JPH0341026B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for switching between driving operation and braking operation of a DC type non-commutator motor.

FIG. 1 is a circuit diagram showing a conventional example of a DC type non-commutator motor capable of operating in both driving and braking modes. In FIG. 1, reference numeral 1 denotes a power supply side converter connected to an AC power supply, and is composed of a thyristor. The DC side terminal of this power supply side converter 1 is connected to the motor side converter 3 via the DC reactor 2, and the motor side converter 3
The AC side terminal of is connected to the synchronous motor 4.
Reference numeral 5 indicates a motor field, and a field current is supplied from a separate power source not shown in this diagram.
is designed to maintain the terminal voltage at a desired value. 6 is a magnetic pole position detector, and 7 is a speed detection generator, both of which are coupled to the rotor of the electric motor 4. 11 is an inverse conversion pulse generator, 12 is a forward conversion pulse generator, and a pulse switch 13 selects one of the pulses generated by both of them and supplies the pulses to the motor-side converter 3. The commutation of the converter 3 on the motor side is generally carried out by the induced voltage of the motor 4 without providing a special commutation circuit, but the commutation phase at that time is mechanically or electrically controlled. It is determined from the grasped position of the rotor or rotating magnetic flux. In the case of the circuit diagram shown in FIG. 1, the inverse conversion pulse generator 11 generates an ignition pulse for inverse conversion of the motor side converter 3 from the signal of the magnetic flux position detector 6 coupled to the rotor of the electric motor 4. The forward conversion pulse generator 12 similarly generates firing pulses for forward conversion, and the pulse switch 13 selects one of the firing pulses to control the phase of the converter on the motor side.

The speed of the electric motor 4 is determined by inputting the signal set by the speed setting device 21 and the speed feedback signal from the speed detection generator 7 to the speed regulator 22, and the current signal output from the speed regulator 22 is absolute. It is input to a current regulator 26 via a value circuit 23. Current transformer 24
The current feedback signal detected by and rectified by the rectifier 25 is also input to the aforementioned current regulator 26, and the firing angle regulator 27 controls the power supply side converter 1 using the output signal of the current regulator 26. The rotational speed of the electric motor 4 is maintained at the set value. A comparator 31 receives a signal from the speed detection generator 7 and determines the rotation direction of the motor 4. A comparator 32 receives a signal from the speed regulator 22 to determine the torque direction of the motor 4, that is, whether the motor is in drive mode or not. It is determined whether the braking operation is being performed, and the comparator 33 detects that the current is zero. The outputs of these comparators 31, 32, and 33 are input to a switching command circuit 34, and the output of this switching command circuit 34 is input to the pulse switch 13 and current regulator 26 described above.

FIG. 2 is a time chart when switching from drive to braking and from braking to drive in the case of the commutatorless motor circuit shown in FIG. 1. This second
The operation of the circuit shown in FIG. 1 will be explained with reference to the drawings.
The horizontal axis in FIG. 2 is a time axis and shows that time passes from left to right, and the driving mode changes from driving to braking to driving as time progresses.

FIG. 2A shows the current command which is the output of the speed regulator 22, and its polarity is reversed when the driving operation changes to the braking operation. FIG. 2B shows the output of the comparator 32, which is characterized in that the polarity of the output of the speed regulator 22 described above is reversed. This comparator 3
2 is input to the switching command circuit 34, and this switching command circuit 34 outputs a pulse shift command of a certain time width to the current regulator 26, as shown in FIG. 2C. In response to this pulse shift command, the current regulator 26 outputs a signal that reaches the maximum control delay angle (hereinafter referred to as α max ) to the firing angle regulator 27, and the situation is shown in FIG. It will be done.

FIG. 3 shows the configuration of the above-mentioned current regulator 26, in which the contact 28 is closed while the pulse shift signal from the switching command circuit 34 is output, and the current is applied to the firing angle regulator 27 . Output a signal.

The current flowing through the power supply side converter 1 is detected and rectified, and the current is shown in Figure 2 E. However, when the comparator 33 detects that the current has become almost zero due to the pulse shift (see Figure 2 F). After the current zero confirmation time T, the pulse shift command sent from the switching command circuit 34 to the current regulator 26 is canceled (see Fig. 2C), but at the same time, the pulse shift command sent from the switching command circuit 34 to the pulse switch 13 is canceled. A command to switch from driving to braking is issued (see Figure 2-G).
As a result, the ignition pulse to the motor-side converter 3 is switched from an inverse conversion pulse to a forward conversion pulse. When the pulse shift command from the switching command circuit 34 is released, the output signal of the current regulator 26 changes from α max according to the signal from the speed regulator 22, and accordingly, the DC voltage of the power supply side converter 1 increases. When the DC voltage changes and becomes balanced with the DC voltage of the converter 3 on the motor side, a current starts to flow. In other words, it takes time for the current to start flowing after the pulse shift is released (see Fig. 2, E).

To summarize the above operation, switching from driving operation to braking operation is performed by cutting off the current by pulse-shifting the power supply side converter 1, switching the ignition phase of the motor side converter 3, and then switching from the power supply side to the braking operation. Side converter 1
This operation prevents DC short circuit accidents by canceling the pulse shift and restarting operation. Switching from braking operation to driving operation is also performed using the same operating procedure as described above.

In this conventional method of switching between driving and braking operations, the pulse shift to α max is changed until the output of the current regulator 26 reaches a value commensurate with the operating state after the pulse shift is released. The disadvantage is that it takes time. Therefore, when a high-speed control response is required, the conventional driving/braking switching method may not be applicable.
In particular, when switching from braking to driving, the amount of change in α after the pulse shift is released is larger than when switching from driving to braking, so the no-current period is also longer.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a control device for a commutatorless electric motor that can overcome the above-mentioned drawbacks and can switch from driving operation to braking operation or vice versa at a very high level.

In the present invention, the output of the current regulator is initially set so that the DC voltage of the power supply side converter becomes a value corresponding to the DC voltage of the motor side converter when the pulse shift is canceled. The above objective is achieved by significantly shortening the no-current period.

FIG. 4 is a circuit diagram showing one embodiment of the present invention. In FIG. 1, 1 is a power supply side converter, 2 is a DC reactor, 3 is a motor side converter, 4 is a periodic motor, and 5 is a field of the motor. 6 is a magnetic pole position detector, and 7 is a speed detection generator. Reference numeral 11 is an inverse conversion pulse generator, 12 is a forward conversion pulse generator, and 13 is a pulse switching device, and the functions of the components having these symbols are the same as those shown in FIG. Speed setter 21, speed regulator 22, absolute value circuit 23, current transformer 24, rectifier 25, firing angle adjuster 27, comparator 31 for determining rotation direction,
Comparator 32 for determining torque direction, comparator 33 for detecting zero current, switching command circuit 3
4 also has the same usage and function as the one shown in FIG.
A control angle voltage generator 40 receives signals from the speed detection generator 7 and the comparator 32 and outputs a signal to an initial value setter 50. 60 is a current regulator. This control angle voltage generator 40 receives a signal from the speed detection generator 7 and controls the phase of the power supply side converter 1 so that the DC voltage of the motor side converter 3 and the DC voltage of the power supply side converter 1 are parallel to each other. Ask for a signal. The initial value setter 50 is for initially setting the output of the current regulator 60 at the moment when the pulse shift is canceled to the output voltage set by the control angle voltage generator 40, and the pulse shift is canceled. and the output of the current regulator 60 instantly switches from α max to the above-mentioned initial setting value.

A control angle voltage generator 40 shown in FIG.
An example of the circuit configuration of the initial value setter 50 and the speed regulator 60 is shown in FIG.

The operating principle of the control angle voltage generator 40 in FIG. 5 is as follows. The power supply voltage is E _s , the motor voltage is E _M , the control lead angle of the motor side converter during driving operation is β _M , the control delay angle of the motor side converter during braking operation is α _{M , and the control lead angle of the motor side converter during braking operation is α M} . When the control angle is α _S , E _S cosα _S ≒E _M cosβ _M ……(1) E _S cosα _S ≒−E _M cosα _M ……(2) Equation (1) applies during driving operation. Yes, and equation (2) is when braking. Calculating α _S from equations (1) and (2), α _S ≒cos ^-1 (E _M ／E _S cosβ _M ...(3) α _S ≒cos ^-1 (−E _M ／E _S cosα _M ... ...(4) Equation (3) is for driving operation, and equation (4) is for braking operation.

In FIG. 5, 41 is a power supply that generates a voltage corresponding to cosβ _M , and 42 is a power supply that generates a voltage corresponding to -cosα _M. A contact 43 is a contact that is closed during driving operation and open during braking operation, and a contact 44 is conversely open during driving operation and closed during braking, and both contacts are operated by the output of comparator 32. . 45 is a function generator, which calculates E _M /E _S from the detected speed value. 46 is a multiplier, 47
is an inverse trigonometric function generator. As a result, the control angle voltage generator 40 calculates the above-mentioned equation (3) or (4), and outputs a voltage of -α _S as a result.

Furthermore, in FIG. 5, 51 is a summing amplifier, 52
is an amplifier, 53 is a contact that is closed only during the pulse shift command period, 61 is a proportional-integral amplifier, 62 and 63
is an operational amplifier, and 64 and 65 are contacts that operate only during the pulse shift command period. In FIG. 5, the output signal of the control angle voltage generator 40 is −α _S
is input to the summing amplifier 51 of the initial value setter 50 together with the output of the proportional-integral amplifier 61, which is a component of the current regulator 60. Therefore, when a pulse shift command is input from the switching command circuit 34, the contact 53 closes and the output of the initial value setter 50 is transferred to the proportional-integral amplifier 6.
1, the output of the proportional-integral amplifier 61 outputs a voltage equal to the absolute value of the voltage −α _S and opposite in polarity, that is, a voltage α _S. At this time, in order to shorten the output setting time of the proportional-integral amplifier 61 as much as possible, the feedback resistor of the amplifier 61 is short-circuited by the contact 64 while the pulse shift command is issued. The output voltage α _S of the proportional-integral amplifier 61 is reversed in sign by the next-stage operational amplifier 62 and becomes −α _S , but during the pulse shift command period, the contact 6
5 is operating, this voltage −α _S is not input to the next stage operational amplifier 63, but can be set separately −
When the voltage α _nax is input, α _nax is set to the firing angle adjuster 27.
As a result, the current of the power supply side converter 1 is cut off. Then, when the pulse shift command is released, the output of the proportional-integral amplifier 61, which is initially set at a voltage α _S , is transferred to the operational amplifiers 62 and 63.
However, at the same time, the contact 53 returns and the output of the initial value setter 50 is cut off.

FIG. 6 is a time chart when driving operation and braking operation are switched by the circuit shown in FIG. 4 which is an embodiment of the present invention. It shows how the signals of various parts change as the driving state changes from driving to braking to driving. In FIG. 6, A is the output of the speed regulator 22 which is the current command, B is the output of the comparator 32 which discriminates driving and braking from the direction of torque, and C is the output from the switching command circuit 34 to the initial value setting circuit 50 and the current regulator. 60, D is the output of the current regulator 60, E is the current signal that is the output of the rectifier 25, F is the output of the comparator 33 that detects zero current, and G is the output from the switching command circuit 34 to the pulse switcher. This is a command to switch between driving and braking to 13.
T is the switching margin time.

As can be seen from FIG. 6, in the present invention, when the pulse shift command is released, the control angle α _S of the thyristor of the power supply side converter 1 is initialized in advance, so that the control angle α S changes from α _nax to α _S. It can be seen that the no-current period is significantly shortened because the control angle is immediately shifted. Especially when switching from braking operation to driving operation, the shift amount of the control angle is large.
The effects of the present invention are remarkable. Furthermore, the present invention can be realized easily and at low cost by combining the control angle voltage generator 40, the initial value setting device 50, and the current regulator 60.

In addition _, the power supply that generates a voltage corresponding to cosβ _M of 41 in FIG. Of course, _M of cosβ _M , −cos may be obtained by using a generator.

FIG. 7 is a circuit diagram showing another embodiment of the present invention. The control angle voltage generator 40, initial value setting device 50, and current regulator 60 in FIG. 4 can be replaced with the current regulator 70 shown in FIG. 7 if the following conditions are satisfied, so the circuit configuration can be further simplified. It becomes easier and costs less. In other words, the control advance angle β _M when the motor-side converter operates as an inverse converter and the control delay angle α _M when it operates as a forward converter are approximately equal, and the control delay value α _S of the power-side converter but
The phase control signal at 90 degrees corresponds to O ^V , and when switching between driving and braking, the motor 4
There is almost no change in speed.

In FIG. 7, 71 is a proportional-integral amplifier, 72 and 73 are operational amplifiers, and a contact 74 is a contact that is switched by a command from the switching command circuit 34.
A contact numbered 5 is a contact that operates during the pulse shift command period. In FIG. 7, while the pulse shift command is being issued, the proportional-integral amplifier 7 is
1 is cut off, and the firing angle adjuster 27 outputs α _nax . When the pulse shift is canceled and the driving and braking commands are switched by a command from the switching command circuit 34, the contact 74 operates and the direction of the feedback circuit of the proportional-integral amplifier 71 is reversed, so that the output of the current regulator 70 will be initially set to the same value with the opposite polarity to the value immediately before the pulse shift.
Switching between driving and braking can be completed in an extremely short time using a simple circuit.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a conventional non-commutator motor capable of driving and braking, FIG. 2 is a time chart of the circuit shown in FIG. 1, and FIG. 3 is a configuration diagram of a conventional current regulator. FIG. 4 is a circuit diagram showing an embodiment of the present invention, FIG. 5 is a configuration diagram showing details of the circuit shown in FIG. 4, FIG. 6 is a time chart according to the embodiment of the present invention, and FIG. 1 is a configuration diagram showing details of a circuit portion, showing another embodiment of the present invention; FIG. 1...Power supply side converter, 2...DC reactor,
3...Motor side converter, 4...Synchronous motor, 6...
...Magnetic pole position detector, 7...Speed detection generator, 11
... Reverse conversion pulse generator, 12 ... Forward conversion pulse generator, 13 ... Pulse switcher, 26 ... Current regulator, 27 ... Firing angle adjuster, 31, 32, 33
... Comparator, 34 ... Switching command circuit, 4
0... Control angle voltage generator, 41... cosβ _M generation power source, 42...-cosα _M generation power source, 43, 44...
Contact, 45... Function generator, 46... Multiplier, 4
7...Inverse trigonometric function generator, 50...Initial value setter, 51...Summing amplifier, 52...Amplifier, 53
... Contact, 60 ... Current regulator, 61 ... Proportional-integral amplifier, 62, 63 ... Operational amplifier, 64, 6
5... Contact, 70... Current regulator, 71... Proportional-integral amplifier, 72, 73... Operational amplifier, 74,
75...Contact.

Claims (1)

[Scope of Claims] 1. A power supply side converter 1 connected to an AC power source and converting alternating current from the AC power source into DC; and a DC intermediate circuit including a DC reactor 2 and connected to the power source side converter; a motor-side converter 3 that converts direct current from the DC intermediate circuit into alternating current to drive a synchronous motor during driving operation, and converts alternating current regenerated by the synchronous motor into direct current and supplies it to the direct current intermediate circuit during braking operation; A speed regulator 22 that outputs a current command signal that makes the rotational speed detection signal of the synchronous motor coincide with a separately set speed command signal, and a current detection signal flowing to the power supply side converter and a current command signal thereof are provided. a current regulator 6 that outputs a control angle signal for controlling the control angle of the power supply side converter so that the current detection signal matches the current command signal;
0, and when switching the synchronous motor from driving operation to braking operation or vice versa, a pulse shift signal for shifting the control angle to the maximum is given to the current regulator, and the DC output of the power supply side converter is In the control device for a non-commutated motor, the control device for a commutatorless motor is configured to reduce the current to zero, continue this for a certain period of time, then reverse the conversion direction of the motor-side converter, and then cancel the pulse shift signal applied to the current regulator. A control angle voltage generator 40 that outputs a control angle signal α _s of the power supply side converter during driving operation or braking operation, and a control angle voltage generator 40 that outputs the control angle signal α s of the power supply side converter during driving operation or braking operation; and an initial value setter 50 which is controlled by the pulse shift signal, and the current regulator 60 includes a proportional integral amplifier 61 having a feedback resistor and a feedback capacitor; A first switch means 64 short-circuits the feedback resistor of the integrating amplifier, and is controlled by the pulse shift signal to switch the current regulator output signal to a separately set control angle maximum signal α _nax during the pulse shift signal issuance period. and a second switch means 65 for applying a value to the power supply side converter, and during a period in which the pulse shift signal is issued when switching the synchronous motor from driving operation to braking operation or vice versa, the initial value setting is The output α _s of the control angle voltage setter, which is given through the converter, continues to be held as the current regulator output signal, and the second switch means sends the maximum control angle signal α _nax to the power supply side converter. and at the same time as the pulse shift signal is released, the output α _s of the control angle voltage generator, which has been kept being held, is given to the power supply side converter as an initial value, and the feedback resistor is short-circuited by the first switch means. 1. A control device for a commutatorless motor, characterized in that upon release, the control device shifts to an adjustment operation during normal driving operation or braking operation. 2. A power supply side converter 1 connected to an AC power supply and converting alternating current from the AC power supply into DC, a DC intermediate circuit including a DC reactor 2 and connected to the power supply side converter, and a DC intermediate circuit connected to the power supply side converter during driving operation. A motor-side converter 3 that converts direct current from a circuit into alternating current to drive a synchronous motor, converts the alternating current regenerated by the synchronous motor into direct current during braking operation, and supplies the direct current to the direct current intermediate circuit, and a rotation speed of the synchronous motor. A speed regulator 22 outputs a current command signal that makes the detection signal coincide with a separately set speed command signal, and a current detection signal flowing to the power supply side converter and the current command signal thereof are supplied and the current detection signal is A current regulator 7 that outputs a control angle signal that controls the control angle of the power supply side converter to match this current command signal.
0, and when switching the synchronous motor from driving operation to braking operation or vice versa, a shift pulse signal for shifting the control angle to the maximum is given to the current regulator, and the DC output of the power supply side converter is In the control device for a commutatorless motor, the control device sets the current regulator to zero, continues this for a certain period of time, then reverses the conversion direction of the motor-side converter, and then cancels the pulse shift signal applied to the current regulator. A phase control signal when the control lead angle when the motor side converter operates as an inverse converter and the delay angle when it operates as a forward converter are almost equal, and the control delay angle of the power supply side converter is 90 degrees. corresponds to OV,
And when there is almost no speed change of the synchronous motor when switching between driving operation and braking operation, the current regulator 70 is a proportional-integral amplifier 71 having a feedback circuit consisting of a resistor and a capacitor.
and a first switch means 75 which is controlled by the pulse shift signal and cuts off the current command signal and the current detection signal given to the current regulator while the pulse shift signal is being issued; a second switch means 74 for switching the polarity of the feedback circuit of the proportional-integral amplifier in accordance with the conversion direction of the motor-side converter while the signal is being issued;
A control device for a commutatorless motor, comprising: