JP2009254032A - Control device of power converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device which reduces the cost of a voltage detection circuit by accurately operating an output voltage estimation value, and is not influenced by an output voltage error or the like. <P>SOLUTION: The control device includes: an current adjusting means 2 which operates first output voltage command values; adding/subtracting means 9d, 9q which operate second voltage command values by correcting the first output voltage command values by using output voltage error correction values; and a means which creates a drive signal for turning on/off a switching element of an inverter INV by using the second output voltage command values. The control device also includes: an output voltage error correction means 8 which obtains the output voltage error correction values by using a difference between reference voltage command values v<SB>dn</SB><SP>*</SP>, v<SB>qn</SB><SP>*</SP>obtained from the second output voltage command values, and output voltage operation values v<SB>d</SB><SP>^</SP>, v<SB>q</SB><SP>^</SP>obtained from an output current detection value and a motor constant setting value; and an output voltage estimation means 20 which operates output voltage estimation values v<SB>dest</SB>, v<SB>qest</SB>from the first output voltage command values v<SB>d0</SB><SP>*</SP>, v<SB>q0</SB><SP>*</SP>, and the output voltage error correction values Δv<SB>d</SB>, Δv<SB>q</SB>. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device for various power converters such as a PWM inverter that drives a motor at a variable speed, and more specifically, a control device that can accurately estimate an output voltage of a power converter and use it for speed control and the like. It is about.

The PWM inverter is widely used when an AC voltage having a desired frequency or amplitude is obtained from a DC voltage by controlling the ON / OFF time of the switching element. In order to accurately control the speed and torque of the motor using the PWM inverter, vector control is known, and it is generally necessary to detect the output current and output voltage of the inverter. In order to perform so-called speed sensorless vector control, the motor speed is estimated and calculated from the output current and output voltage, and therefore the output voltage detection accuracy is particularly important.
The reason is that the primary resistance value of the motor is very small and is about several percent of the impedance obtained from the rated voltage and rated current of the inverter, so that the voltage detection error has a great influence on the estimated value of the current. . For example, if there is a voltage error of 1% with respect to the rated voltage and the primary resistance of the motor is 5% of the impedance of the inverter, the estimated current is divided by 5% according to Ohm's law. As a result, the motor speed control may become impossible, resulting in failure of the apparatus or abnormal stoppage.

It is known that the output voltage error of the PWM inverter is caused by the following causes.
(1) Voltage error due to dead time: In order to prevent the upper and lower arms of the PWM inverter from being short-circuited, it is known that the so-called dead time is given to the on-time of the switching elements of the upper and lower arms. An error occurs between the on-time of the switching element and the actual on-time, and as a result, the actual output voltage may not match the output voltage command value.
(2) On-voltage error: Since the internal resistance exists in a state where the switching element is turned on and a current flows, a voltage drop occurs. Due to this voltage drop, the output voltage command value does not match the actual output voltage.
(3) Signal delay: When a drive signal for turning on / off a switching element is propagated from a control device via an optical element such as a photocoupler, there is a signal delay in the photocoupler, and when it is on and off Since the delay time is different from the above, a voltage error occurs. Further, the time for the switching element to transition from on to off and the time to transition from off to on are not symmetrical, and similarly, the output voltage command value and the actual output voltage do not match.

  In order to reduce such an output voltage error, for example, it may be possible to use a high-precision analog circuit element (resistor, capacitor, operational amplifier, etc.) that does not cause an offset or imbalance due to a temperature change as a voltage detection circuit. These parts cause the cost of the control device to increase. In addition, when performing speed sensorless vector control or the like, the cost required for the voltage detection circuit can be reduced by using the output voltage command value instead of the output voltage detection value. However, as described above, the actual output voltage and the output voltage command value are reduced. Does not match, there is a problem that satisfactory control performance cannot be obtained.

Here, FIG. 7 is a voltage detection circuit of a three-phase voltage source PWM inverter described in Non-Patent Document 1 as a prior art document, and FIG. 8 is an operation waveform diagram thereof.
In FIG. 7, a part of the circuit configuration of the three-phase voltage type PWM inverter INV is omitted and only one phase of output is shown, and the potential (ground potential) serving as the reference of the voltage detection circuit is the DC power supply 300 of the inverter INV The negative electrode side potential is the same.
In FIG. 7, 101 is a voltage dividing circuit connected to both ends of the switching element 302, SW ₀ and SW ₁ are switches (a state connected to the ground side is turned off), 102 is a subtracting circuit, and 103 is an integrating circuit. Circuit 104, zero cross comparator, 105 on / off detection comparator, 106 voltage detection control circuit, 106a and 107b counters.

The operation of this prior art will be described below with reference to FIG.
First, the voltage detection circuit in FIG. 7 sets the apex of the triangular wave carrier of the PWM inverter INV as the start time of one cycle T (t = 0 in FIG. 8), and the output voltage of the inverter INV in the carrier cycle (inverter INV in FIG. 7). The average value of the voltage between the output terminal U and the ground) is detected as a digital quantity.
The specific contents of the detection operation are as follows.
(1) Operation 1
Voltage detection control circuit 106 recognizes the vertices of the triangular wave carrier by carrier synchronization signal input from the control circuit (not shown), a divided voltage v _i by the voltage dividing circuit 101 by turning on the switch SW ₀ of the period T In the meantime, it is possible to input to the + side of the subtraction circuit 102. At the same time, the counter 106a for measuring the rise of the divided voltage v _i starts counting the clock signal. At this time, the switch SW ₁ is turned off, is connected to the ground side.

(2) Operation 2
The counter 106a is the output of the on-off detection comparator 105 the divided voltage v _i is input, counts the time t _{1 (see} FIG. 8) to the rising of the divided voltage v _i, to stop the operation.
(3) Operation 3
After a time 2t _{1 that} is twice t ₁ obtained by the operation 2 has elapsed, the switch SW ₁ is turned on to input the reference voltage V _REF to the minus side of the subtraction circuit 102. At the same time, the counter 106b that measures the time when the reference voltage _VREF is input starts to count the clock signal.
Note that the accumulation circuit 103 are inputted divided voltage v _i from the time of lapse of time t _1, after the elapse of time 2t ₁ is the difference between the divided voltage v _i and the reference voltage V _REF Since a voltage is input, the output voltage of the integrating circuit 103 has a value as shown in FIG.

(4) Operation 4
After the divided voltage v _i falls at time (T−t ₁ ), the input to the integration circuit 103 is only −V _REF, and the output voltage of the integration circuit 103 decreases as shown in FIG.
(5) Operation 5
When the time (2t ₁ + t ₂ ) elapses and the output voltage of the integration circuit 103 becomes 0V, the zero cross detection signal output from the zero cross comparator 104 is input to the voltage detection control circuit 106. Voltage detection control circuit 106, along with turns off the switch SW ₁ to stop input of the reference voltage V _REF to the subtracting circuit 102, it stops the operation of the reference voltage input time measuring counter 106b. Prior to the off switch SW _1, switch SW ₀ at the time of the lapse of time T is off.

With the above operation, the average value V _iave of the _divided voltage v _i in one carrier cycle can be expressed as a function of the reference voltage V _REF , and the average value V _iave can be _multiplied by the voltage dividing ratio of the voltage dividing circuit 101. The average value of the output voltage for one phase of the inverter can be detected.

Hidehiko Sugimoto, Nobuyuki Tanaka, “Development of Voltage Detection Circuit for Three-Phase Voltage Type PWM Inverter”, 2005 IEEJ National Conference on Industrial Applications, I-415 to I-418

In the prior art described in Non-Patent Document 1, it is possible to increase the resolution of the output voltage, that is, the detection accuracy, by increasing the frequency of the clock signal described above. However, in reality, the clock frequency is naturally limited in terms of the characteristics and performance of the electronic components used in the voltage detection circuit, so it is difficult to increase the voltage detection accuracy. For this reason, the output voltage detection value still contains an error, and there is a problem that a desired control performance for the inverter cannot be obtained.
Accordingly, the problem to be solved by the present invention is that it is possible to calculate an output voltage estimated value that is equal to the actual output voltage, reducing the cost required for the voltage detection circuit, and improving the control performance of a load such as an electric motor. Is to provide a simple control device.

In order to solve the above-described problem, the invention according to claim 1 includes a current adjusting unit that calculates the first output voltage command value so as to eliminate a deviation between the output current command value of the power converter and the output current detection value; Means for calculating the second output voltage command value by correcting the first output voltage command value with the output voltage error correction value, and turning on the semiconductor switching element of the power converter using the second output voltage command value A power converter control device comprising: a drive signal generating means for turning off;
Using the difference between the reference voltage command value obtained from the second output voltage command value and the output voltage calculation value obtained from the output current detection value and the load constant set value as the output voltage error correction value. Output voltage error correction means to be obtained;
Output voltage estimating means for calculating an output voltage estimated value of the power converter from a first output voltage command value and the output voltage error correction value.

According to a second aspect of the present invention, there is provided a current adjusting means for calculating a first output voltage command value so as to eliminate a deviation between an output current command value of the power converter and an output current detection value, and a first output voltage command value. Means for calculating the second output voltage command value by correcting the output voltage error correction value, and generating a drive signal for turning on and off the semiconductor switching element of the power converter using the second output voltage command value And a power converter control device comprising:
Using the difference between the reference voltage command value obtained from the second output voltage command value and the output voltage calculation value obtained from the output current detection value and the load constant set value as the output voltage error correction value. Output voltage error correction means to be obtained;
Output voltage estimation means for calculating an output voltage estimated value based on the sum of the first output voltage command value and the output voltage error correction value excluding high-frequency components.

According to a third aspect of the present invention, there is provided a current adjusting means for calculating a first output voltage command value so as to eliminate a deviation between an output current command value of the power converter and an output current detection value, and a first output voltage command value. Means for calculating the second output voltage command value by correcting the output voltage error correction value, and generating a drive signal for turning on and off the semiconductor switching element of the power converter using the second output voltage command value And a power converter control device comprising:
Using the difference between the reference voltage command value obtained from the second output voltage command value and the output voltage calculation value obtained from the output current detection value and the load constant set value as the output voltage error correction value. Output voltage error correction means to be obtained;
Output voltage estimating means for calculating an output voltage estimated value based on a difference between the second output voltage command value and the output voltage error correction value obtained by extracting a high frequency component.

  The inventions according to claims 4 to 6 use the output voltage estimated value and the output current detection value calculated according to any one of claims 1 to 3, or a motor constant such as a resistance of a motor that is a load, or a motor. Means for calculating the rotational speed of the motor or the magnetic flux of the electric motor.

  According to the present invention, it is possible to obtain an output voltage estimated value that is equal to the actual output voltage in consideration of an output voltage error due to a dead time, a signal delay due to a photocoupler, an on-voltage of a switching element, etc. It is possible to provide a low-cost control device capable of controlling the speed and torque of an electric motor or the like that is a load of the machine with high accuracy.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a first embodiment of the present invention. This embodiment is a case where the present invention is applied to a control device for a PWM inverter that drives an electric motor.
In FIG. 1A, the deviation between the d-axis current command value i _d ^* , the q-axis current command value i _q ^* and the d-axis current detection value i _d and the q-axis current detection value i _q is calculated by the addition / subtraction means 1d and 1q. These are calculated, and these deviations are input to the current adjusting means 2. The current adjusting means 2 adjusts the deviation to zero and outputs a d-axis voltage command value v _d0 ^** and a q-axis voltage command value v _q0 ^** .
The primary resistance value R ₁ of the motor _M, the secondary resistance R _2, the leakage inductance L _sigma voltage drop due, d, interference terms due to the cross-term of the q-axis, and q-axis of the counter electromotive force component addition and subtraction means 3d , 4d, 4q, and the d-axis and q-axis correction amounts Δv _d0 ^** , Δv _q0 ^{** obtained} by the addition / subtraction means 5d, 5q, the d-axis voltage command value v _d0 ^** , q-axis voltage command By adding each to the value v _q0 ^** , a d-axis voltage command value v _d0 ^* and a q-axis voltage command value v _q0 ^* are obtained as the first voltage command value.

On the other hand, the current flowing through the motor M is detected by the current detection means 6 and converted by the coordinate conversion means 7 from the stationary coordinate system to the d-axis current detection value i _d and the q-axis current detection value i _q of the rotating coordinate system. These d-axis current detection value i _d and q-axis current detection value i _q are the d-axis current command value i _d ^* , the q-axis current command value i _q ^* , the d-axis voltage command value v _d ^* , and the q-axis voltage. The command value v _q ^* is input to the output voltage error correction means 8, and the output voltage error correction values Δv _d , Δv _q calculated by the output voltage error correction means 8 are added to the d-axis voltage command value by the addition / subtraction means 9 _d , 9 _q. v _d0 ^* is added to the q-axis voltage command v _q0 ^* . Thereby, the d-axis voltage command value v _d ^* and the q-axis voltage command value v _q ^* are calculated as the second voltage command value with the output voltage error corrected.

The d-axis voltage command value v _d ^* and the q-axis voltage command value v _q ^* are converted from the rotating coordinate system to the voltage command value of the stationary coordinate system by the coordinate conversion means 10 and supplied to the PWM inverter INV. In the PWM inverter INV, the semiconductor switching element is turned on and off based on the voltage command value, thereby generating an AC voltage that compensates for a dead time, a signal delay due to a photocoupler, an error voltage due to the ON voltage of the switching element, etc. And supplied to the motor M.

In the above configuration, the output voltage error correction means 8 obtains the output voltage calculation values v _d ^, v _q ^ and the reference voltage command values v _dn ^* , v _qn ^{* as} will be described later, and uses these differences as output voltage error. D-axis voltage command values using the output voltage error correction values Δv _d and Δv _q obtained based on the estimated output voltage error values v _drip ^, v _qrip ^, as well as the estimated values v _drip ^, v _qrip ^ By correcting v _d0 ^* and q-axis voltage command value v _q0 ^* , the voltage distortion caused by the output voltage error is reduced, and torque ripple and rotation unevenness of the motor M are improved.
In this embodiment, as shown in FIG. 1B, the output voltage is calculated using the d-axis voltage command value v _d0 ^* , the q-axis voltage command value v _q0 ^*, and the output voltage error correction values Δv _d and Δv _q. The estimation unit 20 calculates the output voltage estimation values v _dest and v _qest , and the configuration and operation of the output voltage estimation unit 20 will be described later.

Next, FIG. 2 is a block diagram of the output voltage error correction means 8 in FIG.
In this output voltage error correction means 8, the output voltage calculation values v _d ｖ and v _qに_より are obtained by Equation 1 from the d-axis current detection value i _d and the q-axis current detection value i _q on the rotation coordinates.

Here, as shown in Equation 2, the first output voltage command values v _d0 ^* and v _q0 ^* are obtained using the output voltage error correction values Δv _d and Δv _q obtained by the output voltage error correction means 8 of FIG. By correcting, the second output voltage command values v _d ^* and v _q ^* can be obtained.

As shown in FIG. 2, the reactance voltage drop component (interference term) that interferes with the d and q axes from the second output voltage command values v _d ^* and v _q ^* and the counter electromotive force component of the q axis are added / subtracted means 8a and 8b. , 8d, the reference voltage command values v _dn ^* , v _qn ^* are obtained as shown in Equation 3.

The second term on the right side of the d-axis reference voltage command value v _dn ^* in Equation 3 and the second term on the right side of the q-axis reference voltage command value v _qn ^* are reactance voltage drop components, and the q-axis reference voltage command value v _qn ^* The third term on the right side is the back electromotive force component.
As is clear from Equation 3, since ω ₁ (electrical angular frequency) and ω _m (mechanical angular frequency) are small in the low frequency region, the reactance voltage drop component and the back electromotive force component are very small. Even if the voltage command values v _dn ^* and v _qn ^* are calculated as the second output voltage command values v _d ^* and v _q ^* (that is, as v _dn ^* = v _d ^* and v _qn ^* = v _q ^* ) Good.

Then, using the addition and subtraction means 8c, 8e of Figure 2, from Equations 3 and 1, obtaining the output voltage error estimate _v drip _^, the _{v qrip} ^ as Equation 4.

Further, the output voltage error correction values Δv _d and Δv _q are obtained as shown in Expression 5 by passing the estimated output voltage error values v _drip ^ and v _qrip ^ through the low-pass filters 8 f and 8 g having the time constant τ.

The first output voltage command values v _d0 ^* and v _q0 ^* are updated (corrected) according to Equation 2 using the output voltage error correction values Δv _d and Δv _q calculated according to Equation 5.
When the present embodiment is configured by software, Formula 5 is calculated for each calculation cycle to obtain output voltage error correction values Δv _d and Δv _q , and the first output voltage command value v _{d0 is} calculated after one calculation cycle. ^* , V _q0 ^* is corrected by Equation 2.

Output voltage error correction unit 8 described above, the ON voltage of the dead time and the switching elements of the inverter INV, the output voltage error estimate due to the signal delay or the like of the photocoupler v drip ^, obtains the v qrip ^, and the output voltage error The correction values Δv d and Δv q are obtained and the first output voltage command values v d0 * and v q0 * are corrected.
Accordingly, when the output voltage error correction means 8 is effective, the generated output voltage error and the output voltage error correction values Δv d and Δv q coincide with each other, so that the actual output voltage is the first output voltage command value. v d0 *, v q0 * to match, the output voltage command value v d0 *, v q0 * can be used for control of the inverter INV as the output voltage estimate.

However, in practice, there are errors in the set values of the motor constants used for the control delay and the output voltage error correction means 8, and the output voltage error correction means 8 including these also includes the output voltage error correction values Δv _d and Δv. _q is calculated.
For this reason, it is separated whether it is a voltage error that occurs while the inverter INV actually outputs a voltage based on the voltage command value or a voltage error that appears in the actual voltage due to a set value error of the motor constant, etc. The first output voltage command values v _d0 ^* and v _q0 ^* cannot be used as the estimated output voltage (the actual output voltage is the first output voltage command value v _d0 ^* , v _q0 ^Does not match ^* ).

Therefore, in the present embodiment, only the stationary error due to the set value of the motor constant or the like is extracted from the output voltage error correction values Δv _d and Δv _q by the low-pass filter, and the output voltage estimation is performed as in Expression 6. The values v _dest and v _qest are obtained.
FIG. 3 is a block diagram of the output voltage estimating means 20 for calculating Formula 6, wherein 20a and 20c are low-pass filters, and 20b and 20d are addition / subtraction means.

Here, the time constant τ _s of the low-pass filters 20a and 20c is set to a value larger than the time constant τ of the low-pass filters 8f and 8g used in the output voltage error correction means 8 of FIG. The reason for this is that errors due to dead time, on-voltage, etc. become AC components due to the output frequency on the d and q coordinate axes, but set values errors of motor constants etc. become stationary errors and can be regarded as DC components. Accordingly, the output voltage error correction values Δv _d and Δv _q are passed through the low-pass filters 20a and 20c having a large time constant τ _s to extract the direct current component, whereby the components that appear in the actual output voltage and the components that do not appear in the actual output voltage. The output voltage estimated values v _dest and v _qest that are close to the actual output voltage value can be obtained even if there are a plurality of error factors.

FIG. 5 is a waveform diagram of a simulation result showing the effect of the present embodiment.
In this simulation, vector control is performed by setting the dead time error to 5 μs, the carrier period to 100 μs, and the motor constant used for the output voltage error correction means 8 to be 0.5 times the true value, and the actual U-phase output voltage, according to the present embodiment. U-phase output voltage estimated value, current regulator 2 output (first output voltage command value v _d0 ^* , v _q0 ^* ), U-phase output voltage command value (second output voltage command value v _d ^* , v _q ^* ) 4) were compared.

As can be seen from FIG. 5, the waveform of the estimated output voltage according to the present embodiment is substantially equal to the actual output voltage, and the output voltage of the inverter INV is estimated with high accuracy. On the other hand, if the U-phase output voltage command value (second output voltage command value v _d ^* , v _q ^* ) is used, the output voltage error correction means 8 tries to correct the dead time error. When the output of the current adjusting means 2 (first output voltage command values v _d0 ^* , v _q0 ^* ) is used, the set value error of the motor constant is not included and the actual output voltage is used. As can be seen from FIG.
From the above, according to the present embodiment, it is possible to obtain an estimated output voltage value that is not limited to the actual output voltage value. For this reason, it is possible to use a highly accurate output voltage estimated value for speed sensorless vector control or the like, compared to the case where a voltage detection circuit is used as in the prior art.

Next, FIG. 4 shows another configuration example of the output voltage estimation means 20. In FIG. 4, 20 e and 20 g are high-pass filters, and 20 f and 20 h are addition / subtraction means. In this example, the output voltage estimated values v _dest and v _qest are calculated by Equation 7.

In the example of FIG. 3, the low-pass filters 20a and 20c are used to extract the steady components of the output voltage error correction values Δv _d and Δv _q , and these are added to the first output voltage command values v _d0 ^* and v _q0 ^*. The output voltage estimated values v _dest and v _qest were calculated. However, as shown in FIG. 4 and Expression 7, the AC components of the output voltage error correction values Δv _d and Δv _q are extracted using the high-pass filters 20 e and 20 g, and these are extracted as the second output voltage command values v _d ^* , By subtracting from v _q ^* , the output voltage estimated values v _dest and v _qest can be calculated in the same manner.

Next, FIG. 6 is a configuration diagram showing the main part of the second embodiment of the present invention.
In this embodiment, a speed / magnetic flux / resistance estimating means 30 for estimating the rotation speed of the motor, the motor magnetic flux and the resistance value using the output voltage estimated value obtained by the output voltage estimating means 20 is provided.
In so-called speed sensorless vector control, various methods for calculating the motor rotation speed, motor magnetic flux, and resistance value are known. As an example, Toshio Kubota et al. “The speed of an induction motor using an adaptive secondary magnetic flux observer”. There is an operation method described in “Sensorless Direct Vector Control” (The Institute of Electrical Engineers of Japan D, Vol. 111, No. 11, pp. 954-960, 1991).
The contents will be outlined below.

The state variables x, the output current i _s and the motor magnetic flux phi _r of the inverter, when put out to the state equation from the voltage equation of the motor, the equation (8).

In Equation 8 and below, the symbol ^ represents an estimated value, the dot (·) represents a matrix representing differentiation, and A ₁₁ , A ₁₂ , A ₂₁ , A ₂₂ , and B represent constants such as resistance and inductance of the motor. It is a matrix that represents. Further, v _s is the output voltage of the inverter and corresponds to the output voltage estimated value in the present invention.
The state equation of Formula 8 indicates that the output current of the inverter and the motor magnetic flux can be calculated from the output voltage of the inverter, and the output current estimated value and the motor magnetic flux estimated value are calculated from this state equation.

Further, the motor speed estimated value ω _r ^ is calculated as shown in Expression 9 from the difference between the motor magnetic flux estimated value calculated according to Expression 8 and the output current detection value and the output current estimated value according to Expression 8.

Where K _P and K _I are control gains, e _id and e _iq are the difference between the detected value of the d-axis current and the estimated value, the difference between the detected value of the q-axis current and the estimated value, φ _dr ^, φ _qr ^ Represents the d-axis component and the q-axis component of the estimated motor magnetic flux value.
If a control system that adjusts the speed by using the estimated motor speed value calculated by Equation 9 together with the speed command value is configured, the desired speed control and torque control of the motor can be achieved without the speed detection means (speed detection value). It can be performed.
Furthermore, the primary resistance estimated value R _s ^ and the secondary resistance estimated value R _r ^ are calculated as shown in Equation 10.

However, λ ₁ represents the gain, R _srn represents the ratio of the nominal values of the primary resistance and the secondary resistance, and i _ds ^ and i _qs ^ represent the d-axis component and the q-axis component of the output current of the inverter.
If the estimated values of the primary resistance and the secondary resistance calculated by Expression 10 are used to correct the parameters in the state equation of Expression 8 or the motor constant of the output voltage error correction means 8 is corrected, the control accuracy can be further improved. Improvement can be expected, and the control performance of the inverter INV can be improved.

As described above, by using Equation 8 to Equation 10 in the speed / magnetic flux / resistance estimation means 30, the motor speed and the motor constant can be calculated using the high-accuracy output voltage estimation value, which is a feature of the present invention. As a result, the control device can be provided at a lower cost compared to the prior art that requires a highly accurate voltage detection circuit.
The above-described calculation methods for the motor magnetic flux, the motor speed, and the motor constant are merely examples, and these calculation methods are not particularly limited in the present invention. That is, the present invention can be applied to the case where the motor magnetic flux, the motor speed, and the like are calculated using various calculation methods, and the same characteristics as in the case of using a highly accurate and expensive voltage detection circuit can be obtained. .

It is a block diagram which shows 1st Embodiment of this invention. It is a block diagram of the output voltage error correction | amendment means in Fig.1 (a). It is a block diagram of the output voltage estimation means in FIG.1 (b). It is a block diagram of the output voltage estimation means in FIG.1 (b). It is a wave form diagram of the simulation result which shows the effect of a 1st embodiment. It is a block diagram which shows the principal part of 2nd Embodiment of this invention. It is a block diagram which shows a prior art. It is operation | movement explanatory drawing of FIG.

Explanation of symbols

1d, 1q, 3d, 4d, 4q, 5d, 5q, 9d, 9q: addition / subtraction means 2: current adjustment means 6: current detection means 7, 10: coordinate conversion means 8: output voltage error correction means 8a to 8e: addition / subtraction means 8f, 8g: Low-pass filter 20: Output voltage estimation means 20a, 20c: Low-pass filter 20e, 20g: High-pass filters 20b, 20d, 20f, 20h: Addition / subtraction means 30: Speed / magnetic flux / resistance estimation means INV: Inverter M: Electric motor

Claims (6)

Current adjusting means for calculating the first output voltage command value so as to eliminate the deviation between the output current command value of the power converter and the detected output current, and the first output voltage command value is corrected by the output voltage error correction value And a means for calculating a second output voltage command value and a means for generating a drive signal for turning on and off the semiconductor switching element of the power converter by using the second output voltage command value. In the control device of the converter,
Using the difference between the reference voltage command value obtained from the second output voltage command value and the output voltage calculation value obtained from the output current detection value and the load constant set value as the output voltage error correction value. Output voltage error correction means to be obtained;
Output voltage estimation means for calculating an output voltage estimated value of the power converter from a first output voltage command value and the output voltage error correction value;
An apparatus for controlling a power converter, comprising: Current adjusting means for calculating the first output voltage command value so as to eliminate the deviation between the output current command value of the power converter and the detected output current, and the first output voltage command value is corrected by the output voltage error correction value And a means for calculating a second output voltage command value and a means for generating a drive signal for turning on and off the semiconductor switching element of the power converter by using the second output voltage command value. In the control device of the converter,
Using the difference between the reference voltage command value obtained from the second output voltage command value and the output voltage calculation value obtained from the output current detection value and the load constant set value as the output voltage error correction value. Output voltage error correction means to be obtained;
Output voltage estimation means for calculating an output voltage estimated value by the sum of the first output voltage command value and the output voltage error correction value excluding high frequency components;
An apparatus for controlling a power converter, comprising: Current adjusting means for calculating the first output voltage command value so as to eliminate the deviation between the output current command value of the power converter and the detected output current, and the first output voltage command value is corrected by the output voltage error correction value And a means for calculating a second output voltage command value and a means for generating a drive signal for turning on and off the semiconductor switching element of the power converter by using the second output voltage command value. In the control device of the converter,
Using the difference between the reference voltage command value obtained from the second output voltage command value and the output voltage calculation value obtained from the output current detection value and the load constant set value as the output voltage error correction value. Output voltage error correction means to be obtained;
An output voltage estimating means for calculating an output voltage estimated value based on a difference between the second output voltage command value and the output voltage error correction value obtained by extracting a high frequency component;
An apparatus for controlling a power converter, comprising:   Control of a power converter comprising means for calculating a constant of an electric motor that is a load using the output voltage estimated value and the output current detection value calculated according to any one of claims 1 to 3. apparatus.   A power converter comprising: means for calculating a rotation speed of an electric motor as a load using the output voltage estimated value and the output current detection value calculated according to any one of claims 1 to 3. Control device.   Control of a power converter comprising means for calculating a magnetic flux of an electric motor as a load using the output voltage estimated value and the output current detection value calculated according to any one of claims 1 to 3. apparatus.

Images