JP2002354896A - Controller for permanent magnet synchronous generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep a DC voltage constant irrespective of the rotational speed of a permanent magnet synchronous generator and to obtain its output to the maximum extent in a device that takes out DC electric power from the synchronous generator. SOLUTION: This controller for the permanent magnet synchronous generator, which converts the output of the permanent magnet synchronous generator 1 into DC with the output of the generator 1 connected to a power converter 2, comprises a DC voltage controller 5 that detects the DC voltage Vdc of the output of the power converter and outputs a torque command by proportional-plus-integral amplifying deviation between the DC voltage and a DC voltage command, and a torque controller 6 that outputs a signal for controlling the power converter so that the torque of the generator can be controlled in accordance with the torque command of the output of the DC voltage controller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for extracting DC power from a permanent magnet type synchronous generator, and to maintain a constant DC voltage regardless of the rotation speed of the permanent magnet type synchronous generator. The purpose is to obtain the maximum output of the synchronous generator.

[0002]

2. Description of the Related Art An example of a conventional technique is shown in FIG. The three-phase AC power generated by the permanent magnet synchronous generator 1 is full-wave rectified by the power converter 8 based on full-wave rectification, becomes DC power, is smoothed by the capacitor 3, and supplies power to the load 4. . As the power converter 8 using full-wave rectification, for example, a three-phase bridge circuit using diodes is used.

[0003]

In such a configuration, when the power source of the permanent magnet synchronous generator is wind power, the rotational speed of the permanent magnet synchronous generator 1 changes because the wind speed changes. Then, since the induced voltage is proportional to the speed, the input voltage of the power converter 8 by the full-wave rectification fluctuates, and accordingly, the DC voltage, which is the output terminal voltage of the capacitor 3, fluctuates. Therefore, in the case of the load 4 having a narrow allowable range of the DC power supply voltage, this system cannot be applied. For example, if the load 4 is equivalent to a resistor, the power consumed by the load will fluctuate greatly.

When the power source of the permanent magnet type synchronous generator 1 is a diesel engine, it is possible to keep the rotation speed constant. Since the current fluctuates and the voltage drop due to the internal impedance of the permanent magnet type synchronous generator 1 changes, the terminal voltage of the permanent magnet type synchronous generator 1 changes, and therefore the DC voltage which is the terminal voltage of the capacitor 3 also changes.

Further, power is consumed by the winding resistance of the permanent magnet type synchronous generator 1, but since this power consumption is not always minimized, the power generated by the permanent magnet type synchronous generator 1 is reduced. Not available to the fullest. The present invention has been made to solve the above problems.

[0006]

According to a first aspect of the present invention, a power converter is connected to an output of a permanent magnet type synchronous generator so that an output of the permanent magnet type synchronous generator is output. In the control device for the permanent magnet type synchronous generator for converting the DC voltage into DC, the DC voltage Vdc output from the power converter is detected, and the DC voltage is output such that the DC voltage stably follows the DC voltage command. A voltage controller; and a torque controller that outputs a signal for controlling the power converter so as to control the torque of the permanent magnet synchronous generator according to a torque command output from the DC voltage controller. And

According to a second aspect of the present invention, the torque controller detects a d-axis which is a position of a permanent magnet of a rotor of the permanent magnet type synchronous generator, and an output of the permanent magnet type synchronous generator. A current detector for detecting a current and dividing and outputting the component current id on the d-axis and the component current iq on the q-axis orthogonal to the d-axis based on the output of the position detector; A d-axis current command generator for obtaining a high-efficiency condition d-axis component current ide, which is the d-axis component current such that the generator loss is minimized, and outputting a d-axis current component command idr equal to ide; A q-axis current command generator that outputs the q-axis component current command iqr such that the torque of the permanent magnet type synchronous generator follows the torque command of the DC voltage controller output, and an output of the d-axis current command generator The idr
And a current controller that outputs a signal for controlling the power converter so that the output id and iq of the current detector respectively follow the output iqr of the q-axis current command generator. I do.

According to a third aspect of the present invention, a voltage saturation signal Sat having a positive value when the DC voltage command is lower than a DC voltage obtained by full-wave rectifying the input voltage of the power converter and a negative value when the DC voltage command is higher than the DC voltage command. In place of the voltage saturation detector to be output and the d-axis current command generator, a time integration of the voltage saturation signal Sat is limited so as not to be less than the d-axis component current ide in the high efficiency condition. A second d-axis current command generator that outputs a component command idr is used.

According to a fourth aspect of the present invention, a position estimator for estimating the d-axis from an output current and a terminal voltage of the permanent magnet type synchronous generator is used in place of the position detector. Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0010]

FIG. 1 shows an embodiment of the present invention according to the first aspect. In FIG. 1, a permanent magnet type synchronous generator 1
Is converted into DC power by the power converter 2, smoothed by the capacitor 3, and supplies power to the load 4. As the power converter 2, for example, a three-phase bridge circuit in which a switching element such as an IGBT and a diode are connected in anti-parallel is used. The DC voltage controller 5 controls a DC voltage Vdc which is a terminal voltage of the capacitor 3.
And a DC voltage command Vdcr are obtained by an error calculator 51, and its output is amplified by a proportional-integral amplifier 52 and output as a torque command Tr. The torque controller 6 outputs a signal S for controlling the power converter 2 so that the torque of the permanent magnet type synchronous generator 1 follows the torque command Tr.

With the above configuration, for example, the DC voltage Vd
If c becomes smaller than the DC voltage command Vdcr, the torque command Tr increases, and the power obtained from the permanent magnet type synchronous generator 1 increases to exceed the power consumed by the load 4. The voltage Vdc can be increased. Even if the load 4 fluctuates or the rotation speed of the permanent magnet type synchronous generator 1 changes, the DC voltage Vdc is changed to the command Vdcr.
It can be controlled as follows.

An embodiment of the present invention according to claim 2 is shown in FIG. The description of the same reference numerals as in FIG. 1 is omitted.
2, the torque controller 6 includes a position detector 61, a current detector 62, a q-axis current command generator 63, a d-axis current command generator 64, and a current controller 65, and includes a permanent magnet synchronous generator. A signal S for controlling the power converter 2 so that the torque 1 follows the torque command Tr is output. The position detector 61 detects the phase θ of the d-axis, which is the position of the permanent magnet of the rotor of the permanent magnet synchronous generator 1. Current detector 62
Detects the output current of the permanent magnet type synchronous generator 1 and converts the output current of the position detector into a d-axis component current id and a q-axis component current iq orthogonal to the d-axis based on the d-axis phase θ. Output separately. The d-axis current command generator 64 obtains a d-axis component current ide that is a high-efficiency condition d-axis component current that minimizes the loss of the permanent magnet synchronous generator 1 by the following [Equation 1].

[0013]

(Equation 1)

This ide is output as a d-axis current component command idr. Here, φ is the magnetic flux that the magnetic flux generated by the permanent magnet of the rotor of the permanent magnet synchronous generator 1 links to the stator winding, and Ld is the d-axis inductance of the permanent magnet synchronous generator 1. And Lq is the q-axis inductance. [Equation 1] is a condition that minimizes the loss of the permanent magnet type synchronous generator when the loss of the permanent magnet type synchronous generator is only the copper loss due to the winding. That is, if a d-axis current of ide that satisfies [Equation 1] is passed, the permanent magnet type synchronous generator 1
Means that the loss is minimized.
Will be able to make maximum use of the power generated. The q-axis current command generator 63 converts the torque of the permanent magnet type synchronous generator 1 into the torque command Tr output from the DC voltage controller 5.
Is obtained and output by the following [Equation 2].

[0015]

(Equation 2)

The current controller 65 includes a d-axis current command generator 6
4 and i of the output of the q-axis current command generator 63.
A signal S for controlling the power converter 2 is output such that the component currents id and iq output from the current detector 62 follow qr.

With the above configuration, not only can the DC voltage Vdc be controlled in accordance with the command Vdcr, but also the power generated by the permanent magnet type synchronous generator 1 can be used to the maximum.

An embodiment of the present invention according to claim 3 is shown in FIG. 1 and 2 will not be described. In FIG. 3, a voltage saturation detector 7 has a positive value when the DC voltage command Vdcr is lower than a DC voltage obtained by full-wave rectifying the input voltage of the power converter 2, and has a negative value when the DC voltage command Vdcr is high. The saturation signal Sat is output. The second d-axis current command generator 66 performs time integration of the voltage saturation signal Sat instead of the d-axis current command generator 64 shown in FIG. 2 and outputs the same as a d-axis current command idr. In this case, the d-axis component current ide is limited so as not to be lower than the high-efficiency condition d-axis component current ide obtained by [Equation 1].

With the above configuration, the permanent magnet synchronous generator 1
Is low, the terminal voltage of the permanent magnet synchronous generator 1 is relatively small, and the voltage saturation signal Sat has a negative value. Therefore, the output of the time integration in the second d-axis current command generator 66 is , High-efficiency condition The state is limited to the d-axis component current ide, and idr = ide, which is the same as that of FIG. 2, so that the power generated by the permanent magnet type synchronous generator 1 can be used to the maximum. Become like When the rotation speed of the permanent magnet synchronous generator 1 is high, the terminal voltage of the permanent magnet synchronous generator 1 is relatively large, and the voltage saturation signal Sat
Is a positive value, so that idr> ide. Then
The armature reaction of the permanent magnet synchronous generator 1 cancels out the magnetic flux generated by the permanent magnet of the permanent magnet synchronous generator 1, so that the terminal voltage of the permanent magnet synchronous generator 1 decreases. Then Sat is inverted to a negative value and idr is id
Try to approach e. Then, the terminal voltage of the permanent magnet type synchronous generator 1 increases, and Sat is inverted to a positive value. By repeating the above, the DC voltage obtained by full-wave rectifying the terminal voltage of the permanent magnet type synchronous generator 1 which is the input voltage of the power converter 2 can be reduced to the DC voltage command Vdcr or less.

An embodiment of the present invention according to claim 4 is shown in FIG. The description of the same reference numerals as in FIGS. 1, 2 and 3 is omitted. 4, a position estimator 67 estimates the phase θ of the d-axis from the output current and the terminal voltage of the permanent magnet synchronous generator 1 instead of the position detector 61 of FIG. 2 or FIG.

FIG. 5 shows the procedure. First, the initial value of the phase θ of the d-axis is determined appropriately. Based on this phase,
The output current of the permanent magnet synchronous generator 1 detected by the current component decomposer 92 in the same manner as the current detector 62 is decomposed into components to obtain current decomposition components iγ and iδ. This iγ is equivalent to id, and iδ is equivalent to iq, but since it is based on an appropriately determined phase, another variable name is used to distinguish it from the actual value. Similarly, the terminal voltage of the permanent magnet synchronous generator 1 is decomposed into components by the voltage component decomposer 91 to obtain voltage decomposition components vγ and vδ. Then, the position error calculator 93 calculates the following equation (3).

[0022]

(Equation 3)

Thus, the phase difference Δθ between the actual d-axis phase and the phase θ is obtained. Or, the expression of [Equation 4] shown below

[0024]

(Equation 4)

As a result, a signal .DELTA..theta.S having a sign equal to the phase difference .DELTA..theta. Where R is the winding resistance of the permanent magnet synchronous generator, P () represents the time derivative in (), ω is the estimated rotational angular frequency, K is a positive constant, sign {} Is 1 if the inside of {} is positive and -1 if it is negative. Next, Δθ or ΔθS is proportionally integrated and amplified by the proportional-integral amplifier 95 to estimate the rotational angular frequency ω,
The rotational angle frequency ω is time-integrated by the integrator 94 and the d-axis phase θ
Get. In this way, Δθ approaches 0, and the d-axis phase θ coincides with the actual d-axis phase.

The following is the reason why the position error can be obtained by the equation (3). Assuming that the actual d-axis position and θ have an error of Δθ, the permanent magnet synchronous generator has the following formulas (1) and (2)

[0027]

(Equation 5)

Is as follows. Assuming that Δθ is small, sin (Δ
θ) = Δθ, sin (2 · Δθ) = 2 · Δθ, cos
By approximating (Δθ) = 1 and cos (2 · Δθ) = 1 and substituting equations (3), (4) and (5) into equation (1), [Equation 3] is derived. [Delta] [theta] in [Equation 3] is obtained using division. In general, division takes a long time to perform the operation, and if it is only necessary to obtain the [Delta] [theta] sign, multiplication which is considered to be fast can be substituted. When finding the sign [Equation 3]
The numerator and denominator are multiplied. This facilitates the calculation.

The d-axis position can also be estimated in the configuration shown in FIG. The magnetic flux calculator 96 obtains the linkage flux ψ by time integration of the terminal voltage of the permanent magnet type synchronous generator 1 minus the voltage drop due to the winding resistance and inductance of the permanent magnet type synchronous generator 1. The phase differentiator 97 obtains the rotational angular frequency ω1 of the linkage flux ψ by time-differentiating the phase of the linkage flux ψ. Δθ of the output of the position error calculator 93
The rotation angle frequency ω is the sum of the rotation angle frequency ω and the rotation angle frequency ω. In the configuration of FIG. 5, when the rotational speed changes suddenly, unless the gain of the proportional-integral amplifier 95 is increased, the estimated rotational speed ω of the output of the proportional-integral amplifier 95 is greatly delayed from the actual one, and the d-axis Although the position θ greatly deviates from the actual position, the configuration shown in FIG.
And the phase differentiator 97 can estimate the speed without delay, so that even if the rotational speed changes suddenly, the d-axis position does not significantly shift.

[0030]

As described above, according to the present invention, the DC output voltage can be controlled as instructed by the invention of claim 1 even if the load or the rotation speed of the generator changes. According to the second aspect of the invention, the electric power generated by the permanent magnet type synchronous generator can be used to the maximum. Claim 3
According to the invention, the rotation speed of the permanent magnet synchronous generator is increased, and the DC output voltage is commanded even if the DC voltage obtained by full-wave rectifying the terminal voltage of the permanent magnet synchronous generator becomes higher than the DC voltage command. It can be controlled as follows. However, the electric power generated by the permanent magnet synchronous generator cannot be used to the maximum. According to the invention of claim 4, the above three effects can be realized without a position detector.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the invention according to claim 1;

FIG. 2 is a block diagram showing an embodiment of the invention according to claim 2;

FIG. 3 is a block diagram showing an embodiment of the invention according to claim 3;

FIG. 4 is a block diagram showing an embodiment of the invention according to claim 4;

FIG. 5 is a block diagram showing a first example of a position estimator 67.

FIG. 6 is a block diagram showing a second example of the position estimator 67.

FIG. 7 is a block diagram showing an embodiment of the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Permanent magnet type synchronous generator 2 ... Power converter 3 ... Capacitor 4 ... Load 5 ... DC voltage controller 51 ... Error calculator 52 ... Proportional integration amplifier 6 ... torque controller 61 ... position detector 62 ... current detector 63 ... q-axis current command generator 64 ... d-axis current command generator 65 ... current controller 66 ... -2nd d-axis current command generator 67 ... position estimator 7 ... voltage saturation detector 8 ... power converter by full-wave rectification 91 ... voltage component decomposer 92 ... current component decomposer 93 ... Position error calculator 94 ... Integrator 95 ... Proportional integration amplifier 96 ... Flux calculator 97 ... Phase differentiator

Claims (4)

[Claims] 1. A permanent magnet synchronous generator control device for connecting a power converter to the output of a permanent magnet synchronous generator to convert the output of the permanent magnet synchronous generator to DC, wherein the power converter A DC voltage controller that detects a DC voltage Vdc of the output of the DC voltage generator and outputs a torque command such that the DC voltage stably follows the DC voltage command; and a torque controller that controls the torque of the permanent magnet type synchronous generator according to the torque command. A control device for a permanent magnet synchronous generator, comprising a torque controller for outputting a signal for controlling the power converter. 2. A position detector for detecting a d-axis, which is a position of a permanent magnet of a rotor of the permanent magnet type synchronous generator, wherein the torque controller detects an output current of the permanent magnet type synchronous generator. The component current id on the d-axis and the component current iq on the q-axis orthogonal to the d-axis based on the output of the position detector
And a high-efficiency condition d-axis component current ide which is a component current of the d-axis such that the loss of the permanent magnet synchronous generator is minimized, and a d-axis equal to ide A d-axis current command generator for outputting a current component command idr, and a q for outputting the q-axis component current command iqr such that the torque of the permanent magnet synchronous generator follows the torque command of the DC voltage controller output Axis current command generator,
The idr of the output of the d-axis current command generator and the iqr of the output of the q-axis current command generator include i of the current detector output.
2. The control device for a permanent magnet synchronous generator according to claim 1, further comprising a current controller that outputs a signal for controlling the power converter so that d and iq follow each other. 3. A voltage for outputting a voltage saturation signal Sat having a positive value when the DC voltage command is lower than a DC voltage obtained by full-wave rectifying the input voltage of the power converter, and having a negative value when the DC voltage command is high. Instead of the saturation detector and the d-axis current command generator, a time-integrated signal of the voltage saturation signal Sat is limited so as not to be equal to or less than the d-axis component current ide in the high-efficiency condition. The control device for a permanent magnet type synchronous generator according to claim 1 or 2, wherein a second d-axis current command generator that outputs as (1) is used. 4. A position estimator for estimating the d-axis from an output current and a terminal voltage of the permanent magnet type synchronous generator, instead of the position detector.
4. The control device for a permanent magnet type synchronous generator according to 2 or 3.