourth embodiment of the present invention will be described with reference to FIG.

  The same reference numerals as those in FIG. 1 of the first embodiment and FIG. 16 of the third embodiment perform the same operation.

  This embodiment shows an example of a utilization form of conversion from a DC power source (solar cell, fuel cell, etc.) to an AC power source of the PWM inverter device of the third embodiment of the present invention. In other words, the present embodiment is a case where the power conversion direction of the first embodiment is reversed.

  When there is no voltage sensor and the three-phase current reproduction method is used by the bus DC current, the voltage phase estimation processing should be performed in the same manner as in the first and second embodiments before the inverter device is started. Thus, it is possible to detect the phase of the power supply (system) voltage.

  The on / off control signal generation method, current detection method, and phase detection processing of each switching element are the same as those in the first and second embodiments.

  A fifth embodiment of the present invention will be described with reference to FIG. In this embodiment, the three-phase converter device of the first and second embodiments and the motor drive inverter device of the third embodiment are modularized.

  Here, the inverter DC current detection circuit 7a, the converter DC current detection circuit 7, the DC voltage detection circuit 8, and the converter / inverter control unit 6a are configured as a part of a one-chip microcomputer. Further, the one-chip microcomputer, the converter circuit 4 and the inverter circuit 4a are configured on the same substrate and are housed in one module.

  By modularization, it is possible to reduce the parts of the control unit (for example, sharing of a microcomputer, a power supply circuit, and a DC voltage detection circuit). In addition, the control response can be made faster by sharing the control information of the inverter and the converter.

  In FIG. 22, the part which comprises the module 24 is shown with the broken line. The module here means “standardized structural unit”, and is composed of separable hardware / software components. In addition, although it is preferable that it is comprised on the same board | substrate on manufacture, it is not limited to the same board | substrate. From this, it may be configured on a plurality of circuit boards built in the same housing. In the other embodiments, the same configuration can be adopted.

  If the present invention is used, the AC voltage sensor and the AC current sensor are omitted on both the inverter side and the converter side of the above module, so that the control board can be reduced in size and cost.

  As described above, according to the present invention, an AC voltage sensor and a current sensor are not used at all, and the PWM converter device and the motor drive inverter device having an inexpensive circuit configuration are smooth in a short time (no overvoltage and overcurrent phenomenon). ) A PWM converter / inverter module that can be started can be provided.

The block diagram of the PWM converter apparatus which shows the 1st Example of this invention. It is a converter starting sequence of the 1st example of the present invention. The converter circuit and control signal at the time of the phase detection of 1st Example of this invention. It is a figure which shows the control signal generation method at the time of the phase detection of 1st Example of this invention. It is a figure which shows a three-phase power supply voltage waveform and a phase area | region. In the power supply phase regions I and II, it is an equivalent circuit showing energization paths. It is an equivalent circuit showing energization paths in the power supply phase regions IV and V. 3 is an equivalent circuit showing an energization path in the power supply phase region III. In the power supply phase region VI, it is an equivalent circuit showing an energization path. It is a figure which shows the detection electric current waveform of each phase from the bus-line direct current of 1st Example of this invention. It is explanatory drawing of the phase calculation algorithm of the 1st Example of this invention inside a microcomputer. It is a flowchart for performing DC capacitor charge and phase detection to which the first embodiment of the present invention is applied. It is a figure which shows the detected current waveform of U phase from the bus direct current of 2nd Example of this invention, and the current waveform after a moving average process. It is explanatory drawing of the phase calculation algorithm of the 2nd Example of this invention inside a microcomputer. It is a table | surface of the counter value and phase sequence relationship of 2nd Example of this invention. The block diagram of the motor control apparatus which shows the 2nd Example of this invention. It is an equivalent circuit which shows the energization path | route of a Qx ON state in the induced voltage phase area | regions I-III and VI of 2nd Example of this invention. In the induced voltage phase regions I to III and VI of the second embodiment of the present invention, it is an equivalent circuit showing an energization path immediately after switching from Qx on to off. In the induced voltage phase regions IV and V of the second embodiment of the present invention, it is an equivalent circuit in the Qx on state. It is a figure which shows the detection electric current waveform of each phase from the bus | bath direct current of 2nd Example of this invention. It is a block diagram of the inverter apparatus which shows the 3rd Example of this invention. It is a block diagram of the motor control module which shows the 4th Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... AC power source, 2 ... Ripple filter, 3 ... Reactor, 4 ... Converter circuit, 5 ... Smoothing capacitor, 6 ... Converter control part, 7 ... Bus DC current detection circuit, 8 ... DC voltage detection circuit, 9 ... Load, 10 ... DC voltage, 11 ... U phase current, 12 ... ON / OFF control signal, 13 ... U phase command value, 14 ... carrier, 15 ... Qx control signal, 16 ... decomposed current waveform (corresponding to U phase), 17 ... decomposed current waveform (corresponding to V phase), 18 ... decomposed current waveform (corresponding to W phase), 19 ... microcomputer internal counter value, 20 ... U phase current waveform after moving average processing, 21 ... motor, 22 ... Inverter control unit, 23 ... DC power supply, 24 ... module.

Claims (20)

A converter circuit in which an input side is connected to an AC power supply via a reactor, a smoothing capacitor is connected between DC terminals on the output side, and AC is converted to DC;
A bus DC current detection circuit for detecting a bus DC current on the DC side of the converter circuit;
In a converter device comprising control means for controlling the converter using the bus DC current detection value,
It flows by sequentially turning on a plurality of switching elements of the switching element group of only one of the switching element group of the upper arm or the switching element group of the lower arm among the switching element groups constituting the converter circuit one by one. The bus DC current is detected by the bus DC current detection circuit,
A converter device, wherein at least one of a voltage phase, a frequency, and a phase sequence of the AC power supply is calculated using the detected bus direct current. An inverter device comprising: an inverter circuit that converts direct current to alternating current; a bus direct current detection circuit that detects a bus direct current on the direct current side of the inverter circuit; and a control unit that controls the inverter using the bus direct current detection value In
When the motor connected to the inverter circuit is idle, a plurality of switching elements of only one of the switching element group of the upper arm or the switching element group of the lower arm among the switching element groups constituting the inverter circuit The bus DC current that flows by turning on each of them in turn is detected by the bus DC current detection circuit,
An inverter device, wherein at least one of an induced voltage phase, a frequency, and a phase sequence of the motor is detected using the detected bus direct current. An inverter circuit for converting the direct current into alternating current, with the output side connected to an alternating current power source via a reactor, a direct current power source connected between the direct current terminals on the input side,
A reactor connected to the inverter circuit;
A bus DC current detection circuit for detecting a bus DC current on the DC side of the inverter circuit;
In an inverter device comprising control means for controlling the inverter using the bus DC current detection value,
Before starting the inverter device, among the switching element groups constituting the inverter circuit, one switching element group of only one of the switching element group of the upper arm or the switching element group of the lower arm The bus DC current that flows by turning on one by one is detected by the bus DC current detection circuit,
An inverter device that detects a voltage phase, a frequency, and a phase sequence of the AC power supply using the detected bus DC current. In claim 1,
A converter device comprising no power supply voltage sensor for detecting a power supply voltage phase of the AC power supply. In claim 2,
An inverter device comprising no power supply voltage sensor for detecting a power supply voltage phase of the AC power supply. In claim 3,
An inverter device comprising no power supply voltage sensor for detecting a power supply voltage phase of the AC power supply. Oite to claim 1,
When the converter device is in a stopped state, a DC load state of the converter device is estimated from a bus DC current signal detected from the bus DC current detection circuit, and when the estimated DC load state is larger than a set value, the converter device is A converter device, which is activated and keeps the converter device stopped when the estimated DC load state is smaller than a set value. In claim 7,
The converter device is characterized in that the DC load state of the converter device is estimated by subjecting the bus DC current signal to a low pass filter, averaging for a certain time, or both. In claim 1,
A converter device characterized by detecting a section where the bus DC current does not flow by turning on a plurality of switching elements of the switching element group one by one in order, and detecting the voltage phase from the section. In claim 1,
A converter device characterized by detecting a section in which the bus DC current that flows by turning on a plurality of switching elements of a switching element group one by one in order and detecting the voltage phase from the center of the section. In claim 1,
When the plurality of switching elements of the switching element group are turned on one by one in sequence, the time when the bus DC current flowing does not flow, or the time when the bus DC current flows less than a predetermined value, or the time when the bus DC current flows out or more than a predetermined value And a voltage phase is detected based on the detected time. In claim 1,
It flows by sequentially turning on a plurality of switching elements of the switching element group of only one of the switching element group of the upper arm or the switching element group of the lower arm among the switching element groups constituting the converter circuit one by one. The bus DC current is detected by the bus DC current detection circuit,
The detection signal of the detected bus DC current is decomposed for each phase, and the time when the current value of the decomposed current signal of each phase is less than a predetermined value, or the time when the current value exceeds a predetermined value, or the predetermined value A converter device, wherein at least one of a voltage phase, a frequency, and a phase sequence of the AC power supply is detected from a time difference between phases of a time that is less than a predetermined time and an average value time that is equal to or greater than the predetermined value. In claim 1,
It flows by sequentially turning on a plurality of switching elements of the switching element group of only one of the switching element group of the upper arm or the switching element group of the lower arm among the switching element groups constituting the converter circuit one by one. The bus DC current is detected by the bus DC current detection circuit,
The detection signal of the detected bus direct current is decomposed for each phase, and the time when the current value of the current signal of one phase among the decomposed phases is less than a predetermined value, or the time when the current value becomes a predetermined value or more, Alternatively, at least two average values of the time that is less than the predetermined value and the time that is greater than or equal to the predetermined value are checked, and at least one of the voltage phase, frequency, and phase order of the AC power supply is detected from the time difference. The converter device characterized. In claim 1,
It flows by sequentially turning on a plurality of switching elements of the switching element group of only one of the switching element group of the upper arm or the switching element group of the lower arm among the switching element groups constituting the converter circuit one by one. The bus DC current is detected by the bus DC current detection circuit,
The detection signal of the detected bus direct current is decomposed for each phase, and the time when the current value of the current signal of the two phases of the decomposed phases becomes less than a predetermined value, or the time when the current value becomes a predetermined value or more, Alternatively, the converter device is characterized by detecting an average value time between a time when the time is less than the predetermined value and a time when the time is equal to or greater than the predetermined value, and detecting the frequency of the AC power supply from the time difference. In claim 1,
It flows by sequentially turning on a plurality of switching elements of the switching element group of only one of the switching element group of the upper arm or the switching element group of the lower arm among the switching element groups constituting the converter circuit one by one. The bus DC current is detected by the bus DC current detection circuit,
Using the detected bus DC current, the bus DC current detection signal is decomposed for each phase,
A moving average process is performed on a current signal of one of the decomposed phases, and at least one of the voltage phase, frequency, and phase sequence of the AC power supply is detected using the minimum value of the signal after the moving average process. The converter apparatus characterized by this. In claim 1,
The on / off control signal sent to the plurality of switching elements to turn on or off the plurality of switching elements one by one is output in order shifted by an integer multiple of the switching period for operating the switching elements. The converter apparatus characterized by the above-mentioned. In claim 1,
The pulse width of the on / off control signal sent to the plurality of switching elements in order to turn on or off the plurality of switching elements one by one is adjusted so that the DC voltage value between the DC terminals becomes a predetermined value. The converter apparatus characterized by the above-mentioned. In claim 1,
Before the converter device is activated, among the switching element groups constituting the converter circuit, an on / off control signal is sequentially given to an upper arm switching element group or a lower arm switching element group, and the on / off control signal By adjusting the width of the converter, the DC voltage of the smoothing capacitor is boosted to a predetermined value. In claim 2,
The pulse width or frequency of the on / off control signal sent to the plurality of switching elements in order to turn on or off the plurality of switching elements one by one is adjusted so that the bus DC current value becomes a predetermined value. An inverter device characterized by. In claim 2,
The frequency of the on / off control signal sent to the plurality of switching elements to turn on or off the plurality of switching elements one by one is gradually lowered from the maximum set value, and the bus DC current value is a predetermined value. An inverter device characterized by being adjusted to be

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