JP2003306273A - Elevator control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the efficiency of a converting device. <P>SOLUTION: In this control device for controlling an elector motor 6 through a voltage converter 3 and a voltage inverter 5, a DC voltage directive VdcRef varying according to the speed of the elevator motor 6 is generated to control the converter 3 so that the output DC voltage Vdcf of the converter 3 can follow up the DC voltage directive VdcRef, and to control the inverter 5 so that the speed of the elevator motor 6 can follow up a speed directive. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage source converter that rectifies an AC voltage and converts it into a DC voltage, and a DC voltage that is converted into an AC voltage having a variable voltage and a variable frequency and supplied to a drive motor of an elevator hoisting machine. The present invention relates to an elevator control device including a voltage source inverter.

[0002]

2. Description of the Related Art As a large-capacity power conversion device for driving and controlling a drive motor of an elevator hoisting machine, it is composed of a voltage source converter and a voltage source inverter in order to regenerate regenerative power to a power source side and improve energy efficiency. Uses a power converter. By this power conversion device, for example, the energy consumed when the elevator is operated to rise in a fully-loaded state is canceled as much as possible with the energy generated when the elevator is driven to be lowered in a fully-loaded state, so that the entire building is consumed. Power can be saved considerably.

FIG. 13 shows a general elevator control device 2
Indicates 0. Explaining the power supply system of the illustrated elevator motor, the controlled AC power is supplied from the three-phase AC power supply 1 to the motor 6 via the reactor 2, the voltage source converter 3, the smoothing capacitor 4, and the voltage source inverter 5. . A motor 6 drives an elevator hoist (not shown). The converter 3 and the inverter 5 constitute a frequency converter with a DC intermediate circuit. Each of the converter 3 and the inverter 5 is composed of a controllable switching element, and can control an output DC voltage or an output AC current. A control device is provided to control the speed of the motor 6 so as to match a predetermined target value, that is, a speed command. In order to carry out the control by this control device, there are provided first control means for controlling the output DC voltage of the converter 3 and second control means for controlling the output AC current of the inverter 5.

In the first control means, the output DC voltage of the converter 3, that is, the voltage across the capacitor 4 is detected by the DC voltage detector 7, and the detected value Vdcf is, for example, a DC voltage controller (PI controller). AVR) 8 and compares this with the DC voltage command VdcRef generated by the DC voltage command generation circuit 9, and the DC voltage deviation (= Vd)
A current command for setting cRef-Vdcf) to zero is introduced to the current controller (ACR) 10. The detected value of the AC side current of the converter 3 detected by the current detector 11 is also introduced into the current controller 10. The current controller 10 outputs a control signal for making the current deviation zero, and thereby controls the converter 3 via the PWM generator 12. The first control means constitutes a voltage control system for controlling the DC voltage as a whole, and has a minor loop for current control therein.

In the second control means, the rotation speed of the motor 6, that is, the speed of the hoisting machine is detected by the speed detector 14 via the speed sensor 13, for example, a pulse sensor, and the detected value is guided to the speed controller 15. . The speed controller 15 also receives the speed command generated by the speed command generation circuit 16 and the output value of the inverter 5 detected by the current detector 17, that is, the detected value of the input current of the motor 6. The speed controller 15 calculates a current command for making the speed deviation zero, and outputs a control signal for making the resulting current deviation zero, whereby the PW is set.
The inverter 5 is controlled via the M generator 18. The second control means constitutes a speed control system as a whole, and has a minor loop for current control therein.

The operation mode of converter 3 will be described in more detail. If the voltage of the three-phase AC power supply 1 is represented by Vac and the control angle α is zero, the smoothing capacitor 4
DC voltage Vdcf detected at both ends of the
= √2 × Vac.

A description will be given of when the motor 6 is loaded, that is, when the motor 6 is loaded. The DC voltage controller 8 causes the output DC voltage detection value Vdcf of the converter 3 detected by the DC voltage detector 7 to follow the DC voltage command VdcRef generated by the DC voltage command generation circuit 9, that is, the DC voltage. Calculate the current command Ic * that makes the deviation zero. This current command Ic * and the current detector 11
The current controller 10 compares the detected current value with the current controller 10, calculates a control signal for making the deviation, that is, the current deviation zero, and controls the converter 3 via the PWM generator 12 by this control signal. As a result, the DC voltage is controlled so as to follow the DC voltage command VdcRef. The DC voltage Vdcf is always given as a DC voltage command VdcRef of a constant value corresponding to the maximum voltage required by the motor 6 used in the hoisting machine.

FIG. 14 shows an example of an operating speed pattern of an elevator and an example of controlling a DC voltage. Here, the speed command Sref and the actual speed S are shown in the upper part. As a pattern when the speed command Sref rises from one floor of the car and rises and stops at another floor, for example, the speed command gradually increases from zero to reach a constant speed, gradually decreases after maintaining a constant speed state for a while. Then, when it is assumed that the transition becomes zero again, the actual speed S changes in a similar pattern with a slight delay to the speed command Sref. A torque command for achieving the speed command Sref is shown for reference in the middle stage, and a state in which the DC voltage command VdcRef and the DC voltage Vdcf change as constant values is shown in the lower stage.

[0009]

In the conventional control device 20 described with reference to FIGS. 13 and 14, the maximum voltage is always applied to the converter 3 and the inverter 5, so that the switching element Switching losses are large, which reduces the efficiency of the converter.
This decrease in efficiency becomes relatively large as the capacity becomes large, so that the size of the converter itself and the size of the attached cooler are increased, which in turn lowers the efficiency of the elevator. Therefore, an object of the present invention is to provide an elevator control device that can improve the efficiency of the conversion device.

[0010]

In order to achieve the above object, the invention according to claim 1 is a voltage source converter for rectifying an AC voltage to convert it into a DC voltage, and an AC with a variable voltage and a variable frequency. In an elevator control device including a voltage source inverter that is converted into a voltage and supplied to a drive motor of an elevator hoisting machine, a DC voltage command generation unit that generates a DC voltage command that changes according to the speed of the drive motor, It is characterized in that it is provided with a DC voltage control means for controlling the converter so that the DC voltage follows the DC voltage command, and a speed control means for controlling the inverter so that the speed of the drive motor follows the speed command.

According to a second aspect of the present invention, in the elevator control device according to the first aspect, the DC voltage command generating means includes a primary resistance of the drive motor, a primary reactance, a speed,
It is characterized in that a DC voltage command corresponding to the DC voltage required by the drive motor is generated based on the current and the voltage.

The invention according to claim 3 is the invention according to claim 1 or 2.
In the elevator control device described in (1), the DC voltage command generating means selects and outputs the minimum DC voltage as the DC voltage command when the DC voltage command is lower than the minimum DC voltage that the converter can output.

The invention according to claim 4 is the invention according to claim 1 or 2.
In the elevator control device according to, the DC voltage control means, when the DC voltage command is lower than the rectified voltage obtained from the input voltage of the converter, the converter is gate-blocked and driven by the rectified voltage, and the DC voltage command is the rectified voltage. When it is higher, the converter is gate-controlled according to the DC voltage command generated by the DC voltage command generating means.

The invention according to claim 5 is the invention according to claim 1 or 2.
In the elevator control device according to, the DC voltage control means has a reference voltage command value set to a value higher than the rectified voltage obtained when the converter is gate-blocked, and the detected value of the DC voltage is the reference voltage command. When it is lower than the value, the converter is gate-blocked and driven by the rectified voltage, and when the detected value of the DC voltage is higher than the reference voltage command value, the reference voltage command value is used as the DC voltage command to perform the converter gate control. And

The invention according to claim 6 is the invention according to claim 1 or 2.
In the elevator control device according to, the DC voltage control means has a reference voltage command value set to a value higher than the rectified voltage obtained when the converter is gate-blocked, and the detected value of the DC voltage is the reference voltage command. When it is lower than the value, the converter is gate-blocked to output the rectified voltage,
When the detected value of the DC voltage is higher than the DC voltage command value, the gate control of the converter is executed according to the DC voltage command generated by the DC voltage command generation means.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <First Embodiment> FIG. 1 shows a first embodiment of the present invention.

The motor used in the elevator hoisting machine is
In recent years, a permanent magnet synchronous motor or an induction motor has been generally used with the development of control technology and electronics technology. The circuit equation of the permanent magnet type synchronous motor is shown in equation (1).

[0018]

[Equation 1] However, Vd and Vq are d-axis voltage and q-axis voltage in a rectangular coordinate system, R is a primary resistance, L is a primary inductance,
ω is the rotation frequency, id is the d-axis current, iq is the q-axis current, and φ is the secondary magnetic flux.

If the motor speed is substantially proportional to the power supply frequency F, the motor speed, that is, the power supply frequency F and the motor voltage V are in a substantially proportional relationship, and V / F = constant holds.

In the apparatus of FIG. 1, the pulse type speed sensor 13
The speed detector 14 obtains a speed detection signal FR from the pulse signal obtained by the DC voltage command generator 10
Lead to 0. In the DC voltage command generator 100, the absolute value circuit 101 obtains the absolute value Abs (FR) of the speed detection signal FR and guides it to the multiplier 102 as the first input signal. Multiplier 1
The gain Vgain is introduced as the second input signal of 02.
From the multiplier 102, the absolute value Abs (FR) of the speed detection signal FR
Abs (FR) × Vgain, which is the product of the gain and the gain Vgain, is output, and the offset amount VdcOffset is added to the adder 1 if necessary.
The sum is added in 03, and the sum is sent to the DC voltage controller 8 as a DC voltage command VdcRef.

FIG. 2 shows transitions of the DC voltage command VdcRef and the DC voltage Vdcf with respect to the same speed command and torque command as shown in FIG. Here, since the DC voltage command generator 100 is provided, the DC voltage command is generated.
It can be seen that VdcRef and the DC voltage Vdcf change corresponding to the absolute value Abs (FR) of the speed FR and the offset amount VdcOffset.

Thus, according to this embodiment, the DC voltage command VdcRef that changes according to the rotation speed of the motor 6
By avoiding driving with unnecessary high voltage when the motor is stopped or operating at low speed, that is, the DC voltage during low-speed operation is kept low, switching loss of switching elements is suppressed, and converter efficiency is improved. You can

<Second Preferred Embodiment> FIG. 3 shows a second preferred embodiment of the present invention, and is a block diagram of a control system of a controller incorporating a DC voltage command generator 100 according to the first preferred embodiment.

Here, a case where a permanent magnet type synchronous motor is used as an electric motor will be described as an example. The equation of state of the permanent magnet synchronous motor is as shown in equation (1). Since the internal magnetic flux is established by the permanent magnet, the d-axis current id is usually id = 0. Torque is generated by the torque current iq. ω is the rotation frequency. By substituting the above conditions into the equation (1), the voltage vector Vm is obtained.

[0025]

[Equation 2] From equation (2), the motor voltage according to the actual operating conditions and the ideal DC voltage in that state can be expressed by equation (3).

[0026]

[Equation 3] However, VDC is a DC voltage, and Vrate is a modulation factor, that is, a utilization factor of the converter. This utilization rate Vrate is usually 1.0.

In the second embodiment shown in FIG. 3, the speed detection signal FR from the speed detector 14 is supplied to the DC voltage command generator 100.
It is guided to the rotation frequency (ω) calculator 104 in which the rotation frequency ω is calculated. This rotation frequency ω is guided to the ideal DC voltage command generator 105, and the DC voltage VDC obtained based on the equation (3) is given to the multiplier 102 as the ideal DC voltage command VDC *. Multiplier 102 is ideal DC voltage command VD
C * is multiplied by the gain Vgain, and the product VDC * × Vgain is added with the offset amount VdcOffset by the adder 103 as necessary,
The sum is sent to the DC voltage controller 8 as a DC voltage command VdcRef.

FIG. 4 shows an example of the operation pattern according to the present embodiment in a form according to FIG.

Also in the case of the induction motor, the same operation and effect as in the case of the first embodiment can be obtained by using the DC voltage command obtained based on the motor voltage back-calculated from the state equation similar to the equation (1). be able to.

In the second embodiment, the DC voltage command is calculated based on the rotation speed, the current and the voltage of the motor 6 according to the state equation of the motor, thereby setting the minimum necessary DC voltage and switching the converter. The loss can be further reduced.

<Third Embodiment> FIG. 5 is a block diagram showing a third embodiment.

In the converter of FIG. 13, the minimum controllable DC voltage of the converter 3, that is, the minimum DC voltage command VdcR
ef_min can be represented by the equation (4) with the input AC voltage (three phases) as Vps.

[0033]

[Equation 4] The DC voltage command VdcRef calculated according to the first or second embodiment is used as a basic DC voltage command VdcRef_org, and the minimum DC voltage command Vd obtained according to the equation (4) is used.
Comparing cRef_min with the comparator 110, and if VdcRef_min> VdcRef_org, the comparator 110 outputs an output “0”, and this output causes the switcher 111 to output a DC voltage command VdcRef = VdcR.
ef_min is output, and if VdcRef_min <VdcRef_org, the comparator 110 outputs the output "1", and this output causes the switch 111 to output the DC voltage command VdcRef = VdcR.
Output ef_org. The DC voltage command VdcRef output from the switch 111 is introduced into the DC voltage controller 8.

FIG. 6 shows the transition of the DC voltage in the operation pattern according to the embodiment of FIG. In this embodiment,
When the basic DC voltage command VdcRef_org is higher than the minimum DC voltage command VdcRef_min, the DC voltage command VdcRef is used as it is, and when it is lower than that, the DC voltage command VdcRef = VdcRef_min is switched.

According to this embodiment, it is possible to avoid the instability of the voltage control in the extremely low speed range including the elevator stop state and achieve the stable DC voltage control even in the extremely low speed range.

<Fourth Embodiment> FIG. 7 is a block diagram showing a fourth embodiment.

In the converter of FIG. 13, the rectified voltage VdcRec output when the converter 3 is rectifying at the control angle α = 0, if the input AC voltage (three phases) is Vps,
It can be expressed by equation (5).

VdcRec = √2 × Vps (5) The DC voltage command calculated by the DC voltage command generator 100 according to the first embodiment or the second embodiment is set as the DC voltage command value VdcRef_org, which is (5 ) The rectified voltage VdcRec obtained according to the equation is compared with the comparator 110, and if VdcRec> VdcRef_org, the comparator 110 outputs an output “0”, and this output causes the converter 3 to gate block through the PWM generator 18. Then, the rectifier operation in the regenerative mode is performed.

If VdcRec <VdcRef_org, the comparator 110 outputs the output "1", and this output releases the gate block of the converter 3 via the PWM generator 18 and causes the switch 111 to
Output DC voltage command VdcRef = VdcRef_org. This DC voltage command VdcRef is introduced into the DC voltage controller 8, and the converter 3 is gate-controlled according to the DC voltage command VdcRef.

FIG. 8 shows the transition of the DC voltage in the operation pattern according to the embodiment of FIG. 7 together with the gate control mode of converter 3.

According to this embodiment, when the rectified voltage is higher than the DC voltage required by the motor 6 via the inverter 5 in the extremely low speed range including the stopped state, the converter 3 is gate-blocked to regenerate the rectifier. By operating as, the switching loss can be made zero and the total loss of the converter can be reduced.

<Fifth Embodiment> FIG. 9 is a diagram showing a fifth embodiment. In this embodiment, the first of the comparator 110
From the starting voltage reference circuit 120 to the starting voltage reference Vd
Input cRef_Start and connect the DC voltage detector 7 to the second input terminal.
Input the DC voltage Vdcf obtained in. The comparator 110 is
The input starting voltage reference VdcRef_Start is compared with the DC voltage Vdcf. If VdcRef_Start> Vdcf, the gate block signal “0” is output, and if VdcRef_Start <Vdcf, the gate operation signal “1” is output. According to the output of the comparator 110, the gate of the converter 3 is controlled via the PWM generator 12. The operation of converter 3 at the time of gate block and gate control is performed according to the case of the fourth embodiment.

FIG. 10 shows the transition of the DC voltage in the regenerative operation pattern according to the embodiment of FIG. 9 together with the gate control mode of converter 3.

When the converter 3 is performing the rectifying operation through the gate control, it operates as shown in the equation (4).
During the regenerative operation, electric power is regenerated from the motor 6 to the power supply 1 side, and therefore, an operation of regenerating electric power to the power supply 1 via the converter 3 is normally performed. However, in the case of an elevator, it is always in a power running state immediately after starting, and regenerative operation is performed while the speed increases.

FIG. 10 shows the timing for starting the regenerative operation. In FIG. 9, when the electric power regeneration starts, the DC voltage Vdcf starts to rise. At this time, the DC voltage
Reference voltage VdcR generated by the startup voltage reference circuit 120 by Vdcf
When ef_Start is exceeded, the gate operation of the converter 3 is started, and the DC voltage command is set to VdcRef_Start and the converter 3 is started.
Control the output DC voltage Vdcf.

According to the present embodiment, in the extremely low speed range including the stopped state, the converter 3 is gate-blocked until the DC voltage reaches the predetermined voltage reference, and the converter 3 is operated as a regenerative rectifier. The switching loss can be made zero and the total loss of the converter can be reduced.

<Sixth Embodiment> FIG. 11 is a block diagram showing a sixth embodiment. This embodiment corresponds to a combination of the third embodiment (FIG. 5) and the fifth embodiment (FIG. 9). That is, in the device of the fifth embodiment (FIG. 9), the DC voltage reference Vd input to the DC voltage controller 8 is input.
cRef is generated by the apparatus of FIG.

In the apparatus shown in FIG. 11, immediately after the elevator enters the regenerative operation, the starting voltage reference generated by the starting voltage reference circuit 120 is VdcRef_Start, and VdcRef_Start> Vdcf, and at this time, the comparator 112 gates. A block signal “0” is output and a gate block is generated via the PWM generator 12. When the DC voltage Vdcf rises and VdcRef_Start <Vdcf, the output of the comparator 110 changes to "1" and the gate control of the converter 3 is performed.

When the speed S further increases and the required voltage of the motor 5 becomes higher than the DC voltage reference VdcRef_Start, the DC voltage command VdcRef is changed in the following manner.

The DC voltage command VdcRef_org generated by the DC voltage command generator 100 and the minimum DC voltage command VdcRef_min obtained according to the equation (4) are compared by the comparator 112. If VdcRef_min> VdcRef_org, the comparator 112 Outputs "0" and the switch 11
The minimum DC voltage command VdcRef_min is guided to the DC voltage controller 8 via 1, and if VdcRef_min <VdcRef_org, the comparator 112 outputs “1” and the switch 11
A DC voltage command VdcRef_org from the DC voltage command generator 100 is guided to the DC voltage controller 8 via 1.

FIG. 12 shows how the DC voltage Vdcf changes in the operation pattern in the above control mode.

According to this embodiment, when the rotation speed of the motor 6 increases and the voltage required by the motor 6 exceeds a predetermined value, the DC voltage command is changed to the voltage required for the motor 6. As a result, the total loss of the converter can be reduced even during regeneration.

[0053]

According to the present invention, it is possible to provide a highly efficient elevator system in which the switching loss of the switching element is reduced through the control of the DC voltage in the low speed range or the regenerative operation of the converter.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a control device according to the present invention.

FIG. 2 is a diagram showing an example of an operation pattern of the control device of FIG.

FIG. 3 is a block diagram showing a second embodiment of a control device according to the present invention.

FIG. 4 is a diagram showing an example of an operation pattern of the control device of FIG.

FIG. 5 is a block diagram showing a third embodiment of a control device according to the present invention.

FIG. 6 is a diagram showing an example of an operation pattern of the control device of FIG.

FIG. 7 is a block diagram showing a fourth embodiment of a control device according to the present invention.

8 is a diagram showing an operation pattern example of the control device of FIG. 7. FIG.

FIG. 9 is a block diagram showing a fifth embodiment of a control device according to the present invention.

10 is a diagram showing an example of an operation pattern of the control device in FIG.

FIG. 11 is a block diagram showing a sixth embodiment of a control device according to the present invention.

12 is a diagram showing an example of an operation pattern of the control device of FIG.

FIG. 13 is a block diagram showing an example of a conventional control device.

14 is a diagram showing an example of an operation pattern of the control device in FIG.

[Explanation of symbols]

1 Three-phase AC power supply 2 reactor 3 converter 4 Smoothing capacitor 5 inverter 6 motor 7 DC voltage detector 8 DC voltage controller (AVR) 9 DC voltage command generation circuit 10 Current controller (ACR) 11 Current detector 12 PWM generator 13 Speed sensor 14 Speed detector 15 Speed controller 16 Speed command generation circuit 17 Current detector 18 PWM generator 20 Control device 100 DC voltage command generator 101 Absolute value circuit 102 multiplier 103 adder 104 Rotation frequency (ω) calculator 105 Ideal DC voltage calculator 110 comparator 111 Switch 112 comparator 120 Starting voltage reference circuit

Claims (6)

[Claims] 1. A voltage type converter for rectifying an AC voltage and converting it into a DC voltage, and a voltage type inverter for converting the DC voltage into an AC voltage of a variable voltage and variable frequency and supplying it to a drive motor of an elevator hoisting machine. In an elevator control device including: a DC voltage command generating means for generating a DC voltage command that changes according to the speed of the drive motor; and controlling the converter so that the DC voltage follows the DC voltage command. An elevator control apparatus comprising: a DC voltage control means; and a speed control means for controlling the inverter so that the speed of the drive motor follows a speed command. 2. The elevator control device according to claim 1, wherein the DC voltage command generating means makes a request of the drive motor based on a primary resistance, a primary reactance, a speed, a current, and a voltage of the drive motor. An elevator control device, which generates a DC voltage command corresponding to a DC voltage. 3. The elevator control apparatus according to claim 1, wherein the DC voltage command generating means outputs the DC voltage command as the DC voltage command when the DC voltage command is lower than the minimum DC voltage that can be output by the converter. An elevator control device which selects and outputs the lowest DC voltage. 4. The elevator control apparatus according to claim 1, wherein the DC voltage control means gates the converter when the DC voltage command is lower than a rectified voltage obtained from an input voltage of the converter. Driven by the rectified voltage, and when the DC voltage command is higher than the rectified voltage, the converter is gate-controlled according to the DC voltage command generated by the DC voltage command generating means. apparatus. 5. The elevator control apparatus according to claim 1, wherein the DC voltage control means sets a reference voltage command value set to a value higher than a rectified voltage obtained when the converter is gate-blocked. Having, when the detected value of the DC voltage is lower than the reference voltage command value, the converter is gate-blocked and driven by the rectified voltage,
When the detected value of the DC voltage is higher than the reference voltage command value, the gate control of the converter is executed by using the reference voltage command value as the DC voltage command. 6. The elevator control apparatus according to claim 1, wherein the DC voltage control means sets a reference voltage command value set to a value higher than a rectified voltage obtained when the converter is gate-blocked. When the detected value of the DC voltage is lower than the reference voltage command value, the converter is gated to output the rectified voltage, and when the detected value of the DC voltage is higher than the DC voltage command value, An elevator control apparatus, which executes gate control of the converter according to a DC voltage command generated by a DC voltage command generation means.